JP4797769B2 - Elevators and elevator sheaves - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an elevator and an elevator sheave that drives a car by rotating a sheave around which a rope connected to the car is wound, and in particular, to stabilize and wear the friction coefficient between the rope and the sheave. Suitable for reduction.

A rope-type elevator using a wire rope hangs a rope on a sheave attached to a hoisting machine, hangs a car on one side around the sheave, and hangs a counterweight to balance the car on the other side. . Then, the hoisting machine rotates the sheave and moves the car suspended on the rope by the frictional force between the rope and the sheave. Therefore, for proper operation of the elevator, the friction coefficient between the rope and the sheave needs to be sufficient and stable for driving the elevator.
Usually, in an elevator, a steel wire rope using a hemp core impregnated with grease and twisting steel strands is often used. However, in order to obtain smooth, lightweight, corrosion-resistant high durability, a rope in which a steel wire is twisted and covered with a resin or a synthetic fiber rope is used. And since resin-coated ropes and synthetic fiber ropes are softer and easier to deform than metals, the contact surface pressure between the rope and sheave is smaller than that of steel wire ropes. For this reason, foreign matter such as dust, water droplets and oil existing in the hoistway can easily enter between the rope and sheave, and if a large amount of foreign matter adheres, the friction coefficient between the rope and sheave decreases, and the elevator You may not be able to drive properly.

Moreover, in order to transmit traction, that is, driving force, the surface roughness in the circumferential direction of the contact surface of the traction sheave is set to 1 to 3 μm, and the sheave contact surface is hard to improve durability. It is known to perform a corrosion-resistant coating, and is described in Patent Document 1, for example.
Furthermore, in order to drive a synthetic fiber rope, it is known that the surface of the rope groove (sheave) has a roughness grade of N7 to N12 (corresponding to arithmetic average roughness Ra = 1.6 to 50 μm). It is described in.

Special table 2003-512269 gazette JP 2001-139267 A

  In the above prior art, if the surface roughness of the sheave groove is only about several μm, in the case of a resin-coated rope or synthetic fiber rope, a large amount of foreign matter adheres and the foreign matter on the surface is covered by the foreign matter, The coefficient of friction is extremely reduced. For example, if a large amount of oil adheres, the oil covers the surface irregularities and the friction coefficient decreases. In addition, when the surface roughness of the sheave groove is several tens of μm, it is good to prevent a decrease in the friction coefficient against the adhesion of foreign matter, but the resin is softer than metal by increasing the surface roughness. Wear of resin rope increases.

  An object of the present invention is to prevent a decrease in the coefficient of friction and secure traction stably even for resin-coated ropes and synthetic fiber ropes that are easily affected by foreign substances, and to prevent wear of the ropes.

  In order to solve the above problems, the present invention provides a rope-type elevator that drives a car by rotating a sheave around which a rope connected to the car is wound, and a resin in which a steel wire is covered with a twisted resin. And a sheave whose surface roughness in the circumferential direction and width direction of the groove surface is an arithmetic average roughness Ra = 4 to 10 μm, and an average value Zpa of valley heights of the surface roughness curve When the average depth Zva is set, Zva / Zpa = 1.5 to 2.0.

  According to the present invention, even if foreign matter such as oil or water droplets adheres, the friction coefficient is hardly lowered and the reliability in long-term operation can be improved. In addition, since the wear of the rope can be suppressed using a lightweight, corrosion-resistant and highly durable resin rope, the life of the rope is lengthened, its replacement frequency is reduced, maintenance is facilitated, and maintenance costs are reduced. Can be achieved.

