JP3360692B2 - Cab attitude control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the attitude of a cab in a cab-suspended vehicle in which the cab is supported on a vehicle frame by a hydraulic actuator.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cabin posture control device for obtaining a smooth tilt and lock operation of a cabin.

[0002]

2. Description of the Related Art The present applicant has provided a vehicle height sensor for each of a vehicle frame suspension mechanism and a cap suspension mechanism, and has determined the relative displacement of the vehicle frame with respect to each wheel and the relative displacement of the cap with respect to the vehicle frame obtained from each vehicle height sensor. Accordingly, a cap suspension mechanism has been proposed in which the vibration of the cap is suppressed by driving the cap suspension mechanism to improve the ride comfort. According to the above-described cap suspension mechanism,
Since the height of the cab is always kept substantially constant while traveling on a flat road, the vertical vibration of the driver's seat is particularly suppressed, and the visibility is improved.

[0003] However, in the above-described attitude control apparatus for a cab, when the cab is tilted for reasons such as inspection, the following problems occur unless the cab is parked on a horizontal road. If the parked road is inclined left or right or back and forth, or if one of the wheels is running on a step such as the shoulder of the road, the hydraulic actuator that supports the front, rear, left and right parts of the cab by the operation of the attitude control device Since the displacement amount (movement amount) is different, a movement occurs between the engagement portion of the cab and the pedestal of the vehicle frame, and when the cab is returned after the work is completed, the cab may not be locked on the vehicle frame.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to make the cabinet parallel to the vehicle frame even when the vehicle frame is inclined, that is, by making the displacement of each hydraulic actuator equal to each other. It is an object of the present invention to provide a cabin attitude control device which enables smooth locking of the head.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention comprises a hydraulic actuator connected between a vehicle frame and each of the front, rear, left and right supports of the cabinet, and each wheel support of the vehicle frame and the cabinet. A vehicle height sensor disposed on each of the support portions; and a relative displacement amount calculating means for calculating the roll, pitch, and vertical displacement amounts of the cab from the change in the vehicle height of the cab for each wheel detected by each of the vehicle height sensors. Control amount calculating means for obtaining a control force for suppressing each displacement of the cab from each displacement amount of the cab, and oil amount control for individually adjusting the oil amount of each of the hydraulic actuators in accordance with the control force for suppressing each displacement of the cab. When the lock of the valve and the cab is released, the oil amount of each of the hydraulic actuators is made equal, and the cab is maintained parallel to the vehicle frame.

[0006]

[Function] When tilting the cab, the signal of the vehicle height sensor that detects the displacement of the suspension spring of each wheel is ignored, and the hydraulic pressure of the hydraulic actuator that supports the front, rear, left, and right parts of the cab is forcibly applied to the standard vehicle. Set the value when high. It is activated when the lock of the cab is released for the inspection work. For example, the alarm is used as a cab lock sensor, and the cab is set to the standard vehicle height at the same time as the cab lock is released based on the signal of the cab lock sensor.

Since the displacement of each hydraulic actuator becomes equal and the cab is held in parallel with the vehicle frame, if the cab is tilted in this state, when the cab is returned to the normal position, the engagement of the cab will occur. The part smoothly engages with the pedestal of the vehicle frame, and a manual locking operation becomes possible.

[0008]

FIG. 1 is a hydraulic circuit diagram of a cabinet attitude control apparatus according to the present invention. Hydraulic pump 4 driven by engine
Sucks oil from the oil tank 2 and supplies the oil from the pipe 5 to the pressure accumulator 8 of the pipe 7 via the check valve 6. Oil pressure monitoring means A is provided to keep the oil pressure to the pipe 7 at a predetermined value. That is, tube 5
When the detection value of the oil pressure sensor 9 that detects the oil pressure of the oil tank exceeds a predetermined value, the oil pressure control valve 12 is switched, and a part of the oil pressure of the pipe 5 passes through the pipe 10, the oil pressure control valve 12, the pipe 13, and the filter 27. It is returned to the oil tank 2. When the oil pressure at the discharge port of the hydraulic pump 4 becomes abnormally high, a part of the pressure oil in the pipe 5 is returned to the oil tank 2 via the known relief valve 26, the pipe 13, and the filter 27.

The pressure oil in the pipe 7 is supplied to hydraulic actuators 19 for supporting the front, rear, left and right portions of the cabinet 3 on the vehicle frame 25, respectively. The hydraulic actuator 19 has a piston 22 fitted in a cylinder 23, and a rod 24 projecting upward from the piston 22 is connected to the cabinet 3 by a ball joint or the like, while the cylinder 23 is connected to a vehicle frame 25 by a spherical bearing or the like. Cylinder 23 partitioned by piston 22
The upper end chamber and the lower end chamber are communicated by a throttle passage provided in the piston 22.

