WO2021153341A1 - Lateral vibration suppression device - Google Patents

Abstract

A lateral vibration suppression device suppresses lateral vibrations acting on a seat (20) in a vehicle configured such that a movable part (21, 22, 23) which moves in unison with the seat (20) can slide in a left-right direction as seen by an occupant relative to a fixed part (91, 92, 93) that is fixed in the left-right direction to a vehicle body (90). A fluid pressure actuator (30) reciprocally displaces relative positions of the fixed part and the movable part by operating an output part (33) according to magnitudes of fluid pressures in a first fluid chamber (31) and a second fluid chamber (32). A two-way switching valve (50) is provided between an external fluid pressure supply source (60) and the fluid pressure actuator (30), and switches a flow path so as to supply fluid to one of the first fluid chamber (31) or the second fluid chamber (32) and discharge fluid from the other. A control unit (80) obtains information on the lateral vibrations acting on the seat (20) and controls the operations of the fluid pressure actuator (30) by operating the two-way switching valve (50) so as to suppress the lateral vibrations.

Description

Lateral vibration suppression device Cross-reference of related applications

This application is based on Patent Application No. 2020-15287 filed on January 31, 2020, and the contents of the description are incorporated herein by reference.

This disclosure relates to a lateral vibration suppression device.

Conventionally, a device that suppresses low-frequency vibration due to rolling of the vehicle body and enhances the stability of the sitting posture is known. For example, in the seat suspension disclosed in Patent Document 1, a seat support member is provided on a bracket which is a vehicle body side mounting member via a roll absorbing mechanism. The roll absorption mechanism absorbs roll (low-period vibration) caused by a phase shift of the hydraulic suspension of the vehicle.

Japanese Unexamined Patent Publication No. 2014-213752

The device of Patent Document 1 has a passive configuration that only absorbs rolling with a coil spring provided in the rolling direction, and does not realize active control that positively tries to move in the opposite direction to rolling. do not have. Assuming that autonomous driving will become widespread in the future and that occupants will read books and operate terminals while moving, it is thought that the need for further absorption of rolling will increase. Under such circumstances, it is considered that this passive configuration cannot meet the needs of the occupants. In this specification, "lateral vibration" is used below as a term corresponding to "rolling" in Patent Document 1.

An object of the present disclosure is to provide a lateral vibration suppressing device capable of actively suppressing lateral vibration acting on a seat.

The lateral vibration suppression device of the present disclosure acts on the seat in a vehicle in which a movable portion that moves integrally with the seat is configured to be slidable in the left-right direction when viewed from the occupant with respect to the fixed portion that is fixed in the left-right direction to the vehicle body. It is a device that suppresses lateral vibration.

This lateral vibration suppression device includes a fluid pressure actuator, a two-way switching valve, and a control unit. The fluid pressure actuator has a first fluid chamber and a second fluid chamber in which fluid pressure for moving the output units in opposite directions is generated, and outputs according to the magnitude of the fluid pressure between the first fluid chamber and the second fluid chamber. By the operation of the part, the relative position between the fixed part and the movable part is reciprocally displaced.

The two-way switching valve is provided between an external fluid pressure supply source and a fluid pressure actuator, and is a flow path for supplying fluid to one of the first fluid chamber or the second fluid chamber and discharging the fluid from the other. To switch.

The control unit acquires information on the lateral vibration acting on the seat and operates the two-way switching valve to suppress the lateral vibration to control the operation of the fluid pressure actuator. For example, the control unit may predict the lateral vibration acting on the seat in the future based on the information ahead in the traveling direction of the vehicle, and control the operation of the fluid pressure actuator by feedforward control so as to suppress the lateral vibration. .. Alternatively, the control unit may control the operation of the fluid pressure actuator by feedback control based on the detection information of the lateral vibration sensor.

The lateral vibration suppression device of the present disclosure controls the operation of the fluid pressure actuator by operating a two-way switching valve to reciprocally displace the relative position between the fixed portion and the movable portion and slide the seat in the left-right direction. That is, the seat can be positively moved in the opposite direction to the lateral vibration acting on the seat, and the lateral vibration can be actively suppressed.

