JP2023069210A - suspension device - Google Patents

Abstract

To provide an inexpensive suspension device even though it can control the posture of a vehicle body.SOLUTION: According to an embodiment of the present invention, a suspension device 1 includes: damping force variable dampers 2 interposed between a vehicle body B and at least one or more left and right sets of wheels Wrl, Wrr (Wfl, Wfr) to be able to adjust only damping force of an extension side or a contraction side for a vehicle V having the vehicle body B and the wheels Wfl, Wfr, Wrl, Wrr provided over a plurality of rows in a longitudinal direction with respect to the vehicle body B including one left and right set having respective left and right wheels of the vehicle body B; and a controller 4 for controlling the damping force of the damping force variable dampers 2 on the basis of information collected by the vehicle V and acquired from the vehicle V.SELECTED DRAWING: Figure 1

Description

The present invention relates to suspension devices.

A damping force variable damper interposed between the vehicle body and each of the four wheels and each damping force variable damper for the purpose of improving the ride comfort of a four-wheeled vehicle and realizing a vehicle body posture suitable for the driving conditions. Various suspension devices have been proposed that include a controller that controls the damping force of the suspension.

In such a suspension system, the damping force variable dampers arranged on each of the four wheels are capable of adjusting the damping force during extension operation and contraction operation, and the controller controls the damping force of each damping force variable damper. are independently controlled (see Patent Document 1, for example).

JP 2018-47723 A

In such a suspension system, each damping force variable damper exerts a damping force necessary for suppressing vibration of the vehicle body by skyhook control. Therefore, the controller has three acceleration sensors for detecting the vertical acceleration of the vehicle body directly above each of the four wheels, and four stroke sensors for detecting the stroke of each damping force variable damper. Also, each damping force variable damper has a solenoid valve that adjusts the valve opening pressure according to the amount of current supplied from the controller.

The controller obtains the vertical speed of the vehicle body directly above each of the four wheels obtained from the three acceleration sensors, multiplies the speed by the Skyhook damping coefficient, and obtains the damping force to be exerted by each damping force variable damper. . In addition, since the magnitude of the damping force exerted by the variable damping force damper varies depending on the stroke speed, the controller differentiates the stroke displacement detected by the four stroke sensors to calculate the stroke speed of each variable damping force damper. is obtained, and the amount of current to be supplied to the solenoid valve for outputting the damping force obtained as described above at the stroke speed is obtained. The controller has four drive circuits for driving the solenoid valves of the variable damping force dampers, and supplies currents through the drive circuits to the solenoid valves of the variable damping force dampers according to the obtained current amount.

As described above, the conventional suspension device includes a variable damping force damper capable of adjusting the damping force on both the extension side and the contraction side, at least three acceleration sensors, four stroke sensors, and four drive circuits. Although it is excellent in that it can control the damping force of four variable damping force dampers and finely control the posture of the vehicle body, it is very expensive and is not suitable for luxury cars in the high price range. It is a system that can only be installed.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an inexpensive suspension device capable of controlling the posture of a vehicle body.

In order to achieve the above object, the suspension system of the present invention includes one or more left and right wheel trains having wheels on each of the left and right sides of the vehicle body, and is provided in a plurality of rows in the front-rear direction with respect to the vehicle body. a damping force variable damper that is interposed between the vehicle body and at least one or more wheels of the left and right train wheels for a vehicle having wheels, and that is capable of adjusting only the damping force on the extension side or the contraction side. and a controller for controlling the damping force of the damping force variable damper based on information collected by the vehicle V and obtained from the vehicle.

According to the suspension device configured in this manner, the damping force variable damper can be adjusted only on the extension side or the contraction side. Since the damping force of the damping force variable damper is adjusted using information originally collected by the vehicle, there is no need for the suspension device to have its own sensors.

Further, the damping force variable damper in the suspension device can only adjust the damping force on the extension side, and may be interposed between the vehicle body and the wheels of the left and right train wheels on the rear side of the vehicle body. According to the suspension device configured in this way, the damping force on the extension side of the damping force variable damper can be made hard, so that the center of gravity of the vehicle body can be lowered while suppressing roll during turning of the vehicle body and pitching during braking. Therefore, the posture of the vehicle body during running can be stabilized, and deterioration of ride comfort during contraction operation can be suppressed.

Furthermore, the variable damping force damper may be capable of adjusting the damping force in two stages, a normal damping force and a hard damping force higher than the normal damping force. Since the structure of the damping force adjustment valve of the damping force variable damper 2 is simplified, the cost of the suspension device can be further reduced.

The variable damping force damper in the suspension device includes a cylinder, a rod inserted into the cylinder so as to be axially movable, and a rod inserted into the cylinder so as to be axially movable and connected to the rod to move through the cylinder. A damping force adjustment valve that has a solenoid and can adjust the resistance given to the flow of the passing liquid in two stages by turning on and off the energization of the piston. I have. According to the suspension device configured in this way, the configuration of the variable damping force damper and the controller is extremely simple, and the cost is further reduced.

Alternatively, the solenoids in the variable damping force damper may be connected in series, and the controller may have only one drive circuit for energizing the solenoids. The suspension system configured in this way is advantageous in that fail-safe can be automatically performed when one of the damping force variable dampers fails.

The suspension device may include a passive damper whose damping force cannot be adjusted and which is interposed between the vehicle body and the wheels other than the left and right train wheels in which the damping force variable damper is interposed. According to the suspension device configured in this way, the damping force variable dampers are installed only in the left and right wheel trains required for controlling the posture of the vehicle body, and the other left and right wheel trains are provided with less expensive damping force variable dampers than the damping force variable dampers. Since the passive damper is installed, the cost of the suspension device 1 can be further reduced.

Further, the controller in the suspension system may control the damping force of the damping force variable damper based on information that enables at least one of braking, acceleration, and turning to be grasped from the vehicle. According to the suspension device configured in this way, pitching, rolling or squatting of the vehicle body can be suppressed.

As described above, according to the suspension device of the present invention, the posture of the vehicle body can be controlled and the cost can be reduced.

