JPS6013872B2 - Vehicle body mounting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing or reducing vibration noise of a car ball, particularly a car body.

One of the major factors that impairs the comfort of a vehicle is the vibration and noise of the wheels. The vibration noise of a car is caused by the vibrations from the engine or tires being transmitted to the bran body of the car and vibrating the car's arms, creating indoor noise.However, there is a sound reduction method to deal with such vibration noise. Alternatively, noise reduction measures have been proposed, but among them, the vibration isolating effect of rubber cushions, insulators, and other vibration isolators or cushioning materials used in various parts of the car cocoon, such as engine mounts, body mounts, and suspension systems, can significantly reduce noise. It is known to have a sound effect, and for this reason, it has been proposed to add vibration-proof villages to increase the sound reduction effect.

However, conventionally, the sound reduction effect of these vibration-proofing materials depends on the function of each vibration-proofing material, and it is not expected that the effect will be greater than the sum of the vibration-proofing materials, and it is not possible to use vibration-proofing materials frequently. It cannot be said that it is preferable from the point of view of the maneuverability and stability of the car bush, and it has been difficult in practice to improve the sound reduction effect in this area.

Incidentally, in recent years, various sound reduction measures have been taken to reduce vibration noise from the perspective of preventing or reducing noise inside the car in order to improve the comfort of wheels. By analyzing noise, we focused on the fact that when vibrations from a vibration noise source are transmitted to the body through multiple mounts of a body mounting, the vibrations transmitted from each mount to the body are transmitted in the same phase, increasing the vibration noise. However, in order to eliminate such increasing vibration noise, the present invention provides a new device for preventing or reducing vibration noise of a wheel body using body mounting. The present invention provides a wheel body material that is effective from the standpoint of improving the sound reduction effect of vibration isolating materials, especially existing vibration isolating materials or vibration isolating devices using the vibration isolating materials. The present invention provides a device that prevents or reduces vibration noise of a wheel pod caused by pooping. When vibrations are transmitted from the chassis to the body through the plurality of body mountings,
There are dynamic characteristics such as the damping coefficient and spring constant of the vibration isolating material used for the mount, and there are also dynamic characteristics such as the damping coefficient and spring constant of the vibration isolating material used in the mount, and the vibration transmission characteristics of the mount that change the transmitted vibration such as phase delay and amplitude by changing the mounting angle. We focused on a pair of left and right mounts with less vibration-proof body mounting of a car mausoleum, in which the body of the car is supported on the chassis by multiple mounts. At the same time, the forehead slope of the other mount bracket is formed so as to be perpendicular to the vertical plane in the front-rear direction of the wheel and to be perpendicular to the vertical plane in the longitudinal direction of the wheel. A wheel body mounting device has been developed in which the left and right mounting plackets are arranged asymmetrically with respect to the center of the vehicle chassis, and the mounting brackets are formed to have a slope different from that of the one inclined surface. The vibration input to the body is limited by the right and left mountings, thereby reducing the sum vector of the commotion sound and obtaining a change that brings about a predetermined phase difference as a whole, Specifically, the performance of the vibration isolating material and the size of the left and right mounting brackets are improved by changing the mounting direction of one of the right and left mounting brackets to the left and right side frames of the chassis by 900 degrees. A phase difference of 90° can be obtained even when the difference in the slope angle is extremely large, and if necessary, the vibration transmission characteristics of the mounts can be changed between the pair of left and right mounts to achieve a phase difference of 90° or 27°. It is also possible to extract the phase difference between the vibrations transmitted from the chassis to the body through these mounts, or the sound generated from the vibrations, without compromising the original vibration performance of the mounting or the durability of the mounting itself. By creating a phase difference between the two vibrations or sounds, even if the vibrations or sounds of one interfere with the vibrations or sounds of the other, the vibrations or sounds caused by the interference are not forced to become louder, but rather they cancel each other out. It is characterized by preventing or reducing vibration noise of the car ball body.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the present invention is applied between the left and right rear mounts of a cab mounting of a tilt type cab-over type automobile will be described in detail with reference to the drawings.

