KR102173760B1 - Nozzle - Google Patents

Abstract

The present invention relates to a nozzle. In the nozzle, whenever liquid spraying is started and ended, a protruding cleaning portion formed on a needle passes through a liquid spraying hole and cleans a liquid spraying hole. Therefore, it is less likely that the liquid spraying hole is blocked. Even when the liquid spraying hole is blocked due to an unpredictable cause, the liquid spraying hole can be cleaned by retreating and advancing the needle through a manual piston operating unit, while not a spraying-aid cap is not disassembled. The nozzle according to the present invention includes a needle provided with a protruding cleaning portion mounted in such a manner that it may protrude out from the liquid spraying hole. The needle is mounted to a needle mounting hole in such a manner that it may be retreated and advanced. When the needle is retreated and advanced, the protruding cleaning portion passes through the liquid spraying hole to clean the liquid spraying hole.

Description

Nozzle {Nozzle}

The present invention relates to an improvement of a nozzle, and more particularly, to an improvement of a nozzle used to jet a liquid such as a chemical liquid.

In general, nozzles are used to spray liquid, and are often used to spray water or chemicals on agricultural crops or barns, or to apply paint to buildings, ships, or various products.

Most of the nozzles supply the liquid to be sprayed to the nozzle and also supply compressed air to the nozzle so that the liquid can be sprayed as fine particles. Such a nozzle causes a problem in that the liquid is not smoothly sprayed because the material contained in the liquid is fixed to the liquid injection hole due to the evaporation of the liquid after the liquid is injected, and the liquid injection hole is narrowed or blocked. Accordingly, when using a conventional nozzle, the user must clean the nozzle from time to time.

There is one disclosed in Registration No. 10-1505309 (name of invention: liquid atomizer and its nozzle body, inventor: Jeongseok Lee, hereinafter referred to as "prior art") to prevent clogging of the liquid spray hole. In the prior art, the drug is sprayed after the air is sprayed, the air spraying is stopped after the liquid spraying is stopped even before the end, and the needle member is operated to penetrate a part of the liquid spraying hole even while the sprayer is in use. It is disclosed to prevent. However, the prior art is limited because the needle member can penetrate only a part of the liquid injection hole, and the liquid injection hole in front of the needle member to which the needle member cannot enter must be prevented from being blocked only by the injection of air. When the liquid spray hole is clogged, there is a problem in that the operator must drill the liquid spray hole using a separate tool after unscrewing the nut and disassembling the nozzle cap. If you spray a viscous liquid such as paint, this problem will occur more often.

An object of the present invention is to provide a liquid jet nozzle in which clogging of a liquid jet hole hardly occurs.

Another object of the present invention is to provide a liquid jet nozzle capable of piercing a liquid jet hole without disassembling the nozzle even if the liquid jet hole is blocked for an unexpected special reason.

The liquid injection nozzle according to the present invention comprises: a body portion having a needle mounting hole in which the liquid injection hole is disposed at one end; And a protruding cleaning unit protruding out of the liquid injection hole, and is mounted in the needle mounting hole so as to be able to move backward and forward, and when reversing to spray liquid and when returning after completing the liquid injection, the protruding cleaning unit It has a configuration including a needle for cleaning the liquid jet hole while passing through the hole.

The body portion is a cylinder hole communicating with the needle mounting hole, a liquid supply hole providing a passage through which the liquid supplied from the liquid supply portion is supplied to the needle mounting hole, and the compressed air supplied from the compressed air supply portion is supplied to the cylinder hole. A rear coupling portion having a compressed air supply hole providing a passage and forming a cylinder portion with a cylinder hole forming portion that is coupled to a rear portion of the body portion to form the cylinder hole; A sealing part provided between the needle mounting hole and the cylinder hole to prevent the liquid supplied to the needle mounting hole from flowing into the cylinder part, having a through hole allowing passage of the needle and backward and forward movement of the needle; A piston connected to the needle and movably installed in the cylinder portion to retreat the needle while retreating by the pressure of compressed air supplied from the compressed air supply portion; And a spring elastically supporting the piston toward the needle on the opposite side of the needle.

It is preferable that the protruding cleaning part has a liquid injection hole cleaning protrusion which protrudes radially so as to clean foreign substances in the liquid injection hole while passing through the liquid injection hole when the needle moves backward and forward.