1 is a configuration diagram of a suspension device according to an embodiment installed in a vehicle; FIG. It is a schematic longitudinal cross-sectional view of a damping force variable damper. It is a schematic longitudinal cross-sectional view of a passive damper. An example of the configuration of the controller is shown. FIG. 4 is a diagram showing a flowchart showing an example of a processing procedure of an arithmetic processing unit in a controller;

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on embodiments shown in the drawings. As shown in FIG. 1, the suspension system 1 includes a vehicle body B and wheels Wfr, Wfl, Wrr, and Wrl which are arranged in two rows, i.e., a front row and a rear row, in the front-rear direction in a row on the left and right sides of the vehicle body B. A variable damping force damper 2 is interposed between the vehicle body B and the rear wheels Wrr and Wrl, respectively, and the vehicle V is interposed between the vehicle body B and the front wheels Wfr and Wfl. and a controller 4 for controlling the damping force of the damping force variable damper 2.

Each part will be described below. In this embodiment, the vehicle V is a four-wheeled vehicle having wheels Wfl, Wfr, Wrl, and Wrr at four locations on the front, rear, left, and right of the vehicle body B. Wheels Wfl, Wfr and wheels Wrl, Wrr form left and right train wheels, respectively. there is In the present embodiment, since the vehicle V is a four-wheeled vehicle, the wheels Wfl and Wfr of the left and right train wheels on the front side are called front wheels, and the wheels Wrl and Wrr of the left and right train wheels on the rear side are called rear wheels. In addition, when it is necessary to clearly indicate the left and right wheels, the front left wheel Wfl is the front left wheel, the front right wheel Wfr is the front right wheel, and the rear left wheel Wrl is the rear left wheel. , and the rear right wheel Wrr will be referred to as the rear right wheel.

In the suspension system 1 of the present embodiment, the variable damping force dampers 2 form a pair in the left-right direction with respect to the vehicle body B and are interposed between the vehicle body B and the rear wheels Wrl and Wrr forming the left and right wheel trains. is dressed. A passive damper 3 is interposed between the front-row wheels Wfl and Wfr, which are left and right train wheels other than the rear-row wheels Wrl and Wrr on which the damping force variable dampers 2 are provided, and the vehicle body B.

In addition, the left and right train wheels each including two wheels on the left and right sides of the vehicle body B may be provided in three or more rows for one vehicle, and the damping force variable damper 2 may include one or more rows of left and right wheels. The passive dampers 3 are interposed between the wheels of the train and the vehicle body, and the passive dampers 3 are interposed between the wheels and the vehicle body of the left and right train wheels other than the left and right train wheels in which the variable damping force dampers 2 are provided. Therefore, the damping force variable damper 2 may be interposed between all the wheels Wfl, Wfr, Wrl, Wrr of the left and right wheel trains on the front and rear sides of the vehicle V and the vehicle body B. It may be interposed between the wheels Wfl, Wfr of the left and right train wheels on the front side and the vehicle body B. Note that when the damping force variable damper 2 is interposed between all the wheels Wfl, Wfr, Wrl, Wrr of the left and right wheel trains on the front and rear sides of the vehicle V and the vehicle body B, the passive damper 3 is is not installed in In this way, the damping force variable dampers 2 are arranged in pairs on the left and right sides of the vehicle body B with respect to the vehicle V, and are interposed between the wheels forming the left and right train wheels and the vehicle body B. The number of damping force variable dampers 2 installed on the vehicle V is always a multiple of two.

In addition to the left and right wheel trains each including two wheels arranged on the left and right sides of the vehicle body B, the vehicle V may have a row in which only one wheel is arranged in the left and right direction of the vehicle body B. In this case, The damping force variable dampers 2 may be installed in the left and right wheel trains having two wheels arranged on the left and right sides of the vehicle body B, respectively. Therefore, if the vehicle V is a three-wheeled vehicle having only one wheel in either the front row or the rear row, the damping force variable dampers 2 may be provided in the left and right wheel trains each having two wheels on the left and right sides of the vehicle body B. . In other words, the rows having wheels on the left and right sides of the vehicle body B are defined as the left and right train wheels, and the vehicle V includes the vehicle body B and one or more left and right wheel trains in the longitudinal direction with respect to the vehicle body B, and is provided over a plurality of rows. The damping force variable damper 2 may be interposed between the vehicle body B and at least one or more wheels of the left and right train wheels. In other words, the fact that the vehicle V has wheels provided over a plurality of rows including one or more left and right train wheels having wheels on each of the left and right sides of the vehicle body B means that the vehicle V has rows of wheels in the front-rear direction. At least one of the trains is a left and right wheel train having wheels on the left and right sides of the vehicle body B. As described above, the vehicle V is a three-wheeled vehicle. Alternatively, it may be a four-wheeled vehicle having wheels on the front, rear, left, and right of the vehicle body B, or may have six or more wheels equipped with three or more left and right wheel trains in the front-rear direction with respect to the vehicle body B. It may be a vehicle equipped with.

The vehicle V also includes sensors 51 that detect various information of the vehicle V such as engine speed, vehicle speed, wheel speed, steering angle, acceleration, yaw rate, throttle opening, brake on/off signals, and output measurement signals. , and a CAN (Controller Area Network) bus 53 for exchanging information detected by the sensors 51 and for mutual communication between an ECU (Electronic Control Unit) 52 and an object controlled by the ECU 52 (not shown). In this way, in the vehicle V, the information of the vehicle V detected by the mounted sensors 51 is transmitted to the CAN bus 53 via the ECU 52, and is transmitted to the ECU 52 connected to the CAN bus 53 and the control object (not shown). Information on the vehicle V is made available.

Next, as shown in FIG. 2, the damping force variable damper 2 includes, for example, a cylinder 11, a rod 12 inserted into the cylinder 11 so as to be axially movable, and a rod 12 axially movable into the cylinder 11. A reservoir R is provided between a piston 13 which is inserted and connected to a rod 12 to divide the cylinder 11 into an expansion side chamber R1 and a compression side chamber R2 filled with liquid, and a reservoir R which covers the outer circumference of the cylinder 11 and the cylinder 11. The formed outer cylinder 14, the expansion side damping passage 15 that communicates the expansion side chamber R1 and the compression side chamber R2, the damping force adjustment valve DV provided in the expansion side damping passage 15, and the compression side chamber R2 and the expansion side chamber R1 are communicated. a check valve 17 that opens and closes the pressure-side passage 16; a valve case 18 that is provided at the end of the cylinder 11 and separates the pressure-side chamber R2 and the reservoir R; A compression side damping passage 19, a base valve 20 provided in the compression side damping passage 19, a suction passage 21 communicating between the reservoir R and the pressure side chamber R2, and a suction check valve 22 provided in the suction passage 21 are provided.