FIG. 1 is a schematic view showing an elevator according to an embodiment. In FIG. 1, reference numeral 1 denotes a car on which passengers are placed. The car 1 is connected to a rope 2, and the rope 2 is wound around a sheave 4 attached to a hoisting machine 3. Furthermore, the rope 2 is connected to the counterweight 6 through the deflecting wheel 5. A guide rail 7 is installed in the hoistway and is sandwiched between guide shoes 8 attached to the car 1.
When the sheave 4 is rotated by the hoisting machine 3, the rope 2 moves by the rotational force of the sheave 4 being transmitted to the rope 2 due to the frictional force between the rope 2 and the sheave 4, and the car 1 moves along the guide rail 7 in the hoistway. Move up and down along. The positions of the car and the counterweight when the car 1 is raised by one floor are shown by broken lines in FIG.

FIG. 2A is a side view of the sheave 4 and FIG. 2B is a cross-sectional view taken along the line AA. This sheave has three grooves 9 around which the rope is wound.
FIG. 3 is a diagram showing a cross section of the groove 9 of the sheave. The surface of the sheave groove is formed to have an arithmetic average roughness Ra = 4 to 10 μm by, for example, projecting abrasive grains such as shot blasting onto the groove surface. Has been.
FIG. 4 shows the measurement results of the friction coefficient with respect to the arithmetic average roughness Ra of the sheave groove. In addition, the experimental result shown below is a thing when using the resin-coated rope which coat | covered the steel wire with the twisted resin. μa is a coefficient of friction when the rope and sheave are clean, and μb is a coefficient of friction when oil adheres to the rope and sheave. The vertical axis of FIG. 4 shows the ratio of μa and μb as the friction coefficient ratio. When the friction coefficient ratio is large, the difference in the friction coefficient between the clean state and the oil adhesion state becomes large, and the frictional force between the rope and the sheave becomes unstable. When the arithmetic average roughness Ra is 4 μm or more, the friction coefficient ratio decreases to near 1.2 and the difference in the friction coefficient becomes small, so that a stable friction force can be obtained.

  FIG. 5 shows the measurement results of the amount of wear of the rope with respect to the arithmetic average roughness Ra of the sheave groove. Note that the wear amount when the arithmetic average roughness Ra = 1 μm was set to 1, and the measurement results of other wear amounts were shown as relative values. When the abrasion test is performed by sliding a metal sheave and a resin-coated rope whose outer side is coated with a resin, the resin covering the rope is worn. Metal and resin wear is classified into adhesion wear in which the resin adheres to the mating metal and abrasive wear in which the projection of the mating metal scrapes the coating resin. When the arithmetic average roughness of the sheave groove is Ra = 10 μm or less, adhesive wear is dominant, and the amount of wear gradually increases as the arithmetic average roughness Ra increases. However, when the arithmetic average roughness of the sheave groove exceeds Ra = 10 μm, the abrasive wear becomes dominant and the amount of wear rapidly increases. Therefore, in order to keep the wear amount of the coating resin at a low value, the arithmetic average roughness of the sheave groove is preferably Ra = 10 μm or less.

From the friction coefficient measurement result shown in FIG. 4 and the wear amount measurement result shown in FIG. 5, the friction coefficient is stabilized by setting the arithmetic average roughness of the surface of the sheave groove to Ra = 4 to 10 μm, and the elevator operates properly. Can do. Moreover, wear of the rope can be suppressed, and the life of the rope can be extended.
The measurement results shown in FIGS. 4 and 5 show that the relationship between the average value Zpa of the peak height Zp and the average value Zva of the valley depth Zv of the roughness curve described later is Zva / Zpa = 1.5-2. It was obtained in the range of 0.

