Variable boost ratio turbocharger and control method

Abstract

A variable booster and its control method include a stator unit, a rotor unit, a distribution shaft unit, and a hydraulic control unit. The stator unit has a curved inner wall. The rotor unit has a cylindrical body with an inner cavity, on which multiple radial plunger holes are equally spaced along its circumference, penetrating the inner cavity of the cylindrical body and the inner wall of the stator unit. A plunger is installed in each plunger hole, and a roller is installed at the end of the plunger near the stator unit, rolling on the curved surface of the stator unit. The distribution shaft unit has a primary pressure inlet hole along its axial direction in the middle, and multiple radial oil holes along its radial direction. One end of each radial oil hole communicates with the primary pressure inlet hole, and the other end communicates with each plunger hole of the rotor unit when the rotor unit rotates. Distribution holes are provided between adjacent radial oil holes, communicating with each plunger hole of the rotor unit when the rotor rotates. The hydraulic control unit includes multiple solenoid valves mounted on the distribution shaft unit. This invention changes the booster ratio of the booster by changing the number of solenoid valves energized.

Description

Technical Field

[0001] This invention relates to a booster with a variable boost ratio and a control method thereof, belonging to the field of hydraulic transmission and control technology. Background Technology

[0002] The main component used in a hydraulic system booster circuit is the booster cylinder. Its function is to increase the pressure of the low-pressure oil input to the hydraulic system to meet the system's pressure requirements. Hydraulic system booster circuits are mainly used in hydraulic circuits where the system's supply oil pressure is relatively low, but a branch requires higher pressure but a smaller flow rate; or in energy recovery systems where the hydraulic system recovers low-pressure hydraulic oil that cannot be directly used to drive the actuators in the hydraulic system. A booster circuit must be used to increase the pressure to the required level before it can be used. The working principle of the booster cylinder is as follows: when the supplied primary pressure oil (low-pressure oil) enters the large piston chamber of the booster cylinder, the pressure oil generates a thrust on the large piston. The magnitude of this thrust is equal to the product of the input oil pressure and the effective area of ​​the large piston. This thrust pushes the small piston through the connecting rod, which in turn pushes the oil in the small piston chamber to output secondary pressure oil (high-pressure oil). The oil in this chamber also generates a reaction thrust on the small piston. Neglecting friction, the oil thrust on the large and small pistons is equal in magnitude; that is, the product of the oil pressure in the large piston chamber and its area of ​​action is equal to the product of the oil pressure in the small piston chamber and its area of ​​action. Therefore, the ratio of the pressures in the large and small piston chambers, i.e., the ratio of the primary pressure to the secondary pressure, is inversely proportional to the areas of the large and small pistons. The larger the area ratio of the large and small pistons, the larger the ratio of the secondary pressure to the primary pressure.

[0003] Currently, based on the different structures of the booster cylinders used in booster circuits, they are divided into single-acting booster circuits and double-acting booster circuits. A single-acting booster circuit outputs high-pressure oil when the piston moves to one side, but not when it returns. A double-acting booster circuit, on the other hand, outputs high-pressure oil alternately at both ends during the piston's reciprocating motion, achieving continuous boosting. However, the boosting ratio of both types of booster circuits is fixed, thus limiting their applications.

[0004] In the booster circuit of the booster cylinder mentioned above, if the primary pressure increases, the secondary pressure after boosting will also increase proportionally. However, if the secondary pressure required by the system is relatively low compared to the boosted secondary pressure, it is necessary to throttle or reduce the pressure before use. This will cause energy loss, heat up the system, and reduce efficiency. Alternatively, if the required secondary pressure increases but the primary pressure remains unchanged, the boosted secondary pressure oil will not be able to meet the system's pressure requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a turbocharger with a variable boost ratio and a control method thereon, which can achieve a variable boost ratio and expand the applicability of the turbocharger.

[0006] To achieve the above objectives, the present invention provides a booster with a variable boost ratio, comprising a stator unit, a rotor unit, an oil distribution shaft unit, and a hydraulic control unit. The stator unit comprises a cylindrical housing, the inner wall of which has multiple continuously distributed inner curved surfaces along its circumferential direction. Each inner curved surface includes a smooth upward curved section and a downward curved section.

