SE1451140A1

SE1451140A1 - Air supplying system in a vehicle provided with an air operated kneeling system

Info

Publication number: SE1451140A1
Application number: SE1451140A
Authority: SE
Inventors: Jim Nordenvall; Lennart Boethius
Original assignee: Scania Cv Ab
Priority date: 2014-09-29
Filing date: 2014-09-29
Publication date: 2016-03-30
Also published as: DE102015008663A1; SE538476C2

Abstract

Abstract An air supplying system (2) in a vehicle (4) provided with an air operated kneeling system (6) having one or many air spring bellows (8) that exhaust air (10) from the bellows during a kneeling procedure, and also provided with an air-operated door system (12) having one or many air-operated door manoeuvring members (14) for opening and closing one or many doors (16) of the vehicle. The air supplying system (2) comprises a control unit (18) configured to generate at least one control signal (20) including control parameters, and an air pipe arrangement (22) including air pipes (24) for communicating air (10) from the air spring bellow(s) (8) to the door manoeuvring members (14). The air pipe arrangement (22) is provided with at least one valve member (26) configured to control the air flow (10) through the air pipes (24) in dependence of said control parameters of said control signal (20). The control unit (18) is configured to control said valve member(s) (26) such that evacuated air (10) from the air spring bellows (8) during a kneeling procedure is supplied via said air pipe arrangement (22) to said air-operated door manoeuvring members (14) to open the door(s) (16) of said door system (12).

Description

Air supplying system Field of the invention The present invention relates to an air supplying system, and a method in relation to such an air supplying system according to the preambles of the independent claims. In particular the air supplying system and method are intended to be applied in relation to kneeling systems arranged in vehicles, and specifically in buses.

Background of the invention A low-floor bus is a bus that has no steps between one or more entrances and part or the entire passenger cabin. Being low floor improves the accessibility of the bus for the public, particularly the elderly or infirm, or those with push chairs, and increasingly, those in wheelchairs.

The function of lowering the bus in order to improve the accessibility is often referred to as kneeling. One way to implement a kneeling function is by means of an air-operated system that reduces the ground-to-first-step height, allowing the passengers to get on and off the bus more easily. It accomplishes this by removing air from one or many air spring bellows, e.g. the front axle air springs to lower the front end of the vehicle.

The system may be operated by a switch in the driver's instrument panel that controls the system. The driver presses the switch to the "down" position to lower the front end, or tilt the entire bus, of the coach. When the switch is pressed to the "up" position, the front end rises so it is ready to drive.

In a vehicle there are often numerous air-operated systems, e.g. one or many brake systems, a door manoeuvring system and the kneeling system. Normally a pneumatic source, e.g. an air compressor usually powered from a motor pulley. It pumps (compresses) air into tanks for various uses, and is provided for supplying these systems with pressurized air via a system of air pipes, air valves and air tanks containing pressurized air.

In the following one illustrating example of a kneeling system is given.

Under the front end of the coach is a set of air valves which are mounted on the vehicle body that connect to the front axle/suspension via two rods. The right-hand valve (levelling valve) controls the front-end ride height by controlling the air to the front air-suspension air springs during normal operation.

The left-hand valve (kneeling valve) is used by the kneeling system to sense the height as the vehicle rises after the front end was kneeled. Once the front end has kneeled, air is required to be induced into the front air springs to raise the vehicle. This valve senses the raised height of the front end and, by controlling the air pressure to an air switch, electrically disconnects the raise control of the kneeling system when the proper height has been reached.

The kneeling system is controlled by a switch located e.g. in the driver's instrument panel. The system is inhibited from operating unless the park brake is applied, the transmission is in neutral and the front door is closed. By pressing the down position of the switch half, the front end lowers (kneels) to the kneeled position and is ready to allow passengers to get on and off more easily. To return the front end to normal operating height, press down the up (recover) position of the kneeling switch half or release the park brake.

The kneeling switch actuates an electro-pneumatic valve (kneeling module). This valve is made up of an electric air switch and electro-pneumatic air valves mounted in a manifold that are connected to the air system as follows: There are three air supply lines through the kneeling module, two of which go to the front air springs. One comes from an auxiliary air tank and supplies air for the kneeling recovery mode, while the second runs from the levelling valve to obtain the operating front-ride height or driving mode. The last line is the control line from the park brake valve. When the park brake is not applied, the air pressure on this line causes the kneeler to be inhibited from lowering coach front end. It also actuates the raising of the front end if the vehicle is kneeled and the park brake is then released. Thus it acts as a backup to the recovery part of the instrument panel kneel switch should the driver not adequately raise the front end prior to releasing the park brake. There is also an exhaust port on the valve to evacuate air from the front air springs when kneeling.

