JP2008094301A - Hydraulic suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a rope from being loosened when a vehicle equipped with a hydro-pneumatic suspension device is carried by a vehicle carrier. <P>SOLUTION: When ON operation of a lashing switch is detected, a spring constant in the hydro-pneumatic suspension device is increased. Due to this, during carrying, the temperature of air in an accumulator is lowered, and even when hydraulic pressure of a suspension cylinder is lowered, lowering amount of the vehicle height can be reduced. Thus, the loose amount of the rope can be reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hydraulic suspension device mounted on a transported vehicle.

Patent Document 1 describes that when a transported vehicle is transported, a damping characteristic of a vehicle height adjusting device included in a fluid pressure suspension device of the transported vehicle is increased. In the hydraulic suspension system described in Patent Document 1, (i) (a) a hydraulic cylinder provided between a wheel side member and a vehicle body side member, and the inside of the housing is partitioned into two chambers by a piston And (b) a pump that is operated in accordance with a vertical movement of the vehicle body side member with respect to the wheel side member, and hydraulic fluid discharged from the pump is supplied to one of the two chambers. A vehicle height adjusting device for adjusting the vehicle height; and (ii) a variable throttle provided between the one chamber and the accumulator. When the vehicle is in a stopped state, the flow path area between one chamber of the hydraulic cylinder and the accumulator is reduced by the variable throttle. Thereby, it is possible to suppress the vertical change in the vehicle height of the transported vehicle due to vibration during transportation.
Patent Document 2 describes that in a fluid pressure suspension device including a vehicle height adjustment device that adjusts the vehicle height by operating a vehicle height adjustment switch, when the fluid temperature becomes high, that fact is notified. Has been. When the temperature of the fluid increases, the vehicle height increases and the vehicle height adjustment is required, which is notified and the operation of the vehicle height adjustment switch is prompted.
JP-A-8-132840 JP 2001-287530 A

  In general, transported vehicles are transported in a state of being secured to a transportation platform by a securing member. In this case, the securing member is loosened due to a temperature drop or gas leakage during transportation. Or the temperature rises due to vibration during transportation and fluid leakage occurs. The present invention has been made to suppress these problems.

Means and effects for solving the problems

  The hydraulic suspension apparatus according to claim 1 is in a state in which (i) a vehicle including the hydraulic suspension apparatus is secured in a direction including a vertical component by a securing member on a transportation platform as a transported vehicle. And (ii) a fluid pressure in the hydraulic suspension device and a fluid with respect to the amount of change in the vehicle height when the transport preparation detection device detects that the vehicle is in the locked state. A lash detection suspension control unit that controls at least one of a spring constant that is a change amount of pressure is included.

In this fluid pressure suspension device, when the transport preparation detection device detects that the transported vehicle is in a state of being secured by a securing member, at least one of the fluid pressure and the spring constant is controlled.
For example, when the vehicle body of the transported vehicle is secured to the transportation platform of the vehicle transport vehicle with a securing member extending in the direction including the vertical component, the spring constant (the amount of change in fluid pressure / the amount of change in vehicle height) ) Is increased, the amount of change in vehicle height when the amount of change in fluid pressure is the same can be reduced. Even if the fluid pressure decreases during transportation due to temperature drop or gas leakage, the vehicle The height can be made difficult to decrease, and the securing member can be made difficult to loosen.
Further, by increasing the spring constant, it is possible to suppress the amount of change in the height of the transported vehicle due to vibration during transportation. In particular, when an air spring and a shock absorber are provided in parallel between the wheel side member and the vehicle body side member, the amplitude of the periodic change in the vehicle height is reduced, so that the temperature of the hydraulic fluid of the shock absorber is reduced. The rise can be suppressed and liquid leakage can be made difficult to occur.
Furthermore, if the fluid pressure is increased in the secured state, the tension of the secured member can be increased. As a result, even if the fluid pressure decreases during transportation, the securing member can be prevented from loosening, and even if it is loosened, the amount of loosening can be reduced.
Further, when an air spring is provided between the wheel side member and the vehicle body side member, the spring constant can be increased if the air pressure is increased.
The transport preparation detection device is, for example, an operation type lashing switch that can be operated by an operator, or provided at an engagement portion of a lashing member provided on a vehicle body, and the lashing member is hung on the engagement portion, For example, a force detection type lashing switch for detecting the application of tension can be used. In the case of an operation-type lashing switch, it is instructed to operate after the vehicle to be transported is lashed by a lashing member according to work standards or the like.
The lashing member can be, for example, a rope, a cable, a wire, or the like. The lashing member extends in a direction having a vertical component, and is affected by a change in vehicle height. It may extend in a direction parallel to the vertical direction, may extend in a direction inclined with respect to the vertical direction, or may not extend in a direction orthogonal to the vertical direction.
The control of the fluid pressure and the control of the spring constant are not clearly distinguishable, and the spring constant often changes as the fluid pressure is controlled. Also, the fluid pressure often changes by controlling the spring constant.
The transported vehicle may be transported by a vehicle transporter or transported by a transport ship.