[0007] The rotor unit includes a cylindrical body with an inner cavity. Multiple radial plunger holes are equally spaced along the circumference of the cylinder. One end of each plunger hole is connected to the inner cavity of the cylindrical body, and the other end passes through the outer wall of the cylindrical body of the rotor unit. A plunger is slidably installed in each plunger hole. A roller is installed at the end of each plunger near the inner wall of the stator unit housing. The plunger in each plunger hole contacts the roller, and the roller rolls in cooperation on the curved surface inside the stator unit housing.

[0008] The oil distribution shaft unit includes a cylindrical body. A primary pressure oil inlet is formed along the axial direction of the central part of the cylindrical body, and multiple radial oil holes are formed at equal intervals along its radial direction. One end of each radial oil hole is connected to one end of the primary pressure oil inlet, and the other end is connected to each plunger hole of the rotor unit when the rotor rotates. An oil distribution hole is also provided between each adjacent radial oil hole. Each oil distribution hole includes a radial hole and an axial hole formed along the axial direction of the cylindrical body of the oil distribution shaft unit, which communicates with the distribution hole. The oil distribution hole is connected to each plunger hole of the rotor unit when the rotor unit rotates. The other end of the primary pressure oil inlet is connected to a primary pressure inlet, which is located on the oil distribution shaft unit.

[0009] The hydraulic control unit includes multiple solenoid valves mounted on the distribution shaft unit. The P port of each solenoid valve is connected to the axial hole of the distribution port at its location, the A port is connected to the secondary pressure outlet, and the T port is connected to the oil tank through a pipeline. The secondary pressure outlet is located on the distribution shaft unit.

[0010] Furthermore, the stator unit remains stationary during operation, while the rotor unit is installed inside the stator unit. Each plunger hole in the rotor unit contains a plunger and a roller. The plunger and plunger hole maintain a seal and can move radially within the plunger hole. The oil distribution shaft unit is installed in the central hole of the rotor unit and remains stationary, just like the stator unit. The stator unit, rotor unit, and oil distribution shaft unit are coaxial, and the mating surfaces of the oil distribution shaft unit and rotor unit maintain a seal. Initially, the radial oil holes on the oil distribution shaft unit correspond one-to-one with the rising section of the stator unit's curved surface along the radial direction, and the oil distribution holes on the oil distribution shaft unit correspond one-to-one with the descending section of the stator unit's curved surface along the radial direction.

[0011] A control method for a turbocharger with a variable boost ratio includes the following steps:

[0012] Step 1: Low-pressure oil enters through the primary pressure inlet P1, then flows through the primary pressure inlet holes on the distribution shaft unit into the radial oil holes. When the radial plunger hole of the rotor unit communicates with the radial oil hole on the distribution shaft unit, the primary pressure oil enters the radial plunger hole and pushes the plunger towards the inner curved surface of the stator unit. The plunger pushes the roller to roll on the rising section of the inner curved surface of the stator unit. The roller transmits the hydraulic thrust on the plunger to the inner curved surface of the stator unit. The tangential component of the reaction force of the inner curved surface of the stator unit on the roller generates torque on the rotor and drives the rotor to rotate. At this time, the booster operates as a hydraulic motor, and the theoretical torque generated is:

[0013]

[0014] In the formula, V m This refers to the displacement of the turbocharger motor under operating conditions. d is the plunger diameter, e is the plunger extension / retraction amount, z is the number of plungers in the rotor unit, and n is the number of inner curved surfaces in the stator unit.

[0015] Step 2: Under the action of hydraulic thrust, the plunger of the rotor unit continuously extends. When it is fully extended, the rotor unit rotates until the radial plunger hole and the radial oil hole on the distribution shaft unit are disconnected, and low-pressure oil no longer enters. At this time, the roller is at the highest point of the curved surface rising section, i.e., the dead point position on the curved surface. The plunger continues to rotate with the rotor unit to the curved surface falling section. When the radial plunger hole of the rotor unit is connected to the oil distribution hole on the distribution shaft unit, under the action of the curved surface inside the stator unit, the roller pushes the plunger to retract towards the distribution shaft unit and discharge oil until the plunger is completely retracted into the radial plunger hole. The rotor unit rotates to the radial... When the plunger hole is disconnected from the distribution hole on the distribution shaft unit, the plunger is at the lowest point of the descending section of the curved surface, i.e., the bottom dead center of the curved surface, and the oil discharge process ends. During this process, the booster operates as a pump and outputs hydraulic oil. When the roller enters the ascending section of the next inner curved surface, another pressurized oil is injected, and so on. When the rotor unit rotates once, each roller rotates once along the inner curved surface of the stator unit, and each plunger extends and retracts multiple times in the plunger hole. The number of times the plunger extends and retracts is equal to the number of curved surfaces of the stator unit per revolution of the rotor unit. The relationship between the counter-torque generated by the hydraulic pump and the secondary oil pressure output by the hydraulic pump is as follows:

[0016]

[0017] In the formula, V b This refers to the displacement of the booster hydraulic pump under operating conditions. In the formula, d is the plunger diameter, e is the plunger extension / retraction amount, z is the number of plungers in the rotor unit, and n bThe number of stator unit surfaces involved in pump operation;

[0018] Since the torque is equal under motor operating conditions and hydraulic pump operating conditions, that is: T m =T b From the above equation, we get:

[0019]

[0020] Step 3: When all solenoid valves are de-energized, the pump operates by discharging oil from the plunger through the solenoid valves, outputting secondary pressure, i.e., n. b =n, without considering various losses, the secondary pressure outlet pressure P2 = P1;

[0021] When the first solenoid valve is energized, and the rotor unit rotates to connect the plunger hole and the first oil distribution hole, the oil discharged from the plunger hole is returned to the oil tank through the first solenoid valve and does not participate in the output of secondary pressure; when the plunger hole rotates to connect with other oil distribution holes, the plunger hole outputs secondary pressure P2 through the oil distribution holes, the P port of the solenoid valve, and the secondary pressure outlet. At this time, n b =n-1, the output secondary pressure is:

[0022]

[0023] When the first and second solenoid valves are energized, and the rotor unit rotates to connect the plunger orifice with the first and second oil distribution holes respectively, the oil discharged from the plunger orifice is returned to the oil tank through the first or second oil distribution hole, the first or second solenoid valve, and does not participate in the output of secondary pressure. When the plunger orifice rotates to connect with other oil distribution holes, the plunger orifice outputs secondary pressure P2 through the oil distribution hole, the P port of the solenoid valve, and the secondary pressure outlet. At this time, n b =n-2, the output secondary pressure increases as follows:

[0024] Similarly, the boost ratio of the booster is changed by altering the number of solenoid valves energized.

[0025] This invention comprises a stator unit, a rotor unit, and an oil distribution shaft unit, all coaxially mounted from the outside in, and also includes a hydraulic control unit. The inner wall of the cylindrical housing of the stator unit has multiple pairs of continuously distributed inner curved surfaces along its circumference, each including a smooth upward curved section and a downward curved section. The rotor unit has a cylindrical body with an inner cavity, on which multiple pairs of radial plunger holes are equally spaced along its circumference, penetrating the inner cavity of the cylindrical body and the inner wall of the stator unit housing. A plunger is slidably installed in each plunger hole, and a roller is mounted on the end of the plunger closest to the stator unit. The roller... The rotor unit rolls on its inner curved surface; the cylindrical body of the distribution shaft unit has a primary pressure inlet hole in its axial direction and multiple pairs of radial oil holes at equal intervals in its radial direction. One end of each radial oil hole is connected to the primary pressure inlet hole, and the other end is connected to each plunger hole of the rotor unit when the rotor unit rotates; distribution holes are also opened between adjacent radial oil holes. The distribution holes include axial through holes and radial through holes connected to them. The radial through holes are connected to each plunger hole of the rotor unit when the rotor unit rotates; the hydraulic control unit includes multiple solenoid valves installed on the distribution shaft unit. When the first solenoid valve is energized, and the rotor unit rotates to connect the plunger hole and the first distribution hole, the oil discharged from the plunger hole is returned to the oil tank through the first solenoid valve and does not participate in the output of secondary pressure. When the plunger hole is connected to other distribution holes, the oil discharged from the plunger hole is connected to the distribution hole, the P port of the solenoid valve, and the secondary pressure outlet. When the first and second solenoid valves are energized, and the rotor unit rotates to connect the plunger hole to the first and second distribution holes respectively, the oil discharged from the plunger hole is returned to the oil tank through the first or second distribution hole, the first or second solenoid valve, and does not participate in the output of secondary pressure. When the plunger hole is connected to other distribution holes, the oil discharged from the plunger hole is connected to the distribution hole, the P port of the solenoid valve, and the secondary pressure outlet. The secondary pressure value at this time is greater than the secondary pressure value when the number of solenoid valves energized is one. This process is repeated to achieve the change of the boost ratio of the turbocharger by changing the number of solenoid valves energized, thus expanding the applicable range of the turbocharger. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the stator unit structure in this invention;