To actuate kneeling, the kneeling switch on the instrument panel is pushed into the down position. This causes the spool valve in the kneeling module to slide and open the air spring bellows ports to the exhaust ports allowing the air to leave the air springs. At the same time, it blocks the air from the levelling valve and the supply air from the auxiliary air system. To retain a minimum air pressure in the front air springs, the air exhaust is interrupted when the air pressure preset switch on the kneeling module sensing the air spring pressure is actuated. To hold this kneeled position, the exhaust port is then closed and the air is held in the blocked position from the levelling valve and the auxiliary air supply port.

The recovery mode is initiated by either the kneeling switch in the instrument panel or releasing the park brake. The kneeling module spool valve shifts allowing the auxiliary supply air to connect to the front air springs which causes the coach front end to rise until the kneel valve actuates and disconnects the quick recovery system.

The basic function of the system is to exhaust air pressure out of the front axle bellows, dropping the front end down onto the rubber suspension stops. When the recover switch is pressed, the system then brings the suspension back up to normal ride height.

Another air-operated system of a vehicle is the door manoeuvring system.

Bus doors are opened and closed e.g. by a pneumatic (compressed-air operated) cylinder. The control may be a handle or switch close to the driver's seat. The main advantages are that a high output force is generated by a rather small device (cylinder) and the doors may be distant from the driver's seat.

EP-0530366 relates to a vehicle height adjusting device capable of kneeling without discharging air in an air spring into the atmosphere. When the kneeling is performed air inside respective air springs is moved to be stored in air reservoir devices, and when kneeling is to be restored from the kneeling state, air stored in the air reservoir devices is returned to the respective air springs.

The air-operated kneeling function and the air-operated door manoeuvring require much pressurized air. This results in high operating demands of the pneumatic source, e.g. the air compressor, which in turn results in high level of wear of the air compressor and also high power consumption.

It is an object of the present invention to at least partly remove the above deficiencies by decreasing the wear of the pneumatic source which in turn reduces the power consumption which is environmentally advantageous.

Summary of the invention The above-mentioned object is achieved by the present invention according to the independent claims.

Preferred embodiments are set forth in the dependent claims.

Generally, the present invention relates to an air supplying system, and a method in relation to such system, of reusing pressurized air that today, in the presently used kneeling systems, is evacuated from the air spring bellows to the atmosphere when a bus is kneeling, e.g. at a bus stop.

According to the present invention the pressurized air instead is used to manoeuvre, e.g. to open, the pneumatically manoeuvred doors.

By reusing pressurized air to control the pneumatically manoeuvred doors, the pneumatic source, e.g. the air compressor, is subjected to less operational demand resulting in less wear and decreased power consumption.

Short description of the appended drawings Figure 1 is a schematic block diagram illustrating one embodiment of the present invention.

Figure 2 schematically illustrates a vehicle where the present invention is implemented.

Figures 3 and 4 are simplified illustrations of specific features of one embodiment of the air supplying system according to the present invention. Figure 5 is a flow diagram illustrating the present invention.

Detailed description of preferred embodiments of the invention With references to the appended figures the invention will now be disclosed in detail. Throughout the figures the same, or similar items, will have the same reference sign.

In figure 1 is shown a block diagram illustrating one embodiment of the present invention. The invention relates to an air supplying system 2 suitable to be arranged in a vehicle 4, e.g. a bus (see figure 2).

The vehicle 4 is provided with an air operated kneeling system 6 having one or many air spring bellows 8 (see figures 3 and 4) that exhaust air 10 from the bellows during a kneeling procedure. In the background section a general description of kneeling systems has been given.

The kneeling function may be either implemented as a complete kneeling whereas the entire bus is tilted such that all doors at one side may be used for entrance or exit. In that case a number of air spring bellows at the same side of the bus are involved and emptied in a controlled manner. It is also possible to only kneel the front part of the bus, e.g. when there are only passengers that should enter the bus. A complete kneeling would normally result in that approximately 80 - 120 litres of air should be exhausted from the air spring bellows, e.g. dependent upon the number of passagers (i.e. the weight).

