JPS6194871A - Electronic control type power steering device - Google Patents

Abstract

PURPOSE:To secure the safety of steering at high speed driving by controlling the assist power of a power steering device according to the car speed using an electronic control unit. CONSTITUTION:When a handle is steered at driving, the pressurized oil from a pump is supplied to a cylinder and the oil pressure assist power can be obtained. In this case, pressurized oil is supplied to an oil pressure reaction force pressurized oil chamber 14 according to the car speed by an electronic control unit and presses a plunger 16 inside. As a result, the plunger 16 makes contact with the one side wall of a V groove 1a stretching in the axial direction of an input shaft and generates the reaction force that returns a shaft 1 to the neutral direction. By this actuation, a driver can receive a sense of steering that is suitable for the car speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an electronically controlled power steering device which uses an electronic control device to reduce 77 strokes of the power steering according to vehicle speed to ensure safety during high-speed steering.

(Prior art) As shown in Japanese Patent Publication No. 54-9368, the tip of a torsion bar, one end of which is fixed to an input shaft connected to a steering wheel, is fixed to a pinion shaft engaged with an output shaft connected to a steering wheel. Hydraulic power steering devices are known in which the power assist force is controlled by controlling hydraulic pressure by relative angular displacement between an inner valve member formed on the shaft and an outer valve member engaged with the pinion shaft. When a force is applied, an excessive load is applied to the pin that engages the outer valve member and the pinion shaft, causing a serious problem in that the pin part becomes loose and breaks.

(Purpose) The present invention prevents the generation of rattling and damage of the pin portion by preventing excess load from acting on the pin that engages the outer valve member and the pinion shaft even when a large hydraulic reaction force is applied, and prevents the valve itself from being damaged. The purpose is to stabilize the operation of the

(Structure) In order to achieve the above object, the present invention has a torsion bar having one end fixed to an input shaft connected to a steering wheel, fixed to a pinion shaft engaged with an output shaft connected to a steering wheel, and formed on the input shaft. In a hydraulic power steering device that controls power assist force by controlling oil pressure by relative angular displacement between an inner valve member and an outer valve member engaged with a pinion shaft, a plurality of A radial through hole is provided in which each plunger is slidably inserted, the tip of the plunger is fitted into a vertical groove on the outside of the input shaft, and the plunger is pressed inward with hydraulic pressure that corresponds to the vehicle speed. It is characterized by having an electronic control device that reduces the relative angular displacement of the output shaft and the power assist force. Hereinafter, a detailed explanation will be given based on an example.

An input shaft 1 connected to a handle (not shown) is fixedly integrated at each end with a pinion 3 and a tone bar 4 that mesh with a rack 2 of the output shaft. A drive pin 5 is press-fitted into the large end of the pinion 30,
The valve body 6, which is the outer member of the rotary valve, is engaged with and integrated with a groove 7 without play in the rotational direction. The inside of the valve body 6° is fitted with the outer diameter part of the input shaft with a small gap, forming a known rotary valve, and the torsional action of the torsion bar 4 causes a gap between the input shaft 1 and the pinion 3. By causing a relative angular displacement and operating a valve, pressurized oil from a pump (not shown) is supplied from IN port 8, selectively supplied to right cylinder 10 and left cylinder 11, and hydraulic assistance is performed. There is. .

Some pinion heads have two seal rings 12.13.
is provided to form a hydraulic reaction pressure oil chamber 14. The hydraulic reaction force pressure oil chamber 14 is provided with four holes in the radial direction perpendicular to the pinion shaft axis and one hole 15 for the plunger, and the plunger 16, which is fitted with a small gap, receives the pressure oil and moves radially inward. It's a trap so it can slide. The tip of the plunger 16 has a spherical head 16α, which comes into contact with a V-groove 1α extending in the axial direction at one end of the input shaft. The positional relationship among the plurality of V grooves 1α on the input shaft, the plunger hole 15, and the drive pin 5 is similar to that of a rotary valve (valve body 6,
The centers are aligned well so that the reaction force is zero at the valve neutral position of the input shaft 1). Reference numeral 40 denotes an electronic control device that converts pressure oil supplied from a pump (not shown) to the import 8 into hydraulic pressure according to the vehicle speed and supplies it to the port 19 of the hydraulic reaction pressure oil chamber 14 .