The damping force variable damper 2 is installed at two locations between the vehicle body B and the rear wheels Wrl and Wrr by connecting the rod 12 to the vehicle body B and the outer cylinder 14 to the rear wheels Wrl and Wrr.

As shown in FIG. 2, the cylinder 11 has a cylindrical shape, and a rod 12 is slidably inserted into the inner periphery of the upper end of the cylinder 11. An annular rod guide guides the movement of the rod 12 in the axial direction with respect to the cylinder 11. 23 is fitted, and the valve case 18 is fitted to the inner circumference of the lower end, and is housed in the bottomed cylindrical outer cylinder 14 . The cylinder 11 , rod guide 23 and valve case 18 are fixed within the outer cylinder 14 by crimping the open end of the outer cylinder 14 .

The expansion side damping passage 15 and the compression side passage 16 are provided in the piston 13 , and the check valve 17 and the damping force adjustment valve DV are also provided in the piston 13 .

The damping force adjustment valve DV includes a solenoid Sol and a valve body Vb that opens and closes the rebound damping passage 15 . More specifically, the damping force adjustment valve DV provides resistance to the flow of liquid from the expansion side chamber R1 to the compression side chamber R2 via the expansion side damping passage 15, and the pressure in the expansion side chamber R1 is reduced to the compression side. When the pressure in the chamber R2 is exceeded and the difference between the two reaches the valve opening pressure, the valve body Vb opens the extension side damping passage 15 to allow the flow of the aforementioned liquid while giving resistance to the flow. The damping force adjustment valve DV closes and blocks the flow of the liquid that is going from the pressure side chamber R2 to the growth side chamber R1 through the growth side damping passage 15 .

In addition, since the solenoid Sol urges the valve body Vb in the valve closing direction with the thrust exerted by energization, when the solenoid Sol is energized, the damping force adjustment valve DV increases the valve opening pressure and extends the rebound damping passage 15. The resistance given to the liquid flowing from the side chamber R1 toward the pressure side chamber R2 is increased. Conversely, when the solenoid Sol is not energized, the damping force adjustment valve DV reduces the valve opening pressure compared to when the solenoid Sol is energized, and moves the expansion side damping passage 15 from the expansion side chamber R1 toward the compression side chamber R2. To reduce the resistance to the flowing liquid flow. In this manner, the damping force adjustment valve DV can switch the valve opening pressure between two stages, large and small, by turning on and off the energization of the solenoid Sol. The damping force adjustment valve DV described above can adjust the valve opening pressure in two stages depending on whether or not the solenoid Sol is energized. It may also be a valve that changes in stages. When the resistance is adjusted by changing the flow path area, the damping force adjustment valve DV, for example, drives a spool that adjusts the opening area of the hole and the hole that constitutes a part of the rebound damping passage 15, and a spool A solenoid may be included.

The rod 12 has a tubular shape, and a wiring 24 for energizing the solenoid Sol accommodated in the piston 13 is led out of the damping force variable damper 2 through the inside of the rod 12 . Each of the solenoids Sol of the plurality of variable damping force dampers 2 installed in the vehicle V is connected in series through the wiring 24 and connected to the drive circuit 42 of the controller 4 .

When the pressure in the compression-side chamber R2 exceeds the pressure in the expansion-side chamber R1, the check valve 17 opens to allow only the flow of liquid from the compression-side chamber R2 to the expansion-side chamber R1 through the compression-side passage 16. The valve closes to block the flow of liquid that is going from the growth side chamber R1 to the pressure side chamber R2 via 16 .

The compression side damping passage 19 and the suction passage 21 are provided in the valve case 18 , and the base valve 20 and the suction check valve 22 are also provided in the valve case 18 . The base valve 20 provides resistance to the flow of liquid from the compression-side chamber R2 to the reservoir R via the compression-side damping passage 19, and the pressure in the compression-side chamber R2 exceeds the pressure in the reservoir R, When the difference reaches the valve opening pressure, the valve is opened to allow the flow of the aforementioned liquid while giving resistance to the flow. The base valve 20 closes and blocks the flow of liquid from the reservoir R to the compression-side chamber R2 through the compression-side damping passage 19 . The base valve 20 may be a valve such as an orifice or a choke instead of a valve that opens and closes the compression-side damping passage 19 .

The suction check valve 22 opens when the pressure in the reservoir R exceeds the pressure in the pressure-side chamber R2 to allow only the flow of liquid from the reservoir R to the pressure-side chamber R2 via the suction passage 21. The valve closes to prevent the flow of liquid from the pressure side chamber R2 toward the reservoir R via the .

The liquid used for the damping force variable damper 2 can be liquid such as water, aqueous solution, etc., in addition to hydraulic oil. Further, when the damping force variable damper 2 fills the expansion side chamber R1, the compression side chamber R2, and the reservoir R with an electrorheological fluid or a magnetorheological fluid as a liquid, the damping force adjustment valve DV causes an electric field in the expansion side damping passage 15. Alternatively, a coil or the like that applies a magnetic field may be provided, and the amount of resistance given to the flow of liquid flowing through the extension side damping passage 15 may be adjusted depending on whether or not the coil is energized.

