JPS60222374A - Steering device - Google Patents

Abstract

PURPOSE:To make the operating direction of a steering wheel coincident with the running direction of a vehicle on running, irrespective of the direction of the steering wheel, by providing hydraulic steering units respectively for front and rear wheels so that the wheels are steered by means of the hydraulic steering units. CONSTITUTION:In such a condition that no operating signal is delivered to either one of electromagnetic control sections SOL1-4, there is set a front wheel steering operation in which the control direction of a steering wheel SH coincides with the steering direction of front wheels F1, F1', and when the operating signal is delivered to the electromagnetic control section SOL2, there is set a clamp steering operation in which front wheels F1, F1' and rear wheels R1, R1' are steered in opposite directions in proportion to the control amount of the steering wheel SH. Further, when the operating signal is delivered to the electromagnetic control section SOL4, there is set a clamp steering operation in which the front wheels F1, F1' and rear wheels R1, R1' are steered in the same direction in proportion to the control amount of the steering wheel SH. In addition the steering or the rear wheels and rear clamp steering operation may be also made.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steering device that is equipped with a steering wheel and that is operated by its hydraulic steering.

This type of steering device is used in vehicles that require various steering functions, such as construction vehicles that travel on rough terrain. Conventional technologies of this type include Japanese Patent Publication No. 44-18491 or Japanese Patent Publication No. 413gj 1977.
There is something disclosed in No. 1. These technologies are:
It has two steering functions. That is, in FIG. 1, there is a front wheel steering mode in which the rear wheels R7, R, / shown in (a) are fixed in the straight-ahead direction and only the front wheels F1, Fll are steered, and the front wheels F1, F shown in (a) are steered. , / is coupled with the steering of the rear wheels R,,R,' in the opposite direction to reduce the turning radius of the vehicle body. The three steering functions are club steering, which makes the steering directions of the front wheels F1 and Fll the same as shown in RI'O 1tlQ (C), and causes the vehicle to run diagonally forward or backward parallel to its original position. .

For example, the steering device in Japanese Patent Publication No. 44-18491 has the configuration shown in Figure 2.
Two steerings are possible. That is, in FIG. 2, the front wheel steering F is □ hydraulic cylinders F6, l that steer the front wheels F, , F, / which are swingably provided on the vehicle body with pins.
It is equipped with li+67, and this hydraulic cylinder F6, F,
The pressure chambers F6-1 and R6-2/ are connected, the pressure chambers F6-2 and R6-1/ are connected, and the pressure/blade chamber F6-1. When pressure oil is supplied to F6-2', the front wheels F, , F, / are steered to the right, and the pressure chamber F6-
2. When pressure oil is supplied to R6-1', the front wheels F1, F
, / are designed to be steered to the left. The rear wheel steering R also includes hydraulic cylinders R6 and R6t similar to the front wheel steering F, and its pressure chambers R6-1 and R6-2
′ is connected to the foot, pressure chamber R6-2, and stream. -1' is connected. When pressure oil is supplied to the pressure chambers R6-2 and R6-11, the rear wheels R3 and R11 are steered to the right, and when pressure oil is supplied to the pressure chambers R6-1 and R6-2', the rear wheels R3 and R11 are steered to the right. Wheel R1 and horse' are steered to the left. The wheels in Figure 2 are shown as a plan view with the upper part of the figure facing forward, and the switching valve V
When it is in the state shown in the figure, the hydraulic cylinders R, :R, / of the rear wheel steering R are fixed, and the two pressure chambers F6-1 of the hydraulic cylinders F6 and F6' of the front wheel steering F are fixed.
, R6-2/output capo of steering valve S■)
SR, and the pressure chambers F6-1/'F6-2 are connected to the output port SL of the steering valve S■. When the steering wheel/L/WH is operated in the right (Ro) direction, the steering valve S■ discharges pressurized oil to the output port (SR) and sucks it in from the output port SL. Further, when the steering wheels W and H are operated in the left (Lo) direction, hydraulic pressure is discharged to the output port SL and sucked from the output port SR. Therefore, when the switching valve (■) is in the position shown in Fig. 2, when the steering wheel (lzWH) is operated in the right or left direction, the front wheels F1, F, ' will move in the same direction as the operating direction of the steering wheel (lzWH). The front wheels are steered in the direction.

When the switching valve V is operated to the position shown in Fig. 3, the output capo (SL) of the steering valve Sv is transferred to the pressure chambers R6-1 and R6-2 of the hydraulic cylinders R6 and R6' of the rear wheel steering R.
', and the output port SR is connected to the pressure chambers F6-1 and R6-2 of the hydraulic cylinders F6 and R61 of the front wheel steering F.
Pressure chamber F6- of hydraulic cylinder F6, F6/
2. R6-1' and pressure chamber E of hydraulic cylinder R6, R, /
6-1 and R6-2' are connected. Therefore, if you operate the steering wheel/I/W H to the right, the front wheel
,,F,' are steered to the right, and the pressure oil discharged from the hydraulic cylinders F6 and F6' of the front wheel steering F is transferred to the pressure chamber of the hydraulic cylinders R6 and R6' of the rear wheel steering R: R6.
-1, R6-2', so the rear wheels R1, R, t
is steered to the left, and when the steering wheel WH is steered to the left, the front wheels and rear wheels I''ii are steered in the aforementioned direction, which is a clamp steering state.

When steering the club, use the clamp steering state (
After switching the switching valve V to the state shown in Fig. 3), the rear wheels R,
, :R,' in an arbitrary steering direction, and then, in that state, switch the switching valve V to the front wheel steering state (the state shown in FIG. 2) to steer only the front wheels.

In addition, the one of Special Publication No. 18491, 1973 and the one of Special Publication No. 18491 of Special Publication No. 18491.
The difference from that of No.-41391 is that the club steering operation is simplified due to the difference in the structure of the switching valve (2) in the former mentioned above. That is, in the former club steering operation, it is necessary to switch the switching valve ■ to the clamp steering state and operate the steering wheel, and then switch the switching valve ■ to the front wheel steering state. When changing the steering direction, the above-mentioned valve switching operation is always required. In this respect, in the latter case, the valve corresponding to the switching valve V is a 4-point, 3-position switching valve, and each switching position of this switching valve controls front wheel steering,
Each steering state of clamp steering and club steering can be obtained.

By the way, the lane car that runs on rough terrain is
As shown in No. 1391, a crane unit consisting of a driver's seat with a steering link wheel, a boom for a crane, etc. is rotatably provided on the traveling vehicle body.

In conventional steering devices, the relationship between the steering wheel operation direction and the wheels is such that when the crane unit is facing forward, each of the steering directions of front wheel steering, clamp steering, and club steering is the steering wheel operation direction. It corresponds to the direction.

Therefore, the conventional device has the following problems. In other words, if the direction of the crane unit does not match the forward direction of the vehicle body, especially when the crane unit is trying to travel with the crane unit turned 180 degrees, the direction of the vehicle body will not match the direction in which the steering wheel is operated. The direction of travel is reversed.

Therefore, there is a drawback that the driver is likely to make a mistake in steering operation.

The present invention is directed to a steering device in which front wheels and rear wheels are each equipped with hydraulic steering, so that the running direction of the vehicle body can be made to match the direction in which the steering wheel is operated, regardless of the direction of the steering wheel. This is an issue to be addressed.

The technical means of the present invention to achieve this technical problem is provided with two output ports that are linked to the steering wheel and discharge or inhale pressurized oil in opposite directions depending on the direction and amount of operation of the steering wheel. The steering valve includes a front wheel steering and a rear wheel steering which are steered by a hydraulic cylinder, and the output capo-1 of the steering link valve is connected to the front wheel steering and the rear wheel steering through a switching valve. In the steering device connected to a hydraulic cylinder, the switching valve includes a first switching valve section provided between the front wheel steering hydraulic cylinder and one output port of the steering valve, and a first switching valve section provided between the front wheel steering hydraulic cylinder and one output port of the steering valve; It consists of a second switching valve part provided between the cylinder and the other output capo 1- of the steering valve, and the first switching valve part and the second switching valve part are connected to the front wheel steering and the rear wheel steering valve. two sets of switching positions for switching the connection between one output port and the other output port of the steering valve and connecting the discharge side of the hydraulic cylinder to each of the hydraulic cylinders of the steering;
The two output capos 1- of the steering link valve are both switched and connected to the front wheel steering hydraulic cylinder and the rear wheel steering hydraulic cylinder, and the remaining front wheel steering hydraulic cylinder or the rear wheel that is connected thereto. It is characterized in that it is provided with two other sets of switching positions for closing the hydraulic cylinder of the steering wheel.

The present invention provides Q, by operating one of the two sets of switching positions of the eleventh second switching valve part.
The front wheels and rear wheels are steered in opposite directions by operating the steering wheel, and by operating the steering wheel in the other switching position, the connection of the steering link valve is reversed and the steering link is (9) If the wheel operation is the same as above, the same direction is the opposite of the above, so the steering wheel operation direction and the vehicle running direction can be made to match regardless of the direction of the steering wheel and the vehicle body. It is.

In addition, by operating the first and second switching sections to one of the other two switching positions, it is possible to operate only the front wheels or the rear wheels using the steering wheel. By operating the steering valve to the other switching position, the connection of the steering valve will be reversed to that described above, so in this case as well, the operating direction of the steering wheel and the traveling vehicle body will be the same, regardless of the direction of the steering wheel and the traveling vehicle body. It is possible to match the directions.

Since the present invention has the above configuration, it has the following unique effects.

Another technical means for solving the technical problems of the present invention is disclosed in Japanese Utility Model Publication No. 52-27476 shown in FIG. Another technical measure shown in FIG. 4 is that the hydraulic cylinder 6.6 of the front steering wheel 1 is connected to the steering valve 8 via a switching valve (1), and the hydraulic cylinder (10) of the rear steering wheel 2 is connected to the steering valve 8 (10). .7 is connected to the hydraulic power source P and tank T via switching valves ■2 and ■3. The switching valve V1 is in the switching position ■II,
■+2, and when the switching valve ■ is in the switching position ■I+, the operating direction of the steering wheel and the steering direction of the front wheels match, and the switching valve V1 is operated to the switching position v1°. Then, the operating direction of the steering link wheel and the steering direction of the front wheels are reversed. iJ switching valve VV
are provided with switching positions ■2o12)3 v28, v2□ and v80''P+, ■32, respectively.The switching valve V3 is operated by the hydraulic pressure of the hydraulic cylinder 6.6.The switching valve V2 is a switching valve. Like v1, it is operated arbitrarily, and when the switching valve v2 is in the neutral position v2o, the steering direction of the rear wheels 2.2 is fixed.

In this configuration, the directional control valve v2 is in the neutral position,
When the switching valve ■1 is in the switching position ■I+, the rear wheel 2.2
Since the steering direction of the front wheels is fixed, the steering direction of the front wheels, F, / is determined in the direction steered by the steering wheel, and the vehicle body runs on the front wheels in the direction in which the front wheels are steered. When the switching valve V2 is switched to the switching position v2,
The switching valve ■3 is switched by the discharge hydraulic pressure of the steering valve 8 (11), and the front wheels F1,
The steering directions of F, / and rear wheels, R, / are the same, resulting in so-called club steering in which the vehicle body runs diagonally.

When the switching valve ■2 is switched to the switching device v22, the steering direction of the front and rear wheels is reversed, and clamp steering can be performed.When the switching valve V1 is operated to the switching position Mv12, The direction in which the front wheels are steered is opposite to the direction in which the steering wheel is operated. Therefore, the clamp steering is also reversed. That is, even if the direction of the traveling vehicle body and the direction of the crane unit are reversed, the vehicle can still travel in the direction in which the steering wheel is operated.

The other technical means mentioned above is to select the steering direction of the front wheels and the operating direction of the steering link wheel depending on the relationship between the direction of the traveling vehicle body and the crane unit. This is to match the direction. Therefore, the running direction of the vehicle body is determined centering on the rear wheels, so when the vehicle body travels in the direction of the rear wheels, the front wheels behind the vehicle are viewed from the operator with the rear wheels as the center (12). This has the drawback that the steering sensation is different from when the vehicle is driven in the direction of the front wheels.Furthermore, the hydraulic cylinders of the steering devices for the front and rear wheels are not connected to the hydraulic power source. Since they are connected in parallel, if either the front or rear wheels receives a large load during clamp steering or club maneuvering, the amount of pressure oil supplied to that hydraulic cylinder will decrease, causing the steering This has disadvantages in that the amount of operation of the wheel does not match the steering angle of the wheel, and the running direction of the traveling vehicle body does not match the amount of operation of the steering link wheel.

