Guide rail friction coefficient measuring tool and method

Abstract

The application discloses a guide rail friction coefficient measuring tool and method, and relates to the field of elevator safety equipment. The measuring tool comprises a clamping element, a force applying element and a guide shoe. The force applying element and the clamping element are connected into a whole through a frame. The frame is installed on the guide rail of an elevator through the guide shoe. The clamping element is clamped on the guide rail. The force with which the clamping element clamps the guide rail is F. The pulling force provided by the force applying element to overcome the friction is f. The friction coefficient of the guide rail is mu = f / F. The selection of a safety clamp is guided according to the friction coefficient of the guide rail. The application guides the selection of a safety clamp through the on-site measurement of the friction coefficient of the guide rail, and ensures that the car can be safely braked in an emergency. The application can ensure safety and does not need repeated on-site tests. When the measuring tool is used for measurement, no sensors, detectors or other difficult-to-operate electronic devices are needed, and the on-site operators can easily operate the measuring tool, so that the application is easy to popularize.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and in particular to a tooling and method for measuring the coefficient of friction of guide rails. Background Technology

[0002] The domestic elevator industry is dominated by numerous brands, both large and small, leading to fierce competition in the old elevator retrofit market. Consequently, retrofitting old elevators from non-brand companies is very common. When retrofitting these elevators, a common approach is to retain the old guide rails and replace the car. However, when replacing the car, the safety brakes are often replaced as well, raising the issue of compatibility between the existing safety brakes and the unknown performance of the external manufacturer's guide rails.

[0003] For various reasons, some manufacturers have failed to pay attention to this issue and directly use existing safety clamps to match the guide rails of various old elevator renovation projects. In other words, they treat the guide rails of foreign brands as equivalent to their own company's guide rails. Some manufacturers choose to conduct on-site testing of the safety clamp braking after the old elevator renovation is completed to verify the braking performance of the safety clamp when matched with foreign brand guide rails.

[0004] Using existing safety brakes to match the guide rails of various old elevator renovation projects poses a significant safety risk because the friction coefficient of the guide rails on site is unknown. If the friction coefficient is smaller than expected, the deceleration of the car braking will be too small, potentially causing it to hit the buffer in the pit and resulting in a secondary impact on the passengers. If the friction coefficient is larger than expected, the deceleration of the car braking will be too large, and even if the safety brake can effectively stop the car, it will still cause an excessive impact on the passengers.

[0005] Testing old elevators after renovation can easily damage the guide rails during the testing process, affecting the comfort of the elevator after renovation. In addition, if the on-site test results do not meet the requirements, the safety clamp configuration must be replaced and the test must be repeated until the test results are qualified, which is a very complicated process. Summary of the Invention

[0006] The purpose of this invention is to provide a tooling and method for measuring the friction coefficient of guide rails, which can measure the friction coefficient of guide rails of old elevators of foreign brands in advance before the old elevator is modified, and guide the selection of safety clamps, so as to ensure that when the safety clamps used are matched with the guide rails of old elevators of foreign brands, they can stop the car with a suitable deceleration and ensure the safety of the car passengers.

[0007] This invention is achieved through the following technical solution:

[0008] A fixture for measuring the coefficient of friction of a guide rail includes a clamping element, a force-applying element, and a guide shoe. The force-applying element and the clamping element are connected as a whole by a frame. The frame is mounted on the guide rail of an elevator via the guide shoe. The clamping element clamps the guide rail. The force of the clamping element clamping the guide rail is F. The pulling force provided by the force-applying element to overcome friction is f. The coefficient of friction of the guide rail is μ = f / F. The selection of a safety clamp is guided based on the coefficient of friction of the guide rail.

[0009] Furthermore, the clamping element includes a brake wedge, a guide roller, a guide wedge, a spring, and a limiting pad, all respectively installed inside the mounting frame; one end of the spring presses against the inner side of the mounting frame, and the other end of the spring presses against the vertical sidewall of the guide wedge; the inclined sidewall of the guide wedge contacts one side of the guide roller; the other side of the guide roller contacts the inclined sidewall of the brake wedge; the vertical sidewall of the brake wedge contacts the guide rail; the upper side of the limiting pad contacts the inner side of the mounting frame, and the lower side contacts the brake wedge after it has slid upwards.

[0010] Furthermore, the force-applying element has a beam structure; several weights are added to the force-applying element.

[0011] Furthermore, the force-applying element is an electric hoist; the electric hoist is connected to the measuring fixture in sequence via a pull rope, a tension sensor, and a steering pulley.

