JP3850079B2 - Automotive power steering system - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an automotive power steering apparatus using two control cables and a power cylinder on which a tensile force acts, and more particularly to an automotive power steering apparatus capable of detecting in advance a breakage of an inner cable of a control cable.
[0002]
[Prior art]
The applicant of the present patent applies direction control to the power cylinder having a piston rod connected to the front wheel via a steering link mechanism at both ends, and pressure oil supplied to the power cylinder and discharged from the power cylinder at the same time. Rotary type control valve, valve side drum connected to the rotor of the control valve, handle side drum connected to the handle, and inner cable slidably inserted into the flexible outer tube Has filed a patent application for a power steering device for an automobile including two control cables wound around both drums so that a tensile force is applied alternately in the rotation of the handle side drum in an alternating direction. The application was published as No.-2431.
[0003]
[Problems to be solved by the invention]
Since the invention according to this patent application transmits the steering force using the control cable, there is an advantage that it can be bent and routed freely in a narrow engine room, but the inner where only the tensile force acts. The cable uses a twisted strand of many strands. If used for a long time, the strand may break little by little depending on the usage conditions, and the inner cable itself may eventually break. There is a problem.
[0004]
[Means for Solving the Problems]
As a means for solving the above-mentioned problems, the present invention provides the above-described known invention, wherein the outer tube of the control cable is removed and the inner cable is loosely fitted to the exposed portion of at least one of the valve-side drum and the handle-side drum. a bobbin is attached to, along with placing a primary coil and a secondary coil at two locations in the axial direction of the bobbin, and an input device for inputting an AC signal to the primary coil, the induced power induced in the secondary coil And an abnormality detection device that generates an abnormal signal by detecting a change in the above.
[0005]
[Action and effect]
The present invention Ri Do to the above configuration, when Lee runner cable are normal are the constant power corresponding to the AC signal inputted to the primary coil is induced in the secondary coil, the wires of the inner cable Since the electric power induced in the secondary coil changes when the breakage starts, this is detected by the abnormality detection device and an abnormality signal is generated, so that there is an effect that the breakage of the inner cable can be detected in advance. Further, since the bobbin is attached to at least one case of the valve side drum and the handle side drum, there is an effect that it is securely fixed.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0007]
In the figure, reference numeral 1 denotes a handle, which is rotatably supported by a case 2 attached to the vehicle body.
[0008]
A case 2 having the same structure as the case 2 is arranged at the steering position in front of the vehicle body, and two terminals are fixed to the cases 2 and 2 with a cylindrical fixture 3 between the cases 2 and 2. A flexible control cable 4 is routed.
[0009]
The control cable 4 is formed by inserting an inner cable 6 formed by twisting a number of strands into the outer tube 5 so as to slide freely. As shown in FIG. The tool 3 is caulked, and one of the cylindrical fixtures 3 has a male screw 11 formed on the outer periphery thereof screwed into a female screw 12 formed on the case 2 and directly fixed to the case 2. The mounting length of the outer tube 5 is adjusted by rotation and is fixed by the double nuts 13, 13, and the cylindrical fixture 3 that is caulked to the other end of the outer tube 5 is integrated with the case 2. The attachment length of the outer tube 5 is adjusted by being screwed into a hooked nut 31 fixed to the cylindrical portion 30 formed on the tube portion 30, and is fixed by a nut 32. The inner cable 6 is wound around a drum 7 that is rotatably supported in the case 2. The winding directions of the two inner cables 6 are opposite to each other, and their ends are fixed to the drum 7.
[0010]
As shown in FIG. 2, the rotating shaft 8 of the drum 7 protrudes from one surface of the case 2, and on the handle 1 side, on the rotating shaft of the handle 1, on the steering position side, on the rotor 10 of the rotary valve 9 described later, Each is connected.
[0011]
Reference numeral 14 denotes a power cylinder in which a piston 16 is slidably fitted to a cylinder tube 15, and one side of a piston rod 17 fixed to the piston 16 is extended to form a rack 18. The tie rod 20 is connected to the front wheel a via a knuckle arm (not shown).
[0012]
In the present invention, the tie rod 20 and the knuckle arm are collectively referred to as a steering link mechanism.
[0013]
A pinion 21 is fixed to the rotor 10 of the rotary valve 9 and meshes with the rack 18.
[0014]
The supply port 22 of the rotary valve 9 is connected to a hydraulic pump (not shown), the discharge port 23 is connected to a tank (not shown), and the two ports 24 and 25 are connected to the two ports 26 of the cylinder tube 15 by pipes 28 and 29. 27, when the rotor 10 rotates in one direction, pressure oil is supplied to one side of the piston 16 and discharged from the other side, and when rotated in the other direction, pressure oil is supplied to the other side of the piston 16. The piston 16 is operated together with the piston rod 17 by being discharged from one side.
