Elevator equipment
The emergency stop device in elevators improves reliability by using grooves and flat surfaces to manage stress distribution, maintaining consistent braking performance despite thermal deformation and wear.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- HITACHI LTD
- Filing Date
- 2022-11-25
- Publication Date
- 2026-06-24
AI Technical Summary
Existing emergency stop devices in elevators face reliability issues due to stress concentration at the sliding portion adjacent to the taper during the second braking test, resulting from thermal deformation and wear, which affects the braking performance.
The emergency stop device incorporates a brake with a plurality of groove portions and flat surface portions that are parallel to the guide rail, along with tapered surfaces at the ends, to distribute stress and maintain consistent braking performance across multiple tests.
This design enhances the reliability of the emergency stop device by suppressing stress concentration and ensuring equivalent braking characteristics in successive tests, even under thermal deformation and wear.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to an elevator system equipped with an emergency stop device. [Background technology]
[0002] Elevator systems are generally equipped with an emergency stop device that mechanically brings the elevator car to a complete stop if it falls into a predetermined overspeed condition.
[0003] In braking tests of elevator systems using emergency stop devices, it is sometimes stipulated that the emergency stop device be tested two or more times consecutively using the same braker.
[0004] In the first test, the brake element wears down while undergoing thermal deformation due to frictional heat. Depending on the state of thermal deformation and wear at this time, the contact between the sliding surface of the brake element and the guide rail may become insufficient in the second test, and the same braking performance as in the first test may not be obtained.
[0005] As prior art for a brake that can withstand two tests, the technology described in Patent Document 1 is known.
[0006] This conventional brake has a sliding surface facing the guide rail and an inclined surface that tapers from the lower end to the upper end. The sliding surface is flat in the center and has a taper at the upper and lower ends that slope away from the guide rail. As a result, the central part makes sufficient contact with the guide rail during the second test. [Prior art documents] [Patent Documents]
[0007] [Patent Document 1] Japanese Patent Publication No. 2006-131384 [Overview of the project] [Problems that the invention aims to solve]
[0008] In the above prior art, if there are steps due to joints or fluctuations on the surface of the guide rail, stress concentration may occur in the sliding portion adjacent to the taper during the emergency stop operation, and the reliability of the operation of the emergency stop device may be reduced.
[0009] Therefore, the present invention provides an elevator device provided with an emergency stop device that can improve reliability while the brake has a taper.
Means for Solving the Problems
[0010] In order to solve the above problems, an elevator device according to the present invention includes a car, an emergency stop device provided in the car, and a guide rail for guiding the car. The emergency stop device includes a pair of brakes having a braking surface facing the guide rail. The brake includes a plurality of groove portions extending parallel to the side surface of the guide rail and perpendicular to the longitudinal direction of the guide rail on the braking surface side, a tapered surface located at each of the upper end portion and the lower end portion, and a flat surface portion adjacent to the groove portion and continuous with the tapered surface at least at the lower end portion among the upper end portion and the lower end portion. The bottom of the groove is flat. .
Effect of the Invention
[0011] According to the present invention, the reliability of the emergency stop device in which the brake has a taper is improved.
[0012] In addition, problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.
Brief Description of the Drawings
[0013] [Figure 1] It is a configuration diagram showing an elevator device which is Example 1. [Figure 2] It is a front view showing the configuration of the emergency stop device in FIG. 1. [Figure 3] It is a front view showing the configuration of the brake of the emergency stop device (FIG. 2) in Example 1. [Figure 4]This is a front view of the braker and a portion of the guide rail in Example 1. [Figure 5] This is a front view of the brake and a portion of the guide rail in the comparative example. [Figure 6] This is a front view showing the configuration of the brake in the emergency stop device of the elevator system, which is Example 2. [Modes for carrying out the invention]
[0014] Embodiments of the present invention will be described below with reference to the drawings, using Examples 1 and 2. In each figure, elements with the same reference number represent the same or similar functional elements. [Examples]
[0015] Figure 1 is a diagram showing an elevator device according to Embodiment 1 of the present invention.