In the present invention, since the rear wheels are connected to the steering valve regardless of the direction of travel of the vehicle, the steering valve can be operated with the same feeling regardless of the direction of travel of the vehicle. In addition, in club steering and club steering, the hydraulic cylinders of the front wheel steering and rear wheel steering are connected in series with the steering pulp, so regardless of the load acting on the wheels, the amount of wheel operation relative to the amount of steering wheel operation is tll that can match the steering direction of
) has an effect.

Embodiments of the steering device according to the present invention will be described below. In FIG. 5, F is a front wheel steering device, which includes hydraulic cylinders F6 and F61 for controlling the steering direction of the front wheels F3, F, /. R is a rear wheel steering device, which includes hydraulic cylinders R6 and R6' for controlling the steering direction of the rear wheels R, , R, /.

Hydraulic cylinders F6, F6/, R6, R6' are connected to the steering wheel /l/ via valve unit) C (switching valve).
Steering valve S vKI connected to SH continues.

The valve unit C includes a switching valve ■1 to which hydraulic cylinders F6 and F6/ are connected, a switching valve ■2 to which hydraulic cylinders R6 and R6/ are connected, and a switching valve ■3 arranged upstream of the switching valve ■1. It is equipped with In this embodiment, the first switching valve part is composed of two switching valves ■1 and v3 with a two-position switching function, and the second switching valve part is composed of one switching valve ■2 with a three-position switching function.
It is composed of

The switching valves (1), (2), and (3) are electrohydraulic pilot operated type, and are operated by a selection device provided in the cockpit of the crane unit. The switching valve ■1 and the output boat side of switching valve (14) R2 are connected through the first circuit D1. This first circuit connects the output port of the switching valve ■3 to the second circuit D2.
It is connected with.

The switching valve V has a switching position ■I+, R12 and an electromagnetic operation part SQL l, and the switching valve ■3 has two switching positions v3.
1, R32 and an electromagnetic operation part SQL 3, when no actuation signal is given to each electromagnetic actuation part SQL 1, 5OTJ3, it is held at the switching position v, 1, R31, and when an actuation signal is given, it is held in the switching position ■ 12, ■3□. The switching valve ■2 is in the neutral position v2o, switching position V21, V
2□ and an electromagnetic operating section 5OL2.5OTJ4, when an operating signal is given to the electromagnetic operating section SQL2, it switches to the switching position ■21, and when an operating signal is given to the electromagnetic operating section 5QL4, it switches to the switching position ■22. When no actuation signal is applied to any of the electromagnetic operating sections, the switching switch is held at the neutral position v2o.

Fig. 6 shows an example of a switching position selection device for switching valves 1, R2, and R3. In the figure, switch S1 is for clamp operation, and by closing it, An actuation signal is given to the electromagnetic operation section 5OTJ2, and the switch S2 is for club steering, and by closing this, an actuation signal is given to the electromagnetic operation section 5OTJ4, and the switch S3 is used for controlling the rear wheel. Switch S4 is for rear clamp operation, and by closing it, an activation signal is given to the electromagnetic operation parts SQL 3 and SQL 4. Switch S4 is for rear clamp operation, and by closing it, an activation signal is given to the electromagnetic operation parts SQL 3 and SQL 4. SQL l
An activation signal is given to 5OTJ4 and 5OTJ4. In the figure (il,
d2 is a diode.

Next, the steering mode of the running vehicle shown in Table 1 and the switching valve ■1
The operation of this steering device will be explained according to the relationship between the presence and absence of operation command signals to R2 and R3.
6) When no activation signal is given to any of the electromagnetic operation units SQL 1 to SOL 4, p1 is in the state shown in FIG.
The hydraulic cylinders R6 and R61 of the rear wheel steering R are closed by the switching valve 2 to fix the rear wheel R1 and the horse 1. The output port SR of the steering valve S■ is connected to the switching valve v1 via the switching valve ■3, and the output port (17) RL is connected to the switching valve ■ through the switching valve v2.

