Vibration proof mount

Abstract

To provide a vibration proof mount having excellent durability without increasing the weight thereof while having an effect of reducing a peak value of surging vibration.SOLUTION: A vibration proof mount 1, 1A, 1B includes: an outer cylinder 2; an inner cylinder 3, 3A, 3B provided inside a hollow part of the outer cylinder 2; and a plurality of elastic bodies 4 arranged in a peripheral direction at intervals between the outer cylinder 2 and the inner cylinder 3, 3A, 3B, and connecting the outer cylinder 2 with the inner cylinder 3, 3A, 3B. The plurality of elastic bodies 4 include: a plurality of first elastic bodies 41 provided on one side of the inner cylinder 3, 3A, 3B; and a plurality of second elastic bodies 42 provided on the other side of the inner cylinder 3, 3A, 3B. The first elastic body 41 and the second elastic body 42 have different lengths from an outer peripheral surface 31 of the inner cylinders 3, 3A, 3B to the inner peripheral surface 21 of the outer cylinder 2.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an anti-vibration mount for a vehicle. [Background technology]

[0002] Generally, automobiles and other vehicles are equipped with vibration-damping mounts made of rubber elastic materials that support power sources such as engines and motors. While vibration-damping mounts are generally effective in reducing vibrations in many frequency bands, they are unable to achieve sufficient vibration-damping effects in certain frequency bands due to significant deterioration in absolute spring force caused by rubber surging. Various methods have been proposed to reduce this rubber surging.

[0003] For example, Patent Document 1 discloses a motor mount that supports an electric motor for driving an electric vehicle, in which an elastic protrusion that protrudes axially outward and extends circumferentially is formed integrally with the main rubber elastic body at the intermediate portion between the opposing surfaces of an inner shaft member and an outer cylindrical member, and this elastic protrusion elastically deforms with a phase difference from the main rubber elastic body, thereby reducing the peak of the absolute spring constant due to surging of the main rubber elastic body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 175640 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the motor mount described in Patent Document 1, the elastic protrusions increase the weight and are prone to breakage due to repeated large deformation at the base portion.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an anti-vibration mount that has the effect of reducing the peak value of surging vibration, does not increase in weight, and has excellent durability. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides an anti-vibration mount comprising an outer tube, an inner tube arranged within the hollow portion of the outer tube, and a plurality of elastic bodies arranged at intervals circumferentially between the outer tube and the inner tube and connecting the outer tube and the inner tube, wherein the plurality of elastic bodies include a plurality of first elastic bodies arranged on one side of the inner tube and a plurality of second elastic bodies arranged on the other side of the inner tube, and the first elastic bodies and the second elastic bodies have different lengths from the outer peripheral surface of the inner tube to the inner peripheral surface of the outer tube. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an anti-vibration mount that has the effect of reducing the peak value of surging vibration, while not increasing its weight and having excellent durability. Problems, configurations, and effects other than those described above will become clear from the description of the following embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing an example of the configuration of an anti-vibration mount according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 2 is a plan view of the inner cylinder as seen from the direction of the arrow X in FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 10 is a plan view showing one configuration of an anti-vibration mount according to a comparative example. [Figure 6] This is an analytical graph showing the analysis results of the correlation between frequency and absolute spring, and shows the case where the combination of the connection length of the first elastic body and the connection length of the second elastic body in a vibration-proof mount with a diameter R1 is changed. [Figure 7]7 is a table summarizing the peak values ​​of absolute spring for each frequency band in the analysis graph shown in FIG. 6. [Figure 8] This is an analytical graph showing the analysis results of the correlation between frequency and absolute spring, and shows the case where the combination of the connection length of the first elastic body and the connection length of the second elastic body in a vibration-proof mount of diameter R2 is changed. [Figure 9] 9 is a table summarizing peak values ​​of absolute spring for each frequency band in the analysis graph shown in FIG. 8. [Figure 10] FIG. 10 is a plan view showing one configuration of a vibration-proof mount according to Modification 1. [Figure 11] 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 10 is a plan view showing one configuration of a vibration-proof mount according to Modification 2. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, one aspect of an anti-vibration mount according to an embodiment of the present invention will be described, taking as an example a motor mount that supports an electric motor for driving mounted on an electrically driven vehicle such as an electric automobile.

