CN212826536U

CN212826536U - Pneumatic glue sealing nozzle

Info

Publication number: CN212826536U
Application number: CN202021455113.8U
Authority: CN
Inventors: 王军; 李锋
Original assignee: Dongguan Enzes Precision Machinery Co ltd
Current assignee: Dongguan Enzes Precision Machinery Co ltd
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2021-03-30
Anticipated expiration: 2030-07-21

Abstract

The utility model belongs to the technical field of moulds, in particular to a pneumatic glue-sealing nozzle, which comprises a mounting seat, a piston and a glue-sealing needle; the mounting seat is provided with an injection molding runner in a penetrating manner, one end of the injection molding runner, which is connected with the material pipe group of the injection molding machine, is an injection end runner, one end of the injection molding runner, which is connected with the die sprue bush, is an injection end runner, and the tail end of the injection end runner is gradually reduced in diameter to form a conical injection port; a sealing cavity is formed in the middle of the mounting seat, a first air inlet channel communicated with the sealing cavity is formed in the mounting seat, and the piston is hermetically and slidably mounted in the sealing cavity; the glue sealing needle is arranged in the flow channel of the injection end, and the diameter of the glue sealing needle is smaller than that of the flow channel of the injection end; the first end of the glue sealing needle is connected with the piston, the second end of the glue sealing needle is a glue sealing end, and the glue sealing end is matched with the pouring outlet, so that the piston can drive the glue sealing end of the glue sealing needle to seal the pouring outlet or unseal the pouring outlet.

Description

Pneumatic glue sealing nozzle

Technical Field

The utility model belongs to the technical field of the mould, especially, relate to a pneumatic glue that seals penetrates mouth.

Background

In plastic molding, there are many plastic compounds with low viscosity and very high flowability, such as: nylon, PA, PET, LSR, etc. A series of problems are brought to injection molding, the most main problem is leakage, and the leakage of the sizing material brings serious pollution to the surrounding environment, causes unnecessary waste and increases the processing cost. In order to solve the problems, the nozzle is provided, when in injection molding, the channel of the nozzle is opened to inject the sizing material into the mold, and when the injection molding is stopped, the channel of the nozzle is closed to avoid the glue leakage phenomenon. However, the nozzle is originally a nozzle of a lever type oil pressure sealing structure, and has the following disadvantages: the mode that the lever tilts the glue sealing needle to reciprocate is adopted, the glue sealing needle is not subjected to vertical force action, so that the abrasion of the glue sealing needle is accelerated, and the sealing performance is influenced after the abrasion to cause glue leakage.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a pneumatic glue that seals is penetrated mouth aims at solving and penetrates the mouth and adopt the lever to stick up the mode of sealing a rubber needle reciprocating motion among the prior art, seals the rubber needle and receives not the vertical force effect, leads to sealing a rubber needle wearing and tearing to accelerate, influences the technical problem that the leakproofness caused the hourglass to glue after the wearing and tearing.

In order to achieve the above object, an embodiment of the present invention provides a pneumatic glue injection nozzle, which includes a mounting seat, a piston and a glue injection needle; the mounting seat is provided with an injection molding runner in a penetrating manner, one end of the injection molding runner, which is connected with the material pipe group of the injection molding machine, is an injection end runner, one end of the injection molding runner, which is connected with the die sprue bush, is an injection end runner, and the tail end of the injection end runner is gradually reduced in diameter to form a conical injection port; a sealing cavity is formed in the middle of the mounting seat, a first air inlet channel communicated with the sealing cavity is formed in the mounting seat, and the piston is hermetically and slidably mounted in the sealing cavity; the glue sealing needle is arranged in the flow channel of the injection end, and the diameter of the glue sealing needle is smaller than that of the flow channel of the injection end; the first end of the glue sealing needle is connected with the piston, the second end of the glue sealing needle is a glue sealing end, and the glue sealing end is matched with the pouring outlet, so that the piston can drive the glue sealing end of the glue sealing needle to seal the pouring outlet or unseal the pouring outlet.

