JPS58156459A - power steering control valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control pulp for power steering for automobiles, and particularly to a control pulp for power steering that has improved characteristics of steering force.

Conventionally, as a control pulp for controlling the operating direction and power increase degree of a power cylinder, there are rotary type control pulps as shown in, for example, No. 1 II and II 211.

In this device, a rotor 2 is formed at the tip of an input shaft 1, and an output shaft 4, which is connected via an input shaft IK) and a damper 3, is integrally connected to a pulp sleeve 51 by a pin 4aK. A large number of O orifices II are formed at intervals throughout the circumferential direction between the rotor 2 and the pulp sleeve b, and pressure oil introduction boats 1 and outlet caps are placed in the pulp sleeve 5 in correspondence with each orifice II@. -) 110 respectively, and low-
2 has a return boat 11. Pressure oil port 7
and return bow) 11.

Pump bow) 13 and one provided in the pulp housing 12! 9) Connect to 14 respectively, 9, output capo.
) 9.1 The corresponding output capo provided on the Oti valve housing zinc 12 -) 15. Power piston 17 via 161
It communicates with the left and right cylinders m (R, L).

However, from the oil tank (not shown) to the pump boat 1.
3 is supplied with good pressure oil through the throttle section 6.

The flow rate to the tank boat 14 and output port 15.111 is controlled. This changes the amount of pressure oil supplied to the power cylinder 17, thereby increasing the force when switching the steering wheel left and right.

By the way, in the case of conventional control pulp, for example, as shown in FIG. Even if there are 9 sets (4 sets) in the figure, all of them are used in common. That is, the aperture characteristics of each aperture section 6 are all made the same,
As a sum total of the control action of the throttle section 6, the power piston 17 is driven through the output ports 15 and 16. Note that the arrow indicates the direction of flow of pressure oil.

However, when changing the degree of force increase depending on the vehicle speed, i.e., making the steering wheel lighter at low speeds, and conversely making the steering wheel relatively heavier at high speeds to increase stability, generally the carrot rotation speed is A sensitive pump is used to control the amount of pressure oil supplied to the pump port 13 to be large at low speeds and small at 1 ratio high speeds, but with the conventional control pulp configuration, for example, the pump discharge Change the flow rate from 6110sin for low continuous use to 3j/mi for high speed.
If n is replaced by @9, the pump discharge flow rate will become extremely low, so that during sudden steering, pressurized oil from the pump will not be sufficiently supplied to the output capo (15.16) via the throttle part 6. The amount of supplied oil may not follow the change in volume due to the movement of the power piston 17, which may cause the p-handle to feel stuck.

'* Circle, sI era According to the conventional control valve configuration, it takes relatively ms to increase the difference in steering force depending on the vehicle speed.
In addition to this, it was also difficult to individually set the desired boosting characteristics for each of them. For example, as shown in the iris sla, in the past, the steering force simply changed stepwise from high to low at appropriate times, and in most cases the width of each change was small.

The present invention has been made in view of the above circumstances, and is capable of ensuring sufficient changes in steering force according to the vehicle speed without causing a feeling of getting caught when making sharp turns while driving at high speed, and with the ability to It is an object of the present invention to provide a control pulp for power steering, which allows the optimum power increasing characteristics for the driving conditions to be set in various ways as desired.

In order to achieve such an object, the present invention includes a plurality of narrowing portions provided in the circumferential direction between the rotor and the pulp sleeve.
The pulp is divided into two or more groups with different pulp characteristics, and a pressure oil introduction boat is arranged corresponding to each group, and each pressure oil introduction boat is connected to the oil pump via a vehicle speed-sensitive oil passage switching valve. selectively communicated with each other.

In other words, the constriction formed between the rotor and the pulp sleeve is divided into two parts, for example, and one set of constrictions has a large change in the constriction, while the other has a small change, and the hydraulic characteristics are adjusted in the rotary valve itself. It has been made possible.

Below 1 An embodiment of the present invention t-$I4 Figures to tl, x1
This will be explained with reference to the figures.

