JP2000344074A - Limiting system for load proportional type brake cylinder pressure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wrong reading of a load sensor by providing a cutoff means for cutting off temporary bending of a wheel/truck assembly to a rolling stock from a load detecting means, which does not depend on load applied to a vehicle and is caused by ordinary motion when the vehicle runs on rails. SOLUTION: A load proportional type brake cylinder pressure limiting system includes a variable load limiting valve 18 mounted on an upper bracket 24, and a cutoff means having a spring built-in cutoff device 36 fixed to a lower bracket 30 by a first part 39 and a hydraulic damper 42 fixed to an upper bracket 24 by a first block 45. The cutoff device 36 is connected to the hydraulic damper 42 by an input lever 48. During the operation extending over an irregular portion, the input lever 48 is prevented from being substantially moved by the hydraulic damper 42 of the cutoff means, so that wrong load detection input to the variable load limiting valve 18 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load control type brake control system for a railway vehicle, and more particularly, to a load control type brake control system for a railway vehicle.
The present invention relates to a load-sensitive brake pressure control valve for preventing an erroneous reading of a load sensor caused by a movement of a vehicle in a normal state.

[0002]

BACKGROUND OF THE INVENTION For at least 100 years, pneumatic brakes mounted on railway vehicles have been used, in which brake pipes are arranged along the entire length of the train and are attached to individual train vehicles. A source of compressed air is provided. The brake state of the train is controlled by changing the brake pipe pressure using an air valve. In general, a control valve that responds to the state of the brake pipe in a multifunctional role is mounted on each vehicle, and this multifunctional role is to fill air into an air reservoir mounted on each vehicle. And controlling the braking of the train. Such systems are typically of the type ABD, ABDW, ABDX or DB6 with a microprocessor with EPIC or a 26 locomotive brake system sold by the Westinghouse Air Brake Company.
On-board air control valves such as type 0 valves have been utilized. It is common to use pneumatic control valves of the exact same function, evenly distributed to the vehicles throughout the train and with the associated control ordering, so that each vehicle has the same braking ordering. I was Generally, air signals are emitted by towing locomotives in trains. However, some systems have been proposed and used in which brake pipe pressure can be controlled at a rear or intermediate position inside the train.

A vehicle has the following factors: (1) the effective brake cylinder pressure under consideration; (2) the size of the brake cylinder; and (3) the brake cylinder and friction pair (usually a brake shoe and an iron The design of the mechanical link (base brake system) between the treads of the wheels and the disc brake system which is acceptable but rarely used, (4) the weight of the vehicle including its contents, (5) the braking action It has a braking capacity that varies according to the speed of the vehicle at the moment and (6) the frictional force that results from the normal (brake shoe) force due to a specific friction pair. What is used in most North American vehicles is the brake shoe structure on the wheel treads, which contributes to factor (6).
While the speed effect (5) was minimized. Also, the size of the brake cylinder (2) and the mechanical link (3) were selected at the time of design of the vehicle, both were constant and therefore were not valued as variables during train operation. The only important variables during the running of the train are the brake cylinder pressure (1) and the weight of the vehicle including its contents (4).

[0004] The brake cylinder pressure (1) was under the control of the driver as a result of manipulating the brake pipe pressure (eg, via the actuation of the engine's brake valve or electrical control). The weight of the vehicle, including the load, is determined only when the actual load is placed on the vehicle. For vehicles (carrying only coal or wheat), this variable is one of two values. In the case of other vehicles (such as covered trucks for goods and transport of variable loads with variable weight, such as long-haul vehicles), the weight of the vehicle containing the load may vary widely. Absent.

[0005] In either case, as the vehicle weight increases, the braking capacity of the vehicle decreases. Conventionally, the maximum braking force generated by the maximum brake cylinder pressure operable by the driver prevents the wheels of a light vehicle from slipping, while maintaining the maximum possible load at the same maximum brake cylinder pressure. In order to provide an effective braking force, it has been dealt with by selecting the sizes of the basic brake device and the brake cylinder at the time of designing the vehicle. The American Railroad Association standard allows a maximum braking ratio (ratio of brake shoe force to actual vehicle and load weight) of up to about 35%, while
The minimum braking ratio is allowed ± 10%. Therefore, if such a standard is met, the contents of the vehicle can be up to 2.5 times the empty vehicle weight.

Conventionally, freight trains are usually towed by approximately the same number of empty vehicles as the vehicles on which the cargo is loaded, and the average braking ratio of the entire train is the minimum that can be accepted as the individual vehicles described above. It was better than the one. However, two developments have recently made it possible to use a single value for maximum brake shoe force that is not as tolerable as previous magnifications. These include: (1) the so-called heavy use of unit trains, where all vehicles carry the same goods and all trains are full (in this case the average train braking ratio is the braking ratio of the individual vehicles. And (2) the fact that today's innovations allow vehicles to be designed lighter than the old ones with the same carrying capacity. The first condition results in a train braking performance that is lower than the required braking performance, and the second condition results in a loading weight that is much lower (2.5 times the wagon weight) than the equipment design can tolerate. Resulting in a state restricted to

[0007] When a brake is applied at an acceptable braking level for a fully loaded vehicle, the wheels are locked and slippery in a partially loaded vehicle.
It is not possible to use the same level of braking as a loaded vehicle. Therefore, in a special brake device, it is necessary to increase the braking ratio of the loaded vehicle so that the wheel does not slip when the brake is applied to the empty vehicle. Such devices automatically adjust the brake shoe force according to the load condition of the vehicle. These special device structures fall into two categories: dual-capacity, dry / load braking, and multiple-capacity, or continuously variable braking.

In light-duty high-speed and / or mass transit vehicles, overbraking and the resulting locking or slipping of the wheels can cause flats or damage to the wheels during braking of the passenger train. Therefore, what must be avoided is well known to those skilled in the art. Under-braking conditions in heavy-duty railway vehicles can cause long braking distances that can cause the railway vehicle to overrun from the normal stopping position of a station or block. In order to avoid over-braking or under-braking conditions, it is common practice to use a device which detects the load on the vehicle and reduces the brake cylinder pressure of an unloaded vehicle. Examples of these include U.S. Pat.
No. 6,168, No. 5,100,207, No. 5,000
5,915, 5,269,595 and 5,3
No. 40,203.

[0009] To overcome these undesirable limitations, brake manufacturers have responded to the engineer's maximum braking force command by providing greater brake shoe force on loaded vehicles than on empty vehicles. The development of numerous brake application devices has enabled lighter vehicles to carry heavier loads and improved braking forces in the unit train of fully loaded vehicles.

[0010] While these devices, commonly referred to as idle load brake controls, provide satisfactory service when the vehicle is empty or loaded,
It does not provide a complete solution to the problem. An example is a very light vehicle (such as a long haul container with single haul), where the vehicle frequently carries loads intermediate between empty and maximum design loads. The problem here is that as the load increases the weight of the vehicle, the empty / load device cannot generate an increase in the maximum brake cylinder pressure until a certain point is reached, beyond which the maximum (of the loaded vehicle) That is, an increase in brake cylinder pressure can be generated. Thus, if this switch point is at heavy vehicle weight, the brake cylinder pressure will be maintained at the low value selected for empty vehicles, and the performance of the train will be reduced under load without danger of slipping wheels. Allow the vehicle to support higher brake shoe forces. On the other hand, if this switching point occurs at a very light weight of the total vehicle weight, the maximum brake cylinder pressure at full load may be applicable to vehicles that are slightly heavier than an empty vehicle, so the wheels must be It increases the possibility of slipping.

In an ideal state, the maximum value of the allowable brake cylinder pressure should be able to continuously vary according to the increasing or decreasing load. In this case, any undesired state as described above is eliminated.

[0012] Equally important is the ability to operate the equipment on commonly incompatible trains, such as monorail trains, and to use higher load braking ratios by means of a continuous load limiting system, thereby achieving the American Railroad Association standard. The fact that it can provide significantly better control than can be achieved with value. For example, the load braking ratio can be a value currently acceptable for an empty vehicle, ie, ± 30%. Such a solid train consisting of multiple vehicles,
Compared to a solid train consisting of several wagons that are braked at 10% (not abnormal), the braking capacity is tripled and can be safely reduced three times as steep, or smaller. The train can be stopped at a distance of 1/3 as required by the train to be braked. Conversely, in a train with such a wagon, the speed can be increased by 1.732 times (square root of 3) (approximately 73% increase) from the speed of the train that slowly brakes, while stopping at the same braking distance. be able to. This performance improvement can be achieved without requiring improved wheel and track ground adhesions over current practices imposed daily.

In an adaptive load type device, the braking pressure is
The actual load, ie, the weight of the vehicle, is proportional over a wide and wide range. However, the proportional braking pressure is the maximum continuous pressure that can normally be supported by the train (7.72 kg / cm
² (110 psi)). Therefore, when a relatively light surface braking action is generated or when a relatively low continuous pressure (4.92 kg / cm ² (70 p.
If the maximum braking action is generated from si)), the proportional braking pressure will be much smaller than can be supported by the tack requirements. Therefore, in order to prevent an empty vehicle from slipping in the maximum braking state, optimal braking efficiency is required even under a certain braking condition, even in the case of a load-capable braking device as in the case of a single-capacity braking device. It is a reality that it is less than.

