JP4039827B2 - Liquid seal mount - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid seal mount used for an engine mount for automobiles and the like.
[0002]
[Prior art]
Japanese Patent Publication No. 62-23178 discloses a first support member attached to the vibration source side, a cylindrical second support member attached to the vehicle body side, and a conical rubber body provided between the two support members. And forming a liquid chamber for containing the buffer solution therein, providing a thin portion in a part of the rubber body, and further providing a disk-like member protruding from the first support member into the second support member, A liquid-sealed mount that divides the inside of the second support member into two chambers while forming an annular passage between the outer peripheral portion and the inner wall of the second support member, and is provided with a diaphragm at the bottom of the second support member. It is shown.
[0003]
[Problems to be solved by the invention]
According to the above structure, since the purpose is to attenuate vibration due to flow resistance, it can only cope with vibration of about several tens of Hz, and conversely in the middle and high frequency regions (500 to 1000 Hz) of about 100 to 500 Hz. It becomes a high dynamic spring.
[0004]
On the other hand, the rubber wall of the liquid chamber is not provided with such a thin portion, but is formed with a uniform thickness in the circumferential direction, and a disk-shaped member that is connected to the vibration input side and protrudes into the liquid chamber is provided. Thus, it is also known to realize a low dynamic spring in the intermediate frequency region. What is shown as a conventional example in FIG. 3 shows the change of the dynamic spring characteristics with respect to the frequency in such a structure. In such a liquid ring mount, a disk-shaped member acts as a medium frequency device, and the liquid column resonates at a specific frequency in the medium frequency region due to the flow of liquid in the gap with the surrounding rubber wall, thereby minimizing the liquid column mount. Produces the value a.
[0005]
However, this liquid column resonance results in a low dynamic spring in the middle frequency range, but as shown in the peak b due to the subsequent reaction, the high frequency spring becomes a high dynamic spring. On the other hand, in recent years, it has been desired to realize a low dynamic spring in a wide frequency range by reducing dynamic spring characteristics not only in the medium frequency range but also in the high frequency range.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a first invention relating to a liquid seal mount of the present application is provided between a first support member attached to a vibration source side, a second support member attached to a vehicle body side, and the first support member. A liquid chamber having the elastic member as a part of the wall is formed by the substantially conical elastic member, and the liquid chamber is divided into a main chamber and a sub chamber by a partition wall, and the main chamber and the sub chamber are always separated. In a liquid seal mount in which a communicating orifice passage is formed in a partition wall, a medium-high frequency is formed by attaching to the first support member, projecting into the main liquid chamber, and forming a flow space between the inner wall of the conical portion of the elastic member. With medium and high frequency devices to absorb components,
A thin portion for giving a minimum value to the dynamic spring characteristics is formed by generating a membrane resonance in a part of a conical portion of the elastic member by a vibration input in a medium to high frequency region.
[0007]
Here, the membrane resonance means a resonance phenomenon as an elastic membrane that occurs when the thin portion of the elastic member is elastically deformed with a spring property due to the liquid flow in the liquid chamber. In addition, the medium frequency region in the present invention refers to a range of 100 to 500 Hz among general medium frequency regions (40 to 500 Hz).
[0008]
At this time, a plurality of the thin-walled portions can be provided and each can be provided in the same shape at a symmetrical position.
[0009]
In addition, a plurality of the thin portions may be provided, and each may be provided in a different shape at a symmetrical position.
[0010]
In a second aspect based on the first aspect, the partition wall may be an elastic partition wall whose dynamic spring characteristics change according to a change in internal pressure of the liquid chamber.
[0011]
【The invention's effect】
According to the first aspect of the invention, as shown by the characteristic curve (1) in FIG. 3, first, the thin portion of the elastic member causes membrane resonance in the medium frequency region in response to vibration input in the medium and high frequency region, and the dynamic spring characteristic The minimum value A is given. Further, the medium / high frequency device gives the minimum value B of the dynamic spring characteristic by liquid column resonance accompanying the liquid flow in the gap between the medium / high frequency device and the thin portion in the high frequency region.
[0012]
Therefore, the dynamic spring characteristics can be reduced in each of the medium frequency region and the high frequency region, and a low dynamic spring can be realized over a wide range in the medium frequency region.
[0013]
At this time, if a plurality of thin portions are provided and are provided in the same shape at symmetrical positions, the minimum value A can be given singly as shown by the characteristic curve (1).
[0014]
Further, when a plurality of thin portions are provided and are provided in different shapes at symmetrical positions, the minimum value of the membrane resonance can be given as a plurality of C and D as shown by the characteristic curve (2).
