JPH0495633A - Vehicle vibration reducing device - Google Patents

Abstract

PURPOSE:To control the reduction of the vibration of a car body based on a detection result by installing an excitation machine on the car body, and by detecting the temperature of an engine mount on which an engine is installed. CONSTITUTION:A radiator 1 is vertically movable, and an excitation machine 4 is fixed to a center member 5, while a temperature sensor 23 is provided on one of an engine mount 11. The excitation machine 4 is vibrated at a frequency which is proportional to the engine rotational speed. The temperature of the engine mount 11 is detected by the temperature sensor 23, and an optimal map is selected for controlling the phase and the gain of the vibration of the excitation machine 4 according to the temperature of the engine mount. Control is made in such a way that the vibration of a vehicle can be offset by the vibration generated by the excitation machine 4 even when the temperature of the engine mount is changed, and the vibration of the vehicle is thus reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a vehicle vibration reduction device.

[Conventional technology]

Japanese Unexamined Patent Publication No. 61-220925 discloses a system in which a vibration exciter for applying a damping force to the vehicle body is attached to the vehicle body, and an engine is elastically attached to the vehicle body via an engine mount, and the engine speed is adjusted according to the engine speed. A vehicle vibration reduction device is disclosed in which a control signal for a vibration exciter is read out from a predetermined map and the vibration exciter is controlled based on this control signal.

[Problems to be Solved by the Invention] The temperature of the engine mount changes depending on the operating state of the engine, and therefore the spring constant of the engine mount changes. When the spring constant of the engine mount changes, the phase and amplitude of vibrations transmitted from the engine to the vehicle body change even under the same engine operating state. For this reason, if the vibration exciter is controlled based on a map that does not take into account the temperature of the engine mount, as in conventional devices, the vibrations of the vehicle cannot be canceled out by the vibrations generated by the vibration exciter, and the vibration of the vehicle is reduced. The problem arises that it cannot be done.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, a vibration exciter for applying a damping force to the vehicle body is mounted on the vehicle body, an engine is mounted on the vehicle body via an engine mount, and the temperature of the engine mount is detected. Provide temperature detection means for
The vibration exciter is controlled to reduce vibration of the vehicle body based on the detection result of the temperature detection means.

[For production]

The vibration exciter is controlled according to the temperature of the engine mount, so even if the engine mount temperature changes and the phase and amplitude of the vehicle vibration change, the vibration of the vibration exciter will cancel out the vehicle vibration. I can do it.

〔Example〕

FIG. 2 shows a side view of the vehicle vibration reduction device.

In FIG. 2, the left side is the front of the vehicle and the right side is the rear of the vehicle. Referring to FIG. 2, the upper end of the radiator 1 is supported by an upper support 3 via a support 2 made of rubber, so that the radiator 1 can move up and down. The vibrator 4 is fixed on the center member 5 and is arranged below the radiator 1 in parallel with the radiator 1.

An offset arm 7 is made to protrude from below the housing 6 of the vibrator 4 toward the left.
The upper surface of the radiator l is connected to a lower tank 9 of the radiator l via a rubber bushing 8. The engine 1o is arranged to the right of the radiator 1, and is mounted on the center member 5 via a plurality of rubber engine mounts 11. One of the engine mounts 11 is provided with a temperature sensor 23 for detecting the temperature of the engine mount 11.

FIG. 3 shows an enlarged sectional view of the vibrator 4. Referring to FIG. 3, a shaft 12 is fixedly arranged on the center member 5, and a cylindrical stator 13 is attached to the shaft 12.
2 and is fixed. A solenoid 14 is attached to the outer periphery of the stator 13. A cylindrical permanent magnet 15 is arranged opposite to the outer peripheral surface of the solenoid 14, and this permanent magnet 15 is fixed to the inner peripheral surface of the housing 16. The housing 6 is supported movably relative to the stator 13 by compression coil springs 16 and 17 arranged on the upper and lower surfaces of the stator 13. A lock bin hole 18 is formed on the right side surface of the lower tank 9.
A lock pin 19 is arranged on the side surface of the housing 6 facing the housing 6 . Lock pin 19 is lock pin drive coil 2o
It is moved forward and backward by.

The electronic control unit 30 consists of a digital computer with ROMs interconnected by a bidirectional bus 31.
(read only memory) 32, RAM (random access memory) 33, CPU (microprocessor) 3
4, an input port 35 and an output port 36.