[0028] Figure 3 This is a schematic diagram of the oil distribution shaft unit structure in this invention.

[0029] Figure 4 This is a schematic diagram of the hydraulic control unit in this invention.

[0030] In the diagram: 1. Stator unit, 1-A1. First surface rising segment, 1-B1. First surface falling segment, 1-A2. Second surface rising segment, 1-B2. Second surface falling segment, 1-A3. Third surface rising segment, 1-B3. Third surface falling segment, 1-A4. Fourth surface rising segment, 1-B4. Fourth surface falling segment, 1-A5. Fifth surface rising segment, 1-B5. Fifth surface falling segment, 1-A6. Sixth surface rising segment, 1-B6. Sixth surface falling segment, 1-A7. Seventh surface rising segment, 1-B7. Seventh surface falling segment, 1-A8. Eighth surface rising segment, 1-B8. Eighth surface falling segment;

[0031] 2. Rotor unit; 3. Roller; 4. Plunger;

[0032] 5. Oil distribution shaft unit, 5-A, primary pressure oil inlet, 5-A1, first radial oil hole, 5-A2, second radial oil hole, 5-A3, third radial oil hole, 5-A4, fourth radial oil hole, 5-A5, fifth radial oil hole, 5-A6, sixth radial oil hole, 5-A7, seventh radial oil hole, 5-A8, eighth radial oil hole, 5-B1, first oil distribution hole, 5-B2, second oil distribution hole, 5-B3, third oil distribution hole, 5-B4, fourth oil distribution hole, 5-B5, fifth oil distribution hole, 5-B6, sixth oil distribution hole, 5-B7, seventh oil distribution hole, 5-B8, eighth oil distribution hole;

[0033] 6. First solenoid valve, 7. Second solenoid valve, 8. Third solenoid valve, 9. Fourth solenoid valve, 10. Fifth solenoid valve, 11. Sixth solenoid valve, 12. Seventh solenoid valve, 13. Eighth solenoid valve. Detailed Implementation

[0034] The invention will now be further described with reference to the accompanying drawings.

[0035] like Figure 1 and Figure 2As shown, the turbocharger of the present invention includes a stator unit 1, a rotor unit 2, a roller 3, a plunger 4, an oil distribution shaft unit 5, and a hydraulic control unit; the inner wall of the stator unit 1 housing is provided with eight continuously and evenly distributed inner curved surfaces along its circumference, the first inner curved surface includes a first curved surface rising section 1-A1 and a first curved surface falling section 1-B1, the second inner curved surface includes a second curved surface rising section 1-A2 and a second curved surface falling section 1-B2, and the third inner curved surface includes a third curved surface rising section 1-A3 and a third curved surface... The fourth inner surface includes the rising segment 1-A4 and the falling segment 1-B4 of the fourth surface; the fifth inner surface includes the rising segment 1-A5 and the falling segment 1-B5 of the fifth surface; the sixth inner surface includes the rising segment 1-A6 and the falling segment 1-B6 of the sixth surface; the seventh inner surface includes the rising segment 1-A7 and the falling segment 1-B7 of the seventh surface; and the eighth inner surface includes the rising segment 1-A8 and the falling segment 1-B8 of the eighth surface.

[0036] The rotor unit 2 includes a cylindrical body with an inner cavity. Ten radial plunger holes are equally spaced along the circumference of the cylinder. One end of each plunger hole is connected to the inner cavity of the cylindrical body, and the other end passes through the outer wall of the cylindrical body of the rotor unit. A plunger 4 is slidably installed in each plunger hole. A roller 3 is installed at the end of each plunger near the inner wall of the stator unit housing. Each roller 3 rolls on the curved surface inside the stator unit housing.

