JP2004270945A - Vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration control device capable of reducing dynamic spring constant in the forward and backward directions and reducing indoor noise effectively when accelerating and running at high speed. <P>SOLUTION: This vibration control device has a cylindrical main body fitting 1 fixed to a vehicle body side, a boss fitting 2 connected with a vibration generation body side, a rubber elastic body 3 as a vibrationproof body provided between them, front and rear stopper rubber parts 51, 52 fixed to the boss fitting 2 or its upper part and provided in a connection member 4, and stopper members 7 arranged in front and rear of the stopper rubber parts 51, 52 and fixed to the vehicle body side. A small cavity 10 is provided in at least either of the front and rear stopper rubber parts 51, 52. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration device for supporting a power unit such as an automobile engine and other vibration generators in an anti-vibration manner.

  As a vibration isolator for supporting a vibration generator such as an automobile engine so that the vibration is not transmitted to the vehicle body or the like, a rubber elastic body as a vibration isolator is provided between the vibration generator member and the vehicle body member. A non-liquid-filled type body that attenuates vibration using only the characteristics of the rubber elastic body, based on a basic configuration in which the member on the vibration generating body side is supported in a vibration-proof manner by a rubber elastic body. Various types of vibration isolating devices, such as a liquid filling type that uses a liquid flowing effect of an orifice by filling a liquid therein, have been proposed (for example, Patent Documents 1-2 below).

The vibration damping device of FIG. 6 is a vibration damping device according to a comparative example that can be used to support a power unit such as an automobile engine at its side, and includes a cylindrical main body fitting 101 fixed to a vehicle body side. A boss fitting 102 which is arranged slightly above the shaft center portion and is connected to the vibration generator side, and a vibration isolator interposed between the tubular main body fitting 101 and the boss fitting 102 so as to be connected to each other. A rubber elastic body 103, a connecting member 104 for connecting a vibration generator fixed to the upper part of the boss fitting 102, a stopper rubber 105 attached to the connecting member 104, and fixed to the vehicle body at front and rear portions of the apparatus. And an arch-shaped stopper member 107 disposed at a predetermined interval in front and rear and upper portions with respect to the stopper rubber 105 so that vibration from an engine is prevented by the rubber elasticity. With absorbed attenuated by 103, the stopper rubber 105 by contact with the stopper member 107, is configured to regulate the large displacement in the back-and-forth direction and upward.
JP-A-10-220508 JP 2001-280404 A

  By the way, in the vibration isolator having the above-described structure, the rubber portions 151 and 152 in front and behind of the stopper rubber 105 abut against the stopper member 107 with respect to the displacement in the front and rear direction on the vibration generating body side, so that a larger displacement can be obtained. When the vehicle travels, the stopper rubber 105 abuts against the stopper member 107, so that the dynamic spring constant in the front-rear direction tends to increase, and the vibration mainly having a relatively small amplitude is used. There is a dislike that the damping effect cannot be sufficiently obtained.

  In particular, when the vehicle is accelerating or the engine is running at a high speed of 2500 rpm to 4000 rpm, the connecting member 104 on the vibration generator side is displaced rearward, and the rubber portion 152 on the rear side of the stopper rubber 105 is moved relative to the stopper member 107. And remain in contact. Therefore, when a vehicle such as an automobile is accelerating or running at high speed, vibrations and noise on the vibration generator side are easily transmitted to the vehicle body side, and indoor noise is increased.

  On the other hand, when the characteristics such as elastic force are changed by changing the material of the stopper rubber 105, the spring force at the time of the stopper action becomes small, and the stopper action and durability may be impaired.

  That is, in the vibration isolator, the initial contact of the stopper rubber 105 with the stopper member 107 is relatively soft, the dynamic spring constant in the front-rear direction can be reduced, and the stopper action is reliably performed. It is also desired that noise transmission to the vehicle body during acceleration or high-speed running of the vehicle can be suppressed.

  The present invention has been made in view of the above, and in a vibration isolator having the above-described stopper structure, it is possible to reduce the dynamic spring constant in the front-rear direction without affecting characteristics such as durability and stopper action. An object of the present invention is to provide a vibration isolator, and a vibration isolator that can effectively reduce indoor noise during acceleration or high-speed running.

