TWI488760B - Electric vehicle, compound hydraulic power steering system and its driving method - Google Patents

Description

Electric vehicle, composite hydraulic power steering system and driving method thereof

The invention relates to a hydraulic power steering system for an electric vehicle and a driving method thereof, in particular to a hydraulic pump having an oil and electric hybrid driving interface and a driving method thereof.

The traditional internal combustion engine mainly drives the power steering hydraulic pump by the engine power to generate a hydraulic pressure acting on the piston in the power cylinder to assist in pulling the steering link to achieve the steering purpose.

When the above-described conventional steering system is applied to the electric vehicle field, since the power steering hydraulic pump cannot be operated by the engine, it is necessary to electrically drive the aforementioned steering system. However, the electric power of a general electric vehicle is mainly provided by a power battery. However, in addition to supplying power to the steering system, the power battery must also provide a power motor for driving the electric vehicle to travel, so the endurance of the electric vehicle during operation will be used by the accessory system. The amount of continuation of the mileage is limited.

In addition, as shown in Fig. 1, when the engine drives the vehicle to travel and the engine-driven hydraulic power steering system is driven at a high speed, the pump speed is increased, and the hydraulic oil discharge amount is also increased, but flows into the power cylinder. The flow rate is reduced, so the engine-driven hydraulic pump combines the flow control valve to detect the engine speed to adjust the appropriate hydraulic pressure, but in the case of the extended-range electric vehicle engine operation, most engines operate at the highest efficiency. Under the operation, the engine speed has been decoupled from the vehicle speed, so the engine speed and torque output will be limited, and the traditional flow control valve is no longer sufficient.

The object of the present invention is to provide a hybrid power driven hydraulic power steering system and a driving method thereof. The hydraulic power steering system can be converted into a mechanical hydraulic pump driven by an engine in addition to the power of the hybrid hydraulic pumping operation. To achieve the effect of assisted steering.

Another object of the present invention is to provide a hydraulic control system by which a hydraulic control system can provide different hydraulic flow rate control strategies for a hybrid hydraulic pump in different energizing power modes, and provide various speeds required. Steering assist force.

The composite hydraulic power steering system of the present invention comprises: a chamber capable of filling a liquid. A pair of liquid passages including a first passage and a second passage are respectively in communication with the chamber. A DC motor having a freely rotatable or electrically driven rotating shaft, the rotating shaft having a first end and a second end, the first end being located in the chamber and being provided with a liquid pressurizing device. a one-way bearing is sleeved on the outer diameter of the second end of the rotating shaft. A pulley is disposed on the outer ring of the one-way bearing, and the wheel surface of the pulley is provided with at least one guiding groove. A hydraulic adjustment system connects the pair of liquid passages to regulate the flow of the pair of liquid passages.

The hydraulic pressure regulating system has a DC motor having a rotating shaft having a hydraulic adjusting hole, the rotating shaft passing through the first passage, and the hydraulic adjusting hole being located in the first passage.

The driving method of the hybrid hydraulic power steering system of the present invention comprises: providing the aforementioned hydraulic power steering system, the internal combustion engine is connected to the pulley by a belt, and the vehicle accessory battery is electrically connected to the composite Hydraulically pumping the DC motor, the chamber is filled with liquid; when a mode of mechanical energy is supplied to the hybrid hydraulic pump power, the internal combustion engine drives the belt to rotate the shaft to pressurize the liquid Pushing the hydraulic circuit and switching the DC motor power supply circuit to open; and when starting a mode of supplying power to the hybrid hydraulic pump power, switching the DC motor power supply circuit to a path to electrically drive the rotating shaft, and adding the liquid Press to push the hydraulic circuit.

The invention is characterized in that the patent proposes a matching design and strategy of a composite hydraulic power steering system, and the composite hydraulic power steering system can be converted into a mechanical hydraulic pump in addition to the operation of the composite hydraulic pump by electric power. Driven by the engine of the internal combustion engine to achieve the effect of assisted steering. In addition, the present invention can be combined with technical means such as brake recharging and the like, and does not exclude other energy-saving technologies for battery power. The compound hydraulic pump can provide the required steering assist force when the vehicle is turning through the interaction control of the vehicle controller (VCU). Once the internal combustion engine is activated, the DC motor in the hybrid hydraulic power steering system will be converted into a generator. Providing a source of power, in addition to reducing system energy consumption, the hybrid pump provides superior fail-safety. The device of the present invention can be provided by an electric vehicle or an extended-range electric vehicle, and can also be installed in a conventional fuel vehicle, and can be realized by an architecture for charging the system, so that the versatility is extremely high.

