JP2007170509A - Suspension device, automobile and suspension characteristic adjusting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain degradation in the visibility of a vehicular front while permitting a suspension characteristic including rolling rigidity to be adjusted. <P>SOLUTION: The suspension device is equipped with a shock absorber 3 comprising a strut external cylinder 11 connected to an axle under a spring, a piston rod 14 which is connected to a vehicle body 12 above the spring and inserted into the strut external cylinder 11 so as to be able to reciprocate, and a bump stopper 16 which abuts against the strut external cylinder 11 to lock a stroke in a compressing direction when the strut external cylinder 11 and the piston rod 14 stroke in the compressing direction. An abutting plate 17 that can advance and retreat in an abutting direction is interposed between the strut external cylinder 11 and the bump stopper 16. At the periphery of the strut external cylinder 11, there is provided an advancing/retreating mechanism 18 which advances and retreats the abutting plate 17. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a suspension device, an automobile including the suspension device, and a suspension characteristic adjusting method.

Conventionally, an actuator for adjusting the vertical position of the bump stopper has been provided at the upper end of the shock absorber. By adjusting the buffer clearance with this actuator, the roll rigidity is changed, and the desired turning performance is obtained. (See Patent Document 1).
Japanese Patent Laid-Open No. 11-59156

However, in the conventional example described in Patent Document 1, since the actuator is provided at the upper end of the shock absorber, the height of the suspension assembly is increased correspondingly, and the hood ( The height of the bonnet must be raised over the entire surface. This is because it is not realistic to make the hood locally convex for the suspension assembly. Therefore, the corners are difficult to see due to the narrow forward field of view, and the visibility is lowered.
The subject of this invention is suppressing the fall of the visibility of a vehicle front, enabling adjustment of the suspension characteristic containing roll rigidity.

  In order to solve the above-described problems, the suspension device according to the present invention can be connected to one of the body on the spring and the axle below the spring, and connected to the other of the body and the axle, and can be stroked to the cylinder. A piston rod inserted into the cylinder, a bump stopper that abuts the cylinder when the cylinder and the piston rod stroke in the compression direction and locks the stroke in the compression direction, and is interposed between the cylinder and the bump stopper. A contact member capable of moving back and forth in the contact direction, and an advance / retreat mechanism provided on the outer periphery of the cylinder for moving the contact member back and forth.

  According to the suspension device of the present invention, a contact member that can be advanced and retracted in the contact direction is interposed between the cylinder and the bump stopper, and the vertical position of the contact member is changed by the advance and retract mechanism, thereby providing a buffer clearance. Therefore, the suspension characteristics including the roll rigidity can be adjusted to match the turning performance of the vehicle with the desired characteristics. Further, by providing an advancing / retreating mechanism for advancing and retracting the contact member on the outer periphery of the cylinder, an increase in the height of the suspension assembly can be suppressed. Thereby, since the height of the hood in the front body can be suppressed and the field of view in front of the vehicle can be suppressed, a reduction in visibility can be suppressed.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
<< One Embodiment >>
"Constitution"
FIG. 1 is a schematic configuration diagram of the present invention. Each of the wheels 2FL to 2RR of the automobile 1 employs a suspension having strut type shock absorbers 3FL to 3RR, and is configured to be able to adjust a margin distance in the bound direction of the suspension stroke, that is, a buffer clearance. ing.

  As shown in FIG. 2, the shock absorber 3 is connected to a strut outer cylinder 11 connected to an unsprung axle and a vehicle body 12 on a spring via a strut mount 13, and is inserted into the strut outer cylinder 11 so as to be able to advance and retreat. Piston rod 14 is provided. The strut outer cylinder 11 is filled with damper oil, and the piston of the piston rod 14 is formed with an orifice through which the damper oil can pass (not shown). Therefore, the suspension stroke is attenuated by the flow resistance of the damper oil when the strut outer cylinder 11 and the piston rod 14 are relatively stroked.

