Anti-roll control device

Abstract

To provide an anti-roll control device which can achieve both of vehicle running stability and riding comfort in such a manner that right or left one of joint links for connecting an end of an anti-roll bar and a suspension spring lower member is made into an attachable / detachable link, thereby being connected to an anti-roll bar only when necessary, such as when turning.SOLUTION: An anti-roll control device includes: a roll control link which is interposed between a suspension spring lower member on one side of left and right wheels and an end of an anti-roll bar on the same side, and makes free attachment / detachment between the suspension spring lower member and the anti-roll bar by regulating and freeing slide of a piston rod by opening / closing an internal solenoid valve with hydraulic oil inside; each sensor which detects a vehicle speed, a steering angle and a lateral acceleration; and a controller which receives a signal of each sensor, and sends a control signal to the solenoid valve.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an anti-roll control device and, in general, the anti-roll bar links connecting the left and right ends of an anti-roll bar to the unsprung suspension members of the left and right wheels are connecting links of fixed length. However, this invention relates to an anti-roll control device that aims to achieve both the driving stability and soft ride comfort required of a vehicle by making either the left or right side of this connecting link into a freely engageable and disengageable link that can automatically switch between a state in which it is free to expand and contract and a state in which expansion and contraction is restricted depending on the driving conditions. [Background technology]

[0002] Anti-roll bars prevent the vehicle from tilting by using a spring action against the twisting when a stroke difference occurs between the left and right wheels, such as when the vehicle rolls while turning. The connecting link of the anti-roll device as described above connects the left and right suspensions at all times, so it is known that shocks generated on either the left or right side are transmitted to the wheel on the opposite side, causing the vehicle body to rock unnecessarily and reducing ride comfort. Several inventions have been proposed to solve this problem, but none have yet been able to provide an effect that is commensurate with the cost.

[0003] Conventional methods to solve this problem include an invention (Japanese Patent Application Laid-Open No. 2002-296524, Vehicle Stabilizer) in which hydraulic cylinders attached to four points on the front and rear of the anti-roll bar and vehicle body mounting part are controlled to increase or decrease the pressure of the hydraulic source based on the detection values ​​of sensors such as lateral acceleration while traveling, thereby returning the vehicle body to its original position. However, this method requires that the sensor detect the roll, and then hydraulic oil is supplied from the hydraulic source to each hydraulic cylinder to adjust the roll stiffness and vehicle body position, resulting in problems with delays in position control, as well as a heavy installation cost due to the need to equip numerous devices.

[0004] Also, there is an invention that does not use a power unit or the like (JP Patent Publication No. 2011-143788, stabilizer control device), in which a lock pin attached to the neutral position of the cylinder is inserted and removed from a hole drilled in the piston side to switch between engagement and disengagement with the anti-roll bar. However, with this method, even if the coupling control is manually operated, depending on the inclination of the road surface while driving, it is unlikely that the lock pin will immediately fit into the hole in the neutral position of the cylinder, and there are concerns about responsiveness to control and the durability of the pin insertion / removal part to withstand shocks when switching between engagement and disengagement. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 02-296524 Vehicle stabilizer [Patent Document 2] JP2011-143788 Stabilizer control device Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was invented to solve the problems in the background art as described above, and its purpose is to devise a freely engageable and disengageable link that can be switched between a state connected to the anti-roll bar (a state in which extension and contraction are restricted) and a state in which it is unconnected (a state in which extension and contraction is free) by opening and closing an internal solenoid valve on one of the anti-roll bar links (connecting link), which generally use fixed-length rods on both the left and right ends, and to devise an anti-roll control device that does not require a power unit such as a hydraulic source by using control that makes effective use of the torsional repulsive force of the anti-roll bar and the reaction of the suspension, etc. to correct the attitude of the vehicle body, thereby providing driving stability and the opposing soft ride comfort at a low cost. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a vehicle stabilizer equipped with an anti-roll bar, the left and right ends of which are attached to the unsprung members of the suspension via connecting links and the middle part of which is attached so as to be supported by the vehicle body and which generates a torsional repulsive force corresponding to the difference in the up and down movements of the left and right wheels, the stabilizer comprising: a roll control link which is interposed between the unsprung members of the suspension on one side of the left and right wheels and the end of the anti-roll bar on the same side, and which has a function of switching a piston rod which slides within a cylinder filled with hydraulic oil between a state in which it is free to expand and contract and a state in which the sliding is restricted by opening and closing a solenoid valve; Vehicle speed, steering angle and lateral acceleration sensors mounted on the vehicle body; A controller that provides a command value calculation means for controlling roll restraint start and release based on two values ​​received from a vehicle speed sensor and a steering angle sensor while the vehicle is moving, and that automatically sends a signal corresponding to each control to a solenoid valve inside a roll restraint link by identifying the acceleration direction indicated by a lateral acceleration sensor, etc.; The present invention is characterized in that it comprises:

[0008] The roll control link comprises a rod having an upper end portion rotatably attached to an unsprung member of a suspension on one of the left and right wheels, and a lower end portion of the rod member having a hydraulic oil passage that passes through the interior of the member in the longitudinal direction and is opened and closed by a first solenoid valve, and a piston rod integrally formed with a disk-shaped member attached to an upper portion of the first solenoid valve attachment portion at the lower end of the rod, the upper and lower surfaces of which are provided with circumferential grooves on a circumference of about 2 / 3 of the outer diameter, and a piston having a plurality of communication holes for communicating the circumferential grooves on both the upper and lower surfaces; a cylinder having a double-tube housing with inner and outer oil chambers, the lower end of which is rotatably attached to the end of the anti-roll bar on the same side as the piston rod is attached, the inner oil chamber being provided with a connection deviation correction mechanism having a function of correcting the stop position of the piston rod, and the cylinder slidably housing the piston rod through a rod through hole provided at the upper end of the oil chamber; The outer cylinder is surrounded by another oil chamber; a regulating bulkhead provided in a lower end wall of the cylinder with a flow hole for opening and closing the flow between the cylinder oil chamber and the outer oil chamber by a second solenoid valve and a flow hole provided with an outflow check valve for regulating outflow from the cylinder oil chamber to the outer oil chamber, thereby regulating and restricting the flow between the oil chambers; A twin-tube cylinder formed integrally by; A gas space is provided in part of the internal outer oil chamber, and both oil chambers are filled with hydraulic oil at a constant pressure. The actuator has the function of switching between a state in which it is free to expand and contract and a state in which its expansion and contraction is restricted by opening and closing the first solenoid valve and the second solenoid valve.

[0009] The coupling deviation correction mechanism is an extension deviation correction plate having an upper end of an upper chamber coil spring fixed to the upper end wall of a cylinder oil chamber, a donut-shaped disk having the same diameter as a piston attached via the upper chamber coil spring, and a plurality of flow holes each having an extension check valve for restricting flow from above to below at a position where the peripheral groove on the upper surface of the piston overlaps with the bottom surface of the donut-shaped disk; A contraction deviation compensation plate is provided on the lower end wall of the lower oil chamber of the cylinder, symmetrically to the upper end, and has a lower chamber coil spring of the same length as the upper chamber coil spring fixed at its lower end, the lower chamber coil spring being the same length as the upper chamber coil spring, and the donut-shaped disk of the same diameter as the piston attached via the coil spring, and a plurality of flow holes are provided on the upper surface of the donut-shaped disk, at a position where the peripheral groove on the lower surface of the piston overlaps with the contraction check valve that regulates flow from the bottom to the top; and is characterized in that, when both the upper and lower chamber coil springs are in a free length state (neutral state), the two deflection compensation disks are assembled so as to abut against the upper and lower surfaces of the piston, respectively.

[0010] When in the free extension / retraction state, the extension deflection compensation plate slides over a half stroke (extension side) in the upper part of the cylinder chamber while covering the top surface of the piston due to the pressing force of the upper chamber coil spring from above. However, when the piston rod is restricted from sliding in the extension direction to suppress roll, if there is an abnormal deflection at the stopped position, it has the function of correcting the extension deflection in response only to the force in the neutral direction received from the piston rod thereafter. In addition, in the free extension / retraction state, the contraction deviation compensation plate slides on the half stroke (contraction side) of the lower part of the cylinder chamber while covering the lower surface of the piston due to the pressing force of the lower chamber coil spring from below, but when the piston rod's sliding in the contraction direction is restricted to suppress roll, if there is an abnormal deviation at the stop position, it responds only to the force of the piston rod in the neutral direction, as described above, and has the function of correcting the contracted deviation. This is characterized by the fact that even if the left and right wheels are connected at the moment when there is an abnormal stroke difference due to road unevenness, etc., both deviation compensation plates have the function of capturing the reaction force of the rebound of the suspension springs and returning the vehicle body to a more balanced state. Here, the second solenoid valve provided in the restricting bulkhead between the cylinder oil chamber and the outer oil chamber described above is intended to close together with the closing of the first solenoid valve when the roll control link is restraining roll in the contraction direction, to stop the outflow of hydraulic oil from the cylinder to the outer oil chamber. However, the outflow check valve provided in another communication hole provided in the restricting bulkhead serves to allow contraction deviation correction to be performed when communication between the oil chambers is closed by closing the second solenoid valve, by only unrestricting the inflow from the outer oil chamber to the cylinder oil chamber 72, and thus plays a part in the connection displacement correction mechanism described above.

[0011] The need for circumferential grooves on the top and bottom surfaces of the piston is due to the fact that the openings of both the piston's communication hole and the flow hole of the deviation compensation disk that covers it can become misaligned due to rotation caused by twisting and other factors when the cylinder and piston rod extend and retract. This is because the deviation compensation disk connects the two openings together through a ring-shaped flow path created by covering the circumferential groove of the piston.

[0012] The controller is provided with a command value calculation means for obtaining a value (hereinafter referred to as the "calculated lateral acceleration value") that determines whether to command the start or release of roll suppression based on two values ​​detected by the vehicle speed of the traveling vehicle and the steering angle (steering operation angle) sensor, and is characterized by automatically sending control signals corresponding to individual controls to the first and second solenoid valves of the roll control link based on the lateral acceleration direction detected at the same time by the lateral acceleration sensor. This "calculated lateral acceleration value" is intended to obtain strong roll strength by capturing the driver's turning operation value, detecting the turning earlier, and connecting the anti-roll bar while the stroke difference between the left and right wheels is small, but this "calculated lateral acceleration value" cannot be used as a judgment measure when driving on a road surface with a left-right incline, when braking suddenly, or when counter-steering (reverse steering) on ​​a sharp curve. In order to cover this, a control method is adopted in which the actual lateral acceleration value detected by the lateral acceleration sensor at the same time is also added to the judgment measure. In other words, the start of roll suppression is determined when either the "calculated lateral acceleration value" or the actual lateral acceleration value is detected to exceed their respective specified values, and the release is determined when both values ​​are detected to be lower than the specified values. This makes it possible to perform roll suppression without omissions even in special driving such as counter-steering, along with connection at the beginning of a turn to obtain sufficient roll rigidity, which is important in the present invention. Effect of the Invention

[0013] According to the invention of claim 1, the connecting link connecting the lower part of the suspension spring and the anti-roll bar is a freely engageable and disengageable link that can be switched between engaged and uncoupled in response to signals from a steering angle sensor and the like and, thereby, it is possible to achieve both the driving stability required for driving performance and the contradictory soft ride comfort with a simple device.

[0014] The roll control link of claim 1 is Since it can be installed using the mounting space of the existing anti-roll bar connecting link, there is minimal change to the layout of the suspension components, and roll suppression control is possible simply by electrically controlling the solenoid valve inside the enclosed cylinder. It is easy to install, It is possible to provide an anti-roll control device that is inexpensive and requires almost no mechanical maintenance.

[0015] Claim 2According to this invention, the moment a difference in suspension stroke occurs due to a bump or the like caused by a rough road surface, roll suppression control is activated, and even if a connection is made with a large deviation, the vehicle can be driven with a stable vehicle posture because it has a function of returning the vehicle to equilibrium by utilizing reaction forces such as suspension rebound.

[0016] Claim 3 According to the invention, the necessity of control is judged by the "calculated lateral acceleration value" (the calculation method will be described later in Section

[0029] ) which changes depending on the driving operation. time By adopting a method of connecting the anti-roll bar more quickly, the torsional repulsive force of the anti-roll bar can be effectively utilized. 2 By utilizing the suspension rebound described in the effect of (1) to maintain the balance of the vehicle body, an inexpensive anti-roll control device is provided that does not require a hydraulic source or actuator for posture correction. [Brief description of the drawings]

