Straight-through type liquid injection valve

Abstract

The invention relates to the technical field of fluid control, and discloses a straight-through type liquid injection valve which comprises a valve body, a piston arranged in a cavity of the valve body, a liquid injection rod synchronously moving back and forth along with the piston, a plug arranged at one end of the liquid injection rod, and a liquid injection buffering cavity isolated from a cavity where the piston is located. The liquid injection buffer cavity is communicated with a flow channel arranged on the liquid injection rod, the flow channel is communicated with an external liquid supply device, and the liquid injection buffer cavity is provided with a liquid injection port matched with the plug, so that the straight-through type liquid injection valve adopting the structural design can control the flowing of liquid through the back-and-forth movement of the liquid injection rod, and can also facilitate the replacement and cleaning of the liquid injection rod.

Description

Technical Field

[0001] The present application relates to the technical field of fluid control, and in particular to a straight-through liquid injection valve. Background Art

[0002] The injection valve is one of the indispensable and important components in modern industrial production and is widely used in chemical, pharmaceutical, food processing and other industries. With the rapid development of these industries, the requirements for injection accuracy and stability are getting higher and higher. Although traditional injection equipment can meet the basic process requirements, it has some shortcomings in practical applications, such as complex structure, high maintenance cost, slow injection speed and other problems. Therefore, it is of great practical significance to develop a new injection valve with simple structure and reliable performance. At present, in order to solve the above problems, common injection valves usually adopt the following methods: first, multi-level control is achieved through complex mechanical structure, such as using solenoid valves, pneumatic valves and other components to control the injection process; second, precise control is performed through the hydraulic system, and the piston is driven by pressure changes to complete the injection action; third, accurate injection is achieved through electronic control system combined with sensor feedback. These methods have improved the accuracy and stability of injection to a certain extent, but there are still certain limitations. However, a common problem with existing injection valves is that after injection, the liquid remaining on the side wall of the injection port is likely to continue to drip at the injection port, thereby contaminating the product. In addition, the flow channels used for injection are mostly tortuous, so it is difficult to clean and replace them. They may even cause problems such as pipe blockage when used again due to improper cleaning. Summary of the invention

[0003] In order to overcome the above-mentioned technical problems, the present application provides a straight-through liquid injection valve.

[0004] A straight-through liquid injection valve, comprising a valve body, a piston arranged in a cavity of the valve body, a liquid injection rod that moves back and forth synchronously with the piston, a plug arranged at one end of the liquid injection rod, and a liquid injection buffer cavity that is isolated from the cavity where the piston is located; the liquid injection buffer cavity is connected with a flow channel arranged on the liquid injection rod, the flow channel is connected with an external liquid supply device, and the liquid injection buffer cavity is provided with a liquid injection port that cooperates with the plug; When the injection rod moves with the piston toward the end away from the injection port, the plug is separated from the injection port, and the liquid in the injection buffer cavity flows out from the injection port; When the injection rod moves with the piston toward one end close to the injection port, the plug is sealed against the injection port, and at this time, the liquid in the injection buffer cavity stops flowing out from the injection port.

[0005] By adopting the above technical solution, the liquid injection rod can move back and forth along the valve body cavity under the driving action of the piston, and then control the flow of the liquid through the sealing and separation of the plug at the end of the liquid injection rod and the liquid injection port. Since the valve body is provided with a liquid injection buffer cavity, the liquid flow is also made more stable and reliable.

[0006] Preferably, a first sealing guide sleeve and a second sealing guide sleeve are respectively arranged at both ends of the cavity where the piston is located, and the first sealing guide sleeve and the second sealing guide sleeve are respectively in sliding fit with the liquid injection rod.

[0007] By adopting the above technical solution, the first sealing guide sleeve and the second sealing guide sleeve can play a high supporting and guiding role for the liquid injection rod, enabling it to move back and forth smoothly along the axial direction of the valve body cavity.

[0008] Preferably, a spring for resetting the piston is arranged between the first sealing guide sleeve and the piston, and the spring is sleeved on the liquid injection rod; the plug is connected with the liquid injection rod through a movable ball head.

[0009] By adopting the above technical solution, the plug connected to the liquid injection rod through the movable ball head can be kept in a sealed state with the liquid injection port under the action of the spring elastic force in the initial state, thus avoiding liquid leakage; in addition, since the plug is movably connected to the liquid injection rod, it is more convenient for the plug to automatically align with the liquid injection port, avoiding abnormalities such as plug jamming and poor sealing caused by the plug yaw.

