JP4797786B2 - Elevator emergency stop device and elevator - Google Patents

Description

  The present invention relates to an elevator safety device and an elevator, and is particularly suitable for an elevator that operates when the elevator speed exceeds a predetermined speed.

The elevator is obliged to install a safety device, that is, an emergency stop device, that stops the car at an appropriate deceleration when the car descends above a certain level.
The emergency stop device was installed on the wall of the hoistway when the car reached a predetermined speed or more using a brake element with two trapezoidal friction materials inside surrounded by an elastic body. The elevator guide rail is pressed by two brakes to generate the braking force by the force generated by elastic deformation. Conventionally, the brakes are cast iron, copper-based sintered alloy, etc. with appropriate friction coefficient and wear resistance. It is formed of the material.

However, as the number of buildings rises year by year, the specifications of elevators have shifted to higher speeds and larger capacities, and in emergency stop devices, the high temperature due to frictional heat generated between the brake and the guide rail during operation is high. It is required that a stable frictional force can be obtained even in an environment.
In order to obtain stable braking characteristics even under high speed and large capacity, ceramic friction material with excellent heat resistance is used, and the friction material is cylindrical or polygonal with rounded corners and protrudes from the surface of the brake body For example, it is described in Patent Document 1.

  In order to prevent the brake element from hitting the guide rail, a ceramic brake piece (friction material) is embedded on the brake surface side of the brake element so as to protrude from the brake surface. It is known that an annular ring made of a soft metal is disposed on a ring, punches are press-fitted into several places on the annular surface, the annular ring made of a soft metal is locally deformed, and a brake piece is fixed. Are listed.

Japanese Patent Laid-Open No. 10-182031 JP 2000-191252 A

  In the above prior art, when the emergency stop is operated, a non-uniform distribution of the pressing force is generated in the sliding surface of the friction material, and there is a risk that the rotational force acts on the friction material and the rotation cannot be suppressed. . In other words, if the rotational force by the frictional force exceeds the holding force of the caulked friction material, the friction material will rotate, and the friction force acting between the friction material and the rail cannot be secured, and an appropriate deceleration will be obtained. I can't do that. And especially when the falling mass increases, the braking force must be increased proportionally, and the difference in the pressing force in the sliding surface of the friction material also increases, further suppressing the rotation of the friction material. Becomes difficult.

Moreover, the rail chips generated during braking affect the frictional force depending on the arrangement method of the friction material. Specifically, when chips remain in the brake, sliding heat is conducted to the support of the brake via the chips and the support is thermally deformed so that the friction material cannot uniformly contact the rail. , The frictional force becomes smaller.

  An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a highly reliable emergency stop device for an elevator and an elevator that can securely fix a friction material embedded in a brake and can reliably stop a car in an emergency. There is to do.

To achieve the above object, the present invention provides a safety device for elevators which generates a braking force by pressing a braking element in the guide rails to stop the elevator car when an abnormality occurs, the plane part of the cylinder A friction material made of ceramics and made of ceramic so as to form a notched surface, the brake element sandwiching the guide rail with a support holding the friction material, and pressing the brake element against the guide rail An elastic body, and the friction material is arranged such that an end surface of a cylinder is pressed against the guide rail, and the notch surface is parallel to the ascending / descending direction of the car and receives a frictional force and a rotational force The friction material is held on the circumferential surface of the support.

  According to the present invention, even if a biased braking force acts on the friction material serving as a brake piece, a predetermined friction force is secured without rotating the friction material, and the car can be stopped reliably in an emergency. Can be.

Hereinafter, an emergency stop device for an elevator according to the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a car 1 provided in an elevator and an emergency stop device attached to the lower part of the car 1. The car 1 on which a passenger is placed is connected to a drive system (not shown) on the top floor of a building by a rope 3. It is connected. In this figure, detailed illustrations of the door opener and outer frame are omitted for simplification.
On both sides of the hoistway, a pair of guide rails 2 are installed to guide the car 1 when moving up and down. A pair of emergency stop devices 4 are installed at the lower portion of the car 1 so as to sandwich the T-shaped vertical bar portion of each guide rail 2 formed in a T-shaped cross section. The pair of safety devices 4 are connected by a connection mechanism (not shown).