  A cylindrical bump stopper 16 that faces the gland packing 15 of the strut outer cylinder 11 is provided around the base end side of the piston rod 14. Further, a contact plate 17 that can be advanced and retracted in the axial direction while being inserted through the piston rod 14 is interposed between the gland packing 15 and the bump stopper 16, and an advancing and retracting mechanism 18 that advances and retracts the contact plate 17. However, the strut outer cylinder 11 is fixed at two locations on the outer peripheral surface of the strut outer cylinder 11 facing each other with the strut outer cylinder 11 interposed therebetween. Therefore, when the contact plate 17 supported by the advance / retreat mechanism 18 contacts the bump stopper 16, the stroke in the compression direction (bound direction) between the strut outer cylinder 11 and the piston rod 14 is locked. A separation distance between the stopper 16 and the contact plate 17 is a buffer clearance.

Here, as shown in FIG. 3, when the contact plate 17 and the bump stopper 16 come into contact with each other due to the compression stroke of the strut outer cylinder 11 and the piston rod 14, the outer side of the vehicle body in the lateral direction is more outward. In order to contact quickly, the thickness (height) of the contact plate 17 in the contact direction is changed in the lateral direction of the vehicle body so that the outer side is thicker (higher) than the inner side.
As shown in FIG. 2, the advancing / retreating mechanism 18 includes a hydraulic cylinder 19 fixed to the outer peripheral surface of the strut outer cylinder 11 along the axial direction, and a vertical movement according to the hydraulic pressure supplied to the hydraulic cylinder 19. The advancing / retreating rod 20 is configured to have a contact plate 17 fixed to the tip of the advancing / retreating rod 20.

  The hydraulic cylinder 19 is constituted by a backward-acting cylinder that operates both the vertical movement of the advance / retreat rod 20 by hydraulic pressure. Then, by a hydraulic pressure supplied from a hydraulic control circuit 30 to be described later, the contact plate 17 is lowered until it contacts the gland packing 15, and the buffer clearance is maximized, and the contact plate by a predetermined amount from the lower limit position. The advance / retreat rod 20 can be moved up and down between the upper limit position where the buffer clearance is minimized by raising 17 and an arbitrary position can be maintained.

  A sheet-like elastic body 21 is attached to the contact surface of the gland packing 15 with the contact plate 17. Further, when the contact plate 17 that is not in contact with the gland packing 15 contacts the bump stopper 16, the vehicle weight is applied to the hydraulic cylinder 19, and the lower end thereof is reinforced by the bracket 22. If sufficient strength is obtained by welding 19 to the strut outer cylinder 11, the bracket 22 may be omitted.

  The shock absorber 3 is disposed inside a coil spring 23 that suspends the vehicle body 12 so that the hydraulic cylinder 19 and its hydraulic piping pass through the lower seat 24 that supports the lower end of the coil spring 23. Is provided. Alternatively, the entire length of the hydraulic cylinder 19 and the vertical position of the lower seat 24 may be adjusted so that the entire hydraulic cylinder 19 is accommodated above the lower seat 24 so that only the hydraulic piping passes through the lower seat 24.

Further, as shown in FIG. 4, the pair of hydraulic cylinders 19 provided for one shock absorber 3 are arranged at two positions facing each other with the strut outer cylinder 11 sandwiched in the longitudinal direction of the vehicle body. A stroke sensor 25 that detects the stroke amount (vertical position) of the contact plate 17 is attached to the inner side of the strut outer cylinder 11 in the vehicle.
2, the hydraulic control circuit 30 includes a port A communicating with the lower chamber 19a of the hydraulic cylinder 19, a port B communicating with the upper chamber 19b of the hydraulic cylinder 19, a port T communicating with the oil tank 31, And a directional control valve 33 having a port P communicating with the pump 32. This directional control valve 33 is a four-port three-position switching / closed center that can be switched between an “all closed” position, an “A⇔P, B⇔T” position, and an “A⇔T, B⇔P” position. / Consists of both solenoid and spring center type solenoid operated valves.

  Accordingly, when the directional control valve 33 is in the non-excited “all closed” position, the lower chamber 19a and the upper chamber 19b of the hydraulic cylinder 19 are closed. Is maintained. Further, when the pump 32 is driven when the direction control valve 33 is excited and is in the “A⇔P, B⇔T” position, the discharge pressure is supplied to the lower chamber 19 a of the hydraulic cylinder 19 via the direction control valve 33. Therefore, the advance / retreat rod 20 moves upward and the contact plate 17 rises. Further, when the pump 32 is driven when the direction control valve 33 is excited and in the “A⇔T, B⇔P” position, the discharge pressure is supplied to the upper chamber 19 b of the hydraulic cylinder 19 via the direction control valve 33. Therefore, the advance / retreat rod 20 is retracted downward, and the contact plate 17 is lowered.

