JP5427682B2 - Emergency stop device and elevator using the same - Google Patents

Description

  The present invention relates to an emergency stop device for an elevator, and is particularly suitable for an emergency stop device that generates a stable braking force even for a high-speed and large-capacity elevator and an elevator using the same.

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 at a certain speed or higher.
When the car reaches a predetermined speed or more, the emergency stop device pushes the elevator rail installed on the wall of the hoistway with two brakes with trapezoidal friction materials, and elastically deforms the spring. The braking force is generated by the generated force, and the braking element is generally formed of a material such as cast iron or copper-based sintered alloy having an appropriate friction coefficient and wear resistance.

  In addition, the elevator has a high speed and a large capacity, and the emergency stop device is required to generate a stable braking force even in a high temperature environment due to frictional heat generated between the brake and the guide rail.

  Furthermore, it is known that a cylindrical friction material made of ceramics is pressed against the guide rail in order to ensure a predetermined friction force without rotating the friction material even when a biasing braking force acts on the friction material as a brake piece. For example, it is described in Patent Document 1.

  Furthermore, in the brake part, a large number of fine fibers exposed on the surface exhibit the same effect as embedded hard particles, and the dropped particles like hard particles are stable without damaging the rail. It is known that a ceramic fiber or a bundle thereof is embedded in a plate-shaped ceramic base material perpendicularly to a surface to be an opposing surface of a brake shoe so as to have frictional wear characteristics, and is described in Patent Document 2. ing.

JP 2007-302450 A JP 09-71769 A

  In the above prior art, the ceramic cylinder is pressed against the guide rail, so the hardness of the ceramic is extremely higher than that of the general structural rolled steel, which is a rail material, and hardly changes even at high temperatures. The surface of will be shaved. Therefore, if the surface of the guide rail is scraped or the unevenness of the surface becomes extremely rough, the vibration of the car increases and the ride quality decreases, and in the worst case, the rail must be replaced. In the case of a high-rise building, the work of rail replacement would be very time consuming and expensive.

  With the thing of patent document 2, the mechanical strength of a ceramic fiber cannot be ensured, but it cannot endure a frictional force, it destroys, and it is difficult to generate | occur | produce a desired braking force with high speed and large capacity.

  An object of the present invention is to solve the above-described problems of the prior art, to generate a stable braking force up to a high speed and a large capacity, and to prevent damage to the surface of the guide rail.

In order to achieve the above object, the present invention provides an emergency stop device for an elevator that generates a braking force by sliding a guide rail installed in a hoistway against a guide rail by pressing it with a brake to stop an elevator car. A ceramic sheet disposed on the sliding surface of the guide rail and the brake and made into a cloth shape with ceramic fibers, and a support that fixes the end surface of the ceramic sheet to slide with the guide rail; The ceramic sheet is a plain weave, a twill weave, or a weave weave in which warps and wefts twisted with the ceramic fibers are alternately raised and lowered, and cut obliquely with respect to the warps and wefts as viewed from above. The cut end face slides on the guide rail .

The end face of the cloth-like ceramic sheet made of ceramic fibers, which is cut diagonally with respect to the warp and weft, slides with the guide rail, so that the car can be stopped reliably while preventing damage to the guide rail surface. It can be.

The perspective view which shows the brake element of one Embodiment by this invention. The front view which shows the emergency stop apparatus (before operation | movement) of one Embodiment by this invention. The front view which shows the emergency stop apparatus (after operation | movement) of one Embodiment by this invention. The fragmentary perspective view which shows the emergency stop apparatus part of one Embodiment by this invention. The top view (a) and side view (b) explaining the structure of the friction material of one embodiment. The top view and perspective view explaining the direction cut out from the friction material raw material of FIG. 5 in one embodiment. The perspective view which shows the attachment structure of the friction material and support body in one Embodiment. The perspective view which shows the attachment structure of the friction material and support body in other embodiment. The side view explaining comparatively the force which acts on the friction material by one embodiment. The front view which shows the sliding surface when a friction and abrasion test is implemented. The graph which shows the result of having compared the friction coefficient. The graph which shows the result of having compared the abrasion loss of the friction material. The graph which shows the result of having compared the amount of wear of a disk (equivalent to a guide rail).

Hereinafter, an elevator safety device will be described with reference to the drawings.
FIG. 1 shows a brake element 1 of an emergency stop device, which is a quadrangular prism having a trapezoidal cross section in which an upper end side 43 is a short side and a lower end side 44 is a long side. In the brake 1, a plurality (three in the figure) of block-like friction materials 3 are embedded at a predetermined interval on the surface of the support 2 made of cast iron facing the guide rail 7 (not shown).