The above objectives and other objectives, features and advantages of the present disclosure will be clarified by the following detailed description with reference to the accompanying drawings. The drawing is
FIG. 1 is a front view showing a state in which the seat is slid to the right in the lateral vibration suppression device according to the first embodiment. FIG. 2 is a front view showing a state in which the seat is slid to the left in the lateral vibration suppression device according to the first embodiment. FIG. 3 is a front view showing a state in which the seat is slid to the right in the lateral vibration suppression device according to the second embodiment. FIG. 4 is a bottom view of FIG. 3 as viewed from the IV direction. FIG. 5 is a frequency characteristic diagram of the lateral acceleration transmitted to the occupant's head in the second embodiment and the comparative example.

Hereinafter, a plurality of embodiments of the lateral vibration suppression device will be described with reference to the drawings. In a plurality of embodiments, substantially the same configuration is designated by the same reference numerals and description thereof will be omitted. The lateral vibration suppressing device of the present embodiment is a device that suppresses lateral vibration acting on a seat in a vehicle.

(First Embodiment)
The lateral vibration suppression device 101 of the first embodiment will be described with reference to FIGS. 1 and 2. The seat 20 provided with the lateral vibration suppression device 101 is configured to be slidable in the left-right direction when viewed from the occupant. FIG. 1 shows a state in which the seat 20 is slid to the right when viewed from the occupant, and FIG. 2 shows a state in which the seat 20 is slid to the left when viewed from the occupant. In addition, the descriptions on the right and left in the following specifications are also based on the direction seen by the occupants. The "right direction" and "left direction" in FIGS. 1 and 2 are opposite to those on the left and right sides of the paper.

Seat 20 has a cushion 25 and a backrest 26. Slide guides 21 and 22 having sliding holes penetrating in the left-right direction are attached to the lower surface of the seat 20. One slide guide 21 is provided with a bracket 23 to which the piston rod 33 of the fluid pressure cylinder 30 is attached. The slide guides 21, 22 and the bracket 23 correspond to "movable parts" that move integrally with the seat 20.

A pair of fixed blocks 91 and 92 are arranged on both the left and right sides of the seat 20. The fixed blocks 91 and 92 support both ends of the horizontally extending base bar 93. The fixed blocks 91 and 92 and the base bar 93 correspond to "fixed portions" fixed to the vehicle body 90 in the left-right direction. The base bar 93 is inserted into the sliding holes of the slide guides 21 and 22, and guides the slide guides 21 and 22 to move in the left-right direction.

In the present embodiment, as a "fluid pressure actuator", a fluid pressure cylinder 30 having a straight rod shape is installed between the seat 20 and the vehicle body 90 along the vehicle body floor surface. Typically, a hydraulic cylinder using hydraulic oil as the fluid is used. Further, the "straight rod shape" is basically intended to have a cylindrical cylinder body. However, this includes a form in which through holes and screws for mounting are provided at the four corners of the cylinder and the cylinder body is a square cylinder. The main body of the fluid pressure cylinder 30 is fixed to the fixing block 92, and the tip end portion of the piston rod 33 is attached to the bracket 23.

The fluid pressure cylinder 30 has a first fluid chamber 31 and a second fluid chamber 32 separated by a piston portion of the piston rod 33. In the first fluid chamber 31 and the second fluid chamber 32, fluid pressure is generated in which the piston rod 33 as the “output unit” is moved in opposite directions. The fluid pressure cylinder 30 is also referred to as a "linear actuator" because the piston rod 33 reciprocates on a straight line. However, in order to avoid misunderstanding as "linear actuator" in the sense of "actuator using a linear motor", the term "linear actuator" is used as a reference in this specification.

The two-way switching valve 50 is provided between the fluid pump 60, which is an external "fluid pressure supply source", and the fluid pressure cylinder 30. In FIGS. 1 and 2, the part marked above the floor surface of the vehicle body 90 reflects the actual layout, whereas the portion marked below the floor surface of the vehicle body 90 is different from the actual layout. Regardless, only the input and output of fluids and signals are shown.

The two-way switching valve 50 has a path for supplying a fluid from the fluid pump 60 to one fluid chamber of the fluid pressure cylinder 30 and a path from the other fluid chamber of the fluid pressure cylinder 30 to the tank 65 according to a command signal from the control unit 80. Switch between the path for discharging the fluid. Typically, the two-way switching valve 50 is composed of a solenoid valve that operates quickly. When the solenoid valve is not energized, the two-way switching valve 50 is in the shutoff position. For example, a solenoid valve used as a hydraulic control valve in an automatic transmission of a vehicle may be used for the two-way switching valve 50 of the present embodiment.

