JPH0619424Y2 - Power steering device - Google Patents

Description

The present invention relates to an all-hydraulic power steering system for a vehicle.

2. Description of the Related Art In a conventional power steering apparatus of this type, as shown in FIG. 3, a steering wheel a and a steering cylinder b are connected by a hydraulic pipe d via a control valve c.

For this reason, if the hydraulic pipe d were to be damaged, oil could leak even if the handle a was cut and steering could not be performed.

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power steering device that does not become unsteerable even if a pipeline is ruptured.

Means and Actions for Solving Problems A power steering device of the present invention is a control valve for supplying pressure oil to one of a first port 1c and a second port 1d by operating a steering wheel and communicating the other with a tank. 1, a first pipe line 6 connected to the first port 1c, a second pipe line 7 and a third pipe line 12, and a fourth pipe line 11, and the first pipe line Line 6, third line 12 and second line 7
And the fourth conduit 8 are communicated with each other at a first position, the first conduit 6 and the third conduit 12 are communicated with each other, and the second conduit 7 and the fourth conduit 11 are blocked. A first switch that is switched to a second position, a third position that shuts off the first pipeline 6 and the third pipeline 12 and connects the second pipeline 7 and the fourth pipeline 11 to each other. The valve 8, the third conduit 12, the fourth conduit 11 and the fifth conduit 16 connected to the pressure chamber 18 of the steering cylinder 2
The third pipe line 12 and the fifth pipe line 16 and the fourth pipe line 11 and the sixth pipe line 17 respectively, which are provided between the first position and the third pipe line 17. Pipeline 12 and fifth pipeline 1
6, a second position for connecting the fourth pipeline 11 and the sixth pipeline 17 and a third position for blocking the third pipeline 12 and the fifth pipeline 16 and a fourth pipeline. The second switching valve 13 which is switched to the third position for connecting the 11 and the sixth pipeline 17, and the seventh pipeline 24 and the eighth pipeline connected to the second port 1d.
Is provided between the pipeline 23, the ninth pipeline 29, and the tenth pipeline 28, and the seventh pipeline 24, the ninth pipeline 29, and the eighth pipeline 29 are provided.
The first and second conduits 23 and 10 respectively communicating with each other.
Position, a second position where the seventh conduit 24 and the ninth conduit 29 are communicated with each other, and the eighth conduit 23 and the tenth conduit 28 are cut off, the seventh conduit 24 and the A third switching valve 25 that is switched to a third position that shuts off the ninth conduit 29 and connects the eighth conduit 23 and the tenth conduit 28; An eleventh conduit 33 connected to the conduit 28 of 10 and the other pressure chamber 35 of the steering cylinder 2;
The first position, which is provided between the twelfth pipeline 34 and the ninth pipeline 29, the eleventh pipeline 33, and the tenth pipeline 28, and the twelfth pipeline 34, respectively, The 9th pipeline 29, the second position where the 9th pipeline 29 and the 11th pipeline 33 are communicated with each other and the 10th pipeline 28 and the 12th pipeline 34 are cut off.
And a fourth switching valve 30 which is switched to a third position which shuts off the eleventh conduit 33 and connects the tenth conduit 28 and the twelfth conduit 34, and the first conduit 6 And the throttles provided near the control valve 1 in the second pipeline 7, the seventh pipeline 24, and the eighth pipeline 26, respectively, and the fifth pipeline 16, the sixth pipeline 17, and the eleventh pipeline. Pipeline 3
3 and 12th conduits 34 are provided respectively near the steering cylinder 2, and the first switching valve 8 and the second switching valve 13 are connected to the third conduit 12 and the fourth conduit. When the pressure in 11 is equal, the first position is set, when the pressure in the third pipeline 12 is high, the second position is set, and when the pressure in the fourth pipeline 11 is high, the third position is set. The switching valve 25 and the fourth switching valve 30 are set to the first position when the pressure in the ninth conduit 29 and the pressure in the tenth conduit 28 are equal and to the first position when the pressure in the ninth conduit 29 is high. The second position is the third position when the pressure in the tenth conduit 28 is high.