FIG. 2 is a longitudinal sectional view of the emergency stop device, which is configured symmetrically with respect to the guide rail. The emergency stop device 4 has a pair of brake elements formed in a trapezoidal cross section. The brake element 5 has a short side at the upper end side and a long side at the lower end side.
The pair of brake elements 5 are arranged substantially parallel to the guide rail 2 with a slight gap from the guide rail so that the guide rail 2 can be sandwiched. The rear surface of the brake element 5 is a wedge-shaped smooth inclined surface that narrows upward.
A guide plate 8 for guiding the movement is provided on the guide member 10 so that the brake element 5 moves to a predetermined position. The guide member 10 forms an inclined surface parallel to the inclined surface of the brake 5 on the inner side, and is a vertical surface on the outer side, and the vertical surface is sandwiched between the elastic bodies 6. The outer peripheral portion of the guide member 10 is surrounded by an elastic body 6 formed in a U shape with the side facing the guide rail 2 open. The brake 5, the guide plate 8, the guide member 10, and the elastic body 6 are accommodated in a housing 9, and a lifting rod included in driving means (not shown) that activates the emergency stop device is connected to one end of the brake. ing.

FIG. 3 is a view showing a state where the safety device is operated. A plurality of guide rollers 11 are pressed against the inclined surface of the brake 5. The roller 11 is rotatably held by the guide member 10 and acts so that the brake can move smoothly upward.
Since the guide member 10 has an inclined surface parallel to the inclined surface of the brake 5 and the back side of the guide member 10 is a vertical surface, the vertical surface of the guide member 10 is sandwiched between the elastic bodies 6. It has become. Therefore, when the emergency stop device operates, the brake element 5 is pulled up with respect to the guide member 10 and pushes the guide member 10 apart. The reaction force with which the guide member 10 is spread acts on the brake 5, and the brake 5 moves so that the mutual distance is narrowed. And the guide rail 2 is inserted | pinched.

  FIG. 4 is a schematic external view of the brake element, and the brake element 5 includes a square columnar support body 5a made of cast iron and a plurality of support bodies 5a coupled to the guide rail facing surface side of the support body 5a (in this embodiment, 4 and 2 rows of friction materials 12 are provided. The friction material 12 is high performance ceramics such as silicon nitride, silicon carbide, alumina, and sialon. The coupling between the friction material 12 and the support body 5a is held, for example, by shrinking in a state where the tip of the friction material protrudes 1 to 3 mm from the surface of the brake. The friction material 12 slides on the guide rail 2.

FIG. 5 is a perspective view when the support 5a of the brake 5 and the friction material 12 are disassembled. The friction material 12 has a shape in which a part of a columnar shape is cut out, and the cut-out surface 15a has a rectangular shape (hereinafter referred to as a D shape). That is, the friction material 12 has a shape in which a cylinder is cut out so that a flat cutout surface is formed.
The end 13 of the surface that slides with the guide rail 2 and the end 14 of the notch surface are chamfered. Further, the end portions 18a and 18b of the cut-out surface are also chamfered. This is provided for the purpose of relaxing stress concentration because the end portion 18a (or 18b) receives the rotational force of the friction material. However, the end portions 18a and 18b may have gentle curvature surfaces.

The brake element 5 is provided with a concave hole 19 for holding the friction material 12 by shrinkage, for example, by electric discharge machining. The shape of the concave hole 19 is the same D shape as the friction material 12. The notch surface 15b of the recessed hole 19 and the notch surface 15a of the friction material 12 are fitted so as to be at the same position.
The notch surface 15a length L1 of the friction material 12 is slightly longer than the notch surface length L2 of the recessed hole 19 of the support 5b. In other words, the width L3 on the notched side of the sliding surface of the friction material 12 is slightly smaller than the width L4 of the recessed hole 19 of the support 5b. This is because the friction material is reliably held on the circumferential surface of the support 5a when the friction material 12 is baked.

  The friction material is held in the shape as described above to prevent falling off and preventing rotation. The notched surfaces 15a and 15b are provided at positions that are substantially parallel to the car lifting and lowering direction, which is the direction in which the friction material 12 slides on the guide rail 2 when the safety device is operated. That is, the friction material has a shape in which a cylinder is cut out so that a flat cut-out surface is generated, the end face of the cylinder is pressed against the guide rail 2, and the cut-out surface 15a is parallel to the raising / lowering direction of the car. Is arranged.

