Porous pneumatic injection valve and control method thereof

Abstract

The invention relates to a porous pneumatic injection valve and a control method thereof. The porous pneumatic injection valve comprises a valve body structure, a double-valve-element structure, a gas circuit control module and a stroke adjusting module. The double-valve-element structure comprises a first valve element assembly and a second valve element assembly, the first valve element assembly is composed of a first ejector pin, a first piston, a first spring and a first discharging port, and the second valve element assembly is composed of a second ejector pin, a second piston, a second spring and a second discharging port. The stroke adjusting mechanism comprises a T-shaped limiting block and a U-shaped groove which are arranged above the first ejector pin and the second ejector pin respectively. And the gas circuit control module is connected with the double-electromagnetic-valve system and the electric proportional valve. The integrated porous normally-closed pneumatic injection valve has the beneficial effects that a method of arranging a plurality of valve cores in the valve body and integrating a gas circuit is adopted, so that the whole integrated porous normally-closed pneumatic injection valve overcomes the condition that the efficiency and the precision cannot be unified when the total injection amount is relatively large in the current injection field.

Description

Technical Field

[0001] The present invention belongs to the technical field of injection valves, and particularly relates to a porous pneumatic injection valve and a control method thereof. Background Art

[0002] In the process of large-scale factory assembly line production, in order to ensure product quality, factories basically choose high-precision injection valves for raw material proportioning. In the process of industrial production, there are often situations where the total injection volume is large. Especially when the total injection volume is more than twenty kilograms, due to the small flow rate of high-precision injection valves and long injection time, the factory efficiency is low. If the factory chooses to use two injection valves of different sizes for mixed injection, there will be various disadvantages such as cumbersome control, large space occupied by the injection valves, easy control errors, long and messy wiring, etc. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a porous pneumatic injection valve and a control method thereof.

[0004] In a first aspect, a porous pneumatic injection valve is provided, including: a valve body structure, a double valve core structure, a gas path control module, and a stroke adjustment module; Among them, the valve body structure includes an upper end cover and a lower end cover; the double valve core structure includes a first valve core assembly and a second valve core assembly. The first valve core assembly is composed of a first thimble, a first piston, a first spring, and a first discharge port. The second valve core assembly is composed of a second thimble, a second piston, a second spring, and a second discharge port; the gas path control module includes a first air inlet, a second air inlet, a first air outlet, and a second air outlet provided on the upper end cover. The first air inlet and the first air outlet correspond to the first valve core assembly, and the second air inlet and the second air outlet correspond to the second valve core assembly; the stroke adjustment mechanism includes a T-shaped limit block and a U-shaped groove respectively arranged above the first thimble and the second thimble. The protruding part of the T-shaped limit block extends into the U-shaped groove and moves within a limited range. The gas path control module is connected to a double solenoid valve system and an electro-pneumatic proportional valve.

[0005] Preferably, the gas path control module is connected to a double solenoid valve system and an electro-pneumatic proportional valve, including: One end of the electro-pneumatic proportional valve is connected to an air compressor, and the other end is connected to the second air inlet; one end of the first solenoid valve is connected to the second discharge port, and the other end is connected to the first air inlet; one end of the second solenoid valve is connected to the first air outlet, and the other end is connected to the air.

[0006] Preferably, in the stroke adjustment module, threads and through holes are provided above the first thimble and the second thimble, and matching threads are provided on the outside of the T-shaped limit block.

[0007] Preferably, a feed inlet is provided at the lower part of the upper end cover, and raw materials enter the storage cylinder through the feed inlet; a guide sleeve is further provided inside the upper end cover, and the guide sleeve is used to isolate the gas path and the liquid path.

[0008] Preferably, a first thimble seal seat and a second thimble seal seat are provided above the lower end cover, which are respectively matched with the first valve core assembly and the second valve core assembly for sealing.

[0009] Second, a control method for the porous pneumatic injection valve as described in any one of the first aspects is provided, including: Step 1: Control the electric proportional valve to open to the maximum flow rate, open the first solenoid valve, and close the second solenoid valve; Step 2: When the injection volume reaches the first threshold, maintain the maximum flow rate output by the electric proportional valve, close the first solenoid valve, and open the second solenoid valve; Step 3: When the injection volume reaches the second threshold, reduce the flow rate output by the electric proportional valve, close the first solenoid valve, and open the second solenoid valve; the second threshold is greater than the first threshold; Step 4: When the injection volume reaches the third threshold, close the electric proportional valve, open the first solenoid valve and the second solenoid valve; the third threshold is greater than the second threshold.