In the variable damping force damper 2 constructed in this way, when the piston 13 moves upward in FIG. When the differential pressure between the two reaches the valve opening pressure, the damping force adjustment valve DV opens and the liquid in the compression side chamber R1 moves through the compression side damping passage 15 to the compression side chamber R2. Further, when the damping force variable damper 2 is extended, the rod 12 is withdrawn from the cylinder 11 , so the check valve 22 is opened, and the liquid corresponding to the volume of the rod 12 withdrawing from the cylinder 11 flows through the suction passage 21 . It is supplied from the inside of the reservoir R to the inside of the cylinder 11 via. Therefore, when the damping force variable damper 2 is extended, the damping force adjustment valve DV gives resistance to the flow of liquid from the extension side chamber R1 to the compression side chamber R2 to increase the pressure in the extension side chamber R1 and move the piston 11 upward. generates a damping force that prevents movement to Also, the variable damping force damper 2 supplies liquid from the reservoir R into the cylinder 11 to compensate for the volume of the rod 12 withdrawing from the cylinder 11 . Since the damping force adjustment valve DV can adjust the valve opening pressure in two stages depending on whether or not the solenoid Sol is energized, the damping force variable damper 2 is in the extension operation and when the solenoid Sol is not energized. , normal damping force is generated, and when the solenoid Sol is energized, a hard damping force higher than the normal damping force can be generated.

On the other hand, when the damping force variable damper 2 is contracted when the piston 13 moves downward in FIG. It moves through pressure side passage 16 to R1. Further, when the damping force variable damper 2 is contracted, the rod 12 enters the cylinder 11, so that the base valve 20 is opened, and the liquid corresponding to the volume of the rod 12 entering the cylinder 11 is released into the compression side damping passage 19. is discharged to the reservoir R through the Therefore, when the damping force variable damper 2 is contracted, the base valve 20 resists the flow of liquid from the compression side chamber R2 to the reservoir R, thereby increasing the pressure in the cylinder 11 and moving the piston 11 downward. generate a damping force that prevents Also, the damping force variable damper 2 discharges liquid from inside the cylinder 11 to the reservoir R to compensate for the volume of the rod 12 entering the cylinder 11 .

As described above, the variable damping force damper 2 generates a normal damping force and a hard damping force higher than the normal damping force depending on whether the solenoid Sol is energized during the extension operation. Power cannot be adjusted. That is, the variable damping force damper 2 is configured as a damper that can adjust only the damping force on the extension side.

2, the damping force variable damper 2 of the present embodiment is a so-called twin-cylinder damper provided with an outer cylinder 14 forming a reservoir R on the outer circumference of the cylinder 11. The valve case 18, the compression side damping passage 19, the base valve 20, the suction passage 21, the suction check valve 22, the outer cylinder 14, and the reservoir R are abolished, and the free piston in the cylinder 11 divides the air chamber below the compression side chamber R2. In addition, a so-called single-tube damper may be provided in the compression-side passage 16 instead of the check valve 17 with a compression-side damping valve that provides resistance to the flow of the liquid.

Thus, even if the variable damping force damper 2 is a monotube type damper, the damping force can be adjusted in two stages, high and low, when the damping force adjusting valve DV extends and operates. When the damping force variable damper 2 is capable of adjusting only the contraction side damping force, the base valve 20 in the configuration shown in FIG. Therefore, the damping force adjustment valve DV may be eliminated and a valve may be provided in the extension side damping passage 15 to provide resistance to the flow of liquid from the extension side chamber R1 to the compression side chamber R2. If the damping force variable damper 2 is configured in this way, only the damping force on the contraction side can be adjusted by switching ON/OFF the energization of the solenoid Sol of the damping force adjusting valve DV. Further, when the damping force variable damper 2 is a monotube type damper and only the damping force on the contraction side is adjusted in level, the compression side passage 15 is provided with a damping force adjustment valve DV in place of the check valve 17. is eliminated and a valve is provided in the expansion side damping passage 15 to provide resistance to the flow of liquid from the expansion side chamber R1 to the compression side chamber R2. If the damping force variable damper 2 is configured in this way, only the damping force on the contraction side can be adjusted by switching ON/OFF the energization of the solenoid Sol of the damping force adjusting valve DV. In addition, since the damping force variable damper 2 is interposed between the rear wheels Wrl, Wrr of the vehicle V and the vehicle body B in the suspension device 1 of the present embodiment, the extension side of the damping force variable damper 2 is normal. and the damping force characteristics on the contraction side are set so as to be suitable for suppressing the vibration of the vehicle body B immediately above the front wheels Wrl and Wrr of the vehicle V. FIG.

The passive damper 3 is a damper whose damping force cannot be adjusted, and generates a damping force that hinders the expansion and contraction when expanded and contracted by an external force. Among the parts constituting the passive damper 3, the same parts as those of the variable damping force damper 2 are given the same reference numerals as those of the variable damping force damper 2, and detailed explanations thereof are omitted.

For example, as shown in FIG. 3, the passive damper 3 includes a cylinder 11, a rod 12 inserted into the cylinder 11 so as to be axially movable, and a rod 12 inserted into the cylinder 11 so as to be axially movable. 12 and divides the cylinder 11 into an expansion side chamber R1 and a compression side chamber R2 filled with liquid; and an outer cylinder 14 that covers the outer circumference of the cylinder 11 and forms a reservoir R between the cylinder 11. , the expansion side damping passage 15 that communicates the expansion side chamber R1 and the compression side chamber R2, the expansion side damping valve 25 provided in the expansion side damping passage 15, and the compression side passage 16 that communicates the compression side chamber R2 and the expansion side chamber R1. , a check valve 17 that opens and closes the compression side passage 16, a valve case 18 that is provided at the end of the cylinder 11 and separates the compression side chamber R2 and the reservoir R, and a compression side damping passage 19 that communicates the compression side chamber R2 and the reservoir R. , a base valve 20 provided in the compression side damping passage 19, a suction passage 21 communicating between the reservoir R and the compression side chamber R2, and a suction check valve 22 provided in the suction passage 21. The passive damper 3 includes the damping force adjustment valve DV in the extension side damping passage 15 in the damping force variable damper 2, but the extension side damping passage 15 is provided with the extension side damping valve 25 instead of the damping force adjustment valve DV. It is different from the damping force variable damper 2 only in that the damping force variable damper 2 The growth-side damping valve 25 provides resistance to the flow of the liquid from the growth-side chamber R1 to the compression-side chamber R2 through the growth-side damping passage 15, and the pressure in the growth-side chamber R1 becomes the pressure in the compression-side chamber R2. When the difference between the two reaches the valve opening pressure, the valve opens to allow the aforementioned liquid flow while giving resistance to the flow. The growth-side damping valve 25 closes and blocks the flow of liquid that is going from the compression-side chamber R2 to the growth-side chamber R1 through the growth-side damping passage 15 . The rebound damping valve 25 may be a valve such as an orifice or a choke instead of a valve that opens and closes the rebound damping passage 15 .