First, please refer to the exploded perspective view of the composite hydraulic power pump embodiment of the composite hydraulic power steering system of the present invention shown in FIG. 2, and the composite power hydraulic pump of the composite hydraulic power steering system of the present invention shown in FIG. Side view of the embodiment. The hybrid hydraulic power steering system 10 of the present embodiment has a composite power hydraulic pump 20 for circulating a liquid in a hydraulic circuit to assist the steering force. The hybrid hydraulic pump 20 includes a chamber 30, Liquid passage 40, DC motor 50, one-way bearing 60, pulley 70, and hydraulic adjustment system 80.

The chamber 30 is filled with an operating fluid (oil) body. The liquid passages 40 are disposed in pairs, and include a first passage 41 and a second passage 42. One end of the first passage 41 and one end of the second passage 42 are respectively communicated with the chamber 30, and the first passage 41 is further The other end of the second passage 42 is connected to a liquid receiving groove (not shown) and a steering module (not shown). The first channel 41 is provided with a permanent through hole 411. The DC motor 50 has a rotating shaft 51 that is freely rotatable or driven by an electromagnetic force. The rotating shaft 51 has an opposite first end 511 and a second end 512. The first end 511 is located in the chamber 30 and A liquid pressurizing device 5111 is provided, and the liquid pressurizing device 5111 can be an impeller. The one-way bearing 60 has a relatively rotatable inner ring 61 and an outer ring 62. The inner ring 61 is sleeved on the outer diameter of the second end 512 of the rotating shaft 51. The pulley 70 is disposed on the outer diameter of the outer ring 62 of the one-way bearing 60. The wheel surface 71 of the pulley 70 is provided with at least one guiding groove 72, and when the plurality of guiding grooves 72 are provided on the wheel surface 71, In addition to the connection of the guide groove 72 to the engine B described later, the other guide groove 72 may output a mechanical energy such as a generator. The hydraulic adjustment system 80 is connected to the pair of liquid passages 40 to regulate the flow of the operating liquid in the pair of liquid passages 40. Preferably, the hydraulic adjustment system 80 is electrically connected to one of the vehicle controllers A on the vehicle for delivery monitoring. Signal m, the hydraulic adjustment system 80 is a DC motor In the 811 drive, the DC motor 811 has a rotating shaft 812. The rotating shaft 812 has a hydraulic adjusting hole 8121. The rotating shaft 812 passes through the through hole 411 of the first passage 41, and the hydraulic adjusting hole 8121 is located at the rotating shaft 812. Inside the first passage 41. In other applications, the hydraulic adjustment system 80 can be other valves that also regulate the flow of operating liquid in the pair of liquid passages 40.

Please refer to FIG. 4A to FIG. 4D for a schematic plan view of the flow control of the hydraulic pressure regulating system of the present invention. As shown in FIG. 4A, a hydraulic adjusting hole 8121 of the rotating shaft 812 forms a liquid with the first passage 41. The flow area 90 is the smallest, and the liquid flow area 90 shown in FIG. 4A is the smallest. The liquid flow area 90 shown in FIG. 4B and FIG. 4C is relatively increased due to the change of the angle of the rotating shaft 812. FIG. 4D shows that the rotating shaft 812 is turned. The hydraulic regulating hole 8121 is in the same axial direction as the first passage 41, and completely circulates the liquid.

The DC motor 811 of the hydraulic adjustment system 80 may further include an optical encoder 8111 to precisely control the rotation angle of the rotating shaft 812 to precisely adjust the flow area of the first passage 41, thereby controlling the flow rate thereof, thereby controlling the same. The size of the steering assist force.

Continuing to refer to FIG. 5, a block diagram of an embodiment of a mechanical energy operation state system for driving a hybrid hydraulic power steering system for an electric vehicle according to the present invention, and a composite hydraulic power for an electric vehicle of the present invention shown in FIG. A system block diagram of an embodiment of a power-operating state of a driving method of a steering system. The electric vehicle 1 in the present example includes a vehicle controller A, an internal combustion engine B (having a torque output shaft B1), a vehicle accessory system power supply battery C, and a hydraulic power steering system 10. The composite hydraulic power steering system 10 includes a composite power hydraulic pump 20 having The DC motor 50 is electrically connected to the vehicular accessory system power supply battery C to drive the rotating shaft 51 of the DC motor 50. The rotating shaft 51 assembles the pulley 70 through the one-way bearing 60, and the pulley 70 is connected by the belt 73. Torque output shaft B1.