  The present invention solves the above-mentioned problems, and includes a first cylindrical member fixed to a vehicle body side, a second metal member which is disposed slightly above an axial center portion thereof and is connected to a vibration generator side, and The rubber elastic body interposed between the first metal fitting and the second metal fitting, and the front and rear attached to a connecting member of the upper part of the second metal fitting or the vibration generator fixed to the upper part of the second metal fitting And a stopper member disposed in front of and behind the stopper rubber portion and fixed to the vehicle body in the front-rear direction. The stopper rubber portion and the stopper member perform a stopper function in the front-rear direction. In the vibration device, a small cavity is provided in at least one of the front and rear stopper rubber portions. It is particularly preferable that the small cavity is provided at least in the rear stopper rubber portion.

  According to this vibration isolator, the load of the vibration generator is supported by the rubber elastic body as the vibration isolator via the second metal fitting so as not to transmit the vibration to the vehicle body or the like. In this state, the front and rear stopper rubber portions abut against the stopper member against the vibration displacement in the front and rear direction on the side of the vibration generator during the running of the vehicle, thereby performing the front and rear stopper action. In particular, in the case of the present invention, a small cavity is provided in at least one of the front and rear stopper rubber portions, so that the stopper rubber portion is easily elastically deformed up to a certain amplitude range, and Becomes softer.

  Therefore, the dynamic spring constant in the front-rear direction can be reduced, and good vibration-proof characteristics can be exhibited with respect to vibration having a relatively small amplitude. This effect is particularly remarkable when small cavities are provided in both the front and rear stopper rubber portions. In addition, at the time of vibration having a large amplitude, the small cavity is crushed and the wall surface of the small cavity comes into close contact with each other, so that the spring force as a stopper is increased. it can.

  In particular, when a small cavity is provided at least in the stopper rubber portion on the rear side, the coupling member with the vibration generator is displaced rearward when the vehicle is accelerating or when the rotation of the engine is running at a high speed of 2500 rpm to 4000 rpm. Even if the rear stopper rubber portion is kept in contact with the stopper member, the transmission of vibration to the vehicle body in this state is suppressed, and indoor noise can be reduced.

  As at least one of the small cavities of the front and rear stopper rubber portions, either a through hole or a non-through hole in a direction intersecting with the front and rear direction may be used, and depending on the diameter and shape of these holes, the stopper rubber portion has The rigidity can be set appropriately.

  As described above, according to the vibration damping device of the present invention, the dynamic spring constant in the front-rear direction can be reduced without affecting the characteristics such as durability and stopper action, and good vibration damping characteristics can be maintained. In addition, it is possible to effectively reduce indoor noise during acceleration and high-speed running.

  Next, embodiments of the present invention will be described based on examples shown in the drawings.

  FIG. 1 is a longitudinal sectional view showing one embodiment of the vibration isolator according to the present invention, FIG. 2 is a longitudinal sectional view taken along the line II-II of the preceding figure, and FIGS. 5 is a graph showing a comparison of room noise between the device of the present invention and the vibration damping device of the comparative example.

  In the figure, reference numeral 1 denotes a substantially cylindrical cup-shaped main body (first metal fitting) having an open bottom and fixed to the vehicle body side, as described later, and 2 denotes a boss metal fitting arranged slightly above its axial center ( A second metal fitting 3 is a vulcanized adhesive between a lower part of the cylindrical main body metal fitting 1, for example, an inner peripheral surface of a lower portion having an inward tapered shape as shown in the figure and a lower outer peripheral surface of the boss metal fitting 2. A rubber elastic body is used as the vibration isolator fixed and interposed by means. The rubber elastic body 3 basically has a thick, generally frustoconical shape as shown in the figure. A rubber layer 31 integral with the rubber elastic body 3 is provided on the inner peripheral surface of the cylindrical main body fitting 1 for protection thereof, and an outer peripheral surface of the boss fitting 2 is integral with the rubber elastic body 3. A rubber layer 32 is provided.

  Reference numeral 4 denotes a connecting member to the vibration generator side fixed to the boss fitting 2, for example, one end of which is fixed to the upper part of the boss fitting 2 by fastening means with bolts 41, and from the fixed portion in the left-right direction. The other end of the connecting member 4 extending to one side is provided so as to be connected and fixed by a bolt fastening means 42 to a member A on the vibration generator side such as an engine.

  Reference numeral 5 denotes a stopper rubber attached to the outer periphery of one end portion of the connecting member 4 serving as the fixing portion by vulcanization bonding means, and is provided so as to cover at least the front and rear portions and the upper portion of the connecting member 4. The front and rear portions are integrally formed as front and rear stopper rubber portions 51 and 52, and the upper portion is integrally formed as an upper rubber portion 53.

