Constant-force lifting mechanism for safety tongs

Abstract

The invention discloses a safety gear constant force lifting mechanism which comprises a steel wire rope connecting device, a constant force mechanism, a lifting mechanism, a lifting connecting device and a safety gear lifting rod. The constant force mechanism is connected in series in the speed limiter steel wire rope through the steel wire rope connecting device and the lifting mechanism, and the lifting mechanism is connected with the speed limiter steel wire rope through the steel wire rope connecting device; the lifting connecting device is connected with the lifting mechanism, and the safety tongs lifting rod is connected with the lifting connecting device; and when the stress deformation of the constant force mechanism is within a preset deformation range, the stress at the upper end of the constant force mechanism is kept at a preset constant value. Stable lifting force is provided within a certain deformation range of the constant force mechanism, and therefore parts of the speed limiter are prevented from being damaged.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and more specifically to a safety clamp constant force lifting mechanism. Background Technology

[0002] The elevator safety brake is a key component of the elevator safety protection system. It is typically fixed to the elevator car. When the elevator descends at excessive speed and triggers the speed governor, the speed governor's wire rope pulls the safety brake wedge through the safety brake lifting mechanism, causing the safety brake to clamp onto the elevator guide rails and brake the car. This safety brake lifting mechanism needs to transmit the lifting force generated by the speed governor's wire rope to ensure the safety brake can operate smoothly when the elevator overspeeds.

[0003] The lifting force generated by the speed governor on the speed governor wire rope is provided by the friction between the speed governor wire rope and the sheave brake shoes. When the sheave brake shoes are severely worn or the wire rope is not sufficiently lubricated, the wire rope will slip and lag, resulting in a lifting force far exceeding the design value. Since the lifting force required at the safety clamp end is kept within the design range, the greater the travel distance during the elevator car's descent, the greater the wire rope tension, and the greater the force and impact on the speed governor components. In severe cases, the speed governor's sheave, ratchet pawl, frame, and central shaft may deform and be damaged, affecting the normal operation of the safety components.

[0004] Existing safety gear lifting mechanisms are all rigid structures of fixed length, which can satisfy the lifting action, but cannot adjust the force. When the speed limiter's lifting force is too large, it is easy to damage the safety gear and speed limiter components. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a safety clamp constant force lifting mechanism, including a wire rope connecting device, a constant force mechanism, a lifting mechanism, a lifting connecting device, and a safety clamp lifting rod; The constant force mechanism is connected in series with the speed limiter wire rope through a wire rope connecting device and a lifting mechanism. The lifting mechanism is connected to the speed limiter wire rope through the wire rope connecting device. The lifting connecting device is connected to the lifting mechanism, and the safety clamp lifting rod is connected to the lifting connecting device. When the constant force mechanism is deformed within a preset deformation range, the force at the upper end of the constant force mechanism remains at a preset constant value.

[0006] Preferably, the constant force mechanism consists of a positive stiffness mechanism and a negative stiffness mechanism; when the constant force mechanism is subjected to tensile deformation within a preset deformation range, the force at the upper end of the constant force mechanism remains at a preset constant value.

[0007] Preferably, when the tensile deformation of the constant force mechanism is less than the preset deformation range, the force at the upper end of the constant force mechanism increases as the deformation increases.

[0008] Preferably, when the constant force mechanism is subjected to tensile deformation greater than a preset deformation range, the force on the upper end of the constant force mechanism increases with the increase of deformation.

[0009] Preferably, the wire rope connecting device includes a wire rope clamp and a heart-shaped ring.

[0010] Preferably, the safety clamp constant force lifting mechanism further includes a baffle; one end of the baffle is fixed to the car, and the other end is disposed on the upper part of the constant force mechanism; during the process of the safety clamp constant force lifting mechanism lifting the safety clamp wedge, the baffle applies pressure to the upper end of the constant force mechanism. The constant force mechanism is a bellows constant force mechanism. When the constant force mechanism is deformed under pressure within a preset deformation range, the force at the upper end of the constant force mechanism remains at a preset constant value.

[0011] Preferably, when the constant force mechanism is deformed under pressure less than a preset deformation range, the force on the upper end of the constant force mechanism increases as the deformation increases.