When the moving speed of the car 1 reaches a set speed exceeding the rated speed, a speed sensing device (not shown) installed on the top floor operates to capture a governor rope (not shown) connected to the emergency stop device 4. The governor rope is connected to a lifting rod 29, and the lifting rod 29 is connected to the brake element 5. The brake element 5 is lifted relatively to the emergency stop device 4 mounted on the falling car 1, so that the car The guide rail 2 installed on the hoistway walls on both sides of the guide 1 is swallowed, and at the same time, the U-shaped elastic body 6 arranged so as to surround the brake 5 is spread and elastically deformed, A frictional force is generated between the brakes 5 to stop the car 1.
When the friction material 12 of the brake 5 abuts against the guide rail 2, the edge of each friction material 12 moves while slightly cutting the sliding surface of the guide rail 2. As a result, cutting resistance is generated in the guide rail 2 and acts as a frictional force. Therefore, in order to generate cutting resistance in the guide rail 2, it is more effective to sharpen the edges of the friction material 12. However, if sharp corners are provided in the ceramic friction material 12, stress is concentrated at the time of contact and exceeds the material strength. Therefore, a chamfering process is performed to alleviate the stress. Further, by using the heat-resistant ceramic friction material 12, softening and seizure of the friction material due to sliding heat can be prevented.
When a non-uniform friction force acts on the friction material 12, a rotational force acts on the friction material. Then, the end 18a (or 18b) of the D-shaped friction material comes into contact with the notch surface 15b of the support 5a to stop the rotational force. Since the end portion 18a is chamfered, the stress is not concentrated, so that the friction material can be reliably held, and a predetermined braking force can be obtained even if a non-uniform friction force is applied.

Next, calculation of rotational torque acting on the friction material 12 will be described.
The friction coefficient μ between the brake 5 and the guide rail 2 is 0.25, and the pressing force per friction material is about 50 kN from the limit of the material strength. The rotational torque T1 acting on the edge portion of the cylindrical friction material 17 shown in FIG. 6A is calculated by the following equation.
F1 = μN T1 = F1 × r
F1 is a friction force, μ is a friction coefficient, N is a pressing force, and r is a friction material radius.
The average rotational torque T2 in the semicircle when the frictional force acts only on the right semicircle 17b (or the left semicircle 17a) of the friction material 17 shown in FIG. 6B is calculated by the following equation.
F2 = μN / s T2 = 2 / 3F2 × r ³
F2 is a friction force per unit area, μ is a friction coefficient, N is a pressing force, s is a semicircle area of the friction material, and r is a friction material radius.

FIG. 7 is a bar graph showing the calculation results of the rotational torque shown in FIGS. 6A and 6B and the rotational holding torque when the friction material 17 is shrinked. The friction material radius is 6.5 mm (diameter 15 mm, edge chamfer 1 mm).
The rotational torque acting on the edge portion of the friction material 17 which is the worst condition is about 81 N · m. Further, the average rotational torque when the frictional force acts only on the semicircular portion 17b is about 34 N · m. On the other hand, the rotational holding torque of the friction material having a tightening margin of 2 to 3 μm when the friction material 17 and the cast iron as the support are baked is about 11 N · m.
Therefore, with only the holding structure in which the friction material is baked, when the frictional force is extremely imbalanced, the friction material rotates and a predetermined braking force cannot be obtained. Moreover, if the tightening allowance for shrinkage is increased to ensure the rotation holding torque, the stress applied to the friction material becomes excessive, which is not preferable.

Next, the position of the rectangular notch surface provided for suppressing the rotation of the friction material will be described.
The notch surfaces 15a and 15b are provided at positions (side portions) that are substantially parallel to the direction in which the friction material 12 slides with the guide rail 2 when the safety device is operated, that is, the car raising / lowering direction. This is because the stress acting on the friction material due to the frictional force becomes the smallest position.

FIG. 8 shows the stress acting on the friction material due to the frictional force. When a frictional force in the direction of the arrow 22 acts on the surface of the friction material 12, tensile stress is generated at the lower position 20 in the longitudinal direction of the friction material (in the depth direction of the brake element), and the maximum value is shown at the fastening end of the brake element. On the other hand, a compressive stress equivalent to the stress acting on the lower position 20 acts on the upper position 21. That is, the portions bearing the force acting on the friction material 12 during the emergency stop operation are the upper and lower portions of the friction material.
Therefore, in order to suppress the rotation, it is preferable to avoid the lower position where the tensile stress acts on the part that receives the rotational force, and to set the side as the neutral point of the stress. And stress concentration can be avoided by separating the part receiving the frictional force and the part receiving the rotational force.

