JP2004276625A - Vehicle suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow self-diagnosis in vehicle suspension devices disposed between right and left front wheels and right and left rear wheels and a vehicle body and to relate a front wheel cylinder to control a relative displacement between the right and left wheels on a front wheel side to a rear wheel cylinder to control a relative displacement between the right and left wheels on a rear wheel side. <P>SOLUTION: An abnormality determination part determining that accumulator valves are abnormal when an instruction signal fed to the accumulator valves 206 does not match the actual operating state of the accumulator valves is installed in an electronic control unit ECU250 electrically controlling the accumulator valves 206 and 206 installed between the cylinders 52 and 62 and the accumulators 200 and 200 corresponding to each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle suspension device disposed between a left and right front wheel and left and right rear wheels of a vehicle and a vehicle body, and particularly to a technique for self-diagnosing the device.
[0002]
[Prior art]
2. Description of the Related Art In a vehicle, a vehicle suspension device disposed between the left and right front wheels and the left and right rear wheels and the vehicle body has already been used, and an improved example thereof has already been proposed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Publication No. 11-510761
Patent Literature 1 discloses a conventional example of a vehicle suspension device. In this conventional example, a front wheel cylinder and a rear wheel cylinder are provided with a first chamber passage and a second chamber passage. Are fluidly associated with each other.
[0004]
On the front wheel cylinder, on the front wheel side, in order to control the relative displacement between the left and right wheels, generally in the vertical direction of the vehicle body, a piston is fitted to the housing, so that the space inside the housing is both a fluid chamber. It is configured to be divided into a certain first room and a second room.
[0005]
Correspondingly, the rear wheel cylinder is provided with a piston fitted to the housing on the rear wheel side to control the relative displacement between the left and right wheels, generally in the vertical direction of the vehicle body. The space is divided into a first chamber and a second chamber, both of which are fluid chambers, corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively.
[0006]
In the first chamber of the front wheel cylinder and the first chamber of the rear wheel cylinder, a pressure change (increase or decrease) in the same direction occurs as the vehicle body rolls in one direction. Similarly, pressure changes in the same direction occur in the second chamber of the front wheel cylinder and the second chamber of the rear wheel cylinder as the vehicle body rolls in one direction.
[0007]
The first chamber passage is a passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers, and similarly, the second chamber passage is connected to the front wheel cylinder and the rear cylinder. The passage connects the wheel cylinder to each other in the second chambers.
[0008]
In this type of vehicle suspension, a front wheel cylinder and a rear wheel cylinder are connected to each other by a passage, and a fluid is sealed in a pressure circuit formed as a result. The fluid to be sealed is preferably a liquid that is incompressible in the first place, but it is also possible to use a gas whose compressibility has been reduced by, for example, increasing the pressure.
[0009]
As a result, when the pressure is equal between the two cylinders, the sealed fluid is prevented from flowing between the two cylinders. As a result, the sealed fluid becomes rigid, and the piston displacement of the two cylinders is reduced. Both are suppressed. Thereby, the roll rigidity of the vehicle body is improved, and the turning performance and the steering feeling of the vehicle are also improved.
[0010]
On the other hand, if the pressure is not equal between the two cylinders, the sealed fluid is allowed to flow between the two cylinders. As a result, the sealed fluid becomes soft, and the piston displacement of the two cylinders is reduced. Both are acceptable. As a result, the articulation of the suspension (for example, the property that each wheel follows the unevenness of the road and is displaced sharply) is improved, and the flatness of the vehicle body posture during vehicle running and the solid feeling of riding comfort are improved. At the same time, the off-road running performance of the vehicle is improved.
[0011]
Therefore, according to this type of vehicle suspension, the suspension characteristics of the vehicle are automatically adjusted.
[0012]
[Problems to be solved by the invention]
In general, regardless of the type of product, if an abnormality occurs in itself, it is required to detect the abnormality as soon as possible and take necessary measures by itself. Under such circumstances, an object of the present invention is to provide a vehicle suspension device capable of performing self-diagnosis.
[0013]
Means for Solving the Problems and Effects of the Invention
The following aspects are obtained by the present invention. Each aspect is divided into sections, each section is numbered, and if necessary, described in a form in which the numbers of other sections are cited. This is to facilitate understanding of some of the technical features described in the present specification and some of the combinations thereof, and the technical features and the combinations thereof described in the present specification have the following aspects. It should not be construed as limited.
(1) A vehicle suspension device arranged between a vehicle body and left and right front wheels and left and right rear wheels in a vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the first chamber and second chamber passages to allow a flow of a working fluid from each passage toward the at least one accumulator; An accumulator valve for the first chamber and an accumulator valve for the second chamber that switch to a state;
A control device for electrically controlling the accumulator valves,
(A) A command signal to be supplied to the accumulator valves for the first chamber and the second chamber is determined according to whether a predetermined condition is satisfied, and the determined command signal is supplied to the accumulator valves. A supply unit;
(B) for each accumulator valve, when the command signal supplied to the accumulator valve and the actual operating state of each accumulator valve do not match each other, an abnormality determination unit that determines that each accumulator valve is abnormal.
With
A vehicle suspension device including:
[0014]
Among the failure modes of each accumulator valve itself, there is a phenomenon that when the failure mode occurs, the command signal supplied to each accumulator valve and the actual operation state of each accumulator valve do not match each other. There are cases.
[0015]
Based on such knowledge, in the device according to this section, when the command signal supplied to each accumulator valve and the actual operation state of each accumulator valve do not match each other, each accumulator valve is It is determined to be abnormal.
[0016]
Therefore, according to this device, for example, the operation state of each accumulator valve can be diagnosed.
[0017]
It should be noted that the “front wheel cylinder” in this section may be of a type commonly installed for the left and right front wheels, or may be of a type separately installed for the left and right front wheels. According to the former type, for example, an aspect having one cylinder in common for the left and right front wheels corresponds, and according to the latter type, for example, one cylinder is provided for each of the left front wheel and the right front wheel. The aspect which has is applicable. The above interpretation also applies to the “rear wheel cylinder” in this section.
[0018]
In addition, the “accumulator” in this section can be, for example, of a type capable of storing a working fluid under pressure.
(2) the at least one accumulator includes first and second chamber accumulators individually provided in association with the first and second chamber accumulator valves;
The vehicle suspension further includes first and second room accumulator pressure sensors for detecting the pressures of the first and second room accumulators, respectively.
The abnormality determination unit determines whether or not each accumulator valve is abnormal based on whether or not there is a temporal change in a pressure-related amount, which is a pressure detected by a corresponding accumulator pressure sensor, for each of the accumulator valves. The vehicle suspension according to item (1), including an abnormality determination unit that performs the abnormality determination.
[0019]
Focusing on the accumulators corresponding to the same accumulator valve and the fluid chambers of the front wheel and rear wheel cylinders, the cylinder pressure, which is the pressure of the fluid chamber, tends to have more time fluctuations than the accumulator pressure. Is strong. Further, in a state where the accumulator valve interposed between the fluid chamber and the accumulator actually shuts off the fluid chamber and the accumulator, the temporal fluctuation of the cylinder pressure is not transmitted to the accumulator pressure. On the other hand, when the accumulator valve actually connects the fluid chamber and the accumulator to each other, the temporal fluctuation of the cylinder pressure is transmitted to the accumulator pressure.
[0020]
Therefore, if the time course of the accumulator pressure is monitored in a state where the cylinder pressure is fluctuated over time, or if the time course of the difference between the cylinder pressure and the accumulator pressure is monitored, the actual accumulator valve The operation state can be estimated.
[0021]
Based on such knowledge, in the device according to this section, for each accumulator valve, based on whether or not there is a temporal change in the pressure-related amount, which is the pressure detected by the corresponding accumulator pressure sensor, each accumulator valve is It is determined whether or not it is abnormal.
(3) the at least one accumulator includes first and second chamber accumulators individually provided in association with the first and second chamber accumulator valves;
The vehicle suspension further comprises:
An accumulator pressure sensor for the first chamber and a second chamber for detecting the pressure of the accumulator for the first chamber and the accumulator for the second chamber, respectively;
A first chamber and a second chamber cylinder pressure sensors for detecting the pressures of the first chamber and the second chamber, respectively;
Including
The abnormality determination unit determines whether there is a temporal change in a pressure-related amount, which is a difference between the pressure detected by the corresponding accumulator pressure sensor and the pressure detected by the corresponding cylinder pressure sensor, for each of the accumulator valves. The vehicle suspension according to (1), further including abnormality determination means for determining whether each accumulator valve is abnormal based on the information.
[0022]
In this device, based on the same findings as described in the above (2), for each accumulator valve, the pressure detected by the corresponding accumulator pressure sensor and the pressure detected by the corresponding cylinder pressure sensor are determined. It is determined whether or not each accumulator valve is abnormal based on the presence or absence of a temporal change in the pressure-related amount that is the difference.
[0023]
The “cylinder pressure sensor” in this section can be, for example, a type that directly detects the pressure of the corresponding fluid chamber of the corresponding cylinder, or a type that indirectly detects, that is, a type that estimates the pressure. It is.
