Safe starting valve group for plastic extruder

Abstract

The utility model relates to the field of valves, in particular to a safe starting valve group for a plastic extruder, which comprises a liquid inlet pipeline and an overflow pipeline, one end of the liquid inlet pipeline is a liquid inlet, and one end of the liquid inlet pipeline is a liquid outlet; the liquid inlet pipeline and the overflow pipeline are transversely and longitudinally crossed, a first flow guide opening is formed in the crossed position of the liquid inlet pipeline and the overflow pipeline, a first piston is connected into the overflow pipeline in a sliding mode, a second flow guide opening is formed in the first piston, and the first piston can slide to enable the first flow guide opening and the second flow guide opening to be mutually overlapped or staggered. The safe starting valve group for the plastic extruder disclosed by the utility model can preferably prevent liquid from flowing into a subsequent hydraulic system and then overflowing.

Description

Technical Field

[0001] The utility model relates to a valve, in particular to a safety starting valve group used for a plastic extruder. Background Art

[0002] The safety start valve, also called the overflow valve, plays a role of safety protection in the hydraulic system. When the system pressure exceeds the specified value, the safety valve opens and discharges part of the liquid in the system into the atmosphere, so that the system pressure does not exceed the allowable value, thereby ensuring that the system does not cause accidents due to excessive pressure. Common overflow valves are shown in the publication number CN113719656B, which is named a follow-up valve core assembly, a direct-acting overflow valve, and a pilot overflow.

[0003] The existing overflow valve can achieve pressure relief while allowing liquid to flow into the subsequent hydraulic system. Although overflow pressure relief can be achieved, it cannot completely stop the liquid from flowing into the subsequent hydraulic system. Utility Model Content

[0004] Technical purpose: In order to overcome the deficiencies in the prior art, the utility model provides a safety start valve group for a plastic extruder.

[0005] Technical solution: To achieve the above purpose, the utility model discloses a safety start valve group for a plastic extruder, comprising a liquid inlet pipeline, one end of which is a liquid inlet, and one end of which is a liquid outlet;

[0006] The overflow pipe, the liquid inlet pipe and the overflow pipe intersect horizontally and vertically, a first guide port is arranged at the intersection of the liquid inlet pipe and the overflow pipe, a first piston is slidably connected in the overflow pipe, the first piston is provided with a second guide port, the first piston can slide until the first guide port and the second guide port overlap or stagger each other.

[0007] Furthermore, the overflow pipe includes a pipe body and a bushing, the bushing is fixedly connected to the pipe body, and the first piston is slidably connected to the bushing.

[0008] Furthermore, a first spring, a second spring and a second piston are slidably connected in the bushing, the first spring and the second spring are disposed on both sides of the first piston, a first limiting ring is fixedly connected in the bushing, and the second piston is disposed between the second spring and the first limiting ring.

[0009] Furthermore, a second limiting ring is arranged in the bushing, a pin piston is arranged on one side of the second limiting ring, a closing plate is arranged on one side of the pin piston, and the pin piston is connected to a third spring. Under the action of the third spring, the pin piston has a tendency to move away from the closing plate.

[0010] Furthermore, a guide groove is provided on the inner wall of the bushing, and the guide groove is provided on the side wall of the ejector piston.

[0011] Furthermore, a chamber is formed between the second piston and the ejector piston, and the chamber is connected to the liquid inlet through a pipe.

[0012] Furthermore, two ends of the bushing are respectively connected with a first plug and a second plug.

[0013] Furthermore, sealing rings are respectively arranged on the first piston, the second piston and the ejector piston.

[0014] The utility model discloses a safety start valve group for a plastic extruder, which has the following beneficial effects:

[0015] When the liquid inlet pressure increases to a certain level, it preferentially pushes the first piston to make the first guide port and the second guide port staggered with each other, so that the liquid no longer flows out of the liquid outlet, thereby protecting the subsequent hydraulic system; then the ejector piston breaks the sealing plate to complete the unloading. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the utility model;

[0017] Figure 2 It is a structural sectional view of the utility model.

[0018] In the figure, 1. liquid inlet pipe; 2. liquid inlet; 3. liquid outlet; 4. overflow pipe; 5. first guide port; 6. second guide port; 7. first piston; 8. pipe body; 9. bushing; 10. first spring; 11. second spring; 12. second piston; 13. first limiting ring; 14. second limiting ring; 15. ejector piston; 16. closing plate; 17. third spring; 18. guide groove; 19. chamber; 20. first plug; 21. second plug. DETAILED DESCRIPTION

[0019] The following is combined with Figure 1 To Attachment Figure 2 The principles and features of the present invention are described, and the examples given are only used to explain the present invention, and are not used to limit the scope of the present invention.

[0020] A safety start valve group used in a plastic extruder includes a liquid inlet pipe 1 and an overflow pipe 4, the liquid inlet pipe 1 and the overflow pipe are intersected horizontally and vertically, and their inner cavities are interconnected. The overflow pipe 4 includes a pipe body 8 and a bushing 9, and the bushing 9 is fixedly connected to the pipe body 8. A first guide port 5 is provided on the bushing 9, and the first guide port 5 is located at the intersection of the liquid inlet pipe 1 and the overflow pipe 4. The first piston 7 is slidably connected in the overflow pipe 4, specifically, slidably connected in the bushing 9. The first piston 7 is provided with a second guide port 6, and the first piston 7 can slide to make the first guide port 5 and the second guide port 6 overlap or stagger each other. One end of the liquid inlet pipe 1 is a liquid inlet 2, and the other end of the liquid inlet pipe 1 is a liquid outlet 3. The first guide port 5 is circular, and the second guide port 6 is waist-shaped. The liquid enters from the liquid inlet 2 and flows out from the liquid outlet 3 after passing through the first guide port 5 and the second guide port 6. When the first flow guide port 5 and the second flow guide port 6 completely overlap, the amount of liquid that can pass through is the largest; when the first flow guide port 5 and the second flow guide port 6 are completely staggered, the flow between the liquid inlet 2 and the liquid outlet 3 is intercepted.