  The friction material 3 is composed of ceramic fibers bonded together (hereinafter referred to as a ceramic sheet), and the friction material 3 and the support 2 are in a state in which the tip of the friction material 3 slightly protrudes from the surface of the brake 1. It is combined with. The ceramic sheet 42 which is the friction material 3 slides on the guide rail 7. Stop plates 4 for fixing the friction material 3 are fixed to both side surfaces of the support 2 with screws 5.

  FIG. 2 is a longitudinal sectional view of the safety device, and the safety device 6 is configured symmetrically with the guide rail 7 interposed therebetween. The pair of brake elements 1 are arranged substantially parallel to the guide rail 7 with a slight gap so that the guide rail 7 can be clamped. The rear surface of the brake element 1 is a wedge-shaped smooth inclined surface that narrows upward.

  A guide plate 8 for guiding the movement is provided on the guide member 11 so that the brake element 1 moves to a predetermined position. The guide member 11 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 the elastic bodies 10. The outer peripheral portion of the guide member 11 is surrounded by an elastic body 10 formed in a U shape (FIG. 4) whose side facing the guide rail 7 is open. The brake 1, the guide plate 8, the guide member 11, and the elastic body 10 are accommodated in the housing 9. At one end of the brake 1, there is a lifting rod included in a driving means (not shown) that activates the emergency stop device 6. It is connected.

  FIG. 3 shows a state in which the emergency stop device is operated. When the emergency stop device is operated, when the brake element 1 is pulled up with respect to the guide member 11 along the guide plate, the distance between the brake elements 1 increases. Move to narrow. At this time, the brake element 1 pushes the guide member 11 and the elastic body 10 in the direction of the arrow 13. The reaction force generated by the guide member 11 and the elastic body 10 being spread acts on the brake 1 to sandwich the guide rail 7.

Multiple sets of emergency stop devices are installed depending on the specifications of the elevator. The braking force F required to stop the car at a predetermined deceleration is:
F = 4 μN = m × (a + g)
Here, μ: coefficient of friction between brake and rail, N: pressing force of elastic body (N), m: falling mass (kg), a: deceleration (m / s ² ), g: gravity acceleration (9. 8 m / s ² ).

In the case of a one-stage emergency stop device, the number of brake elements is four (2 / rail × 2 rails). Therefore, the braking force is quadrupled. The braking force F is directly proportional to the falling mass. Since there is a limit to the force that can be generated by the elastic body in manufacturing, when the falling mass becomes heavy, the emergency stop is divided into a plurality of stages to ensure the braking force. Further, as the rated speed increases, the coefficient of friction between the brake and the rail decreases, so that the falling mass that requires multi-stage shifts to the lighter side at higher speeds. Therefore, double deck elevators and elevators for high-rise buildings with two-story elevators are multi-tiered. For example, the braking force required to stop at a deceleration of 5.88 m / s ² with a drop mass of 25,000 kg is 392 KN. If μ = 0.2 and the maximum pressing force Fmax is 400 kN, 72 KN is insufficient in the one-stage assembly, and two stages are necessary. In the speed range of 30 to 240 m / min for low-rise buildings with the largest number of units in the market, the one-stage assembly is mostly used.

FIG. 4 is a perspective view showing an outline of an elevator car provided with an emergency stop device.
A passenger car 46 on which passengers are placed is connected to a drive system (not shown) on the top floor of the building by a rope 45. For the sake of simplification, details of the door opener and outer frame are not shown in the figure. On both sides of the hoistway, guide rails 7 that guide the raising and lowering of the car 46 are installed. An emergency stop device 6 is installed at the lower end of the car 46 so as to sandwich the guide rail 7. The emergency stop device 6 is also provided on the opposite guide rail (not shown), and both are connected by a connection mechanism (not shown). Further, the emergency stop device 6 has simplified details such as a housing.

  The length of the guide rail 7 is the guide rail vertical direction 41, the direction in which the brake 1 is opposed to the guide rail across the guide rail is the guide rail thickness direction 40, and the direction in which the left and right guide rails 7 face each other is the guide rail width direction 39. Is defined.

The operation of the emergency stop device will be described with reference to FIGS.
When the moving speed of the car reaches a set speed exceeding the rated speed, a speed sensing device (not shown) installed on the top floor operates to raise the brake 1, and the brake 1 is a hoistway wall on both sides of the car. The guide rail 7 installed in is sandwiched. And the brake element 1 expands the U-shaped elastic body 10 and elastically deforms it, thereby generating a frictional force between the guide rail 7 and the brake element 1 and stopping the car.

  A ceramic sheet 42 which is the friction material 3 of the brake 1 is brought into contact with the guide rail 7, and a frictional force due to adhesion and cutting resistance is generated between each ceramic sheet 42 and the guide rail 7 to obtain a braking force. By using the ceramic sheet 42 for the friction material 3, it is possible to prevent softening or seizure of the friction material 3 due to sliding heat during sliding even when the speed is increased or the load capacity is increased, and a predetermined braking force can be secured.

  In addition, since the ceramic sheet 42 is composed of an aggregate of ceramic fibers, it is possible to ensure predetermined friction / wear characteristics while suppressing damage to the guide rail 7 and to reliably stop the car. It can be a high elevator safety device.

FIG. 5 shows an overview of a material that is the ceramic sheet 42 that is the friction material 3. The ceramic sheet 42 is formed by intertwining ceramic fibers or twisting them into a yarn to form a cloth. (A) is a top view of the ceramic sheet 42. A block-like ceramic sheet 42 is formed by forming a plain-woven sheet-like woven fabric in which warp yarns 14 and weft yarns 15 woven with ceramic fibers are alternately woven. Therefore, even if the proportion of ceramic fibers is high, the mechanical strength can be secured by weaving each other. Although the strength in the vertical direction (in FIG. A, the direction perpendicular to the paper surface) tends to be lower than the other directions when viewed from above, the support structure for the friction material 3 and compressive force is applied in the vertical direction as will be described later. In order to prevent destruction.
(B) is a side view of a ceramic sheet. The cross section of the warp yarns 14 is arranged side by side so that the weft yarns 15 are sewn (plain weave: a fabric in which warp yarns and weft yarns are alternately raised and lowered). Depending on how the fibers are woven, unlike the structure shown in the figure, twill weaves (a warp fabric in which two or three warp yarns are crossed and one under the weft yarns are crossed), Shusu (Akiko) A weaving method (woven fabric in which warp yarns and weft yarns are alternately raised and lowered to reduce the float of either yarn) or a sheet-like nonwoven fabric in which fibers are entangled without being woven may be used.

  The ceramic sheet 42 is hot pressed at a high temperature to form a bonded body. Since the ceramic fiber has high mechanical properties and excellent heat resistance, the ceramic sheet 42 is also excellent in mechanical strength and heat resistance, and has a lower hardness than those using a fine ceramic as a base material. For example, the hardness of silicon nitride is about 1400 HV, whereas the hardness of the ceramic sheet 42 is about 1000 HV (100 HS) in terms of a converted value.

  Since the wear of the mating material increases in proportion to the hardness of the friction material 3, it is possible to suppress damage to the guide rail if the hardness of the friction material 3 is reduced. According to the friction test, it has been confirmed that the damage of the rail material is within an allowable range in the friction between the ceramic sheet 42 and the guide rail material.

  6A shows the cutting direction of the material of the ceramic sheet, and the friction material 3 is inclined with respect to the warp yarn 14 and the weft yarn 15 as viewed from the top as shown by the cut line 16 (in the figure, the fiber It is preferable that the cut end face is cut with the guide rail 7 (about 45 degrees with respect to the longitudinal direction).

  FIG. 6B shows a perspective view of the ceramic sheet after being cut out based on FIG. 6A, and the cut-out ceramic sheet 42 forms a rectangular parallelepiped. Therefore, in the figure, the fiber end surfaces 18 of the warp and the weft are respectively substantially elliptical on the surface of the fiber cross section in two directions adjacent to the cut surface 17.

  FIG. 7 shows the embedding direction of the ceramic sheet into the support 2. The cut out ceramic sheet 42 is arranged such that the longitudinal direction of the end surface is the guide rail vertical direction 41 and the end surface slides on the guide rail 7. A fixed amount protrudes from the support 2 and is embedded. That is, the braking force is generated by sliding the end surfaces of the warp and weft yarns and the guide rail 7.

  A plurality of ceramic sheets 42 are laminated in the rail width direction 19 and are fixed to the support 2 by being sandwiched between the stop plates 4 in FIG. The stopper plate 4 applies a compressive force to the stacking direction of the ceramic sheets 42 (rail width direction 19).

  Since the lamination direction 19 of the ceramic sheets 42 is the rail width direction, the friction force hardly acts in the peeling direction between the laminations to prevent peeling failure. In addition, by applying a compressive force in the stacking direction in advance with the stopper plate, even if a tensile stress acts in the direction of peeling between the stacks, the compressive force is canceled out and breakage can be further prevented.

  FIG. 8 is a view showing another combined shape of the friction material 3 and the support 2. An inclined surface 35 is provided below the friction material 34 made of a ceramic sheet. Specifically, an inclined surface having an acute angle is provided in a direction away from the guide rail sliding surface (not shown). And the support body 2 is carved in the same shape, and the inclined surface 38 is provided. At this time, the length of the rail to be carved in the vertical direction is slightly longer than that of the friction material to make a loose fit. Thereby, unnecessary stress at the time of fastening does not occur in the friction material. Then, the friction material 34 is inserted from the side surface of the support 2. Further, the friction material 34 is sandwiched between stop plates (not shown) and fixed to the support 2.

  An inclined surface may be provided above the friction material 34. However, since an upward frictional force acts on the friction material 34, the contact between the friction material 34 and the support 2 is more stable when the surface receiving the frictional force is flattened. To do. By adopting the shape as described above, the inclined surfaces 35 and 38 both serve to prevent the rail from coming off, and the friction material 34 does not fall off the support 2 even if the stop plate is removed.

  FIG. 9 is a diagram for explaining a state when a frictional force is applied to the ceramic sheet 42 that is the friction material 3. (A) A figure is a figure when the ceramic fiber is vertically embedded from the sliding surface as a comparative example. When a frictional force acts on the end faces of the ceramic fibers 20 to 22 on the arrow 23, the fibers 20 to 22 are embedded independently and bend in the same direction as the frictional force. If there is no supporting member, the fiber on the end side of the friction material loses frictional force, and the fiber may break. As a result, the required braking force cannot be obtained.

  (B) The figure has shown the structure which twisted the ceramic fiber by the ceramic sheet 42, and woven it as warp and weft. The frictional force indicated by the arrow 32 acts on the end face in a state where each fiber is woven (at least a sheet in which the fibers are intertwined without being woven). However, since the frictional force can be supported at the woven positions 29 and 31, the fiber does not break.

  The fiber 27 is supported by the fiber 24, the fiber 25, and the fiber 29. The fiber 28 is supported by the fiber 25, the fiber 26, and the fiber 24. Similarly, other fibers are supported by surrounding fibers. (It is the same if at least the fibers are intertwined.) Since the fiber diameter is around 10 μm, the support position is slightly away from the sliding surface, and the bending of the fibers is small. As a result, the fiber does not lose the frictional force generated between the guide rails 7, and the necessary braking force can be obtained.

Next, the results of comparing the friction / wear characteristics will be described with reference to FIGS.
FIG. 10 is a diagram showing the conditions of the sliding surface of the friction material 3 when the friction characteristics are compared using a commercially available fiber binder for the ceramic sheet. (A) A figure shows the case where the surface which weaved warp and weft, ie, the surface where the longitudinal direction of a fiber can be seen, is made into a sliding surface, and let this surface be A surface. (B) The figure shows a case in which warp and weft are woven, and the surface on which either the warp or weft fiber end face can be seen is a sliding surface. (C) In the figure, the sliding surface is the same surface as that of the ceramic sheet described in FIG. 7 and the surface where both end surfaces of the warp and weft can be seen (the surface formed by cutting the fibers obliquely). This surface is defined as C surface.

The friction test was performed using a pin-on-disk tester. A disk (disk) made of the same material as the guide rail 7 is rotated at a predetermined speed, the friction material 3 is pressed against the disk surface with a predetermined pressing force, and the disk speed is stopped at a predetermined deceleration by a motor. Specifically, the initial speed was 1500 m / min, the pressing force was about 6500 N, and the deceleration was 5.88 m / s ² .

FIG. 11 shows the results of measuring the friction coefficient on the A, B, and C surfaces.
The average coefficient of friction was determined from the ratio of the friction force generated in the friction material 3 from the start of deceleration to the stop and the pressing force. Then, the friction coefficient slid on the A surface was set as a reference value 1, and the relative friction coefficients of the B surface and the C surface were compared. As a result, the friction coefficient was found to be about 1.25 times higher than the A-plane, since the friction coefficient was A-plane <B-plane <C-plane.

  In the case of the C surface, all the fiber end surfaces are exposed to the sliding surface, and the resistance is also applied by scratching the disk by the fiber edges. The effect is the same on the B side, though the effect is small. That is, it is effective if at least the end surface of the ceramic sheet 42 slides on the guide rail 7.

  In addition, when the B and C surfaces after the friction test are observed with an electron microscope, chips generated by scratching the disk material are attached to the end portions of the fibers, and the fallen particles escape into the fibers and the disks. Prevents direct sliding with the material.

FIG. 12 shows the result of comparison of the wear amount of the friction material 3.
If the amount of wear when sliding on the A side is a reference value 1, the B side is about 0.4 and the C side is about 0.13. The wear of the A side was intense because of the shearing force acting between the fibers, and the fibers were evenly filled with the oxide that was present on the surface of the raw material fibers, but the bonds between the fibers were interwoven. This is because it is weaker and easier to peel off than the other direction. Therefore, the overlapping fibers are peeled off rather than the fibers being worn. On the other hand, since the separation between the fibers does not occur on the B surface and the C surface, wear is suppressed. The reason why the C surface is more difficult to wear than the B surface is that the fiber occupying ratio of the surface receiving the frictional force is wide.

FIG. 13 shows the result of comparison of the wear amount of the disk (corresponding to the guide rail 7).
For the friction material 3, fine ceramics made of silicon nitride as a comparative material and a commercially available fiber bonded body as the material described with reference to FIG. It was found that the amount of relative wear when sliding the C surface was as small as 0.1. This is related to the material hardness of both. The Vickers hardness of the SS400 material of the disk material was about 120 HV (Brinell hardness 115 HB) in terms of the converted value, and the hardness of the comparative material was about 1400 HV, so that the comparative material was hardly worn and the disk was markedly worn.

  On the other hand, the hardness of the embodiment material described in FIG. 7 is about 1000 HV (Shore hardness about 100 HS) in terms of a converted value, and disc wear can be suppressed by being worn by itself. Further, the degree of roughness of the disk surface due to the scratching force by the fiber end face was also slight. Further, the appearance of the friction material subjected to the friction / wear test was observed, but there was no breakage of the fiber or breakage of the end portion.

  As described above, a friction material in which ceramic fibers are woven in two directions and laminated as a ceramic sheet is used, and the fiber end surface is exposed to the sliding surface, thereby preventing damage to the counterpart material (guide rail 7) and Friction and wear characteristics can be ensured, and even if the rated speed of the elevator is 480 to 1500 m / min and the car mass (falling mass) is 20 tons or more, it should be reliable enough to stop the car reliably. Can do.

  The ceramic sheet can be made into a cloth shape by intertwining ceramic fibers, or twisted ceramic fibers into a woven fabric shape, or applied to an elevator having a rated speed of 360 m / min or less. A braking force can be generated and damage to the guide rail surface can be suppressed.

DESCRIPTION OF SYMBOLS 1 Braking element 2 Support body 3,34 Friction material 7 Guide rail 14 Warp yarn 15 Weft 17 Cutting surface 18 End surface 19 Lamination direction 35 Inclined surface 42 Ceramic sheet

Claims (6)

In order to stop the elevator car, in the elevator emergency stop device that generates braking force by sliding the guide rail installed in the hoistway with a brake,
A ceramic sheet disposed on a sliding surface between the guide rail and the brake, and made into a cloth shape with ceramic fibers;
A support that fixes the end face of the ceramic sheet so as to slide with the guide rail;
The ceramic sheet is a plain weave, a twill weave, or a weave weave in which warps and wefts twisted with the ceramic fibers are alternately raised and lowered, and cut obliquely with respect to the warps and wefts as viewed from above. An emergency stop device in which the cut end face slides with the guide rail .   The emergency stop device according to claim 1, wherein the ceramic sheet is disposed so that a longitudinal direction of an end face of the ceramic sheet is a vertical direction of the guide rail.   2. The emergency stop device according to claim 1, wherein a plurality of the ceramic sheets are laminated in the width direction of the guide rail so that a longitudinal direction of an end surface thereof is a vertical direction of the guide rail.   The emergency stop device according to claim 1, wherein a plurality of the ceramic sheets are laminated in the guide rail width direction, and a compressive force is applied in the lamination direction. In order to stop the elevator car, in an elevator having an emergency stop device that generates a braking force by pressing and sliding a guide rail installed in a hoistway with a brake,
The emergency stop device is
A ceramic sheet disposed on a sliding surface between the guide rail and the brake, and made into a cloth shape with ceramic fibers;
A support that fixes the end face of the ceramic sheet so that it slides on the guide rail, and the ceramic sheet is a plain weave or twill weave in which warps and wefts twisted with the ceramic fibers are alternately raised and lowered. Or an elevator weave, cut obliquely with respect to the warp and weft when viewed from above, and the cut end face slides on the guide rail . 6. The elevator according to claim 5, wherein the rated speed of the car is 480 to 1500 m / min.

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