Parking brake valve and brake system for trailer and method for controlling parking brake

Abstract

The invention relates to a parking brake valve (12) for a trailer (202), comprising a supply port (10) for connection to a pneumatic pressure supply line (206) of a towing vehicle (300), a delivery port (18) for connection to a parking brake actuator (228), preferably via a brake module (226), an exhaust port (24) and an internal line (30). Furthermore, the parking brake valve (12) comprises a main valve (26) comprising a first position (48) connecting the inner line (30) to the delivery port (18) for providing pneumatic pressure at the inner line (30) to the delivery port (18) and a second position (32) connecting the exhaust port (24) to the delivery port (18) for discharging pneumatic pressure at the delivery port (18) to the exhaust port (24). Furthermore, the parking brake valve (12) comprises an internal valve (28), the internal valve includes a first position (50) connecting the supply port (10) to the internal line (30) to provide pneumatic pressure at the pneumatic pressure supply line (206) to the internal line (30), a second position (36) blocking a connection between the internal line (30) and the supply port (10), and a pilot port (16) for connecting to a pneumatic pressure control line (210) of a trailer (202) connected to a tractor vehicle (300), the internal valve (28) is arranged to switch from the second position (36) to the first position (50) when a pneumatic pressure above a switching pressure threshold (78) is provided on the pilot port (16). The invention also relates to a braking system for a trailer, a vehicle (200), a vehicle combination (100) and a method (68) for controlling a parking brake (230).

Description

Technical Field

[0001] The invention relates to a parking brake for a vehicle, in particular to a parking brake valve for controlling a parking brake actuator of a trailer. The invention also relates to a brake system comprising the parking brake valve, a vehicle, in particular a trailer comprising the parking brake valve or the brake system, and a vehicle combination comprising the trailer. Furthermore, the invention relates to a method for controlling a parking brake. Background Art

[0002] Parking brakes are known in the prior art. Parking brakes for vehicles include at least one parking brake actuator, which is preferably a spring-loaded actuator. In particular, on the rear axle of the vehicle, the spring-loaded actuator is integrated into the service brake to form a so-called three-stop brake cylinder. In addition, the parking brake includes an air supply that provides pneumatic pressure for the parking brake actuator. The spring-loaded actuator forming the parking brake actuator is usually configured to close by the force of a spring in the absence of pneumatic pressure and to open against the force of the spring when compressed air applies a pneumatic pressure exceeding a certain pressure threshold.

[0003] Therefore, to open the spring loaded actuator, the compressed air source must supply compressed air to the actuator, and to close the actuator, the compressed air must be exhausted to reduce the pneumatic pressure of the actuator. Therefore, the pneumatic pressure in the spring loaded actuator must be controlled, which is done by the parking brake valve.

[0004] According to the prior art, the described parking brake is used for heavy tractors or trucks and trailers. When the tractor is coupled to the trailer, the parking brake of the trailer is released as soon as the pneumatic pressure supply line of the trailer is pressurized by compressed air supplied by the tractor. In case the trailer is parked on a slope, the trailer may move. This may lead to safety problems (especially for the driver). The reason for this is that the pneumatic pressure provided to the trailer via the pneumatic pressure supply line when the trailer interface is connected to the tractor is provided to the parking brake actuator via the parking brake valve. As a result, the spring-loaded actuator opens and the parking brake is released.

[0005] Therefore, it is known in the prior art to provide a safety mechanism on the parking brake valve. The safety mechanism comprises a button on the parking brake valve which, after connecting the pressure supply line from the tractor to the trailer, must be pushed or pulled manually to open the parking brake valve blocking the connection in the supply line. By pushing or pulling the button, the parking brake is released. However, despite the presence of this safety button, the safety problem is not completely eliminated. In this case, for example, if the tow bar of the trailer is not properly connected to the hitch of the tractor, which remains unnoticed by the driver, the trailer may move without the driver's control when the pneumatic supply line is connected and the button is pushed or pulled. Summary of the invention

[0006] It is therefore desirable to solve at least one of the above problems. In particular, an object of the present invention is to find a device and a method that increase safety during the release of a parking brake of a vehicle. Another object of the present invention is to propose an alternative to the prior art.

[0007] According to the invention, this object is solved in a first aspect by a parking brake valve for a vehicle according to claim 1 .

[0008] According to the invention, a parking brake valve for a vehicle, in particular a trailer, is proposed, which comprises a supply port for connection to a pneumatic pressure supply line of a tractor vehicle. Furthermore, the parking brake valve comprises a delivery port for controlling a parking brake actuator, in particular by means of a spring-loaded actuator. Furthermore, the parking brake valve comprises an exhaust port, which is preferably an outlet connected to ambient pressure.

[0009] Furthermore, the parking brake valve comprises a main valve having a first position and a second position. In the first position, the internal pipeline of the parking brake valve is connected to the delivery port for providing the pneumatic pressure at the internal pipeline to the delivery port. In the second position of the main valve, the exhaust port is connected to the delivery port for exhausting the pneumatic pressure at the delivery port to the exhaust port. In particular, in the second position of the main valve, the parking brake is applied, and the first position of the main valve is used to release the parking brake actuator.