[0017] [Figure 1] 1 is a perspective view showing a state in which a roll control link is attached to a MacPherson strut type suspension. [Diagram 2] 1 shows a cross section of a roll control link in a sliding axis direction. [Diagram 3] This shows a cross-sectional view of the roll control link when it is contracted and the top surface of the piston, etc. [Figure 4] 1 shows the electrical connections of the devices of the present invention. [Diagram 5] The timing of roll control is shown as t1 to t6 in a graph image showing the change in lateral acceleration relative to vehicle speed and steering. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In this embodiment, as shown in FIG. 1, the vehicle type is an SUV which uses a MacPherson strut type suspension system for both the front and rear wheels, with the upper end 7 of roll control link 5 attached to the unsprung member 4 (strut section) of the suspension on the right side of the vehicle body, and the lower end 8 of roll control link 5F attached to the right end 9 of the anti-roll bar on the same side of the vehicle body, and a roll control link 5R is similarly attached to the rear wheel suspension as shown in FIG. 4. A connecting link 6F 6R of the same length as when the right roll control link 5F 5R is in a neutral state is attached to the left suspension section to which no roll control link is attached, and the controller 10 controls the two front and rear roll control links 5F 5R simultaneously. Note that the neutral state of the roll control link here means that the internal upper and lower chamber coil springs 76 79 are both in a free length state, and the upper and lower surfaces of the piston 52 in the center of the cylinder 71 are in contact with the extension and contraction deflection compensation disks 66 61, respectively.

[0019] The roll control link 5F 5R shown in Fig. 2 can be manufactured with strength and durability by using the known technology of the internal twin-tube cylinder 70 and piston rod 51 sliding structure and their shields, many of which are already commercialized, for the fluid-filled twin-tube shock absorbers, and the upper / lower chamber coil springs 76 79 and the extension / contraction deflection compensation boards 61 66 can be molded into the shape shown in Fig. 3. Also, solenoid valves are currently being commercialized in a compact form for use in variable damping shock absorbers, and these can also be applied. As for the check valves provided on the deflection compensation board, small ones are attached to each of the flow holes as shown in Figs. 2 and 3 here, but it is believed that it would be easier to manufacture and more responsive to the operation if they were a single doughnut-shaped thin flat plate that can open and close all the holes by applying pressure with a spring.

[0020] The sticking prevention pin 57 shown in the cross section of the line DD in the top view of the piston in Fig. 3 is about 1 mm longer than the thickness of the disk of the piston 52, and is attached to the hole penetrating the upper and lower surfaces of the piston disk so that it can move up and down freely, and is a pin to prevent both the upper and lower surfaces of the piston 52 from contacting both the deviation compensation disks 66-61 at the same time. That is, when the piston rod 51 of the roll restraining link is in a state where it can freely expand and contract, the upper and lower disk surfaces of the piston and both the deviation compensation disks 66-61 repeatedly contact and separate, but there is a problem of the contact surface sticking due to the viscosity of the hydraulic oil at this time, and as a preventive measure, the deviation compensation disk on the side where the coil spring is contracted by the sliding of the piston pushes away and separates the deviation compensation disk on the opposite side through the sticking prevention pin 57 attached through the piston. There are other methods of preventing this, such as forming the disk surface of the deviation compensation disk that does not need to be in contact into a lattice shape to reduce the contact area, and it is considered that an appropriate method can be adopted for each design.

[0021] Although it is possible to obtain the same effect by simply installing it on the existing vehicle without changing the suspension settings, the most common modifications to obtain a more satisfactory effect are (1) appropriately lowering the suspension spring constant and damper damping force, and (2) appropriately increasing the spring constant of the anti-roll bar. Naturally, the degree of increase or decrease in the spring constant, etc., will differ depending on the design concept, etc.

[0022] It is assumed that roll suppression when the vehicle turns right (lateral acceleration to the left) is performed by closing and connecting the first and second solenoid valves 54 73 to prevent the piston rod of the roll control link 5F from sliding in the direction of contraction from the neutral position, and that roll suppression when the vehicle turns left (lateral acceleration to the right) is performed by closing and connecting only the first solenoid valve 54 to prevent the piston rod from sliding in the direction of extension from the neutral position. As a safety measure against malfunctions, these solenoid valves are designed to close when de-energized. EXAMPLES

[0023] In this embodiment, the roll control link 5F has an upper end 7 of a piston rod 51 at its upper end attached to the strut portion 4 of the right suspension, and at the lower part of the rod there is a hydraulic oil passage 53 that runs through the inside of the rod for communicating hydraulic oil between the upper and lower chambers of the cylinder partitioned by the piston 52, and by opening and closing a first solenoid valve 54 attached to the lower end of the rod, the roll control link 5F itself can be switched between a state in which it is free to extend and retract and a state in which its extension and retraction is restricted. Furthermore, the second solenoid valve 73 is closed at the same time as the first solenoid valve 54 when suppressing roll in the direction in which the roll control link 5F contracts, but the reason that the second solenoid valve 73 is also closed when regulating the contraction sliding here is that if only the first solenoid valve 54 is closed, when a strong force in the contraction (downward) direction is applied to the piston rod 51, a strong negative pressure state will occur in the upper chamber of the cylinder, which could cause cavitation (due to boiling of hydraulic oil, etc.) and make it impossible to suppress the force; to avoid this, the second solenoid valve 73 is closed at the same time to stop the outflow to the outer oil chamber 75, and the contraction force is turned into a pressurizing force on the lower chamber of the cylinder 71, making it possible to withstand a strong roll.

[0024] When the first and second solenoid valves 54 73 of the roll control link 5F are open, the piston 52 can freely slide up and down through the respective flow paths, the extension deflection compensation disk 66 slides up and down in the upper half of the cylinder oil chamber 72 while covering the upper surface of the piston 52 by the pressing force of the upper chamber coil spring 76 from the top surface of the piston, and the contraction deflection compensation disk 61 slides up and down in the lower half of the cylinder oil chamber 72 while covering the lower surface of the piston 52 by the pressing force of the lower chamber coil spring 79. When the extension sliding caused by turning left begins and the first solenoid valve 54 is closed, communication between the upper and lower chambers of the piston 52 is cut off and the extension check valve 67 of the extension deviation compensation plate 66 that covers the piston also restricts communication from the upper chamber to the lower chamber, so that the extension sliding is restricted and the anti-roll bar 3F is connected, suppressing subsequent roll. In addition, when turning right, contraction sliding begins and the first and second solenoid valves 54 and 73 are closed simultaneously, restricting the flow from the lower chamber to the upper chamber and also stopping the flow from the lower chamber of the cylinder to the outer chamber, restricting the sliding and connecting with the anti-roll bar to suppress subsequent roll.

[0025] Figure 3 shows a cross section of the roll control link 5F when it is contracted, the surface of the displacement compensation plate, and the top surface of the piston 52. If the roll control link 5F, which is free to expand and contract, is controlled and connected at the moment it contracts significantly while traveling on an uneven road surface as shown in Figure 3, and if this state is maintained, the vehicle posture will become unbalanced, but the connection displacement compensation mechanism has the function of correcting this.

[0026] The movement of hydraulic oil between the upper and lower chambers of the cylinder when the piston rod is returned to the neutral position with the first and second solenoid valves 54 and 73 closed and connected during deflection correction will be described. First, regarding the hydraulic oil flow path from the lower chamber of the cylinder to the upper chamber when the piston is extended during left turning, the lower surface of the piston during extension is located above the neutral position and is away from the contraction deflection correction plate 61 which is in the neutral position, and the hydraulic oil in the lower chamber of the cylinder 72 flows in through the multiple communication holes 55 opened on the lower surface of the piston 52, from there it enters the annular flow path formed by the extension deflection correction plate 66 covering the circumferential groove 56 on the upper surface of the piston 52, and then passes through the multiple extension check valves 67 (non-restricted direction) provided on the extension deflection correction plate 66 to the upper chamber of the cylinder 71. Conversely, when correcting the contracted deflection during a right turn, the piston, which has contracted and is located downward, is away from the underside of the extension deflection compensation disk 66, and the hydraulic oil moves from the upper chamber to the lower chamber of the cylinder 71 through the multiple communicating holes 55 opening on the upper surface of the piston 52, enters a ring-shaped flow path created by the contraction deflection compensation disk 61 covering the circumferential groove 56 on the lower surface, and then travels through the multiple contraction check valves 62 provided on the compensation disk 61 to the lower chamber of the cylinder.

[0027] The above is the passage for hydraulic oil movement between the upper and lower cylinder chambers partitioned by the piston 52, but hydraulic oil movement accompanying deviation correction is also necessary between the cylinder oil chamber 72 and the outer oil chamber 75, and when correcting from the extended position to the neutral direction, hydraulic oil equivalent to the intrusion volume of the piston rod 51 flows out to the outer oil chamber 75 through the second solenoid valve 73 (not closed at this time) in the regulating bulkhead 80. Also, when correcting from the contracted position to the neutral direction, the volume of hydraulic oil that the piston rod 51 escapes from the cylinder oil chamber 72 flows from the outer oil chamber 75 through the outflow check valve 78 (non-regulated direction) into the cylinder chamber.