The vehicle is also provided with an air-operated door system 12 having one or many air-operated door manoeuvring members 14 for opening and closing one or many doors 16 (see figure 2) of the vehicle. In figure 2 the kneeling is indicated by double-arrows. An air-operated member 14 may be implemented as a piston movable in a cylinder, and the piston is connected to a rod that in turn is connected to the door to be open. In figures 3 and 4 one such implementation is briefly disclosed.

In order to open air-operated doors of a bus the required air volume ranges from approximately 10 litres to 50 litres dependent on the number of doors to be opened.

Thus, in normal operation the available air volume from the air spring bellows that will be exhausted during kneeling is well above the air volume required for opening all doors of a bus.

The air supplying system 2 comprises a control unit 18 configured to generate at least one control signal 20 including control parameters.

The system further comprises an air pipe arrangement 22 including air pipes 24 for communicating air 10 from the air spring bellow(s) 8 (see figure 3 and 4) to the door manoeuvring members 14. The air pipe arrangement 22 is provided with at least one valve member 26 configured to control the air flow 10 through the air pipes 24 in dependence of the control parameters of the control signal 20 being applied to the valve member(s) 26.

As been discussed above a kneeling system normally comprises a number of air spring bellows, e.g. two arranged in relation to each axle of the vehicle, which results in at least three or four air spring bellows when the entire side of the vehicle should kneel. Thus, all these air spring bellows may be connected to air pipes 24 of the air pipe arrangement 22 that in turn are connected to at least one but normally two doors of the vehicle, i.e. to e.g. two air-operated door manoeuvring members 14.

The control unit 18 is configured to control the valve member(s) 26 such that evacuated air 10 from the air spring bellows 8 during a kneeling procedure is supplied via the air pipe arrangement 22 to the air-operated door manoeuvring members 14 to open the door(s) 16 of the door system 12.

The control unit 18 may be separate unit, e.g. a processor, but may also be entirely or partly implemented in a processor system of the vehicle. The control signal 20 is preferably an electrical signal which is configured to control the valve member.

The air pipes may be flexible pipes made from e.g. plastic or rubber. As an alternative metallic pipes may be used. The air pipes have an outer diameter of 10-12 mm, and in some cases up to 14-16 mm.

The valve member 26 is preferably an electrically controlled valve, for example a solenoid valve.

The control unit 18 is further configured to receive a kneeling sensor signal 28 from the kneeling system 6. The kneeling sensor signal 28 includes one or many kneeling parameters related to the kneeling function, including a kneeling parameter indicating the start of a kneeling procedure, and preferably also a parameter indicating the end of a kneeling procedure, i.e. when the vehicle is in its lowest kneeling position.

The control unit 18 is further configured to receive a door sensor signal 30 from the door system 12 related to the opening of the door(s) 16. The door sensor signal 30 includes one or many door manoeuvring parameters related to the manoeuvring of the door(s) 16, including a door opening parameter that indicates the end of a door opening procedure. Preferably, the door sensor signal 30 also includes a parameter that indicates the start of the door opening procedure.

Normally, the air volume from a kneeling procedure is larger than the air volume required opening the doors. Therefore, excess air must be evacuated when the doors have been opened. The air pipe arrangement 22 is preferably configured to evacuate air 10 from said air pipes 24 when said door(s) 16 have been opened.

According to one embodiment this is implemented by providing the valve member 26 with an exhaust air outlet 32 to evacuate air 10 when the door(s) 16 have been opened.

The valve member 26 is, according to one embodiment, provided with one air inlet 34 configured to be in air communication to said kneeling system 6 via the air pipes 24, and two air outlets 32, 36. One outlet 36 is configured to be in air communication to the door system 12 via the air pipe 24, and one exhaust air outlet 32 is in communication to the atmosphere.

As an alternative, the exhaust air outlet to be in communication to the atmosphere may be embodied in a separate valve member arranged along the air pipes.

The valve member 26 is preferably configured to be in three states to be controlled by the control parameters. A closed state when air is prevented from passing the valve member 26, a door opening state where air 10 is communicated to the door system, and an exhaustion state where air 10 is exhausted to the atmosphere. Specifically, the valve member 26 changes state from the door opening state to the exhaustion state when the door opening parameter is received from the control unit 18. Furthermore, the valve member must be in its closed state when the doors should be closed, and also during the part of the kneeling procedure when the vehicle is raised back to its normal driving position.

