A turbocharger valve cover assembly

Abstract

The present invention describes a turbocharger valve cover assembly, including a rocker arm, a valve cover and a positioning gasket. The valve cover assembly is arranged at one end of the exhaust gas bypass channel. One end of the rocker arm is clamped to the upper part of the valve cover through the positioning gasket to form a linkage with the valve cover, so as to improve the control performance and control accuracy of the valve body through the valve cover assembly. The valve cover is provided with a sealing surface and a hemispherical valve surface. A through hole penetrating the valve cover is arranged in the middle of the hemispherical valve surface. By using the pressure difference at both ends of the through hole, the gas near the side part of the rocker arm is sucked, and the high-speed gas impacting the sealing surface of the valve cover is blown away through the through hole, effectively reducing the force and load on the valve cover and reducing the actuating torque.

Description

Technical Field

[0001] The present invention relates to the technical field of superchargers, and in particular to a valve cover assembly of a turbocharger, specifically, an exhaust gas bypass valve cover assembly for an automotive turbocharger. Background Art

[0002] Automotive turbochargers are important components for improving the performance and grade of engines, capable of increasing power density, reducing emissions, and eliminating the problem of insufficient power during driving on plateaus. This technology has been widely applied to engines.

[0003] For automotive engine superchargers, especially the design of turbochargers for passenger cars, both the low-speed torque of the engine and the maximum power of the engine need to be considered. The size of the turbine determines the flow capacity of the exhaust gas at the turbine end and is also the main factor affecting the low-speed transient response of the turbine. Because if the turbine is designed to be larger, the moment of inertia will also be relatively large, resulting in poor low-speed response. If the turbine is designed to be smaller, the low-speed response will be better, but the flow capacity will be relatively low and cannot meet the requirements of the maximum exhaust gas flow of the engine. If the turbine is designed to be larger, it can meet the engine flow requirements, but the low-speed performance will be relatively poor. This is a contradiction point. At this time, the exhaust gas bypass valve at the turbine end comes into being. As the name implies, the exhaust gas bypass valve bypasses the excess exhaust gas at the turbine end and does not allow the exhaust gas to pass through the turbine, so that a smaller turbine design can be achieved, and at the same time, the requirements of the maximum exhaust gas volume of the engine can be met.

[0004] The exhaust gas bypass valve can effectively improve the low-speed torque and low-speed response of the turbocharger and the engine. The low-speed torque of the engine is an important performance index. A turbine with an exhaust gas bypass valve has a smaller volute, which can improve the energy conversion coefficient of the engine exhaust at low speeds. Thus, when the engine is running at low speeds, the turbine can obtain more energy and rotational speed, increase the air flow, and improve the low-speed torque. When the engine is running at high speeds, the bypass valve opens, allowing some exhaust gas to flow directly without passing through the turbine, avoiding overspeeding of the supercharger.

[0005] The valve cover of the exhaust gas bypass valve is a key component affecting the control performance and cost of the supercharger. The sealing effect, noise, opening-flow characteristic, and opening-torque characteristic of the exhaust gas bypass valve are mainly determined by the shape of the valve cover. As the requirements for comfort in passenger cars are getting higher and higher, the noise control, flow control, etc. of the bypass valve are also required to be more and more strict. At the same time, the valve cover can also affect the maximum torque of the actuator, and reducing the torque can reduce the cost of the actuator.

[0006] In the prior art, most of the surfaces of the valve covers of exhaust gas bypass valves of turbochargers facing the valve holes are flat, and their limitation is poor control performance, and the opening angle-bypass flow curve is relatively steep. Moreover, the valve cover is subjected to a large load, and a large torque is required for the actuator. Summary of the Invention

[0007] The object of the present invention is to provide a valve cover assembly for a turbocharger. By redesigned the valve cover, the valve cover is provided with a sealing surface and a hemispherical valve surface, and a through hole is provided, aiming to significantly improve the control performance of the valve body and reduce the force and load on the valve cover.

[0008] To achieve the above object, the technical solution of the present invention is: a valve cover assembly for a turbocharger, including a volute and an exhaust gas bypass channel provided in the volute, characterized in that: the valve cover assembly includes a rocker arm, a valve cover and a positioning gasket. The valve cover assembly is arranged at one end of the exhaust gas bypass channel for controlling and regulating the air release of the exhaust gas bypass channel; one end of the rocker arm is clamped on the upper part of the valve cover through the positioning gasket to form a linkage with the valve cover. The valve cover is provided with a sealing surface and a hemispherical valve surface, and a through hole penetrating the valve cover is provided in the middle of the hemispherical valve surface. By using the pressure difference at both ends of the through hole, the gas near the side part of the rocker arm is sucked, and the high-speed gas impacting the sealing surface of the valve cover is dispersed through the through hole.

[0009] Preferably, a valve seat is provided in the volute, and an exhaust gas bypass valve is arranged on the valve seat. The size of the sealing surface of the valve cover matches the top surface of the valve seat; a bypass valve hole is provided at the top of the exhaust gas bypass channel, and the hemispherical valve surface of the valve cover cooperates with the bypass valve hole, and the diameter of the hemispherical valve surface is smaller than the diameter of the bypass valve hole.

[0010] Furthermore, the through hole is perpendicular to the rocker arm rotation axis, the through hole is a single-hole structure, the through hole is in a nozzle structure or a flared tube structure, one end is an air inlet port, and one end is an air outlet port, and the area of the air inlet port is larger than the area of the air outlet port.

[0011] Furthermore, the through hole includes a main through hole and a branched air outlet hole. The main through hole is perpendicular to the rocker arm rotation axis, the main through hole is in a nozzle structure or a flared tube structure, and a main air inlet end and a main air outlet end are respectively provided at both ends of the main through hole. The diameter of the main air inlet end is larger than the diameter of the main air outlet end; the branched air outlet hole is connected to the main through hole, and the included angle between the branched air outlet hole and the main through hole ranges from 1° to 180°.

[0012] Still further, the through hole is a structure with air inlet and outlet ends provided at both ends and the side wall is fully sealed. Or the outer side wall of the through hole is a partially closed structure, and the closed part accounts for 1 / 4 - 2 / 3 of the length of the through hole. Or the through hole is in a ditch shape, and the outer side wall of the through hole communicates with the outer surface of the hemispherical valve surface.

[0013] Compared with the prior art, the technical solution of the present invention includes not only the improvement of the overall technical solution, but also many improvements in details. Specifically, it has the following beneficial effects:

[0014] 1. In the improvement scheme of the present invention, the valve cover assembly is arranged at one end of the exhaust gas bypass passage to control and regulate the exhaust gas release of the exhaust gas bypass passage. One end of the rocker arm is clamped on the upper part of the valve cover through a positioning gasket to form a linkage with the valve cover, thereby improving the control performance and control accuracy of the valve body through the valve cover assembly.

[0015] 2. In the technical scheme of the present invention, the valve cover is provided with a sealing surface and a hemispherical valve surface. When the supercharger does not need to release exhaust gas, the sealing surface of the valve cover contacts and cooperates with the valve seat plane to seal the exhaust gas in the exhaust gas bypass passage, ensuring low-speed torque. When the supercharger needs to release exhaust gas, the valve cover follows the rocker arm to rotate and open around the rocker arm shaft. The larger the opening angle, the more exhaust gas is released. Thus, when the engine is operating at high load, the turbine speed can be controlled within a safe range. Since the sealing surface of the valve cover can better fit with the valve seat when closed, a surface seal is established to avoid exhaust gas leakage and improve turbine efficiency.

[0016] 3. The hemispherical valve surface of the valve cover of the present invention cooperates with the bypass valve orifice. The diameter of the hemispherical valve surface is smaller than the diameter of the bypass valve orifice. The hemispherical valve surface makes the "valve opening - bypass flow" correspondence relationship gentle and close to linear, so as to improve the control characteristics of the actuator and the control accuracy of the flow rate.

[0017] 4. By setting through holes in the present invention, using the pressure difference at both ends of the through holes, the gas near the side of the rocker arm is sucked, and the high-speed gas impacting the sealing surface of the valve cover is dispersed through the through holes, effectively reducing the force and load on the valve cover, reducing the actuator torque. At the same time, the through holes can also reduce the weight of the valve cover, making the components lighter. Description of the Drawings

[0018] Figure 1 is a schematic diagram of the volute structure described in the present invention.