Switching position of switching valve ■4. Now, front wheel steering F
Hydraulic cylinders F6, F6/hydraulic chambers F6-1, R6-
21 is connected to the output port SR, and the hydraulic chamber F6. -17
, R6-2 are connected to the output port (SL). In this state, steering valve/1. The operating direction of /SH and the steering of front wheels F1 and R1 match.

b. When only the clamp steering switch S1 is closed and an activation signal is applied to the electromagnetic operating section 5OL2, the switching valve ■2 is in the switching position ■2.b, as shown in FIG. The output capo of the steering valve S■) SR is connected from the switching valve ■3 to the hydraulic chambers F6-1 and R6-2' of the hydraulic cylinders F6 and Ii+67 via the switching valve ■1, and the output Port SL is the hydraulic chamber R6-2/, R6-1 of hydraulic cylinder R6, R6'.
/ and hydraulic cylinders F6, F6', R6
, R61 hydraulic chamber F6-2', F 6-1 / and R6-
1 and R6-21 are connected through the first circuit D1. That is, the hydraulic cylinders F6, F6/ and R6, R6/ are connected in series to the steering valve Sv. Due to this connection, (18) hydraulic cylinders F16, F'6/ and R6, R6' operate in the same direction in the figure. This is useless, front wheel F, ,
F,' and rear wheel R1, horse' is steering wheel/1z
It is steered in the opposite direction in proportion to the amount of SH operation. At this time, the front wheels F, , F, / are the same as the operating direction of the steering wheel.

C. When only the club steering switch S2 is closed and an activation signal is applied to the electromagnetic operation unit 5QL4, the switching valve v2 is switched to the switching position v22 as shown in FIG. 8, and the steering link valve Output port SR of S■ is connected to hydraulic chamber F6 of hydraulic cylinders F6 and F6' via switching valve ■3 and switching valve ■1.
-1, R6-27, and the output capo-1, S L is connected to the hydraulic chambers R6-1, R6-2' of the hydraulic cylinders R6, R6/ via the switching valve v2. In addition, the hydraulic chambers F6-2 and R6-P of the hydraulic cylinders F6 and R61 and the hydraulic pressure 7
The hydraulic chambers R6-2 and R6-1' of the seven das R6 and R6/ are connected via the switching valve (2), the first circuit D1, and the switching valve (1). Compared to the clamp steering connection, this connection is the opposite in that only the rear wheel hydraulic cylinders are connected. By connecting this (19), hydraulic cylinders F6, R61 and R6, R
6' operates in the opposite direction in the figure. Therefore, the front wheels F1, F, / and the rear wheels R1, R, / are steered in the same direction in proportion to the amount of operation of the steering wheel /l/'SH.

a' Only the rear wheel steering switch S3 is closed, and the electromagnetic operation section 5QL3.5
When the activation signal is applied to OTJ4, the switching valves ■2 and ■3 are switched to the switching positions ■22 and R32, as shown in Fig. 9, and the output cap of the steering valve SV is
) SR is connected to the pressure chambers R6-2, :R6- of the hydraulic cylinders R6, R6/ via the switching valve v3, the second circuit D2, and the switching valve ■.
1' and is connected to the output capo of the steering valve S■)
SL is the pressure chamber R6-1, R of the hydraulic cylinder R6, R6/
6-2', and closes the hydraulic cylinders F6 and R6 of the front wheel steering F by the switching valve (1) and the switching valve (v2). Therefore, the rear wheel R1' is steered by the steering link valve Sv, and the steering wheel S
It is operated in the same direction as the H operation direction.