The vehicle frame 25 supports an axle or suspension member 30 for supporting the wheels 20 by a known hydraulic shock absorber 29.
The hydraulic shock absorber 29 is formed by inserting a piston into a cylinder,
A cylinder is connected to the suspension member 30, and a rod projecting upward from the piston is connected to the vehicle frame 25. The coil spring 21 is interposed between the cylinder and the vehicle frame 25. Instead of the coil spring 21, the suspension member 30 may be supported on the vehicle frame 25 by a known leaf spring. A vehicle height sensor 28 for detecting a relative vertical displacement between the cap 3 and the vehicle frame 25;
A vehicle height sensor 31 for detecting a relative vertical displacement between the vehicle and the suspension member 30 is provided.

The pressure oil in the pipe 7 is supplied to a check valve 14, an oil amount control valve 1 comprising a general neutral position closed type electromagnetic proportional pressure control valve.
6. The air is supplied to the pressure accumulator or the air spring 18 through the throttle 18a, and further supplied to the lower end chamber of the cylinder 23 of the hydraulic actuator 19. The oil pressure supplied to the lower end chamber of the cylinder 23 is detected by the oil pressure sensor 17. When the oil amount control valve 16 is switched, the oil in the lower end chamber of the cylinder 23 is returned to the oil tank 2 via the oil amount control valve 16, the check valve 15, the pipe 13, and the filter 27.

The front and rear, left and right hydraulic actuators 19 of the cab 3 are independently provided with check valves 14 and 15 and an oil amount control valve 1 respectively.
6, a throttle 18a, an air spring 18, a hydraulic sensor 17, and a vehicle height sensor 28. Although not shown, a vehicle height sensor 31 is also provided in each of the front, rear, left, and right frame suspension mechanisms.

Each oil quantity control valve 16 controls the hydraulic pressure of each hydraulic actuator 19 in a feedback manner in accordance with a control voltage from an electronic control unit comprising a microcomputer. When the front, rear, left and right hydraulic actuators 19 are specified, subscripts of FL, FR, RL, and RR are added.

Now, the relative vehicle height of the vehicle frame 25 with respect to each wheel 20 is hFL to hRR, and the vehicle frames 25 of the front, rear, left and right portions of the cabinet 3 are provided.
Assuming that the relative vehicle height to hcFL to hcRR is
Vertical displacement xFL ~ xRR, vertical displacement xcFL of Cab 3
~ XcRR is represented by the following equation (1).

.Times..times..times..times..times..times..times..times..times..times. 1) However, hFL0 to hRR0: standard vehicle height of each wheel support of the vehicle frame hcFL0 to hcRR0: standard vehicle height of front, rear, left and right portions of the cab Relative roll displacement Δφ, pitch displacement Δθ, relative to wheel of vehicle frame 25, vertical Displacement Δx, car frame 25 of cab 3
Roll displacement Δφc, pitch displacement Δ
θc and the vertical displacement Δxc are expressed by the following equation (2).

Δφ = kφ1 (xFL−xFR) + kφ2 (xRL−xRR) Δθ = kθ1 (xFL + xFR) −kθ2 (xRL + xRR) Δx = kx1 (xFL + xFR) + kx2 (xRL + xRR) Δφc = kc φ1 (xcFL−xcFR) + kφ xcRL-xcRR) [Delta] [theta] c = kc [theta] 1 (xcFL + xcFR) -kc [theta] 2 (xcRL + xcRR) [Delta] xc = kcx1 (xcFL + xcFR) + kcx2 (xcRL + xcRR) ... [1], k1; Determined constants kφ2, kθ2, kx2: Constants determined by vehicle specifications kc φ1, kcθ1, kcx1: Constants determined by vehicle specifications kcφ2, kcθ2, kcx2: Constants determined by vehicle specifications Roadside input of vehicle frame 25 Assuming that the roll displacement is φ1, the pitch displacement is θ1, and the vertical displacement is x1, the roll displacement φ2, pitch displacement θ2, vertical displacement x2 of the cab 3 is given.
Can be expressed by the following equation (3).

Φ2 = φ1 + Δφ + Δφc θ2 = θ1 + Δθ + Δθcx2 = x1 + Δx + Δxc (3) Therefore, in order to keep the cab 3 flat (parallel to the road surface), the roll control force to be applied to the cab 3 by each hydraulic actuator 19- F12, pitch control force-F22, and vertical control force-F32 can be expressed by the following equation (4).