[0010] Preferably, in step 1, the first spring and the second spring are compressed, and both the first piston and the second piston are pushed to the uppermost position. At this time, both the first discharge port and the second discharge port maintain the maximum opening degree.

[0011] Preferably, in step 2, the second spring is compressed, and the second piston is pushed to the uppermost position; air is discharged through the second solenoid valve, and the air pressure drops. Due to its own elastic force, the first spring pushes the first piston back to its original position. At this time, the first discharge port is blocked by the first thimble and the first thimble seal seat, and the second discharge port maintains the maximum opening degree.

[0012] Preferably, in step 3, the second piston is gradually pushed back to its original position, and due to its own elastic force, the first spring pushes the first piston back to its original position. At this time, the first discharge port is blocked by the first thimble and the first thimble seal seat, and the second discharge port gradually decreases in flow rate due to the gradual descent of the second thimble caused by the descent of the second piston.

[0013] Preferably, in step 4, due to its own elastic force, the first spring pushes the first piston back to its original position. At this time, the first discharge port is blocked by the first thimble and the first thimble seal seat, and due to its own elastic force, the second spring pushes the second piston back to its original position. At this time, the second discharge port is blocked by the second thimble and the second thimble seal seat, and the flow rate of the second discharge port is 0.

[0014] The beneficial effects of the present invention are: 1. The present invention adopts the method of arranging multiple valve cores in the valve body and integrating the gas path, enabling the entire integrated multi-hole normally closed pneumatic injection valve to overcome the situation in the current injection field where it is impossible to unify efficiency and accuracy when the total injection volume is relatively large, especially when the total injection volume is over 20 kilograms. At the same time, compared with the method of setting a large and a small injection valve separately, the present invention has the advantages of smaller overall volume, shorter gas path length, and simpler control, achieving the goal of unifying efficiency and accuracy, and also having the advantages of small valve body volume, shorter gas path length, and simple control.

[0015] 2. The present invention designs a stroke-adjustable structure at the ejector pin, realizing the adjustable stroke of the limit block. Therefore, it overcomes the problem in the prior art that the limit block cannot be changed according to the actual required accuracy, enabling the present invention to adapt to changes in the dosage of different raw materials. Description of the Drawings

[0016] Figure 1 is a cross-sectional view of the normally closed double solenoid valve multi-hole pneumatic injection valve provided by the present invention; Figure 2 is a partial enlarged cross-sectional view of the normally closed double solenoid valve multi-hole pneumatic injection valve provided by the present invention; Figure 3 is another partial enlarged cross-sectional view of the normally closed double solenoid valve multi-hole pneumatic injection valve provided by the present invention; Figure 4 is the injection working diagram of the normally closed double solenoid valve multi-hole pneumatic injection valve provided by the present invention; Figure 5 is the control method flow chart of the normally closed double solenoid valve multi-hole pneumatic injection valve provided by the present invention; Description of the reference numerals: upper end cover 1, lower end cover 2, first ejector pin 301, first piston 302, first spring 303, first discharge port 304, second ejector pin 401, second piston 402, second spring 403, second discharge port 404, first air inlet 501, second air inlet 502, first air outlet 503, second air outlet 504, T-shaped limit block 6, U-shaped groove 7, feed port 8, guide sleeve 9, closed end cover 10, first ejector pin seal seat 1101, second ejector pin seal seat 1102, raw material barrel 12, barrel cover 13, nitrogen pressure air inlet 14, sealing ring 15, raw material 16. Detailed Embodiments

[0017] The following further describes the present invention in conjunction with embodiments. The description of the following embodiments is only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0018] Example 1: To solve the problems of the prior art, Example 1 of the present application provides a porous pneumatic injection valve, including: a valve body structure, a double spool structure, a gas path control module, and a stroke adjustment module; Among them, the valve body structure includes an upper end cover 1 and a lower end cover 2; the double spool structure includes a first spool assembly and a second spool assembly. The first spool assembly consists of a first thimble 301, a first piston 302, a first spring 303, and a first discharge port 304. The second spool assembly consists of a second thimble 401, a second piston 402, a second spring 403, and a second discharge port 404; the gas path control module includes a first air inlet 501, a second air inlet 502, a first air outlet 503, and a second air outlet 504 provided on the upper end cover 1 for connecting to the external gas path. The first air inlet 501 and the first air outlet 503 correspond to the first spool assembly, and the second air inlet 502 and the second air outlet 504 correspond to the second spool assembly; the stroke adjustment mechanism includes a T-shaped limit block 6 and a U-shaped groove 7 respectively provided above the first thimble and the second thimble; the protruding part of the T-shaped limit block 6 extends into the U-shaped groove 7 and moves within a limited range; sealing rings 15 are provided at the joints of the first thimble 301 and the second thimble 401 that cooperate with the outside of the T-shaped limit block 6 and the upper end cover 1. Sealing rings 15 are provided at the joints of the closed end cover 10 and the first thimble 31. Sealing rings 15 are provided at the joints of the first piston 302 and the second piston 402 and the upper end cover 1. Sealing rings 15 are provided at the joints of the first thimble 301 and the upper end cover 1. A sealing ring 15 is provided at the joint of the guide sleeve 9 and the second thimble 401. A sealing ring 15 is provided at the joint of the guide sleeve 9 and the upper end cover 1.

