JPH0343482Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dynamic damper that effectively suppresses the vibration of a structure subjected to forced vibration.

[Prior Art] In order to support a drive device including an engine which is a vibration generator in a structure such as a car body, it is necessary to
A vibration isolating rubber device as disclosed in Japanese Patent No. 29830 is used. According to this anti-vibration rubber device, the spring constant changes depending on the driving conditions of the vehicle, for example, when the vehicle is started/accelerated and when the vehicle is running at a constant speed, and vibrations transmitted to the vehicle interior can be efficiently suppressed.

Furthermore, as disclosed in Japanese Utility Model Application No. 58-196447, a dynamic damper has been proposed that cancels a specific vibration frequency that most affects riding comfort. As shown in FIG. 9, this is attached to a side member 30 as a reinforcing member in a passenger car having a monocot type structure, for example, with bolts 8 and nuts. Specifically, as shown in FIGS. 10 and 11, the side member 30 has an inverted U-shaped cross section.
It is constructed by supporting a weight 1 of a predetermined weight via an elastic material 2 on the top wall 30a or side wall 30b of.

The dynamic damper A attached to the top wall 30a of the side member 30 has a vertical natural frequency of the side member 30, and the dynamic damper B attached to the side wall 30b has the same frequency as the side member 30.
The mass of the weight 1 and the spring constant of the elastic material 2 are selected so as to be approximately equal to the natural frequency in the lateral direction of This is intended to cancel out vibrations and suppress the vibrations transmitted to the passenger compartment.

However, as mentioned above, this type of dynamic damper not only requires accuracy in the mass of the weight 1 and the spring constant of the elastic material 2, but even if it can be set accurately, it will not work as shown in Fig. 12. Another problem is that the elastic material 12 is hard at low temperatures and soft at high temperatures, resulting in a discrepancy between the unique frequency at which vibration is to be suppressed and the frequency at which actual vibration damping effect is expected.

[Problems to be solved by the invention] The purpose of the invention is to create a dynamic damper whose vibration frequency, which exhibits the damping effect, does not change with temperature.
An object of the present invention is to provide a dynamic damper that can effectively suppress vibrations at a specific frequency (natural frequency) that is always required.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the present invention is such that a mounting plate is connected to one end of a rod-shaped elastic member, a weight is connected to the other end, and the elastic member is connected to the mounting plate. An annular bag with a rectangular cross section is housed in the space between the elastic material and the cup-shaped holding member that surrounds the bag, and the contact pressure between the bag and the elastic material changes as the pressure changes with the temperature of the fluid filled in the bag. It changes the

[Operation] A bag filled with pressurized fluid supported by the structure or attachment is pressed against the circumferential surface of the elastic material, and the temperature characteristics of the elastic material are regulated. Since the regulating force of the bag is strong at high temperatures and weak at low temperatures, the spring constant of the elastic material is maintained approximately constant. Therefore,
Vibration at a specific frequency determined by the mass of the weight and the spring constant of the elastic material can be effectively suppressed regardless of temperature changes.

[Embodiment of the invention] As shown in FIGS. 1 and 2, a mounting plate 3 is supported by bolts 6 on a mounting body 7 that supports a vibration generating body such as a car body or receives forced vibration from the outside. A weight 1 is connected to 3 via an elastic member 2 having a circular cross section, that is, a rod shape. An elastic material 2 such as rubber is integrally baked and bonded to protrusions protruding into the elastic material 2 from the weight 1 and the mounting plate 3, respectively. Such a configuration is almost the same as the conventional one.

According to the present invention, the flange 5b of the cup-shaped holding member 5 is fixed to the mounting body 7 together with the mounting plate 3 by bolts 6. End wall 5a of presser member 5
A bag 4 filled with pressurized air is placed between the mounting plate 3 and the mounting plate 3.
is interposed. The bag 4 is provided with an injection device 15 and is filled with pressurized air from the outside.

As shown in FIG.
a is integrally formed, a base 17 is inserted into the pipe 4a, and the pipe 4a is fastened with a clip 16. The end of the cap 17 is closed by screwing a cap 19 with a gasket 18.

The bag body 4 is configured as an annular body having a rectangular cross section. The inner circumferential surface of the bag body 4 is pressed against the circumferential surface of the elastic material 2. The contact area between the inner circumferential surface of the bag body 4 and the elastic material 2 changes depending on the temperature. A hole 5c from which the elastic material 2 protrudes is provided in the end wall 5a of the holding member 5, and a sufficient distance is provided between the hole 5c and the elastic material 2.