It is preferable that a cross-sectional reduction part is formed in the protruding cleaning part behind the liquid injection hole cleaning protrusion and gradually decreases in cross-sectional area from the rear toward the liquid injection hole cleaning protrusion.

It is preferable to include a piston manual operation unit connected to the piston and installed to protrude to the rear of the cylinder unit through the cylinder unit, so that the piston can be manually retracted.

The piston has a piston body formed with a through hole through which the needle passes through a front end and is opened toward the rear, and a part of the needle is exposed to the front of the piston through a through hole at the tip of the piston body, and the needle inside the piston There is formed a locking protruding portion that is caught on the inner surface of the piston body and prevents the needle from being separated forward, a rear member having a hole at the rear portion of the piston body is coupled, and the piston manual actuating unit It is preferable that it is installed to be exposed to the rear through the hole and configured to be integrally connected with the needle, the piston, and the piston manual operation unit.

It is more preferable to include a needle retraction limit adjustment part for adjusting the retraction limit of the needle by being screwed to the rear coupling part so as to protrude into the cylinder part to adjust the distance with the piston.

It is connected to the piston and is installed to protrude from the cylinder portion to the rear of the cylinder portion through a rear member coupled to the rear portion of the piston from the cylinder portion, comprising a piston manual operating portion for manually retracting the piston, It is preferable that a hole through which the manual piston actuator can pass is formed along the inside of the needle retraction limit adjustment unit.

It is preferable that a compressed air guiding hole is formed in the body portion so that the compressed air supplied from the compressed air supplying part is supplied to both sides of the liquid injection hole and sprayed forward.

It has a compressed air injection hole coupled to the front of the body part and communicates with the compressed air induction hole, and has an air injection part disposed on opposite sides of the circumference of the protruding cleaning part, and an injection aid that is open to the other sides of the protruding cleaning part. It is better to include a cap.

The compressed air guiding hole is formed with at least two paths so that compressed air is respectively injected from both sides of the liquid injection hole, the cross-sectional area of the compressed air guiding hole is larger than the cross-sectional area of the compressed air supply hole, and the cross-sectional area of the compressed air injection hole is It is preferable that it is smaller than the cross-sectional area of the compressed air guiding hole.

According to the present invention, since the protruding cleaning part formed in the needle passes through the liquid injection hole and cleans the liquid injection hole at the beginning of the liquid injection and each time the liquid injection ends, there is almost no fear of clogging the liquid injection hole.

Even if the liquid injection hole is clogged due to an unexpected cause, it is convenient to clean the liquid injection hole by manually retracting the needle through the piston manual operation part and moving forward without disassembling the cap part.

1 is a perspective view of a nozzle according to the present invention,
2 is an exploded perspective view of a nozzle according to the present invention,
3 is a rear perspective view of the nozzle of FIG. 1;
Figure 4 is a rear exploded perspective view of the nozzle of Figure 1;
5 is a longitudinal sectional view of the nozzle of FIG. 1;
Fig. 6 is a longitudinal sectional view of the nozzle of Fig. 1 at the time of spraying liquid;
7 is a partial sectional view showing an example of an air passage formed toward a liquid injection hole;
8 is a partial enlarged view of a needle showing an enlarged protruding cleaning portion of the needle,
9 is a cross-sectional view showing a state in which the open portion of the liquid injection hole is finely adjusted by reducing the backward limit of the needle;
10 is a longitudinal sectional view of a nozzle showing a modified example of FIG. 5.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 8, the nozzle 100 according to the present invention includes a body part 110, a rear coupling part 130, a needle 140, a sealing part 150, a piston 160, and a spring 170. ) Is provided.

The body part 110 enables the installation of various components necessary for the configuration of the nozzle and provides a supply passage for liquid for spraying and compressed air required for spraying the liquid, and as shown in FIGS. 5 and 6 Needle mounting holes 111 are formed long in front and rear. A liquid injection hole 112 is formed at the front end of the needle mounting hole 111. The liquid injection hole 112 has a smaller cross-sectional area than the needle mounting hole 111. Preferably, a first inclined surface 111a formed as the cross-sectional area of the inner peripheral surface gradually decreases is formed at the front end of the needle mounting hole 111 meeting the liquid injection hole 112.

