JPH0224699Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a hydraulic reaction force device for obtaining an appropriate steering force in accordance with the traveling speed of a vehicle in a power steering device.

[Conventional technology]

In recent years, power steering devices known as power steering have become widely installed in various vehicles, including small cars, and their steering assist power reduces the driver's steering effort and allows for easier steering operations. Various configurations have been known in the past, which can be effective in reducing driver fatigue and the like.

By the way, in this type of power steering device,
The system appropriately controls the operation of the device based on various driving conditions, including the steering force and steering angle according to the driver's steering operation, as well as the vehicle's running speed, so that the steering assist force can be obtained as needed. It is desired that the system be structured as follows. In other words, for vehicles equipped with this type of power steering device, extremely light steering force can be obtained when performing steering operations when the vehicle is stationary, so-called stationary operations, or when driving at low speeds. Therefore, it is necessary to have a configuration that can output a large steering assist force. but,
On the other hand, when the vehicle is traveling at high speeds, if a large steering assist force is generated as described above when traveling at low speeds, the operating force on the steering wheel becomes too light, causing the driver to feel uneasy. This leads to problems such as increasing the steering wheel's weight, which is not practical in terms of optimizing the driving sensation. A configuration that increases the force is required.

For this reason, hydraulic reaction force devices have conventionally been developed that can control the stiffness (steering reaction force) of the steering wheel when the vehicle is running at high or low speeds by applying an appropriate steering reaction force to the steering wheel. For example, as shown in Japanese Unexamined Patent Publication No. 102092/1983, at least one pair of plungers and a hydraulic reaction chamber for driving them are installed in a part of the rotary control valve for switching the flow path. The plunger is driven by supplying pressure oil according to the running speed of the vehicle to apply a reaction force proportional to the steering resistance to the steering wheel, thereby maintaining an appropriate steering sensation for the driver. It is known that this has been made possible. and,
The conventional structure described above can perform steering force control that is extremely efficient and has excellent followability, does not require installation space, and can be easily assembled, making it suitable for use as a power steering device. This makes it possible to achieve advantages such as the ability to make the device smaller and more compact.

[Problem that the invention attempts to solve]

However, according to the conventional structure described above, it is extremely difficult due to the structure to make the neutral position of the pair of plungers constituting the hydraulic reaction device coincide with the neutral position of the flow path switching control valve. However, there were also problems in that high processing precision was required for the components of these parts. That is, in the conventional device described above, a pair of plungers that are movable according to the vehicle speed are urged by hydraulic pressure or the like in opposite rotational directions, and the pressing force of one of them is used to control the rotation of the input side member of the control valve. restrain,
This controls the steering force, and is very effective, but the tips of the pair of plungers, which are slidably supported by the output side member of the control valve, are connected to the controlled part of the input side member. Due to problems in the molding process, the position where it engages with the output side member and the position where it abuts against the stopper formed on the output side member tend to deviate, resulting in looseness between them. It had the disadvantage of being difficult to obtain. This is because the stopper of the output side member and the controlled portion of the input side member are both faced between the pair of plunger tips mentioned above, and the plunger engages with them. Although strict processing accuracy is required, it is easy to understand that it is virtually impossible to meet such demands.
Therefore, in this type of hydraulic reaction device,
It is desired to take some measures that can solve the above-mentioned problems such as backlash between the input and output side members with a simple configuration.

[Means for solving problems]

In order to meet the above-mentioned requirements, the hydraulic reaction force device of the power steering device according to the present invention is arranged oppositely so as to restrain the rotational displacement of the input side member of the control valve by the hydraulic pressure supplied according to the vehicle speed. plunger,
The plungers are slidably held on the output side member so as to be able to come into contact with the controlled part on the input side member side of the control valve from mutually opposite rotational directions, and each of these plungers has its opposing end connected to the output side member. A protrusion is integrally provided with an adjustable protrusion amount that engages with the controlled portion of the input side member in a neutral state where the input member is stopped by a stopper formed on the input member.

