JPH02114065A - Steering angle detector in rack and pinion type steering device - Google Patents

Abstract

PURPOSE:To improve the mounting performance of a steering angle sensor by forming a rack gear for detecting the steering angle at a part of a steering gear member (rack) and meshing a pinion for detecting the steering angle with said rack gear and operating a steering angle sensor by the revolution of the pinion. CONSTITUTION:A rack gear 11 for detecting the steering angle is formed along the axis line direction between a part of a rack 5 which constitutes a steering link mechanism 4 for turning a steering wheel according to the steering operation, in other words, the rack teeth 5a part and a rod part 5b constituting a power cylinder part 9. A pinion 12 for detecting the steering angle which converts the max. displacement of the rack 5 at most to one revolution is meshed with the rack gear 11, and a steering angle sensor 13 for taking out the revolution as the steering angle detection signal is installed onto the revolution shaft of the pinion 12, and a steering angle detector 11 is constituted. Therefore, a steering angle sensor 13 can be installed onto the side part of the body cylindrical part 3b part having the allowance in the installation space, and the mounting performance can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a steering angle detection device in a rack and pinion type steering device equipped with a steering angle sensor.

[Conventional technology]

Rack and pinion type steering devices have advantages such as a relatively simple structure, small size and light weight, and are advantageous in terms of installation space, as well as excellent steering performance. It is widely respected by various vehicles.

For example, a rack and pinion type steering device for manual steering generally includes a pinion provided at the tip of a steering shaft connected to the steering handle,
A rack that has rack teeth that mesh with the pinion teeth and that forms part of the steering link mechanism by being suspended horizontally between the steering wheels (front wheels) of the vehicle is incorporated into the steering body as a steering gear member. A steering link mechanism is constructed by connecting tie rods connected to both ends of the rack to a pitman arm on the steering wheel side via a bolt. In addition, for power steering, a rotary flow path switching valve is installed between the above-mentioned steering shaft and pinion, and a power cylinder is formed in a part of the rack in the axial direction. It is configured to provide steering assist force.

By the way, the above-mentioned rack and pinion type steering device is equipped with sensors that detect the steering force, steering angle, etc. according to the driver's steering operation, and together with a vehicle speed sensor that detects the running speed of the vehicle, etc. It has come to be used as an information source to confirm the driving state of the vehicle, and to appropriately control the drive of various on-vehicle devices and devices, which have become increasingly computerized in recent years, in accordance with the driving state of the vehicle. For example, a steering device for power steering (power steering device) outputs a large steering assist force to enable light steering operations when the vehicle is stopped or driving at low speeds, but on the other hand, when driving at high speeds, it outputs a large steering assist force to enable easy steering operations. It is desirable to reduce the auxiliary force so that the operating force of the steering wheel is at a certain level to eliminate the driver's anxiety caused by the steering wheel being too light. , the above-mentioned steering angle sensor and the like are necessary even for small vehicles. especially,
Recently, common hydraulic power steering systems have become known, such as those that use solenoid valves for hydraulic control, and those that connect a pump to the engine via an electromagnetic clutch for efficient operation. .

Furthermore, an electric motor is used to drive an oil pump, and a transmission motor is used to directly drive and control a steering shaft, and the various detection sensors described above are indispensable.

Also, in rear wheel steering devices etc. of four-wheel steering vehicles,
Rear wheel steering control was performed by attaching the aforementioned steering angle sensor to the front wheel steering device, etc., and determining the rear wheel steering angle according to the magnitude of the steering angle. .

Conventionally, when attaching such a steering angle sensor, in the above-mentioned rack and pinion type steering device, for example, a rotary sensor capable of detecting rotational displacement is provided on the pinion shaft, etc. that is rotated in accordance with the steering wheel. Or the roller 2 that meshes with this pinion and moves in the axial direction.
It has generally been common practice to provide a linear sensor capable of detecting linear displacement.