Next, the effect will be explained. In this embodiment, when steering to the right, the pinion 3 does not rotate due to the rotation of the input shaft 1 because it is engaged with the movable head rack 2 due to the turning resistance, which causes torsional displacement in the torsion bar 4. Displacement occurs between the valve bodies 6, and pressure oil from a pump (not shown) moves 8→
Cylinder port 10 → Supplies to the right cylinder and is hydraulically assisted. On the other hand, the return oil from the left cylinder is returned to the left cylinder → cylinder port 11 → return oil passage 20 → return port 9 → tank (not shown). At this time, the electronic control device 40 supplies pressure oil from the IN line to the hydraulic reaction pressure oil chamber 14 at a hydraulic pressure corresponding to the vehicle speed.
Press plunger 16 inward. The input shaft 1 is displaced as shown in Fig. 4, and the plunger 16 is fitted into the pinion side hole, so it moves upward while contacting the left side slope of the v3t-t. Since the load is applied inward in the radial direction due to reaction pressure, it receives a downward load. That is, it functions to return the V-groove 1α to the zero point.

Therefore, the driver can use the conventional torsion bar reaction force +
Since it receives a vehicle speed-sensitive hydraulic reaction force, it can receive a steering sensation that corresponds to the vehicle speed.

In addition, even when the steering wheel is in a neutral state (straight ahead state) when driving at high speed, when reaction pressure oil is applied to the hydraulic reaction pressure oil chamber 14, the plunger is at the initial position and the pressure load is applied in the radial direction as shown in Fig. 3. The pinion 3 is inserted through the plunger 16 to receive it inside.
Since the power assist force is eliminated and the input shaft 1 is integrated, the neutral stiffness of the steering wheel is increased and safe steering is possible without the steering wheel wobbling.

(Effects) According to the present invention, the tip of a torsion bar with one end fixed to an input shaft connected to a steering wheel is fixed to a pinion shaft engaged with an output shaft connected to a steering wheel, and an inner valve member formed on the input shaft and a pinion In a hydraulic power steering device that controls hydraulic pressure and power assist force by relative angular displacement between outer valve members engaged with the shaft, a portion of the pinion shaft has a plurality of radial passages. A hole is provided and each plunger is slidably inserted into the hole, the tip of the plunger is fitted into the vertical groove on the outside of the input shaft, and the plunger is pressed inward with hydraulic pressure according to the vehicle speed, thereby connecting the input shaft and output shaft. It has an electronic control device that reduces the power assist force by reducing the relative angular displacement, so even if a large hydraulic reaction force is applied, there is no excess load on the pin that engages the outer valve member and the pinion shaft. This prevents the occurrence of backlash and damage to the pin portion, and stabilizes the operation of the valve itself.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view including an oil passage system according to an embodiment of the present invention, FIG. 2 is a plane cross-sectional view taken along the line A-A in FIG. 1, and FIG. 3 is an enlarged plan view of the main part of FIG. FIG. 4 is a plan view of the main part during operation as shown in FIG. 3. ■...Input shaft, 1α...V groove, 3...Binion,
4... Torsion bar, 5... Dry hinge, 6...
... Valve body, 7... Groove, 14... Hydraulic reaction pressure oil chamber, 15... Plunger hole, 16... Plunger, 16α... Spherical head of plunger. Patent applicant Koyo Automatic Machinery Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4 Procedures Amendment 8 (voluntarily submitted) December 21, 1980 Commissioner of the Patent Office Manabu Shiga 1, Indication of the case 1982 Patent Application No. 216369 2, Name of the invention Electronically controlled power steering device 3, Relationship with the person making the amendment Patent applicant Address 333-2, Toichi-cho, Kashihara City, Nara Prefecture Name Koyo Jiki Co., Ltd. 4, Agent Personal address: 2-2-5-5 Shinbashi, Minato-ku, Tokyo, date of amendment order: 6, subject of amendment: Drawing 7, details of amendment: Figure 1 of the drawing is amended as shown in the attached sheet. Figure 1

Claims (1)

[Claims] The tip of a torsion bar with one end fixed to an input shaft connected to a steering wheel is fixed to a pinion shaft engaged with an output shaft connected to a steering wheel, an inner valve member formed on the input shaft and an outer valve member engaged with the pinion shaft. In a hydraulic power steering device that controls power assist force by controlling oil pressure by relative angular displacement between pinion shafts, a plurality of radial through holes are provided in a part of the pinion shaft, and each plunger slides through a plurality of radial holes. The tip of the plunger fits into the vertical groove on the outside of the input shaft, and the plunger is pressed inward with hydraulic pressure according to the vehicle speed, reducing the relative angular displacement between the input and output shafts to provide power assist. Electronically controlled power steering device with an electronic control device that reduces the force.