Pressure balance regulating valve between double common rail pipes

Abstract

The utility model relates to a pressure balance regulating valve between double common rail pipes, which consists of a balance valve core 1, an electric actuator 2, a return spring 3, a valve body 4, an oil inlet joint 5, a sealing screw seat 6, a stroke limiter 7, a left oil outlet joint 8, a left sealing bolt 9, a right sealing bolt 10 and a right oil outlet joint 11, the balance valve core 1 is arranged in a balance valve hole of the valve body 4, the electric actuator 2 is connected with one end of the balance valve core 1, and the other end of the balance valve core 1 is connected with the other end of the electric actuator 2. The reset spring 3 achieves reset after the balance valve element 1 moves, the stroke limiter 7 limits the maximum movement displacement of the balance valve element 1, the sealing screw seat 6 achieves sealing of a balance valve cavity and fixing of the displacement limiter 7, the oil inlet connector 5 achieves that high-pressure fuel enters the valve body 4, and the left oil outlet connector 8 and the right oil outlet connector 11 achieve branch output of the high-pressure fuel respectively. Different control signals of the electric actuator enable the balance valve element 1 to be located at the left position, the middle position and the right position respectively, fuel oil is controlled to flow to the designated common rail pipe, and pressure balance adjustment between the double common rail pipes is achieved.

Description

1. Technical Field

[0001] The utility model relates to a high-pressure fuel injection system for a diesel engine with dual common rails, and particularly to a pressure balance regulating valve between two common rails, belonging to the high-pressure common rail pressure control technology of a diesel engine. 2. Background Art

[0002] The high-pressure common rail fuel injection system can independently adjust the fuel injection pressure, injection timing and injection quantity, and can realize multiple injections and injection rate control. It is an effective technology for diesel engines to reduce fuel consumption and harmful emissions, and has been widely applied to small-power diesel engines. With the increasing requirements for energy conservation and emission reduction of large-power diesel engines, the high-pressure common rail fuel injection system is more and more applied in combination with large-power diesel engines. Although the number of cylinders and the structural dimensions of diesel engines are quite different, the dual common rail fuel injection system composed of two or more common rails has become the main structural form of large-power diesel engines. The single-pump dual common rail, dual-pump dual common rail and dual-pump multi-common rail forms will be one of the available options. The single-pump dual common rail fuel injection system is a suitable choice for large-power diesel engines. The parallel connection of the single-pump dual-rail pipes can save space and is compact in layout.

[0003] The single-pump dual common rail fuel injection system supplies fuel to two common rails by one fuel injection pump, and the two common rails are arranged in parallel near the left and right cylinder banks of the V-shaped angle of the diesel engine. When the single-pump dual common rail fuel injection system works, the electronically controlled fuel injector injects fuel at regular intervals and in sequence according to the firing order requirements of the diesel engine. Since the cylinders of the left and right cylinder banks fire alternately, after each fuel injection of the electronically controlled fuel injector, the fuel pressure in the two common rails fluctuates. In a short interval, there is a certain difference in the fuel pressure between the left and right common rails, which affects the consistency of the fuel injection quantity of the left and right cylinders. There are two conventional solutions: one is to use a three-way valve at the inlet, that is, a three-way valve is connected at the inlet of the dual common rail pipes and the high-pressure oil pipe after the high-pressure fuel pump, so that the fuel in the left and right common rails is in a connected state. Although it can suppress the amplitude of the pressure fluctuation in the two common rails, it cannot eliminate the propagation of the pressure fluctuation caused by each fuel injection; the other is to use a one-way valve at the inlet, and a one-way valve is installed at the inlet of each common rail, so that the fuel delivered by the high-pressure fuel pump enters one common rail through the one-way valve. After each fuel injection of the electronically controlled fuel injector, when the fuel pressure in a single common rail drops, due to the pressure difference before and after the inlet, the one-way valve is opened. When the pressure fluctuation caused by each fuel injection causes the fuel pressure in the common rail to rise, due to the pressure difference before and after the inlet, the one-way valve is closed. In this way, the influence on the fuel pressure of the other common rail can be eliminated, but it is required that the one-way valve has a very fast response speed and opens and closes quickly. These two methods have some problems: one is that the response speed of the mechanical one-way valve is relatively slow, and the high-frequency opening and closing requires a high surface quality of the sealing cone surface, which cannot meet the requirements of high-frequency operation at high engine speeds; the other is that the three-way valve method cannot eliminate the propagation of the fuel pressure fluctuation in the common rail after fuel injection, and cannot completely eliminate the pressure difference between the two common rails.

