KR102090535B1 - Driving apparatus for electric vehicle - Google Patents

Abstract

Disclosed is a driving device for an electric vehicle, which has several power features to realize optimal power according to a driving situation of a vehicle, and enables efficient driving according to driving conditions of the vehicle. The driving device includes a housing having a storage space therein; A drive shaft disposed in the storage space and rotatably extending in a longitudinal direction; A first motor and a second motor having a higher rated output than the first motor, which are coaxially coupled to the drive shaft and spaced along the longitudinal direction; And a single control unit controlling the first and second motors to be rotated at the same rotational speed by controlling the same voltage and frequency.

Description

Driving apparatus for electric vehicle

The present invention relates to a driving device for an electric vehicle, which has several power features to realize optimal power according to a driving situation of the vehicle, and enables efficient driving according to driving conditions of the vehicle.

Since the electric vehicle secures driving performance by realizing all power with one electric motor, the electric motor must be large enough to drive the vehicle, and a multi-stage transmission is used to realize acceleration performance and climbing ability.

When one electric motor is used, a large-capacity motor is used to satisfy all driving patterns according to driving conditions. In general driving situations, energy efficiency is reduced and unnecessary power is consumed by using only a part of the motor performance.

To solve this, for example, in Korean Patent Registration No. 10-0680377, a high voltage motor driven by receiving power from a high voltage power system, a low voltage motor driven by receiving power from a low voltage power system, and driving of each motor It comprises a high-voltage motor controller and a low-voltage motor controller for controlling the, and the high-voltage motor and the low-voltage motor are disposed on the coaxial so as to drive the same rotating shaft, the high-voltage motor controller operates and controls the high-voltage motor to rotate the rotating shaft Driving a high-voltage power system or a high-reliability single-axis dual-motor device using a dual power supply, characterized in that the low-voltage motor is driven under the control of the low-voltage motor controller as an auxiliary means when an abnormality occurs in the high-voltage power system or the high-voltage motor. It is disclosed.

According to this patent, a high voltage power system and a high voltage motor are used to drive a rotating shaft, but when an abnormality occurs in any one of the high voltage power system and a high voltage motor, an auxiliary means for driving the low voltage power system and the low voltage motor to the rotating shaft By using as, it has the effect that the rotating shaft can be driven normally, and eventually the reliability of the device is improved.

However, there is a problem in that manufacturing cost increases because the high voltage motor and the low voltage motor are controlled by independent motor controllers, respectively.

Further, in Japanese Patent Publication No. 2017-43236, the rotational speed of the engine is rotated by providing a rotating member that is arranged coaxially with the input shaft connected to the engine and is coupled with the input shaft via a one-way clutch and coupled with the rotor of the motor. Disclosed is a driving device for a vehicle that allows the rotational force of the engine to be transmitted to the rotor by locking the one-way clutch to the input shaft when it is faster than the rotational speed of the member.

According to this patent publication, there is an advantage that the driving device can be downsized by removing the engine from the driving device for a vehicle and allowing it to be used as a driving device for an electric vehicle.

However, in addition to the two motor generators, an additional engine is required, as well as a separate input shaft connected to the engine, so that a separate one-way clutch is required to transmit the rotational power of the engine to the motor generator, and the structure is complicated. .

Accordingly, an object of the present invention is to drive an electric vehicle that has a pair of motors to realize optimal power according to the driving situation of the vehicle and to enable efficient driving according to the driving conditions of the vehicle while improving reliability of power generation. Is to provide a device.

Another object of the present invention is to provide a drive device for an electric vehicle that is economical in terms of cost ratio, has a low failure rate, and can reduce the overall size.

Another object of the present invention is to provide a drive device for an electric vehicle having a simple structure and improved power transmission efficiency.

Another object of the present invention is to provide an apparatus for driving an electric vehicle capable of driving an optimal motor according to driving conditions and extending the driving distance under the same battery conditions.