[0012] Furthermore, the frame is equipped with an anti-detachment element to prevent the measuring fixture from detaching from the guide rail and to restrict the measuring fixture to slide up and down only along the guide rail.

[0013] Furthermore, the measuring fixture is installed on the top of the car via a pressure sensor; the movement of the car drives the measuring fixture to move.

[0014] Furthermore, a method for measuring the coefficient of friction of a guide rail includes the following steps:

[0015] Step S1: Insert the measuring fixture into the guide rail;

[0016] Step S2: Manually lift the brake wedge of the clamping element so that the brake wedge clamps the guide rail to prevent the measuring fixture from falling.

[0017] Step S3: Load a weight onto the force-applying element; the measuring fixture moves downward a short distance under force, and the brake wedge slides upward relative to the measuring fixture as a whole, forcing the spring to open, generating braking force, and stopping the measuring fixture from moving downward;

[0018] Step S4: Continue to load the weight onto the force-applying element until the measuring fixture moves down continuously, and the test is completed;

[0019] Step S5: By measuring the spring's opening, the added weight of the counterweight, and the preset spring stiffness, the coefficient of friction of the guide rail is calculated, thereby guiding the selection of the safety clamp.

[0020] The beneficial effects of this invention are:

[0021] The measuring fixture for measuring the coefficient of friction in this invention mainly consists of a clamping element and a force-applying element. The coefficient of friction μ = f / F can be obtained by using the clamping force F provided by the clamping element and the pulling force f required to overcome friction provided by the force-applying element. By measuring the coefficient of friction of the guide rail on-site, the selection of the safety clamp can be guided to ensure that the car can brake safely in an emergency. This ensures safety and eliminates the need for repeated on-site testing. When using this measuring fixture, no difficult-to-operate electronic devices such as sensors and detectors are required, making it easy for on-site operators to implement. It is highly operable and easy to promote. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the function of the safety clamp in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the measuring fixture (without added weights) according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the measuring fixture (with added weights) according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram illustrating the formula for calculating the friction coefficient of the guide rail in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the clamping element structure according to an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the measuring fixture structure with anti-detachment element according to an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram illustrating the use of an electric hoist as an external force for tool movement in an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram illustrating how the car maintenance operation serves as the external force for tool movement in an embodiment of the present invention.

[0030] In the attached diagram: 100-measuring fixture; 200-safety clamp; 1-clamping element; 2-force application element; 3-guide shoe; 4-frame; 5-anti-detachment element; 6-guide rail; 7-weight; 8-pressure sensor; 9-car; 11-mounting frame; 12-brake wedge; 13-guide roller; 14-guide wedge; 15-spring; 16-limiting pad; 21-electric hoist; 22-pull rope; 23-tension sensor; 24-steering pulley. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0032] It should be noted that all directional indicators (such as up, down, left, right, front, back, upper end, lower end, top, bottom, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0033] In this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention.

[0035] Combination Figure 1The diagram illustrates the function of the safety clamps. Safety clamps 200 are installed on both sides of the elevator car 9. During normal elevator operation, the safety clamps 200 follow the car 9 and move up and down along the guide rails without contacting them. In emergency situations such as the car 9 falling at excessive speed, the safety clamps 200 activate, and the wedges inside the safety clamps 200 clamp the guide rails, stopping the car 9 and ensuring passenger safety.

[0036] like Figure 2 As shown, a guide rail friction coefficient measuring fixture 100 includes a clamping element 1, a force-applying element 2, and a guide shoe 3. The force-applying element 2 and the clamping element 1 are connected as a whole by a frame 4. The frame 4 is mounted on the elevator guide rail 6 via the guide shoe 3. The clamping element 1 clamps onto the guide rail 6. The force of the clamping element 1 clamping the guide rail 6 is F. The pulling force provided by the force-applying element 2 to overcome friction is f. The friction coefficient of the guide rail 6 is μ = f / F. The selection of safety clamps is guided based on the friction coefficient of the guide rail. It should be noted that when using this measuring fixture 100 for measurement, there is no need for difficult-to-operate electronic equipment such as sensors and detectors, making it easy for on-site operators to operate. It has high operability and is easy to promote. By setting the guide shoe 3, it is ensured that the measuring fixture 100 can only move up and down along the guide rail 6.

