JP2001099223A - Negative pressure changeover type liquid sealed type vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stopper mechanism for changeover which has excellent stability, in a negative pressure changeover type liquid sealed type vibration control device suitable for changeover of different frequency. SOLUTION: A fixed part 53b of a stopper member 50 inside a switching chamber 12 is press fitted to a bottom wall projecting part 60 of a tubular metal fitting 25, an inner end of a negative pressure introducing pipe 51 inserted in a loosely engaging state into an introducing hole 61 formed in the projecting part 60 is extendedly provided at the switching chamber 12 side, and the inner end is press fitted to a center through hole of the stopper member 50. A sealing rubber 55 is interposed between the fixed part 53b of the stopper member 50 and the projecting part 60, thereby realizing a stable fixing of the stopper 50 and preventing the negative pressure introducing pipe 51 from disengaging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled type vibration damping device mainly used for supporting a vibration generator such as an automobile engine and the like. The present invention relates to a negative pressure switching type liquid filled type vibration damping device that exhibits a frequency damping effect.

[0002]

2. Description of the Related Art A liquid-filled type vibration damping device such as an engine mount for supporting the vibration of a vibration generator such as an automobile engine so as not to be transmitted to a vehicle body includes a liquid chamber between a vibration damping base of the device body and a diaphragm. An orifice is formed in the partition body that divides the pressure into two, and a switching valve that switches the communication state of the orifice is provided in the diaphragm, and the reaction force of the spring that biases the switching valve in the valve closing direction is switched between negative pressure and atmospheric pressure. There has been known an arrangement in which a counterbalance is exerted so as to exert an attenuation effect of a different frequency.

In such a negative pressure switching type liquid filled type vibration damping device, a switching chamber for switching between negative pressure and atmospheric pressure is provided on the side opposite to the liquid chamber of the diaphragm, and a negative pressure communicating with the outside to the switching chamber is provided. An introduction pipe is provided, and a stopper member for regulating the opening direction of the switching valve is provided.

In the conventional negative pressure switching type liquid filled type vibration damping device, the stopper member and the negative pressure introducing pipe are separately provided, and the stopper member is vulcanized and bonded or incorporated in the central region of the diaphragm. In addition, the negative pressure introducing pipe has been fixed to the bottom or the bottom plate of the mounting bracket constituting the switching chamber.

[0005]

However, as in the prior art, when the stopper member is integrated with the diaphragm, the mass supported by the spring is increased, so that the diaphragm that is movable when switching between negative pressure and atmospheric pressure is used. May not be able to move smoothly.

On the other hand, the negative pressure introducing pipe is fixed to the mounting bracket by:
Generally, the length of the fixed part is short and the seal fee is small,
It was weak against external force, and there was a possibility that the introduction pipe would fall off and the sealing would be poor.

[0007]

Means for Solving the Problems The present inventors have paid attention to the above-mentioned problems, and have intensively studied the arrangement and mounting method of the stopper member and the negative pressure introducing pipe. First, the stopper member is moved in the switching chamber. By disposing it on the bottom wall opposite to the diaphragm to be removed, a large mass portion can be eliminated on the diaphragm side, and it has been found that the diaphragm moves smoothly when switching the switching valve.

In the negative pressure switching type liquid-filled type vibration damping device provided with the stopper member, a space formed between the vibration damping base of the device body and the mounting bracket is formed by a diaphragm so that the liquid on the vibration damping base side is formed. A switching valve that is partitioned into a chamber and a switching chamber on the mounting bracket side, and that adjusts a communication state of an orifice formed on the liquid chamber side, and a spring that biases the switching valve in a valve closing direction. There is no particular limitation as long as the reaction force is offset by switching between the negative pressure and the atmospheric pressure in the switching chamber to exert an attenuation effect of a different frequency.

