EGR valve for natural gas engine

Abstract

The invention discloses an EGR valve for a natural gas engine, comprising an EGR valve seat, on which an EGR valve is fixedly connected; the EGR valve comprises a flange end and an insertion end riveted together, the insertion end comprises a guide sleeve seat, on which a guide sleeve is arranged, and a center rod is arranged in the guide sleeve; the lower part of the center rod is fixedly connected to an upper valve core and a lower valve core, and the EGR valve seat is divided into three working chambers, which are an upper outlet working chamber, an inlet working chamber and a lower outlet working chamber from right to left; the upper outlet working chamber and the lower outlet working chamber are connected to the inlet working chamber; a water storage tank is arranged at the lowest part of the inlet working chamber. The invention has the advantages of simple structure, small volume, light weight, fast response speed and simple assembly method.

Description

Technical Field

[0001] The invention relates to the technical field of automobile manufacturing, and more specifically to an EGR valve for a natural gas engine. Background Art

[0002] Exhaust Gas Recirculation (EGR) is a low-cost, minimally modified internal combustion engine that can effectively reduce NO X Emission measures have been increasingly widely used in the field of internal combustion engine emission control.

[0003] The electric EGR valve can reintroduce an appropriate amount of engine combustion exhaust gas into the intake pipe, mix it with fresh air and then enter the cylinder for secondary combustion, which reduces the temperature in the cylinder during combustion. Since NOx is generated under high temperature and oxygen-rich conditions, the generation of NOx is suppressed. The use of EGR valves is becoming more and more frequent. The EGR valves currently available on the market are heavy, large in size, and complex in structure. In addition, natural gas engines themselves have a large amount of water vapor. After the engine is turned off, condensed water is easily generated. Once condensed water is generated, it is easy to freeze in cold weather, and the EGR valve will not open. In addition, the exhaust gas of natural gas engines has a certain degree of corrosiveness to the valve, which is easy to corrode the EGR valve. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an EGR valve for a natural gas engine to solve the problem that the existing EGR valve is prone to generate condensed water after flameout and is prone to freezing in cold weather, so as to prevent the EGR valve from accumulating condensed water.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0006] An EGR valve for a natural gas engine comprises an EGR valve seat installed obliquely, to which an EGR valve is fixedly connected by screws; the EGR valve comprises a flange end located at the upper part for providing power and an insertion end located at the lower part and arranged in the EGR valve seat, the insertion end and the flange end being movably riveted together; the insertion end comprises a guide sleeve seat arranged in the center of the EGR valve, the guide sleeve seat is provided with a guide sleeve, and a center rod is equipped in the guide sleeve; the lower part of the center rod is fixedly connected to an upper valve core and a lower valve core which are arranged vertically to the center rod and are spaced a distance apart and of the same size; the upper valve core, the lower valve core and the center rod divide the EGR valve seat into three working chambers, which are, from right to left, an upper outlet working chamber, an inlet working chamber and a lower outlet working chamber; the upper outlet working chamber and the lower outlet working chamber are connected to the inlet working chamber; a water storage tank for gathering condensed water is arranged at the lowest point of the inlet working chamber.

[0007] To further optimize the technical solution, the upper valve core is fixedly connected to a first sealing ring for preventing gas from leaking through the upper valve core, and the lower valve core is fixedly connected to a second sealing ring for preventing gas from leaking through the lower valve core.

[0008] To further optimize the technical solution, a sealing gasket for sealing is provided between the insertion end and the flange end of the EGR valve.

[0009] To further optimize the technical solution, U-shaped grooves for facilitating welding are provided on both sides below the valve plate of the upper valve core.

[0010] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.

[0011] The EGR valve for a natural gas engine provided by the present invention has a split design of the EGR valve, and the insertion end is designed to be stainless steel, which can rotate 360° and adapt according to different boundaries, thereby increasing the flexibility of product matching; the flange end is designed to be cast aluminum, taking into account both weight reduction and corrosion resistance. The EGR valve is designed to be installed at an angle, and the two ends of the air outlet of the upper outlet working chamber and the lower outlet working chamber in the EGR valve are directly connected to the air inlet pipe of the inlet working chamber, so condensed water cannot be gathered. A water storage tank is designed at the air inlet, and the condensed water will gather in the water storage tank. The present invention can prevent the condensed water gathered in the EGR valve from freezing and causing the valve core to be unable to open, and has the advantages of simple structure, small size, light weight, strong adaptability, and high corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention;

[0013] Figure 2 It is a structural schematic diagram of the insertion end and the flange end in the present invention;

[0014] Figure 3 It is a schematic diagram of the connection structure of the upper valve core, the lower valve core and the center rod of the present invention;

[0015] Wherein: 1. Insert end, 2. Flange end, 3. EGR valve seat, 4. EGR valve, 5. Sealing gasket, 6. Upper valve core, 7. Lower valve core, 8. Center rod, 9. First sealing ring, 10. Second sealing ring, 11. Water storage tank, 12. U-shaped groove, 13. Inlet working chamber, 14. Upper outlet working chamber, 15. Lower outlet working chamber, 16. Guide sleeve seat, 17. Guide sleeve. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] EGR valve for natural gas engine, combined Figures 1 to 3As shown, it includes an insertion end 1, a flange end 2, an EGR valve seat 3, an EGR valve 4, a sealing gasket 5, an upper valve core 6, a lower valve core 7, a center rod 8, a first sealing ring 9, a second sealing ring 10, a water storage tank 11, a U-shaped groove 12, an inlet working chamber 13, an upper outlet working chamber 14, and a lower outlet working chamber 15.