According to a second aspect of the present invention, there is provided a hydraulic suspension system comprising: (a) a hydraulic cylinder provided between a vehicle body side member and a wheel side member; and (b) the hydraulic cylinder as the vehicle height changes. A plurality of accumulators for exchanging hydraulic fluid between them and (c) one or more of the plurality of accumulators and the hydraulic cylinder, and the one or more accumulators and hydraulic cylinders A flow state switching mechanism capable of switching the flow of hydraulic fluid between the permissible state and the blocked state, and the suspension control unit at the time of detection of lashing controls the flow state switching mechanism. A spring constant control unit that sets the spring constant to a set value or more is included.
The hydraulic fluid is exchanged between the hydraulic cylinder and one or more of the accumulators in accordance with the relative displacement in the vertical direction between the vehicle body side member and the wheel side member, that is, the change in vehicle height. Is called. The accumulator has two volume chambers partitioned by a partition member. A hydraulic cylinder is connected to one of the two volume chambers (a working fluid storage chamber), and a gas is sealed in the other (the gas chamber). . The partition member can be a bladder, a bellows, or a piston.
In the accumulator, the force (hydraulic force) applied to the partition member by the hydraulic pressure in the hydraulic fluid storage chamber and the force (elastic force) applied to the partition member by the gas in the gas chamber are always balanced. When hydraulic fluid is supplied to the hydraulic fluid storage chamber due to a change in vehicle height, the volume of the hydraulic fluid storage chamber increases. Since the volume of the gas chamber decreases, the pressure increases and the hydraulic pressure force increases (the hydraulic pressure of the hydraulic cylinder increases). When the volume of the hydraulic fluid storage chamber is reduced, the pressure is reduced and the hydraulic pressure of the hydraulic cylinder is reduced. As described above, the elastic force of the accumulator has a magnitude corresponding to the hydraulic pressure of the hydraulic cylinder, and changes according to the change in the capacity of the hydraulic fluid storage chamber. The change amount corresponds to the change amount of the vehicle height. It becomes size. From this, the accumulator functions as a spring, and its spring constant corresponds to the spring constant of the hydraulic suspension device.
The spring constant of the accumulator is controlled by controlling the flow state switching mechanism. The spring constant is larger when the number of accumulators connected to the hydraulic cylinder is small than when it is large. Further, when the accumulator connected to the hydraulic cylinder has a large spring constant, the spring constant becomes larger than when the accumulator is small. For example, when the gas pressure sealed in the gas chamber is high, the amount of pressure change when the volume change amount is the same is larger than when the gas pressure is low, as shown in FIG. From this fact, if it is detected that a locked state is detected, if the number of accumulators connected to the hydraulic cylinder is reduced or a large spring constant is connected, the hydraulic suspension The spring constant of the device can be increased.
In the accumulator, as shown in FIG. 10, when the gas temperature is lowered, the gas pressure when the volume is constant is lowered, so that the hydraulic pressure of the hydraulic cylinder is lowered. Further, when the gas leaks, the gas pressure decreases and the hydraulic pressure in the hydraulic cylinder decreases.
On the other hand, when a suspension spring is provided in parallel with the hydraulic cylinder in the hydraulic suspension, the load W applied to the wheel (size corresponding to the weight of the vehicle body), the elastic force Fa applied by the accumulator, the elasticity of the suspension spring When the force Fs is assumed, in the steady state of the transported vehicle (Fa0, Fs0: 0 is attached), generally, the equation W = Fa0 + Fs0
Is established. From this equation, when the load applied to the wheel is constant, as shown in FIG. 11, when the vehicle height is low, the elastic force Fa of the accumulator decreases and the elastic force Fs of the spring increases, but the vehicle height When it is high, it can be seen that the elastic force Fa applied to the hydraulic cylinder by the accumulator increases and the elastic force Fs of the spring decreases.
When a transported vehicle is transported, the vehicle is usually secured by a securing member in a state where the vehicle height is lower than the height (standard height) in a steady state. The tension Fr is applied to the securing member by the elastic force Fs of the spring and the elastic force Fa applied to the hydraulic cylinder by the accumulator. It is desirable that this tension be equal to or greater than the force necessary for keeping the transported vehicle in a stopped state (necessary lashing tension). In this locked state, the general formula W + Fr = Fa + Fs
Is established. That is, as compared with the case in the steady state of the vehicle, the elastic forces Fa and Fs are larger than the elastic forces Fa0 and Fs0 by the amount of the tension Fr of the securing member, but the elastic force of the spring is uniquely determined by the vehicle height. Therefore, the tension Fr of the securing member can be controlled by the elastic force Fa of the accumulator.
From this state, when the hydraulic pressure of the hydraulic cylinder decreases due to a temperature drop or the like, the elastic force Fa applied by the accumulator decreases, and accordingly, the tension Fr of the lashing member decreases. Further, when the elastic force Fa is decreased, the vehicle height is decreased and the securing member is loosened as shown in FIG. In this case, when the spring constant is large, the amount of change in the vehicle height with respect to the amount of decrease in the elastic force Fa is smaller than when the spring constant is small. Therefore, the amount of looseness of the tension Fr of the tying member can be reduced. In FIG. 11, the amount of decrease in vehicle height is depicted very large, but actually the amount of decrease in hydraulic pressure due to temperature change is small and the amount of change in vehicle height is slight.
Further, if the spring constant is increased, the amplitude of the vibration of the vehicle height of the transported vehicle due to the vibration during transportation can be reduced.
The set value of the spring constant is determined in consideration of these factors.For example, even if the hydraulic pressure decreases during transportation, the amount of loosening of the securing member is within an allowable range, and the vehicle height The magnitude of the change may be within an allowable range.
The fluid pressure suspension device according to claim 3 includes a fluid pressure control mechanism capable of controlling the fluid pressure of the output unit, and the suspension control unit at the time of binding detection controls the fluid pressure control mechanism, thereby The fluid pressure type suspension device according to claim 4 includes a fluid pressure control mechanism capable of controlling the fluid pressure of the output unit, and includes the fluid pressure control unit that controls the fluid pressure of the output unit. When the suspension control unit detects the fluid pressure of the output unit by controlling the fluid pressure control mechanism, the transport preparation detection device detects that the fluid pressure and the environmental temperature are in the locked state. It is assumed that the control unit corresponding to the situation at the time of detection of binding is changed so as to change more than the set change pressure determined by at least one of the above.
In the fluid pressure suspension device according to claim 5, (a) a hydraulic cylinder provided between the vehicle body side member and the wheel side member, and (b) the hydraulic pressure as the vehicle height changes. One or more accumulators that exchange hydraulic fluid with a cylinder, and the fluid pressure control mechanism includes at least a pump device that can pressurize the hydraulic fluid and supply the hydraulic fluid to the hydraulic cylinder, A hydraulic pressure control mechanism capable of controlling the hydraulic pressure in the hydraulic cylinder using the hydraulic fluid supplied from the pump device is included.
When hydraulic fluid is supplied to the hydraulic cylinder (which is one mode of the output unit) in a state where the transported vehicle is secured by a securing member oriented in the vertical direction, the hydraulic pressure increases. The elastic force Fa of the accumulator increases and the tension Fr applied to the tying member increases.
Therefore, if the hydraulic pressure of the hydraulic cylinder is increased in advance when a locked state is detected, even if the hydraulic pressure decreases after that due to temperature drop or gas leakage during transportation, The member can be made difficult to loosen. Even if the tying member is not loosened or loosened, the loosening amount can be reduced.
The hydraulic pressure of the hydraulic cylinder is controlled so as to be equal to or higher than the set hydraulic pressure, but the set hydraulic pressure can be set so that the tension applied to the lashing member is equal to or higher than the set tension. Even if the hydraulic pressure is lowered, it can be set to a size that can secure the necessary securing tension.
In addition, when the temperature of the hydraulic fluid at the time of detection of lashing is low, the amount of increase in hydraulic pressure can be made larger than when the temperature is high. When the temperature of the hydraulic fluid is low, the hydraulic pressure is often lower and the vehicle height is lower than when the hydraulic fluid is high. Therefore, when the length of the lashing member is determined in advance, if the amount of increase in the hydraulic pressure is increased, the tension applied to the lashing member can be satisfactorily increased to the set tension. In addition, when the temperature is high, the amount of increase in hydraulic pressure is smaller than when the temperature is low. It can avoid that the tension | tensile_strength added becomes large more than necessary, and can improve durability of a securing member. The temperature of the working fluid can be detected directly or indirectly. The temperature of the hydraulic fluid can be considered to be the same as the outside air temperature, or can be estimated based on the outside air temperature, the temperature in the passenger compartment, and the like.
Furthermore, when the temperature of the hydraulic fluid before transportation (at the time of detecting lashing) is higher than the outside air temperature, it is considered that the temperature is lowered to the outside air temperature during transportation. For this reason, when the value (difference) obtained by subtracting the outside air temperature from the temperature of the hydraulic fluid when the locked state is detected is large, it is estimated that the amount of decrease in the hydraulic pressure of the hydraulic cylinder is larger than when the value is small. On the other hand, if the value obtained by subtracting the outside air temperature from the temperature of the hydraulic fluid is large, if the amount of increase in the hydraulic pressure of the hydraulic cylinder is made larger than when it is small, even if the hydraulic pressure drops during transportation, The securing member can be made difficult to loosen. In addition, if the temperature of the working fluid at the time of detecting the locked state is known in advance, the amount of increase in the hydraulic pressure can be increased when the outside air temperature is low than when it is high.
Conversely, when the temperature of the working fluid before transportation is lower than the outside air temperature, it is considered that the temperature rises to the outside air temperature during transportation. If the hydraulic pressure of the hydraulic cylinder becomes high during transportation (because the vehicle height does not become higher than the height determined by the lashing member), the tension applied to the lashing member may become excessive. On the other hand, when the outside air temperature is higher, the amount of increase in the hydraulic pressure of the hydraulic cylinder can be decreased or the hydraulic pressure can be maintained (not increased) when detecting lashing. ) Or to be reduced, it is possible to avoid applying an excessive force to the securing member during transportation. For example, when the outside air temperature is higher than a predetermined set value than the temperature of the hydraulic fluid before transportation, the hydraulic pressure of the hydraulic cylinder can be reduced.
When the accumulator is of a gas-filled type, the spring constant of the accumulator can be increased by increasing the hydraulic pressure of the hydraulic cylinder. In the accumulator, if the hydraulic pressure in the hydraulic fluid storage chamber is increased, the pressure in the gas chamber is increased, and as described above, the spring constant is increased. Therefore, when the locked state is detected, the change in the vehicle height can be suppressed by increasing the hydraulic pressure of the hydraulic cylinder and increasing the spring constant.
The fluid pressure suspension device according to claim 6 includes: (a) a shock absorber and an air chamber provided in parallel between the vehicle body side member and the wheel side member; and (b) pressurizing air to increase the air pressure. A pump device capable of being supplied to the chamber; and (c) an air pressure control mechanism capable of controlling an air pressure in the air chamber using at least air supplied from the pump device, wherein the suspension controller The air pressure control mechanism controls the air pressure in the air chamber, and includes an air pressure-dependent spring constant controller that sets the spring constant to a set value or more.
Since the volume of the air chamber (which is one form of the output unit) is substantially constant in a state where the vehicle body is secured in a direction including the vertical component by the securing members, air pressure is supplied by supplying air. Becomes higher. Also, when the air pressure is high, the spring constant becomes larger than when the air pressure is low. Therefore, if the air pressure is controlled, the spring constant can be controlled.
When the air chamber and the shock absorber are provided in parallel between the vehicle body side member and the wheel side member, if the air pressure in the air chamber is low and the spring constant is small, the vehicle height increases with vibration during transportation. The amplitude when it changes periodically increases. As a result, the temperature of the working fluid is increased in the shock absorber, and there is a risk of liquid leakage. On the other hand, if the air pressure in the air chamber is increased to increase the spring constant, the amplitude can be reduced, and the temperature of the hydraulic fluid in the shock absorber is suppressed from increasing, and liquid leakage is less likely to occur. Can do.
Further, as described above, the spring constant is smaller when the temperature of the air is low than when it is high. Therefore, when the air temperature is low, if the amount of increase in the air pressure is increased as compared with the case where the air temperature is high, the spring constant can be satisfactorily made the set value or more even if the air temperature is low. Further, it is possible to avoid an unnecessarily large spring constant when the air temperature is high.
Furthermore, the air temperature changes to the outside air temperature during transportation. Therefore, when the temperature of the air at the time of detection of lashing is higher than the outside air temperature, the increase amount of the air pressure can be made larger when the difference between them is large than when the difference is small. Also, if the air temperature at the time of lashing detection is lower than the outside air temperature, the amount of increase in air pressure is reduced, the air pressure is maintained, or if the difference between them is large, the air pressure is decreased in advance. You can do it.
The fluid pressure suspension device according to claim 7 further includes: (a) a damping characteristic control mechanism capable of controlling a damping characteristic of the fluid pressure suspension apparatus; and (b) controlling the damping characteristic control mechanism. A damping characteristic control unit configured to set a damping characteristic such that a damping force generated when the change rate of the vehicle height is the same is greater than that before being detected when the secured state is detected by the transport preparation detection device; It is supposed to include.
Furthermore, if the damping characteristic of the fluid pressure suspension device is a characteristic that increases the damping force, the vehicle height can be made difficult to change accordingly.
In the hydrostatic suspension device according to claim 8, when it is detected that the transported vehicle is in the lashed state and is scheduled to release lashing by the lashing member, A suspension release suspension control unit that reduces at least one of the fluid pressure and the spring constant is included.
If the spring constant and the fluid pressure are reduced before releasing the lashing by the tying member, the tying member can be easily loosened and removed easily. The fact that the lashing by the lashing member is to be released can be detected by, for example, a switch operation by an operator. The fluid pressure and the spring constant can be returned to the magnitude before the locked state is detected. At least one of the fluid pressure and the spring constant controlled by the suspension control unit at the time of detection of lashing can be returned to the size before the detection of the lashing state.