[Effect]

According to the present invention, a protrusion whose protrusion amount can be adjusted is formed at the tip of the plunger that applies hydraulic reaction force to the input side member, and the tip of the protrusion is brought into contact with the controlled portion of the input side member. Because of this structure, the amount of protrusion of this protrusion can be adjusted by simple post-processing to match the neutral position of the output side member.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

1 to 4 show an embodiment of a hydraulic reaction force device for a power steering device according to the present invention,
In these figures, first, the schematic structure of the rotary control valve 2 as a flow path switching control valve in a power steering device, which is indicated by the reference numeral 1 in its entirety, will be briefly described. , a pinion shaft on the output side having a pinion 10a meshing with a rack (not shown); 11 is this pinion shaft 1;
The input shaft is coaxially connected to the right end of the steering wheel 0 via a torsion bar 12, and the right end thereof is connected to a steering wheel (not shown), and both shafts 10 and 11 are rotated as appropriate in the steering direction. Reference numeral 13 indicates that these two shafts 10 and 11 are disposed through each other, and the relative rotational displacement thereof is used as an input to control the flow between the oil pump P, oil tank T, and the left and right cylinder chambers C _L and C _R of the power cylinder. This housing 13 is a valve housing of a control valve 2 that performs path switching.
A rotor 14 and a sleeve 15, which are integrally provided to the shafts 11 and 10, respectively, are rotatably housed and supported.

Here, the rotor 14 and sleeve 1 described above
5. Furthermore, the hydraulic circuit configuration in the housing 13 is well known, and as is clear from FIG. Passage grooves 14a and 15a are formed at predetermined intervals, and the above-mentioned hydraulic circuit is switched and controlled by selectively opening and closing these passage grooves 14a and 15a. Furthermore, in the figure, 16 and 17 are suction ports into which pressure oil flows from the oil pump P, and return ports which return pressure oil to the oil tank T; 18A and 18B are the left side of the power cylinder;
These are the left and right discharge ports connected to the right cylinder chambers C _L and C _R , and also 19a, 19b, 20a, 20
b, 20c are passage holes formed in the rotor 14 and sleeve 15, 21a, 21b, 21c, 21
d is an annular groove 22a, 22b, 2 formed on the outer periphery of the sleeve 15 and communicating with each port;
2c is a bearing that rotatably supports each part, 2
3 is an oil seal. Note that the configuration and operation of such a rotary control valve 2 are conventionally well known, and a detailed explanation thereof will be omitted.

Now, according to the present invention, in the power steering device 1 equipped with the rotary control valve 2 for flow path switching having the above-described configuration, as shown in FIGS. 1 and 2,
The control valve 2 is connected between the input and output side members 11 and 10 of the flow path switching control valve 2, which distributes and controls pressure oil according to relative rotational displacement according to the steering operation, by means of hydraulic pressure supplied according to the vehicle speed. It includes plungers 30 and 31 that are arranged opposite to each other so as to restrain the rotational displacement of the input side member 11, and an annular groove 32 that forms a hydraulic reaction chamber to which hydraulic pressure supplied in accordance with the vehicle speed is guided to the outer end thereof. A hydraulic reaction force device 3 is interposed therebetween.
In this hydraulic reaction device 3, the pair of plungers 30 and 31 are mounted on a pair of lever portions 33 that protrude in the radial direction on the tip side of the rotor 14 of the control valve 2. A sleeve 1 constituting the output side member 10 so as to be able to come into contact with the engagement pin 34 as a control part from mutually opposite rotational directions.
Each plunger 3 is slidably held within a cylindrical body 35 integrally connected to
0 and 31, opposite ends thereof are formed in the cylindrical body 35 and have a stopper 36 (stopper surface 36a,
36b), protrusions 37 and 38 are integrally provided to protrude, and the amount of protrusion that engages with the engagement pin 34 on the rotor 14 side can be adjusted in a neutral state.

That is, according to the present invention, by adopting the above-described configuration, the plungers 30, 3 constituting the hydraulic reaction force device 3 that applies hydraulic reaction force to the input side member
1 neutral position, that is, the stopper surfaces 36a, 36b
The deviation that occurs between the locked position and the neutral position of the control valve 2 made up of the rotor 14 and the sleeve 15, that is, the position where the engagement pin 34 faces between the plungers 30 and 31, is determined by the above-mentioned protrusion amount. This can be easily solved by using the protrusions 37 and 38 that can be adjusted. As shown in FIG. 1, this allows the plungers 30, 31 to be
a, 36b, the tips of the protrusions 37, 38 are post-processed by cutting, etc., so that they make contact with the engagement pin 34, which is the controlled part on the input side. This is obtained by adjusting the amount of protrusion of the protrusions 37 and 38, and will be easily understood. With this configuration, it is possible to obtain high precision without causing rattling or the like as in the past, so it is possible to obtain reliable hydraulic reaction force and perform appropriate steering force control. Furthermore, the structure is simple, the adjustment work is easy, and the cost is low.

Here, to explain in detail the above-mentioned hydraulic reaction force device 3, as shown in FIG. It is slidably held in a plunger hole formed in a continuous cylindrical body 35, and its outer end is held by a leaf spring 39 with a weak biasing force screwed to the cylindrical body 35. This prevents it from falling off. In addition, according to this embodiment, a case is shown in which two sets of the plungers 30 and 31 described above are used.

