JPH0130643B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable caster device that provides an optimal caster trail to front wheels depending on vehicle speed and the like.

In an automobile, if the front wheel caster rail is set to high caster, there will be less steering change due to external influences during high-speed driving, that is, straight-line performance will be improved and anti-dive will be stronger. Furthermore, if the caster rail is set smaller than the above, the steering force increases when running at medium and low speeds, creating a moderate steering feeling. Furthermore, if the caster start rail is set smaller, the steering force at extremely low speeds is reduced.

By the way, in Utility Model No. 52-60025, a steering wheel was attached to the vehicle body so that it could swing back and forth, and
A cylinder for rocking the steering wheel is provided, and the drive of the cylinder is linked to the forward/reverse switching operation of the vehicle,
A caster switching device is disclosed that switches the caster start rail of a steered wheel into two stages, positive and negative.

However, since the system simply switches between positive and negative stages and has no relation to vehicle speed, it is not possible to obtain the optimum caster start rail according to the vehicle speed mentioned above, and the caster start rail may be adjusted depending on the driver's preference. It was also impossible to change the rail steplessly.

The present invention has been made in view of the above circumstances.
The purpose of this is to focus on the front suspension damper, and use its body mount to swing the damper back and forth in relation to the vehicle speed, and even in accordance with the driver's preference, resulting in changes in steering during high-speed driving. It is possible to strengthen the anti-dip effect, provide a moderate steering force at medium and low speeds, and significantly reduce the steering force at very low speeds. A variable caster device that can provide the front wheels with the desired caster rail, making it possible to eliminate the need for power assist steering in medium and light vehicles, and furthermore, allowing the driver to obtain any caster trail according to his/her preference. It is on offer.

In order to achieve such an object, the present invention provides a front suspension for an automobile, in which a damper mount base is fixed to the vehicle body of the automobile, a slider is engaged with a rail so as to be slidable in the longitudinal direction with respect to the damper mount base, and A mount plate provided at the top of the damper is connected to the slide, the slider is interlocked with a drive source, and the drive of the drive source is controlled by a controller, so that the front wheel caster rail is configured to be steplessly variable. The gist is:

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic side view of the front wheel portion to explain the caster start rail. In the present invention, the kingpin shaft K attachment point P of the front wheel W is moved rearward, and the caster start rail L is gradually increased as the vehicle speed increases. do what you can.

FIG. 2 is a schematic plan view of the main parts inside the engine room provided at the front of the automobile, and in this example,
The present invention is applied to a strut type front suspension.

Damper mount sliders 20, 20 are arranged so as to be slidable in the front and back directions on the left and right sides of the engine room 1, and the slider 20 is assembled with two threaded rods 16, 16 so as to be able to be moved back and forth.
A drive shaft 30 is orthogonally meshed with the rear end of the drive shaft 16 using a worm gear, and an electric motor 35 is fixed to the rear wall 2 of the engine room 1.
0,30 and flexible joint 33,33
Connect via.

The motor 35 is driven and controlled by a controller 36, which inputs vehicle speed information from a vehicle speed sensor 37, and further controls a manual slider adjuster 38 provided on the instrument panel at the front of the passenger compartment.
connected to.

The slider mechanism is as shown in Figures 3 and 4, with a damper mount base 1 fixed to the vehicle body.
0. The slider 20 is engaged with the rail. That is, the base 10 is long in the front-rear direction, and its flat plate part 11 has an oblong hole 12 in the front-rear direction, and U-shaped parts 13, 13 are provided on the left and right side walls in the front-rear direction. A slide rail 14 is fitted into the inside of the slide rail 13 . On the other hand, the slider 20 is
It has a circular hole 22 in a flat plate portion 21 approximately half of 0,
Side walls 23, 23 are suspended from the left and right sides, and a slide piece 2 bent outward is provided at the bottom of the side wall 23.
4, and the left and right slide pieces 24, 24 are inserted into and engaged with the rails 14, 14.