It is common knowledge in a load-sensitive braking device to mount a spring-loaded proportional valve between a train body and a wheel bogie assembly. The load on a railway vehicle is determined by the amount of deflection between the bouncing vehicle body and the non-bounceable wheel bearing and related bogie components. Thus, for example, the maximum distance from the bottom of a railcar to the top of a cargo-type three-part wheel bogie assembly indicates the case of an empty vehicle, while a full vehicle is the bottom of the railcar and the cargo-type three-part wheel. It is characterized by a minimum distance from the top of the bogie assembly. However, this separation distance is not kept constant for empty vehicles or loaded railway vehicles. If the wheels of the bogie assembly pass through the track while traveling, the vehicle and / or wheel assembly is prone to flexing or locking and rolling. Slight imperfections in the track height, such as rail joints and bumps, cause the wheel bogie to swing up and down relative to the railcar body. Further, in the curved portion of the track, one side of the wagon is more likely to be closer to the bogie assembly than the other side, and typically occurs inside the curved portion of the track. These deflections affect the input to the load sensing valve assembly, which may cause the adaptive braking system to "sense" a lighter or heavier vehicle than it actually is.

Therefore, what is needed is a system that increases the braking efficiency of a railway vehicle while minimizing errors in the load detection braking system due to normal vehicle movement.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an adaptive-load train braking system capable of continuously changing the maximum value of the brake cylinder pressure according to the increasing weight of the vehicle.

It is also an object of the present invention to provide means for isolating an error caused by the deflection of a normal railway vehicle during a typical train running from the adaptive load detection braking system.

Another object of the present invention is to provide an adaptive load limiting valve which can operate continuously even in an empty vehicle or in a full load.

It is a further object of the present invention to provide an easily adjustable maximum pressure output that can be used with different types of vehicles.

It is another object of the present invention to provide a ratio control which can easily adjust the vehicle height to the maximum brake cylinder pressure.

[0021]

SUMMARY OF THE INVENTION The above and other objects are achieved by the present invention, and, more simply, a load limiting valve comprises a load sensing valve in combination with a shut-off mechanism. The load detection valve includes a unit that continuously changes a fluid pressure supplied to a fluid-operated braking device mounted on a railway vehicle according to a load applied to the vehicle, and a unit that detects a load supported by the railway vehicle. . The blocking means does not depend on the load applied to the vehicle,
The transient deflection of the wheel / trolley assembly with respect to the railway vehicle caused by the normal deflection that occurs while the vehicle is traveling on rails is isolated from the load detection means.

In a load proportional system consisting of a circuit breaker and a load limiting valve, the circuit breaker absorbs the transient deflection of the wheel / trolley assembly so that the load sensing axis of the load limiting valve does not flex. I do. Once the load is loaded on the wagon, the deflection of the vehicle body relative to the wheel / trolley assembly reaches a "static" position and the circuit breaker recognizes the normal position at the point of deflection of the loaded vehicle, so the breaking mechanism Shuts off the input lever of the load detection valve from dynamic effects when the vehicle is traveling on the track. Therefore, load fluctuations only affect the adaptive load limiting valve, while dynamic effects due to normal track deflection only affect the shut-off means.

A load limiting valve for use in a vehicle braking control system is also provided. This valve is arranged between the vehicle control valve and the brake cylinder device and adjusts the maximum allowable brake cylinder pressure during braking according to the vehicle load. The adaptive load limiting valve is
A valve body having an inlet port connected to the control valve device and an outlet port connected to the brake cylinder device; The detection piston is slidably disposed inside the valve body, defines a pressure chamber between the valve body adjacent to the outlet port, and provides a fluid communication passage between the inlet port and the outlet port. I do. The load detection means is operatively connected to the detection piston to provide an indication according to the vehicle load and operates between an empty position and a full load position. The load detecting means includes a knob operatively cooperating with the shut-off mechanism, and an input shaft protruding into the valve body. The limiting check valve prevents flow to the brake cylinder when the maximum braking pressure is reached, and the control valve (eventually air) from the brake cylinder during brake release
It is arranged to allow the flow to. One end of the input shaft is in contact with the check valve and separates a valve seat connected to the detection piston and movable together.
The limiting check valve is mounted by a spring on the lower part of the detection piston with respect to the input shaft. A detection piston and an associated valve seat are provided in an `` empty '' position in which a detection spring located between the bottom of the detection piston and the valve body facing the pressure chamber is slightly biased by the pressure supplied to the brake cylinder; It can be moved to and from a "full load" position where the spring load is even greater.

In operation, air from the control valve is introduced into the load limiting valve and, after passing through the limiting check valve, into the upper chamber above the sensing piston, where the upper chamber, or pressure chamber, is braked. It is always in communication with the cylinder. The pressure in the upper chamber increases the compression of the sensing spring and acts to move the sensing piston in a direction to move the valve seat away from the top of the valve body and the knob of the sensing means, causing the input shaft to slide downward. . When the valve seat moves from the bottom of the input shaft to the point where the restriction check valve is separated, the brake cylinder pressure is reduced because the valve chamber is necessarily closed by the valve seat to prevent further pressure build-up in the upper chamber and the brake cylinder. However, the value is limited to a value corresponding to a static vehicle height.

