Rail brake device for track-bound machine

Abstract

To provide a compact rail brake device of a track traveling type machine capable of generating sufficient and uniform braking force even to a rail having waviness, and capable of surely preventing runaway of the track traveling type machine by a gust not only in ordinary operation but also in power failure.SOLUTION: The rail brake device includes a fluid pressure cylinder (13) that is extended by expansion of high-pressure gas sealed in a pressure accumulation chamber 13c by releasing oil pressure for operation lock during braking to press brake pads (14) against a rail (4), and is contracted while compressing the high-pressure gas in the pressure accumulation chamber 13c against an expansion force by introducing the oil pressure for operation lock during non-braking to hold the brake pads (14) in a separated state from the rail (4). And a hydraulic unit 17 for performing extending operation and contracting operation by supplying and discharging hydraulic pressure for locking to the fluid pressure cylinder 13.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rail brake device for a track-traveling machine. [Background technology]

[0002] FIG. 5 shows an example of a container crane as a general track-traveling machine, in which the reference numeral 1 denotes a container crane, 2 denotes the port where the container crane 1 is deployed, 3 denotes a quay at the port 2, and 4 denotes rails laid on the quay 3 so as to extend in a direction perpendicular to the plane of the paper in FIG. 5, and a traveling device 8 having traveling wheels 7 that can roll freely along the rails 4 is attached to the support legs 6 of the crane body 5 of the container crane 1.

[0003] If the container crane 1 is blown by a strong wind during loading and unloading operations, it may not stop moving against the operator's will and may run away, which may result in a collision with adjacent machinery or nearby structures or even collapse. Therefore, a clamping device such as that disclosed in Patent Document 1 has already been proposed as a device to prevent such runaway.

[0004] This type of clamping device comprises a clamping mechanism that connects a pair of contacts, each with a clamping portion formed at its tip, so that their approximately middle portion can rotate freely around an axis; a spring mechanism that is provided at the base end of the contacts in the clamping mechanism and that narrows the gap between the base ends of the contacts, causing the contacts to rotate in a closing direction so that the clamping portions constantly clamp the rail; and a rotating cam that drives cam receiving portions formed at the base ends of the pair of contacts in a pushing-open direction from the inside, thereby releasing the clamping of the rail by the clamping portions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-72690 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-247944 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the clamping device disclosed in Patent Document 1 uses a method of clamping the rail from both sides, so if the contact surface of the clamping device has jagged teeth to increase the coefficient of friction with the side of the rail, or if the contact surface is hardened and made like a file, there is a possibility that the side of the rail will be scratched.In addition, if the precision of the side of the rail is low and there is a difference in the dimension from the center line to the side in the width direction between the left and right, or if the rail is corroded, the clamping part will not clamp evenly, which could significantly reduce the clamping force and make it impossible to obtain sufficient holding force.

[0007] In order to eliminate such problems, rail brake devices have been developed that have a fluid pressure cylinder that can press brake pads against and separate them from the running surface on which the running wheels of the rail roll. For example, in the rail brake device disclosed in Patent Document 2, the fluid pressure cylinder is configured to include a cylinder body that is attached to the crane body so as to extend in a direction perpendicular to the running surface of the rail, a piston that is inserted into the internal space of the cylinder body so as to be able to slide freely in the axial direction, a piston rod that protrudes from the piston to the outside of the cylinder body and to which the brake pads are attached, and a disc spring that is pressed into the cylinder body so as to urge the piston rod of the piston in a direction that causes it to protrude from the cylinder body.

[0008] By preventing the pressure of the working fluid from acting inside the internal space of the cylinder body, the biasing force of the disc spring moves the piston rod of the piston in a direction that causes it to protrude from inside the cylinder body, pressing the brake pad against the running surface of the rail to apply braking, while by applying the pressure of the working fluid inside the internal space of the cylinder body, the piston rod of the piston moves in a direction that causes it to contract inside the cylinder body against the biasing force of the disc spring, moving the brake pad away from the running surface of the rail to release the brake.