A vehicle speed sensor 21 that detects vehicle speed and a rotational speed sensor 22 that detects engine rotational speed are connected to input port 35 .

Further, a temperature sensor 23 that detects the temperature of the engine mount 11 is connected to an input port 35 via an A/D converter 37. On the other hand, the output port 36 has a corresponding drive circuit 38
and 39 to the lock pin drive coil 20 and the solenoid 14, respectively.

In order to cause the vibrator 4 to generate vibrations that cancel out the vibrations generated in the vehicle, a control current having a predetermined frequency, phase, and gain is applied to the solenoid 14 according to the engine rotation speed. . This causes the housing 6 of the vibrator 4 to vibrate to offset the vibrations of the vehicle.

When the lock pin 19 moves forward, the lock pin 19 is inserted into the lock pin hole 18. As a result, the vibration of the radiator l caused by the vibration of the housing 6 is reduced to the lock bin 1.
9 to the center member 5. On the other hand, when the lock bin 19 moves backward, the engagement between the lock bin 19 and the lower tank 9 is released. Therefore, the vibration of the radiator 1 caused by the vibration of the housing 6 is transmitted to the center member 5 via the rubber bush 8.

The vibrator 4 is caused to vibrate at a frequency proportional to the engine speed. FIG. 4 shows the relationship between the vibration transmission force from the radiator 1 to the center member 5 and the engine speed when the amplitude of the vibrator 4 is constant.

Referring to FIG. 4, the lock pin 19 is inserted into the lock pin hole l.
The vibration of the radiator 1 is inserted into the rubber bush 8.
In the case where the vibration is transmitted to the center member 5 without going through the radiator 1, the transmission force of the vibration from the radiator 1 to the center member 5 is proportional to the square root of the engine rotation speed.

Therefore, in this case, the lower the engine speed, the lower the vibration transmission force. Therefore, when the engine speed is low, vibrations of the vehicle cannot be sufficiently reduced.

-4. When the lock pin 19 moves back and the lock pin 19 is released from the lock pin 19 and the lower tank 9 and the vibrations of the radiator 1 are transmitted to the center member 5 via the rubber bush 8, the engine speed is relatively low. It has a resonance point at . Therefore, in this case, the vibration transmission force decreases in a region where the engine speed is high. Therefore, when the engine speed is high, vibrations of the vehicle cannot be sufficiently reduced.

The engine speed N1 at which the transmission force is maximum when the lock pin 19 is retracted is determined by the following formula in the case of a 4-cylinder engine: N = 30W Here, W7 is the natural frequency of the radiator system, such as radiator 1 etc. is determined by the mass of the rubber bush 8 and the spring constant of the rubber bush 8. The spring constant of the rubber bushing 8 is N to reduce vibration during idling.

is determined to be the optimal value. lock pin 1
engine rotation speed N at which the transmission force when the lock pin 9 moves forward is equal to the transmission force when the lock pin 19 moves backward;
is given by the following equation.

N, = (D N1 In this embodiment, these characteristics are combined to obtain a high vibration transmission force over the entire range of engine speeds, thereby sufficiently reducing vehicle vibration over the entire range of engine speeds. For this reason, when the engine speed is less than N, the lock pin 19 is moved backward, and when the engine speed is higher than N1, the lock pin 19 is moved forward.

By the way, when the temperature of the engine mount 11 changes depending on the operating state of the engine 10, the spring constant of the engine mount 11 changes. When the spring constant of the engine mount 11 changes, the phase and amplitude of vibrations transmitted from the engine 10 to the vehicle body, such as the center member 5, change even under the same engine operating state. Therefore, if the vibration exciter 4 is controlled based on a map that does not take into account the temperature of the engine mount 11, the vibrations of the vehicle cannot necessarily be offset by the vibrations generated by the vibration exciter 4, and the temperature of the engine mount 11 In some cases, a problem arises in that vehicle vibration cannot necessarily be reduced.

Therefore, in this embodiment, a plurality of maps are provided in order to detect the temperature of the engine mount 1 and control the phase and gain of the vibration of the vibration exciter 4 according to the temperature of the engine mount 1. We try to select the most suitable map depending on the temperature.

As a result, even if the temperature of the engine mount 11 changes, the vibrations of the vehicle can always be offset by the vibrations generated by the vibrator 4, and thus the vibrations of the vehicle can be sufficiently reduced.

FIG. 1 shows a routine for executing this embodiment.
This routine is executed by interrupts at regular intervals.