[0010] Preferably, elastic seals are respectively arranged on the sides of the first sealing guide sleeve and the second sealing guide sleeve away from the piston, and the two elastic seals are respectively tightly sealed with the inner wall of the cavity of the valve body and the liquid injection rod.

[0011] By adopting the above technical solution, the setting of the elastic seals can increase the sealing performance of the piston chamber, and then prevent the liquid from penetrating into the piston chamber and affecting the normal movement of the piston.

[0012] Preferably, both of the two elastic seals are arranged in a flared shape, and are respectively provided with a first opening and a second opening. The first opening is tightly sealed with the inner wall of the cavity of the valve body, and the second opening is sleeved on the liquid injection rod and tightly sealed with the liquid injection rod; the inner diameter of the first opening of the elastic seal is larger than the inner diameter of the second opening; the first openings of the two elastic seals are both arranged towards the side away from the plug.

[0013] By adopting the above technical solution, while ensuring the sealing performance of the piston chamber, it will not affect the back-and-forth movement of the liquid injection rod.

[0014] Preferably, the injection rod is axially provided with the flow channel, the end of the valve body away from the plug is provided with a liquid inlet, and the end of the injection rod close to the plug is radially provided with a through hole connected with the flow channel; the gap between the injection rod and the inner wall of the valve body cavity forms the injection buffer cavity, and the through hole is connected with the injection buffer cavity.

[0015] By adopting the above technical solution, the liquid can flow directly into the injection buffer cavity through the liquid inlet along the flow channel in the injection rod. In addition, since the injection rod is arranged axially along the cavity of the valve body, the disassembly and cleaning of the injection rod is also convenient.

[0016] Preferably, the valve body includes a valve cylinder, a valve seat and a valve cover arranged at two ends of the valve cylinder, a valve sleeve sealed and fastened to the valve cover, and a valve mouth matching the valve sleeve; the inner diameter of the valve sleeve is smaller than the inner diameter of the valve cylinder, and the injection buffer chamber is arranged between the valve sleeve and the injection rod.

[0017] By adopting the above technical solution, the structure is stable and reliable, the straight-through liquid injection valve can be easily disassembled and assembled, and the liquid injection rod can be easily replaced or cleaned.

[0018] Preferably, the side wall of the cavity where the piston is located is provided with an air inlet and an air outlet connected to an external pneumatic device.

[0019] By adopting the above technical solution, the setting of the air inlet and the exhaust port can be conveniently connected to an external pneumatic device, thereby driving the piston to move.

[0020] In summary, the present application includes at least one of the following beneficial technical effects: 1. The injection rod is arranged axially along the valve body cavity, and moves back and forth along the valve body cavity with the piston. It can not only conveniently control the flow of liquid through the plug arranged at the end of the injection rod, but also facilitate the replacement or cleaning of the injection rod; and it can also avoid the dripping phenomenon of liquid at the injection port after injection.

[0021] 2. The injection buffer chamber is sealed and isolated from the chamber where the piston is located by an elastic seal, which can effectively improve the sealing performance of the chamber where the piston is located and prevent the liquid in the injection buffer chamber from flowing in. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an axonometric diagram of a straight-through liquid injection valve of the present application.

[0023] Figure 2 yes Figure 1 main view.

[0024] Figure 3 yes Figure 2 Cross-sectional view of section AA.

[0025] Figure 4 yes Figure 2 Cross-sectional view of section BB.

[0026] Figure 5 yes Figure 1 Axonometric view with valve body removed.

[0027] Description of reference numerals: 1. Valve body; 11. Valve cylinder; 12. Valve seat; 121. Liquid inlet; 13. Valve cover; 14. Valve nozzle; 15. Valve sleeve; 2. Piston; 3. Injection rod; 31. First injection rod; 32. Second injection rod; 321. Through hole; 4. Plug; 5. Injection buffer chamber; 51. Injection port; 61. First sealing guide sleeve; 62. Second sealing guide sleeve; 7. Spring; 8. Elastic sealing member. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with the accompanying drawings.

