JPH04358963A - Totally hydraulic power steering system - Google Patents

Abstract

PURPOSE:To provide such a totally hydraulic power steering system as capable of preventing a steering wheel slipping phenomenon from occurring without requiring any difficult working operation. CONSTITUTION:Voltage is impressed on an optional electrode part among plural pieces of electrode parts of a control valve 1 on the basis of various signals, generating an electric field, and viscosity, namely, flowing resistance of an electrical viscous fluid, flowing in this electic field, is increased, through which the flowing direction and flow rate of this electrical viscous fluid being fed or exhausted to or from a power cylinder 97 via the control valve 1 and a trochoid pump 75 are controlled.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention relates to a fully hydraulic power steering system, and more particularly, the present invention relates to an electrorheological fluid (hereinafter referred to as E
This invention relates to a device that can prevent the occurrence of handle slippage without requiring difficult machining work by using R fluid (referred to as R fluid).

0002

2. Description of the Related Art Conventional fully hydraulic power steering systems use rotary valves or spool valves as their valve mechanisms.

0003

[Problems to be Solved by the Invention] The above conventional configuration has the following problems. Generally, if there is internal oil leakage between parts that make up a valve mechanism, a handle slipping phenomenon occurs. In order to prevent this handle slipping phenomenon, it is necessary to reduce the clearance of the switching valve section. However, in order to achieve this, the component parts must be machined with high precision, which poses a problem in that difficult machining operations are required and productivity is reduced. Further, even if such a machining operation is carried out, variations in machining accuracy occur, and the occurrence of the above-mentioned handle slipping phenomenon cannot be reliably prevented.

The present invention has been made based on the above points, and its object is to provide a fully hydraulic power system that makes it possible to prevent the occurrence of handle slippage without requiring difficult machining work. An object of the present invention is to provide a steering device.

[0005]

[Means for Solving the Problems] In order to achieve the above object, a fully hydraulic power steering device according to the present invention provides a working fluid that supplies and discharges an electro-rheological fluid as a working fluid whose viscosity changes depending on the magnitude of an electric field. a supply section;
A power cylinder that outputs a power assist force for steering the wheels, a control valve that is arranged between the working fluid supply section and the power cylinder and has a plurality of electrode sections in a case, and is connected to the control valve. a trochoid pump that is connected to the steering handle and measures the electrorheological fluid supplied to the power cylinder via the control valve; and a trochoid pump that measures the electrorheological fluid supplied to the power cylinder via the control valve; A voltage is applied to generate an electric field, which increases the viscosity and flow resistance of the electrorheological fluid flowing through it, and the flow direction and flow rate of the electrorheological fluid that is supplied to and discharged from the power cylinder via the control valve and trochoid pump. The present invention is characterized by comprising a control section that controls.

[0006]

[Operation] First, operate the steering handle connected to the trochoid pump. This operation of the steering wheel is detected via various signals and input to the control section. Based on the signal, the control section applies a voltage to any one of the plurality of electrode sections of the control valve. Then, the viscosity of the electrorheological fluid flowing therein, and hence the flow resistance, increases. Such a phenomenon occurs at all electrode sections to which a voltage is applied, thereby controlling the flow direction and flow rate of the electrorheological fluid within the control valve. and,
The flow direction and flow rate of the electrorheological fluid supplied to and discharged from the power cylinder are controlled via the control valve and the trochoid pump.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 9. FIG. 1 is a diagram showing the overall configuration of a fully hydraulic power steering device according to this embodiment.
There is a control valve 1. Inside the case 3 of the control valve 1, four electrode parts 5, 7, 9, and 11 are arranged at intervals.

As shown in FIG. 2, the electrode section 5 includes two annular anode electrodes 13, 13 and one annular cathode electrode 15.
It is equipped with These two annular anode electrodes 13, 13
One annular cathode electrode 15 is fixed between a pair of insulating support plates 19, 19 fixed to an insulating support shaft 17. The support plate 19 is shown in FIG.
As shown, it has a cross shape. Other electrode parts 7
, 9, and 11 also have the same structure as the electrode section 5 described above.

