JP4832689B2 - Elevator tension member - Google Patents

Description

[0001]
【Technical field】
The present invention relates to elevator systems, and more particularly to tension members for such elevator systems.
[0002]
[Background]
A typical towed elevator system includes a car, a counterweight, a plurality of ropes connecting the car and the counterweight, a towing pulley for moving the rope, and a hoist that rotates the towing pulley . The rope is made of a steel wire bundled or twisted, and the pulley is made of cast iron. As the hoisting machine, either a gear hoisting machine or a gearless hoisting machine can be used. When a gear type hoisting machine is used, a high-speed motor can be used. High speed motors are small and low cost, but require additional maintenance and space.
[0003]
Common round steel ropes and cast iron pulleys have been found to be reliable and cost effective, but their use is limited. One such limitation is the traction between the rope and the pulley. Such tractive force can be increased by increasing the winding angle of the rope or by providing a cut in the pulley. However, when these techniques are used, the durability of the rope decreases due to increased wear (winding angle) or increased rope pressure (cut). Another way to increase traction is to place a synthetic material liner in the groove of the pulley. Such a liner increases the coefficient of friction between the rope and the pulley, while at the same time reducing the wear between the rope and the pulley.
[0004]
Another limitation on the use of round steel ropes is the flexibility and fatigue properties of round steel wire ropes. Currently, according to elevator safety standards, each steel rope has the smallest diameter d (dmin = 8 mm (CEN); dmin = 9.5 mm (3/8 ″) (ANSI)) and in the case of towed elevators It is required that the D / d ratio is 40 or more (D / d ≧ 40), where D is the diameter of the pulley, and therefore the pulley diameter D is at least 320 mm (380 mm for ANSI). The greater the diameter D of the pulley, the greater the torque required for the hoist to drive the elevator system.
[0005]
Another disadvantage of typical circular ropes is that the higher the rope pressure, the shorter the life of the rope. The rope pressure (P _rope ) is generated when the rope moves on the pulley, and is proportional to the rope tension (F) and inversely proportional to the pulley diameter D and the rope diameter d (ie, P _rope). Is proportional to F / (Dd)). Furthermore, the maximum rope pressure applied to the rope also increases depending on the shape of the pulley groove portion (including a technique for increasing the traction force such as cutting of the pulley groove portion).
[0006]
Despite the existence of the technology described above, scientists and technicians under the guidance of the assignee of the applicant endeavor to develop more effective and durable methods and devices for driving elevator systems. ing.
[0007]
DISCLOSURE OF THE INVENTION
According to the present invention, the aspect ratio of the tension member for the elevator is set to 1 or more. Here, the aspect ratio is defined as the ratio between the width w and the thickness t of the tension member (aspect ratio = w / t).
[0008]
The main feature of the present invention is that the tension member is flat. By increasing the aspect ratio, the engagement surface (defined by the width dimension) of the tension member is suitable for distributing the rope pressure. Thus, the maximum pressure is reduced inside the tension member. Furthermore, by making the aspect ratio larger than that of the circular rope (the aspect ratio is 1), it is possible to reduce the thickness of the tension member while keeping the cross-sectional area of the tension member constant.
[0009]
Furthermore, according to the present invention, a plurality of independent cords, strands and / or wires for load transport are disposed within the common coating layer of the tension member. The common coating layer separates the individual cords, strands and / or wires and defines an engagement surface that engages the traction pulley.
[0010]
With this configuration of the tension member, the rope pressure can be uniformly distributed throughout the tension member. As a result, the maximum rope pressure is much lower than elevators with prior art ropes with comparable load carrying capacity. Furthermore, the effective rope diameter “d” (measured in the bending direction) to obtain the same load resistance is reduced. Therefore, the diameter “D” of the pulley can be reduced without reducing the D / d ratio. Further, by reducing the diameter D of the pulley, a low-cost and small high-speed motor can be used as a hoist without using a gear box.
[0011]
The cords, strands and / or wires within the tension members of the present invention are preferably composed of various combinations of steel and organic fibers. These two materials can be used in an independent state, and can be placed inside a common coating as independent steel cords and organic fiber cords. These two materials can be combined to form a single cord, and a plurality of cords can be dispersed within the common jacket. It is also possible to surround one of these materials with the other material and place it inside the common jacket in a predetermined arrangement. It is possible to disperse the steel cords in the common jacket and to disperse the organic fibers irregularly in the common jacket.