[0029] Reference Figures 1 to 5 As shown, the present embodiment provides a straight-through liquid injection valve, which includes a valve body 1, a piston 2 arranged in the cavity of the valve body 1, an injection rod 3 that moves back and forth with the piston 2, a plug 4 arranged at the end of the injection rod 3, and a liquid injection buffer cavity 5 isolated from the cavity where the piston 2 is located, wherein the liquid injection buffer cavity 5 is connected with a flow channel arranged in the injection rod 3, and the flow channel is connected with an external liquid supply device, and a liquid injection port 51 that cooperates with the above-mentioned plug 4 is arranged at the end of the liquid injection buffer cavity 5.

[0030] With the straight-through liquid injection valve of the above-mentioned structural design, when the liquid injection rod 3 moves with the piston 2 toward the end away from the liquid injection port 51, the plug 4 is separated from the liquid injection port 51, and the liquid in the liquid injection buffer chamber 5 will flow out from the liquid injection port 51; conversely, when the liquid injection rod 3 moves with the piston 2 toward the end close to the liquid injection port 51, the plug 4 will be sealed with the liquid injection port 51, and the liquid in the liquid injection buffer chamber 5 will stop flowing out from the liquid injection port 51; the liquid injection rod 3 is driven to move back and forth by the piston 2 to control the opening and closing of the liquid injection port 51 cooperating with the plug 4; in addition, since the flow channel is arranged along the liquid injection rod 3, the liquid flow path can also be shortened, so that the liquid can flow into the liquid injection buffer chamber 5 efficiently and quickly, and it is also convenient to clean the flow channel after the liquid injection rod 3 is disassembled.

[0031] More specifically, in order to facilitate the installation of the injection rod 3 and to enable it to reciprocate along the axial direction of the cavity of the valve body 1 stably and reliably, and to reduce the deflection of the injection rod 3 during the movement, Figure 3 and Figure 4As shown, a first sealing guide sleeve 61 and a second sealing guide sleeve 62 for mounting the injection rod 3 are respectively provided at both ends of the cavity where the piston 2 is located, so as to ensure that the injection rod 3 slides back and forth along the first sealing guide sleeve 61 and the second sealing guide sleeve 62 while having good guiding performance to prevent deflection during movement.

[0032] In order to further increase the sealing performance of the cavity where the piston 2 is located, elastic seals 8 are respectively provided on the side of the first sealing guide sleeve 61 and the second sealing guide sleeve 62 away from the piston 2. The two elastic seals 8 are respectively sealed and fastened to the inner wall of the cavity of the valve body 1 and the injection rod 3, so as to increase the airtightness of the cavity where the piston 2 is located. Preferably, the piston 2 in this scheme is pneumatically driven, and an air inlet and an exhaust port connected to an external pneumatic device are provided on the side wall of the cavity where the piston 2 is located, so that after being connected to the external pneumatic device, the piston 2 can be driven to move stably and reliably.

[0033] In order to ensure that the above-mentioned two elastic seals 8 can ensure the sealing of the piston 2 cavity while allowing the injection rod 3 to move back and forth with the piston 2, preferably, the two elastic seals 8 are both arranged in a trumpet shape and are respectively provided with a first opening and a second opening. During installation, the first opening can be sealed and fastened to the inner wall of the cavity of the valve body 1, and the second opening can be sleeved on the injection rod 3 and sealed and fastened to the injection rod 3; and the inner diameter of the first opening of the elastic seal 8 is larger than the inner diameter of the second opening; after installation, the first openings of the two elastic seals 8 are both arranged to face the side away from the plug 4, thereby ensuring the consistency of force when the injection rod 3 moves and satisfying the movement stroke of the injection rod 3 to the greatest extent.

[0034] The specific connection between the first opening and the second opening and the inner wall of the cavity of the valve body 1 and the injection rod 3 is not limited to any detachable installation method such as snap-on connection and external component compression, as long as it can ensure the sealing performance and facilitate subsequent disassembly and maintenance.

[0035] The two elastic seals 8 designed in the above manner are both made of plastic material with strong tensile resistance, corrosion resistance and certain flexibility. When the piston 2 drives the injection rod 3 to move back and forth, the two elastic seals 8 can be synchronously flipped up and down by the traction of the injection rod 3. In this way, the injection rod 3 can move back and forth within the preset stroke while fully isolating the chamber where the piston 2 is located from the injection buffer chamber 5, thereby ensuring the sealing of the chamber of the piston 2 and then ensuring the normal movement of the piston 2.