Figure 1 shows the cab mounting of a cab-over type automobile. A pair of asymmetrical roller mounts 4, 4' are arranged on the left and right sides of the chassis 2 based on the present invention.
vibrationally supported.

That is, for the front mounts 3 and 3r, general-purpose bush-type anti-vibration rubber is used for the front mount of the tail cab on the left and right sides, and the rear mounts 4 and 4' are shown in Figs. 2 to 5. The left and right IJ mounts are composed of several cross-section mounts with different structures.The structure will be explained in detail.
As shown in FIGS. 3 and 4, the upper end of the mount bracket 8 fixed to the left side of the vehicle chassis 2 has a mount bracket 8 that is perpendicular to the vertical plane in the width direction of the wheel and inclined at an angle of 450 degrees with respect to the horizontal plane. A slope 8a is provided and two parallel mounting plates 1 are installed in advance.
The vibration isolating rubber 12 is bonded between the mounting plates 10 and 11 between the mounting plates 10 and 11 by integral vulcanization, and one of the mounting plates 10 is fixed by bolting to the inclined surface 8a to form the seat plate. A configuration in which the bracket la of the cab 1, which is provided on a horizontal seat surface 13a formed at the upper end of the cab 13 and protruding from the lower left of the rear end of the cab, is fixed, and the seat plate 13 and the bracket la are tightened by bolts 6a. It is.

The other (right) rear mount 4 is attached to the upper end of a mount bracket 15 fixed to the right side of the vehicle chassis 2, as shown in FIGS. Slanted surface 15a having an inclination of 600 with respect to the horizontal plane
will be established.

The bracket 15 has a sub-bracket turtle 6 whose one end is fixed to the right side of the chassis 2 in order to reinforce the bracket 15.
The other end is fixed to one side of the inclined surface 15a of the mount bracket 16. Two mounting plates i of the rear mount 4 above
The configuration and structure in which the vibration isolating rubber 12 is bonded between the parallel mounting plates 17 and 11 are the same, and the vibration isolating rubber 19 is bonded integrally with the mounting plates 17 and 18 between the parallel mounting plates 17 and 18. The mounting plate 11 is fixed to the inclined surface 5a of the mount bracket 15 by tightening bolts. On the other mounting plate turtle 8, a seat portion 20a is formed by bending the crease side of a single metal plate into a substantially square shape.
A seat plate 20 formed by folding the seat plate 20 is fixed with bolts to the mounting plate 8 with the seat part 20a facing upward, and the rear end of the cab 1 is attached to the horizontal upper surface 20a of the seat part 20a of the seat plate 20. The bracket lb of the cab tortoise protrudes from the lower right side of the seat plate 20 and the bracket lb are tightened with bolts 6b. As mentioned above, in the left and right rear mounts 4 and 4', the vibration isolating rubber 12 of the left rear mount 4 and the vibration isolating rubber 19 of the right rear mount 4 are the same;
and the inclined surface 8a of the right IJ mountain 4' which is in different directions from each other.
, i5e, and are arranged in different directions, so that their structures and functions are substantially different from each other. Next, the sound reduction effect of the cab mounting of the above embodiment will be described.

First, Figures 6 and 7 show the results of an experiment comparing the indoor noise of the cab 1 due to engine vibration in the cab mounting of the embodiment with that in the case of conventional cab mounting. When accelerating, the seventh
The figure shows the noise generated when the engine decelerates, and the noise is measured at the driver's ears in the seated position.

As shown in FIG. 8, the conventional cab mounting used for comparison with the embodiment is the same as the left rear mount 41' and the left rear mount 4 of the embodiment, and the right rear mount 2 is the same as the left rear mount 4. It consists of a symmetrical mount configuration with the camera mounts mounted in opposite directions.

In Figure 6, the conventional example (solid line) has an engine speed of 8.
The sound pressure and bell are almost constant until day 0 and 2, but when the engine speed exceeds 8 Z, the sound pressure and bell increases rapidly and reaches its peak when the engine speed reaches 115Hz. The maximum rotation speed of 120Hz is rapidly decreased.