[0010] Furthermore, according to the present invention, the parking brake valve further comprises an internal valve. The internal valve comprises a first position and a second position. In the first position of the internal valve, the supply port is connected to the internal line for providing the pneumatic pressure at the pneumatic pressure supply line of the tractor to the internal line when the pneumatic pressure supply line is connected to the compressed air supply of the tractor. Furthermore, in the second position of the internal valve, the connection between the internal line and the supply port is blocked. Furthermore, the internal valve comprises a pilot port for connecting to a pneumatic pressure control line of the tractor. In particular, the pneumatic pressure control line of the tractor is a line that does not provide pneumatic pressure until the driver applies a foot brake pedal on the tractor. When a force is applied to the foot brake pedal, the force results in an increased pressure on the pneumatic pressure control line. However, the internal valve is arranged to switch from the second position to the first position when a pneumatic pressure above the switching pressure threshold is provided on the pilot port.

[0011] Therefore, in order to release the parking brake of the trailer, the two sub-valves of the parking brake valve need to be in a defined position. When the two sub-valves (i.e. the main valve and the internal valve) are in a defined position, they allow the pneumatic pressure provided at the supply line to be forwarded to the brake actuator. However, although the driver brings the main valve to the position that connects the internal line to the delivery port, the internal valve stays in the blocking position, i.e. the second position, until the driver pushes the foot brake pedal. In fact, pushing the foot brake pedal causes the internal valve to switch from the second position to the first position. Therefore, the supply port of the parking brake valve is connected to the delivery port via the main valve, the internal line and the internal valve. Therefore, it is ensured that the driver is in the cab when the parking brake is released, and therefore, including: if the trailer is parked on a slope and the trailer's tow bar is not connected or incorrectly connected to the hitch, the trailer that moves away without the driver's control cannot injure the driver. In addition, the parking brake valve combines the functions of the two sub-valves in one housing, wherein only one button is provided to control the main valve, and wherein in addition, the internal valve automatically switches.

[0012] According to a first development of the invention, the pilot port of the internal valve is connected to the pneumatic pressure control line. Furthermore, the internal valve comprises an internal pilot port, wherein the internal valve is arranged to maintain the first position when a pneumatic pressure above an internal switching pressure threshold is provided on the internal pilot port, wherein the internal pilot port is connected to the internal line.

[0013] Thus, by connecting the internal pilot port to the internal line, the first position of the internal valve is maintained after the pneumatic pressure provided on the pilot port, which is above the switching pressure threshold, is reduced to below the switching pressure threshold. This occurs because, after providing a pneumatic pressure on the pilot port, which is above the switching pressure threshold, to switch the internal valve from the second position to the first position, the internal line is connected to the supply port and thus the pneumatic pressure of the pneumatic pressure supply line of the tractor is provided to the internal line. By connecting the internal pilot port to the internal line, a pneumatic pressure is provided on the internal pilot port of the internal valve and is used to maintain the internal valve in the first position.

[0014] Thus, it is ensured that when the driver does not apply the foot brake pedal, the internal valve stays in the first position and the parking brake remains released independently of the foot brake pedal position and thus independently of the pneumatic pressure at the pneumatic pressure control line of the tractor. This function may be referred to as a self-holding function.

[0015] According to a further development, the internal valve comprises a reset device, in particular a reset spring. The reset device in the parking brake valve is arranged at the internal valve to place the internal valve in the second position when the pneumatic pressure on the pilot port or the internal pilot port is below the switching pressure threshold or below the internal switching pressure threshold, respectively. Thus, when the pneumatic pressure on the pneumatic pressure supply line drops below the switching pressure threshold or the internal switching pressure threshold, the connection between the supply port and the internal line is blocked. In this case, when the internal valve is switched to the second position, the internal line is preferably connected to the other exhaust port or the exhaust port via the internal valve. Thus, without applying a force to the foot brake pedal, independently of increasing the pneumatic pressure on the supply port, the internal valve will still be closed and the parking brake will be applied.

[0016] According to a further development, the parking brake valve comprises a reservoir port for providing the main valve with pneumatic pressure.The main valve comprises a third position in which the reservoir port is connected to the delivery port.

[0017] Therefore, independently of the position of the internal valve, when a pneumatic pressure reservoir is provided and connected to the brake valve, the main valve is able to provide pressure to release the parking brake without the need for a towing vehicle. With pneumatic pressure provided on the reservoir port, by switching the main valve to the third position, pneumatic pressure is provided to the delivery port to release the parking brake by piloting the parking brake actuator.

[0018] Thus, the trailer can be maneuvered without the aid of an external pneumatic pressure source provided by the tractor.