The passive dampers 3 are installed at two locations between the vehicle body B and the front wheels Wfl and Wfr by connecting the rod 12 to the vehicle body B and the outer cylinder 14 to the front wheels Wfl and Wfr.

In the passive damper 3 constructed in this way, when the piston 13 moves upward in FIG. When the pressure in the chamber R2 is exceeded and the differential pressure between the two reaches the valve opening pressure, the expansion side damping valve 25 opens and the liquid in the expansion side chamber R1 moves through the expansion side damping passage 15 to the compression side chamber R2. Further, when the damping force variable damper 2 is extended, the rod 12 is withdrawn from the cylinder 11 , so the check valve 22 is opened, and the liquid corresponding to the volume of the rod 12 withdrawing from the cylinder 11 flows through the suction passage 21 . It is supplied from the inside of the reservoir R to the inside of the cylinder 11 via. Therefore, during the extension operation, the passive damper 3 gives resistance to the flow of liquid from the extension side chamber R1 to the compression side chamber R2 by the extension side damping valve 25 to increase the pressure in the extension side chamber R1 and move the piston 11 upward. Generates a damping force that hinders movement. The passive damper 3 also supplies liquid from within the reservoir R into the cylinder 11 to compensate for the volume of the rod 12 withdrawing from within the cylinder 11 .

On the other hand, in the passive damper 3, when the piston 13 moves downward in FIG. 2 with respect to the cylinder 11, the liquid in the pressure side chamber R2 compressed by the piston 13 flows into the expansion side chamber R1, which opens the check valve 17 and expands. It moves through the pressure side passage 16 . Further, when the damping force variable damper 2 is contracted, the rod 12 enters the cylinder 11, so that the base valve 20 is opened, and the liquid corresponding to the volume of the rod 12 entering the cylinder 11 is released into the compression side damping passage 19. is discharged to the reservoir R through the Therefore, when the damping force variable damper 2 is contracted, the base valve 20 resists the flow of liquid from the compression side chamber R2 to the reservoir R, thereby increasing the pressure in the cylinder 11 and moving the piston 11 downward. generate a damping force that prevents Also, the damping force variable damper 2 discharges liquid from inside the cylinder 11 to the reservoir R to compensate for the volume of the rod 12 entering the cylinder 11 .

As described above, the passive damper 3 generates a damping force by the extension side damping valve 25 during the extension operation, and generates a damping force by the base valve 20 during the contraction operation, but the damping force generated during expansion and contraction cannot be adjusted. That is, the passive damper 3 is configured as a damper whose damping force cannot be adjusted. In the suspension device 1 of the present embodiment, the passive damper 3 is interposed between the front wheels Wfl and Wfr of the vehicle V and the vehicle body B. are set so as to be suitable for suppressing vibration of the vehicle body B directly above the front wheels Wfl and Wfr of the vehicle V.

3, the passive damper 3 of the present embodiment is a so-called double-cylinder damper provided with an outer cylinder 14 forming a reservoir R on the outer circumference of the cylinder 11. 18. The compression side damping passage 19, the base valve 20, the suction passage 21, the suction check valve 22, the outer cylinder 14 and the reservoir R are abolished, and the free piston in the cylinder 11 divides the air chamber below the compression side chamber R2. Alternatively, a so-called monotube damper may be provided in the compression-side passage 16 instead of the check valve 17 with a compression-side damping valve that provides resistance to the flow of the liquid.

As described above, the variable damping force damper 2 can adjust only the damping force on the extension side between the normal damping force and the hard damping force higher than the normal damping force. Among the rows, each pair of wheels Wrl and Wrr are interposed between the vehicle body B and the wheels Wrl and Wrr in the left and right train wheels on the rear side. The other passive damper 3 cannot adjust the damping force on both sides of the expansion and contraction. They are interposed one by one in pairs.

The damping force variable damper 2 and the passive damper 3 expand and contract when the wheels Wfl, Wfr, Wrl, and Wrr are relatively displaced with respect to the vehicle body B due to road surface input while the vehicle V is running, and generate a damping force that suppresses the relative displacement. do. When the damping force on the extension side of the variable damping force damper 2 is switched from normal to hard, the variable damping force damper 2 generates a hard damping force that is higher than the normal damping force when the variable damping force damper 2 is extended. The vehicle body B is less likely to rise compared to when a normal damping force is generated.

When the passenger of the vehicle V steps on the brake pedal while the vehicle V is running and the vehicle V enters a braking state, pitching occurs in which the front side of the vehicle body B sinks and the rear side of the vehicle body B rises. When the damping force on the extension side of 2 is switched to hard, the lifting of the rear side of the vehicle body B is suppressed, so the pitching of the vehicle body B is suppressed, the position of the center of gravity of the vehicle body B is lowered, and the braking distance is shortened.

Further, when the vehicle V turns, the centrifugal force acting on the vehicle body B causes a roll in which the vehicle body B inclines to the opposite side of the turning center about the longitudinal direction as an axis. When the vehicle body B rolls to the left or right, either the left wheel Wrl or the right wheel Wrr of the left and right train wheels in the rear row always performs an extension operation. Therefore, when the damping force on the extension side of the variable damping force damper 2 is switched hard when the vehicle V turns, the variable damping force damper 2 that is arranged in a pair on the left and right wheel trains exhibits an extension operation. Since the damper 2 generates a high hard damping force, the roll amount of the vehicle body B is smaller than when the damping force variable damper 2 generates a normal damping force during the extension operation. Therefore, if the damping force on the extension side of the variable damping force damper 2 is switched hard when the vehicle V turns, the roll of the vehicle body B can be reduced, and the ground load fluctuation of the rear wheel on the inner side of the turn is suppressed. Understeer can be reduced.