[0004] In a dual common rail tube fuel injection system, since the pressures of the left and right common rail tubes are controlled by a closed-loop pressure control circuit composed of a single high-pressure oil pump outlet metering valve and a common rail pressure sensor, the purpose is to make the actual common rail pressure close to the target pressure value. Given that the two common rail tubes are accumulators with one input for fuel supply and multiple outputs, and lacking a hydraulic valve for regulating the pressure of a single common rail tube, there must be a certain difference in the fuel pressures of the two common rail tubes in a short period. To completely solve the deficiencies of the dual common rail tube fuel injection system, an electronically controlled pressure balance regulating valve needs to be introduced, which can not only solve the fuel pressure balance of the two common rail tubes but also eliminate the mutual influence of the fuel pressure fluctuations between the two common rail tubes.

[0005] To achieve the balance and regulation of the fuel pressures in the two common rail tubes during the injection process, it is necessary to add an electric actuator on the basis of the existing three-way valve and one-way valve structures, change the original arrangement of the valve core components, add corresponding parts, and complete the function of pressure balance regulation between the two common rail tubes during the fuel injection process. III. Summary of the Invention

[0006] The purpose of the present utility model is to solve the above technical problems and improve the performance of the diesel engine dual high-pressure common rail fuel injection system. The present utility model is realized as follows: A pressure balance regulating valve between two common rail tubes is composed of a balance valve, an electric actuator, a return spring, a valve body, an oil inlet joint, a stroke limiter, a sealing screw seat, a left oil outlet joint, and a right oil outlet joint. The balance valve is installed in the central hole of the valve body. The electric actuator is integrally connected to one end of the balance valve to drive the movement of the balance valve. The return spring realizes the reset of the movement of the balance valve. The stroke limiter limits the movement displacement of the balance valve to a fixed position. The sealing screw seat realizes the length adjustment of the balance valve stroke limiter. The left oil outlet joint and the right oil outlet joint respectively output high-pressure fuel, and the oil inlet joint completes the entry of high-pressure fuel into the valve body. The electric actuator and the valve body are designed separately, which is convenient for disassembly, installation, and maintenance.

[0007] The technical benefit of the present utility model is: It can achieve the fuel pressure balance of the two common rail tubes and eliminate the mutual influence of the fuel pressure fluctuations between the two common rail tubes. IV. Description of the Drawings

[0008] Figure 1 It is a schematic structural diagram of the pressure balance regulating valve between two common rail tubes;

[0009] Figure 2 It is a schematic structural diagram of the balance valve core;

[0010] Figure 3 It is a longitudinal sectional schematic diagram of the electric actuator;

[0011] Figure 4 It is a schematic diagram of the return spring;

[0012] Figure 5 It is a full sectional view of the valve body;

[0013] Figure 6 Longitudinal sectional view of the fuel inlet joint;

[0014] Figure 7 Partial sectional view of the sealing screw base;

[0015] Figure 8 External view of the stroke limiter. V. Specific implementation mode

[0016] A pressure balance regulating valve between two common rail pipes is composed of a balance valve core 1, an electric actuator 2, a return spring 3, a valve body 4, a fuel inlet joint 5, a sealing screw base 6, a stroke limiter 7, a left oil outlet joint 8, a left sealing bolt 9, a right sealing bolt 10, and a right oil outlet joint 11, as shown in the appendix Figure 1 shown. The balance valve core 1 is installed in the balance valve hole of the valve body 4. The electric actuator 2 is integrally connected to one end of the balance valve core 1 to drive the movement of the balance valve core 1. The return spring 3 realizes the reset of the balance valve core 1 after movement. The stroke limiter 7 limits the movement displacement of the balance valve core 1. The sealing screw base 6 realizes the sealing of the balance valve cavity and the fixation of the stroke limiter 7. The fuel inlet joint 5 realizes the entry of high-pressure fuel into the valve body. The left oil outlet joint 8 and the right oil outlet joint 11 respectively realize the branched output of high-pressure fuel.

[0017] The balance valve core 1 is a multi-cylindrical structure, composed of a positioning boss, a left large cylinder 12, a middle thin cylinder 13, a right large cylinder 14, a connecting rod seat 15, and a connecting rod 16, as shown in the appendix Figure 2 shown. The positioning boss is a cylindrical structure, located at the center of the left end face of the left large cylinder 12. The middle thin cylinder 13 connects the left large cylinder 12 and the right large cylinder 14. The length of the middle thin cylinder 13 is equal to the center distance between the left and right fuel inlet channels of the valve body 4. The connecting rod seat 15 is located on the right side of the right large cylinder 14. The connecting rod 16 is located at the center of the connecting rod seat 15 and is composed of a connecting rod body 161, a fixing pin hole 162, and a connecting tongue 163. The connecting rod body 161 is a slender cylindrical structure. The structure of the connecting tongue 163 is a cuboid, arranged along the diameter direction of the outer end face of the connecting rod body 161. The fixing pin hole 162 is provided on the connecting tongue 163.