[0019] According to a further development, the parking brake valve comprises a pressure actuator, in particular a pneumatic cylinder with a piston, wherein the pressure actuator, in particular the cylinder, is connected to the supply port. The pneumatic cylinder is arranged to push the main valve from the third position to the first position, in particular via the piston, when a pneumatic pressure above a supply pressure threshold is provided by the supply port of the parking brake valve. Thus, when the main valve is in the third position in release mode for maneuvering a trailer without a tractor and the trailer is to be coupled to the tractor, by connecting the supply port to the pneumatic pressure supply line, the main valve is automatically pushed into the first position and, therefore, the parking brake remains released and ready for the driving mode in case the driver applies the foot brake pedal to switch the internal valve.

[0020] According to a further development, the main valve comprises a pilot button for switching from any one of the first position, the second position and the third position of the main valve to any one of the first position, the second position and the third position of the main valve. The main valve can be switched manually between the three positions by means of a pilot button which is preferably provided with a reset device for fixing the position of the main valve. Thus, the pilot button is used to switch the parking brake valve to a parking mode, a driving mode or a release mode. In particular, in the release mode, the position of the main valve corresponds to the third position, in the parking mode to the second position, and in the drive mode to the first position.

[0021] Preferably, in addition to manual switching by the pilot button, the pressure actuator is also arranged to push the main valve from the third position to the first position. In order to control the main valve, no further reset device or actuator is provided or required beside the pressure actuator and the pilot button.

[0022] According to a further development, the parking brake valve comprises a check valve connected between the supply port and the reservoir port. The check valve has an installation orientation to block fluid flow from the reservoir port to the supply port and to allow fluid flow from the supply port to the reservoir port.

[0023] Thus, the parking brake valve is used to load the reservoir connected to the reservoir port with pneumatic pressure from the pneumatic pressure supply line (i.e., by the pressure provided by the tractor). After releasing the connection between the supply port and the pneumatic pressure supply line, the pneumatic pressure provided in the reservoir will be maintained in the reservoir, preferably supplying the parking brake actuator when the main valve is shifted to the third position.

[0024] Thus, no additional valves or ports are required to fill the reservoir.

[0025] According to a further development, the switching pressure threshold is arranged by designing the parking brake valve in the range of 1.5 bar to 3.5 bar, more preferably in the range of 2 to 3 bar, in particular the switching pressure threshold corresponds to 2.5 bar. Alternatively or additionally, when the parking brake valve comprises an internal pilot port, the internal switching pressure threshold is lower than the switching pressure threshold, wherein the internal switching pressure threshold is in the range between 1 bar and 2 bar, in particular the switching pressure threshold corresponds to 1.5 bar. Finally, the supply pressure threshold is preferably in the range of 0.5 bar to 1.5 bar, preferably the supply pressure threshold corresponds to 1 bar.

[0026] In a second aspect of the invention, a braking system is proposed. The braking system comprises at least one parking brake valve according to the first aspect of the invention. In addition, the braking system comprises: at least one parking brake actuator, which is preferably connected to the delivery port of the parking brake valve via a brake module; a pneumatic pressure control line, which preferably has a foot pedal for providing a control pressure, which is connected to the pilot port of the internal valve of the parking brake valve; and a pneumatic pressure control line, which is connected to the supply port of the parking brake actuator, wherein the pneumatic pressure control line is preferably connected to a pneumatic source.

[0027] According to a third aspect of the present invention, a vehicle is provided. The vehicle is particularly a trailer, or more particularly may be a semitrailer, a mid-axle trailer or a drawbar trailer. The vehicle comprises a parking brake valve according to the first aspect or a brake system according to the second aspect.

[0028] According to a fourth aspect of the present invention, a vehicle combination is provided, comprising: a vehicle according to the third aspect of the present invention; and a tractor.

[0029] Furthermore, according to a fifth aspect of the present invention, a method for controlling a parking brake, in particular by means of a parking brake valve according to the first aspect of the present invention, is proposed.

[0030] The method comprises the following steps for directing the parking brake from the braking mode to the driving mode: receiving a pneumatic pressure at least above a supply pressure threshold on a supply port of the parking brake valve. In addition, receiving a force on a pilot button of the main valve to switch the main valve from a second position to a first position, in which the exhaust port is connected to the delivery port of the parking brake valve. In the first position, an internal pipeline of the parking brake valve is connected to the delivery port for providing the pneumatic pressure of the internal pipeline to the delivery port. In addition, receiving a pneumatic pressure above the switching pressure threshold from a pneumatic pressure control pipeline of the tractor on the pilot port of the internal valve of the parking brake valve to switch the internal valve from the second position to the first position, in which the connection between the internal pipeline and the supply port is blocked, and in the first position, the supply port is connected to the internal pipeline for providing the pneumatic pressure at the supply port to the internal pipeline.

[0031] According to one development of the method, the method comprises the following steps for directing the parking brake to the release mode: receiving a force on a pilot button of the main valve to switch the main valve from a second position to a third position. In the second position, the exhaust port is connected to the delivery port. In the third position, the delivery port is connected to a reservoir port of the parking brake valve.