[0016] As shown in Figure 1, within the elevator shaft 13 installed in the building, the elevator car 2 and the counterweight 3 are connected by a main rope 4. The main rope 4 is wrapped around a traction sheave 5 and a deflector wheel 6, which are part of a hoisting machine installed in a machine room formed at the top of the elevator shaft 13. Therefore, the elevator car 2 and the counterweight 3 are suspended within the elevator shaft 13 by the main rope 4. The main rope 4 is driven by the traction sheave 5. When the main rope 4 is driven, the elevator car 2 moves up and down within the elevator shaft 13 along the guide rail 7. The machine room also houses a control device (not shown) for controlling the hoisting machine and a governor 10, among other things.
[0017] The elevator car 2 has multiple rail guide devices (not shown), which are slidably engaged with the guide rail 7. As a result, the elevator car 2 moves up and down within the elevator shaft 13 along the guide rail 7. In other words, the guide rail 7 guides the elevator car 2 in the up and down direction. Here, "up and down direction" means the direction in which the elevator car 2 and the counterweight 3 move up and down.
[0018] The counterweight 3 has multiple rail guide devices (not shown). These rail guide devices slidably engage with guide rails (not shown) for the counterweight, which are fixed to the wall surface of the elevator shaft 13. As a result, the counterweight 3 is guided in the vertical direction by the guide rails for the counterweight and moves up and down within the elevator shaft 13.
[0019] The elevator car 2 and counterweight 3 are suspended within the hoistway 13 by the main rope 4. The main rope 4 is wound around the outer groove of the traction sheave 5. When the traction sheave 5 is rotationally driven by a drive device (e.g., an electric motor; not shown) of the hoisting machine installed in the machine room, the main rope 4 is frictionally driven by the frictional force acting between the main rope 4 and the outer groove of the traction sheave 5. As a result, the elevator car 2 and counterweight 3 move up and down within the hoistway 13.
[0020] When the elevator car 2's ascent speed exceeds the rated speed and reaches a first overspeed (for example, 1.3 times the rated speed), the governor 10 shuts off the power supply to the drive unit that drives the traction sheave 5 and the power supply to the control unit that controls this drive unit. Furthermore, when the elevator car 2's descent speed reaches a second overspeed (for example, 1.4 times the rated speed), the governor 10 activates the emergency stop device 8. This causes the elevator car 2 to come to a mechanical emergency stop.
[0021] The emergency stop device 8 is installed on the elevator car 2 and, in an emergency, grips the guide rail 7 with a braker to stop the elevator car 2 from moving up or down. The operating lever 9 is pivotally mounted on the elevator car 2 and drives the emergency stop device 8. This operating lever 9 is connected to the governor rope 21.
[0022] An endless governor rope 21 is wound around the pulley 22 of the governor 10 and a lower pulley 33 installed at the bottom of the elevator shaft 13. The lower pulley 33 faces the pulley 22 in the up and down direction and is equipped with a tension weight 34 to apply tension to the governor rope 21. The governor rope 21 is taut throughout the entire up and down stroke of the elevator shaft 13 by the tension applied by the tension weight 34.
[0023] The elevator car 2 is equipped with an emergency stop device 8 that grips the guide rail 7 with a brake in an emergency, and an operating lever 9 that drives the emergency stop device 8 and is pivotally supported on the elevator car 2 side. A governor rope 21 is connected to the operating lever 9. When the emergency stop device 8 is activated, the governor 10 grips the governor rope 21. As a result, the operating lever 9 is activated, and when the brake of the emergency stop device 8 grips the guide rail 7, the elevator car 2 comes to a sudden stop.
[0024] The elevator car 2 and the counterweight 3 are connected at their respective lower ends by a compensating rope 11. The compensating rope 11 is wrapped around a compensating pulley 12 in the lower part of the elevator shaft 13. The compensating pulley 12 is supported so as to be able to move vertically by a compensating rail (not shown) erected at the bottom of the elevator shaft 13. This compensating rope 11 compensates for the load imbalance caused by the difference in length of the main rope 4 on the elevator car 2 side and the counterweight 3 side.
[0025] Figure 2 is a front view showing the configuration of the emergency stop device 8 in Figure 1. In Figure 2, the emergency stop device 8 is in a non-operational state. That is, the elevator system is in its normal operating state or in the state before the start of the braking test.