FIG. 6 is a cross-sectional view of the sheave groove, and the alternate long and short dash line in the figure is an average line when the cross-sectional shape is a roughness curve, and the protrusions above the average line are peaks and the protrusions below are valleys. . In the cross-sectional view of FIG. 6A, the average value Zpa of the peak height Zp and the average value Zva of the valley depth Zv of the roughness curve are substantially the same. On the other hand, in the cross section of FIG. 6B, the protrusion at the top of the mountain is cut, and Zva is larger than Zpa.
Average value Zva average value Zpa and valley depth Zv of the peak height Zp is the peak height contained in the roughness curve of the sheave groove surface (Zp ₁ ~Zp _n), the valley depth (Zv ₁ ~Zv _m ) Was calculated and divided by the number of peaks n and the number of valleys m.
FIG. 6A shows an irregular polygonal abrasive grain having a diameter of 450 μm projected from the normal direction of the surface of the sheave groove, and the arithmetic average roughness of the surface of the sheave groove is processed to Ra = 6.0 μm. In FIG. 6B, an irregular polygonal abrasive grain having a diameter of 1500 μm is projected from the normal direction of the surface of the sheave groove, and then an irregular polygonal abrasive grain having a diameter of 110 μm is projected from the tangential direction of the surface of the sheave groove. The arithmetic mean roughness of the surface of the sheave groove is processed to Ra = 6.0 μm. Compared to FIG. 6A, the projection at the tip of the ridge is shaved by projection from the tangential direction of the abrasive grains. The diameter of the abrasive grains used is preferably 100 to 1700 μm, preferably 400 to 1700 μm for processing from the normal direction and 100 to 600 μm for processing from the tangential direction. The diameter of the abrasive grains used for processing from the tangential direction is preferably smaller than the diameter of the abrasive grains used for processing from the normal direction.

  FIG. 7 shows the measurement result of the ratio of the average value Zpa of the peak height Zp and the average value Zva of the valley depth Zv and the friction coefficient on the sheave groove surface. The friction coefficient when the rope and sheave are clean is μa, and the friction coefficient when oil adheres to the rope and sheave is μb. When Zva / Zpa is 2.0 or less, the ratio of μa, which is the friction coefficient in the clean state, to μb, which is the friction coefficient in the oil adhesion state, decreases to nearly 1.2, and the friction coefficient is almost the same. This is because oil is easily accumulated on the surface of the sheave groove, and the friction coefficient is less likely to be lowered even in an oil-attached state. When Zva / Zpa is 2.0 or more, an oil sump is hardly formed, and oil remains on the contact surface between the rope and the sheave. Therefore, the coefficient of friction in the oil adhesion state decreases. That is, μa / μb increases.

FIG. 8 shows the measurement result of the ratio of the average value Zpa of the peak height Zp and the average value Zva of the valley depth Zv on the surface of the sheave groove and the wear amount of the coating resin. The wear amount when the arithmetic average roughness Zva / Zpa = 3.0 was set to 1, and the measurement results of other wear amounts were shown as relative values.
If Zva / Zpa is 1.5 or less, the amount of wear on the rope increases due to the protrusion on the surface of the sheave groove. By setting Zva / Zpa to 1.5 or more, protrusions on the surface of the sheave groove are reduced, so that wear of the rope can be reduced.
Therefore, the friction coefficient is stabilized by setting Zva / Zpa, which is the ratio of the average value Zpa of the peak height Zp and the average value Zva of the valley depth Zv, to 1.5 to 2.0 on the surface of the sheave groove. Driving. Moreover, wear of the rope can be suppressed, and the life of the rope can be extended. Note that the measurement results shown in FIGS. 7 and 8 show the arithmetic average roughness Ra = 4 to 4 on the sheave groove surface.
It is measured in the range of 10 μm.

  As a method of setting Zva / Zpa to 1.5 to 2.0, as shown in FIG. 9A, an irregular polygonal or spherical powder 10 is projected from the normal direction of the groove 9 of the sheave 4. Thereafter, as shown in FIG. 9B, the irregular polygonal or spherical powder 10 is projected from the tangential direction of the groove 9 of the sheave 4 to remove the front end protrusion on the surface.