Optionally, the mounting seat comprises a connecting seat, a cylinder seat and a nozzle seat which are connected in sequence; the injection end flow passage is arranged on the connecting seat, the injection end flow passage is arranged on the nozzle seat, a connecting flow passage is connected between the injection end flow passage and the injection end flow passage, and the connecting flow passage penetrates through the cylinder seat; the cylinder body seat is provided with a groove in a digging mode at one end close to the nozzle seat, a sealing end is arranged at one end, close to the cylinder body seat, of the nozzle seat in a protruding mode, and the sealing end is connected with the groove in an inserting mode, so that the sealing cavity is formed inside the groove.

Optionally, a connecting hole communicated with the sealing cavity is formed in one end, close to the connecting seat, of the cylinder body seat, and the first end of the rubber sealing needle movably penetrates through the connecting hole to be connected with the piston; the cylinder body seat is also provided with a sealing flange at the connecting hole, and the sealing flange is in sealing sliding connection with the sealing rubber needle; the connecting seat is also provided with a clearance groove for avoiding the sealing flange.

Optionally, one end of the connecting seat, which is far away from the cylinder seat, is narrowed to form a connecting part, a nozzle is arranged at the end of the connecting part, and the injection outlet is arranged in the nozzle.

Optionally, an insertion protrusion is convexly arranged at the end of the connecting portion, an insertion groove is arranged at one end of the nozzle close to the connecting portion, and the insertion protrusion is inserted into the insertion groove in a matched manner.

Optionally, the end of the nozzle is provided with a smooth conical shape.

Optionally, the connecting seat is provided with a cooling channel around the flow channel of the injection end.

Optionally, at least three pairs of coaxial bolt connecting holes are arranged on the connecting seat and the cylinder body seat in a penetrating manner, at least three pairs of threaded holes are arranged on the nozzle seat, and the threaded holes and the bolt connecting holes are arranged coaxially; and the bolt penetrates through the bolt connecting hole to be in threaded connection with the threaded hole, so that the connecting seat, the cylinder body seat and the nozzle seat are fixedly connected.

Optionally, one end of the nozzle base is provided with a filling opening matched with the injection molding machine material pipe group; the injection end flow channel is a double injection end flow channel, and the first ends of the two injection end flow channels are intersected at the injection port; the connecting flow channel is also a double connecting flow channel, the two connecting flow channels are respectively communicated with the second ends of the two injection end flow channels, and the two connecting flow channels are communicated with the injection end flow channel.

Optionally, a second air inlet channel is arranged on the cylinder body seat and is connected with the sealing cavity, and channel openings of the second air inlet channel and the first air inlet channel, which are located in the sealing cavity, are located on two sides of the piston respectively.

Compared with the prior art, the utility model discloses a pneumatic glue that seals is penetrated the mouth and is had one of following technological effect:

1. during injection molding, the second air inlet channel is used for air inlet to push the piston to move rightwards, the piston pushes the glue sealing needle to move rightwards, the glue sealing end of the glue sealing needle is far away from the injection port, and the injection port is unsealed to open the injection port; injecting the rubber material into a mold cavity from the injection port through the injection runner by the injection molding machine material pipe group; after the glue is filled, the first air inlet channel is filled with air to push the piston to move left, the piston pushes the glue sealing needle to move left, the glue sealing end of the glue sealing needle is abutted to the glue outlet to seal the glue outlet, so that the glue outlet is closed, glue sealing is carried out, glue leakage is avoided, and the processing cost is saved. Because the driving force of the piston is the same as the moving direction of the glue sealing needle, the glue sealing needle cannot deviate in the moving process, the friction between the glue sealing needle and the mounting seat and between the glue sealing end and the pouring outlet is small, the glue sealing needle and the glue sealing end are not easy to wear, the service life of the glue sealing needle is prolonged, and meanwhile, when the pouring outlet is closed, the tight sealing of the glue sealing end and the pouring outlet can be ensured.

