Long-distance gradually changing brake force friction plate type energy absorber

Abstract

The application discloses a long-distance gradually changing braking force friction plate type energy absorber, which comprises a machine base, a fixed mandrel fixed to the machine base, a secondary roller coaxially connected to the fixed mandrel in sequence from left to right, a sliding nut, a plurality of springs, a compression block and a main roller, a main steel wire rope wound around the main roller and a secondary steel wire rope wound around the secondary roller, a plurality of fixed friction plates installed on the fixed mandrel, a plurality of movable friction plates coaxially and alternately contacted with the fixed friction plates and installed in holes of the main roller, and the secondary steel wire rope is fixedly connected with the extending end of the main steel wire rope; the outer thread of the sliding nut is matched with the inner thread B of the secondary roller, the outer thread B of the secondary roller is matched with the inner thread A of the machine base, the outer thread B and the inner thread B have the same rotation direction, the secondary steel wire rope drives the secondary roller to rotate when the sports car brakes, so that the secondary roller moves to the side of the compression spring, and the pitch of the outer thread B is slightly larger than that of the inner thread B, so that the sliding nut slowly compresses the spring to increase the friction force, and the long-distance mechanical autonomous buffer braking advantage is achieved, and the safety of people and machines is effectively ensured.

Description

Technical Field

[0001] This invention belongs to the field of mining equipment technology, specifically relating to anti-runaway devices and energy absorbers in mine transportation, and more specifically to a long-distance gradually changing braking force friction plate energy absorber. Background Technology

[0002] Inclined shaft transportation is a crucial mode of transportation in mines, playing a vital role in mine production. Safe and efficient inclined shaft transportation is of paramount importance for coal mine safety. Runaway accidents in inclined shaft transportation are a significant concern in coal mine safety and require effective prevention. Most mines now employ protective devices, using a combination of barriers and energy absorbers to brake runaway vehicles and prevent serious accidents.

[0003] The most widely used anti-runaway devices for mine cars in inclined shaft mine roadways are low-maintenance mechanical friction energy absorbers. One type utilizes a steel wire rope to drive a rope storage drum, causing dynamic and stationary friction plates to move and absorb energy through friction. A typical example is the spring-pressed friction plate type. The braking force of this friction is adjusted by the spring preload. However, this method suffers from problems such as the steel wire rope breaking if the spring is too tight, and limited energy absorption if it's too loose. Furthermore, the spring preload is preset during installation and cannot be changed during runaway braking, resulting in a large initial impact force and severely impacting the safety of the transport equipment and its drivers during runaway braking. The prior art (application number CN 201010135482.3) discloses an automatic variable resistance energy absorber, comprising a right support, a central screw, a roller, and a left support. One end of the central screw is threaded and connected to the right support and roller via the thread; the other end is connected to a sleeve via a key. The sleeve is fitted into a bushing and mounted on the left support. One side of a clamping plate is connected to the bushing, and the other side is connected to a compression spring. The other end of the compression spring is mounted inside the right support. Dynamic friction plates are installed on the inner surface of the roller, alternately connected to static friction plates mounted on the bushing. Two steel wire ropes are evenly wound on the outer surface of the roller, and the steel wire ropes are positioned by a rope-pressing block. The right and left supports are fixedly connected by a ground-angle screw. The working principle of this technology is that when the vehicle brakes, the roller rotates, and the threaded connection drives the central screw to slide, pushing the clamping plate to compress the spring, thus changing the friction braking force. However, there are still some problems in practical applications: (1) To achieve a large braking force, the friction plate energy absorber must increase the spring clamping force (e.g., a positive pressure of up to 30-50 tons, which is especially important for a monorail crane with a large mass and high speed). At this time, the diameter and pitch of the screw used to provide the clamping force of the spring will be very large. Then the drum will reach the maximum compression stroke of the spring after rotating a few times, and it is impossible to gradually increase the friction braking force during the large stroke or full stroke of the wire rope. (2) To provide a large positive pressure, ordinary cylindrical springs have the problem of large size and non-compactness. However, when replacing with a disc spring with a large spring force, the compression stroke is smaller (e.g., 10 mm), which means that the drum will reach the maximum compression stroke of the spring after rotating fewer times. However, for a monorail crane with a large mass and high kinetic energy (e.g., 50 tons, with a speed of 22 m / s), the safe stopping and braking distance must reach 50 m. How to achieve long-distance gradual force flexible braking is especially important for the safety of people / machines.