[0019] The gas path control module is connected to a double solenoid valve system and an electro-pneumatic proportional valve.

[0020] Among them, the size specifications of the first spool assembly and the second spool assembly are different. For example, as Figure 1 shown, the size of the first spool assembly is larger than that of the second spool assembly. Among them, the size of the first thimble 301 is larger than that of the second thimble 401, and the opening of the first discharge port 304 is larger than that of the second discharge port 404.

[0021] In addition, the position of the T-shaped limit block 6 can be controlled through the U-shaped groove 7, so that the maximum flow rates of the first discharge port 304 and the second discharge port 404 can be controlled by controlling the maximum opening degrees of the first thimble 301 and the second thimble 401.

[0022] Example 2: On the basis of Example 1, Example 2 of the present application provides a more specific porous pneumatic injection valve, including: a valve body structure, a double spool structure, a gas path control module, and a stroke adjustment module.

[0023] The gas path control module is connected to the double solenoid valve system and the electro-pneumatic proportional valve. Specifically, one end of the electro-pneumatic proportional valve is connected to the air compressor, and the other end is connected to the second air inlet 502, which is used to control the entire pneumatic injection valve. The double solenoid valve system includes a first solenoid valve and a second solenoid valve; one end of the first solenoid valve is connected to the second discharge port 404 through an airtight air pipe, and the other end is connected to the first air inlet 501, and the control of the first thimble 301 and the second thimble 401 is realized through a gas path; one end of the second solenoid valve is connected to the first air outlet 503, and the other end is connected to the air through an air pipe, which is used to exhaust gas in specific steps.

[0024] In the stroke adjustment module, threads and through holes are provided above the first thimble 301 and the second thimble 401, and matching threads are provided on the outside of the T-shaped limit block 6. Specifically, the T-shaped limit block 6 above the second thimble 401 can be screwed into the upper part of the second thimble 401, and the U-shaped groove 7 above the second thimble 401 can make the protruding part of the T-shaped limit block 6 extend and move within a certain range. The T-shaped limit block 6 above the first thimble 301 can be screwed into the upper part of the first thimble 301, and the U-shaped groove 7 above the first thimble 301 can make the protruding part of the T-shaped limit block 6 extend and move within a certain range.

[0025] A large hole and a small hole are provided at the top of the upper end cover 1, which are used for assembling with the first thimble 301 and the second thimble 401 respectively. A closed end cover 10 is provided above the upper end cover 1 to realize airtightness of the gas path.

[0026] When the upper end cover 1 is assembled with the first thimble 301, an annular large air passage will appear for gas path connection; when the upper end cover 1 is assembled with the second thimble 401, a small air passage will appear for gas path connection. A first piston 302 is provided above the large air passage, and a second piston 402 is provided above the small air passage. Springs are connected above the first piston 302 and the second piston 402, and the other ends of the springs are connected to the tops of the large air passage and the small air passage. The connections between the first piston 302 and the second piston 402 and the first thimble 301 and the second thimble 401 are all rigid connections.

[0027] A feed port 8 is provided at the lower part of the upper end cover 1, and raw materials enter the storage barrel through the feed port 8; a guide sleeve 9 is also provided inside the upper end cover 1, and the guide sleeve 9 is tightly combined with the first thimble 301 and the second thimble 401 to isolate the gas path and the liquid path. Moreover, the feed port 8 is docked with the raw material barrel 12, and a barrel cover 13 is provided above the raw material barrel, and a nitrogen pressure inlet 14 is opened above the barrel cover 13.