  An accumulator 34 that absorbs hammering and pulsation in the hydraulic circuit is connected to a flow path that connects the port P of the direction control valve 33 and the pump 32. Further, in the flow path that connects the port A of the direction control valve 33 and the lower chamber 19a of the hydraulic cylinder 19, the hydraulic pressure is limited to a predetermined value or less by the return to the oil tank 31 when the hydraulic pressure exceeds a predetermined value. A relief valve 35 is connected.

As shown in FIG. 1, the hydraulic control circuit 30 is driven and controlled by, for example, a controller 4 composed of a microcomputer. The controller 4 controls the stroke amount of the contact plate 17, the vehicle speed, the steering angle, the yaw rate, The drive control process of FIG. 5 is executed based on various data such as the lateral acceleration, the brake operation amount, and the road surface friction coefficient.
The road surface friction coefficient is estimated based on the restoring moment of the wheel and the cornering force, or based on the fluctuation phenomenon of resonance between the wheel and the tire surface as described in JP-A-8-324414. To estimate. Further, the estimation is based on the slip ratio and the brake operation amount, the estimation is based on the road surface image data and the temperature, and the estimation is based on the detection result of the road surface discrimination sensor (GVS: Grand View Censor). Further, it may be acquired from the infrastructure.
Other data is detected by various sensors.

Next, drive control processing executed by the controller 4 will be described with reference to the flowchart of FIG. In the present embodiment, a case where the target turning characteristic is set to neutral steer will be described.
First, in step S1, as an initial setting when the ignition is turned ON, the hydraulic pressure control circuit 30 is driven and controlled so that the respective contact plates 17 in the wheels 2FL to 2RR reach the initial positions. The initial position is variable according to the driving mode selected by the driver, but may be a predetermined position set in advance.

In subsequent step S2, it is determined whether or not the vehicle speed V is equal to or greater than a predetermined value Vs and the steering angle θ is equal to or greater than a predetermined value θs.
The predetermined values Vs and θs are set according to the road surface friction coefficient μ. Specifically, as shown in FIG. 6, when the road surface friction coefficient μ is equal to or greater than a predetermined value μs, the vehicle speed Vs is set to a predetermined value V1 (for example, 40 km / h), and the steering angle θs is set to a predetermined value θ1 (for example, 90 deg). When the road surface friction coefficient μ is less than the predetermined value μs, the vehicle speed Vs is set to a predetermined value V2 (for example, 20 km / h), and the steering angle θs is set to a predetermined value θ2 (for example, 45 deg).

  Here, as long as the determination result is “V <Vs or θ <θs”, the vehicle is not turning so that the suspension reaches the stroke end at the turning outer wheel, that is, the bump stopper 16 contacts the contact plate 17. And the process of step S2 is continued. On the other hand, when the determination result is “V ≧ Vs and θ ≧ θs”, it is determined that the vehicle is turning so that the suspension reaches the stroke end at the turning outer wheel, and the process proceeds to step S3.

In step S3, it is determined based on the steering angle and the yaw rate whether or not the turning state of the vehicle has an understeer tendency. If it is determined that there is no understeer tendency, the process proceeds to step S5 described later. On the other hand, if it determines with it being an understeer tendency, it will transfer to step S4.
In step S4, for the purpose of suppressing the understeer tendency, the hydraulic control circuit 30 is driven and controlled so that the abutting plate 17 of the turning outer rear wheel rises, and then the process returns to step S2.

  In order to suppress the understeer tendency, the rear wheel cornering force may be reduced. Here, as shown in FIG. 7, the relationship between the wheel load and the cornering force is shown. As the wheel load increases, the cornering force increases at the beginning, but the rate of increase gradually decreases. From some point, the cornering force begins to decrease. That is, if the wheel load is further increased when the cornering force is in the vicinity of the upper limit (limit value), the cornering force can be decreased. When the bump stopper 16 comes into contact with the contact plate 17 with the turning outer ring, it is considered that the cornering force of the turning outer wheel is already in the vicinity of the upper limit value. Therefore, the wheel contact plate 17 is pushed up to increase the wheel load. By doing so, the cornering force of the rear outer wheel decreases, so that the rear wheel cornering force that combines the left and right wheels decreases, and as a result, the understeer tendency is suppressed.

