JP2021062670A - Vehicular vehicle height control device - Google Patents

Abstract

To provide a vehicular vehicle height control device that is compact and is independent of a suspension.SOLUTION: A vehicle height control device 10 is constituted of a support frame 30 constituted of a link mechanism and an electric actuator 31. The support frame 30 has: an upper pedestal portion 32; a lower pedestal portion 33; a first link portion 34 coupling respective one-side ends of the upper pedestal portion 32 and the lower pedestal portion 33 to each other; and a second link portion 35 linking the respective other-side ends of the upper pedestal portion 32 and the lower pedestal portion 33 to each other. An interval between the first link portion 34 and the second link portion 35 is enlarged/reduced, so that an interval in a vertical direction between the upper pedestal portion 32 and the lower pedestal portion 33 is enlarged/reduced. The electric actuator 31 has an electric motor 49 and an expansion and contraction mechanism 50 which is arranged across the first link portion 34 and the second link portion 35, and converts rotation motion of an output shaft of the electric motor 49 to linear motion and extends and contracts a whole length thereof.SELECTED DRAWING: Figure 9

Description

The present invention relates to a vehicle height adjusting device for vehicles.

Conventionally, it has been widely practiced that a vehicle such as a bus is provided with a vehicle height adjusting device for adjusting the height of the vehicle body in order to facilitate getting on and off the occupants. Further, vehicles such as trucks are also provided with a vehicle height adjusting device in order to keep the vehicle height constant regardless of the load capacity.

A vehicle height adjusting device having a conventional structure mounted on a vehicle such as a bus or a truck constitutes an air suspension provided for each wheel, as described in, for example, Japanese Patent Application Laid-Open No. 2004-359124 (Patent Document 1). By adjusting the air pressure inside the air spring, the vehicle height can be adjusted. Further, as a vehicle height adjusting device having a conventional structure, a structure in which the vehicle height can be adjusted by using flood control is also known.

Japanese Unexamined Patent Publication No. 2004-359124 JP-A-2019-138410

In recent years, in response to the trend toward fossil fuel reduction, research on electric vehicles has progressed and is being carried out in some areas. The drive devices that make up an electric vehicle have traditionally been designed exclusively for each gross vehicle weight, which is one of the factors that increase the manufacturing cost of electric vehicles.

In view of these circumstances, the present inventors have configured a drive device that electrically drives the wheels as a unit independent of the vehicle body for the purpose of reducing the manufacturing cost of the electric vehicle, and the total of the vehicle body. I got a new idea to assemble the number of drive devices according to the weight to the car body. However, when an electric vehicle is composed of a vehicle body and a plurality of drive devices, the weight supported by the wheels becomes uneven due to the uneven load load, which causes variations in the life of the drive devices and during cornering. , The vehicle balance may become unstable.

Therefore, it is conceivable to incorporate a vehicle height adjusting device between the vehicle body and the driving device, but the vehicle height adjusting device having a conventional structure has a large size such as a tank or a compressor in order to supply compressed air or pressure oil. Auxiliary equipment is needed. Therefore, the installation space of the vehicle height adjusting device becomes large, and it becomes difficult to incorporate the vehicle height adjusting device between the vehicle body and the driving device. Further, since the vehicle height adjusting device having a conventional structure is incorporated in the suspension and forms a part of the suspension, the riding comfort of the vehicle may be lowered depending on the setting of the vehicle height.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle height adjusting device that is compact and independent of suspension.

The vehicle height adjusting device for a vehicle according to one aspect of the present invention is arranged between a vehicle body and a driving device that electrically drives wheels, and is for adjusting the height of the vehicle body, and includes a support frame and a support frame. , Equipped with an electric actuator.
The support frame is composed of a link mechanism, and has an upper pedestal portion fixed to the vehicle body and a lower pedestal portion arranged below the upper pedestal portion substantially parallel to the upper pedestal portion and fixed to the drive device. A first link portion connecting the portion, one end of the upper pedestal portion and one end of the lower pedestal portion, the other end of the upper pedestal portion, and the lower pedestal portion. The upper pedestal portion and the lower pedestal portion are provided by having a second link portion that connects the other end portion of the portion and expanding or contracting the distance between the first link portion and the second link portion. The vertical interval between and is expanded or contracted.
The electric actuator is arranged so as to bridge between the electric motor having an output shaft and the first link portion and the second link portion, and converts the rotational motion of the output shaft into a linear motion to reduce the total length. It has an expansion and contraction mechanism that expands and contracts.

In the vehicle height adjusting device for a vehicle according to one aspect of the present invention, the expansion / contraction mechanism may have a ball screw mechanism.

In the vehicle height adjusting device for a vehicle according to one aspect of the present invention, the electric actuator is further provided with an inverse differential prevention mechanism for preventing the linear motion of the telescopic mechanism from being converted into the rotational motion of the output shaft. Can be made to.

In the vehicle height adjusting device for a vehicle according to one aspect of the present invention, the first upper link piece is connected to the first upper link piece in which the tip portion is rotatably connected to one end portion of the upper pedestal portion, and the tip end portion. A first lower link piece rotatably connected to one end of the lower pedestal and a base end rotatably connected to the base end of the first upper link piece. The second upper link piece is rotatably connected to the other end of the upper pedestal, and the tip is rotatably connected to the other end of the lower pedestal. It may have a second lower link piece rotatably connected to the side end and rotatably connected to the base end of the second upper link piece. ..

In the vehicle height adjusting device for a vehicle according to one aspect of the present invention, the first link portion is rotatably supported with respect to the base ends of the first upper link piece and the first lower link piece. A first casing piece that supports one end of the telescopic mechanism is further provided, and the second link portion is provided at the base end portion of each of the second upper link piece and the second lower link piece. It is possible to further have a second casing piece that is rotatably supported with respect to the other and supports the other end of the telescopic mechanism.

In the vehicle height adjusting device for a vehicle according to one aspect of the present invention, the upper pedestal portion and the lower pedestal portion are horizontally arranged between the upper pedestal portion and the lower pedestal portion on the support frame. A guide member may be further provided to prevent relative displacement.

