JP5060196B2 - Diaphragm - Google Patents

Description

  The present invention relates to a rubber diaphragm that forms a liquid chamber of a liquid-filled vibration isolator.

  2. Description of the Related Art Conventionally, an engine mount for automobiles is well known as a liquid-filled vibration isolator in which a liquid chamber is formed by a rubber diaphragm. The basic structure is that a rubber elastic body is interposed between the engine-side connecting bracket and the vehicle body-side supporting bracket, which are supported, and both the brackets change its volume as the rubber elastic body deforms. A liquid chamber is formed therebetween, the liquid chamber is divided into a pressure receiving chamber and an equilibrium chamber, and an orifice passage is provided to communicate the pressure receiving chamber and the equilibrium chamber. When the liquid flows through the orifice passage, engine vibration in a predetermined frequency region can be effectively absorbed and attenuated.

There are various types of diaphragms used in liquid-filled vibration damping devices. For example, a substantially bowl-shaped diaphragm that opens downward, or the center portion of the diaphragm is folded upward as shown in Patent Document 1. For example, a diaphragm having a substantially W-shaped cross section is known.
JP-A-7-71508

  The diaphragm may be stacked so as not to take a place until it is assembled to the liquid-filled vibration isolator. If a load is applied to the stacked diaphragms in the stacking direction, the diaphragms may stick to each other and become difficult to separate. In such a case, the work process such as the assembly process may be delayed.

  The present invention has been made in view of such points, and the object of the present invention is to prevent the diaphragms from sticking to each other even when a load is applied to the stacked diaphragms in the stacking direction. is there.

A first invention is a rubber diaphragm having a substantially W-shaped cross section used in a liquid-filled vibration isolator, and an annular ring portion having a substantially rectangular cross section, and an inner peripheral portion of the ring portion, A diaphragm main body having a cylindrical peripheral wall extending obliquely inward from one corner in the height direction, which is the axial direction of the ring, to the inner side of the ring, and any of the diaphragm main bodies If the thickness in the height direction of the part is A and the thickness of the ring part is B, a diaphragm that satisfies the relational expression of B > A and has the same shape and size as the diaphragm is the diaphragm. Are formed in such a shape that the corner on the other side in the height direction of the inner peripheral portion of the ring portion does not contact the peripheral wall portion of the diaphragm stacked on the other side. Have It is characterized in.

  In the first invention, the thickness A in the height direction of the diaphragm main body and the thickness B of the ring portion are set to values such that the stacked diaphragms do not adhere to each other in a surface contact state. Even when a load is applied to the stacked diaphragms in the stacking direction, the diaphragms can be prevented from sticking to each other. Therefore, it is possible to avoid delaying work processes such as the diaphragm assembling process. Furthermore, it is possible to suppress the diaphragm from being deformed due to the suction between the diaphragms.

A second invention is a substantially hat-shaped rubber diaphragm used in a liquid-filled vibration isolator, and includes an annular ring portion having a substantially rectangular cross section, and an inner peripheral portion of the ring portion. A diaphragm main body having a flange extending radially inward, and a cylindrical peripheral wall extending obliquely toward one side in the height direction that is the axial direction of the ring and from the inner peripheral edge of the collar, If the thickness in the height direction of an arbitrary portion of the diaphragm main body is A and the thickness of the ring portion is B , a diaphragm having the same shape and size as the diaphragm is used as the diaphragm. In order to prevent the diaphragms from sticking to each other when they are placed coaxially and in the same direction, the relational expression B > A is satisfied.

  According to the present invention, it is possible to prevent the stacked diaphragms from sticking to each other, so that the assembly process and the like can be prevented from being delayed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
As shown in FIG. 2, the diaphragm 1 according to the present embodiment is a bowl-shaped rubber diaphragm 1 that opens upward as a whole, and includes a diaphragm body 1a and a ring portion 1b.

  The diaphragm main body 1a has a cylindrical peripheral wall portion 11 extending linearly in cross section from the inner peripheral side of the ring portion 1b, and an annular roll portion 12 curved downward is continuously formed on the lower edge thereof. Yes. The central portion 13 of the diaphragm body 1a folded back by the roll portion 12 is curved upward. That is, the diaphragm body 1a has a substantially W-shaped cross section with the central portion 13 folded back upward.

  The ring portion 1b is formed in an annular shape so as to go around the opening edge of the diaphragm 1, and an annular reinforcing member 15 is embedded over the entire circumference. Further, the fillet is integrally formed at the connection portion with the peripheral wall portion 11 in the ring portion 1b. The two protrusions formed on the upper surface of the ring portion 1b are seal lips 14, which prevent liquid from leaking from between the orifice plate 6 and the ring portion 1b when assembled to the liquid-filled vibration isolator 2. (See FIG. 10).

-Detailed structure of diaphragm-
When a load is applied to the stacked conventional diaphragms 21 in the stacking direction, the diaphragms 21 may stick to each other. As shown in FIG. 3, the case where sticking occurs in this way is the outer surface (lower surface) of the diaphragm body 21a of the upper diaphragm 21 and the inner surface (upper surface) of the diaphragm body 21a of the lower diaphragm 21 as shown in FIG. When closely contacting in a contact state, or when the inner peripheral surface of the ring portion 21b of the lower diaphragm 21 and the outer peripheral surface of the peripheral wall portion 11 of the upper diaphragm 21 are in close contact with each other as shown in FIG. Is assumed. In these cases, one diaphragm 21 is greatly elastically deformed and air in the space 10 between the upper and lower diaphragms 21 and 21 is released. At the same time, the elastically deformed diaphragm 21 is restored to its original shape by its own elastic force. As a result, the space 10 between the upper and lower diaphragms 21 and 21 is sealed in a state where air is removed. For this reason, the inside of the space 10 between the upper and lower diaphragms 21 and 21 is in a low atmospheric pressure state, and a difference from the outside atmospheric pressure is generated, so that the upper and lower diaphragms 21 and 21 stick to each other.

Therefore, in this embodiment, in order to suppress the diaphragms 1,... That are placed on each other from sticking to each other, the thickness of the diaphragm body 1 a in the height direction is A, and the thickness of the ring portion 1 b is B. The distance from the central axis of the ring portion 1b to the intersection V (see FIG. 6) between the extension line of the outer peripheral surface of the peripheral wall portion 11 and the extension line of the lower surface of the ring portion 1b (surface on the peripheral wall portion 11 side) is C , Where D is the half length of the inner diameter of the ring portion 1b,
The diaphragm 1 is formed so as to satisfy two relational expressions of B > A (1) and D ≧ C (2). Hereinafter, the reason for this definition will be described.

  First, as shown in FIG. 5, it is assumed that the outer surface of the diaphragm main body 1a of the upper diaphragm 1 and the inner surface of the diaphragm main body 1a of the lower diaphragm 1 are in line contact with each other along a circumferential line. Hereinafter, for the sake of convenience, description will be made on a cross section of the diaphragm 1 including an arbitrary point P on the circumferential line. The point on the inner surface of the upper diaphragm 1 corresponding to the point P on the lower diaphragm 1 is P ′, the thickness of the diaphragm body 1a in the height direction is A ′, and the thickness of the ring portion 1b is B. , X is the length in the height direction from the point P ′ to the lower surface of the ring portion 1b. The thickness B includes not only the thickness of the ring portion 1b but also the protruding height of the seal lip 14.

Here, when the length in the height direction from the point P to the upper end of the seal lip 14 in the upper diaphragm 1 is h,
h = B + X + A ′ (3)
It can be expressed as.

Further, since the lower diaphragm 1 and the upper diaphragm 1 have the same shape and size and are coaxially stacked in the same direction, from the point P ′ to the lower surface of the ring portion 1b of the upper diaphragm 1 And the height direction length from the point P to the lower surface of the ring portion 1b of the lower diaphragm 1 are the same value X. Therefore, when the length in the height direction from the point P on the lower diaphragm 1 to the upper end of the seal lip 14 of the upper diaphragm 1 is H,
H = B + B + X (4)
It can be expressed as.

Here, when H and h are equal, the upper and lower diaphragms 1 and 1 are in contact with each other at point P, and when H is larger than h, the upper and lower diaphragms 1 and 1 are not in contact with each other. Therefore,
H > h (5)
Since the outer surface of the diaphragm main body 1a of the upper diaphragm 1 and the inner surface of the diaphragm main body 1a of the lower diaphragm 1 are not in close contact with each other, the upper and lower diaphragms 1, 1 stick to each other. Can be suppressed.

Substituting Equation (3) and Equation (4) into Equation (5),
B + B + X > B + X + A ′
And when the left and right sides are organized,
B > A '(6)
Get.

Since the diaphragm 1 of the present embodiment satisfies the above formula (1), that is, the thickness B of the ring portion 1b is set to a value exceeding the thickness A in the height direction of the diaphragm body 1a. The relationship of the formula (6) is satisfied over the entire surface of the diaphragm main body 1a. Therefore, the upper and lower diaphragms 1 and 1 can be prevented from sticking to each other.

  On the other hand, when the conventional diaphragms 21 are stacked, as shown in FIG. 4, the inner peripheral surface of the ring portion 21b of the lower diaphragm 21 and the outer peripheral surface of the peripheral wall portion 11 of the diaphragm main body 21a of the upper diaphragm 21 are arranged. May adhere in a surface contact state. In order to suppress such close contact between the ring portion 21 b and the peripheral wall portion 11, the inner peripheral surface of the ring portion 21 b is at the same position as the outer periphery of the peripheral wall portion 11 or the outer periphery of the peripheral wall portion 11 in the radial direction of the ring portion 21. What is necessary is just to be located outside.

Specifically, as shown in FIG. 6, in the sectional view of the diaphragm 1, the inner peripheral surface of the ring portion 1 b of the lower diaphragm 1 is an extension line and ring of the outer peripheral surface of the peripheral wall portion 11 of the upper diaphragm 1. If it is located at the same position as the intersection V with the extension line of the lower surface of the portion 1b or outside the intersection V, the inner peripheral surface of the ring portion 1b of the lower diaphragm 1 and the peripheral wall portion of the diaphragm body 1a of the upper diaphragm 1 It can suppress that 11 outer peripheral surfaces closely_contact | adhere in a surface contact state. That is, when the distance from the center axis of the ring portion 1b to the intersection V is C and the length of the half of the inner diameter of the ring portion 1b is D,
D ≧ C (2)
Since the upper and lower diaphragms 1 and 1 do not come into close contact with each other in the surface contact state, the lower diaphragm 1 can be prevented from compressing the upper diaphragm 1.

  Here, when the protruding height of the seal lip 14 is low, the upper surface of the ring portion 1b of the lower diaphragm 1 and the fillet formed on the lower surface of the ring portion 1b of the upper diaphragm 1 may be in line contact. However, since the reinforcing member 15 is embedded in each ring portion 1b and is not easily elastically deformed, the upper and lower ring portions 1b and 1b do not come into close contact with each other.

  Note that the ring portion 1b of the present embodiment has a shape in which the inner peripheral surface thereof is scraped off more than the inner peripheral surface of the conventional ring portion 21b (two-dot chain line in FIG. 7) in order to satisfy the expression (2). I am doing. For this reason, the peripheral wall portion 11 of the conventional diaphragm 21 extends in a straight section from the upper surface of the ring portion 21b, whereas the peripheral wall portion 11 of the diaphragm 1 of the present embodiment has a straight cross section from the inner peripheral side of the ring portion 1b. It extends in a shape. By adopting such a shape of the ring portion 1b and setting the thickness of the ring portion 1b to a value that satisfies the expression (1), a load is applied to the stacked diaphragms 1,. Even in the case, the diaphragms 1,... Do not stick to each other (see FIG. 1).

-Overall configuration of liquid-filled vibration isolator-
Hereinafter, for reference, a liquid-filled vibration isolator 2 in which the diaphragm 1 according to this embodiment is assembled will be described.

  FIG. 10 shows an automobile engine mount 2 that is an embodiment of the liquid-filled vibration isolator 2. The engine mount 2 includes an automobile engine and a transmission (not shown) (hereinafter, both are collectively referred to as a power plant). Interposed between the vehicle body and the vehicle body to support a static load of the power plant and absorb or attenuate vibrations from the power plant to suppress transmission to the vehicle body.

  The engine mount 2 of this embodiment has a substantially cylindrical connecting fitting 3 attached to a power plant as a supported body via a bracket or the like (not shown) and a cylindrical shape that supports this from below via a rubber elastic body 5. And a pair of legs 30, 30 welded to the front and rear sides (hereinafter simply referred to as the front and rear sides) of the automobile on the lower outer periphery of the support bracket 4, respectively. It is supposed to be fixed. The support fitting 4 also functions as a case for the mount 2 together with a stopper fitting 80 described later.

  The connecting fitting 3 has a flange portion 3b at an intermediate portion in the direction of the axis Z, and a tapered portion 3a sunk downward is formed on the lower side, and a shaft portion 3c is formed on the upper side. A bracket on the power plant side is attached to the upper end surface of the shaft portion 3c, and a bolt (not shown) is screwed into the bolt hole 22. In the illustrated example, the collar portion 3b has an annular shape centering on the axis Z, and annular stopper rubbers 51 and 52 are provided on the upper surface and the outer peripheral surface thereof, respectively.

  Furthermore, a passage 23 is formed in the connection fitting 3 so as to extend downward from the lower end of the bolt hole 22 and open to the tip of the tapered portion 3a. The passage 23 is smaller in diameter than the bolt hole 22 and communicates with the bolt hole 22 through a taper portion that extends upward, and serves as a path for supplying liquid to the liquid chamber 7. A sealing material 24 such as a steel ball is driven into the upper end of the passage 23 to seal the liquid chamber 7.

  The rubber elastic body 5 is vulcanized and bonded with the upper portion covering the lower taper portion 3a of the connecting metal fitting 3, and a thick umbrella-like portion 5a extending radially downward from there, It consists of a cylindrical part 5 b that extends continuously downward from the lower end of the umbrella-shaped part 5 a, and this cylindrical part 5 b is fixed to the inner periphery of the support fitting 4. That is, the support fitting 4 has a double structure composed of an inner cylinder 41 and an outer cylinder 42 in the example shown in the figure, and the inner cylinder 41 is embedded and integrated in the cylindrical portion 5b of the rubber elastic body 5. At the same time, the cylindrical portion 5b is caulked from above via a stopper fitting 80 described later by a flange formed at the upper end of the outer cylinder 42 and fixed to the outer cylinder 42.

  Further, the cylindrical portion 5b of the rubber elastic body 5 has an inner diameter enlarged on the lower side to form an annular step portion. The orifice plate 6 is inserted from below as the step portion, and the orifice A rubber diaphragm 1 is disposed so as to cover the panel 6 from below. As described above, the reinforcing member 15 is embedded in the ring portion 1 b of the diaphragm 1, and the ring portion 1 b thus reinforced is superimposed on the lower surface of the orifice plate 6 in a liquid-tight manner, so that the inner cylinder 41 of the support fitting 4 is provided. It is caulked from below by a flange formed inwardly at the lower end of the. The volume of the diaphragm 1 changes greatly when the center portion 13 and the annular roll portion 12 surrounding the center portion 13 are turned upside down.

  The lower end of the cylindrical portion 5 b is closed by the diaphragm 1 whose volume changes in this way, and a liquid chamber 7 in which a liquid is sealed is formed inside the rubber elastic body 5. The liquid chamber 7 is divided into upper and lower portions by an orifice plate 6, the upper side thereof is a pressure receiving chamber 8, and the lower side, that is, the portion partitioned by the orifice plate 6 and the diaphragm 1 is an equilibrium chamber 9. When the vibration from the power plant is input and the rubber elastic body 5 is deformed, the volume of the pressure receiving chamber 8 changes mainly, and the liquid flows between the equilibrium chamber 9 via the orifice passage 100. As the liquid flows in and out, the diaphragm 1 is deformed as described above, and the volume of the equilibrium chamber 9 changes (volume compensation).

  The orifice plate 6 is composed of a main body member 60 (partition member: hereinafter also referred to as the orifice plate main body 60) and a lid member 61 to form a relatively thick disk as a whole, and the inside thereof is made of rubber. The movable plate 62 is accommodated. When an engine vibration having a relatively high frequency and a small amplitude is input, the movable plate 62 absorbs the fluid pressure fluctuation in the pressure receiving chamber 8 by vibrating in synchronization with the vibration.

  That is, the orifice board main body 60 has an annular standing wall portion (annular protrusion) standing on the upper surface of a circular plate, and accommodates the movable plate 62 between the upper and lower lid members. . A plurality of through holes 61a,... Are formed in the lid member 61 so as to allow the storage chamber to communicate with the pressure receiving chamber 8, and similarly, the inner circumference of the orifice plate main body 60 is relatively set to communicate the storage chamber with the equilibrium chamber 9. Through holes 60b,... Are also formed in the close range.

  Further, on the outer periphery of the standing wall portion 60a, a groove portion that is surrounded by the lid member 61 and opens to the outer periphery side is formed over the entire periphery, and this groove portion is formed by the cylindrical portion 5b of the rubber elastic body 5 from the outer periphery side. By being surrounded, an annular orifice passage 100 is formed. One end of the orifice passage 100 faces the pressure receiving chamber 8 through an opening (not shown) on the upper surface of the lid member 61, and the other end faces the equilibrium chamber 9 through an opening (not shown) opened on the lower surface of the orifice panel main body 60. It is out. The orifice passage 100 is tuned to vibration with a relatively low frequency and large amplitude.

  On the other hand, a stopper fitting 80 having a cylindrical shape substantially the same diameter as the outer cylinder 42 is attached to the upper end of the support fitting 4 so as to surround the upper portion of the mount 2 such as the umbrella-like portion 5a of the rubber elastic body 5. ing. A flange projecting outward is formed at the lower end of the stopper fitting 80, and this flange is placed on the upper end of the cylindrical portion 5 b of the rubber elastic body 5 and caulked by a flange formed at the upper end of the outer cylinder 42. .

  The stopper fitting 80 regulates the relative displacement of the connecting fitting 3 in the front-rear direction by coming into contact with the stopper rubber 52 of the collar portion 3b. A flange extending toward the inner peripheral side is formed at the upper end of the stopper fitting 80 so as to surround the shaft portion 3c of the connecting fitting 3, and the lower surface of the flange contacts the stopper rubber 51 on the upper surface of the collar portion 3b. As a result, the upward displacement of the connection fitting 3 is restricted. The upper surface of the flange is in contact with an unillustrated bracket on the engine side so that the upward movement is restricted, in other words, the rubber so as to restrict the downward relative displacement of the connection fitting 3. A layer 81 is provided.

-Effect-
In this embodiment, from the thickness A of the diaphragm body 1a in the height direction, the thickness B of the ring portion 1b, and the central axis of the ring portion 1b, the extension line of the outer peripheral surface of the peripheral wall portion 11 and the lower surface of the ring portion 1b. The distance C to the intersection V with the extension line and the length D, which is half the inner diameter of the ring portion 1b, are set to such values that the stacked diaphragms 1,. Therefore, even when a load is applied to the stacked diaphragms 1,... In the stacking direction, the diaphragms 1,. Therefore, it is possible to reliably avoid a delay in work processes such as the assembly process of the diaphragm 1. Further, it is possible to prevent the diaphragm 1 from being deformed due to the sticking between the diaphragms 1.

  In the present embodiment, the seal lip 14 is provided on the ring portion 1b, but it may not be provided. In this case, the thickness B means the thickness of the ring portion 1b.

(Embodiment 2)
In the present embodiment, the shape of the diaphragm 1 is different from that of the first embodiment. Hereinafter, differences from the first embodiment will be described.

  As shown in FIG. 8, the diaphragm 1 according to this embodiment is a bowl-shaped rubber diaphragm 1 that opens downward as a whole, and includes a ring portion 1b and a diaphragm body 1a. The diaphragm main body 1a has a cylindrical peripheral wall portion 11 extending linearly in cross-section from the inner peripheral side of the ring portion 1b via an annular collar portion 16, and has an upper conical truncated cone shape on the upper edge thereof. The central part 13 of the is continuously in a top hat shape.

-Detailed structure of diaphragm-
As shown in FIG. 9, in the diaphragm 1 according to the present embodiment, since the flange portion 16 is interposed between the ring portion 1 b and the peripheral wall portion 11, the inner peripheral surface of the ring portion 1 b of the lower diaphragm 1 is It is always located outside the outer peripheral surface of the peripheral wall portion 11 of the upper diaphragm 1. Therefore, the half length of the inner diameter of the ring portion 1b satisfies the above formula (2). Further, since the thickness of the ring portion 1b is set to a value that satisfies the above expression (1), the upper and lower diaphragms 1 and 1 are attracted to each other even when the diaphragms 1 and 1 are stacked. There is no.

-Effect-
In the present embodiment, the shape of the diaphragm main body 1a is substantially a top hat shape, but the length D and the thickness B that are half the inner diameter of the ring portion 1b satisfy the expressions (1) and (2). Similarly to the first embodiment, it is possible to prevent the stacked diaphragms 1... From adhering to each other. Thereby, it can avoid that work processes, such as an assembly | attachment process, are delayed, and can prevent reliably that the diaphragm 1 deform | transforms.

(Other embodiments)
In the first embodiment, the diaphragm 1 having a substantially W-shaped cross section is used, and in the second embodiment, the diaphragm 1 having a substantially silk hat shape is used. However, the present invention is not limited to this and can be applied to the diaphragm 1 having various shapes.

  The present invention is not limited to the embodiments, and can be implemented in various other forms without departing from the spirit or main features thereof.

  As described above, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the present invention is useful for a rubber diaphragm or the like used in a liquid-filled vibration isolator.

It is a figure which shows typically the state by which the diaphragm which concerns on Embodiment 1 was piled up. 1 is a cross-sectional view of a diaphragm according to Embodiment 1. FIG. It is a figure which shows typically the state by which the conventional diaphragm was piled up. It is a figure which shows typically the state by which the conventional diaphragm was piled up. It is a figure explaining the relationship between the height direction length of a diaphragm main body, and the thickness of a ring part. It is a figure explaining the positional relationship in the radial direction of the ring part of the surrounding wall part of a diaphragm main body, and the internal peripheral surface of a ring part. It is the figure which compared the ring part of the diaphragm of the conventional diaphragm and the diaphragm of this embodiment. It is sectional drawing of the diaphragm which concerns on Embodiment 2. FIG. It is a figure which shows typically the state by which the diaphragm which concerns on Embodiment 2 was piled up. It is a longitudinal cross-sectional view which shows the state which assembled the diaphragm to the liquid enclosure type vibration isolator.

DESCRIPTION OF SYMBOLS 1 Diaphragm 1a Diaphragm main body 1b Ring part 2 Liquid enclosure type vibration isolator 11 Perimeter wall part

Claims (2)

A rubber diaphragm having a substantially W-shaped cross section used in a liquid-filled vibration isolator,
An annular ring portion having a substantially rectangular cross section;
A diaphragm main body having a cylindrical peripheral wall portion extending obliquely inward from the corner on one side in the height direction, which is the axial direction of the ring, in the inner circumferential portion of the ring portion. Has
If the thickness in the height direction of any part of the diaphragm body is A and the thickness of the ring part is B,
B > A height direction in the inner peripheral portion of the ring portion in a state where a diaphragm satisfying the relational expression A and having the same shape and size as the diaphragm is placed on the diaphragm coaxially and in the same direction. A diaphragm characterized in that a corner portion on the other side is formed in a shape that does not contact a peripheral wall portion of the diaphragm stacked on the other side. A substantially hat-shaped rubber diaphragm used in a liquid-filled vibration isolator,
An annular ring portion having a substantially rectangular cross section;
A collar portion extending radially inward from the ring portion from the inner peripheral portion of the ring portion, and an obliquely extending from the inner peripheral edge of the collar portion toward one side in the height direction that is the axial direction of the ring and toward the inner side. A diaphragm main body having a cylindrical peripheral wall, and
If the thickness in the height direction of any part of the diaphragm body is A and the thickness of the ring part is B,
When a diaphragm having the same shape and size as the diaphragm is placed on the diaphragm coaxially and in the same direction, the relationship of B > A is satisfied in order to prevent the diaphragms from adsorbing to each other. Diaphragm.

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