Referring to FIG. 1, first, in step 5o, the vehicle speed ■
It is determined whether or not the speed is less than 3 km/h, that is, whether the vehicle is stopped. If the vehicle speed exceeds 31ai/H, the routine proceeds to step 51, where it is determined whether the engine speed N is greater than or equal to N (see FIG. 4). In the case of N≧Nh, the transmission force becomes larger when the lock pin 19 is advanced, so the process proceeds to step 52 and the lock pin 19 is advanced. This results in a high transmission force. On the other hand, if it is determined in step 51 that N<Nk, the transmission force will be greater if the lock pin 19 is moved back, so the process proceeds to step 53 and the lock pin 19 is moved back. Step 5
In step 4, it is determined whether the engine mount temperature T is equal to or higher than T1. When T≧T, the process advances to step 55 and map 1 is selected. When T<T, proceed to step 56 and T≧T2
It is determined whether or not. When T≧T, the process advances to step 57 and map 2 is selected. T<T.

When , proceed to the next step, and in step 58 T≧T,
, it is determined whether or not. When T≧T, -1, step 59
Then, map n-1 is selected. When T〈T7-3, the process proceeds to step 60 and map n is selected.The relationship between these temperatures is TI>T〉...〉Tゎ-8, and the difference between these temperatures is, for example, 10 ℃ or less, and this temperature difference may be uneven. Map 1, Map n
The zero phase φ and gain F shown in FIGS. 5 and 6 are stored in relation to the engine rotational speed N, and the same is true for maps 2 to n-1. Each map is set in advance so that the vibrations of the vibrator 4 cancel out the vibrations of the vehicle in each temperature range. Next, in step 61, the phase φ and gain F for operating the vibrator 4 are determined based on the selected ma-tub. Then step 62
The vibrator 4 is operated based on the phase φ and the gain F.

In this way, even if the temperature of the engine mount 11 changes, the vibrations of the vehicle can always be sufficiently reduced. Furthermore, vibrations of the vehicle can be sufficiently reduced over the entire range of engine speeds. As a result, muffled noise when the vehicle is running can be sufficiently reduced.

If it is determined in step 50 that ■≦3 km/H, that is, if it is determined that the vehicle is stopped, the process proceeds to step 63, where it is determined whether the engine speed N is between Nc and N4. Since the idle vibration becomes large when Nc≦N≦N, the vibration exciter 4 is activated at this time to reduce the idle vibration. Therefore, N is determined so that the transmission force between Nc and N is large. N
When C≦N≦N4, proceed to step 53 and lock pin 19
is moved backward, and then the vibrator 4 is activated.

Therefore, idle vibration is reduced. Step 6
If it is determined in step 3 that Nc≦N≦N4 is not satisfied, the process proceeds to step 64 and the vibrator 4 is not activated. In this case, since the idle vibration is small, the vibration exciter 4
There is no need to activate it.

Although the temperature of one engine mount 11 is detected in this embodiment, the temperatures of a plurality of engine mounts 11 may be detected and the average value thereof may be taken.

Further, in this embodiment, maps are provided according to each temperature, but the basic map may be corrected according to the detected temperature of the engine mound.

〔Effect of the invention〕

Even if the temperature of the engine mount changes, vehicle vibration can be sufficiently reduced.

[Brief explanation of drawings]

Figure 1 is a flowchart for controlling the operation of the lock bin and vibration exciter, Figure 2 is a side view of the vehicle vibration reduction device, Figure 3 is an enlarged sectional view of the vibration exciter, and Figure 4 is a diagram showing the engine speed and The diagrams illustrating the relationship between vibration and transmission force, FIGS. 5 and 6, are maps of phase and gain. 4... Vibrator, 5... Center member, 1
0...Engine, 11...Engine mount, 23
...Temperature sensor. Fig. 2 4...ηn vibration machine 5 Center point... 1Q...Eng//no 11...E//n mount 23...Damage Senosa Nc Na NdNb Engine speed chart ψ11 F++ Fig. Fig. Fig. 2

Claims (1)

[Claims] A vibration exciter for applying damping force to the vehicle body is mounted on the vehicle body, an engine is mounted on the vehicle body via an engine mount, a temperature detection means is provided for detecting the temperature of the engine mount, and the vibration exciter is mounted on the vehicle body. A vehicle vibration reduction device that controls to reduce vibration of a vehicle body based on the detection result of the temperature detection means.