For example, it is possible to adopt a configuration in which a damping effect of a different frequency is exerted by adjusting the opening / closing degree of one orifice, or a configuration in which the liquid chamber and the switching chamber are partitioned by one diaphragm. It is preferable to apply the present invention to a vibration isolator in which two orifices are formed in a partition disposed in a liquid chamber, and one of the orifices is adjusted by opening and closing a switching valve to exert an attenuation effect of different frequencies. . Further, a first diaphragm with a switching valve defining a liquid chamber, and a second diaphragm with a pressing member for pressing the switching valve on the switching chamber side, the second diaphragm and the body mounting bracket The closed space is used as the switching room,
In addition, the present invention is preferably applied to a vibration isolator in which an equilibrium chamber for buffering a pressure difference between a liquid chamber (sub-liquid chamber) and a switching chamber is formed between the second diaphragm and the second diaphragm.

[0010] The chamber wall of the switching chamber is constituted by a bottom wall portion of a lower mounting bracket having a bottomed cylindrical shape and a diaphragm mounted inside the lower mounting bracket of the upper and lower mounting brackets connected by the vibration isolating base. As a position for attaching the stopper member, either a mode in which the bottom wall of the mounting bracket is used as it is or a mode in which another thin bottom plate is mounted on the bottom wall and this bottom plate is used may be adopted.

As the means for fixing the stopper member disposed on the bottom wall portion of the switching chamber, various modes such as welding and caulking can be adopted, but a flange-shaped fixing portion is extended below the stopper member radially outward. On the other hand, it is preferable that the bottom wall is provided with a protruding portion protruding toward the switching chamber, and the fixing portion is press-fitted into the peripheral wall of the protruding portion, since this is the easiest way to attach. In addition, the inner end of the negative pressure introducing pipe fixed to the bottom of the switching chamber extends to the switching chamber side, and this inner end is press-fitted or vulcanized and bonded to a through hole formed in the stopper member. It is also possible to adopt a configuration of fixing via a tube.

Next, when the prevention of falling of the negative pressure introducing pipe and the elimination of the sealing failure were examined, the stopper member and the negative pressure introducing pipe were connected as long as the stopper member was arranged on the bottom wall of the switching chamber as described above. Based on the finding that the aspect in which the combination of the above is preferable in view of the arrangement relationship of the bottom wall portion, a negative pressure introducing pipe which forms a through hole penetrating in the axial direction in the stopper member and penetrates the bottom wall portion of the switching chamber If the inner end is extended toward the switching chamber and the inner end is pressed into the through hole of the stopper member, the length of the fixed portion of the negative pressure introducing pipe can be increased, and the introduction pipe can be prevented from falling off. At the same time, they have found that the sealing property between them can be ensured.

In consideration of the air sealing property of the switching chamber in this case, it is necessary to seal the space between the negative pressure introducing pipe and the bottom wall of the switching chamber. If the stopper member fixing means by the projecting portion of the wall portion is adopted, and the structure between the fixing portion and the projecting portion is sealed by seal rubber, the negative pressure introducing pipe and the bottom wall portion of the switching chamber are not sealed. And the seal fee increases,
A reliable air sealing function can be exhibited. Moreover, with such a seal structure, there is no need to match the outer diameter of the negative pressure introduction pipe with the introduction hole in the bottom wall of the switching chamber that penetrates the negative pressure introduction pipe. The negative pressure introducing pipe can be penetrated in a loosely fitted state, and mounting and positioning of the negative pressure introducing pipe can be easily performed.

The press-fitting and fixing structure between the fixing portion of the stopper member and the projecting portion of the bottom wall is not limited to the cylindrical type, and at least a half or more of the projecting portion is provided on the peripheral wall of the projecting portion. What is necessary is just a mode which can secure a press-fit margin. Therefore,
It is also possible to adopt a configuration in which an open portion is formed partially outside the side wall of the protruding portion, the outer end side of the negative pressure introducing tube is bent in a direction perpendicular to the axis, and the outer end is laterally oriented.

The stopper member may have any structure as long as the rubber-like elastic body is vulcanized and bonded to the stopper fitting. If the member is constituted by a stopper fitting including a fixing part and a stopper rubber vulcanized and bonded to the stopper fitting, and the through hole of the stopper member is constituted by a cylindrical portion of the stopper fitting, negative pressure can be introduced. The press-fitting of the tube and the air sealing therebetween can be easily performed. In this case, the stopper fitting may have either an integrated structure or a two-piece split structure of a cylindrical portion and a flange portion, and may be made of either metal or resin.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a perspective view of a negative pressure switching type liquid filled type vibration damping device showing a first embodiment of the present invention, and FIG. Longitudinal sectional view of FIG. 3
FIG. 4 is a longitudinal sectional view of the switching chamber in a negative pressure state, and FIG. 4 is a sectional view of a main part showing the same stopper mechanism.