[0024]
When the latter type is adopted, the “cylinder pressure sensor” includes, for example, a turning state quantity (eg, lateral speed, lateral acceleration, yaw angle, yaw rate, roll angle, roll rate) of the vehicle, and a vertical stroke of the suspension of each wheel. It is possible to include a sensor unit for detecting the vertical acceleration and the like of each wheel, and a signal processing unit for estimating the cylinder pressure based on the output signal of the sensor unit.
(4) When the abnormality determining means is provided with the first command signal for switching each of the accumulator valves to the blocking state in a case where there is a temporal variation in the pressure-related amount, The vehicle suspension according to (2) or (3), including first means for determining that there is an abnormality that each accumulator valve is actually in the allowable state.
[0025]
According to this device, for each accumulator valve, it is possible to detect an abnormality that each accumulator valve is actually in the permissible state even though the first command signal for switching the accumulator valve to the blocking state is supplied. Becomes possible.
(5) When the abnormality determination means determines that there is no temporal variation in the pressure-related amount in a state where the second command signal for switching the accumulator valve to the allowable state is supplied to each of the accumulator valves, The vehicle suspension according to (2) or (3), further including second means for determining that there is an abnormality that each accumulator valve is actually in the blocking state.
[0026]
According to this device, for each accumulator valve, it is possible to detect an abnormality that each accumulator valve is actually in the blocking state even though the second command signal for switching the accumulator valve to the allowable state is supplied. Becomes possible.
(6) The abnormality determining means supplies a second command signal to each of the accumulator valves for switching the accumulator valves to the permissible state, and when the vehicle is running, the pressure-related amount of the accumulator valves is reduced. The vehicle suspension according to (2) or (3), further including third means for determining that there is an abnormality that each accumulator valve is actually in the blocking state when there is no temporal fluctuation.
[0027]
Generally, the temporal variation of the pressures of the front wheel and rear wheel cylinders is more remarkable when the vehicle is traveling than when the vehicle is stopped.
[0028]
Therefore, despite the fact that each accumulator valve is supplied with the second command signal for switching the accumulator valve to the permissible state, the phenomenon that there is no temporal fluctuation of the pressure-related amount exists in the state where the vehicle is running. , It is possible to determine that the accumulator valve is actually in the blocking state with higher accuracy than when the same phenomenon occurs when the vehicle is stopped.
[0029]
Based on such knowledge, the device according to this section was proposed.
(7) A vehicle suspension device arranged between the left and right front wheels and the left and right rear wheels and the vehicle body in the vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the first chamber and second chamber passages to allow a flow of a working fluid from each passage toward the at least one accumulator; An accumulator valve for the first chamber and an accumulator valve for the second chamber that switch to a state;
A control device for electrically controlling the accumulator valves,
(A) A command signal to be supplied to the accumulator valves for the first chamber and the second chamber is determined in accordance with whether a predetermined condition is satisfied, and the determined command signal is shared by the accumulator valves. A signal supply unit for supplying
(B) when the actual operating states of the accumulator valves do not match each other, an abnormality determining unit that determines that one of the accumulator valves is abnormal.
With
A vehicle suspension device including:
[0030]
In this device, a command signal to be commonly supplied to the first and second chamber accumulator valves is determined according to whether or not a predetermined condition is satisfied, and the determined command signal is supplied to the accumulator valves. Supplied in common.
[0031]
Therefore, as long as both the first and second chamber accumulator valves are normal, the actual operating states of the accumulator valves should match each other.
[0032]
By paying attention to such a fact, in the device according to this section, when the actual operation states of the accumulator valves do not match each other, it is determined that one of the accumulator valves is abnormal.
[0033]
Thus, with this device, it is not essential, for example, to monitor the pressure-related quantity in order to detect an accumulator valve malfunction.
(8) Further, when the abnormality determination section determines that the accumulator valve for the first chamber and the accumulator valve for the second chamber are normal, the actual operation state of the accumulator valve is determined to be abnormal. Any of (1) to (7) including an alternative control section for performing an alternate control on the accumulator valves by supplying a command signal to the normal accumulator valves to match the actual operation state of the valves. A vehicle suspension device according to any one of claims 1 to 3.
[0034]
One of the first and second chamber accumulator valves may be abnormal while the others are normal. In this case, if the normal accumulator valve is left as it is, a difference in operating state occurs between the accumulator valve and the difference may induce a difference in operating characteristics between the front wheel and rear wheel cylinders. is there. The difference in the operating characteristics may lead to, for example, a difference in the roll rigidity of the vehicle body or a change in the articulation property of the wheels depending on the direction in which the vehicle body tries to roll.
[0035]
Therefore, in the device according to this section, when the abnormality determination unit determines that the operation is abnormal, the actual operation states of the normal accumulator valves for the first chamber and the second chamber are determined to be abnormal. A command signal is provided to the normal accumulator valves to match the actual operating condition of certain accumulator valves, thereby providing alternative control over those accumulator valves.
(9) A vehicle suspension device arranged between the left and right front wheels and the left and right rear wheels and the vehicle body in the vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the first chamber and second chamber passages to allow a flow of a working fluid from each passage toward the at least one accumulator; An accumulator valve for the first chamber and an accumulator valve for the second chamber that switch to a state;
A control device for electrically controlling the accumulator valves,
(A) determining whether a predetermined condition is satisfied, and determining a command signal to be commonly supplied to the first and second chamber accumulator valves according to the determination result; and determining the determined command signal. Signal supply unit for supplying the accumulator valve
(B) For each accumulator valve, an abnormality determination unit that determines that the determination result is abnormal when the actual condition of the predetermined condition and the actual operation state of each accumulator valve do not match each other. When
With
A vehicle suspension device including:
[0036]
In this device, it is determined whether or not a predetermined condition is satisfied, and a command signal to be commonly supplied to the first and second chamber accumulator valves is determined according to the determination result. The determined command signal is commonly supplied to the accumulator valves.
[0037]
In this device, the determination as to whether or not the predetermined condition is satisfied is performed using an output signal of an electric component such as a sensor for detecting a driving state amount, a vehicle state amount, or a traveling environment state amount of the vehicle. There are cases. Here, the “driving state amount” includes, for example, a driver's operation amount (steering angle, brake operation amount, accelerator operation amount), and the “vehicle state amount” is a state amount generated in the vehicle during vehicle movement. And, for example, vehicle speed, wheel speed, longitudinal acceleration, lateral acceleration, yaw rate, roll rate, and the like. In addition, the “running environment state quantity” includes, for example, the surface state of the road surface (the coefficient of friction and the degree of unevenness), the state of the wind blown to the vehicle, and the shape of the road (information acquired by an on-board navigation system or communication device). And the like are obtained on the basis of
[0038]
On the other hand, a failure mode that can be assumed in this device includes a failure mode for components such as an accumulator valve and a failure mode for an electrical signal output component such as a sensor.
[0039]
If the latter failure mode is assumed for this device, there is a possibility that an error may occur in the determination result even though the predetermined condition is actually satisfied. If the judgment result is wrong, even if the accumulator valves for the first chamber and the second chamber are normal in themselves, an incorrect command signal is supplied to the accumulator valves. -The actual operating state of the valve is unexpected.
[0040]
However, in this device, when the actual success or failure of the predetermined condition and the actual operation state of each accumulator valve do not match each other for each accumulator valve, the determination result of the success or failure of the predetermined condition is obtained. Is determined to be abnormal.
(10) The vehicle further includes a turning state related quantity sensor for detecting a physical quantity for detecting a turning state of the vehicle,
The predetermined condition includes a turning condition that should be satisfied when the vehicle is in a turning condition,
The signal supply unit determines whether or not the turning condition is satisfied based on an output signal of the turning state related amount sensor, and when it is determined that the turning condition is satisfied, the accumulator valve blocks the accumulator valve. Means for supplying a command signal for switching to the state,
The abnormality determination unit is configured to determine whether the accumulator valve actually satisfies the turning condition and determines whether or not the accumulator valve meets the actual condition of the turning condition when the continuous time that the accumulator valve continues to be in the blocking state exceeds a limit time. The vehicle suspension according to item (9), including means for determining that the operating states of the vehicle do not match each other.
[0041]
In this device, it is determined based on an output signal of a turning state related amount sensor whether or not a turning condition that is satisfied when the vehicle is in a turning state is satisfied. When it is determined that the turning condition is satisfied, each accumulator is determined. A command signal is supplied to the valve to switch it to the blocking state.
[0042]
By the way, there is usually a limit to the length of time that the vehicle continuously turns, and the limit has a substantially common size regardless of the traveling environment of the vehicle and the driver. I have. Therefore, if each accumulator valve is monitored to see if the continuous time it actually remains in the blocking state exceeds the time limit, the operating state of each accumulator valve will correctly reflect the turning condition of the vehicle. It is possible to estimate whether or not there is.
[0043]
Based on such knowledge, in the device according to this section, for each accumulator valve, if the continuous time during which the accumulator valve continues to be in the blocking state exceeds the limit time, the actual success or failure of the turning condition is satisfied. And the actual operating state of each accumulator valve is determined to be inconsistent with each other.
