A high-pressure common rail system electrically controlled pressure relief valve valve seat

Abstract

The application provides a valve seat of an electric control pressure relief valve of a high-pressure common rail system, wherein a pressure relief cavity and a high-pressure oil cavity are arranged in the valve seat; one end of the pressure relief cavity is connected with the electric control pressure relief valve; one end of the high-pressure oil cavity is connected with a common rail pipe; after the electric control pressure relief valve is opened, fuel in the high-pressure oil cavity is discharged into the pressure relief cavity through a discharge hole of the electric control pressure relief valve, and is communicated with an oil return pipeline through a threaded hole and the oil return pipeline. The application has the beneficial effects that the valve seat of the electric control pressure relief valve of the high-pressure common rail system can meet the installation requirements of electric control pressure relief valves of different specifications of the high-pressure common rail system, can play a role of adapting, can solve the problems of installation and sealing caused by the mismatch between the external thread of the electric control pressure relief valve and the internal thread of the common rail pipe, can improve the service life of the common rail pipe through the transition effect, can avoid the damage of the common rail pipe caused by the frequent replacement of the electric control pressure relief valve, can affect the installation and high-pressure sealing performance, and can improve the economy of the high-pressure common rail system.

Description

Technical Field

[0001] This invention belongs to the technical field of engine fuel injection systems, and in particular relates to a valve seat for an electronically controlled pressure relief valve in a high-pressure common rail system. Background Technology

[0002] With the continuous improvement of the power density of diesel engines, higher requirements are placed on the fuel injection system, which is the "heart" of the diesel engine. Due to its high injection pressure, precise and controllable injection quantity, injection timing, and flexible and adjustable injection pattern, the high-pressure common rail fuel injection system has gradually become the mainstream fuel injection system.

[0003] One of the biggest advantages of a high-pressure common rail system is the pressure accumulator function of its common rail, which decouples rail pressure from engine speed. The presence of the accumulator volume also reduces system pressure fluctuations, improving injection stability and consistency. Therefore, stable rail pressure control is particularly important for high-pressure common rail systems. In actual application, the use of injectors without static return, the delayed rail pressure regulation characteristics of the fuel metering valve, and sudden operating conditions during vehicle operation can all lead to abnormal increases in rail pressure, affecting system safety. Therefore, an electronically controlled pressure relief valve needs to be installed on the common rail to reduce abnormal rail pressure to the target rail pressure, improving system safety. However, the installation thread dimensions of electronically controlled pressure relief valves from different manufacturers, models, and with different performance levels vary, while the installation thread dimensions of common rails of different specifications are generally uniform. This limits the application of different specifications of electronically controlled pressure relief valves, or necessitates machining a corresponding common rail for a specific specification of electronically controlled pressure relief valve, which is time-consuming, labor-intensive, and costly. Meanwhile, the electrically controlled pressure relief valve is a consumable part. Frequent replacement will damage and wear the internal threads and internal high-pressure sealing surface of the common rail pipe, affecting installation and high-pressure sealing performance, shortening the service life of the common rail pipe, and increasing the cost of the high-pressure common rail system. Summary of the Invention

[0004] In view of this, the present invention aims to provide an electrically controlled pressure relief valve seat for a high-pressure common rail system, so as to solve at least one of the problems in the prior art.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A valve seat for an electrically controlled pressure relief valve in a high-pressure common rail system, wherein the valve seat is provided with a pressure relief chamber and a high-pressure oil chamber;

[0007] One end of the pressure relief chamber is connected to an electrically controlled pressure relief valve;

[0008] One end of the high-pressure oil chamber is connected to the common rail pipe;

[0009] After the electronically controlled pressure relief valve is opened, the fuel in the high-pressure oil chamber is discharged into the pressure relief chamber through the oil drain hole of the electronically controlled pressure relief valve, and is connected to the return oil line through the threaded hole of the return oil line.

[0010] Furthermore, a high-pressure sealing cone surface is provided between the pressure relief chamber and the high-pressure oil chamber.

[0011] Furthermore, the valve seat is provided with an internal thread for mounting a pressure relief valve, which engages with the external thread of an electrically controlled pressure relief valve.

[0012] Furthermore, the valve seat is provided with an external valve seat mounting thread, which engages with the internal thread of the common rail pipe.

[0013] Furthermore, the top of the valve seat is provided with an O-ring sealing surface, which is used to cooperate with the O-ring of the electrically controlled pressure relief valve to prevent oil return leakage.