[0032] According to a further development, the method comprises the following steps of directing the parking brake to the braking mode: in one step, a force is received on a pilot button of the main valve to switch the main valve to the second position. Alternatively, a pneumatic pressure on the supply port below an internal switching threshold is received on the internal pilot port, in particular when the supply line is disconnected, in particular no pneumatic pressure on the supply port is received.

[0033] According to a further embodiment of the method, the method comprises the following steps for directing the parking brake from a release mode to a drive mode:

[0034] In one step, a pneumatic pressure from a supply port that is higher than a supply pressure threshold is received to shift the main valve from the third position to the first position through a pressure actuator. In addition, a pneumatic pressure from a control line that is higher than a switching pressure threshold is received on a pilot port of the internal valve to switch the internal valve from the second position to the first position. In addition, a pneumatic pressure from an internal line that is higher than an internal switching pressure on an internal pilot port maintains the internal valve in the first position. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawings, in which:

[0036] Figure 1 is a vehicle combination according to a first embodiment of the present invention;

[0037] Figure 2 is a parking brake valve in a braking mode according to the first embodiment;

[0038] Figure 3 It is in drive mode Figure 2 Parking brake valve;

[0039] Figure 4 It is in release mode Figure 2 and Figure 3 Parking brake valve;

[0040] Figure 5 are steps of a method for controlling a parking brake according to an embodiment;

[0041] Figure 6are steps of a method for directing a parking brake valve to a release mode;

[0042] Figure 7 are steps of a method for directing a parking brake valve to a braking mode;

[0043] Figure 8 are steps of a method for directing a parking brake valve from a release mode to a drive mode; and

[0044] Figures 9 to 13 Detailed description of the hardware configuration of a parking brake valve according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] Figure 1 A vehicle combination 100 is shown, which comprises a vehicle 200, namely a trailer 202, towed by a tractor 300. The trailer 202 comprises a parking brake 230. The tractor 300 comprises a tractor pneumatic pressure interface 310 connected to a pressure source 320. The pressure source 320 provides the pneumatic pressure and is, for example, a pressure tank which originates from a compressor, which is not shown in the figure. In addition, a foot pedal 330 is provided in the tractor 300, which can be applied by the driver. Figure 1 3 is a schematic diagram in which the pressure source 320 and the foot pedal 330 are directly connected to the pneumatic pressure interface 310 of the tractor. However, according to another embodiment, the pressure source 320 and the foot pedal 330 are indirectly connected to the pneumatic pressure interface 310 via the tractor braking system. Figure 1 The tractor brake system is not shown in detail.

[0046] The pressure source 320 provides a pneumatic pressure supply on the red output coupling 340. Furthermore, on the yellow output coupling 350, a pneumatic pressure control is provided. The pneumatic pressure on the pneumatic pressure control depends on the position of the foot pedal 330. The red output coupling 340 is connected to the trailer pneumatic pressure supply input 204 via the pneumatic pressure supply connection line 205 to provide pneumatic pressure on the pneumatic pressure supply line 206 of the trailer 202. Furthermore, the yellow output coupling 350 is connected to the pneumatic pressure control input 208 via the pneumatic pressure control connection line 209 to provide pneumatic pressure control on the pneumatic pressure control line 210. Thus, the interface 212 of the trailer 202 forwards the pneumatic pressure to the supply port 10 of the parking brake valve 12 via the pneumatic pressure supply line 206. The reservoir port 14 of the parking brake valve 12 is connected to a pneumatic reservoir 224 of the trailer 202, wherein the pneumatic pressure from the pneumatic pressure supply line 206 is forwarded to the pneumatic reservoir 224 via the parking brake valve 12. The pneumatic reservoir 224 is also connected to a brake module 226, which is able to provide pneumatic pressure to a brake actuator 228 of the trailer 202. The pneumatic pressure forwarded to the brake actuator 228 in the driving mode of the vehicle combination 100 depends on the position of the foot pedal 330, wherein the position is forwarded by the pneumatic pressure control line 210, which is connected to the brake module 226 via the pneumatic pressure interface 212 of the trailer 202.

[0047] In addition, the pneumatic pressure control line 210 is connected to the pilot port 16 of the parking brake valve 12 via the interface 212 of the trailer 202. The delivery port 18 of the parking brake valve 12 is also connected to the brake module 226 to provide pneumatic pressure for guiding the brake actuator 228 into the parking position or releasing it from the parking position. In addition, the parking brake valve 12 includes a pilot button 34 for manually switching the mode of the parking brake valve 12.