[0015]
As described above, except that the cylindrical portion 30 is formed on the case 2, it has been described in the above publication, but in the present embodiment, as shown in FIG. 33, a primary coil 34 and a secondary coil 35 are wound on both sides thereof, and an input device 37 built in the box 36 shown in FIG. 1 is connected to the primary coil 34 on the handle side and the valve side, Similarly, an abnormality detection device 38 incorporated in the box 36 is connected to the secondary coil 35 on the handle side and the valve side.
[0016]
The input device 37 inputs a constant AC signal to the two primary coils 34, and the abnormality detection device 38 separately receives the change in power induced in the two secondary coils 35 by mutual induction as a change in voltage. When at least one value falls below a predetermined threshold value, the alarm lamp 39 is turned on or a buzzer is sounded.
[0017]
Next, the operation of the present embodiment will be described.
[0018]
When the handle 1 is rotated in one direction, the drum 7 on the handle 1 side is rotated by the same angle as the handle 1 and the inner cable 6 of the two control cables 4 wound around the drum 7 and the drum 7 on the steering position side. One of the two is wound around the drum 7 on the handle 1 side, tension is generated, and the inner cable 6 is drawn out from the drum 7 on the steering position side, and the drum 7 and the rotating shaft 8 rotate in one direction. At that time, the inner cable 6 of the other control cable 4 is drawn out from the drum 7 on the handle 1 side and wound around the drum 7 on the steering position side.
[0019]
When the handle 1 is rotated in the other direction, the drum 7 on the steering position side and the rotating shaft 8 are rotated in the other direction by the same operation.
[0020]
When the rotating shaft 8 of the drum 7 on the steering position side rotates in one direction, the rotor 10 connected thereto rotates in the same direction, and the piston rod 17 tries to operate in one direction due to the engagement of the pinion 21 and the rack 18. However, at this time, the rotation of the rotor 10 causes pressure oil to be supplied from one of the ports 24 and 25 of the rotary valve 9 to one of the ports 26 and 27 of the power cylinder 14 and the piston rod 17 operates in the same direction as described above. The wheel a faces one side through the steering link mechanism.
[0021]
When the rotation center shaft 8 of the drum 7 on the steering position side rotates in the other direction, the wheel a faces the other side by the same operation.
[0022]
Here, the strands constituting the inner cable 6 by friction with the outer tube 5 as in the case where excessive tension is applied to the inner cable 6 due to long-term use or clearance at the time of engine stop, etc. May be broken little by little, and the inner cable 6 becomes thinner little by little. Finally, the inner cable 6 itself may break and become unmanageable.
[0023]
As shown in FIG. 4, in a normal state where the strand of the inner cable 6 is not broken, the output voltage of the rectified secondary coil 35 is constant, but the strand break starts and the inner cable 6 As the diameter of the coil gradually decreases, the electric power induced in at least one of the secondary coils 35 decreases and the output voltage starts to decrease and eventually breaks. However, when the output voltage reaches a preset threshold value. Then, the abnormality detection device 38 issues an abnormality signal and the warning light 39 is turned on, or the driver is warned before the buzzer sounds and the inner cable 6 is broken.
[0024]
For this reason, the occurrence of an accident is prevented.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention.
FIG. 2 is a perspective view of a drum according to an embodiment of the present invention.
FIG. 3 is a partially cutaway front view showing a control cable attachment length adjusting mechanism according to an embodiment of the present invention.
FIG. 4 is a graph showing changes in output voltage.
[Explanation of symbols]
1: Handle 4: Control cable 5: Outer tube 6: Inner cable 7: Drum 9: Control valve 10: Rotor 14: Power cylinder 17: Piston rod 20: Tie rod 33: Bobbin 34: Primary coil 35: Secondary coil 37: Input device 38: Anomaly detection device 39: Warning light a: Front wheel

Claims (1)

A power cylinder having a piston rod connected to the front wheel via a steering link mechanism at both ends, and a rotary control valve that controls the direction of the pressure oil supplied to the power cylinder and discharged from the power cylinder at the same time And an inner cable comprising a valve side drum connected to the rotor of the control valve, a handle side drum connected to the handle, and a stranded wire slidably inserted into a flexible outer tube. In a power steering apparatus for an automobile, including two control cables wound around the drums so that a tensile force is alternately actuated in rotation in an alternate direction of the handle side drum,
A bobbin wherein the removing the Au Tachi cube control cable is loosely fitted in the exposed portion of the inner cable is attached to at least one case of the handle-side drum and the valve side drum,
With arranging the axial direction of the primary and secondary coils in two places of the bobbin, by detecting an input device for inputting an AC signal to the primary coil, the change in induced power induced in the secondary coil An anomaly detector that emits an anomaly signal;
Power steering device for automobiles equipped with

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