[0036] Combination Figure 3 and Figure 4As shown, in order to further ensure that the plug 4 can have good automatic centering with the injection port 51 when it moves with the injection rod 3, it is preferred that the plug 4 arranged at the end of the injection rod 3 is movably connected to the injection rod 3 through a movable ball head, and the plug 4 and the inner wall of the injection port 51 are both conical, so that the plug 4 can slide along the inner wall of the injection port 51 and automatically correct under the driving action of the injection rod 3, and then fit tightly with the inner wall of the injection port 51, so as to control the opening and closing of the injection port 51, improve the sealing at the injection port 51, and prevent liquid leakage.

[0037] The injection port 51 arranged in this way can greatly shorten the depth of the injection port 51 compared with the traditional injection valve because the inner wall of the injection port 51 is shorter and connected with the injection buffer chamber 5, thereby avoiding the occurrence of continuous dripping caused by liquid remaining on the inner wall of the injection port 51 after the injection is completed.

[0038] In addition, in order to make the injection port 51 of the straight-through injection valve in a normally closed state in the initial state, preferably, a spring 7 for resetting the piston 2 is also provided between the above-mentioned first sealing guide sleeve 61 and the piston 2. When the air pressure in the cavity where the piston 2 is located decreases, as the force of the spring 7 is released, the piston 2 will drive the injection rod 3 to move toward one end of the injection port 51, and finally drive the plug 4 and the injection port 51 to be sealed.

[0039] Furthermore, in order to enable external liquid to be smoothly introduced into the above-mentioned injection buffer chamber 5 through the flow channel arranged in the injection rod 3, preferably, the above-mentioned flow channel is arranged along the axial direction of the injection rod 3, and a through hole 321 that is connected to the flow channel is radially arranged at one end close to the plug 4, and the through hole 321 is connected to the injection buffer chamber 5, and the injection buffer chamber 5 is formed by the gap between the inner wall of the cavity of the valve body 1 and the injection rod 3.

[0040] In addition, a liquid inlet 121 connected to an external liquid supply device is provided at the upper end of the cavity of the valve body 1. When the liquid inlet 121 of the straight-through liquid injection valve is connected to the external liquid supply device, liquid can flow in from the liquid inlet 121 and then flow into the liquid injection buffer cavity 5 through the flow channel from the through hole 321.

[0041] In addition, preferably, the first opening of the elastic seal 8 arranged at the upper end of the injection rod 3 faces the liquid inlet 121, and the elastic seal 8 is sealed and fastened to the inner wall of the cavity of the valve body 1 and the injection rod 3. Therefore, the elastic seal 8 also has a funnel-like effect to redirect the overflowed liquid into the flow channel in the injection rod 3.

[0042] Furthermore, combined Figures 3 to 5As shown, the valve body 1 includes a valve cylinder 11, a valve seat 12 and a valve cover 13 arranged at two ends of the valve cylinder 11, a valve sleeve 15 sealed and fastened to the valve cover 13, and a valve mouth 14 matched with the valve sleeve 15; wherein, the inner diameter of the valve sleeve 15 is smaller than the inner diameter of the valve cylinder 11, the valve sleeve 15 is sleeved on the part of the injection rod 3 exposed outside the valve cylinder 11, and the above-mentioned injection buffer chamber 5 is formed between the valve sleeve 15 and the injection rod 3.

[0043] Preferably, in order to facilitate the sealing and fastening of the two elastic seals 8 and the valve body 1, the first opening of the elastic seal 8 located at the upper end of the injection rod 3 is pressed and sealed with the first sealing guide sleeve 61 through the valve seat 12, and the first opening of the elastic seal 8 located at the lower end of the injection rod 3 is pressed and sealed with the second sealing guide sleeve 62 through the valve cover 13.

[0044] Similarly, in order to facilitate the sealing and fastening of the two elastic seals 8 and the injection rod 3, and also to facilitate the processing and installation of the injection rod 3, the above-mentioned injection rod 3 adopts a two-stage setting, that is, the injection rod 3 includes a first injection rod 31 mounted between the first sealing guide sleeve 61 and the second sealing guide sleeve 62, and a second injection rod 32 inserted in the valve sleeve 15 and fastened to the first injection rod 31, and the second opening of the elastic seal 8 located here is clamped and sealed by the first injection rod 31 and the second injection rod 32.