Further increases in pressure from the control valve have no effect on brake cylinder pressure. However, if the brake cylinder pressure drops due to a leak, the detection piston slides up the input shaft and is pulled back toward the knob on the detection means, and the bottom of the input shaft contacts the restricted check valve again. And the air is urged away from the valve seat, thereby allowing air to be supplied from the control valve to the brake cylinder again until the value of the brake cylinder required by the height detecting means is reconstructed.

Various objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the drawings.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, FIG. 1 shows a load proportional type brake cylinder pressure limiting system 1 according to the present invention.
5 is shown. The system comprises two basic components, a load limiting valve 18 and a shut-off means 21. Via the upper bracket 24 all the components of the system 15 are installed on the railcar 27, and via the small lower bracket 30 the system 15 is operatively connected to the vehicle wheels or bogie assemblies 33. Connected. The upper bracket 24 may be welded to a portion of the vehicle body, while the lower bracket may be welded to a compression member of a side frame of the wheel bogie. When the mounted wheel bogie assembly is to be removed from a railway vehicle, that is, directly below the vehicle, it is only necessary to remove the link mechanism of the blocking means 21 from the lower bracket 30 in order to perform the removal. Conversely, if a truck equipped with this system is required, the upper bracket 24
Is attached to a trolley bolster, and the lower bracket 30 is attached to a side frame, for example, an edge of a spring housing member.

The load proportional brake cylinder pressure limiting system 15 according to the present invention is shown in more detail in FIG. The system includes a load limiting valve 18 mounted on the upper bracket 24 and a first portion 39 attached to the lower bracket 30.
And a hydraulic damper 42 fixed to the upper bracket 24 by the first section 45.
And blocking means further comprising: The circuit breaker 36 is connected to the hydraulic damper 42 by an input lever 48. More specifically, the input lever 48 is operatively associated with the adaptive load limiting valve 18 by input means 51. The first end 54 of the input lever is rotatably mounted on the second portion 57 of the circuit breaker 36 and the second end 60 is rotatably mounted on the second section 63 of the hydraulic damper. The input lever 48 is connected to the intermediate section 66 of the upper bracket 24 with a bolt 67 or the like.
It is rotatably mounted at. Therefore, the connection between the input lever and the bracket of the bogie frame is not a fixed link, as shown in FIG.
It is a nested type with a built-in spring designed to expand and contract when exceeding 53 kg (about 10 pounds). More specifically, this load is called a cage load, and the height of the circuit breaker when no excessive load is applied is constant, and is called a cage height 69. A second or upper portion 57 of circuit breaker 36 is connected to a first end of input lever 48 and a second end 60 of the input lever is connected to a second or upper compartment 63 of hydraulic damper 42. You. Hydraulic dampers have a very slow stroke ratio which matches the force limited to 10 pounds of the circuit breaker. Such an arrangement of the three members serves to cut off the rotation of the input lever 48 from the short-term dynamic effects of a railway vehicle passing through a track as a train. Therefore, the three cooperating members are:
It consists of blocking means 15, the operation of which can be easily understood with reference to FIG.

Referring to FIG. 3, circuit breaker 36 includes a second portion or body 57 attached to first end 54 of input lever 48 and a lower portion connected to lower bracket 30 by bolts 72. That is, the lower bracket is shown in cross section together with the compression tube 39, for example, by welding or the like.
Securely fixed to the wheel bogie assembly. The different figures show the action and operation of the blocking means 21 when a bump in the vertical direction of the track is encountered, for example, when the wheel bogie assembly is flexed with respect to the railcar. FIG. 3A shows the circuit breaker 36 at a normal height. During operation over irregular portions, the hydraulic damper 42 of the shut-off means prevents the input lever 48 from being essentially moved, thus preventing an erroneous load detection input to the load control valve 18. . FIG. 3A
The circuit breaker indicates its normal position on a light or empty vehicle, as shown in FIG. When the vehicle encounters a bump in the track and the wheel bogie assembly 33 bounces upward (FIG. 3).
B), the lower bracket 30 moves up almost simultaneously with the wheel bogie assembly, moving a pull rod 75 attached to the lower bracket upward, and furthermore, a lock nut 78 at the lower end of this rod is used to move the compression tube 39
To compress the compression tube into the circuit breaker body (second part).
Press into 57. Therefore, the compression tube guide 80 located at the top of the compression tube 39 compresses the shut-off spring 81 against the extension tube guide 84, and stops the upward movement by the top of the breaker body.

As shown in FIG. 3B, the upper guide 87 of the pull rod moves upward away from the bottom of the extension tube 90. Over a relatively short period of time in which such momentum and vibration continue, the force for bending the blocking spring 81 is:
As will be explained further below, the hydraulic damper 42 will be slightly moved.