[0028] The lower end cover 2 is combined with the upper end cover 1, and the lower end cover 2 is provided with a first discharge port 304 and a second discharge port 404. Above the lower end cover 2, there are a first thimble seal seat 1101 and a second thimble seal seat 1102, which are respectively matched with the first spool assembly and the second spool assembly for sealing.

[0029] It should be noted that the same or similar parts in this embodiment and Embodiment 1 can be referred to each other, and will not be elaborated in this application.

[0030] Embodiment 3: Based on Embodiment 2, Embodiment 3 of the present application provides a control method for a porous pneumatic injection valve, as Figure 5 shown, including: Step 1: Control the electric proportional valve to open to the maximum flow rate, open the first solenoid valve, and close the second solenoid valve.

[0031] In Step 1, the first spring 303 and the second spring 403 are compressed, and the first piston 302 and the second piston 402 are both pushed to the uppermost position. At this time, both the first discharge port 304 and the second discharge port 404 maintain the maximum opening degree. At this time, by injecting nitrogen into the raw material barrel, the air pressure in the injection barrel increases, and the raw material is injected into the finished product barrel through the first discharge port 304 and the second discharge port 404.

[0032] Step 2: When the injection volume reaches the first threshold, maintain the maximum flow rate output by the electric proportional valve, close the first solenoid valve, and open the second solenoid valve.

[0033] In Step 2, the air compressor presses in air, and the air passes through the electric proportional valve. The electric proportional valve controls the air pressure input to the second air inlet 502 to reach the maximum value. The second spring 403 is compressed, and the second piston 402 is pushed to the uppermost position; the air is discharged through the second solenoid valve, and the air pressure drops. The first spring 303 pushes the first piston 302 back to its original position due to its own elastic force. At this time, the first discharge port 304 is blocked by the first thimble 301 and the first thimble seal seat 1101, and the second discharge port 404 maintains the maximum opening degree. At this time, by injecting nitrogen into the raw material barrel, the air pressure in the injection barrel increases, and the raw material is injected into the finished product barrel through the second discharge port 404.

[0034] Step 3: When the injection volume reaches the second threshold, reduce the flow rate output by the electric proportional valve, close the first solenoid valve, and open the second solenoid valve; the second threshold is greater than the first threshold.

[0035] In step 3, the air compressor compresses air, which passes through the electrical proportional valve. This valve controls the gradual reduction of the air pressure input to the second air inlet 502, gradually pushing the second piston 402 back to its original position. The first spring 303, due to its inherent elasticity, pushes the first piston 302 back to its original position. At this point, the first discharge port 304 is blocked by the first ejector pin 301 and the first ejector pin sealing seat 1101. The second discharge port 404 gradually descends due to the lowering of the second piston 402, causing the second ejector pin 401 to gradually descend, resulting in a gradual decrease in the flow rate at the second discharge port 404. Nitrogen is then injected into the raw material barrel, slowly injecting the raw material into the finished product barrel through the second discharge port 404 until the third threshold is reached. During this process, the position of the second piston 402, and thus the flow rate at the second discharge port 404, is controlled by controlling the air pressure through the electrical proportional valve, achieving continuous flow adjustment and ensuring accurate injection. The upper limit of the second piston 402's displacement is controlled by a T-shaped stopper 6. Specifically, the T-shaped limit block 6 rotates with respect to the U-shaped groove 7 thereon to control the position of the limit (ie, the maximum control of the opening and closing of the valve core).

[0036] Step 4: When the injection amount reaches a third threshold, close the electrical proportional valve and open the first solenoid valve and the second solenoid valve; the third threshold is greater than the second threshold.

[0037] In step 4, the air compressor presses into the air, and the air passes through the electric proportional valve. The first spring 303 pushes the first piston 302 to its original position due to its own elastic action. At this time, the first discharge port 304 is blocked by the first ejector pin 301 and the first ejector pin sealing seat 1101. The second spring 403 pushes the second piston 402 to its original position due to its own elastic action. At this time, the second discharge port 404 is blocked by the second ejector pin 401 and the second ejector pin sealing seat 1102. The flow rate of the second discharge port 404 is 0, and the raw material injection process is completed.

[0038] In addition, a weighing device is provided under the finished barrel, and the data is fed back to the computer, which controls the opening and closing status of the electric proportional valve, the first solenoid valve, and the second solenoid valve.

[0039] It should be noted that the system provided in this embodiment is a method corresponding to the device provided in Example 2. Therefore, the parts in this embodiment that are the same or similar to those in Example 2 can be referenced to each other and will not be repeated in this application.