[0014] Furthermore, the internal thread size of the electronically controlled pressure relief valve is determined based on the external thread size of the electronically controlled pressure relief valve to ensure that the high-pressure sealing cone surface of the valve seat is pressed tightly against the sealing cone surface of the electronically controlled pressure relief valve. The cone angle of the high-pressure sealing cone surface of the valve seat is 20° larger than the cone angle of the sealing cone surface of the electronically controlled pressure relief valve to ensure that a cone seal is formed between the two to prevent high-pressure fuel leakage.

[0015] Furthermore, the inner diameter of the pressure relief chamber is the same as the inner diameter of the internal thread of the electrically controlled pressure relief valve.

[0016] Furthermore, the inner diameter of the threaded hole in the return oil pipeline is larger than the diameter of the drain hole in the electrically controlled pressure relief valve to prevent throttling of the return oil and affecting the pressure relief effect.

[0017] Furthermore, the upper part of the O-ring sealing surface is designed with a chamfer to facilitate O-ring installation and prevent the O-ring from cutting and affecting the seal; the lower part of the O-ring sealing surface is designed with a chamfer to prevent damage to the internal threads of the electrically controlled pressure relief valve during installation.

[0018] Furthermore, during the assembly process of the valve seat external thread and the common rail internal thread, it is necessary to ensure that the high-pressure sealing ring is pressed tightly against the common rail sealing surface to prevent high-pressure fuel leakage.

[0019] The high-pressure sealing ring of the valve seat is pressed tightly against the sealing surface of the common rail. The inner and outer chamfer angles of the high-pressure sealing ring of the valve seat are 45° and 15° respectively, in order to seal the high-pressure fuel in the common rail.

[0020] Compared with the prior art, the valve seat of the electrically controlled pressure relief valve for a high-pressure common rail system described in this invention has the following advantages:

[0021] (1) The valve seat of the high pressure common rail system electrically controlled pressure relief valve created by the present invention can meet the installation requirements of the high pressure common rail system electrically controlled pressure relief valve of different specifications. It can play the role of adapter and solve the problem of inability to install and seal caused by the mismatch between the external thread of the electrically controlled pressure relief valve and the internal thread of the common rail pipe.

[0022] (2) The valve seat of the electrically controlled pressure relief valve of the high pressure common rail system created by the present invention can improve the service life of the common rail pipe, avoid frequent replacement of the electrically controlled pressure relief valve which would damage the common rail pipe, affect installation and high pressure sealing, and improve the economy of the high pressure common rail system. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the cross-sectional structure of the valve seat of the electrically controlled pressure relief valve in the high-pressure common rail system according to an embodiment of the present invention;

[0025] Figure 2 This is a partially enlarged structural diagram of the high-pressure sealing ring belt according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the valve seat structure of the electrically controlled pressure relief valve in the high-pressure common rail system according to an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1-O-ring sealing surface; 2-Inner thread for mounting the electrically controlled pressure relief valve; 3-Pressure relief chamber; 4-High-pressure sealing cone surface; 5-High-pressure oil chamber; 6-High-pressure sealing ring; 7-External thread for valve seat mounting; 8-Threaded hole for connecting the return oil pipeline; 9-External hexagon. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] This solution discloses a valve seat for an electrically controlled pressure relief valve in a high-pressure common rail system, including an O-ring sealing surface, an internal thread for mounting the electrically controlled pressure relief valve, a pressure relief chamber, a high-pressure sealing cone surface, a high-pressure oil chamber, a high-pressure sealing ring, an external thread for valve seat mounting, a threaded hole for connecting the return oil pipeline, and an external hexagonal socket.

[0032] The valve seat is installed with the external thread of the common rail pipe and the internal thread of the common rail pipe. Using a socket wrench, the valve seat is tightened onto the common rail pipe through the external hex wrench to ensure that the high-pressure sealing ring is pressed tightly against the sealing surface of the common rail pipe to prevent high-pressure fuel leakage.

[0033] The internal thread of the electrically controlled pressure relief valve is fitted with the external thread of the electrically controlled pressure relief valve to ensure that the sealing cone surface of the electrically controlled pressure relief valve is pressed tightly against the high-pressure sealing cone surface of the valve seat to prevent high-pressure fuel leakage.

[0034] After the electronically controlled pressure relief valve is opened, the fuel in the high-pressure oil chamber is discharged into the pressure relief chamber through the drain hole of the electronically controlled pressure relief valve, and is connected to the return oil pipeline through the threaded hole of the return oil pipeline to achieve pressure relief. At the same time, the top of the valve seat is provided with an O-ring sealing surface, which cooperates with the O-ring sealing ring of the electronically controlled pressure relief valve to prevent return oil leakage.