[Problem to be solved by the invention]

However, the rack and pinion type steering device equipped with a large steering angle sensor and the like sometimes causes some problems in assembling it into a vehicle. In other words, it is preferable to install the steering angle sensor in a portion of the steering body that faces the tip of the pinion shaft that engages with the rack, in terms of the relationship with the mechanical components that make up the steering device. On the other hand, if such a sensor is provided so as to protrude from the outside of the body corresponding to the tip end side of the pinion shaft, a problem arises in that the installation space cannot be secured depending on the layout on the vehicle side. In addition, in the case where the pinion shaft and the sensor shaft are supported in parallel with the pinion shaft in the body, and each gear is provided with a gear for transmitting rotation, an opening on the body side for incorporating this transmission mechanism or There is also the problem that it is difficult to satisfy the sealing performance between the lid body which is closed and where sensors and the like are provided.

This is because, as mentioned above, in the two-wheel configuration parallel to each other,
This was because the shape of the opening was non-circular, and reliability could not be achieved with a simple seal.

Furthermore, it is necessary to provide a gear at the tip of the pinion shaft for transmitting rotation to the sensor side, or to process the gear, which poses a problem in terms of processability.

Furthermore, such a pinion shaft can be rotated several times in both the left and right directions by steering operation, and in order to detect this with a rotation sensor such as a potentiometer and detect the steering angle, it is necessary to set the pinion shaft to the neutral position. In addition to precisely positioning and combining the pinion with respect to the sensor, the speed reduction mechanism reduces the rotation of the pinion shaft so that it rotates within one rotation of the gear, and the amount of displacement from the neutral position can be extracted as a steering angle detection signal. It is necessary, and the processing and assembly work of each part becomes troublesome.
There was also the problem of high costs.

In particular, such a steering angle detection device is not limited to detecting the steering state of the steered wheels via the steering gear member by the pinion and rack due to the above-mentioned steering operation, but also detects the reaction force from the steered wheels when the vehicle is running. It is also necessary to be able to appropriately detect the steering angle for the vehicle, and it is necessary to take some measures in consideration of this point to ensure that the above-mentioned steering angle detection can be carried out appropriately and reliably.

[Means to solve the problem]

In order to meet such demands, the steering angle detection device for the rack and pinion type power steering device according to the present invention has a rack gear for detecting the steering angle installed in a part of the rack that is incorporated into the steering body as a steering gear member in the axial direction. A steering angle sensor is provided with a pinion for detecting a steering angle that is formed along the rack gear and converts the maximum displacement of the rack into rotation within one rotation, and extracts the rotation of this pinion as a steering angle detection signal. It has been established.

[Effect]

According to the present invention, the movement of the pinion and rack accompanying the steering operation is detected by the steering angle detection pinion that meshes with the steering angle detection cheek gear provided on the rack E and detects the amount of rotational displacement. Accordingly, the rotation is within one rotation, and this is extracted as a steering angle detection signal by a steering angle sensor.

〔Example〕

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

1 to 3 show an embodiment of a rack and pinion type steering device to which the steering angle detection device according to the present invention is applied. In this embodiment, the configuration of the device with power steering is shown, and its main parts are shown. Only the steering mechanism section 1 provided with a steering angle detection device 10 is shown.

First, this steering mechanism part l will be briefly explained using FIG. 1. In the figure, reference numeral 2 is a steering shaft extending from a steering handle (not shown), and its tip end is a steering body indicated by reference numeral 3. A pinion (not shown) is fitted into the main body 3a and is provided at its tip, and the pinion in parentheses is the pinion that constitutes the steering link mechanism 4 that is horizontally suspended between the steering wheels (not shown) of the vehicle. is meshed with a rack 7 having meshing rack teeth 5a.

