JPH04334677A - Suspension device for crawler - Google Patents

Abstract

PURPOSE:To suppress the oscillation of a body so as to improve riding comfort in a crawler provided with a hydraulic/pneumatic pressure suspension device by performing the independent suction/discharge of pressure oil to/from the hydraulic cylinders of an active suspension unit according to the oscillation of the body, and also performing the high-low change-over of a variable control valve. CONSTITUTION:When a body is oscillated at the time of travelling on the uneven ground or riding over a protrusion, the respective detection signals of pitch angle speed detected by a gyroscope 12, the vertical acceleration of the body detected by an accelerometer 11, the displacement of a suspension arm detected by a synchronous resolver 29 and cylinder pressure detected by a pressure sensor 60 are transmitted to a controller 13. In the controller 13, the respective detection signals are computed as weight functions and converted into the solenoid switching signals of a control valve 62 for supplying/ discharging oil pressure to/from an active suspension hydraulic cylinder unit E and the switching signal of the high-low damping change-over solenoid valve 68 or the like of a damping valve unit D. The oscillation of the body is thereby suppressed to improve riding comfort.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension system for a special tracked vehicle that combines an active suspension unit and an in-arm suspension unit.

0002

[Prior Art] Conventional hydraulic suspension systems for special vehicles include:
The newest one is a suspension unit that integrates a hydraulic cylinder, damping valve, and accumulator as shown in FIGS. 2 and 3. However, in the conventional type, it is not possible to take oil in and out of the hydraulic cylinder or to vary the damping force.

0003

In conventional suspension systems for special vehicles, a predetermined amount of oil in a hydraulic cylinder is sealed and partitioned, so that the movement of the wheels to the vehicle body relative to unevenness on the road surface is proportional. (If the wheels shake a lot, the vehicle body will also shake a lot). In addition, the damping force pattern generated by the damping valve is one-mode, so if you set the damping force too hard to suppress vehicle body vibration, it will result in a bumpy and uncomfortable ride, and if you set it to a soft damping force, it will become bouncy and the vibration will not subside. It is difficult to satisfy both sides.

[0004] A special need for special vehicles is to improve the firing speed while driving on rough terrain, and it is necessary to suppress the vibration of the chassis, which is the platform of the gun, as much as possible. Suppression of such oscillations is in high demand from the viewpoint of improving passenger comfort and improving the vibration resistance of onboard electronic equipment. SUMMARY OF THE INVENTION An object of the present invention is to provide a suspension system for a special vehicle that suppresses vibration of a vehicle body and improves ride comfort.

[0005]

[Means for solving the problem] At the front and rear of the vehicle,
An active suspension unit with built-in hydraulic cylinders, accumulators, variable damping valves, hydraulic piping, etc. is installed, and an in-arm suspension unit with built-in hydraulic cylinders, accumulators, damping valves, etc. is placed in the center of the vehicle. Sensors such as a gyroscope and accelerometer are installed in the center of the vehicle body, and a synchro resolver and a
Sensors such as position detectors are installed at the center of the steering wheel and brake pedal operation.

According to the vibration of the vehicle body, pressure oil is supplied and discharged to and from the hydraulic cylinders of the active suspension unit independently, and the height of the variable damping valve is also switched.

[0007]

[Operation] Accurately detects changes in vehicle body posture using various sensors,
By operating controllers and control valves in real time, supplying and discharging pressure oil independently to the active suspension units installed at the front and rear of the vehicle body, and switching the height of the damping valve, random vehicle body suppress agitation,
Pitching of the vehicle body can be effectively suppressed.

[0008] Since the in-arm suspension unit provided at the center of the vehicle body has no protrusion on the inside, it is easy to install a basket for a passenger or the like at the center of the vehicle body.