[0018] The electric actuator 2 is a solenoid electromagnet, composed of a moving iron core 21, a mounting base plate 22, a coil 23, a coil skeleton body 24, an electromagnet housing 25, and a wiring plug 26, as shown in the appendix Figure 3As shown in the figure. The moving iron core 21 is a slender cylindrical structure, which consists of a connecting tongue groove 211, a fixing hole 212, a spring fixing seat 213, and an iron core body 214. The connecting tongue groove 211 is located at one end of the moving iron core 21, with an intermediate groove arranged along the diameter direction of the cylinder. Fixing holes 212 are arranged on the outer cylindrical surface. The right end face of the spring fixing seat 213 is provided with a spring positioning ring groove. The mounting seat plate 22 is a disc structure, provided with four mounting holes 221, a housing fixing hole 222, and a coil bobbin fixing hole 223. The coil bobbin body 23 is installed on the mounting seat plate 22 by screws through the coil bobbin fixing hole 223. The coil 24 is wound around the coil bobbin body 23. The electromagnet housing 25 is installed on the mounting seat plate 22 through the housing fixing hole 222. The wiring plug 26 is located at the center of one end face of the electromagnet housing 25.

[0019] The return spring 3 is a conical spiral structure, as shown in the appendix Figure 4 As shown in the figure, it consists of an upper end face 31, a steel wire 32, and a lower end face 33. The upper end face 31 is placed on the end face of the mounting seat plate 22, and the lower end face 33 is placed in the positioning ring groove of the spring fixing seat 213.

[0020] The valve body 4 is a cuboid structure, which consists of a right oil outlet process hole 41, a right oil outlet hole 42, a sealing ring groove 43, an electric actuator installation threaded hole 44, an oil inlet hole 45, a balance valve hole 46, a left oil outlet hole 47, and a left oil outlet process hole 48, as shown in the appendix Figure 5 As shown in the figure. The right oil outlet process hole 41 is arranged on the right side of the front end face of the cuboid. The inner wall of the mouth of the right oil outlet process hole 41 is provided with a connecting thread 411. The right oil outlet hole 42 is arranged in the front part of the right side face of the cuboid, presenting a blind hole structure and communicating with the right oil outlet process hole 41. The inner wall of the mouth of the blind hole is provided with a thread 421. The oil inlet hole 45 is arranged on the rear end face of the rear part of the cuboid. The inner wall of the mouth of the oil inlet hole 45 is provided with a thread 451. The balance valve hole 46 is arranged on both side faces of the rear part of the cuboid, presenting a through hole structure and horizontally communicating with the oil inlet hole 45. The inner wall of one side mouth of the through hole is provided with a connecting thread 461. The left oil outlet hole 47 is arranged in the front part of the left side face of the cuboid, presenting a blind hole structure. The inner wall of the mouth of the blind hole is provided with a connecting thread 471. The left oil outlet process hole 48 is arranged on the left side of the front end face of the cuboid and communicates with the left oil outlet hole 47. The inner wall of the mouth of the left oil outlet process hole 48 is provided with a thread 481.

[0021] The oil inlet joint 5 is a combined structure of three sections of cylinders and a hexahedron, which consists of a right cylinder 51, a central hole 52, a fastening outer hexahedron 53, a connecting cylinder 54, and a left cylinder 55, as shown in the appendix Figure 6As shown in the figure. The right cylinder 51 is located on the right side of the oil inlet joint 5. The connecting thread 511 is located on the outer cylindrical surface of the right cylinder 51. The fastening external hexagon 53 is arranged on the left side of the right cylinder 51. The central hole 52 is located at the center of the right end face of the right cylinder 51 and penetrates to the left side face of the left cylinder 55. The connecting cylinder 54 connects the fastening external hexagon and the left cylinder 55. The left tapered inner hole 551 is provided at the center of the left end face of the left cylinder 55 and communicates with the central hole 52. The connecting thread 552 is located on the outer cylindrical surface of the left cylinder 55. The oil inlet joint 5 is screwed into the connecting thread 451 of the oil inlet hole 45.

