Emergency stop devices for elevators and elevators

Abstract

To provide an elevator emergency stop device capable of ensuring a braking force by stably generating adhesion between a damper and a guide rail under a condition that friction heat between the damper and the guide rail is relatively low in initial braking, and an elevator.SOLUTION: The elevator emergency stop device comprises a damper installed in a car of an elevator, and generates a braking force in the car by pressing and sliding the damper to a guide rail for guiding the car in emergency. The damper has first and second members 9a and 9b. The first member 9a constitutes a part including the sliding surface 10 of the damper which slides with respect to the guide rail. The second member 9b constitutes a part not including the sliding surface 10 of the damper. The heat conductivity of the second member 9b is lower than that of the first member 9a.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] The present invention relates to an emergency stop device for an elevator and an elevator.

Background Art

[0002] Generally, an elevator is provided with an emergency stop device in the car as a safety device for stopping the car at a predetermined deceleration when the car descends at a speed higher than the specified speed due to an abnormality or the like.

[0003] In the case of an emergency when the car reaches a speed higher than the predetermined descending speed, this emergency stop device sandwiches a guide rail installed on the wall of the hoistway through which the car passes by pressing a brake provided with at least one pair of trapezoidal friction materials against the guide rail by an elastic body, and uses the wedge effect of the brake to strongly press the friction material provided on the brake against the guide rail, and decelerates and stops the car by the friction between the brake and the guide rail. In addition, an emergency stop device may be installed on the counterweight in the same manner.

[0004] As an example of an emergency stop device for an elevator, for example, there is Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-126681). Patent Document 1 includes a brake having a support member and first and second friction pieces provided on the support member and contacting the guide rail during a braking operation. The first friction piece has a higher hardness at a high temperature due to frictional heat with the guide rail than the second friction piece, and the second friction piece has a higher friction coefficient with respect to the guide rail than the first friction piece, and an emergency stop device for an elevator is described.

[0005] In the emergency stop device 5 of Patent Document 1, since a first friction piece having a higher hardness at a high temperature due to frictional heat with the guide rail than the second friction piece and a second friction piece having a higher friction coefficient with respect to the guide rail 1 than the first friction piece are used in combination, the brake can be more reliably raised to a predetermined position during the braking operation, a predetermined pressing force can be ensured, and a sufficient pressing force can be ensured even at a high temperature due to frictional heat with the guide rail. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-126681 [Overview of the project] [Problems that the invention aims to solve]

[0007] In recent years, brakes in emergency braking systems often use inexpensive, low-hardness materials. When the hardness difference between the brake and the guide rail is small, adhesion between the metals is likely to occur. In such low-hardness materials, it is thought that braking force is obtained through adhesion at the true contact point between the brake and the guide rail, and through shear at the adhered point. In other words, in order to obtain stable deceleration performance in an emergency braking system using a low-hardness brake, it is necessary to ensure stable adhesion between the guide rail and the brake.

[0008] The adhesion between metals is deeply related to the heat generated by the sliding surfaces. Under harsh conditions where the operating speed and load of the emergency brake device are high and sufficient frictional heat is generated, braking force can easily be obtained through adhesion between the braker and the guide rail. On the other hand, under gentle conditions where the initial braking speed is low or the load is small, sufficient frictional heat cannot be generated, leading to adhesion and thus unstable braking force.

[0009] Regarding emergency braking devices for elevators, each country has its own standards, and to meet these standards, it is necessary to obtain a stable braking force even under gentle conditions such as low initial braking speed or light load.

[0010] Japan: Article 129-10 of the Enforcement Order of the Building Standards Act, Ministry of Construction (Ministry of Land, Infrastructure, Transport and Tourism) Notification No. 1423, JIS (Japanese Industrial Standard) A 4305 China:GB7588 TSG T7007 Europe: PD ISO TR 8100-24 Patent Document 1 does not address obtaining braking force through adhesion between the braker and the guide rail under conditions where sufficient frictional heat cannot be obtained.