[0009] However, the rail running surface is not perfectly horizontal but undulates. Therefore, the spring rate of the fluid pressure cylinders using disc springs for braking is too large, resulting in large variations in thrust depending on the stroke. Furthermore, the stroke itself is not long enough, meaning that the brake pads cannot be pressed firmly against the rail running surface in areas that are concave due to the undulations, making it difficult to achieve a uniform braking force. Furthermore, the elastic deformation of the crane body to which the rail brake device is attached also reduces braking force and causes instability. Furthermore, even if a disc spring were used to achieve the required braking force, the fluid pressure cylinder would end up being significantly larger.

[0010] For this reason, it has been considered to use a general fluid pressure cylinder that does not use a disc spring, but there is a risk that the brake will not be able to be activated if the pump stops during a power outage.Incidentally, the general definition of a rail brake device in the past was that it was necessary to use a mechanical mechanism such as a spring to ensure that the equipment could be braked reliably even in the event of a power outage, and it was considered problematic to simply use a fluid pressure cylinder that requires electricity to drive the pump.

[0011] The present invention has been made in consideration of the above-mentioned problems of the conventional technology, and aims to provide a compact rail brake device for track-running machinery that can generate a sufficient and uniform braking force even on undulating rails and can reliably prevent the track-running machinery from running away due to a sudden gust of wind not only during normal operation but also during a power outage. [Means for solving the problem]

[0012] The present invention relates to a rail brake device for a track-traveling machine equipped with traveling devices that move along rails via traveling wheels, comprising a fluid pressure cylinder that, when braking, releases hydraulic pressure for locking operation to cause the expansion of high-pressure gas sealed in an accumulator chamber to cause the cylinder to extend, pressing the brake pads against the rail, and when not braking, introduces hydraulic pressure for locking operation to compress the high-pressure gas in the accumulator chamber against the expansion force, causing the cylinder to contract, holding the brake pads away from the rail, and a hydraulic unit that supplies and discharges hydraulic pressure for locking to the fluid pressure cylinder to perform the extension and contraction operations.

[0013] Furthermore, in the present invention, it is preferable that the fluid pressure cylinder comprises a cylinder body that stands upright in a direction perpendicular to the rail, a piston that is fitted inside the internal space of the cylinder body so as to be slidable in the axial direction of the cylinder body, a piston rod that projects from the piston toward the rail below, a pressure accumulator chamber that seals high-pressure gas above the piston in the internal space of the cylinder body, and a hydraulic chamber that supplies and discharges hydraulic pressure from a hydraulic unit to and from a piston below the piston in the internal space of the cylinder body.

[0014] The hydraulic unit may also preferably include a pump that supplies hydraulic pressure for locking by pressure-feeding hydraulic oil in one direction toward the fluid pressure cylinder via a check valve, and a switching valve that releases the hydraulic pressure for locking when braking and maintains it when not in operation.

[0015] Furthermore, in carrying out the present invention more specifically, it is preferable that the brake pads be attached to the underside of a fixed frame that is larger than the brake pads, and that the fixed frame be supported by a plurality of fluid pressure cylinders so that it can be raised and lowered. [Effects of the Invention]

[0016] The rail brake device for track-traveling machinery of the present invention uses a fluid pressure cylinder that extends and applies braking due to the expansion force of high-pressure gas sealed in an accumulator chamber when the hydraulic pressure for locking the operation is released.This allows the spring rate to be kept lower than in conventional devices that use disc springs, reducing the difference in thrust relative to the stroke amount and allowing the stroke amount to be sufficiently long.This means that a sufficient and uniform braking force can be generated even on undulating rails without being affected by the elastic deformation of the crane body.It can also reliably prevent the track-traveling machine from running away due to sudden gusts of wind not only during normal operation but also in the event of a power outage.Furthermore, the use of a compact fluid pressure cylinder has the excellent effect of allowing the device configuration to be significantly reduced in size. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an overall side view showing an embodiment of the present invention. [Figure 2] FIG. 10 is an explanatory diagram of the operation of the present embodiment in a non-braking state. [Figure 3] FIG. 3 is a view taken along the arrows III-III in FIG. 2. [Figure 4] 10A and 10B are explanatory diagrams illustrating the operation of the present embodiment during braking. [Figure 5] FIG. 1 is an overall side view showing an example of a general container crane. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] Figures 1 to 4 show an embodiment of a rail brake device for a track-traveling machine of the present invention, and in the figures, parts with the same reference numerals as in Figure 5 represent the same objects. In a container crane 1 as a track-traveling machine as shown in Figure 1, a lower frame 6a is provided between support legs 6 of a crane body 5, extending along the rails 4 so as to connect the support legs 6, and a plurality of (two in the example of Figure 1) traveling devices 8 are provided on the bottom side of the lower frame 6a.