As shown in the drawing, a negative pressure switching type liquid filled type vibration damping device 1 comprises an upper mounting bracket 2 mounted on a vibration generator such as an engine, a lower mounting bracket 3 mounted on a vehicle body side, and both of them. A vibration-proof base 4 made of a rubber-like elastic body that connects the mounting brackets 2 and 3 to each other, and a liquid-proof body disposed between the vibration-proof base 4 and the lower mounting bracket 3 facing the vibration-proof base 4. A first diaphragm 6 constituting the chamber 5 and a liquid chamber 5
And a first liquid chamber 5a and a first liquid chamber 5b.
A switching valve 8 arranged in the central area of the diaphragm 6 for opening and closing the communication state of the inner orifice 16 of the two orifices 15 and 16 formed in the partition 7
A second diaphragm 10 disposed below the first diaphragm 6 to form a balance chamber 9 with the first diaphragm 6, and a bottom of the second diaphragm 10 and the lower mounting member 3. A switching chamber 12 capable of switching between a negative pressure and an atmospheric pressure between the switching chamber 11 and a spring 13 disposed in the switching chamber 12 to bias the switching valve 8 in a valve closing direction; Is canceled by switching between the negative pressure and the atmospheric pressure in the switching chamber 12 so as to exhibit the damping effect of different frequencies.

The upper mounting member 2 is formed in a flat plate shape, and a mounting bolt 20 projecting upward and supporting an engine or the like is fixed at the center thereof.
A screw 22 for positioning the base end of a stopper 21 for absorbing a large displacement is fixed.

The lower mounting bracket 3 includes a bottomed outer cylindrical bracket 25.
And an inner metal fitting 26 internally fitted in the large diameter portion 25a on the upper part thereof.
It is composed of The bottomed outer cylindrical metal fitting 25 includes a cylindrical large-diameter portion 25a and a bottomed cylindrical small-diameter portion 25 in order from the upper side.
b are continuously formed integrally with each other, and a step 25c is provided in the middle thereof.
Is formed in a deep-bottomed cup shape having The upper end of the large diameter portion 25a is expanded outward in the radial direction,
An outer cylinder side mounting flange 27 and a fastening portion 28 having a U-shaped cross section that is open inside are formed.

The inner cylinder 26 is a large diameter portion 2 of the outer cylinder 25.
An outer flange 29 which is formed in a cylindrical shape so as to be able to be fitted inside in close contact with 5a, the upper end of which is expanded outward in the radial direction, and which is inserted into the fastening portion 28 of the outer cylinder fitting 25; Extended flange portion 29a overlapped with mounting flange 27
And the stopper core 3 facing the tip of the stopper fitting 21
0 is formed.

The upper end outer flange 29 of the inner cylinder fitting 26 is inserted into the fastening portion 28 of the outer cylinder fitting 25, and both are fixed by caulking. The large-diameter portion 25a of the outer tube fitting 25
A part of the upper end is notched, and the upper end stopper core 30 of the inner cylindrical fitting 26 projects radially outward beyond the notch. Further, the outer cylinder mounting flange 27 and the extended flange portion 29a of the inner cylinder fitting 26 are overlapped with each other to form a mounting hole 32 penetrating both, and the mounting hole 32 is attached to the vehicle body through a bolt or the like. In addition,
Attachment of the vibration isolator 1 to the vehicle body is performed by using the flange 27,
The outer periphery of the small-diameter portion 25b of the outer tube fitting 25 may be attached to the vehicle body via a bracket (not shown) without the 29a.