FIG. 3C shows the position of the circuit breaker 36 when the wheel bogie assembly rebounds or the axle "falls into the hole." In this position, the pull rod 75 is pulled down by the extension of the breaker, and by pulling the upper guide 87 of the pull rod down in the extension tube 90, the breaking spring 81 is brought into contact with the bottom edge 93 of the breaker body 57. It is compressed between the stationary compression tube guide 80 and the downwardly extending extension tube guide 84. Therefore, also in this case, the blocking spring is compressed. Preferably, the total breaker stroke 96 of the circuit breaker is equal to the rebound stroke 9
Like 9, it is 10 cm (4 inches) and can tolerate a total of 20 cm (8 inches) deflection of the vehicle body relative to the bogie frame without significant movement of the input lever 48.

The effect of mounting the restriction system 15 on a railway vehicle can be understood with reference to FIG. If the position of the wheel bogie assembly is maintained constant with respect to the track, the lower bracket 30 will be maintained at the position indicated by reference line 100. However, the vehicle body, and thus the upper bracket 24 attached to the vehicle body, bends by a flexure 102 represented by the vehicle load (depending on the particular mounting structure between the vehicle body 27 and the wheel bogie assembly 33). . If the vehicle has a load, the process usually takes some time, but the circuit breaker 36 is first compressed (similar to the bouncing condition in FIG.
As shown in (2), the compressed state is maintained so that the hydraulic damper 42 can move upward for a sufficient time. The isolation spring is first compressed and the operation is stopped by the return of the isolation spring to the cage height 69 (FIG. 4A). This causes the circuit breaker 36 to return to its initial length, but the hydraulic damper is shortened by the damper flexure 105 (FIG. 4B). The input lever 48 and the contact knob 108 of the input means 51 correspondingly push down the input shaft 111 of the adaptive load limiting valve 18 to reflect the new load on the vehicle. The damper deflection 105 is proportional to the weight of the vehicle that changes the height 102 of the vehicle body relative to the wheel bogie assembly, as is the position 114 of the input means 51 for the adaptive load limiting valve.

The effect of the rebound / rebound in the blocking means with the mechanism at the new height position is the same for the same track perturbation as at the light vehicle position, and in fact is the same at any load setting and longer. Periodic load fluctuations only affect the length of the damper flexure of the blocking means, whereas short-period dynamic fluctuations only affect the breaking length of the blocking means.

In the design of the hydraulic damper, the breaking spring 81
Of the cage load is 5.08 cm / min (2 when the same load as the cage load acts on the hydraulic damper).
The hydraulic damper 42 is selected to be compressed at a rate not exceeding inches / minute. Thus, during a half cycle of vehicle movement, the hydraulic damper will have a distance S = (t / 60) ×
Move by 2, where t is the half-cycle time (seconds), f
Is the frequency (Hz) of the railway vehicle body. The maximum suspension frequency is about 1-2 Hz, the worst at 1 Hz. This movement will be represented by S = 1/60 × 2 = 1/30 = 0.033 inch (0.84 mm). Assuming that a transition from a light vehicle (FIG. 4A) to a full vehicle (FIG. 4B) requires 1.5 inches (3.81 cm) of suspension.
1. the maximum error of 0.033 inches divided by 1.5 inches
2% is introduced at the position of the input lever 48. Expressed in another way, if the device is used to produce a constant 20% braking ratio in a vehicle, this error will cause the braking ratio to increase from 20% to 20 × 1.022 = 20.44%.
Rise to This represents a negligible error in the braking system. A damping ratio of 5.08 cm / min (2 inches / min) will at the same time ensure that the correction ends with a load variation within 45 seconds. If a 50 foot long coal hauler full load at 91 cm / s (3 ft / s) requires, for example, 17 seconds, the effect of a 45 second change in time on the train can be ignored.

The operation of the adaptive load limiting valve 18 according to the present invention will be described below in detail with reference to FIGS. The adaptive load limiting valve includes a valve body 120 and an input means 51, and a contact knob 108 of the input means contacts an intermediate section 66 of the input lever between the shaft bearing 67 of the input lever 48 and the second end 60. The input lever 48 is connected to the second section 6 of the hydraulic damper 42.
3 is rotatably mounted. Further, the adaptive load limiting valve includes a detection piston 123 housed inside the valve body 120 and connected to the input shaft 111 at the other end of the input means remote from the knob 108 and the input lever. A control valve port 126 connected to a fluid source, such as compressed air, is in fluid communication with an outlet port 129 via a detection piston 123, and the outlet port 129 is a brake operatively connected to an air brake on a railway vehicle. Fluid communication with cylinder. Detection piston, detection piston inlet 135 and first
An annular passage 132 around the chamber 138 establishes fluid communication between the inlet port and the outlet port, and the first chamber 38 is in fluid communication with the second or upper chamber 141 by an annular shaft passage 144. The second chamber 141 communicates with the outlet port 129. The limit check valve 147 is
Attached to the lower portion 148 of the detection piston 123 by 50, the spring 150 biases the check valve against the bottom of the input shaft 111. A second or pressure chamber 141 exists between the top portion 153 of the detection piston 123 and the top portion 156 of the valve body 120 and is in fluid communication with an outlet port 129 to the brake cylinder. The detection piston 123 is
The detection spring 159 and the adjusting screw 162 allow the valve body 12
0.