[0015]
According to the second invention, the partition wall is constituted by an elastic partition wall whose dynamic spring characteristics change according to the change in the internal pressure of the liquid chamber, so that the elastic partition wall can be used in addition to the internal pressure absorption by the elastic deformation of the elastic partition wall. Since the dynamic spring characteristic itself changes with respect to the frequency and the membrane resonates at a specific resonance frequency, the elastic partition is combined with the structure having the thin portion of the elastic member and the medium-frequency device in the first invention. Each membrane resonance in the wall and thin wall portion and the liquid column resonance by the medium / high frequency device are combined, and as shown in characteristic curve (3) in FIG. It becomes even more prominent.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
1 is a full sectional view of an engine mount according to a first embodiment of the present invention (a sectional view taken along the direction of line 1-1 in FIG. 2), FIG. 2 is a schematic plan view of an elastic member, and FIG. Is a graph in which the vertical axis represents the dynamic spring and the horizontal axis represents the frequency.
[0017]
In FIG. 1, the engine mount includes a first support member 1 attached to the engine side which is a vibration source, a second support member 2 attached to the vehicle body side, and an elastic member 3 provided therebetween. ing.
[0018]
The first support member 1 has an axial shape extending inward of the second support member 2 in parallel with the input direction X of the main vibration. The elastic member 3 is made of an appropriate elastic material such as rubber or elastomer, and a conical portion 4 and a cylindrical portion 5 having a substantially conical shape are integrally formed.
[0019]
A pair of concave portions 6 having the same shape are formed in the axially symmetrical position on the inner wall of the conical portion 4, and the conical portion 4 of the concave portion 6 is a thin portion 7. The recess 6 is continuously formed up to the inner surface of the cylindrical portion 5.
[0020]
The cylindrical portion 5 is integrated with the inner surface of the cylindrical portion 8 of the second support member 2, and forms a liquid chamber inside the diaphragm 9 and the elastic member 3 fixed in the cylindrical portion 8.
[0021]
This liquid chamber is partitioned into a main liquid chamber 11 on the first support member 1 side and a sub liquid chamber 12 on the diaphragm 9 side by a partition member 10 provided on the inner side of the diaphragm 9, and the periphery of the partition member 10 and the diaphragm 9. The orifice 13 communicates with the portion 13 through an orifice passage 14.
[0022]
The orifice passage 14 communicates with the main liquid chamber 11 at an inlet 15 formed in the partition member 10, and communicates with the sub liquid chamber 12 at an outlet 16 formed in the elastic member 3.
[0023]
The first support member 1 extends long along the center of the elastic member 3, and one end of the first support member 1 projects into the main liquid chamber 11, and a substantially cup-shaped medium / high frequency device 17 is fixed thereto by caulking. The medium-frequency device 17 has a circular shape when viewed from the axial direction of the first support member 1.
[0024]
A predetermined orifice gap 18 is formed between the medium-frequency device 17 and the inner surface of the conical portion 4 so as to absorb vibration input in the high-frequency region by liquid column resonance.
[0025]
Further, the thin-walled portion 7 adjusts the size and depth of the recess 6 to change the film thickness and area, thereby absorbing vibration by membrane resonance with respect to vibration input in a specific medium frequency region. ing.
[0026]
Next, the operation of this embodiment will be described. 3, as shown as a characteristic curve ▲ 1 ▼, when there is input of vibration in the medium frequency region, the thin portion 7 is caused to film resonance, the minimum value A Te in advance the specific frequency set.
[0027]
Furthermore, if there is vibration input of a high frequency region, the liquid column resonance in the orifice gap 18 between the inner surface of the thin portion 7 and the conical portion 4 Te in particular frequency becomes the minimum value B.
[0028]
As a result, two local minimum values A and B are formed in the medium and high frequency region, and the dynamic spring characteristics are lowered and a remarkably low dynamic spring is realized with respect to the conventional example (virtual line) lacking such consideration. Note that a dynamic spring resonance peak P1 due to the reaction of the membrane resonance A is formed between both minimum values AB.
[0029]
The characteristic curve {circle around (2)} in the figure relates to the second embodiment. In this embodiment, as shown by the broken line in only one of the thin portions 7 in FIG. This is an example in which a thinned emphasis portion 19a is provided, and the thin portion 7 formed by the recess 6 and the thin emphasis portion 19a formed by the deep recess 19 are asymmetric thin portions having different shapes. In this case, since the membrane resonance frequencies of the thin portion 7 and the thin portion emphasizing portion 19a are different, two minimum values of CD are generated in the middle peripheral region, and a lower dynamic spring can be realized.