[0004] In general, flexible braking energy absorbers used in runaway protection devices typically do not need to be activated for several years (ideally, runaway accidents should never occur), but once activated, their energy absorption and braking reliability must be ensured. However, existing friction plate energy absorbers cannot achieve a long-stroke, gradual braking effect. With the increasing size of mine cars or transportation equipment (such as monorails) and the increase in tunnel length, the energy that needs to be absorbed by braking is enormous. If the braking process cannot achieve gradual energy absorption, the resulting impact force is sufficient to pull out the top anchor rod of the monorail, leading to a serious safety accident. Therefore, it is particularly important to innovate a friction plate energy absorber for runaway protection in inclined shafts that features long-distance gradual braking force, reliable operation, and low manufacturing / maintenance costs. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a long-distance gradually increasing friction braking force friction plate energy absorber, which can gradually increase the friction braking force during long-distance vehicle braking, achieving long-distance mechanical autonomous buffer flexible braking, and effectively ensuring the safety of personnel and machinery during inclined shaft vehicle braking.

[0006] The technical solution adopted in this invention is: a long-distance gradual braking force friction plate energy absorber, comprising a base, a fixed spindle mounted on support holes on the left and right sides of the base and restricted to rotation and axial movement by a fixed seat, a rotatable main drum fixed to the right side of the fixed spindle by a bearing, a main steel wire rope fixed at one end to the main drum and wound around the main drum, a plurality of fixed friction plates coaxially mounted on the fixed spindle and only axially sliding, a plurality of moving friction plates coaxially and alternately contacting the fixed friction plates and installed in the cylindrical hole of the main drum, and a right end pressed against the fixed spindle. The leftmost fixed friction plate includes a clamping block, several springs coaxially connected to the fixed spindle to provide positive pressure to the clamping block, a sliding nut and a secondary roller arranged coaxially with the fixed spindle, and a secondary steel wire rope fixed at one end and wound around the secondary roller. The other end of the secondary steel wire rope is fixed to the main steel wire rope and together they are connected to the vehicle blocking device in the runaway protection device. The outer cylinder of the left side section of the fixed spindle is provided with several axially oriented guide grooves A, and the cylindrical hole wall of the sliding nut is provided with several guide bosses. The sliding nut and the fixed spindle are coaxially engaged, and their guide bosses engage with the guide grooves A to achieve their respective functions. It slides only axially, and the right end face of the sliding nut presses against the left end face of the spring; a support seat with a stepped cylindrical through hole, coaxial with the fixed spindle, is fixed between the left and right supports of the machine base. A cylindrical tube extends from the left end of the support seat, and the cylindrical hole of the cylindrical tube has an internal thread A and a stepped groove A from left to right; the secondary drum is a double-layer cylindrical tube coaxial structure with a gap. The outer cylindrical tube is used to wind and store the secondary wire rope, and the right end of the inner cylindrical tube of the secondary drum has an external thread B, and its inner cylindrical hole has an internal thread B and a stepped groove from right to left. B; The external thread of the sliding nut is threadedly engaged with the internal thread B of the secondary drum, and the external thread B of the secondary drum is threadedly engaged with the internal thread A of the support seat in the machine base; the external thread B and the internal thread B have the same direction of rotation. When the trolley brakes, the secondary wire rope drives the secondary drum to rotate, causing the secondary drum to move towards the compression spring. The pitch of the external thread B is slightly larger than that of the internal thread B. Due to the slight difference in pitch, the sliding nut slides slowly to the right relative to the fixed mandrel to compress the spring, thereby gradually increasing the friction force during long-distance braking, that is, gradually increasing the traction braking force of the main wire rope.

[0007] Preferably, in the long-distance gradual braking force friction plate type energy absorber, the inner cylindrical surface B of the outer cylindrical tube of the secondary roller and the outer cylindrical surface A of the cylindrical tube of the support seat in the base are coaxially and have the same radius sliding fit, so as to realize the axial movement guidance of the secondary roller and enhance its motion stability; the spring can be a combination of disc springs or cylindrical springs, preferably disc springs, which can obtain a large positive pressure within a small compression stroke, making the energy absorber more compact and small.

[0008] Preferably, in the long-distance gradual braking force friction plate energy absorber, the total length of the main wire rope is less than or equal to the length of the secondary wire rope; the axial length of the stepped groove B of the secondary roller is slightly greater than the axial length of the sliding nut, and the axial length of the stepped groove A in the base is slightly greater than the axial length of the external thread B in the secondary roller; when the energy absorber is working, the spring is compressed to the maximum set value, at which time the sliding nut is located in the stepped groove B and the external thread B in the secondary roller is located in the stepped groove A, the sliding nut and the secondary roller no longer slide axially, and are in the state of maintaining the spring compression force, and the secondary wire rope does not need to be broken.

