JPH06241277A - Shock absorber - Google Patents

Abstract

PURPOSE:To provide a shock absorber that has a nonlinear reaction characteristic where a spring constant grows larger stepwise. CONSTITUTION:A weight 12 is hung down from a base end of a lever 8 pivotally supported on a base 5 via a fulcrum shaft 9, a lever stopper 14, holding this lever 8 in almost horizontality, is installed in the base 5, a first shock absorbing member 17 made of a plate spring being small in its spring constant is installed in a tip part of the lever 8, and a contact member 25 coming into contact with a ship 2 is installed in the front of a lower end of this first shock absorbing member 17. In succession, a spring stopper 18 which checks such a possibility that the lower end of the first shock absorbing member 17 might be displaced in the rear as far as more than the specified interval, is installed in the tip part of the lever 8, and the base end of the lever 8 is displaced upward, whereby a second shock absorbing member 27 made of a plate spring being large in its spring constant and being displaced upward by the base end of the lever 8 is installed in the base 5 as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber used as a fender for ships and marine structures and as a train stopper for train stations.

[0002]

2. Description of the Related Art For example, as shown in FIG. 4, a fender 3 is attached to a side surface of a wharf 1 in order to buffer a shock when the ship 2 is brought into berth.

As the fender 3, a leaf spring or a coil spring has been conventionally used.

[0004]

Since the fender 3 made of the above-mentioned conventional leaf spring or coil spring has a reaction force characteristic having a linear spring constant in which the load and the displacement are in a constant proportional relationship. As shown by (a) in FIG. 5, when the spring constant is small, the displacement of the ship 2 is large at the initial stage of berthing of the ship 2.
Although it does not give a shock to the ship, it is compressed and hardly displaced in the latter half of the berth, so there is a drawback that a large shock is given to the ship 2. Moreover, as shown in FIG. Although the ship 2 is displaced and does not give an impact to the ship 2 even in the latter part of the berth, there is a problem that the ship 2 is given an impact at the beginning of the berth because the displacement amount is small.

Therefore, as shown in FIG. 5C, it is considered to use rubber having a non-linear reaction force characteristic in which the spring constant increases stepwise as the fender 3. According to this, the initial linear reaction force part a, the middle constant reaction force part b, and the latter part linear reaction force part c can absorb the initial, middle, and late impacts of the berth, but in reality, the spring constant However, in order to obtain a rubber cushioning member having a desired non-linear reaction force characteristic, it is necessary to manufacture a large number of prototypes, which is disadvantageous in that it takes many days and costs.

In view of the above-mentioned conventional problems, the present invention provides a shock absorber having a non-linear reaction force characteristic in which a spring constant increases stepwise and capable of obtaining a desired reaction force characteristic. Has an aim.

[0007]

In order to achieve the above object, the present invention has a weight hanging from a base end portion of a lever lever pivotally supported on a base so as to be vertically rotatable, and the lever lever is also attached. A lever lever stopper that abuts the lower surface of the base end of the lever to hold the lever in a substantially horizontal state is provided on the base, and a first cushion member made of a leaf spring is vertically provided at the tip of the lever. ,
An abutting member is provided on the front surface of the lower end portion of the first cushioning member so as to come into contact with the shock absorber, and a spring stopper for preventing the lower end portion of the first cushioning member from being displaced rearward by a predetermined distance or more is provided at the tip end of the lever. And a second cushioning member made of a leaf spring that is displaced upward by the base end portion of the lever lever and is displaced upward by the base end portion of the lever rod. To do.

[0008]

In the above structure, when the shock-absorbing body comes into contact with the abutting member, a load is applied to the first cushioning member and the lever rod, but since the weight is suspended at the base end portion of the lever rod, First
Only the lower end of the cushioning member is displaced rearward, and the impact at the initial stage of contact is absorbed. Then, when the lower end of the first buffer member hits the spring stopper, the first buffer member is not displaced any more, and the lever lever is rotated by the load applied to the contact member, and the base end of the lever rod is rotated. The part is displaced upward, and the shock in the middle of contact is absorbed. After that, the second cushioning member is displaced upward by the base end portion of the lever, and the impact in the latter stage of contact is absorbed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show an example in which the shock absorber of the present invention is used as the fender 3 shown in FIG. 4, and a pair is provided on a base 5 fixed to the side surface of the quay 1 at predetermined intervals. Cushioning mechanisms 6 and 6 are provided.