In the state shown in FIG. 1, the fluid is supplied from the fluid pump 60 to the first fluid chamber 31, and the fluid is discharged from the second fluid chamber 32 to the tank 65. Therefore, the fluid pressure in the first fluid chamber 31 becomes larger than the fluid pressure in the second fluid chamber 32, and the piston rod 33 extends. When the piston rod 33 extends, the movable portions 21, 22, and 23 slide to the right with respect to the fixed portions 91, 92, and 93 together with the seat 20.

In the state shown in FIG. 2, the fluid is supplied from the fluid pump 60 to the second fluid chamber 32, and the fluid is discharged from the first fluid chamber 31 to the tank 65. Therefore, the fluid pressure in the second fluid chamber 32 becomes larger than the fluid pressure in the first fluid chamber 31, and the piston rod 33 degenerates. When the piston rod 33 retracts, the movable portions 21, 22, and 23 slide to the left with respect to the fixed portions 91, 92, and 93 together with the seat 20. In this way, the fluid pressure cylinder 30 has the fixed portions 91, 92, 93 and the movable portions 21, 22, by the operation of the piston rod 33 according to the magnitude of the fluid pressure between the first fluid chamber 31 and the second fluid chamber 32. The position relative to 23 is reciprocally displaced.

The control unit 80 acquires information on the lateral vibration acting on the seat 20 and operates the two-way switching valve 50 so as to suppress the lateral vibration to control the operation of the fluid pressure cylinder 30. Hereinafter, sensors that detect information related to lateral vibration such as acceleration sensors are collectively referred to as "lateral vibration sensors". For example, the control unit 80 acquires the detection information fed back (“FB” in the figure) from the lateral vibration sensor, operates the two-way switching valve 50 so as to suppress the lateral vibration, and controls the operation of the fluid pressure cylinder 30. do.

Instead of or in addition to the feedback control, the control unit 80 may acquire forward information which is information ahead in the traveling direction of the vehicle and perform feedforward (“FF” in the figure) control based on the forward information. .. In that case, the control unit 80 predicts the lateral vibration acting on the seat 20 in the future, and controls the operation of the fluid pressure cylinder 30 by feedforward control so as to suppress the lateral vibration.

Examples of forward information include map information including a dynamic map, road surface information by a camera, behavior information of a vehicle in front, and the like. If the road surface in front is inclined or uneven, it is predicted that lateral vibration will occur depending on the road surface condition. Further, when the own vehicle turns left or right according to the navigation, or when the lane is changed due to the behavior of the vehicle in front, it is predicted that the lateral acceleration acts on the seat 20. By controlling the operation of the fluid pressure cylinder 30 in advance based on these predictions, more active control becomes possible. When the vehicle is traveling backwards, the information behind the vehicle corresponds to the information ahead in the traveling direction.

The lateral vibration suppression device 101 of the present embodiment operates the two-way switching valve 50 to control the operation of the fluid pressure cylinder 30, so that the fixed portions 91, 92, 93 and the movable portions 21, 22, 23 are relative to each other. The position is reciprocally displaced, and the seat 20 is slid in the left-right direction. That is, the seat 20 can be positively moved against the lateral vibration acting on the seat 20, and the lateral vibration can be actively suppressed. This makes it possible for the occupant to control the vibration comfortably, not just the vibration control.

Further, in the present embodiment, a fluid pressure cylinder 30 having a straight rod shape is installed between the seat 20 and the vehicle body 90 along the vehicle body floor surface. As a result, the space in the height direction can be suppressed, and the lateral vibration suppression device 101 can be installed in a form close to the seat layout of the current vehicle.

(Second Embodiment)
The lateral vibration suppression device 102 of the second embodiment will be described with reference to FIGS. 3 and 4. The notes regarding the illustration in FIG. 3 are based on those in FIGS. 1 and 2. The lateral vibration suppressing device 102 of the second embodiment further includes a coil spring 40 as an "elastic member" capable of absorbing vibration with respect to the lateral vibration suppressing device 101 of the first embodiment. The coil spring 40 has a tubular shape, and is installed between the seat 20 and the vehicle body 90 adjacent to the fluid pressure cylinder 30 along the vehicle body floor surface. As a result, the dead space under the seat 20 can be reduced and the space can be effectively utilized.

FIG. 5 shows the frequency characteristics of the lateral acceleration transmitted to the occupant's head in the second embodiment and the comparative example. A comparative example is a rigid configuration in which lateral vibration suppression control is not performed. In the comparative example, the peak of the lateral acceleration appears in the low frequency region and the high frequency region, which means that the occupant feels a great deal of shaking. The low-frequency vibration is rolling due to the structure of the vehicle or the like, and the high-frequency vibration is vibration due to the unevenness of the road surface or the like.