[0009] Preferably, in the long-distance gradual braking force friction plate energy absorber, the total length of the main wire rope is greater than the total length of the secondary wire rope, and the allowable breaking force of the connection joint between the secondary wire rope and the main wire rope is less than the allowable breaking force of the secondary wire rope, so that the secondary wire rope remains on the side of the stationary energy absorber instead of moving with the vehicle braking device, thus ensuring safety.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention uses the external thread of the sliding nut to engage with the internal thread B of the secondary roller, and the external thread B of the secondary roller engages with the internal thread A of the support seat in the machine base; the external thread B and the internal thread B have the same direction of rotation. When the vehicle brakes, the secondary wire rope drives the secondary roller to rotate, causing the secondary roller to move towards the compression spring. The pitch of the external thread B is slightly larger than that of the internal thread B. Due to the small pitch difference between the two, the sliding nut slides slowly to the right relative to the fixed spindle to compress the spring, thereby gradually increasing the friction force during the long-distance vehicle braking process, that is, gradually increasing the traction braking force of the main wire rope. It has the advantage of long-distance mechanical autonomous buffer flexible braking, effectively ensuring the safety of the vehicle brake personnel / machine. (2) The present invention can realize the slow and small displacement of the large diameter and large pitch thread to slowly compress the spring to increase the friction braking force, effectively solving the contradiction between the thread size and the small compression displacement of the spring under large positive pressure, realizing the gradual increase of friction force during the long-distance braking process. It is especially suitable for disc springs with small compression stroke and large elastic force, and has the advantage of more compact structural size. (3) In this invention, the total length of the main wire rope should be less than or equal to the length of the secondary wire rope; the axial length of the stepped groove B of the secondary roller is slightly greater than the axial length of the sliding nut, and the axial length of the stepped groove A in the base is slightly greater than the axial length of the external thread B in the secondary roller; when the energy absorber is working, the spring is compressed to the maximum set value, at this time the sliding nut is located in the stepped groove B and the external thread B in the secondary roller is located in the stepped groove A, the sliding nut and the secondary roller no longer slide axially, and are in the state of maintaining the spring clamping force, and the secondary wire rope does not need to be broken, thus avoiding the flying injury caused by the secondary wire rope being broken. Attached Figure Description

[0011] Figure 1 This is a top view of the long-distance gradually changing braking force friction plate energy absorber of the present invention.

[0012] Figure 2 for Figure 1 Sectional view along the AA direction.

[0013] Figure 3 This is an isometric view of a long-distance, gradually varying braking force friction plate energy absorber.

[0014] Figure 4 This is a cross-sectional view of the base in this invention.

[0015] Figure 5 This is an axonal view of the fixed mandrel in this invention.

[0016] Figure 6 This is a cross-sectional view of the secondary roller in this invention.