−F12 = −k1 [φ] −k2d [φ] dt−k7Σ [φ] dt−F22 = −k3 [θ] −k4d [θ] dt−k8− [θ] dt−F32 = −k5 [x] −k6 d [x] dt−k9 Σ [x] dt (4) where [φ] = Δφ + Δφc [θ] = Δθ + Δθc [x] = Δx + Δxc k1 to k9: constant Σ: integrated for convenience Symbol (▲ ◆ ▼).

As shown in FIG. 2, according to the present invention, the vehicle height sensor 31 detects the vehicle heights hFL to hRR of the vehicle frame 25 based on the above-described principle.
From the vehicle height sensor 28, the vehicle height hcFL to hcR of the cab 3.
R are respectively detected, and the vehicle heights hFL to hRR of the vehicle frame 25 and the vehicle heights hcFL to hcR of the cab 3 are calculated by the relative displacement amount calculating means 35.
R, the vehicle height change amounts xFL to xRR of the vehicle frame 25 and the vehicle height change amounts xcFL to xcRR of the cap 3 are obtained. Further, the relative roll displacement Δφ, pitch displacement Δθ, vertical displacement of the vehicle frame 25 with respect to each wheel. The amount Δx and the cabinet 3 for the vehicle frame 25
Relative roll displacement Δφc, pitch displacement Δθc,
The vertical displacement amount Δxc is obtained.

Next, the relative roll displacement Δφ, pitch displacement Δθ, vertical displacement Δx of the vehicle frame 25 with respect to each wheel, the relative roll displacement Δφc of the cab 3 with respect to the vehicle frame 25, and the pitch by the control amount calculating means 37. Displacement Δθc
From the vertical displacement .DELTA.xc, the roll control force F12, pitch control force F22, and vertical control force F32 of the cab 3 are obtained.

From the above results, control voltages VcFL to VcRR of each oil amount control valve 16 represented by the following equation (5) are obtained.

VcFL = -KV1 F12-KV2 F22 + KV5 F32 VcFR = + KV1 F12-KV2 F22 + KV5 F32 VcRL = -KV3 F12 + KV4 F22 + KV6 F32 VcV2 + KV6F32 VcV = + KV3F12 VcRR = + KV3V12 + KV3F12 + KV3V12 + KV3V12 + KV3F12 + KV3V12 + KV3V12 + KV3F12 + KV3F12 + KV3V12 + KV3F32 + cV5V32 + cV3V32 + cV3. By driving each oil amount control valve 16 and controlling the hydraulic actuator 19 by using the feedback signal voltages FsFL to FsRR of the hydraulic pressure sensor 17, the attitude of the cab 3 can be maintained substantially flat (parallel to the road surface). .

Further, in order to obtain a smooth lock after the tilt operation of the cap 3, a lock mechanism 41 for locking the cap 3 to the vehicle frame 25 is provided with a cap sensor 41. Specifically, it is preferable to use a switch of an alarm that sounds when the lock mechanism is released as the lock sensor 41. Based on the signal from the captive sensor 41, the vehicle height change amounts xFL to xRR of the vehicle frame 25 for each wheel 20 to be applied to the relative displacement amount calculating means 35 are set to 0, and the cabinet 3 is supported in parallel to the vehicle frame 25.

FIGS. 3 to 5 are flow charts of a control program for performing the above-mentioned control by an electronic control unit composed of a microcomputer. This control program is repeatedly executed at predetermined time intervals. p11-p23, p41-p46, p61-p67
Represents each step of the control program. The control program is started at p11, initialization is performed at p12, and the process proceeds to the hydraulic pressure monitoring routine shown in FIG. 4 at p13, where the hydraulic control valve 12 is driven.
The output oil pressure pm is maintained at a predetermined value pc.

At p14, the vehicle height hFL-hRR of the vehicle frame 25 is obtained from the vehicle height sensor 31 and the vehicle height hcF of the cab 3 is obtained from the vehicle height sensor 28.
L to hcRR are read from the hydraulic pressure sensor 17 as the hydraulic pressures pFL to pRR of the hydraulic actuator 19, respectively. At p15, the vehicle height change amount xFL of the vehicle frame 25 from the vehicle height hFL ~ hRR of the vehicle frame 25
xRR is calculated from the vehicle heights hcFL to hcRR of the cab 3, respectively.

At p16, it is determined whether or not the lock of the cab 3 has been released. When the lock of the cab 3 has been released, the relative displacements .DELTA..phi., .DELTA..theta., .DELTA.x of the vehicle frame 25 are electrically set to 0 at p17, and the program proceeds to p19. If the lock of the cab 3 has not been released, the vehicle height change amount xFL of the vehicle frame 25 is determined at p18.
From xRR, the relative displacement of the vehicle frame 25, that is, the roll displacement Δφ, the pitch displacement Δθ, and the vertical displacement Δx are obtained. p
19: Cab 3 from the height change xcFL ~ xcRR of Cab 3
, Ie, roll displacement Δφc, pitch displacement Δθc, and vertical displacement Δxc.