Each annular anode electrode 13, 13 of the electrode parts 5, 7, 9, 11 is connected to a voltage generator 21 via an insulated conductor, and this voltage generator 21 is connected to a control circuit 2.
Connected to 3. The control circuit 23 receives various signals such as a steering torque signal and a steering angle signal, and drives the voltage generator 21 based on these signals. Further, the annular cathode electrode 15 of the electrode portions 5, 7, 9, 11
is grounded.

A sealing member 25 is installed between the annular anode electrode 13 at the outermost position of the electrode portions 5, 7, 9, and 11 and the case 3. Further, a sealing member 2 is also provided between the annular anode electrode 13 at the innermost circumferential position and the support shaft 17.
7 is installed. Further, a sealing member is also attached to the penetrating portion of the insulated conductive wire. The above electrode parts 5, 7, 9
, 11 and case 3, there are chambers 29, 31, 33, 3.
5, 37 are formed. Also, the chamber 33 is the pump 3
9, and rooms 29 and 37 are connected to tank 41.

The chambers 29 and 31 are connected through a detour 43, and the chambers 35 and 37 are connected through a detour 45. The detour 43 includes electrode portions 47, 4
9 and 51 are arranged. Further, electrode portions 53, 55, and 57 are also arranged on the detour path 45. The electrode section 47
As shown in FIG. 2, one annular anode electrode 59 and one
These one annular anode electrode 59 and one annular cathode electrode 61 are supported by insulating support members 63 and 65, as shown in FIGS. 4 and 5. Fixed and supported. Note that the other electrode portions 49, 51, 53, 55, and 57 have similar configurations.

[0012] The annular anode electrode 59 of each of the electrode sections 47 to 57 is connected to the voltage generator 21 described above via an insulating coated conducting wire. Moreover, each electrode part 47 to 57
The annular cathode electrode 61 is grounded. Between each of the electrode sections 47 to 57, chambers 67, 69, 71,
73 is formed.

A trochoid pump 75 is connected to the chambers 69 and 71. This trochoid pump 75 is
The configuration is as shown in FIG. First, there is a housing 77 in which a distribution valve 79 is accommodated. A steering handle 83 is connected to the distribution valve 79 via a shaft 81, and a sensor 85 is attached to the shaft 81.

The distribution valve 79 is fixed to the housing 77 by a plug 87, and an oil seal 89 and a bearing 91 are installed between the plug 87 and the housing 77. The distribution valve 79 is connected to the drive shaft 9
2 is installed. A trochoid inner 93 is disposed on the tip side of the drive shaft 92, and a trochoid outer 9 is disposed outside the trochoid inner 93.
5 is installed. The trochoid inner 93 and the trochoid outer 95 have a relationship as shown in FIG. 7, and the housing 77 and distribution valve 79 have a relationship as shown in FIG. Furthermore, the distribution valve 79 has an appearance as shown in FIG.

A power cylinder 97 is connected to the chambers 67 and 73 already mentioned. This power cylinder 97 is composed of a cylinder 99 and a piston 101 movably disposed within the cylinder 99. The piston 101 is fixed to a shaft 103, and a pair of wheels (not shown) are connected to both ends of the shaft 103.

In the case of this embodiment, ER is used as the working fluid.
Fluid 105 is used. The viscosity of this ER fluid 105 changes depending on the magnitude of the electric field.

The operation will be explained based on the above configuration. For example, assume that the steering wheel 83 is rotated to the right. This rotational operation of the steering handle 83 is detected by the sensor 85, and a detection signal is output to the control circuit 23. The control circuit 23 controls the voltage generator 2 based on the detection signal.
1 to apply a voltage to the electrode parts 7 and 11. At the same time, a voltage is applied to the electrode sections 47, 51, and 55.

By applying the above voltage, the electrode parts 7 and 11
Then, an electric field is generated in the electrode portions 47, 51, and 55, and the viscosity of the ER fluid 105 flowing therein increases, increasing flow resistance. As a result, a pressure difference is generated between each chamber, and the ER fluid 105 supplied from the pump 39 is transferred to the chamber 33.
, flows out into the chamber 71 via the electrode section 9, the chamber 35, and the electrode section 57, and flows from there toward the trochoid pump 75.