[0037] like Figure 3 As shown, the oil distribution shaft unit 5 includes a cylindrical body. A primary pressure oil inlet 5-A is formed along the axial direction of the middle of the cylindrical body, and eight radial oil holes are formed at equal intervals along its radial direction: the first radial oil hole 5-A1, the second radial oil hole 5-A2, the third radial oil hole 5-A3, the fourth radial oil hole 5-A4, the fifth radial oil hole 5-A5, the sixth radial oil hole 5-A6, the seventh radial oil hole 5-A7, and the eighth radial oil hole 5-A8. One end of each radial oil hole is connected to the primary pressure oil inlet 5-A, and the other end is connected when the rotor unit 2 rotates. It communicates with each plunger hole of rotor unit 2; between each adjacent radial oil hole, there are also oil distribution holes, namely the first oil distribution hole 5-B1, the second oil distribution hole 5-B2, the third oil distribution hole 5-B3, the fourth oil distribution hole 5-B4, the fifth oil distribution hole 5-B5, the sixth oil distribution hole 5-B6, the seventh oil distribution hole 5-B7, and the eighth oil distribution hole 5-B8; each oil distribution hole includes a radial hole and an axial hole that communicates with it along the axial direction of the cylindrical body of the oil distribution shaft unit 5. The radial oil holes and the oil distribution holes communicate with each plunger hole of rotor unit 2 when rotor unit 2 rotates;

[0038] like Figure 4As shown, the hydraulic control unit includes a first solenoid valve 6, a second solenoid valve 7, a third solenoid valve 8, a fourth solenoid valve 9, a fifth solenoid valve 10, a sixth solenoid valve 11, a seventh solenoid valve 12, and an eighth solenoid valve 13. The P port of the first solenoid valve 6 is connected to the first distribution port 5-B1 on the distribution shaft; the P port of the second solenoid valve 7 is connected to the second distribution port 5-B2 on the distribution shaft; the P port of the third solenoid valve 8 is connected to the third distribution port 5-B3 on the distribution shaft; the P port of the fourth solenoid valve 9 is connected to the fourth distribution port 5-B4 on the distribution shaft; and the fifth solenoid valve 10... The P port of the first solenoid valve 6 is connected to the fifth oil distribution hole 5-B5 on the oil distribution shaft; the P port of the sixth solenoid valve 11 is connected to the sixth oil distribution hole 5-B6 on the oil distribution shaft; the P port of the seventh solenoid valve 12 is connected to the seventh oil distribution hole 5-B7 on the oil distribution shaft; and the P port of the eighth solenoid valve 13 is connected to the eighth oil distribution hole 5-B8 on the oil distribution shaft. The A ports of the first solenoid valve 6 to the eighth solenoid valve 13 are respectively connected to the secondary pressure outlet; and the T ports of the first solenoid valve 6 to the eighth solenoid valve 13 are connected to the oil tank through pipelines. The primary pressure inlet hole 5-A on the oil distribution shaft unit is connected to the primary pressure inlet.

[0039] The stator unit 1 is fixed during operation. The rotor unit 2 is installed inside the stator 1. Each plunger hole of the rotor unit 2 is equipped with a plunger 4 and a roller 3. The plunger 4 is sealed to the plunger hole and can move radially within the plunger hole. The oil distribution shaft unit 5 is installed in the center hole of the rotor unit 2 and is fixed like the stator unit 1. The stator unit 1, rotor unit 2 and oil distribution shaft unit 5 are concentric, and the mating surfaces of the oil distribution shaft unit 5 and rotor unit 2 are sealed. The first radial oil hole 5-A1 to the eighth radial oil hole 5-A8 on the oil distribution shaft unit 5 correspond one-to-one with the first curved surface rising segment 1-A1 to the eighth curved surface rising segment 1-A8 on the stator unit 1 along the radial direction. That is, the first radial oil hole 5-A1 corresponds to the first curved surface rising segment 1-A1, the second radial oil hole 5-A2 corresponds to the second curved surface rising segment 1-A2, and so on. The first oil distribution hole 5-B1 to the eighth oil distribution hole 5-B8 on the oil distribution shaft unit 5 correspond one-to-one with the first curved surface falling segment 1-B1 to the eighth curved surface falling segment 1-B8 on the stator unit 1 along the radial direction. That is, the first oil distribution hole 5-B1 corresponds to the first curved surface falling segment 1-B1, the second oil distribution hole 5-B2 corresponds to the second curved surface falling segment 1-B2, and so on.