The braking action 5 show a variable load limiting valve having an input means 51 located between the full position 165 and an empty position 168 of the rail vehicle. Brake cylinder port of control valve (not shown)
From the control valve inlet port 126 of the adaptive load limiting valve 18 through the sensing piston 123 and the annular passage 132 around the sensing piston inlet 135 and above the limiting check valve 147 in the sensing piston. It flows to one room 138. Since the restriction check valve is initially separated from the valve seat 171 by the input shaft 111, the compressed air passes through the check valve and the detection piston and passes through the input shaft passage 144 to the pressure chamber above the detection piston 123. Continue to 141,
The compressed air acts on the top or top surface 153 of the detection piston to urge the detection piston downward against the force of the detection spring 159. As described above, the second or pressure chamber 141 is in constant communication with the outlet port 129 to the brake cylinder.

As shown in FIG. 6, when the pressure in the second chamber 141 rises to a value that moves the detection piston 123 (downward in the figure), this movement of the detection piston supports the detection piston. The surface of the check valve valve seat 171 contacts the surface of the check valve 147 and becomes larger due to the greater pressure until the valve seat is moved slightly down toward the end of the input shaft 111. When a predetermined value is reached, the check valve 147
When the seat is seated, the fluid communication with the pressure chamber 141 is cut off, so that the air flow to the annular shaft passage 144 is cut off, and the air pressure in the brake cylinder is prevented from further increasing. In this condition, the active detection piston of the control valve is active rather than in the "service overlap" position, so any leakage of brake cylinder pressure is replenished from the air reservoir. Similarly, if the weight of the vehicle increases during the braking operation, for example, when a coal train is full of coal while loading on a train composed of multiple wagons, the check valve 147 may be set to the corresponding downward movement of the input shaft 111. The corresponding downward movement with movement causes the brake cylinder pressure to reach the new value required by the restrictor valve (after sufficient time has passed for the new vehicle height to affect the input lever 48). And therefore the communication between the inlet port 126 and the first chamber 138 is re-established.

The cutoff point merely depends on the position of the input means as determined by the input lever, and the pressure at the time of cutoff is determined by the hardness of the detection spring 159 and the initial adjustment.

When the brake release brake is released , the control valve inlet port 126
Pressure decreases to atmospheric pressure and, regardless of the position of the input means 51, the flow of air goes from the outlet port 129 to the brake cylinder to the pressure chamber 141 and from there through the annular shaft passage 144 of the detection piston 123. Passing downward, the restricting check valve 147 is pushed downward away from the check valve seat 171 against the force of the check valve spring 150.
In this way, the valve can be free of brake application. Further, as the brake cylinder pressure decreases, the detection piston 123 and the valve seat 171 of the check valve move upward,
The movement of the input shaft 111 with respect to the check valve 147 biases the check valve so as to keep the check valve away from the valve seat,
Achieve complete release of the brakes.

Stable minimum braking In the proposed system, the input lever is disconnected from the normal input, or the input lever is biased to a position that limits the brake cylinder pressure to a value lower than the desired pressure of the light vehicle. As a result, breakers or other parts of the link may be destroyed or damaged. Further, it is not desirable to provide a maximum brake cylinder pressure of less than about 20 PSA. This is because such low pressure, friction and release spring effects cause the actually applied brake shoe force to be substantially lower than the force provided by these effects. For these two reasons, the adaptive load limiting valve is provided with an internal stop 174 designed to limit the brake cylinder pressure to very low values and prevent the brake from losing due to friction and release spring effects. Engage. FIG. 7 shows the position of the restriction valve in a light vehicle or a low load state. More specifically, referring to this figure, the input shaft 111 is completely prevented from moving upward by the internal stopper 174 that comes into contact with the shaft retainer 177. In this position, the size of the detection piston 123 and the length of the input shaft are such that the check valve 147 is held away from the valve seat 171 by a minimum rising amount 180. When the brake is applied in this state, the brake cylinder pressure rises before the detection piston 123 starts moving downward. The pressure at which this state appears can be adjusted by the adjusting spring adjustment screw 162, while the pressure rise above this point as a function of vehicle height is determined by the spring constant of the detecting spring 159. This hinders the manufacture of a range of brake cylinders depending on spring travel, gross weight including vehicle weight and load, and operating conditions of the vehicle.

While particular embodiments of the present invention have been described in detail, those skilled in the art will recognize that various modifications and alterations may be made in light of the overall teachings of the present disclosure. Accordingly, the specific structures disclosed are merely illustrative and are not limiting upon the scope of the invention, which is set forth by the appended claims and all equivalents.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a load proportional brake cylinder pressure limiting system according to the present invention.

FIG. 2 is a detailed view showing a structure of a load proportional restriction valve shown in FIG.