Therefore, the hydraulic pressure control circuit 30 is driven and controlled so that the stronger the understeer tendency is, the larger the pressure for pushing up the contact plate 17 of the rear outer wheel is.
On the other hand, in step S5, based on the steering angle and yaw rate, it is determined whether or not the turning state of the vehicle has an oversteer tendency. Here, if it is determined that there is no oversteer tendency, it is determined that the vehicle is in a substantially neutral steer state, and the process directly returns to step S2. On the other hand, if it is determined that there is an oversteer tendency, the process proceeds to step S6.

In step S6, for the purpose of suppressing the oversteer tendency, the hydraulic control circuit 30 is driven and controlled so that the abutting plate 17 of the outer front wheel is raised, and then the process returns to step S2.
In order to suppress the oversteer tendency, the front wheel cornering force should be reduced. When the bump stopper 16 comes into contact with the contact plate 17 with the turning outer ring, it is considered that the cornering force of the turning outer wheel is already in the vicinity of the upper limit value, so the contact load 17 of the front wheel is pushed up to increase the wheel load. By doing so, the cornering force of the front outer wheel decreases, so the front wheel cornering force that combines the left and right wheels decreases, and as a result, the oversteer tendency is suppressed.

Therefore, the hydraulic pressure control circuit 30 is driven and controlled so that the stronger the oversteer tendency, the greater the pressure for pushing up the contact plate 17 of the outer front wheel.
From the above, the strut outer cylinder 11 corresponds to the “cylinder”, the contact plate 17 corresponds to the “contact member”, the hydraulic cylinder 19 corresponds to the “fluid pressure cylinder”, and the relief valve 35 corresponds to the “relief circuit”. The hydraulic control circuit 30 and the controller 4 correspond to “control means”.

<Operation>
Next, the operation of one embodiment will be described.
As shown in FIG. 2, when the abutment plate 17 is at the lower limit position where it contacts the gland packing 15 without the suspension being stroked, the separation distance between the abutment plate 17 and the bump stopper 16, that is, the buffer clearance is Maximum. In this state, when the suspension strokes in the bound direction, a suspension stroke substantially equivalent to that of the conventional product in which the gland packing 15 and the bump stopper 16 come into contact with each other is allowed, so that the suspension acts on the bump stopper 16 as shown in FIG. The rising of the load becomes the normal mode.

  Further, when the direction control valve 33 is switched to the “A⇔P, B⇔T” position and the pump 32 is driven to increase the hydraulic pressure in the lower chamber 19a of the hydraulic cylinder 19 while the suspension is not stroked. Since the advance / retreat rod 20 is raised, the contact plate 17 approaches the bump stopper 16, and the buffer clearance is reduced. When the abutting plate 17 reaches a desired position, the direction control valve 33 is switched to the “all closed” position again, and the drive of the pump 32 is stopped. The vertical position of the contact plate 17 is maintained. In this state, when the suspension strokes in the bounce direction, the bump stopper 16 is locked earlier. Therefore, as shown in FIG. 8, the rising of the load acting on the bump stopper 16 is faster than the normal mode. Become.

Further, when the hydraulic pressure in the lower chamber 19a of the hydraulic cylinder 19 is increased while the bump stopper 16 is in contact with the contact plate 17, the bump plate 16 is pushed up by the contact plate 17 as shown in FIG. As a result, the wheel load increases in response to the vehicle weight.
In the state where the contact plate 17 is raised, the direction control valve 33 is switched to the “A⇔T, B⇔P” position, and the pump 32 is driven so that the hydraulic pressure in the upper chamber 19b of the hydraulic cylinder 19 is increased. When it is increased, the advance / retreat rod 20 is lowered, so that the contact plate 17 is moved away from the bump stopper 16 and the buffer clearance is increased. When the abutting plate 17 reaches a desired position, the direction control valve 33 is switched to the “all closed” position again, and the drive of the pump 32 is stopped. The vertical position of the contact plate 17 is maintained.