[0011] In view of the above circumstances, the present invention aims to provide an emergency stop device for elevators and an elevator that can reliably generate adhesion between the brake element and the guide rail and obtain braking force under conditions where the frictional heat between the brake element and the guide rail is relatively low, such as in the initial stages of braking. [Means for solving the problem]

[0012] One aspect of the present invention for achieving the above objective is an emergency stop device for an elevator, which has a braker provided in the elevator car and generates braking force on the elevator car by pressing and sliding the braker against a guide rail that guides the elevator car in an emergency, wherein the braker has a first member and a second member, the first member constitutes a portion of the braker including a sliding surface that slides against the guide rail, and the second member constitutes a portion of the braker that does not include the sliding surface. Furthermore, it has a shape that becomes thinner towards the bottom of the braker. Furthermore, the elevator emergency stop device is characterized in that the thermal conductivity of the second member is lower than that of the first member.

[0013] Another aspect of the present invention provides an elevator emergency stop device comprising a car connected to one end of a main rope, a counterweight connected to the other end of the main rope, and a braker provided on the car, which generates braking force on the car by pressing and sliding the braker against a guide rail that guides the car in an emergency, wherein the braker comprises a first member and a second member, the first member comprising a portion of the braker including a sliding surface that slides against the guide rail, and the second member comprising a portion of the braker not including the sliding surface Furthermore, it has a shape that becomes thinner towards the bottom of the braker. Furthermore, the elevator is characterized in that the thermal conductivity of the second member is lower than that of the first member.

[0014] A more specific configuration of the present invention is described in the claims.

Advantages of the Invention

[0015] According to the present invention, it is possible to provide an elevator emergency stop device and an elevator that can stably generate adhesion between a brake and a guide rail under conditions where the frictional heat between the brake and the guide rail, such as at the initial stage of braking, is relatively low, and reliably obtain a braking force.

[0016] Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0017] [Figure 1] Schematic diagram showing an example of an elevator of the present invention [Figure 2] Diagram showing details of the emergency stop device in FIG. 1 [Figure 3A] Perspective view schematically showing a first example of a brake constituting the emergency stop device in FIG. 1 [Figure 3B] Side view schematically showing a first example of a brake constituting the emergency stop device in FIG. 1 [Figure 4] Side view schematically showing a second example of a brake constituting the emergency stop device in FIG. 1 [Figure 5] Perspective view schematically showing a third example of a brake constituting the emergency stop device in FIG. 1 [Figure 6] Schematic diagram of a friction test device used in the examples and comparative examples

Modes for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the text or drawings. However, the structures, materials, and other specific numerical values shown in the present invention are not limited to the embodiments described here, and can be appropriately combined and improved without changing the gist. In addition, elements not directly related to the present invention are omitted from the illustration.

[0019] Figure 1 is a schematic diagram showing an example of the elevator of the present invention. As shown in Figure 1, the elevator 100 of the present invention comprises a car 1 connected to one end of a main rope 4 and a counterweight 2 connected to the other end of the main rope 4. A sheave 3 and pulley 5 of a hoisting machine (not shown) that drives the main rope 4 are arranged at the top of the main rope 4. The car 1 moves up and down the elevator shaft 6 along the guide rail 8 by the drive of the main rope 4.

[0020] The elevator car 1 is equipped with an emergency stop device 7 that brings the elevator car to an emergency stop if the elevator car's descent speed exceeds a specified speed.

[0021] Figure 2 shows the details of the emergency stop device shown in Figure 1. As shown in Figure 2, the emergency stop device 7 comprises a brake 9 provided opposite the guide rail 8, a lifting rod 12 that pulls up the brake 9 in the direction of the black arrow in the figure, and a support member 11 that provides a driving force to press the brake 9 against the guide rail 8 via a roller 13.

[0022] If the descending speed of the elevator car 1 exceeds the specified speed, the lifting rod 12 pulls up the brake 9 in the opposite direction to the descending direction of the elevator car 1 (in the direction of the black arrow in Figure 2). In addition, the support member 11 applies force to the brake 9 in the direction of the roller 13 (in the direction of the white arrow in Figure 2), causing the sliding surface 10 of the brake 9 to come into contact with the guide rail 8. As a result, the sliding surface 10 of the brake 9 and the guide rail 8 adhere to each other, and braking force is obtained.