3A, 3B, and 3C are state diagrams showing the effect of a short-term change in the vehicle height of a railway vehicle body due to normal vehicle operation in the present invention.

FIG. 4 is a schematic diagram consisting of FIGS. 4A and 4B and showing the effect of the load on the railway vehicle in the circuit breaker according to the present invention.

FIG. 5 is a cross-sectional view of a vehicle load limiting valve according to the present invention, showing a partially loaded vehicle in a brake relaxed state.

FIG. 6 is a cross-sectional view of the vehicle load limiting valve according to the present invention, showing the partially loaded vehicle shown in FIG. 5 in a braking state;

FIG. 7 is a cross-sectional view of a vehicle load limiting valve according to the present invention, showing a vehicle with a light load or no load in a brake released state.

[Procedure amendment]

[Submission date] June 12, 2000 (2006.1.
2)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 5

FIG. 3

FIG. 4

FIG. 6

FIG. 7

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Thomas H. Engle United States, New York, Clayton, P.O. Box 10F term (reference) 3D045 AA07 BB00 BB37 CC05 GG14

Claims (23)

[Claims] 1. A system for adjusting a brake cylinder pressure of a vehicle according to a load state of the vehicle, wherein a pressure of a fluid supplied to a fluid-operated braking device of the vehicle according to the load carried by the vehicle. And a limit valve means having a load detecting means for detecting a load supported by the vehicle wheel assembly; and a transient deflection of the vehicle independent of the load on the vehicle. And a shutoff means for shutting off the load detecting means from the vehicle brake cylinder pressure adjusting system. 2. The blocking means includes: an upper bracket fixed to a vehicle body; a lower bracket fixed to the vehicle wheel assembly; a first section fixed to the upper bracket;
A damper having a second section movably attached to the section; a first section fixed to the lower bracket; a circuit breaker having a second section slidably attached to the first section;
And a first rotatably mounted on the second portion of the circuit breaker.
An input lever having an end and a second end rotatably mounted on the second section of the damper, wherein the upper bracket is in an intermediate section between the first end and the second end. 2. The vehicle brake cylinder pressure adjusting system according to claim 1, further comprising an input lever rotatably mounted on said input valve and operatively cooperating with said load detecting means of said restriction valve. 3. A valve body having an inlet port connected to a control valve device and an outlet port connected to a brake cylinder device, and said restriction valve means is slidably disposed inside said valve body. A detection piston defining a pressure chamber between the valve body and the valve body adjacent to the outlet port, and further providing a fluid communication passage between the outlet port and the inlet port; The load detecting means slidably connected between the empty load position and the full load position to provide a displayed indication, and the detection piston is in contact with one end of the load detection means and is movable together. And a valve seat operably connected to and moveable with the sensing piston, wherein a first chamber is provided between the valve seat and the limit check valve. Position and the brake 2. The vehicle brake cylinder according to claim 1, further comprising: a valve seat movable between a closed position where the valve seat contacts the restricting check valve to close the fluid communication passage under pressure to a cylinder device. Pressure adjustment system. 4. The valve body having an inlet port connected to a control valve device and an outlet port connected to a brake cylinder device, the control valve means being slidably disposed inside the valve body, A detection piston defining a pressure chamber between the valve body adjacent to the outlet port and providing a fluid communication path between the outlet port and the inlet port, wherein the detection piston complies with the vehicle load. Said detection piston slidably connected to said load detecting means operative between an empty load position and a full load position to provide an indication; and wherein said detection piston is in contact with one end of said load detection means and is movable together. A restricting check valve, and a valve seat operably connected to and movable together with the sensing piston, wherein an open position wherein a first chamber is provided between the valve seat and the restricting check valve. , And the brake 3. The vehicle brake cylinder of claim 2, further comprising: a valve seat movable between a closed position where the valve seat contacts the restricted check valve to close the fluid communication passage under pressure to a cylinder device. Pressure adjustment system. 5. The load detecting means includes an input shaft slidably connected to the valve body, and the detecting piston further includes a first part disposed between a lower part and the lower part.
2. The load-responsive load of claim 1 including an upper portion defining a chamber, wherein said limiting check valve is resiliently connected to said lower portion, and said first chamber is in fluid communication with said inlet port. Restriction valve. 6. A limit check valve seat connected to the top of the detection piston and including an annular passage between the detection piston and the load detecting means, wherein the first chamber defines the annular passage. 6. The adaptive load limiting valve according to claim 5, wherein the variable pressure limiting valve is in fluid communication with the pressure chamber through a pressure chamber. 7. The adaptive load limiting valve according to claim 6, further comprising a shut-off spring connected between the lower portion of the detection piston and the valve body. 8. The restriction check valve is connected to the lower portion of the detection piston by a spring that biases the restriction check valve against the load detection means, thereby connecting the fluid communication passage. 7. The load limiting valve according to claim 6, wherein the detection piston is movable relative to the limiting check valve such that the limiting check valve seat can contact the limiting check valve to close. 