Furthermore, in occasions when no kneeling is performed, normal door opening should be applied. Also in occasions when, for some reasons, the exhausted air from a kneeling procedure does not suffice, the normal air supply for door opening should be used.

Figures 3 and 4 are simplified illustrations of specific features of one embodiment of the air supplying system according to the present invention.

In figure 3 an air spring bellow 8 is filled up with air via an input line 38. The valve member 26 is in its closed state preventing air from passing from the air spring bellow to the door manoeuvring member 14. The door manoeuvring member 14 is schematically illustrated and comprises a piston 40 that is movably arranged in a cylinder 42.

In figure 4 is illustrated the situation at the end of a kneeling procedure, the valve member 26 is in its door opening stated allowing air to be supplied to the door manoeuvring member 14 resulting in that the piston 40 is moved and urging the door (not shown) to open. When the door is open excess air is released from the valve member 26 which is indicated by a dashed vertical arrow.

The present invention also relates to a method in an air supplying system 2 of the kind that has been described above. The method will now be described with references to the flow diagram illustrated in figure 5.

The air supplying system is suitable to be arranged in a vehicle 4 which is provided with an air operated kneeling system 6 having one or many air spring bellows 8 that exhaust air 10 from the bellows during a kneeling procedure. The vehicle is also provided with an air-operated door system 12 having one or many air-operated door manoeuvring members 14 for opening and closing one or many doors 16 of the vehicle.

The method comprises: communicating evacuated air from the kneeling system to the door system, using an air pipe arrangement including at least one controllable valve member, supplying the air to at least one air-operated door manoeuvring member of the door system, and opening at least one of the door(s).

Furthermore, the method preferably comprises receiving a kneeling sensor signal, by a control unit, from the kneeling system. The kneeling sensor signal includes one or many kneeling parameters related to the kneeling function, including a kneeling parameter indicating the start of a kneeling procedure. In addition the parameters may include a parameter indicating the end of a kneeling procedure. 10 The method preferably also comprises receiving a door sensor signal, by the control unit, from the door system related to the opening of the door(s). The door sensor signal includes one or many door manoeuvring parameters related to the manoeuvring of the door(s), including a door opening parameter that indicates the end of a door opening procedure, and preferably also a parameter indicating the start of the door opening procedure.

As discussed above the air volume exhausted from the air spring bellows normally is larger than the air volume required for opening the doors. Therefore, the method preferably comprises evacuating air from the air pipes to the atmosphere when the door(s) have been opened. In that regard the method comprises evacuating air from the air pipes via an air outlet of the valve member when the door(s) have been opened. In the figure this preferred method step has been indicated by a dashed box.

Advantageously, the method comprises controlling the valve member to be in one of three states, a closed state when air is prevented from passing the valve member, a door opening state where air is communicated to the door system, and an exhaustion state where air is exhausted to the atmosphere. In particular, the valve member changes state from the door opening state to the exhaustion state when a door opening parameter is received.

The invention also relates to a computer program (P) that comprises a computer program code to cause the control unit, or a computer connected to the control unit, to perform the method steps that have been described above.

And finally, the invention relates to a computer program product comprising a computer program code stored at a non-transitory computer-readable medium to perform the method steps that have been described above, when the computer program code is executed by the control unit or by a computer connected to the control unit.

The present invention is not limited to the above-described preferred embodiments. Various alternatives, modifications and equivalents may be used.

Therefore, the above embodiments should not be taken as limiting the scope of the invention, which is defined by the appending claims.

Claims

11 Claims

1. An air supplying system (2) in a vehicle (4) provided with an air operated kneeling system (6) having one or many air spring bellows (8) that exhaust air (10) from the bellows during a kneeling procedure, and also provided with an air-operated door system (12) having one or many air-operated door manoeuvring members (14) for opening and closing one or many doors (16) of the vehicle, ch a r a cte r iz ed i n that said air supplying system (2) comprises a control unit (18) configured to generate at least one control signal (20) including at least one control parameter, an air pipe arrangement (22) including at least one air pipe (24) for communicating air (10) from the air spring bellow(s) (8) to the door manoeuvring member(s) (14), and that said air pipe arrangement (22) is provided with at least one valve member (26) configured to control the air flow (10) through the air pipes (24) in dependence of said control parameter(s) of said control signal (20) being applied to said valve member(s) (26), wherein said control unit (18) is configured to control said valve member(s) (26) such that evacuated air (10) from the air spring bellows (8) during a kneeling procedure is supplied via said air pipe arrangement (22) to said air-operated door manoeuvring members (14) to open the door(s) (16) of said door system (12).

