JP2018034921A - Emergency stop device and elevator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that the deceleration of an emergency stop device becomes small due to the lowering of a friction coefficient, however, since the deceleration should be suppressed within a specified range by performing a plurality of times of tests by using the same braking piece depending on a specification, it is necessary to suppress a variation of the friction coefficient.SOLUTION: An emergency stop device for stopping a car by a friction force which is generated by pressing a braking piece 1 against a guide rail 8 at an emergency brake comprises: a plurality of protrusions 3 for digging up a processing-hardened part of a guide rail surface on a friction face of the braking piece 1; and an edge 2 extending to a substantially-horizontal direction for scraping out the processing-hardened part. The edge 2 is located at a downstream side with respect to a fall direction of the car rather than the protrusions 3, and the edge 2 is located in the vicinity of a salient part apex point with a friction face of the braking piece 1 as a protrusive curved face with respect to a guide rail longitudinal direction 8.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an elevator, and more particularly, to an emergency stop device included in the elevator.

  Conventionally, an elevator is provided with an emergency stop device as a safety device for stopping the car at an appropriate deceleration when the car descends beyond a certain speed limit.

  When the car has reached a predetermined lowering speed or more, the emergency stop device brings two wedge-shaped brakes into contact with the guide rails installed in the hoistway and brings them into contact with the brake springs. In general, a braking force is generated by applying a restoring force by elastic deformation, and a friction material having an appropriate friction coefficient and wear resistance is generally incorporated in the braking element. Such an emergency stop device is described in Patent Document 1, for example.

JP 2001-289270 A

  The guide rail basically has dimensions, chemical components, mechanical properties, etc. determined by the standard, but the processing method is not particularly defined and is left to each manufacturer. In order to finish the guide rail to a predetermined dimension, surface finishing is performed by a polishing machine after pre-processing such as milling, broaching, or planar processing. In general, when a metal material is plastically processed, the resistance to deformation increases as the degree of deformation increases, and it becomes harder than a material that has not undergone deformation. This is called work hardening. This is called a dislocation and relates to a linear defect in the guide rail crystal. The hardness of the metal is determined by the ease of dislocation movement, and it is hard if it is difficult to move. As plastic deformation increases, dislocations increase and accumulate, and entanglement dislocations become difficult to move, resulting in hardening.

  Therefore, the hardness of the machined surface is determined by how much plastic deformation occurs during machining. Processing methods and conditions such as cutting speed, machining allowance, polishing method, abrasive material, etc. are set independently by each manufacturer, so that the amount of plastic deformation changes and a difference in surface hardness appears. Then, the hardness gradually decreases as it goes deeper in the guide rail, and in a deep region, the hardness value of the material itself is shown without undergoing plastic deformation. The difference in hardness with respect to the depth of the guide rail tends to be large near the surface and small at the deep portion.

  When the guide rail hardness is different, the friction force and the friction coefficient generated in the brake and the guide rail change. As the guide rail becomes harder, the frictional force and coefficient of friction become smaller. This is because the true contact area a between the guide rail and the brake is reduced when the hardness is high. The frictional force F is expressed by F = a × s, where s is a shearing force per unit area. Therefore, if the contact area a is small, the frictional force F is small, so the friction coefficient is small.

  The standard of the emergency stop device stipulates that the same brake is used to perform a plurality of tests so that a predetermined deceleration is achieved. Deceleration is reduced by a decrease in spring force and coefficient of friction.

  Since the cause of the decrease in the spring force is due to wear of the brake element, in the prior art, the brake element is appropriately hardened to ensure wear resistance and suppress the decrease in spring force to some extent. On the other hand, as one of the causes of the lowering of the friction coefficient, the contact of the guide rail in the second test is unstable due to non-uniform adhesion of the guide rail chips to the brake that was tested for the first time. become. Further, since the chip adhesion layer is softer than the brake, the biting on the guide rail is weakened and the surface of the guide rail cannot be cut sufficiently. Therefore, in the second test, the friction coefficient becomes small because the friction is in the vicinity of the rail surface having high hardness. In particular, in a specification with a low rated speed, the braking distance is short and the above phenomenon tends to become remarkable. As a result, there is a possibility that a predetermined deceleration cannot be secured in a plurality of tests.

  Therefore, an object of the present invention is to provide an elevator including an emergency stop device that can maintain a stable braking characteristic with a small coefficient of friction variation even when the same brake element is used a plurality of times.

In order to solve the above problems, an elevator according to one aspect of the present invention includes an emergency stop device that stops a car by a frictional force generated by pressing a brake against a guide rail during emergency braking. The emergency stop device is a first sliding portion in which a plurality of projections formed in a conical shape facing the guide rail and having a narrow sliding surface on the tip side and a wide skirt are arranged in the horizontal direction of the sliding surface. And a second slide formed on the upper surface of a groove that is arranged below the first sliding portion in the vertical direction and extends in a direction substantially orthogonal to the guide rail and horizontally in the sliding surface. And a brake having a moving part. The sliding surface of the brake element has a convex curved surface in the vertical direction with respect to the guide rail, and the second sliding portion is located in the vicinity of the convex portion vertex.
The emergency stop device includes a plurality of protrusions that dig up a work hardened portion on the surface of the guide rail on the friction surface of the brake and an edge extending in a lateral direction to peel off the work hardened portion, and the edge is more than the protrusion. The edge is located in the vicinity of the convex portion, with the friction surface of the brake element being a convex curved surface with respect to the guide rail longitudinal direction.

  In addition, the emergency stop device is installed so that the roller installation density of the roller unit provided on the back surface of the brake element is higher in the vicinity of the edge than in the vicinity of the back surface other than near the edge in order to press the brake element against the guide rail. May be.

  In addition, the brake element of the emergency stop device has a convex curved surface with respect to the rear face of the brake element and the guide member that presses the roller unit against the rear face of the brake element, and the vicinity of the convex portion is the horizontal position near the edge of the brake element. Good.

  In addition, in order to press the brake element of the emergency stop device against the guide rail, the spring provided on the back surface near the edge of the brake element among the plurality of springs provided on the back side of the brake element has a larger spring force than other parts. Set to.

  According to one aspect of the present invention, it is possible to provide an elevator including an emergency stop device that can maintain a stable braking characteristic with a small coefficient of friction variation even when the same brake element is used a plurality of times.

The figure which shows the structure of the elevator in an Example. The front view and longitudinal cross-sectional view which show the brake element of the emergency stop apparatus which is one Embodiment by this invention. The front view which shows the emergency stop apparatus which is one embodiment by this invention. The figure explaining the hardness change degree with respect to the depth direction of a guide rail. The front view which shows the brake element of a comparative example. The figure explaining how the guide rail surface is shaved for the first time when the brake element of the comparative example is used. The figure explaining how to cut the guide rail surface for the second time when the brake element of the comparative example is used. The figure explaining how to cut the guide rail surface for the first time when the brake element of the emergency stop device of the present invention is used. The figure explaining how to cut the guide rail surface for the first time when the brake element of the emergency stop device of the present invention is used. The figure which showed the fluctuation ratio of the friction coefficient in the brake of the comparative example and the emergency stop device of the present invention. The front view which shows the emergency stop apparatus which is further another form by this invention.

  FIG. 1 shows the configuration of an elevator equipped with an emergency stop device. In FIG. 1, a passenger car 46 on which a passenger is placed is connected to a drive system (not shown) on the top floor of a building by a plurality of ropes 45. In FIG. 1, details of the door opening and closing machine and the outer frame are not shown.

  A pair of guide rails 8 are provided on the hoistway walls on both sides of the hoistway to guide the raising and lowering of the car 46. Although not shown, the emergency stop device 7 is also provided on the guide rail 8 on the opposite side, and both are connected by a connection mechanism not shown. The pair of brake elements 1 are arranged with a slight gap from the guide rail 8 so that the guide rail 8 can be sandwiched. The rear surface of the brake element 1 is a wedge-shaped smooth inclined surface that narrows upward. The material of the guide rail 8 is made of metal, for example, general structural rolled steel. Moreover, it has a work hardening part in the predetermined depth from the surface of the guide rail 8, and hardness becomes high, so that it approaches the surface. An emergency stop device 7 is installed at the lower end of the car 46 so as to sandwich the guide rails 8. The emergency stop device 7 has a housing 9, and a plurality of brakes 1 are included in the housing 9.

  The plurality of brakes 1 sandwich the guide rails 8 when the car 46 comes into contact with the safety device 6. Further, the brake element 1 may be configured symmetrically with respect to the guide rail 8.

  FIG. 2 is a front view and a longitudinal sectional view of the brake element 1 of the safety device 7 according to one embodiment of the present invention. From the front view, the friction surface that contacts the guide rail 8 shown in FIG. 1 is provided with a plurality of protrusions 3 and an edge 2 (hereinafter referred to as a lateral edge 2) 2 extending in a substantially horizontal direction (arrow 36). The protrusion 3 has a substantially diamond-shaped friction surface 3a. The friction surface 3a can be obtained, for example, by processing the plurality of oblique grooves 4a and 4b with a predetermined interval between the friction surfaces. Although the angle of both the diagonal grooves 4a and 4b is approximately 90 degrees, the present invention is not limited to this. On the other hand, the lateral edge 2 is obtained by machining a groove in the direction of the arrow 36 of the brake 1, for example. The lateral edge 2 is located downstream of the position of the protrusion 3 with respect to the car falling direction (arrow 35) and is located near the center of the brake element longitudinal direction.

  The cross-sectional view shows a cut view of the AA portion of the front view. The brake element 1 has a wedge shape with a narrow upper side and a wide lower side. On the friction surface, a convex curved surface 27 is formed in the car falling direction (arrow 35), and the back surface is a smooth inclined surface. For example, the protrusion height 26 of the convex curved surface of the friction surface is about several tens of microns. The cross-sectional shape of the groove 6 of the protrusion 3 is substantially V-shaped, and the inclination angle with respect to the arrow 37 is approximately ± 45 degrees. Therefore, the protrusion 3 has a pyramid shape in which the friction surface 3a on the tip side is narrow and the skirt on the groove bottom side is wide. With this pyramid shape, the strength is maintained even with a small protrusion, and even if a frictional force acts on the friction surface, it does not break. The lateral edge 2 is formed by two surfaces, the friction surface 2a and the upper surface 2b of the recessed groove extending in the horizontal direction (arrow 36) provided on the friction surface, and the angle between the two surfaces is approximately 90 degrees.

  That is, the emergency stop device 7 is a first in which a plurality of projections 3a that are opposed to the guide rail 8 and that are formed in a conical shape with a narrow sliding surface on the tip side and a wide skirt are arranged in the horizontal direction of the sliding surface. And a groove 2b that is disposed on the lower side 36 in the vertical direction from the first sliding portion 3 and extends in a direction substantially orthogonal to the guide rail 8 and horizontally in the sliding surface. A brake 1 having a second sliding portion 2a formed on the upper surface is provided. The sliding surface of the brake 1 is formed with a convex curved surface 27 in the vertical direction with respect to the guide rail 8, and the second sliding portion 2a is located in the vicinity of the vertex of the convex portion.

  As the material of the brake 1, for example, an SK material having appropriate friction characteristics and wear resistance, for example, used for tool steel can be applied. The convex curved surface can be processed by general machining.

  FIG. 3 is a front view showing an emergency stop device according to an embodiment of the present invention. The emergency stop device 7 is configured to be symmetrical with respect to the guide rail 8. The material of the guide rail 8 is made of metal, for example, general structural rolled steel. The pair of brake elements 1 are arranged with a slight gap from the guide rail 8 so that the guide rail 8 can be sandwiched. The rear surface of the brake element 1 is a wedge-shaped smooth inclined surface that narrows upward. The pair of guide members 10 has an inclined surface parallel to the inclined surface of the brake 1, the outer surface is a vertical surface, and the vertical surface is sandwiched between springs 11. The spring 11 is U-shaped with the side facing the guide rail 8 open. A roller unit 12 is provided between the brake element 1 and the guide member 10. Below the brake element 1, there is provided a lifting plate 4 which is provided with a driving means (not shown) that activates the safety device 7. The brake element 1, the lifting plate 4, the guide member 10, and the spring 11 are accommodated in the housing 9.

  As shown in FIG. 1, the emergency stop device is installed separately in the descending direction of the car ascending / descending direction, for example, in two guide rails installed on the hoistway wall.

  FIG. 4 is a diagram for explaining the degree of hardness change with respect to the depth direction of the guide rail. The hardness of the guide rail 15 tends to be lower as the surface is higher and deeper in the depth direction. This is due to the work hardening described above. This is because the amount of plastic deformation on the surface of the guide rail changes depending on the processing method and conditions of the guide rail depending on the processing manufacturer, and a difference in hardness appears. This work-hardened part is only 0.04 to 0.1 mm deep from the guide rail surface, although there are some differences, and since it shows the hardness value of the material itself without being subjected to plastic deformation in a deeper area than this, it is almost constant. Value. Further, the hardness difference with respect to the depth of the guide rail tends to be large near the surface and small at the deep portion. Furthermore, although not shown in the drawing, the hardness gradually increases as it approaches the other surface (back surface) of the guide rail.

  Next, the hardness difference is compared in the guide rail depth direction. The hardness at depth position D1 is H4, the hardness at depth position D2 is H3, the hardness at depth position D3 is H2, the hardness at depth position D4 is H1, and the difference between depth positions D2-D1 and D4-D3 is Assuming that they are equal, the relationship between the hardness difference H4-H3 between the depths D2 and D1 and the hardness difference H2-H1 between the depths D4 and D3 is H4-H3> H2-H1. That is, as the depth from the surface of the guide rail increases, the amount of plastic deformation decreases rapidly, indicating the hardness value of the material itself. Therefore, even if the same depth position difference occurs, the difference in hardness increases on the surface side. Then it gets smaller.

  FIG. 5 is a front view of a braking element of a comparative example with respect to the braking element of the present embodiment shown in FIG. Compared with the brake element of the present embodiment, only the protrusion 3 having no lateral edge is formed on the friction surface. When the brake is mounted on the emergency stop device and the spring force is adjusted, a predetermined frictional force is exerted between the brake and the guide rail, and a prescribed deceleration is obtained in the first test.

  FIG. 6 is a diagram for explaining how the surface of the guide rail is scraped for the first time when the brake element of the comparative example is used. In (a), the cross-sectional view of the guide rail 8 is shown. The horizontal axis indicates the guide rail width direction, and the vertical axis indicates the guide rail depth direction. A position deeper than the guide rail surface position is defined as D2. The cross section of the guide rail is schematically shown by dividing it into a work hardened portion 16 and an unhardened portion 17. The work hardening part 16 has a positional relationship deeper than the depth D2.

  (B) shows how the guide rail surface is shaved when the guide rail is rubbed with a brake. In addition, a positional relationship in which the protrusion 3 of the brake element rubs is also shown. When the brake is pressed against the guide rail by a spring from the state of (a) and rubbed, the protrusion 3 of the brake bit bites into the surface of the work hardened portion 16 of the guide rail 8 while the work hardened portion 16 of the guide rail 8 is being scraped. Friction is exerted. Here, at the center position 19 of the longest diamond-shaped projection 3 that contacts the work-hardened portion 16 of the guide rail 8 the longest, the cut depth of the work-hardened portion 16 of the guide rail 8 is deep, and the left end side of the diamond-shaped protrusion 3 18; at the right end 20 the shaving depth is shallower. Therefore, variation occurs in the shaving depth of the guide rail. By narrowing the interval between the protrusions 3, this tendency is alleviated. However, if the interval is reduced, the chips are clogged into the groove, and the chips obstruct the friction to reduce the frictional force (friction coefficient). Therefore, there is a limit to reducing the interval.

  The degree of shaving depth of the work hardening portion 16 of the guide rail is affected by the hardness of the guide rail, the surface pressure that presses the brake against the guide rail, and the contact length of the brake. When the hardness is high, the shaving depth is shallow and remains in the region of the work hardened portion. In addition, the protrusion 3 alone causes a variation in the cutting depth, in other words, friction in a region having a hardness distribution. Nevertheless, if the spring force is adjusted, the specified deceleration can be obtained in the first test.

  FIG. 7 is a diagram for explaining how the second guide rail surface is shaved when the brake element of the comparative example is used. When the second test is performed, the guide rail uses an unused part, so that (a) is the same as FIG. (B) shows how the guide rail surface is scraped when the guide rail is rubbed with a brake, as in FIG. The friction surface of the second brake is in a state in which the chips 25 shaved from the guide rail in the first test are melted and adhered to the surface. From this state, when the brake is pressed against the guide rail by a spring and rubbed, the protrusion 3 of the brake bites into the surface of the work hardened portion 16 of the guide rail 8, and the work hardened portion 16 of the guide rail 8 is scraped and frictional force is applied. Demonstrated. However, the biting depth is suppressed, and only the shallow D2 is compared with the first depth D1. This is because the chips stuck to the brake interfered. Usually, the chip hardness (≈ guide rail hardness) is smaller than the hardness of the brake. The guide rail hardness is about half of the brake element hardness including work hardening. Therefore, the apparent hardness of the surface of the brake element is lowered and the shaving depth of the guide rail is suppressed.

  Therefore, when the hardness of the guide rail in the first and second tests is applied to the hardness change degree graph with respect to the depth direction of the guide rail shown in FIG. 4, the hardness difference between the two becomes D2-D1, corresponding to this hardness difference. As a result, the coefficient of friction decreases, and in some cases, the specified deceleration may not be obtained in the second test.

  In addition, when the surface pressure is increased, the protrusions 3 are abruptly worn, the spring force is reduced, the frictional force is reduced, and the braking performance at the specified number of times cannot be maintained. Increasing the length of the brake element is not preferable because the size of the device increases.

  FIG. 8 is a diagram for explaining how the guide rail surface is scraped for the first time when the brake element of the safety device of the present embodiment is used. (A), (b) shows the same state as FIG. (C) shows a diagram simulating the state after the lateral edge 2 is rubbed. When the lateral edge 2 rubs from a state in which the shaving depth varies with the friction of only the projection 3 shown in (b), the lateral edge 2 bites into the work hardening portion 16 of the guide rail in which the surface is dug up by the projection 3. It becomes easy to penetrate into the deep position of the guide rail, and if it rubs in this state, it can be rubbed with the lateral edge 2 while scraping almost the depth portion to the work hardened portion of the guide rail. In addition, the lateral edge is provided at the most protruding position of the brake element with a convex friction surface, so that the pressing force when the brake element is pressed against the guide rail is greater than the protrusion position, and the work of the guide rail is hardened. It is possible to cut to a deep part D4 that is equal to or greater than the part.

  FIG. 9 is a diagram for explaining how the second guide rail surface is scraped when the brake element of the safety device of the present embodiment is used. (A), (b) shows the same state as FIG. In the second test, as described above, since chips adhere to the surface of the brake, biting into the guide rail by the protrusions can be suppressed. (C) shows a diagram simulating the state after the lateral edge 2 is rubbed. Although chips bite on the vertical surface 2a forming the horizontal edge, the biting action of the horizontal edge is somewhat weakened, but it can be rubbed while cutting into the position D3 near the work hardened portion depth of the guide rail.

  Therefore, when the hardness of the guide rail in the first test and the second test is applied to the hardness change degree graph with respect to the depth direction of the guide rail shown in FIG. 4, the hardness difference between the two becomes D4-D3. The difference between the first and second tests can be reduced by cutting the work-hardened portion almost as compared with D1-D2, and thus reducing the difference. As a result, if the spring force is adjusted so that the first deceleration is in the vicinity of the median value of the specified range, the decrease in the second deceleration is small, so that it is difficult to fall below the specified range lower limit value.

  FIG. 10 is a diagram showing the rate of decrease in the coefficient of friction by mounting the brake element of the emergency stop device of the present embodiment and the brake element of the comparative example on the emergency stop device, performing two consecutive drop tests, respectively. . A predetermined spring force was set at a rated speed of 90 m / min and a falling mass of 2300 kg, and a brake with only a protrusion 3 and a brake with a lateral edge 2 at the protruding position of a convex curve were compared. As a result, assuming that the reduction rate of the friction coefficient in Comparative Example 23 is 1, the reduction in the friction coefficient in Example 24 having the lateral edge 2 is about 0.45, which is suppressed to half or less. In Comparative Example 23, the second deceleration was a braking characteristic lower than the specified range lower limit value.

  FIG. 11 is a front view showing an emergency stop device according to another embodiment of the present invention. In (a), a large number of rollers 12a in the roller unit 12 provided between the brake element 1 and the guide member 11 are arranged at positions where the lateral edges 2 are provided. Further, (b) is set so that the surface of the guide member 11 that contacts the roller unit 12 is a convex curved surface 11a and the lateral edge 2 of the brake 1 is positioned in the vicinity of the apex of the protrusion. Further, (c) divides the spring member in the vertical direction, and if the spring member 11b for pressing the lateral edge against the guide rail is set to a spring larger than the other spring members 11a, 11c, the cutting performance of the guide rail 8 is improved. The coefficient of friction variation can be reduced.

  In addition, if there are multiple combinations of multiple protrusions and edges that have been described so far, the effect of peeling off the work-hardened part is even greater, and even if multiple tests are performed, chips that adhere to the brake face will be removed. It is less affected and the coefficient of friction variation can be reduced. For example, the emergency stop device according to the present embodiment is suitable for an emergency stop device that is less susceptible to the physical properties of the guide rail.

1 Brake 2 Horizontal edge 2
3 Protrusion 3
4 Obtuse angle part 5 Right angle part 6 Groove 7 Emergency stop device 8 Guide rail 9 Housing 10 Guide 11 Spring 12 Roller unit 16 Work hardening part 25 Chip 27 Convex curve

Claims (5)

In the emergency stop device that stops the car by the frictional force generated by pressing the brake against the guide rail during emergency braking,
A plurality of protrusions that dig up the work hardened portion of the guide rail surface on the friction surface of the brake and an edge extending in a substantially horizontal direction to peel off the work hardened portion, and the edge of the car is more than the protrusion. An emergency stop device that is located downstream with respect to the falling direction, and that the friction surface of the brake element is a convex curved surface with respect to the longitudinal direction of the guide rail, and the edge is located in the vicinity of the vertex of the convex portion.   The emergency stop device according to claim 1, wherein the installation density of the rollers of the roller unit provided on the back surface of the brake element for pressing the brake element against the guide rail is compared with the back position other than the vicinity of the edge. An emergency stop device characterized in that the vicinity is set high.   2. The emergency stop device according to claim 1, wherein the shape of the guide member that presses the roller unit against the back surface of the brake element is a convex curved surface with respect to the rear surface of the brake element, and the vicinity of the vertex of the convex portion is the vicinity of the edge of the brake element. An emergency stop device characterized by being in a horizontal position.   2. The emergency stop device according to claim 1, wherein a spring provided on a back surface in the vicinity of the edge of the brake element among a plurality of springs provided on a back side of the brake element for pressing the brake element against a guide rail. 3. The emergency stop device is characterized in that the spring force of is larger than the spring force of the spring provided in the other part. A car that goes up and down the hoistway,
A guide rail installed in the hoistway for guiding the raising and lowering of the car;
An emergency stop device for generating a braking force by pressing and sliding a brake element on the guide rail, and stopping an elevator car;
The emergency stop device is a first slide in which a plurality of protrusions formed in a conical shape facing the guide rail and having a narrow sliding surface on the front end side and a wide skirt are arranged in the horizontal direction of the sliding surface. And an upper surface of a groove that is disposed below the first sliding portion in the vertical direction and extends in a direction substantially orthogonal to the guide rail and horizontally in the sliding surface. A brake member having a second sliding portion, and the sliding surface of the brake member is formed with a convex curved surface in a direction perpendicular to the guide rail, and the second sliding portion is in the vicinity of the vertex of the convex portion. Located in the elevator.

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