Shock absorber for elevator

Abstract

To provide a shock absorber for an elevator capable of securing a specified stroke by preventing sinking of a plunger.SOLUTION: A shock absorber (30,31) for an elevator includes a cylinder (40) filled with hydraulic oil (43), a plunger (41) composed of at least one plunger portion and slidably fitted into the cylinder, an orifice (48) through which the hydraulic oil can pass, and a return mechanism (45) that pushes up the pushed-down plunger to a predetermined position, and includes a holding mechanism that holds the plunger at the predetermined position in a portion (A) where the cylinder and the plunger are in contact with each other in a standby state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a buffer device for an elevator. [Background technology]

[0002] In the event that an abnormality occurs in the elevator system and the car or counterweight passes the terminal floor, a shock absorber is provided in the hoistway to reduce the impact force on the car or counterweight.

[0003] As prior art related to elevator buffer devices, the techniques described in Patent Documents 1 and 2 are known.

[0004] In the technology described in Patent Document 1, a plunger is inserted into the cylinder from the upper end of the cylinder that stands upright from the bottom of the elevator shaft. When the plunger is pushed down by the car, hydraulic oil in the cylinder flows into the plunger through an oil injection hole formed at the bottom of the plunger. This generates a braking force due to the orifice effect. When the car separates from the plunger, a spring installed in the cylinder pushes it up to a predetermined position.

[0005] In the technology described in Patent Document 2, first to third plungers are sequentially connected to a base cylinder fixed to a pit in a hoistway. The first plunger has a control rod at its bottom, and the second and third plungers and the base cylinder each have an oil chamber. When each plunger is pushed down by a car or a counterweight, hydraulic oil in each oil chamber flows through an oil passage formed at the bottom of the base cylinder into an oil chamber of a return mechanism cylinder arranged on the outer periphery of the base cylinder. When the control rod of the first plunger is inserted into the oil passage, a strong braking force is generated due to the orifice effect. When the car or counterweight is raised, the piston is pushed down by gas pressure in a compressed gas chamber of the return mechanism cylinder, forcing hydraulic oil in the oil chamber of the return mechanism cylinder through the oil passage and into the base cylinder. As a result, when the pressure in the base cylinder increases, the hydraulic oil pushes each plunger up to its normal position. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 8-108984 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-28698 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-mentioned prior art, when the spring wears down or the gas pressure drops, the plunger sinks under its own weight, making it difficult to obtain the specified stroke.

[0008] Therefore, the present invention provides an elevator buffer device that can prevent the plunger from sinking and ensure a specified stroke. [Means for solving the problem]

[0009] In order to solve the above problems, the elevator buffer device of the present invention comprises a cylinder filled with hydraulic oil, a plunger consisting of at least one plunger portion that is slidably fitted into the cylinder, an orifice through which the hydraulic oil can pass, and a return mechanism that pushes the depressed plunger up to a predetermined position, and also comprises a holding mechanism that holds the plunger in a predetermined position at the part where the cylinder and plunger come into contact in the standby state. [Effects of the Invention]

[0010] According to the present invention, even if the function of the return mechanism is deteriorated, the plunger can be prevented from sinking.

[0011] Problems, configurations, and effects other than those described above will become clear from the following description of the embodiments. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall configuration diagram of an elevator according to an embodiment of the present invention; [Figure 2] 1 is a longitudinal cross-sectional view showing a schematic configuration of a shock absorber according to an embodiment. [Figure 3] 3 is a longitudinal cross-sectional view showing the configuration of a holding mechanism for a cylinder 40 and a plunger 41. FIG. [Figure 4] 3 is a horizontal cross-sectional view showing the configuration of a holding mechanism for a cylinder 40 and a plunger 41. FIG. [Figure 5] 4 is a partial development view of the outer surface of the plunger 41, showing a first configuration example of the recess 41b (FIG. 3). FIG. [Figure 6] 10 is a partial development view of the outer surface of plunger 41, showing a second configuration example of recess 41b (FIG. 3). FIG. [Figure 7] 10 is a partial development view of the outer surface of plunger 41, showing a third configuration example of recess 41b (FIG. 3). FIG. [Figure 8] 10 is a partial development view of the outer surface of the plunger 41, showing a fourth configuration example of the recess 41b (FIG. 3). FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same components or components having similar functions.

[0014] FIG. 1 is a diagram showing the overall configuration of an elevator according to one embodiment of the present invention.

[0015] As shown in Fig. 1, a sheave 9 and a deflector sheave 10 are provided in a machine room 101 located above a hoistway 100 in a building. A main rope 21 is wound around the sheave 9 and the deflector sheave 10. A car 20 and a counterweight 22 are connected to one end and the other end of the main rope 21, respectively. The car 20 and the counterweight 22 are suspended within the hoistway 100 by the main rope 21.