On the other hand, in this embodiment (broken line), the engine rotation speed is approximately 100.
Up to HZ, the sound pressure level is the same as the conventional example, but when the engine speed exceeds 100Hz, the sound pressure increases, but the sound pressure level is much lower than that of the conventional example. ing.

Although there are some differences, FIG. 7 also shows almost the same results as FIG. 6.

The sound pressure bells shown in Figures 6 and 7 above include some engine air propagation costs, but are mostly just the sound pressure generated when engine vibrations are transmitted from the chassis to the cab via the mounts. This is an extract of the following.

However, in general, cabin noise is not only caused by engine vibration noise, but is also generated by the transmission of various noises generated from various parts of the wheels, and as shown in Figures 6 and 7, engine vibration noise is constantly generated. Even if noise is generated, it is not recognized as noise if it is low compared to other noises, but it is recognized only when it becomes higher than other noises, and as shown in Figures 6 and 7. The approximate sound pressure levels of these other noises are shown by lines a and b, respectively. Therefore, in the figure, the vibration noise of the engine, which is a problem in the conventional example, is the engine rotational speed of 100.
Regarding the noise of 120 days 2), this example only shows a sound pressure lower than that of the a-line and b-line, so the cab mounting of this example is clearly different from the conventional example. It can be said that it has a sound reduction effect and eliminates the problem of engine vibration noise. The sound reduction effect of this embodiment as described above is achieved by using the left and right rear mounts 4 as described above in the embodiment.
．． The reason is to explore configurations where 4' is asymmetric.

In other words, the anti-vibration rubber 12 used in the left IJ mount 4 and the anti-vibration rubber 19 used in the right IJ mount 4' are the same, but because they are installed in different directions, one In other words, the rear mount 4' has a damping coefficient that is different from that of the rear mount 4 in all directions of the top, bottom, left, right, front and back of the car bran. Since the rear mount 4 has different force characteristics such as spring constant, the rear mount 4 exhibits different vibration transmission characteristics than the rear mount 4' with respect to vibrations in all of the directions.

Therefore, the left and right rear mounts 4, which have different vibration transmission characteristics,
When engine vibration is transmitted from the chassis 2 to the rear mount 4', the vibration is transmitted to the cab 1 via each rear mount 4, 4'. The vibrations transmitted from the rear mount 4 to the cab 1 due to changes in vibration such as phase and amplitude are transmitted to the cab 1, and the vibrations transmitted from the rear mount 4 to the cab 1 due to changes in vibration such as different phases, When both of the vibrations transmitted to the cab vibrate the car wall of cab 1, they interfere with each other, or when both vibrate the car wall and the vibrations become vibrations in the air inside the car and propagate through the car, they interfere with each other. In that case, if the mutual phase difference is appropriate (for example, 90° to 2700°), even if one vibration or sound interferes with the other vibration or sound, it will be strengthened by the phase shift of both vibrations or sounds. If they do not match and instead act in the opposite way or cancel each other out, it is thought that the vibrations of the car wall or the air will be reduced, resulting in lower indoor noise. As explained above in the examples, in the past, vibrations transmitted from the vibration noise source of the vehicle through various parts of the vehicle such as overlapping and transmitted to the podium from multiple mounts of the body mounting interfere and strengthen each other, resulting in vibration noise. Therefore, the present invention reduces vibrations by changing the vibration transmission characteristics of one mount between a pair of left and right mounts of a body mounting that vibration-proofly supports a wheel body on a chassis using a plurality of mounts from that of the other mount. Vibration transmitted from the chassis to the body through mounts with different transmission characteristics creates an appropriate phase difference and interferes with the vibration of the vehicle body, or interferes when the vibration of the vehicle body is converted into air vibration and propagates. However, based on the spirit of the present invention, the vibrations of the body or the air are reduced by acting so as to reduce the vibrations of the body or the vibrations of the air, preferably by acting inversely or canceling each other out, without exerting force on each other due to the phase difference. In order to change the vibration transmission characteristics of the mount, the same vibration isolating rubber 12 and rubber 9 are provided in different directions on the left and right rear mounts 4 and 4' as in the embodiment, but in addition, the left and right rear mounts are In addition to the above-mentioned rear mounts, in which one side is rotated by 90 degrees and the other is arranged in different directions to create a phase difference, vibrations can be transmitted between the mounts by changing the vibration isolating material such as vibration isolating rubber. You can also change its characteristics.