  Here, if the length L1 (FIG. 5) of the notch surface of the friction material is too short, it does not act as a detent, and if it is too large, it overlaps with the region that receives the frictional force as described above, resulting in stress. Since it concentrates, about 1/5-1/2 of a friction material diameter is preferable.

A method of machining a D-shaped concave hole in a brake according to another embodiment will be described.
FIG. 9 is an exploded perspective view of the brake element, and the drilled cylindrical holes 24 are processed by the number of friction material fastenings (six in FIG. 9). Next, in order to cut a part of the cylindrical hole 24, the groove 25 is dug by passing the central portion in the width direction of the brake element in the vertical direction by, for example, milling. The machining of the groove 25 is facilitated by making the cutout positions of the cylindrical holes 24 face each other. Further, the rectangular bar 23 slightly wider than the groove 25 is processed, the brake is heated to widen the concave hole, a friction material (not shown) is inserted, and the rectangular bar 23 is inserted into the groove 25 to be assembled. Thereby, machining costs can be reduced compared to electrical discharge machining. Further, for assembling the square bar 23, a square bar 23 slightly smaller than the groove 25 may be prepared, and bolt fastening, adhesion, welding, or the like may be used in combination.

  The friction material 12 shown in FIG. 5 may be fastened to the support 5a with an adhesive. In this case, the size of the concave hole of the support 5a is processed to be slightly larger than the diameter of the friction material. Then, an adhesive is interposed between the recessed hole and the friction material 12. The type of the adhesive is preferably a heat-resistant ceramic particle as a base material.

FIG. 10 shows a longitudinal sectional shape of a friction material according to another embodiment.
The friction material is provided with a plurality of notched surfaces, and the friction material 26 is provided with two notched surfaces 27 and 28 at positions facing each other, so that the rotational force can be received at two locations and the stress concentration. Can be further avoided.

FIG. 11 shows another arrangement of the friction material 12 on the support 5a. In order to ensure the frictional force, in addition to preventing the friction material 12 from rotating as described above, the friction material 12 is closely arranged in the rail width direction to ensure the sliding width, and at the time of braking. It is important to discharge the generated rail chips out of the brake. When chips remain in the brake, sliding heat is conducted to the support of the brake via the chips, the support is thermally deformed, and the friction material cannot uniformly contact the rail, and the frictional force is small. Become.

  Therefore, as shown in FIG. 11, the eight friction materials are arranged in a three-row staggered arrangement. The staggered arrangement means that the friction materials arranged adjacent to each other are shifted in the vertical direction. Generally, it arrange | positions so that the half of a friction material size may overlap.

  In this embodiment, two types of friction materials are used. Of the three rows, the friction members 30 and 31 in the end row have a D-shaped shape with one cutout surface, and the friction material 32 in the center row has a shape with two cutout surfaces. All the notch surfaces are provided in parallel with the hoistway direction of the car, and of these, the notch surfaces 30a and 31a of the friction members 30 and 31 in the end row are provided so as to face the center side.

  The distance between the friction material 30 arranged in the end row and the friction material 31 in the other end row arranged at the same height as the friction material is W1, and the friction material 30 is adjacent to the friction material 30 and shifted in the vertical direction of the rail. When the distance in the vertical direction of the rail with the friction material 32 in the center row is W2, the relationship of W1 <W2 is established.

Further, the two notch surface end portions 32a and 32b of the friction material 32 in the central row and the one notch surface 30a and 31a of the friction material 30 and 31 in the end row are on the same line ( Dotted lines 33a and 33b). That is, in the rail width direction, the friction materials do not overlap and are arranged without a gap.

  The operation of the emergency stop device including the brake element in which the friction material is arranged as described above will be described. FIG. 12 shows the relationship between the arrangement of the friction material of the brake and the discharge direction of the chips.

  When the friction material made of ceramic comes into contact with the rail, the brake element moves while slightly cutting the sliding surface of the rail by the edge of each friction material. At this time, chips are generated. For example, of the chips cut by the friction materials 30 and 31, the chips passing through the gap 34 between the friction materials 30 and 31 collide with the friction material 32 and flow to both ends of the brake element indicated by the arrows 35a and 35b to be outside the brake element. Discharged. At this time, compared to the gap width W3 of the friction materials 30 and 31 arranged at the same height position in the rail width direction, the vertical gap width W4 of the friction materials 30 and 32 arranged adjacently shifted in the rail vertical direction is wider. Therefore, the chips are easily discharged without accumulating between the friction materials in the brake. Further, since the friction material 32 in the center row has two notched surfaces, a gap is further increased in the brake and the discharge of chips becomes easy. Furthermore, by making the notch portion of the end row face the center side, a wide gap width W3 can be ensured, and chips do not easily accumulate in the gap 34.