[0023] Figure 3A is a schematic perspective view showing a first example of the brake element constituting the emergency stop device in Figure 1, and Figure 3B is a schematic side view showing a first example of the brake element constituting the emergency stop device in Figure 1. As shown in Figures 3A and 3B, the brake element 9 of the elevator emergency stop device 7 of the present invention has a first member 9a and a second member 9b. The first member 9a has a sliding surface 10 that contacts the guide rail 8. The second member 9b is provided to suppress the propagation of heat generated on the sliding surface 10 of the first member 9a (dotted arrow in Figure 3A). With this configuration, the heat generated on the sliding surface 10 is not allowed to escape, and adhesion between the guide rail 8 and the sliding surface 10 can be reliably generated. Note that the direction of heat propagation (dotted arrow) shown in Figure 3A is an example described to make the present invention easier to understand and is not based on actual measurements.

[0024] The material of the first member 9a having the sliding surface 10 is not particularly limited as long as it ensures the strength and reliability required for the brake 9, but it is preferably made of steel. Specifically, rolled steel, tool steel, alloy steel, carbon steel, etc. are preferred.

[0025] The second member 9b is made of a material with a higher thermal conductivity than the first member 9a in order to suppress the propagation of heat from the sliding surface 10 of the first member 9a. For example, it is preferable to use a composite material in which the material constituting the first member 9a, such as steel, is used as the base material, and a low thermal conductivity material such as ceramics is mixed with the base material. The braker 9, including such a first member 9a and second member 9b, can be manufactured using powder metallurgy. That is, the first member 9a and the second member 9b can be manufactured by preparing material powders, heating them, and sintering them.

[0026] There are no particular limitations on low thermal conductivity materials as long as they meet the requirements for thermal insulation. Examples include alumina (Al2O3), zirconia (ZrO2), and titania (TiO2). Two or more of these can be combined.

[0027] The low thermal conductivity material included in the second member 9b preferably accounts for 1-20% by volume, and more preferably 5-20%. If the volume percentage of the low thermal conductivity material is less than 1%, sufficient heat insulation effect cannot be obtained. Also, if the volume percentage of the low thermal conductivity material is more than 20%, cracks are more likely to occur at the interface with the first member 9a.

[0028] The second member 9b is positioned to suppress the propagation of heat generated by the first member 9a. When viewed from the side in Figure 3B, the second member 9b is preferably positioned such that, in the lateral direction of the braker 9 (the X direction in Figure 3A), the distance from the sliding surface 10 to the closest end (dimension A in Figure 3B) is 1 mm or more, and the distance from the sliding surface 10 to the furthest end (dimension B in Figure 3B) is 30 mm or less. More preferably, A: 3 mm or more, B: 10 mm or less. If the distance from the sliding surface 10 is less than 1 mm, wear of the first member 9a may cause the second member 9b to be exposed to the sliding surface 10, potentially leading to a decrease in braking force. If the distance is greater than 30 mm, it becomes difficult to obtain a heat insulating effect.

[0029] Furthermore, since the upper part of the brake element 9 comes into contact with the guide rail 8 and generates heat during the initial stages of braking, it is preferable to provide a second member 9b on the upper part of the brake element 9. Specifically, as shown in Figure 3B, it is desirable that the second member 9b be positioned from the upper part of the brake element 9 to a position up to 1 / 3 of the length of the brake element (the dimension in the Y direction in Figure 3B).

[0030] Figure 4 is a schematic side view showing a second example of the brake element that constitutes the emergency braking device in Figure 1. The lower part of the brake element 9 is significantly damaged by frictional heat in the later stages of braking. Therefore, as shown in Figure 4, it is preferable that the second member 9b has a shape that tapers towards the lower part of the brake element 9 (towards the direction of the white arrow in Figure 4) (the second member 9b becomes thinner).

[0031] Furthermore, in order to suppress cracking during the fabrication (powder metallurgy) of the brake 9, the concentration of the low thermal conductivity material in the second member 9b may be gradient in the lateral direction of the brake 9. That is, the concentration of the low thermal conductivity material may be increased in the lateral direction of the brake 9 (in the direction of the black arrow in Figure 4). By adopting such a configuration, the stress generated between the first member 9a and the second member 9b can be relieved, and cracking during sintering can be prevented.

[0032] In the example described above, the first member 9a and the second member 9b were used as a composite material, but the second member 9b can also be formed by coating the surface of the first member 9a with the composite material. In that case, a heat insulating coating can be used as the second member 9b.

[0033] Figure 5 is a schematic perspective view showing a third example of the brake element constituting the emergency stop device of Figure 1. Figure 5 shows a configuration in which the second member 9b is applied to one surface of the first member 9a. Note that the surface to which the second member 9b is applied is not limited to the surface shown in Figure 5, and may be applied to other surfaces of the first member 9a.

[0034] The aforementioned heat-insulating coating can be, for example, an aqueous emulsion coating containing dissolved alumina particles, zirconia particles, titania particles, etc. A multi-layer coating can also be formed by layering two or more types of heat-insulating coatings. Methods for applying these materials include spray coating, vapor deposition by PVD (Physical Vapor Deposition) or CVD (Chemical Vapor Deposition), sputtering, and ion plating. The thickness of the heat-insulating coating is preferably 1 to 500 μm, and more preferably 1 to 250 μm. If the heat-insulating coating is thinner than 1 μm, it is difficult to ensure heat insulation. Furthermore, if the heat-insulating coating is thicker than 500 μm, the cost increases. [Examples]

[0035] The following describes examples and comparative examples that demonstrate the effects of the present invention.

[0036] [Example 1] A brake was constructed with the configuration shown in Figure 3A and subjected to friction tests. The first component 9a was made of S45C as specified in JIS (Japanese Industrial Standards) G4051. Its composition was C (carbon): 0.42~0.48, Si (silicon): 0.15~0.35, Mn (manganese): 0.60~0.90, Fe (iron): remainder. The second component 9b was made of S45C containing 20% ​​alumina by volume. The second component 9b was positioned at a distance A of 3 mm and a distance B of 7 mm from the sliding surface 10. It was placed in the upper 1 / 3 of the brake. The surface hardness of the first component 9a was 265 Hv. The thermal conductivity of the brake 9, calculated from the constituent materials of the first component 9a and the second component 9b, was 40 W / (m·K).

[0037] A friction test was conducted on the braker 9 of Example 1 described above, and the coefficient of friction was calculated. Figure 6 is a schematic diagram of the friction testing apparatus. As shown in Figure 6, a disc brake type friction testing machine was used for the friction test. The brake element 9 of Example 1 was pressed against a disc 14 made of the same steel material as the guide rail in the direction of the arrow in the figure and slid to calculate the coefficient of friction. The sliding surface pressure was 4 MPa and the pressing speed was 1 m / s. Sensors attached to the testing apparatus measured the frictional force acting in the sliding direction and the normal force acting perpendicular to the contact surface. The ratio of the frictional force to the normal force was taken, and the average value for the first second of the test was used as the coefficient of friction.

[0038] [Example 2] The first component 9a constituting the brake element 9 was made of SCM440 as specified in JIS G3479. Its composition was C: 0.38-0.43, Si: 0.15-0.35, Mn: 0.60-0.90, Cr: 0.90-1.20, Mo: 0.15-0.30, Fe: remainder. The second component 9b was made of a material containing 15% zirconia by volume in SCM440. The surface hardness of the first component 9a was 296 Hv. The thermal conductivity of the brake element 9, calculated from the constituent materials of the first component 9a and the second component 9b, was 39 W / (m·K). A friction test was performed on the brake element 9 of Example 2 in the same manner as in Example 1, and the coefficient of friction was calculated.

[0039] [Example 3] In this example, a braker with the configuration shown in Figure 5 was fabricated and a friction test was conducted. S45C was used for the first component 9a of the braker 9, and water-based paint was used for the second component 9b. The second component 9b was applied to both sides and the back (the side opposite to the sliding surface 10) of the braker 9. The film thickness of the second component 9b was 200 μm. The surface hardness of the first component 9a was 270 Hv. The thermal conductivity of the braker 9, calculated from the constituent materials of the first component 9a and the second component 9b, was 43 W / (m·K). A friction test was conducted on the braker 9 of Example 3 in the same manner as in Example 1, and the coefficient of friction was calculated.

[0040] [Comparative Example 1] In Comparative Example 1, the first component 9a was made solely of S45C. The surface hardness of the first component 9a was 266 Hv, and the thermal conductivity of the damper 9 was 45 W / (m·K).

[0041] Table 1 shows the relative values ​​of the friction coefficients for Examples 1 to 3 and Comparative Example 1.

[0042] [Table 1]

[0043] As shown in Table 1, the brakes of Examples 1 to 3, which were composed of the first member 9a and the second member 9b, all had lower thermal conductivity and a higher coefficient of friction than the brake 9 of Comparative Example 1, which was composed of only the first member 9a. It is presumed that the brakes of Examples 1 to 3 achieved a higher coefficient of friction than the comparative example by having the second member 9b suppress the dissipation of heat generated from the sliding surface of the first member 9a, thereby causing stable adhesion between the steel material and the brake 9.

[0044] As described above, the present invention provides an emergency stop device for elevators and an elevator that can reliably generate adhesion between the braker and the guide rail and obtain braking force under conditions where frictional heat between the braker and the guide rail is relatively low, such as in the initial stages of braking.

[0045] The emergency stop device for elevators according to the present invention and the elevator equipped therewith have excellent reliability, particularly because they stably cause adhesion to the guide rail under a wide range of braking speeds and load conditions.

[0046] The embodiments described above are provided specifically to aid in understanding the present invention, and the present invention is not limited to having all the configurations described. For example, it is possible to replace parts of the configuration of one embodiment with those of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. Furthermore, it is possible to delete, replace, or add parts of the configuration of each embodiment. [Explanation of Symbols]

[0047] 1... elevator car, 2... counterweight, 3... sheave, 4... main cable, 5... pulley, 6... hoistway, 7... emergency stop device, 8... guide rail, 9... brake, 9a... first component, 9b... second component, 10... sliding surface, 11... support component, 12... lifting rod, 13... roller, 100... elevator.

Claims

1. An elevator emergency stop device having a braker installed in the elevator car, which generates braking force on the elevator car by pressing and sliding the braker against a guide rail that guides the elevator car in an emergency, The braker has a first member and a second member, The first member comprises a portion including a sliding surface that slides against the guide rail of the brake, The second member constitutes the portion of the brake that does not include the sliding surface of the brake, and has a shape that becomes thinner towards the bottom of the brake. An elevator emergency stop device characterized in that the thermal conductivity of the second member is lower than that of the first member.

2. The elevator emergency stop device according to claim 1, characterized in that the second member is arranged to suppress the propagation of heat generated from the sliding surface.

3. The elevator emergency stop device according to claim 1, characterized in that the second member is positioned at a distance of 3 mm from the sliding surface and at a distance of 10 mm from the sliding surface when viewed from the side of the braker.

4. The elevator emergency stop device according to claim 1, characterized in that the second member is provided at a position from the top of the braker to one-third of the length of the braker.

5. An elevator emergency stop device according to any one of claims 1 to 4, characterized in that the first member is made of steel, and the second member is a composite material of steel and a material with a lower thermal conductivity than steel.

6. The elevator emergency stop device according to claim 5, characterized in that the second member is made of a composite material of ceramics and steel.

7. The elevator emergency stop device according to claim 5, characterized in that, when the side surface of the braker is viewed, the concentration of the material with low thermal conductivity increases from the end closer to the sliding surface of the braker toward the end further away from the sliding surface.

8. The elevator emergency stop device according to claim 5, characterized in that the content of the material with low thermal conductivity in the second member is 1 to 20% by volume.

9. An emergency stop device for an elevator, comprising a braker provided in the elevator car, which generates braking force on the elevator car by pressing and sliding the braker against a guide rail that guides the elevator car in an emergency, The braker has a first member and a second member, The first member comprises a portion of the brake that includes a sliding surface that slides against the guide rail of the brake, and is made of steel. The second member constitutes the portion of the brake that does not include the sliding surface, and is made of a composite material of steel and a material with a lower thermal conductivity than steel. Furthermore, the second member is characterized in that, when viewed from the side of the brake, the concentration of the material with low thermal conductivity increases from the end closer to the sliding surface of the brake towards the end further away from the sliding surface of the brake.

10. A cage connected to one end of the main rope, A counterweight connected to the other end of the main rope, The elevator includes an emergency stop device which has a braker provided in the elevator car, and in an emergency, presses and slides the braker against a guide rail that guides the elevator car to generate braking force in the elevator car, The braker has a first member and a second member, The first member comprises a portion including a sliding surface that slides against the guide rail of the brake, The second member constitutes the portion of the brake that does not include the sliding surface of the brake, and has a shape that becomes thinner towards the bottom of the brake. An elevator characterized in that the thermal conductivity of the second member is lower than that of the first member.

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