Hereinafter, an hydraulic / pneumatic suspension apparatus as a hydraulic suspension apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.
In this embodiment, as shown in FIGS. 1 and 2, a case where a transported vehicle (transported vehicle) A, which is a vehicle on which the hydraulic / pneumatic suspension apparatus is mounted, is transported by a vehicle transport vehicle B will be described. .
The transported vehicle A is placed on the loading platform C of the vehicle transport vehicle B. And the attitude | position which the rope G as a lashing member extended in the up-down direction substantially between the hook E provided in the vehicle body D of the to-be-transported vehicle A, and the hook F provided in the loading platform C of the vehicle transport vehicle B The transported vehicle A is secured to the loading platform C of the vehicle transport vehicle B.
The hydraulic / pneumatic suspension device mounted on the transported vehicle A includes a vehicle height adjusting device. As shown in FIG. 3, in each of the front, rear, left and right wheels 4FL, FR, RL, RR, a suspension cylinder is provided between the wheel holding device 6FL, FR, RL, RR for holding the wheel 4 and the vehicle body 8, respectively. 10FL, FR, RL, and RR are provided together with the suspension spring 21. The suspension cylinders 10FL, FR, RL, and RR are operated by hydraulic fluid as fluid. In the following, when it is necessary to distinguish by wheel position, it is used with the symbols FL, FR, RL, RR or L, R indicating the wheel position. use.
The suspension cylinders 10FL, FR, RL, and RR have the same structure, and each includes a housing 11, a piston 12 that is fitted inside the housing 11 so as to be relatively movable, and a piston rod 14. The rod 14 is secured to the vehicle body 8 and the housing 11 is secured to the wheel holding device 6 so as not to be relatively movable in the vertical direction. The piston 12 is provided with a communication passage 20 that communicates the two liquid chambers 16 and 18 partitioned by the piston 12, and the communication passage 20 is provided with a fixed throttle. The fixed throttle generates a damping force according to the relative movement speed of the piston 12 with respect to the housing 11 (the flow rate of the working fluid flowing through the throttle). The suspension cylinder 10 functions as a shock absorber.

As shown in FIG. 3, the piston rod 14 is attached to a spring retainer 22 that holds the suspension spring 21 via an elastic member such as rubber, and the spring retainer 22 is attached to the vehicle body 8 so as not to be relatively movable in the vertical direction. Further, a bound side stopper 24 is attached to the spring retainer 22. The movement limit on the bounce side is defined by the outer upper end surface 26 of the cylinder body 11 coming into contact with the bounce side stopper 24.
On the other hand, a rebound side stopper 28 is provided on the side of the piston 12 where the piston rod 14 is provided. When the inner upper end surface 30 of the main body 11 contacts the rebound side stopper 28, the rebound side movement limit is defined.

Individual passages 32FL, FR, RL, and RR are connected to the liquid chambers 16 of the suspension cylinders 10FL, FR, RL, and RR, respectively.
In each of the individual passages 32FL, FR, RL, RR, there are two accumulators 34FL, FR, RL, RR, accumulators 36FL, FR, RL in parallel with each other corresponding to each of the suspension cylinders 10FL, FR, RL, RR. , RR is connected. Spring constant switching valves 38FL, FR, RL, and RR are provided between the suspension cylinders 10FL, FR, RL, and RR and the accumulators 36FL, FR, RL, and RR, respectively.
Each of the accumulators 34 and 36 has a function as a spring (gas spring), and includes, for example, a housing and a partition member for partitioning the inside of the housing, and an individual passage is provided in one volume change chamber of the partition member. 32 is communicated to be a hydraulic fluid storage chamber, and gas is stored in the other volume change chamber to be a gas chamber. The partition member can be a bladder or a bellows.
In the accumulators 34 and 36, the hydraulic pressure force applied to the partition member by the hydraulic pressure of the hydraulic fluid storage chamber and the elastic force applied to the partition member by the pressure of the gas chamber are always balanced. The elastic force changes with the change in the volume of the hydraulic fluid storage chamber, and the change amount becomes a magnitude corresponding to the change amount of the volume of the hydraulic fluid. The accumulators 34 and 36 function as gas springs in the hydraulic / pneumatic suspension device, and the spring constants of the accumulators 34 and 36 correspond to the spring constants of the hydraulic / pneumatic suspension device.

In each of the accumulators 34 and 36, as shown in FIG. 10, when the pressure and volume of the gas accommodated in the gas chamber are Pgas and Vgas, and the gas temperature is Tgas, the equation Pgas · Vgas = K · Tgas
Is established. If the temperature Tgas is constant, the pressure Pgas and the volume Vgas of the gas chamber change while maintaining a relationship in which the product of the pressure Pgas and the volume Vgas is constant (Pgas · Vgas: constant).
In addition, as shown in FIG. 10, when the pressure is high, the amount of change in the pressure when the volume change is the same is larger than when the pressure is low. Therefore, when the pressure enclosed in the gas chamber is high, the spring constant is lower than when the pressure is low. growing. In this embodiment, since the pressure of the gas sealed in the gas chamber of the accumulator 34 is higher than the pressure of the gas sealed in the gas chamber of the accumulator 36, the spring constant of the accumulator 34 is larger than the spring constant of the accumulator 36. Is done. Hereinafter, the accumulator 34 is referred to as a high pressure accumulator, and the accumulator 36 is referred to as a low pressure accumulator. The spring constant switching valve 38 is a normally open electromagnetic on-off valve, and in this embodiment, a spring constant switching mechanism is configured.
In the individual passages 32FL, FR, RL, and RR, variable throttles 40FL, FR, RL, and RR are provided, respectively. As described above, the hydraulic fluid flows in and out in the liquid chamber 16 by the vertical movement of the wheel holding device 6 relative to the vehicle body 8. In this case, the flow area of the individual passage 32 is controlled by the variable throttle 40. As a result, the damping force generated in the suspension cylinder 10 is controlled, and the damping characteristic is controlled.

