JP2003192250A - Buffer for elevator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a buffer for an elevator capable of achieving a stable load-displacement characteristic and capable of achieving miniaturization at low cost. <P>SOLUTION: This buffer for the elevator is provided in a pit 6 positioned in the lowermost part of an elevator shaft 1 or under a car 2 of the elevator so as to absorb impact energy of the car 2 or a balance weight 4. The buffer 7 for the elevator is a structure having plural flanges 7A and a thin cylindrical part 7B provided between the flanges 7A. When the structure is operated as the buffer 7, bellowslike buckling 7C or 7D in an axisymmetic mode is generated in the thin cylindrical part 7B. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator shock absorber provided in a pit or a car at the bottom of a hoistway of an elevator and absorbing the collision energy of the car or the counterweight.

[0002]

2. Description of the Related Art Generally, a shock absorber for an elevator (hereinafter simply referred to as a shock absorber) is a safety device for an elevator, and can ensure passenger safety when a car or a counterweight enters a pit without stopping at the bottom floor. As the buffer performance, the performance of stopping at an average deceleration of 1 G or less is required. Also,
It is required that the acceleration of 2.5 G or more does not last for 0.04 seconds or more. That is, the shock absorber must be stable at all times and have excellent shock absorbing performance so that a large acceleration does not occur.

As a structure of a conventional shock absorber, depending on the size of the rated operating speed of the elevator, a low speed region (generally 45 to 6) is used.
Generally, a spring-type shock absorber is used for 0 m / min or less), and a hydraulic shock absorber is used for lifting equipment exceeding the low speed region.

The spring type shock absorber is a shock absorber that absorbs collision energy by the elasticity of a coil spring, and the hydraulic shock absorber is a resistance force of oil filled in a cylinder when a piston enters the cylinder at the time of buffering. Is a mechanism that controls the braking force by controlling the throttle to produce a predetermined cushioning performance.

However, the spring type shock absorber has a drawback that the free length becomes large due to the structure of the hydraulic type shock absorber due to its strength. Further, the hydraulic shock absorber is inevitably expensive due to its structure.

In addition, recently, there is an increasing demand for reducing the size of pits, and there is a demand for downsizing of the shock absorber, especially for reducing the free height. Therefore, the inventor uses a conventional spring or hydraulic type by using a shock absorber of a type that buckles like a bellows in the axial direction as proposed in Japanese Patent Application Laid-Open No. 50-61581, although the field of use is different. We thought that we could provide a shock absorber that is smaller and cheaper than the shock absorber.

[0007]

By the way, the shock absorber for elevators is one of the important safety devices, and it is important that the necessary shock absorbing characteristics are always obtained stably. That is, in a shock absorber utilizing buckling, it is necessary that the load-displacement characteristic when a load is applied in the axial direction be stably obtained.
In particular, in order to obtain a somewhat large deformation stroke,
It is necessary that a continuous and regular bellows-like buckling deformation be obtained.

However, in the above-mentioned proposed example, the relationship between the load and the displacement is shown in FIG. 7, which is an explanatory view for explaining the buckling deformation when the axial load is applied to the 2 mm thick cylinder 10 having no flange. As shown in FIG. 8 which is an explanatory diagram described, as the buckling deformation progresses, variations in the buckling deformation shape due to the initial irregularity of the cylinder 10 are accumulated, and the load-displacement characteristics vary. In particular, when trying to take a long deformation stroke, this tendency appears remarkably, and since the elongated cylinder 10 is formed, Euler buckling in which the cylinder 10 bends into a "dogleg" occurs, and the load sharply decreases. There is such a problem. This is caused by a sudden flattening of the cylindrical cross section, which reduces the rigidity in the cross section in one direction.

In the elevator shock absorber, it is important that the stroke of the shock absorber is clear. For example, if the stroke of the shock absorber on the counterweight side becomes larger than the planned value, the car connected via the rope will approach the hoistway ceiling more than expected, and if it becomes worse, there is a possibility of collision and it is dangerous. . Normally, a certain allowance is provided for the stroke dimension of the hoistway, but in recent years there has been an increasing demand for downsizing of the hoistway, and it is desirable that the shock absorber stroke does not exceed the planned value as much as possible. After the continuous buckling deformation occurs, a large load suddenly acts when there is no part that can buckle, but the position of this inflection point is due to the initial imperfections of the cylinder in the proposed structure. Due to the variation of the deformed shape, the variation greatly varies, and it is difficult to clearly determine the stroke planned value. In addition, a large load value is generated in the initial stage, which is not preferable because it gives an excessive acceleration to the car during cushioning.

As described above, there is a problem that it is difficult to use the proposed one as it is for the elevator shock absorber.

An object of the present invention is to provide an elevator shock absorber which can obtain load-displacement characteristics in a stable manner and which can be inexpensive and miniaturized.

[0012]

In order to achieve the above object, according to the present invention, a shock absorber for an elevator, which is provided in a lowermost pit or a car of a hoistway of an elevator and absorbs collision energy of the car or the counterweight. In this shock absorber for elevators, a structure having a plurality of flanges and a thin-walled cylindrical portion provided between the flanges, and when operating as a shock absorber, the thin-walled cylindrical portion is provided with an axisymmetric mode bellows-like seat. The feature is that it is designed to generate buckling.

As described above, since the flanged cylinder can be used as a shock absorber, an inexpensive and small shock absorber can be provided as compared with the conventional spring type and hydraulic type shock absorbers, and the pit of the hoistway can be made shallow. You can also In addition, it is much smaller and lighter than conventional ones, so it can be installed under a car or under a counterweight, which reduces the equipment in the pit and improves maintainability.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A shock absorber for an elevator according to the present invention will be described below with reference to the drawings of the embodiments.

FIG. 1 is an overall configuration diagram of an elevator used in the elevator shock absorber according to the present invention, FIG. 2 is a front view showing the elevator shock absorber according to an embodiment of the present invention, and FIG. 3 is FIG.
4 is a table showing the dimensional relationship of the shock absorber of FIG. 4, FIG. 4 is an explanatory view for explaining the relationship between the load and the displacement when the shock absorber of FIG. 2 is operated, and FIG. Explanatory view of deformed shape when accordion-shaped buckling is generated.
It is a deformation | transformation shape explanatory drawing at the time of generating the bellows-shaped buckling of the axisymmetric mode of a wave.

In FIG. 1, reference numeral 1 denotes a hoistway, in which a car 2 and a counterweight 3 are provided connected by a rope 4 so that the sheave 5 can be hoisted up and down. 6 is a pit formed under the hoistway 1,
A buffer 7 is provided in the pit 6.

FIG. 2 shows a concrete structure of the shock absorber 7. The shock absorber 7 is composed of a plurality of flanges 7A provided at predetermined intervals and a thin-walled cylindrical portion 7B formed between the flanges 7A. Has been done. The overall size L of the shock absorber 7, the inner diameter φd, the thickness t of the thin-walled cylindrical portion 7B, and the flange 7A.
The height h is as shown in FIG.

The shock absorber 7 is made of aluminum and is JIS A1.
It is made of 050 annealed material, and the buckling section is provided with 6 steps, and the wall thickness is gradually changed. This is intended to deform the thin-walled cylindrical portion 7B in order. Also, the load characteristics can be controlled by changing the wall thickness.
Further, h / t at this time has a value of 7.2 to 9.0.

As is clear from FIG. 4 which shows the result of the actual test conducted with the shock absorber of FIG. 2, the shock absorber 7 of the present invention does not generate an initial excessive load and has a continuous and stable buckling. It can be seen that a stable load characteristic is obtained.
Moreover, it can be seen that the average load gradually increases due to the change in wall thickness, and the load characteristics can be controlled. Thereby, it is possible to design the shock absorber 7 having a free shock absorbing performance. In addition, regarding the load-displacement characteristic, it can be seen that the load sharply increases as the deformation progresses. This is the thin cylindrical portion 7
This is because all of B buckled and there was no deformed portion. This is the same state as the turn short circuit in the spring shock absorber, and the point A in FIG. 4 can be defined as the stroke of this shock absorber 7. With this, a clear stroke can be determined, and the car can be stopped within the planned value.

FIG. 5 shows a deformed shape of the thin-walled cylindrical portion 7B when a two-wave axially symmetric bellows-shaped buckling 7C is generated, and FIG. The deformed shape in the case of generating the bending 7D is shown.

The relationship between the height h and the thickness t of the thin-walled cylindrical portion when one-wave or two-wave bellows buckling is generated in the thin-walled cylindrical portion is as follows. When generating buckling 7D, 7.0 <h / t <9.8, when generating bellow-shaped buckling 7C of two-wave axisymmetric mode, 14.0 <h
/ T <22 should be set. In the case of two waves, there is an advantage that the stroke δ1 with respect to the entire length can be made larger than δ2 in the case of one wave. On the other hand, in the case of one wave, the inner diameter φd as shown in FIG.
On the other hand, there is a feature that the bulge amount is small, and for example, there is an advantage that the guide cylinder 8 can be passed therethrough for restraining the shock absorber.

According to the above-mentioned embodiment, since the cylindrical body with flange can be used as a shock absorber, it is possible to provide a cheaper and smaller shock absorber as compared with the conventional spring type and hydraulic type shock absorbers, and the pit of the hoistway. Can be shallow. In addition, since it is much smaller and lighter than the conventional one, it can be installed under a car or under a counterweight, the number of equipment in the pit is reduced, and it is easy to secure the flow line, improving maintainability.

[0023]

According to the present invention, it is possible to provide an inexpensive and small shock absorber as compared with the conventional spring type and hydraulic type shock absorbers, and it is possible to make the pit of the hoistway shallow. Further, since it is much smaller and lighter than the conventional one, it can be mounted under a car or under a counterweight, and the remarkable effect that the equipment in the pit is reduced and the maintainability is improved can be achieved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an elevator using a damper for an elevator which is an object of the present invention.

FIG. 2 is a front view showing an elevator shock absorber according to an embodiment of the present invention.

FIG. 3 is a table showing dimensional relationships of the shock absorber of FIG.

FIG. 4 is an explanatory diagram illustrating a relationship between a load and a displacement when the shock absorber in FIG. 2 is operated.

FIG. 5 is an explanatory diagram of a deformed shape in the case where two-wave axially symmetric bellows-shaped buckling is generated in the thin-walled cylindrical portion.

FIG. 6 is an explanatory diagram of a deformed shape in the case where a bellows-like buckling of one wave in an axisymmetric mode is generated in the thin-walled cylindrical portion.

FIG. 7: Thickness of 2 mm without flange, which has been conventionally proposed
It is explanatory drawing explaining the buckling deformation at the time of giving an axial load to a cylinder.

8 is an explanatory diagram illustrating a relationship between a load and a displacement of the shock absorber shown in FIG.

[Explanation of symbols] 1 hoistway Two baskets 3 baskets 4 rope 5 sheaves 6 pits 7 shock absorber 7A flange 7B Thin-walled cylindrical part 7C 2 wave bellows buckling 7D 1 wave bellows buckling h Thin cylinder height t Thin wall thickness

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masayuki Shigeta             2 days at 832 Horiguchi, Hitachinaka City, Ibaraki Prefecture             Tachimito Engineering Co., Ltd. (72) Inventor Hidehiro Nakamura             1070 Ichimo, Hitachinaka City, Ibaraki Prefecture Stock Association             Hitachi Systems Building Systems Group F-term (reference) 3F304 DA61                 3J066 AA23 BC01 BD07 BG10

Claims (6)

[Claims] 1. An elevator shock absorber provided in a pit or a car bottom of a hoistway of an elevator and absorbing collision energy of the car or the counterweight, wherein the elevator shock absorber has a plurality of flanges. An elevator shock absorber, characterized in that a thin cylindrical portion is provided between the flanges, and a bellows-like buckling is generated in the thin cylindrical portion during operation as a shock absorber. 2. When a one-wave bellows-like buckling is generated in the thin-walled cylindrical portion, the ratio of the thickness t of the thin-walled cylindrical portion to the height h of the thin-walled cylindrical portion is 7.0 <h / t. <9.8, The shock absorber for an elevator according to claim 1. 3. When two-wave bellows-like buckling is generated in the thin-walled cylindrical portion, the ratio of the thickness t of the thin-walled cylindrical portion to the height h of the thin-walled cylindrical portion is set to 14 <h / t <22. The shock absorber for an elevator according to claim 1, wherein 4. The elevator shock absorber according to claim 1, wherein the bellows-like buckling is in an axially symmetric mode. 5. The elevator shock absorber according to claim 1, wherein the wall thickness t is gradually increased from an upper stage of the flange to a lower stage thereof. 6. The shock absorber for an elevator according to claim 1, wherein the bellows-like buckling occurs only outside the thin-walled cylindrical portion.