At p20, the control amount of the cab 3, that is, the roll displacement φφ, the pitch displacement θθ, the vertical displacement Δx, the pitch displacement φφc, the pitch displacement θθc, The control force F12, pitch control force F22, and vertical control force F32 are determined. The oil amount control valve 16 corresponding to the control amounts F12, F22, and F32 of the cap 3 at p21.
Of the control voltages VcFL to VcRR are obtained. At p22, the process proceeds to the hydraulic actuator driving routine shown in FIG. 6, in which the oil amount of each hydraulic actuator 19 is adjusted by each oil amount control valve 16,
It ends at p23.

As shown in FIG. 4, the hydraulic pressure monitoring routine is p
It starts at 41, and at p42 the hydraulic pump 4
The output oil pressure pm is read, and it is determined at p43 whether the output oil pressure pm is larger than the predetermined value pc. If the output oil pressure pm is smaller than the predetermined value pc, the hydraulic control valve 12 is closed at p44 and the program proceeds to p46. If the output hydraulic pressure pm is larger than the predetermined value pc, the hydraulic pressure control valve 12 is opened at p45 to open the output hydraulic pressure pm.
Is lowered to a predetermined value pc, and the program returns to the program at p46.

As shown in FIG. 5, the hydraulic actuator drive routine starts at p61, reads the hydraulic pressures pFL-pRR of each hydraulic actuator 19 from each hydraulic pressure sensor 17 at p62, and converts the hydraulic pressures pFL-pRR to voltages VsFL-VsRR at p63. Convert to At p64, the above-described control voltages VcFL to VcRR and voltage VsF
From L to VsRR, the excitation voltages VeFL to V of each oil amount control valve 16 are obtained.
Find eRR. Exciting each oil amount control valve 16 at p65 and supplying or discharging the oil amount QFL to or from each hydraulic actuator 19
~ QRR is adjusted, and each hydraulic actuator 19
Is driven, and the program returns to p67 in p67.

As shown in FIG. 6, the amount of oil QFL to QRR to each hydraulic actuator 19 is adjusted by the excitation voltage VeFL to VeRR of each oil amount control valve 16.

[0031]

According to the present invention, the posture of the cab is kept almost flat and the riding comfort is improved. On the other hand, when the cab is tilted, the cab is parallel to the vehicle frame even if the cab is parked on a slope. As described above, that is, since the oil amounts of the respective hydraulic actuators become equal to each other, it is possible to avoid a situation in which the cap cannot be locked.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a cabinet attitude control device according to the present invention.

FIG. 2 is a block diagram of the attitude control device.

FIG. 3 is a flowchart of a control program of the attitude control device.

FIG. 4 is a flowchart of a control program of the attitude control device.

FIG. 5 is a flowchart of a control program of the attitude control device.

FIG. 6 is a diagram illustrating a relationship between an excitation voltage of an oil amount control valve and an oil amount.

[Explanation of symbols]

3: Cab 16: Oil amount control valve 19: Hydraulic actuator 20: Wheel 25: Vehicle frame 28, 31: Vehicle height sensor 35: Relative displacement amount calculating means 37: Control amount calculating means 41: Cab block sensor

────────────────────────────────────────────────── ─── Continuation of the front page (72) Katsuya Toyofuku, Inhouse Isatsu Central Research Institute Co., Ltd. 8 Tsurana, Fujisawa, Kanagawa Prefecture (56) References JP-A-2-197471 (JP, A) 158481 (JP, U) JP-A-3-118808 (JP, U) JP-A-3-98189 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62D 24/02 B60G 17 / 015 B62D 33/07

Claims (1)

(57) [Claims] 1. A hydraulic actuator connected between a vehicle frame and each of front, rear, left and right support portions of a cab, a vehicle height sensor disposed on each wheel support portion of the vehicle frame and each support portion of the cab, and each of the vehicle heights Relative displacement calculation means for calculating the roll, pitch, and vertical displacements of the cab from the height change of the cab for each wheel detected by the sensor, and control force for suppressing each displacement of the cab from each displacement of the cab. Control amount calculating means,
An oil amount control valve for individually adjusting the oil amount of each hydraulic actuator in accordance with the control force for suppressing each displacement of the cab, and equalizing the oil amount of each hydraulic actuator when the lock of the cab is released. A cabin attitude control device characterized by being maintained parallel to the other.