[0011] <Configuration of Anti-Vibration Mount 1> First, the configuration of the vibration isolation mount 1 will be described with reference to FIGS.

[0012] Fig. 1 is a perspective view showing an example of the configuration of an anti-vibration mount 1 according to an embodiment of the present invention. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a plan view of an inner cylinder viewed from the direction of arrow X in Fig. 1. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3.

[0013] The vibration-proof mount 1 comprises an outer cylinder 2, an inner cylinder 3 disposed in the hollow portion of the outer cylinder 2, and a plurality of (four in this embodiment) elastic bodies 4 connecting the outer cylinder 2 and the inner cylinder 3.

[0014] In this embodiment, the outer cylinder 2 is formed into a cylindrical shape by bending a metal plate. The outer cylinder 2 does not necessarily have to be cylindrical, and may be, for example, a rectangular cylinder. In other words, the axial end face or the cross section of the outer cylinder 2 when cut in the radial direction does not necessarily have to be circular, and may be, for example, a polygonal shape such as a square or hexagon.

[0015] In this embodiment, the inner cylinder 3 is formed of a rectangular prism-shaped metal member. As shown in Fig. 3, the inner cylinder 3 has a square cross section when cut in the axial direction or the radial direction, but this does not necessarily have to be square and may be, for example, circular or hexagonal.

[0016] 2 and 4, an axial hole 30 penetrating in the axial direction (extension direction) is formed in the center of the inner tube 3. In this embodiment, the axial hole 30 is located at the center position C of the inner tube 3 (the intersection of a pair of diagonal lines D1, D2 connecting the four corners of the inner tube 3) as shown in Fig. 3. Note that in Fig. 3, the directions of the pair of diagonal lines D1, D2 (shown by dashed dotted lines) connecting the four corners of the inner tube 3 correspond to the up-down and left-right directions in the figure.

[0017] 3, the multiple elastic bodies 4 are arranged side by side at predetermined intervals in the circumferential direction between the outer cylinder 2 and the inner cylinder 3. In this embodiment, four elastic bodies 4 are arranged side by side at equal intervals in the circumferential direction between the outer cylinder 2 and the inner cylinder 3.

[0018] The elastic bodies 4 are made of rubber. Note that each elastic body 4 does not necessarily have to be made of rubber elastic material, and there are no particular restrictions on the material as long as it is capable of absorbing vibrations.

[0019] The multiple elastic bodies 4 include multiple first elastic bodies 41 arranged on one side of the inner cylinder 3 and multiple second elastic bodies 42 arranged on the other side of the inner cylinder 3. In this embodiment, as shown in Fig. 3, of the four elastic bodies 4, two are first elastic bodies 41 and the remaining two are second elastic bodies 42.

[0020] Each of the first elastic bodies 41 and each of the second elastic bodies 42 has a different length (hereinafter referred to as "connection length") from the outer peripheral surface 31 of the inner cylinder 3 to the inner peripheral surface 21 of the outer cylinder 2. In this embodiment, as shown in FIGS. 3 and 4, the connection length W1 of each of the first elastic bodies 41 is set shorter than the connection length W2 of each of the second elastic bodies 42 (W1 <W2)。

[0021] In this embodiment, since the inner tube 3 is rectangular prism-shaped, the length from the outer surface 31 of the inner tube 3 to the inner surface 21 of the outer tube 2 varies depending on the location, but the connection length W1 of each first elastic body 41 and the connection length W2 of each second elastic body 42 are both the maximum length from the outer surface 31 of the inner tube 3 to the inner surface 21 of the outer tube 2.

[0022] The plurality of first elastic bodies 41 and the plurality of second elastic bodies 42 differ only in their connection length, and all other components such as dimensions and materials other than the connection length are common to them.

[0023] 3 and 4, in this embodiment, the two first elastic bodies 41 are arranged on one side in the direction of the load applied to the inner cylinder 3, and the two second elastic bodies 42 are arranged on the other side in the direction of the load applied to the inner cylinder 3. The two first elastic bodies 41 and the two second elastic bodies 42 are arranged symmetrically with respect to the axial hole 30 of the inner cylinder 3.

[0024] In Figures 3 and 4, the load direction acting on the inner tube 3 is in the up and down direction in each figure, with the two first elastic bodies 41 being positioned above the center position C of the inner tube 3 and the two second elastic bodies 42 being positioned below the center position C of the inner tube 3.