[0019] Figure 2 is a cross-sectional view of the valve cover assembly arranged in the volute described in the present invention.

[0020] Figure 3 is a cross-sectional view of the valve cover assembly described in the present invention.

[0021] Figure 4 is a schematic diagram of one side of the valve cover assembly described in the present invention.

[0022] Figure 5 is a schematic diagram of the other side of the valve cover assembly described in the present invention.

[0023] Figure 6 is a partial bottom view of the valve cover assembly described in the present invention.

[0024] Figure 7 is a schematic diagram of the structure of another embodiment of the valve cover assembly described in the present invention.

[0025] Figure 8 is Figure 7 the A-A sectional view of

[0026] Reference numerals:

[0027] 1 volute, 2 valve cover assembly, 3 rocker arm, 4 valve cover, 5 positioning gasket, 6 exhaust gas bypass channel;

[0028] 41 sealing surface, 42 hemispherical valve surface, 43 through hole;

[0029] 431 main air inlet end, 432 branched air outlet hole. Specific embodiments

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0032] The present invention provides a valve cover assembly of a turbocharger. Referring to Figure 1 , it includes a volute 1 and an exhaust gas bypass channel 6 provided in the volute. The difference from the prior art is that the valve cover assembly 2 includes a rocker arm 3, a valve cover 4 and a positioning gasket 5. The valve cover assembly is arranged at one end of the exhaust gas bypass channel to control and adjust the gas discharge of the exhaust gas bypass channel. One end of the rocker arm is clamped on the upper part of the valve cover through the positioning gasket to form a linkage with the valve cover. The valve cover is provided with a sealing surface 41 and a hemispherical valve surface 42. A through hole 43 penetrating the valve cover is provided in the middle of the hemispherical valve surface. By using the pressure difference at both ends of the through hole, the gas near the side of the rocker arm is sucked, and the high-speed gas impacting the sealing surface of the valve cover is blown away through the through hole.

[0033] The valve cover is provided with a sealing surface and a hemispherical valve surface. The hemispherical valve surface bulges outwards in the middle of the valve cover, and the diameter of the hemispherical valve surface is smaller than the diameter of the bypass valve hole. Compared with a flat valve cover, it can make the change of flow rate with the increase of the opening angle become gentle and approach linearity, which is beneficial to improving the control characteristics and enhancing the control accuracy. The part of the valve cover with a diameter larger than the diameter of the hemispherical valve surface is the sealing surface. Compared with the valve assembly with line sealing, it fits better with the valve seat when the valve is closed, establishing surface sealing and avoiding exhaust gas leakage to reduce the turbine efficiency.

[0034] Specifically, the top of the valve cover is provided with an installation protrusion, and one end of the rocker arm is provided with an installation slot that matches the installation protrusion. The rocker arm is fixed to the top of the valve cover by riveting or welding and further fixed and positioned by a positioning gasket, so that a linkage structure is formed between the rocker arm and the valve cover.

[0035] Preferably, an exhaust gas bypass passage and a valve seat are provided in the volute. The exhaust gas bypass valve is arranged on the valve seat to control the exhaust gas release speed and the exhaust gas volume of the exhaust gas bypass passage. The size of the sealing surface of the valve cover matches the top surface of the valve seat. When the supercharger does not need to release gas, the sealing surface of the valve cover contacts and cooperates with the top surface of the valve seat to seal the exhaust gas in the exhaust gas bypass passage and ensure low-speed torque. When the supercharger needs to release gas, the valve cover rotates and opens following the rocker arm around the rocker arm shaft. The larger the opening angle, the more exhaust gas is released, so as to ensure that the turbine speed is controlled within a safe range when the engine is working at high load.

[0036] The top of the exhaust gas bypass passage is provided with a bypass valve hole, and the hemispherical valve surface of the valve cover cooperates with the bypass valve hole. The diameter of the hemispherical valve surface is smaller than the diameter of the bypass valve hole. The purpose is to make the "valve opening - bypass flow rate" correspondence relationship gentle and close to linearity, so as to improve the control characteristics of the actuator and the control accuracy of the flow rate.

[0037] In one embodiment, a through hole is provided in the hemispherical valve surface part of the valve cover. The through hole is perpendicular to the rocker arm rotating shaft. The main purpose is to reduce the impact load of the exhaust gas on the valve cover when the valve is opened.