By configuring the present invention as described above, it is possible to suppress specific vibration frequencies in the shearing direction of the elastic member 2, that is, in the front-rear, left-right, or up-down directions.
That is, at high temperatures, the pressure of the pressurized fluid inside the bag 4 increases, the contact area between the inner peripheral surface of the bag 4 and the elastic material 2 increases, and the force restraining the elastic material 2 also increases, causing the elastic material to Since the elastic material 2 is strongly restrained, a decrease in the spring constant due to the elastic material 2 becoming soft at high temperatures can be suppressed.

Conversely, at low temperatures, the elastic material 2 becomes hard, but the bag body 4
The pressure of the pressurized air filled in the elastic material 2 decreases, and the elastic material 2
Since the restraining force is weakened, an increase in the spring constant can be suppressed. In this way, a substantially constant spring constant can always be maintained against temperature changes. Therefore, the required specific frequency (natural frequency)
vibration can be suppressed.

In the embodiment shown in FIGS. 4 and 5, the bag 4 is filled with liquid (preferably antifreeze) or the like from an injection device 15. In the embodiment shown in FIGS. The bag 4 is configured as an annular body having a rectangular cross section, and the inner peripheral surface of the bag 4 is pressed against the outer peripheral surface of the elastic material 2, and the upper and lower end surfaces of the bag 4 are pressed against the end wall 5a of the presser member 5 and the reaction force. It is sandwiched between the plate 13 and the plate 13.
The end wall 5a is provided with a cylindrical portion 5d into which the elastic material 2 is fitted, and the elastic material 2 is supported slidably along the cylindrical portion 5b.

The reaction plate 13 is connected to the elastic member 2 through a coupling fitting 14 through a recess provided in the center. A bolt 10 extending from the coupling fitting 14 is inserted into a hole in the reaction plate 13, and a nut 9 is screwed onto the bolt 10. In this way, the reaction force plate 13 and the elastic member 2 are coupled together, and the spring 12 is interposed between the reaction force plate 13 and the mounting body 7.

In this embodiment, at high temperatures, the expansion of the liquid in the bag body 4 causes the elastic material 2 to spring 12 together with the reaction force plate 13.
is pushed down against the force of Therefore, the length l of the elastic material 2 between the upper end edge of the cylindrical portion 5d and the weight 1 becomes shorter, the spring constant of the elastic material 2 increases, and the spring constant decreases due to the softening of the elastic material 2. is canceled out.

Conversely, at low temperatures, the liquid in the bag body 4 contracts, the protruding length l of the elastic material 2 from the cylindrical portion 5d increases, the spring constant of the elastic material 2 increases, and the elastic material 2 hardens at low temperatures. The increase in spring constant is canceled out.
Therefore, the spring constant in the lateral direction of the elastic member 2 is kept almost constant regardless of temperature changes, and the specific vibration frequency (natural frequency) in the direction parallel to the mounting surface of the mounting body 7 is maintained.
vibration can be suppressed.

As shown in FIG. 5, instead of forming the presser member 5 in a cylindrical shape, if the inner diameter of the lower half gradually increases downward, the elastic material 2 will be able to withstand temperature changes as shown in FIG. A restraining force that more closely approximates the change in spring constant can be applied to the bag body 4.

In the embodiment shown in FIGS. 6 to 8, the elastic member 2 has a substantially rectangular cross section, a shaft 21 is coupled to the lower end of the elastic member 2 together with a circular mounting plate 3, and the upper end of the elastic member 2 A block-shaped weight 1 is connected to. The mounting plate 3 is rotatably supported by the mounting body 7 by an annular holding plate 5A. The holding plate 5A is fixed to the mounting body 7 with bolts 6. A lever 22 is fixedly supported at the lower end of the shaft 21. That is, the lever 22 is fitted onto the shaft 21 by serrations, and the seat plate 23 is fixed by screwing the nut 24 into a threaded shaft portion formed at the end of the shaft 21.

As shown in FIG. 8, one end of a rod 26 is connected to the tip of the lever 22 by a pin 25. As shown in FIG. At the other end of the rod 26, a diaphragm 28 constituting the bag body 4 is held between a flange 29 and a seat plate 32.
Then, the nut 31 is screwed onto the rod 26 and fastened. The bag body 4 is constructed by connecting the peripheral edge of the diaphragm 28 to a cup-shaped cylinder 35. A bracket 33 having an L-shaped cross section is coupled to the bottom of the cylinder 35. The bracket 33 is fixed to the mounting body 7 by bolts 34. Bracket 33 and lever 2
A spring 27 is stretched between the two.