Explaining the cushioning mechanisms 6 and 6, the lever 8 is rotatably supported by a strut 7 projecting on the base 5 so as to be vertically rotatable via a pivot shaft 9, and the lever 8 has a base end portion. Connecting pin 1
A weight 12 is suspended from a base end side supporting member 11 which is hung vertically through 0, and the height adjusting bolt is screwed at a substantially intermediate position between the pivot shaft 9 of the lever 8 and the connecting pin 10. A lever lever stopper 14 for holding the lever rod 8 in a substantially horizontal state by abutting on the lower end portion of the lever 13 is provided on the base 5 so as to project therefrom, and the tip end of the lever rod 8 hung vertically via a connecting pin 15 A first cushion member 17 made of a leaf spring having a small spring constant and an upper end portion of a steel spring stopper 18 having a small spring constant are fastened to the front and rear surfaces of the lower end of the side support member 16 by bolts and nuts 19.

The first cushioning member 17 and the spring stopper 18 extend in parallel with each other at a predetermined interval α, and the lower end portion of the spring stopper 18 has a space between the spring stopper 18 and the first cushioning member 17. A space adjusting bolt 23 for adjusting the space α is screwed, and a contact member 25 for contacting the ship (damped body) 2 via the connecting rod 24 is provided at the lower end portion of the first buffer member 17. And a supporting rod 20 fixed at a substantially intermediate position between the pivot shaft 9 of the lever rod 8 and the connecting pin 15.
A stopper member 22 is attached to the rear surface of the tip-side support member 16 to prevent the tip-side support member 16 from rotating rearward. When it comes into contact with, the lower end portion of the first cushioning member 17 is displaced rearward (see the phantom line in FIG. 1) to absorb the impact at the initial stage of berthing. In this case, since the leaf spring having a small spring constant is used as the first cushioning member 17, the ship 2 is not impacted. Then, when the lower end of the lever hits the spring stopper 18, the first cushioning member 17 is not displaced any further, and the lever 8 pivots around the pivot shaft 9 due to the load applied to the contact member 25, and The base end of the rod 8 is displaced upward (see the phantom line in FIG. 1) to absorb the shock during the middle berth.

In this embodiment, the stopper member 2
A load cell is used as 2, and the load applied to the contact member 25 can be detected.
Further, as shown in FIG. 2, the contact members 25, 25 of both the cushioning mechanisms 6, 6 are integrally formed with each other.

A second cushioning member 27 made of a leaf spring and a steel spring stopper 2 having a large spring constant on both upper and lower ends of a horizontal support member 26 projecting from the upper end of the column 7 to the rear in the horizontal direction.
The base end portion of 8 is fixed by bolts and nuts 29. The second cushioning member 27 and the spring stopper 28 extend in parallel with each other with a predetermined gap β between them, and at the tip of the spring stopper 28, the gap β between the spring stopper 28 and the second cushioning member 27. An interval adjusting bolt 30 for adjusting the contact angle is screwed, and an abutting pin 31 facing the upper surface of the base end portion of the lever rod 8 at a predetermined interval γ is provided at the tip of the second cushioning member 27 so as to project therefrom. When the base end portion of the lever rod 8 is displaced upward and comes into contact with the second cushioning member 27, the tip end portion of the second cushioning member 27 is displaced upward (see the phantom line in FIG. 1),
It absorbs the shock of the second half of the berth. In this case, the second cushioning member 2
Since a leaf spring having a large spring constant is used as 7, the excessive load in the latter half of the berth is reliably absorbed, and the ship 2 is not impacted. Then, when the tip of the second cushioning member 27 hits the spring stopper 28, the second cushioning member 27 is prevented from further displacing.

In FIG. 2, reference numerals 33 and 34 denote laser displacement gauges for measuring the displacements of the first and second cushioning members 17 and 27, respectively. The targets 35 and 36 for the displacement gauges 33 and 34 are attached. Further, 37 is a waterproof protective cover, and 38 is a waterproof bellows provided between the waterproof protective cover 37 and the connecting rod 24.

The cushioning action will be described with reference to the reaction force characteristic diagram of FIG. 3. When the boat 2 comes into contact with the abutment member 25 for berthing, a load is applied to the first cushioning member 17 and the lever rod 8.
Since the weight 12 is suspended from the base end portion of the lever rod 8, only the lower end portion of the first cushioning member 17 is displaced rearward (see the phantom line in FIG. 1). In this case, as shown in (d) of FIG. 3, the first cushioning member 17 is linearly displaced as the load increases, and can absorb the shock at the initial stage of berthing.