[0026] As shown in Figure 2, in the emergency stop device 8, a pair of wedge-shaped brakes 81 are positioned on either side of the guide rail 7 (dashed line in Figure 2). When the emergency stop device 8 is not in operation, the guide rail 7 and the brakes 81 are positioned with a small gap between them so that they do not come into contact with each other. When the lifting mechanism (not shown) is operated by the operating lever 9 (Figure 1), the brakes 81 move upward, guided by the guide 82 and guide plate 85. At this time, the brakes 81 move smoothly upward due to the roller 83 located between the brakes 81 and the guide 82.
[0027] As the pair of brakes 81 move upward, they engage with the guide rail 7 due to the wedge effect between the guide 82 and the roller 83, and are pressed by the elastic force of the U-shaped leaf spring 84, which is an elastic body, via the guide 82 and the roller 83. As a result, the guide rail 7 is clamped between the pair of brakes 81, and the frictional force acting between the guide rail 7 and the brakes 81 causes the elevator car 2 (Figure 1) to come to a sudden stop.
[0028] The guide plate 85 is provided on each of the pair of guide elements 82. The guide plate 85 is fixed to the guide element 82, for example, by bolt fastening. Note that in Figure 2, only the guide plate 85 provided on the left-hand guide element 82 is shown.
[0029] The guide plate 85 covers the space where the roller 83 is located between the brake element 81 and the guide element 82, as well as a portion of the plane of the brake element 81. The end of the guide plate 85 on the brake element 81 side has a bent portion that is bent toward the plane of the brake element 81. The bent portion of the guide plate 85 slidably engages with a guide groove 90 provided on the plane of the brake element 81. This guide plate 85 guides the brake element 81 and restricts the movement of the roller 83 to the space between the brake element 81 and the guide element 82. The brake element 81, guide element 82, roller 83, U-shaped leaf spring 84, and guide plate 85 are housed in the housing 80.
[0030] Figure 3 is a front view showing the configuration of the braker of the emergency stop device (Figure 2) in Example 1.
[0031] Note that Figure 3 shows only one of the pair of brakes. A side view (view in the direction of arrow A) is also included.
[0032] The brake 81 has a plurality of grooves (g1 to g6) and a plurality of braking surfaces (a1 to a5) on its side surface facing the guide rail 7 for the elevator car, extending in a direction parallel to the side surface of the guide rail 7 and perpendicular to the longitudinal direction of the guide rail 7. Each braking surface is located between two adjacent grooves. Therefore, the grooves and braking surfaces are arranged alternately along the longitudinal direction of the guide rail 7. The braking surfaces (a1 to a5) come into contact with the side surface of the guide rail 7 when the emergency stop device 8 is activated.
[0033] Since each braking surface is located between two adjacent grooves, the portion of the braker 81 having a braking surface constitutes a projection (81a1 to 81a5) located between the two grooves. The multiple projections (81a1 to 81a5) extend in the direction in which the grooves and braking surfaces extend. Furthermore, the grooves and projections are arranged alternately along the longitudinal direction of the guide rail 7.
[0034] In this embodiment 1, the bottom of the grooves (g1 to g6) is flat. If the direction perpendicular to the braking surface is defined as the depth direction of the grooves and the height direction of the projections (the same applies hereafter), then the depth d of each groove is equal, and the height h of each projection from the bottom of the groove is equal. In this embodiment 1, the depth d of each groove and the height h of each projection are equal. The depth of the grooves and the height of the projections are set considering the thermal stress and bending stress in the grooves and projections.
[0035] The brake 81 of this embodiment 1 is preferably applied to low-speed elevators (e.g., rated speed ≤ 45 m / min) or medium-speed elevators (e.g., rated speed 60 to 105 m / min). In this embodiment 1, the bottom of the groove is simply made flat to take into consideration the stress in the brake of a low-to-medium-speed elevator.
[0036] When the emergency stop device is activated and the brake 81 slides against the guide rail 7, metal powder generated from wear on the brake 81 is discharged to the outside of the brake 81 through multiple grooves (g1 to g6). This prevents abnormalities in frictional force between the brake 81 and the guide rail 7.
[0037] Multiple braking surfaces (a1 to a5) are located within a virtual plane F parallel to the side surface of the guide rail 7, to which each braking surface contacts when the emergency stop device is activated. In the brake 81, the side surface opposite to the side surface facing the guide rail 7 is an inclined surface. If the direction perpendicular to the braking surface is defined as the height direction of the inclined surface, the height of the inclined surface from the braking surface increases from the upper end to the lower end of the brake 81. As shown in Figure 2, the inclined surface faces the inclined surface of the guide 82 via the roller 83.
[0038] If the longitudinal direction of the guide rail is defined as the width direction of the projections (81a1~81a5), braking surfaces (a1~a5), and grooves (g1~g6), then in this embodiment 1, the width of each projection, i.e., the width W of each braking surface, is defined as the width of each projection. a They are equal, and the width W of each groove is equal. b They are equal. The width of the projection W a The height of the protrusion is uniform, and the width of the groove W b The density is uniform in the depth direction of the groove.
[0039] Width of the protrusion W a The width W of the groove is set considering factors such as the total area of the braking surface that can obtain the desired braking force. b This is set taking into consideration factors such as the discharge of metal powder.
[0040] The braking element 81 applies the above-described conventional technology. That is, the braking element 81 has tapered surfaces 81b and 81c that are inclined so as to move away from the guide rail 7 toward the upper end and the lower end, respectively, on the side surfaces facing the guide rail 7 at the upper end portion and the lower end portion. In this way, since the braking element 81 has an upper end portion having the tapered surface 81b and a lower end portion having the tapered surface 81c, the warpage of the braking surface after the thermal deformation in the first braking test is recovered is compensated. Thereby, in the second braking test, braking characteristics equivalent to those in the first time can be obtained.
[0041] The braking element 81 in the present embodiment has a flat surface portion a that is continuous with the tapered surface 81b at the upper end portion on the side surface facing the guide rail 7 U and a flat surface portion a that is continuous with the lower end portion L In the first embodiment, the flat surface portion a U ,a L extends in the direction in which the groove portions (g1 to g6) and the braking surfaces (a1 to a5) extend, as shown in the arrow A view.
[0042] The height of the flat surface portion a U ,a L from the bottom of the groove portion is equal to the depth d of the groove portion. In the first embodiment, since the depth d of the groove portion is equal to the height h of the protrusion, the height of the flat surface portion a U ,a L from the bottom of the groove portion is equal to the height h of the protrusion and the braking surface.
[0043] Thereby, the flat surface portion a U ,a L is located in a virtual plane F parallel to the side surface of the guide rail 7 together with the plurality of braking surfaces (a1 to a5). Therefore, when the emergency stop device is activated, the flat surface portion a U ,a L contacts the side surface of the guide rail 7 together with the plurality of braking surfaces (a1 to a5). Thereby, even if the braking element 81 has upper and lower end portions having tapered surfaces, when the descending speed of the car 2 becomes excessive and the emergency stop device is activated, stress concentration at the protrusion 81a5 having the braking surface a5 adjacent to the lower end portion having the tapered surface 81c is suppressed.
[0044] Furthermore, when the emergency stop device is activated, flat section a U ,a L A frictional force is generated between the braking surface (a1~a5) and the flat part a. U ,a L This may be used to obtain the desired braking force.
[0045] Figure 4 is a front view of the braker 81 and a part of the guide rail 7 in this embodiment 1.
[0046] Figure 4 shows an example of the contact state between the braker 81 and the guide rail 7 when the emergency stop device is activated.
[0047] As shown in Figure 4, if there is a step on the side surface of the guide rail 7, when the emergency stop device is activated, the projections (81a1 to 81a5) of the braker 81 may come into contact with the step. The braker 81 of this embodiment 1 has a flat portion a at the lower end portion 81L which has a tapered surface 81c L However, from the moment the emergency stop device starts operating, it is pressed against the guide rail 7 along with the multiple braking surfaces (a1 to a5) and comes into contact with the side surface of the guide rail 7. As a result, the tapered surface 81c of the lower end 81L comes into contact with the stepped portion before the projection 81a5, which is located at the lowest of the multiple projections and has a braking surface a5 adjacent to the lower end having a tapered surface 81c, comes into contact with the stepped portion. This suppresses stress concentration at the projection 81a5.
[0048] The steps on the side of the guide rail 7 are caused by undulations on the surface of the guide rail and by the joints of the guide rail. Figure 4 shows the steps caused by the joints of the guide rail.
[0049] Figure 5 is a front view of the brake 81 and a portion of the guide rail 7 in a comparative example. Figure 4 shows an example of the contact state between the brake 81 and the guide rail 7 when the emergency stop device is activated. As with Figure 4, there is a step on the side of the guide rail 7.
[0050] Unlike in Example 1, the braker 81 in this comparative example has upper and lower ends 81U and 81L that are continuous with the respective tapered surfaces 81c and 81b (in Example 1 (Figure 3), a U ,a L ) does not have. The other configurations of this comparative example are the same as those of Example 1 (Figure 3).
[0051] If the direction perpendicular to the longitudinal direction of the guide rail 7 is defined as the height direction, then the height h from the bottom of the groove g6 to the top S of the tapered surface 81c is defined as follows: S This is set to be equal to the height from the bottom of the groove to the braking surface, i.e., the height h of the projection 81a5.
[0052] When manufacturing the brake of this comparative example, h S A tapered surface is created by machining so that it is equal to h. At this time, when the emergency stop device is activated, each braking surface is made to contact the guide rail 7 so that h S The tolerances for the cutting process are set such that ≤h. Therefore, if the emergency stop device is activated, as shown in Figure 5, the projection 81a5, which has a braking surface a5 and is adjacent to the lower end having a tapered surface 81c, may come into contact with the stepped portion of the guide rail 7.
[0053] When the projection 81a5 comes into contact with the stepped portion of the guide rail 7, stress concentration occurs at the projection 81a5. Consequently, the reliability of the braker 81 is reduced.
[0054] In this embodiment 1, including machining tolerances, h s =h is set, and in the manufacturing process, the flat part a U ,a L This is formed simultaneously with the braking surfaces (a1~a5). As a result, the flat portion a U ,a L This can be easily positioned within a virtual plane F parallel to the side surface of the guide rail 7, along with multiple braking surfaces (a1 to a5).
[0055] As described above, according to Example 1, the height from the bottom of the groove is the same as the braking surface, and the flat portion a is continuous with the tapered surfaces 81b and 81c.U ,a L By providing this feature, stress concentration in the brake 81 is suppressed even though the brake 81 has tapered upper and lower ends. Therefore, the reliability of the emergency braking device is improved.
[0056] In this embodiment 1, the upper and lower ends of the brake element have flat surfaces. However, considering the state of the brake element shown in Figure 4, and the fact that the emergency stop device operates when the elevator car descends, it is sufficient that at least the lower end has a flat surface.
[0057] Furthermore, in this embodiment 1, the width W of each braking surface a While the widths are equal (Figure 3), the brake surfaces are not limited to this, and the widths may be varied for each braking surface. For example, the width of the braking surface may be increased from the top to the bottom of the brake. This ensures that a sufficient area of the effective braking surface is secured. [Examples]
[0058] Figure 6 is a front view showing the configuration of the brake in the emergency stop device of an elevator system, which is Embodiment 2 of the present invention. A side view (view in the direction of arrow B in the figure) is also shown.
[0059] The differences from Example 1 (Figure 3) will be explained below.
[0060] The brake 81 according to this embodiment 2 is suitable for high-speed elevators (e.g., rated speed 120-300 m / min) or ultra-high-speed elevators (e.g., rated speed ≥ 360 m / min).
[0061] The bottom portion b of the grooves (g1 to g6) of the brake element 81 is arc-shaped, for example, a circular arc or a U-shape. This suppresses stress concentration due to thermal deformation in the grooves.
[0062] The depth d of the grooves (g1~g6), i.e., the height (h1~h5) of the projections (81a1~81a5), are equal to each other, as in Example 1. However, as in Example 1, the depth of the grooves and the height of the projections are set considering the thermal stress and bending stress in the grooves and projections, so they may be larger in brakes for high-speed elevators or ultra-high-speed elevators than in brakes for low-speed elevators (e.g., rated speed ≤ 45 m / min) or medium-speed elevators (e.g., rated speed 60~105 m / min).
[0063] In this embodiment 2, the length L1 of the tapered surface 81c in the inclination direction is the length of the flat portion a L The length of the tapered surface 81c in the vertical direction is longer than the length L2 (L1 > L2). Similarly, the length of the flat portion a U It is longer than the length in the vertical direction. As a result, when the emergency braking device is activated while traveling at high speed or very high speed, the flat part a U ,a L Even if wear occurs, the tapered surfaces 81b and 81c will remain. Therefore, equivalent braking characteristics can be reliably obtained in two braking tests.
[0064] In addition, in the brake of Example 1, the length of the tapered surface in the inclination direction may be longer than the length of the flat portion in the vertical direction.
[0065] Furthermore, the present invention is not limited to the embodiments and modifications described above, and various modifications are possible. For example, the embodiments described above were explained in detail in order to clearly illustrate the present invention. This refers to a system that does not necessarily have all the configurations described. Furthermore, it is possible to add, delete, or replace some of the configurations in the embodiment with other configurations.
[0066] For example, the emergency braking device is not limited to the configuration shown in Figure 2; it may have any so-called wedge-shaped brake. Furthermore, the emergency braking device may be a multi-stage emergency braking device equipped with multiple pairs of brakes.
[0067] Furthermore, the elastic body that presses against the brake is not limited to a U-shaped leaf spring; a disc spring or the like may also be used.
[0068] Furthermore, elevator systems are so-called mechanical systems in which the hoisting machine and control device are installed within the hoistway. Roomless elevators are also acceptable. [Explanation of symbols]
[0069] 1...Elevator device, 2...Elevator car, 3...Counterweight, 4...Main rope, 5...Traction sheave, 6...Derailment vehicle, 7...Guide rail, 8...Emergency stopper, 9...Operating lever, 10...Governor, 11...Compensator rope, 12...Compensator pulley, 13...Hoistway, 21...Governor rope, 22...Pulley, 33...Lower pulley, 34...Tension weight, 80...Housing, 81...Brake, 82...Guide, 83...Roller, 84...U-shaped leaf spring, 85...Guide plate, 90...Guide groove, 81a1, 81a2, 81a3, 81a4, 81a5... protrusions, 81b, 81c... Tapered surface, 81s... Inclined surface, 81L... Lower end, 81U... Upper end, a1,a2,a3,a4,a5...braking surface, aL,aU...flat surface, g1, g2, g3, g4, g5, g6... grooves
Claims
1. A cart, An emergency stop device provided in the aforementioned elevator car, Guide rails for guiding the aforementioned elevator car, In an elevator system equipped with, The emergency stop device comprises a pair of brakes having braking surfaces facing the guide rail, The brake element, on the braking surface side, Multiple grooves extending parallel to the side surface of the guide rail and perpendicular to the longitudinal direction of the guide rail, Tapered surfaces located at the upper and lower ends, A flat portion adjacent to the groove, and which is continuous with the tapered surface at least at the lower end of the upper end and the lower end, Equipped with, An elevator device characterized in that the bottom of the groove is flat.
2. In the elevator device according to claim 1, An elevator device characterized in that, when the emergency stop device is activated, the flat portion comes into contact with the guide rail.
3. In the elevator device according to claim 1, An elevator device characterized in that the height of the flat portion from the bottom of the groove is equal to the height of the braking surface from the bottom.
4. In the elevator device according to claim 1, An elevator device characterized in that the height of the flat portion from the bottom of the groove is equal to the depth of the groove.
5. In the elevator device according to claim 1, Multiple protrusions located between the multiple grooves are provided with the braking surface, An elevator device characterized in that the height of the flat portion from the bottom of the groove is equal to the height of the projection from the bottom.
6. In the elevator device according to claim 1, The elevator device is characterized in that the planar portion extends in a direction parallel to the side surface of the guide rail and perpendicular to the longitudinal direction of the guide rail.
7. In the elevator device according to claim 1, An elevator device characterized in that the length of the tapered surface in the inclination direction is longer than the length of the flat portion in the vertical direction.