The vibration-proof base 4 is made of a rubber-like elastic body formed in an umbrella shape to form a main rubber part. The vibration-proof base 4 is formed by adding the inner surface of the cylindrical reinforcing fitting 26 of the upper fitting 2 and the lower fitting 3. The two are connected by sulfuric bonding to exert the function of insulating the vibrations transmitted from the vibration generator in the axial direction and in the direction perpendicular to the axis. Further, the rubber-like elastic body of the vibration-proof base 4 is vulcanized and adhered so as to surround the stopper core 30 of the inner tube fitting 26 to form the stopper 31. The stopper portion 31 is disposed so as to be surrounded by a stopper fitting 21 having a rectangular cross section, and a cooperation mechanism of the both forms a stopper mechanism (stabilizer mechanism) for absorbing a large displacement.

The outer peripheral portions of the second diaphragm 10, the first diaphragm 6, and the partition 7 are placed on the intermediate step portion 25c of the bottomed outer cylindrical metal member 25 in order from the bottom. From the inner surface to the lower end of the tube fitting 26, it is sandwiched between the seal rubber portion 33 and the vulcanized adhesive.

The partition member 7 is formed of a rigid material such as metal or resin in the shape of a disk, has a U-shaped orifice groove 15a which is open outward over substantially the entire outer periphery thereof, and has an inner orifice 16 in the center. An opening 16a to be formed is formed. The partition 7 is airtightly fitted to a seal rubber portion 33a formed on the inner peripheral surface of the inner cylindrical metal fitting 26, and a space surrounded by the seal rubber portion 33a and the orifice groove 15a is filled in the first orifice 15a. It has been.
Openings 34 and 35 communicating with the main liquid chamber 5a and the sub liquid chamber 5b are formed at two places of the orifice groove 15a, respectively.
The orifice 15 exerts a vibration damping function. An outer peripheral portion of a lower end of the partition body 7 extends radially outward, and the extended portion 36 is provided between the intermediate step portion 25 c of the bottomed outer cylindrical metal fitting 25 and the lower end seal rubber portion 33 of the cylindrical inner cylindrical metal fitting 26. It is pinched.

On the other hand, a switching valve 8 is fitted in an opening 16a formed through the center of the partitioning body 7 so as to be able to be detachably seated in the axial direction (vertical direction in FIG. 2). An inner orifice 16 is formed between the opening and the wall of the opening 16a.

The switching valve 8 is formed integrally with the central portion of the first diaphragm 6, and the lower surface of the peripheral portion of the central opening 16a of the partition member 7 is used as a valve seat surface, and the switching valve 8 is a flat plate which can be detached and seated on it. A structure comprising a portion 8a and a projecting portion 8b of a slightly smaller diameter fitted in the central opening 16a at the center thereof, and an inverted bowl-shaped core metal fitting 36 corresponding to the sectional shape thereof is covered with a rubber-like elastic body. It has become. The rubber-like elastic film 6a of the first diaphragm 6 is hung down on the outer peripheral portion of the lower surface of the flat plate portion 8a, and a concave portion 43 for internally fitting the central pressing member 42 of the second diaphragm 10 is formed on the inner surface thereof.

Further, at a plurality of positions around the protruding portion 8b, inclined ribs 37 are integrally formed for preventing the lateral displacement when the switching valve 8 is seated on the peripheral edge of the central opening of the partition body 7. A plurality of locations in the circumferential direction defined by 37 function as the inner orifices 16 respectively.

The first diaphragm 6 has a thin flexible rubber-like elastic film 6a in which the switching valve 8 is integrated at the center, and the inner end of an annular diaphragm fitting 41 is embedded in the outer periphery. The metal fitting 41 is held by the intermediate step 25 c of the outer metal fitting 25, and the liquid chamber 5 is provided between the metal fitting 41 and the vibration-proof base 4.
Is formed.

The second diaphragm 10 has a thick rubber-like elastic film 10a obtained by integrally vulcanizing a central pressing member 42 fitted into the lower surface concave portion 43 of the switching valve 8, and has an annular diaphragm fitting on its outer peripheral portion. The metal fitting 45 is held by the intermediate step 25 c of the outer cylindrical metal fitting 25.