[0045] The working principle of the present application is as follows: in the initial state, the injection rod 3 is acted upon by the elastic force of the spring 7 arranged above the piston 2, so that the plug 4 at the lower end of the injection rod 3 is sealed with the injection port 51; when the external liquid supply device is connected to the liquid inlet 121 on the valve seat 12, the liquid flows along the flow channel in the injection rod 3 into the injection buffer chamber 5 at the lower end of the straight-through injection valve. When injection is required, the injection rod 3 is driven upward by the piston 2 to separate the plug 4 from the injection port 51. After the injection is completed, the injection rod 3 is driven downward by the piston 2 again to seal the plug 4 from the injection port 51.

[0046] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A straight-through liquid injection valve, characterized in that: The invention comprises a valve body (1), a piston (2) arranged in a cavity of the valve body (1), a liquid injection rod (3) which moves back and forth synchronously with the piston (2), a plug (4) arranged at one end of the liquid injection rod (3), and a liquid injection buffer cavity (5) which is isolated from the cavity where the piston (2) is located; the liquid injection buffer cavity (5) is connected with a flow channel arranged on the liquid injection rod (3), the flow channel is connected with an external liquid supply device, and the liquid injection buffer cavity (5) is provided with a liquid injection port (51) which cooperates with the plug (4); When the injection rod (3) moves with the piston (2) toward the end away from the injection port (51), the plug (4) separates from the injection port (51), and at this time, the liquid in the injection buffer chamber (5) flows out from the injection port (51); When the injection rod (3) moves with the piston (2) toward one end close to the injection port (51), the plug (4) and the injection port (51) are sealed, and at this time, the liquid in the injection buffer chamber (5) stops flowing out from the injection port (51).

2. A straight-through liquid injection valve according to claim 1, characterized in that: A first sealing guide sleeve (61) and a second sealing guide sleeve (62) are respectively provided at both ends of the cavity where the piston (2) is located. The first sealing guide sleeve (61) and the second sealing guide sleeve (62) are respectively slidably matched with the injection rod (3).

3. A straight-through liquid injection valve according to claim 2, characterized in that: A spring (7) for resetting the piston (2) is provided between the first sealing guide sleeve (61) and the piston (2), and the spring (7) is sleeved on the injection rod (3); the plug (4) is connected to the injection rod (3) via a movable ball head.

4. A straight-through liquid injection valve according to claim 2, characterized in that: The first sealing guide sleeve (61) and the second sealing guide sleeve (62) are respectively provided with elastic sealing members (8) on the side away from the piston (2), and the two elastic sealing members (8) are respectively sealed and fastened to the inner wall of the cavity of the valve body (1) and the injection rod (3).

5. A straight-through liquid injection valve according to claim 4, characterized in that: The two elastic sealing members (8) are both arranged in a trumpet shape and are respectively provided with a first opening and a second opening, the first opening being sealed and fastened to the inner wall of the cavity of the valve body (1), and the second opening being sleeved on the injection rod (3) and sealed and fastened to the injection rod (3).

6. A straight-through liquid injection valve according to claim 5, characterized in that: The inner diameter of the first opening of the elastic sealing member (8) is greater than the inner diameter of the second opening; the first openings of the two elastic sealing members (8) are both arranged towards a side away from the plug (4).

7. A straight-through liquid injection valve according to claim 1, characterized in that: The flow channel is arranged axially along the injection rod (3); and a through hole (321) which is in communication with the flow channel is radially arranged at one end of the injection rod (3) close to the plug (4).

8. A straight-through liquid injection valve according to claim 7, characterized in that: The gap between the liquid injection rod (3) and the inner wall of the cavity of the valve body (1) forms the liquid injection buffer cavity (5), and the through hole (321) is connected to the liquid injection buffer cavity (5).

9. The straight-through liquid injection valve according to claim 1, characterized in that: The valve body (1) comprises a valve cylinder (11), a valve seat (12) and a valve cover (13) arranged at two ends of the valve cylinder (11), a valve sleeve (15) sealed and fastened to the valve cover (13), and a valve mouth (14) matched with the valve sleeve (15); the inner diameter of the valve sleeve (15) is smaller than the inner diameter of the valve cylinder (11), and the injection buffer chamber (5) is arranged between the valve sleeve (15) and the injection rod (3).

10. The straight-through liquid injection valve according to claim 1, characterized in that: The side wall of the cavity where the piston (2) is located is provided with an air inlet and an air outlet connected to an external pneumatic device.

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