Centralized high-pressure common rail system
By designing a centralized high-pressure common rail system, the problem of large fluctuations in the left and right rail pressures of the diesel engine in a decentralized system was solved, achieving consistent oil pressure and ease of maintenance.
Patent Information
- Application Number
- PCT/CN2025/144712
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-12-31
- Filing Date
- 2025-12-23
- Publication Date
- 2026-07-09
Smart Images

Figure CN2025144712_09072026_PF_FP_ABST
Abstract
Description
Centralized high-voltage common rail system Technical Field
[0001] This invention relates to the field of oil pumps, and in particular to centralized high-pressure common rail systems. Background Technology
[0002] A common rail system is a fuel supply system that completely separates the generation of injection pressure from the injection process within a closed-loop system consisting of a high-pressure fuel pump, pressure sensor, and electronic control unit (ECU). Existing decentralized common rail systems have a wide variety of high-pressure pipelines, resulting in significant fluctuations in rail pressure on both sides of the diesel engine, unstable rail pressure, and inconvenience for routine maintenance. Technical issues
[0003] To overcome the shortcomings of existing high-pressure common rail systems, such as instability and inconvenience in maintenance, this invention provides a centralized high-pressure common rail system. Technical solutions
[0004] The technical solution adopted by this invention to solve its technical problem is: a centralized high-pressure common rail system, including a PVC valve, a right crossrail connecting pipe, a left crossrail connecting pipe, a right high-pressure common rail, a left high-pressure common rail, high-pressure oil pipe A, high-pressure oil pipe B, high-pressure oil pipe C, a safety valve, and a rail pressure sensor. One side of the PVC valve is connected to the right high-pressure common rail through the right crossrail connecting pipe, and the other side of the PVC valve is connected to the left high-pressure common rail through the left crossrail connecting pipe. A rail pressure sensor is installed at the end of the right high-pressure common rail, and a safety valve is installed at the end of the left high-pressure common rail. Several high-pressure oil pipes A, several high-pressure oil pipes B, and several high-pressure oil pipes C are connected to both the right and left high-pressure common rails.
[0005] According to another embodiment of the present invention, both the right high-pressure common rail and the left high-pressure common rail are composed of an outer pipe, an inner pipe, a conversion joint, and a retaining ring. The outer pipe is composed of several interconnected pipe sections. The inner pipe is placed inside the outer pipe. A leakage oil passage is provided between the outer pipe and the inner pipe. A conversion joint is provided at both ends of the outer pipe, and a retaining ring is provided on the conversion joint.
[0006] According to another embodiment of the present invention, the ball joint is provided at the junction of adjacent outer tubes, and a positioning screw sleeve is provided on the inner tube. The ball joint is positioned on the outer tube by the positioning screw sleeve. The ball joint is connected to the inner cavity of the inner tube. The tail ends of high-pressure oil pipe A, high-pressure oil pipe B, and high-pressure oil pipe C are respectively connected to the ball joint.
[0007] According to another embodiment of the present invention, an O-ring is further provided between the outer tube and the ball joint.
[0008] According to another embodiment of the present invention, the ball joint is further provided with a plurality of oil grooves on its inner wall, and the inner wall of the ball joint is in direct contact with the inner tube.
[0009] According to another embodiment of the present invention, the outer tube is further provided with a plurality of oil grooves on its inner wall.
[0010] According to another embodiment of the present invention, the PVC valve is further provided with a pressure relief hole and a screw plug.
[0011] According to another embodiment of the present invention, the PVC valve is further fixed on the connecting block bracket, and the connecting block bracket is fixedly connected to the machine body by bolts.
[0012] According to another embodiment of the present invention, the right cross-rail connecting pipe and the left cross-rail connecting pipe are respectively fixedly connected to the machine body by pipe clamp assembly.
[0013] According to another embodiment of the present invention, the right high-pressure common rail and the left high-pressure common rail are respectively fixedly connected to the machine body by fixed brackets. Beneficial effects
[0014] The beneficial effects of this invention are that, by connecting the left and right high-pressure common rails at the rear end of the diesel engine, the oil pressure in the oil chambers of the left and right high-pressure common rails tends to be consistent; the high-pressure common rail adopts a double-layer pipe structure, and the high-pressure oil pipe and the high-pressure common rail are connected and sealed with a ball joint; the inner pipe of the high-pressure common rail adopts a single integral steel pipe, and the outer pipe of the high-pressure common rail adopts a segmented steel pipe, which has better safety and sealing performance. Attached Figure Description
[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0016] Figure 1 is a schematic diagram of the structure of the present invention;
[0017] Figure 2 is a schematic diagram of the right-side high-pressure common rail structure of the present invention;
[0018] Figure 3 is a schematic diagram of the ball joint of the present invention;
[0019] In the diagram: 1. PVC valve, 2. Right crossrail connecting pipe, 3. Left crossrail connecting pipe, 4. Right high-pressure common rail, 5. Left high-pressure common rail, 6. High-pressure oil pipe A, 7. High-pressure oil pipe B, 8. High-pressure oil pipe C, 9. Safety valve, 10. Rail pressure sensor, 11. Oil tank two, 12. Pressure relief hole, 13. Plug, 14. Connecting block bracket, 15. Pipe clamp assembly, 16. Fixed bracket, 41. Outer pipe, 42. Inner pipe, 43. Adapter, 44. Snap ring, 45. Ball joint, 46. Oil tank one, 47. Positioning screw sleeve, 48. O-ring seal. Embodiments of the present invention
[0020] Figure 1 is a structural schematic diagram of the present invention; Figure 2 is a structural schematic diagram of the right high-pressure common rail of the present invention; Figure 3 is a structural schematic diagram of the ball joint of the present invention.