According to the present invention, it is possible to realize a vehicle height adjusting device that is compact and independent of the suspension.

FIG. 1 (A) is a perspective view showing an example of an electric vehicle provided with a vehicle height adjusting device according to the first example of the embodiment, and FIG. 1 (B) is a lower left side of FIG. 1 (A). It is a side view seen from the side, and FIG. 1 (C) is an end view seen from the left side of FIG. 1 (B). FIG. 2 is a perspective view showing a wheel drive unit including the vehicle height adjusting device according to the first example of the embodiment. FIG. 3 is a side view showing the vehicle height adjusting device and one wheel removed from the wheel drive unit shown in FIG. FIG. 4 is a perspective view showing the drive device taken out from the wheel drive unit shown in FIG. FIG. 5 is a schematic view of the drive device shown in FIG. FIG. 6 is a perspective view showing the vehicle height adjusting device and its peripheral members taken out from FIG. FIG. 7 is a side view showing the vehicle height adjusting device according to the first example of the embodiment in a state where the distance between the upper pedestal portion and the lower pedestal portion is increased in the vertical direction. FIG. 8 is a cross-sectional view taken along the line AA of FIG. 7 (A). FIG. 9 is a side view showing the vehicle height adjusting device according to the first example of the embodiment, and FIG. 9A shows a state in which the vertical distance between the upper pedestal portion and the lower pedestal portion is reduced. (B) shows a state in which the vertical distance between the upper pedestal portion and the lower pedestal portion is increased.

[First Example of Embodiment]
A first example of the embodiment will be described with reference to FIGS. 1 to 9.

[Overall configuration of electric vehicle]
As shown in FIG. 1, the electric vehicle 1 is equipped with a vehicle body 2, a plurality of (four in the illustrated example) wheel drive units 3 according to the total weight of the vehicle body 2, and two for each wheel drive unit 3. It is provided with the wheels 4a and 4b (a total of eight in the illustrated example). The electric vehicle 1 may be an automatically driven vehicle that can be driven without a human performing a driving operation, or may be a manually driven vehicle that is operated by a human being.

All the wheel drive units 3 included in the electric vehicle 1 have the same configuration as each other, and each wheel drive unit 3 is supplied with electric power (and oil pressure as needed) from the vehicle body 2 and a control signal. Is sent. The wheel drive unit 3 realizes the basic performances of the electric vehicle 1, such as running, turning, and stopping.

<Body>
The vehicle body 2 includes a rectangular box-shaped vehicle body body 5 and a pair of eaves-shaped supported portions 6a and 6b protruding from the lower portion of both side surfaces of the vehicle body body 5 in the traveling direction (longitudinal direction). The vehicle body body 5 includes a battery (power supply) for supplying electric power to the wheel drive unit 3, a control device for controlling the wheel drive unit 3, and a space such as a passenger space and a luggage compartment space. Each of the supported portions 6a and 6b is provided to prevent the space of the vehicle body body 5 from becoming narrow by directly assembling the wheel drive unit 3 to the lower part of the vehicle body body 5, and the wheel drive unit to be mounted is provided. The size can be appropriately changed according to the number of 3.

The traveling direction is the traveling direction of the electric vehicle 1 in a state where the pair of wheels 4a and 4b driven by the respective wheel drive units 3 are directed in the straight-ahead direction (longitudinal direction of the vehicle body 5) (FIG. 1 (B). ), The left-right direction of FIGS. 3 and 7 to 9). Further, one side in the traveling direction corresponds to the front side of the electric vehicle 1, and the other side in the traveling direction corresponds to the rear side of the electric vehicle 1. The width direction refers to the width direction of the electric vehicle 1 (the left-right direction of FIGS. 1 (C) and 5 and the vertical direction of FIG. 8) with the pair of wheels 4a and 4b facing in the straight-ahead direction.

<Wheel drive unit>
As shown in FIG. 2, the wheel drive unit 3 includes a drive device 7 for electrically driving a pair of wheels 4a and 4b, a support device 8 for suspending the pair of wheels 4a and 4b, and a pair. A turning device 9 for enabling the steering of the wheels 4a and 4b, a vehicle height adjusting device 10 for adjusting the height of the vehicle body 2 from the road surface, and a braking device 11 for applying a braking force. Be prepared. Further, the wheel drive unit 3 includes a weight sensor for measuring the weight supported by the pair of wheels 4a and 4b, and an angle sensor for measuring the steering angle of the pair of wheels 4a and 4b. The mounting position of the weight sensor and the angle sensor is not particularly limited, and can be mounted on, for example, the swivel device 9.

《Drive》
As shown in FIGS. 4 and 5, the drive device 7 includes a housing 12, a pair of motors 13a and 13b, and a pair of drive shafts 14a and 14b to which wheels 4a and 4b are attached to their respective tips. A pair of torque transmission devices 16a and 16b for transmitting the rotational torque of the motor output shafts 15a and 15b of the motors 13a and 13b to the pair of drive shafts 14a and 14b are provided.

The housing 12 is made of a light alloy such as an aluminum alloy, a synthetic resin, or the like, and is made of a combination of a plurality of parts. The housing 12 includes a housing main body 17 having a storage space inside, and an arm portion 18 extending from a lower end of the housing main body 17 toward the other side in the traveling direction. A pair of motors 13a and 13b, a pair of drive shafts 14a and 14b, a pair of torque transmission devices 16a and 16b, and the like are stored in the storage space of the housing body 17.

The housing body 17 includes a connector portion 19 on the upper portion thereof. The connector portion 19 is connected to a pair of motors 13a and 13b and various sensors constituting the drive device 7 by a cable. Further, the connector portion 19 is connected to the battery and the control device mounted on the vehicle body 2 by a harness. As a result, electric power can be supplied to the pair of motors 13a and 13b, and output signals of various sensors can be transmitted to the control device.