[0020] The traveling device 8 comprises an upper equalizer beam 9a, a middle equalizer beam 9b, a lower equalizer beam 9c, and traveling wheels 7, and the upper equalizer beam 9a is supported at its middle part by a rocker pin 10a extending horizontally perpendicular to the traveling direction on the bottom side of the lower frame 6a, allowing it to swing freely.

[0021] The intermediate equalizer beam 9b is supported at its intermediate portion by rocker pins 10b extending horizontally perpendicular to the running direction at both ends of the upper equalizer beam 9a in the running direction, and is arranged to be able to swing freely, while the lower equalizer beam 9c is supported at its intermediate portion by rocker pins 10c extending horizontally perpendicular to the running direction at both ends of the intermediate equalizer beam 9b in the running direction, and is arranged to be able to swing freely. The traveling wheels 7 are arranged at both ends of the lower equalizer beam 9c in the running direction so as to be able to roll freely along the rails 4.

[0022] That is, in the example shown in FIG. 1, an equalizer device 9A consisting of an upper equalizer beam 9a and a middle equalizer beam 9b, and an equalizer device 9B consisting of the middle equalizer beam 9b and a lower equalizer beam 9c are formed in two stages, one above the other.

[0023] Incidentally, the upper equalizer beam 9a in the upper equalizer device 9A is the upper equalizer beam, and the middle equalizer beam 9b is the lower equalizer beam. Also, the middle equalizer beam 9b in the lower equalizer device 9B is the relatively upper equalizer beam, and the lower equalizer beam 9c is the lower equalizer beam.

[0024] However, depending on the scale of the container crane 1 as the track-traveling machine, the equalizer unit 9A may be formed in only one stage, and the traveling wheels 7 may be arranged on the lower equalizer beam (in this case, the middle equalizer beam 9b).Alternatively, the equalizer units may be formed in three or more stages, and the traveling wheels 7 that can roll freely along the rails 4 may be arranged on both ends in the traveling direction of the lower equalizer beam of the equalizer unit in the lowest stage.

[0025] The lower equalizer beam 9c (lower equalizer beam) is constructed by arranging a plurality of plates 9cp (two in the example shown in Figure 2) at required intervals in the width direction of the rail 4, and arranging plates 9cq that connect the plates 9cp.

[0026] Each of the traveling devices 8 is provided with a braking mechanism 11. However, it is not necessary to provide a braking mechanism 11 for each of the traveling devices 8, and only one braking mechanism 11 may be provided as long as sufficient braking force can be obtained.

[0027] The braking mechanism 11 is attached to the lower equalizer beam 9c (lower equalizer beam) on which the traveling wheels 7 are arranged, and as shown in FIG. 2, has a pressing frame 12, a fluid pressure cylinder 13, and brake pads 14, and the pressing frame 12 of the braking mechanism 11 is arranged between the lower equalizer beam 9c (lower equalizer beam) and the rail 4 so as to protrude in the horizontal direction perpendicular to the rail 4.

[0028] Furthermore, the fluid pressure cylinder 13 of the braking mechanism 11 is interposed between both horizontal ends of the pressing frame 12 perpendicular to the rails 4 and both side surfaces of the lower equalizer beam 9c (lower equalizer beam) so as to raise and lower the pressing frame 12, a fixed frame 15 is attached to the lower equalizer beam 9c (lower equalizer beam), a cylinder body 13a of the fluid pressure cylinder 13 is suspended from a support bracket 16 extending from the fixed frame 15, and the tip of a piston rod 13b hanging down from the cylinder body 13a is pivotally attached to the upper surface of the pressing frame 12.

[0029] In addition, the fixed frame 15 has stopper portions 15a facing both end faces of the pressing frame 12 in the longitudinal direction of the rail 4, and the stopper portions 15a restrict the movement of the pressing frame 12 in the longitudinal direction of the rail 4 (see Figures 2 and 3).