(11) Further, when it is determined by the abnormality determination section that the vehicle is abnormal, the first and second accumulator valves are transmitted to the first and second chamber accumulator valves irrespective of the determination result of whether or not the turning condition is satisfied. The vehicle suspension according to (9) or (10), further including an alternative control unit that performs an alternative control on the accumulator valves by supplying a command signal for switching to the allowable state.
[0044]
In this device, when it is determined by the abnormality determination section that the vehicle is abnormal, the determination result of whether or not the turning condition is satisfied is ignored, so that the accumulator valves for the first chamber and the second chamber are used. A command signal is supplied to switch the accumulator valves to an allowable state, whereby alternative control is performed on the accumulator valves.
(12) A vehicle suspension device arranged between the left and right front wheels and the left and right rear wheels and the vehicle body in the vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the first chamber and second chamber passages to allow a flow of a working fluid from each passage toward the at least one accumulator; An accumulator valve for the first chamber and an accumulator valve for the second chamber that switch to a state
Including, and
A vehicle suspension in which both accumulator valves switch to the permissible state when the continuous time both of the accumulator valves are actually in the blocking state exceeds a time limit.
[0045]
This device expresses the device according to the above mode (11) by paying particular attention to the physical configuration and the operation mode of the device, which are easily visible.
(13) A plurality of cylinders having pistons are provided between the vehicle body and the plurality of wheels in the vehicle, and spaces in the respective cylinders correspond to each other among the plurality of cylinders among the plurality of fluid chambers partitioned by the respective pistons. A vehicle suspension device having a passage connecting objects to each other,
A storage chamber capable of storing a working fluid,
A valve device that is provided between the passage and the storage chamber, and that switches a flow state of the working fluid between the passage and the storage chamber between a communication state and a shutoff state;
A pressure sensor for detecting the pressure of the storage chamber,
A determining unit that determines whether the vehicle suspension device is abnormal based on the flow state of the valve device and the output of the pressure sensor;
Vehicle suspension device provided with.
[0046]
According to this device, the self-diagnosis of the vehicle suspension device can be performed by focusing on the fact that the relationship between the flow state of the valve device and the output of the pressure sensor changes depending on the presence or absence of an abnormality in the vehicle suspension device. It becomes possible.
[0047]
Here, the “determination unit” can be implemented, for example, in a form that specifies at least one of the position and type of a plurality of components of the vehicle suspension device that are determined to be abnormal.
(14) A plurality of cylinders having pistons are provided between the vehicle body and the plurality of wheels in the vehicle, and spaces in the cylinders correspond to each other among the plurality of fluid chambers among the plurality of fluid chambers partitioned by the pistons. A vehicle suspension device having a passage connecting objects to each other,
A storage chamber capable of storing a working fluid,
A valve device that is provided between the passage and the storage chamber, and that switches a flow state of the working fluid between the passage and the storage chamber between a communication state and a shutoff state;
A traveling state quantity sensor for detecting a traveling state quantity of the vehicle,
A controller that controls the valve device by supplying a command signal based on the output of the traveling state quantity sensor to the valve device, and the vehicle suspension device is configured to control the valve device based on a supply state of the command signal to the valve device. It has a judgment unit to judge whether it is abnormal
Vehicle suspension device provided with.
[0048]
According to this device, the vehicle suspension device is self-diagnosed by focusing on the fact that the relationship between the actual operation state of the valve device and the traveling state quantity of the vehicle changes depending on whether or not the vehicle suspension device is abnormal. It is possible to do.
[0049]
Here, the “running state quantity sensor” includes, for example, a sensor that detects a running state quantity related to the turning motion of the vehicle, or includes a sensor that detects a running state quantity related to the inclination or height of the vehicle body. It is possible to include a sensor for detecting a running state quantity related to the acceleration in the lateral direction or the vertical direction.
(15) The means according to the above mode (14), wherein the determination unit includes means for determining whether or not the vehicle suspension device is abnormal based on a length of continuous time during which the same command signal is supplied to the valve device. Vehicle suspension system.
[0050]
In this device, the fact that the same command signal is supplied to the valve device for as long as it is normal may not exceed the limit. In this case, it is possible to determine whether or not the device is abnormal based on the length of the continuous time.
[0051]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, some of the embodiments of the present invention will be described more specifically with reference to the drawings.
[0052]
FIG. 1 shows a vehicle suspension device (hereinafter, simply referred to as “suspension device”) according to a first embodiment of the present invention in a state where the vehicle is mounted. This suspension device is mounted on a vehicle having left and right front wheels 10, 10 and left and right rear wheels 12, 12 supported by a vehicle body (not shown), arranged between the wheels 10, 12 and the vehicle body. .
[0053]
The vehicle body is connected to left and right front wheels 10, 10 and left and right rear wheels 12, 12 via a suspension 20 so as to be relatively displaceable. On the front wheel side, the suspension 20 swingably supports the left and right wheels 10, 10 on the vehicle body via left and right lower arms 22, 22. Furthermore, on the rear wheel side, the suspension 20 connects the left and right wheels 12, 12 to the vehicle body via a rear axle housing 26 that rotatably holds a rear axle (not shown) that rotates coaxially with the left and right wheels 12, 12. It is swingably supported. The rear axle distributes the driving torque of a drive shaft (not shown) to the left and right rear wheels 12, 12 via a differential 28, as is well known.
[0054]
The suspension 20 includes stabilizer bars 30 and 32 on the front wheel side and the rear wheel side, respectively. As is well known, each of the stabilizer bars 30, 32 extends generally in the left-right direction of the vehicle body on the front wheel side and the rear wheel side, and connects the left and right wheels to each other. Each of the stabilizer bars 30 and 32 includes a rod-shaped torsion portion 36 extending in the left-right direction of the vehicle body. I have.
[0055]
On the front wheel side, each end of the pair of arm portions 38, 38 of the stabilizer bar 30 is relatively rotated to a portion of the corresponding lower arm 22, 22, which is displaced from the swing center of the lower arm 22, in the lateral direction of the vehicle body. Supported as possible. On the other hand, on the rear wheel side, the respective ends of the pair of arms 38, 38 of the stabilizer bar 32 are supported by the rear axle housing 26 so as to be relatively rotatable.
[0056]
The stabilizer bar 30 for the front wheels acts to increase the roll rigidity of the vehicle body when the left and right wheels 10, 10 move in opposite phases. The stabilizer bar 32 for the rear wheel also acts to increase the roll rigidity of the vehicle body when the left and right wheels 12, 12 move in opposite phases.
[0057]
Each stabilizer bar 30, 32 basically controls the roll rigidity of the front wheel and the rear wheel independently of each other. On the other hand, in the present embodiment, the front wheel stabilizer bar 30 and the rear wheel stabilizer bar 32 are mechanically linked to each other, and the suspension device is used to realize the link. .
[0058]
In this suspension device, the stabilizer bar 30 for the front wheels is attached to the vehicle body at two portions of the torsion portion 36 thereof, which are opposite to each other from the vehicle body front-rear center line. One of the two parts is connected to the vehicle body via a connection rod 50 of invariable length, and the other is connected to the vehicle body via a cylinder 52 of variable length. Both the connecting rod 50 and the cylinder 52 generally extend in the vertical direction of the vehicle body.
[0059]
On the other hand, the stabilizer bar 32 for the rear wheel is attached to the vehicle body at two portions of the torsion portion 36 of the torsion portion 36 which are oppositely separated from the center line of the vehicle body in the same manner as the stabilizer bar 30 for the front wheel. . One of these two parts is connected to the vehicle body via a connection rod 60 of invariable length, and the other is connected to the vehicle body via a cylinder 62 of variable length. Both the connecting rod 60 and the cylinder 62 extend generally in the vertical direction of the vehicle body.
[0060]
That is, in the present embodiment, the cylinder 52 is an example of a “front wheel cylinder”, and the cylinder 62 is an example of a “rear wheel cylinder”.
[0061]
In addition, in the present embodiment, in the present embodiment, each of the cylinders 52 and 62 connects the corresponding stabilizer bar 30, 32 and the vehicle body so as to be relatively displaceable with each other. For example, the corresponding stabilizer bar is connected to the right portion and the left portion. It is possible to carry out the invention in such a way that each cylinder is used to separate the two parts so that they can be displaced relative to one another. This is because it is sufficient for the cylinder to realize relative displacement between the left and right wheels, generally in the vertical direction of the vehicle body.
[0062]
In addition, it is not essential for each cylinder to connect the corresponding wheel to the vehicle body via a stabilizer bar. For example, each cylinder may be connected to the left and right front wheels 10, 10 and the left and right rear wheels 12, 12. It is also possible to implement the invention in such a way that the members arranged individually and moving with each wheel are connected to the vehicle body.
[0063]
The front wheel cylinder 52 and the rear wheel cylinder 62 are common to each other in structure, and are shown in a front sectional view in FIG. Each of the cylinders 52 and 62 includes a hollow housing 70 whose both ends are closed, and a piston 72 fitted to the housing 70 in a substantially liquid-tight and slidable manner. By this fitting, the space in the housing 70 is divided into two spaces. In the present embodiment, since each of the cylinders 52 and 62 is mounted on the vehicle in a posture extending generally in the vertical direction of the vehicle body, the upper one of the two spaces is the upper chamber 74 and the lower one is the lower chamber. 76.