Thereby, when one of the third conduit 12 and the fourth conduit 11 bursts, the first switching valve 8 and the second switching valve 13 switched to the second position or the third position and burst. If one of the ninth pipe line 29 and the tenth pipe line 28 ruptures similarly, the pressure oil is circulated only in the other pipe line by shutting off one pipe line, and the third switching valve 25 and the fourth pipe line Since the switching valve 30 switches to the second position or the third position and shuts off one of the ruptured pipe lines and allows the pressure oil to flow only to the other pipe line, the third pipe line 12, the fourth pipe line
Even if one of the pipeline 11, the ninth pipeline 29, and the tenth pipeline 28 of the control valve 1 and the steering cylinder 2 is ruptured.
Since pressure oil can be circulated between and, steering is possible.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the drawing, 1 is a control valve and 2 is a steering cylinder. A handle 3 is connected to the spool of the control valve 1. The pump port 1a of the control valve 1 is connected to the discharge side of the pump 4, and the tank port 1b is connected to the tank 5.

The port 1c of the control valve 1 is connected to the ports 8a and 8b of the first switching valve 8 via pipes 6 and 7, and the pipes 6 and 7 are provided with throttles 9 and 10. The ports 8c and 8d of the first switching valve 8 are connected to the ports 13a and 13b of the second switching valve 13 via the conduits 11 and 12, respectively. The pilot pipe lines 14 and 15 branched from these pipe lines 11 and 12 are connected to the pilot ports 8e and 8f of the first switching valve 8. The ports 13c and 13d of the second switching valve 13 are connected to one pressure chamber 18 of the steering cylinder 2 via the pipes 16 and 17, and the pipes 16 and 1
7, diaphragms 19 and 20 are provided. In addition, the pipe line 11,
Pilot pipe lines 21 and 22 are branched from 12, and these pilot pipe lines 21 and 22 are connected to the pilot ports 13e and 13f of the second switching valve 13.

The port 1d of the control valve 1 is connected to the conduits 23, 2
4 is connected to the ports 25a and 25b of the third switching valve 25, and these pipes 23 and 24 are throttled 26 and 27.
Is provided. Ports 25c, 25 of the third switching valve 25
d is connected to the ports 30a and 30b of the fourth switching valve 30 via the pipes 28 and 29. These pipelines 28, 29
The pilot pipe lines 31 and 32 branched from are connected to the pilot ports 25e and 25f of the third switching valve 25. The ports 30c and 30d of the fourth switching valve 30 are connected to the conduit 3
The other pressure chamber 35 of the steering cylinder 2 via
And the pipes 33, 34 are provided with throttles 36, 37. Pilot pipes 38 and 39 are branched from the pipes 28 and 29.
8, 39 are pilot ports 30 of the fourth switching valve 30.
e, 30f.

Next, the operation will be described.

The control valve 1 is switched by operating the steering wheel 3 to flow pressure oil in the direction of the arrow, for steering through the first switching valve 8, the pipelines 11 and 12, the second switching valve 13 and the pipelines 16 and 17, for steering. Supplying oil to one pressure chamber 18 of the cylinder 2,
The steering cylinder 18 is operated to carry out steering.

In this case, if the pipe line 12 is ruptured, the pilot pressure detectors a and b will be at atmospheric pressure, but the other pilot pressure detectors c and d will be at a pressure higher than atmospheric pressure due to the throttles 9, 10, 19 and 20. Then, pressure acts on the pilot ports 8e, 13e of the first and second switching valves 8, 13 to switch the positions, and the positions A, B are located on the port side. For this reason, the line 12 that has ruptured is blocked and the line 1
Only with 1, the pressure oil is sent to the steering cylinder 2 to enable steering.

FIG. 2 shows another embodiment of the present invention. In this embodiment, electromagnetic valves are used for the first to fourth switching valves 8, 13, 25, 30 and one solenoid 40, 41 of the first and second switching valves 8, 13 is connected to the contact of the pressure switch 42. Connect to 43,
The other solenoid 44 of the first and second switching valves 8 and 13,
45 is connected to the contact point 46 of the pressure switch 42, the contact piece 47 of the pressure switch 42 is connected to the power source 49 via the buzzer 48, and the pressure sensitive portion 50, 51 of the pressure switch 42 is connected to the conduit 1
Pilot pipelines 52 and 53 branched from 1 and 12 are connected, and the third and fourth switching valves 25 and 30 have the same configuration as above.

When the pipeline 12 is ruptured, the contact piece 47 is connected to the contact point 43 by the pilot pressure from the pipeline 11, and the positions of the first and second switching valves 8 and 13 are switched to shut off the pipeline 12. The pressure oil is sent to the steering cylinder 2 only by the pipe line 11 and steered.

Further, when the conduit 12 is ruptured, the buzzer 48 is activated to notify the operator.