[0048] Figure 2A connection diagram of a parking valve 12 in a braking mode 20 is shown. The parking brake valve 12 comprises a supply port 10 and a reservoir port 14 as well as a pilot port 16 and a delivery port 18. In addition, an exhaust port 24 is shown. In addition, the main elements of the parking brake valve 12 are a main valve 26 and an internal valve 28. The main valve 26 and the internal valve 28 are connected by an internal pipeline 30. The main valve 26 is shown in a second position 32, wherein the exhaust port 24 is connected to the delivery port 18. In the second position, the pneumatic pressure at the delivery port 18 can be discharged by the exhaust port 24 through the main valve 26. However, the main valve can be manually switched to two other positions by a pilot button 34, which are explained in other figures. In addition, the internal valve 28 is held in a second position 36 by a reset device 37 (i.e., a spring 38), wherein the connection between the internal pipeline 30 and the supply port 10 is blocked. However, if the pneumatic pressure on the supply port 10 is higher than the pressure on the reservoir port 14 , fluid flows from the supply port 10 through the check valve 40 to the reservoir port 14 in order to fill the pneumatic reservoir 224 .

[0049] exist Figure 2 In the illustrated braking mode 20, the brake actuator 228 is vented via the brake module 226 and the delivery port 18 connected to the exhaust port 24. The brake actuator 228 (e.g., a spring loaded brake) is in the braking position and the trailer 202 is held in place by the actuator 228 even when parked on a slope.

[0050] Figure 3 An actuation mode 46 of the parking brake valve 12 is shown. The driver has switched the main valve 26 to the first position 48 by means of the button 34. The internal line 30 is connected to the delivery port 18. Furthermore, the internal valve 28 is switched to the first position 50 by means of the pressure received via the pilot port 16 against the force of the spring 38. In this position, the pneumatic pressure received at the supply port 10 is forwarded to the internal line 30 via the internal valve 28, which connects the internal line 30 with the supply port 10. Furthermore, the internal line is connected to the internal pilot port 54 of the internal valve 28 to keep the internal valve 28 in the first position 50, even if the pressure on the pilot port 16 drops below a threshold value. Furthermore, the pneumatic pressure on the internal line 30 is forwarded to the delivery port 18 via the main valve 26. Thus, the pneumatic pressure on the supply port 10 is forwarded to the delivery port 18, which releases the brake actuator 228 via the brake module 226.

[0051] Figure 4A release mode 60 of the parking brake valve 12 is shown, wherein the internal valve 28 is in the second position 36. The release mode 60 may be applied after the braking mode 20, or if the pressure on the supply port 10 drops below a threshold. Thus, the spring 38 resets the internal valve 28 to the second position, the reset position.

[0052] Although there is no pneumatic pressure above the threshold on the supply port 10, if pneumatic pressure is available in the reservoir 224 connected to the reservoir port 14, the brake actuator 228 can be released via the parking brake valve 12. This can be achieved by the main valve 26, which can be brought into the third position 62 by the driver via the button 34. In this position, the reservoir port 14 is connected to the delivery port 18, and the pneumatic pressure in the reservoir is forwarded to the brake actuator 228 via the brake module 226. The release mode 60 is used to operate the trailer 202 without the need for the towing vehicle 300.

[0053] However, when in release mode 60, pneumatic pressure is supplied to the supply port 10, the pressure actuator 64 drives the piston 66, which is connected to the supply port 10 through its cylinder 65, and the piston 66 pushes the main valve 26 from the third position 62 to the first position, so that at least the main valve 26 automatically enters the drive mode 46. The internal valve 28 stays in the second position 36, in which the connection between the supply port 10 and the internal line 30 is blocked. In fact, the internal line 30 is connected to the exhaust port 24 via the internal valve 28. Therefore, the brakes on the trailer 202 will be ventilated and the trailer 202 will be braked until a pressure above the threshold is applied via the pilot port 16 to switch the internal valve 28 from the second position 36 to the first position 50.

[0054] Figure 5 The steps of a method 68 for controlling a parking brake having a parking brake valve 12 into a drive mode 46 are shown. In a first step 70, a pneumatic pressure having a release pressure value 72 is received on the supply port 10. In a next step 74, a force on the pilot button 34 of the main valve 26 is received to switch the main valve 26 from the second position to the first position. In step 76, a pneumatic pressure above a switching pressure threshold 78 is received from the pilot port 16 of the parking brake valve 12 to switch the internal valve 28 from the second position 36 blocking the connection between the internal line 30 and the supply port 10 to the first position 50 connecting the supply port 10 to the internal line 30 for providing pneumatic pressure to the internal line 30. In step 84, a pneumatic pressure above the internal switching pressure threshold 92 is received on the internal pilot port 54 to maintain the internal valve in position 50.

[0055] Figure 6The steps of a method for directing the parking brake into the release mode 60 are shown. In step 80 , a force on the pilot button 34 is received to switch the main valve 26 to the third position 62 in step 82 .

[0056] Figure 7 The steps of a method according to an embodiment for directing the parking brake into the braking mode 20 are shown. In step 86, a force on the pilot button 34 is received to switch the main valve 26 to the second position 32 in step 88. Alternatively, in step 90, a pneumatic pressure is received on the supply port 10 that is lower than the internal switching pressure threshold 92 to switch the internal valves 28, 29 to the second position 36.

