JPH037265Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a power steering device equipped with a hydraulic reaction force mechanism.

<Prior art> In a power steering device equipped with a hydraulic reaction force mechanism that controls the steering force of the power steering device according to vehicle speed, etc., hydraulic pressure is applied to a counter cylinder chamber of the hydraulic reaction mechanism in accordance with vehicle speed, etc. In order to supply this, a part of the pressure oil discharged from the power steering pump is divided to control the pressure, or a dedicated pump for reaction force is provided.

<Problems to be solved by the invention> However, in the former method, the hydraulic circuit becomes complicated due to the diversion of oil to the reaction side and the pressure control action, and in the latter method, a separate pump must be provided. There are problems such as not being able to do so.

<Means for Solving the Problems> The present invention was made to solve the above-mentioned conventional problems, and includes an introduction pipe for introducing the governor pressure of the torque converter into the reaction cylinder chamber of the hydraulic reaction mechanism. , a pressure reducing valve provided in the introduction pipe to reduce the governor pressure, a linear solenoid controlling the reduced pressure of the pressure reducing valve, and a current value applied to the linear solenoid controlled in accordance with a vehicle speed signal or a steering angle signal. It is constructed by a solenoid drive circuit.

<Examples> Examples of the present invention will be described below based on the drawings. In FIG. 1, reference numeral 10 denotes a gear housing forming the main body of the power steering device, and a pinion shaft (output shaft) 11 is rotatably supported in this gear housing 10, and this pinion shaft 11 is rotated in a direction crossing this. It is meshed with a rack shaft 14 which can be slid on. Both ends of the rack shaft 14 are connected to steering wheels via a required steering linkage, and the rack shaft 14
Although not shown in the figure, the piston of the power cylinder is operatively connected.

The gear housing 10 includes a valve housing 18.
is fixed, and a rotary type servo valve 20 is housed within this valve housing 18. The rotary type servo valve 20 is composed of a sleeve valve member 21 and a rotor valve member 22 that are relatively rotatable about the axis of the pinion shaft 11, and the rotor valve member 22 is connected to a steering shaft (input (shaft) 24. Steering shaft 24
is flexibly connected to the pinion shaft 11 via a torsion bar 25 and engaged via an engaging portion 23 so as to be relatively rotatable by a predetermined amount.

A plurality of port grooves 21a, 22 are provided on the inner circumference of the sleeve valve member 21 and the outer circumference of the rotor valve member 22.
a are formed at equal angular intervals on the circumference, and by relative rotation of the sleeve valve member 21 and the rotor valve member 22, the supply port 26 is communicated with one of the supply and discharge ports 28 and 29 connected to both chambers of the power cylinder. The other end is connected to the discharge port 27.

A cylindrical portion 30 that rotatably fits into the valve housing 18 is formed at one end of the pinion shaft 11, and one end of this cylindrical portion 30 is connected to the sleeve valve member 21 via a connecting pin 31. . A reaction force cylinder chamber 33 is formed in the cylindrical portion 30 concentrically with the pinion shaft 11, and a flange-shaped reaction force receiving portion 34 formed on the steering shaft 24 can be relatively rotated in this reaction force cylinder chamber 33. It is fitted.
A ring-shaped reaction piston 35 is fitted into the reaction cylinder chamber 33 so as to be slidable in the axial direction, facing the reaction receiving portion 34 . It is prevented from rotating with respect to the shaft 11. The inner periphery of the reaction piston 35 is fitted onto the steering shaft 24, and the reaction piston 35 divides the reaction cylinder chamber 33 into a left chamber and a right chamber. A plurality of conical recesses 34a, 35a are formed on the circumference of the opposing surfaces of the reaction force receiving portion 24 and the reaction force piston 35, and these recesses 34a, 35a
A retainer 37 holding a plurality of circumferential engagement balls 36 (see FIG. 2) that engage with the reaction force receiving portion 34 and the reaction piston 35 is interposed between the reaction force receiving portion 34 and the reaction force piston 35. Thus, the reaction piston 35 is always pressed in a direction into which it engages the engagement ball 36 by the web washer 39 provided on its back surface.

Reference numeral 40 indicates a torque converter that generates governor pressure according to the vehicle speed, and the governor pressure of this torque converter 40 is introduced into the left chamber of the reaction force cylinder chamber 33 through an introduction pipe 41 and an introduction port 42. ing. Note that the right chamber of the reaction force cylinder chamber 33 is communicated with the drain port 43.

A pressure reducing valve 50 is provided in the introduction pipe 41 as shown in FIG. A solenoid drive circuit 52 is provided for control according to the steering angle signal θ.

In the above configuration, when the vehicle speed is low, the governor pressure introduced into the left chamber of the reaction cylinder chamber 33 is low, and therefore, when the steering shaft 24 is rotated by steering wheel operation, the reaction piston 35 is moved toward the web washer 39. The sleeve valve member 21 and the rotor valve member 22 are easily retracted against the generated force, whereby the sleeve valve member 21 and the rotor valve member 22 are rotated relative to each other, and a normal power steering action is performed.

However, when the governor pressure increases as the vehicle speed increases, this governor pressure is applied to the pressure reducing valve 50 in the introduction pipe 41.
is introduced into the left chamber of the reaction force cylinder chamber 33 via
The pressing force of the reaction piston 35 against the engagement ball 36 is increased. This increases the manual torque that causes the sleeve valve member 21 and the rotor valve member 22 to rotate relative to each other, and provides vehicle speed sensitivity in which the manual torque increases as the vehicle speed increases. In this case, by controlling the current value applied to the linear solenoid 51 according to the vehicle speed signal V or the steering angle signal θ, the reaction oil pressure to the vehicle speed can be freely controlled.
It also becomes possible to control the reaction oil pressure according to the steering angle.

<Effects of the invention> As described above, the present invention includes an introduction pipe for introducing the governor pressure of the torque converter into the reaction force cylinder chamber of the hydraulic reaction force mechanism, and a pressure reducer provided in the introduction pipe for reducing the governor pressure. The valve, a linear solenoid that controls the pressure reduction of this pressure reducing valve, and a solenoid drive circuit that controls the current value applied to this linear solenoid according to the vehicle speed signal or steering angle signal, so it can be used for power steering. Compared to those that use oil discharged from a pump or those that use a pump exclusively for reaction force, the configuration is simpler, and the reaction oil pressure can be freely controlled depending on the vehicle speed or steering angle.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a diagram showing a power steering device equipped with a hydraulic reaction force mechanism, and FIG. 2 is a diagram showing the main parts of the present invention. 33...Reaction force cylinder chamber, 35...Reaction force piston, 40...Torque converter, 41...Introduction pipe, 50...Pressure reducing valve, 51...Linear solenoid, 52...Solenoid drive circuit.

Claims (1)

[Scope of utility model registration request] In a power steering device equipped with a hydraulic reaction force mechanism that controls steering force according to vehicle speed or steering angle, an introduction pipe for introducing governor pressure of a torque converter into a reaction force cylinder chamber of the hydraulic reaction force mechanism; A pressure reducing valve installed in the pipe to reduce the governor pressure, a linear solenoid controlling the reduced pressure of the pressure reducing valve, and a solenoid drive controlling the current value applied to the linear solenoid according to a vehicle speed signal or a steering angle signal. A power steering device equipped with a hydraulic reaction force mechanism configured by a circuit.