Subsequently, the controller 4, as shown in FIG. 4, determines whether the damping force when the damping force variable damper 2 is extended is normal or hard, and determines whether or not to energize the solenoid Sol. and a drive circuit 42 for supplying current to the solenoid Sol of the damping force variable damper 2 according to a command from the arithmetic processing unit 41, and a CAN bus 53 mounted on the vehicle V. and an interface circuit 43 for acquiring information from the sensors 51 .

In this embodiment, the processing unit 41 takes in the information collected by the vehicle V through the interface circuit 43 and transmitted to the CAN bus 53, and sets the damping force on the expansion side of the damping force variable damper 2 to normal. Judge whether it is hard or not. The arithmetic processing unit 41 is, for example, although not shown, a ROM (Read Only Memory) that stores an arithmetic processing unit and a program necessary for the processing of the arithmetic processing unit and provides a storage area necessary for the processing of the arithmetic processing unit. and a storage unit such as a RAM (Random Access Memory). decide whether to

Specifically, as shown in FIG. 5, the arithmetic processing unit 41 receives a brake on/off signal (step S1) and determines whether or not the brake on/off signal indicates that the brake is on (step S2). . If the on/off signal indicates that the brake is on, the processing unit 41 determines that the extension side damping force of the variable damping force damper 2 should be set hard because the vehicle V is being braked (step S3). . Further, the arithmetic processing unit 41 takes in the steering angle (step S1) and determines whether or not the steering angle is greater than or equal to a predetermined steering angle threshold (step S4). If the steering angle is greater than or equal to the steering angle threshold, the arithmetic processing unit 41 determines that the extension-side damping force of the variable damping force damper 2 should be set to hardware because the vehicle V is turning (step S3). The determinations in steps S2 and S4 above by the arithmetic processing unit 41 are performed in parallel, and either the brake on/off signal indicates that the brake is on or the steering angle is equal to or greater than the steering angle threshold value. When the condition is satisfied, the arithmetic processing unit 41 determines that the extension side damping force of the variable damping force damper 2 should be hard set.

Then, when the processing unit 41 determines that the damping force on the extension side of the variable damping force damper 2 should be hard set, it gives a command to the drive circuit 42 to energize each solenoid Sol (step S5). The drive circuit 42 receives a command and energizes each solenoid Sol to drive the solenoid Sol. Therefore, the variable damping force damper 2 generates a damping force according to expansion and contraction in a state where the damping force on the extension side is made hard.

When the signal does not indicate that the brake is on and the steering angle is less than the steering angle threshold value, the arithmetic processing unit 41 determines that the extension-side damping force of the variable damping force damper 2 should be set to normal. (step S6). When it is determined that the extension side damping force of the damping force variable damper 2 should be set to normal, the arithmetic processing unit 41 does not give a command to the drive circuit 42, and the drive circuit 42 does not energize each solenoid Sol. Therefore, the variable damping force damper 2 generates a damping force in response to expansion and contraction with normal damping force on the extension side. The arithmetic processing unit 41 repeats the processing of the procedure described above at a predetermined arithmetic cycle to control the damping force variable damper 2 .

In this manner, the controller 4 hard switches the damping force on the extension side of the damping force variable damper 2 during braking and turning of the vehicle V, so the suspension device 1 can suppress the pitching and rolling of the vehicle body B. Note that the controller 4 acquires the longitudinal acceleration of the vehicle body B as information that can be used to determine that the vehicle V is in a braking state. The damping force of the damper 2 may be switched hard. In addition, the controller 4 acquires the yaw rate of the vehicle body B as information that can be used to ascertain that the vehicle V is in a turning state. The damping force may be switched hard, or the steering angular velocity may be acquired and the damping force of the variable damping force damper 2 may be switched hard when the absolute value of the steering angular velocity is equal to or greater than a threshold. Furthermore, the controller 4 recognizes that an emergency avoidance operation is being performed from the characteristics of signals such as the brake, steering angle, and steering angular velocity that are output when the driver of the vehicle V performs an emergency avoidance operation, and determines the damping force. The damping force of the variable damper 2 may be switched hard.

When the variable damping force dampers 2 are interposed between the vehicle body B and the front wheels Wfl and Wfr, respectively, and the passive dampers 3 are interposed between the vehicle body B and the rear wheels Wrl and Wrr, respectively, the vehicle body B rolls. At this time, either the left wheel Wfl or the right wheel Wfr of the left and right train wheels in the front row always exhibits an extension operation. Therefore, when the damping force on the extension side of the variable damping force damper 2 is switched hard when the vehicle V turns, the variable damping force damper 2 that is arranged in a pair on the left and right wheel trains exhibits an extension operation. Since the damper 2 generates a high hard damping force, the roll amount of the vehicle body B is smaller than when the damping force variable damper 2 generates a normal damping force during the extension operation. Therefore, when the vehicle V turns, the roll of the vehicle body B can be reduced by switching the damping force on the extension side of the variable damping force damper 2 to hard. Further, in this case, if the damping force on the extension side of the damping force variable damper 2 is switched to hard, it is possible to prevent the front side of the vehicle body B from rising and the rear side from sinking, so that squatting during acceleration of the vehicle V can be suppressed. In order to suppress the squat, the controller 4 acquires information from the vehicle V that enables it to know that the vehicle V is accelerating, and switches the damping force of the damping force variable damper 2 to hardware. The controller 4 only needs to obtain information from the vehicle V that enables it to know that the vehicle V is accelerating. The controller 4 may switch the damping force of the damping force variable damper 2 to hard when the throttle opening becomes equal to or greater than a predetermined throttle opening threshold, or the rearward acceleration of the vehicle body B becomes equal to or greater than the predetermined acceleration threshold. Then, the damping force of the damping force variable damper 2 may be switched hard.