On the other hand, by performing the lateral vibration suppression control according to the first embodiment and the second embodiment, it is possible to reduce the transmission of the lateral acceleration mainly in the low frequency region as shown by the arrow A. Further, in the second embodiment, by providing an elastic member such as a coil spring 40, as shown by an arrow B, it is possible to absorb vibration in a high frequency range that cannot be absorbed by the operation of the fluid pressure cylinder 30. It is preferable to design the specifications of the coil spring 40 according to the frequency at which vibration is desired to be suppressed. Thereby, in the second embodiment, the influence of the lateral vibration on the occupant can be reduced more appropriately.

(Other embodiments)
(1) The "fixed portion fixed to the vehicle body 90 in the left-right direction" and the "movable portion that moves integrally with the seat 20" are not limited to the configurations shown in FIGS. It suffices if it can slide in the left-right direction. For example, contrary to FIGS. 1 to 4, a shaft portion provided in the movable portion may be guided by a sliding hole provided in the fixed portion and slide. Further, the connection structure between the fluid pressure actuator and the fixed portion and the movable portion does not matter.

(2) The fluid pressure actuator is not limited to the straight rod-shaped fluid pressure cylinder 30 shown in the above embodiment, and the “output unit” is formed according to the magnitude of the fluid pressure between the first fluid chamber 31 and the second fluid chamber 32. Any actuator may be used as long as it operates in opposite directions. In that case, the form of the "output unit" is not limited to the piston rod 33 that operates linearly, and may be a rectangular or fan-shaped plate or the like.

(3) In the second embodiment, the coil spring, which is a tubular elastic member, is installed, for example, via a member provided with a notch for allowing the pipe to escape, so that the fluid pressure cylinder 30 avoids interference with the pipe. It may be extrapolated around. Further, as the elastic member, rubber, resin, foaming material or the like may be used in addition to the coil spring. Further, a plurality of elastic members having different vibration frequency ranges to be absorbed may be used in combination.

As described above, the present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the present embodiment.

The controls and methods thereof described in the present disclosure are realized by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. May be done. Alternatively, the controls and methods thereof described in the present disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and method thereof described in the present disclosure may be a combination of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured. Further, the computer program may be stored in a computer-readable non-transitional tangible recording medium as an instruction executed by the computer.

This disclosure has been described in accordance with the embodiments. However, the present disclosure is not limited to such embodiments and structures. The present disclosure also includes various variations and variations within an equal range. Also, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are within the scope and ideas of the present disclosure.

Claims (4)

1. The movable parts (21, 22, 23) that move integrally with the seat (20) can slide in the left-right direction when viewed from the occupant with respect to the fixed parts (91, 92, 93) that are fixed in the left-right direction to the vehicle body (90). A device that suppresses lateral vibration acting on the seat in a vehicle configured in
   It has a first fluid chamber (31) and a second fluid chamber (32) in which fluid pressure for moving the output unit (33) in opposite directions is generated, and the fluid pressure between the first fluid chamber and the second fluid chamber. A fluid pressure actuator (30) that reciprocates the relative position between the fixed portion and the movable portion by the operation of the output unit according to the magnitude of the above.
   A flow path provided between an external fluid pressure supply source (60) and the fluid pressure actuator so as to supply fluid to one of the first fluid chamber or the second fluid chamber and discharge the fluid from the other. Two-way switching valve (50) to switch between
   A control unit (80) that acquires information on the lateral vibration acting on the seat and operates the two-way switching valve to suppress the lateral vibration to control the operation of the fluid pressure actuator.
   A lateral vibration suppression device equipped with.
2. The lateral vibration suppression device according to claim 1, wherein the fluid pressure actuator is composed of a fluid pressure cylinder having a straight rod shape and is installed between the seat and the vehicle body along the floor surface of the vehicle body.
3. The lateral vibration according to claim 2, further comprising an elastic member (40) that is installed adjacent to the fluid pressure actuator or is tubular and extrapolated around the fluid pressure actuator to absorb vibration. Suppressor.
4. The control unit acquires forward information, which is information ahead in the traveling direction of the vehicle, and obtains forward information.
   Any one of claims 1 to 3 which predicts the lateral vibration acting on the seat in the future based on the forward information and controls the operation of the fluid pressure actuator by feedforward control so as to suppress the lateral vibration. The lateral vibration suppression device described in the section.

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