[0037] Combination Figure 5 The structural principle diagram of the clamping element 1 is shown below. Specifically, in this embodiment, the clamping element 1 includes a brake wedge 12, a guide roller 13, a guide wedge 14, a spring 15, and a limiting pad 16, all installed inside the mounting frame 11. One end of the spring 15 presses against the inner side of the mounting frame 11, and the other end of the spring 15 presses against the vertical sidewall of the guide wedge 14. The inclined sidewall of the guide wedge 14 contacts one side of the guide roller 13. The other side of the guide roller 13 contacts the inclined sidewall of the brake wedge 12. The vertical sidewall of the brake wedge 12 contacts the guide rail 6. The upper side of the limiting pad 16 contacts the inner side of the mounting frame 11, and the lower side contacts the brake wedge 12 after it has slid upwards. It should be noted that when the brake wedge 12 moves upward, the guide roller 13 forces the guide wedge 14 to move horizontally, thereby compressing the spring 15 and generating a clamping force between the brake wedge 12 and the guide rail 6. The clamping force can be determined by measuring the compression amount ΔL of the spring 15 and combining it with the pre-set spring stiffness. The limiting pad 16 is used to limit the upward movement of the brake wedge 12, thereby limiting the maximum compression amount of the spring 15. The clamping element 1 achieves clamping through a spring; the magnitude of the clamping force F can be determined based on the set spring stiffness and spring opening amount.

[0038] It should be noted that clamping element 1 can also be the existing safety clamp of the elevator company, without the need for a separate design (because the clamping force of the company's own safety clamp is known, and the clamping force F can be directly determined by using a certain specification of the existing safety clamp).

[0039] Reference Figure 3 Specifically, in this embodiment, the force-applying element 2 is designed as a beam structure that facilitates the addition of weights. Several weights 7 are added to the beam structure of the force-applying element 2. The weights 7 are designed to be lightweight, making it easy for on-site workers to add or remove weights 7. The force-applying element 2 is achieved by adding weights 7 of known weight. When the weights 7 are added until the tooling begins to slide, the magnitude of the pulling force f required to overcome friction can be determined.

[0040] Specifically, in this embodiment, the force-applying element 2 is an electric hoist 21; the electric hoist 21 is connected to the measuring fixture 100 in sequence via a pull rope 22, a tension sensor 23, and a steering pulley 24. Combined with... Figure 7 The diagram illustrates the use of an electric hoist 21 as the external force for tool movement. The force-applying element 2 can be a lifting device such as an electric hoist 21, and the force can be converted to a suitable pulling direction via pulleys. The magnitude of the pulling force needs to be read by a tension sensor 23. For some working conditions, it is not necessary to know the exact value of the friction coefficient; it is sufficient to know that its value is not less than a specific value. In such cases, a tension sensor can be omitted, and a lifting device with a suitable rated lifting capacity can be used. When the maximum lifting capacity of the lifting device is exceeded, if the tool 100 still does not slip, the minimum possible value of the friction coefficient can be calculated.

[0041] Reference Figure 6 Specifically, in this embodiment, the frame 4 is equipped with an anti-detachment element 5 to prevent the measuring fixture 100 from detaching from the guide rail 6 and to restrict the measuring fixture 100 to slide up and down along the guide rail 6.

[0042] Specifically, in this embodiment, the measuring fixture 100 is mounted on the top of the car 9 via a pressure sensor 8; the movement of the car 9 drives the measuring fixture 100. Combined with... Figure 8 The diagram illustrates the use of the car 9 for maintenance and operation as the external force for tool movement. The measuring tool 100 is installed on the top of the car 9, and the pressure sensor 8 is set in the middle. The car 9's operation drives the measuring tool 100 to move, which serves as the required external force for the force application element 2.

[0043] If the old elevator does not have any major faults and can still be repaired and operated, the tooling can be installed on the top of the car, with a pressure sensor 8 in the middle. The movement of the car will drive the measuring tooling 100 to move, which will act as the external force required for the force application element 2.

[0044] Specifically, in this embodiment, a method for measuring the friction coefficient of a guide rail includes the following steps:

[0045] Step S1: Insert the measuring fixture 100 into the guide rail 6;

[0046] Step S2: Manually lift the brake wedge 12 of the clamping element 1 so that the brake wedge 12 clamps the guide rail 6 to prevent the measuring fixture 100 from falling.

[0047] Step S3: Load the weight 7 onto the force-applying element 2; the measuring fixture 100 moves downward a short distance under force, and the brake wedge 12 slides upward relative to the measuring fixture 100 as a whole, forcing the spring 15 to open, generating braking force, and the measuring fixture 100 stops moving downward.