[0030]
FIG. 4 shows a third embodiment in which an elastic partition wall is provided at the lower part of the engine mount in the first embodiment. In addition, since this embodiment is a modification of the first embodiment, a common reference numeral is used for the common part, and description of overlapping parts is omitted as much as possible. The explanation about the equivalent part shall be used. An elastic partition wall 31 made of an elastic film such as rubber faces the hole 30 formed in the center of the ring-shaped partition member 10. The periphery of the elastic partition wall 31 on the bottom side forms an integral thick portion 32, and a leg portion 33 that is deformed in accordance with the deformation of the elastic partition wall 31 is integrally formed at the bottom.
[0031]
The portion of the elastic partition wall 31 that faces the hole 30 is a thin portion with respect to the thick portion 32 and has a spring property so that it functions as a kind of rubber spring, and is elastic according to changes in the internal pressure of the main liquid chamber 11. The film is deformed and resonates.
[0032]
The leg portion 33 abuts on a wall portion 35 formed integrally with the lower support member 34, and gives a non-linear spring characteristic to the deformation of the elastic partition wall 31. The lower support member 34 is a resin member that supports the outer peripheral side bottom of the thick portion 32, and is bent upward at substantially right angles from the inner peripheral side to form a wall portion 35. The wall portion 35 is fitted into a ring groove 36 formed at the bottom of the thick portion 32, and the side of the leg portion 33 that contacts the wall portion 35 is separated from the other thick portion 32 by the ring groove 36. And is freely movable.
[0033]
Reference numeral 9 in the drawing is a diaphragm, and 14 is formed in the circumferential direction in the thick portion of the thick portion 32, and communicates the main liquid chamber 11 and the sub liquid chamber 12. 1a is a resin bracket integrated around the first support member 1 which is a forged product.
[0034]
According to the present embodiment, as shown by the characteristic curve (3) in FIG. 3, the elastic partition wall 31 absorbs the internal pressure of the main liquid chamber 11 by its own elastic deformation, so that the dynamic spring constant in the intermediate frequency region is Compared with the characteristic curve (1), it decreases by ΔK. In addition, the elastic partition wall 31 performs membrane resonance by the liquid flow in the main liquid chamber 11.
[0035]
Since the membrane resonance caused by the elastic partition wall 31 is combined with the membrane resonance of the thin portion 7 in the conical portion 4 and the liquid column resonance caused by the medium-frequency device 17, the minimum value AB seen in the characteristic curve {circle around (1)} The dynamic spring peak is smoothed, and the entire dynamic spring is lowered significantly.
[0036]
Note that the dynamic spring peak P2 in the figure is generated by one of the elastic partition walls 31 of the present embodiment at a plurality of frequencies, and is smooth due to liquid column resonance by the medium-frequency device 17. This is a portion that remains without being made, and becomes a slightly higher dynamic spring in the middle frequency region than the characteristic curve (1), etc., but this degree is sufficiently allowed in reducing the overall dynamic spring.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an engine mount according to first and second embodiments. FIG. 2 is a schematic plan view of an elastic member. FIG. 3 is a graph showing dynamic spring characteristics. Figure corresponding to Figure 1 [Explanation of symbols]
1: 1st support member, 2: 2nd support member, 3: Elastic member, 4: Conical part, 7: Thin part, 10: Partition member, 14: Orifice passage, 17: Medium frequency device, 21: Cutting Notch, 31: elastic partition wall

Claims (4)

The elastic member is a part of the wall by the first support member attached to the vibration source side, the second support member attached to the vehicle body side, and the substantially conical elastic member provided therebetween. In a liquid seal mount in which a liquid chamber is formed, the liquid chamber is partitioned into a main chamber and a sub chamber by a partition wall, and an orifice passage that always communicates with the main chamber and the sub chamber is formed in the partition wall.
A medium-high frequency device for absorbing a medium-high frequency component by being attached to the first support member protruding into the main liquid chamber and forming a flow space between the inner wall of the conical portion of the elastic member;
A liquid-sealed mount characterized in that a thin portion for giving a minimum value to dynamic spring characteristics is formed in a part of a conical portion of an elastic member by generating a membrane resonance by vibration input in a medium-high frequency region.   The liquid seal mount according to claim 1, wherein a plurality of the thin-walled portions are provided and are provided in the same shape at symmetrical positions. The liquid seal mount according to claim 1, wherein a plurality of the thin portions are provided and each is provided in a different shape at a symmetrical position.
The liquid seal mount according to claim 1.   The liquid seal mount according to claim 1, wherein the partition wall is an elastic partition wall whose dynamic spring characteristics change according to a change in internal pressure of the liquid chamber.

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