[0040] During operation, low-pressure oil enters through the primary pressure inlet P1 and then flows into the radial oil holes via the primary pressure inlet holes on the distribution shaft unit. When the radial plunger hole of the rotor unit is connected to the radial oil hole on the distribution shaft unit, the primary pressure oil enters the radial plunger hole and pushes the plunger towards the inner curved surface of the stator unit. The plunger pushes the roller 3 to roll on the curved rising section of the stator unit 1. The roller 3 transmits the hydraulic thrust of the plunger to the inner curved surface of the stator unit 1. The tangential component of the reaction force of the inner curved surface of the stator unit 1 on the roller 3 generates torque on the rotor and drives the rotor unit 2 to rotate. At this time, the intensifier operates as a hydraulic motor, and the theoretical torque generated is:

[0041]

[0042] In the formula, V m This refers to the displacement of the turbocharger motor under operating conditions. d is the plunger diameter, e is the plunger extension / retraction amount, z is the number of plungers in the rotor unit, and n is the number of inner curved surfaces on the inner wall of the stator unit.

[0043] Under the action of hydraulic thrust, the plunger 4 of rotor unit 2 extends continuously. When it is fully extended, rotor unit 2 rotates until the radial plunger hole and the radial oil hole on the distribution shaft unit 5 are disconnected, and low-pressure oil no longer enters. At this time, the plunger is at the highest point of the curved surface rising section, that is, the dead point position on the curved surface. As the plunger continues to rotate with rotor unit 2 to the curved surface falling section, when the radial plunger hole of rotor unit 2 is connected to the oil distribution hole on the distribution shaft unit 5, under the action of the curved surface inside the stator unit, the roller 3 pushes the plunger to retract towards the distribution shaft unit 5 and discharge oil until the plunger 4 is fully retracted to the radial surface. Inside the plunger bore, rotor unit 2 rotates until the radial plunger bore disconnects from the distribution hole on the distribution shaft unit. At this point, plunger 4 is at the lowest point of the downward section of the curved surface, i.e., the bottom dead center of the curved surface, and the oil discharge process ends. During this process, the booster operates as a pump and outputs hydraulic oil. When the roller enters the upward section of the next curved surface, another pressurized oil is injected, and so on. Rotor unit 2 rotates once, and each roller 3 rotates once along the inner curved surface of stator unit 1. Each plunger extends and retracts multiple times in the plunger bore. The relationship between the counter-torque generated by the hydraulic pump and the secondary oil pressure output by the hydraulic pump is as follows:

[0044]

[0045] In the formula, V b This refers to the displacement of the booster hydraulic pump under operating conditions. In the formula, d is the plunger diameter, e is the plunger extension / retraction amount, z is the number of plungers in the rotor unit, and n b The number of surfaces in stator unit 1 that participates in pump operation;

[0046] Since the torque is equal under motor operating conditions and hydraulic pump operating conditions, that is: Tm =T b From the above equation, we get:

[0047]

[0048] When all solenoid valves are de-energized, the pump operates by discharging oil from the plunger through the solenoid valves, outputting secondary pressure, i.e., n. b =n, without considering various losses, the secondary pressure outlet pressure P2 = P1;

[0049] When the first solenoid valve 6 is energized, and the rotor unit 2 rotates to connect the plunger hole and the first oil distribution hole 5-B1, the oil discharged from the plunger hole is returned to the oil tank through the first solenoid valve 6 and does not participate in the output of secondary pressure; when the plunger hole rotates to connect with other oil distribution holes, the plunger hole outputs secondary pressure P2 through the oil distribution holes, the solenoid valve P port, and the secondary pressure outlet. At this time, n b =n-1, the output secondary pressure is: In this embodiment, when the number of inner wall curved surfaces of stator unit 1 is 8, then