Note that the rack 5 constituting the above-mentioned steering link mechanism 4
As is well known, both ends of the steering wheel are connected to the steering wheel side via a tie rod, a king pin, a pitman arm, etc., using a pole joint (not shown) or the like. Furthermore, in this example,
A metal vibro etc. is connected to one end side of the cylindrical part 3b of the steering body 3 mentioned above, and a sealing material 8a for sealing the piston 7 provided on the rod part 5b of the roller 25 and both ends thereof, A well-known power cylinder part 9 is formed by a pair of left and right cylinder chambers 7a and 7bi by 8b, and a flow according to a steering operation by a rotary flow path switching valve (not shown) provided in the body main body part 3& is formed. The road switching function is configured to generate a steering assist force in a desired direction. Note that the configuration and operation of each part in this type of rack and pinion type steering device are well known, and detailed description thereof will be omitted.

Now, according to the present invention, as the steering angle detection device @io, the steering link mechanism 4 deflects the steered wheels according to the steering operation.
A part of the rack 5 that constitutes the rack tN15a, that is, the rack tN15a
A rack gear 11 for detecting the steering angle is formed along the axial direction between the rod part 5b constituting the power cylinder part 9, and the maximum displacement of the rod 5 is determined by one rotation. The steering wheel is characterized by the provision of a steering angle detecting pinion 12 that converts the rotation within the range of rotation, and a steering angle sensor 13 that extracts the rotation of the bracket pinion 12 as a steering angle detection signal. Here, in this embodiment, the rack gear 11 for detecting the steering angle is installed separately from the rack 5a in which the pinion as a steering gear member engages, and is separately fitted into other parts of the rack 5 as a sub-rack gear 11. and the sensor shaft 13aJ of the sensor 13:
A pinion 12 for detecting a steering angle supported by the steering angle detecting pinion 12 is provided in mesh with the steering angle detecting pinion 12 . In the configuration in which the steering angle is detected using the sub-rack gear 11 and the sub-pinion 12, the sub-rack gear it is connected to the rack tooth 5 which becomes the steering gear.
It can be manufactured separately from a, and costs can be reduced. In particular, the rack gear 11 for detecting the steering angle only needs to be able to transmit rotational torque to the sensor 13 side, and can be formed inexpensively from a resin material, etc., which has a great advantage, but is not limited to this. The gears may be directly cut into a part of the rack 5 or formed by forging.In short, the gears are provided along the axial direction of the rack 5, taking into consideration the maximum displacement of the rack 5, so as to cover the entire stroke. Good.

Also, a pinion 12 that meshes with the rack gear 11 described above.
Therefore, it is desired that the maximum displacement of the rack 5 be converted into rotation within one revolution by appropriately selecting a gear ratio. With such a configuration, an inexpensive potentiometer can be used as the steering angle sensor 13.

In addition, 14 in the figure is a sensor that closes an opening 14a formed on the cylindrical part 3b of the steering body 3 in a side part axially away from the main body part 3a so as to cover the pinion 12, etc. It is a part cover.

According to such a configuration, the movement of the pinion and rack 5 as a steering gear accompanying a steering operation is meshed with the rack gear 11 for detecting the steering angle provided on the rack 5, and the amount of rotational displacement is determined. The rudder angle detection pinion 12 detects the rotation within one rotation, and the rudder angle sensor 13 extracts this as a rudder angle detection signal.
It can be used as a required detection signal, and its advantages are easily understood.

According to the device IO of the present invention having the above configuration, the steering angle sensor 13 can be provided on the side of the body cylindrical portion 3b, which has sufficient space for installation into the vehicle, and the pinion, which has been a problem in the past, can be installed. Shaft tip side (body main part 3a tip #
) is advantageous in terms of mountability on vehicles with limited space, and in addition, the steering angle sensor 13 can be installed in a location where there are no mechanical parts that may get in the way or interfere. It is easy to assemble and has excellent workability, and also has excellent effects such as reliable and accurate steering angle detection according to the movement of the rack 5. In particular, according to the invention:
The steering angle can be detected from the amount of displacement of the rack 5 by rotation of the steering angle detection pinion 12 within one rotation, and a potentiometer, which is an inexpensive rotary sensor, can be used.

According to the steering angle detection device 10 described above.