[0028] FIG. 5 is a graph image showing the timing of lateral acceleration and roll control with respect to vehicle speed and steering. The controller 10 divides the vehicle speed into three speed ranges, low speed, medium speed, and high speed, and controls the vehicle in a different control mode for each speed range. In the low speed range, which includes going over curbs and steps, the vehicle runs in a mode in which the controller 10 constantly sends a control signal to the roll control link 5F not to connect with the anti-roll bar 6F. In the medium speed range, the controller 10 determines whether or not roll restraint is required based on a calculated value of two values ​​from the vehicle speed sensor 11 and the steering angle sensor 14 while running, and controls by selecting whether or not to connect with the anti-roll bar (hereinafter referred to as roll control ON) or not (hereinafter referred to as roll control OFF). In the high speed range, the mode is set to a mode in which the roll control ON signal is constantly sent to obtain running stability. The controller 10 automatically controls the roll control ON and OFF and switches the control mode simultaneously for the front and rear wheel roll control links 5F 5R, but the driver can also manually control them at his discretion.

[0029] Here, the automatic control by the controller 10 in the medium speed range will be specifically described. As described in

[0011] , when controlling special driving conditions such as a spin caused by sudden steering or a sloped road, the "actual lateral acceleration value" is used to make command decisions. However, for the sake of simplicity, control for general driving that does not involve these will be explained here. When the first and second solenoid valves 54-73 are both open and roll control is OFF, and steering is performed while driving and a turn begins, the controller 10 automatically sends a signal to the first or second solenoid valve 54-73 to control opening or closing according to the right or left direction indicated by the lateral acceleration sensor 12 at that time when the "calculated lateral acceleration value" calculated from the two detected values ​​of the vehicle speed and steering angle exceeds a lateral acceleration value (hereinafter referred to as the "command value") that is set in advance to command roll suppression. When the turning gradually ends and the steering is returned so that the "calculated lateral acceleration value" becomes lower than the "command value", the controller 10 sends a control signal to open the first or second solenoid valve 54 or 73 that was closed until then, thereby releasing the connection and restoring a soft ride.

[0030] As mentioned above, the "command value" is recognized as the start of a turn and is used as a guide for sending a control signal to turn the roll control ON. If this value is set to a low value, the vehicle will be connected while the inclination of the vehicle body is still small, and roll control can be effectively made use of the torsional repulsive force of the anti-roll bar 9. However, if this value is set too low, it will recognize things that have not yet reached a turn, resulting in more unnecessary suppression control and a loss of ride comfort. Taking these factors into consideration, in this embodiment, the "command value" is set to 0.1G (G is the gravitational acceleration of 9.8m / sec 2 The "command value" should not be fixed to the vehicle, but should be adjustable within a certain range at any time based on the loading situation and the individual driver's judgment.

[0031] Next, a description will be given of a means for calculating a "calculated lateral acceleration value" for determining whether to start or release a roll restraint command by comparing the "command value" during running. Generally speaking, if the vehicle speed while driving is v (m / sec) and the turning radius is r (m), then Lateral acceleration a(m / sec 2 )teeth a=v 2 / r ·····························(1) It is expressed as: If the turning radius is r, the steering angle (handle angle) is α (deg), the steering gear ratio of this vehicle is R, and the wheelbase is w (m), then the turning radius of this vehicle is r=w / sin(Rα) ········(2) An approximate value can be obtained using the formula: If the wheelbase w of this vehicle is 2.5 (m) and the steering gear ratio R is 1 / 16 (0.062), the turning radius r is calculated by rearranging equation (2). r=2.5 / sin(0.062α) *0.062α is the steering angle of the axle Putting this r into equation (1) and rearranging it gives a=v 2 sin(0.062α) / 2.5 ·······(3) The lateral acceleration a in the formula (3) is set to 0.1 G (0.98 m / sec) as the "command value" in this embodiment. 2 ) and rearrange it: sin(0.062α)=2.45 / v 2 ...(4) This equation (4) is applied to the vehicle while it is moving, giving it a "command value" of 0.1G (0.98 m / sec 2 This is an equation that represents the relationship between the vehicle speed v and the steering angle α that generates a lateral acceleration equivalent to the vehicle speed v and the steering angle α, and is used as an equation for the command value calculation means. For example, when the vehicle speed is 40km / h (11.11m / s), the steering angle α that generates a "command value" of 0.1G is given by the following equation (4): Vehicle speed v is 40km / h Putting in (11.11m / s) sin(0.062α)=0.0198 The inverse trigonometric function Arcsin is calculated as 0.0198 to obtain a value of 0.062α=1.135(deg). α=18.2(deg) When this value is exceeded, a roll control ON signal is sent. By the same calculation Vehicle speed v is 50km / h (13.88m / sec) α=12.3(deg) Vehicle speed v is 70km / h (19.44m / sec) α=6.0(deg) The steering angle when it reaches the "command value" decreases significantly as the vehicle speed increases. In this way, the controller 10 continuously performs calculations on the two sensor inputs that change with the vehicle speed v and the steering angle α, and outputs a command value of 0.1G (0.98m / sec 2 ) the roll control is turned ON, and when it falls below that value the roll control is turned OFF.

[0032] Fig. 5 shows a graph image of the "calculated lateral acceleration value" output according to changes in vehicle speed and steering, with the timings t1 to t6 at which the control signal is issued, and will be described below using this. When the vehicle speed exceeds 30 km / h t1 from the low-speed mode in which roll control is always OFF in the low-speed range and enters the medium-speed range, the controller 10 switches to the medium-speed mode in which control is performed by the "calculated lateral acceleration value". When the steering wheel is started to be turned to the right while driving in the medium-speed range, at the timing t2 when the "calculated lateral acceleration value" exceeds the "command value" of 0.1 G, the controller 10 judges that roll control is ON and detects the leftward direction (contraction direction) indicated by the lateral acceleration sensor 12, sends a signal to close both the first and second solenoid valves 54 and 73, and connects them, suppressing roll due to the subsequent strong lateral acceleration and turning to the right.

[0033] When the right turn gradually ends and the steering returns, the controller 10 detects that the “calculated lateral acceleration value” and the “actual lateral acceleration value” of the lateral acceleration sensor have fallen below the “command value” at t3, and opens the first and second solenoid valves 54 and 73, causing the vehicle to enter straight-ahead driving with a soft ride. Thereafter, while traveling at medium speed with roll control OFF, the steering wheel is turned left to make a left turn and the vehicle begins to roll to the right. At t4, it is detected that the "calculated lateral acceleration value" has exceeded the "command value" and the lateral acceleration sensor 12 detects lateral acceleration to the right (extension direction). The controller 10 then closes only the first solenoid valve 54 to suppress the roll and make a left turn.

[0034] After that, after turning to the right as described in the previous section, the vehicle speed increases, and when the vehicle speed sensor detects a speed exceeding 80 km / h t5, the controller switches the control to high-speed mode. However, at the point where the vehicle speed of 80 km / h is detected, the roll control link 5F 5R closes only the first solenoid valve 54, and the roll control link 5F 5R extends in the extension direction. for Roll suppression, The linkage deviation correction mechanism corrects the piston toward the neutral position, but after At the time t6 when the lateral acceleration in the contraction direction is detected, the second solenoid valve 73 is also closed to reduce the roll strength in both the left and right directions. You will gain. Both solenoid valves remain closed while the vehicle is traveling at high speeds thereafter. The reason for following this procedure when switching to high speed mode is that if the roll control link is extended due to slight right lateral acceleration or the like, and the second solenoid valve 73 is closed, the tilt of the roll control links 5F 5R will not be corrected due to their structure, and the vehicle will continue to travel without this happening, so this control procedure is to avoid this. This control does not pose any safety issues or cause any discomfort to the driver. [Industrial Applicability]

[0035] The device of the present invention has the characteristic of being applicable to a wide range of vehicle types, including passenger cars that use anti-roll bars, but the vehicle types for which it is particularly effective include off-road vehicles with a high center of gravity, minivans, SUVs, microbuses, and vehicles with a large difference in the amount of passengers and cargo loaded and unloaded. In addition, if this roll control link is installed at four locations on the left, right, front, and rear wheels to accommodate off-road vehicles with particularly long suspension strokes, the allowable suspension stroke difference when roll control is OFF (uncoupled) can be doubled. In addition, as a method of making this product of the present invention more rational, if information such as the curvature of the curve ahead from camera images of driving assistance systems currently being developed by various companies can be used as controller input for the device of the present invention, it is believed that this would be an ideal anti-roll control device that can predict and control turning. As described above, as a low-cost component that combines a soft ride and strong roll resistance regardless of vehicle type, it is conceivable that this component could be made standard equipment on mass-produced cars, and there is also the possibility that this could give rise to new production businesses for mass production. [Explanation of symbols]