The above object is, a housing having a storage space therein; A drive shaft disposed in the storage space and rotatably extending in a longitudinal direction; A first motor and a second motor having a higher rated output than the first motor, which are coaxially coupled to the drive shaft and spaced along the longitudinal direction; And a single control unit controlling the first and second motors to rotate at the same rotational speed by controlling the same voltage and frequency, and the first and second motors are coupled to the driving shaft to form the first and second motors. A one-way clutch selectively transmitting the rotational force of the two motors to the drive shaft; A rotor coupled to the drive shaft via the clutch and having a permanent magnet installed on its outer circumferential surface; And a stator spaced apart from the rotor corresponding to the rotor and installed on the inner surface of the housing, wherein the one-way clutch has a rotation speed of the drive shaft smaller than or equal to that of the first and second motors, It is achieved by the driving device of the electric vehicle, characterized in that coupled to the rotor of the first motor and the second motor.

The above object is, a housing having a storage space therein; A drive shaft disposed in the storage space and rotatably extending in a longitudinal direction; A first motor and a second motor having a lower rated power than the first motor, which are coaxially coupled to the drive shaft and spaced along the longitudinal direction; And a single control unit controlling the first and second motors to rotate at the same rotational speed by controlling the same voltage and frequency. The first and second motors are induction electric motors, and the first motors include: It consists of a rotor coupled to the drive shaft, and a stator installed on the inner surface of the housing spaced apart from the rotor in correspondence to the rotor, and the second motor is coupled to the drive shaft to increase the rotational force of the second motor. It is composed of a one-way clutch selectively transmitted to the drive shaft, a rotor coupled to the drive shaft via the clutch, and a stator installed on an inner surface of the housing spaced apart from the rotor corresponding to the rotor, and the one-way clutch Is, if the rotational speed of the drive shaft is less than or equal to the rotational speed of the first motor, engage with the rotor of the second motor, and The first motor is driven by the main motor, the second motor is powered off, and both the first and second motors are driven during high-speed driving, and the rotational force of the second motor is additionally transmitted to the drive shaft by the one-way clutch. It is achieved by a driving device for an electric vehicle characterized in that.

Preferably, the high-speed driving may include starting and accelerating and climbing.

According to one embodiment of the above, by arranging a plurality of motors controlled by the same voltage and frequency in series and coaxial in a single housing, the structure is simple and enables efficient driving according to the driving situation of the vehicle, and also increases reliability of power generation. Can be improved.

In addition, it is possible to extend the driving distance under the same battery condition by driving the optimum motor according to the driving conditions.

According to another embodiment of the present invention, the cost ratio is good by using an induction electric motor having a low failure rate and a low cost as a main motor during constant speed driving, and by applying another induction electric motor as an auxiliary motor, downsizing the rated output of the main motor The overall size can be reduced, and power consumption can be reduced as much. As a result, the driving distance is increased.

1 shows a driving device for an electric vehicle according to an embodiment of the present invention.
2 shows a driving device for an electric vehicle according to another embodiment of the present invention.

It should be noted that the technical terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. In addition, technical terms used in the present invention should be interpreted as meanings generally understood by a person having ordinary knowledge in the technical field to which the present invention belongs, unless defined otherwise. It should not be interpreted as the meaning of phosphorus or excessively reduced. In addition, when the technical term used in the present invention is a wrong technical term that does not accurately represent the spirit of the present invention, it should be understood as being replaced by a technical term that can be correctly understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or in context before and after, and should not be interpreted as an excessively reduced meaning.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a driving device for an electric vehicle according to an embodiment of the present invention.

Inside the housing 10, one drive shaft 20 extends along the longitudinal direction from left to right in the drawing, and bearings 30 and 32 are interposed in contact portions with the housing 10, respectively.

In the storage space inside the housing 10, a pair of motors 100 and 200 are coaxially coupled to the drive shaft 20 and are arranged in series. In this embodiment, two motors 100 and 200 are exemplified, but are not limited thereto.

The motors 100 and 200 are spaced apart from the rotors 120 and 220 with permanent magnets 130 and 230 attached to the side edges, and the permanent magnets 130 and 230 by a predetermined distance, respectively. Accordingly, the housing 10 is composed of stators 110 and 210 installed on the inner surface. Reference numerals 112 and 212 denote stator coils, respectively.

As shown in FIG. 1, the permanent magnets 130 and 230 may be attached to the outer cross-sections of the rotors 120 and 220, but may otherwise be embedded inside the outer cross-section.

