JPH0142867B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a vehicle for use in various vehicles, which includes a steering wheel on each of the left and right driver's seats and a power steering device operated by the steering wheel. This invention relates to a double-handle steering device that is configured so that steering operations can be performed on both sides, and in particular, a dual-handle steering device that is configured to give priority to steering operations on one driver's seat side over the other side. Regarding improvements.

For example, road work vehicles such as road sweeping vehicles need to be driven as far to the left as possible in order to clean the side edges of the road, guardrails, etc. without preventing other vehicles from running. However, in vehicles where the steering wheel is located on the right side of the driver's seat, as in other vehicles, it requires considerable skill for the driver to drive the vehicle with the vehicle completely to the left. It's also very tiring.

Therefore, in such road cleaning vehicles, steering wheels are provided on both sides of the driver's seat so that the vehicle is normally operated from the driver's seat on the right side, and when working on the road, the driver's seat on the left side is used. equipment is desired. A device using a power steering device called power steering for such a dual-handle type steering device has already been proposed in Japanese Patent Application Laid-open No. 19678/1983.

To briefly describe this, in this device, switching is controlled by a manual lever or the like between the power steering device attached to each of the left and right steering handles and the supply source that supplies working fluid to these devices. A directional switching valve is interposed, and by manually switching the directional switching valve when necessary, the working fluid is supplied only to the power steering device on the steering handle side to be used. According to such a configuration, there is an advantage that only the necessary steering wheel is connected to the steering link side due to the simple configuration, and stable steering operation can be performed.

However, with the above-mentioned device, when replacing the steering wheel that can be steered, it is necessary to manually switch the directional control valve, which results in a two-step steering operation, which not only makes the operation complicated, but also causes errors in operation. The problem was that it was easy to do.

Such operational problems become a major problem when the above-mentioned double-handle steering device is applied to a training vehicle used at a driving school, for example, and it is possible to solve this problem. It is desired that the system be configured as follows.

In other words, in the above-mentioned training vehicle, a steering wheel is provided not only on the right driver's seat where the student sits, but also on the left driver's seat where the instructor sits, so that steering operations can be performed from this side as well. This is a great advantage for instructors to help inexperienced students with steering operations, to prevent unskilled students from colliding with other vehicles or obstacles, and for instructors to teach students correct driving techniques. .

However, when implementing this on such a training vehicle, the necessity of switching the manual lever etc. as a preparatory step to steering as described above makes it difficult for young children to use the steering in an emergency situation where the instructor needs to take the helm. There may be a time delay and you may not be able to make it in time. Therefore, with such a dual-handle steering device, even when a student is driving a training vehicle, the instructor can directly operate the steering wheel without requiring any special switching operations. It is desirable to have a configuration that allows quick and reliable steering operation just by steering.

In addition, in a configuration using a directional switching valve as described above, the switching operation may generate surge pressure in the fluid circuit, which may have an adverse effect on various parts.Furthermore, if the switching operation is incomplete, both This causes problems such as no working fluid being supplied to the power steering device and both handles becoming manual, making it impossible to perform proper steering. Further, if the switching operation is mistakenly performed while the vehicle is running, there is a risk of an accident, etc., so it is necessary to take this point into consideration. In particular, when the directional control valve is switched to the opposite side, no working fluid is supplied to the power steering device on the side that is attempting to perform steering operations, and the steering wheel must be operated manually. This was a problem for stable steering operations.

The present invention was made in view of the above circumstances, and it supplies working fluid to each power steering device through independent paths, and uses the output of one of the power steering devices to supply the working fluid. By increasing the fluid pressure or increasing the cylinder diameter of the power cylinder, the simple configuration allows the output to be set higher than the output on the other side, eliminating the troublesome and unreliable directional switching of conventional methods. The dual-handle steering system eliminates the need for valve switching operations, allows quick and reliable steering operations from either side, and always gives priority to one side over the other. This is what we provide.

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 is a schematic perspective view showing an embodiment in which the dual-handle steering device according to the present invention is applied to a large vehicle such as a truck. In this embodiment, a case will be explained in which this is used as a training vehicle. do.

In the same figure, to briefly explain this, numerals 1 and 2 are left and right steering handles arranged at the left and right driver seats of a vehicle (not shown), and 3 and 4 are handle shafts of the respective steering handles 1 and 2. A power steering device disposed on the lower end side of 1a, 2a, these power steering devices 3,
A control valve that switches a fluid pressure flow path in accordance with the steering direction of the steering handles 1 and 2, and a power cylinder section (both not shown) that generates a steering assist force are disposed within the steering wheel 4. . These power steering devices 3 and 4 each have a pitman arm 3.
It is connected to the steering ring mechanism via a, 4a. In addition, 5a and 6a in the figure are drag links,
5b and 6b are knuckle arms, 5c and 6c are king pins, 7 is a front axle, 8 is a tie rod, and 9a and 9b are knuckle spindles.