[0064]
As shown in FIG. 2, a piston rod 80 extends coaxially from one side of the piston 72 and penetrates the housing 70 to be exposed to the atmosphere. In the present embodiment, a piston rod 80 extends downward from a side facing the lower chamber 76 of both sides of the piston 72. The distal end of the piston rod 80 is connected to the stabilizer bar 30 so as to be relatively rotatable, as shown in FIG. As shown in FIG. 2, a fixed rod 84 extends coaxially from the end of the housing 70 opposite to the end through which the piston rod 80 penetrates. In the present embodiment, as shown in FIG. 1, the distal end of the fixed rod 84 is connected to a vehicle body (not shown) so as to be relatively rotatable.
[0065]
As is clear from the above description, as shown in FIG. 1, each of the stabilizer bars 30, 32 is connected to the vehicle body via the cylinders 52, 62 on one side and the connecting rods 50, 60 on the other side. It is being done. The positions of the cylinders 52 and 62 are commonly set on the front wheel side and the rear wheel side, and both are set on the right side of the vehicle body in FIG.
[0066]
Therefore, in this embodiment, when the vehicle body tries to roll to the right, the piston 72 rises (the piston rod 80 is displaced to the contraction side) in both the front wheel cylinder 52 and the rear wheel cylinder 62. , In the upper chamber 74.
[0067]
Therefore, in the present embodiment, the upper chamber 74 is an example of the “first chamber” and the lower chamber 76 is an example of the “second chamber” on both the front wheel side and the rear wheel side.
[0068]
As shown in FIG. 1, the upper chamber 74 of the front wheel cylinder 52 and the upper chamber 74 of the rear wheel cylinder 62 are connected to each other by a passage 90. Similarly, the lower chamber 76 of the front wheel cylinder 52 and the lower chamber 76 of the rear wheel cylinder 62 are connected to each other by a passage 92. That is, in the present embodiment, the passage 90 forms an example of the “first room passage”, and the passage 92 forms an example of the “second room passage”.
[0069]
As shown in FIG. 1, a hydraulic unit 100 is connected in the middle of the passage 90, and a hydraulic unit 102 is connected in the middle of the passage 92 in the same manner.
[0070]
FIG. 3 conceptually shows a hardware configuration and a software configuration of the suspension device according to the present embodiment.
[0071]
As shown in FIG. 3, the hydraulic unit 100 includes an accumulator 200. As is well known, the accumulator 200 is configured such that a piston is substantially slidably and slidably fitted in a housing having a bottom. A high pressure chamber filled with nitrogen gas as a compressed gas is formed behind the piston, and a storage chamber capable of storing the working fluid under pressure is formed in the front.
[0072]
The accumulator 200 is connected to the passage 90 via a solenoid valve 206. As is well known, although not shown, a solenoid valve 206 generates a magnetic force when energized, and a valve unit that operates based on the magnetic force and switches between an open state and a closed state of the internal passage. And is configured to include: In the present embodiment, the solenoid valve 206 is of a normally open type. In a non-energized state, the solenoid valve 206 is in a communication position (open state) that allows the passage 90 and the accumulator 200 to communicate with each other. The switch is switched to a blocking position (closed state) for blocking the 90 and the accumulator 200 from each other.
[0073]
In the open state of the solenoid valve 206, if the hydraulic fluid in each of the cylinders 52 and 62 thermally expands to increase its volume, the hydraulic fluid is absorbed by the accumulator 200 by the increased amount. Thereby, the volume of the hydraulic fluid in each of the cylinders 52 and 62 is compensated for the temperature rise.
[0074]
Further, when the volume of the hydraulic fluid in each of the cylinders 52 and 62 decreases in the open state of the solenoid valve 206, the hydraulic fluid is replenished from the accumulator 200 by the reduced amount. Thereby, the volume of the hydraulic fluid in each of the cylinders 52 and 62 is compensated.
[0075]
Therefore, in the present embodiment, the solenoid valve 206 constitutes an example of the “accumulator valve”.
[0076]
Similarly, the hydraulic unit 102 is configured to include the accumulator 200 and the solenoid valve 206 in the middle of the passage 92.
[0077]
As shown in FIG. 3, the suspension device is provided with an electronic control unit (hereinafter, referred to as “ECU”) 250 for controlling the two solenoid valves 206. The ECU 250 includes information about the pressure of the accumulator 200, information about the wheel speed, information about the lateral acceleration of the vehicle body, and information about the steering angle at which the driver has rotated the steering wheel of the vehicle as information about the vehicle state quantity. , The solenoid valve 206 is controlled, and necessary information is displayed to the driver via the indicator 252.
[0078]
FIG. 4 is a block diagram conceptually showing the software configuration of ECU 250. The ECU 250 is mainly configured by a computer 260. As is well known, the computer 260 is configured by connecting a CPU 262, a ROM 264, and a RAM 266 to each other via a bus 268. The computer 260 is connected to various external devices via an I / O port (not shown).
[0079]
Specifically, as shown in FIG. 3, the ECU 250 is connected to two accumulator pressure sensors 280 and 280 that detect the pressures of the two accumulators 200 and 200, respectively. The ECU 250 is further connected to a lateral acceleration sensor 282 for detecting a lateral acceleration of the vehicle body and a steering angle sensor 284 for detecting the steering angle. The sensors 282 and 284 can be used to determine whether the vehicle is turning or not and to determine the degree of rolling motion of the vehicle body. The ECU 250 further includes four wheel speed sensors 268 (only one is shown in FIG. 3) for detecting the angular velocities of the left and right front wheels 10, 10 and the left and right rear wheels 12, 12 as wheel speeds. Connected). The wheel speed sensors 268 can be used to determine whether the vehicle is turning.
[0080]
The ECU 250 is further connected to the solenoid valves 206, 206 and the indicator 252. The indicator 252 can be used to visually transmit necessary information to the driver by characters, graphics, and the like. The indicator 252 is an example of an output device, and an alarm device (e.g., a buzzer, a pseudo sound output device) that audibly transmits necessary information to the driver can be used instead or together with the output device. .
[0081]
The ROM 264 stores various programs to be executed by the computer 260 to operate the suspension device. One of them is a valve control program for controlling the solenoid valves 206, and is conceptually represented by a flowchart in FIG.
[0082]
This valve control program is repeatedly executed after a driver turns on a vehicle switch such as an ignition switch. At the time of each execution, first, in a step (hereinafter, referred to as “S1”; the same applies to other steps), the vehicle is turning based on signals from the lateral acceleration sensor 282, the steering angle sensor 284, and the like. Is determined.
[0083]
Assuming that the vehicle is not turning this time, the determination in S1 is NO, and in S2, the solenoid of each solenoid valve 206 is turned off for both the front wheel side and the rear wheel side.
[0084]
As described above, all the solenoid valves 206 are of the normally open type, and therefore are in an open state prior to a series of executions of the valve control program. The front wheel cylinder 52 and the rear wheel cylinder 62 are in communication with the accumulator 200. Therefore, if the volume of the hydraulic fluid in each cylinder increases due to thermal expansion, the increased amount of hydraulic fluid The pressure is absorbed by the accumulator 200 through the solenoid valve 206.
[0085]
Since the current execution of S2 corresponds to the first execution of the series of executions of the valve control program, each solenoid valve 206 is maintained in the open state (communication position) despite the execution of S2. It will be.
[0086]
This completes one execution of the valve control program.
[0087]
On the other hand, if it is assumed that the vehicle is turning this time, the determination in S1 is YES, and in S2, the solenoid of each solenoid valve 206 is turned ON for both the front wheel side and the rear wheel side. As a result, each solenoid valve 206 disconnects the front wheel cylinder 52 and the rear wheel cylinder 62 from the accumulator 200, and the pressure circuits 240, 242 formed by connecting the cylinders 52, 62 to each other by the passages 90, 92. (See FIG. 3).
[0088]
This completes one execution of the valve control program.
[0089]
In a state where the front wheel cylinder 52 and the rear wheel cylinder 62 are cut off from the accumulator 200 and the hydraulic fluid is sealed in the pressure circuits 240 and 242, when the vehicle body tries to roll during turning of the vehicle, the front wheel cylinder 52 and the rear wheel cylinder 62 The pressure becomes equal between the rear wheel cylinders 52 and 62, and the flow of the hydraulic fluid between the cylinders 52 and 62 is prevented. As a result, in each of the cylinders 52 and 62, the stroke of the piston 72 in the same direction (for example, the stroke in the direction in which the wheels bounce) is prevented. Therefore, the stabilizer bars 30 and 32 can be twisted in the same manner as in a vehicle that does not have the front wheel and rear wheel cylinders 52 and 62, and the stabilizer bars 30 and 32 can effectively exhibit their original functions. As a result, the body roll is suppressed.