2. The connecting portion of connecting seat is equipped with penetrates the mouth, penetrate the mouth often in the mould contact, penetrate the mouth and wear and tear easily, when penetrating the mouth wearing and tearing, direct change penetrate the mouth can, need not to change the connecting seat, save the cost.

3. The connecting seat is in be equipped with the cooling runner around the notes play end runner, the cooling runner is used for cooling notes play end runner with penetrate the mouth, prevent that thermosetting plastics from solidifying in the notes export of penetrating the mouth and annotating the play end runner, can not block up gluey.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive labor.

Fig. 1 is a first cross-sectional view of the pneumatic sealing nozzle of the present invention.

Fig. 2 is a second cross-sectional view of the pneumatic sealing nozzle of the present invention.

Wherein, in the figures, the respective reference numerals:

the injection molding device comprises a mounting seat 100, an injection molding flow channel 110, an injection end flow channel 111, an injection end flow channel 112, a connecting flow channel 113, an injection port 114, a sealing cavity 120, a first air inlet channel 130, a connecting seat 140, a connecting part 141, an insertion protrusion 142, a bolt connecting hole 145, a cylinder seat 150, a groove 151, a connecting hole 152, a sealing flange 153, a second air inlet channel 154, a nozzle seat 160, a sealing end 161, a threaded hole 162, an injection port 163, a nozzle 170, an insertion groove 171, a smooth cone 172, a bolt 180, a piston 200, an oil sealing groove 210, a sealing glue needle 300 and a sealing glue end 310.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary and intended to explain the embodiments of the present invention and are not to be construed as limiting the present invention.

In the description of the embodiments of the present invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings, which is only for convenience in describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element so indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as fixed or detachable connections or as an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the embodiments of the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, referring to fig. 1 and 2, a pneumatic sealing glue nozzle is provided, which comprises a mounting base 100, a piston 200 and a sealing glue needle 300.

Referring to fig. 1 and 2, an injection molding runner 110 is provided through the mounting seat 100, and the injection molding runner 110 is a passage through which the glue flows. The end of the injection molding runner 110 connected with the injection molding machine material pipe group is an injection end runner 111, the end of the injection molding runner 110 connected with the mold sprue bush is an injection end runner 112, and the tail end of the injection end runner 112 is tapered to form a conical injection outlet 114.

Referring to fig. 1 and 2, a seal cavity 120 is disposed in the middle of the mounting seat 100, a first air inlet channel 130 communicated with the seal cavity 120 is disposed on the mounting seat 100, and the piston 200 is sealingly and slidably mounted in the seal cavity 120. A circle of oil seal groove 210 is dug on the outer wall of the piston 200 close to the seal cavity 120, an oil seal is arranged in the oil seal groove 210, and the piston 200 is connected with the inner wall of the seal cavity 120 in a sealing manner through the oil seal on the oil seal groove 210.

Referring to fig. 1 and 2, the glue sealing needle 300 is installed in the flow channel 112 of the injection end, the glue sealing needle 300 can reciprocate along the flow channel 112 of the injection end, and the diameter of the glue sealing needle 300 is smaller than that of the flow channel 112 of the injection end, so that a gap for passing glue is formed between the glue sealing needle 300 and the flow channel 112 of the injection end. The first end of the glue sealing needle 300 is connected to the piston 200, the second end of the glue sealing needle 300 is a glue sealing end 310, and the glue sealing end 310 is adapted to the outlet 114, so that the piston 200 can drive the glue sealing end 310 of the glue sealing needle 300 to seal the outlet 114 or unseal the outlet 114. Specifically, the sealing end 310 is set to be a cone shape adapted to the outlet 114, and the sealing end 310 is accommodated in the outlet 114 and blocks the outlet 114 to realize sealing.