  The front and rear stopper rubber portions 51 and 52 are not limited to those integrally formed by the stopper rubber 5 as shown in the figure, but may be separately formed front and rear and attached. Further, depending on the form of the boss fitting 2 or the connection structure between the boss fitting 2 and the member A on the vibration generator side, the stopper rubber portions 51 and 52 may be provided above the boss fitting 2.

  Reference numeral 6 denotes a holding cylinder which has a substantially cup shape with an open bottom and fixes and holds the cylindrical main body fitting 1 by press fitting as shown in the figure. The holding cylinder 6 has substantially L-shaped legs 61, 61 extending downward from both front and rear sides and bent outward, and fastened to a vehicle body-side member B such as a vehicle body frame by a bolt nut or the like. The cylindrical body fitting 1 press-fitted and fixed as described above is provided slightly above the member B on the vehicle body side. Of course, other supporting means can be connected and fixed to the outer periphery of the cylindrical main body fitting 1 to support it.

  Reference numeral 7 denotes an arch-shaped stopper member fixed to the vehicle body-side member B together with the legs 61, 61 of the holding cylinder 6 at the front and rear portions of the apparatus. The stopper rubber 5 attached to the outer periphery, that is, the front and rear stopper rubber portions 51 and 52 and the upper rubber portion 53 are moved back and forth so as to have a required interval set according to the vibration isolation function and the stopper action. It is arranged straddling.

  That is, the stopper rubber 5 is provided at a position of the connecting member 4 corresponding to an inner portion of the stopper member 7. Thus, the relatively thick stopper rubber portions 51, 52 of the front and rear portions abut against the front and rear support portions 71, 72 of the stopper member 7 against the vibration displacement of the connecting member 4 in the front-rear direction. In addition, the upper rubber portion 53 comes into contact with the upper portion 73 of the stopper member 7 against the upward displacement of the connecting member 4 so as to perform a stopper function. Reference numeral 8 denotes a stopper rubber portion that regulates the downward displacement of the connecting member 4. 1 and 2 show a state in which no load is applied.

  The stopper member 7 does not necessarily have to have an arch shape as shown in the figure, but may be a stopper member separated front and rear, and is fixed to the opening end of the holding cylinder by caulking means. You can also.

  In the vibration damping device of the present invention, at least one of the front and rear stopper rubber portions 51 and 52, for example, as shown in the drawing, the rear stopper rubber portion 52 is provided in the front and rear direction as shown in the sectional view of FIG. A small cavity 10 having a through-hole having the same diameter in the direction intersecting with the stopper member 7 is provided, so that the stopper rubber portion 52 is softened when it comes into contact with the stopper member 7 and the dynamic spring constant in the front-rear direction is reduced. It can be reduced.

  That is, in a state where the vehicle engine is supported, the front and rear stopper rubber portions 51 and 52 abut against the stopper member 7 with respect to the longitudinal vibration displacement on the side of the vibration generating body when the vehicle travels, so that a larger displacement is generated. In this case, since the small cavity 10 is provided in at least one of the front and rear stopper rubber portions 51 and 52, at least one of the stopper rubber portions 51 and / or up to a certain amplitude range. 52 is easily elastically deformed, and the contact with the stopper member 7 becomes soft.

  For this reason, the dynamic spring constant in the front-rear direction can be reduced, and good vibration isolation characteristics can be exhibited with respect to vibration having a relatively small amplitude. In particular, when the small cavities 10 are provided in both the front and rear stopper rubber portions 51 and 52, the contact becomes soft in any of the front and rear directions, and the effect of reducing the dynamic spring constant is further improved. growing. In addition, at the time of vibration with a large amplitude, the small cavity 10 is crushed and the wall surface of the small cavity 10 comes into close contact with each other, so that the spring force as a stopper is increased, and a good stopper action is performed as in the conventional case, and the durability is impaired. Not even.

  Further, when the vehicle is accelerating or when the engine is running at a high speed of 2500 rpm to 4000 rpm, the connecting member 4 on the vibration generator side is displaced rearward, and the rear stopper rubber portion 52 is kept in contact with the stopper member 7. However, when the small cavity 10 is provided at least in the rear stopper rubber portion 52 as in the illustrated embodiment, the contact of the rear stopper rubber portion 52 with the stopper member 7 is soft. Therefore, the transmission of vibration to the vehicle body in this state is suppressed, and the indoor noise can be reduced as compared with the conventional product.