  Further, since the friction material is arranged without a gap in the rail width direction, there is no portion left to be cut in the rail cutting width W5, and the effective sliding width is widened to ensure a large braking force.

  Similarly, in the case of four or more rows of staggered arrangements, if the friction material is arranged densely in the rail width direction and coarsely in the rail vertical direction, it is easy to discharge chips as well, but the number of rows increases too much. Since it becomes difficult to discharge the chips generated on the center side, it is not so preferable.

  Further, in this embodiment, two types of friction materials are used to facilitate chip discharge. However, even if one type is used in order to reduce the processing cost, the effect is not drastically reduced. If other friction material detent means is used, the arrangement of the friction material according to the present embodiment is not limited to the friction material having a notch surface.

1 is a perspective view showing an elevator car according to an embodiment of the present invention. The front view which shows the safety device of FIG. FIG. 3 is a partial perspective view of the safety device of FIG. 2. The perspective view of the brake which the emergency stop apparatus of FIG. 2 has. The fragmentary perspective view which shows the relationship between the friction material and support body by one Embodiment. The figure explaining the rotational torque which acts on the friction material by one embodiment. The graph which shows the comparison of the rotational torque and holding torque by one Embodiment. The figure explaining the stress which acts on the friction material by one embodiment. The perspective view which shows the brake element by other embodiment. The side view which shows the friction material by other embodiment. The side view which shows arrangement | positioning of the friction material by one Embodiment. The side view which shows arrangement | positioning of the friction material by other one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ride car, 2 ... Guide rail, 4 ... Emergency stop device, 5 ... Brake, 5a ... Support body, 6 ... Elastic body, 8 ... Guide plate, 10 ... Guide member, 12, 17 ... Friction material, 15a ... Notched surface,
19 ... recessed hole.

Claims (6)

In the emergency stop device for elevators that generates braking force by pressing the brakes against the guide rail to stop the elevator car when an abnormality occurs,
A friction material made of ceramic with a shape in which a part of a cylinder is notched so that a flat notch surface is formed;
The brake element that sandwiches the guide rail with a support that holds the friction material;
An elastic body for pressing the brake against the guide rail;
The friction material is arranged such that the end face of the cylinder is pressed against the guide rail, the notch surface is arranged in parallel with the raising / lowering direction of the car, and a part for receiving a frictional force and a part for receiving a rotational force are provided. An elevator emergency stop device , wherein the friction material is held on a circumferential surface of the support . The thing of Claim 1 WHEREIN: The said some friction material is shifted and arrange | positioned to an up-down direction in 3 rows, and the said friction material of the edge part row | line | column is a shape of one notch surface, and a center row | line | column. The shape of the friction material notch surface of the two provided,
The friction material arranged in the end row and the rail width direction interval of the friction material in the other end row arranged at the same height as the friction material are adjacent to each other arranged by shifting the friction material in the rail vertical direction. Smaller than the rail vertical distance between the friction material in the center row,
An emergency stop for an elevator, characterized in that two notch surface end portions of the friction material in the center row are arranged on the same line as one notch surface of the friction material in the end row, respectively. apparatus.   2. The elevator emergency stop device according to claim 1, wherein a plurality of the friction materials are provided, and the notch surfaces are arranged in the same direction.   2. The elevator emergency according to claim 1, wherein the friction material has a plurality of notch surfaces, and the notch surfaces are arranged so as to be parallel to an ascending / descending direction of the car. Stop device.   2. The elevator emergency stop device according to claim 1, wherein the length of the notch surface is 1/5 to 1/2 of the friction material diameter. In an elevator that generates braking force by pressing a brake against the guide rail to stop the elevator car when an abnormality occurs,
A friction material in which a part of a cylinder is notched so that a flat notch surface is generated and is made of ceramic, the brake member that sandwiches the guide rail with a support body that holds the friction material, and the brake member the example Bei a, an elastic member for pressing the guide rails, divided region where the notch surface is subjected to site a rotating force receiving a frictional force is disposed so as to be parallel to the lifting direction of the car, the friction An elevator characterized in that the material has an emergency stop device held on the circumferential surface of the support .

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