The stator coils 112 and 212 may use a winding method in which the height protruding to the outside can be minimized, for example, a straight wire or a head pin method for a deployed core.

The motors 100 and 200 have different rated outputs, and in consideration of a typical electric vehicle, for example, the output of the motor 100 may be 32 Hz and the output of the motor 200 may be 56 Hz.

Each of the motors 100 and 200 is controlled by the same voltage and frequency by a single control unit 300 to have the same rotation speed, and the control unit 300 has one motor control unit (MCU) and torque control unit (TCU). It is provided.

The TCU is interposed between the MCU and the motor to select and rotate the motors 100 and 200, and the TCU is selected in connection with the torque of the drive shaft 20 of the motor to select and operate the optimal motor.

According to this structure, the rotational force of the motors 100 and 200 is transmitted to the drive shaft 20 independently or together by the motors 100 and 200 having different rated outputs in one housing 10 and transmitted to the wheels. Therefore, it is possible to optimize driving modes and various driving modes corresponding to various outputs.

In order to transmit the rotational force of the motors 100 and 200 to the drive shaft 20 independently or together, the rotors 120 and 220 of each of the motors 100 and 200 drive the shaft 20 through the one-way clutches 140 and 240. ).

The one-way clutches 140 and 240 literally mean a clutch that rotates only in one direction, and a vehicle is provided between the rotors 120 and 220 and the drive shaft 20 in one direction, that is, a rotational force in the forward direction by providing a clutch configuration. It performs the function of transferring or separating.

When the rotational speed of the drive shaft 20 is greater than the rotational speed of the rotors 120 and 220 of the motors 100 and 200, the coupling of the one-way clutch 240 and the rotors 120 and 200 is released, and vice versa That is, when the rotational speed of the drive shaft 20 is equal to or smaller than the rotational speed of the rotors 120 and 220 of the motors 100 and 200, the one-way clutch 240 is locked and rotates with the rotors 120 and 200. Combine.

Therefore, in this embodiment, the one-way clutch 140, 240 transmits the rotational force of the motors 100 and 200 to the drive shaft 20, so that the engine rotational force of the engine in Patent Publication No. 2017-43236 is described above. It acts as opposed to a one-way clutch that delivers to.

The one-way clutch 140, 240 is composed of, for example, inner rings 142, 242 and outer rings 144, 244 that are coaxially coupled through a bearing, and the inner rings 142, 242 are constrained with the drive shaft 20. , The outer ring (144, 244) is coupled to or disengaged from the rotor (120, 220) to transmit the rotational force or performs a separation function.

Hereinafter, the operation of the drive device for an electric vehicle having the above structure will be described.

As described above, each of the motors 100 and 200 is controlled at the same voltage and the same frequency by the control unit 300 to drive at the same rotational speed.

In addition, as described above, the output of the motor 100 is assumed to be 32 Hz, and the output of the motor 200 is assumed to be 56 Hz.

1) Low torque driving

When power is applied to the motor 100, the rotational speed of the motor 100 is greater than the rotational speed of the stopped drive shaft 20, so that the one-way clutch 140 is locked and the rotational force of the motor 100 is one-way clutch 140 ) Is transmitted to the drive shaft 20.

At this time, the motor 200 is in a power-off state, and because the rotational speed of the drive shaft 20 rotated by the motor 100 is greater than the rotational speed of the rotor 220 of the motor 200, the one-way clutch 240 ) Is released, and the rotor 220 maintains a rotation stop state.

As a result, a low torque travel is performed with an output of 32 Hz from the motor 100 to which power is applied.

Here, the stator 210 of the motor 200 and the permanent magnet 230 of the rotor 220 are kept in a restrained state with strong magnetic force and cannot generate regenerative power.

2) Medium torque driving

When the driving condition of the intermediate torque is required, the controller 300 cuts off the power applied to the motor 100 and applies power to the motor 200. As described above, the motor is applied with the same voltage and frequency. 100) is increased at the same rotational speed and the rotational force of the motor 200 is transmitted to the drive shaft 20.

At this time, the power applied to the motor 100 is cut off, so that the motor 100 is stopped by strong magnetic force between the stator 110 and the permanent magnet 130 of the motor 100.