Subsequently, when the lower end of the first cushioning member 17 hits the spring stopper 18, the first cushioning member 17 is not displaced any further, and the lever 8 is actuated by the load applied to the contact member 25.
Rotates about the pivot 9, and the base end of the lever rod 8 is displaced upward (see the phantom line in FIG. 1). In this case, as shown in FIG. 3 (e), the base end portion of the lever rod 8 is displaced by a constant load, and the impact in the middle berthing period can be absorbed.

Thereafter, the base end portion of the lever rod 8 comes into contact with the second cushioning member 27, whereby the tip end portion of the second cushioning member 27 is displaced upward (see the phantom line in FIG. 1). In this case,
As shown in (f), the second cushioning member 27 is linearly displaced as the load increases, and it is possible to absorb the impact in the latter half of the berthing.

In FIG. 3, the displacement amount D of the initial linear reaction force portion d is the displacement amount E of the medium-term constant reaction force portion e by setting the spring constant of the first buffer member 17 and adjusting the spacing α by the spacing adjustment bolt 23. By adjusting the interval γ with the height adjusting bolt 13 and adjusting the weight of the weight 12, the displacement amount F of the latter-stage linear reaction force portion f is set by the spring constant of the second buffer member 27 and the interval adjusting bolt. The distance β can be adjusted by adjusting the interval β by 30, so that a desired nonlinear reaction force characteristic in which the spring constant increases stepwise can be realized.

Although the pair of buffer mechanisms 6 and 6 are used in the above embodiment, only one of them may be used. Further, in the above embodiment, the case where the shock absorber is applied to the fender of the ship has been described, but for example, the shock absorber can also be applied to the fender when mooring an offshore structure on the sea. The invention can be applied to a stop device for stopping runaway of a train at a station or the like, and further to an experimental device for examining reaction force characteristics of a fender in a mooring floating body.

When the reaction force characteristic is tested by using a conventional rubber cushioning member, it is performed in a scaled down state, so it is very difficult to carry out the experiment in a state suitable for an actual machine. However, according to the configuration of this embodiment,
Since the reaction force characteristics can be adjusted freely, it is possible to carry out experiments that match the actual machine.

[0021]

According to the present invention, when the shock-absorbing body comes into contact with the contact member, the first shock-absorbing member, the lever rod and the second shock-absorbing member are sequentially displaced, and the spring constant increases stepwise. The impact can be reliably absorbed in the initial, middle, and late stages of the contact.

Further, the spring constant can be set by appropriately setting the interval between the first shock absorbing member and the spring stopper, the spring constants of the first and second shock absorbing members, and the weight of the weight suspended on the lever. A desired nonlinear reaction force characteristic can be set extremely easily.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a shock absorber according to an embodiment of the present invention used as a fender.

FIG. 2 is a horizontal sectional view of the same.

FIG. 3 is a reaction force characteristic diagram of the shock absorber.

FIG. 4 is a schematic side view showing a mounted state of a fender.

FIG. 5 is a reaction force characteristic diagram of a conventional example.

[Explanation of Codes] 2 Vessel (Buffered Object) 5 Base 8 Lever Rod 9 Pivot Shaft 12 Weight 14 Lever Rod Stopper 17 First Buffer Member 18 Spring Stopper 25 Abutment Member 27 Second Buffer Member

Claims (1)

[Claims] 1. A weight is suspended from a base end portion of a lever rod pivotally supported on a base so as to be vertically rotatable, and is brought into contact with a lower surface of the base end portion of the lever rod so that the lever rod is substantially horizontal. A lever lever stopper for holding in a state is provided on the base, a leaf spring first cushioning member is hung vertically on the tip end of the lever rod, and a shock absorber is provided on the lower end front surface of the first cushioning member. An abutting member that abuts is provided, and a spring stopper that prevents the lower end portion of the first cushioning member from being displaced rearward by a predetermined distance or more is provided at the tip end portion of the lever rod, and the base end portion of the lever rod is displaced upward. The cushioning device is characterized in that a second cushioning member made of a leaf spring that is displaced upward by the base end of the lever rod is provided on the base.