In II, 18 is a valve housing, 19 is a pulp sleeve, 20 is a rotor, and 21ti)-jumper. MKt with valves IJ-bu 19 and rotor 20! ,
Convex line 22 of El-layer 20 and concave line 2 of pulp sleeve 19
3, a plurality of them are formed in the aperture part 24' at intervals in the central direction. In this, [91124 is divided into two groups with different pulp characteristics. For example, aperture s
24 are formed at eight locations (to be exact, S pairs since they are on both sides of one convex strip) at equal intervals in the local direction. Of these, there are two convex apertures US that are in contact with m, two convex apertures s that are adjacent to these in an axially symmetrical arrangement, one set t, and another set. Then, one set is for high speed (2
4A), and the other one is for low speed (24B)). High and low applicable aperture parts 5R4A and 24 of each aperture part
The valve specifications of B are described below.

The pressure oil introduction boat provided in the pulp sleeve 19 is as follows.

A pair of objects 25A whose positions are different in the axial direction.

25B. The high speed introduction bow) 25A is arranged in the circumferential direction corresponding to the high speed constriction part 24A, and the low speed introduction bow) 25B is arranged in the circumferential direction corresponding to the low speed constriction part 24A.
The circumferential arrangement corresponds to B. These introduction boats 25A and 25BH are connected to the pump boats 27A and 27A of the pump 18 through the annular grooves 26A and 26B, respectively.
27B, and each pump bow) 27A,
Pressure oil is supplied to 27B using a vehicle speed sensitive oil passage switching valve, fl.
As shown in FIG. 6, a spool valve 2B installed in the nozzle knob 1 housing 18 is used to switch the spool valve according to the vehicle speed. This Suburunokurupu 28
No (lupu w1) installed in a part of Barpuno Uzing 18
The spool valve 29 has a spring 30 (a valve 31 is provided (see Fig. 6), and the spool valve 31 is
1' For example, it is driven by hydraulic pressure (Pv) proportional to the vehicle speed from an automatic transmission (1 not shown), and a communication path 32 to the pump is connected to a communication path 33A to the high-speed pump boat 27 or a low-speed pump depending on the vehicle speed. The communication path 33B to the boat 27B is selectively switched to communicate with the communication path 33B. This is the boat for returning 34Vi leaked oil to the tank.

Note that the output port 35A provided in the valve sleeve 19,
35B is provided commonly to each aperture section 24A, 24B. The same applies to the return boat 36 provided on the rotor 20. In addition, the tank boat 39 is connected to the return boat 36 through the outer peripheral gap M of the torsion bar 21 and through the communication passage 3'138 of the cylinder 20 and the valve nose housing 18.
It connects to.

Next, the parameters of the apertures 1124A and 24B will be explained.

The structure Ds has a cross-sectional shape and dimensions as shown in FIGS. 7 and 8. In other words, the curl characteristic is rotor 2
Thickness A of the protruding line 22 of 0, end face width B (portion left after chamfering) of this protruding line 22, 1 chamfer p angle 0, and teno of the chamfered part 9 (length F of the part).

It can be set according to the valve specifications (such as the concave @OSC of the valve scoop 1). The valve specifications are set such that the steering force for the high-speed throttle section 24A is heavy, and the steering force for the low-speed throttle section 24B is set to be light. For example, by setting each of the dimensions as shown in the table below, characteristics of the aperture section for high speed and low continuous use can be provided.

Generally, the ci method is often used in a fixed manner.

However, at low speeds, the transmission oil pressure (
Pv) is small, the spool pulp 31
Since the spool pulp 31 is pushed by the shaft/gage 30 and displaced in one direction, the spool pulp 31 becomes in a state where the communication path 32 to the bong 1 is connected to the communication path 33B to the low-speed introduction bow 251 [Fig. reference).

In this case, oil from the pump is supplied only to the low-speed constriction section 24B via the low-speed pressure oil introduction boat 25B. Therefore, if it is full, then when turning right, it will be 1
For example, as shown in FIG. 9, by changing the position of the throttle part, oil from the pressure oil introduction boat 25B is supplied to the power increasing output boat 35A on the right side of the power cylinder.
The oil from the left power cylinder is returned to the tank via the return boat 36, and the right-hand power increasing action is performed due to the valve characteristics of this low-speed throttle section.

For example, as shown in FIG. 11, the oil pressure changes along a predetermined curve depending on the steering torque. In this case, by setting the valve characteristics based on the valve specifications, a wider range of changes can be made than in the conventional characteristics shown in the iris diagram.