During injection molding, the second air inlet channel 154 is filled with air to push the piston 200 to move right, the piston 200 pushes the glue sealing needle 300 to move right, the glue sealing end 310 of the glue sealing needle 300 is far away from the injection port 114, and the injection port 114 is unsealed, so that the injection port 114 is opened. The injection molding machine manifold injects the molding compound from the injection port 114 into the mold cavity via the injection runner 110. After the glue is filled, the first air inlet channel 130 is filled with air to push the piston 200 to move left, the piston 200 pushes the glue sealing needle 300 to move left, the glue sealing end 310 of the glue sealing needle 300 is abutted to the glue outlet 114 to seal the glue outlet 114, so that the glue outlet 114 is closed to seal the glue, glue leakage is avoided, and the processing cost is saved. Because the pushing force of the piston 200 is the same as the moving direction of the glue sealing needle 300, the glue sealing needle 300 does not deviate in the moving process, the friction between the glue sealing needle 300 and the mounting base 100 and between the glue sealing end 310 and the pouring outlet 114 is small, the glue sealing needle 300 and the glue sealing end 310 are not easy to wear, the service life of the glue sealing needle 300 is prolonged, and meanwhile, when the pouring outlet 114 is closed, the close sealing between the glue sealing end 310 and the pouring outlet 114 can be ensured.

Referring to fig. 1 and 2, the mount base 100 includes a connection base 140, a cylinder base 150, and a nozzle base 160, which are connected in sequence. The injection end flow passage 112 is disposed on the connecting seat 140, the injection end flow passage 111 is disposed on the nozzle seat 160, a connection flow passage 113 is connected between the injection end flow passage 111 and the injection end flow passage 112, and the connection flow passage 113 passes through the cylinder seat 140. The injection-side runner 111, the connection runner 113, and the injection-side runner 112 form the injection runner 110.

Referring to fig. 1 and 2, a groove 151 is dug in one end of the cylinder base 150 close to the nozzle base 160, a sealing end 161 is convexly disposed at one end of the nozzle base 160 close to the cylinder base 150, the sealing end 161 is inserted into the groove 151, and the sealing end 161 is hermetically connected with the inner wall of the groove 151 through an O-ring, so that the sealing cavity 120 is formed inside the groove 151. The first air inlet passage 130 is disposed on the nozzle seat 160, and the first air inlet passage 130 is L-shaped. The ends of the first air inlet channel 130 and the second air inlet channel 154 face the piston 200, so that the high-pressure gas entering through the first air inlet channel 130 and the second air inlet channel 154 pushes the piston 200 in the forward direction, and the piston 200 pushes the glue sealing needle 300 to move in a force balance manner.

Referring to fig. 1 and 2, a second air inlet channel 154 is provided on the cylinder block 150 and the seal chamber 120, a start end of the second air inlet channel 154 is located on an outer wall of the nozzle block 150, and a tail end of the second air inlet channel 154 and a tail end of the first air inlet channel 130 are located in the seal chamber 120 on both sides of the piston 200. The starting ends of the first and second

air intake passages

130 and 154 are connected to a pneumatic valve (not shown) communicating with an air pump (not shown) through an air pipe.

When the injection molding machine performs an injection action, the injection molding machine gives an electric signal to the pneumatic valve through a computer, the air passages of the pneumatic valve are switched, air enters the second air inlet passage 154, the air pressure of the left side of the piston 200 connected with the second air inlet passage 154 is larger than the air pressure of the right side of the piston 200 connected with the first air inlet passage 130, the piston 200 drives the glue sealing needle 300 to move rightwards, the glue sealing end 310 of the glue sealing needle 300 is far away from the injection port 114, and the injection port 114 is unsealed, so that the injection port 114 is opened. After the injection action is completed, the pneumatic valve loses an electric signal, the air passage of the pneumatic valve is switched, the first air inlet channel 130 is filled with air, when the air pressure of the left side of the piston 200 connected with the second air inlet channel 154 is smaller than the air pressure of the right side of the piston 200 connected with the first air inlet channel 130, the piston 200 drives the glue sealing needle 300 to move leftwards, the glue sealing end 310 of the glue sealing needle 300 is close to the injection port 114, and the injection port 114 is sealed, so that the injection port 114 is closed. Wherein, the pneumatic valve can be according to the electrical signal that injection molding machine computer provided, a device that switches the inlet position of high-pressure gas.

