JPH04217577A - Oil-immersed buffer for elevator - Google Patents

Abstract

PURPOSE:To lower the level of an oil-immersed buffer even to a high-speed elevator by supporting an expansion cylinder, superposed with plural plungers doming to a small diameter successively, elastically in a base cylinder erected in a pit of an elevator shaft. CONSTITUTION:When an elevator cage or balancing weight collides with an oil-immersed buffer for something wrong or other, each of expansion plungers 14, 16, 17 elastically supported in a base cylinder 11 is pressed down against elastic force of a hydraulic fluid 13 and a reset spring 15. At this time, these expansion plungers are shortened in the vertical direction as concentrically superposing the first to third hollow plungers 14, 16, 17 formed in a small diameter each successively. In this connection, when the cage or balancing weight is lifted up after colliding with the buffer, each expansion plungers is reset to the original position by the reset spring 15.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-filled shock absorber for elevators, and more particularly to an oil-filled shock absorber for elevators used in high-speed elevators.

0002

[Prior art] What causes oil-filled buffers for elevators?
For example, if the limit switch does not work due to overcrowding and exceeds the rope slip limit, or if the brake torque is not produced, and the elevator car goes too far past the bottom floor and descends into the hoistway pit, avoid applying shock if possible. This is a safety device that reduces the number of stops. As a conventional oil-filled shock absorber for elevators of this type, there is a technique disclosed in Japanese Patent Publication No. 32233/1983.

FIG. 2 is a schematic diagram of a hoistway in which a conventional oil-filled shock absorber for elevators is installed, and FIG. 3 is a longitudinal sectional view of the conventional oil-filled shock absorber for elevators. In the figure, 1 is the hoistway where the elevator car 2 goes up and down, 1a is the pit of the hoistway 1, and 3
A hoisting machine is installed in a machine room 4 at the upper part of the hoistway 1, and is used to raise and lower the elevator car 2 via a rope 5. 21 is an oil-filled buffer installed vertically in the pit 1a of the hoistway 1, and when the elevator car 2 passes the bottom floor due to some abnormality, it reduces the impact on the elevator car 2 and prevents injuries to the passengers inside. This is to prevent damage to the elevator car 2. 22 is a cylinder in which hydraulic oil 23 is sealed, and 24 is a control rod erected within the cylinder 22, which has a taper that becomes thicker toward the bottom. 25 is a plunger that moves up and down within the cylinder 22;
25a is an orifice hole provided at the bottom of the plunger 25, 26 is a return spring that elastically supports the plunger 25, and 27 is a buffer rubber provided at the top of the plunger 25 and in contact with the bottom of the elevator car 2. .

Next, the operation of the conventional oil-filled shock absorber for elevators constructed as described above will be explained. When the elevator car 2 collides with the buffer rubber 27 of the oil-filled shock absorber 21 installed upright in the pit 1a due to some abnormality, the plunger 25
is pushed down against the elastic force of the return spring 26. Then, the hydraulic oil 23 in the cylinder 22 is pressed against the lower surface of the plunger 25 and is ejected into the plunger 25 from the orifice hole 25a. At this time, the orifice hole 25a has a taper that becomes thicker as the control rod 25 moves downward, so as the plunger moves down, the area through which the hydraulic oil 23 passes through the orifice hole 25a becomes smaller, and the resistance of the hydraulic oil 23 decreases. gradually increases to reduce the descending speed and gradually absorb the impact.

[0005]

By the way, the depth P of the pit 1a of the hoistway 1 depends on the height L of the oil-filled buffer 21. The height L of the oil-filled buffer 21 is 2 of the stroke S.
In addition, the stroke S requires a deceleration of 9.8 m/m when the elevator car 2 collides with the stroke S.
sec2] or less, so S = V2/2g, where g: gravitational acceleration 9.8 [m/sec2] V: the speed at which the elevator car 2 collides with the buffer rubber 27, and the velocity of the elevator car 2 is The length increases in proportion to the square of the collision speed. Therefore, in a high-speed elevator, the depth P of the pit 1a becomes very deep. For this reason, the economic efficiency of construction work is poor, it is difficult to ensure the safety of workers during maintenance and inspection, and work efficiency is reduced during carrying-in and installation work of the oil-filled shock absorber 21 due to its long length. Although it is possible to reduce the length by about half by compressing it, it requires a separate operation to press the return spring 26, and there is a risk of impact due to the elastic force at the time of return. Furthermore, since the return spring 26 is also long, there are problems in that the cost is increased and the ease of assembly is reduced.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an oil-filled shock absorber for an elevator that can reduce the height of the oil-filled shock absorber even for high-speed elevators and does not require a deep pit.