[0018] The EGR valve seat 3 is installed at an angle, and the EGR valve 4 is fixedly connected to the EGR valve seat 3 by screws. The EGR valve 4 includes a flange end 2 and an insertion end 1, the flange end 2 is located at the upper part of the EGR valve seat 3, and the insertion end 1 is located at the lower part and is arranged in the EGR valve seat 3. The insertion end 1 is made of stainless steel, and the flange end is made of cast aluminum, which is light in weight and has good corrosion resistance. A sealing gasket 5 is provided between the insertion end 1 and the flange end 2 of the EGR valve 4, which is used to seal the EGR valve 4 and isolate it from the outside. The insertion end 1 and the flange end 2 are movably riveted together, and the insertion end can be used according to the design and can be rotated 360°, so that it can be adapted according to different boundaries, increasing the flexibility of product matching and effectively reducing the problem of opening molds due to small changes.

[0019] The insertion end 1 includes a guide sleeve seat 16 arranged in the center of the EGR valve 4, a guide sleeve 17 is arranged on the guide sleeve seat 16, and a center rod 8 is installed in the guide sleeve 17. The lower part of the center rod 8 is fixedly connected to the upper valve core 6 and the lower valve core 7. The upper valve core 6 and the lower valve core 7 are both arranged vertically with the center rod 8, and the upper valve core 6 and the lower valve core 7 are separated by a distance and have the same size. The upper valve core 6, the lower valve core 7 and the center rod 8 divide the EGR valve seat 3 into three working chambers, which are the upper outlet working chamber 14, the inlet working chamber 13 and the lower outlet working chamber 15 from right to left. The upper outlet working chamber 14 and the lower outlet working chamber 15 are connected to the inlet working chamber 13. A water storage tank 11 is arranged at the lowest point of the inlet working chamber 13 to collect condensed water and prevent condensed water from accumulating at the valve core of the EGR valve 4.

[0020] The upper valve core 6 is fixedly connected to the first sealing ring 9 to prevent gas leakage through the upper valve core 6; the lower valve core 7 is fixedly connected to the second sealing ring 10 to prevent gas leakage through the lower valve core 7. The flow of exhaust gas is controlled by the size of the opening of the upper valve core 6 and the lower valve core 7. After being inserted into the EGR valve seat 3, the upper and lower cavities are isolated by the first sealing ring 9 and the second sealing ring 10, and the seal 5 isolates it from the outside world. In this double valve core structure, air is taken in from the air inlet of the middle inlet working chamber 13. The driving force of the gas on the upper valve core 6 is upward, and the driving force of the gas on the lower valve core 7 is downward. In this way, in general, the total force on the valve core is zero, which can avoid the impact of gas fluctuations on the valve.

[0021] U-shaped grooves 12 are arranged on both sides of the valve sheet below the upper valve core 6, and after assembly, the U-shaped grooves 12 are welded for fixing. Through strength test, the welding U-shaped grooves 12 have a higher welding strength than the previous welding at the bottom.

[0022] When the present invention is actually used, when the exhaust gas enters the exhaust gas inlet through the inlet working chamber 13 in the EGR valve seat 3, the exhaust gas acts on the upper valve core 6 and the lower valve core 7. The force acting on the upper valve core 6 is perpendicular to the upper valve core 6 and upward, and the force acting on the lower valve core 7 is perpendicular to the lower valve core 7 and downward. Because the upper valve core 6 and the lower valve core 7 are valve plates of equal diameter, the forces acting on the upper valve core 6 and the lower valve core 7 are opposite in direction and cancel each other out. Because there is a lot of water vapor in the natural gas engine, the condensed water that is easily stored in the water storage tank 11 after the flameout is turned off prevents the EGR valve 3 from being unable to open due to the accumulation of liquid water in the EGR valve 3 and freezing when it is cold, thereby ensuring the normal operation of the EGR valve 4 for the natural gas engine in a low temperature environment.

Claims

1. EGR valve for natural gas engine, characterized by: The invention comprises an EGR valve seat (3) installed obliquely, and an EGR valve (4) is fixedly connected to the EGR valve seat (3) by screws; the EGR valve (4) comprises a flange end (2) located at the upper part and used for providing power, and an insertion end (1) located at the lower part and arranged in the EGR valve seat (3), and the insertion end (1) and the flange end (2) are movably riveted together; the insertion end (1) comprises a guide sleeve seat (16) arranged in the center of the EGR valve (4), and a guide sleeve (17) is arranged on the guide sleeve seat (16), and a center rod (8) is installed in the guide sleeve (17); the lower part of the center rod (8) is fixedly connected to the center rod (8) vertically An upper valve core (6) and a lower valve core (7) of the same size are arranged in a straight line and separated by a distance; the upper valve core (6), the lower valve core (7) and the center rod (8) divide the EGR valve seat (3) into three working chambers, which are respectively an upper outlet working chamber (14), an inlet working chamber (13) and a lower outlet working chamber (15) from right to left; the upper outlet working chamber (14) and the lower outlet working chamber (15) are connected to the inlet working chamber (13); a water storage tank (11) for collecting condensed water is arranged at the lowest point of the inlet working chamber (13); U-shaped grooves (12) for facilitating welding are arranged on both sides below the valve plate of the upper valve core (6).

2. The EGR valve for a natural gas engine according to claim 1, characterized in that: The upper valve core (6) is fixedly connected to a first sealing ring (9) for preventing gas from leaking through the upper valve core (6), and the lower valve core (7) is fixedly connected to a second sealing ring (10) for preventing gas from leaking through the lower valve core (7).

3. The EGR valve for a natural gas engine according to claim 1, characterized in that: A sealing gasket (5) for sealing is provided between the insertion end (1) and the flange end (2) of the EGR valve (4).

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