Referring to fig. 1 and 2, a connection hole 152 communicating with the sealing cavity 120 is formed at one end of the cylinder block 150 close to the connection seat 140, and a first end of the glue sealing needle 300 movably passes through the connection hole 152 to be connected with the piston 200. The cylinder body seat 150 is further provided with a sealing flange 153 at the connecting hole 152, and the sealing flange 153 is in sealing sliding connection with the glue sealing needle 300 to prevent the gas in the sealing cavity 120 from leaking from the connecting hole 152. The connecting base 140 is further provided with a clearance groove for clearance of the sealing flange 153.

Referring to fig. 1 and 2, one end of the connecting seat 140, which is away from the cylinder seat, is narrowed to form a connecting portion 141, an end of the connecting portion 141 is provided with a nozzle 170, the injection port 114 is provided in the nozzle 170, and when the sealing end 310 is away from the injection port 114, the material pipe set of the injection molding machine injects the rubber material into the mold cavity through the gap between the injection port runner 112 and the sealing needle 300 and through the injection port 114.

Referring to fig. 1 and 2, an insertion protrusion 142 is convexly disposed at an end of the connecting portion 141, an insertion groove 171 is disposed at an end of the nozzle 170 close to the connecting portion, the insertion protrusion 142 is inserted into the insertion groove 171 in a matching manner, and the nozzle 170 is detachably and fixedly mounted on the insertion protrusion 142 by combining with a screw. The nozzle 170 is often contacted with a mold, the nozzle 170 is easy to wear, and when the nozzle 170 is worn, the nozzle 170 can be directly replaced without replacing the connecting seat 140, so that the cost is saved.

Referring to fig. 1 and 2, the tip of the nozzle 170 is provided with a smooth conical shape 172 for mating connection with a mold sprue bushing.

Referring to fig. 1 and 2, at least one pair of coaxial bolt connection holes 145 are formed through the connection seat 140 and the cylinder block 150, at least three pairs of threaded holes 162 are formed in the nozzle block 160, and the threaded holes 162 are coaxially arranged with the bolt connection holes 145. The bolt 180 is threaded with the threaded hole 162 through the bolt connection hole 145, so that the connection seat 140, the cylinder block 150 and the nozzle block 160 are fixedly connected, and the installation is convenient and the connection is firm.

Referring to fig. 1 and 2, one end of the nozzle holder 160 is provided with a sprue 163 adapted to a material tube set of an injection molding machine. The injection end flow channel 111 is a dual injection end flow channel, and first ends of the two injection end flow channels 111 meet at the injection port 163. The connecting flow channel 113 is also a dual connecting flow channel, the two connecting flow channels 113 are respectively communicated with the second ends of the two injection end flow channels 111, and the two connecting flow channels 113 are communicated with the injection end flow channel 112. The arrangement of the double injection end flow channel and the double connection flow channel can enable the rubber to rapidly flow into the injection end flow channel 112 through two sides, and the rubber is converged in the injection end flow channel 112 to form pressurization, so that the rubber is rapidly injected into a mold cavity, the injection molding effect is good, and the rubber is not easily blocked.

The connecting seat 140 is provided with cooling channels (not shown) around the injection end channel 112, the cooling channels are connected to a circulating cooling water tank (prior art), and the cooling channels are used for cooling the injection end channel 112 and the injection nozzle 170, so as to prevent thermosetting plastic from solidifying in the injection port 114 and the injection end channel 112 of the injection nozzle 170, and prevent glue blockage.

The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments shown and described. To the utility model belongs to the technical field of the ordinary technical personnel, do not deviate from the utility model discloses under the prerequisite of design, its framework form can be nimble changeable, can derive series of products. But merely as a matter of simple deductions or substitutions, should be considered as belonging to the scope of patent protection of the present invention as determined by the claims submitted.