[0021] As shown in Figure 1, a centralized high-pressure common rail system includes a PVC valve 1, a right crossrail connecting pipe 2, a left crossrail connecting pipe 3, a right high-pressure common rail 4, a left high-pressure common rail 5, high-pressure oil pipes A6, B7, and C8, a safety valve 9, and a rail pressure sensor 10. One side of the PVC valve 1 is connected to the right high-pressure common rail 4 via the right crossrail connecting pipe 2, and the other side of the PVC valve 1 is connected to the left high-pressure common rail 5 via the left crossrail connecting pipe 3. A rail pressure sensor 10 is installed at the end of the right high-pressure common rail 4, and a safety valve 9 is installed at the end of the left high-pressure common rail 5. Several high-pressure oil pipes A6, B7, and C8 are connected to both the right high-pressure common rail 4 and the left high-pressure common rail 5.
[0022] The rear end of the diesel engine connects the right high-pressure common rail 4 and the left high-pressure common rail 5 to ensure that the oil pressure in the high-pressure oil chambers of the right high-pressure common rail 4 and the left high-pressure common rail 5 tends to be consistent.
[0023] As shown in Figure 2, both the right-side high-pressure common rail 4 and the left-side high-pressure common rail 5 consist of an outer pipe 41, an inner pipe 42, a conversion joint 43, and a retaining ring 44. The outer pipe 41 is composed of several interconnected pipe sections. The inner pipe 42 is placed inside the outer pipe 41. A leakage oil passage is provided between the outer pipe 41 and the inner pipe 42. Conversion joints 43 are provided at both ends of the outer pipe 41, and retaining rings 44 are provided on the conversion joints 43. The retaining rings 44 prevent the outer pipe 41 from escaping. The leakage oil passage is used for the leakage of high-pressure fuel. The inner cavity of the inner pipe 42 is a high-pressure oil chamber.
[0024] A ball joint 45 is provided at the connection of adjacent outer tubes 41, and a positioning screw sleeve 47 is provided on the inner tube 42. The ball joint 45 is positioned on the outer tube 41 by the positioning screw sleeve 47. The ball joint 45 is connected to the inner cavity of the inner tube 42. The tail ends of high pressure oil pipe A6, high pressure oil pipe B7 and high pressure oil pipe C8 are respectively connected to the ball joint 45.
[0025] The outer tube 41 and the inner tube 42 form a double-layer tube structure. The high-pressure oil pipes A6, B7, and C8 are connected and sealed with the right high-pressure common rail 4 and the left high-pressure common rail 5 using ball joints 45. The inner tube 42 is made of a single integral steel pipe, while the outer tube 41 is made of segmented steel pipe, which has better safety, sealing performance and assembly processability.
[0026] An O-ring 48 is provided between the outer tube 41 and the ball joint 45. The O-ring 48 can improve the sealing performance between the outer tube 41 and the ball joint 45.
[0027] As shown in Figure 3, the inner wall of the ball joint 45 is provided with several oil grooves 46, and the inner wall of the ball joint 45 is in direct contact with the inner tube 42.
[0028] Several oil grooves are provided on the inner wall of the outer tube 41.
[0029] Since direct contact between the ball joint 45 and the inner tube 42 would prevent the leakage oil passage from being connected, an oil trough 46 is provided to allow the leakage oil passage to be connected.
[0030] The PVC valve 1 is provided with a pressure relief hole 12 and a screw plug 13.
[0031] The PVC valve 1 is fixed on the connecting block bracket 14, and the connecting block bracket 14 is fixedly connected to the machine body by bolts.
[0032] The right cross-rail connecting pipe 2 and the left cross-rail connecting pipe 3 are fixedly connected to the machine body by pipe clamp assembly 15.
[0033] The right high-pressure common rail 4 and the left high-pressure common rail 5 are fixedly connected to the machine body by fixed brackets 16.