[0012]
Each combination described above provides a material-mixed flexible flat tensile member having strength and advantages not obtainable with a flat tensile member made of steel cord or an organic fiber flat tensile member. Advantages of each material include that steel can be inspected nondestructively, has excellent heat resistance, and has low extensibility. The advantages of organic fibers are low weight, high extensibility, and excellent corrosion resistance. By effectively using steel and organic fibers in the tension member to distribute the load to them, the properties of the tension member can be greatly improved. The present invention has various embodiments capable of “distributing load” between two materials. In order to distribute the load, such a synergistic effect is obtained by considering the load carrying capacity of various materials, resistance to long-term bending fatigue, extensibility, and belt tracking stability. There is a need.
[0013]
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments and the accompanying drawings.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a towed elevator system 12. The elevator system 12 includes a car 14, a counterweight 16, a traction drive device 18, and a hoisting machine 20. The traction drive device 18 includes a tension member 22 that connects the car 14 and the counterweight 16, and a traction pulley 24. The tension member 22 is engaged with the traction pulley 24 so that the tension member 22 (and hence the car 14 and the counterweight 16) moves as the pulley 24 rotates. The hoist 20 engages and rotates the pulley 24. Although the gear type hoisting machine 20 is illustrated, such a configuration is merely an example, and the present invention is applicable to both a gear hoisting machine and a gearless hoisting machine. is there.
[0015]
The present invention provides a material-mixed flat flexible tensile member having characteristics superior to those of a flexible flat tensile member made of a single type of material. Not all possible combinations of load carrying materials will have a synergistic effect on the formed tensile member. Rather, it is necessary to carefully analyze the structural load carrying capacity in order to balance the applied load between various load carrying materials and stabilize the tension member track, as well as to obtain excellent properties. is there.
[0016]
Referring to FIG. 2, there is schematically shown a cross-sectional view of the material mixed flexible flat tensile member of the first embodiment of the present invention. The tension member 22 includes a common jacket 26 made of urethane or other polymer material. A steel load carrying member is disposed in region 28 and an organic material load carrying member is shown as 30. As can be appreciated by those skilled in the art, the load carrying material is spaced relatively evenly across the entire width of the tension member 22. In order to balance the track on both sides, it is preferable to arrange two steel cords side by side at the central position of the tension member 22. In order to stabilize the track of the tension member on the pulley, it is important that both sides of the longitudinal center line of the tension member are symmetrical.
[0017]
In the figure, the cross-sectional area of the organic material fiber 30 is larger than that of the steel cord 28, but this is not necessary. Rather, what matters is the desired weight ratio, the desired heat resistance, and similar parameters. Accordingly, the amount of organic material fiber and the amount of steel cord to be used is determined by performing mathematical calculations (calculations that can be performed by those skilled in the art). Such calculations are performed to distribute the load to the various cords within the flat tension member, thereby taking advantage of the benefits and characteristics of each cord. Furthermore, it is important that the axial stiffness of the tension member is such that the elastic response of the tension member is distributed to both types of cords under any load. The twist and structure of these two types of cords are selected so that such load distribution is possible. In obtaining such an effect, there is no limitation on the size, number and distribution of the cord itself (except when considering the trajectory), and it is not necessary to equalize the number of organic fiber cords and steel cords. It is important to balance the properties of the two types of cords with the properties desired for the tension member so that such desired properties are obtained. There can be multiple designs such as cords and dimensions for each desired effect. Distribution is important for stabilizing the trajectory of the tension member, and an easy distribution method for optimizing the trajectory is to distribute the cord evenly over the axial centerline of the tension member.
[0018]
One parameter that it is desirable to control is bending. Preferably, the steel cord is damaged prior to the organic material cord during bending so that the integrity of the tensile member can be inspected by a non-destructive inspection method. An example of such a method is one that measures electrical resistance or magnetic flux leakage.
