JPS60148882A - Oil immersed shock absorber for elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention alleviates the collision force by using an appropriate deceleration speed when a counterweight that straddles a rope elevator ride descends past its normal stopping position. Related to oil-filled shock absorbers.

[Background of the invention]

Elevators are equipped with a shock absorber at the bottom of the hoistway in order to cushion the impact when the elevator car descends beyond a predetermined stopping position. FIG. 1 shows an example of such a shock absorber, and is a sectional view of a conventional oil-filled shock absorber.

In FIG. 1, a shock absorber 10 includes a cylinder 12 erected at the bottom of a hoistway and filled with a shock absorbing hydraulic oil 14. At the center bottom of the cylinder 12 is a seed plate with a needle 16 that gradually becomes thinner toward the top. A flange 18 is formed at the upper end of the cylinder 12.
The guide 2 fitted into the cylinder 12 on this flange 18
The upper end of 0 is fixed with a bolt 22. Furthermore, a pair of oil reservoir chambers 24 and 26 are attached to the side of the cylinder 12 so that the hydraulic oil 14 in the cylinder 12 can enter and exit the oil reservoir chambers 24 and 26 through single oil holes 28 and 30. It has become.

A plunger 32 inserted into the kite 20 is hollow, and a receiving plate 3 for receiving a rider or a counterweight at its upper end.
4 is installation. A communication hole 36 is formed in the center of the bottom of the plunger 32, and the tip of the needle 16 penetrates into the communication hole 36. And plunger 3
A stopper portion 38 is formed on the lower part of the outer circumferential surface of No. 2. This stopper portion 38 receives the biasing force of a spring 40 that is compressed between the lower end of the plunger 32 and the bottom of the cylinder 12 and comes into contact with the lower end of the guide 20, preventing the plunger 32 from coming out of the cylinder 12. It is completely prevented. Note that the spring 40 plays the role of returning the plunger 32 that has been lowered. When the plunger 32 is at the upper limit, the hydraulic oil 1 in the cylinder 12
4 slightly penetrates into the plunger 32 through the communication hole 36'i-.

(The night surface 42 is located at a higher position than the bottom surface of the plunger 32, and the inside of the plunger 32 is filled with air at atmospheric pressure.

In a conventional shock absorber having such a structure, when a rider or a counterweight (not shown) descends excessively and rests on the receiving plate 34, the plunger 32 moves downward. At this time, the hydraulic oil 14 in the cylinder 12 is ejected and flows into the plunger 32 through the circulation hole 36, and acts as a buffer. That is, the flow passage cross-sectional area of the flow hole 36 consists of a space between the inner peripheral surface of the flow hole 36 and the outer peripheral surface of the needle 16, and has an orifice groove path. The hydraulic oil in the cylinder 12 is
When the fluid ejects and flows into the plunger 32 as the plunger 32 descends, a braking force is applied to the descent of the plunger 32 due to the orifice effect of the flow hole 36 . This braking force is generated by the needle 16 which is tapered as the plunger 32 moves downward, the cross-sectional area of the flow passage of the flow hole 36 becomes smaller, the jet of hydraulic oil 14 is reduced, and the spring 40 increases as the repulsive force increases.

On the other hand, the air within the plunger 32 is compressed as the plunger 32 descends, becoming high pressure, which contributes to braking against the descent of the plunger 32. However, if the pressure inside the plunger 32 increases more than necessary, the braking force will increase more than necessary, and a large impact will be applied to the car riding on the receiving plate 34. This pressure increase in the plunger 32 causes the oil level 42 to rise as the plunger 32 descends, increasing the pressure rise 'e-IW. That is, when the plunger 32 descends by a legally defined descending stroke S, a volume consisting of this descending stroke S and the wall thickness of the plunger sinks into the hydraulic oil 14, and the oil level 42 rises by that amount. There, the oil level is high.

However, the conventional oil storage chambers 24 and 26 have approximately the same diameter as the cylinder 12, which has the disadvantage that the external size of the shock absorber 1° becomes large. It is undesirable for the external size of this shock absorber to become large in relation to the installation space for other equipment in the floor plan of the elevator. In particular, as elevators become larger, two oil-filled shock absorbers are often installed in parallel, and there are cases where it is not possible to install a slow-flowing device equipped with an oil storage chamber.

Note that the above-mentioned downward stroke S is determined by the following equation.

S--(V
g Here・g is the acceleration of gravity, and ■ indicates the speed of the elevator.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an oil-filled shock absorbing device for an elevator that can avoid an unnecessarily increased pressure inside a plunger and reduce the external dimensions of the device.