2. The air supplying system (2) according to claim 1, wherein the control unit (18) is further configured to receive a kneeling sensor signal (28) from said kneeling system (6), wherein said kneeling sensor signal (28) includes one or many kneeling parameters related to the kneeling function, including a kneeling parameter indicating the start of a kneeling procedure.

3. The air supplying system (2) according to claim 1 or 2, wherein the control unit (18) is further configured to receive a door sensor signal (30) from said door system (12) related to the opening of the door(s) (16), wherein said door sensor signal (30) includes one or many door manoeuvring parameters related to the manoeuvring of the door(s) (16), including a door opening parameter that 12 indicates the end of a door opening procedure.

4. The air supplying system (2) according to any of claims 1-3, wherein said air pipe arrangement (22) is configured to evacuate air (10) from said air pipes (24) when said door(s) (16) have been opened.

5. The air supplying system (2) according to any of claims 1-4, wherein said valve member (26) is provided with an exhaust air outlet (32) to evacuate air (10) when said door(s) (16) have been opened.

6. The air supplying system (2) according to any of claims 1-5, wherein said valve member (26) is provided with one air inlet (34) configured to be in air communication to said kneeling system (6) via said air pipes (24), and two air outlets (32, 36), where one outlet (36) is configured to be in air communication to said door system (12) via said air pipe (24), and one exhaust air outlet (32) in communication to the atmosphere.

7. The air supplying system (2) according to any preceding claim, when dependent on claim 3, wherein said valve member (26) is configured to be in three states to be controlled by said control parameters, a closed state when air is prevented from passing the valve member (26), a door opening state where air (10) is communicated to the door system, and an exhaustion state where air (10) is exhausted to the atmosphere, and wherein said valve member (26) changes state from said door opening state to said exhaustion state when said door opening parameter is received.

8. A method in an air supplying system (2) in a vehicle (4) provided with an air operated kneeling system (6) having one or many air spring bellows (8) that exhaust air (10) from the bellows during a kneeling procedure, and also provided with an air-operated door system (12) having one or many air-operated door manoeuvring members (14) for opening and closing one or many doors (16) of the vehicle, 13 characterized in that said method comprises: 1. communicating evacuated air from said kneeling system to said door system, using an air pipe arrangement including at least one controllable valve member, 2. supplying said air to at least one air-operated door manoeuvring member of said 5 door system, 3. opening at least one of said door(s).

9. The method according to claim 8, wherein the method comprises receiving a kneeling sensor signal from said kneeling system, wherein said kneeling sensor signal includes one or many kneeling parameters related to the kneeling function, including a kneeling parameter indicating the start of a kneeling procedure.

10. The method according to claim 8 or 9, wherein the method comprises receiving a door sensor signal from said door system related to the opening of the door(s), wherein said door sensor signal includes one or many door manoeuvring parameters related to the manoeuvring of the door(s), including a door opening parameter that indicates the end of a door opening procedure.

11. The method according to any of claims 8-10, wherein the method comprises evacuating air from said air pipes to the atmosphere when said door(s) have been opened.

12. The method according to any of claims 8-11, wherein the method comprises evacuating air from said air pipes via an air outlet of said valve member when said door(s) have been opened.

13. The method according to any of claims 8-12, wherein the method comprises controlling said valve member to be in one of three states, a closed state when air is prevented from passing the valve member, a door opening state where air is communicated to the door system, and an exhaustion state where air is exhausted to the atmosphere, and wherein said valve member changes state 14 from said door opening state to said exhaustion state when a door opening parameter is received.

14. A computer program (P), wherein said computer program (P) 5 comprises a computer program code to cause a control unit, or a computer connected to said control unit, to perform the method steps according to any of claims 8-13.

15. A computer program product comprising a computer program code 10 stored at a non-transitory computer-readable medium to perform the method steps according to any of the claims 8-13, when said computer program code is executed by a control unit or by a computer connected to said control unit.