FIG. 10 shows the relationship between wavelength and amplitude obtained by FFT (Fast Fourier Transform) on the cross-sectional shape shown in FIG. As the FFT window function, Hanning (a window having a characteristic in which side lobes are sharply cut off and measurement with a wide dynamic range is possible) was used. Further, the result obtained by FFT was regarded as a sound wave, and the respective amplitudes were obtained at the center frequency of 1/3 octave. And the reciprocal of the frequency was calculated | required and converted into the wavelength.
In FIG. 10, the waveform shown in FIG. 6A is the comparative example 3-1, and the waveform shown in FIG. 6B is the example 3-1. Also, in FIG. 10, an irregular polygonal abrasive grain having a diameter of 400 to 500 μm is projected from the normal direction of the sheave groove surface, and then projected from the tangential direction of the sheave groove surface to calculate the arithmetic average roughness of the sheave groove surface. The shape of the sheave groove processed to Ra = 4.0 μm is shown as Example 3-2. Table 1 shows specific processing methods and arithmetic average roughness Ra of Examples 3-1 and 3-2 and Comparative Example 3-1.

  FIG. 11 shows the results of wear tests on the sheave grooves and ropes of the comparative example and the example shown in FIG. The vertical axis of FIG. 11 shows the wear amount of the coating resin as a relative wear amount when the wear amount obtained in the experiment of Example 3-1 is 1. That is, compared with Example 3-1 and Example 3-2, the amount of wear in Comparative Example 3-1 is large, and even if the Ra of the sheave groove is the same, if the amplitude of each wavelength component is different, the coating resin The amount of wear differs.

FIG. 12 shows the result of FFT analysis of the surface of the sheave groove produced by changing the projection conditions of the abrasive grains, and the produced sheave grooves are referred to as Examples 3-3 and 3-4. Comparing the amplitude of each wavelength component, Example 3-4 has a larger amplitude with a wavelength of less than 70 μm than Example 3-3. Wear tests were conducted using these sheaves, and the amount of wear was almost the same. Therefore, the wavelength 70
Amplitudes less than μm have little effect on wear. This is because the amplitude of the wavelength of less than 70 μm is small, so that the protrusion on the surface of the sheave groove hardly bites into the resin.

  FIG. 13 shows the result of FFT analysis of the surface of the sheave groove produced by changing the abrasive projection conditions. The manufactured sheave grooves are referred to as Examples 3-5 and 3-6. Comparing the amplitudes of the respective wavelength components, the amplitude of the wavelength exceeding 140 μm is larger in Example 3-6 than in Example 3-5. These wear tests were conducted and the amount of wear was almost the same. Therefore, the amplitude of the wavelength exceeding the wavelength of 140 μm hardly affects the wear. This is because, when the wavelength is 140 μm or more, the contact area between the rope and the sheave increases, so that the surface pressure decreases and the resin is less likely to adhere, and the resin is difficult to scrape.

  From the amplitude of the wavelength component shown in FIG. 10, in Examples 3-1 and 3-2, the amplitude of the wavelength 70 to 140 μm is smaller than 0.5 μm to 1.0 μm, which is 1/140 of the wavelength. On the other hand, the amplitude of the wavelength 70 to 140 μm of Comparative Example 3-1 having a large amount of wear is larger than 1/140 of the wavelength. Therefore, the wear of the rope coating resin can be reduced and the life of the rope can be extended by making the amplitude of the component having a wavelength of 70 μm to 140 μm smaller than 1/140 of the wavelength of the sheave groove surface. Even if a part of the amplitude of the wavelength 70 to 140 μm is 1/140 or more of the wavelength, the wear of the rope is reduced, but all of the amplitude of the wavelength 70 to 140 μm is 1/140 or less of the wavelength. It is desirable.