5 and 7, a cylinder hole 114 communicating with the needle mounting hole 111 is disposed behind the needle mounting hole 111. The cylinder hole 114 is formed in the cylinder hole forming portion 115 disposed at the rear portion of the body portion 110, and is formed in a cross-sectional area larger than that of the needle mounting hole 111. In addition, between the needle mounting hole 111 and the cylinder hole 114, a sealing mounting portion 116 having a larger cross-sectional area than the needle mounting hole 111 and a smaller cross-sectional area than the cylinder hole 114 is formed. Accordingly, the needle mounting hole 111 and the stepped step are formed in the sealing mounting portion 116, and preferably, a female spiral is formed on the inner circumferential surface of the sealing mounting portion 116.

A first connector 181 and a second connector 182 to respectively connect the liquid supply unit and the air supply unit for supplying liquid for spraying and compressed air into the body unit 110 are mounted. The first connector mounting portion 118 and the second connector mounting portion 119 are installed at intervals. The first connector mounting portion 118 to which the liquid supply unit is connected is connected to the needle mounting hole 111 through the liquid supply hole 118a. That is, the liquid supply hole 118a provides a passage through which the liquid supplied from the liquid supply unit is supplied to the needle mounting hole 111.

The second connector mounting portion 119 to which the compressed air supply unit is connected is connected to the cylinder hole 114 through the compressed air supply hole 119a. The compressed air supplied from the compressed air supply unit is supplied to the cylinder hole 114 through the compressed air supply hole 119a. That is, the compressed air supply hole 119a provides a passage through which compressed air supplied from the compressed air supply unit is supplied to the cylinder hole 114.

Referring to FIG. 7, the compressed air induction hole is supplied to the body part 110 from the second connector mounting part 119 to both sides of the liquid injection hole 112 so that it can be sprayed to the front of the liquid injection hole 112. (119b) is formed. Compressed air induction hole (119b) is formed in at least two paths so that compressed air is supplied to each of the two compressed air injection holes 206 so that compressed air is injected from both sides of the liquid injection hole 112, preferably, the cylinder part ( It has a larger cross-sectional area than the compressed air supply hole 119a for supplying compressed air to 120).

As shown, the rear coupling portion 130 is coupled to the rear portion of the body portion 110. The rear coupling part 130 forms the cylinder part 120 together with the cylinder hole forming part 115 and serves to couple other parts. In this embodiment, a spiral is formed on the outer circumferential surface of the cylinder hole forming part 115 and is composed of a first cap 131 screwed to the spiral and a second cap 136 coupled to the rear end of the first cap 131 Although the rear coupling part 130 is illustrated, it may be formed with only one cap member in some cases. The first cap 131 has a hole 132 in which a spiral 133 is formed on the inner circumferential surface so that the needle retreat limit adjustment unit 210 is screwed and passed, and a second cap ( 136) is screwed. The second cap 136 is also formed with a hole 137 that allows the needle retreat limit adjustment unit 210 to pass.

The needle 140 is mounted in the needle mounting hole 111 to be installed so as to move backward and forward, and has a protruding cleaning part 141 that is mounted to protrude out of the liquid injection hole 112, which constitutes a feature of the present invention. . In a state in which the liquid injection nozzle 100 is not operated, the protruding cleaning part 141 maintains a state protruding out of the liquid injection hole 112. When the liquid spray nozzle 100 is not operated, a portion of the needle 140 disposed behind the protruding cleaning portion 141, preferably a portion of the needle 140 behind the cross-sectional reduction portion 142 described later This liquid injection hole 112 is blocked.

The protruding cleaning part 141 of the needle 140, which constitutes one feature of the present invention, is radially protruded and passes through the liquid injection hole 112 when the needle 140 moves backward and forward, while removing foreign substances in the liquid injection hole 112. It includes a liquid spray hole cleaning protrusion 143 for cleaning. Preferably, the liquid spray hole cleaning protrusion 143 is installed at the front end of the protruding cleaning part 141, and passes through the liquid spray hole 112 to separate foreign substances adhering to the inner wall of the liquid spray hole 112. One such liquid injection hole cleaning protrusion 143 is sufficient, but in some cases, two or more may be installed at intervals in front and rear. In this case, each of the liquid spray hole cleaning protrusions 143 may be formed by varying the height protruding radially.

Preferably, a second inclined surface 144 is formed on the front portion of the liquid spray hole cleaning protrusion 143. 6 and 8, the second inclined surface 144 is formed at an angle smaller than the first inclined surface 111a with respect to the center line in the longitudinal direction of the needle 140. In this case, the passage of the liquid injected from the liquid injection hole 112 during liquid injection is preferably formed to be wider inward and narrower toward the outside.