A hydraulic fluid supply / discharge device 70 is connected to the individual passages 32FL, FR, RL, and RR.
The hydraulic fluid supply / discharge device 70 includes a hydraulic pressure source 76 having a high pressure source 72 and a reservoir 74 as a low pressure source, a vehicle height control valve device 80, and the like.
The high pressure source 72 includes a pump device 84 having a pump 81 and a pump motor 82, a pressure accumulator 86, and the like. The pump device 84, the pressure accumulator 86, and the like are provided in a hydraulic fluid supply / discharge passage (control passage) 88. The hydraulic fluid in the reservoir 74 is pumped up and discharged by the pump 81, and is stored under pressure in the pressure accumulator 86.
The accumulator 86 for pressure accumulation is connected to the hydraulic fluid supply / discharge passage 88 via a pressure accumulation control valve 90 which is a normally closed electromagnetic on-off valve. The pressure accumulation control valve 90 can be switched between an open state that allows inflow / outflow of the hydraulic fluid in the pressure accumulation accumulator 86 and a closed state that prevents inflow / outflow of the hydraulic fluid in the pressure accumulation accumulator 86.
The hydraulic fluid supply / discharge passage 88 is provided with a hydraulic pressure sensor 92 as a pressure detection device. A discharge valve of the pump 81 in the hydraulic fluid supply / discharge passage 88 is provided with a check valve 94 for preventing backflow to the pump 81 and a muffler. An accumulator 96 is provided.
In addition, an outflow passage 104 that connects the high pressure side of the pump 81 (the suspension cylinder side from the check valve 94) and the low pressure side is provided, and an outflow control valve 106 is provided in the outflow passage 104. The outflow control valve 106 is a mechanical on-off valve that uses a pump discharge fluid pressure as a pilot pressure. When the pump 81 is not in operation, the communication state is established. However, when the discharge fluid pressure is increased by the operation of the pump 81, the communication state is cut off. The pump 81 is a gear pump.

  The hydraulic pressure sensor 92 is originally provided to detect the hydraulic pressure when the hydraulic fluid supply / discharge device 70 functions as a hydraulic fluid supply device (high pressure source). Specifically, in the operating state of the pump 81 (when the outflow control valve 106 is in the closed state), the discharge pressure of the pump 81 is detected, or the hydraulic pressure of the hydraulic fluid stored in the accumulator 86 is detected. To do. Further, the hydraulic pressure of the suspension cylinder 10 may be detected when the hydraulic pressure of the hydraulic fluid supply / discharge passage 88 and the hydraulic pressure of the suspension cylinder 10 are the same. On the other hand, when the pump 81 is in a non-operating state (when the outflow control valve 106 is in an open state), the hydraulic fluid supply / discharge passage 88 is communicated with the reservoir 74, so that the pressure detected by the hydraulic pressure sensor 92 is detected. The value is the reservoir pressure (atmospheric pressure). The hydraulic fluid supply / discharge device 70 functions as a low pressure source, and the pressure when the hydraulic fluid sensor 92 functions as a low pressure source is detected.

The vehicle height control valve device 80 includes vehicle height control valves 110FL, FR, RL, and RR as individual control valves provided in the individual passages 32FL, FR, RL, and RR. Further, a left and right communication valve 112 is provided in the front wheel side left and right communication passage 111 connecting the individual passages 32FL and FR, and a left and right communication valve 114 is provided in the rear wheel side left and right communication passage 113 connecting the individual passages 32RL and RR.
These vehicle height control valves 110FL, FR, RL, RR, and left and right communication valves 112, 114 are normally closed electromagnetic on-off valves. When the left and right communication valves 112, 114 are closed, the vehicle height control valves 110FL, FR, RL, By individually controlling RR, in each of the wheels 4FL, FR, RL, RR, the wheel holding device 6FL, FR, RL, RR and the corresponding part of the vehicle body 8 (suspension cylinders 10FL, FR, RL, RR) The vehicle height, which is the distance between the vehicle and the portion corresponding to (1), can be controlled independently.

This suspension apparatus is controlled by a suspension ECU 200 mainly including a computer. The suspension ECU 200 includes an execution unit 204, a storage unit 206, an input / output unit 208, and the like. The input / output unit 208 includes a spring constant switching valve 38, a coil of the variable throttle 40, and a hydraulic fluid supply / discharge device 70 (control valve for pressure accumulation). 90, the vehicle height control valve 110, the coils of the left and right communication valves 112 and 114, the pump motor 82, etc.) are connected via a drive circuit (not shown), and are provided for each of the hydraulic pressure sensor 92 and the front, rear, left and right wheels, A vehicle height sensor 220 for detecting the vehicle height, a vehicle height adjustment mode selection switch 224, a vehicle height adjustment instruction switch 226, an ignition switch 228, a traveling state detection device 230, a securing switch 232, a temperature sensor 234, etc. are connected to each other. . The storage unit 206 stores a plurality of programs such as a spring constant control program and a vehicle height adjustment program represented by the flowchart of FIG.
The vehicle height sensor 220 is provided for each of the front, rear, left, and right wheels 4FL, FR, RL, and RR. For each wheel 4FL, FR, RL, and RR, the relative position between the vehicle body 8 and the wheel 4 in the vertical direction. The vehicle height that is the relationship is detected.
The vehicle height adjustment mode selection switch 224 is operated by the driver, and the operation of the switch 224 selects either the automatic mode or the manual mode.
The vehicle height adjustment instruction switch 226 is a switch that is operated when the vehicle height is increased, when the vehicle height is decreased, and the like, and is switched by a driver's manual operation.
The traveling state detection device 230 detects the traveling state of the vehicle, and detects, for example, whether the vehicle is turning or traveling straight. The traveling state detection device 230 can include, for example, a yaw rate sensor, a steering angle sensor, a traveling speed sensor, a lateral G sensor, and the like.
The lashing switch 232 can be operated by a person. The lashing switch 232 is placed on the loading platform C of the vehicle carrier B and secured with the rope G, and then an ON operation is performed (from the OFF state to the ON state). After being transported to the destination by the vehicle carrier B, an OFF operation is performed before the rope G is removed (switched from the ON state to the OFF state).
The temperature sensor 234 detects the temperature of the hydraulic fluid. The temperature of the working fluid can be directly detected, or the ambient temperature such as the outside air temperature can be detected. Note that the temperature of the hydraulic fluid can be considered to be the same as the temperature of the gas in the accumulators 34 and 36.

The operation of the hydraulic / pneumatic suspension apparatus configured as described above will be described.
The spring constant is switched by the control of the spring constant switching valve 38.
When the spring constant switching valve 38 is opened, the two accumulators 34 and 36 are communicated with the liquid chamber 16 so that the spring constant is small, and the spring constant switching valve 38 is closed. In this case, since the low-pressure accumulator 36 is shut off from the liquid chamber 16 and the high-pressure accumulator 34 is communicated, the spring constant is increased. In this embodiment, the spring constant switching valve 38 is closed when it is detected that the vehicle is turning by the traveling state detection device 230, or when an ON operation of the lashing switch 232 is detected, as will be described later. State.
In each of the suspension cylinders 10, the damping characteristic is controlled by controlling the variable throttle 40.
When the flow area of the individual passage 32 is reduced by the variable restrictor 40 (when the restrictor is large), the suspension damping characteristics are hard (occurred when the relative movement speed in the vertical direction between the wheel 4 and the vehicle body 8 is the same). When the flow path area is increased (when the aperture is small), the software is soft (when the relative moving speed is the same, the damping force is small).

The vehicle height corresponding to the four wheels 4FL, FR, RL, RR is controlled by the control of the hydraulic fluid supply / discharge device 70.
When the automatic mode is selected by the vehicle height adjustment mode selection switch 224, the vehicle height adjustment is performed when a predetermined condition is satisfied (when the vehicle height adjustment request is satisfied), or in the manual mode. When the vehicle height adjustment instruction switch 226 is instructed (when the vehicle height adjustment request is satisfied), the operation is performed in response to the instruction.
For example, when the vehicle height is increased for the left and right front wheels 4FL, 4FR, the pump 81 is operated and the vehicle height control valves 110FL, 110FR are opened. Since the outflow control valve 106 is closed by the operation of the pump 81, the hydraulic fluid discharged from the pump 81 is supplied to the suspension cylinders 10FL and 10FR, and the vehicle height increases. When the average value of the vehicle heights of the left front wheel 4FL and the right front wheel 4FR reaches the target value, the vehicle height control valves 110FL and 110FR are closed and the operation of the pump 81 is stopped. When hydraulic fluid is supplied to the suspension cylinders 10FL, 10FR in a state where the vehicle body D and the loading platform C are secured by the rope G, that is, in a state where the vehicle height is kept constant, the suspension cylinders 10FL, FR fluid pressure increases. When the hydraulic fluid is supplied to the suspension cylinders 10FL and 10FR (when the spring constant switching valves 38FL and FR are opened), the hydraulic fluid is also supplied to the accumulators 34FL, FR, 36FL and FR. In the accumulators 34FL, FR, 36FL, FR, the pressure in the gas chamber increases and the spring constant increases.
When the vehicle height is lowered, the vehicle height control valves 110FL and 110FR are opened. Since the pump 81 is in a stopped state, the outflow control valve 106 is in an open state. The working fluid flows out from the suspension cylinders 10FL, 10FR to the reservoir 74. When the average values of the vehicle heights of the left front wheel 4FL and the right front wheel 4FR reach the target values, the vehicle height control valves 110FL and 110FR are closed.
The same applies to the case where the vehicle height is adjusted for the left and right rear wheels 4RL and RR.