In addition, since the rotational speed of the drive shaft 20 driven by the motor 200 is higher than the rotational speed of the rotor 120 of the motor 100 that is powered off, the rotation of the one-way clutch 140 and the motor 100 is higher. The coupling of the electrons 120 is separated.

As a result, the intermediate torque is driven with the output of 56 kW from the motor 200 to which power is applied.

3) High torque driving

In the case of attempting to perform high torque during intermediate torque driving, when the controller 300 applies power to the motor 100, the motor 100 rises at the same rotational speed as the motor 200.

Therefore, while the rotational speed of the motor 100 becomes equal to the rotational speed of the drive shaft 20 driven by the motor 200, the motor 100 is combined with the one-way clutch 140 and the rotor 120 of the motor 100. ) Is transmitted to the drive shaft 20.

As a result, the output of 32 kW from the motor 100 and the 56 kW output from the motor 200 are summed, resulting in high torque travel with an output of 88 kW.

In the past, for example, in the case of Hyundai Motor's Ionic (trademark) vehicle to which the motor is applied, the driving motor of the HV (Hybrid Vehicle) vehicle is 32 km, and the driving motor of the EV (Electric Vehicle) car is 88 km. HV vehicles have no problems with driving performance in the city and low torque areas, and have excellent fuel efficiency. EV vehicles satisfy the full range of torque and have very good driving performance, but have shortcomings.

Therefore, when the driving device of the present invention is applied, the rated output is different in one housing, and two motors that are power-controlled with the same voltage and frequency are connected in series coaxially, thereby driving at 32 kW at low torque and at intermediate torque. The vehicle automatically switches to 56㎾, and when a driving condition requiring high torque occurs, it can be switched to 32＋ + 56㎾ = 88㎾ to completely satisfy the required driving performance.

In addition, it is possible to solve the problem that may occur due to physical collision between two motors or unnecessary regenerative power generation by using a one-way clutch, and the optimal motor that meets the driving conditions of the vehicle operates, thus reducing battery energy and extending mileage. .

The above embodiment is a structure in which reverse and regenerative power generation is impossible due to a one-way clutch operating in response to the forward direction of the vehicle, so a structure capable of reverse and regenerative power generation may be added according to driving conditions.

2 shows a driving device for an electric vehicle according to another embodiment of the present invention.

In one embodiment of the above, a permanent magnet motor is used, and since the permanent magnet used in each motor has characteristics that are demagnetized by temperature or the like, there may be a problem in reliability of power generation. In addition, since the price of the permanent magnet motor is expensive, it is not economical in terms of cost-effectiveness, and the failure rate may be large.

In this embodiment, it is proposed to solve this problem.

Referring to Figure 2, basically having a structure similar to the above-described embodiment, the motors 100 and 200 arranged in series and coaxial to the drive shaft in the storage space inside the housing 10 are all induction motors, and the motor 200 is used as a main motor, and the motor 100 having a one-way clutch 130 is different in that it is used as an auxiliary motor.

The motor 100, which is an auxiliary motor, is spaced apart from the rotor 120 and the rotor 120 coupled to the drive shaft 10 via a one-way clutch 140, and a housing 10 along the rotor 120. It consists of a stator 110 installed on the inner surface.

The main motor, the motor 200, does not have a one-way clutch, and is spaced a predetermined distance from the rotor 220 and the rotor 220 fixed to the drive shaft 20 along the rotor 220 in the housing 10. It consists of a stator 210 installed on the side.

According to this structure, since the induction electric motor having a low failure rate and a low price is used as the main motor for constant speed driving, the cost ratio is inevitably good.

In addition, by applying another induction electric motor as an auxiliary motor, the rated output of the main motor is downsized to reduce the overall size and thus reduce power consumption, thereby increasing the driving distance.

The rotor 120 of the motor 100 is coupled to the drive shaft 10 via a one-way clutch 140. Since the one-way clutch 140 has the same structure as the one embodiment described above, detailed description thereof is omitted. do.

Hereinafter, the operation of the electric vehicle drive device of this embodiment will be described.

As in the above embodiment, the motors 100 and 200 are controlled with the same voltage and frequency by a single control unit 300 to have the same rotational speed, and the control unit 300 has one motor control unit (MCU). And a TCU (Torque Control Unit).

The output of the motor 100 is assumed to be 32 Hz, and the output of the motor 200 is assumed to be 56 Hz.

As described above, the motor 200 is applied as a main motor, and the motor 100 is applied as an auxiliary motor. Only the motor 100, which is an auxiliary motor, is a one-way clutch interposed between the rotor 120 and the drive shaft 20. In (140), the inner ring 142 is in a restrained relationship with the drive shaft 20, and the outer ring 144 performs a function of transmitting or separating the rotational force in a constrained state with the rotor 120.

During constant speed driving, power is applied to the motor 200 to optimize low electric energy consumption by driving at a low torque with an output of 56 ,, where the motor 100 is in a power-off state and the rotational speed of the drive shaft 20 is a motor ( Since it is larger than the rotational speed of the rotor 120 of 100), the one-way clutch 140 is released and the rotor 120 maintains a rotation stop state.

At this time, since the rotor 120 of the motor 100 is in a state where the mechanical rotational power is stopped, when the regenerative power generation characteristic of the stator 110 occurs, the stator 110 and the rotor 120 are forced to be restrained. You cannot rotate.

On the other hand, in the case of driving that requires high torque, such as when starting, accelerating, or climbing, when power is applied to the motor 100, which is the auxiliary motor, the motor 200 is energized at the same voltage and frequency as the motor 200. ), And as a result, the one-way clutch 140 is coupled to the rotor 120 to transmit the rotational force of the motor 100 to the drive shaft 20.

As a result, the output of 56 kW from the motor 200 and the output of 32 kW from the motor 100 are summed up, resulting in high-speed torque travel with an output of 88 kW.

In other words, when two motors are connected in series in one housing in a coaxial manner, in constant speed driving, the main motor 200 is driven to drive at 56 km, and when high power is required, such as during start-up, acceleration, or climbing. , It is converted to 32 모터 + 56㎾ = 88㎾ condition by using the motor 100, which is an auxiliary motor, in combination, so that the driving performance can be completely satisfied.

In addition, two motors connected to the same drive shaft can solve the problem that may occur due to physical collisions or unnecessary regenerative generation using a one-way clutch, and the optimal motor for driving conditions of the vehicle is operated, saving battery energy and driving distance. Extension is possible.

In particular, by downsizing an induction electric motor from 88 ㎾ to 56 사용 and using it as the main motor, the overall size can be reduced, thereby reducing power consumption, thereby increasing the driving distance.

In addition, since the induction electric motor having a low failure rate and a low price is used as the main motor for constant speed driving, the cost ratio is good.

The above-described contents will be able to be modified and modified without departing from the essential characteristics of the present invention to those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10: housing
20: drive shaft
30, 32: bearing
100, 200: motor
110, 210: stator
120, 220: rotor
130, 230: permanent magnet
140, 240: one-way clutch
300: control unit

Claims (7)