<Action>
Next, the operation of the embodiment will be described.
Now, when the driver turns on the ignition of the automobile 1, the buffer clearances of the wheels 2FL to 2RR are initialized (step S1). That is, when the strut outer cylinder 11 and the piston rod 14 stroke in the compression direction, the suspension characteristic is adjusted by adjusting the locking position of the stroke.

  For example, if the driver selects the normal mode, the bump stopper 16 is lowered as shown in FIG. 8 by lowering the contact plate 17 until it contacts the gland packing 15 to maximize the buffer clearance. The rise of the load acting on the normal mode is set. On the other hand, if the driver has selected the sport mode, the rising of the load acting on the bump stopper 16 is made faster than the normal mode by raising the contact plate 17 and reducing the buffer clearance. The

  By the way, when the bump stopper 16 comes into contact with the contact plate 17 that is not in contact with the gland packing 15 due to a suspension stroke when traveling on a rough road or when riding a large protrusion, the hydraulic cylinder 19 becomes excessive. A load may be applied. However, when the hydraulic pressure in the lower chamber 19a of the hydraulic cylinder 19 exceeds a predetermined value, the relief valve 35 that returns to the oil tank 31 is provided, so that the hydraulic pressure in the hydraulic cylinder 19 is always limited to a predetermined value or less. .

  Further, as shown in FIG. 10, since the ground contact point of the shock absorber 3 and the wheel 2 is shifted by L, when the suspension strokes in the bound direction and receives the reaction force of W from the wheel 2, the shock absorber 3 A bending moment M (= L × W) acts on. On the other hand, since the thickness of the abutting plate 17 is thicker on the outer side than the inner side, when the bump stopper 16 abuts on the abutting plate 17, the outer side abuts faster than the inner side in the vehicle body lateral direction. . At this time, the contact position between the shaft of the shock absorber 3 and the contact plate 17 is shifted by L1, so that when the load W1 is received from the bump stopper 16, the shock absorber 3 receives a moment M1 in a direction opposite to the bending moment M. Works. Therefore, the bending moment M acting on the shock absorber 2 during the suspension stroke is canceled and reduced by the moment M1 generated when the contact plate 17 and the bump stopper 16 contact each other.

When the vehicle is turning so that the suspension reaches the stroke end (the determination in step S2 is “Yes”), in order to maintain neutral steering, the upper and lower surfaces of the contact plates 17 on the wheels 2FL to 2RR are adjusted as necessary. Adjust the position.
For example, it is assumed that an understeer tendency occurs during a left turn (the determination in step S3 is “Yes”). In this case, as shown in FIG. 7, the hydraulic cylinder 19 is actuated in the direction in which the contact plate 17 is pushed up so that the wheel load of the right rear wheel 2RR whose cornering force is close to the upper limit value is increased (step S4). . As a result, the cornering force of the right rear wheel 2RR is reduced and the rear wheel cornering force of the left and right wheels combined is reduced, so that an understeer tendency is suppressed.

  On the other hand, it is assumed that an oversteer tendency occurs during a left turn (the determination in step S5 is “Yes”). In this case, the hydraulic cylinder 19 is operated in the direction in which the contact plate 17 is pushed up so that the wheel load of the right front wheel 2FR whose cornering force is in the vicinity of the upper limit value increases (step S6). As a result, the cornering force of the right front wheel 2FR is reduced, and the front wheel cornering force including the left and right wheels is reduced, so that an oversteer tendency is suppressed.

Further, when the contact plate 17 is lowered to the lower limit position in contact with the gland packing 15, the contact plate 17 contacts the gland packing 15 via the elastic body 21. Is alleviated.
By the way, if an actuator for adjusting the vertical position of the bump stopper 16 is provided at the upper end of the shock absorber 3 as in the prior art, the height of the suspension assembly is increased correspondingly, and the front body has a hood. You must increase the height of the (bonnet). That is, as shown in FIG. 11, it is not realistic to make the hood locally convex by the amount of the suspension assembly, so the hood height must be increased over the entire surface as shown by the thick line.