9. The shut-off means according to claim 4, wherein said first portion of said circuit breaker is slidably mounted on said second portion by a spring. 10. The spring having a limiting force substantially equivalent to a damper ratio such that the input lever does not provide an input based on deflection of the wheel assembly with respect to the vehicle body to the load limiting valve. Item 10. A blocking means according to Item 9. 11. A spring having a limiting force substantially equivalent to a damper ratio such that said input lever does not provide said adaptive load limiting valve with input based on deflection of said wheel assembly with respect to said vehicle body. 3. The breaking means according to claim 2, wherein the first part of the circuit breaker is slidably mounted on the second part. 12. A system for use in a vehicle braking control system operatively disposed between a brake cylinder device and a vehicle control valve for adjusting a brake cylinder pressure during braking according to a vehicle load. A load limiting valve, comprising: a valve body having an inlet port connected to the control valve and an outlet port connected to the brake cylinder device; and the outlet port slidably disposed inside the valve body. A sensing piston defining a pressure chamber between the valve body and the valve body adjacent to the valve body and further providing a fluid communication passage between the inlet port and the outlet port; and providing an indication according to the vehicle load. A load detecting means slidably connected to the detection piston and operable to fluctuate between an empty load position and a full load position; and contactable with one end of the load detection means and movable together. A restrictive check valve, and a valve seat operatively connected to and movable together with the detection piston, wherein a first chamber is provided between the valve seat and the restrictive check valve and Between an open position in fluid communication with an inlet port and the pressure chamber and a closed position where the valve seat contacts the restricted check valve to close the fluid communication passage under pressure to the brake cylinder device. A load limiting valve having the movable valve seat. 13. The load detecting means includes an input shaft slidably connected to the valve body, wherein the input shaft has an internal stop such that a minimum pressure chamber is defined at the empty load position. 13. The adaptive load limiting valve according to claim 12, including: 14. The detection piston further has a lower portion and a top defining the first chamber between the lower portion, and the restricting check valve is provided on the lower portion. 13. The load limiting valve of claim 12, wherein the first chamber is resiliently connected and the first chamber is in fluid communication with the inlet port. 15. A restriction check valve seat connected to the top of the detection piston and including an annular passage between the detection piston and the load detection means, wherein the first chamber defines the annular passage. 15. The variable load limiting valve of claim 14, wherein the variable pressure limiting valve is in fluid communication with the pressure chamber through a pressure chamber. 16. The load detecting means includes an input shaft slidably connected to the valve body, and the detecting piston further includes a first chamber between a lower portion and the lower portion. 13. The response of claim 12, comprising a top defining a first non-return valve, wherein the restriction check valve is resiliently connected to the lower portion and the first chamber is in fluid communication with the inlet port. Load limiting valve. 17. A restriction check valve seat connected to a top portion of the detection piston and including an annular passage between the detection piston and the load detection means, wherein the first chamber defines the annular passage. 17. The adaptive load limiting valve of claim 16, which is in fluid communication with the pressure chamber through a pressure chamber. 18. The adaptive load limiting valve according to claim 15, further comprising a shut-off spring connected between the lower portion of the detection piston and the valve body. 19. The restriction check valve is connected to the lower portion of the detection piston by a spring that biases the restriction check valve against the load detection means, thereby connecting the fluid communication passage. 15. The load limiting valve according to claim 14, wherein the detection piston is movable relative to the limiting check valve such that the limiting check valve seat can contact the limiting check valve to close. 20. The detection piston further includes an inlet, and the fluid communication passage is defined by the inlet port, the inlet of the detection piston, the first chamber, the annular passage, the pressure chamber, and the outlet port. The adaptive load limiting valve according to claim 14, which is formed. 21. A vehicle body, a wheel assembly, an adaptive load limiting valve, and shutoff means for isolating a transient deflection of the wheel assembly with respect to the vehicle body from the adaptive load limiting valve. A braking system, wherein the blocking means comprises: an upper bracket fixed to the vehicle body; a lower bracket fixed to the wheel assembly; a first section fixed to the upper bracket; And the first
A damper having a second section movably attached to the section; a first section fixed to the lower bracket; a circuit breaker having a second section slidably attached to the first section;
And a first rotatably mounted on the second portion of the circuit breaker.
An input lever having an end and a second end rotatably mounted on the second section of the damper, wherein the input lever is to an upper bracket in an intermediate section between the first end and the second end. Blocking means comprising a rotatable bearing and said input lever operatively associated with said load limiting valve. 22. The breaking means according to claim 21, wherein said first portion of said circuit breaker is slidably attached to said second portion by a spring. 23. The spring having a limiting force substantially equivalent to a damper ratio such that the input lever does not provide an input based on deflection of the wheel assembly with respect to the vehicle body to the load limiting valve. Item 23. The blocking means according to Item 22.