Each of the pair of motors 13a and 13b has the same rated output and rated rotation speed (rated rotation speed), and the rotation speed (rotation speed) and rotation direction of the respective motor output shafts 15a and 15b are independent. It is configured to be controllable. Each of the pair of motors 13a and 13b is arranged so as to overlap in the traveling direction with the tip portions of the motor output shafts 15a and 15b facing in opposite directions. The motor output shafts 15a and 15b are arranged in parallel with each other. Rotation sensors 20a and 20b are arranged around the portion of the motor output shafts 15a and 15b that protrudes from the side surface of the housing body 17. This makes it possible to detect the rotation speed (rotation speed) of the motor output shafts 15a and 15b.

The pair of drive shafts 14a and 14b are rotatably supported with respect to the housing body 17 in a state of being coaxial with each other and with their tip portions facing in opposite directions. Wheels 22 constituting wheels 4a and 4b and braking rotating bodies (brake rotors) 23 constituting braking devices 11 are attached to each of the pair of drive shafts 14a and 14b via hub unit bearings 21. ..

In this example, each of the pair of torque transmission devices 16a and 16b is composed of a gear type speed reducer. Therefore, each of the pair of torque transmission devices 16a and 16b transmits the torque to the pair of drive shafts 14a and 14b while increasing the rotational torque of the motor output shafts 15a and 15b. The torque transmission device is not limited to the gear type speed reducer, and may be composed of a speed reducer using a belt or a chain, or may be composed of a worm speed reducer. Further, each of the pair of torque transmission devices may be composed of a continuously variable transmission or a stepped transmission whose reduction ratio can be adjusted.

According to the drive device 7, the rotation speed and the rotation direction of the pair of wheels 4a and 4b can be appropriately changed by controlling the rotation speed and the rotation direction of the motor output shafts 15a and 15b, respectively. Specifically, the rotation speed and the rotation direction of the pair of wheels 4a and 4b can be the same, and the rotation speed and / or the rotation direction of the pair of wheels 4a and 4b can be different from each other.

<< Support device (suspension device) >>
The support device 8 is arranged between the drive device 7 and the vehicle body 2 (supported portions 6a and 6b (see FIG. 1)), and suspends a pair of wheels 4a and 4b. The support device 8 supports the vehicle body 2 while pressing the outer peripheral surface (tread) of the tire 24 constituting each of the wheels 4a and 4b against the road surface, and the vibration transmitted from the road surface to the vehicle body 2 via each of the wheels 4a and 4b. Has the function of alleviating. As shown in FIGS. 3 and 4, the support device 8 includes a mount member 25, a connecting member (leaf spring) 26, and a damper 27.

The mount member 25 is arranged on the upper side of the drive device 7 substantially parallel to the road surface. The mount member 25 is fixed to the lower surface of the vehicle body 2 via the turning device 9 and the vehicle height adjusting device 10.

The connecting member 26 is formed of a leaf spring having a substantially arc shape or a substantially U shape, and is arranged on one side (right side in FIG. 3) in the traveling direction with respect to the drive device 7. The connecting member 26 is elastically deformed so that the curvature of the curved portion becomes large (the radius of curvature becomes small), and the connecting member 26 has an end portion on one side in the traveling direction of the mounting member 25 and an end portion on the lower side of the housing 12. It is passed between. That is, the connecting member 26 connects and fixes the upper end portion to the one-sided end portion in the traveling direction of the mount member 25, and connects and fixes the lower end portion to the lower end portion of the housing 12. .. In this example, since the connecting member 26 composed of leaf springs is arranged on one side of the driving device 7 in the traveling direction, pebbles and the like are wound up by the wheels 4a and 4b when the electric vehicle 1 travels forward. Even in such a case, the connecting member 26 can prevent pebbles and the like from colliding with the drive device 7.

The damper 27 is, for example, an oil type shock absorber, which is configured to be expandable and contractible in its entire length, and is arranged on the opposite side (left side in FIG. 3) of the drive device 7 in the traveling direction. The damper 27 has a function of damping the periodic vibration in the vertical direction caused by the elastic deformation of the connecting member 26, and the upper end portion (piston) can be rotated to the other end portion in the traveling direction of the mounting member 25. It is supported (pistoned) and the lower end (cylinder) is rotatably supported by the arm portion 18 of the housing 2.

The support device 8 configured as described above presses the outer peripheral surface of the tire 24 against the road surface by the force that the connecting member 26 tries to elastically restore. Further, the support device 8 absorbs and relaxes the vibration transmitted from the road surface to the vehicle body 2 by elastically deforming the connecting member 26 and contracting the damper 27 to generate a damping force.

<< Swivel device (steering device) >>
As shown in FIG. 3, the swivel device 9 attaches the mount member 25 of the support device 8 to the supported portions 6a and 6b of the vehicle body 2 via the vehicle height adjusting device 10 in the vertical direction axis (kingpin axis, vertical axis). It supports rotation around the turning shaft C, which is a shaft), and enables steering of a pair of wheels 4a and 4b. That is, when the swivel device 9 rotationally drives the pair of wheels 4a and 4b by the drive device 7 so that the respective rotation speeds and / or rotation directions are different from each other, the pair of wheels 4a and 4b (and the drive device) 7 and the support device 8) can rotate (steer) with respect to the vehicle body 2 about the turning shaft C.

As shown in FIG. 3, the swivel device 9 includes a fixing member 28 and a rotating member 29, each of which has its central axis aligned with the swivel axis C and is rotatably combined relative to each other. The fixing member 28 is supported and fixed to the lower surface of the vehicle height adjusting device 10. The rotating member 29 is supported and fixed on the upper surface of the mount member 25 of the support device 8.

In this example, the swivel shaft C is arranged at a twisted position with respect to each of the pair of drive shafts 14a and 14b. Specifically, as shown in FIG. 3, the swivel shaft C is arranged offset to one side in the traveling direction with respect to the pair of drive shafts 14a and 14b. As a result, the turning shaft C is positioned on one side in the traveling direction with respect to the ground contact point of the tire 24 with respect to the road surface, and the caster trail is secured.