[invention, ready-made]

The present invention increases the internal content of the plunger (8t) and eliminates the conventionally required oil storage chamber, thereby suppressing the total pressure rise within the plunger to below a certain value and reducing the external dimensions of the entire device. This is what I did.

[Embodiments of the invention]

A preferred embodiment of the oil-filled shock absorbing device for elevators according to the present invention will be described in detail with reference to accompanying drawings. Note that the same reference numerals are given to the parts corresponding to those explained in the above embodiment, and the explanation thereof will be omitted! Ill.

ε1Mo2 is a sectional view of an embodiment of the oil-filled shock absorber for an elevator according to the present invention. The IC guide 20 shown in FIG. 2 and placed at the top of the cylinder 12 is formed deeper (longer in the axial direction) than the conventional one. As a result, the plunger 32 has the same diameter as the conventional one.

The 2:'Ai section 44 inside the cylinder 12 is enlarged and functions similarly to a conventional oil storage chamber.

Therefore, since the plunger 32 has descended by the downward stroke S and the receiving plate 34 has come to the position 348, the oil level 42 has become 42.
．． Even if the pressure rises to 2, the pressure inside the plunger 32 can be maintained at an appropriate value. In order to avoid a large impact force, the upper limit value of this internal pressure is preferably 12 atmospheres or less, and is particularly preferably 10 atmospheres or less. The volume within the plunger 32 required to avoid excessive pressure rise within the plunger can be determined as follows.

The internal pressure before the plunger 32 descends is tri”o.

If the internal pressure after descending by the descending stroke S is p, the following equation holds true according to Boyle's law.

Ap (S+)Ia +Ho l l)o =Ap)
lap +++・++ (2) Here, l(. indicates the height of the rise of the oil level hill, and H, indicates the height of the guide 20 from the raised oil level 42a.
It is the distance to iA. Further, Ap is the cross-sectional area of the plunger 32 due to its inner diameter. Since the oil level 42 is generally located at a position slightly higher than the bottom surface of the plunger 32, the following relationship holds true between the oil level 42 and the length Ha of the guide 20.

Ho # H-+ Ho ・・・・・・(3) Therefore (
2) The formula is as follows.

Ap (S+Ho) po = Ap (Ha − Ha
)p-(41Here, the oil level rise height HO is plunger 3
2, where the area due to the inner diameter is 'tAp, and the area due to the wall thickness of the plunger is Aw, it can be determined by the following equation.

1-1o-A p''= 5-A= --(6) By substituting this force equation into equation (5), the internal volume of the plunger before and after the operation of the plunger 32 can be obtained.

In this way, by considering the limits of oil level rise and air pressure rise in the plunger 32, etc., and increasing the guide pressure H,'ak and the pressure inside the plunger 32, the oil retainer that was previously required can be In chambers 24, 26 - can be eliminated.

As a result, although the height of the gentle IJj device increases, it is possible to obtain a compact shock absorber that has deceleration characteristics that are not affected by air pressure ◇In addition, in the above embodiment, the diameter of the plunger 32 is the same as that of the conventional one. As explained above, by increasing the diameter of the plunger 32, not only can the height of the entire device be reduced, but also a smaller shock absorber than the conventional one can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain a shock absorber having a small external shape without excessive pressure rise inside the plunger.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional oil-filled shock absorber for elevators.
FIG. 2 is a cross-sectional view of an embodiment of an oil-filled shock absorber for elevators between headquarters. 10...Buffer device, 12...Cylinder, 14...
・Hydraulic oil, 16... Needle, 20... Kite, 2
4.26... Oil distillation chamber, 32... Granger, 36.
...Flow hole, 4o...spring. Agent Ben J■shi Tatsuyuki Unuma's funeral 1 illustration

Claims (1)

[Claims] 1. A cylinder filled with hydraulic oil, and a hollow plunger that descends in the cylinder by receiving the elevator ride or the counterweight when the elevator ride or the counterweight descends excessively. a circulation hole formed at the bottom of the plunger through which the hydraulic oil flows; a spring that biases the plunger upward when the plunger is lowered; and an oil into which a portion of the hydraulic oil in the cylinder flows when the plunger descends. 1. An oil-filled shock absorber for an elevator having an oil retention chamber, wherein the plunger also serves as the oil retention chamber. 2. The plunger according to claim 1, wherein the plunger has an internal volume such that the final internal pressure is 10 times or less as compared to the initial internal pressure when the plunger is lowered a predetermined distance. Oil-filled shock absorber for elevators.