[0012] Preferably, when the constant force mechanism is deformed under pressure beyond a preset deformation range, the force on the upper end of the constant force mechanism increases with the increase of deformation.

[0013] Preferably, the lifting mechanism includes a connector, a connecting rod, an upper mounting plate for the constant force mechanism, a lower mounting plate for the constant force mechanism, a safety clamp lifting mounting plate connecting device, and a safety clamp lifting mounting plate; the constant force mechanism is mounted on the connecting rod via the upper and lower mounting plates, the lower mounting plate and the connecting rod are fixed, the upper mounting plate and the connecting rod retain axial freedom, and the constant force mechanism can be compressed axially; the connecting rod passes upward through the baffle and is assembled and connected to the connector, the connector is connected to the wire rope connecting device; the lower end of the connecting rod is assembled and connected via the safety clamp lifting mounting plate connecting device, the safety clamp lifting mounting plate, and the lifting connecting device.

[0014] The present invention has the following technical effects: When the car overspeeds during descent, triggering the speed limiter, the constant force lifting mechanism of this invention provides a stable lifting force within a certain deformation range. When the friction between the speed limiter wire rope and the sheave brake shoe is too large, the constant force mechanism compensates for the car's movement distance by deformation and maintains a constant force, ensuring that the pulling force of the lifting mechanism on the speed limiter wire rope does not become excessive as the car's movement distance increases, thereby avoiding damage to the speed limiter's components. Attached Figure Description

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the safety clamp constant force lifting mechanism in Example 1; Figure 2 This is a schematic diagram of the force-displacement curve of the constant force mechanism in Example 1; Figure 3 This is a schematic diagram of the constant force mechanism in Example 1; Figure 4 This is a schematic diagram of the constant force mechanism in Example 1 before and after lifting; Figure 5 This is a schematic diagram of the bellows constant force mechanism in Example 2; Figure 6 This is a schematic diagram of the metal bellows structure in Example 2; Figure 7 This is a schematic diagram of the force-displacement curve of the constant force mechanism in Example 2; Figure 8 This is a schematic diagram of the safety clamp constant force lifting mechanism in Example 2. Detailed Implementation

[0016] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. Example 1

[0017] like Figure 1 This embodiment provides a safety clamp constant force lifting mechanism, including a wire rope connecting device 2, a constant force mechanism 3, a lifting mechanism 4, a lifting connecting device 5, and a safety clamp lifting rod 6. The wire rope connecting device 2 includes a wire rope clamp 201 and a heart-shaped ring 202.

[0018] The upper end of the constant force mechanism 3 is connected to the speed limiter wire rope 1 via the wire rope connecting device 2, and the lower end of the constant force mechanism 3 is connected to the upper end of the lifting mechanism 4. The lifting mechanism 4 is connected to the speed limiter wire rope 1 via the wire rope connecting device 2. The lifting connecting device 5 is connected to the lifting mechanism 4, and the safety clamp lifting rod 6 is connected to the lifting connecting device 5. The safety clamp lifting rod 6 can drive the safety clamp wedge 7 to move upward.

[0019] The force-displacement curve of a constant force mechanism is as follows: Figure 2 As shown, the vertical axis represents the tensile force on the constant force mechanism, the horizontal axis represents the deformation of the constant force mechanism after being subjected to force, and kc is the total stiffness of the constant force mechanism.

[0020] exist Figure 2 The curve includes a fast response zone (a), a constant force zone (b), and an over-limit zone (c). In the fast response zone (a), the force on the upper end of the constant force mechanism increases with the increase of deformation, and can quickly reach the design force value; within the preset deformation range of the constant force zone (b) (e.g., Figure 2 In the d1 to d2 interval, the total stiffness of the constant force mechanism is approximately zero, keeping the force value constant so that the force on the upper end of the constant force mechanism remains at a preset constant value; when the constant force mechanism reaches the over-limit zone (c), the stiffness is positive, and the force value continues to increase as the deformation increases.

