JP2568971Y2 - Liquid-filled mount - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-proof liquid-filled mount for holding a cab of a construction machine such as a power shovel on a vehicle body.
The anti-vibration effect against vibration of z or more is improved.

[0002]

2. Description of the Related Art In recent construction machines, the speed of operation has been increased. For example, the maximum speed of a power shovel has been increased from 3 km / h to 6 km / h. A large vibration is applied to the driver's seat. For this reason, in a construction machine, a conventional rubber mount has insufficient damping properties, and a cab mount having high damping properties is required.

Conventionally, as a cab mount, a liquid-filled mounting device using an elastic body and a high-viscosity damping liquid has been known (Japanese Utility Model Application Laid-Open No. 64-11450). In this liquid-filled mounting device, as shown in FIG. 3, a cylindrical elastic body 13 is interposed between a stud 11 attached to a cab and a casing metal fitting 12, and inner and outer joining surfaces of the cylindrical elastic body 13 are press-fitted. It has become. A damping plate 14 is attached to the lower end of the stud 11, and a silicone oil 15 is sealed in a space inside the casing fitting 12 where the damping plate 14 is provided. When a vertical impact or load acts on the stud 11, the damping plate moves up and down in the silicone oil, and the up-and-down movement is buffered by the silicone oil, and is further buffered by the elastic body on the outer periphery of the stud.

[0004]

The conventional liquid-filled mount can obtain a large damping force in a wide frequency range to some extent, but its main purpose is to attenuate the vibration of the cab. For this reason, it is not considered that the dynamic spring constant is sufficiently reduced, and measures for reducing the vibration in the sound region are insufficient. In construction machinery, to drive various hydraulic equipment,
The driving sound is transmitted to the driver's seat of the cab and includes vibrations in the sound area, so that it is annoying and may hinder operation at the driver's seat. An object of the present invention is to reduce the dynamic spring constant of a liquid-filled mount so that vibrations in a sound region can be sufficiently prevented, and to maintain a large tan δ as a loss factor for quickening the vibrations.

[0005]

According to the present invention, a casing metal fitting is formed in a shape having a large-diameter cylindrical part having a bottom at a lower end of a small-diameter cylindrical part whose axial direction is vertical, and a cylindrical elastic body is provided in the casing metal fitting. The above object has been achieved in a liquid-filled mount in which a stud is mounted via a stud, a damping plate is attached to a lower end of the stud, and a damping liquid is filled in a casing fitting at a position surrounding the damping plate. That is, a stopper made of an elastic material was attached to the upper surface of the damping plate, a flange member for regulating the position of the stopper was attached to the large-diameter cylindrical portion, and a sponge-like elastic member was attached to the lower surface of the damping plate.

[0006]

In the liquid-filled mount of the present invention, the sponge-like elastic body is attached to the lower surface side of the damping plate, so that when the vibration including the sound region acts from the casing side, the high-viscosity damping liquid forms the damping plate. Before being pressed, the sponge-like elastic body is deformed, thereby absorbing minute vibrations having a frequency of 50 Hz or more.
Therefore, transmission of vibration when the hydraulic drive device is driven can be prevented, so that noise in the cab can be reduced. In addition, since the cylindrical elastic body is interposed between the stud and the casing bracket, most of the cylindrical elastic body contributes to the buffer in the axial direction and the horizontal direction, and tan δ as a loss factor increases in a wide frequency range. Value, so that the spring constant in the horizontal direction can be higher than in the vertical direction, the sway of the cab can be suppressed, and there is a large damping force for each natural frequency distributed in a wider frequency range. . In addition, it has a high absorption capacity even with a large impact force.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the embodiment shown in the drawings. It should be noted that the present invention is not limited by this. FIG. 1 is a cross-sectional view of one embodiment of a liquid-filled mount according to the present invention. The liquid-filled mount of the present invention holds the cab 20 of the construction machine with a cushioning function.
, And the stud 3 is attached to the cab 20. The casing metal fitting 1 has a small-diameter cylindrical portion 1 whose axis is vertically oriented.
It is formed in a shape having a large-diameter cylindrical portion 1c having a bottom at the lower end of the small-diameter cylindrical portion, and a flange portion 1b at each of the upper and lower ends of the small-diameter cylindrical portion. A cylindrical elastic body 2 is provided in the small-diameter cylindrical portion 1a of the casing fitting 1.
Are baked and adhered. A radially extending portion 2a is provided at an upper portion of the cylindrical elastic body 2, and the overhanging portion 2a acts so as to oppose a downward moving force of the stud 3. The lower end of the cylindrical elastic body 2 is set slightly above the lower end position of the small diameter cylindrical portion 1a.