[0022] The sealing screw seat 6 is a combined structure of a bolt and a seal, consisting of an external hexagon 61, a sealing cylindrical surface 62, a sealing groove 63, a positioning seat 64, a fastening external thread 65, a seat surface central hole 66, and an internal thread 67, as shown in the appendix Figure 7 As shown in the figure, the external hexagon 61 is arranged on the leftmost side of the sealing screw seat 6. The sealing groove 63 is arranged on the outer circumferential surface of the sealing cylinder 62. The positioning seat 64 is of a cylindrical structure. The fastening external thread 65 is arranged on the outer cylindrical surface of the positioning seat 64. The seat surface central hole 66 is arranged on one end face of the positioning seat 64. The internal thread 67 is located on the inner wall of the seat surface central hole 66.

[0023] The stroke limiter 7 is composed of a combination of two cylinders and a hexagon, and is composed of an adjusting rod 71, an adjusting thread 72, a locking nut 73, an adjusting hexagon 74, and a stroke limiting rod 75, as shown in the appendix Figure 8 As shown in the figure. The adjusting rod 71 is located on one side of the stroke limiter 7 and is of a cylindrical structure. The adjusting thread 72 is provided on the outer cylindrical surface of the adjusting rod 72 and has a length greater than the length of the internal thread 67 of the sealing screw seat 6. The locking nut 73 is screwed into the adjusting thread 72. The adjusting hexagon 74 is located in the middle of the stroke limiter 7. The stroke limiting rod 75 is located on the other side of the stroke limiter 7 and is of a cylindrical structure with a length adapted to the balance valve core 1.

[0024] The left oil outlet joint 8 has the same structure as the oil inlet joint 5. The left oil outlet joint 8 is screwed into the connecting thread 471 of the left oil outlet hole 47.

[0025] The right oil outlet joint 11 has the same structure as the left oil outlet joint 8. The right oil outlet joint 11 is screwed into the connecting thread 421 of the right oil outlet hole 42.

[0026] When the dual common-rail high-pressure fuel injection system is operating, if the pressures in the two common-rail pipes do not reach the set target pressures simultaneously, the electric actuator 2 is controlled according to the given control pulse width signal, so that the balance spool 1 is in the middle position. The left large cylinder 12 and the right large cylinder 14 respectively open the left fuel outlet process hole 48 and the right fuel outlet process hole 41. The high-pressure fuel enters the valve body 4 from the fuel inlet joint 5, passes through the balance valve hole 46, the left fuel outlet process hole 48, and the right fuel outlet process hole 41, and flows into the left fuel outlet hole 47 and the right fuel outlet hole 42, and then enters the dual common-rail pipes from the left fuel outlet joint 8 and the right fuel outlet joint 11 respectively, so that the pressures in the dual common-rail pipes approach the target values simultaneously; after the fuel injector injects fuel according to the firing order of each cylinder, if it is detected that there is a difference between the pressure in the left common-rail pipe and the target pressure value, starting from the given control pulse width signal, the control pulse width signal of the electric actuator 2 is gradually reduced. The balance spool 1 moves leftward from the middle position, the flow-through clearance between the left large cylinder 12 and the left fuel outlet process hole 48 increases, and the flow-through clearance between the right large cylinder 14 and the right fuel outlet process hole 41 decreases. The high-pressure fuel entering the balance valve hole 46 from the fuel inlet joint 5 flows through the left fuel outlet process hole 48 into the left fuel outlet hole 47, and then enters the left common-rail pipe from the left fuel outlet joint 8. The control signal of the electric actuator 2 is continuously adjusted to increase or decrease the displacement of the balance spool 1 until it is detected that the pressure in the left common-rail pipe approaches the target pressure value; if it is detected that there is a difference between the pressure in the right common-rail pipe and the target pressure value, starting from the given control pulse width signal, the control pulse width signal of the electric actuator 2 is gradually increased. The balance spool 1 moves rightward from the middle position, the flow-through clearance between the right large cylinder 14 and the right fuel outlet process hole 41 increases, and the flow-through clearance between the left large cylinder 12 and the left fuel outlet process hole 48 decreases. The high-pressure fuel entering the balance valve hole 46 from the fuel inlet joint 5 flows through the right fuel outlet process hole 41 into the right fuel outlet hole 42, and then enters the right common-rail pipe from the right fuel outlet joint 11. The control signal of the electric actuator 2 is continuously adjusted to increase or decrease the displacement of the balance spool 1 until it is detected that the pressure in the right common-rail pipe approaches the target pressure value.

