Emergency stop device and elevator

Abstract

This emergency stop device is provided with: two braking elements that are provided to an elevating body and that sandwich a guide rail on which the elevating body slides; a guide member that movably supports the braking elements; and a biasing member that biases the two braking elements toward the guide rail via the guide member. A facing surface that is a surface of the braking element and that faces the sliding surface of the guide rail has a first sliding surface part comprising a flat surface part parallel to the sliding surface and a second sliding surface part having a plurality of protrusions protruding toward the guide rail more than the flat surface part.

Description

Emergency stop devices and elevators

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

[0002] Generally, rope-type elevators have long components such as a main rope and compensating ropes that connect the car and the counterweight, and a governor rope that is used to detect the speed of the car or the counterweight. Furthermore, elevators are required to be equipped with an emergency stop device as a safety device that automatically stops the car when the speed of the car ascending or descending along the guide rail exceeds a specified value.

[0003] An example of such technology is described in Patent Document 1. Patent Document 1 describes that the brake shoe is made of a material having friction characteristics in which the coefficient of friction tends to decrease as the product of the surface pressure and the sliding speed increases, and that the sliding surface is formed in multiple stages.

[0004] Japanese Patent Application Publication No. 9-104572

[0005] Furthermore, when the safety device is activated in an emergency, the brake shoe and the guide rail come into contact at high speed, causing wear on one surface of the brake shoe. Furthermore, the biasing force of the biasing member that holds the brake shoe decreases as the distance between the two brake shoes narrows. However, with the technology described in Patent Document 1, protrusions are formed on the entire surface of the brake shoe that faces the guide rail. Therefore, with the technology described in Patent Document 1, the entire brake shoe wears out during an emergency, causing a decrease in the biasing force of the biasing member.

[0006] Furthermore, in the case of a brake shoe without a protrusion, sufficient frictional force cannot be obtained when the brake shoe and the guide rail are brought into contact at a speed lower than that during an emergency operation, such as during maintenance and inspection.

[0007] In consideration of the above problems, the present invention aims to provide an emergency stop device and an elevator that can provide sufficient frictional force not only during emergency operations but also during maintenance and inspection.

[0008] In order to solve the above problems and achieve the object, the safety device includes two brake shoes that are provided on the lifting body and sandwich the guide rail along which the lifting body slides, a guide member that movably supports the brake shoes, and a biasing member that biases the two brake shoes toward the guide rail via the guide member. The opposing surface of the brake shoes that faces the sliding surface of the guide rail has a first sliding surface portion consisting of a flat portion parallel to the sliding surface, and a second sliding surface portion that has multiple protrusions that protrude beyond the flat portion toward the guide rail.

[0009] The elevator also includes a lifting body that moves up and down within the elevator shaft, guide rails that are erected within the elevator shaft and support the lifting body so that it can slide, and an emergency stop device that stops the movement of the lifting body based on the state of the lifting body's upward and downward movement.The emergency stop device is the same as the one described above.

[0010] According to the emergency stop device and elevator having the above configuration, sufficient friction force can be obtained not only during emergency operations but also during maintenance and inspection.

[0011] Fig. 5 is a schematic configuration diagram showing an elevator according to an embodiment. Fig. 6 is a front view showing an emergency stop device according to an embodiment. Fig. 7 is a front view showing a brake shoe of an emergency stop device according to an embodiment. Fig. 8 is a side view showing a brake shoe of an emergency stop device according to an embodiment. Fig. 9 shows the state of the brake shoe during maintenance and inspection (low-speed operation) of an emergency stop device according to an embodiment, where Fig. 5(a) is a view showing the brake shoe and guide rail, and Fig. 5(b) is an enlarged view showing the second sliding surface portion of the brake shoe and the guide rail. Fig. 10 shows the state of the brake shoe during emergency operation (high-speed operation) of an emergency stop device according to an embodiment, where Fig. 11(a) is a view showing the brake shoe and guide rail, and Fig. 11(b) is an enlarged view showing the second sliding surface portion of the brake shoe and the guide rail.

[0012] Hereinafter, embodiments of the safety device and elevator will be described with reference to Figures 1 to 6. Note that common members in the figures are given the same reference numerals.

[0013] 1. Example of embodiment 1-1. Configuration of elevator First, the configuration of an elevator according to an example of embodiment (hereinafter referred to as "this example") will be described with reference to Figures 1 to 3. Figure 1 is a schematic diagram showing the configuration of an elevator.

[0014] The elevator 100 of this example is installed in a hoistway formed within a building structure. The elevator 100 includes a car 1, which is an example of a lifting body for carrying people and luggage, a main rope 6, and a counterweight 3, which is another example of a lifting body. The elevator 100 also includes a hoisting machine 5, a safety device 10, a speed governor 7, and a lower pulley 8.

[0015] A traction machine 5 is installed in a machine room provided at the top of the hoistway. A main rope 6 is wound around a sheave of the traction machine 5. In addition, a deflector sheave on which the main rope 6 is mounted is provided near the traction machine 5.

[0016] An upper portion of the car 1 is connected to one end of the main rope 6, and an upper portion of the counterweight 3 is connected to the other end of the main rope 6. When the hoist 5 is driven, the car 1 and the counterweight 3 move up and down in the elevator shaft. Hereinafter, the direction in which the car 1 and the counterweight 3 move up and down is referred to as the up and down direction.

[0017] The car 1 is slidably supported on two guide rails 2, 2 via a guide device. Similarly, the counterweight 3 is slidably supported on two weight-side guide rails 4, 4 via a guide device. The two guide rails 2, 2 and the weight-side guide rails 4, 4 extend vertically within the hoistway.

[0018] In addition, two emergency stop devices 10 are provided at the bottom of the car 1 to emergency stop the up and down movement of the car 1. The emergency stop devices 10 are arranged at the bottom of the car 1 in positions facing the guide rails 2. The detailed configuration of the emergency stop devices 10 will be described later.

[0019] The governor 7 is installed in a machine room located at the top of the elevator shaft. The lower pulley 8 is located at the bottom of the elevator shaft, vertically below the governor 7. A governor rope 9 is wound around the governor pulley of the governor 7 and the lower pulley 8. A governor weight is attached to the lower pulley 8. Therefore, a predetermined load is applied to the lower pulley in the vertically downward direction by the governor weight. A predetermined tension is applied to the governor rope 9 wound around the lower pulley 8 via the lower pulley 8.

[0020] The governor rope 9 is formed in a so-called endless shape, with both axial ends connected. A connecting member 11 is provided on the governor rope 9. The connecting member 11 is connected to an emergency stop device 10 provided on the car 1. The governor rope 9 circulates between the governor pulley and the lower pulley 8 of the governor 7 in accordance with the ascending and descending movement of the car 1. The governor 7 detects the ascending and descending speed of the car 1 from the circulating speed of the governor rope 9.

[0021] 1-2. Emergency Stop Device Next, the configuration of the emergency stop device 10 will be described with reference to Fig. 2. Fig. 2 is a front view showing the emergency stop device 10. As shown in Fig. 2, the emergency stop device 10 has an upper frame 20, a lower frame 21, a biasing member 22, two side frames 27, a lifting portion 23, two brake shoes 25 that face the guide rail 2, a guide member 24, and a connecting member 26. Hereinafter, the direction that is perpendicular to the up-down direction and in which the two brake shoes 25 face the guide rail 2 will be referred to as the width direction.

[0022] The upper frame 20 is disposed at the top in the vertical direction of the safety device 10. The lower frame 21 is disposed at the bottom in the vertical direction of the safety device 10, and is disposed opposite the upper frame 20 in the vertical direction. The upper frame 20 is formed with an upper opening 20a through which the guide rail 2 is inserted. The lower frame 21 is also formed with a lower opening 21a through which the guide rail 2 and two brake shoes 25, 25 described below are inserted.

[0023] The two side frames 27, 27 are disposed at both widthwise ends of the upper frame 20 and the lower frame 21. The side frame 27 connects the upper frame 20 and the lower frame 21 in the up-down direction. The upper frame 20, the lower frame 21, and the side frames 27, 27 form the housing of the safety device 10. The brake shoe 25 and the guide member 24 are housed in the housing.

[0024] The two brake shoes 25, 25 are arranged facing each other in the width direction with the guide rail 2 therebetween. Before the safety device 10 is activated, a predetermined gap is formed between the two brake shoes 25, 25 and the guide rail 2. The detailed configuration of the brake shoes 25 will be described later.

[0025] The two brake shoes 25, 25 are supported by a connecting member 26 so as to be movable in the width direction. The two brake shoes 25, 25 are connected by the connecting member 26. A lifting portion 23 is connected to the connecting member 26. The lifting portion 23 protrudes upward in the vertical direction from the upper frame 20. The lifting portion 23 is connected to the connecting member 11 (see FIG. 1 ). When the lifting portion 23 is pulled upward in the vertical direction, the two brake shoes 25, 25 and the connecting member 26 move upward in the vertical direction.

[0026] A guide member 24 is arranged on the other surface of the brake shoe 25 opposite to the surface facing the guide rail 2. The guide member 24 movably supports the brake shoe 25. The two guide members 24, 24 are arranged so that they approach the guide rail 2 from bottom to top in the vertical direction. In other words, the two guide members 24, 24 are arranged so that the widthwise distance between them narrows from bottom to top in the vertical direction.

[0027] In addition, a biasing member 22 is arranged on the other surface of the guide member 24 opposite to the surface facing the brake shoe 25. The biasing member 22 is configured, for example, by a leaf spring having a U-shaped cross section when cut horizontally perpendicular to the up-down direction. Both end portions 22a of the biasing member 22 face each other with a predetermined gap in the width direction, with the guide rail 2 sandwiched therebetween. The guide member 24 is fixed to one surface of both end portions 22a of the biasing member 22 facing each other. In addition, both end portions 22a of the biasing member 22 are supported by the side frame 27 via support members 28.

[0028] The biasing member 22 is not limited to a U-shaped leaf spring, but may be, for example, a compression coil spring or any other type of elastic member.

[0029] When the lifting section 23 is pulled up in the vertical direction in an emergency, the two brake shoes 25, 25 and the connecting member 26 connected to the lifting section 23 are also pulled up. Then, the two brake shoes 25, 25 are guided by the guide members 24, 24 and move toward the guide rail 2, clamping the guide rail 2. Furthermore, when the two brake shoes 25, 25 move up in the vertical direction, the two brake shoes 25, 25 are pressed against the guide rail 2 by the biasing force of the biasing member 22 via the guide member 24. As a result, the up and down movement of the car 1 is braked.

[0030] 1-3 Brake shoe Next, the detailed structure of the brake shoe 25 will be described with reference to Figures 3 and 4. Figure 3 is a front view showing the brake shoe 25, and Figure 4 is a side view showing the brake shoe 25.

[0031] 3 and 4, the opposing surface 31 of the brake shoe 25 that faces the sliding surface 2a of the guide rail 2 (see FIGS. 5 and 6) is formed parallel to the sliding surface 2a of the guide rail 2, i.e., parallel to the vertical direction. The other surface of the brake shoe 25 opposite the opposing surface 31 is inclined so as to approach the guide rail 2 from the bottom to the top in the vertical direction. Therefore, the brake shoe 25 is formed in a wedge shape.

[0032] The opposing surface 31 of the brake shoe 25 is formed with a first sliding surface portion H1 and a second sliding surface portion H2. The first sliding surface portion H1 is formed with a flat portion 32 that is parallel to the sliding surface 2a of the guide rail 2 (see FIGS. 5 and 6 ). The first sliding surface portion H1 is also formed with a groove portion 34. The groove portion 34 is recessed inward in the width direction from the opposing surface 31 of the brake shoe 25. The groove portion 34 extends in a direction perpendicular to the up-down direction and the width direction. When the brake shoe 25 comes into contact with the guide rail 2, the groove portion 34 discharges chips that are generated when part of the brake shoe 25 is scraped off to the outside of the brake shoe 25.

[0033] The second sliding surface portion H2 is disposed vertically lower than the first sliding surface portion H1 on the opposing surface 31. That is, the second sliding surface portion H2 is formed in an area of ​​the brake shoe 25 that is longer in the width direction than the first sliding surface portion H1. The proportion (area) of the area in which the second sliding surface portion H2 is formed is set smaller than the proportion (area) of the area in which the first sliding surface portion H1 is formed.

[0034] The second sliding surface portion H2 has a plurality of protrusions 33 formed thereon. The plurality of protrusions 33 protrude from the opposing surface 31 toward the guide rail 2. The protrusions 33 are ridges extending in a direction perpendicular to the vertical and width directions. The angle θ1 (see FIG. 5( b)) formed between the lower surface of the protrusion 33 in the vertical direction and the opposing surface 31 is an acute angle. Therefore, the plurality of protrusions 33, when viewed in a direction perpendicular to the vertical and width directions, are formed in a sawtooth shape protruding downward in the vertical direction.

[0035] In this example, the protrusions 33 are described as being configured as sawtooth ridges, i.e., as having a flat grain pattern, but this is not limited thereto and may be twill-like protrusions. Furthermore, while the protrusions 33 are configured as having an acute angle protruding downward in the vertical direction, this is not limited thereto and various other shapes may be used. However, in order to efficiently insert the protrusions 33 into the sliding surface 2 a of the guide rail 2 during low-speed operation (maintenance and inspection) described below, it is preferable that the protrusions 33 be configured as having an acute angle protruding downward in the vertical direction.

[0036] Furthermore, it is preferable that the projections 33 are made of a material and have a size that does not wear during low-speed operation (maintenance inspection) but wears during high-speed operation (emergency operation).

[0037] 2. Operational Example of the Emergency Stop Device Next, an operational example of the emergency stop device 10 having the above-described configuration will be described with reference to Figures 5 and 6. 2-1. During Low-Speed ​​Operation (Maintenance and Inspection) First, low-speed operation will be described with reference to Figure 5. Figures 5(a) and 5(b) are diagrams showing the state of the brake shoe 25 and the guide rail 2 during low-speed operation.

[0038] During maintenance and inspection of the safety device 10, the lifting portion 23 is intentionally pulled upward in the vertical direction, and as shown in Figure 5(a), the brake shoe 25 is brought closer to the guide rail 2. Note that during maintenance and inspection of the safety device 10, the brake shoe 25 comes into contact with the guide rail 2 at a slower speed than when the safety device 10 is actually braked.

[0039] As described above, the multiple protrusions 33 constituting the second sliding surface portion H2 protrude further toward the guide rail 2 than the flat portion 32 constituting the first sliding surface portion H1. Therefore, as shown in Figures 5(a) and 5(b), when the brake shoe 25 approaches the guide rail 2, the second sliding surface portion H2 of the brake shoe 25 comes into contact with the guide rail 2 before the first sliding surface portion H1.

[0040] At this time, the brake shoe 25 receives a downward force in the vertical direction from the car 1. Furthermore, the protrusions 33 protrude downward in the vertical direction. Therefore, the multiple protrusions 33 provided on the second sliding surface portion H2 bite into the sliding surface 2a of the guide rail 2. The protrusions 33 biting into the guide rail 2 generates a frictional force (resistance force). As a result, even during low-speed operation such as during maintenance and inspection of the safety device 10, a sufficient frictional force can be obtained from the second sliding surface portion H2, and the safety device 10 can brake the up and down movement of the car 1.

[0041] The biasing force of the biasing member 22 acts more strongly in a portion of the brake shoe 25 that is longer in the width direction than in a portion that is shorter. The second sliding surface portion H2 on which the protrusion 33 is provided is formed in an area of ​​the brake shoe 25 that is longer in the width direction below the first sliding surface portion H1 in the vertical direction. Therefore, by arranging the second sliding surface portion H2 in a portion where the biasing force of the biasing member 22 acts more strongly, it is possible to generate a large resistance force even during low-speed operation, such as during maintenance and inspection of the safety device 10.

[0042] 2-2. High-Speed ​​Operation (Emergency Operation) First, with reference to Fig. 6, an emergency operation of the car 1, that is, a high-speed operation in which the car 1 and the safety device 10 move at a higher speed than during maintenance and inspection, will be described. Fig. 6(a) and Fig. 6(b) are diagrams showing the state of the brake shoe 25 and the guide rail 2 during high-speed operation.

[0043] When the descending speed of the car 1 exceeds the rated speed and reaches a predetermined speed due to, for example, a break in the main rope 6, the governor 7 pulls up the lifting portion 23 of the safety device 10 in the vertical direction via the connecting member 11, thereby activating the safety device 10. As a result, as shown in Figures 6(a) and 6(b), the brake shoe 25 is pressed against the guide rail 2 at a higher speed than during maintenance and inspection.

[0044] At this time, the second sliding surface portion H2 of the brake shoe 25 comes into contact with the guide rail 2 before the first sliding surface portion H1, but the car 1 is moving at a higher speed than during maintenance and inspection. Therefore, as shown in FIG. 6(b), the protrusion 33 of the second sliding surface portion H2 rubs against the sliding surface 2a of the guide rail 2, causing it to wear. As a result, the second sliding surface portion H2 is deformed into a flat shape, similar to the first sliding surface portion H1. Furthermore, the area of ​​the second sliding surface portion H2 is set smaller than the area of ​​the first sliding surface portion H1. Therefore, the area of ​​the brake shoe 25 that deforms during high-speed operation (emergency operation) can be reduced compared to when protrusions are provided on the entire brake shoe 25.

[0045] Then, the flat surface portion 32 of the first sliding surface portion H1 and the second sliding surface portion H2 deformed into a flat shape, i.e., the entire opposing surface 31 of the brake shoe 25, come into contact with the sliding surface 2a of the guide rail 2. Furthermore, frictional heat generated when the opposing surface 31 of the brake shoe 25 comes into contact with the sliding surface 2a of the guide rail 2 at high speed causes the first sliding surface portion H1 and the second sliding surface portion H2 of the brake shoe 25 to adhere to the sliding surface 2a of the guide rail 2. In this way, adhesion of the first sliding surface portion H1 and the second sliding surface portion H2 of the brake shoe 25 to the sliding surface 2a of the guide rail 2 can generate a large frictional force (resistance force), and the lifting and lowering movement of the car 1 can be braked by the safety device 10 even during high-speed operation (emergency operation).

[0046] Here, when the protrusion 33 of the brake shoe 25 wears, the length of the brake shoe 25 in the width direction changes, and the biasing force of the biasing member 22 that biases the brake shoe 25 decreases. In contrast, in the safety device 10 of this example, the second sliding surface portion H2 is formed on part of the opposing surface 31 of the brake shoe 25. Therefore, compared to when protrusions are provided on the entire brake shoe 25, the area of ​​the brake shoe 25 that deforms (wears) during high-speed operation (emergency operation) can be reduced, and the biasing force of the biasing member 22 can be prevented from decreasing.

[0047] Furthermore, the area of ​​the second sliding surface portion H2 is set smaller than the area of ​​the first sliding surface portion H1, which reduces the area where the brake shoe 25 deforms (wears) during high-speed operation (emergency operation), and prevents the biasing force of the biasing member 22 from decreasing.

[0048] In this way, according to the emergency stop device 10 of this example, by providing the opposing surface 31 of the brake shoe 25 with a first sliding surface portion H1 consisting of a flat portion 32 and a second sliding surface portion H2 consisting of a plurality of protrusions 33, it is possible to obtain sufficient frictional force not only during emergency operation but also during maintenance and inspection.

[0049] The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made within the scope of the invention as set forth in the claims.

[0050] In the above-described embodiment, the second sliding surface portion H2 provided with the protrusion 33 is disposed vertically below the first sliding surface portion H1 consisting of the flat portion 32 on the brake shoe 25, but this is not limiting. For example, the second sliding surface portion H2 may be disposed vertically above the first sliding surface portion H1. Alternatively, the second sliding surface portion H2 may be disposed in the middle of the brake shoe 25 in the vertical direction.

[0051] However, the brake shoe 25 is formed so that its widthwise length is longer at the bottom than at the top in the vertical direction. Therefore, by arranging the protrusion 33 at the bottom of the brake shoe 25 in the vertical direction, the rate of change in the widthwise length of the brake shoe 25 when the protrusion 33 wears can be kept smaller than when the protrusion 33 is arranged at the top in the vertical direction of the brake shoe 25. Furthermore, the biasing force of the biasing member 22 acts more strongly when the widthwise distance between both end portions 22a is longer. Therefore, it is preferable to arrange the second sliding surface portion H2 at the bottom of the brake shoe 25 in the vertical direction, which more effectively prevents a decrease in the biasing force of the biasing member 22.

[0052] Furthermore, the lifting body is not limited to the car 1, but may be a counterweight 3. The safety device 10 is not limited to braking the lifting and lowering movement of the car 1, but may be provided on the counterweight 3 to brake the lifting and lowering movement of the counterweight 3.

[0053] For example, the above-described embodiments have described the configurations of the devices and systems in detail and specifically in order to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of the embodiments described here with the configuration of other embodiments, and it is also possible to add the configuration of one embodiment to the configuration of another embodiment. Furthermore, it is also possible to add, delete, or replace part of the configuration of one embodiment with other configurations.

[0054] In this specification, the words "parallel" and "orthogonal" are used, but these do not mean only "parallel" and "orthogonal" in the strict sense, but also include "parallel" and "orthogonal" and may also mean a "substantially parallel" or "substantially orthogonal" state within a range in which the functions can be exerted.

[0055] DESCRIPTION OF SYMBOLS 1...car (lifting body), 2...guide rail, 2a...sliding surface, 3...counterweight (lifting body), 4...weight side guide rail, 5...hoist, 6...main rope, 7...governor, 9...governor rope, 10...emergency stop device, 11...connecting member, 20...upper frame, 21...lower frame, 22...urging member, 22a...both ends, 23...lifting portion, 24...guide member, 25...brake shoe, 26...coupling member, 27...side frame, 28...support member, 31...opposing surface, 32...flat portion, 33...projection, 34...groove portion, 100...elevator, H1...first sliding surface portion, H2...second sliding surface portion

Claims

1. An emergency stop device comprising: two brake shoes attached to an elevating body and sandwiching a guide rail along which the elevating body slides; a guide member which movably supports the brake shoes; and a biasing member which biases the two brake shoes towards the guide rail via the guide member, wherein the opposing surfaces of the brake shoes which face the sliding surface of the guide rail include a first sliding surface portion consisting of a flat surface portion parallel to the sliding surface, and a second sliding surface portion having a plurality of protrusions which protrude further towards the guide rail than the flat surface portion.

2. The safety device according to claim 1, wherein the proportion of the second sliding surface portion in the opposing surface is set smaller than the proportion of the first sliding surface portion.

3. The emergency stop device according to claim 1, wherein the second sliding surface portion is positioned lower than the first sliding surface portion in the vertical direction in which the lifting body moves up and down.

4. The safety device according to claim 3, wherein the width of the brake shoe, which is the direction facing the guide rail, is set to be longer at the bottom than at the top in the vertical direction.

5. The safety device according to claim 1, wherein the projection has a lower surface in the vertical direction and an angle formed between the opposing surface and the lower surface is an acute angle.

6. The emergency stop device according to claim 1, wherein the projection does not wear during maintenance inspection, but wears and deforms into a flat shape during emergency operation which operates faster than during maintenance inspection.

7. An elevator comprising: a lifting body which moves up and down within a shaft; a guide rail which is erected within the shaft and slidably supports the lifting body; and an emergency stop device which stops the movement of the lifting body based on the state of the lifting body's upward and downward movement; two brakes which are provided on the lifting body and which clamp the guide rail; a guide member which movably supports the brakes; and a biasing member which biases the two brakes towards the guide rail via the guide member, wherein the opposing surfaces of the brakes which face the sliding surface of the guide rail include a first sliding surface portion consisting of a flat portion parallel to the sliding surface, and a second sliding surface portion having a plurality of protrusions which protrude further towards the guide rail than the flat portion.

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