Preferably, the protruding cleaning part 141 behind the liquid injection hole cleaning protrusion 143 is formed with a cross-sectional reduction part 142 whose cross-sectional area gradually decreases from the rear toward the liquid injection hole cleaning protrusion 143.

The sealing part 150 is installed in the sealing mounting part 116 between the needle mounting hole 111 and the cylinder hole 114. The sealing part 150 is mounted between the needle mounting hole 111 and the cylinder hole 114 to prevent the liquid supplied to the needle mounting hole 111 from flowing into the cylinder part 120. This sealing unit 150 is configured to allow passage of the needle 140 and backward and forward movement of the needle 140. Preferably, the sealing unit 150 is provided with an O-ring 151 and a through hole 153a through which the needle 140 passes in close contact with the stepped portion of the sealing mounting unit 116 in a state coupled to the outer circumferential surface of the needle 140, and sealing An O-ring pressing member 153 is provided that is screwed to the mounting portion 116 and presses the O-ring 151 toward the stepped portion so that the O-ring 151 can seal between the needle mounting hole 111 and the cylinder unit 120 It is composed by The O-ring 151 pressurized by the O-ring pressing member 153 is in close contact with the stepped and the O-ring pressing member 153 and the surface of the needle 140 so that the liquid supplied to the needle mounting hole 111 is supplied to the cylinder unit 120. Blocks from entering the interior.

The piston 160 is installed to be able to move back and forth within a certain range within the cylinder unit 120, and the piston body 160a having an O-ring mounting groove 161 on the outer circumferential surface and an O-ring 163 mounted in the O-ring mounting groove 161 Have. The piston 160 is connected to the needle 140 to move back and forth within the cylinder unit 120 to move the needle 140 backward and forward together. When compressed air is supplied into the cylinder unit 120, the piston 160 retreats as shown in FIG. 6 by the pressure of the compressed air, and the needle 140 also retreats while retreating. At this time, the protruding cleaning part 141 cleans the liquid spray hole 112 while passing through the liquid spray hole 112 and enters the liquid spray hole 112 to open the liquid spray hole 112 to open the needle mounting hole 111 ) To be sprayed to the outside through the liquid injection hole 112. The piston body 160a of the piston 160 has a configuration in which a through hole 165 through which the needle 140 passes is formed at the front end and is opened toward the rear side, and preferably, on the inner circumferential surface of the piston body 160a A spiral is formed, and a rear member 167 having a hole 167a in the spiral is screwed. That is, as the rear member 167, a ring-shaped screw member having a spiral formed on the outer circumferential surface is suitable.

Part of the needle 140 is exposed to the front of the piston 160 through a through hole 165 formed at the tip end of the piston body 160a, and the needle 140 inside the piston 160 is located on the inner surface of the tip of the piston body 160a. The hooking protrusion 145 is formed to prevent the hooking needle 140 from being separated forward.

A piston manual operating unit 190 is connected to the piston 160. The piston manual operation unit 190 is installed to be exposed to the rear through a hole 167a formed in the rear member 167 from the inner side of the piston 160. The piston manual operation unit 190 is integrally connected with the needle 140 and the piston 160. The piston manual operating part 190 inside the piston 160 is formed with a locking projection 191 for preventing the piston manual operating part 190 from being separated from the rear by being caught by the rear member 167, and the piston manual operating part A ring-shaped handle 192 is installed at the outer end of the 190 so that a person can pull it back by hand.

In addition, a spring 170 that elastically supports the piston 160 toward the needle 140 from the opposite side of the needle 140 is installed in the cylinder 120. When the supply of compressed air supplied to the cylinder unit 120 is released, the spring 170 pushes the piston 160 retracted or retracted forward by the compressed air to return to the initial state as shown in FIG. 5. Upon return, the protruding cleaning part 141 cleans the liquid spray hole 112 while passing through the liquid spray hole 112 and is exposed to the outside of the liquid spray hole 112.

That is, in the liquid injection nozzle 100 according to the present invention, the needle 140 retreats when the liquid injection starts, and the liquid injection hole cleaning protrusion 143 passes through the liquid injection hole 112 while the liquid injection hole 112 When the supply of compressed air is stopped by completing the liquid injection, the needle 140 moves forward and the liquid injection hole cleaning protrusion 143 passes through the liquid injection hole 112 to clean the liquid injection hole 112. Therefore, there is no fear of clogging the liquid injection hole 112. Therefore, the liquid spray nozzle 100 according to the present invention can be suitably used for spraying water or general chemical liquids, as well as being particularly useful for spraying liquids such as high viscosity paint.