[0021] Specifically, a first spring 10, a second spring 11, a second piston 12, a ejector piston 15 and a third spring 17 are slidably connected in the bushing 9. Figure 2 , from left to right are the first spring 10, the first piston 7, the second spring 11, the second piston 12, the ejector piston 15 and the third spring 17, respectively. The first piston 7, the second piston 12 and the ejector piston 15 are provided with sealing rings. The first spring 10 and the second spring 11 are arranged on both sides of the first piston 7, and the first plug 20 and the second plug 21 are arranged at both ends of the bushing 9; one end of the first spring 10 presses against the first plug 20, and the other end of the first spring 10 presses against the first piston 7; the elastic force of the first spring 10 should be greater than the elastic force of the second spring 11. The bushing 9 is provided with a first limiting ring 13 and a second limiting ring 14. The second piston 12 is arranged between the second spring 11 and the first limiting ring 13. One side of the second piston 12 fits against the first limiting ring 13, the other side of the second piston 12 presses against the second spring 11, and the other end of the second spring 11 presses against the first piston 7. The second plug 21 is used to fix the closing piece 16 to the bushing 9. A ejector piston 15 is provided on one side of the second limiting ring 14, a closing plate 16 is provided on one side of the ejector piston 15, and a third spring 17 is provided between the ejector piston 15 and the closing plate 16. Under the action of the third spring 17, the ejector piston 15 has a tendency to move away from the closing plate 16. The closing plate 16 is an aluminum sheet, and rubber gaskets are provided on the edges of both sides thereof. The elastic force of the third spring 17 is the largest. The second plug 21 is in the shape of a nut so that the ejector piston 15 can penetrate the closing plate 16. A chamber 19 is formed between the second piston 12 and the ejector piston 15, and the chamber 19 is connected to the liquid inlet 2 through the pipe fitting 9 (hose). A guide groove 18 is provided on the inner wall of the bushing 9, and the guide groove 18 is provided on the side wall of the ejector piston 15.

[0022] When the liquid inlet pressure of the liquid inlet 2 is not large, although a part of the liquid enters the chamber 19, since the elastic force of the first spring 10 is greater than the pressure of the second spring 11, the liquid entering the chamber 19 is not sufficient to push the first piston 7 to slide; as the liquid pressure at the liquid inlet 2 increases, the first piston 7 gradually slides toward the side of the first spring 10; when the liquid pressure at the liquid inlet 2 increases to move the first piston 7 to the maximum distance, the first guide port 5 and the second guide port 6 are staggered with each other, and the liquid outlet 3 no longer flows out of the liquid; at this time, all the liquid enters the chamber 19, and the ejector piston 15 starts to move until the closing plate 16 is broken. At this time, the ejector piston 15 also moves to the guide groove 18, and the liquid flows out through the guide groove 18 and the closing plate 16 to complete the unloading.

[0023] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A safety start valve group for a plastic extruder, characterized in that: include A liquid inlet pipeline (1), one end of the liquid inlet pipeline (1) being a liquid inlet (2), and one end of the liquid inlet pipeline (1) being a liquid outlet (3); The overflow pipe (4) is provided with a first guide port (5), wherein the liquid inlet pipe (1) and the overflow pipe (4) intersect each other in the horizontal and vertical directions, and a first guide port (5) is provided at the intersection of the liquid inlet pipe (1) and the overflow pipe (4). A first piston (7) is slidably connected in the overflow pipe (4), and the first piston (7) is provided with a second guide port (6). The first piston (7) can slide until the first guide port (5) and the second guide port (6) overlap or stagger with each other.

2. The safety start valve group used in the plastic extruder according to claim 1, characterized in that: The overflow pipe (4) comprises a pipe body (8) and a bushing (9), wherein the bushing (9) is fixedly connected inside the pipe body (8), and the first piston (7) is slidably connected inside the bushing (9).

3. The safety start valve group used in the plastic extruder according to claim 2, characterized in that: A first spring (10), a second spring (11) and a second piston (12) are also slidably connected in the bushing (9); the first spring (10) and the second spring (11) are disposed on both sides of the first piston (7); a first limiting ring (13) is fixedly connected in the bushing (9); and the second piston (12) is disposed between the second spring (11) and the first limiting ring (13).

4. The safety start valve group used in the plastic extruder according to claim 3, characterized in that: A second limiting ring (14) is arranged in the bushing (9), a pin piston (15) is arranged on one side of the second limiting ring (14), a closing plate (16) is arranged on one side of the pin piston (15), and the pin piston (15) is connected to a third spring (17). Under the action of the third spring (17), the pin piston (15) has a tendency to move away from the closing plate (16).

5. The safety start valve group used in the plastic extruder according to claim 4, characterized in that: A guide groove (18) is provided on the inner wall of the bushing (9), and the guide groove (18) is provided on the side wall of the ejector piston (15).

6. The safety start valve group used in the plastic extruder according to claim 5, characterized in that: A chamber (19) is formed between the second piston (12) and the ejector piston (15), and the chamber (19) is connected to the liquid inlet (2) via a pipe.

7. The safety start valve assembly for a plastic extruder according to claim 6, characterized in that: The two ends of the bushing (9) are respectively connected to a first plug (20) and a second plug (21).

8. The safety start valve assembly for a plastic extruder according to claim 7, characterized in that: The first piston (7), the second piston (12) and the ejector piston (15) are respectively provided with sealing rings.

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