[0017] In the diagram, 1-base; 101-support hole; 102-internal thread A; 103-stepped groove A; 104-inner cylindrical surface A; 105-outer cylindrical surface A; 2-positioning nut; 3-sleeve; 4-fixed spindle; 401-positioning plane; 402-guide groove A; 403-guide groove B; 5-main drum; 6-main wire rope; 7-moving friction plate; 8-fixed friction plate; 9-clamping block; 10-spring; 11-sliding nut; 12-secondary drum; 121-inner cylindrical surface B; 122-external thread B; 123-internal thread B; 124-stepped groove B; 13-fixed seat; 14-secondary wire rope; 15-bearing. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] In the description of this invention, it should be noted that the terms "middle," "upper," "lower," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] like Figures 1-3 As shown, a long-distance gradual braking force friction plate type energy absorber includes a base 1, a fixed spindle 4 mounted on support holes 101 on the left and right sides of the base 1 and restricted from rotation and axial movement by a fixed seat 13 and a positioning nut 2, a rotatable main roller 5 fixed to the right side of the fixed spindle 4 by a bearing 15 and a sleeve 3, a main steel wire rope 6 fixed at one end to the main roller 5 and wound around the main roller 5, a plurality of fixed friction plates 8 coaxially mounted on the fixed spindle 4 and only axially sliding, a plurality of moving friction plates 7 coaxially and alternately contacting the fixed friction plates 8 and installed in the cylindrical holes of the main roller 5, a clamping block 9 coaxially slidingly fitted to the fixed spindle 4 and pressing the right end against the leftmost end of the fixed friction plate 8, and a plurality of springs 10 coaxially connected to the fixed spindle 4 to provide positive pressure to the clamping block 9; Figure 5 As shown, the fixed mandrel has a positioning plane 401 on the cylinder of the support hole 101, and the fixed seat 13 also has a matching plane to restrict the rotational movement of the fixed mandrel. The long-distance gradual braking force friction plate energy absorber also includes a sliding nut 11 and a secondary roller 12 arranged coaxially with the fixed mandrel 4, a secondary steel wire rope 14 fixed at one end and wound around the secondary roller 12, and the other end of the secondary steel wire rope 14 is fixed to the main steel wire rope 6 and connected together to the vehicle blocking device in the runway protection device. Figure 2 and Figures 4-6As shown, the outer cylindrical section of the left side of the fixed mandrel 4 is provided with several axially oriented guide grooves A 402, and the cylindrical hole wall of the sliding nut 11 is provided with several guide bosses. The sliding nut 11 is coaxially engaged with the fixed mandrel 4 and its guide bosses engage with the guide grooves A 402 to achieve axial sliding only. The right end face of the sliding nut 11 presses against the left end face of the spring 10. A support seat with a stepped cylindrical through hole coaxial with the fixed mandrel 4 is fixed between the left and right side brackets of the machine base 1. A cylindrical tube extends from the left end of the support seat. The cylindrical hole of the cylindrical tube is provided with an internal thread A 102 and a stepped groove A 103 from left to right. The secondary roller 12 is a double-layer cylindrical tube coaxial structure with a gap. The outer cylindrical tube is used to wind and store the secondary wire rope 14. The right end of the inner cylindrical tube of the secondary roller 12 is provided with an external thread B 122, and its inner cylindrical hole is provided with an internal thread B 123 and a stepped groove B 123 from right to left. 124; The external thread of the sliding nut 11 is threadedly engaged with the internal thread B 123 of the secondary roller 12, and the external thread B 122 of the secondary roller 12 is threadedly engaged with the internal thread A 102 of the support seat in the base 1; the external thread B 124 and the internal thread B 123 have the same direction of rotation. When the trolley brake is working, the secondary wire rope 14 drives the secondary roller 12 to rotate and moves the secondary roller 12 towards the compression spring. The pitch of the external thread B 122 is slightly larger than that of the internal thread B 123. Due to the slight difference in pitch, the sliding nut 11 slides slowly to the right relative to the fixed spindle 4 to compress the spring 10, thereby gradually increasing the friction force during long-distance vehicle braking, that is, gradually increasing the traction braking force of the main wire rope 6. It has the advantage of long-distance mechanical autonomous buffer flexible braking, effectively ensuring the safety of people / machines during trolley braking.

[0022] Preferably, such as Figure 2 , Figure 4 and Figure 6 As shown, the inner cylindrical surface B 121 of the outer cylindrical tube of the secondary roller 12 is coaxially and has the same radius sliding fit with the outer cylindrical surface A 1015 of the cylindrical tube of the support seat in the machine base 1, so as to realize the axial movement guidance of the secondary roller 12 and enhance its motion stability; the inner cylindrical surface A of the support seat in the machine base 1 is slidingly fitted with the outer cylindrical surface of the left end of the main roller, which enhances the stability of its rotational motion.

[0023] Preferably, Figure 2 The middle spring 10 can be a combination of disc springs or cylindrical springs. Disc springs are preferred because they can provide a large positive pressure within a small compression stroke, making the energy absorber more compact.

[0024] Preferably, the total length of the main wire rope 6 is less than or equal to the length of the secondary wire rope 14; the axial length of the stepped groove B 124 of the secondary roller 12 is slightly greater than the axial length of the sliding nut 11, and the axial length of the stepped groove A 103 in the base 1 is slightly greater than the axial length of the external thread B 122 in the secondary roller 12; when the energy absorber is working, the spring 10 is compressed to the maximum set value, at which time the sliding nut 11 is located in the stepped groove B 124 and the external thread B 122 in the secondary roller 12 is located in the stepped groove A 103, the sliding nut 11 and the secondary roller 12 no longer slide axially, and the clamping force of the spring 10 is maintained. This scheme ensures that the secondary wire rope 14 is not broken, avoiding the flying injury caused by the secondary wire rope 14 being broken.