  The shape (cross-sectional shape), size, arrangement position and number of the small cavities 10, the direction of the holes, and the like can be variously changed in accordance with the required rigidity, dynamic spring constant, vibration isolation characteristics, and the like.

  For example, the small cavity 10 may be a non-through hole formed by leaving a non-through portion 11 as shown in FIG. 4 in addition to the above-described through hole. In the case of the small cavity 10 having the non-through hole, the position and the wall thickness of the non-penetrating portion 11 can be set as appropriate, and the tuning of the rigidity is facilitated by changing the position and the wall thickness or the hole diameter.

  In both cases of the through hole and the non-through hole of the small cavity 10, in addition to being formed in the middle part of the thickness of the front and rear stopper rubber portions 51 or 52, they are disposed near the tip end or near the connecting member 4. In addition, a plurality of rubber portions 51 and / or 52 can be arranged at the front and rear, or the cross-sectional shape of the hole can be substantially triangular or flat, and the direction of the hole can be arranged in the vertical direction. You can also. In any of these cases, the contact with the stopper member can be softened as described above, and the dynamic spring constant in the front-rear direction can be reduced, and noise transmission during acceleration or high-speed running can be reduced.

  FIG. 5 shows a case where the device of the present invention having a stopper rubber structure having a small cavity of the embodiment shown in FIG. 1 is used as a mount for supporting an engine mounted on an automobile, and a small cavity according to a comparative example shown in FIG. The results of measuring the sound pressure level at the driver's seat side in the room while varying the engine speed are shown in order to compare the indoor noise with the case where a vibration isolator with no stopper rubber structure is used. . The solid line in the figure is the case of the vibration damping device of the comparative example, and the broken line is the case of the device of the present invention.

  As is clear from the measurement results, in the high-speed running range where the engine speed is about 2500 rpm to about 4000 rpm, the sound pressure level of the device of the present invention is several decibels to 5 decibels compared to the device of the comparative example. The front and rear portions are also low (hatched portions in FIG. 5), which indicates that noise can be reduced by the device of the present invention.

  In the illustrated embodiment, the case of a non-liquid-filled type vibration damping device using only a rubber elastic body is shown, but the present invention uses a liquid flow effect of an orifice by filling a liquid inside the main body. The present invention can also be implemented in a liquid-sealed type vibration damping device, and the same effect can be exerted.

It is a longitudinal section showing one example of a vibration control device concerning the present invention. FIG. 2 is a vertical sectional view taken along the line II-II in the preceding figure. It is a cross-sectional view of the small cavity part of an apparatus same as the above. It is a cross-sectional view of the small cavity part which shows another Example. It is a graph which shows the comparison of the indoor noise about the apparatus of this invention and the apparatus of a comparative example. It is a longitudinal cross-sectional view which shows the vibration isolator of a comparative example.

Explanation of reference numerals

A member on vibration generator side B member on vehicle body 1 cylindrical main body fitting 2 boss fitting 3 rubber elastic body 4 connecting member 5 rubber for stopper 6 holding cylinder 7 stopper member 10 small cavity 11 non-penetrating portion 51, 52 stopper rubber before and after Part 53 Upper rubber part 61, 61 Leg part 71, 72 Front and rear support part

Claims (4)

A cylindrical first metal fitting fixed to the vehicle body side, a second metal fitting arranged slightly above the axial center portion and connected to the vibration generator side, and an intermediate member between both the first metal fitting and the second metal fitting; A front and rear stopper rubber portion attached to a connecting member of a rubber elastic body provided, an upper portion of the second metal fitting or a vibration generator fixed to an upper portion of the second metal fitting, and a front and rear of the stopper rubber portion. A vibration isolator that has a front-rear direction stopper member arranged and fixed to the vehicle body side and performs a front-rear direction stopper action by the stopper rubber portion and the stopper member.
A vibration isolator, wherein a small cavity is provided in at least one of the front and rear stopper rubber portions.   The vibration isolator according to claim 1, wherein the small cavity is provided at least on a stopper rubber portion on a rear side.   The vibration isolator according to claim 1, wherein the small cavity is a through hole in a direction crossing the front-back direction.   The vibration isolator according to claim 1, wherein the small cavity is a non-through hole in a direction crossing the front-back direction.

Images