[0021] In this embodiment, the constant force mechanism is composed of a combination of mechanisms with different stiffnesses, such as... Figure 3 As shown, it includes a positive stiffness mechanism 301 and a negative stiffness mechanism 302. The combination of the two can achieve the following design: Figure 2 The force-displacement curve is shown.

[0022] When the speed governor is triggered, the speed governor pulley brakes, and one end of the speed governor wire rope is braked by clamping friction. The car continues to move downward, and the lower end of the constant force mechanism is under tension. The deformation of the constant force mechanism increases rapidly, reaching the designed lifting force value. The constant force mechanism 3 drives the lifting mechanism 4 to complete the lifting action of the safety clamp wedge; then, within the deformation range of the constant force zone (b), the force value remains constant. Figure 4 As shown, during the descent of the car, although the distance between the upper end 303 and the lower end 304 of the constant force mechanism increases, the force on the upper end 303 of the constant force mechanism will not increase accordingly, and the tension on the speed limiter wire rope will remain within a stable range, and will not become too large and be transmitted to the speed limiter end, causing damage to its components.

[0023] When the car travels a distance exceeding the constant force zone and reaches the over-limit zone (c) of the constant force mechanism, the lifting force provided by the upper end 303 of the constant force mechanism will also increase rapidly to prevent insufficient lifting force. Since the displacement of the constant force zone is designed to be long enough, it generally will not reach the over-limit zone; the over-limit zone is designed to ensure the safety of the car braking. Compared with no constant force mechanism, this embodiment improves the lifting force and avoids brake failure by increasing the design buffer displacement through the constant force mechanism. Example 2

[0024] like Figure 8 As shown, this embodiment provides another embodiment of a safety clamp constant force lifting mechanism. It includes a wire rope connecting device 2, a constant force mechanism 8, a lifting mechanism 4, a lifting connecting device 5, a safety clamp lifting rod 6, and a baffle 9.

[0025] The lifting mechanism 4 includes a connector 401, a connecting rod 402, an upper mounting plate 403 for the constant force mechanism, a lower mounting plate 404 for the constant force mechanism, a safety clamp lifting mounting plate connecting device 405, and a safety clamp lifting mounting plate 406. The constant force mechanism 8 is mounted on the connecting rod 402 via the upper mounting plate 403 and the lower mounting plate 404. The lower mounting plate 404 and the connecting rod 402 are fixed together, while the upper mounting plate 403 and the connecting rod 402 retain axial freedom, allowing the constant force mechanism to compress axially. One end of the baffle 9 is fixed to the car, and the other end is located at the upper part of the constant force mechanism. The connecting rod 402 passes upward through the baffle 9 and is then assembled and connected to the connector 401. The connector 401 is connected to the wire rope connecting device 2. The lower end of the connecting rod 402 is assembled and connected to the safety clamp lifting mounting plate connecting device 405, the safety clamp lifting mounting plate 406, and the lifting connecting device 5. The lifting connecting device 5 is connected to the safety clamp lifting rod 6.

[0026] During the process of the constant force lifting mechanism of the safety clamp lifting the safety clamp wedge, the baffle applies pressure to the upper end of the constant force mechanism; the constant force mechanism 8 is a bellows constant force mechanism, and when the constant force mechanism is deformed under pressure within a preset deformation range, the force at the upper end of the constant force mechanism remains at a preset constant value.

[0027] like Figure 5 As shown, the bellows constant force mechanism 8 includes a metal bellows 801, an end plate 802, and a connector 803. The internal structure of the metal bellows 801 is as follows: Figure 6 As shown, The force-displacement curve of the bellows constant force mechanism is as follows: Figure 7 As shown, the right side is the tensile region (i.e., the bellows constant force mechanism is subjected to tension), which includes the fast response region (a) and the elastic region (b); the left side is the compression region (i.e., the bellows constant force mechanism is subjected to pressure), which includes the fast response region (a), the constant force region (b), and the over-limit region (c).