The ER fluid 105 measured by the trochoid pump 75 flows into the chamber 69 and is supplied to the cylinder chamber on the left side in the figure of the power cylinder 97 via the electrode section 49 and the chamber 67. As a result, the shaft 103 moves to the right in the figure and steers the wheels. At this time, the ER fluid 105 returning from the cylinder chamber on the right side in the figure of the power cylinder 97 is returned to the tank 41 via the chamber 73, the electrode section 53, and the chamber 37.

On the other hand, when the steering wheel 83 is rotated to the left, the effect is opposite to that described above, and ER fluid is supplied into the cylinder chamber on the right side in the figure of the power cylinder 97. Further, when the steering handle 83 is held neutral, the ER fluid 105 simply flows back into the tank 41, and the power cylinder 97 is not driven.

According to this embodiment, the following effects can be achieved. First, since there is extremely little internal leakage of the working fluid as in the conventional case, it is possible to reliably prevent the steering wheel from slipping. At this time, it is not necessary to reduce the clearance of each component through difficult machining operations as in the past. Further, unlike the conventional structure, since there is no moving part of the component parts, there is no wear due to friction between the component parts, and this also makes it possible to prevent the occurrence of the above-mentioned handle slipping phenomenon.

It should be noted that the present invention is not limited to the above embodiment. For example, the number of electrodes in each electrode section is not limited to what is shown in the figures. Furthermore, various configurations can be considered for the grounding method of the cathode electrode of each electrode section.

[0023]

[Effects of the Invention] As described in detail above, according to the fully hydraulic power steering system of the present invention, there is no need for difficult machining work to prevent the steering wheel from slipping, unlike in the conventional case. The handle slipping phenomenon can be effectively prevented. This is because an electrorheological fluid is used as the working fluid, and the flow direction and flow rate are controlled by applying appropriate voltages to multiple electrode sections. This is because the structure has an extremely low internal leakage of fluid.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating an embodiment of the present invention, and is a diagram illustrating the overall configuration of a fully hydraulic power steering device.

FIG. 2 is a diagram illustrating an embodiment of the present invention, and is a diagram illustrating the configuration of a control valve.

FIG. 3 is a diagram showing one embodiment of the present invention, and is a diagram showing an embodiment of the present invention;
II is a sectional view.

FIG. 4 is a perspective view of a support member, showing one embodiment of the present invention.

FIG. 5 is a perspective view of a support member showing an embodiment of the present invention.

FIG. 6 is a cross-sectional view of a trochoid pump, showing one embodiment of the present invention.

FIG. 7 is a diagram showing one embodiment of the present invention, and is a diagram showing VII-V of FIG.
II is a sectional view.

FIG. 8 is a diagram showing an embodiment of the present invention, and is a diagram showing an embodiment of the present invention.
VIII is a sectional view.

FIG. 9 is a perspective view of a distribution valve showing an embodiment of the present invention.

[Explanation of symbols]

1 Control valve 3 Case 5 Electrode part 7 Electrode part 9 Electrode part 11 Electrode part 21 Voltage generator (part of the control part) 23 Control circuit (part of the control part) 39 Pump (part of the working fluid supply part) 41 Tank (part of working fluid supply section) 47 Electrode section 49 Electrode section 51 Electrode section 53 Electrode section 55 Electrode section 57 Electrode section 75 Trochoid pump 97 Power cylinder

Claims (1)

[Claims] 1. A working fluid supply section that supplies and discharges an electrorheological fluid as a working fluid whose viscosity changes depending on the magnitude of an electric field; a power cylinder that outputs a power assist force for steering wheels; a control valve disposed between the working fluid supply section and the power cylinder and having a plurality of electrode sections inside the case; and a control valve connected to the control valve and connected to the steering handle and connected to the power cylinder via the control valve. A trochoid pump that measures the supplied electrorheological fluid; and a trochoidal pump that applies voltage to any one of the plurality of electrodes of the control valve based on various signals to generate an electric field, and the electrorheological fluid that flows therethrough. a control unit that increases the viscosity and flow resistance of the electrorheological fluid and controls the flow direction and flow rate of the electrorheological fluid supplied to and discharged from the power cylinder via the control valve and the trochoid pump. type power steering device.