The liquid injection nozzle 100 according to the present invention has a needle retraction limit adjustment unit 210. Needle retraction limit adjustment unit 210 is provided with a helical portion 211 screwed to the helical 133 formed in the rear coupling unit 130, the cylinder part 120 inside the cylinder part 120 It is to be screwed to the rear coupling portion 130 so as to protrude to adjust the distance with the piston 160 so that the retraction limit of the needle 140 can be adjusted. The needle retraction limit adjustment unit 210 has a rotation operation unit 213 formed in the shape of a head of a bolt so that a person can easily rotate it by hand to adjust the degree of screwing on the outside of the cylinder unit 120. A hole 215 through which the piston manual operation unit 190 for manually retracting the piston 160 is formed along the inside of the needle retraction limit adjustment unit 210 is formed.

In front of the body portion 110, the injection auxiliary cap 200 is coupled through a nut 202. The injection auxiliary cap 200 is formed in the center so that the liquid injection hole 112 can communicate with the front and faces the periphery of the through hole 201 and the protruding cleaning part 141 to allow the protruding cleaning part 141 to pass through. The beam has air injection parts 204 arranged in both sides. The compressed air injection hole 206 communicating with the compressed air guiding hole 119b is formed in the air injection part 204.

Referring to FIG. 7, the inner surface of the injection auxiliary cap 200 around the through hole 201 is mounted to be spaced apart from the front of the body portion 110 so that the compressed air supplied to the compressed air induction hole 119b is supplied to the compressed air injection hole 206 ) To be supplied.

Preferably, the compressed air injection hole 206 is formed with a smaller cross-sectional area than the compressed air inducing hole 119b. Both sides of the injection auxiliary cap 200 are open to the side. Accordingly, when compressed air is injected into the compressed air injection holes 206 on both sides, negative pressure is generated in front of the liquid injection hole 112, and the liquid in the needle mounting hole 111 is outside the liquid injection hole 112 due to negative pressure. Is sprayed. At this time, the liquid flowing out of the liquid injection hole 112 is sprayed in an elliptical shape while spreading to both sides opened without the air injection part 204.

When the sprayed liquid is a chemical liquid, the sprayed liquid is blown away by the wind of the blower.

When the liquid is sprayed in the state of FIG. 6 and the particles of the liquid sprayed are to be made finer, the piston 160 is moved forward by rotating the needle retraction limit adjustment unit 210 as shown in FIG. 9. It is sufficient to reduce the opening gap of 112 than in FIG. 6. In this state, by adjusting the degree of screwing of the needle retreat limit adjustment unit 210, if the needle 140 is finely advanced or retracted, the opening interval of the liquid injection hole 112 can be finely adjusted, and the liquid injected accordingly The particle size of can also be finely adjusted.

On the other hand, referring to FIGS. 5 and 10 together, the shape of the liquid ejection hole cleaning protrusion 143 may be formed differently from that described in the previous embodiment and without a second slope according to the type of liquid to be sprayed. The diameter of 140 can also be increased or decreased as needed. As shown in FIG. 10, when the diameter of the needle 140 at the portion disposed in the needle mounting hole 111 is configured to be small, a relatively wider injection air space for liquid than the previous embodiment can be formed.

The rest are the same as described earlier.

The present invention may be used to spray liquids such as water and chemicals, and may be used to spray liquids with high viscosity such as paint.

100: liquid spray nozzle 110: body
111: needle mounting hole 111a: first slope
112: liquid injection hole 114: cylinder hole
115: cylinder hole forming portion 118a: liquid supply hole
119a: compressed air supply hole 119b: compressed air induction hole
120: cylinder part 130: rear coupling part
140: needle 141: protruding cleaning part
142: section reduction portion 143: liquid spray hole cleaning protrusion
144: second slope 150: sealing portion
160: piston 170: spring
190: piston manual operation part 200: injection auxiliary cap
210: needle retraction limit adjustment unit

Claims (10)