[0007]

[Means for Solving the Problems] The oil-filled shock absorber for an elevator according to the present invention includes a base cylinder that is installed upright in a pit of a hoistway and that has hydraulic oil sealed inside, and a plurality of cylinders that are sequentially formed to have smaller diameters. A telescoping plunger configured by concentrically polymerizing hollow plungers so as to be expandable and retractable in the vertical direction via hydraulic oil, and comprising a telescoping plunger elastically supported within the base cylinder, and a return spring for returning the telescoping plunger to its original position. It is composed of

[0008]

In the present invention, when the elevator car or the counterweight collides due to an abnormality, the telescopic plunger elastically supported within the base cylinder is pushed down against the elastic force of the hydraulic oil and the return spring. At this time, the telescopic plunger is
A plurality of hollow plungers formed in successive smaller diameters are concentrically superimposed and shortened in the vertical direction. Therefore, the total height of the oil-filled shock absorber for elevators can be made smaller than before. Note that, after the collision, if the elevator car or the counterweight is released, the telescopic plunger returns to its original position by the return spring.

[0009]

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a longitudinal sectional view showing an oil-filled shock absorber for an elevator according to an embodiment of the present invention. In the figure, 11 is an anchor bolt, etc. (not shown) attached to the pit 1a of the hoistway 1.
The base cylinder 11a, which is erected, is a partition plate that divides the inside of the base cylinder 11 into an upper chamber 11b and a lower chamber 11c at a substantially middle height, and has a circular hole bored in the center. Reference numeral 12 denotes a control rod that is erected at the center of the bottom of the base cylinder 11 and has a taper that becomes thicker toward the bottom. 13
is hydraulic oil.

Reference numeral 14 denotes a first plunger composed of a hollow upper plunger part 14a and a hollow lower plunger part 14b, and the lower plunger part 14b is connected to the base cylinder 11.
The partition plate 1 is housed in the upper chamber 11b of the partition plate 1 by a return spring 15 disposed on the outer periphery of the lower plunger portion 14b.
It is inserted through a hole drilled in 1a and is elastically supported so as to be movable up and down. 14c is an oil passage bored in the lower part of the upper plunger part 14a, 14d is an orifice hole bored in the lower surface of the lower plunger part 14b, through which the control rod 12 passes,
As the first plunger 14 descends, the opening area formed between it and the control rod 12 gradually becomes smaller. 1
6 is a hollow second plunger 16 which is movable up and down by passing through a hole bored in the upper surface of the first plunger 14;
a is an oil passage. Reference numeral 17 designates a hollow third plunger that is inserted into a hole formed in the upper surface of the second plunger 16 and moves up and down within the second plunger 16 . Reference numeral 18 denotes a cushioning rubber attached to the top of the third plunger 17.

That is, this oil-filled shock absorber for an elevator has a concentric four-layer structure as a whole including the base cylinder 11. Note that the hydraulic oil 13 is also sealed in the first plunger 14 and the second plunger 16.

Next, the operation of the oil-filled shock absorber for elevators of this embodiment constructed as described above will be explained. When the elevator car 2 collides with the buffer rubber 18 at the top of the oil-filled buffer for elevators due to some abnormality, the third plunger 17 first slides down along the inner wall of the second plunger 16, and at the same time the lower surface 2 presses the hydraulic oil 13 in the plunger 16. Then, part of the hydraulic oil 13 passes through the oil passage 16a of the second plunger 16 and is ejected into the cavity 14e in the first plunger.
Transmits the pressing force to the bottom surface of the

In response to this pressing force, the second plunger 16 further presses the hydraulic oil 13 in the first plunger 14, so a portion of the hydraulic oil 13 in the first plunger 14 similarly passes through the oil passage 14c. Space 1 inside the base cylinder 11
1d and presses the first plunger 14. Therefore, the first plunger 14 is pushed down against the elastic force of the return spring 15 and the viscoelastic force of the hydraulic oil 13 in the lower chamber 11c of the base cylinder 11, so that the hydraulic oil 13 in the base cylinder 11 is 1 plunger 14 and the lower plunger part 1 is pressed from the orifice hole 14d.
It squirts into 4b. At this time, the orifice hole 14d is
Since the control rod 12 has a taper that becomes thicker as it goes downward, as the first plunger 14 descends, the area through which the hydraulic oil 13 passes through the orifice hole 14d becomes smaller.
The resistance of the hydraulic oil 13 gradually increases to reduce the descending speed and gradually absorb the impact. In addition, in the above operation, the impact force when the shock absorber 18 collides with the shock absorber 18 is transmitted to the base cylinder 11 via the hydraulic oil 13 in a very short time.

Thereafter, when the cause of the abnormality is removed and the elevator car 2 is separated from the elevator oil-filled shock absorber, the first plunger 14 is pushed up by the elastic force of the return spring 15, and, contrary to the above, the empty space is removed. The hydraulic oil 13 in 11d is in the oil passage 14
Then, the second plunger 16 and the third plunger 17 are successively pushed up and returned to their original positions.