《Vehicle height adjustment device》
The vehicle height adjusting device 10 is arranged between the supported portions 6a and 6b (see FIG. 1) of the vehicle body 2 and the driving device 7 via the supporting device 8 and the turning device 9, and is arranged from the road surface of the vehicle body 2. It has a function to adjust the height (vehicle height) of the vehicle. The vehicle height adjusting device 10 is a pantograph type vehicle height adjusting device, and is arranged at the upper end of the wheel drive unit 3. As shown in FIGS. 2, 6 to 9, the vehicle height adjusting device 10 includes a support frame 30 configured by a link mechanism and an electric actuator 31.

[Support frame]
The support frame 30 is formed in a substantially rectangular frame shape as a whole, and its dimensions in the vertical direction and the traveling direction can be changed. The vertical dimension of the support frame 30 increases when the dimension in the traveling direction is reduced, and the vertical dimension decreases when the dimension in the traveling direction is increased. The support frame 30 includes an upper pedestal portion 32, a lower pedestal portion 33, a first link portion 34, and a second link portion 35, each of which is made of an iron-based alloy.

The upper pedestal portion 32 is formed in a substantially rectangular plate shape, and is supported and fixed to the lower surfaces of the supported portions 6a and 6b constituting the vehicle body 2 by a plurality of bolts (not shown). The lower pedestal portion 33 is formed in a substantially rectangular plate shape, is arranged below the upper pedestal portion 32 substantially in parallel with the upper pedestal portion 32, and is arranged with respect to the upper surface of the fixing member 28 constituting the swivel device 9. , It is supported and fixed by multiple bolts. Therefore, the orientation of the support frame 30 does not change even when the pair of wheels 4a and 4b are steered, and is constant. Further, the lower pedestal portion 33 is indirectly fixed to the drive device 7 via the swivel device 9 and the support device 8.

The first link portion 34 is arranged on one side in the traveling direction of the support frame 30, and has an end on one side in the traveling direction of the upper pedestal portion 32 and an end on one side in the traveling direction of the lower pedestal portion 33. Are connected to each other.

The first link portion 34 has a first upper link piece 36, a first lower link piece 37, and a first casing piece 38. The first upper link piece 36 is formed in a substantially rectangular plate shape, and the tip portion (upper end portion) located on the other side in the traveling direction is in the width direction with respect to the end portion on one side in the traveling direction of the upper pedestal portion 32. It is rotatably connected by a pair of connecting pins 39a arranged coaxially with each other on both sides. The first lower link piece 37 is formed in a substantially rectangular plate shape, and has a tip portion (lower end portion) located on the other side in the traveling direction with respect to an end portion on one side in the traveling direction of the lower pedestal portion 33. It is rotatably connected by a pair of connecting pins 39b arranged coaxially with each other on both sides in the width direction. The base end (lower end) located on one side of the first upper link piece 36 in the traveling direction and the base end (upper end) located on one side of the first lower link piece 37 in the traveling direction are in the width direction. A pair of first pivots 40 arranged coaxially with each other on both sides are rotatably connected to each other. The first casing piece 38 is arranged between the first upper link piece 36 and the first lower link piece 37, and is the base end portion (lower end portion) of the first upper link piece 36 and the first lower link piece 37. A pair of first pivots 40 are rotatably supported with respect to the base end portion (upper end portion) of the above.

The second link portion 35 is arranged on the other side portion in the traveling direction of the support frame 30, and has an end portion on the other side in the traveling direction of the upper pedestal portion 32 and an end portion on the other side in the traveling direction of the lower pedestal portion 33. Are connected to each other.

The second link portion 35 has a second upper link piece 41, a second lower link piece 42, and a second casing piece 43. The second upper link piece 41 is formed in a substantially rectangular plate shape, and the tip portion (upper end portion) located on one side in the traveling direction is in the width direction with respect to the end portion on the other side in the traveling direction of the upper pedestal portion 32. It is rotatably connected by a pair of connecting pins 44a arranged coaxially with each other on both sides. The second lower link piece 42 is formed in a substantially rectangular plate shape, and has a tip portion (lower end portion) located on one side in the traveling direction with respect to the other end portion in the traveling direction of the lower pedestal portion 33. It is rotatably connected by a pair of connecting pins 44b arranged coaxially with each other on both sides in the width direction. The base end (lower end) located on the other side of the second upper link piece 41 in the traveling direction and the base end (upper end) located on the other side of the second lower link piece 42 in the traveling direction are in the width direction. A pair of second pivots 45 arranged coaxially with each other on both sides are rotatably connected to each other. The second upper link piece 41 and the first upper link piece 36 are common parts, and the second lower link piece 42 and the first lower link piece 37 are common parts. The second casing piece 43 is arranged between the second upper link piece 41 and the second lower link piece 42, and is the base end portion (lower end portion) of the second upper link piece 41 and the second lower link piece 42. A pair of second pivots 45 are rotatably supported with respect to the base end portion (upper end portion) of the above.

The support frame 30 changes the size of the opening angle between the first upper link piece 36 and the first lower link piece 37 centered on the first pivot 40, and at the same time, the second pivot frame 45 is centered on the second pivot 45. By changing the size of the opening angle between the upper link piece 41 and the second lower link piece 42, the dimensions in the vertical direction and the traveling direction can be changed.

The support frame 30 allows only the upper pedestal portion 32 and the lower pedestal portion 33 to be relatively displaced in the vertical direction (axial direction of the swivel axis C) while remaining parallel to each other, and is orthogonal to the horizontal direction (orthogonal to the swivel axis C). A plurality of (two in the illustrated example) guide members 46 are further provided in order to prevent relative displacement in the direction (in the illustrated example).

Each of the guide members 46 includes a cylindrical support sleeve 47 and a cylindrical support shaft 48 (see FIG. 8). The support sleeves 47 are fixed to the upper surface of the lower pedestal portion 33 in a state where their central axes are arranged in parallel with each other and in the vertical direction. The support shafts 48 are fixed to the lower surface of the upper pedestal portion 32 in a state where their central axes are arranged in parallel with each other and in the vertical direction. Then, each of the support shafts 48 is inserted inside the support sleeve 47 so as to be relatively movable (sliding) in the vertical direction without rattling. A cylindrical guide sleeve is interposed between the support sleeve 47 and the support shaft 48 in order to improve the slidability of the support sleeve 47 and the support shaft 48.