A rod-shaped stud 3 is adhered in the central hole of the tubular elastic body 2 by baking, and the upper end protruding portion is connected to the cab 20.
It is to be connected to. A damping plate 4 is attached to a lower end of the stud 3, and a stopper 5 formed of an elastic body is attached to an outer peripheral portion of the upper surface thereof. It is being regulated. Also, the attenuation plate 4 has
A throttle hole 6 communicating between the upper and lower portions is provided.
Also serves as an air escape hole. A high-viscosity damping liquid 7 such as silicone oil is sealed in the large-diameter cylindrical portion 1c of the casing fitting 1, and the high-viscosity damping liquid 7 flows through the throttle hole 6 or the outer periphery of the damping plate 4 to be attenuated from the stud 3. The vertical shock acting on the plate 4 is buffered. Note that a small air chamber is provided between the lower surface of the cylindrical elastic body 2 and the high-viscosity damping liquid 7 to contribute to buffering. In addition, at the bottom of the casing 1, there is provided an inlet for introducing the high viscosity attenuation liquid 7, which is closed by a seal bed 8.

Further, in the liquid-filled mount according to the present invention shown in FIG. 1, a sponge-like elastic body 10 in the form of a ring plate is attached to the lower surface of the damping plate 4, and the damping plate 4 applies the high viscosity damping liquid 7 by vibration. Before being pressed, the sponge-like elastic body 10 is deformed, thereby absorbing vibrations at a frequency of 50 Hz or more. Since the sponge-like elastic body 10 is used in a liquid, it is desirable that the sponge-like elastic body be of a closed cell type in which the liquid is not mixed into the sponge. Although the thickness of the sponge-like elastic body 10 is about 2 mm in the present embodiment, the thickness is adjusted according to the area of the plane, and the position where the sponge-like elastic body 10 is adhered to the damping plate 4 also depends on the shape of the damping plate 4. Various changes can be made in accordance with.

[0010] A liquid-filled mount having the above structure is prepared,
Measure the dynamic spring constant and the loss factor tan δ,
The result is shown in FIG. For comparison, FIG. 2 also shows the results of the same measurement for a conventional liquid-filled mount. As can be seen from FIG. 2, tan δ is
At a vibration of 0 Hz or more, there is almost no difference between the liquid-filled mount of the present invention and the conventional liquid-filled mount.
However, it can be seen that the dynamic spring constant of the liquid-filled mount of the present invention is improved to about half that of the conventional liquid-filled mount at a vibration of 50 Hz or more in frequency. The measurement of the axial dynamic characteristics of the liquid-filled mount of the present invention shown in FIG. 2 was performed under the condition that the vibration amplitude was ± 0.1 mm. The liquid-filled mount of the present invention can be used not only as a liquid-filled mount for construction machinery but also as a vibration damping mount for general automobiles, trains, machine tools, and the like.

[0011]

[Effect of the invention] According to the liquid-filled mount of the invention,
A large damping force can be obtained for vibrations in a wide frequency range, and particularly for vibrations of 50 Hz or more, the dynamic spring constant can be improved to about half that of the conventional liquid-filled mount. Thus, if the liquid-filled mount of the present invention is used in, for example, a construction machine, it is possible to prevent the vibration in the sound region of the hydraulic drive device or the like from being transmitted to the cab. Even if a sponge-like elastic body is attached to the damping plate, tan δ as a loss factor can be sufficiently increased.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a liquid-filled mount according to the present invention.

FIG. 2 is a graph showing dynamic characteristics of the liquid-filled mount according to the present invention.

FIG. 3 is a sectional view showing an example of a conventional liquid-filled mount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing fitting 2 Cylindrical elastic body 3 Stud 4 Damping plate 5 Stopper 10 Sponge-like elastic body

Claims (1)

(57) [Scope of request for utility model registration] 1. A casing having a large-diameter tubular portion having a bottom at a lower end of a small-diameter tubular portion whose axial direction is up and down, and a stud is mounted in the casing via a tubular elastic body. Attach a damping plate to the lower end of the
In a liquid-filled mount filled with damping liquid in a casing fitting at a position surrounding the damping plate, a stopper made of an elastic material is attached to the upper surface side of the damping plate, and a flange member that regulates the position of the stopper is a large-diameter cylindrical portion. And a sponge-like elastic body attached to the lower surface of the damping plate.