[0009]

[Embodiment] An embodiment of the present invention will be explained with reference to FIGS. 1 to 6. A is a special vehicle with hybrid suspension, B is an active suspension unit, C is an in-arm suspension unit, D
is a variable damping valve unit, E is a hydraulic cylinder unit for active suspension, F is an accumulator unit for active suspension, G is a hydraulic cylinder section for in-arm suspension, H
1 is the in-arm suspension accumulator part, 1 is the vehicle body, 2 is the engine, 3 is the transmission, 4 is the starting wheel, 5 is the guide wheel,
6 is a crawler track, 7 is a lower roller, 8 is an upper roller, 9 is a stopper (for regulating the upward stroke of the lower roller 7), 10 is a hydraulic pump (driven by the engine), 11 is an accelerometer, 12 is a gyroscope , 13 is a controller (calculates the sensor signal and converts it into a solenoid activation signal), 13a is a power supply, 1
3b is an operation panel, 14 is a valve block (sends main pressure and pilot pressure to each leg), 15 is a suspension arm,
16 is a suspension casing, 16a is a case attachment (bolts and washers), 16b is a cover, 17 is a link (spline fitting with the suspension arm 15), 18 is a connecting pin A,
19 is connecting rod A, 20 is piston A, 21
22 is the cylinder hydraulic chamber, 22 is the accumulator hydraulic chamber, 23 is the cylinder hydraulic chamber.
is a free piston A, 24 is a seal A, 25 is a nitrogen gas chamber A, 26 is a gas filling valve A, 27 is a cover, 28 is a cable holder, 29 is a synchro resolver (suspension arm operation detection and standard vehicle height detection), 30 is a cap,
31 is a bearing (large), 32 is a bearing (small), 33 is a seal (large), 34 is a seal (small), 35 is a cable, 40 is a floating seal, 41 is a bearing, 4
2 is a nut, 43 is a bracket, 43a is a bracket fixture, 44 is an in-arm suspension casing, 44a is a case cover, 45 is a link (engages with the bracket 43)
, 46 is connecting rod B, 47 is connecting pin B, 4
8 is a piston B, 49 is a free piston B, 50 is a seal B, 51 is a nitrogen gas chamber B, 52 is a gas filling valve B,
53 is a cap, 54 is a damping valve, 55 is an orifice, 56 is a check valve, 57 is a bearing (large), 58
is a bearing (small), 59 is a seal, 60 is a pressure sensor,
61 is a stop valve, 62 is a control valve, 63 is an unloader valve (for setting circuit pressure), 64 is a tank, 6
5 is a pilot check valve (valve opens by pilot pressure), 65a is pilot pressure, 66 is a relief valve (for pressure assurance of solenoid valve 68),
67 is a poppet valve (bypasses the oil in the cylinder hydraulic chamber 21 to the accumulator hydraulic chamber 22), 68 is a solenoid valve (switches between high and low damping valves), 6
9 is an overload relief valve (regulates the maximum pressure applied to the circuit), 70 is a check valve, 71 is an orifice, 72 is a check valve, and 73 is a low pressure damping valve (
74 is a high-pressure damping valve (obtains a hard damping force), 75 is a solenoid valve (sends pressure oil to each leg and guide wheel cylinder by a signal), 76
is the pilot check, 77 is the pressure reducing valve (setting the track tension), 78 is the guide wheel cylinder, 79 is the overload relief valve, 80 is the pressure piping (thick solid line),
81 is the drain circuit (thin solid line), 82 is the sensor signal line (wavy line), 83 is the command signal line (dotted chain line), 8
4 is a steering wheel angle sensor, 85 is a brake sensor (turns on when the pedal is pressed), and 88 is a basket.

