JPH076066Y2 - Steering device for connected vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a steering device for an articulated vehicle.

(Prior Art) In a coupled vehicle such as a tractor trailer, there is a large inner ring difference between the tractor and the trailer at the time of turning, and therefore there is a driving difficulty that the tractor has to make a large turn when traveling at a predetermined turning angle. .

Therefore, it has been proposed that the rear wheels of the trailer can also be steered according to the steering angle of the tractor (JP-A-56-163968).
No. 61-60379).

(Problems to be solved by the invention) By the way, in such a steering device, the operation of the hydraulic actuator for steering the rear wheels of the trailer is controlled by a computer or the like via an electromagnetic valve. However, the structure was complicated and there was a problem in terms of cost.

(Means for Solving the Problems) In order to solve such problems, the present invention provides a connected vehicle in which a towed vehicle connected to a towed vehicle via a coupler is provided with a hydraulic actuator for steering rear wheels. In the steering device, the connecting angle detecting means for making a stroke in accordance with the intersection angle about the joint point in the coupler of the towed vehicle and the towed vehicle, and the stroke in accordance with the intersection angle of the detecting means are interlocked with each other. A control valve that controls the steering hydraulic pressure that is supplied to the actuator, and a control valve that interlocks with the rear wheel steering device of the towed vehicle and shuts off the steering hydraulic pressure when the steering angle reaches a predetermined amount. And a pump driven by wheel rotation as a hydraulic pressure generation source for supplying operating hydraulic pressure to the hydraulic actuator.

(Operation) When a bending angle (intersection angle) is generated between the towing vehicle and the towed vehicle during turning of the vehicle, the connection angle detecting means makes a stroke accordingly and controls the hydraulic pressure of the hydraulic actuator via the control valve. To do. Therefore, the rear wheels of the towed vehicle are steered according to the steering angle of the towed vehicle, and at this time, the hydraulic actuator feeds back the steering angle to the control valve via the connecting rod.
When the rear wheels are steered by a predetermined amount, they are locked.

In this case, it suffices to mechanically connect (linkage) the control valve to the connection angle detecting means and the rear wheel, and no computer or electric circuit is used for hydraulic control of the actuator, so that the configuration is simple and cost effective. . In addition, since it has a pump as a hydraulic power source that is driven by wheel rotation,
It can also be applied to vehicles that do not have a hydraulic source (normal commercial vehicles, passenger vehicles).

(Embodiment) FIG. 1 is a schematic diagram showing a mechanical structure applied to a semi-trailer type coupled vehicle. A fifth wheel coupler 3 is attached to the tractor 1 slightly ahead of the rear axle, and the trailer 2 is a part of the weight. Is connected to the tractor 1 by a connecting pin 4 (king pin). The fifth wheel coupler 3 is, as shown in FIGS. 2 and 3, a saddle 5 that forms a mounting surface of the trailer 2.
And saddle 5 with rolling pin 6 and pitching pin 7
It consists of a bracket 8 etc. that is supported via a saddle 5
A guide groove 9 for guiding engagement of the connecting pin 4 of the trailer 2 with the pin hole 10 is formed therein. The trailer 2 is provided with an engaging member 13 movably via a roller 12 on a rail 11 attached on an arc centering on the connecting pin 4, and the engaging member 13 of the fifth wheel coupler 3 is connected to the tractor 1 when connected to the tractor 1. It engages with the guide groove 9 and moves on the rail 11 as the saddle 5 rotates about the connecting pin 10. An arm 14 is provided on one side of the engaging element 13.
The end of the arm 14 is connected to the spool 36 of the control valve 30 described later via the rod 15.

On the other hand, the rear wheel 16 of the trailer 2 has kingpins 18 at both ends of the axle 17.
A steering arm 19 is provided so as to project from the knuckle 19 by being steerable. 20 is a power cylinder that steers the rear wheels 16 by the hydraulic pressure from the control valve 30.
As shown in the figure, a double-effect type in which a piston rod 23 is connected to both sides of a piston 22 in a cylinder 21 is adopted, and the cylinder 21 is connected to an axle 17 and the left and right piston rods 23 are connected to a steering arm 19 respectively. . Reference numeral 24 denotes a return spring that biases the piston rod 23 to the neutral position.

The control valve 30 is a tank port as shown in FIG.
31, a pump port 32 and a sleeve 35 having left and right cylinder ports 33, 34, and a spool 36 that slides in the sleeve 35 in the axial direction. The spool 36 blocks the four ports 31 to 34 in the neutral position. Together with the tank port 31
Then, 34 or 33 is communicated with the pump port 32. In this case, the sleeve 35 is slidably supported in the same direction as the spool 36 via the holder 37 with respect to the vehicle body of the trailer 2, and is connected to the steering arm 19 of the rear wheel 16 of the trailer via the rod 38 on the rear end side. It

In the middle of the rod 15 that connects the spool 36 of the control valve 30 and the arm 14 of the engagement element 13, a limit that absorbs an excessive input in the event of a hydraulic pressure failure and prevents damage to the control valve 30 and the engagement element 13. The device 40 is interposed. Limit device
As shown in FIG. 6, the piston 40 is normally held in the cylinder 41 at the neutral position by the return spring 43 as shown in FIG. 6, and when an excessive input acts on the left and right piston rods 44 from one direction, a relief valve (described later) is used. The piston rod 44 expands and contracts while releasing the hydraulic pressure to the low pressure side.