  For example, if the hood is raised about 100 mm without changing the driver's eye point, the blind spot on the lower front side will increase, and the distance will be about 1.7 times that before raising the hood, based on the ground contact point of the front wheel. , The front view for the driver is narrowed. Therefore, it is difficult to see the corners, and it becomes impossible to run at the desired turning speed, especially on winding roads, etc., and even if it can be driven at the desired turning speed, mental fatigue is increased. Will fall.

Although it is conceivable to increase the eye point together with the hood height, for example, if the seating position is raised, the boarding / exiting performance decreases, and if the overall vehicle height is increased, the vehicle weight increases or the center of gravity height increases. The turning performance may be lowered due to the rise, and a new problem will be caused.
Therefore, in the present embodiment, the advancement / retraction mechanism 18 for advancing / retreating the contact plate 17 is provided on the outer periphery of the strut outer cylinder 11, so that the increase in the height of the suspension assembly can be suppressed. Thereby, since the height of the hood in the front body can be suppressed and the field of view in front of the vehicle can be suppressed, a reduction in visibility can be suppressed.

《Application example》
In the above-described embodiment, the shock absorber 3 in which the strut outer cylinder 11 is coupled to the unsprung axle and the piston rod 14 is coupled to the body 12 on the spring is employed. However, the invention is not limited thereto. Instead of this, a shock absorber in which the strut outer cylinder 11 is connected to the body 12 on the spring and the piston rod 14 is connected to the axle below the spring may be adopted.

In the above-described embodiment, the bump stopper 16 and the contact plate 17 are arranged coaxially with the piston rod 14. However, the present invention is not limited to this and may be offset.
In the above embodiment, the hydraulic cylinder 19 is employed as the advance / retreat mechanism 18 for moving the contact plate 17 up and down. However, the present invention is not limited to this, and a pneumatic cylinder using compressed air is used. It may be adopted. Furthermore, you may employ | adopt the electric drive mechanism which converts the rotational motion of an electric motor into a linear motion, and moves the contact plate 17 up and down.

In the above-described embodiment, the initial position of the abutment plate 17 can be changed to two levels, that is, the normal mode and the sport mode. However, the present invention is not limited to this. It may be changeable in stages.
In the above-described embodiment, the thickness of the contact plate 17 in the contact direction is changed between the inner side and the outer side in the lateral direction of the vehicle body. However, the present invention is not limited to this. The point is that when the contact plate 17 and the bump stopper 16 are in contact with each other, the outer side of the vehicle body in the lateral direction may be contacted earlier than the inner side thereof. The thickness may be changed between the inner side and the outer side in the lateral direction of the vehicle body, and the thicknesses of both the contact plate 17 and the bump stopper 16 may be changed.

  In the above embodiment, the target turning characteristic is set to neutral steer. However, the present invention is not limited to this and may be set to understeer or oversteer. That is, in order to strengthen the understeer tendency, the advancing / retreating mechanism 18 may be driven and controlled so that the wheel load of the turning outer front wheel whose cornering force is in the vicinity of the upper limit value is increased. Conversely, in order to increase the oversteer tendency, the advance / retreat mechanism 18 may be driven and controlled so that the wheel load of the turning outer rear wheel whose cornering force is in the vicinity of the upper limit value is increased.

"effect"
(1) A strut outer cylinder 11 connected to an unsprung axle, a piston rod 14 connected to a body 12 on a spring and inserted into the strut outer cylinder 11 so as to be able to advance and retreat, the strut outer cylinder 11 and the piston rod 14 And a bump stopper 16 that abuts the strut outer cylinder 11 to lock the stroke in the compression direction when the cylinder strokes in the compression direction, and is interposed between the strut outer cylinder 11 and the bump stopper 16 to advance and retreat in the contact direction. A possible contact plate 17 and an advancing / retreating mechanism 18 provided on the outer periphery of the strut outer cylinder 11 for moving the contact plate 17 back and forth are provided.

  As a result, the buffer clearance can be adjusted by changing the vertical position of the contact plate 17, so that the suspension characteristics including the roll rigidity can be adjusted, and the turning performance of the vehicle can be matched with the desired characteristics. Further, by providing the advancing / retracting mechanism 18 for advancing and retracting the contact plate 17 on the outer periphery of the strut outer cylinder 11, an increase in the height of the suspension assembly can be suppressed. Thereby, since the height of the hood in the front body can be suppressed and the field of view in front of the vehicle can be suppressed, a reduction in visibility can be suppressed.