[0038] The through hole is a single-hole structure. The through hole is in the structure of a nozzle or a flared pipe body. One end is an air inlet port, and the other end is an air outlet port. The area of the air inlet port is larger than the area of the air outlet port. The diameter of the air inlet port is smaller than or equal to the diameter of the air outlet port (see Figure 6In the middle), the intake port is circular to facilitate the suction of high-speed gas, and the outlet port is flat. The purpose is to accelerate the gas flowing through this place while increasing the influence and radiation range of the ejected gas. It is convenient to blow and disperse, and at the same time, it can make the high-speed gas quickly diffuse. When passing through the entire through-hole, it will not be blocked too much, thus affecting the speed of the blown gas. In this way, the air pressure balance on both sides of the valve cover can be achieved. In order to blow away the gas impacting the sealing surface within the largest range and reduce the impact load borne by the valve cover. Further, the width of the outlet port here can reach 2 / 3 - 3 / 4 of the diameter of the hemispherical valve surface, so as to achieve the best gas absorption and dispersion effect.

[0039] Due to the existence of the through-hole, by using the pressure difference on both sides of the hole, the gas originally impacting the valve cover near the rocker arm side is sucked to blow away the high-speed gas impacting the sealing surface of the valve cover far from the rocker arm side, thereby reducing the impact load received by the valve cover, reducing the maximum torque required for the actuator, and reducing costs. At the same time, the through-hole can also reduce the weight of the valve cover, making the parts lighter and saving materials.

[0040] The nozzle structure described here means that the upper side wall of the through-hole is a flat side wall or an arc groove-shaped side wall. The side wall is designed as a flat surface or a smooth arc surface, which can reduce the frictional loss and local loss caused when the air flow passes through, and maintain a higher head. The width of the flat side wall or the arc groove-shaped side wall gradually decreases from the intake port to the outlet port, and the center line of the upper side wall is perpendicular to the center line of the valve cover. The lower side wall of the through-hole is an arc-shaped curved surface provided with a bending part, and the bending part is arranged at the intake port, and the bending angle is 80 - 110 degrees, and the preferred angle is 100 - 105 degrees.

[0041] The side wall of the through-hole here is a fully enclosed structure or a semi-enclosed structure, and the enclosed part accounts for 1 / 4 - 2 / 3 of the length of the through-hole. The through-hole can also be designed as an open semi-enclosed groove to reduce the processing difficulty, but it will weaken the effect of reducing the valve cover torque and improving the control performance.

[0042] Since the shape of the through-hole is a nozzle shape, the contour area near the axis of rotation of the rocker arm is large to suck away as much gas generating impact at this place as possible. The hole area far from the axis of rotation of the rocker arm is small and narrow, and its longer side is close to parallel to the sealing surface of the valve cover to maintain a relatively high kinetic energy of the through gas and blow away the gas impacting the sealing surface within as large a range as possible with a sufficient speed.

[0043] In another embodiment, the valve cover assembly includes a rocker arm, a valve cover, and a positioning gasket. The valve cover assembly is arranged at one end of the exhaust gas bypass channel to control and regulate the gas release of the exhaust gas bypass channel.

[0044] When the valve is closed, under the influence of the sealing moment applied by the rocker arm, the valve cover sealing surface is in close contact with the valve seat sealing surface, ensuring a good sealing effect, avoiding leakage of high-temperature exhaust gas, and ensuring high efficiency of the turbine.

[0045] When the valve is opened, relative to the flat valve cover, when the valve opening angle changes, the flow area changes smoothly, making the relationship between the valve opening angle and the flow area of the bypass valve more linear. Furthermore, the opening angle and the bypass flow rate are linear, which is beneficial to improving the control characteristics of the actuator and the control accuracy of the flow rate.

[0046] A through hole penetrating the valve cover is provided inside the valve cover. The through hole includes a main through hole and branched air outlet holes. The main through hole is single, and the branched air outlet holes are distributed on the side of the main through hole. 2 - 4 branched air outlet holes are provided. The intake end of the branched air outlet hole is connected to the main ventilation hole, and the outlet end corresponds to the position of the sealing surface. Since the sealing surface is arranged along the valve seat, the branched air outlet holes are also arranged in a dispersed manner on the side of the main through hole.