Despite the simple and inexpensive configuration, the amount of steering angle displacement of the steered wheels can be detected appropriately and reliably, so that it can be applied to various power steering devices to exhibit its effects. That is, according to the steering angle detection device IO according to the present invention, it is possible to reliably detect the deflection of the steered wheels based on the amount of movement in the axial direction of the rack 5 portion that constitutes a part of the steering linkage mechanism 4. Therefore, this is an electric power steering ml! The return movement of the steering wheel, which is a problem when applied to a vehicle, can be easily controlled by a motor. Further, these advantages are the same in a power steering device that combines a hydraulic motor with a motor.

Furthermore, in hydraulic power steering systems, electromagnetic clutches are used to control hydraulic reaction force to optimize steering force control in high and low speed driving conditions, or to disconnect the oil pump from the engine when driving straight ahead. It can be used effectively as a control means to increase the steering force as the steering angle increases, and can also be used as information for the rear wheel steering device of a four-wheel steering vehicle. Various uses are possible.

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 necessary. For example, in the above-described embodiment, a case has been described in which the device according to the present invention is attached between the rack tooth 5a portion on the rack 5 and the rod portion 5b forming the power cylinder portion 9, but the present invention is not limited to this. It can be attached to a location on the rack 5 where there is sufficient space, and various modifications may be considered.

Further, in the above-described embodiment, the rack and pinion type steering device is used for power steering, but it goes without saying that it may be used for manual steering.

〔Effect of the invention〕

As explained above, according to the steering angle detection device for a rack and pinion type power steering device according to the present invention, a rack gear for detecting the steering angle is formed along the axial direction in a part of the rack that is a steering gear member. A pinion for detecting the steering angle that meshes with this and converts the maximum displacement of the rack into rotation within one rotation is provided, and a steering angle sensor is provided that extracts the rotation of this pinion as a steering angle detection signal. Although the structure is simple and inexpensive, the steering angle sensor can be installed in the cylindrical part of the body, which has plenty of space for installation in the vehicle, which is advantageous in terms of installation in the vehicle, and it is easy to assemble the sensor. The attachment can be installed in a location where there are no mechanical parts that may get in the way or interfere, making the assembly process easy, and also enables reliable and accurate steering angle detection according to the movement of the roller. It has various excellent effects such as being able to perform. Furthermore, according to the present invention, the rack gear for detecting the steering angle provided on the rack side only needs to rotate the pinion on the sensor side. This simplifies the production of rack gears and reduces costs. Further, according to the present invention, the pinion that transmits the movement of the rack side to the steering angle sensor can be configured so that the maximum displacement of the rack can be tolerated within one rotation, and an inexpensive sensor means such as a potentiometer or a meter can be used. It becomes possible to use it.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing a steering mechanism section showing an embodiment of a power steering type rack and pinion type steering device to which a steering angle detection device according to the present invention is applied;
The figure is a sectional view taken along the ■-■ line in Figure 1, and Figure 3 is the arrow m in Figure 1.
It is a sectional view of the main part seen from the direction. l... Steering mechanism part in rack and pinion type steering device, 2... Steering shaft, 3...
... Steering body, 3a ... Main body, 3b
... Cylindrical part, 4... Steering link mechanism, 5...
... Rack, 5a ... Rack teeth, 5b ... Rod part, 10 ... Rudder angle detection device, 11 ... Rack gear for rudder angle detection, 12 ... For rudder angle detection pinion, 1
3... Rudder angle sensor, 13a... Sensor shaft, 14
...Sensor part cover

Claims (1)

[Claims] In a rack and pinion type steering device in which a steering gear member consisting of a pinion and a rack for steering the steered wheels in response to a steering operation is incorporated into a steering body, a rack gear for detecting a steering angle is installed in a part of the rack in the axial direction. A steering angle sensor is provided with a pinion for detecting a steering angle that is formed along the rack gear and converts the maximum displacement of the rack into rotation within one rotation, and extracts the rotation of this pinion as a steering angle detection signal. A steering angle detection device in a rack and pinion type steering device, characterized in that it is provided with.