The pressing member 42 is made of a rigid material such as resin or metal and is formed in an inverted cup shape having an open lower surface, and a ring as a seating surface for receiving the upper end of the spring 13 is provided on the lower surface of the top portion 42a. A concave part 42b is formed. Further, the outer peripheral portion of the top portion 42a is fitted into the central concave portion 43 of the switching valve 8, so that both can move integrally. Accordingly, in the present embodiment, an example is shown in which both diaphragms 6 and 10 are formed separately, but they may be integrally formed.

A closed space, which is an outer peripheral portion of the pressing member 42 and is surrounded by the first and second diaphragms 6 and 10, is the equilibrium chamber 9. The equilibrium chamber 9 serves to reduce the pressure difference between the sub liquid chamber 5b and the switching chamber 12 and to ensure stable operation of the first diaphragm 6 defining the sub liquid chamber 5b. Other than the closed space as in the present embodiment, a form open to the atmospheric pressure may be used.

The second diaphragm 10 and the outer cylinder 2
The switching chamber 12 formed between the switching chamber 8 and the bottom 11 has a spring 13 and a stopper member 50 for regulating the lowering position of the switching valve 8 to hold the inner orifice 16 at a desired flow volume. A negative pressure introducing pipe 51 for selectively switching the switching chamber 8 between a negative pressure state and an atmospheric pressure state is provided.

As shown in FIG. 4, the stopper member 50 includes a stopper metal fitting 53 and a stopper rubber 54 covering the side and upper surfaces thereof. The stopper fitting 53 is
A cylindrical portion 53a which is formed of a rigid material such as metal or resin and forms a hole wall of a through-hole into which the negative pressure introducing tube 51 is press-fitted; 53b and a reinforcing flange 53c bent outward from the upper end of the tubular portion 53a. Fixed part 53
b is formed in the shape of an inverted deep dish from a flange 53e that is bent horizontally from the lower end of the tubular portion 53a and expands, and a cylindrical press-fit wall 53f that hangs down from the outer peripheral edge thereof. is there.

The stopper rubber 54 is formed around the cylindrical portion 53a by vulcanization molding so as to embed the reinforcing flange 53c. It is set to be. Note that a slit may be formed in the upper surface of the stopper rubber 54 to prevent striking and sticking.

On the other hand, a cylindrical projection 60 projecting toward the switching chamber 12 is press-formed at the center of the bottom wall 11 of the outer cylinder fitting 25 for fixing the stopper member 50.
The fixing portion 53b of the stopper member 50 is press-fitted and fixed to the outer peripheral wall at the upper end of the zero.

A ring-shaped seal rubber portion 55 is vulcanized and bonded to the inner surface of the corner portion between the flange 53e of the fixing portion 53b and the press-fitting wall 54f. As a result, the air seal function is simultaneously performed at the same time as the positioning of the outer tube fitting 25 and the stopper fitting 53.

The negative pressure introducing pipe 51 is formed of a rigid material such as metal or resin, penetrates an introducing hole 61 formed on the upper surface of the projecting portion 60, and has an inner end connected to the switching chamber 12.
The inner end 51 a of the stopper fitting 53 is press-fitted into the cylindrical portion 53 a of the stopper fitting 53. The outer diameter of the introduction tube 51 is formed smaller than the diameter of the introduction hole 61 of the protruding portion 60, and the introduction tube 51 is loosely fitted into the introduction hole 61.

A pipe is connected to the outer end of the negative pressure introducing pipe 51 by various connecting means such as a connector, and selectively communicates with the negative pressure source via a switching valve (not shown). It has become. As the negative pressure source, a negative pressure generated in the intake system of the internal combustion engine can be used.

The spring 13 is a coil-shaped member interposed between the ring-shaped concave portion 42b of the pressing member 42 and the upper surface of the fixing portion 53c of the stopper fitting 53. It is urged upward (to close the valve). Since the lowering position of the switching valve 8 is determined by the pressure when the negative pressure is introduced into the switching chamber 12 and the spring constant of the spring 13, the spring 13 normally controls the switching chamber 12 while accurately restraining the first diaphragm 6. Is set to such a degree that it is compressed together with the switching valve 8 toward the bottom wall 11 of the outer cylinder fitting 25 by the introduction of the negative pressure.