Effect of the Invention When one of the third conduit 12 and the fourth conduit 11 is ruptured, the first switching valve 8 and the second switching valve 13 are at the second position or the third position.
When one of the ninth conduit line 29 and the tenth conduit line 28 ruptures, one of the ninth conduit line 29 and the tenth conduit line 28 ruptures. The switching valve 25 and the fourth switching valve 30 are switched to the second position or the third position to shut off one of the ruptured pipe lines and allow the pressure oil to flow only to the other pipe line.

Therefore, even if one of the third pipe line 12, the fourth pipe line 11, the ninth pipe line 29, and the tenth pipe line 28 is ruptured, the pressure oil is applied between the control valve 1 and the steering cylinder 2. Since it can be distributed, there is no possibility of steering.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of one embodiment of the present invention, FIG. 2 is a structural explanatory view of another embodiment of the present invention, and FIG. 3 is a structural explanatory view of a conventional power steering apparatus. 1 is a control valve, 2 is a steering cylinder, 11,
12, 28, 29 are pipes, 8, 13, 25, 30 are switching valves, 9, 10, 19, 20, 26, 27, 36, 37 are throttles.

Claims (1)

[Scope of utility model registration request] 1. A control valve 1 for supplying pressure oil to one of a first port 1c and a second port 1d by operating a handle and communicating the other to a tank, and a first valve connected to the first port 1c. The first pipeline 6, the second pipeline 7, the third pipeline 12, and the fourth pipeline 11 are provided between the first pipeline 6, the third pipeline 12, and the second pipeline. Pipeline 7
And a fourth position that communicates with the fourth conduit 11 respectively.
Of the second pipeline 7 and the third pipeline 12 of the second pipeline 7
And a second position for shutting off the fourth conduit 11, the first conduit 6
A first switching valve 8 that is switched to a third position that shuts off the third pipeline 12 and connects the second pipeline 7 and the fourth pipeline 11 together; and the third pipeline 12 , The fifth conduit 16 connected to the fourth conduit 11 and one pressure chamber 18 of the steering cylinder 2, the sixth conduit
Is provided between the third conduit 12 and the fifth conduit 17, and the fourth conduit 11 and the sixth conduit 17 are connected to each other. Pipeline 12 and fifth pipeline 1
6, a second position for connecting the fourth pipeline 11 and the sixth pipeline 17 and a third position for blocking the third pipeline 12 and the fifth pipeline 16 and a fourth pipeline. The second switching valve 13 which is switched to the third position for connecting the 11 and the sixth pipeline 17, and the seventh pipeline 24 and the eighth pipeline connected to the second port 1d.
Is provided between the pipeline 23, the ninth pipeline 29, and the tenth pipeline 28, and the seventh pipeline 24, the ninth pipeline 29, and the eighth pipeline 29 are provided.
The first and second conduits 23 and 10 respectively communicating with each other.
Position, a second position where the seventh conduit 24 and the ninth conduit 29 are communicated with each other, and the eighth conduit 23 and the tenth conduit 28 are cut off, the seventh conduit 24 and the A third switching valve 25 that is switched to a third position that shuts off the ninth conduit 29 and connects the eighth conduit 23 and the tenth conduit 28; An eleventh conduit 33 connected to the conduit 28 of 10 and the other pressure chamber 35 of the steering cylinder 2;
The first position, which is provided between the twelfth pipeline 34 and the ninth pipeline 29, the eleventh pipeline 33, and the tenth pipeline 28, and the twelfth pipeline 34, respectively, The 9th pipeline 29, the second position where the 9th pipeline 29 and the 11th pipeline 33 are communicated with each other and the 10th pipeline 28 and the 12th pipeline 34 are cut off.
And a fourth switching valve 30 which is switched to a third position which shuts off the eleventh conduit 33 and connects the tenth conduit 28 and the twelfth conduit 34, and the first conduit 6 And throttles provided in the second pipeline 7, the seventh pipeline 24, and the eighth pipeline 23 near the control valve 1, respectively, the fifth pipeline 16, the sixth pipeline 17, and the eleventh pipeline. Pipeline 3
3 and 12th conduits 34 are provided respectively near the steering cylinder 2, and the first switching valve 8 and the second switching valve 13 are connected to the third conduit 12 and the fourth conduit. When the pressure in 11 is equal, the first position is set, when the pressure in the third pipeline 12 is high, the second position is set, and when the pressure in the fourth pipeline 11 is high, the third position is set. The switching valve 25 and the fourth switching valve 30 are set to the first position when the pressure in the ninth conduit 29 and the pressure in the tenth conduit 28 are equal and to the first position when the pressure in the ninth conduit 29 is high. The power steering device is set to the second position and the third position when the pressure in the tenth conduit 28 is high.