When the damping force variable dampers 2 are interposed between the vehicle body B and the front wheels Wfl and Wfr, respectively, and the passive dampers 3 are interposed between the vehicle body B and the rear wheels Wrl and Wrr, If it is desired to suppress the pitching of the vehicle body B during braking, the damping force on the contraction side of the damping force variable damper 2 may be adjusted in two stages, normal and hard. When the vehicle body B rolls, either the left wheel Wfl or the right wheel Wfr in the same left and right wheel train always contract. Therefore, if the damping force of the variable damping force damper 2 on the contraction side can be switched to hard, if the damping force of the variable damping force damper 2 is switched to hard, the variable damping force damper 2 will have a normal damping force on the contraction side. The amount of roll of the vehicle body B can be reduced compared to the case of generating

Further, when the damping force variable damper 2 can switch the damping force on the contraction side to hard, the damping force variable damper 2 is interposed between the vehicle body B and the rear wheels Wrl and Wrr, respectively, and the passive damper 3 is installed. When the damping force on the contraction side of the variable damping force damper 2 is switched to hard by interposing it between the vehicle body B and the wheels Wfl and Wfr of the front row, in addition to the roll of the vehicle body B when turning, the vehicle body B Squaring during acceleration can be suppressed.

In this way, the damping force variable damper 2 can switch the damping force only on the extension side between normal and hard, and also can switch the damping force only on the contraction side between normal and hard. may be assumed. Depending on whether the pitching of the vehicle body B is to be suppressed or the squatting is to be suppressed, the damping force variable damper 2 is selected from either the left and right wheel trains on the front side of the vehicle body B or the left and right wheel trains on the rear side of the vehicle body B. should be set to

In addition, in the damper used for the suspension of the vehicle V, the damping force on the extension side is generally set higher than the damping force on the contraction side. Generates high damping force. If the characteristics of the damping force on the extension side and the contraction side of the damper are set in this way, the center of gravity will tend to drop when the vehicle body B repeatedly vibrates, stabilizing the posture of the vehicle during running, and the damping force on the contraction side will be hard. Therefore, it is possible to prevent the ride comfort of the vehicle V from deteriorating due to the push-up input. Therefore, when only the damping force on the expansion side of the variable damping force damper 2 can be switched between normal and hard, when only the damping force on the contraction side of the variable damping force damper 2 can be switched between normal and hard, In comparison, since the damping force of the hardware can be made higher, the effect of suppressing the roll of the vehicle body B and the pitching or squatting of the vehicle body B is enhanced, and deterioration of the ride comfort can be suppressed.

Also, the damping force variable damper 2 may be installed in all the left and right wheel trains of the vehicle V. As shown in FIG. Therefore, in the present embodiment, since the vehicle V is a four-wheel vehicle, the damping force variable damper 2 is provided between the vehicle body B and all the wheels Wfl, Wfr, Wrl, and Wrr of the left and right wheel trains in the front and rear rows. May be interposed. In this case, the variable damping force damper 2 can switch the damping force on the extension side in two stages or the damping force on the contraction side in two stages. If the damping force is made hard, the rolling, pitching and squatting of the vehicle body B can be suppressed.

Furthermore, when the suspension device 1 wants to suppress only the rolling, pitching, or squatting of the vehicle body B when turning, damping is performed only when the vehicle V turns, only during braking, or only during acceleration. The damping force of the force variable damper 2 may be switched hard.

As described above, the suspension device 1 of the present embodiment includes a vehicle body B and one or more left and right wheel trains having wheels on the left and right sides of the vehicle body B, respectively, and is provided in a plurality of rows in the front-rear direction with respect to the vehicle body B. For a vehicle V having wheels Wfl, Wfr, Wrl, and Wrr, it is interposed between the vehicle body B and at least one or more wheels Wrl, Wrr (Wfl, Wfr) of the left and right train wheels, and is on the extension side. Alternatively, it comprises a variable damping force damper 2 capable of adjusting only the damping force on the contraction side, and a controller 4 for controlling the damping force of the variable damping force damper 2 based on information collected by the vehicle V and obtained from the vehicle V. ing.

In the suspension device 1 configured as described above, the damping force variable damper 2 can be adjusted only on the extension side or the contraction side. 4 adjusts the damping force of the damping force variable damper 2 using the information originally collected by the vehicle V, so the suspension device 1 need not have its own sensors. Therefore, according to the suspension device 1 of the present embodiment, no unique sensors are required, and only the damping force variable damper 2, which has a simple structure, is used for damping force adjustment. Although the posture of the vehicle body B can be controlled by adjustment to suppress rolling, pitching, or squatting of the vehicle body B, the cost of the entire system can be reduced.

Further, the controller 4 in the suspension system 1 of the present embodiment controls the damping force of the damping force variable damper 2 based on the information collected by the vehicle V and obtained from the vehicle V. FIG. Therefore, when the suspension device 1 is mounted on the vehicle V for which collision avoidance control and driving support control are performed in addition to the passenger's operation, the suspension device 1 performs collision avoidance prior to the passenger's driving operation of the vehicle V. In a situation where braking or turning is performed by control or driving support control, the braking or turning of the vehicle V can be quickly detected from the information of the vehicle V, and the attitude control of the vehicle body B can be quickly performed.

In the suspension device 1 of the present embodiment, the damping force variable damper 2 is configured so that the damping force on the expansion side or the contraction side can be adjusted in two stages, normal and hard higher than normal, as described above. However, the damping force on the extension side or contraction side may be adjustable in multiple steps or steplessly. However, if the damping force variable damper 2 can adjust the damping force in two stages, a normal damping force and a hard damping force higher than the normal damping force, the damping force adjustment valve DV of the damping force variable damper 2 Since the configuration is simplified, the suspension device 1 can be made even more inexpensive. Further, the controller 4 may supply current from the drive circuit 42 to the solenoid Sol at an on-duty ratio corresponding to the vehicle speed obtained through the CAN bus 53 when the vehicle V is braked. Further, when the vehicle V is braked, the controller 4 may supply current from the drive circuit 42 to the solenoid Sol through the CAN bus 53 at an on-duty ratio corresponding to the brake pressure. Furthermore, when the vehicle V turns, the controller 4 may supply current from the drive circuit 42 to the solenoid Sol at an on-duty ratio corresponding to the steering angular velocity obtained by differentiating the steering angle. In this way, even if the damping force variable damper 2 that can switch the damping force between normal and hard is used, the damping force can be arbitrarily changed between normal and hard by changing the on-duty ratio. Height can be adjusted.