[0090]
On the other hand, when one of the front and rear wheels on the same side is about to float when the vehicle is traveling on an uneven road surface, the front and rear cylinders 52 and 62 are used between the front and rear cylinders 52 and 62. It is no longer a pressure, and the flow of the hydraulic fluid between the cylinders 52 and 62 is allowed. As a result, in each of the cylinders 52 and 62, the stroke of the piston 72 in the opposite direction (stroke in the direction in which the wheel bounces in one cylinder and in the direction in which it rebounds in the other cylinder) is allowed. Therefore, unlike the vehicle without the front-wheel and rear-wheel cylinders 52, 62, the stabilizer bars 30, 32 are prevented from being twisted, and the stabilizer bars 30, 32 exhibit their original functions. As a result, the articulation property of the suspension 20 (for example, the property that each wheel is displaced sharply following irregularities on the road surface) is improved.
[0091]
The ROM 264 further stores a self-diagnosis program. FIG. 6 is a flow chart conceptually showing the contents of the self-diagnosis program.
[0092]
This self-diagnosis program is also executed repeatedly. At the time of each execution, first, in S101, the pressure of each accumulator 200 is detected by each accumulator pressure sensor 280.
[0093]
Next, in step S102, whether each of the solenoid valves 206 or a sensor (a lateral acceleration sensor 282, a steering angle sensor 284, etc.) that outputs a signal referred to by the computer 260 to execute the valve control program of FIG. It is determined whether or not. The details of S102 will be described later.
[0094]
This time, assuming that it is determined that the devices are not abnormal, in S103, continuation of the normal control for the two solenoid valves 206, 206 is permitted. Specifically, the execution of the valve control program of FIG. 5 by the computer 260 is permitted.
[0095]
Thus, one execution of the self-diagnosis program ends.
[0096]
On the other hand, if it is assumed that these devices are determined to be abnormal this time, in S104, alternative control is performed on those devices as a fail-safe measure for the devices. Since this alternative control is a control that replaces the normal control, when it is executed, the execution of the valve control program of FIG. 5 by the computer 260 is stopped. The details of S104 will be described later.
[0097]
After that, in S105, the driver is notified that there is something abnormal in those devices.
[0098]
Thus, one execution of the self-diagnosis program ends.
[0099]
In S102, the following four determinations are performed.
(1) Open sticking determination for determining whether or not each solenoid valve 206 has stuck open in the open state.
(2) A determination of whether or not each solenoid valve 206 has been locked in the closed state and whether or not a closed lock has occurred.
(3) Since the turning state sensor such as the lateral acceleration sensor 282 is abnormal, the computer 260 incorrectly determines that the vehicle is turning while the vehicle is not actually turning. An erroneous command determination for determining whether or not an erroneous command has been output to the solenoid valves 206, 206 as well by outputting a closing signal (a signal for turning on each solenoid) for closing the solenoid valves.
(4) Abnormal high pressure determination to determine whether the hydraulic fluid is abnormally high pressure
FIG. 7 is a flowchart conceptually showing the contents of an open sticking determination program executed by the computer 260 for the above-described open sticking determination.
[0100]
To explain conceptually the principle of the determination in the open sticking determination program, in a state where each solenoid valve 206 outputs a close signal for closing it, each solenoid valve 206 normally responds to the close signal. If it is closed, the corresponding accumulator 200 is shut off from any of the cylinders 52 and 62. Therefore, in this case, the accumulator pressure does not fluctuate despite the pressure fluctuations of the cylinders 52 and 62.
[0101]
On the other hand, if each solenoid valve 206 is stuck in the open state, the close signal is invalidated. As a result, the corresponding accumulator 200 communicates with any of the cylinders 52 and 62. Therefore, the pressure fluctuation of the cylinders 52 and 62 is transmitted to the accumulator 200, and the accumulator pressure fluctuates.
[0102]
FIG. 8 shows that when the close signal is supplied, the upper chamber-side solenoid valve 206 is open and fixed, while the lower chamber-side solenoid valve 206 is normally closed, and the upper chamber-side accumulator is used. A graph shows that the pressure P of the accumulator 200 on the lower chamber side does not fluctuate while the pressure P of 200 fluctuates with time t.
[0103]
7 is repeatedly executed according to the above-described determination principle, and in each execution, first, in S201, it is determined whether or not a close signal is output to each solenoid valve 206. This time, assuming that no output has been made, the determination is NO, and one execution of this open sticking determination program ends immediately.
[0104]
In contrast, this time, assuming that a close signal has been output to each solenoid valve 206, the determination in S201 is YES, and in S202, the output signal of the accumulator pressure sensor 280 corresponding to each solenoid valve 206 is Then, it is determined whether or not the accumulator pressure fluctuates based on a time-series signal indicating a temporal transition of the accumulator pressure.
[0105]
In this case, if it is assumed that the accumulator pressure is fluctuating for both or one of the two solenoid valves 206, the determination is YES, and in S203, it is determined that the corresponding solenoid valve 206 is in the open and fixed state. You.
[0106]
On the other hand, this time, if it is assumed that the accumulator pressure does not fluctuate in any of the solenoid valves 206, 206, the determination in S202 is NO, and in S204, all the solenoid valves 206, 206 are in the open and fixed state. Is determined not to be.
[0107]
In any case, one execution of the open sticking determination program is completed.
[0108]
FIG. 9 is a flow chart conceptually showing the contents of a closed sticking determination program executed by the computer 260 to determine the closed sticking.
[0109]
To explain conceptually the principle of determination in this program for determining whether the solenoid valve is closed or closed, in a state where an open signal for causing each solenoid valve 206 to open it (a signal for turning off each solenoid) is output. If the solenoid valve 206 is normally opened in response to the opening signal, the corresponding accumulator 200 communicates with any of the cylinders 52 and 62, and the accumulator pressure fluctuates according to the pressure fluctuation of the cylinders 52 and 62. .
[0110]
On the other hand, if each solenoid valve 206 is stuck in the closed state, the open signal is invalidated, and as a result, the corresponding accumulator 200 is shut off from any of the cylinders 52 and 62. Therefore, the pressure fluctuation of the cylinders 52 and 62 is not transmitted to the accumulator 200, and the accumulator pressure does not fluctuate.
[0111]
FIG. 10 shows that when the open signal is supplied, the upper chamber side solenoid valve 206 is closed and fixed, while the lower chamber side solenoid valve 206 is normally open, the upper chamber side accumulator A graph shows that the pressure P of the accumulator 200 on the lower chamber side fluctuates while the pressure P of 200 does not fluctuate with time t.
[0112]
By the way, when the vehicle is stopped and pressure fluctuations do not occur in the cylinders 52 and 62 in the first place, whether the solenoid valve 206 is in the open state or the closed state is determined according to the presence or absence of the pressure fluctuation in the accumulator 200. Is difficult to determine.
[0113]
Therefore, in the present embodiment, when the accumulator pressure does not fluctuate even while the vehicle is running, it is determined that the solenoid valve 206 is in the closed state. Is improved.
[0114]
In accordance with the above-described determination principle, the closed / fixed determination program of FIG. 9 is repeatedly executed, and in each execution, first, in S231, it is determined whether or not the open signal is output to each solenoid valve 206. In this case, assuming that no output has been made, the determination is NO, and one execution of the close-stuck determination program ends immediately.
[0115]
On the other hand, this time, assuming that the open signal is output to each solenoid valve 206, the determination in S231 is YES, and in S232, based on the output signal of the wheel speed sensor 286 that reflects the vehicle speed, It is determined whether the vehicle is running. In this case, if it is assumed that the vehicle is not running, the determination is NO, and one execution of the close-stuck determination program ends immediately.
[0116]
On the other hand, if it is assumed that the vehicle is running this time, the determination in S232 is YES, and in S233, the output signal of the corresponding accumulator pressure sensor 280 and the time of the accumulator pressure are output for each solenoid valve 206. It is determined whether or not the accumulator pressure has fluctuated based on the time-series signal indicating the temporal transition.
[0117]
This time, assuming that the accumulator pressure has not fluctuated for both or one of the two solenoid valves 206, the determination is YES, and in S234, it is determined that the corresponding solenoid valve 206 is in the closed and fixed state.
[0118]
In contrast, this time, assuming that the accumulator pressure is fluctuating for any of the solenoid valves 206, the determination in S233 is NO, and in S235, it is determined that none of the solenoid valves 206 is in the closed and fixed state. Is determined.
[0119]
In any case, one cycle of the execution of the program for determining whether or not the vehicle is closed is completed.
[0120]
FIG. 11 is a flowchart conceptually showing the contents of an erroneous command determination program executed by the computer 260 for the erroneous command determination.
[0121]
To explain conceptually the determination principle in the erroneous command determination program, if the turning state sensor used to determine whether the vehicle is in a turning state is normal, the vehicle is actually in a turning state. Only in this case, both of the two solenoid valves 206 output a close signal. The length of time that the vehicle is continuously turning is usually limited. Therefore, it is determined whether or not the time during which the close signal is continuously output to both of the two solenoid valves 206, 206, that is, the continuous time T, exceeds a threshold value Tth (which is an example of the limit time) corresponding to the limit. Then, it can be determined whether or not the turning state sensor is abnormal.
[0122]
FIG. 12 shows that if the continuous time T during which the close signal is output to both of the two solenoid valves 206, 206 increases by the period Δt every time the erroneous command determination program is repeated, the continuous time T becomes the threshold value Tth. If it does not exceed, the turning state sensor is determined to be normal, and if it exceeds, the manner in which the turning state sensor is determined to be abnormal is represented by a graph.