When the transported vehicle A is transported by the vehicle transport vehicle B, the spring constant in the hydraulic suspension device is increased.
The transported vehicle A is generally fixed to the loading platform C with a rope G extending in the vertical direction. However, when the transported vehicle A is transported by the vehicle transport vehicle B, the temperature of the suspension cylinder 10 is reduced. The fluid pressure may be lowered, or the fluid pressure may be lowered due to gas leakage in the accumulators 34 and 36. In the accumulators 34 and 36, when the gas temperature Tgas is lowered, as shown in FIG. 10, when the volume Vgas is constant, the pressure Pgas is lowered by ΔPdown. When the gas pressure Pgas decreases by ΔPdown, the hydraulic pressure of the suspension cylinder 10 also decreases by ΔPdown. Further, even if gas leakage occurs in the accumulators 34 and 36 (gas leaks from the gas chamber), the hydraulic pressure is lowered.
When the load W applied to the wheel 4 (the magnitude corresponding to the sprung weight), the elastic force Fa applied by the accumulators 34 and 36, and the elastic force Fs of the suspension spring 21, the steady state (person, In a state in which no load is loaded and the vehicle is at the standard height (Fa0, Fs0: 0 is attached), generally, the equation W = Fa0 + Fs0
Is established. From this equation, when the load applied to the wheel 4 is constant, as shown in FIG. 11, when the elastic force Fa of the accumulators 34 and 36 decreases, the vehicle height decreases and the elastic force Fs of the spring 21 decreases. You can see it grows.
On the other hand, when the transported vehicle A is transported, it is secured by the rope G in a state where the vehicle height is lower than the standard vehicle height (sometimes referred to as a normal vehicle height). The tension Fr is applied to the rope G by the elastic force Fs of the suspension spring 21 and the elastic force Fa applied to the suspension cylinder 10 by the accumulators 34 and 36, and this tension keeps the transported vehicle A in a stopped state. It is secured so that it becomes more than necessary force (necessary securing tension). In this locked state, the general formula W + Fr = Fa + Fs
Is established. That is, the elastic forces Fa and Fs are larger than the elastic forces Fa0 and Fs0 by the amount of the tension Fr of the rope G as compared with the case in the steady state of the vehicle, but the elastic force of the suspension spring 21 is uniquely determined by the vehicle height. Therefore, the tension Fr of the rope G is changed in accordance with the change of the elastic force Fa of the accumulators 34 and 35.

When the hydraulic pressure of the suspension cylinder 10 decreases from this locked state, the elastic force Fa of the accumulators 34 and 36 decreases, and accordingly, the tension Fr of the rope G decreases. However, the elastic force Fa further decreases. When it becomes smaller, as shown in FIG. 11, the vehicle height becomes lower and the rope G becomes loose.
Therefore, in this embodiment, when the lashing switch 232 is switched from the OFF state to the ON state, the spring constant switching valve 38 is switched from the open state to the closed state, and the high spring state is set. The spring constant in the hydraulic suspension device is increased, the amount of decrease in vehicle height is reduced, and the rope G is hardly loosened. Further, if the spring constant is increased, it is possible to reduce the amplitude of the vibration of the vehicle height of the transported vehicle A caused by the vibration during transportation.

The spring constant control program represented by the flowchart of FIG. 4 is executed at predetermined time intervals. In step 1 (hereinafter abbreviated as S1. The same applies to other steps), it is determined whether or not the lashing switch 232 is in the ON state. If it is in the ON state, the spring constant is determined in S2. The switching valve 38 (all 38FL, FR, RL, RR) is closed and is in a high spring state. In this embodiment, the spring constant in the high spring state is larger than the set value, and the amount of looseness of the rope G is within the allowable range even if the temperature drops during transportation and the hydraulic pressure drops. It is.
On the other hand, when the lashing switch 232 is in the OFF state, it is determined in S3 whether or not the spring constant switching valve 38 is in the closed state. In S4, the lashing switch 232 is now in the ON state. It is determined whether or not the state has been switched from OFF to OFF. If it is switched to the OFF state this time, in S5, the spring constant switching valve 38 is opened to a low spring state.

FIG. 5 shows the relationship between the vehicle height and the hydraulic pressure of the suspension cylinder 10 when the spring constant is large (accumulator 34) and when the spring constant is small (accumulators 34 and 36). The change in hydraulic pressure when the spring constant is large is indicated by a solid line, and the spring constant at normal vehicle height is indicated by a broken line. The change in hydraulic pressure when the spring constant is small is indicated by a one-dot chain line, and the spring constant at a normal vehicle height is indicated by a two-dot chain line. When the hydraulic pressure reduction amount ΔPdown due to temperature drop and gas leakage is substantially the same, the amount of reduction in vehicle height is smaller when the spring constant is large than when it is small (ΔHk1 <ΔHk2). Looseness can be reduced.
Further, since the spring constant is increased, it is also possible to suppress a periodic change in the vehicle height of the transported vehicle A due to vibration (external force) in the vehicle transport vehicle B.
Furthermore, since the spring constant is reduced before the rope G is removed by the operator after the transportation is completed, the work for removing the rope G can be facilitated.
In the present embodiment, a flow state switching mechanism is constituted by the spring constant switching valve 38 and the like, and the portion for storing and executing S1 and S2 of the spring constant control program represented by the flowchart of FIG. A distribution control unit is configured. These flow control unit, spring constant switching valve 38 and the like constitute a suspension control unit when detecting lashing. Of the spring constant switching valve 38 and the flow control unit, a portion for storing S3-5, a portion for executing the suspension control portion, and the like constitute a suspension release suspension control unit.

In the above embodiment, the spring constant switching valve 38 is switched to the closed state to increase the spring constant and make the rope G difficult to loosen. However, by increasing the hydraulic pressure of the suspension cylinder 10, the rope G can be made difficult to loosen.
When the hydraulic fluid is supplied to the suspension cylinder 10 in the locked state (in a state where the vehicle height is kept substantially constant), the hydraulic pressure increases and the tension of the rope G increases. As described above, if the tension of the rope G is increased in advance at the start of transportation, the rope G will not be loosened even if the hydraulic pressure is lowered and the tension is reduced thereafter. The amount can be reduced.
In the present embodiment, in the locked state, the hydraulic pressure of the suspension cylinder 10 is controlled so as to be equal to or higher than the set pressure Pss. The set pressure Pss is such that the tension of the rope G becomes equal to or higher than the set tension. Thus, even if the hydraulic pressure is lowered due to the temperature drop, the rope G is kept at a tension that is higher than the necessary securing tension. The hydraulic pressure of the suspension cylinder 10 may be controlled for the front and rear wheels 4FL, FR, RL, and RR at the same time, or for the left and right front wheels 4FL, FR, and the left and right rear wheels 4RL and RR. Alternatively, each wheel may be controlled.

The lashing hydraulic pressure control program represented by the flowchart of FIG. 6 is executed at predetermined time intervals. In S11 and S12, it is determined whether or not the lashing switch 232 is turned on. That is, it is determined whether or not it is currently in the ON state and was in the OFF state last time. If the determinations in S11 and S12 are YES, an ON operation (switched from the OFF state to the ON state) is performed. Can be done. In that case, in S13-18, the system hydraulic pressure is increased until it reaches the set pressure Pss.
The pump motor 81 is operated, the vehicle height control valve 110 is switched to the open state, and the hydraulic pressure is detected by the hydraulic pressure sensor 92. It can be considered that the vehicle height control valve 110 is in the open state, and the hydraulic pressure detected by the hydraulic pressure sensor 92 is the same as the hydraulic pressure (system pressure) of the hydraulic cylinder 10. The hydraulic fluid is supplied from the pump motor 81 until the hydraulic pressure detected by the hydraulic pressure sensor 92 reaches the set pressure Pss. When the detected hydraulic pressure reaches the set pressure Pss, the vehicle height control valve 110 is closed. It is switched and the pump motor 81 is stopped. The tension applied to the rope G is the set tension.