The bag body 4 is filled with fluid, and when the rod 26 is moved upward in FIG. 8 due to thermal expansion of the fluid due to temperature rise, the elastic material 2 along with the shaft 21 moves counterclockwise in FIG. Rotate in the direction. Therefore, the spring constant of the elastic member 2 with respect to the vibration of the weight 1 in the vertical direction (unmarked in FIG. 7) becomes large, and the decrease in the spring constant caused by the softening of the elastic member 2 is canceled out.

Conversely, at low temperatures, the fluid in the bag body 4 contracts as shown in FIG.
It is rotated clockwise around the center. Therefore, in FIG. 7, the elastic member 2 rotates clockwise and becomes horizontally elongated, and the spring constant against vibration in the direction of the arrow becomes smaller, canceling out the increase in the spring constant due to hardening of the elastic member 2. In this way, the elastic member 2 is rotated within a range of 90° in response to a temperature change, the posture or cross-sectional shape of the elastic member 2 with respect to the vibration direction changes, and the change in the spring constant of the elastic member 2 is canceled out.

In addition, in the above embodiment, instead of the weight 1,
A dynamic damper that suppresses vibrations of the vehicle body is constructed by supporting functional parts attached to the vehicle, such as batteries, radiators, bumpers, pumps, motors, etc., on the vehicle body in combination with elastic materials with appropriate spring constants. I can do it.

[Effects of the invention] As described above, the present invention combines a mounting plate at one end of a rod-shaped elastic member and a weight at the other end, and a cup-shaped holding member surrounding the elastic member connected to the mounting plate and the elastic member. An annular bag with a rectangular cross section is housed in the space between the bag and the contact pressure between the bag and the elastic material changes as the pressure changes with the temperature of the fluid filled in the bag. In response to changes, the binding force exerted on the elastic material of the bag becomes weak at low temperatures, and conversely becomes strong at high temperatures, so a nearly constant spring constant is always maintained, and the vibration of the natural frequency of the attached body is A suitable spring constant and mass are maintained to suppress the

The dynamic damper of this invention can always provide a stable vibration damping effect against seasonal changes without the need for manual adjustment or expensive control devices such as computers, and is simple in construction, lightweight, and compact. Since it is small and can be provided at low cost, it can be placed particularly at a desired location on the wall of the vehicle interior to suppress vibrations propagated into the vehicle interior and provide a quiet and comfortable ride.

Since the present application uses a bag as the temperature compensating member, there is no risk of damaging the mating member. Since the bag itself has damping properties, it has excellent durability. Since the damping properties can be freely adjusted by adjusting the pressure of the fluid filled into the bag, highly accurate vibration damping characteristics can be easily obtained.

[Brief explanation of drawings]

FIG. 1 is a front cross-sectional view of a dynamic damper according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the same plane,
FIG. 3 is a front sectional view of a device for injecting fluid into a bag body, FIG. 4 is a front sectional view of a dynamic damper according to a second embodiment of the present invention, and FIG. 5 is a main part of a partially modified embodiment of the same. 6 is a front sectional view of a dynamic damper according to a third embodiment of the present invention, and FIG. 7 is a plan view showing the relationship between the weight, the elastic material, and the mounting plate in the dynamic damper. , FIG. 8 is a plan sectional view of the bag body attached to the dynamic damper, FIG. 9 is a side view of the vehicle body showing how the conventional dynamic damper is used, and FIG.
11 is a front sectional view showing another mounting state of the dynamic damper, and FIG. 12 is a diagram showing the spring characteristics of the elastic material with respect to temperature. 1: Weight, 2: Elastic material, 3: Mounting plate, 4: Bag body,
5: Pressing member, 7: Mounting body.

Claims (1)

[Scope of utility model registration request] A mounting plate is connected to one end of a rod-shaped elastic material and a weight is connected to the other end, and an annular ring having a rectangular cross section is installed in the space between the elastic material and a cup-shaped holding member that surrounds the elastic material connected to the mounting plate. A dynamic damper that accommodates a bag and is characterized by changing the contact pressure between the bag and an elastic material in response to changes in pressure with respect to the temperature of the fluid filled in the bag.