Also, at high speeds, the transmission oil pressure (P
vl becomes high, and as a result, the spool pulp 31 moves in the opposite direction against the spring 30, and the communication direction t of the oil path is switched from the state shown in FIG. 6, and the communication path 32
．． By communicating with each other, the pressure oil supply direction to the high-speed pressure oil introduction boat 25A is switched. Therefore, in this case, the pump oil is
The valve is supplied to the throttle section 24A, and a force increasing action is performed based on the valve characteristics based on the valve specifications of the throttle section 24A. For example, as shown in Fig. 10, when turning to the right, the oil flow increases the force as in the case of low speed, and as shown in Fig. 11, the steering torque can be adjusted over a wide range.
Be able to do it. In this case, compared to the conventional one shown in FIG. 3, the torque characteristics can be changed significantly by setting various valve specifications.

Then, prepare the aperture parts 24A and 24B to be used.

Since it is used differently depending on the low speed, unlike the conventional system where all the throttle parts are used at once, a pump with a constant supply of oil tfJ can be used, unlike the conventional system that uses a six-rpm pump. By adopting the cylinder 1, etc., the disadvantage of insufficient pressure oil supply tracking due to changes in the pressure oil supply amount is eliminated, and smooth switching becomes possible. Therefore, for example, even if the vehicle is suddenly steered at high speed, there is no risk of the vehicle getting stuck as in the conventional case.

Of course, it is possible to use this method in combination with a method in which the amount of supply from the pump to the throttle section 24 is varied depending on the vehicle speed, but it is also possible to set the boosting characteristics widely enough even as a method that does not change the valve characteristics. can do.

In the above embodiment, the spool valve 31 is proportional to the vehicle speed and the hydraulic pressure (P) is used to switch between low speed and high speed. It is also possible to control oil path switching using valves and microcomputers. Moreover, it is also possible to substitute this stool valve 31t with a valve of a different type.

t, as mentioned above! Although the 1 to 5 high speed throttle section 24A and the low-speed coarse throttle section 91124B are used separately in the above example, they may be used simultaneously depending on the case. For example, at low speeds, if a large amount of supplied oil is adopted and the 6. The entire constriction section 24 may be used, and the high-speed constriction section 24A may be used only at 1% speed.

As described above, the present invention not only eliminates the risk of getting stuck when making sharp turns while driving at high speed, but also ensures sufficient differences in steering force changes depending on the vehicle speed, as well as ensuring the optimum steering force for each driving condition. Increased power characteristics ti! It can be set in various ways as desired, and the force increasing characteristics can be improved compared to conventional ones.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional examples, with Figure 1 being a vertical cross-sectional view of the first part, Figure 2 being a cross-sectional view taken along line B-H in Figure 1,
Fig. 3 is a characteristic diagram, Figs. 4 to 11 show an example of an actual plant of the present invention, Fig. 111E4 is a vertical cross-sectional view of the main part, and Fig. 5 is a cross section taken along the line ■-V of Fig. 4. FIG. 6 is an enlarged sectional view of a vehicle speed-sensitive oil passage switching valve, and FIG. 7 is an enlarged sectional view showing valve specifications. Figure 8 is a perspective view of the same, Figures 189 and 10 are sectional views showing the action, and Figure 11 is a characteristic diagram. 19... Valve sleeve, 2o... Rotor. 24 (24A, 24B)... Throttle part, 25A... Pressure oil introduction port for high speed), 25B... Pressure oil introduction port for low speed, 35A, 35B... Output boat, 28... Vehicle speed sensitive Type oil line switching valve. Agent Tatsuyuki Unuma (and 2 others) Figure 1 Figure 2 Figure 3 B, Chiyuki Hitorso Ishi Lρ
(kgm) Figure 4 Figure 5 Figure 7 Figure 8 Figure 9 Figure 1I

Claims (1)

[Claims] (1) A plurality of orifices US are formed at intervals in the circumferential direction between the rotor and the pulp sleeve, and the pulp sleeve is provided with 9 pressure oil inflowing from the pressure oil introduction port to power the pressure oil through the 9 parts of the orifice. At the control valve of a rotary power steering system, which is supplied to the output port to the piston, 9 parts of Zeng Qi is divided into two or more types of pulp with different pulp characteristics (as well as being divided into two or more types and corresponding to each group). A control pulp for power steering, in which a pressure oil introduction port is arranged and selectively communicated with each pressure oil introduction port 7 through a vehicle speed sensitive type oil passage switching valve. .