[0030] As shown in FIG. 3, two fluid pressure cylinders 13 are provided on one side, but the number can be set to one or three or more as required. Furthermore, brake pads 14 of the braking mechanism 11 are attached to the underside of the pressing frame 12.

[0031] Further, to provide a supplementary explanation of the detailed structure of the fluid pressure cylinder 13, the fluid pressure cylinder 13 comprises a cylinder body 13a that stands upright in a vertical direction relative to the rail 4, a piston 13e that is fitted inside the internal space of the cylinder body 13a so as to be slidable in the axial direction thereof, a piston rod 13b that protrudes from the piston 13e toward the rail 4 below, a pressure accumulator chamber 13c that is filled with high-pressure gas (nitrogen gas, etc.) above the piston 13e in the internal space of the cylinder body 13a, and a pressure accumulator chamber 13c that is filled with high-pressure gas (nitrogen gas, etc.) above the piston 13e in the internal space of the cylinder body 13a. A hydraulic chamber 13d to which hydraulic pressure is supplied and discharged by the hydraulic unit 17 is provided below the piston 13e, and when braking, the hydraulic pressure for locking operation of the hydraulic chamber 13d is released, causing the high-pressure gas sealed in the pressure accumulator chamber 13c to expand and cause the hydraulic chamber 13d to expand, pressing the brake pads 14 against the rail 4, and when braking is not being applied, the hydraulic pressure for locking operation is introduced into the hydraulic chamber 13d, causing the high-pressure gas in the pressure accumulator chamber 13c to compress against the expansion force and cause the hydraulic chamber 13d to contract, thereby maintaining the brake pads 14 in a state separated from the rail 4.

[0032] Here, the hydraulic unit 17 connects a reservoir tank 19 in which hydraulic oil 18 is stored and the hydraulic chamber 13d of the cylinder body 13a via a hydraulic line 20, and is provided with a pump 22 driven by a motor 21 and a check valve 23 in the hydraulic line 20 to prevent backflow of the hydraulic oil 18 pressurized by the pump 22, and a circulation line 24 for returning the hydraulic oil 18 to the reservoir tank 19 is branched off and connected to the hydraulic line 20 downstream of the check valve 23, and is provided with an electromagnetic switching valve 25 (switching valve) in the circulation line 24 that can be switched between a circulation position 25A that allows the hydraulic oil 18 to circulate from the hydraulic line 20 to the circulation line 24 and a closed position 25B that prevents the hydraulic oil 18 from circulating from the hydraulic line 20 to the circulation line 24.

[0033] In addition, a relief line 26 is provided which branches off from the middle of the hydraulic line 20 between the pump 22 and the check valve 23 and is connected to the middle of the circulation line 24 downstream of the electromagnetic switching valve 25, and a relief valve 27 is provided in the middle of the relief line 26 which opens when the pressure of the hydraulic oil 18 in the hydraulic line 20 exceeds a set pressure to return the hydraulic oil 18 to the reservoir tank 19 via the circulation line 24.

[0034] Thus, during braking as shown in FIG. 4, the electromagnetic switching valve 25 is switched to the circulation position 25A, the hydraulic oil 18 pumped by the pump 22 is returned from the hydraulic fluid line 20 through the circulation line 24 to the reservoir tank 19, and the hydraulic pressure for locking the operation of the hydraulic chamber 13d in the fluid pressure cylinder 13 is released, causing the high-pressure gas sealed in the pressure accumulator chamber 13c to expand, which causes the fluid pressure cylinder 13 to extend and pressurize the brake pads 14 against the rail 4, thereby applying the brakes and disabling the container crane 1 from traveling.

[0035] In this case, if the braking is applied by extension caused by the expansion force of the high-pressure gas sealed in the pressure accumulator chamber 13c when the hydraulic pressure for locking the operation is released as in this embodiment, the spring rate can be kept lower than in the conventional device using a disc spring, the difference in thrust relative to the stroke amount is smaller, and the stroke amount can be made sufficiently long, so that even if the running surface 4a of the rail 4 is not completely horizontal but undulates, the brake pads 14 can always be pressed firmly against the running surface 4a of the rail 4, thereby obtaining a uniform braking force. Also, even if the crane body 5 to which the brake device is attached elastically deforms, the brake pads 14 are pressed firmly against the running surface 4a of the rail 4, so the braking force does not decrease and is stable.