As shown in FIG. 9B, the total lengths of the support sleeve 47 and the support shaft 48 have a vertical distance between the upper pedestal portion 32 and the lower pedestal portion 33 (vertical dimensions of the support frame 30). Even when it is maximized, the length is set so that the fitting length between the support sleeve 47 and the support shaft 48 can be sufficiently secured. In the illustrated example, the total length of the support shaft 48 is longer than the total length of the support sleeve 47, and as shown in FIG. 9A, the upper pedestal portion 32 and the lower pedestal portion 33 Each lower end portion of the support shaft 48 is projected downward through a through hole formed in the lower pedestal portion 33 in a state where the vertical distance is minimized.

[Electric actuator]
The electric actuator 31 is for changing the vertical dimension of the support frame 30, and as shown in FIG. 8, the electric motor 49, the expansion / contraction mechanism 50, the reduction mechanism 51, and the inverse differential prevention mechanism 52 are provided. Be prepared. In this example, the electric actuator 31 is supported by the support frame 30.

The electric motor 49 includes an output shaft 53, and is supported by a second casing piece 43 constituting the second link portion 35. Specifically, the electric motor 49 is supported by the other end of the second casing piece 43 in the traveling direction in a state where the output shaft 53 is arranged substantially horizontally in the traveling direction. The rotation direction and rotation angle of the output shaft 53 of the electric motor 49 are controlled by a control device provided in the vehicle body 2.

The expansion / contraction mechanism 50 includes a linear motion mechanism 54 and a connecting shaft 55. In this example, as the linear motion mechanism 54, a ball screw mechanism including a ball screw shaft 56, a ball nut 57, and a plurality of balls (not shown) is adopted. However, as a linear motion mechanism, the male screw portion having a trapezoidal cross section formed on the outer peripheral surface of the screw shaft and the female screw portion having a trapezoidal cross section formed on the inner peripheral surface of the nut are directly screwed without using a ball. A fed screw mechanism may be adopted. If such a feed screw mechanism is adopted, it is necessary to use a large electric motor having a large output torque as compared with the case where the ball screw mechanism is adopted, but since the reverse differential can be prevented by the feed screw mechanism. , It is not necessary to provide a reverse differential prevention mechanism separately.

The ball screw shaft 56 is arranged substantially parallel to the output shaft 53 of the electric motor 49, and has a spiral male ball screw groove (not shown) in one half (first half) of the outer peripheral surface in the traveling direction. .. The portion of the ball screw shaft 56 that is separated from the male ball screw groove is supported only rotatably inside the second casing piece 43 via the bearing device 58.

The bearing device 58 has a tubular case 59 and a pair of angular contact ball bearings 60a and 60b internally fitted inside the case 59. The case 59 is supported inside the second casing piece 43 so as to be unable to perform relative displacement and relative rotation in the traveling direction. The pair of angular contact ball bearings 60a and 60b are provided with a frontal combination type contact angle, and are fitted externally to the intermediate portion of the ball screw shaft 56 in the traveling direction.

The ball nut 57 has a spiral female-side ball screw groove (not shown) on the inner peripheral surface, and is arranged around the ball screw shaft 56. The ball nut 57 is arranged inside the second casing piece 43 so that it can be displaced in the traveling direction (the axial direction of the ball screw shaft 56) and cannot rotate relative to the second casing piece 43.

Each of the plurality of balls is arranged between the male side ball screw groove of the ball screw shaft 56 and the female side ball screw shaft of the ball nut 57.

The connecting shaft 55 is arranged coaxially with the ball screw shaft 56, and is bridged between the first casing piece 38 and the second casing piece 43. The end portion (tip portion) on one side of the traveling direction of the connecting shaft 55 is fixed to the first casing piece 38 so as to be unable to perform relative rotation and relative displacement in the traveling direction, and the end portion on the other side in the traveling direction. The (base end portion) is supported with respect to the second casing piece 43 so that it cannot rotate relative to the second casing piece 43 and can be displaced relative to the traveling direction. The connecting shaft 55 has an end on the other side in the traveling direction that is externally fitted to the ball nut 57 so as not to rotate relative to the ball nut 57. For this purpose, the connecting shaft 55 has a hollow portion 61 on the other side in the traveling direction, and the ball nut 57 and the half portion on one side in the traveling direction of the ball nut 57 and the ball screw shaft 56 are arranged inside the hollow portion 61. doing.

When the ball screw shaft 56 is rotated, the ball nut 57 and the connecting shaft 55 are displaced relative to the ball screw shaft 56 in the traveling direction. As a result, the total length of the expansion / contraction mechanism 50, which corresponds to the length from the one-sided end (tip) of the connecting shaft 55 in the traveling direction to the other end (base end) of the ball screw shaft 56 in the traveling direction, is , It expands and contracts by rotating the ball screw shaft 56.

In this example, in order to transmit the rotational torque of the output shaft 53 of the electric motor 49 to the ball screw shaft 56 constituting the expansion / contraction mechanism 50, a reduction mechanism 51 is provided between the output shaft 53 and the ball screw shaft 56. ing. The speed reduction mechanism 51 is a gear type speed reducer, and transmits the torque to the ball screw shaft 56 while increasing the rotational torque of the output shaft 53. The speed reduction mechanism 51 includes an intermediate shaft 62 and two gears 63a and 63b.

The intermediate shaft 62 is arranged coaxially with the output shaft 53 of the electric motor 49, and is supported only rotatably inside the second casing piece 43 by the double row ball bearing 64. The intermediate shaft 62 is connected to the output shaft 53 via an inverse differential prevention mechanism 52.

The first gear 63a is fixed to the intermediate shaft 62 or integrally formed with the intermediate shaft 62, and rotates in synchronization with the intermediate shaft 62.

The second gear 63b is fixed to the end of the ball screw shaft 56 on the other side in the traveling direction, and rotates in synchronization with the ball screw shaft 56. The second gear 63b has a larger diameter than the first gear 63a and has more teeth on the outer peripheral surface than the first gear 63a. The second gear 63b meshes with the first gear 63a.