A body portion having a needle mounting hole in which a liquid injection hole is disposed at one end; And
A protruding cleaning part protruding outward from the liquid injection hole is provided, and the protruding cleaning part is mounted in the needle mounting hole so as to be able to move backward and forward. And a needle for cleaning the liquid jet hole while passing through the hole,
The body portion is a cylinder hole communicating with the needle mounting hole, a liquid supply hole providing a passage through which the liquid supplied from the liquid supply portion is supplied to the needle mounting hole, and the compressed air supplied from the compressed air supply portion is supplied to the cylinder hole. It has a compressed air supply hole providing a passage,
A rear coupling portion coupled to a rear portion of the body portion to form a cylinder portion together with a cylinder hole forming portion forming the cylinder hole;
A sealing part provided between the needle mounting hole and the cylinder hole to prevent the liquid supplied to the needle mounting hole from flowing into the cylinder part, having a through hole allowing passage of the needle and backward and forward movement of the needle;
A piston connected to the needle and movably installed in the cylinder portion to retreat the needle while retreating by the pressure of compressed air supplied from the compressed air supply portion; And
And a spring elastically supporting the piston toward the needle at the opposite side of the needle,
A nozzle comprising a piston manual operation unit connected to the piston and installed to protrude to the rear of the cylinder unit through the cylinder unit, so that the piston can be manually retracted. delete The method of claim 1, wherein the protruding cleaning part has a liquid injection hole cleaning protrusion for cleaning foreign substances in the liquid injection hole while passing through the liquid injection hole when the needle is moved backward and forward. Nozzle. The nozzle according to claim 3, wherein a cross-sectional area of the protruding cleaning part behind the liquid injection hole cleaning protrusion is formed with a cross-sectional area gradually decreasing from the rear toward the liquid injection hole cleaning protrusion. delete In claim 1, wherein the piston has a piston body having a through hole through which the needle passes at a front end and opened toward a rear surface,
A portion of the needle is exposed to the front of the piston through the through hole of the piston body, and the needle inside the piston is formed with a locking projection that is caught by the inner surface of the piston body and prevents the needle from being separated forward,
A rear member having a hole is coupled to a rear portion of the piston body, and the piston manual actuating part is installed to be exposed to the rear through the hole from the inner side of the rear member, so that the needle, the piston and the piston manual actuating part are integrated Nozzle, characterized in that configured to be connected. delete A body portion having a needle mounting hole in which a liquid injection hole is disposed at one end; And
A protruding cleaning part protruding outward from the liquid injection hole is provided, and the protruding cleaning part is mounted in the needle mounting hole so as to be able to move backward and forward. And a needle for cleaning the liquid jet hole while passing through the hole,
The body portion is a cylinder hole communicating with the needle mounting hole, a liquid supply hole providing a passage through which the liquid supplied from the liquid supply portion is supplied to the needle mounting hole, and the compressed air supplied from the compressed air supply portion is supplied to the cylinder hole. It has a compressed air supply hole providing a passage,
A rear coupling portion coupled to a rear portion of the body portion to form a cylinder portion together with a cylinder hole forming portion forming the cylinder hole;
A sealing part provided between the needle mounting hole and the cylinder hole to prevent the liquid supplied to the needle mounting hole from flowing into the cylinder part, having a through hole allowing passage of the needle and backward and forward movement of the needle;
A piston connected to the needle and movably installed in the cylinder portion to retreat the needle while retreating by the pressure of compressed air supplied from the compressed air supply portion; And
And a spring elastically supporting the piston toward the needle from the opposite side of the needle,
It includes a needle retraction limit adjustment portion for adjusting the retraction limit of the needle by being screwed to the rear coupling portion so as to protrude into the cylinder portion to adjust the distance with the piston,
It is connected to the piston and is installed to protrude from the cylinder portion to the rear of the cylinder portion through a rear member coupled to the rear portion of the piston from the cylinder portion, and includes a piston manual operating portion for manually retracting the piston,
A nozzle, characterized in that a hole through which the piston manual operation unit can pass is formed along the inside of the needle retraction limit adjustment unit. In any one of claims 1, 3, 4, 6 and 8, the compressed air supplied from the compressed air supply unit is supplied to both sides of the liquid injection hole to the front Nozzle, characterized in that the compressed air guiding hole is formed to be sprayed. The method of claim 9, wherein the body has a compressed air injection hole coupled to the front of the body part and communicates with the compressed air guiding hole, and has air injection parts disposed on opposite sides of the circumference of the protruding cleaning part, The nozzle, characterized in that it comprises an open injection aid cap.

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