The outer ends of the plungers 30 and 31 face the annular groove 32 forming the hydraulic reaction chamber, and the hydraulic pressure introduced into the annular groove 32 from the control port 40 bored in the housing 13 is applied. The structure is such that it can move forward and backward within the hole accordingly.
Here, the above-mentioned control port 40 is connected to a hydraulic pressure source Q that can send out hydraulic pressure according to the vehicle speed, such as pressure oil sent out from a pump P, and is inputted by the plungers 30 and 31 driven by this. Axis 11
Apply the required steering reaction force to the side. In other words, at low speeds, low pressure oil pressure is introduced and the above-mentioned input shaft 1 is
The steering reaction force on the first side is reduced to enable light steering operation, and at high speeds, high pressure hydraulic pressure is introduced to increase the steering reaction force and increase the steering stiffness.

Furthermore, as shown in FIG. 3, the lever portions 33, 33 at the tip of the rotor 14 on the input side are connected to a concave portion 41 formed in a cylindrical body 35 integrally connected to the sleeve 15 on the output side. They are combined to be able to swing by a predetermined angle within the interior, thereby forming a fail-safe mechanism. Furthermore, in the figure, 42 is a pin that connects the cylindrical body 35 and the sleeve 15, which are separate components, in the rotational direction.

Note that the present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part may be modified and changed as appropriate. For example, instead of the protrusions 35 and 36 integrally formed at the tips of the plungers 30 and 31 in the embodiment described above, a screw shaft 50 is used as the protrusion, as shown in FIG. 5, and the tips are configured to move forward and backward. By doing so, the amount of protrusion may be adjusted more easily. In this case, after the above-mentioned adjustment, it is preferable to caulk and fix the screw shaft 50 or use a lock nut. In addition, this screw shaft 50
If you apply sealant in advance,
It is possible to ensure oil tightness in this part, which has a great advantage in terms of operational reliability.

[Effect of idea]

As explained above, according to the hydraulic reaction force device for a power steering device according to the present invention, the amount of protrusion can be adjusted at the tip of the plunger that applies a hydraulic reaction force by contacting the controlled part of the input side member. Since the protrusion is provided, the configuration is simple and inexpensive, but by adjusting the amount of protrusion of the protrusion described above, the neutral position on the hydraulic reaction device side can be easily and appropriately adjusted to the neutral position on the control valve side. This allows for highly accurate positioning without causing rattling, which is the case with conventional methods, resulting in reliable hydraulic reaction force and appropriate steering force control. Furthermore, it has various excellent practical effects such as its simple structure, easy adjustment work, and low cost.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of essential parts showing an embodiment of the hydraulic reaction device of a power steering device according to the present invention, FIG. 2 is a schematic vertical sectional view showing a control valve portion of the power steering device, and FIG. 4 and 4 are enlarged cross-sectional views taken along lines - and - in FIG. 2, and FIG. 5 is an enlarged cross-sectional view of essential parts showing another embodiment of the present invention. 1... Power steering device, 2... Rotary control valve for flow path switching, 3... Hydraulic reaction force device, 10... Pinion shaft (output side member), 11... Input shaft (input side member) , 12... Torsion bar, 13... Valve housing, 14... Rotor (input side member), 1
5... Sleeve (output side member), 16... Suction port, 17... Return port, 18A, 18B...
Discharge port, 30, 31... Plunger, 32...
...Annular groove (hydraulic reaction force chamber), 33...Lever part, 3
4... Engagement pin (controlled part), 35... Output side cylindrical part, 36, 36a, 36b... Stopper, 3
7, 38... Protrusion, 40... Control port, 50
...Screw shaft, P...Pump, T...Tank, C _L ,
C _R ……Left and right cylinder chambers of power cylinder, Q
...Hydraulic power source.

Claims (1)

[Scope of utility model registration request] A control valve for flow path switching that distributes and controls pressurized fluid according to relative rotational displacement according to steering operation is inserted between the input and output side members, and the input side is controlled by hydraulic pressure supplied according to the vehicle speed. In a hydraulic reaction device having plungers arranged to face each other so as to restrain the rotational displacement of a member, the paired plungers abut a controlled portion on the input side member side of the control valve from mutually opposite rotational directions. Each of these plungers is slidably held on the output side member side so that the output side member receives the output side member, and each of these plungers is in a neutral state in which the opposite end thereof is locked by a stopper formed on the output side member. A hydraulic reaction force device for a power steering device, characterized in that a protrusion that engages with a controlled portion of a side member and whose protrusion amount can be adjusted is integrally protruded.