[0123]
In accordance with the above-described determination principle, the erroneous command determination program of FIG. 11 is repeatedly executed. In each execution, first, in S301, it is determined whether or not the close signals are output to both of the two solenoid valves 206, 206. . If it is not output this time, the determination is NO, and in S302, the reset flag representing OFF does not reset the continuous time T and the reset flag representing ON resetting is turned ON.
[0124]
On the other hand, if it is assumed that the close signals are output to both of the two solenoid valves 206 and 206 this time, the determination in S301 is YES, and in S303, the reset flag is turned off. Subsequently, in S304, the continuous time T is increased by the period Δt.
[0125]
In any case, thereafter, in S305, it is determined whether or not the current value of the continuous time T has exceeded the threshold value Tth. In this case, if it is not exceeded, the determination is NO, and it is determined in S306 that the output of the close signal to the two solenoid valves 206, 206 was not based on an erroneous command. On the other hand, if it is assumed that the current value of the continuous time T has exceeded the threshold value Tth this time, the determination in S305 becomes YES, and in S307, the output of the close signal to the two solenoid valves 206 It is determined that it was based on the erroneous command.
[0126]
In any case, thereafter, in S308, it is determined whether or not the reset flag is turned ON. If it is turned ON, the determination becomes YES, and the continuous time T is reset to 0 in S309. On the other hand, if the reset flag has not been turned ON, the determination in S308 is NO, and S309 is skipped.
[0127]
In any case, one execution of this erroneous command determination program is completed.
[0128]
FIG. 13 is a flowchart conceptually showing the contents of an abnormally high pressure determination program executed by the computer 260 for the above-mentioned abnormally high pressure determination.
[0129]
This abnormally high pressure determination program is repeatedly executed. In each execution, first, in S331, it is determined whether or not the pressure P of each accumulator 200 exceeds the allowable value P0 based on the output signal of each accumulator pressure sensor 280. . In this case, assuming that it has not exceeded, the determination is NO, and in S332, the reset flag representing OFF does not reset the continuous time T and the reset flag representing ON resetting is turned ON.
[0130]
On the other hand, this time, assuming that the pressure P of each accumulator 200 has exceeded the allowable value P0, the determination in S331 is YES, and the reset flag is turned off in S333. Subsequently, in S334, the continuous time T is increased by the period Δt.
[0131]
In any case, thereafter, in S335, it is determined whether or not the current value of the continuous time T has exceeded the threshold value Tth. This time, if it is assumed that it has not exceeded, the determination is NO, and it is determined in S336 that the hydraulic fluid is not abnormally high in pressure. On the other hand, if it is assumed that the current value of the continuous time T has exceeded the threshold value Tth this time, the determination in S335 is YES, and in S337, it is determined that the hydraulic fluid is abnormally high in pressure.
[0132]
In any case, thereafter, in S338, it is determined whether or not the reset flag is turned ON. If it is ON, the determination is YES, and the continuous time T is reset to 0 in S339. On the other hand, if the reset flag has not been turned ON, the determination in S338 is NO, and S339 is skipped.
[0133]
In any case, the above completes one execution of the abnormally high pressure determination program.
[0134]
FIG. 14 is a flowchart conceptually showing the details of S104 in FIG. 6 as an alternative control program.
[0135]
When one of the two solenoid valves 206, 206 is in the open and fixed state and the other is in the normally closed state, the upper chambers 74, 74 to which the solenoid valve 206 in the open and fixed state is connected, and the lower chamber 74, 74 are connected to each other. In one of the chambers 76, 76, the working fluid flows out to the accumulator 200, but in the other, the working fluid does not flow out to the accumulator 200. Therefore, among the leftward and rightward rolls of the vehicle body, the rolls corresponding to the cylinder chambers from which the hydraulic fluid flows into the accumulator 200 are not suppressed, whereas the rolls in the opposite direction are suppressed. Therefore, the roll rigidity of the vehicle body differs depending on the direction of the roll.
[0136]
Therefore, in this alternative control program, an open signal is output to a normal one of the two solenoid valves 206, 206, thereby realizing a state in which the two solenoid valves 206, 206 are both opened. This avoids a phenomenon in which the roll rigidity of the vehicle body varies depending on the direction of the roll.
[0137]
If the two solenoid valves 206 continue to close because the sensor used to detect the turning state of the vehicle is abnormal, the hydraulic fluid in the cylinders 52, 62 or the hydraulic fluid in the passages 90, 92 There is a possibility that the temperature of the hydraulic fluid becomes high and the hydraulic fluid becomes high pressure due to thermal expansion caused by the temperature.
[0138]
Therefore, in this alternative control program, the flow of the hydraulic fluid between the two accumulators 200, 200 and the two cylinders 52, 62 is enabled by outputting an open signal to both of the two solenoid valves 206, 206. I do. Thereby, the pressure drop of the working fluid is promoted.
[0139]
Further, in this alternative control program, when the accumulator pressure is abnormally high, an open signal is output to both of the two solenoid valves 206, 206, so that the two accumulators 200, 200 and the two cylinders 52, 62 To allow the hydraulic fluid to flow between Thereby, the pressure drop of the working fluid is promoted.
[0140]
The outline of the alternative control program has been described above. Specifically, the alternative control program is repeatedly executed. At each execution, at least one of the alternative control programs is first executed in S361 by executing the open sticking determination program. It is determined whether or not it is determined that the solenoid valve 206 is in the open fixed state. If it is determined that at least one solenoid valve 206 is in the open and fixed state, the determination in S361 is YES, and subsequently, in S362, an open signal is output to both of the two solenoid valves 206, 206. Thereby, the normal one of the two solenoid valves 206, 206 is opened, and as a result, the two solenoid valves 206, 206 are both opened.
[0141]
On the other hand, when it is not determined that at least one of the solenoid valves 206, 206 is in the open fixed state, the determination in S361 is NO, and S362 is skipped.
[0142]
In any case, thereafter, in S363, it is determined whether or not it has been determined that an erroneous command has been generated by executing the erroneous command determination program. If it is determined that an erroneous command has occurred, the determination in S363 is YES, and subsequently, in S364, an open signal is output to both of the two solenoid valves 206, 206 for a set time. The two solenoid valves 206, 206 are both opened with a time limit.
[0143]
On the other hand, if it is determined that no erroneous command has been generated, the determination in S363 becomes NO, and S364 is skipped.
[0144]
In any case, thereafter, in S365, it is determined whether or not the execution of the abnormally high pressure determination program has determined that an abnormally high pressure has occurred. If it is determined that an abnormally high pressure has occurred, the determination in S365 is YES, and subsequently, in S366, an open signal is output to both of the two solenoid valves 206, 206. This output is continued, for example, until it is determined that the abnormally high pressure is no longer generated by executing the abnormally high pressure determination program, and thereafter, the output can be released.
[0145]
In either case, the single execution of this alternative control program is completed.
[0146]
FIG. 15 is a flowchart conceptually showing details of S105 in FIG. 6 as an abnormality warning program.
[0147]
This abnormality warning program is repeatedly executed. In each execution, first, in S401, it is determined whether or not at least one solenoid valve 206 has been determined to be in the open and fixed state by the execution of the above-described open and fixed determination program. If it is determined that the solenoid valve is in the open fixed state, the determination in S401 is YES, and in S402, the driver is notified via the indicator 252 that at least one solenoid valve 206 is in the open fixed state. Thus, one execution of the abnormality warning program is completed.
[0148]
On the other hand, when it is not determined that at least one solenoid valve 206 is in the open and fixed state, the determination in S401 is NO, and in S403, the execution of the closed / fixed determination program causes at least one solenoid valve 206 to open. Is determined to be in the closed and fixed state. When it is determined that the solenoid valve 206 is in the closed and fixed state, the determination in S403 is YES, and in S404, the driver is notified via the indicator 252 that the at least one solenoid valve 206 is in the closed and fixed state. Thus, one execution of the abnormality warning program is completed.
[0149]
On the other hand, when it is not determined that at least one solenoid valve 206 is in the closed and fixed state, the determination in S403 is NO, and in S405, it is determined that an erroneous command has been generated by executing the erroneous command determination program. It is determined whether or not a determination has been made. If it is determined that an erroneous command has occurred, the determination in S405 becomes YES, and in S406, the driver is notified via the indicator 252 that the erroneous command has occurred. Thus, one execution of the abnormality warning program is completed.
[0150]
On the other hand, when it is not determined that the erroneous command has been generated, the determination in S405 is NO, and in S407, it is determined whether or not it has been determined that the abnormally high pressure has been generated by the execution of the abnormally high pressure determination program. Is done. If it is determined that an abnormally high pressure has occurred, the determination in S407 is YES, and in S408, the driver is notified via the indicator 252 that the abnormally high pressure has occurred. Thus, one execution of the abnormality warning program is completed.
[0151]
On the other hand, when it is not determined that the abnormally high pressure has occurred, the determination in S407 is NO, and one execution of the abnormality warning program is immediately terminated.
[0152]
As is apparent from the above description, in the present embodiment, the ECU 250 constitutes an example of the “control device” in the above item (1), and the portion of the computer 260 that executes the valve control program in FIG. And the part that executes the open sticking determination program in FIG. 7 and the closed sticking determination program in FIG. 9 constitutes an example of the “abnormality determining unit” in the same section. .