[0016] A shock absorber 30 for the car and a shock absorber 31 for the counterweight are provided at the bottom of the elevator shaft 100, i.e., at the pit. The shock absorber 30 for the car is provided at the terminal floor (the lowest floor F L The counterweight shock absorber 31 receives the car 20 descending beyond the terminal floor (the lowest floor F L ) and receives the counterweight 22 descending.

[0017] When the sheave 9 is driven to rotate by an electric motor (not shown) supplied with power from a power converter (not shown) provided in the elevator control device 1, the main rope 21 is driven. As a result, the car 20 and the counterweight 22 are moved in the hoistway 100 (the lowest floor F L and the top floor F H The car 20 ascends and descends in opposite directions between the destination floors (between the destination floor and the landing). In this case, the car 20 moves within the elevator shaft 100 between a plurality of floors. When the car 20 arrives at the destination floor and stops, a car door 24 provided on the car 20 and a landing door 23 provided on the landing are mechanically engaged. As a result, the car door 24 and the landing door 23 are both driven to open and close by a door drive device (not shown) provided on the car 20.

[0018] FIG. 2 is a longitudinal cross-sectional view showing a schematic configuration of the shock absorber according to this embodiment.

[0019] FIG. 2 shows the configuration of the car shock absorber 30 (FIG. 1), but the counterweight shock absorber 31 (FIG. 1) also has a similar configuration.

[0020] In FIG. 2, the car shock absorber 30 is in a standby state (non-operating state).

[0021] The car shock absorber 30 includes a hollow cylindrical cylinder 40 and a hollow cylindrical plunger 41 slidably fitted into the cylinder 40 .

[0022] The cylinder 40 has a base portion 42 that closes an opening at one end of the cylinder 40. By fixing the base portion 42 to the bottom of the elevator shaft 100, the elevator car shock absorber 30 is installed upright at the bottom of the elevator shaft 100.

[0023] The cylinder 40 is filled with hydraulic oil 43. The cylinder 40 has an adjustment rod 44 that is located inside the cylinder 40 and adjusts the hydraulic pressure. The adjustment rod 44 is fixed to the base portion 42 at one end in the longitudinal direction.

[0024] The cylinder 40, plunger 41, and adjustment rod 44 are arranged so that the central axes of the cylinder 40, plunger 41, and adjustment rod 44 in the longitudinal direction are aligned with each other.

[0025] The cylinder 40 also has a coil-shaped compression spring 45 that is located inside the cylinder 40 and through which the adjustment rod 44 passes. When the car shock absorber 30 is returned from the operating state to the standby state, the compression spring 45 pushes up the plunger 41 and returns it to the standby position. In other words, the compression spring 45 functions as a return mechanism for the plunger 41.

[0026] The plunger 41 is inserted into the cylinder 40 through an opening at one end of the cylinder 40. The plunger 41 has a disk-shaped receiving plate portion 46 that closes the opening at one end of the plunger 41 that is located outside the cylinder 40. The plunger 41 is located at the lowest floor F L The receiving plate portion 46 receives the elevator car 20 (FIG. 1) that descends without stopping.

[0027] The plunger 41 has a disk-shaped bottom plate portion 47 that closes the opening at the other end of the plunger 41 that is located inside the cylinder 40. The bottom plate portion 47 has an orifice 48 that constitutes a small oil passage hole that passes through the center of the bottom plate portion 47. The orifice 48 serves as a passage for hydraulic oil 43 between the cylinder 40 and the plunger 41. The adjustment rod 44 passes through the orifice 48. The adjustment rod 44 is a rod-shaped body that controls the braking force of the car shock absorber 30, as will be described later.

[0028] An abnormality occurs in the elevator device, and the car 20 (Fig. 1) reaches the lowest floor F. L If the car 20 is unable to stop at the stop position (FIG. 1) and descends, the shock absorber for cars 30 receives the car 20 at the receiving plate portion 46. When the plunger 41 is pressed down by the car 20, the hydraulic oil 43 in the cylinder 40 flows into the plunger 41 through the orifice 48. A braking force is generated by the fluid resistance caused by the hydraulic oil passing through the orifice 48. This reduces the impact when the car 20 collides with the shock absorber for cars 30.

[0029] The hydraulic oil 43 passes through the gap between the adjusting rod 44 and the inner wall of the bottom plate portion 47 in the orifice 48, so that the braking force is increased.

[0030] Although not shown, the horizontal cross sections of the orifice 48 and the adjusting rod 44 are circular, and the diameter of the circular cross section of the adjusting rod 44 gradually increases toward the base portion 42. Therefore, the gap through which the hydraulic oil 43 passes gradually narrows as the plunger 41 descends. Therefore, the braking force of the car shock absorber 30 gradually increases as the plunger 41 descends. In this way, the adjusting rod 44 controls the braking force of the car shock absorber 30 by changing the flow path area of ​​the hydraulic oil 43 in the orifice 48.

[0031] When restoring the elevator system, if the car 20 moves away from the car shock absorber 30, the plunger 41 is pushed up to a predetermined position by the elastic force of the compression spring 45 in contact with the bottom plate portion 47. Furthermore, when the car shock absorber 30 is in a standby state, the compression spring 45 supports the plunger 41 and holds it in a predetermined position. When the plunger 41 is in the predetermined position, the stroke of the car shock absorber 30 becomes a specified value.

[0032] In the passenger car shock absorber 30, the cylinder 40 and plunger 41 further include a holding mechanism at part A in Fig. 2 to hold the plunger 41 at a predetermined position and maintain the stroke at a specified value. The holding mechanism is provided on an inner wall of the cylinder 40 at an upper part of the cylinder 40 and an outer wall of the plunger 41 at a lower part of the plunger 41, which face each other when the stroke is at the specified value.

[0033] FIG. 3 is a vertical cross-sectional view showing the configuration of the holding mechanism portion (portion A in FIG. 2) of the cylinder 40 and the plunger 41. As shown in FIG.

[0034] In the holding mechanism, the cylinder 40 has a recess 40b formed by groove machining on the inner wall of the cylinder 40. A member 50 made of a friction material (hereinafter referred to as a "high-friction material") that increases frictional force is embedded in the recess 40b. The exposed surface of the member 50 forms part of the cylindrical inner surface 40a of the cylinder 40 and is in slidable contact with the outer surface of the plunger 41.

[0035] The coefficient of friction between the high-friction material and the constituent material of the plunger 41 (for example, steel) is greater than the coefficient of friction between the constituent material of the cylinder 40 (for example, steel) and the constituent material of the plunger 41. Therefore, when the car shock absorber 30 is in a standby state, the holding mechanism in this embodiment supports the plunger 41 by the friction force acting between the member 50 and the plunger 41. This reduces the portion of the plunger 41's own weight that is borne by the compression spring 45. This prevents the plunger 41 from sinking due to the compression spring 45 becoming worn, and ensures the stroke of the car shock absorber 30.

[0036] The high-friction material may be, for example, a resin material such as rubber. It is preferable to use a material that is softer than the material of the plunger 41 in order to improve the frictional force and prevent damage to the sliding surface (outer surface) of the plunger 41.

[0037] In this embodiment, as shown in Fig. 3, the holding mechanism further includes a recess 41b formed by groove machining on the outer surface 41a of the plunger 41. This improves the frictional force between the member 50 and the plunger 41. This reliably prevents the plunger 41 from sinking, ensuring the stroke of the car shock absorber 30. If the member 50 is softer than the material of the plunger 41, this, combined with the recess 41b, improves the frictional force between the member 50 and the plunger 41.

[0038] FIG. 4 is a horizontal cross-sectional view showing the configuration of the holding mechanism portion (portion A in FIG. 2) of the cylinder 40 and the plunger 41. As shown in FIG.

[0039] 4, the member 50 in the cylinder 40 is embedded in an annular shape along the inner edge of the cylinder 40. Therefore, the recess 40b (FIG. 3) in which the member 50 is embedded is also annular.

[0040] The recess 41b in the plunger 41 is provided uniformly along the outer edge of the plunger 41 and faces the annular member 50 over the entire circumference of the member 50. This improves the frictional force between the member 50 and the cylinder 40.

[0041] Next, configuration examples of recess 41b in plunger 41 will be described with reference to Figures 5 to 8. Each figure is a development showing a part of the outer surface (curved surface) of plunger 41 in the holding mechanism. In each figure, the black lines indicate recess 41b provided in outer surface 41a.

[0042] FIG. 5 is a partial development of the outer surface of plunger 41, showing a first configuration example of recess 41b (FIG. 3).

[0043] In the first configuration example, the recess 41b is made up of a plurality of horizontally striped grooves. When viewed in a horizontal cross section (FIG. 4) of the stroke holding portion A, each groove is annular. This makes it relatively easy to form the recess 41b.

[0044] FIG. 6 is a partial development of the outer surface of plunger 41, showing a second configuration example of recess 41b (FIG. 3).

[0045] In the second configuration example, the recess 41b is made up of a plurality of grooves in a cross stripe pattern. According to this configuration example, the total groove length per unit area can be increased, and the friction force between the member 50 and the plunger 41 can be improved.

[0046] The horizontally striped grooves are annular when viewed in a horizontal cross section (FIG. 4) of the stroke retaining portion A. The vertically striped grooves are linear segments extending along the longitudinal direction of the plunger 41. This makes it relatively easy to form the recesses 41b.

[0047] FIG. 7 is a partial development of the outer surface of plunger 41, showing a third configuration example of recess 41b (FIG. 3).

[0048] In the third configuration example, the recess 41b is made up of a plurality of wavy grooves (triangular wave grooves in FIG. 7). According to this configuration example, the total groove length per unit area can be increased, thereby improving the frictional force between the member 50 and the plunger 41.

[0049] FIG. 8 is a partial development of the outer surface of plunger 41, showing a fourth configuration example of recess 41b (FIG. 3).

[0050] In the fourth configuration example, the recess 41b is composed of a number of bowl-shaped or hemispherical depressions that are uniformly distributed along the outer edge of the plunger 41 and are provided facing the annular member 50 over the entire circumference of the member 50.

[0051] The multiple recesses are formed, for example, by shot blasting.

[0052] According to this configuration example, the outer surface of the plunger 41 facing the member 50 is a uniformly rough surface, so that the friction force between the member 50 and the plunger 41 can be improved.

[0053] As described above, in the car shock absorber 30 and the counterweight shock absorber 31 of this embodiment, the member 50 made of a friction material is provided on the inner surface of the cylinder 40 as a holding mechanism that holds the plunger 41 at a predetermined position where a predetermined stroke is obtained at the portion (A) where the cylinder 40 and the plunger 41 contact in the standby state. This prevents the plunger 41 from sinking from the predetermined position even if the function of the return mechanism made of the compression spring 45 deteriorates due to sagging of the compression spring 45, so that the predetermined stroke can be secured.

[0054] Furthermore, by providing recess 41b on the outer surface of plunger 41, the frictional force between member 50 and plunger 41 is improved, so that plunger 41 can be reliably prevented from sinking.

[0055] Unlike the above-described embodiment, the member 50 may be provided on the outer surface of the plunger 41, and a recess similar to the recess 41b may be provided on the inner surface of the cylinder 40.

[0056] In the above embodiment, the plunger 41 has only one stage of plunger portions, but the plunger may have multiple stages of plunger portions. In this case, a holding mechanism may be provided between the plunger portions.

[0057] The return mechanism may also use compressed gas. In this case, the holding mechanism of this embodiment can prevent the plunger 41 from sinking even if the function of the return mechanism is reduced due to a drop in gas pressure.

[0058] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to add, delete, or replace part of the configuration of the embodiments with other configurations.

[0059] For example, the compression spring constituting the return mechanism is not limited to being provided inside the cylinder, but may be provided inside the plunger, inside the cylinder, or outside the cylinder.

[0060] The elevator system may also be a so-called machine room-less elevator in which the hoisting machine and the control device are provided inside the elevator shaft. [Explanation of symbols]

[0061] 9 Sheave 10. Reverse Wheel 20 Car 21 Main Rope 22 Counterweight 23 Landing door 24 Cage door 30. Shock absorber for passenger cars 31 Buffer device for counterweight 40 cylinders 41 Plunger 42 Base 43 Hydraulic oil 44 Adjustment rod 45 compression spring 46 Receiving plate part 47 Bottom plate part 48 Orifice 50 components 100 Elevator 101 Machine room

Claims

1. a cylinder filled with hydraulic fluid; a plunger having at least one plunger portion slidably fitted into the cylinder; an orifice through which the hydraulic oil can pass; a return mechanism that pushes the depressed plunger up to a predetermined position; In an elevator buffer device comprising:

10. An elevator buffer device comprising: a holding mechanism for holding the plunger at the predetermined position at a portion where the cylinder and the plunger contact each other in a standby state.

2. The elevator buffer device according to claim 1, The holding mechanism includes: An elevator buffer device comprising a member made of a friction material provided on one of the cylinder and the plunger.

3. The elevator buffer device according to claim 2, An elevator buffer device, characterized in that the coefficient of friction between the member and the other component of the cylinder and the plunger is greater than the coefficient of friction between the component of the cylinder and the component of the plunger.

4. The elevator buffer device according to claim 2, 10. An elevator buffer device, comprising: a member that is more flexible than the other of the cylinder and the plunger;

5. The elevator buffer device according to claim 2, 10. An elevator buffer device, wherein the friction material is a resin material.

6. The elevator buffer device according to claim 2, The elevator buffer device is characterized in that the member is embedded in a recess provided in one of the cylinder and the plunger.

7. The elevator buffer device according to claim 2, The elevator buffer device according to claim 1, wherein the holding mechanism includes a recess provided in the other of the cylinder and the plunger.

8. The elevator buffer device according to claim 2, The elevator buffer device according to claim 1, wherein the retaining mechanism includes a roughened surface on the other of the cylinder and the plunger.

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