Next, the total height of the oil-filled shock absorber for elevators of this embodiment will be explained. In this embodiment, as shown in FIG. 1, the stroke S1 of the first plunger 14, the stroke S2 of the second plunger 16, and the stroke S2 of the third plunger 1
Although three-stage compression is used as shown in stroke S3 in No. 7, first, let us consider a general case of n-stage compression. According to the law, the stroke of the oil-filled shock absorber must be calculated assuming that the oil-filled shock absorber for the elevator absorbs all the kinetic energy of the elevator car 2, and the total height L of the conventional oil-filled shock absorber for the elevator is The value had to be set by adding this stroke S directly to the basic dimension.

In contrast, in the present invention, the strokes of each plunger can be overlapped by n-stage compression.
If the strokes of each plunger are all equal, the total height L of the oil-filled shock absorber for an elevator can be determined by adding S/n to the basic dimension. Therefore, it is possible to shorten the length by S-S/n compared to the conventional one. Thereby, an effect can be obtained when n≧2 or more. In this embodiment, since n=3, SS/3=2/3S can be shortened.

As described above, the oil-filled shock absorber for an elevator according to the above embodiment has a base cylinder 11 which is installed upright in the pit 1a of the hoistway 1 and has a hydraulic oil 13 sealed therein, and a base cylinder 11 which is formed in successively smaller diameters. The first plunger 14 and the second plunger 1
6 and the third plunger 17 are concentrically superimposed so that the telescopic plunger is elastically supported in the base cylinder 11, and the telescopic plunger is elastically supported in the base cylinder 11, and the telescopic plunger is returned to its original position. It is composed of a return spring 15.

Therefore, according to the above embodiment, when the elevator car 2 collides due to an abnormality, the telescopic plunger elastically supported within the base cylinder 11 is pushed down against the elastic force of the hydraulic oil 13 and the return spring 15. When the first plunger 14 and the second plunger 16 are formed to have smaller diameters,
Since the third plunger 17 is polymerized and shortened, the total height of the elevator oil-filled shock absorber can be made smaller than before. Therefore, the pit 1a of the hoistway 1 can be made shallow,
Not only can construction costs be reduced, but also the danger to workers during maintenance and inspection work inside the pit 1a can be reduced. In addition, it is possible to improve the working efficiency during carrying-in and installation work, and furthermore, by shortening the length of the return spring 15, it is possible to reduce costs and improve ease of handling.

By the way, the telescopic plunger of the above embodiment has a three-stage structure, but when implementing the present invention,
The structure is not limited to this, and may be a two-stage structure or a four-stage structure or more. However, as can be seen from the above formula,
If the number of stages is increased more than necessary, the structure becomes more complicated, but the shortening effect cannot be obtained that much. Further, in the above embodiment, the control rod 12, the orifice hole 14d, and the return spring 15 are provided only between the base cylinder 11 and the first plunger 14, but the present invention is not limited to this. Instead, between the first plunger 14 and the second plunger 16, the second plunger 16 and the third plunger 1
It can also be provided between 7. The oil-filled shock absorber for an elevator in the above embodiment is shown as one that cushions the impact of the elevator car 2, but it can be similarly applied to an oil-filled shock absorber for an elevator for a counterweight.

[0020]

As described above, the oil-filled shock absorber for an elevator of the present invention has a telescopic plunger configured to be able to expand and contract in the vertical direction by superimposing a plurality of plungers formed in successive small diameters. It is elastically supported in a base cylinder that stands upright, and is provided with a return spring that returns it to its original position. Therefore, when the elevator car or counterweight collides due to an abnormality and the telescopic plunger is pushed down, the plurality of plungers formed in successive smaller diameters overlap and shorten, reducing the total height of the oil-filled shock absorber for the elevator. Can be made smaller than before. Therefore, the hoistway pit can be made shallower, reducing construction costs, and
It is possible to reduce the danger to workers during maintenance and inspection work inside the pit. In addition, work efficiency during delivery and installation work can be improved, and furthermore, by shortening the return spring, it is possible to reduce costs and improve ease of handling.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an oil-filled shock absorber for an elevator according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a hoistway in which a conventional oil-filled shock absorber for elevators is installed.

FIG. 3 is a longitudinal sectional view of a conventional oil-filled shock absorber for an elevator.

[Explanation of symbols]

1 Hoistway 1a Pit 11 Base cylinder 13 Hydraulic oil 14 First plunger 15 Return spring 16 Second plunger 17 Third plunger

Claims (1)

[Claims] Claim 1: A base cylinder, which is installed upright in a pit of a hoistway and has hydraulic oil sealed inside, and a plurality of hollow plungers formed in successively smaller diameters are concentrically superimposed, and the hydraulic oil is passed through the base cylinder in the vertical direction. An oil-filled shock absorber for an elevator, characterized in that the oil-filled shock absorber for an elevator is provided with a telescopic plunger configured to be extendable and retractable, and elastically supported within the base cylinder, and a return spring for returning the telescopic plunger to its original position.