Claims

1. A porous pneumatic injection valve, characterized in that, Comprising: Valve body structure, double spool structure, gas path control module and stroke adjustment module; Among them, the valve body structure includes an upper end cover and a lower end cover; the double spool structure includes a first spool assembly and a second spool assembly. The first spool assembly consists of a first thimble, a first piston, a first spring and a first discharge port. The second spool assembly consists of a second thimble, a second piston, a second spring and a second discharge port. The gas path control module includes a first air inlet, a second air inlet, a first air outlet and a second air outlet provided on the upper end cover. The first air inlet and the first air outlet correspond to the first spool assembly, and the second air inlet and the second air outlet correspond to the second spool assembly. The stroke adjustment mechanism includes a T-shaped limit block and a U-shaped groove respectively arranged above the first thimble and the second thimble. The protruding part of the T-shaped limit block extends into the U-shaped groove and moves within a limited range. The gas path control module is connected to a double solenoid valve system and an electro-hydraulic proportional valve.

2. The porous pneumatic injection valve according to claim 1, characterized in that The gas path control module is connected to a double solenoid valve system and an electro-hydraulic proportional valve, including: One end of the electro-hydraulic proportional valve is connected to an air compressor, and the other end is connected to the second air inlet. One end of the first solenoid valve is connected to the second discharge port, and the other end is connected to the first air inlet. One end of the second solenoid valve is connected to the first air outlet, and the other end is connected to the air.

3. The porous pneumatic injection valve according to claim 2, wherein, In the stroke adjustment module, threads and through holes are provided above the first thimble and the second thimble, and matching threads are provided on the outside of the T-shaped limit block.

4. The porous pneumatic injection valve according to claim 3, characterized in that, A feed port is provided at the lower part of the upper end cover, and raw materials enter the storage cylinder through the feed port. A guide sleeve is also provided inside the upper end cover, and the guide sleeve is used to isolate the gas path from the liquid path.

5. The porous pneumatic injection valve according to claim 4, characterized in that, A first thimble seal seat and a second thimble seal seat are provided above the lower end cover, and are respectively matched with the first spool assembly and the second spool assembly for sealing.

6. A control method for the porous pneumatic injection valve according to any one of claims 1 to 5, characterized in that, Comprising: Step 1: Control the electro-hydraulic proportional valve to open to the maximum flow rate, open the first solenoid valve, and close the second solenoid valve; Step 2: When the injection volume reaches the first threshold, maintain the electro-hydraulic proportional valve to output the maximum flow rate, close the first solenoid valve, and open the second solenoid valve; Step 3: When the injection volume reaches the second threshold, reduce the output flow rate of the electro-hydraulic proportional valve, close the first solenoid valve, and open the second solenoid valve; the second threshold is greater than the first threshold; Step 4: When the injection volume reaches the third threshold, close the electro-hydraulic proportional valve, and open the first solenoid valve and the second solenoid valve; the third threshold is greater than the second threshold.

7. The control method of the porous pneumatic injection valve according to claim 6, characterized in that, In Step 1, the first spring and the second spring are compressed, and both the first piston and the second piston are pushed to the uppermost position. At this time, both the first discharge port and the second discharge port maintain the maximum opening degree.

8. The control method of the porous pneumatic injection valve according to claim 7, characterized in that, In Step 2, the second spring is compressed, and the second piston is pushed to the uppermost position. Air is discharged through the second solenoid valve, and the air pressure drops. Due to its own elastic force, the first spring pushes the first piston back to its original position. At this time, the first discharge port is blocked by the first thimble and the first thimble seal seat, and the second discharge port maintains the maximum opening degree.

9. The control method of the porous pneumatic injection valve according to claim 8, characterized in that, In Step 3, the second piston is gradually pushed back to its original position, and due to its own elasticity, the first spring pushes the first piston back to its original position. At this time, the first discharge port is blocked by the first ejector pin and the first ejector pin seal seat. As the second piston descends, the second ejector pin gradually descends, resulting in a gradual decrease in the flow rate of the second discharge port.

10. The control method of the porous pneumatic injection valve according to claim 9, characterized in that, In Step 4, due to its own elasticity, the first spring pushes the first piston back to its original position. At this time, the first discharge port is blocked by the first ejector pin and the first ejector pin seal seat. Due to its own elasticity, the second spring pushes the second piston back to its original position. At this time, the second discharge port is blocked by the second ejector pin and the second ejector pin seal seat, and the flow rate of the second discharge port is 0.

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