Now, according to the present invention, in the double-handle steering device having the above-described configuration, the working fluid supply paths for the pair of left and right power steering devices 3 and 4 are formed independently, thereby improving the efficiency of the conventional steering device. The troublesome and unreliable manual switching operation of the directional switching valve is not required, and the output from the power steering device 3 (power cylinder section 10) is set to be larger than that on the other side, so that steering operations on one side can always be performed with priority over the other side.

This will be explained in detail using the fluid pressure circuit shown in Fig. 2. In the figure, reference numerals 10 and 11 are power cylinder parts that generate a steering assist force according to the supplied fluid pressure, and 12 and 13 are power cylinder parts that generate a steering assist force according to the supplied fluid pressure. The left and right pressure chambers 1 of the power cylinder parts 10 and 11 are provided integrally or separately, depending on the steering direction of the steering handles 1 and 2.
0a, 10b; Control valves that supply working fluid to 11a, 11b, which form a pair of left,
Right power steering devices 3 and 4 are configured.

These left and right power steering devices 3,
4, each independent fluid pressure supply pipe line 1
Two pumps 16 with different discharge pressures at 4 and 15,
Working fluid from 17 is supplied. That is, according to this embodiment, two pumps 16 and 17
By constantly supplying working fluid to each of the power steering devices 3 and 4, it is possible to quickly and reliably steer the vehicle regardless of whether the steering handles 1 or 2 are operated.

In the figure, reference numerals 18 and 19 are filters provided in the suction side pipes 16a and 17a of the pumps 16 and 17, and each pipe line 16a and 17a is connected to the tank 20. Furthermore, well-known flow rate and pressure control units 21 and 22, which are normally provided integrally with the pump, are arranged on the discharge side of each pump 16 and 17,
It is configured to maintain the flow rate and pressure discharged from each pump 16, 17 below a certain value. To explain this simply, in the figure, 23 and 24 are flow rate detection orifices provided in the fluid pressure supply pipes 14 and 15, and 25 and 26 are actuated by these orifices to detect a flow rate of a certain amount or more in the tank 20. Of course, the set flow rates of these flow rate control valves 25 and 26 are set larger on the left side. Also, 2
Relief valves 7 and 28 are connected downstream of the orifices 23 and 24 via drain orifices 27a and 28a, and the relief valves 27 and 28 are connected to the tank 20.

Reference numerals 29 and 30 indicate return pipes for returning the working fluid from the power steering devices 3 and 4 to the tank 20, and a reverse valve is provided between the return pipes 29 and 30 and the supply pipes 14 and 15. 31 and 32 are present.

In the double-handle steering device with such a configuration, when the student operates the right steering handle 2, the control valve 13 is switched to the corresponding steering direction unless the instructor operates the left steering handle 1. , whereby the left and right cylinder chambers 11a, 11
The fluid pressure in b changes, the power cylinder section 11 operates according to the amount of change, and the steered wheels are turned in a desired direction via the steering link mechanism. At this time, the rotation of the right steering wheel 2 is transmitted to the left steering wheel 1 via the steering link mechanism.
It becomes idle. However, the left control valve 12 does not switch the fluid pressure flow path, and the working fluid from the pump 16 is returned to the tank 20 from the supply side pipe 14 through the return pipe 29.

Furthermore, when the student's steering operation is incomplete and the instructor needs to assist, when the instructor operates the left steering wheel 1, the control valve 12
is switched, fluid pressure is supplied to the cylinder chamber 10a or 10b of the power cylinder section 10, and its output is transmitted to the steering link mechanism to control the steering of the steered wheels.

The important point to note here is that when the instructor operates the steering wheel, even if the student is operating the steering wheel, the instructor's power steering system must be able to overcome this and control the steering wheel. Removal device 3
The output (output of the power cylinder section 10) is
It is set larger than that on the student side, so that the instructor's steering operation always takes priority over the student's side.

In the circuit configuration described above, in order to give priority to the instructor's steering wheel operation, it is necessary to
Of the pumps 16 and 17 on the stand, pump 1 on the instructor side
6 may be set to be large, and the fluid pressure of the working fluid to the power steering device 3 may be set higher than the other pressure. In addition, the output of the power cylinder section 10 itself is
For example, it is possible to make one larger than the other by increasing the cylinder diameter or changing the control valve appropriately.

If the output of the power steering device 3 on the instructor's side is increased in this way, even if the student is operating the steering wheel, the instructor's steering operation will be on the student's side due to the magnitude relationship between the left and right outputs. It is automatically transmitted to the steering linkage mechanism with priority over the above, and safe and reliable turning control of the steered wheels can be performed.