[0025] When a load is applied downward in each diagram, as in this embodiment, it is desirable to position the second elastic body 42 with the longer connection length below the center position C of the inner cylinder 3. Conversely, when a load is applied upward in each diagram, it is desirable to position the second elastic body 42 with the longer connection length above the center position C of the inner cylinder 3.

[0026] There are no particular limitations on the arrangement of the multiple elastic bodies 4 as long as the peak value of the surging vibration generated in the electric motor can be effectively reduced by the multiple elastic bodies 4. Two variations in the arrangement of the multiple elastic bodies 4 will be described later as modified examples.

[0027] <Surge vibration reduction effect of anti-vibration mount 1> Next, the effect of reducing surging vibrations by the vibration-isolating mount 1 will be described with reference to FIGS.

[0028] Before describing the effect of reducing surging vibrations by the vibration isolation mount 1, the configuration of a vibration isolation mount 100 according to a comparative example will be described with reference to FIG.

[0029] Fig. 5 is a plan view showing one configuration of an anti-vibration mount 100 according to a comparative example. In Fig. 5, components common to the anti-vibration mount 1 according to the embodiment are given the same reference numerals and description thereof will be omitted.

[0030] In the vibration-proof mount 100 according to the comparative example, all four elastic bodies 43 are set to the same connection length W3. That is, unlike the elastic bodies 4 according to the embodiment, the elastic bodies 4 do not include a plurality of first elastic bodies 41 and a plurality of second elastic bodies 42 with different connection lengths.

[0031] As in the embodiment, the four elastic bodies 43 are arranged at equal intervals in the circumferential direction between the outer cylinder 2 and the inner cylinder 3, with two elastic bodies 43 arranged on one side of the load direction applied to the inner cylinder 3 and the remaining two elastic bodies 43 on the other side of the load direction applied to the inner cylinder 3. The four elastic bodies 43 are arranged symmetrically with respect to the axial hole 30 of the inner cylinder 3.

[0032] Here, if the total connection length W1+W2, which is the sum of the connection length W1 of the first elastic body 41 and the connection length W2 of the second elastic body 42 in the vibration-proof mount 1 of the embodiment, is represented as "100%", the ratio (W1:W2) of the connection length W1 of the first elastic body 41 to the connection length W2 of the second elastic body 42 can be expressed as a percentage ratio.

[0033] For example, in the case of the vibration-proof mount 100 according to the comparative example, the connection length W1 of the first elastic body 41 and the connection length W2 of the second elastic body 42 are the same W3, and therefore the ratio (W1:W2) of the connection length W1 of the first elastic body 41 to the connection length W2 of the second elastic body 42 is expressed as (50%:50%).

[0034] Next, the results of analyzing the correlation between the applied frequency and absolute spring (the sum of the absolute spring of the first elastic body 41 and the absolute spring of the second elastic body 42) in vibration-proof mounts 1 in which the combination of the connection length W1 of the first elastic body 41 and the connection length W2 of the second elastic body 42 is changed will be explained using Figures 6 to 9.

[0035] Fig. 6 is an analytical graph showing the results of an analysis of the correlation between frequency and absolute spring, showing the case where the combination of the connection length W1 of the first elastic body 41 and the connection length W2 of the second elastic body 42 in an anti-vibration mount 1 of diameter R1 is changed. Fig. 7 is a table summarizing the peak values ​​of absolute spring for each frequency band in the analytical graph shown in Fig. 6.

[0036] Fig. 8 is an analytical graph showing the results of an analysis of the correlation between frequency and absolute spring, showing the case where the combination of the connection length W1 of the first elastic body 41 and the connection length W2 of the second elastic body 42 in an anti-vibration mount 1 of diameter R2 is changed. Fig. 9 is a table summarizing the peak values ​​of absolute spring for each frequency band in the analytical graph shown in Fig. 8.

[0037] In this analysis, the combination (W1+W2) of the connection length W1 of the first elastic body 41 and the connection length W2 of the second elastic body 42 was used as the comparison standard (50%+50%), which corresponds to the vibration-proof mount 100 of the comparative example, and was also changed to five other combinations: (48%+52%), (44%+56%), (40%+60%), (36%+64%), and (32%+68%).