When the output shaft 53 is rotationally driven by energizing the electric motor 49, the rotation of the output shaft 53 is transmitted to the intermediate shaft 62 via the reverse differential prevention mechanism 52. The rotation of the intermediate shaft 62 is transmitted to the ball screw shaft 56 via the meshing portion between the first gear 63a and the second gear 63b. In this way, the rotational torque of the output shaft 53 of the electric motor 49 is increased by the reduction mechanism 51 and then transmitted to the ball screw shaft 56.

The reverse differential prevention mechanism 52 transmits rotational torque from the output shaft 53 of the electric motor 49 to the intermediate shaft 62 regardless of the rotation direction of the output shaft 53, but the output shaft of the electric motor 49 is transmitted from the intermediate shaft 62. The 53 has a function of not transmitting rotational torque regardless of the rotational direction of the intermediate shaft 62. That is, the inverse differential prevention mechanism 52 mechanically prevents the linear motion of the expansion / contraction mechanism 50 (linear motion mechanism 54) from being converted into the rotational motion of the output shaft 53 of the electric motor 49. Specifically, the connecting shaft 55 and the ball nut 57 are displaced relative to the ball screw shaft 56 in the traveling direction, so that the ball screw shaft 56 that rotates in synchronization with the output shaft 53 of the electric motor 49 rotates. To prevent. This also prevents the connecting shaft 55 and the ball nut 57 from being displaced relative to the ball screw shaft 56 in the traveling direction.

As the reverse differential prevention mechanism 52, for example, the reverse input cutoff clutch described in Japanese Patent Application Laid-Open No. 2019-138410 (Patent Document 2) can be used. However, the inverse differential prevention mechanism is not limited to the structure described in Japanese Patent Application Laid-Open No. 2019-138410, and various conventionally known structures can be adopted.

In order to adjust the vehicle height of the electric vehicle 1 by the vehicle height adjusting device 10 of this example, the electric motor 49 is energized, and the ball screw shaft 56 is set in a predetermined direction via the reverse differential prevention mechanism 52 and the reduction mechanism 51. Rotate by a predetermined angle. As a result, the ball nut 57 and the connecting shaft 55 are relatively displaced with respect to the ball screw shaft 56 by a predetermined amount in the traveling direction to expand and contract the entire length of the expansion / contraction mechanism 50. When the entire length of the expansion / contraction mechanism 50 is expanded / contracted in this way, the distance between the first link portion 34 (first pivot 40) and the second link portion 35 (second pivot 45) in the traveling direction is expanded / contracted, and the upper pedestal portion The vertical distance between the 32 and the lower pedestal portion 33 is expanded or contracted.

Specifically, when the ball nut 57 and the connecting shaft 55 are displaced relative to one side in the traveling direction with respect to the ball screw shaft 56 to extend the total length of the expansion / contraction mechanism 50 as shown in FIG. 9A, The distance between the first link portion 34 (first pivot 40) and the second link portion 35 (second pivot 45) in the traveling direction is widened, and the opening angle between the first upper link piece 36 and the first lower link piece 37 is widened. As the value becomes smaller, the opening angle between the second upper link piece 41 and the second lower link piece 42 becomes smaller. As a result, the vertical distance between the upper pedestal portion 32 and the lower pedestal portion 33 (the vertical dimension of the support frame 30) is reduced, and the vehicle height of the vehicle body 2 is lowered.

On the other hand, when the ball nut 57 and the connecting shaft 55 are displaced relative to the ball screw shaft 56 on the other side in the traveling direction to reduce the total length of the expansion / contraction mechanism 50 as shown in FIG. The distance between the 1 link portion 34 (first pivot 40) and the second link portion 35 (second pivot 45) in the traveling direction is shortened, and the opening angle between the first upper link piece 36 and the first lower link piece 37 is increased. As the size increases, the opening angle between the second upper link piece 41 and the second lower link piece 42 increases. As a result, the vertical distance between the upper pedestal portion 32 and the lower pedestal portion 33 is increased, and the vehicle height of the vehicle body 2 is increased. The adjustment width of the vehicle height by the vehicle height adjusting device 10 can be, for example, about several tens of mm to 100 mm.

According to the vehicle height adjusting device 10, the vehicle body 2 fixed to the upper surface of the upper pedestal portion 32 by adjusting the vertical distance between the upper pedestal portion 32 and the lower pedestal portion 33 as described above. The vehicle height can be adjusted. When adjusting the distance between the upper pedestal portion 32 and the lower pedestal portion 33, the electric actuator 31 moves in parallel in the vertical direction to the intermediate portion in the vertical direction between the upper pedestal portion 32 and the lower pedestal portion 33. To position.

《Brake device》
As shown in FIGS. 2 and 3, the braking device 11 is used for reducing the traveling speed of the electric vehicle 1 and stopping the electric vehicle 1, and is provided with two for each wheel drive unit 3. Has been done. Each of the braking devices 11 is composed of a disc brake device, and includes a brake caliper 65 supported and fixed to the housing 12, and a braking rotating body 23 which is a brake rotor and rotates together with the drive shafts 14a and 14b. At the time of braking, the brake caliper 65 is operated electrically or hydraulically, and the braking rotating body 23 is sandwiched by a pair of pads provided on the brake caliper 65. Further, by using the pair of motors 13a and 13b constituting the drive device 7 as a generator, the electric vehicle 1 can be decelerated by regenerative braking. As the braking device, a drum braking device in which a rotating body for braking is used as a brake drum can also be adopted.

The electric vehicle 1 of this example controls the rotation speed and the rotation direction of the pair of wheels 4a and 4b for each wheel drive unit 3 based on a control device provided in the vehicle body 2 or a command from the driver. The traveling direction and the traveling speed can be controlled, and the electric vehicle 1 can be stopped by controlling the respective braking devices 11 of the wheel drive unit 3.