[0047] Furthermore, the main through hole is perpendicular to the rocker arm rotating shaft. The main through hole is in the structure of a nozzle or a horn-shaped pipe body. The two ends of the main through hole are respectively provided with a main intake port end and a main outlet port end. The diameter of the main intake port end is larger than that of the main outlet port end. The branched air outlet hole is connected to the main through hole, and the included angle between the branched air outlet hole and the main through hole ranges from 1° to 180°, and the preferred included angle range is 30 - 120 degrees. It can improve the valve control performance and accuracy, and while not reducing the sealing performance, reduce the impact load by 8%.

[0048] In an embodiment of a through hole, the through hole includes a main through hole and branched air outlet holes (see Figure 7 , Figure 8 ). The main through hole is single, and the branched air outlet holes 432 are distributed on the side of the main through hole. 2 symmetrically distributed branched air outlet holes are provided. The intake end of the branched air outlet hole is connected to the main ventilation hole. The included angle between the branched air outlet hole and the main through hole is 110 degrees. The area of the main intake port end 431 is larger than the sum of the areas of the two branched air outlet holes, which can increase the outlet gas velocity so as to achieve the effect of jetting and dispersing high-speed gas. At the same time, this structure is also easy to process and form, and is convenient for popularization.

[0049] In an embodiment of a through hole, the through hole is in a ditch shape, that is, one side is open, and the outer side wall of the through hole is in communication with the outer surface of the hemispherical valve surface, which makes the through hole easier to process and form and reduces the manufacturing cost.

[0050] The specific embodiments of the present invention have been described in detail above, but they are only examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, equivalent transformations and modifications made without departing from the spirit and scope of the present invention should all be covered within the scope of the present invention.

Claims

1. A turbine supercharger valve cover assembly, comprising a volute casing and an exhaust gas bypass channel provided in the volute casing, characterized in that: The valve cover assembly includes a rocker arm, a valve cover, and a positioning gasket. The valve cover assembly is arranged at one end of the exhaust gas bypass passage to control and regulate the gas discharge of the exhaust gas bypass passage. One end of the rocker arm is clamped on the upper part of the valve cover through the positioning gasket to form a linkage with the valve cover. The valve cover is provided with a sealing surface and a hemispherical valve surface. A through hole penetrating the valve cover is arranged in the middle of the hemispherical valve surface. By using the pressure difference at both ends of the through hole, the gas near the side of the rocker arm is sucked, and the high-speed gas impacting the sealing surface of the valve cover is blown away through the through hole. A valve seat is arranged in the volute, and the exhaust gas bypass valve is arranged on the valve seat. The size of the sealing surface of the valve cover matches the top surface of the valve seat. A bypass valve hole is arranged at the top of the exhaust gas bypass passage, and the hemispherical valve surface of the valve cover cooperates with the bypass valve hole. The diameter of the hemispherical valve surface is smaller than the diameter of the bypass valve hole. The through hole is of a single-hole structure, perpendicular to the rocker arm rotation axis, and is in the shape of a nozzle structure; or the through hole includes a main through hole and a branched air outlet hole. The main through hole is perpendicular to the rocker arm rotation axis, the main through hole is in the shape of a nozzle structure, the branched air outlet hole is connected to the main through hole, and the included angle between the branched air outlet hole and the main through hole ranges from 1° to 180°.

2. The turbine supercharger valve cover assembly according to claim 1, characterized in that: One end of the through hole with a single-hole structure is an air inlet port, and the other end is an air outlet port. The area of the air inlet port is larger than the area of the air outlet port.

3. A turbine supercharger valve cover assembly according to claim 1, characterized in that: The main inlet port end and the main outlet port end are respectively arranged at both ends of the main through hole. The diameter of the main inlet port end is larger than the diameter of the main outlet port end.

4. A turbine supercharger valve cover assembly according to claim 2, characterized in that: The outer side wall of the through hole with a single-hole structure penetrates through the outer surface of the hemispherical valve surface.

5. The turbine supercharger valve cover assembly according to claim 3, characterized in that: The outer side wall of the main through hole penetrates through the outer surface of the hemispherical valve surface.

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