FIG. 14 shows the result of analyzing the surface of the sheave groove having an arithmetic average roughness of Ra = 3 μm by FFT and obtaining the amplitude of each wavelength component as Comparative Example 4-1. The figure also shows the relationship between the wavelength and amplitude of Comparative Example 3-1 and Examples 3-1 and 3-2 shown in FIG. In Comparative Example 4-1, the arithmetic average roughness Ra is smaller than those of other Comparative Examples and Examples, and therefore the amplitude of each wavelength component is also small.
FIG. 15 shows the results of measuring the friction coefficient between the sheaves and the ropes of Comparative Examples 3-1 and 4-1 and Examples 3-1 and 3-2 shown in FIG. The friction coefficient ratio is approximately 1 for Comparative Example 3-1 and Examples 3-1 and 3-2, but the friction coefficient ratio is 3 for Comparative Example 4-1, and the friction during clean and oil adhesion The difference in coefficient is large. From FIG. 14, it can be seen that in Comparative Example 4-1, the amplitude of the component having the wavelength of 70 to 140 μm is smaller than 0.05 to 0.10 μm, which is 1400 of the wavelength. Thus, when the amplitude of the wavelength of 70 to 140 μm is smaller than 0.05 to 0.10 μm, an oil sump cannot be formed when the oil adheres, and the oil enters the contact surface between the rope and the sheave, resulting in a friction coefficient. descend. Accordingly, by reducing the amplitude of the component having a wavelength on the surface of the sheave groove of 70 to 140 μm to be less than 1/400 of the wavelength, it is possible to prevent a decrease in the friction coefficient when no foreign matter is attached.

  In the above embodiment, the sheave diameter is good at 200 mm, and when the sheave diameter becomes 200 mm or more, the contact surface pressure between the rope and the sheave decreases, so the arithmetic average roughness Ra, the sheave groove surface by the increase rate of the sheave diameter with respect to 200 mm The amplitude of each wavelength component analyzed by FFT and Zva / Zpa, which is the ratio of the average value Zpa of the peak height Zp and the average value Zva of the valley depth Zv, may be sufficient.

FIG. 16 is a cross-sectional view of the sheave groove surface in which the abrasive grains are projected from the normal direction of the sheave groove surface, and then the abrasive grains are projected from the tangential direction of the sheave groove surface, and the metal plating 11 is further processed. FIG. 17 is an enlarged view of the plating part of FIG. The plating has a two-layer structure, and is composed of a metal plating 11 and a metal plate 12 containing a low friction resin. The contact surface with the sheave is metal plating (nickel plating) containing a low friction resin. Electroless nickel phosphorus plating is suitable for metal plating and ethylene tetrafluoride is suitable for low friction resin. Further, the plating thickness at this time is preferably 10 to 25 μm including the two layers, and if it is thinner than 10 μm, if there is a defect in the material to be plated, a pinhole is generated in the plating. On the other hand, if the thickness is larger than 25 μm, the peaks and valleys of the sheave groove are filled with plating, and if a large amount of foreign matter, particularly oil, adheres to the surface, the oil will cover the surface irregularities and the friction coefficient will be reduced.
The plating layer containing the tetrafluoroethylene resin is preferably 10 to 15 μm, and if it is thinner than 10 μm, if there is a defect in the material to be plated, there is a possibility that pinholes are generated in the plating. On the other hand, when the thickness is 15 μm or more, it becomes difficult to uniformly disperse the tetrafluoroethylene resin in the plating. For this reason, the thickness of the plating layer containing tetrafluoroethylene resin is 10-15.
μm is preferred