In addition, in the above-mentioned configuration, when the left and right steering handles 1 and 2 are operated, the outputs of both power cylinder parts 10 and 11 are transmitted to the steering link mechanism, so this steering link mechanism, etc. strength is required compared to conventional ones.

In addition, when both handles 1 and 2 are not operated and the vehicle is traveling straight, the control valves 12 and 13 are in the neutral position shown in FIG.
The working fluid from 6, 17 is connected to pipes 14, 29; 1
5 and 30 and is returned to the tank 20 side.

Further, when the supply sources of working fluid to both power steering devices 3 and 4, that is, the pumps 16 and 17, etc. are out of order, both handles 1 and 2 can be operated manually. At this time, the check valves 31 and 3 are controlled by switching the control valves 12 and 13.
2 is opened and the left side of each power cylinder part 10, 11,
The working fluid in the right cylinder chambers 10a, 10b; 11a, 11b is replaced to assist in manual steering operations.

Therefore, according to the above-described configuration, separate fluid pressure supply sources (pumps 16, 17) are connected to each of the left and right power steering devices 3, 4.
It is possible to steer independently of each other, and steering can be done quickly and reliably from both sides.Moreover, by giving priority to one by setting the fluid pressure of one of them to a high pressure, it is possible to assist the instructor. The system can automatically perform automatic steering safely and reliably, and can be used effectively in, for example, a training vehicle.

FIG. 3 shows another embodiment of the present invention, in which the same or corresponding parts as those in FIG. 2 are given the same reference numerals and their design details will be omitted.

Now, the characteristic feature of this embodiment is that one pump 16 is used as a supply source of working fluid to the left and right power steering devices 3 and 4, and that the discharge side pipe 16b is This is because a flow divider valve 40 that divides the discharge fluid is interposed in the middle. Even with such a configuration, the working fluid is supplied to each power steering device 3, 4 through an independent path (pipe line 14, 15), and the same effect as in the above-described embodiment is achieved. It is easy to understand that it is effective. Also, in order to give priority to one steering wheel operation,
This can also be easily implemented by, for example, dividing the fluid discharged from the pump 16 at different fluid pressures using the flow dividing valve 40.

In the above-mentioned embodiments, the case where the dual-handle steering device according to the present invention is applied to a training vehicle has been described, but the application is not limited to this, and for example, the dual-handle steering device of other types such as road cleaning vehicles and other types of vehicles are used. Needless to say, it can be applied to vehicles that require

As explained above, according to the double-handle steering device according to the present invention, working fluid is supplied to the left and right power steering devices through independent paths, and one of the power steering devices is supplied with working fluid through independent paths. The output on one side can be set larger than the output on the other side by increasing the supply fluid pressure of the working fluid and increasing the cylinder diameter of the power cylinder, so the simple configuration allows This eliminates the need for manual switching of directional valves, which is cumbersome and lacking in reliability as in the past, and allows quick and reliable steering operations from either side. Due to the simple structure of using a higher pressure than the conventional one, priority is given to steering wheel operation on one side, which has excellent effects such as being useful for use in training vehicles. Further, according to the present invention, since the conventional directional switching valve is not required, there is no need to worry about surge pressure in the fluid pressure circuit due to switching, and it is also advantageous in terms of strength and reliability of each part. There are advantages.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an example of a dual-handle steering device according to the present invention, FIG. 2 is a circuit diagram showing an example of a fluid pressure circuit of the dual-handle steering device according to the present invention, and FIG. The figure is a circuit diagram showing another embodiment of the present invention. 1, 2...Left, right steering wheel, 3, 4...
A pair of power steering devices, left and right, 10, 11...left,
Right power cylinder section, 12, 13...Left, right control valve, 14, 15...Left, right fluid pressure supply pipe, 1
6, 17...left, right pump, 20...tank, 4
0...Diversion valve.

Claims (1)

[Scope of Claims] 1. A steering wheel is provided at each of the left and right driver's seats, and a common steering wheel is controlled by a pair of left and right power steering devices that are respectively controlled by these steering handles. In a double-handle steering device configured to perform turning control, working fluid is supplied from a supply source to the pair of power steering devices through independent paths, and one of the power steering devices is supplied with working fluid from a supply source. A double-handle steering device characterized in that the output from one side is set to be greater than the output from the other side. 2. The dual-handle steering device according to claim 1, wherein the pressure of the working fluid supplied to one power steering device is set to be higher than that of the other side. 3. The dual-handle steering device according to claim 1 or 2, characterized in that the cylinder diameter of the power cylinder constituting one power steering device is larger than that of the other side.