delete delete delete A housing having a storage space therein;
A drive shaft disposed in the storage space;
A first motor and a second motor having a higher rated output than the first motor, which are coaxially coupled to the drive shaft along the axial direction; And
It includes a single control unit for controlling the first and second motors to rotate at the same rotation speed by controlling with the same voltage and frequency,
The first and second motors,
A one-way clutch composed of an inner ring constrained to the drive shaft and an outer ring coaxially coupled to the inner ring;
A rotor coupled to the drive shaft via the one-way clutch and a permanent magnet installed on an outer circumferential surface; And
It is composed of a stator installed on the inner surface of the housing spaced apart from the rotor corresponding to the rotor,
The outer ring of the one-way clutch is selectively coupled to the rotor to selectively transmit the rotational force of the first and second motors to the drive shaft,
In the one-way clutch, when the rotational speed of the drive shaft is greater than the rotational speed of the first and second motors, the coupling is disengaged with the rotors of the first and second motors, and the rotational speeds of the drive shafts are the first and first If less than or equal to the rotational speed of the two motors, the driving device for the electric vehicle, characterized in that coupled to the rotor of the first motor and the second motor. A housing having a storage space therein;
A drive shaft disposed in the storage space;
A main motor spaced apart along the axial direction and coaxially coupled to the drive shaft, and an auxiliary motor having a lower rated output than the main motor; And
It includes a single control unit for controlling the main and auxiliary motors to rotate at the same rotation speed by controlling with the same voltage and frequency,
The main motor and the auxiliary motor are induction electric motors,
The main motor is composed of a rotor coupled to the drive shaft, and a stator installed on an inner surface of the housing spaced apart from the rotor corresponding to the rotor,
The auxiliary motor includes a one-way clutch composed of an inner ring constrained to the drive shaft and an outer ring coaxially coupled to the inner ring, a rotor coupled to the drive shaft via the one-way clutch, and spaced apart from the rotor corresponding to the rotor It consists of a stator installed on the inner surface of the housing, the outer ring of the one-way clutch is selectively coupled to the rotor of the auxiliary motor to selectively transmit the rotational force of the auxiliary motor to the drive shaft,
The one-way clutch, if the rotational speed of the drive shaft is greater than the rotational speed of the main and auxiliary motors, releases the coupling from the rotor of the auxiliary motor, and the rotational speed of the drive shaft is less than or equal to the rotational speed of the main and auxiliary motors Driving device for an electric vehicle, characterized in that coupled to the rotor of the auxiliary motor. The first and second motors, which are spaced apart in the axial direction of the drive shaft disposed in the storage space provided in the housing and are coaxially coupled and have different rated outputs, control the first and second motors with the same voltage and frequency. It is a method of driving a driving device for an electric vehicle including a single control unit that controls to rotate at the same rotational speed.
Each of the first and second motors,
A one-way clutch composed of an inner ring constrained to the drive shaft and an outer ring coaxially coupled to the inner ring;
A rotor coupled to the drive shaft via the one-way clutch and a permanent magnet installed on an outer circumferential surface; And
It is composed of a stator installed on the inner surface of the housing spaced apart from the rotor corresponding to the rotor,
In order to drive the first torque in a stopped state, power is applied to the first motor and power is cut off to the second motor so that the one-way clutch of the first motor engages with the drive shaft, so that the rotational force of the first motor is the drive shaft. Being delivered to,
For continuous second torque driving, power is applied to the second motor to maintain the same rotational speed as the first motor so that the one-way clutch of the second motor engages with the drive shaft so that the rotational force of the second motor is the The power transmitted to the drive shaft, the power applied to the first motor is cut off, and the one-way clutch of the first motor is disengaged from the drive shaft,
For continuous third torque driving, power is applied to the first motor to maintain the same rotational speed as the second motor so that the one-way clutch of the first motor engages with the drive shaft so that the rotational force of the first motor is the A driving method of a driving device for an electric vehicle, characterized in that it is transmitted to the driving shaft together with the rotational force of the second motor. The main motor that is coaxially coupled and spaced apart in the axial direction of the drive shaft disposed in the storage space provided in the housing, the auxiliary motor having a lower rated output than the main motor, and the main and auxiliary motors are controlled with the same voltage and frequency to rotate the same. It is a method of driving a driving device for an electric vehicle including a single control unit for controlling to rotate at a speed,
The auxiliary motor,
A one-way clutch composed of an inner ring constrained to the drive shaft and an outer ring coaxially coupled to the inner ring;
A rotor coupled to the drive shaft via the one-way clutch and a permanent magnet installed on an outer circumferential surface; And
It is composed of a stator installed on the inner surface of the housing spaced apart from the rotor corresponding to the rotor,
In order to travel at a constant speed in a stopped state, power is cut off to the auxiliary motor so that the one-way clutch is disengaged from the rotor of the auxiliary motor, and power is applied to the main motor to transmit the rotational force of the main motor to the drive shaft. ,
In order to run requiring higher torque in the constant speed driving, power is applied to the auxiliary motor to maintain the same rotational speed as the main motor so that the one-way clutch of the auxiliary motor is engaged with the driving shaft, so that the rotational force of the auxiliary motor is A driving method of a driving device for an electric vehicle, characterized in that it is transmitted to the driving shaft together with the rotational force of the main motor.

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