In S <b> 1 and 19, it is determined whether or not the lashing switch 232 is turned off. That is, this time, the lashing switch 232 is in the OFF state, and it is determined whether or not it was in the ON state last time. If the determination in S1 is NO and the determination in S19 is YES, the OFF operation is performed. Can be done. In that case, in S20 to 23, the hydraulic pressure of the hydraulic cylinder 10 is returned to the normal height (standard hydraulic pressure) P0. The normal height P0 is the size P0 before the start of the hydraulic pressure control, and is a standard vehicle height that can maintain the vehicle body D (sprung mass: no person or luggage loaded).
The vehicle height control valve 110 is switched to the open state, and the hydraulic fluid in the suspension cylinder 10 is caused to flow into the reservoir 74. When the hydraulic pressure in the suspension cylinder 10 decreases to the standard hydraulic pressure P0, the vehicle height control valve 110 is switched to the closed state.

In this way, if the tension applied to the rope G is detected to be equal to or higher than the set tension when the locked state is detected, then the hydraulic pressure is lowered and applied to the rope G due to a temperature drop or the like. Even if the tension decreases, the necessary securing tension can be secured and the rope G can be prevented from loosening. Moreover, even if the vehicle height decreases due to a decrease in hydraulic pressure, the amount of decrease in vehicle height can be reduced, and the amount of looseness can be suppressed.
Further, if the hydraulic pressure in the suspension cylinder 10 is increased, the gas pressure in the accumulators 34 and 36 is increased, so that the spring constant is substantially increased. Therefore, the change in the vehicle height of the transported vehicle A due to the vibration of the vehicle transport vehicle B can be reduced.
Furthermore, since tension | tensile_strength is made small before removing the rope G, the operation | work which removes the rope G can be made easy.
In the present embodiment, a hydraulic pressure control mechanism as a fluid pressure control mechanism is configured by the hydraulic fluid supply / discharge device 70 and the like, and S11 to 18 of the hydraulic pressure control program represented by the flowchart of FIG. 6 of the suspension ECU 200 are stored. The part, the part to be executed, etc. constitute a fluid pressure control unit as a fluid pressure control unit. In addition, the suspension control unit at the time of securing release is configured by a part that stores S19 to 23, a part that executes S19 to 23, and the like.

Furthermore, in S19-23, before removing the rope G, it is not indispensable to lower the hydraulic pressure to the level before the increase. It can be easily removed.
Further, the amount of increase in the hydraulic pressure (temperature-dependent increase amount) can be determined based on the temperature of the hydraulic fluid, and the hydraulic pressure of the suspension cylinder 10 can be increased by the temperature-dependent increase amount.
When the temperature of the hydraulic fluid (accumulator gas temperature) is low, the hydraulic pressure of the suspension cylinder 10 is lower than when the hydraulic fluid is high. Therefore, when the length of the rope G is determined, the tension of the rope G becomes small. There are many cases. On the other hand, if the amount of increase in the hydraulic pressure is increased when the temperature is low than when it is high, the tension of the rope G can be increased to the set tension even when the temperature is low. In addition, when the temperature is high, the tension of the rope G is not increased more than necessary and the durability of the rope G is increased compared to the case where the increase amount is the same when the temperature is high and low. Can be improved.
In this case, the relationship between the temperature and the hydraulic pressure increase is tabulated and stored in advance as represented by the map of FIG.

The hydraulic control program corresponding to the situation at the time of lashing represented by the flowchart of FIG. 8 is executed at predetermined time intervals. Steps having the same contents in the binding detection situation corresponding hydraulic control program and the hydraulic control program represented by the flowchart of FIG. 6 are given the same step numbers and description thereof is omitted.
In the hydraulic control program corresponding to the situation at the time of lashing, when the ON operation of the lashing switch 232 is detected, the temperature is detected by the temperature sensor 234 at S31, and the table shown by the map of FIG. From this, the temperature-dependent increase amount ΔP is obtained. Thereafter, the pressure increase control is performed. In S15, the fluid pressure first detected by the fluid pressure sensor 92 (YES in S33) is stored in S34 as the initial value P0, and the actual fluid pressure is controlled. The pressure increase amount is set to a value obtained by subtracting the initial value P0 from the hydraulic pressure P detected by the hydraulic pressure sensor 92 thereafter (P-P0). In S35, it is determined whether or not the actual hydraulic pressure increase amount is equal to or greater than the temperature-dependent increase amount ΔP determined in S32. While the actual hydraulic pressure increase amount is smaller than the temperature-dependent increase amount, the vehicle height control valve 110 is kept open. However, when the temperature-dependent increase amount is exceeded, the vehicle height control valve 110 is closed in S17 and S18. In this state, the pump motor 81 is stopped.
In S19 to 23, when the securing switch 232 is turned off, the hydraulic pressure is reduced to the initial pressure P0, and the tension of the rope G is reduced.

In this way, the amount of increase in the hydraulic pressure can be determined based on the temperature of the gas, and the system hydraulic pressure can be controlled based on that.
In the present embodiment, the binding-time-situation control unit is composed of a part for storing S11 to 16, 17, 18, 31 to 35 of the suspension-control-situation hydraulic control program for the suspension ECU 200, a part to execute, and the like. Is done.

In addition, the outside temperature sensor which detects outside temperature can be provided, and the temperature of the hydraulic fluid (corresponding to the temperature of the gas) can be estimated based on the outside temperature. When the transported vehicle A has been outdoors for a long time, it can be considered that the temperature of the hydraulic fluid or gas is the same as the outside air temperature.
Moreover, the fall amount of the hydraulic pressure during conveyance can be estimated based on the outside air temperature, and the increase amount can be acquired based on the estimated amount. For example, when the gas (working fluid) temperature Tgas is higher than the outside air temperature Tout at the time of detection of lashing, the temperature decreases during transportation and the hydraulic pressure decreases. In this case, when the expected temperature drop ΔT (Tgas−Tout) is large, the amount of increase in the hydraulic pressure at the time of detection of lashing can be made larger than when the temperature decrease ΔT (Tgas−Tout) is small. This is because when the amount of decrease in temperature is large, the amount of decrease in hydraulic pressure during transportation is larger than when it is small, and the rope G is easy to loosen. In the present embodiment, it is possible to avoid loosening of the rope G even if the temperature drops during transportation. In addition, there is an advantage that the tension of the rope G is not increased more than necessary when the temperature drop is estimated to be small.
On the other hand, when the gas temperature Tgas is lower than the outside air temperature Tout at the time of detection of lashing, it is considered that the temperature rises during transportation and the hydraulic pressure increases. In this case, since the possibility that the rope G is loosened is low, the amount of increase in the hydraulic pressure can be reduced or the hydraulic pressure can be maintained. Further, when the expected temperature rise (Tout-Tgas) is large, the hydraulic pressure can be reduced. This is because if the temperature of the hydraulic fluid becomes high during transportation and the hydraulic pressure becomes excessive, liquid leakage or the like may occur.
In the present embodiment, the temperature of the gas (hydraulic fluid) and the outside air temperature at the time of detection of lashing (before transportation and when preparation for transportation is completed) may be detected by separate temperature sensors. Based on the detected value and the estimated value, the temperature of the outside air and the temperature of the working fluid can be obtained by estimating the temperature of the gas (working fluid) based on the estimated temperature. When the transport vehicle A is indoors, the temperature of the hydraulic fluid may be estimated to be a preset temperature.

Furthermore, when a locked state is detected, the damping characteristic in the hydraulic / pneumatic suspension device can be made a hard characteristic. In the present embodiment, when the ON operation of the lashing switch 232 is detected, the flow path area is reduced by controlling the variable throttle 40. The variable throttle 40 is usually in a state where the flow path area is large and the attenuation characteristic is soft, but it is a hard characteristic during transportation.
The flowchart of FIG. 9 is executed at predetermined time intervals. In S51 and S52, it is determined whether or not the ON operation of the securing switch 232 has been performed this time. If the ON operation is detected, the suspension cylinder 10 and the accumulators 34 and 36 are controlled by the control of the variable throttle 40. The flow path area between is made small. The channel area can be reduced to a predetermined size (to a size that provides a desired attenuation characteristic), or can be a size determined based on temperature or the like. As a result, the generated damping force is increased, and the vehicle height can be hardly changed.
On the other hand, if an OFF operation of the lashing switch 232 is detected, the determination in S54 is YES, and in S55, the flow path area is increased and the soft characteristics are restored.