In addition, in the suspension device 1 of the present embodiment, the damping force variable damper 2 can only adjust the damping force on the extension side, and the wheels Wrl and Wrr of the vehicle body B and the left and right train wheels on the rear side of the vehicle body B is interposed between According to the suspension device 1 configured in this way, since the damping force on the extension side of the damping force variable damper 2 can be made hard, the rolling of the vehicle body B during turning and the pitching during braking are suppressed, while the By lowering the center of gravity, the posture of the vehicle body during running can be stabilized, and deterioration of ride comfort during contraction can be suppressed.

Furthermore, the damping force variable damper 2 in the suspension device 1 of the present embodiment includes a cylinder 11, a rod 12 inserted axially movably into the cylinder 11, and an axially movably inserted rod 12 inserted into the cylinder 11. A piston 13 that is connected to a rod 12 and partitions the cylinder 11 into an expansion side chamber R1 and a compression side chamber R2 filled with liquid, and a solenoid Sol. and a damping force adjustment valve DV that can adjust the resistance given to the flow of air in two stages. According to the suspension device 1 configured in this manner, the damping force of the damping force variable damper 2 can be easily switched between normal and hard by turning on and off the energization of the solenoid Sol, facilitating energization control and damping. The structure of the force variable damper 2 becomes very simple. Further, since the damping force of the damping force variable damper 2 can be switched between normal and hard by turning ON/OFF the energization of the solenoid Sol, the configuration of the drive circuit in the controller 4 can be greatly simplified. Furthermore, the controller 4 can set the damping force of the damping force variable damper 2 to either normal or hard, and does not need to perform complicated calculations. The suspension device 1 configured in this manner is even more inexpensive.

If only the damping force variable damper 2 of either the left wheel or the right wheel has a failure, the damping force variable damper 2 is placed between the vehicle body B and the left wheel and the right wheel of at least one or more left and right wheel trains. Therefore, if only the damping force of the damping force variable damper 2 that is not malfunctioning is switched to hard, only one of the left and right sides of the vehicle body B will easily roll and pitch or squat, and there is a possibility that it will become unstable. There is However, in the suspension device 1 according to the present embodiment, the solenoids Sol in the damping force variable damper 2 are connected in series, and the controller 4 has only one drive circuit 42 for energizing the solenoids Sol. According to the suspension device 1 configured in this manner, the damping force of the variable damping force dampers 2 can be switched by one drive circuit 42 regardless of the number of the variable damping force dampers 2 installed in the vehicle V. In addition, if there is a failure in one solenoid Sol among the plurality of variable damping force dampers 2 or in the wiring 24 for energizing the solenoid Sol, the damping force adjustment of all the variable damping force dampers 2 cannot be forcibly performed. Therefore, it is possible to automatically avoid the situation in which the vehicle body B tends to roll and pitch or squat in only one of the left and right sides. Although the solenoid Sol of each damping force variable damper 2 can be connected in parallel to the drive circuit 42, the solenoid Sol is connected in series and the controller 4 has only one drive circuit 42 that energizes the solenoid Sol. As described above, the suspension device 1 having the above structure is advantageous in that fail-safe can be automatically performed when one of the damping force variable dampers 2 has a failure.

In addition, the suspension device 1 of the present embodiment includes passive dampers 3 whose damping force cannot be adjusted, which are interposed between the vehicle body B and wheels other than the left and right wheel trains in which the damping force variable dampers 2 are interposed. It has According to the suspension device 1 configured in this manner, the damping force variable dampers 2 are installed only in the left and right wheel trains required for controlling the posture of the vehicle body B, and the damping force variable dampers 2 are installed in the other left and right wheel trains. Since the passive damper 3, which is cheaper than the above, is installed, the suspension device 1 can be made even more inexpensive.

The controller 4 in the suspension system 1 of the present embodiment controls the damping force of the damping force variable damper 2 based on information that enables at least one of braking, acceleration and turning from the vehicle V to be grasped. According to the suspension device 1 configured in this manner, pitching, rolling, or squatting of the vehicle body B can be suppressed.

Although preferred embodiments of the invention have been described in detail above, modifications, variations, and changes are possible without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1... Suspension apparatus 2... Variable damping force damper 3... Passive damper 4... Controller 11... Cylinder 12... Rod 13... Piston 42... Drive circuit, B: vehicle body, DV: damping force adjustment valve, R1: expansion side chamber, R2: compression side chamber, Sol: solenoid, V: vehicle, Wfl, Wfr, Wrl , Wrr... wheels

Claims (7)

A vehicle having a vehicle body and wheels provided in a plurality of rows in the front-rear direction with respect to the vehicle body, including one or more left and right train wheels having wheels on each of the left and right sides of the vehicle body. a damping force variable damper interposed between at least one or more wheels of the left and right train wheels and capable of adjusting only the damping force on the extension side or the contraction side;
and a controller that obtains information collected by the vehicle from the vehicle and controls the damping force of the variable damping force damper based on the information. The variable damping force damper is capable of adjusting only the damping force on the extension side, and is interposed between the vehicle body and the wheels of the left and right train wheels on the rear side of the vehicle body. 2. The suspension device according to 1. 3. The suspension system according to claim 1, wherein the variable damping force damper is capable of adjusting the damping force in two stages, a normal damping force and a hard damping force higher than the normal damping force. The damping force variable damper is
a cylinder;
a rod axially movably inserted into the cylinder;
a piston inserted axially movably into the cylinder and connected to the rod to partition the cylinder into an expansion-side chamber and a compression-side chamber filled with a liquid;
4. A damping force adjustment valve having a solenoid and capable of adjusting resistance given to a flow of liquid passing through the solenoid in two steps by turning on/off energization of the solenoid. Suspension device according to. Each of the solenoids in the variable damping force damper is connected in series,
5. The suspension device according to claim 4, wherein the controller has only one drive circuit for energizing the solenoid. 6. A passive damper whose damping force cannot be adjusted and which is interposed between the vehicle body and wheels other than the left and right train wheels in which the variable damping force damper is interposed. The suspension device according to any one of Claims 1 to 3. 7. The controller controls the damping force of the damping force variable damper on the basis of information that enables at least one of braking, acceleration, and turning to be grasped from the vehicle. 10. Suspension device according to paragraph.

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