The hydraulic pump 50 as a source of the hydraulic pressure supplied to the power cylinder 20 and the limit device 40 is attached to the knuckle 19 of the rear wheel 16 of the trailer and the pump pulley 52 of the drive shaft 15 is Via a V-belt 53, it is linked to a wheel pulley 55 formed on the tire wheel 54 of the rear wheel 16.

FIG. 9 shows the hydraulic circuit of the entire apparatus, and the hydraulic pressure from the hydraulic pump 50 driven by the rotation of the rear wheels of the trailer 2 is accumulated in the accumulator 62. Since the hydraulic pressure of the accumulator 62 may decrease and become insufficient when the vehicle runs at a low speed, an electric pump 64 that operates by power supply from the power source 63 on the tractor 1 side is provided. When the hydraulic pressure of the accumulator 62 drops below a predetermined value, the motor 65 of the electric pump 64 is energized via a relay 67 that is closed by turning on the pressure switch 66, and drives the pump 64.

The hydraulic pressure from the accumulator 62 is supplied to the power cylinder 20 via the control valve 30 and to the limit device 40 via the check valve 68. 69 is a double operate check valve that oil locks the power cylinder 20 in the event of a hydraulic pressure failure, 60 is a relief valve that releases the high pressure in the cylinder 41 generated by excessive input in the limit device 40 to the tank 61 side, and 70 is a hydraulic pump 50, 64 unloading valve, 71
Indicates a relief valve that regulates the hydraulic pressure supplied from the accumulator 62 to a prescribed value or less.

With such a configuration, when the vehicle turns, for example, when the vehicle turns left at a corner as shown in FIG. 10, the engaging element is inserted through the saddle 5 of the fifth wheel coupler 3 as the tractor 1 is steered.
13 moves to the right on the rail 11 and displaces the spool 36 of the control valve 30 from the sleeve 35 to the left side (drawing direction) in the figure via the rod 15. As a result, the left cylinder port 33 becomes the tank port 31, and the right cylinder port 33
When 34 communicates with the pump port 32, the power cylinder 20 steers the rear wheel 16 to the right through the piston rod 23 by the hydraulic pressure supplied to the right oil chamber. Control valve 30 through 38 Sleeve 35
Is pushed toward the front of the vehicle with respect to the holder 37, and the spool
Return the position relative to 36 to the neutral position, and
Cut off the hydraulic pressure supply to.

By the way, in this case, in order to reduce the inner ring difference between the tractor 1 and the trailer 2 in the turning state, improve the drivability and prevent an accident involving the vehicle, the fifth wheel coupler 3 rotates integrally with the saddle 5. A control valve 30 for controlling the hydraulic pressures of the engagement element 13 and the power cylinder 20 is provided, and the spool 36 of the control valve 30 is attached to the arm 14 of the engagement element 13, the sleeve 35 is attached to the steering arm 19 of the rear wheel 16, and the rods 15 and 38 are attached. Since the steering wheel can be controlled by the mechanical structure connected through the rear wheel 16, the structure is simpler and more cost effective than the case where a computer or an electric circuit is used for hydraulic control of the power cylinder 20. Become. Further, since the hydraulic pump 50 driven by the rotation of the rear wheels of the trailer 2 is provided, it can be used in a vehicle without a hydraulic power source.

When the hydraulic pressure is lost due to some reason, the trailer rear wheel 16 is kept straight by the action of the caster angle of the return spring 24 of the power cylinder 20 and the knuckle 19 and the oil lock action of the double operate check valve 69. Further, since the limit device 40 expands and contracts to absorb excessive input, damage to the engagement element 13 and the control valve 30 can be prevented.

11 to 16 show another embodiment, in which the fifth wheel coupler 3 is used.
In order to ensure turning characteristics at low speed running and maneuverability at high speed running, the trailer rear wheel 16 steering mode is provided in the middle of the rod 15 connecting the engaging element 13 interlocking with the saddle 5 and the control valve 30. A mode switching device (80) for switching between the in-phase and the in-phase depending on the vehicle speed condition is provided.

In the mode switching device 30, a lever 82 is rotatably attached to the vehicle body of the trailer 2 via a fulcrum 81, and one end of the lever 82 is connected to a rod 15A on the side of the engaging element 13 and a long hole 8 of the lever 82.
3 is provided with a control cylinder 85 with a breather for movably engaging the rod 15B on the control valve 30 side and moving the rod 15B along the elongated hole 83. The control cylinder 85 is connected to the other end of the lever 82, and when a hydraulic pressure of a predetermined value or more is supplied from the illustrated initial state (extended state), the piston 86 compresses the return spring 87 and, via the piston rod 88, The tip of the rod 15B is moved to the opposite side of the fulcrum 81.