  In addition, the strut mount 13 can be a conventional product as it is, and the design change is not required for the attachment portion to the vehicle body 12, so that the vehicle body 12 can be shared. In addition, by attaching the advance / retreat mechanism 18 to the strut outer cylinder 11 which is a rigid body, it is possible to ensure sufficient strength to withstand an impact when the contact plate 17 and the bump stopper 16 contact each other.

(2) The contact plate 17 and the advance / retreat mechanism 18 are disposed inside the coil spring 23.
Thereby, the contact plate 17 and the advancing / retreating mechanism 18 can be protected from the jumping stone or the like. In addition, the vehicle body structure (common name, strut tower) that covers the coil spring 23 is not required to be changed in design and can be shared.

(3) The advancing / retreating mechanisms 18 are arranged at two locations facing each other with the strut outer cylinder 11 sandwiched in the longitudinal direction of the vehicle body.
Thereby, it is possible to stably support the contact plate 17, to prevent an eccentric load from being input when contacting the bump stopper 16, and to protect both the advancing and retracting mechanisms 18 from spring stones and the like. That is, when the advancing / retreating mechanism 18 is opposed to the vehicle body in the lateral direction, the outer advancing / retreating mechanism is likely to receive a jumping stone or the like.
(4) The advance / retreat mechanism 18 is constituted by a hydraulic cylinder 19.
Thereby, enlargement can be suppressed.
(5) A relief valve 35 for limiting the hydraulic pressure of the hydraulic cylinder 19 to a predetermined value or less is provided.
As a result, the hydraulic circuit can be protected from an excessive input such as when traveling on a rough road or riding a large protrusion.

(6) When the abutting plate 17 and the bump stopper 16 are brought into contact with each other by the stroke of the strut outer cylinder 11 and the piston rod 14 in the compression direction, the outer side comes into contact more quickly than the inner side in the vehicle body lateral direction. The thickness of the contact plate 17 in the contact direction was changed between the inside and the outside in the lateral direction of the vehicle body.
As a result, the bending moment M acting on the shock absorber 2 during the suspension stroke can be canceled and reduced by the moment M1 generated when the contact plate 17 and the bump stopper 16 are in contact with each other, resulting in improved riding comfort. Can do.

(7) An elastic body 21 is interposed between the gland packing 15 and the contact plate 17.
Thereby, the shock when the contact plate 17 contacts the gland packing 15 can be reduced, and the interference sound can be reduced.
(8) Control means for individually driving and controlling the advancing and retracting mechanisms 18 in the front, rear, left and right wheels and changing the vertical position of each contact plate 17 is provided.
Thereby, since the buffer clearance of each wheel can be adjusted, the turning performance of the vehicle can be matched with a desired characteristic.

(9) The control means changes the position of each contact plate 17 according to the turning traveling state of the vehicle.
Thereby, it is possible to adjust to any turning characteristic such as neutral steer, understeer, oversteer.
(10) The control means changes the initial position of each contact plate 17 according to the selected travel mode.
Thereby, the rising of the load acting on the bump stopper 16 can be arbitrarily adjusted to a normal mode, a sport mode faster than the normal mode, or the like.

It is a schematic block diagram of this invention. It is a schematic block diagram of a shock absorber. It is the figure which looked at the shock absorber from the vehicle body front. It is a layout view of a hydraulic cylinder. It is a flowchart which shows a drive control process. It is a graph explaining the setting of predetermined value Vs and (theta) s. It is the figure which shows the relationship between a wheel load and a cornering force, and the figure explaining suppression of the understeer tendency by the reduction | decrease of a rear-wheel cornering force. It is a graph which shows the rising characteristic of the load which acts on a bump stopper. The bump stopper is pushed up by the contact plate. It is a figure explaining reduction of a bending moment. It is a figure explaining the problem of the prior art.

