JP7747545B2 - vibration-damping material - Google Patents

Description

This disclosure relates to vibration-damping members.

Damping materials are used in a wide range of fields, including automobiles, electrical appliances, and housing equipment, by being placed between two components to absorb vibrations that occur between those components and suppress their transmission. For example, in the automobile industry, if various components such as the battery, electronic circuit boards, and auxiliary equipment are directly connected to the vehicle body, vibrations from the vehicle body will be transmitted to those components and cause malfunctions. For this reason, various components are connected to the vehicle body via metal wave washers or rubber elastic bodies.

Damping members used to reduce vibrations transmitted between two members, i.e., for vibration control, are disclosed in, for example, Patent Documents 1 and 2.

Patent Document 1 discloses a wave washer (23) used in a motor for an electric power steering device. The wave washer is attached so as to apply preload to the rolling bearing that rotatably supports the rotor shaft, and suppresses noise caused by vibrations from various directions (see paragraphs [0004] and [0007] and Figure 4 of Patent Document 1).

Patent Document 2 discloses a vibration isolation device installed between the engine housing (2) of an outboard motor and a steering handle (3) rotatably connected to the engine housing. This vibration isolation device has a wave washer (7) interposed between two members on the steering handle side, and a rubber elastic body (8) interposed between the steering handle and the engine housing (see paragraphs [0017] and [0018] of Patent Document 2).

JP 2009-124785 A Japanese Patent Application Publication No. 11-210830 Japanese Utility Model Publication No. 60-186856 Japanese Patent Application Laid-Open No. 2002-257239

Yuya Noguchi and three others, "Rubber Deterioration Cases and Test Methods," Nissin Electric Technical Report, Nissin Electric Co., Ltd., October 2019, Vol. 64, No. 2, pp. 34-40

Wave washers do not have the damping properties of rubber elastic bodies. For this reason, when wave washers are used as vibration-damping members (see, for example, Patent Document 1), they do not provide sufficient vibration-reducing effects. However, rubber elastic bodies do have a damping effect, so when used as vibration-damping members, good vibration-reducing effects can be expected (see, for example, Patent Document 2).

On the other hand, rubber elastic bodies are temperature dependent and prone to deterioration over time. This means they can deform due to environmental temperature and deterioration over time, making it difficult to achieve the desired characteristics. For examples of deterioration of rubber elastic bodies, please refer to Non-Patent Document 1.

Patent Document 3 discloses an example configuration in which a wave washer (23) and a rubber elastic body (rubber washer (22)) are stacked in a row (see Patent Document 3, page 10, line 16 to page 12, line 3, and Figure 2-4). It is expected that by using two types of elastic bodies in this way, the weaknesses of each can be compensated for. However, stacking a wave washer and a rubber elastic body in a row takes up a large amount of space, increasing the assembly man-hours. Improvements are needed.

Patent Document 4 discloses an example of a gas seal that uses a disc spring (2) as the metal spring, in which a first rubber-like elastic body (3) is baked onto one side of the disc spring and a second rubber-like elastic body (4) is baked onto the opposite side (see paragraph [0028] of Patent Document 4). However, this gas seal is intended to counter noise generated by engine vibrations being transmitted to the disc spring, and the disc spring is not used as a vibration-damping member like a wave washer. Rather, Patent Document 4 recognizes the disc spring as a source of vibration.

The objective of this disclosure is to obtain a vibration-damping member that combines the characteristics of both a wave washer and a rubber elastic body, while occupying a small space and not increasing the number of assembly steps.

One type of vibration-damping member comprises a wave washer having a circular ring shape that undulates in the axial direction along the circumferential direction, and having alternating peaks that contact the two components when sandwiched between them and valleys that do not, and elastic restrictors made of rubber that are provided on the front and back surfaces of the valleys to determine the amount of compressive deformation of the wave washer and absorb vibrations by elastic deformation in the axial direction.

It is possible to obtain a vibration-damping member that combines the properties of both a wave washer and a rubber elastic body, while occupying a small space and not increasing the number of assembly steps.

1A is a side view of a wave washer, and FIG. 1B is a side view of a vibration-damping member according to an embodiment. 1A is a front view of a wave washer, and FIG. 1B is a front view of a vibration-damping member. 10A is a front view of a wave washer, and FIG. 10B is a front view of a vibration-damping member, showing another embodiment. 1A is a longitudinal cross-sectional side view showing a vibration-damping member disposed between two members before being compressed and deformed, and FIG. 1B is a longitudinal cross-sectional side view showing a vibration-damping member sandwiched between two members and being compressed and deformed. 1 is a graph showing the relationship between the stroke (horizontal axis) when compressed and the load (vertical axis) generated at that time for three types of samples: a vibration-damping member, a wave washer (Comparative Example 1), and a rubber elastic body (Comparative Example 2). 10 is a graph showing the temperature dependency and aging deterioration of a vibration-damping member based on the relationship between the stroke (horizontal axis) when compressed and deformed and the load (vertical axis) generated at that time. 10 is a graph showing the temperature dependency and aging deterioration of a rubber elastic body (Comparative Example 2) based on the relationship between the stroke (horizontal axis) when compressed and deformed and the load (vertical axis) generated at that time. 6 is a graph illustrating a method for determining the stroke of a vibration-damping member so as to obtain a required load. FIG. 10 is a front view showing another embodiment of a vibration damping member. FIG. 10 is a front view showing yet another embodiment of a vibration damping member.

The embodiment will be described with reference to the drawings. The description will be made along the following items.
1. Configuration (1) Overview (2) Wave washer (3) Cover (4) Elastic regulating body 2. Effects (1) Usage (2) Vibration damping action (3) Occupied space (4) Assembly man-hours (5) Temperature dependency (6) Deterioration over time (7) Stroke setting (8) Summary 3. Other embodiments and modified examples (1) Other embodiments (2) Further other embodiments (3) Modified examples

1. Configuration (1) Overview This embodiment is an example of a vibration-damping member 101 that is sandwiched between two members 11 and mounted in a compressed state. One of the two members 11, member 11A, is, for example, the body of an automobile, and the other member 11B is a battery, electronic circuit board, or auxiliary equipment mounted on the body of the automobile. As another example, one of the two members 11, member 11A, is an electric fan attached to the indoor or outdoor unit of an air conditioner, and the other member 11B is a housing for the indoor or outdoor unit. In these two examples, one member 11A generates vibrations, and the vibration-damping member 101 absorbs the generated vibrations and suppresses their transmission to the other member 11B.

As shown in Figures 1(A) and 1(B) and 2(A) and 2(B), the framework of the vibration-damping member 101 is the wave washer 111. The vibration-damping member 101 has the wave washer 111 covered with a rubber covering 131, and an elastic regulating body 151 is provided integrally with the covering 131.

(2) Wave Washer As shown in Figures 1A and 2A, the wave washer 111 is a metal member having a circular ring shape centered on axis A, and is wavy in the axial direction (the direction of axis A) along the circumferential direction. The wavy shape creates peaks 112 and valleys 113 on the front and back surfaces of the wave washer 111.

The peak portion 112 is the area that comes into contact with the two members 11 when the wave washer 111 is sandwiched between the two members 11.

The valley portion 113 is located between two adjacent peak portions 112 and is an area that does not come into contact with the two members 11 when the wave washer 111 is sandwiched between the two members 11.

The peaks 112 and valleys 113 alternate along the circumferential direction of the wave washer 111. In this embodiment, six peaks 112 and six valleys 113 are provided.

(3) Covering Body As shown in Figures 1(B) and 2(B), the wave washer 111 is entirely covered with a covering body 131 (see also Figures 4(A) and 4(B)). The covering body 131 is, for example, rubber that is vulcanized and bonded to the wave washer 111.

As an example, the covering 131 covers the wave washer 111 with a uniform thickness. Of course, it is not necessary for the covering 131 to be of a uniform thickness, and various modifications and variations are permissible, such as making the portion covering the peaks 112 thicker than the portion covering the valleys 113.

In this embodiment, the cover 131 has a thickness that allows it to absorb vibrations through elastic deformation in the axial direction (the direction of axis A). In other words, the cover 131 not only performs a protective function to protect the wave washer 111 and the two members 11 that sandwich the wave washer 111, but also plays a role in providing vibration damping. If the thickness of the cover 131 is not uniform, the thickness setting that allows it to absorb vibrations through elastic deformation in the axial direction is applied at least to the region of the peak portion 112.

Due to the structure in which the wave washer 111 is covered with the covering 131, the vibration damping member 101 also has a wavy shape along the peaks 112 and valleys 113. For ease of explanation, the peaks 112 of the wave washer 111 covered with the covering 131 will be referred to as peaks 112R, and the valleys 113 will be referred to as valleys 113R.

(4) Elastic Regulating Body The elastic regulating body 151, which is molded integrally with the cover 131, is a cylindrical member provided on the front and back surfaces of the valley portion 113 of the wave washer 111. The elastic regulating body 151 is provided at the same axial position on the front and back surfaces of the valley portion 113. Therefore, when the wave washer 111 is sandwiched between the two members 11 and elastically deforms, the elastic regulating body 151 functions to regulate the amount of compressive deformation. At this time, the elastic regulating body 151 also has a vibration-damping function that absorbs vibrations by elastic deformation in the axial direction (the direction of axis A).

As shown in Figure 2 (B), in this embodiment, elastic regulating bodies 151 are arranged in all of the valley portions 113. Therefore, when a pair of elastic regulating bodies 151 provided on the front and back surfaces of the wave washer 111 at the same axial position is counted as one set, there are six sets (twelve) of elastic regulating bodies 151 provided, which matches the number of valley portions 113.

However, it is not necessarily necessary to provide elastic regulating bodies 151 in all valley portions 113. In practice, elastic regulating bodies 151 may be provided in only some of the valley portions 113.

However, due to the placement constraint of being placed in the valley portions 113 of the wave washer 111, the number of sets of elastic regulating bodies 151 that can be placed depends on the number of valley portions 113 (valley portions 113R). For example, the example shown in Figure 3 is a vibration-damping member 101 that mainly consists of a wave washer 111 that has three peak portions 112 and three valley portions 113. The number of sets of elastic regulating bodies 151 that can be placed on this vibration-damping member 101 depends on the number of valley portions 113 (valley portions 113R), and is up to three sets (six).

2. Effects (1) Usage As shown in Figures 4(A) and 4(B), the vibration-damping member 101 is disposed between one member 11A that generates vibration and another member 11B that is fixed to the member 11A, and is compressed and deformed by fastening these two members 11 together, and is interposed between the two members 11. At this time, the wave washer 111 of the vibration-damping member 101 is compressed and elastically deformed in the axial direction, and the cover 131 and elastic regulating body 151 are also compressed and elastically deformed in the axial direction (see Figure 4(B)).

Looking more closely, the wave washer 111 is not completely crushed because the amount of compressive deformation is regulated by the elastic regulating body 151, and is therefore maintained in a state where there is room for further deformation in the axial direction. The same is true for the cover 131 and the elastic regulating body 151, which are also maintained in a state where there is room for further deformation in the axial direction.

(2) Vibration-damping effect When vibration occurs in one of the two members 11, member 11A, the vibration-damping member 101 exerts vibration-damping effects due to the wave washer 111 and the covering body 131, which is an elastic rubber body, and the elastic regulating body 151, thereby absorbing the vibration and suppressing its transmission.

Figure 5 is a graph showing the results of measuring the stroke and the load generated when three types of samples were compressed and deformed: the vibration-damping member 101 of this embodiment, a wave washer (Comparative Example 1), and a rubber elastic body (Comparative Example 2). The horizontal axis represents the stroke, and the vertical axis represents the load. In Figure 5, (1) represents the measurement results for the vibration-damping member 101 of this embodiment, (2) for the wave washer, and (3) for the rubber elastic body.

The wave washer sample used in Comparative Example 1 is the same as the wave washer 111 that forms part of the vibration-damping member 101 of this embodiment. The rubber elastic body sample used in Comparative Example 2 is approximately the same size as the vibration-damping member 101.

In Comparative Example 1, which used a wave washer alone, the load increased linearly as the stroke increased (see (2) in Figure 5). This is because wave washers do not have the damping properties of elastic rubber.

In the case of Comparative Example 2, which used a rubber elastic body alone, the load did not increase in the early stages of stroke increase, as it did with the wave washer. It was found that the load only gradually increased once the stroke had increased to a certain extent, eventually exceeding the load generated by the wave washer (see (3) in Figure 5). This increase curve is due to the nonlinearity of the rubber.

The vibration-damping member 101 of this embodiment has a combined structure of a wave washer 111, a rubber elastic covering 131, and an elastic regulating body 151. Therefore, in the initial stage of stroke increase, the linear load increase characteristic seen in the wave washer of Comparative Example 1 appears as is. As the stroke increases, the characteristics of the wave washer 111 are superimposed on the characteristics of the rubber elastic covering 131 and elastic regulating body 151, and the load increases in a curved line.

From the above results, when comparing the load at stroke S1, for example, after the load on the rubber elastic body has risen, it was found that the vibration damping member 101 of this embodiment generates a larger load than comparative examples 1 and 2.

(3) Occupied Space The vibration damping member 101 of this embodiment is provided with elastic regulating bodies 151 on the front and back surfaces of the valley portions 113 of the wave washer 111. Although the elastic regulating bodies 151 rise from the positions of the valley portions 113, they do not exceed the height of the peak portions 112 of the wave washer 111. Therefore, the increase in thickness of the vibration damping member 101 relative to the thickness of the wave washer 111 is only an amount corresponding to the thickness of the cover 131. Therefore, the vibration damping member 101 of this embodiment can occupy a smaller space than a vibration damping member in which a wave washer and a rubber elastic body are arranged axially (see Patent Document 3).

However, as another embodiment, a configuration in which the elastic regulating body 151 exceeds the height of the peaks 112 of the wave washer 111 is also permitted. Even in this case, the elastic regulating body 151 rises from the position of the valleys 113 of the wave washer 111, so it does not significantly exceed the height of the peaks 112. Therefore, compared to a vibration-damping member in which a wave washer and a rubber elastic body are arranged axially (see Patent Document 3), it is still possible to reduce the space occupied.

(4) Assembly Man-Hours The vibration damping member 101 of this embodiment is formed by integrally molding the wave washer 111, the covering body 131, which is a rubber elastic body, and the elastic regulating body 151. Therefore, compared to a vibration damping member in which a wave washer and a rubber elastic body are arranged in the axial direction (see Patent Document 3), the number of man-hours required for assembly between the two members 11 is reduced, and the workability of the assembly work can be improved.

(5) Temperature Dependence The vibration damping member 101 of this embodiment has less temperature dependency than the vibration damping member made of only a rubber elastic body shown as Comparative Example 2 in the graph of Fig. 5. This will be explained using the graphs of Fig. 6 and Fig. 7.

Figure 6 is a graph showing the results of measurements of the stroke and the load generated when a new vibration-damping member 101 and a vibration-damping member 101 that has deteriorated over time undergo compressive deformation, measured at room temperature, high temperature, and low temperature. The horizontal axis represents stroke, and the vertical axis represents load. In Figure 6, the measurement results for the new vibration-damping member 101 at room temperature are indicated by NO, the measurement results for the high temperature by NH, and the measurement results for the low temperature by NL. The measurement results for the vibration-damping member 101 that has deteriorated over time are indicated by DO, the measurement results for the high temperature by DH, and the measurement results for the low temperature by DL.

Figure 7 is a graph showing the results of measurements of the stroke and the load generated when compressively deformed for new Comparative Example 2 and aged Comparative Example 2 at room temperature, high temperature, and low temperature. The horizontal axis represents stroke, and the vertical axis represents load. In Figure 7, the measurement results for new Comparative Example 2 at room temperature are indicated by NO, the measurement results for high temperature are indicated by NH, and the measurement results for low temperature are indicated by NL. For aged Comparative Example 2, the measurement results for room temperature are indicated by DO, the measurement results for high temperature are indicated by DH, and the measurement results for low temperature are indicated by DL.

Here, we focus on the load changes D1 and D2 when the temperature changes from low to high for a new vibration-damping member 101 and Comparative Example 2. The load changes D1 and D2 indicate how many times the load increases when the temperature drops to low, assuming the load at high temperature is 1.

Comparative reference to the graphs in Figures 6 and 7 reveals that the load change D2 in Comparative Example 2 was approximately 2.0 times, while the load change D1 in the vibration-damping member 101 was approximately 1.5 times. Therefore, the vibration-damping member 101 of this embodiment has lower temperature dependency than Comparative Example 2, making it possible to reduce the effect of environmental temperature on vibration-damping performance. As a result, a more stable vibration-damping effect can be expected.

(6) Deterioration over Time The vibration damping member 101 of this embodiment utilizes the covering body 131 and the elastic regulating body 151, which are rubber elastic bodies, as part of the vibration damping member. Therefore, as can be seen by comparing the measurement results (NO, NH, NL) showing the load when new with the measurement results (DO, DH, DL) showing the load after deterioration over time in the graph of Figure 6, deterioration over time is inevitable. This is also true for Comparative Example 2.

On the other hand, compared to Comparative Example 2 shown in Figure 7, the vibration-damping member 101 of this embodiment shown in Figure 6 has the characteristic of maintaining a load equal to or greater than the target load (load L1 shown in Figure 8) even after deterioration over time. Therefore, the vibration-damping member 101 can satisfy the target load even after deterioration over time.

(7) Stroke Setting The graph shown in FIG. 8 is the same as the graph shown in FIG. 6, but with an additional line indicating the relationship between the required load and the stroke at that time.

When installing a vibration-damping member 101 between two members 11, a load that can provide appropriate vibration-damping action is required. For example, assuming that a load L1 is required for the vibration-damping member 101, as can be seen from the graph in Figure 8, the stroke of the vibration-damping member 101 installed between two members 11 is not uniform, but varies depending on the degree of deterioration and the ambient temperature.

On the other hand, the load generated by the vibration-damping member 101 is lowest when the individual unit is placed in a high-temperature environment after aging. Therefore, the measurement result DH that generates the lowest generated load is selected, and the stroke S2 corresponding to the required load L1 is obtained. By setting the stroke S2 as the stroke of the vibration-damping member 101 to be attached between the two members 11, the vibration-damping member 101 will always be able to generate the required load L1, regardless of aging or environmental temperature.

(8) Summary While wave washers have the advantage of being free from temperature dependency and deterioration over time, they lack damping, making it difficult to achieve a sufficient vibration reduction effect. Rubber elastic bodies with damping provide a sufficient vibration reduction effect, but are inevitably temperature dependent and deteriorate over time. As described above, the vibration-damping member 101 of this embodiment inherits all of the advantages of wave washers and rubber elastic bodies, while eliminating their disadvantages through the mutual complementation of the wave washer 111, the covering body 131, and the elastic regulating body 151.

Therefore, the vibration-damping member 101 of this embodiment combines the excellent properties of both a wave washer and a rubber elastic body, while, as mentioned above, occupying a small space and not increasing the number of assembly steps.

3. Other Embodiments and Modifications (1) Other Embodiments Fig. 9 is a front view showing another embodiment of the vibration damping member 101. The same parts as those of the vibration damping member 101 described with reference to Figs. 1 to 8 are designated by the same reference numerals, and description thereof will be omitted.

The vibration-damping member 101 of this embodiment does not have a covering 131, and the elastic regulating body 151 is directly fixed to the front and back surfaces of the valley portion 113 of the wave washer 111. Fixing the elastic regulating body 151 to the front and back surfaces of the valley portion 113 can be achieved using any method, such as vulcanization adhesion or adhesion with an adhesive.

The vibration-damping member 101 configured in this manner exhibits the same effects as the vibration-damping member 101 described with reference to Figures 1 to 8, except that it does not provide the protective function of the covering 131 for the two members 11 and the wave washer 111, nor the vibration-damping function provided by the covering 131.

(2) Yet Another Embodiment Fig. 10 is a front view showing yet another embodiment of the vibration damping member 101. The same parts as those of the vibration damping member 101 described with reference to Figs. 1 to 8 are designated by the same reference numerals, and description thereof will be omitted.

In the vibration-damping member 101 of this embodiment, the covering body 131 is provided only on the peaks 112 of the wave washer 111, and not on the valleys 113. Due to this structure, the elastic regulating body 151 is directly fixed to the front and back surfaces of the valleys 113 of the wave washer 111. Fixing the elastic regulating body 151 to the front and back surfaces of the valleys 113 can be achieved using any method, such as vulcanization bonding or bonding with an adhesive.

The vibration damping member 101 configured in this manner exhibits the same effects as the vibration damping member 101 described with reference to Figures 1 to 8.

(3) Modifications In the present embodiment, several modifications have been introduced. In addition to these modifications, various modifications and changes are possible when implementing the present invention.

11 Two members 11A One member 11B Another member 101 Vibration damping member 111 Wave washer 112 Peak 112R Peak 113 Valley 113R Valley 131 Cover 151 Elastic regulator A Shaft D1 Variation D2 Variation L1 Load S1 Stroke S2 Stroke

Claims (6)

a wave washer having a circular ring shape that is wavy in an axial direction along a circumferential direction, and having a plurality of peaks that contact the two members and a plurality of valleys that do not contact the two members when sandwiched between the two members;
elastic restriction bodies made of rubber provided on the front and rear surfaces of the valley portions to regulate the amount of compressive deformation of the wave washer and to absorb vibrations by elastic deformation in the axial direction;
A vibration damping member comprising: A rubber covering is provided to cover the ridge portion.
The vibration damping member according to claim 1 . The covering absorbs vibrations by elastic deformation in the axial direction.
The vibration damping member according to claim 2 . The covering body covers the entire wave washer and integrally includes the elastic regulating body.
The vibration damping member according to claim 2 or 3. The elastic regulating body is vulcanization bonded to the wave washer.
The vibration damping member according to claim 1 . The covering is vulcanization bonded to the wave washer.
5. The vibration damping member according to claim 2.