[0057] Figure 8 The steps of a method for directing the parking brake from the release mode 60 into the drive mode 46 are shown. In step 96, a pneumatic pressure above the supply pressure threshold 91 is received from the supply port 10 and in step 97, the main valve is shifted from the third position 62 to the first position 48 by the pressure actuator 64. In step 94, a pneumatic pressure above the switching pressure threshold 78 is received on the pilot port 16 to switch the internal valve 28 from the second position 36 to the first position 50 in step 95.

[0058] Figures 9 to 13 A schematic hardware configuration of the parking brake valve 12 according to an embodiment of the present invention is shown.

[0059] Figures 9 to 13 The parking brake valve 12 with parking safety function in the embodiment of the present invention includes five ports and three key modes. The ports of the parking brake valve 12 include a supply port 10, a reservoir port 14, a pilot port 16, a delivery port 18, and an exhaust port 24. The modes for parking the parking brake valve 12 include a braking mode 20, a driving mode 46, and a release mode 60.

[0060] like Fig. 9 The parking brake valve 12 shown in FIG. 1 comprises a main valve 26 having a main valve core 120 manually operated by means of a button 34 to obtain the main functions of applying the parking brake in the braking mode 20 and releasing the parking brake in the release mode 60 and the driving mode 46. Fig.12 As shown in FIG. 1 , the bottommost air chamber 122 in the device serves as an automatic pop-up function of the main valve core 120, which automatically changes the mode from the release mode 60 to the drive mode 46 once the supply port 10 is pressurized. Figure 4 The ejection function is described in detail. The bottom air chamber 122 is equivalent to Figure 4 The air chamber of the pressure actuator 64 is defined by the pneumatic cylinder 65 and the piston 66.

[0061] The parking safety function is implemented by a built-in parking safety module, namely, an internal valve 28. The internal valve 28 includes a pilot-operated spool 124, which implements the following functions based on a pneumatic pressure control signal received via the pilot port 16 from a foot pedal valve trigger: Fig.10 The parking safety is activated in its second position 36 shown in FIG. Fig.11 The deactivated main function is shown in its first position 50 .

[0062] When the tractor 300 is coupled to the trailer 200, the trailer pneumatic pressure supply line 206 is pressurized and compressed air flows through the supply port 10 into the parking brake valve 12 and into the air chamber 126, as shown in FIG. Fig. 9 At the same time, compressed air also flows into the automatic ejection chamber. If the button is in the release position, i.e. if the main valve 26 is in the third position 62, this flow line in the parking brake valve 12 ensures that the button 34 and the main valve 26 are switched to the actuated position, i.e. the first position 48.

[0063] In the absence of a control signal from the foot pedal valve, i.e. if no pneumatic pressure is received via the pilot port 16, the supply port 10 will not be connected to the delivery port 18, thereby ensuring that the parking brake or emergency brake is not released. In this position, the parking safety module spool 124 of the internal valve 28 rests in the second position 36 due to the spring force of the spring 38, as shown in FIG. Fig.10 shown.

[0064] Once the driver steps into the tractor and squeezes the foot pedal valve, the pilot port 16 is energized and pushes the control piston 128 upward, resulting in deactivation of the parking safety function, such as Fig.11 Now, the internal valve 28 is in its first position 50 and allows the supply air pressure from the chamber 126 via the second input 52 of the internal valve 28 to flow into the other chamber 130 via the first output 55 of the internal valve 28, as shown. Fig.11 and 12 shown.

[0065] Fig.12 A flow path is shown from chamber 130 through the flow path created by the internal lines and main valve 26 (ie, by distributor plate 132 , main valve core 120 , sealing element and main housing 136 ) to delivery port 18 for releasing the emergency brake.

[0066] The built-in configuration of the park safety module (ie, self-retaining feature) ensures that the park safety function remains in the deactivated condition despite the removal of control pressure (ie, pressure on pilot port 16). When control line pressure is energized, the park safety is in its deactivated position, as described above.

[0067] Supply pressure flows into the self-holding chamber via a hole in the spool 124 and ensures that the parking brake is in a released condition regardless of the control pressure.

[0068] To enable the release function or release mode 60, the button 34 will be pushed to bring the main valve 26 to the third position 62. The compressed air in the reservoir tank flows through the distributor plate 132, the main valve 120 and through the sealing element through the reservoir port 14 to the delivery port 18. The delivery of compressed air from the delivery port 18 is used as an input pressure to release the emergency or parking brake.

[0069] Fig.13 The parking brake valve 12 is shown in its actuation mode 46. However, to activate the parking mode, the button 34 is pulled to its parking position, i.e. the main valve 26 is pulled to the second position 32. The compressed air in the delivery port 18 flows to the exhaust chamber through the housing, sealing elements, gaskets and flow channels in the distribution plate. The exhaust port 24 is connected by flow channels provided in the distribution plate 132 and the housing. The evacuation of the delivery pressure releases the emergency or parking brake.

[0070] Reference numerals (part of the specification)

[0071] 10 Supply port

[0072] 12 Parking brake valve

[0073] 14 Storage Port

[0074] 16 Pilot port

[0075] 18 Delivery port

[0076] 20 Braking mode

[0077] 24 Exhaust port

[0078] 26 Main valve

[0079] 28 Internal valve

[0080] 30 Internal pipeline

[0081] 32 Second position of main valve

[0082] 34 Buttons

[0083] 36 Second position of internal valve

[0084] 37 Reset device

[0085] 38 Spring

[0086] 40 Check valve

[0087] 46 Drive Mode

[0088] 48 Main valve first position

[0089] 50 First position of internal valve

[0090] 54 Internal pilot port

[0091] 60 Release Mode

[0092] 62 Third position of main valve

[0093] 64 Pressure actuator

[0094] 65 Pneumatic Cylinder

[0095] 66 Piston

[0096] 68 Method Steps

[0097] 70 First Step

[0098] 72 Release pressure value

[0099] 74 Steps

[0100] 76 Steps

[0101] 78 Switching pressure threshold

[0102] 80 Steps

[0103] 82 Steps

[0104] 84 Steps

[0105] 86 Steps

[0106] 88 Steps

[0107] 90 steps

[0108] 91 Supply Pressure Threshold

[0109] 92 Internal switching pressure threshold

[0110] 94 Steps

[0111] 95 Steps

[0112] 96 Steps

[0113] 97 Steps

[0114] 100 Vehicle Combinations

[0115] 120 Valve core

[0116] Room 122

[0117] 124 Valve core

[0118] Room 126

[0119] 128 Control piston

[0120] Room 130

[0121] 132 Distribution Board

[0122] 136 main housing

[0123] 200 vehicles

[0124] 202 Trailer

[0125] 204 Trailer Pneumatic Supply Input

[0126] 205 Pneumatic pressure supply connection line

[0127] 206 Trailer pneumatic pressure supply line

[0128] 208 Trailer pneumatic control input

[0129] 209 Pneumatic pressure control connecting line

[0130] 210 Trailer pneumatic pressure control line

[0131] 212 Interface

[0132] 224 Pneumatic accumulator

[0133] 226 Braking module

[0134] 228 Brake actuator

[0135] 230 Parking brake

[0136] 300 Tractor

[0137] 310 Pneumatic pressure interface for tractor

[0138] 320 Pneumatic Source

[0139] 330 Pedals

[0140] 340 Red output connector

[0141] 350 Yellow output connector

Claims

1. A parking brake valve (12) for a trailer (202), comprising: - a supply port (10) for connection to a pneumatic pressure supply line (206) of a tractor (300); a delivery port (18) for connection to a parking brake actuator (228), preferably via a brake module (226); - an exhaust port (24); - internal pipeline (30); - a main valve (26), said main valve (26) comprising: a first position (48) connecting the internal line (30) to the delivery port (18) for providing the pneumatic pressure at the internal line (30) to the delivery port (18); a second position (32) for connecting the exhaust port (24) to the delivery port (18) for discharging the pneumatic pressure at the delivery port (18) to the exhaust port (24), The features include: - an internal valve (28), said internal valve (28) comprising: a first position (50) connecting the supply port (10) to the internal line (30) for providing the pneumatic pressure at the pneumatic pressure supply line (206) to the internal line (30); a second position (36) which blocks the connection between the internal line (30) and the supply port (10); - a pilot port (16) for connection to a pneumatic pressure control line (210) of said trailer (202) connected to a tractor (300), Wherein the internal valve (28) is arranged to switch from the second position (36) to the first position (50) when a pneumatic pressure above a switching pressure threshold (78) is provided on the pilot port (16).

2. The parking brake valve (12) according to claim 1, wherein: - the pilot port (16) of the internal valve (28) is connected to a pneumatic pressure control line (210), and - the internal valve (28) comprises an internal pilot port (54) connected to the internal pipeline (30), wherein the internal valve (28) is arranged to maintain the first position (50) when a pneumatic pressure above an internal switching pressure threshold (92) is provided on the internal pilot port (54).

3. The parking brake valve (12) according to claim 1 or claim 2, wherein: The internal valve (28) comprises a reset device (37), in particular a reset spring (38), for placing the internal valve (28) in the second position (36) when the pneumatic pressure on the pilot port is below the switching pressure threshold (78) or when the pneumatic pressure on the internal pilot port (54) is below the internal switching pressure threshold (92).

4. The parking brake valve (12) according to any one of the preceding claims, wherein: The parking brake valve (12) includes a reservoir port (14) for providing pneumatic pressure to the main valve (26), wherein the main valve (26) includes a third position (62) connecting the reservoir port (14) to the delivery port (18).

5. The parking brake valve (12) according to claim 4, wherein: The parking brake valve (12) comprises a pressure actuator (64), which in particular comprises a pneumatic cylinder (65) with a piston (66), wherein the pressure actuator (64), in particular the pneumatic cylinder (65), is connected to the supply port (10), and wherein the pressure actuator (64), in particular the piston (66), is arranged to: when a pneumatic pressure above a supply pressure threshold (91) is provided by the supply port (10), push the main valve (26) from the third position (62) to the first position (48).

6. The parking brake valve (12) according to any one of the preceding claims, wherein: The main valve (12) includes a pilot button (34) for switching the main valve (26) from any one of a first position (48), a second position (32) and a third position (62) of the main valve (26) to any other of the first position (48), the second position (32) and the third position (62) of the main valve (26).

7. The parking brake valve (12) according to any one of the preceding claims, wherein: The parking brake valve (12) includes a check valve (40) between the supply port (10) and the reservoir port (14), wherein the check valve (40) has an installation direction to block fluid flow from the reservoir port (14) to the supply port (10) and allow fluid flow from the supply port (10) to the reservoir port (14).

8. The parking brake valve (12) according to any one of the preceding claims, wherein The parking brake valve (12) is arranged to define: the switching pressure threshold (78) in the range of 1.5 bar to 3.5 bar, preferably in the range of 2 bar to 3 bar, more preferably, the switching pressure threshold (78) corresponds to 2.5 bar; and / or the internal switching pressure threshold (92) below the switching pressure threshold (78), wherein the internal switching pressure threshold (92) is in particular in the range of 1 bar to 2 bar, in particular (92) corresponds to 1.5 bar; and / or the supply pressure threshold (91) in the range of 0.5 bar to 1.5 bar, in particular the supply pressure threshold (91) corresponds to 1 bar.

9. A braking system for a trailer, comprising: - at least one parking brake valve (12) according to any one of the preceding claims; - at least one parking brake actuator (228), the at least one parking brake actuator (228) being connected to the delivery port (18) of the parking brake valve (12); a pneumatic pressure control line (210) connected to a pilot port (16) of an inner valve (28) of the parking brake valve (12), in particular to a foot pedal (330) for providing a control pressure; - a pneumatic pressure supply line, preferably connected to a pneumatic source (320) for providing pneumatic pressure, the pneumatic pressure supply line being connected to a supply port (10) of the parking brake valve (12).

10. A vehicle (200), in particular a trailer (202), more particularly a semitrailer, a center axle trailer or a drawbar trailer (202), comprising a parking brake valve (12) according to any one of claims 1 to 8 or a brake system according to claim 9.

11. A vehicle combination (100), comprising: The vehicle according to claim 10; and a tractor (300) comprising a parking brake valve (12) according to any one of claims 1 to 8 or a brake system according to claim 9.

12. A method (68) for controlling a parking brake (230), in particular by means of a parking brake valve (12) according to claims 1 to 8, the method comprising: To switch the parking brake from the braking mode (20) to the driving mode (46): - receiving (70) a pneumatic pressure at least higher than a release pressure (72) at a supply port (10) of the parking brake valve (12); - receiving (74) a force on a pilot button (34) of the main valve (26) to switch the main valve (26) from a second position (32) for connecting the exhaust port (24) to the delivery port (18) to a first position (48) for connecting the internal line (30) to the delivery port (18); - receiving (76) a pneumatic pressure above a switching pressure threshold (78) from a pneumatic pressure control line (210) of a tractor (300) on a pilot port (16) of an internal valve (28), for switching the internal valve (28) from a second position (36) blocking a connection between the internal line (30) and the supply port (10) to a first position (50) connecting the supply port (10) to the internal line (30), for providing the pneumatic pressure on the supply port (10) to the internal line (30), and preferably, - receiving (84) a pneumatic pressure on the internal pilot port (54) above an internal switching pressure threshold (92) to maintain the internal valve in the first position (50).

13. The method (68) of claim 12, comprising: To direct the parking brake (230) to the release mode (60): - receiving (80) a force on a pilot button (34) of the main valve (26) to switch (82) the main valve from the second position (32) to a third position (62) connecting a reservoir port (14) to the delivery port (18).

14. The method (68) of claim 12 or 13, further comprising: To bring the parking brake (230) into braking mode (20): - receiving (86) a force on a pilot button (34) of the main valve (26) to switch (88) the main valve (26) to the second position (32); and / or - In particular, when the supply line is disconnected, a pneumatic pressure below an internal switching threshold (92) on the supply port (10) is received (90) on the internal pilot port (54), in particular no pneumatic pressure is received (90) to switch (88) the internal valve (28) to the second position (36).

15. The method (68) according to any one of claims 12 to 14, further comprising: To direct the parking brake (230) from the release mode (60) to the drive mode (46), - receiving (96) a pneumatic pressure above a supply pressure threshold (91) from the supply port (10) and switching (97) the main valve (26) from the third position (62) to the first position (48) via a pressure actuator (64); and - receiving (94) a pneumatic pressure above a switching pressure threshold (78) on a pilot port (16) of the internal valve (28), thereby switching (95) the internal valve (28) from the second position (36) to the first position (50).

Images