[0153]
Further, in the present embodiment, the part of the computer 260 that executes S202 to S204 in FIG. 7 and S232 to S235 in FIG. 9 constitutes an example of the “abnormality determining means” in the above item (2). .
[0154]
Further, in the present embodiment, the part of the computer 260 that executes S202 to S204 in FIG. 7 constitutes an example of the “first means” in the above item (4), and the part that executes S232 to S235 in FIG. Constitutes an example of the "third means" in the above item (6).
[0155]
Further, in the present embodiment, the ECU 250 constitutes an example of the “control device” in the above item (7), and the portion of the computer 260 that executes the valve control program in FIG. One example is constituted, and the part that executes the open sticking determination program in FIG. 7 and the closed sticking determination program in FIG. 9 constitutes an example of the “abnormality determining unit” in the same section.
[0156]
Further, in the present embodiment, the part of the computer 260 that executes S361 and S362 in FIG. 14 constitutes an example of the “alternative control unit” in the above item (8).
[0157]
Further, in the present embodiment, the ECU 250 constitutes an example of the “control device” in the above item (9), and the portion of the computer 260 that executes the valve control program of FIG. One example is shown, and the part that executes the erroneous command determination program in FIG. 11 forms an example of the “abnormality determination unit” in the same section.
[0158]
Furthermore, in the present embodiment, the part of the computer 260 that executes the erroneous command determination program of FIG. 11 constitutes an example of the “means for determining that they do not match each other” in the above item (10).
[0159]
Further, in the present embodiment, the part of the computer 260 that executes S363 and S364 in FIG. 14 constitutes an example of the “substitution control unit” in the above (11).
[0160]
Next, a second embodiment of the present invention will be described. However, this embodiment differs from the first embodiment only in a part of the hardware configuration and a part of the software configuration, and the other parts are common. Therefore, only the different parts will be described in detail, and the common parts will be described. Will be referred to using the same name or symbol, and detailed description will be omitted.
[0161]
As shown in FIG. 16, in the present embodiment, two hydraulic units 400 and 402 corresponding to the two hydraulic units 100 and 102 in the first embodiment are replaced by all the components of the hydraulic units 100 and 102. It is provided in a state of having. The upper chamber-side hydraulic unit 400 further includes a passage pressure sensor 410 that detects the pressure of the passage 90. Similarly, the lower chamber side hydraulic unit 402 further includes a passage pressure sensor 410 for detecting the pressure of the passage 92. Each passage pressure sensor 410 detects the pressure of the corresponding one of the passages 90 and 92 as the pressure (cylinder pressure) of the corresponding one of the upper chamber 74 and the lower chamber 76. Both of these passage pressure sensors 410, 410 are connected to an ECU 420 corresponding to the ECU 250 in the first embodiment.
[0162]
As a result, in this embodiment, in addition to detecting the pressure of each accumulator 200 by each accumulator pressure sensor 280, the pressure of each passage 90, 92, that is, the pressure of each cylinder 52, 62, by each passage pressure sensor 410. It is also possible to detect.
[0163]
The ROM 266 of the computer 260 of the ECU 420 stores a valve control program and a self-diagnosis program as in the first embodiment. The self-diagnosis program is configured to include an open-stuck determination program, a closed-stuck determination program, an erroneous command determination program, and an abnormally high pressure determination program, as in the first embodiment.
[0164]
In the first embodiment, the determination of the open sticking and the determination of the closed sticking are performed by referring to only the accumulator pressure as the information on the pressure and comparing it with a threshold value. Reference is also made to the pressure at 92 and this is done by comparing the difference between it and the accumulator pressure with a threshold value.
[0165]
Since the solenoid valves 206, 206 are interposed between the passages 90, 92 and the accumulators 200, 200, the actual operation state of whether the solenoid valves 206, 206 are open or closed is determined by the passages. It is desirable to monitor as the difference between the pressure of 90, 92 and the pressure of accumulators 200, 200. In the first embodiment, the pressures of the accumulators 200 and 200 are referred to as absolute values. In the present embodiment, the accumulator pressure PACC that is the pressure of the accumulators 200 and 200 is the passage that is the pressure of the passages 90 and 92. It can be considered to be referred to as a relative value to the pressure PPSG.
[0166]
Further, in the present embodiment, when the absolute value of the difference ΔP between the accumulator pressure PACC and the passage pressure PPSG corresponding to each other for the same solenoid valve 206 is equal to or smaller than the threshold value ΔPth, the solenoid valve 206 is opened. It is determined that there is. On the other hand, when the absolute value of the difference ΔP is larger than the threshold value ΔPth, it is determined that the solenoid valve 206 is in the closed state.
[0167]
FIG. 17 is a flow chart conceptually showing the contents of the open sticking determination program in the present embodiment. This open sticking determination program is repeatedly executed. In each execution, first, in S501, the accumulator pressure PACC is detected by the corresponding accumulator pressure sensor 280 for each accumulator 200. Next, in S502, the passage pressure PPSG is detected by the corresponding passage pressure sensor 420 for each of the passages 90 and 92.
[0168]
Subsequently, in S503, the difference ΔP between the detected value of the accumulator pressure PACC and the detected value of the passage pressure PPSG for the same solenoid valve 206 is calculated. Further, it is determined whether or not the absolute value of the calculated difference ΔP is equal to or smaller than threshold value ΔPth. If the absolute value of the difference ΔP is not equal to or smaller than the threshold value ΔPth, the determination is NO, and in S504, the reset flag representing OFF does not reset the continuous time T and the reset flag representing ON resetting turns ON in S504. Is done.
[0169]
On the other hand, if the absolute value of the difference ΔP is equal to or smaller than the threshold value ΔPth, the determination in S503 becomes YES, and in S505, the reset flag is turned off. Subsequently, in S506, the continuous time T is increased by the period Δt.
[0170]
In any case, thereafter, in S507, it is determined whether or not the current value of the continuous time T has exceeded the threshold value Tth. This time, if it is assumed that the value does not exceed, the determination is NO, and it is determined in S508 that none of the solenoid valves 206, 206 is in the open fixed state. On the other hand, if it is assumed that the current value of the continuous time T has exceeded the threshold value Tth this time, the determination in S507 becomes YES, and in S508, the absolute value of the difference ΔP between the two solenoid valves 206 Those that are equal to or smaller than the threshold value Tth are determined to be in the open fixed state.
[0171]
In any case, thereafter, in S510, it is determined whether or not the reset flag is turned ON. If it is turned ON, the determination becomes YES, and the continuous time T is reset to 0 in S511. On the other hand, if the reset flag has not been turned ON, the determination in S510 is NO, and S511 is skipped.
[0172]
In any case, one execution of the open sticking determination program is completed.
[0173]
FIG. 18 is a flowchart conceptually showing the contents of the close-stuck determination program in the present embodiment. This program is repeatedly executed. In each execution, first, in S601, the accumulator pressure PACC is detected by the corresponding accumulator pressure sensor 280 for each accumulator 200. Next, in S602, the passage pressure PPSG is detected by the corresponding passage pressure sensor 410 for each of the passages 90 and 92.
[0174]
Subsequently, in S603, a difference ΔP between the detected value of the accumulator pressure PACC and the detected value of the passage pressure PPSG corresponding to each other for the same solenoid valve 206 is calculated. Further, it is determined whether or not the absolute value of the calculated difference ΔP is equal to or greater than threshold value ΔPth. If the absolute value of the difference ΔP is not equal to or greater than the threshold value ΔPth, the determination is NO, and in S604, the reset flag representing OFF does not reset the continuous time T, and the reset flag representing ON resetting turns ON in S604. Is done.
[0175]
On the other hand, when the absolute value of the difference ΔP is equal to or larger than the threshold value ΔPth, the determination in S603 becomes YES, and in S605, the reset flag is turned off. Subsequently, in S606, the continuous time T is increased by the period Δt.
[0176]
In any case, thereafter, in S607, it is determined whether or not the current value of the continuous time T has exceeded the threshold value Tth. In this case, if it is not exceeded, the determination is NO, and in S608, it is determined that none of the solenoid valves 206, 206 is in the closed and fixed state. On the other hand, if it is assumed that the current value of the continuous time T has exceeded the threshold value Tth this time, the determination in S607 becomes YES, and in S608, the absolute value of the difference ΔP between the two solenoid valves 206, 206 becomes Those having the threshold value Tth or more are determined to be in the closed and fixed state.
[0177]
In any case, thereafter, in S610, it is determined whether or not the reset flag is ON. If it is ON, the determination is YES, and the continuous time T is reset to 0 in S611. On the other hand, if the reset flag has not been turned ON, the determination in S610 becomes NO, and S611 is skipped.
[0178]
In any case, one cycle of the execution of the program for determining whether or not the vehicle is closed is completed.
[0179]
As is apparent from the above description, in the present embodiment, the part of the computer 260 that executes the open sticking determination program shown in FIG. 17 and the closed sticking determination program shown in FIG. This constitutes an example.