blltsu clamp steering 20) Only switch S4 is closed, and electromagnetic operation parts 5QL1, S
When the actuation signal is applied to QL4, the switching valves V7 and V2 are switched to the switching positions V, R22 as shown in Fig. 1o, and the output cap of the steering valve SV is
) SR is connected to hydraulic chambers F6-2 and R6-1' of hydraulic cylinders F6 and R61 by a switching valve v1, and output capo)
SL is connected to the hydraulic chambers of hydraulic cylinders R6 and R61, R6-1 and lR6-2' through a switching valve v2. Hydraulic cylinder F6, R61 and hydraulic chamber F6-1 of R6, R61,
R6-2/, hydraulic chamber R6-2, and horse-1' are connected via the switching valve ■2, the first circuit D1, and the switching valve ■, so that the front wheels F, , F1' and the rear wheel R , , R, / are connected in series to the steering valve Sv. Due to the above connection, the hydraulic cylinders F6, R61 and R6, R6 operate in the same direction in the figure. For this reason, the front wheels F1, F, /
and for rear wheels, R1/ means steering wheel/1zsH
is steered in the opposite direction in proportion to the amount of operation. At this time, the rear wheels R1 and R1' are in the same direction as the steering wheel /l/SH.

FIG. 11 shows the valve unit (21
) This shows a modification of C, in which the switching valve (2) of the previous embodiment is left as is, and the switching valve (2) and the switching valve (3) are combined into one switching valve (4) with a 3-position switching function. .

This valve unit) C/ switching valve ■4 has a configuration in which switching valve ■1 name: switching valve ■3 switching position ■32 and 5OTJ3 are added, and the selection device shown in FIG.
1. By giving the same activation signal to SQL 2 and SQL 3, the same steering mode as shown in Table 1 is obtained.

As can be understood from the above embodiments and variations thereof, the switching valve (first switching valve section) provided between the front wheel steering and one output port of the steering valve, and the rear wheel steering and the output of the other steering valve. Each switching valve of the switching valve (second switching valve section) provided between the port and the port serves as one or more switching valves.

[Brief explanation of drawings]

FIG. 1 is a plan view of the wheels showing various steering states with the upper side facing forward. (a) shows the front wheel steering state, (1)) shows the Franz steering state, (C) shows the club steering state, and (C) shows the front wheel steering state. Figure 2 is (2
2) A schematic plan view showing a conventional steering device together with its hydraulic circuit, FIG. 3 is a partial view showing the device in FIG. 2 in a different state, FIG. 4 is a hydraulic circuit diagram of another conventional steering device, and FIG. The figure is a hydraulic circuit diagram of an embodiment of the present invention, FIG. 6 is an electric circuit diagram showing an example of a switching position selection device for each switching valve of the same embodiment, and FIGS. 7 to 10 are respectively similar to FIG. 5. A hydraulic circuit diagram showing eight different states of the same hydraulic circuit diagram. FIG. 11 is a hydraulic circuit diagram showing a modification of the valve unit of the embodiment shown in FIG. 5. SI (...Steering wheel, Sv...Steering valve, F...Front wheel steering link, R...Rear wheel steering, R1, R2, R3...Switching valve (■,
and R3...first switching valve section, R2...second switching valve section)
, F F'...Front wheel, R8, R,/...Rear wheel,
R6, F6/ ・11 Summer...Front wheel steering link hydraulic cylinder, R6, R6'
...Hydraulic cylinder for the rear Nutepring. Patent applicant: Japan Air Brake Co., Ltd., Kobe Steel, Ltd. Representative: Satoshi Shimizu and 2 others (23) of(

Claims (1)

[Claims] (1) A steering valve equipped with three output ports that are linked to the steering wheel and discharge or inhale pressurized oil in opposite directions depending on the direction and amount of operation of the steering wheel, and a six-wheel steering wheel that is steered by a hydraulic cylinder. and a rear wheel steering link, wherein an output port of the steering valve is connected to respective hydraulic cylinders of the front wheel steering and the rear wheel steering via a switching valve, wherein the switching valve is connected to the front wheel steering a first switching valve section provided between a hydraulic cylinder for the rear wheel steering and one output port of the steering valve; a hydraulic cylinder for the rear wheel steering, the other output port for the steering wheel and the hydraulic pressure for the rear wheel steering Each of the cylinders has two switching positions for switching the connection between one output port and the other output port of the steering valve and connecting the discharge side of the hydraulic cylinder, and two sets of switching positions for connecting the two output ports of the steering valve to the front wheel. two other sets of switching positions that are switchably connected to the steering hydraulic cylinder and the rear wheel steering hydraulic cylinder and close the remaining front wheel steering hydraulic cylinder or the rear wheel steering hydraulic cylinder connected thereto; A steering device comprising: