JPS6318535Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle vibration reduction device, and more particularly to a vehicle vibration reduction device that reduces idling vibration and shake that occurs during high-speed driving.

In general, in vehicles, especially FF vehicles, when the engine is idling, the frequencies of the engine's roll resonance, the two-node bending vibration of the vehicle body, and the engine torque reaction force match or approach each other, causing the vehicle to vibrate and cause discomfort to the driver. give.

In addition, when driving at high speed, the vehicle speed is approximately 150km/h.
In the vicinity, the frequency of the force generated by the rotation of the tires and the frequency of the two-node bending of the vehicle body match, so vibrations called shakes occur, causing discomfort to the driver and the like.

The present invention was developed with the aim of reducing the above-mentioned idle vibration and shake.

In order to achieve the above object, the configuration of the present invention detects the bending vibration of the car body, and applies vibration to the car body with the same frequency and amplitude as this vibration, but with a phase shift of 180 degrees. . As a result, the bending vibration of the vehicle body and the vibration whose phase is shifted by 180 degrees are superimposed, and the vibration of the vehicle is reduced.

Furthermore, since the frequency of idling vibration and the frequency of shake are different, it is preferable to vibrate at the engine explosion primary frequency during idling, and to vibrate at the tire rotation primary frequency when driving at high speed. In this case, the phase and amplitude of the vehicle body vibration are detected at the antinode of the vibration mode, and the vibration is applied to the antinode of the vibration mode.

Embodiments of the present invention will be described in detail below with reference to the drawings. This embodiment reduces the two-node bending vibration of the car body.The phase and vibration of the two-node bending vibration are detected at the tip of the car body, and the period is set to the engine explosion primary frequency or tire rotation primary frequency. The spare tire mounted at the rear was vibrated. FIG. 1 shows the vibration mode of two-node bending vibration of the vehicle body. This two-node bending vibration creates nodes near the front and rear wheels, and an antinode at the front, tail, and center portions of the vehicle body.

FIG. 2 shows an embodiment of the present invention. A vibration pickup 4 is attached to the tip of the vehicle body 2 for detecting vibrations of the vehicle body 2 and outputting electrical signals in response to the vibrations. The output end of this vibration pickup 4 is connected to an adder 10 via a charge amplifier 6 and a filter 8. Furthermore, an engine rotation speed sensor 12 that detects the engine rotation speed is installed inside the distributor housing, and a tire rotation speed sensor 14 that detects the tire rotation speed is installed on the output shaft of the transmission, etc. It is being This engine speed sensor 12
The tire rotation speed sensor 14 is connected to the adder 10 via a changeover switch 16 and a synchronous oscillator 18, which are automatically switched at a predetermined engine rotation speed or a predetermined tire rotation speed. The output end of the adder 10 is connected via a power amplifier 20 to a vibration device 22 that vibrates a spare tire 24.

Next, regarding the vibration device 22, see FIGS. 3 and 4.
This will be explained using figures. First, spare tire 24
is housed in a space surrounded by a concave rear floor 26 and a deck board 28. As the vibration device, an electrostrictive vibration device 22a shown in FIG. 3 or a hydraulic vibration device 22b shown in FIG. 4 is used,
A fixed portion of the vibration device is fixed to a substantially central portion of the rear floor 26. The rim of a spare tire 24 is fixed to the vibrating section of the vibration excitation device, so that the spare tire 24 does not come into contact with the rear floor 26 and the deck board 28.

Next, the operation of this embodiment will be explained. First, when the engine is idling (the engine speed is
1000 r.p.m or less), the changeover switch 16 is switched, and the engine rotation speed sensor 12 and the synchronous oscillator 18 are connected. As a result, the engine explosion primary frequency is detected by the engine rotation speed sensor 12, and the synchronous oscillator 18 outputs a signal having the same frequency as the engine explosion primary frequency.
Further, when the vehicle is running (engine speed is 1000 rpm or more), the changeover switch 16 is switched and the tire rotation speed sensor 14 and the synchronous oscillator 18 are connected. As a result, the tire rotation frequency is detected by the tire rotation speed sensor 14 and the synchronous oscillator 18
outputs a signal with the same frequency as the tire rotation frequency. On the other hand, vibrations at the tip of the vehicle body detected by the vibration pickup 4 are amplified by a charge amplifier 6, vibrations other than the two-node bending vibrations of the vehicle body are removed by a filter 8, and the vibrations are input to an adder 10. Adder 10 outputs a signal having the same frequency as the output signal of synchronous oscillator 18 and the same amplitude and phase as the output signal of filter 8.
The power amplifier 20 then vibrates the vibration device 22 based on the output of the adder 20 to vibrate the spare tire 24 . As a result, a reaction force due to the vibration of the spare tire is applied to the vehicle body.

In the above case, the two-node bending vibration of the car body
In order to apply vibrations that are 180 degrees out of phase to the car body, when the tip of the car body moves downward due to the vibration (this is the same amplitude and phase as the vibration at the tail end of the car body as shown in Figure 1), It is necessary to select the polarity of the vibration device 22 and connect it to the power amplifier 20 so that the reaction force applied by the spare tire 24 is directed upward. By doing this, vibrations that are 180 degrees out of phase with vibrations at the tail end of the vehicle body are applied to the tail end of the vehicle body.

As described above, according to the present invention, the unique effect of reducing vehicle vibration can be obtained.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the two-node bending vibration mode of the vehicle body, Fig. 2 is a block diagram showing an embodiment of the present invention, and Figs. 3 and 4 show the installation state of the vibration device. FIG. 4... Vibration pickup, 12... Engine rotation speed sensor, 14... Tire rotation speed sensor, 18
... Synchronous oscillator, 22 ... Excitation device.

Claims (1)

[Scope of utility model registration request] a vibration pickup that is attached to a vehicle body and detects vibrations of the vehicle body; an engine rotation speed sensor that detects engine rotation speed; a tire rotation speed sensor that detects tire rotation speed; and the engine rotation speed sensor and the tire rotation. a changeover switch for changing over each detection signal from the several sensors; an addition means for adding the output from the vibration pickup and the output from the engine rotation speed sensor or the tire rotation speed sensor output via the changeover switch; an excitation device that applies vibrations to the vehicle body that have the same frequency and amplitude as the output from the adding means and are out of phase by 180°;
A vehicle vibration reduction device characterized by applying vibration to a spare tire fixedly placed inside a vehicle body.