For example, the electric vehicle 1 can travel straight forward or backward by making the rotation speeds and rotation directions of all the wheels 4a and 4b the same. Further, the electric vehicle 1 steers the wheels 4a and 4b by the turning device 9 provided in each of the wheel drive units 3 by adjusting the rotation speeds of the wheels 4a and 4b to appropriate values, and turns. can do. At this time, the rotation speeds of the wheels 4a and 4b are reduced as the wheels are closer to the turning center. Further, for each of the wheel drive units 3, if the rotation direction of one wheel 4a and the rotation direction of the other wheel 4b are opposite to each other, only the direction of the wheel drive unit 3 is changed (steering) on the spot. )can do. Therefore, if each direction of the wheel drive unit 3 is rotated by 90 degrees from the traveling direction, the electric vehicle 1 can be driven in the width direction.

In this example, the wheel drive unit 3 that rotationally drives the pair of wheels 4a and 4b is configured as a unit independent of the vehicle body 2, and the number of wheel drive units 3 corresponding to the total weight of the vehicle body 2 is assembled to the vehicle body 2. It constitutes the electric vehicle 1. Therefore, the wheel drive unit 3 can be used in common regardless of the total weight of the vehicle body 2. Therefore, the manufacturing cost of the electric vehicle 1 can be reduced. In particular, when the electric vehicle 1 is an autonomous vehicle provided with a large number of expensive sensors, the cost reduction effect due to the common use of the wheel drive units 3 can be remarkably obtained.

Since the wheel drive unit 3 has individual functions such as running, turning, and stopping, even if a part of the wheel drive units 3 fails, the remaining wheel drive units 3 can be used to some extent (for example,). You can continue to run on your own (as long as you evacuate to the shoulder). Further, the electric vehicle 1 can be easily repaired by replacing the failed wheel drive unit 3 together, and is excellent in maintainability.

The electric vehicle 1 includes a vehicle height adjusting device 10 for each of the plurality of wheel drive units 3. Therefore, the height of the portion of the vehicle body 2 to which the wheel drive unit 3 is attached from the road surface can be individually adjusted. Therefore, if each of the vehicle height adjusting devices 10 is adjusted based on the measured values of the weight sensors provided in the wheel drive unit 3, the weight of the vehicle body 2 can be reduced regardless of the bias of the load of the vehicle body 5. The wheels 4a and 4b can be used in a well-balanced manner. Further, at the time of cornering, the vertical dimension of the support frame 30 of the vehicle height adjusting device 10 arranged on the side closer to the turning center in the width direction is reduced, and the vehicle height adjustment arranged on the side far from the turning center in the width direction. By increasing the vertical dimension of the support frame 30 of the device 10, it is possible to prevent the heights of the vehicle body 2 from being inconsistent in the width direction and to stabilize the vehicle balance. Further, when the occupant gets on and off and the cargo is loaded and unloaded, the boarding / alighting port side of the vehicle body 2 can be lowered to facilitate the boarding / alighting operation and the loading / unloading work.

In particular, in this example, the vehicle height adjusting device 10 is composed of a support frame 30 composed of a link mechanism and an electric actuator 31 having an expansion / contraction mechanism 50, and the expansion / contraction mechanism 50 is expanded / contracted by an electric motor 49. , The vertical dimension of the support frame 30 can be adjusted. Therefore, according to the vehicle height adjusting device 10, the vehicle height of the vehicle body 2 can be adjusted without using a large auxiliary machine such as a tank or a compressor, so that the vehicle height adjusting device 10 can be made compact. .. Further, since the vehicle height adjusting device 10 is configured independently of the support device 8 that functions as a suspension, it is not necessary to reduce the riding comfort of the vehicle by setting the vehicle height.

The vehicle height adjusting device 10 can convert the expansion / contraction operation of the expansion / contraction mechanism 50 arranged in the horizontal direction into an operation (displacement) in the vertical direction by using the support frame 30 configured by the link mechanism. Therefore, the expansion / contraction mechanism 50 having a bulky overall length can be arranged in the horizontal direction instead of the vertical direction, and the vehicle height adjusting device 10 can be downsized. Further, since the support frame 30 configured by the link mechanism is used to convert the horizontal expansion / contraction operation of the expansion / contraction mechanism 50 into the vertical operation, as compared with the case where the expansion / contraction mechanism is arranged in the vertical direction, Even if the expansion / contraction amount of the expansion / contraction mechanism 50 (the stroke amount of the ball nut 57 and the connecting shaft 55) is small, the expansion / contraction amount of the upper pedestal portion 32 and the lower pedestal portion 33 in the vertical direction can be increased. Therefore, the time required for adjusting the vehicle height can be shortened.

Since the vehicle height adjusting device 10 employs a ball screw mechanism as the linear motion mechanism 54 constituting the expansion / contraction mechanism 50, the torque required for driving can be reduced, and the electric motor 49 can be miniaturized. .. Therefore, the vehicle height adjusting device 10 can be downsized and the electricity cost can be reduced. Further, since the rotational torque of the output shaft 53 of the electric motor 49 is increased by the reduction mechanism 51 and transmitted to the ball screw shaft 56 constituting the linear motion mechanism 54, the electric motor 49 can be further miniaturized.

The support frame 30 constituting the vehicle height adjusting device 10 bears (a part of) the weight of the vehicle body 2. Therefore, the upper pedestal portion 32 and the lower pedestal portion 33 are brought closer to the support frame 30 in the vertical direction, and the first link portion 34 (first pivot axis 40) and the second link portion 35 (second pivot shaft 45) are brought close to each other. A force acts to move the and away in the direction of travel. In order to maintain the posture of the support frame 30 regardless of such a force, it is necessary to maintain the distance between the first link portion 34 and the second link portion 35 by the expansion / contraction mechanism 50. That is, it is necessary not to change the total length of the expansion / contraction mechanism 50 regardless of the force for moving the first link portion 34 and the second link portion 35 away in the traveling direction. In this example, the reverse differential prevention mechanism 52 mechanically prevents the linear motion of the expansion / contraction mechanism 50 (linear motion mechanism 54) from being converted into the rotational motion of the output shaft 53 of the electric motor 49, and the connecting shaft 55. And the ball nut 57 is prevented from being displaced relative to the ball screw shaft 56 in the traveling direction. Therefore, in order to keep the total length of the expansion / contraction mechanism 50 constant, it is not necessary to energize the electric motor 49. Therefore, the posture (vertical dimension) of the support frame 30 can be maintained without consuming electric power.