[0180]
As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are merely examples, and the embodiments described in the above-mentioned section “Means for Solving the Problems and Effects of the Invention” will be described. As a result, it is possible to implement the present invention in other forms with various modifications and improvements based on the knowledge of those skilled in the art.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a vehicle suspension device according to a first embodiment of the present invention.
FIG. 2 is a front sectional view showing a cylinder in FIG. 1;
FIG. 3 is a diagram conceptually showing a hardware configuration of the vehicle suspension device of FIG. 1 with a pressure circuit diagram and a block diagram.
FIG. 4 is a block diagram conceptually showing a configuration of an electronic control unit ECU 250 in FIG.
5 is a flowchart conceptually showing the contents of a valve control program executed by a computer 260 in FIG.
6 is a flowchart conceptually showing the contents of a self-diagnosis program executed by a computer 260 in FIG.
FIG. 7 is a flowchart conceptually showing the contents of an open sticking determination program constituting a part of S102 in FIG. 6;
FIG. 8 is a graph for explaining the principle of determination in the open sticking determination program of FIG. 7;
FIG. 9 is a flowchart conceptually showing the contents of a closed sticking determination program which constitutes another part of S102 in FIG.
FIG. 10 is a graph for explaining a principle of determination in the closed / fixed determination program of FIG. 9;
11 is a flowchart conceptually showing the contents of an erroneous command determination program constituting still another part of S102 in FIG.
FIG. 12 is a graph for explaining an example of execution of an erroneous command determination program in FIG. 11;
FIG. 13 is a flowchart conceptually showing the contents of an abnormally high pressure determination program constituting still another part of S102 in FIG.
14 is a flowchart conceptually showing details of S104 in FIG. 6 as an alternative control program.
FIG. 15 is a flowchart conceptually showing details of S105 in FIG. 6 as an abnormality warning program.
FIG. 16 is a diagram conceptually showing a hardware configuration of a vehicle suspension device according to a second embodiment of the present invention using a pressure circuit diagram and a block diagram.
FIG. 17 is a flowchart conceptually showing the contents of an open sticking determination program constituting a part of a self-diagnosis program executed by computer 260 of ECU 420 in FIG.
FIG. 18 is a flowchart conceptually showing the contents of a closed sticking determination program constituting another part of the self-diagnosis program executed by the computer 260 of the ECU 420 in FIG.
[Explanation of symbols]
10 Front wheel
12 rear wheel
52 Cylinder for front wheel
62 Cylinder for rear wheel
70 Housing
72 piston
74 Upper room
76 lower room
90 Passage for upper room
92 Passage for lower chamber
200 accumulator
206 Solenoid valve
250 ECU
280 accumulator pressure sensor
410 Passage pressure sensor

Claims (10)

A vehicle suspension device arranged between the left and right front wheels and left and right rear wheels and the vehicle body in the vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the first chamber and second chamber passages to allow a flow of a working fluid from each passage toward the at least one accumulator; An accumulator valve for the first chamber and an accumulator valve for the second chamber that switch to a state;
A control device for electrically controlling the accumulator valves,
(A) A command signal to be supplied to the accumulator valves for the first chamber and the second chamber is determined according to whether a predetermined condition is satisfied, and the determined command signal is supplied to the accumulator valves. A supply unit;
(B) each accumulator valve has an abnormality determining unit that determines that each accumulator valve is abnormal when the command signal supplied thereto and the actual operation state of each accumulator valve do not match each other; Vehicle suspension system including: The at least one accumulator includes first and second chamber accumulators individually associated with the first and second chamber accumulator valves;
The vehicle suspension further includes first and second room accumulator pressure sensors for detecting the pressures of the first and second room accumulators, respectively.
The abnormality determination unit determines whether or not each accumulator valve is abnormal based on whether or not there is a temporal change in a pressure-related amount, which is a pressure detected by a corresponding accumulator pressure sensor, for each of the accumulator valves. The vehicle suspension according to claim 1, further comprising an abnormality determination unit that performs the abnormality determination. The at least one accumulator includes first and second chamber accumulators individually associated with the first and second chamber accumulator valves;
The vehicle suspension further comprises:
An accumulator pressure sensor for the first chamber and a second chamber for detecting the pressure of the accumulator for the first chamber and the accumulator for the second chamber, respectively;
A first chamber and a second chamber cylinder pressure sensor for detecting pressures of the first chamber and the second chamber, respectively.
The abnormality determination unit determines whether there is a temporal change in a pressure-related amount, which is a difference between the pressure detected by the corresponding accumulator pressure sensor and the pressure detected by the corresponding cylinder pressure sensor, for each of the accumulator valves. The vehicle suspension according to claim 1, further comprising an abnormality determination unit that determines whether each of the accumulator valves is abnormal based on the abnormality. The abnormality determining means supplies a second command signal to each of the accumulator valves for switching the accumulator valve to the permissible state, and in a state where the vehicle is running, a temporal variation of the pressure-related amount. 4. The vehicle suspension according to claim 2, further comprising means for determining that there is an abnormality that each of the accumulator valves is actually in the blocking state when the valve does not exist. A vehicle suspension device arranged between the left and right front wheels and left and right rear wheels and the vehicle body in the vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the first chamber and second chamber passages to allow a flow of a working fluid from each passage toward the at least one accumulator; An accumulator valve for the first chamber and an accumulator valve for the second chamber that switch to a state;
A control device for electrically controlling the accumulator valves,
(A) A command signal to be supplied to the accumulator valves for the first chamber and the second chamber is determined in accordance with whether a predetermined condition is satisfied, and the determined command signal is shared by the accumulator valves. A signal supply unit for supplying
(B) an abnormality determination unit that determines that one of the accumulator valves is abnormal when the actual operation states of the accumulator valves do not match each other. Further, when the abnormality determination section determines that the accumulator valve is abnormal, the actual operation state of the first and second chamber accumulator valves that is normal is changed to the actual accumulator valve that is abnormal. The vehicle suspension according to any one of claims 1 to 5, further comprising an alternative control unit that performs an alternative control on the accumulator valves by supplying a command signal for matching the operation state of the accumulator valves to the normal accumulator valves. apparatus. A vehicle suspension device arranged between the left and right front wheels and left and right rear wheels and the vehicle body in the vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the first chamber and second chamber passages to allow a flow of a working fluid from each passage toward the at least one accumulator; An accumulator valve for the first chamber and an accumulator valve for the second chamber that switch to a state;
A control device for electrically controlling the accumulator valves,
(A) determining whether a predetermined condition is satisfied, and determining a command signal to be commonly supplied to the first and second chamber accumulator valves according to the determination result; and determining the determined command signal. Signal supply unit for supplying the accumulator valve
(B) For each accumulator valve, an abnormality determination unit that determines that the determination result is abnormal when the actual satisfaction or failure of the predetermined condition and the actual operation state of each accumulator valve do not match each other. And a vehicle suspension including: Furthermore, the vehicle includes a turning state related amount sensor that detects a physical quantity for detecting a turning state of the vehicle,
The predetermined condition includes a turning condition that should be satisfied when the vehicle is in a turning condition,
The signal supply unit determines whether or not the turning condition is satisfied based on an output signal of the turning state related amount sensor, and when it is determined that the turning condition is satisfied, the accumulator valve blocks the accumulator valve. Means for supplying a command signal for switching to the state,
The abnormality determination unit is configured to determine whether or not each of the accumulator valves is actually satisfied or not and whether or not each of the accumulator valves satisfies the actual condition of the turning-time establishment condition when the continuous time in which the accumulator valves continue to be in the blocking state exceeds a limit time. 8. The vehicle suspension according to claim 7, further comprising means for determining that the operating states of the vehicle do not match each other. Further, when it is determined by the abnormality determination section that the vehicle is abnormal, the accumulator valves for the first chamber and the second chamber are set in the allowable state regardless of the result of the determination as to whether the turning condition is satisfied. 9. The vehicle suspension according to claim 7, further comprising an alternative control unit that performs an alternative control on the accumulator valves by supplying a command signal for switching to the accumulator valve. A vehicle suspension device arranged between the left and right front wheels and left and right rear wheels and the vehicle body in the vehicle,
A front-wheel cylinder for controlling relative displacement between the left and right wheels on the front wheel side, generally in the up-down direction of the vehicle body. A room divided into a first room and a second room,
A rear wheel cylinder for controlling a relative displacement between the left and right wheels on the rear wheel side and generally in the vertical direction of the vehicle body, wherein a piston is fitted into the housing, so that a space in the housing is reduced. A first chamber and a second chamber, both of which are fluid chambers, each of which is partitioned into those corresponding to the first chamber and the second chamber of the front wheel cylinder, respectively;
A first chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the first chambers,
A second chamber passage connecting the front wheel cylinder and the rear wheel cylinder to each other in the second chambers,
At least one accumulator capable of containing the working fluid of the front wheel cylinder and the rear wheel cylinder;
An obstruction provided between the at least one accumulator and each of the passages for the first chamber and the second chamber for permitting a flow of a working fluid from each passage toward the at least one accumulator; A first chamber accumulator valve and a second chamber accumulator valve that switch to a state, and
A vehicle suspension in which both accumulator valves switch to the permissible state when the continuous time both of the accumulator valves are actually in the blocking state exceeds a time limit.

Images