Next, the operation of this device will be explained. In FIG. 1, when the vehicle A sways due to uneven ground or over a protrusion, the gyroscope 12 indicates the pitch angular velocity, the accelerometer 11 indicates the vertical acceleration of the vehicle body, the synchro resolver 29 indicates the suspension arm displacement, and the pressure sensor 60 indicates the cylinder It detects pressure, etc. and sends each sensor signal to the controller 13. Although not driving over a protrusion, depressing the brake pedal or rotating the steering wheel causes a change in the vehicle body posture, so signals from these sensors 85 and 84 are also input to the controller 13. In the controller 13, each signal is calculated as a weight function, and is used as a solenoid switching signal for the control valve 62 for supplying and discharging oil to the actig suspension hydraulic cylinder unit E, and a high/low damping switching solenoid valve 68 for the damping valve unit D. It is converted into a switching signal such as, and used as a drive signal to drive various solenoids. Here, controller 1
The solenoid drive signal No. 3 is set in advance to perform servo control according to the set vehicle body attitude angle and angular velocity.

Therefore, for example, when the vehicle pitch angular velocity exceeds a certain set value, the damping valve unit D is switched from the low damping valve 73 to the high damping valve 74, and works to reduce the vehicle pitch angular velocity, that is, to suppress shaking. That's true. Also, in response to signals from the gyroscope 12, synchro resolver 29, pressure sensor 60, and others, the control valve 62 is opened to supply oil (or extract oil) to each hydraulic cylinder unit E located at the front and rear of the vehicle.
By controlling the positions of the suspension arm 15 and the wheels 7, the vehicle body vibration is controlled to be stabilized. In addition, the operation panel 13b is controlled by the driver's judgment regardless of the disturbance from the ground.
By operating the switch, it is possible to raise and lower the vehicle body posture (including forward raising and forward lowering), etc. using the same mechanism. Figure 4, Figure 5
The in-arm suspension unit shown in Figure 1 constitutes an oil-sealed independent hydraulic suspension, so there is no need to take oil in or out from the outside. Damping valves, orifices, etc. that control vehicle body vibration are
It is a built-in type as shown at 54 and 55 in the figure.

FIGS. 7 and 8 show other embodiments of the present invention,
1 is the vehicle body, 6 is the track, and J is the power room (stores the engine, transmission, etc.).A turret 86 is installed above the center of the vehicle body 1, and a basket 88 for accommodating a crew member 87 is located below the turret 86. has been done. The construction of the suspension system is the same as in the previous embodiment. In the case of a special vehicle with a vehicle weight of several tens of tons, on which the present invention is implemented, the static load per leg (
The supporting load) reaches 3 to 5 tons. If we consider suspending such a load using hydraulic pressure, and then pumping oil in and out of each hydraulic cylinder in almost real time to suppress sudden vehicle body movements, suppose the vehicle weighs approximately 50 tons and Taking an example in which the height is approximately 20 cm and is crossed at medium vehicle speed, the required power to control it will reach well over 3000 ps, and it is not feasible in terms of the engine capacity that can be mounted on a special vehicle and the capacity of the hydraulic equipment. Poor.

Unlike four-wheeled vehicles such as passenger cars, multi-legged (tracked) vehicles have a very high resistance to rolling motion (roll stiffness), and the tread widths of the left and right tracks are relatively large, which affects ride comfort. Not much of a problem. Vehicle pitching motion governs shooting accuracy and riding comfort during driving, which is important for special vehicles. Naturally, when a vehicle pitches, it oscillates around the center of gravity of the sprung mass in the center of the vehicle, so the shaking (displacement) is greater at the front and rear ends of the vehicle body and the legs farther from the center of gravity. In other words, the piston stroke of the suspended hydraulic cylinder increases, and the amount of oil flowing in and out increases.