[0025] In another implementation, the total length of the main wire rope 6 is greater than the total length of the secondary wire rope 14. The allowable breaking force of the connection joint between the secondary wire rope 14 and the main wire rope 6 is less than the allowable breaking force of the secondary wire rope 14. This ensures that when the vehicle brakes, the secondary wire rope 14 disconnects from the main wire rope 6 after the spring 10 is pressed into place. The secondary wire rope 14 remains stationary on the energy absorber side instead of moving with the braking device, thus ensuring safety.

[0026] This invention enables the slow, minute displacement of a large-diameter, large-pitch thread to gradually compress the spring and increase the frictional braking force. It effectively solves the contradiction between the thread size and the small compression displacement of the spring under large positive pressure, and realizes the gradual increase of frictional force during long-distance braking. It is especially suitable for disc springs with large elastic force and small compression stroke, and has the advantage of more compact structural size.

Claims

1. A long-distance gradual braking force friction plate type energy absorber, comprising a base, a fixed spindle mounted on support holes on the left and right sides of the base and restricted to rotation and axial movement by a fixed seat, a rotatable main drum fixed to the right side of the fixed spindle by a bearing, a main steel wire rope fixed at one end to the main drum and wound around the main drum, a plurality of fixed friction plates coaxially mounted on the fixed spindle and only axially sliding, a plurality of moving friction plates coaxially and alternately contacting the fixed friction plates and mounted in the cylindrical holes of the main drum, a clamping block coaxially and slidably fitted to the fixed spindle and pressing the right end against the leftmost fixed friction plate, and a plurality of springs coaxially connected to the fixed spindle to provide positive pressure to the clamping block; characterized in that, It also includes a sliding nut and a secondary roller arranged coaxially with the fixed spindle, a secondary steel wire rope fixed at one end and wound around the secondary roller, the other end of the secondary steel wire rope being fixedly connected to the main steel wire rope and together connected to the vehicle blocking device in the runaway protection device; the outer cylinder of the left side section of the fixed spindle is provided with several axially oriented guide grooves A, the cylindrical hole wall of the sliding nut is provided with several guide bosses, the sliding nut is coaxially engaged with the fixed spindle and its guide bosses engage with the guide grooves A to achieve axial sliding only, and the right end face of the sliding nut presses against the left end face of the spring; a support seat with a stepped cylindrical through hole coaxial with the fixed spindle is fixed between the left and right side brackets of the machine base, the left end of which extends out of a cylindrical tube, the cylindrical tube The cylindrical hole has an internal thread A and a stepped groove A arranged sequentially from left to right. The secondary roller is a double-layered cylindrical structure with a gap. The outer cylindrical section is used to wind and store the secondary wire rope. The right end of the inner cylindrical section of the secondary roller has an external thread B, and the inner cylindrical hole has an internal thread B and a stepped groove B arranged sequentially from right to left. The external thread of the sliding nut is threadedly engaged with the internal thread B of the secondary roller. The external thread B of the secondary roller is threadedly engaged with the internal thread A of the support seat in the machine base. The external thread B and the internal thread B have the same direction of rotation. When the trolley brakes, the secondary wire rope drives the secondary roller to rotate, causing the secondary roller to move towards the compression spring. The pitch of the external thread B is slightly larger than that of the internal thread B.

2. The long-distance gradually changing braking force friction plate energy absorber according to claim 1, characterized in that, The inner cylindrical surface B of the outer cylindrical tube of the secondary roller is in a sliding fit with the outer cylindrical surface A of the cylindrical tube of the support seat in the machine base, which is coaxial and has the same radius; the spring is a combination of disc springs or cylindrical springs.

3. The long-distance gradually changing braking force friction plate energy absorber according to claim 1, characterized in that, The total length of the main wire rope is less than or equal to the length of the secondary wire rope; the axial length of the stepped groove B of the secondary drum is slightly greater than the axial length of the sliding nut, and the axial length of the stepped groove A in the base is slightly greater than the axial length of the external thread B in the secondary drum; when the energy absorber is working, the spring is compressed to the maximum set value, at which time the sliding nut is located in the stepped groove B and the external thread B in the secondary drum is located in the stepped groove A, and neither the sliding nut nor the secondary drum slides axially.

4. The long-distance gradually changing braking force friction plate energy absorber according to claim 1, characterized in that, The total length of the main wire rope is greater than the total length of the secondary wire rope, and the allowable breaking force of the connection joint between the secondary wire rope and the main wire rope is less than the allowable breaking force of the secondary wire rope.

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