[0038] The analysis results of the (50% + 50%) combination serving as the comparison standard are shown by solid lines in the graphs of FIGS. 6 and 8, and by dotted shading in the tables of FIGS. 7 and 9, respectively. Further, the analysis results of the (48% + 52%) combination are shown by a solid line connecting a plurality of * in the graphs of FIGS. 6 and 8.

[0039] Further, the analysis results of the (44% + 56%) combination are shown by a solid line connecting a plurality of ◆ in the graph of FIG. 6 and by a solid line connecting a plurality of ■ in the graph of FIG. 8, respectively. Also, the analysis results of the (40% + 60%) combination are shown by a solid line connecting a plurality of ■ in the graph of FIG. 6 and by a solid line connecting a plurality of ◆ in the graph of FIG. 8, respectively.

[0040] Further, the analysis results of the (36% + 64%) combination are shown by a solid line connecting a plurality of ▲ in the graphs of FIGS. 6 and 8. Also, the analysis results of the (32% + 68%) combination are shown by a solid line connecting a plurality of ● in the graphs of FIGS. 6 and 8.

[0041] In the analysis of the vibration isolator 1 with the inner diameter of the outer cylinder 2 being R1, as shown in FIG. 6, the frequency range of 0 to 2,000 Hz propagated from the electric motor to the vibration isolator 1 is divided into three frequency ranges according to the peak value of the absolute spring in the (50% + 50%) combination serving as the comparison standard.

[0042] Specifically, among the frequency range of 0 to 2,000 Hz, the frequency range of 0 to 650 Hz is defined as the primary band, the frequency range of 650 to 1,350 Hz is defined as the secondary band, and the frequency range of 1,350 to 2,000 Hz is defined as the tertiary band.

[0043] On the other hand, in the analysis of the vibration isolator 1 with the inner diameter of the outer cylinder 2 being R2 (<R1), as shown in FIG. 8, the frequency range of 0 to 2,000 Hz propagated from the electric motor to the vibration isolator 1 is divided into two frequency ranges according to the peak value of the absolute spring in the (50% + 50%) combination serving as the comparison standard.

[0044] Specifically, within the frequency range of 0 to 2,000 Hz, the frequency range of 0 to 1,200 Hz is defined as the primary band, and the frequency range of 1,200 to 2,000 Hz is defined as the secondary band. However, in this secondary band (frequency range of 1,200 to 2,000 Hz), no peak absolute spring value was observed in the comparison standard combination (50% + 50%), so the peak absolute spring values ​​in the table in Figure 9 are all indicated with a "-".

[0045] As shown in Figures 6 to 9, the combinations (48% + 52%), (44% + 56%), (40% + 60%), (36% + 64%), and (32% + 68%) all contain peak absolute spring values ​​that are lower than the peak absolute spring value of the comparison standard combination (50% + 50%).

[0046] In this way, the vibration-proof mount 1 has multiple elastic bodies 4 including multiple first elastic bodies 41 and multiple second elastic bodies 42 with different connection lengths, which allows the peak value of the surging vibration generated in the electric motor to be further reduced compared to when all the connection lengths are the same.

[0047] In particular, as shown in Figures 7 and 9, in the combinations of (48% + 52%), (44% + 56%), and (40% + 60%), the peak absolute spring values ​​are reduced in all frequency ranges compared to the peak absolute spring value in the comparison standard combination of (50% + 50%).

[0048] Therefore, it is desirable that the ratio (W1:W2) of the connection length W1 of the first elastic body 41 to the connection length W2 of the second elastic body 42 of the vibration-proof mount 1 be set in the range of (40%:60%) to (48%:52%).

[0049] In addition, the vibration-proof mount 1 has a configuration in which the multiple elastic bodies 4 include multiple first elastic bodies 41 and multiple second elastic bodies 42 with different connection lengths, thereby reducing the peak value of surging vibrations and preventing large localized deformation, making it highly durable.

[0050] <Modification> Next, vibration isolation mounts 1A and 1B according to modified examples of the present invention will be described with reference to Figures 10 to 12. Note that components in the modified examples that are common to those described in the above embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

[0051] Fig. 10 is a plan view showing one configuration of an anti-vibration mount 1A according to Modification 1. Fig. 11 is a cross-sectional view taken along line XI-XI in Fig. 10.

[0052] In the vibration-proof mount 1A according to the first modification, the axial hole 30A of the inner cylinder 3A is positioned below the center position C of the inner cylinder 3, that is, shifted toward the second elastic body 42 having the longer connection length.