[0034] Fuel is pressurized by four electronically controlled pumps and enters its corresponding high-pressure fuel line A6. From there, it enters the high-pressure fuel chambers of the right-side high-pressure common rail 4 and the left-side high-pressure common rail 5. These high-pressure fuel chambers have a sufficiently large volume to serve as accumulators for the injectors, balancing pressure and reducing pressure fluctuations. The high-pressure fuel in these chambers then enters the corresponding injectors through high-pressure fuel lines B7 and C8 for injection. The right crossrail connecting pipe 2 and the left crossrail connecting pipe 3 connect the right-side high-pressure common rail 4 and the left-side high-pressure common rail 5 via a connecting block. The system ensures pressure balance in the high-pressure oil chambers of the right-side high-pressure common rail 4 and the left-side high-pressure common rail 5. The rail pressure sensor 10 is used to detect the pressure in the high-pressure oil chamber. The safety valve 9 is for safety; when the diesel engine malfunctions or fails, if the pressure in the high-pressure oil chamber exceeds the set value, the safety valve opens to quickly release the high-pressure fuel in the high-pressure oil chamber to prevent the pipeline from bursting. The PVC valve 1 is mainly used to release the high-pressure fuel remaining in the high-pressure oil chamber through the pressure relief hole 12 after the diesel engine stops, in order to protect the pipeline and facilitate pipeline maintenance and repair.
Claims
1. A centralized high-pressure common rail system, characterized in that it includes: PVC valve (1), right cross-rail connecting pipe (2), left cross-rail connecting pipe (3), right high-pressure common rail (4), left high-pressure common rail (5), high-pressure oil pipe A (6), high-pressure oil pipe B (7), high-pressure oil pipe C (8), safety valve (9), rail pressure sensor (10). One side of the PVC valve (1) is connected to the right high-pressure common rail (4) through the right cross-rail connecting pipe (2), and the other side of the PVC valve (1) is connected to the left high-pressure common rail (5) through the left cross-rail connecting pipe (3). A rail pressure sensor (10) is installed at the end of the right high-pressure common rail (4), and a safety valve (9) is installed at the end of the left high-pressure common rail (5). Several high-pressure oil pipes A (6), several high-pressure oil pipes B (7), and several high-pressure oil pipes C (8) are connected to both the right high-pressure common rail (4) and the left high-pressure common rail (5).
2. The centralized high-pressure common rail system according to claim 1, characterized in that, The right high-pressure common rail (4) and the left high-pressure common rail (5) are both composed of an outer pipe (41), an inner pipe (42), a conversion joint (43), and a retaining ring (44). The outer pipe (41) is composed of several interconnected pipe sections. The inner pipe (42) is placed inside the outer pipe (41). A leakage oil passage is provided between the outer pipe (41) and the inner pipe (42). Both ends of the outer pipe (41) are provided with conversion joints (43), and retaining rings (44) are provided on the conversion joints (43).
3. The centralized high-pressure common rail system according to claim 2, characterized in that, A ball joint (45) is provided at the connection of adjacent outer tubes (41), and a positioning screw sleeve (47) is provided on the inner tube (42). The ball joint (45) is positioned on the outer tube (41) by the positioning screw sleeve (47). The ball joint (45) is connected to the inner cavity of the inner tube (42). The tail ends of high pressure oil pipe A (6), high pressure oil pipe B (7), and high pressure oil pipe C (8) are respectively connected to the ball joint (45).
4. The centralized high-pressure common rail system according to claim 2, characterized in that, An O-ring (48) is provided between the outer tube (41) and the ball joint (45).
5. The centralized high-pressure common rail system according to claim 3, characterized in that, The inner wall of the ball joint (45) is provided with several oil grooves (46), and the inner wall of the ball joint (45) is in direct contact with the inner tube (42).
6. The centralized high-pressure common rail system according to claim 2, characterized in that, The inner wall of the outer tube (41) is provided with several oil grooves (11).
7. The centralized high-pressure common rail system according to claim 1, characterized in that, The PVC valve (1) is provided with a pressure relief hole (12) and a screw plug (13).
8. The centralized high-pressure common rail system according to claim 1, characterized in that, The PVC valve (1) is fixed on the connecting block bracket (14), and the connecting block bracket (14) is fixedly connected to the machine body by bolts.
9. The centralized high-pressure common rail system according to claim 1, characterized in that, The right cross-rail connecting pipe (2) and the left cross-rail connecting pipe (3) are fixedly connected to the machine body by pipe clamp assembly (15).
10. The centralized high-pressure common rail system according to claim 1, characterized in that, The right high-pressure common rail (4) and the left high-pressure common rail (5) are fixedly connected to the machine body by a fixed bracket (16).