Further, the electric vehicle 1 may be an extended-range electric vehicle having a power battery D electrically connected to the vehicle accessory system power supply battery C (connectable through an exchanger if voltages are different), and the internal combustion engine B An engine that provides electric power for the electric vehicle 1 is not provided. A generator E can be further connected to the internal combustion engine B. The generator E is electrically connected to the power battery D, and the power battery D can be charged by the generator when the internal combustion engine B is actuated. The power battery D is electrically connected to a motor driver F to drive the power motor G connected to the motor driver F, and is electrically connected to the power motor G by a vehicle speed detector H to further collect the current vehicle speed (or power). The speed of the motor G) is reported and returned to the vehicle controller A.

Please refer to FIG. 7 for a flow chart of the steps of the driving method embodiment of the hybrid hydraulic power steering system of the present invention. In this embodiment, the driving method of the composite hydraulic power steering system is applicable to a vehicle having an internal combustion engine B and a vehicle accessory system power supply battery C, particularly an electric vehicle 1 and an extended-range electric vehicle. The driving method includes: Step S10: providing a hydraulic power steering system 10 as described above, the internal combustion engine B is connected to the pulley 70 by a belt 73, and the vehicle accessory battery power supply battery C is electrically connected to the DC motor 50 of the hybrid hydraulic pump 20, The chamber 30 is filled with liquid; please refer to FIG. 5 at the same time, step S20: when starting a mechanical energy supply to the complex In the mode of the power hydraulic pump 20 power, the internal combustion engine B drives the belt 73 to rotate the shaft 51 to pressurize the liquid in the chamber 30 to push the hydraulic circuit (in this case, the inside of the one-way bearing 60) There is no relative rotation between the ring 61 and the outer ring 62, and the power supply circuit of the DC motor 50 is switched to be an open circuit. The hydraulic adjustment system 80 includes a vehicle speed and a steering module according to the monitoring signal m associated with the vehicle controller A. The amount of displacement, the angle of rotation of the steering wheel, the speed of the power motor, etc., to determine the flow rate of the hydraulic circuit (such as applying the optical encoder 8111 to precisely control the rotation angle of the rotating shaft 812 of the DC motor 811 to change the hydraulic adjustment hole 8121 and the The flow area between the channels 41 further changes the pressure thereof; after the step of switching the power supply circuit of the DC motor 50 to open the motor shaft to mechanically drive the shaft 50, the step S21 is performed: the composite hydraulic power steering system is The DC motor 50 is converted into a generator to supply power to the battery C for the vehicle accessory system.

Referring to FIG. 6 simultaneously, step S30: when a mode for supplying power to the hybrid hydraulic pump 20 is started, the power supply circuit of the DC motor 50 is switched to be a path for electrically driving the rotating shaft 51, thereby being in the chamber 30. The liquid is pressurized to push the hydraulic circuit (at this time, the inner ring 61 of the one-way bearing 60 rotates relative to the outer ring 62, and the pulley 70 does not interlock with the rotating shaft 51). In this mode, the pressure of the hydraulic circuit is directly controlled by the vehicle controller. A controls the rotational speed of the direct current motor 50 to generate a suitable pressure. When the hydraulic pressure adjusting system 80 fixes the flow opening degree (i.e., the flow area) to the maximum in this mode, the flow regulating operation is stopped.

In the above switching, the DC motor 50 power supply circuit is a path for power After the step of driving the rotating shaft 50, step S31 is performed to stop the internal combustion engine B to drive the belt 73, for example, to stop the internal combustion engine B, or to cause the friction output shaft B1 of the internal combustion engine B to lose friction with the belt 73. .

In addition, when the above-mentioned system is applied to an extended-range electric vehicle, the power battery D is electrically connected to the vehicle accessory system power supply battery C, and the internal combustion engine B is an engine that does not provide the electric vehicle traveling power, and the power is determined. The relationship between the residual power of the battery D and the insurance power may determine the starting engine mode or the power mode, that is, the mode in which the starting mechanical energy is supplied to the hybrid hydraulic pump 20 is performed by step S11: the residual power of the power battery D is less than or The mode is triggered when the power is equal to a fuse power; and the mode for starting the power supply to the power of the hybrid hydraulic pump 20 is triggered by step S12: when the residual power of the power battery D is greater than the fuse amount.

The aforementioned insurance power is one for the electric vehicle to travel a certain mileage to facilitate the charging or refueling power value. Of course, the value of the insurance power can also be adjusted by the user.

In summary, the present invention proposes a matching design and strategy of a composite hydraulic power steering system, which can be converted into a mechanical hydraulic pump driven by an internal combustion engine by means of electric power to operate the composite hydraulic pump. The effect of assisted steering. The structural characteristics of the present invention are technical means capable of recombining energy-saving charging such as brake back charging, and do not exclude other energy-saving technologies for battery power consumption. The invention can provide the required steering steering force required for the vehicle to turn through the interaction control of the vehicle controller (VCU). Once the internal combustion engine is activated, the DC motor in the composite hydraulic power steering system will be converted. In addition to reducing the system's energy consumption, the combined pump provides excellent fail-safety. The device of the present invention can be provided by an electric vehicle or an extended-range electric vehicle, and can also be installed in a conventional fuel vehicle, and can be realized by an architecture for charging the system, so that the versatility is extremely high.

The embodiments or examples of the technical means adopted by the present invention are not intended to limit the scope of implementation of the present patent. That is, the equivalent changes and modifications made in accordance with the scope of the patent application of the present invention or the scope of the invention are covered by the scope of the invention.

1‧‧‧Electric vehicle

10‧‧‧Hydraulic power steering system

20‧‧‧Composite power hydraulic pump

30‧‧‧ chamber

40‧‧‧Liquid channel

41‧‧‧First Passage

411‧‧‧through holes

42‧‧‧second channel

50‧‧‧DC motor

51‧‧‧ shaft

511‧‧‧ first end

5111‧‧‧Liquid pressurizing device

512‧‧‧ second end

60‧‧‧ one-way bearing

61‧‧‧ Inner Ring

62‧‧‧ outer ring

70‧‧‧ Pulley

71‧‧‧90

72‧‧‧ Guide slot

73‧‧‧Land

80‧‧‧Hydraulic adjustment system

811‧‧‧DC motor

8111‧‧‧Optical encoder

812‧‧‧Rotary axis

8121‧‧‧Hydraulic adjustment hole

90‧‧‧Liquid circulation area

A‧‧‧Complete vehicle controller

B‧‧‧ Internal combustion engine

B1‧‧‧Torque output shaft

C‧‧‧Vehicle accessory system power supply battery

D‧‧‧Power battery

E‧‧‧Generator

F‧‧‧Motor drive

G‧‧‧Power Motor

H‧‧‧speed detector

I‧‧‧Voltage Converter

m, m1‧‧‧ monitoring signal

Step S10, S11, S12‧‧‧ method step flow

Step S20, S21, S30, S31‧‧‧ method step flow

1 is a state diagram of a flow change state of a hydraulic power steering system at a fixed speed of an engine of the prior art.

2 is an exploded perspective view of a hybrid hydraulic pumping embodiment of a hybrid hydraulic power steering system of the present invention.

3 is a side elevational view of a hybrid hydraulic pump embodiment of a hybrid hydraulic power steering system of the present invention.

4A to 4D are schematic plan views showing the operation of the flow rate control of the hydraulic pressure regulating system of the present invention.

Fig. 5 is a block diagram showing an embodiment of a power-operating state system of a driving method of a hybrid hydraulic power steering system for an electric vehicle according to the present invention.

Fig. 6 is a system block diagram showing an embodiment of a mechanically active state of a driving method of a hybrid hydraulic power steering system for an electric vehicle according to the present invention.

7 is a flow chart showing the steps of an embodiment of a driving method of the hybrid hydraulic power steering system of the present invention.

20‧‧‧Composite power hydraulic pump

30‧‧‧ chamber

40‧‧‧Liquid channel

41‧‧‧First Passage

411‧‧‧through holes

42‧‧‧second channel

50‧‧‧DC motor

51‧‧‧ shaft

511‧‧‧ first end

5111‧‧‧Liquid pressurizing device

512‧‧‧ second end

60‧‧‧ one-way bearing

61‧‧‧ Inner Ring

62‧‧‧ outer ring

70‧‧‧ Pulley

71‧‧‧90

72‧‧‧ Guide slot

73‧‧‧Land

80‧‧‧Hydraulic adjustment system

811‧‧‧DC motor

8111‧‧‧Optical encoder

812‧‧‧Rotary axis

8121‧‧‧Hydraulic adjustment hole

Claims (11)

A composite hydraulic power steering system has a hybrid hydraulic pump that provides a hydraulic circuit to transmit pressure to assist steering force. The hybrid hydraulic pump includes: a chamber for filling liquid; a pair of liquid passages, The first channel and the second channel respectively communicate with the chamber, the first channel wall surface is provided with a consistent perforation; the DC motor has a rotating shaft, and the rotating shaft has a first end and a second end The first end is located in the chamber and is provided with a liquid pressurizing device; a one-way bearing has an inner ring and an outer ring, the inner ring is sleeved on the outer diameter of the second end of the rotating shaft; a pulley The outer ring of the one-way bearing is disposed, the wheel surface of the pulley is provided with at least one guiding groove; and a hydraulic adjusting system is connected to the pair of liquid passages to adjust the flow of the liquid in the pair of liquid passages, the hydraulic adjustment The system is electrically connected to a vehicle controller for conveying a monitoring signal. The hydraulic adjustment system has a DC motor, and the DC motor has a rotating shaft, and the rotating shaft has a hydraulic adjusting hole, and the rotating shaft has a hydraulic adjusting hole. The line passes through the through hole of the first channel, and the hydraulic pressure adjusting hole is located within the first channel. The composite hydraulic power steering system according to claim 1, wherein the liquid pressurizing device set in the direct current motor is an impeller. The composite hydraulic power steering system of claim 2, wherein the DC motor of the hydraulic adjustment system comprises optical coding Device. An electric vehicle comprising: an internal combustion engine having a torque output shaft; a vehicle accessory system power supply battery; and a hybrid hydraulic power steering system as described in claim 1. An electric vehicle according to claim 4, wherein the electric vehicle is an extended-range electric vehicle having a power battery electrically connected to the vehicle accessory system power supply battery, and the internal combustion engine is not provided with an electric vehicle traveling power Engine. A driving method of a composite hydraulic power steering system, which is suitable for a vehicle having an internal combustion engine and a vehicle accessory system power supply battery, the driving method comprising: providing a hydraulic power steering system according to claim 1 of the patent scope, the internal combustion engine The pulley is connected by a belt, and the vehicle is electrically connected to the DC motor of the hybrid hydraulic pump by an accessory system power supply battery, wherein the chamber is filled with liquid; when a mechanical energy is supplied to the hybrid hydraulic pump power mode Driving the belt with the engine of the internal combustion engine, rotating the rotating shaft to pressurize the liquid to push the hydraulic circuit, and switching the power supply circuit of the DC motor to be an open circuit, and the hydraulic adjusting system is based on the monitoring signal of the vehicle speed according to the vehicle controller To determine the flow rate of the hydraulic circuit, thereby changing its pressure; and initiating a mode of supplying electrical energy to the hybrid hydraulic pump power Switching the DC motor power supply circuit to a path to electrically drive the rotating shaft, and pressurizing the liquid to push the hydraulic circuit. In the mode, the hydraulic regulating system fixes the flow opening degree to a maximum and then stops the flow regulating. action. The driving method of claim 6, further comprising stopping the driving of the belt after the step of switching the DC motor power supply circuit to electrically drive the rotating shaft. The driving method of claim 7, wherein the method of stopping the engine of the internal combustion engine to stop the belt is to stop the internal combustion engine or to cause the torque output shaft of the internal combustion engine engine to lose frictional force with the belt. The driving method of claim 6, further comprising: after the switching the DC motor power supply circuit is an open circuit to mechanically drive the rotating shaft step, causing the DC motor in the hybrid hydraulic power steering system to generate electricity, The battery output power is supplied to the vehicle accessory system. The driving method of claim 6, wherein the vehicle is an extended-range electric vehicle having a power battery electrically connected to the vehicle accessory system power supply battery, and the internal combustion engine is not provided with an electric vehicle traveling power The engine, and the mode in which the starting mechanism can supply the hybrid hydraulic pump power is triggered by the residual power of the power battery being less than or equal to a fuse amount. The driving method of claim 10, wherein the mode of starting the power supply to the hybrid hydraulic pump power is triggered by the residual power of the power battery being greater than the insurance power.