[0053] FIG. 12 is a plan view showing one configuration of an anti-vibration mount 1B according to the second modification.

[0054] In the vibration-proof mount 1B of variant example 2, two first elastic bodies 41 are arranged on one side of the intersecting direction (orthogonal direction in Figure 12) that intersects with the load direction acting on the inner tube 3B, and two second elastic bodies 42 are arranged on the other side of the intersecting direction.

[0055] 12, the two first elastic bodies 41 are arranged to the left of the center position C (diagonal line D2 extending in the up-down direction) of the inner cylinder 3B, and the two second elastic bodies 42 are arranged to the right of the center position C of the inner cylinder 3B. In this case, the axial hole 30B of the inner cylinder 3B is positioned to the right of the center position C of the inner cylinder 3B, that is, shifted toward the second elastic body 42 with the longer connection length.

[0056] In this way, the relative positions of the multiple first elastic bodies 41 and the multiple second elastic bodies 42 can be changed depending on the installation location of the vibration-proof mounts 1A, 1B and the vehicle specifications, and the vibration-proof mount 1A according to variant example 1 and the vibration-proof mount 1B according to variant example 2 also achieve the same functions and effects as the vibration-proof mount 1 of the embodiment.

[0057] The above describes the embodiments and modifications of the present invention. Note that the present invention is not limited to the above-described embodiments and modifications, and various other modifications are also included. For example, the above-described embodiments and modifications have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of this embodiment and modifications with configurations of other embodiments, and it is also possible to add configurations of other embodiments to the configuration of this embodiment and modifications. Furthermore, it is possible to add, delete, or replace part of the configuration of this embodiment and modifications with other configurations.

[0058] For example, in the above embodiments and variants, the vibration isolation mounts 1, 1A, 1B have been described as motor mounts that support an electric motor, but the vibration isolation mounts 1, 1A, 1B do not necessarily have to be motor mounts and may also be, for example, engine mounts that support an engine. [Explanation of symbols]

[0059] 1, 1A, 1B: Anti-vibration mount 2: Outer cylinder 3,3A,3B: Inner cylinder 4: Elastic body 21: Inner surface 30,30A,30B: Shaft hole 31: Outer surface 41: First elastic body 42: Second elastic body C: Center position W1, W2: Connection length

Claims

1. An outer tube and an inner cylinder disposed in a hollow portion of the outer cylinder; a plurality of elastic bodies arranged at intervals in the circumferential direction between the outer cylinder and the inner cylinder and connecting the outer cylinder and the inner cylinder; In a vibration isolation mount comprising: The plurality of elastic bodies are a plurality of first elastic bodies arranged on one side of the inner cylinder; a plurality of second elastic bodies arranged on the other side of the inner cylinder; Including, The first elastic body and the second elastic body are The length from the outer peripheral surface of the inner cylinder to the inner peripheral surface of the outer cylinder is different An anti-vibration mount characterized by:

2. 2. The vibration isolation mount according to claim 1, When the total length of the first elastic body and the second elastic body is expressed as 100%, The ratio of the length of the first elastic body to the length of the second elastic body is It is set in the range of 40%:60% to 48%:52%. An anti-vibration mount characterized by:

3. 2. The vibration isolation mount according to claim 1, the plurality of first elastic bodies are arranged on one side in a load direction applied to the inner cylinder, The second elastic bodies are disposed on the other side in the load direction. An anti-vibration mount characterized by:

4. 4. The vibration isolation mount according to claim 3, The first elastic body and the second elastic body are The inner cylinder is symmetrically arranged with the axial hole of the inner cylinder as the center, The axial hole is Located at the center of the inner cylinder An anti-vibration mount characterized by:

5. 4. The vibration isolation mount according to claim 3, The first elastic body and the second elastic body are The inner cylinder is symmetrically arranged with the axial hole of the inner cylinder as the center, The axial hole is The inner cylinder is positioned at a position shifted from the center position of the inner cylinder toward the elastic body having the longer length. An anti-vibration mount characterized by:

6. 2. The vibration isolation mount according to claim 1, the plurality of first elastic bodies are arranged on one side in a direction intersecting with a load direction applied to the inner cylinder, The plurality of second elastic bodies are disposed on the other side in the intersecting direction. An anti-vibration mount characterized by:

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