Explanation of symbols

1 Car 2FL-2RR Wheel 3FL-3RR Shock Absorber 4 Controller 11 Strut outer cylinder (cylinder)
12 Car body 13 Strut mount 14 Piston rod 15 Gland packing 16 Bump stopper 17 Contact plate (contact member)
18 Advancing and retracting mechanism 19 Hydraulic cylinder (fluid pressure cylinder)
20 Retracting rod 21 Elastic body 22 Bracket 23 Coil spring 24 Lower seat 25 Stroke sensor 30 Hydraulic control circuit 31 Oil tank 32 Pump 33 Directional control valve 34 Accumulator 35 Relief valve (relief circuit)

Claims (13)

  A cylinder connected to one of a vehicle body on a spring and an axle below the spring; a piston rod connected to the other of the vehicle body and the axle and inserted into the cylinder so as to allow stroke; the cylinder and the piston rod And a bump stopper that contacts the cylinder when the stroke in the compression direction and stops the stroke in the compression direction, and a contact member that is interposed between the cylinder and the bump stopper and that can advance and retreat in the contact direction And a forward / backward mechanism provided on the outer periphery of the cylinder for moving the contact member back and forth.   The suspension device according to claim 1, wherein the contact member and the advance / retreat mechanism are arranged inside a coil spring that suspends the vehicle body.   The suspension device according to claim 1 or 2, wherein the advancing / retreating mechanism is disposed at two locations facing each other with the cylinder sandwiched in the longitudinal direction of the vehicle body.   The suspension device according to any one of claims 1 to 3, wherein the advance / retreat mechanism comprises a fluid pressure cylinder.   The suspension apparatus according to claim 4, further comprising a relief circuit that limits a fluid pressure of the fluid pressure cylinder to a predetermined value or less.   When the contact member and the bump stopper contact each other due to the stroke of the cylinder and the piston rod in the compression direction, the contact member and the contact member The suspension device according to any one of claims 1 to 5, wherein a thickness in a contact direction of at least one of the bump stoppers is changed on an inner side and an outer side in a lateral direction of the vehicle body.   The suspension device according to any one of claims 1 to 6, wherein an elastic body is interposed between one end of the cylinder and the contact member.   The suspension apparatus according to any one of claims 1 to 7, further comprising a control unit that individually controls driving of the advancing and retreating mechanisms in front, rear, left and right wheels, and changes the position of each of the contact members. .   The suspension device according to claim 8, wherein the control means changes the position of each of the contact members according to a turning traveling state of the vehicle.   10. The suspension device according to claim 8, wherein the control unit changes an initial position of each of the contact members according to a selected travel mode. A cylinder connected to one of a vehicle body on a spring and an axle below the spring; a piston rod connected to the other of the vehicle body and the axle and inserted into the cylinder so as to allow stroke; the cylinder and the piston rod And a bump stopper that contacts the cylinder when the stroke in the compression direction and stops the stroke in the compression direction, and a contact portion between the bump stopper provided on the outer periphery of the cylinder in the contact direction. With advance and retreat mechanism to advance and retreat,
Suspension characterized by adjusting a locking position of the stroke when the cylinder and the piston rod stroke in the compression direction by advancing and retracting the abutting portion of the cylinder in the abutting direction by the advance / retreat mechanism. apparatus. In a car equipped with a suspension device,
The suspension device is
A cylinder connected to one of a vehicle body on a spring and an axle below the spring; a piston rod connected to the other of the vehicle body and the axle and inserted into the cylinder so as to allow stroke; the cylinder and the piston rod And a bump stopper that contacts the cylinder when the stroke in the compression direction and stops the stroke in the compression direction, and a contact member that is interposed between the cylinder and the bump stopper and that can advance and retreat in the contact direction And an advancing / retreating mechanism provided on an outer periphery of the cylinder for advancing / retreating the contact member. A cylinder connected to one of a vehicle body on a spring and an axle below the spring; a piston rod connected to the other of the vehicle body and the axle and inserted into the cylinder so as to allow stroke; the cylinder and the piston rod And a bump stopper that contacts the cylinder when the stroke in the compression direction and stops the stroke in the compression direction, and a contact portion between the bump stopper provided on the outer periphery of the cylinder in the contact direction. With advance and retreat mechanism to advance and retreat,
Suspension characterized by adjusting a locking position of the stroke when the cylinder and the piston rod stroke in the compression direction by advancing and retracting the abutting portion of the cylinder in the abutting direction by the advance / retreat mechanism. Characteristic adjustment method.

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