The side view which shows schematic structure of the elevator apparatus by one embodiment of this invention. The side view and sectional drawing of the sheave by one embodiment. Sectional drawing of the sheave groove | channel surface by one Embodiment. The graph which shows the relationship between arithmetic mean roughness Ra of the sheave groove | channel surface, friction coefficient (mu) a, and friction coefficient (mu) b ratio at the time of oil adhesion in one Embodiment. The graph which shows the arithmetic mean roughness Ra of the sheave groove | channel surface, and the relative abrasion loss W of a rope in one Embodiment. Sectional drawing of the sheave groove | channel surface in one Embodiment. In one embodiment, the relationship between the ratio Zva / Zpa of the average value Zpa of the peak height of the sheave groove surface and the average value Zva of the valley depth Zva and the ratio of the friction coefficient μa and the friction coefficient μb at the time of oil adhesion is shown. Graph. The graph which shows the relationship between ratio Zva / Zpa of the average value Zpa of the peak height of the sheave groove | channel surface, and the average value Zva of a valley depth, and the relative wear amount W of a rope in one Embodiment. The side view which showed the direction which projects powder on a sheave in one embodiment. The figure which analyzed the sheave groove | channel surface in each Example by FFT, and showed the relationship between a wavelength and an amplitude. The figure which showed the relative wear amount W of the rope when a wear test was done in each Example. The figure which analyzed the sheave groove | channel surface in each Example by FFT, and showed the relationship between a wavelength and an amplitude. The figure which analyzed the sheave groove | channel surface in each Example by FFT, and showed the relationship between a wavelength and an amplitude. The figure which analyzed the sheave groove | channel surface in each Example by FFT, and showed the relationship between a wavelength and an amplitude. In each Example, the figure which showed ratio of the friction coefficient (mu) a and the friction coefficient (mu) b at the time of oil adhesion. Sectional drawing which shows the sheave groove | channel surface which processed the metal plating by one Embodiment. The enlarged view of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Car, 2 ... Rope, 3 ... Hoisting machine, 4 ... Sheave, 5 ... Baffle, 6 ... Counterweight, 7 ... Guide rail, 8 ... Guide shoe, 9 ... Groove, 10 ... Powder, 11 ... Metal plating, 12 ... metal plating containing low friction resin.

Claims (10)

In a rope type elevator that drives a car by rotating a sheave around which a rope connected to the car is wound,
A resin-coated rope obtained by coating a steel wire with a twisted resin, and the sheave in which the surface roughness in the circumferential direction and the width direction of the groove surface is an arithmetic average roughness Ra = 4 to 10 μm;
And an average value Zpa of peak heights and an average value Zva of valley depths of the surface roughness curve, Zva / Zpa = 1.5 to 2.0.   2. The elevator according to claim 1, wherein the amplitude of the component whose wavelength of the surface roughness curve is 70 to 140 [mu] m is smaller than 0.5 [mu] m to 1.0 [mu] m.   2. The elevator according to claim 1, wherein when the diameter of the sheave is 200 mm or more, the value of Zva / Zpa is increased by an increase rate of the diameter with respect to 200 mm.   2. The component according to claim 1, wherein when the diameter of the sheave is 200 mm or more, the amplitude of the component whose wavelength of the surface roughness curve is 70 to 140 μm increases from 200 μm to 0.5 μm to 1.0 μm. An elevator characterized by being made smaller than a value increased by a percentage.   2. The elevator according to claim 1, wherein the sheave groove is subjected to a metal plating treatment having a thickness of 10 to 25 [mu] m.   2. The elevator according to claim 1, wherein the sheave groove is subjected to a metal plating process containing a low friction resin.   The sheave groove according to claim 1, wherein the sheave groove is processed by projecting an irregular polygon or spherical powder from the normal direction of the surface of the sheave groove and then projecting from the tangential direction. Elevator. The sheave groove according to claim 1, wherein the sheave groove is processed by projecting an irregular polygon or spherical powder from the normal direction of the surface of the sheave groove and then projecting from the tangential direction. Elevator.   9. The elevator according to claim 8, wherein the sheave groove is subjected to a metal plating process containing a low friction resin. In an elevator sheave in which a resin-coated rope connected to a car is wound around the sheave and the car is driven by rotating the sheave.
In the groove of the sheave, the surface roughness in the circumferential direction and the width direction of the groove surface is an arithmetic average roughness Ra = 4 to 10 μm, the average value Zpa of the peak height of the surface roughness curve, and the average value of the valley depth An elevator sheave characterized by Zva / Zpa = 1.5 to 2.0 when Zva is used.

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