[0048] Step S4: Continue to load the weight 7 onto the force-applying element 2 until the measuring fixture 100 moves continuously downwards, and the test is completed;

[0049] Step S5: By measuring the opening of spring 15, the added weight of weight 7, and the preset spring stiffness, the coefficient of friction of the guide rail is calculated to guide the selection of the safety clamp. Combined with... Figure 4 The diagram illustrates the formula for calculating the coefficient of friction. The force F that the brake wedge 12 uses to clamp the guide rail 6, and the pulling force f provided by the force-applying element 2 to overcome the frictional force, can be used to derive the coefficient of friction μ = f / F.

[0050] The beneficial effects of this invention are:

[0051] The measuring fixture 100 for measuring the coefficient of friction of this invention mainly consists of a clamping element 1 and a force-applying element 2. The coefficient of friction μ = f / F can be obtained by using the clamping force F provided by the clamping element 1 and the pulling force f required to overcome friction provided by the force-applying element 2. By measuring the coefficient of friction of the guide rail on-site, the selection of safety clamps can be guided to ensure that the car can brake safely in an emergency. This ensures safety and eliminates the need for repeated on-site testing. When using the measuring fixture 100 for measurement, no difficult-to-operate electronic devices such as sensors and detectors are required, making it easy for on-site operators to operate. It is highly operable and easy to promote.

[0052] The technical solutions provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the embodiments above are only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A fixture for measuring the friction coefficient of a guide rail, characterized in that: The measuring fixture includes a clamping element, a force-applying element, and a guide shoe; the force-applying element and the clamping element are connected as a whole by a frame; the frame is mounted on the elevator guide rail via the guide shoe; the clamping element is clamped to the guide rail; the frame is equipped with an anti-detachment element to prevent the measuring fixture from detaching from the guide rail and to restrict the measuring fixture to slide only up and down along the guide rail; the force of the clamping element clamping the guide rail is F; the pulling force provided by the force-applying element to overcome friction is f; the coefficient of friction of the guide rail is μ=f / F, and the selection of the safety clamp is guided by the coefficient of friction of the guide rail; when using this measuring fixture, no sensor or detector is required, and the selection of the safety clamp is guided by measuring the coefficient of friction of the guide rail on site.

2. The guide rail friction coefficient measuring fixture according to claim 1, characterized in that: The clamping element includes a brake wedge, a guide roller, a guide wedge, a spring, and a limiting pad, all installed inside the mounting frame. One end of the spring presses against the inner side of the mounting frame, and the other end of the spring presses against the vertical sidewall of the guide wedge. The inclined sidewall of the guide wedge contacts one side of the guide roller. The other side of the guide roller contacts the inclined sidewall of the brake wedge. The vertical sidewall of the brake wedge contacts the guide rail. The upper side of the limiting pad contacts the inner side of the mounting frame, and the lower side contacts the brake wedge after it has slid upwards.

3. The guide rail friction coefficient measuring fixture according to claim 1, characterized in that: The force-applying element has a beam structure; several weights are added to the force-applying element.

4. The guide rail friction coefficient measuring fixture according to claim 1, characterized in that: The force-applying element is an electric hoist; the electric hoist is connected to the measuring fixture in sequence via a pull rope, a tension sensor, and a steering pulley.

5. The guide rail friction coefficient measuring fixture according to claim 1, characterized in that: The measuring fixture is mounted on the top of the car via a pressure sensor; the movement of the car drives the measuring fixture.

6. A method for measuring the coefficient of friction of a guide rail, characterized in that, The tooling for measuring the coefficient of friction of a guide rail according to any one of claims 1-5 includes the following steps: Step S1: Insert the measuring fixture into the guide rail; Step S2: Manually lift the brake wedge of the clamping element so that the brake wedge clamps the guide rail to prevent the measuring fixture from falling. Step S3: Load a weight onto the force-applying element; the measuring fixture moves downward a short distance under force, and the brake wedge slides upward relative to the measuring fixture as a whole, forcing the spring to open, generating braking force, and stopping the measuring fixture from moving downward; Step S4: Continue to load the weight onto the force-applying element until the measuring fixture moves down continuously, and the test is completed; Step S5: By measuring the spring's opening amount, the added weight of the counterweight, and the preset spring stiffness, the coefficient of friction of the guide rail is calculated, thereby guiding the selection of the safety clamp.

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