[0028] When the speed governor is triggered, the speed governor pulley brakes, and one end of the speed governor wire rope is braked by clamping friction, causing the car to continue moving downwards. The upper end of the bellows 801 is compressed, and the lower end is stretched. Under the action of the baffle 9, the displacement of the upper end of the bellows 801 is greater than the displacement of the lower end, causing the bellows 801 to be compressed as a whole. The constant force mechanism initially increases rapidly with the increase of compression, reaching the designed lifting force value. The constant force mechanism drives the lifting mechanism to lift the safety clamp wedge block upwards. Then, within the displacement range of the constant force zone (b), the force value remains unchanged. During the descent of the car, the distance between the upper and lower ends of the bellows 801 decreases, but the force on the upper end of the constant force mechanism does not increase accordingly. The tension on the speed governor wire rope also remains within a stable range and will not become too large to be transmitted to the speed governor end, causing damage to its components. When the car travels a distance beyond the constant force zone and reaches the constant force mechanism over-limit zone (c), the lifting force provided by the upper end of the constant force mechanism will also increase rapidly to prevent insufficient lifting force.

[0029] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A safety clamp constant force lifting mechanism, characterized in that, Includes wire rope connection device, constant force mechanism, lifting mechanism, lifting connection device and safety clamp lifting rod; The constant force mechanism is connected in series with the speed limiter wire rope via a wire rope connecting device and a lifting mechanism. The lifting mechanism is connected to the speed limiter wire rope via the wire rope connecting device. The lifting connecting device is connected to the lifting mechanism. The safety clamp lifting rod is connected to the lifting connecting device. When the deformation of the constant force mechanism is within the preset deformation range, the force at the upper end of the constant force mechanism remains at a preset constant value.

2. The safety clamp constant force lifting mechanism according to claim 1, characterized in that, The constant force mechanism consists of a positive stiffness mechanism and a negative stiffness mechanism; when the constant force mechanism is subjected to tensile deformation within a preset deformation range, the force at the upper end of the constant force mechanism remains at a preset constant value.

3. The safety clamp constant force lifting mechanism according to claim 2, characterized in that, When the tensile deformation of the constant force mechanism is less than the preset deformation range, the force on the upper end of the constant force mechanism increases as the deformation increases.

4. The safety clamp constant force lifting mechanism according to claim 2, characterized in that, When the constant force mechanism is subjected to tensile deformation greater than the preset deformation range, the force on the upper end of the constant force mechanism increases with the increase of deformation.

5. The safety clamp constant force lifting mechanism according to claim 1, characterized in that, The wire rope connection device includes a wire rope clamp and a heart-shaped ring.

6. The safety clamp constant force lifting mechanism according to claim 1, characterized in that, The constant force lifting mechanism of the safety clamp also includes a baffle; one end of the baffle is fixed to the car, and the other end is set on the upper part of the constant force mechanism; during the process of the constant force lifting mechanism of the safety clamp lifting block lifting the safety clamp wedge, the baffle applies pressure to the upper part of the constant force mechanism. The constant force mechanism is a bellows constant force mechanism. When the constant force mechanism is deformed under pressure within a preset deformation range, the force at the upper end of the constant force mechanism remains at a preset constant value.

7. The safety clamp constant force lifting mechanism according to claim 6, characterized in that, When the constant force mechanism is deformed under pressure less than the preset deformation range, the force on the upper end of the constant force mechanism increases as the deformation increases.

8. The safety clamp constant force lifting mechanism according to claim 6, characterized in that, When the constant force mechanism is deformed under pressure beyond the preset deformation range, the force on the upper end of the constant force mechanism increases with the increase of deformation.

9. The safety clamp constant force lifting mechanism according to claim 6, characterized in that, The lifting mechanism includes a connector, a connecting rod, an upper mounting plate of the constant force mechanism, a lower mounting plate of the constant force mechanism, a safety clamp lifting mounting plate connecting device, and a safety clamp lifting mounting plate; The constant force mechanism is mounted on the connecting rod via an upper mounting plate and a lower mounting plate. The lower mounting plate and the connecting rod are fixed, while the upper mounting plate and the connecting rod retain axial freedom. The constant force mechanism can be compressed axially. After the connecting rod passes upward through the baffle, it is assembled and connected to the joint. The joint is connected to the wire rope connecting device. The lower end of the connecting rod is assembled and connected through the safety clamp lifting mounting plate connecting device, the safety clamp lifting mounting plate and the lifting connecting device.

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