In this embodiment, the spring 13
Is seated on the fixing portion 53c of the stopper fitting 53, but the present invention is not limited to this.
A configuration in which the seat 5 is seated on the bottom wall 11 may be employed.

The switchable liquid-filled type vibration damping device 1 having the above-described structure is
The outer cylinder fitting 25, the stopper member 50, and the negative pressure introducing pipe 51 are assembled, the first and second diaphragms 6, 10 are placed on the step 25c, and then these members are immersed in the liquid.
After assembling the partition body 7 with the assembly of the upper mounting fitting 2 and the inner cylinder fitting 26 connected by the vibration isolating base 4, taking out the same into the atmosphere and adjusting the residual liquid, the upper end 29 of the inner cylinder fitting 26 is adjusted.
Is caulked and fixed by the upper end fastening portion 28 of the outer tube fitting 25 to complete the product.

The assembling work of the outer cylinder fitting 25 with the stopper member 50 and the negative pressure introducing pipe 51 is performed first by using the stopper member 5.
The negative pressure introducing pipe 51 is inserted into the cylindrical portion 53a of the
While the outer end of the negative pressure introduction pipe 51 is inserted into the introduction hole 61 of the bottom wall projection 60 from the inside of the outer cylinder fitting 25, and the fixing portion 53 b of the stopper fitting 53 is inserted into the projection 6.
The two are fixed by press-fitting to outside.

In this case, since the stopper member 50 is installed on the outer cylindrical member 25 which is a fixed member, the positioning of the stopper member 50 can be performed without affecting other parts as compared with the case where the stopper member 50 is provided on a movable member such as the diaphragm 10. Can be performed. Moreover,
Since only the stopper member needs to be changed in accordance with the restriction position of the switching valve 8, the corresponding action can be easily performed.

The stopper member 50 and the negative pressure introducing pipe 5
In the seal of the switching chamber 12 associated with the arrangement of the stopper mechanism consisting of the seal member 55, a seal rubber 55 is vulcanized and bonded to the inner surface R-shaped corner portion of the fixed portion 53b. As a result, the switching chamber 12 is air-sealed at the same time as the positioning of the projection 60 of the outer cylinder and the stopper member 50, and the negative pressure introduction pipe 51 and the introduction hole 61 of the projection 60 are formed. Can be easily sealed with the air in the switching chamber 12 even if is loosely fitted. Moreover, the inner end of the negative pressure introducing pipe 51 is press-fitted into the cylindrical portion 53a of the stopper fitting 53, and the length of the fixed portion can be increased.
1 can be prevented from falling off, and the airtightness between the stopper member 50 and the negative pressure introducing pipe 51 can be sufficiently ensured by press-fitting in an airtight state.

The stopper fitting 53 of the negative pressure introducing pipe 51
By adjusting the press-fit load to the negative pressure introduction pipe 51,
Either before or after the press fitting of the stopper fitting 53 into the outer cylinder fitting 25 may be performed.

When the switchable liquid-filled vibration isolator 1 having the above configuration is used, the vibration isolating base 4 is deformed by vibration generated from a vibrating body such as an engine, and the deformation partitions the liquid from the main liquid chamber 5a. It flows in and out through the orifices 6 and 10 of the body 7 and exerts a vibration damping effect by the resonance characteristics of the orifices 6 and 10.

FIG. 2 shows the state of the switching chamber 12 under the atmospheric pressure.
When the atmospheric pressure is introduced through the first diaphragm 6, the switching valve 8 at the center of the first diaphragm 6 is urged upward by the spring 13, and the projection 8 b of the switching valve 8 fits into the central opening 16 a of the partition 7. Then, the flat plate portion 8a of the switching valve 8 is seated on the periphery of the opening, and the inner orifice 16 is closed.
The inflow and outflow of liquid at the inner orifice 16 are blocked, and the liquid flow effect is exerted only at the outer orifice 15 to effectively attenuate a predetermined frequency range, for example, shake vibration.