Thus, in this embodiment, since the damping characteristic is a hard characteristic during transportation, even if vibration (external force) of the vehicle transport vehicle B is applied to the transported vehicle A during transport, Change can be suppressed.
In the present embodiment, a damping characteristic control mechanism is configured by the variable diaphragm 40 and the like, and the damping characteristic control unit is configured by a part for storing and executing a damping characteristic control program represented by the flowchart of FIG. Composed.
As described above, the control of the spring constant, the hydraulic pressure control, and the control of the damping characteristic in the hydraulic / pneumatic suspension apparatus have been described, but two or three of these three controls are executed. be able to. If two or more controls are executed, the rope G can be made more difficult to loosen.

Next, a hydraulic / pneumatic suspension apparatus according to another embodiment of the present invention will be described.
In FIG. 12, reference numerals 300FL, FR, RL, and RR are provided between the wheel side member 6FL, FR, RL, and RR and the vehicle body side member 8 corresponding to the left and right and front and rear wheels provided in the vehicle. FIG.
Corresponding to each wheel, shock absorbers 310FL, FR, RL, RR as damping devices are provided in parallel with the air springs 300FL, FR, RL, RR. In each of the shock absorbers 310FL, FR, RL, and RR, the cylinder body 338 is connected to the wheel side member 6, and the piston rod 340 of the piston 339 slidably provided on the cylinder body 338 is connected to the vehicle body side member 8. The In the present embodiment, the air springs 300FL, FR, RL, RR and the shock absorbers 310FL, FR, RL, RR are provided coaxially.

The air springs 300FL, FR, RL, and RR are provided so as not to move relative to the air chamber 350 fixed to the vehicle body side member 8 and the cylinder body 338 of the shock absorbers 310FL, FR, RL, and RR, respectively. An air piston 352 and a diaphragm 354 fixed to the air piston 352 and the chamber 350 are formed, and a fluid pressure chamber 356 is formed by these.
The air piston 352 is moved relative to the air chamber 350 along with the relative movement in the vertical direction between the wheel side member 6 and the vehicle body side member 8.

  Further, when the amount of fluid existing in the fluid pressure chamber 356 is large, the volume of the fluid pressure chamber 356 increases when the fluid pressure, temperature, etc. are the same, and the vehicle body side member 8 and the wheel are The distance to the side member 6 increases and the vehicle height increases. In the air springs 300FL, FR, RL, and RR, since the volume of the fluid pressure chamber 356 is suppressed from increasing in the lateral direction (because it is deformed along the rolling guide), by supplying air, The shock absorbers 310FL, FR, RL, RR are extended, and the distance between the wheel side member 6FL, FR, RL, RR and the vehicle body side member 8 is increased.

  Each of the shock absorbers 310FL, FR, RL, and RR has adjustable damping characteristics, and the relative movement speeds of the wheel side members 6FL, FR, RL, and RR and the vehicle body side member 8 are the same by controlling the damping characteristics. It is possible to control the damping force when. The damping force control is well known and will not be described, but the flow area of the communication path provided in the piston 339 of the shock absorber is controlled by the control of the damping characteristic control motor 360 (the valve is controlled). The damping characteristic is controlled. When the flow path area is large, the attenuation characteristic is softer than when the flow path area is small. The hydraulic fluid between the upper chamber and the lower chamber on both sides of the piston 339 easily flows, and the damping force when the moving speed is the same is reduced.

The fluid pressure chambers 536 of the air springs 300FL, FR, RL, RR are connected to the air source device 380 via the individual passages 370FL, FR, RL, RR and the common passage 378, respectively.
The air source device 380 includes an air supply device 382 and an exhaust valve 384 as an outflow valve.
The air supply device 382 includes a compressor 390, a high-pressure tank 392, and the like. The compressor 390 includes a pump 400, a pump motor 402, a discharge valve 404, a suction valve 406, and the like. The pump 400 is operated by the pump motor 402. Air is sucked from the atmosphere through the filter 408 and the suction valve 406, pressurized, and discharged through the discharge valve 404. In the present embodiment, the air discharged from the compressor 390 is stored in the high-pressure tank 392. The pump motor 402 is controlled so that the pressure of the air stored in the high-pressure tank 392 is within the set range. The air pressure in the high-pressure tank 392 is detected by the system pressure sensor 410.
A high pressure tank valve 412 is provided between the high pressure tank 392 and the common passage 378. The high-pressure tank valve 412 is a normally closed valve that can be opened and closed by controlling the supply current to the solenoid.

In the common passage 378, a dryer 420, a flow restriction device 422, and the like are provided. The flow restriction device 422 includes a throttle 426 and a relief valve 428 provided in parallel with each other. The relief valve 428 prevents the flow of air from the air spring side to the compressor side, but allows the air flow from the compressor side to the air spring side when the pressure on the compressor side becomes higher than the set pressure by the air spring side. Further, the flow of air in the common passage 378 is suppressed by the throttle 426.
The exhaust valve 384 is provided between the dryer 420 of the common passage 378 and the compressor 390. The air discharged from the fluid pressure chambers 356 of the air springs 300FL, FR, RL, RR is discharged to the atmosphere through the exhaust valve 384. The air that has flowed out of the fluid pressure chamber 356 is discharged to the atmosphere through the throttle 426 and the exhaust valve 384, and a rapid decrease in the pressure in the fluid pressure chamber 356 is suppressed. The exhaust valve 384 is a normally closed valve that is opened and closed by controlling the current supplied to the solenoid.

The individual passages 370FL, FR, RL, RR are provided with vehicle height control valves 430FL, FR, RL, RR, respectively. The vehicle height control valves 430FL, FR, RL, and RR are normally closed valves that are opened and closed by controlling the current supplied to the solenoid, and the air springs 300FL, FR are controlled by opening and closing the vehicle height control valves 430FL, FR, RL, and RR. , RL, and RR, the inflow and outflow of air in each fluid pressure chamber 356 can be individually controlled.
As described above, the common passage 378 is provided with the compressor 390, the exhaust valve 384, the dryer 420, the flow restriction device 422, and the high-pressure tank 392 in series, and the fluid pressure chamber 356 is connected to the high-pressure tank side of the air source device 380. Is done. A system pressure sensor 410 is provided between the high pressure tank side of the air source device 380 and the air springs 300FL, FR, RL, RR (vehicle height control valves 430FL, FR, RL, RR). When any of 430FL, FR, RL, and RR is in the open state, the fluid pressure in the fluid pressure chamber 56 in the open state is detected.

  The suspension ECU 500 mainly includes a computer including an execution unit 502, a storage unit 504, an input / output unit 506, and the like. The input / output unit 506 includes a system pressure sensor 410, vehicle height sensors 510 to 516, vehicle height adjustment mode selection switch 224, vehicle height adjustment instruction switch 226, ignition switch 228, travel state detection device 230, securing switch 232, temperature A sensor 234 and the like are connected, and a high pressure tank valve 412, an exhaust valve 384, a vehicle height control valve 430 FL, FR, RL, RR solenoids, a pump motor 402, a damping characteristic control motor 360 FL, FR, RL, RR, etc. They are connected via a drive circuit (not shown). The storage unit 504 stores an air pressure control program represented by the flowchart of FIG. 13, a damping characteristic control program represented by the flowchart of FIG.

The air pressure control program represented by the flowchart in FIG. 13 is a program corresponding to the fluid pressure control program represented by the flowchart in FIG. 6, and the control target is different between the air pressure and the fluid pressure. Steps having similar contents are denoted by the same step numbers and description thereof is omitted.
In the fluid pressure chamber 356 in the air chamber 350, the relationship shown in FIG. 10 is established between the air pressure P and the volume V. Therefore, when the air pressure P is high, the spring constant is larger than when the air pressure P is low. Therefore, the air pressure set pressure Psa is set so that the spring constant is equal to or greater than the set value, and air is supplied to the fluid pressure chamber 356 so that the actual air pressure becomes the set pressure Psa. In the state of being bound by the rope G, the volume of the fluid pressure chamber 356 is substantially constant, so that the air pressure is increased by supplying air.