Brackets 15 are installed on the front and back of both sides of the base 10, and the left and right brackets 1
5 have threaded rods 16, 16 supported by respective bearings, and a worm wheel 17 is provided at the rear end of the threaded rod 16 protruding from the rear bracket 15. Furthermore, a holder 19 is fixedly installed on the rear end of the base 10 behind both rear brackets 15, 15, and left and right brackets 19, 19 are provided behind the holder 18.
is provided protrudingly, and a drive shaft 3 is attached to both brackets 19, 19.
0 is supported by a bearing, and worms 31, 31 are provided on the left and right sides of the drive shaft 30, and both worms 3
1 and 31 are orthogonally meshed with the worm wheels 17 and 17 from below. The inner end of this drive shaft 30 and the electric motor 35 are interlocked and connected by a flexible joint 33.

Further, movers 25, 25 are provided protrudingly on the left and right sides of the slider 20, and both movers 25, 25 are connected to the threaded rods 16, 1.
It meshes with the threaded portions 16a, 16a of No.6.

To assemble the damper, place the upper part of the damper on base 1.
The slider 2 faces upward from the oblong hole 12 of 0.
A mount plate 26 provided on the upper part of the damper is bolted to the lower surface of the damper.

Next, the electrical control system will be specifically explained with reference to FIGS. 5 and 6.

Fig. 5 is a control system circuit diagram of a feedback control method using a position detection sensor that detects the position of the slider 20 of the damper, and Fig. 6 is a control system circuit diagram of a process control method that does not use such a position detection sensor. show. In each figure, the same parts as in FIG. 2 are given the same reference numerals to clarify the structure.

First, the feedback control method will be explained based on FIG.

A position detection sensor 39 detects the position of the damper slider 20 and outputs a voltage e1 proportional to the position, and this output is supplied to the voltage comparator 40. Further, a voltage e2 proportional to the vehicle speed is obtained from the vehicle speed sensor 37 and supplied to the comparator 40 via the changeover switch 41. This comparator 4
0 compares each voltage e1 and e2 and calculates the difference voltage (±
△e), and this difference voltage (±△e) is supplied to the DC amplifier 42 and amplified to a predetermined magnitude.
It is supplied to the bases (switching circuits) of the NPN transistor 43A and the PNP transistor 43B. The collectors of each transistor 43A, 43B are connected to a relay coil 44C of a reverse relay 44 and a relay coil 45C of a forward relay 45.
are connected respectively, and relay switches 44X, 44Y, 44Z, 44 are activated by excitation of relay coil 44C.
W are opened and closed respectively, and on the other hand, relay coil 45C
Relay switches 45X, 45Y,
45Z and 45W are opened and closed, respectively. Each of these relay switches is connected between the motor 35 and a DC power supply (vehicle battery) 46 that drives it, and causes the motor 35 to reverse rotation by excitation of the relay coil 44C, and by excitation of the relay coil 45C.
Rotate forward. Incidentally, reference numeral 47 indicates an overcurrent detection circuit, and 48, 49, and 50 indicate power supply terminals, respectively. Further, the manual slide adjuster 38, which can be manually set regardless of the vehicle speed, is connected to the changeover switch 41, and by switching the changeover switch 41, the voltage e2 from the vehicle speed sensor 37 and the slide adjuster 38 are adjusted. The set voltage e3 can be selectively supplied to the voltage comparator 40.

Next, the operation of such a control system will be explained. First, in the case of automatic setting based on vehicle speed, if voltages e1 and e2 are at the same level and the potential difference (△e) is zero, each transistor 43A, 43B is in an OFF state, and each relay coil 44C, 45 is in an OFF state.
Both C and C are non-excited and the motor 35 is not driven and is in a stopped state. In other words, in this case, the optimum caster start rail corresponding to the vehicle speed is set. On the other hand, when the vehicle speed changes and the voltage e2 changes to large or small, the potential difference is (+△e) or (-△
e), which corresponds to each transistor 43A.
Or turn on 43B. As a result, when the transistor 43A is turned on, the relay coil 44C is excited, forming a circuit that reverses the motor 35, and when the other transistor 43B is turned on, the relay coil 45C is excited. Thus, a circuit for rotating the motor 35 in the normal direction is formed. In any of these cases, as the motor 35 rotates, the position sensor 3
When the magnitude of the voltage e1 of No. 9 changes and the voltage e1 matches the voltage e2, that is, when the caster start rail is set to correspond to the magnitude of the vehicle speed after the change, the rotation of the motor 35 is stopped. Next, the process control method will be explained based on FIG. This control system does not use the position sensor 39, and the controller 36 is composed of, for example, a microcomputer, and is stored in memory in advance based on information d proportional to the vehicle speed (such as the number of pulses proportional to the vehicle speed) from the vehicle speed sensor 37. According to the set data, the motor 35 moves to the position of the slider 20 corresponding to the vehicle speed.
(in this case, a step motor or the like is used), and the optimum caster start rail corresponding to the vehicle speed can be set as in FIG. 5. In this case, similar to the feedback control method described above, the input of the vehicle speed sensor 37 and the manual slider adjuster 3
8 inputs can be selectively supplied to enable manual setting by the regulator 38 that is independent of vehicle speed.

Next, the mechanical control system driven by the motor 35 in the variable caster device described above will be explained.

In the automatic case, the motor 35 is driven to rotate according to the vehicle speed at that time, which rotates the drive shaft 30 via the flexible joint 33, and the worm gear rotates the threaded rods 16, 16, which are screwed together. Slider 20 integrated with movable pieces 25, 25
slides on the base 10 to the optimum position forward and backward. In this way, the upper part of the damper can be moved in the longitudinal direction, thereby changing the caster angle α of the kingpin axis K of the front wheel W, thereby giving the front wheel W an optimum caster trail L according to the vehicle speed.

In the case of manual operation, the motor 35 is rotationally driven by the manual slide adjuster 38, so that an arbitrary caster rail L can be obtained according to the driver's preference.

As is clear from the above explanation, according to the variable caster device of the present invention, the front wheel caster rail is continuously variable controlled in relation to the vehicle speed so as to be optimal for the vehicle speed situation at that time, so the high caster is set when driving at high speed. to reduce steering change,
Anti-dive can be made strong, and appropriate steering force can be applied when driving at medium to low speeds, and when driving at very low speeds, the steering force can be significantly reduced by using low caster, thus providing steering characteristics that match the vehicle speed. This makes it possible to eliminate the need for power assist steering in medium and light vehicles, and furthermore, it has excellent advantages such as being able to obtain any caster trail according to the driver's preference. In addition, because the slider is rail-engaged to the damper mount base so that it can slide forward and backward, the variable caster device can be made more compact and unitized, and it also has high rigidity against loads that act on the damper in directions other than the front and rear directions. A variable caster device can be provided.

[Brief explanation of drawings]

Figure 1 is a schematic side view of the front wheel portion to explain the caster rail, Figure 2 is a schematic plan view of the main parts inside the engine room provided at the front of the automobile, and Figure 3
4 is a sectional view taken along the line of FIG. 3, FIG. 5 is a control system circuit diagram of a feedback control system, and FIG. 6 is a control system circuit diagram of a process control system. In addition, 10 in the drawing is the damper mount base, 14
is a slide rail, 16 is a threaded rod, 17 is a worm wheel, 20 is a damper mount slider,
24 is a slide piece, 25 is a movable piece, 30 is a drive shaft, 31 is a worm, 33 is a flexible joint, 35 is a motor, 36 is a controller, 37
is the vehicle speed sensor, 38 is the manual slide adjuster, 39
is the position sensor, 41 is the changeover switch, W is the front wheel,
K is the kingpin shaft and L is the caster rail.

Claims (1)

[Scope of Claims] 1. In a front suspension of an automobile, a damper mount base is fixed to the vehicle body of the automobile, a slider is engaged with a rail so as to be slidable in the longitudinal direction with respect to the damper mount base, and an upper part of the damper is attached to the slide. a mount plate provided on the mount plate, and operatively connects the slider with a drive source;
A variable caster device, characterized in that the driving of the drive source is controlled by a controller, and a caster rail of a front wheel is configured to be variable in a stepless manner.