Claims

1. A pneumatic glue sealing nozzle is characterized by comprising a mounting seat, a piston and a glue sealing needle; the mounting seat is provided with an injection molding runner in a penetrating manner, one end of the injection molding runner, which is connected with the material pipe group of the injection molding machine, is an injection end runner, one end of the injection molding runner, which is connected with the die sprue bush, is an injection end runner, and the tail end of the injection end runner is gradually reduced in diameter to form a conical injection port; a sealing cavity is formed in the middle of the mounting seat, a first air inlet channel communicated with the sealing cavity is formed in the mounting seat, and the piston is hermetically and slidably mounted in the sealing cavity; the glue sealing needle is arranged in the flow channel of the injection end, and the diameter of the glue sealing needle is smaller than that of the flow channel of the injection end; the first end of the glue sealing needle is connected with the piston, the second end of the glue sealing needle is a glue sealing end, and the glue sealing end is matched with the pouring outlet, so that the piston can drive the glue sealing end of the glue sealing needle to seal the pouring outlet or unseal the pouring outlet.

2. The pneumatic molding nozzle of claim 1, wherein: the mounting seat comprises a connecting seat, a cylinder body seat and a nozzle seat which are connected in sequence; the injection end flow passage is arranged on the connecting seat, the injection end flow passage is arranged on the nozzle seat, a connecting flow passage is connected between the injection end flow passage and the injection end flow passage, and the connecting flow passage penetrates through the cylinder seat; the cylinder body seat is provided with a groove in a digging mode at one end close to the nozzle seat, a sealing end is arranged at one end, close to the cylinder body seat, of the nozzle seat in a protruding mode, and the sealing end is connected with the groove in an inserting mode, so that the sealing cavity is formed inside the groove.

3. The pneumatic molding compound nozzle of claim 2, wherein: one end of the cylinder body seat close to the connecting seat is provided with a connecting hole communicated with the sealing cavity, and the first end of the rubber sealing needle movably penetrates through the connecting hole to be connected with the piston; the cylinder body seat is also provided with a sealing flange at the connecting hole, and the sealing flange is in sealing sliding connection with the sealing rubber needle; the connecting seat is also provided with a clearance groove for avoiding the sealing flange.

4. The pneumatic molding compound nozzle of claim 2, wherein: one end of the connecting seat, which is far away from the cylinder body seat, is reduced to form a connecting part, the end part of the connecting part is provided with a nozzle, and the injection outlet is arranged on the nozzle.

5. The pneumatic molding nozzle of claim 4, wherein: the end part of the connecting part is convexly provided with an inserting projection, one end of the nozzle, which is close to the connecting part, is provided with an inserting groove, and the inserting projection is inserted into the inserting groove in a matching manner.

6. The pneumatic molding nozzle of claim 4, wherein: the end part of the nozzle is set to be smooth and conical.

7. The pneumatic molding nozzle of claim 4, wherein: and cooling channels are arranged on the connecting seat around the flow channel of the injection end.

8. The pneumatic molding compound nozzle of claim 2, wherein: at least three pairs of coaxial bolt connecting holes are arranged on the connecting seat and the cylinder body seat in a penetrating way, at least three pairs of threaded holes are arranged on the nozzle seat, and the threaded holes and the bolt connecting holes are arranged coaxially; and the bolt penetrates through the bolt connecting hole to be in threaded connection with the threaded hole, so that the connecting seat, the cylinder body seat and the nozzle seat are fixedly connected.

9. The pneumatic molding compound nozzle of claim 2, wherein: one end of the nozzle seat is provided with an injection port matched with the material pipe group of the injection molding machine; the injection end flow channel is a double injection end flow channel, and the first ends of the two injection end flow channels are intersected at the injection port; the connecting flow channel is also a double connecting flow channel, the two connecting flow channels are respectively communicated with the second ends of the two injection end flow channels, and the two connecting flow channels are communicated with the injection end flow channel.

10. The pneumatic molding compound nozzle of claim 2, wherein: and a second air inlet channel which is connected with the sealing cavity is arranged on the cylinder body seat, and channel openings of the second air inlet channel and the first air inlet channel, which are positioned in the sealing cavity, are respectively positioned at two sides of the piston.