[0050] When the first solenoid valve 6 and the second solenoid valve 7 are energized, and the rotor unit 2 rotates to connect the plunger orifice with the first oil distribution port 5-B1 and the second oil distribution port 5-B2 respectively, the oil discharged from the plunger orifice returns to the oil tank through the first oil distribution port 5-B1 or the second oil distribution port 5-B2, the first solenoid valve 6 or the second solenoid valve 7, and does not participate in the output of secondary pressure; when the plunger orifice rotates to connect with other oil distribution ports, the plunger orifice outputs secondary pressure P2 through the oil distribution port, the solenoid valve P port and the secondary pressure outlet, at this time n b =n-2, the output secondary pressure increases as follows: In this embodiment, when the number of inner curved surfaces of stator unit 1 is 8, then Similarly, the relationship between the energization frequency of the solenoid valve and the secondary pressure is shown in Table 1:

[0051] Table 1 Relationship between secondary pressure and solenoid valve energization.

[0052]

[0053] Generally, boosting the low-pressure oil by about 2 times can meet the actual pressure requirements. As can be seen from Table 1, keeping 4 to 5 solenoid valves energized during operation can achieve a 2-fold increase ratio. The boost ratio of the booster can be changed by controlling the number of solenoid valves energized.

Claims

1. A control method for a booster with variable boost ratio, wherein the booster includes a stator unit (1), a rotor unit (2), an oil distribution shaft unit (5), and a hydraulic control unit, wherein the stator unit (1) includes a cylindrical housing, and the inner wall of the housing has multiple continuously distributed inner curved surfaces along its circumferential direction, each inner curved surface including a smooth curved surface rising section and a curved surface falling section; The rotor unit (2) includes a cylindrical body with an inner cavity. Multiple radial plunger holes are equally spaced along the circumference of the cylinder. One end of each plunger hole is connected to the inner cavity of the cylindrical body, and the other end passes through the outer wall of the cylindrical body of the rotor unit (2). A plunger (4) is slidably installed in each plunger hole. A roller (3) is installed at the end of each plunger (4) near the inner wall of the stator unit (1) housing. Each roller (3) rolls on the curved surface inside the stator unit (1) housing. The oil distribution shaft unit (5) includes a cylindrical body. A primary pressure oil inlet hole (5-A) is opened in the middle of the cylindrical body along its axial direction. Multiple radial oil holes are opened at equal intervals along its radial direction. One end of each radial oil hole is connected to one end of the primary pressure oil inlet hole (5-A), and the other end is connected to each plunger hole of the rotor unit (2) when the rotor unit (2) rotates. An oil distribution hole is also provided between each adjacent radial oil hole. Each oil distribution hole includes a radial hole and an axial hole opened along the axial direction of the cylindrical body of the oil distribution shaft unit (5) and connected to it. The oil distribution hole is connected to each plunger hole of the rotor unit (2) when the rotor unit (2) rotates. The other end of the primary pressure oil inlet hole (5-A) is connected to the primary pressure inlet, which is opened on the oil distribution shaft unit (5). The hydraulic control unit includes multiple solenoid valves installed on the distribution shaft unit (5). The P port of each solenoid valve is connected to the axial hole of the distribution hole at its location, the A port is connected to the secondary pressure outlet, and the T port is connected to the oil tank through a pipeline. The secondary pressure outlet is located on the distribution shaft unit (5). Its features are, Includes the following steps: Step 1: Low-pressure oil enters through the primary pressure inlet P1 and enters the radial oil holes through the primary pressure inlet hole (5-A) on the distribution shaft unit (5). When the radial plunger hole of the rotor unit (2) is connected to the radial oil hole on the distribution shaft unit (5), the primary pressure oil enters the radial plunger hole and pushes the plunger (4) towards the inner curved surface of the stator unit (1). The plunger pushes the roller (3) to roll on the rising section of the inner curved surface of the stator unit (1). The roller (3) transmits the hydraulic thrust of the plunger (4) to the inner curved surface of the stator unit (1). The tangential component of the reaction force of the inner curved surface of the stator unit (1) on the roller (3) generates torque on the rotor and drives the rotor to rotate. At this time, the booster works in the condition of a hydraulic motor, and the theoretical torque generated is: ； In the formula, V m This refers to the displacement of the turbocharger motor under operating conditions. d is the diameter of the plunger (4), e is the extension and retraction