Claims

1. A dual common rail pressure balance regulating valve, characterized in that The invention comprises a balancing valve core (1), an electric actuator (2), a reset spring (3), a valve body (4), an oil inlet joint (5), a sealing screw seat (6), a stroke limiter (7), a left oil outlet joint (8), a left sealing bolt (9), a right sealing bolt (10), and a right oil outlet joint (11). The balancing valve core (1) is installed in a balancing valve hole of the valve body (4). The electric actuator (2) is connected to one end of the balancing valve core (1) to drive the balancing valve core (1) to move. The reset spring (3) realizes the reset of the balancing valve core (1) after the movement. The stroke limiter (7) limits the movement displacement of the balancing valve core (1). The sealing screw seat (6) realizes the sealing of the balancing valve cavity and the fixing of the stroke limiter (7). The oil inlet joint (5) completes the entry of high-pressure fuel into the valve body. The left oil outlet joint (8) and the right oil outlet joint (11) respectively realize the branch output of high-pressure fuel.

2. A dual common rail pressure balance regulating valve as claimed in claim 1, characterized in that The balancing valve core (1) is a multi-cylindrical structure, which is composed of a positioning boss, a left large cylinder (12), a middle thin cylinder (13), a right large cylinder (14), a connecting rod seat (15), and a connecting rod (16). The positioning boss is a cylindrical structure, which is located at the center of the left end face of the left large cylinder (12). The middle thin cylinder (13) connects the left large cylinder (12) and the right large cylinder (14). The length of the middle thin cylinder (13) is equal to the center of the left and right oil inlet passages of the valve body (4). The connecting rod seat (15) is located on the right side of the right large cylinder (14), and the connecting rod (16) is located at the center of the connecting rod seat (15). The connecting rod (16) is composed of a connecting rod body (161), a fixing pin hole (162), and a connecting tongue (163). The connecting rod body (161) is a slender cylindrical structure, and the connecting tongue (163) is a rectangular parallelepiped structure arranged along the diameter direction of the outer end surface of the connecting rod body (161). The fixing pin hole (162) is provided on the connecting tongue (163).

3. A dual common rail pressure balance regulating valve as claimed in claim 1, characterized in that When the pressures in the dual common rail pipes do not reach the set target pressures at the same time, the electric actuator (2) is controlled according to the given control pulse width signal to make the balance valve core (1) in the middle position, and the left large cylinder (12) and the right large cylinder (14) open the left oil outlet process hole (48) and the right oil outlet process hole (41) respectively, and the high-pressure fuel enters the valve body (4) from the oil inlet connector (5), passes through the balance valve hole (46), the left oil outlet process hole (48), and the right oil outlet process hole (41), and flows into the left oil outlet hole (47) and the right oil outlet hole (42). Then, the oil enters the dual common rail pipe from the left oil outlet joint (8) and the right oil outlet joint (11) respectively, so that the pressure of the dual common rail pipe approaches the target value at the same time; after the injector sprays oil, if it is detected that the pressure of the left common rail pipe is different from the target pressure value, the control pulse width signal of the electric actuator (2) is gradually reduced starting from the given control pulse width signal, and the balance valve core (1) moves from the middle position to the left, the flow gap between the left large cylinder (12) and the left oil outlet process hole (48) is increased, and the flow gap between the right large cylinder (14) and the right oil outlet process hole (41) is increased. The clearance is reduced, and the high-pressure fuel in the balancing valve hole (46) flows from the left oil outlet process hole (48) into the left oil outlet hole (47), and then enters the left common rail pipe from the left oil outlet joint (8). The control signal of the electric actuator (2) is continuously adjusted to increase or decrease the displacement of the balancing valve core (1) until the pressure of the left common rail pipe is detected to be close to the target pressure value. If the pressure of the right common rail pipe is detected to be different from the target pressure value, the control pulse width signal of the electric actuator (2) is gradually increased starting from the given control pulse width signal, and the balancing valve core (1) is moved to the left common rail pipe. ) moves from the middle position to the right, the flow clearance between the right large cylinder (14) and the right oil outlet process hole (41) increases, and the flow clearance between the left large cylinder (12) and the left oil outlet process hole (48) decreases. The high-pressure fuel in the balance valve hole (46) flows from the right oil outlet process hole (41) into the right oil outlet hole (42), and then enters the right common rail pipe from the right oil outlet joint (11). The control signal size of the electric actuator (2) is continuously adjusted to increase or decrease the displacement of the balance valve core (1) until it is detected that the pressure of the right common rail pipe is close to the target pressure value.

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