As in the case of the hydraulic pressure control program shown in the flowchart of FIG. 6, when the ON operation of the lashing switch 232 is detected, the pump motor 402 is activated and the vehicle height control valve 430 is opened. Can be switched. In S101, the air pressure is detected, and in S102, it is determined whether or not the actual air pressure has become equal to or higher than the set pressure Psa. When the actual air pressure becomes equal to or higher than the set pressure Psa, the vehicle height adjusting valve 430 is closed and the pump motor 402 is stopped.
In addition, when the OFF operation of the lashing switch 232 is detected, the air pressure is returned to the level before the ON operation of the lashing switch 232 is detected. In this case, the exhaust valve 384 is turned on in S103. In the open state, the vehicle height control valve 430 is opened in S20. The air in the fluid pressure chamber 356 is discharged to the atmosphere through the exhaust valve 384. When the air pressure detected in S104 is returned to the original magnitude P0a, the determination in S105 is YES, and in S23 and 106, the vehicle height control valve 430 is closed and the exhaust valve 384 is closed. The
As described above, when the air pressure in the fluid pressure chamber 356 is increased, the spring constant is increased as shown in FIG. As a result, in the shock absorber 330, since the amount of movement of the piston when the external force applied to the transported vehicle A is the same magnitude is suppressed, the increase in the temperature of the hydraulic fluid is suppressed, and the leakage of liquid is suppressed. be able to.
In the present embodiment, an air pressure control mechanism is configured by the air source device 380, the vehicle height control valve 430, etc., and S11 to 18, 101, 102 of the air pressure control program represented by the flowchart of FIG. The air pressure control unit is configured by the storing part, the executing part, and the like.
Note that the air pressure can be increased by an increase determined based on the temperature. When the temperature is high, the air pressure becomes higher than when the temperature is low, and the spring constant becomes large. Therefore, the increase amount of the fluid pressure chamber 356 is determined in consideration of this.

The damping characteristic control program represented by the flowchart of FIG. 15 is a program corresponding to the damping characteristic control program represented by the flowchart of FIG. 9, and the controlled object is the solenoid of the variable aperture 40 in the above embodiment. In contrast, the present embodiment is different in that it is a damping characteristic control motor 360. When the ON operation of the lashing switch 232 is detected, in S111, the flow path area provided in the piston is reduced and the damping characteristic is increased by the control of the damping characteristic control motor 360. When the flow path area (attenuation characteristic) is changed stepwise, the characteristic is set to a predetermined number of steps. When the OFF operation of the lashing switch 232 is detected, the attenuation characteristic is returned to the normal number of stages in S112. It is regarded as a soft characteristic.
If the damping characteristic is increased, the vibration of the transported vehicle A can be suppressed.

Further, both the control of the air pressure in the air spring 300 and the control of the damping characteristic in the shock absorber 310 can be performed, and by doing so, the working fluid in the shock absorber 310 can be further improved. An increase in temperature can be suppressed, and liquid leakage can be further suppressed.
In addition, the present invention can be applied to an oil / pneumatic suspension device of a transported vehicle that is transported by a train running on a ship or railroad. It can implement in the aspect which gave the change and improvement of.

It is a figure which shows the state in which the vehicle carrying the hydraulic / pneumatic suspension apparatus which is one Example of this invention is conveyed by a vehicle transporter. It is a figure which shows the loading platform of the said vehicle transport vehicle. It is a figure which shows the said hydraulic / pneumatic suspension apparatus whole. It is a flowchart showing the spring constant control program memorize | stored in the memory | storage part of suspension ECU of the said hydraulic / pneumatic suspension apparatus. It is a figure which shows the relationship between the hydraulic pressure at the time of the said spring constant control program being performed, and vehicle height. It is a flowchart showing the hydraulic pressure control program memorize | stored in the memory | storage part of the said suspension ECU. It is a flowchart showing the fluid pressure control program corresponding to the situation at the time of securing detection memorize | stored in the memory | storage part of the said suspension ECU. It is a map showing the temperature corresponding | compatible increase determination table memorize | stored in the memory | storage part of the said suspension ECU. It is a flowchart showing the damping characteristic control program memorize | stored in the memory | storage part of the said suspension ECU. It is a figure which shows the relationship between the gas pressure and volume in the accumulator of the said hydraulic / pneumatic suspension apparatus. It is a figure which shows the relationship between the hydraulic pressure in the said hydraulic pneumatic suspension apparatus, and vehicle height. It is a figure which shows the whole hydraulic-pneumatic suspension (air suspension) apparatus which is another one Example of this invention. It is a flowchart showing the air pressure control program memorize | stored in the memory | storage part of suspension ECU of the said air suspension apparatus. It is a figure which shows the relationship between the air pressure at the time of the said air pressure control program being performed, and vehicle height. It is a flowchart showing the damping characteristic control program memorize | stored in the memory | storage part of the said suspension ECU.

Explanation of symbols

  10: Suspension cylinder 34, 36: Accumulator 38: Spring constant switching valve 40; Variable throttle 70: Hydraulic fluid supply / discharge device 110: Vehicle height control valve 200: Suspension ECU 232: Locking switch 234: Temperature sensor 300: Air spring 310 : Shock absorber 356: Air chamber 360: Damping characteristic control motor 380: Air source device 430: Vehicle height control valve 500: Suspension ECU

Claims (8)

A hydraulic suspension device for a vehicle,
A transport preparation detection device for detecting that a vehicle including the fluid pressure suspension device is in a state of being secured in a direction including a vertical component by a securing member on a transportation platform as a transported vehicle;
When the transport preparation detecting device detects that the vehicle is in the locked state, at least one of a fluid pressure in the fluid pressure suspension device and a spring constant that is a change amount of the fluid pressure with respect to a change amount of the vehicle height is calculated. A fluid pressure suspension device, comprising: a suspension detection unit for controlling lashing to be controlled.   The fluid pressure suspension device operates between (a) a hydraulic cylinder provided between the vehicle body side member and the wheel side member, and (b) the hydraulic cylinder as the vehicle height changes. A plurality of accumulators for transferring and receiving liquid; and (c) one or more of the plurality of accumulators and the hydraulic cylinder, and the operation between the one or more accumulators and the hydraulic cylinder A distribution state switching mechanism that can be switched between a state that allows and prevents a liquid flow, and the suspension control unit at the time of binding detection sets the spring constant by controlling the flow state switching mechanism The fluid pressure suspension device according to claim 1, further comprising a spring constant control unit that is greater than or equal to a value.   The fluid pressure type suspension device includes a fluid pressure control mechanism capable of controlling the fluid pressure of the output unit, and the suspension control unit at the time of binding detection detects the fluid pressure of the output unit by controlling the fluid pressure control mechanism. The fluid pressure suspension device according to claim 1, further comprising a fluid pressure control unit that controls the pressure to be equal to or higher than a set pressure.   The fluid pressure type suspension device includes a fluid pressure control mechanism capable of controlling the fluid pressure of the output unit, and the suspension control unit at the time of lash detection detects the fluid pressure by controlling the fluid pressure control mechanism. A binding detection situation response control unit that changes a set change pressure determined by at least one of a temperature of the fluid and an environmental temperature when the preparation detection device detects that the locked state is detected. 4. The fluid pressure suspension device according to any one of 3.   The fluid pressure suspension device operates between (a) a hydraulic cylinder provided between the vehicle body side member and the wheel side member, and (b) the hydraulic cylinder as the vehicle height changes. One or more accumulators for transferring and receiving liquid, and the fluid pressure control mechanism includes a pump device capable of pressurizing hydraulic fluid and supplying the hydraulic fluid to the hydraulic cylinder, and at least the operation supplied from the pump device 5. The fluid pressure suspension device according to claim 3, further comprising a fluid pressure control mechanism capable of controlling fluid pressure in the fluid pressure cylinder using fluid.   The fluid pressure suspension device includes: (a) a shock absorber and an air chamber provided in parallel between a vehicle body side member and a wheel side member; and (b) a pump capable of pressurizing and supplying air to the air chamber. An air pressure control mechanism capable of controlling the air pressure in the air chamber using at least air supplied from the pump device, and the suspension control unit includes the air pressure control mechanism The fluid pressure suspension according to any one of claims 1 to 4, further comprising an air pressure-dependent spring constant control unit that controls air pressure in the air chamber by controlling the pressure to make the spring constant equal to or greater than a set value. apparatus.   The fluid pressure suspension device further includes: (a) a damping characteristic control mechanism capable of controlling the damping characteristic of the fluid pressure suspension device; and (b) controlling the damping characteristic control mechanism to The damping characteristic control part which makes the characteristic which the damping force generate | occur | produced when the high change speed is the same becomes larger than before detecting when the said securing state is detected by the said transport preparation detection apparatus is included. 7. The hydraulic suspension device according to any one of items 6 to 6.   The fluid pressure suspension device further includes the fluid pressure and the spring when it is detected that the transported vehicle is in the locked state and is scheduled to release the binding by the binding member. The hydraulic suspension apparatus according to any one of claims 1 to 7, further comprising a suspension release suspension control unit that reduces at least one of the constant.

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