[0019]
In another embodiment of the present invention, as shown in FIG. 3, each cord itself of the tension member 22 is made of a mixed material. A cross section of the tension member is shown, and an organic fiber material is disposed in an annulus 32 around a steel core 34. In this figure, only one material structure of the tension member is shown, but it is also possible to form a core from an organic fiber material and arrange steel in a ring. Furthermore, it is not necessary to use the same type of core material for all cords used in such embodiments. It is also possible to use steel for the core 34 of one or a plurality of cords and use organic fibers for the core 34 of one or a plurality of other cords. This must be taken into account because the twist and structure of each cord at the level of the ring and the core also influence the properties of the entire tension member. Those skilled in the art will know how to determine various twists and structures that can provide the desired properties to the entire tension member. The degree to which the elastomer should penetrate each cord should also be considered for the placement and dimensions of the cords used. If the cords are placed in contact with each other, fretting must be considered. In the preferred construction of such an embodiment, the same number of “s” cord structures and “z” cord structures are disposed along the axial centerline of the tension member.
[0020]
FIG. 4 shows another embodiment of the present invention. In this figure, only two codes 38 are shown enlarged to show the configuration of each code. In such an embodiment, each cord 38 is composed of a plurality of strands (for example, nine strands (one strand is surrounded by eight strands)), and each strand itself is a material mixture molding. ing. In this figure, the strand 40 comprises a central organic material wire 42 and eight steel wires 44 surrounding it. Further, six strands are arranged around the central strand 46, and thereby a material mixed cord 38 is formed. It is also possible to reverse the arrangement of the steel wire 44 and the organic fiber 42. Calculations similar to those described in the above embodiments need to be applied to such embodiments. Such a calculation can be understood by those skilled in the art. Furthermore, the material-mixed cord is useful in that the specific structure of the cord can be changed for a specific application. For example, if a crowned sheave (not shown) is used in a particular elevator where tension members are used to improve the track, the crown is near or directly on the crown. A larger load is applied to the cord in contact with the cord than other cords inside the tension member. The material mixed cord can be configured so as to cope with such a large load.
[0021]
Referring now to FIG. 5, a further embodiment of the present invention is shown. In FIG. 5, only two codes are shown enlarged. In such an embodiment, each steel cord 50 is preferably composed of seven wires in a pattern in which six wires are surrounded around one wire, and the steel cord 50 itself is a material mixture molding. Does not have a structure. The individual organic material fibers 52 are arranged inside the common coating material 28 surrounding the cord. For this reason, the tension member 22 itself has a material-mixed structure. The fibers 52 are preferably oriented parallel to the major axis of the tension member and are distributed throughout the material 28. In such an embodiment, the stiffness of the steel cord 50 is controlled by the stiffness of the steel wire while these stiffnesses are obtained by the organic fibers. The material 28 of such an embodiment is preferably made of polyurethane, similar to the embodiment described above.
[0022]
In all the embodiments described above, the elastic modulus of the tension member can be increased by increasing the volume ratio of the steel contained in the tension member. As will be appreciated by those skilled in the art, the calculation of the elastic modulus is based on the “rule of combination”, ie:
[0023]
E ₁₁ = U _f1 E _11f1 + V _f2 E _11f2 + V _m E _m
Where E ₁₁ = longitudinal FFR modulus of _EFR , E _11f1 = elastic modulus of fiber 1 in the longitudinal direction, E _11f2 = elastic modulus of fiber 2 in the longitudinal direction, E _m = elastic coefficient of substrate V _f1 = volume ratio of fiber 1, V _f2 = volume ratio of fiber 2 and V _m = volume ratio of substrate.
[0024]
The change in elastic modulus is shown in the graph of FIG.
[0025]
The calculated tensile strength of an exemplary tensile member of the present invention as a function of the content of steel / organic fibers (eg, Kevlar) in the common coating of the tensile member (ie, the preferred embodiment polyurethane coating). This is shown in the graph of FIG. Here, the volume ratio of steel / Kevlar to the common coating material is constant at 60 v / o (volume percent), but the ratio of steel to Kevlar is changing.
[0026]
In the graph, the exact change point of the curve is the point where steel is 24% and Kevlar 29 is 16% (the value is different in the case of Kevlar 49). On the right side of the 24/16 point, the strength curve is controlled by Kevlar, and on the left side, the strength curve is controlled by steel. Steel is damaged by 2.0% strain and Kevlar is damaged by 3.6% strain. In areas controlled by steel, damage to the steel due to strain causes the Kevlar to be overloaded and damaged. However, in the region controlled by Kevlar, even if the steel is damaged by 2.0% strain, this will not damage the Kevlar. This is because Kevlar can withstand a strain of 3.6%.
[0027]
At change point 24/16, even if the Kevlar material has deteriorated, damaged or destroyed, the steel is strong enough for use in an elevator system with such a tension member inside the tension member. Have In order to obtain such an effect on various volume ratios of the cord material to the coating material, the following equation must be satisfied.
[0028]
V _s ≧ (σ _k / σ _s ) V _k
V _s = volume ratio of steel V _k = volume ratio of Kevlar σ _k = tensile strength of steel σ _s = tensile strength of Kevlar Although preferred embodiments have been illustrated and described, departures from the spirit and scope of the invention Rather, various changes and substitutions can be made to these embodiments. Accordingly, the present invention has been described by way of example and not limitation.
[Brief description of the drawings]
FIG. 1 is a perspective view of an elevator system including a traction drive device using a tension member of the present invention.
FIG. 2 is a schematic cross-sectional view of a first embodiment of a material-mixed flexible flat tensile member of the present invention.
FIG. 3 is a schematic cross-sectional view of a second embodiment of the material-mixed flexible flat tensile member of the present invention.
FIG. 4 is a schematic cross-sectional view of a third embodiment of the material-mixed flexible flat tensile member of the present invention.
FIG. 5 is a schematic sectional view of a fourth embodiment of the material-mixed flexible flat tensile member of the present invention.
FIG. 6 is a graph showing the elastic modulus of the tensile member of the present invention.
FIG. 7 is a graph showing the strength of the tensile member of the present invention.

Claims (5)

A tension member for applying a lifting force to a car of an elevator system,
A plurality of load transport members including a plurality of steel load transport members and a plurality of organic fiber load transport members;
A coating that substantially surrounds the plurality of load transport members and has an aspect ratio defined as a ratio of a width to a cross-sectional thickness of the tension member of 1 or more;
With
Before SL plurality of steel load carrying member and a plurality of organic fiber load carrying member, respectively, are arranged symmetrically with respect to the longitudinal centerline of the tension member,
The plurality of load conveying members are composed of independent material mixed-molded cords formed by integrating a steel load conveying member and an organic fiber load conveying member,
The code is, tensile member you wherein the cyclic organic textiles or Ranaru surrounding steel core and the core. A tension member for applying a lifting force to a car of an elevator system,
A plurality of load transport members including a plurality of steel load transport members and a plurality of organic fiber load transport members;
A coating that substantially surrounds the plurality of load transport members and has an aspect ratio defined as a ratio of a width to a cross-sectional thickness of the tension member of 1 or more;
With
Before SL plurality of steel load carrying member and a plurality of organic fiber load carrying member, respectively, are arranged symmetrically with respect to the longitudinal centerline of the tension member,
The plurality of load conveying members are composed of independent material mixed-molded cords formed by integrating a steel load conveying member and an organic fiber load conveying member,
The code is, tensile member you wherein the annular steel or Ranaru surrounding the core and the core of organic fibers. A tension member for applying a lifting force to a car of an elevator system,
A plurality of load transport members including a plurality of steel load transport members and a plurality of organic fiber load transport members;
A coating that substantially surrounds the plurality of load transport members and has an aspect ratio defined as a ratio of a width to a cross-sectional thickness of the tension member of 1 or more;
With
Before SL plurality of steel load carrying member and a plurality of organic fiber load carrying member, respectively, are arranged symmetrically with respect to the longitudinal centerline of the tension member,
The plurality of load conveying members are composed of independent material mixed-molded cords formed by integrating a steel load conveying member and an organic fiber load conveying member,
The code consists of a plurality of strands, said strands, tensile member you characterized in that which is combined steel wire and organic fiber wires. A tension member for applying a lifting force to a car of an elevator system,
A plurality of load transport members including a plurality of steel load transport members and a plurality of organic fiber load transport members;
A coating that substantially surrounds the plurality of load transport members and has an aspect ratio defined as a ratio of a width to a cross-sectional thickness of the tension member of 1 or more;
With
The steel load carrying member is a plurality of independent cords arranged symmetrically with respect to the longitudinal center line of the tension member, and these cords are composed of a plurality of steel wires, and the organic fiber load carrying The member has a smaller diameter than the wire and is individually dispersed inside the coating, whereby the load is distributed to the plurality of steel load conveying members and the plurality of organic fiber load conveying members. A tensile member characterized by. The tensile member according to claim 4, wherein the organic fiber load carrying member is oriented parallel to a longitudinal axis of the tensile member.

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