[0036] 1 Front wheel 54 First solenoid valve 2 Rear wheel 55 communication hole 3F Front wheel anti-roll bar 56 Circumferential groove 3R Rear anti-roll bar 57 Anti-stick pin 4 Strut section (unsprung part) 61 Shrinkage deflection compensation plate 5F Front wheel roll control link 62 Contraction check valve 5R Rear wheel roll control link 66 Extension deviation compensation board 6F Front wheel anti-roll bar link 67 Extension check valve 6R Front wheel anti-roll bar link 69 Gas space 7 Upper end of roll control link 70 Double cylinder 8 Lower end of roll control link 71 Cylinder 9 Right end of anti-roll bar 72 Cylinder oil chamber 10 Controller 73 Second solenoid valve 11 Vehicle speed sensor 74 Outer 12 Lateral acceleration sensor 75 Outer oil chamber 13 Steering wheel 76 Upper chamber coil spring 14 Steering angle sensor 77 Rod through hole 50 Rod cover 78 Outflow check valve 51 Piston rod 79 Lower chamber coil spring 52 Piston 80 Regulating bulkhead 53 Hydraulic oil passage

Claims

1. a stabilizer for a vehicle having an anti-roll bar, the ends of which are attached to an unsprung member of a suspension via connecting links, and the middle part of which is attached so as to be supported by a vehicle body and generates a torsional repulsive force according to the difference in vertical movement between the left and right wheels, the stabilizer comprising: a roll control link interposed between the suspension unsprung member on one side of the left and right wheels and the end of the anti-roll bar on the same side, the upper end of a rod member which is the upper end of the anti-roll bar is rotatably attached to the unsprung member of the suspension, the lower end of the rod member having a hydraulic oil passage passing through the inside of the rod member which is opened and closed by a first solenoid valve; and a piston rod which is integral with the piston rod, the upper and lower surfaces of which are disc-shaped members attached above the first solenoid valve attachment part of the rod, each of which has a circumferential groove at a position on the circumference at about 2 / 3 of the outer diameter, and the piston rod having a plurality of communication holes to communicate the circumferential grooves on the upper and lower surfaces; a cylinder having a double oil chamber, an inner one and an outer one, the lower end of which is rotatably attached to the end of the anti-roll bar of the vehicle body on the same side as the end of the piston rod, the inner oil chamber of which is provided with a connection deviation correction mechanism having a stop position correction function of the piston rod, and which slidably accommodates the piston rod through a rod through hole provided at the upper end of the oil chamber; an outer cylinder having a shape in which another oil chamber entirely encloses the outside of the cylinder, and a gas space is provided in a part of the oil chamber; a restricting partition provided in a lower end wall of the cylinder, the restricting partition having a flow hole through which a second solenoid valve opens and closes the flow of hydraulic oil between the cylinder oil chamber and the outer oil chamber, and a flow hole provided with an outflow check valve for restricting outflow from the cylinder oil chamber to the outer oil chamber; and a twin-cylinder formed integrally with the restricting partition, the hydraulic oil being sealed inside the oil chamber at a constant pressure; the roll control link being capable of switching itself between a freely extending and retracting state and a state in which the extension and retraction is restricted by controlling the opening and closing of the first and second solenoid valves; a vehicle speed sensor, a steering angle sensor, and a lateral acceleration sensor mounted on a vehicle body; a controller that receives a signal from the sensor, determines whether roll restraint is required, and sends an opening / closing control signal to the first and second solenoid valves of the roll control link; An anti-roll control device comprising:

2. The connection deviation correction mechanism includes an extension deviation correction plate having an upper end fixed to an upper end of the cylinder oil chamber, an upper chamber coil spring fixed via the upper chamber coil spring, and a donut-shaped disk having the same diameter as the piston, and a plurality of flow holes each having an extension check valve for restricting flow from above to below, the flow holes being disposed at positions overlapping the circumferential groove on the upper surface of the piston; a contraction deviation compensation plate, the lower end of which is fixed to the bottom of the cylinder oil chamber by a lower chamber coil spring having the same length as the upper chamber coil spring, the donut-shaped disk having the same diameter as the piston attached via the lower chamber coil spring, and a plurality of flow holes each having a contraction check valve for restricting flow from below to above, the plurality of flow holes being disposed at positions overlapping the circumferential groove on the lower surface of the piston; 2. The anti-roll control device according to claim 1, wherein the extension and contraction deviation correction disks slide up and down together with the piston while covering the upper and lower surfaces of the piston by the pressure of a coil spring, and when there is a deviation in the position where the piston rod stops due to the sliding being restricted, the extension and contraction deviation correction disks have a function of correcting the deviation.

3. 2. The anti-roll control device according to claim 1, wherein the controller is provided with a command value calculation means for controlling the start and release of roll restraint in response to a vehicle speed of a traveling vehicle and a detection value of a steering angle (steering operation angle) sensor, and sends a switching control signal to the first and second solenoid valves inside the roll control link.

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