The oil chamber side of the control cylinder 85 is connected to the discharge side of the hydraulic pump 50 driven by the rotation of the rear wheels of the trailer 2 as shown in FIG. 14, and the discharge amount of the pump 50 (proportional to the pump rotation) is provided immediately downstream thereof. ) To increase the oil pressure
90 is inserted.

Therefore, when the vehicle travels at a low speed, the discharge amount of the pump 50 is small and the hydraulic pressure rise by the throttle 90 is small, so that the control cylinder 85 is in the extended state by the urging force of the return spring 87, that is, the tip of the rod 15B on the control valve 30 side is formed into the elongated hole
Hold at one end of 3. In this state, for example, when the tractor 1 is steered to the left side as shown in FIG. 15, the engaging element 13 interlocking with the fifth wheel coupler 3 causes the rods 15A and 1
Since 5B strokes in the same direction, the control valve 30 supplies hydraulic pressure to the right oil chamber of the power cylinder 20 to steer the trailer rear wheel 16 in the opposite direction according to the steering angle of the tractor 1.

Further, when the vehicle travels at a high speed, the increase in the discharge amount of the pump 50 also increases the hydraulic pressure due to the throttle 90. Therefore, the control cylinder 85 moves in the contracted state against the return spring 87, that is, the tip of the rod 15B moves along the long hole 83. And holds it on the other end side beyond the fulcrum 81. When the tractor 1 is steered to the left in this state, the rod 15A on the engaging element 13 side causes the rod 15B on the control valve 30 side to stroke in the opposite direction via the lever 82, as shown in FIG. Power cylinder 20
The rear wheel 16 of the trailer is steered in the same phase via. in this case,
The trailer rear wheel 16 may be steered smaller than the tractor 1 side, and therefore, the lever rotation center 81 of the mode switching device 80 may be used.
Rod 15B from control valve 30 side from (fulcrum) to left and right
The moving amount (stroke amount) of the tip is set smaller on the high speed side than on the low speed side.

The same parts as those in the above embodiment are designated by the same reference numerals.

(Effects of the Invention) In short, according to the present invention, in the steering device for a coupled vehicle, in which the hydraulic actuator for steering the rear wheels is provided in the towed vehicle that is coupled to the towed vehicle via the coupler, Connection angle detecting means for making a stroke according to an intersection angle centered on a joint point in a coupler with the towing vehicle,
A control valve for controlling the hydraulic pressure of the actuator in conjunction with the detection means, a connecting rod for feeding back the rear wheel steering angle of the towed vehicle to the control valve, and a pump as a hydraulic pressure generation source driven by wheel rotation are provided. Since it is provided, it is possible to control the rear wheel steering of the towed vehicle based on the configuration in which the connection angle detecting means and the control valve are mechanically connected, without using any computer or electric circuit.
Therefore, it is possible to obtain the effect that the structure is simple and the cost is advantageous.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention, FIG. 2 is a partially cutaway side view showing a connecting structure of a tractor and a trailer, FIG. 3 is a plan view thereof, and FIG. 4 is a power cylinder. FIG. 5 is a sectional view of the control valve, FIG. 6 is a sectional view of the limiter, FIG. 7 is a side view showing the mounting state of the hydraulic pump, and FIGS. 8A and 8B are front and plan views thereof, and FIG. Similarly, FIG. 10 is a hydraulic circuit diagram of the entire device, FIG. 10 is an operation explanatory diagram at the time of turning, FIG. 11 is a schematic diagram showing another embodiment, FIG. 12 is a partially cutaway plan view of the mode switching device, and FIG. The same figure shows a partially cutaway front view, and FIG. 14 also shows a hydraulic circuit diagram of the entire device.
FIG. 15 and FIG. 16 are explanatory diagrams of the operation at the time of turning in low speed running and high speed running, respectively. 1 ... tractor, 2 ... trailer, 3 ... fifth wheel coupler, 4 ... connecting pin, 13 ... engaging element, 16 ... trailer rear wheel, 19 ... steering arm, 20 ... power cylinder, 30 ...... Control valve, 35 ...... Sleeve, 36 ...... Spool, 38 ...... Connecting rod, 50 ...... Hydraulic pump

Claims (1)

[Scope of utility model registration request] 1. A steering system for a towed vehicle, wherein a towed vehicle connected to a towed vehicle via a connector is provided with a hydraulic actuator for steering rear wheels. A connection angle detecting means for making a stroke according to an intersection angle about a joint point, a control valve for controlling a steering hydraulic pressure supplied to the actuator in association with a stroke according to the intersection angle of the detecting means, and a towed vehicle. A connecting rod that operates in conjunction with the rear wheel steering system of the vehicle to drive the control valve to a position that shuts off the steering hydraulic pressure when the steering angle reaches a predetermined amount, and the hydraulic pressure that supplies the operating hydraulic pressure to the hydraulic actuator. A steering device for a coupled vehicle, comprising a pump driven by wheel rotation as a generation source.