[0035] The external thread size of the valve seat is determined according to the internal thread size of the common rail pipe to ensure matching between the two. The thread length, upper relief groove and lower concave platform size are designed to ensure that after the valve seat is tightened on the common rail pipe, the high-pressure sealing ring of the valve seat is pressed against the sealing surface of the common rail pipe. The sealing ring width is 0.2mm, and it is tempered to a hardness of 55-65HRC (the hardness of the remaining part is 35-45HRC). The inner and outer chamfer angles of the ring are 45° and 15° respectively to seal the high-pressure fuel in the common rail pipe. The tightening torque of the electronically controlled pressure relief valve seat is ≥110N·m, and a socket wrench must be used.

[0036] The internal thread size of the electrically controlled pressure relief valve is determined according to the external thread size of the electrically controlled pressure relief valve to ensure matching between the two. This ensures that the high-pressure sealing cone surface of the valve seat is pressed tightly against the sealing cone surface of the electrically controlled pressure relief valve. The cone angle of the high-pressure sealing cone surface of the valve seat is 20° larger than that of the sealing cone surface of the electrically controlled pressure relief valve to ensure that a cone seal is formed between the two, preventing high-pressure fuel leakage.

[0037] The inner diameter of the pressure relief chamber is the same as the inner diameter of the internal thread of the electrically controlled pressure relief valve. The design of the pressure relief chamber should ensure that the pressure relief hole of the electrically controlled pressure relief valve is located exactly in the middle of the pressure relief chamber to prevent throttling.

[0038] The inner diameter of the threaded hole connecting the return oil pipeline must be larger than the diameter of the drain hole of the electrically controlled pressure relief valve to prevent throttling of the return oil and affect the pressure relief effect.

[0039] The inner diameter of the O-ring sealing surface is designed according to the specifications of the O-ring and the shaft diameter of the electrically controlled pressure relief valve, in accordance with GB / T3452.1-2005. The upper part of the O-ring sealing surface is designed with a chamfer to facilitate O-ring installation and prevent O-ring cutting, which would affect the seal. The lower part of the O-ring sealing surface is designed with a chamfer to prevent damage to the internal threads of the electrically controlled pressure relief valve during installation.

[0040] The following is a detailed description of this scheme in conjunction with the accompanying drawings:

[0041] like Figures 1 to 3 As shown, the present invention creates a pressure relief system for abnormal working conditions of a high-pressure common rail system, which together with an electrically controlled pressure relief valve and a high-pressure common rail pipe. The present invention includes an O-ring sealing surface 1, an internal thread for mounting the electrically controlled pressure relief valve 2, a pressure relief chamber 3, a high-pressure sealing cone surface 4, a high-pressure oil chamber 5, a high-pressure sealing ring 6, an external thread for mounting the valve seat 7, a threaded hole for connecting the return oil pipeline 8, and an external hexagonal 9.

[0042] like Figure 2 , Figure 3As shown, the valve seat is installed with external thread 7 and internal thread of common rail pipe. Using a socket wrench, the valve seat is tightened onto common rail pipe through external hexagon 9. The tightening torque of the electrically controlled pressure relief valve seat is ≥110 N·m. The sealing ring is 0.2 mm wide, heat-treated, and has a hardness of 55-65 HRC (the hardness of the remaining parts is 35-45 HRC). The inner and outer chamfer angles of the ring are 45° and 15° respectively, to ensure that the high-pressure sealing ring 6 is pressed tightly against the sealing surface of common rail pipe to prevent high-pressure fuel leakage.

[0043] like Figure 1 As shown, the internal thread 2 of the electrically controlled pressure relief valve is fitted with the external thread of the electrically controlled pressure relief valve. The cone angle of the high-pressure sealing cone surface of the valve seat is 20° larger than that of the sealing cone surface of the electrically controlled pressure relief valve, ensuring that a cone seal is formed between the two to prevent high-pressure fuel leakage. When installing the electrically controlled pressure relief valve on the valve seat, use an open-end wrench to hold the outer hexagon 9 of the valve seat and use a socket wrench to tighten the electrically controlled pressure relief valve on the valve seat. The tightening torque is ≥110 N·m.

[0044] Under normal operating conditions, the electronically controlled pressure relief valve is closed, and high-pressure fuel is stored in the high-pressure oil chamber 5 without leakage. Under abnormal rail pressure conditions, the electronically controlled pressure relief valve opens, and fuel in the high-pressure oil chamber 5 is discharged into the pressure relief chamber 3 through the drain hole of the electronically controlled pressure relief valve. The inner diameter of the pressure relief chamber 3 is the same as the inner diameter of the internal thread of the electronically controlled pressure relief valve. The design of the pressure relief chamber must ensure that the drain hole of the electronically controlled pressure relief valve is located exactly in the middle of the pressure relief chamber to prevent throttling. The valve is connected to the return oil pipeline through the threaded hole 8 of the return oil pipeline to achieve pressure relief. The inner diameter of the threaded hole 8 of the return oil pipeline connection must be larger than that of the electronically controlled pressure relief valve. The diameter of the oil drain hole of the pressure relief valve is designed to prevent backflow throttling and affect the pressure relief effect. Simultaneously, an O-ring sealing surface 1 is provided on the top of the valve seat to cooperate with the O-ring of the electrically controlled pressure relief valve, preventing backflow leakage. The inner diameter of the O-ring sealing surface 1 is designed according to the specifications of the electrically controlled pressure relief valve's sealing O-ring and shaft diameter, in accordance with GB / T3452.1-2005. A chamfer is designed on the upper part of the O-ring sealing surface 1 to facilitate O-ring installation and prevent O-ring cutting, which would affect the seal. A chamfer is also designed on the lower part of the O-ring sealing surface 1 to prevent damage to the internal threads during installation of the electrically controlled pressure relief valve.

[0045] This invention can meet the installation requirements of electrically controlled pressure relief valves for high-pressure common rail systems of different specifications. The valve seat of the electrically controlled pressure relief valve can act as a transition, solving the problem of installation failure and sealing caused by the mismatch between the external thread of the electrically controlled pressure relief valve and the internal thread of the common rail pipe. At the same time, the electrically controlled pressure relief valve is a consumable part, and frequent replacement will damage and wear the internal thread of the common rail pipe and the internal high-pressure sealing surface, affecting installation and high-pressure sealing performance. The transition function of the valve seat of the electrically controlled pressure relief valve can improve the service life of the common rail pipe and improve the economy of the high-pressure common rail system.

[0046] Those skilled in the art will recognize that the units and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0047] In the several embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of units described above is merely a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. The aforementioned units may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention according to actual needs.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0049] The above description is only a preferred embodiment of the present invention and is 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 within the protection scope of the present invention.

Claims

1. A high pressure common rail system electronically controlled pressure relief valve seat, characterized by: The valve seat is provided with a pressure relief cavity (3) and a high-pressure oil cavity (5); One end of the pressure relief cavity (3) is connected with an electronic control pressure relief valve; One end of the high-pressure oil cavity (5) is connected with a common rail pipe; After the electronic control pressure relief valve is opened, the fuel in the high-pressure oil cavity (5) is discharged into the pressure relief cavity (3) through the oil discharge hole of the electronic control pressure relief valve, and is communicated with the oil return pipeline through the oil return pipeline connecting threaded hole (8); A high-pressure sealing cone surface (4) is arranged between the pressure relief cavity (3) and the high-pressure oil cavity (5); The size of the electronic control pressure relief valve mounting internal thread (2) is determined according to the size of the electronic control pressure relief valve external thread, so as to ensure that the valve seat high-pressure sealing cone surface (4) is pressed against the electronic control pressure relief valve sealing cone surface, the cone angle of the valve seat high-pressure sealing cone surface (4) is 20° larger than that of the electronic control pressure relief valve sealing cone surface, so as to form a cone surface sealing between the two, and prevent high-pressure fuel leakage; During the assembly of the valve seat mounting external thread (7) and the common rail pipe internal thread, the high-pressure sealing ring (6) needs to be pressed against the common rail pipe sealing surface to prevent high-pressure fuel leakage; The valve seat high-pressure sealing ring (6) is pressed against the common rail pipe sealing surface, and the inner and outer chamfer angles of the valve seat high-pressure sealing ring (6) are 45° and 15° respectively, so as to seal the high-pressure fuel in the common rail pipe; The valve seat top is provided with an O-ring sealing surface (1) for cooperating with the O-ring sealing ring of the electronic control pressure relief valve to prevent oil leakage; The inner diameter of the pressure relief cavity (3) is the same as that of the electronic control pressure relief valve mounting internal thread (2); The inner diameter of the oil return pipeline connecting threaded hole (8) is larger than the diameter of the oil discharge hole of the electronic control pressure relief valve, so as to prevent oil return throttling and affect the pressure relief effect; The upper part of the O-ring sealing surface (1) is designed with a side chamfer to facilitate O-ring installation and prevent O-ring cutting and affect sealing; the lower part of the O-ring sealing surface (1) is designed with a side chamfer to prevent damage to the electronic control pressure relief valve mounting internal thread (2); The valve seat is provided with an electronic control pressure relief valve mounting internal thread (2), which cooperates with the electronic control pressure relief valve external thread.

2. The electrically controlled pressure relief valve seat for a high-pressure common rail system according to claim 1, characterized in that: The valve seat is provided with a valve seat mounting external thread (7), which cooperates with the common rail pipe internal thread.

3. The electrically controlled pressure relief valve seat for a high pressure common rail system according to claim 1, characterized in that: ​

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