In addition, in actual application, the car bran podium is accompanied by a complex vibration structure and resonance phenomenon due to its complicated panel structure, and the t-vibration noise includes not only the engine vibration in the example but also the car bran podium. It also occurs due to vibrations in various places. Therefore, it is difficult to immediately detect the countermeasures from the occurrence of abnormal vibration and noise, and the vibration phenomena and therefore the countermeasures also vary depending on the difference in the car body structure depending on the car model, so it is not possible to provide a general rule. Therefore, it is practical to experimentally investigate the mount that should be addressed and the vibration transmission characteristics of the mount.In addition, in the example above, the vibration transmission characteristics of the mount are applied only to the left and right rear mounts. Since wheel vibration noise is caused by complicated factors, for example, in the embodiment, the present invention is implemented only between the left and right front mounts, or the present invention is implemented both between the left and right front mounts and between the left and right rear mounts. ``If necessary, body massaging is performed on all or appropriate locations of multiple pairs of mounts, and appropriate vibration transmission characteristics are set for the mounts.As explained above, this method The invention reduces the vibration noise of the car body by reducing the number of vibrations and noise of the car body on the car chassis using a plurality of mounts.In a pair of left and right mounts, the rough slope of one mount bracket is fixed to the width of the car cocoon. The mirror slope of the other mount bracket is formed so as to be perpendicular to the vertical plane of the direction and inclined with respect to the horizontal plane, and the mirror slope of the other mount bracket is 900 degrees different from the one mount bracket in the vertical plane in the longitudinal direction of the vehicle face. The left and right rear mounts are formed such that they are perpendicular to the rear mounts and have a frame different from the one side face with respect to the horizontal plane, and the left and right mount brackets are disposed asymmetrically with respect to the center of the vehicle chassis. By rubbing in different directions, even if the vibrations transmitted to the body via each mount interfere with each other based on the phase difference, they do not become stronger, but instead act to cancel each other out, reducing the sound. In addition to the sound reduction effect of the vibration isolating material of the body mounting on the wheel body mounting, it also has a new sound reduction effect, which reduces the vibration noise of the pode and also adds to the existing pode mounting. There is ease of application in implementation.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of the vicinity of the cab mount of a cab-over type automobile in which the present invention is applied to the cab mounting.
The figure is the configuration of the rear mountain in Figure 1. Figure 3 is an enlarged view of the main parts of Figure 2, Figure 4 is an enlarged view of the left side of the rear mountain in Figure 3, and Figure 5 is the same as in Figure 3. Figures 6 and 7 are diagrams showing the experimental results of vibration and noise caused by the cab mounting of this example. Figure 8 is a comparison with the vibration and noise experiments of Figures 6 and 7. It is a diagram showing conventional cab mountings used for. Tortoise...cab, 2...car chassis, 3, 3'...front mount, 4, 4'...rear mount "5..."・Engine, 12, 19... Vibration isolating rubber.Figure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 8?Figure 8

Claims (1)

[Claims] 1. In a vehicle body mounting system in which the vehicle body is supported on the undercarriage in a vibration-proof manner using multiple mounts, with a pair of left and right mounts, the inclined surface of one mount bracket is perpendicular to the vertical plane in the width direction of the vehicle and relative to the horizontal plane. At the same time, the inclined surface of the other mount bracket is formed in a direction 90 degrees different from the one mount bracket, perpendicular to the vertical plane in the longitudinal direction of the vehicle, and inclined with respect to the horizontal plane. A mounting device for a vehicle body, wherein the left and right mounting brackets are formed to have an inclination different from the plane and are arranged asymmetrically with respect to the center of the vehicle body.