of the plunger (4), z is the number of plungers (4) in the rotor unit (2), and n is the number of inner curved surfaces in the stator unit (1). Step 2: Under the action of hydraulic thrust, the plunger (4) of the rotor unit (2) extends continuously. When it is fully extended, the rotor unit (2) rotates until the radial plunger hole and the radial oil hole on the distribution shaft unit (5) are disconnected, and low-pressure oil no longer enters. At this time, the plunger (4) is at the highest point of the curved surface rising section, that is, the dead point position on the curved surface. The plunger (4) continues to rotate with the rotor unit (2) to the curved surface falling section. When the radial plunger hole of the rotor unit (2) is connected to the oil distribution hole on the distribution shaft unit (5), under the action of the inner curved surface of the stator unit (1), the roller (3) pushes the plunger (4) to retract towards the distribution shaft unit (5) and discharge oil until the plunger (4) is fully retracted to the radial surface. As the rotor unit (2) rotates into the plunger hole, it disconnects from the oil distribution hole on the distribution shaft unit (5). At this time, the plunger (4) is at the lowest point of the downward section of the curved surface, i.e., the bottom dead center of the curved surface. The oil discharge process ends. During this process, the booster outputs hydraulic oil in pump mode. When the roller (3) enters the upward section of the next curved surface, it injects pressure oil again. This process continues. As the rotor unit (2) rotates once, each roller (3) rotates once along the inner curved surface of the stator unit (1). The number of times each plunger (4) extends and retracts in the plunger hole is equal to the number of curved surfaces of the stator unit (1). The relationship between the counter-torque generated by the hydraulic pump and the secondary oil pressure output by the hydraulic pump is as follows: ； In the formula, V b This refers to the displacement of the booster hydraulic pump under operating conditions. In the formula, d is the diameter of the plunger (4), e is the extension / retraction of the plunger (4), z is the number of plungers (4) in the rotor unit (2), and n b The number of surfaces in the stator unit (1) participating in the pump operation; Since the torque is equal under motor operating conditions and hydraulic pump operating conditions, that is: From the above equation, we get: ; Step 3: When all solenoid valves are de-energized, the pump operating condition plunger (4) discharges oil through the solenoid valves, outputting secondary pressure, i.e., n b =n, without considering various losses, the secondary pressure outlet pressure P2=P1; When the first solenoid valve (6) is energized, and the rotor unit (2) rotates to connect the plunger hole and the first oil distribution hole (5-B1), the oil discharged from the plunger hole is discharged back to the oil tank through the first solenoid valve (6) and does not participate in the output of secondary pressure; when the plunger hole rotates to connect with other oil distribution holes, the plunger hole outputs secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet. At this time, n b =n-1, the output secondary pressure is: ; When the first solenoid valve (6) and the second solenoid valve (7) are energized, and the rotor unit (2) rotates to connect the plunger hole with the first oil distribution hole (5-B1) and the second oil distribution hole (5-B2) respectively, the oil discharged from the plunger hole is discharged back to the oil tank through the first oil distribution hole (5-B1) or the second oil distribution hole (5-B2), the first solenoid valve (6) or the second solenoid valve (7), and does not participate in the output of secondary pressure; when the plunger hole rotates to connect with other oil distribution holes, the plunger hole outputs secondary pressure P2 through the oil distribution hole, the solenoid valve P port and the secondary pressure outlet, at this time n b =n-2, the output secondary pressure increases as follows: ; Similarly, the boost ratio of the booster is changed by altering the number of solenoid valves energized.

2. The control method for a turbocharger with a variable boost ratio according to claim 1, characterized in that, The stator unit (1) is fixed, and the rotor unit (2) is installed inside the stator unit (1); the oil distribution shaft unit (5) is fixedly installed in the center hole of the inner cavity of the rotor unit (2); the stator unit (1), the rotor unit (2) and the oil distribution shaft unit (5) are kept coaxial, and the mating surfaces of the oil distribution shaft unit (5) and the rotor unit (2) are kept sealed; during initial installation, the radial oil holes on the oil distribution shaft unit (5) correspond one-to-one with the rising section of the curved surface of the stator unit (1) along the radial direction, and the oil distribution holes on the oil distribution shaft unit (5) correspond one-to-one with the descending section of the curved surface of the stator unit (1) along the radial direction.

Images