The support frame 30 constituting the vehicle height adjusting device 10 allows only the upper pedestal portion 32 and the lower pedestal portion 33 to be relatively displaced in the vertical direction while remaining parallel to each other, and is allowed to be relatively displaced in the horizontal direction. Since the guide member 46 for preventing is provided, it is possible to improve the robustness (rigidity) against an external force acting in the horizontal direction. Therefore, it is possible to prevent the riding comfort of the electric vehicle 1 from being lowered due to the provision of the vehicle height adjusting device 10.

When carrying out the present invention, the first link portion and the second link portion constituting the support frame of the vehicle height adjusting device are on the upper side by expanding or contracting the distance between the first link portion and the second link portion. The structure is not limited to the structure described in the embodiment as long as the distance between the pedestal portion and the lower pedestal portion in the vertical direction can be expanded or contracted. Further, in the embodiment, the case where the support frame is attached to the vehicle body so that the first link portion and the second link portion are arranged in the traveling direction (front-rear direction) of the electric vehicle has been described, but the upper pedestal has been described. As long as the portion and the lower pedestal portion are arranged in the vertical direction, the orientation of the support frame is not limited, and even if the first link portion and the second link portion are attached so as to be arranged in the width direction of the electric vehicle, for example. Good.

The guide member for preventing the relative displacement of the upper pedestal portion and the lower pedestal portion in the horizontal direction is not limited to the structure described in the embodiment, and other structures are adopted as long as the function can be exhibited. be able to.

When carrying out the present invention, the respective structures of the drive device, the support device, and the swivel device are not limited to the structures described in the embodiments. Other structures can be adopted as long as the functions required for the drive device, the support device and the swivel device can be exhibited.

1 Electric vehicle 2 Body 3 Wheel drive unit 4a, 4b Wheel 5 Body body 6a, 6b Supported part 7 Drive device 8 Support device 9 Swivel device 10 Vehicle height adjustment device 11 Braking device 12 Housing 13a, 13b Motor 14a, 14b Drive shaft 15a, 15b Motor output shaft 16a, 16b Torque transmission device 17 Housing body 18 Arm part 19 Connector part 20a, 20b Rotation sensor 21 Hub unit bearing 22 Wheel 23 Braking rotating body 24 Tire 25 Mounting member 26 Connecting member 27 Damper 28 Fixing member 29 Rotating member 30 Support frame 31 Electric motor 32 Upper pedestal 33 Lower pedestal 34 1st link 35 2nd link 36 1st upper link piece 37 1st lower link piece 38 1st casing piece 39a, 39b Pin 40 1st pivot 41 2nd upper link piece 42 2nd lower link piece 43 2nd casing piece 44a, 44b Connecting pin 45 2nd pivot 46 Guide member 47 Support sleeve 48 Support shaft 49 Electric motor 50 Telescopic mechanism 51 Deceleration mechanism 52 Reverse differential prevention mechanism 53 Output shaft 54 Linear movement mechanism 55 Connecting shaft 56 Ball screw shaft 57 Ball nut 58 Bearing device 59 Case 60a, 60b Angular ball bearing 61 Hollow part 62 Intermediate shaft 63a, 63b Gear 64 Double row ball bearing 65 Brake Caliper

Claims (6)

A vehicle height adjusting device for adjusting the height of the vehicle body, which is arranged between the vehicle body and a driving device that electrically drives the wheels.
Equipped with a support frame and an electric actuator,
The support frame is composed of a link mechanism, and has an upper pedestal portion fixed to the vehicle body and a lower pedestal portion located below the upper pedestal portion substantially parallel to the upper pedestal portion and fixed to the drive device. A first link portion connecting the portion, one end of the upper pedestal portion and one end of the lower pedestal portion, the other end of the upper pedestal portion, and the lower pedestal portion. The upper pedestal portion and the lower pedestal portion are provided by having a second link portion that connects the other end portion of the portion and expanding or contracting the distance between the first link portion and the second link portion. The vertical distance between the and is expanded or contracted.
The electric actuator is arranged so as to bridge between the electric motor having an output shaft and the first link portion and the second link portion, and converts the rotational motion of the output shaft into a linear motion to reduce the total length. Has an expansion and contraction mechanism that expands and contracts,
Vehicle height adjustment device. The vehicle height adjusting device for a vehicle according to claim 1, wherein the telescopic mechanism has a ball screw mechanism. The electric actuator according to any one of claims 1 and 2, further comprising an inverse differential prevention mechanism for preventing the linear motion of the telescopic mechanism from being converted into the rotational motion of the output shaft. Vehicle height adjustment device for vehicles. The first link portion includes a first upper link piece in which the tip portion is rotatably connected to one end portion of the upper pedestal portion and the tip portion is rotated to one end portion of the lower pedestal portion. It has a first lower link piece that is movably connected and has a base end portion that is rotatably connected to the base end portion of the first upper link piece.
The second link portion includes a second upper link piece in which the tip portion is rotatably connected to the other end portion of the upper pedestal portion and the tip portion is rotated to the other end portion of the lower pedestal portion. It has a second lower link piece that is movably connected and has a base end portion that is rotatably connected to the base end portion of the second upper link piece.
The vehicle height adjusting device for a vehicle according to any one of claims 1 to 3. The first link portion is rotatably supported with respect to the base ends of the first upper link piece and the first lower link piece, and supports one end of the telescopic mechanism. With more casing pieces
The second link portion is rotatably supported with respect to the base end portions of the second upper link piece and the second lower link piece, and supports the other end portion of the telescopic mechanism. With more casing pieces,
The vehicle height adjusting device for a vehicle according to claim 4. The support frame further includes a guide member between the upper pedestal portion and the lower pedestal portion to prevent the upper pedestal portion and the lower pedestal portion from being displaced relative to each other in the horizontal direction. , The vehicle height adjusting device for a vehicle according to any one of claims 1 to 5.

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