[0036] Furthermore, when the brakes are not applied as shown in FIG. 2, the electromagnetic switching valve 25 is switched to a closed position 25B, and the hydraulic oil 18 pumped by the pump 22 is not returned to the reservoir tank 19 from the hydraulic line 20 via the circulation line 24. Meanwhile, hydraulic pressure for locking the operation is introduced into the hydraulic chamber 13d, and the high-pressure gas in the accumulator chamber 13c is compressed against the expansion force, causing the fluid pressure cylinder 13 to contract, and the brake pads 14 are held in a state away from the rail 4. As a result, the brakes are released and the container crane 1 becomes able to travel.

[0037] However, in the event of a power outage, the solenoid of the electromagnetic switching valve 25 is de-energized and the brake operating position 23A is mechanically switched to by spring force. Therefore, when a power outage occurs, the hydraulic pressure for locking the operation of the hydraulic chamber 13d is released and the high-pressure gas in the pressure accumulator chamber 13c expands, causing the fluid pressure cylinder 13 to extend, thereby pressing the brake pads 14 against the rail 4 and enabling braking to be applied.

[0038] Therefore, according to the above embodiment, by employing a fluid pressure cylinder 13 that applies braking by expanding due to the expansion force of the high-pressure gas sealed in the pressure accumulator chamber 13c when the hydraulic pressure for locking the operation is released, the spring rate can be kept lower than in conventional devices that use disc springs, reducing the difference in thrust relative to the stroke amount, and the stroke amount can also be made sufficiently long, so that a sufficient and uniform braking force can be generated even on undulating rails 4 without being affected by the elastic deformation of the crane body 5, and it is possible to reliably prevent the track-traveling machine from running away due to a gust of wind not only during normal operation but also during a power outage, and moreover, by being able to achieve this with a compact fluid pressure cylinder, it is possible to significantly reduce the size of the device configuration.

[0039] The rail brake device for track-traveling machines of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0040] 1. Container crane (track-traveling machine) 4 Rail 5 Crane body 7 Running wheels 8 Running gear 13 Fluid pressure cylinder 13a Cylinder body 13b Piston rod 13c Accumulator 13d Hydraulic chamber 13e Piston 14 Brake pads 15 Fixed Frame 17 Hydraulic unit 18 Hydraulic oil 22 Pump 23 Check valve 25 Solenoid controlled switching valve (switching valve)

Claims

1. A rail brake device for a track-traveling machine equipped with a traveling device that moves along a rail via traveling wheels, comprising: a fluid pressure cylinder that, when braking, releases hydraulic pressure for locking operation to cause the high-pressure gas sealed in a pressure accumulator to expand and thereby press the brake pads against the rail, and when not braking, introduces hydraulic pressure for locking operation to compress the high-pressure gas in the pressure accumulator against the expansion force and thereby contract, maintaining the brake pads in a state away from the rail; and a hydraulic unit that supplies and discharges hydraulic pressure for locking operation to the fluid pressure cylinder to perform the extension and contraction operations.

2. 2. The rail brake device for a track-running machine according to claim 1, wherein the fluid pressure cylinder comprises: a cylinder body that stands upright in a direction perpendicular to the rail; a piston that is fitted within the internal space of the cylinder body so as to be slidable in its axial direction; a piston rod that projects from the piston toward the rail below; a pressure accumulator chamber that seals high-pressure gas above the piston in the internal space of the cylinder body; and a hydraulic chamber that supplies and discharges hydraulic pressure from a hydraulic unit to a section below the piston in the internal space of the cylinder body.

3. 3. A rail brake device for a track-traveling machine according to claim 1 or 2, wherein the hydraulic unit comprises a pump that supplies hydraulic pressure for locking by pressure-feeding hydraulic oil in one direction toward the fluid pressure cylinder via a check valve, and a switching valve that releases the hydraulic pressure for locking when braking and maintains it when not in operation.

4. 4. A rail brake device for a track-traveling machine according to claim 1, 2 or 3, wherein the brake pads are attached to the underside of a fixed frame which is larger than the brake pads, and the fixed frame is supported so as to be able to move up and down by a plurality of fluid pressure cylinders.

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