FIG. 3 shows a negative pressure state of the switching chamber 12. In this state, when the switching chamber 12 has a negative pressure, the second diaphragm 10 moves the bottom wall 11 of the outer cylinder fitting 25. Side, the switching valve 8 also moves downward against the urging force of the spring 13, and the opening 16 of the partition 7 is opened.
Since the valve a is opened, the inner orifice 16 is opened, and the communication between the main liquid chamber 5a and the sub liquid chamber 5b is established. Since the inner orifice 16 has a larger cross-sectional area and a shorter flow path than the outer orifice 15, the liquid flows preferentially to the inner orifice 16 and effectively attenuates vibration in a predetermined frequency range, for example, idle vibration. Can be.

[Second Embodiment] FIG.
0 is a sectional view showing a second embodiment of the present invention. In this embodiment, the stopper fitting 53 is made of a resin cylindrical portion 53a,
Flange-shaped metal fixing portion 53b arranged underneath
The negative pressure introducing pipe 51 to be press-fitted into the cylindrical portion 53a is also made of resin. In this case, the same operation and effect as those of the first embodiment can be obtained.

The spring 13 can be disposed with the fixing portion 53b of the stopper member 50 as a seating surface, as in the first embodiment. However, as shown in FIG.
May be seated on the bottom wall portion 11 around the periphery. Other configurations and operations are the same as those in the first embodiment.

[Third Embodiment] FIG. 6 is a sectional view showing a third embodiment of the stopper mechanism. In this embodiment, a part of the cylindrical projection provided on the bottom wall of the outer tube fitting 25 is depressed to form an opening 63 on a part of the side wall.
The outer end side 51b of the negative pressure introducing pipe 51 is bent in a direction perpendicular to the axis so as to be oriented laterally from the opening 63.

In this case, the parts constituting the opening 63 are
Less than half the circumference of the projection 60, preferably the negative pressure introduction pipe 51
It is sufficient that the width is slightly larger than the outer diameter of the protruding portion 60, and the stopper fitting 53 in the protruding portion 60 has a press fitting allowance of 周 or more rounds of the protruding portion 60. The switching chamber 12 side constituting the top part of the opening 63 is a flat part 63a, and a flat part 53d is also formed in the fixing part 53b correspondingly.

The flat portion 63a on the open portion 63 side has a groove 6 so as to be continuous with the upper end corner of the protruding portion 60.
The seal rubber 55 on the side of the fixed portion 53b is inserted and pressed into the groove 64.

As described above, the outer cylinder projecting portion 60 does not need to be cylindrical, and the stopper member 50 can be caulked and fixed if there is a press-fit allowance of 1/2 or more. In addition, if the protruding portion 60 is provided with an opening 63 that opens to the side, the orientation of the negative pressure introducing pipe 51 can be freely set when the outer tube fitting 25 is attached to the vehicle body side.

[Fourth Embodiment] FIG. 7 is a sectional view showing a fourth embodiment of the stopper member. In this embodiment, as a means for fixing the stopper member 50 and the outer cylindrical member 25, instead of caulking and fixing the projecting portion 60 and the stopper member 53 of the above embodiment, a negative pressure introducing pipe 51 is used. The end 51a is largely protruded toward the switching chamber, and
Is fixed to the bottom wall portion 11 by welding, and the inner end thereof is
Cylindrical portion 5 of stopper fitting 53 forming zero through hole 59
3a.

In this case, the length of the fixed portion of the negative pressure introducing pipe 51 can be made large by welding with the outer tube fitting 25 and press fitting into the stopper member 50.
Can be sufficiently secured by pressing the negative pressure introducing pipe 51 into the stopper fitting 53 and pressing the stopper rubber 54 against the bottom wall portion 11 of the outer cylinder fitting 25.

[0057]

As is apparent from the above description, according to the present invention, since the stopper member for regulating the opening position of the switching valve is disposed on the chamber wall side of the switching chamber, the stopper is provided on the diaphragm side as in the prior art. Compared to the configuration in which the members are arranged, the mass of the diaphragm can be made smaller, the switching can be made smoother, and if the negative pressure introducing pipe is pressed into the through hole formed in this stopper member, the negative pressure can be reduced. It is possible to prevent the introduction pipe from falling off, and to provide a vibration isolator having excellent stability.

[Brief description of the drawings]

FIG. 1 is a perspective view of a negative pressure switching type liquid filled type vibration damping device showing a first embodiment according to the present invention.

FIG. 2 is a vertical sectional view of the switching chamber in an atmospheric pressure state.

FIG. 3 is a longitudinal sectional view of the same switching chamber negative pressure state.

FIG. 4 is a sectional view of a main part showing the same stopper mechanism.

FIG. 5 is a sectional view showing a second embodiment of the stopper mechanism.

FIG. 6 is a sectional view showing a third embodiment of the stopper mechanism.

FIG. 7 is a cross-sectional view showing a fourth embodiment of the stopper mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid-filled type vibration isolator 2 Upper mounting bracket 3 Lower mounting bracket 4 Anti-vibration base 5 Liquid chamber 5a Main liquid chamber 5b Sub liquid chamber 6 First diaphragm 7 Partition member 8 Switching valve 9 Equilibrium chamber 10 Second diaphragm DESCRIPTION OF SYMBOLS 11 Bottom wall part 12 Switching chamber 15 Outer orifice 16 Inner orifice 25 Outer tube fitting 26 Inner tube fitting 50 Stopper member 51 Negative pressure introducing pipe 53 Stopper fitting 60 Projecting part 61 Introducing hole 63 Opening part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Takabayashi 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. (72) Inventor Shinya Yoshida 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor (72) Inventor Kazumasa Kuze 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F Term (Reference) 3D035 CA05 CA06 3J047 AA03 CA12 CB10 CD12 DA02 FA02

Claims (8)

[Claims] A space formed between a vibration isolating base and a mounting bracket of an apparatus body is divided by a diaphragm into a liquid chamber on a vibration isolating base side and a switching chamber on a mounting bracket side. A switching valve for adjusting the communication state of the formed orifice; and a spring for biasing the switching valve in a valve closing direction, wherein a reaction force of the spring is canceled by switching between negative pressure and atmospheric pressure in the switching chamber. A negative pressure switching type liquid filled type vibration damping device that exerts an attenuation effect of a different frequency, wherein a stopper member that regulates a valve opening direction of the switching valve is provided on the switching chamber on a side opposite to the diaphragm. Negative pressure switching type liquid filling type vibration damping device arranged on the bottom wall side of the mounting bracket located at the position. 2. A deep plate flange-shaped fixing portion extends radially outward from a lower portion of the stopper member, and a protrusion protruding toward the switching chamber is formed on the bottom wall portion. The negative pressure switching type liquid filled vibration isolator according to claim 1, wherein the fixed portion is press-fitted. 3. A stopper formed with a through-hole penetrating in the axial direction in the stopper member, and an inner end of a negative pressure introducing pipe for introducing a negative pressure or an atmospheric pressure into the switching chamber is formed in the bottom wall portion. 3. The negative pressure switching type liquid-filled vibration damping device according to claim 1, wherein the switching member is projected through the hole into the switching chamber, and an inner end thereof is press-fitted into the through hole of the stopper member. 4. An outer end side of said negative pressure introducing pipe is bent in a direction perpendicular to an axis, and an outer end thereof is oriented sideways from an opening formed on a part of a side wall of said projection. 3. The negative pressure switching type liquid filled vibration isolator according to 3. 5. The negative pressure switching type liquid filled type vibration damping device according to claim 3, wherein a seal portion for air sealing between the fixing portion of the stopper member and the projecting portion is provided. 6. The negative pressure switching type liquid filled vibration isolator according to claim 5, wherein said negative pressure introducing pipe penetrates through an introducing hole formed in a bottom wall portion of said switching chamber in a loosely fitted state. 7. The stopper member includes a stopper fitting including the fixing part, and a stopper rubber part vulcanized and bonded to the stopper fitting, and press-fits the negative pressure introducing pipe into a peripheral wall of the through hole. The negative pressure switching type liquid filled vibration isolator according to any one of claims 3 to 6, wherein the cylindrical portion of the stopper fitting is disposed. 8. The negative pressure switching type liquid filled vibration isolator according to claim 7, wherein said stopper fitting has a two-piece divided structure of said tubular portion and said fixed portion.