According to the present invention, an active suspension unit that attempts to control the vehicle body by controlling the amount of oil in and out is installed in the areas where a large amount of oil enters and exits during pitching of the vehicle, that is, in the front and rear ends of the vehicle that are far from the center of gravity of the vehicle. By placing an in-arm suspension unit for active control and light loads in the center of the vehicle body, where it does not shake much, it is possible to rationally share the vehicle body control function and vehicle weight support function, resulting in efficient control. Furthermore, a suspension system that requires less control horsepower can be realized. Furthermore, as an advantage of combining the active suspension units at the front and rear of the vehicle body with the in-arm suspension units at the center of the vehicle body, as shown in FIG.
, and the basket 88 is placed in the center of the vehicle body as shown in FIG. 7, with active suspension as shown in FIG. 2, the suspension casing 16 protrudes into the interior, making it difficult to place the basket 88. (By the way, in-arm suspension does not have anything protruding on the indoor side as shown in Figure 4) Also, when comparing the device weight and price of active suspension and in-arm suspension, in-arm suspension has a lower
Because it is light and inexpensive, the present invention in which a plurality of in-arm suspension legs are arranged in the center of the vehicle body has the advantage of reducing vehicle weight and cost compared to a case where all suspension units are active suspensions.

[0015]

[Effects of the Invention] The suspension system for a tracked vehicle according to the present invention has the following features:
In a tracked vehicle that has a hydraulic suspension system such as a trailing arm or a leading arm with multiple legs, an in-arm suspension unit containing a hydraulic cylinder, an accumulator, a damping valve, etc. is placed in the center of the vehicle, and An active suspension unit with built-in hydraulic cylinders, accumulators, variable damping valves, hydraulic piping, etc. is placed at the rear, and sensors such as gyroscopes, accelerometers, position detectors, hydraulic pumps, control valves, etc. are placed at predetermined positions on the vehicle body. Hydraulic equipment is installed, and pressure oil is supplied and discharged to each of the active suspension units independently according to signals from the sensors according to the vibration of the vehicle body, thereby reducing vibration of the vehicle body. It has the following effects.

[0016] Various sensors accurately detect the degree of shaking of the vehicle body, and the controller and control valves are operated in real time to supply and withdraw oil to and from each hydraulic cylinder, and to switch between high and low damping force of each damping valve. Each is controlled independently to suppress random body vibrations. In addition, depending on the vehicle body vibration,
The hydraulic cylinders of the active suspension units installed at the front and rear of the vehicle are independently pumped in and out of oil, and the damping valves are switched between high and low to reduce vehicle pitching and rolling angular velocity, as well as vehicle vertical acceleration. be able to. Since an in-arm suspension unit is used as the suspension system in the center of the vehicle, it is lighter in weight and cheaper than when all suspension units are active.
Furthermore, it becomes easier to install the passenger basket in the center of the vehicle body.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of a suspension system for a tracked vehicle according to the present invention.

FIG. 2 is a sectional view taken along the Z-Z line in FIG. 1 and a front view of the active suspension unit.

FIG. 3 is a sectional view taken along line XX in FIG. 2;

FIG. 4 is a YY cross-sectional view of FIG. 1 and a front view of the in-arm suspension unit.

FIG. 5 is a cross-sectional side view of the arm of FIG. 4;

6 is a partial diagram of the hydraulic and electrical circuits of the device shown in FIG. 1; FIG.

FIG. 7 is a schematic side view of another embodiment of the invention.

8 is a sectional view taken along the line WW in FIG. 7. FIG.

[Explanation of symbols]

B Active suspension unit C In-arm suspension unit 1 Vehicle body 6 Crawler track 10 Hydraulic pump 11 Accelerometer 12 Gyroscope 13 Controller 14 Valve block

Claims (1)

[Claims] Claim 1: In a tracked vehicle having a hydraulic suspension system such as a plurality of trailing arms and leading arms, an in-arm suspension unit containing a hydraulic cylinder, an accumulator, a damping valve, etc. is arranged in the center of the vehicle. , active suspension units with built-in hydraulic cylinders, accumulators, variable damping valves, hydraulic piping, etc. are placed at the front and rear of the vehicle, and sensors such as gyroscopes, accelerometers, position detectors, etc. and hydraulic pressure are placed at predetermined positions on the vehicle body. Hydraulic equipment such as pumps and control valves are installed, and pressure oil is supplied and discharged to each of the active suspension units independently according to signals from the sensors in response to vehicle body vibration, thereby reducing vehicle body vibration. A suspension system for a tracked vehicle characterized by comprising: