Pneumatic braking device for a utility vehicle

Abstract

A pneumatic braking device for a utility vehicle includes at least one pneumatically controllable spring accumulator for a parking brake of the utility vehicle with an electronic parking brake device. The electronic parking brake device has at least one electronic control unit, at least one first bistable valve unit, at least one second bistable valve unit, at least one valve device which can be connected in such a way that when there is a decrease in the system pressure for supplying the parking brake of the trailer of the traction vehicle, the parking brake of the trailer can be activated, and a traction vehicle protection valve.

Claims

1. A pneumatic brake device for a utility vehicle, comprising: at least one pneumatically actuable spring store for a parking brake of the utility vehicle; an electronic parking brake device, comprising at least one electronic control unit, at least one first bistable valve unit and at least one second bistable valve unit, at least one valve device which is connectable such that, when there is a drop in system pressure for supplying a parking brake of a trailer of the tractor vehicle, the parking brake of the trailer is activatable, and a tractor vehicle protection valve; wherein one or both of the first and the second bistable valve units comprise a bistable valve with feedback; wherein the bistable valve is a relay valve; and wherein the bistable valve unit further has a pressure sensor.

2. The pneumatic brake device as claimed in claim 1, wherein the parking brake of the utility vehicle is actuatable by the first bistable valve unit and the parking brake of the trailer is actuatable by the second bistable valve unit.

3. The pneumatic brake device as claimed in claim 1, wherein the tractor vehicle protection valve is a constituent part of the electronic parking brake device.

4. The pneumatic brake device as claimed in claim 1, wherein the tractor vehicle protection valve is a constituent part of an air treatment system of the pneumatic brake device.

5. The pneumatic brake device as claimed in claim 1, wherein the valve device has at least one pressure sensor by which a drop in the system pressure below a prespecified threshold value is determinable and a signal can be generated, it being possible for the parking brake of the trailer to be activated by the electronic control unit on the basis of said signal.

6. The pneumatic brake device as claimed in claim 1, wherein the valve device comprises at least one pneumatic valve by which the parking brake of the trailer is activatable.

7. The pneumatic brake device as claimed in claim 1, wherein the relay valve for the first bistable valve unit is the relay valve of the utility vehicle.

8. The pneumatic brake device as claimed in claim 1, wherein the relay valve for the second bistable valve unit is the relay valve of the trailer.

9. The pneumatic brake device as claimed in claim 1, wherein the bistable valve unit further has a throttle.

10. The pneumatic brake device as claimed in claim 1, wherein the bistable valve unit further has at least two solenoid valves.

11. The pneumatic brake device as claimed in claim 1, wherein the valve device is jointly formed by the relay valve of the trailer.

12. The pneumatic brake device as claimed in claim 11, wherein the valve device further has at least two solenoid valves, a pressure sensor and a throttle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic drawing of an exemplary embodiment according to the invention of a pneumatic brake device for a utility vehicle.

(2) FIG. 2 is a schematic illustration of a first embodiment of an electronic parking brake device.

(3) FIG. 3 is a schematic illustration of a second embodiment of an electronic parking brake device.

(4) FIG. 4 is a schematic illustration of a third embodiment of an electronic parking brake device.

(5) FIG. 5 is a schematic illustration of a fourth embodiment of an electronic parking brake device.

(6) FIG. 6 is a schematic illustration of a fifth embodiment of an electronic parking brake device.

(7) FIG. 7 is a schematic illustration of a sixth embodiment of an electronic parking brake device.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) FIG. 1 shows a pneumatic brake device 10 for a utility vehicle, for example a truck (not illustrated in any detail).

(9) The pneumatic brake device 10 has a plurality of pneumatically actuable spring stores 12 for the parking brake of the utility vehicle, also called tractor vehicle, and also pneumatically actuable brake cylinders 13 of the service brake for the front axle and also for the rear axle or the rear axles. In the exemplary embodiment shown, the spring store 12 and the brake cylinder 13 are designed as a spring store brake cylinder on the rear axle, with the spring store 12 for the parking brake function and with the brake cylinder 13 for the service brake.

(10) Furthermore, a compressor 14 which is connected to an electronic parking brake device 16 is provided.

(11) Furthermore, a parking valve switching element 18 which can have a first switch 20 and a second switch 22 is provided.

(12) The electronic parking brake device 16 has a control electronics system 24, a first bistable valve unit 26, an air treatment arrangement 28 and also a second bistable valve unit 30 and a valve device 32. A first compressed-air container 34 and a second compressed-air container 36 are provided downstream of the electronic parking brake device 16.

(13) The foot brake valve 38 of the brake device 10 is further shown. Furthermore, a tractor vehicle protection valve 40 is provided.

(14) The pneumatic brake device 10 further has a connection 42 for the parking brake of a trailer of the utility vehicle and also a further separate connection 44 for the service brake of the trailer.

(15) The compressor 14 is connected to the parking brake device 16 via a line 46. Lines 48 and 50, which lead to the container 34 and, respectively, to the container 36 adjoin the air treatment arrangement 28 downstream of the parking brake device 16.

(16) The foot brake valve 38 is connected to the first container 34 via the line 52 and to the second container 36 via the line 54. The supply lines and line branches adjoin the brake cylinders and, respectively, spring store brake cylinders 12 downstream of the foot brake valve 38. The tractor vehicle protection valve 40 is likewise connected to said line, wherein the compressed air which flows from said line branch to the tractor vehicle protection valve 40 and then flows further to the connection 44 for the service brake of the trailer or to the connection 42 for the spring store of the trailer, initially has to be routed through the tractor vehicle protection valve 40. The foot brake valve 38 is connected to the tractor vehicle protection valve 40 via a line 56.

(17) The first bistable valve unit 26 is connected to the spring store brake cylinders of the rear axle via a line 58.

(18) The valve device 32 is connected to the connection 42 for the spring stores of the trailer via a line 60.

(19) The control electronics system 24 is connected to the parking valve switching element 18, wherein a first signal line 62 from the first switch is connected to the control electronics system 24 and a second line 64 is connected to the electronics system 24 which establishes a connection to the second switch of the parking valve switching element 18.

(20) The pneumatic brake device 10 therefore has a plurality of pneumatically actuable spring stores 12 for the parking brake of the utility vehicle, and also an electronic parking brake device 16 which itself in turn has a control electronics system 24.

(21) Furthermore, a constituent part of the electronic parking brake device 16 is a first bistable valve unit 26 for aerating and deaerating the spring stores 12 of the parking brake of the tractor vehicle, and also a second bistable valve unit 30 for aerating and deaerating the spring store brake cylinders of the trailer, so that the spring stores of the parking brake device of the trailer of the tractor vehicle can be aerated by means of the second bistable valve unit 30, and also a valve device 32 which can be connected up in such a way that the parking brake device of the trailer can be activated when there is a drop in the system pressure for the parking brake of the trailer of the tractor vehicle.

(22) The parking brake of the tractor vehicle with the spring stores 12 can be actuated by means of the first bistable valve unit 26 and the parking brake of the trailer can be actuated by way of the second bistable valve unit 30, also by means of the valve device 32. The second bistable valve unit 30 is connected to the connection 42 to the spring store brake cylinders of the parking brake of the trailer via the line 60.

(23) Here, the tractor vehicle protection valve 40 is a constituent part of the brake device, but, as an alternative, can also be designed as a constituent part of the electronic parking brake device 16 or as a constituent part of the air treatment system 28 of the pneumatic brake device 10.

(24) The functioning of the pneumatic brake device 10 is as follows here:

(25) The electronic parking brake device 16 comprises a control electronics system 24 and processes the control signals which are transmitted by the electronic parking valve 18.

(26) Furthermore, information exchange takes place with the control electronics system 24 of the truck (not shown in detail).

(27) The first bistable valve unit 26 and the second bistable valve unit 30 also each maintain their current condition without electricity. Said valves can aerate or deaerate the spring store brake cylinders 12 of the tractor vehicle or of the trailer (via the line 60 and the connection 42) directly or jointly by means of one or more relay valves.

(28) The second bistable valve unit 30 can aerate the spring stores of the trailer when the spring stores of the truck are deaerated. This is necessary, for example, for the trailer test function.

(29) The valve device 32 can deaerate the spring stores of the trailer, specifically via the line 60 and the connection 42, when the spring stores of the truck are aerated. This includes, in particular, an emergency brake functionality which activates the parking brake of the trailer (so-called emergency braking function) when there is a drop in the system pressure for the trailer below a specific threshold value.

(30) Actuation of the brake device 10 by means of the parking valve switching element 18 comprising the switches 20 and 22 can be performed for the following operating states as follows.

(31) In the driving state, the switch 20 for operating the parking brake device of the tractor vehicle and the switch 22 for operating the parking brake device of the trailer for example are pressed (as an alternative other operating positions are also feasible).

(32) As a result, the first bistable valve unit 26 and the second bistable valve unit 30 are connected through, while the valve device 32 is not connected through.

(33) As a result, both the spring store brake cylinders 12 of the tractor vehicle and also the spring store brake cylinders 12 of the trailer are released.

(34) In the parked state, the two switches 20 and 22 are pulled, so that the first bistable valve unit 26 and the second bistable valve unit 30 and the valve device 32 are not connected through.

(35) Therefore, the spring store brake cylinders 12 of the tractor vehicle are switched in such a way that the brakes of the tractor vehicle are activated. This is also true of the spring store brake cylinders 12 of the trailer which are likewise switched in such a way that the brakes of the trailer are activated.

(36) An operating state in which the parking brake of the tractor vehicle is activated, but that of the trailer is not, can be used for the purpose of filling the trailer. This can also be used in order to carry out the so-called trailer test. The switch 20 is pulled and the switch 22 is pressed (activated). As a result, the first bistable valve unit 26 is not connected through, but the second bistable valve unit 30 is connected through. The valve device 32 is likewise not connected through.

(37) The result of this is that the spring stores 12 of the parking brake of the tractor vehicle are switched in such a way that the tractor vehicle is braked and the spring stores of the parking brake of the trailer are switched in such a way that said spring stores are released.

(38) In the Park trailer operating state (braking only by means of the trailer), the switch 20 is pressed and the switch 22 is pulled.

(39) Consequently, the first bistable valve unit 26 is activated, the second bistable valve unit 30 is not activated, and the valve device 32 is not activated.

(40) The result of this is that the spring stores 12 of the parking brake of the tractor vehicle are switched in such a way that the tractor vehicle is unbraked and the spring stores of the parking brake of the trailer are activated, so that the trailer is braked.

(41) In the Emergency braking operating state which is automatically activated, specifically when a drop in the system pressure for the parking brake of the trailer is detected, the tractor/trailer combination, comprising tractor vehicle and trailer, is usually in the driving state, that is to say the switch 20 and the switch 22 are both pressed. In contrast to the above-described driving state in which the first bistable valve unit 26 and the second bistable valve unit 30 are connected through but the valve device 32 is not connected through, the valve device 32 is now activated and the second bistable valve unit 30 is moved from the connected-through state to the non-connected-through state.

(42) The result is that the spring stores 12 of the parking brake of the tractor vehicle are further switched in such a way that the tractor vehicle is unbraked, but the spring store brake cylinders of the trailer are switched in such a way that they are switched from the unbraked state to the braked state.

(43) FIGS. 2 to 5 relate to possible embodiments of the electronic parking brake device with feedback, as can be used in the exemplary embodiment shown in FIG. 1 of a pneumatic brake device 10.

(44) Each of the shown embodiments of the electronic parking brake devices 116 (FIG. 2), 216 (FIG. 3), 316 (FIG. 4) and 416 (FIG. 5) is intended to be understood as a possible embodiment of the electronic parking brake device 16, as roughly schematically shown in FIG. 1.

(45) FIG. 2 shows a first possible embodiment of an electronic parking brake device 116 comprising a bistable valve unit 126 with feedback.

(46) The bistable valve unit 126 with feedback comprises the functionally interacting relay valve of the tractor vehicle 126a, a solenoid valve 126b, a further solenoid valve 126c, a pressure sensor 126d and also a throttle 126e.

(47) The second bistable valve unit 130 comprises the functionally interacting relay valve of the trailer 130a, a solenoid valve 130b, a further solenoid valve 130c, a pressure sensor 130d and also a throttle 130e.

(48) The valve device 132 is functionally formed by the relay valve of the trailer 130a, the solenoid valve 130c, the pressure sensor 130d and also the throttle 130e.

(49) Both for the first bistable valve unit 126, the second bistable valve unit 130 and the valve device 132, the solenoid valves, the pressure sensor and also the throttles serve to actuate and set the relay valves, to set the switching points and also to ensure a bistable function.

(50) FIG. 3 shows a schematic view of a further exemplary embodiment of an electronic parking brake device 216 which illustrates a possible embodiment of the parking brake device 16 shown in FIG. 1.

(51) The electronic parking brake device 216 according to FIG. 3 is an embodiment with a pressure sensor, but without additional elements.

(52) The first bistable valve unit 226 is formed by the relay valve of the tractor vehicle 226a, a solenoid valve 226b, a further solenoid valve 226c, a pressure sensor 226d and a throttle 226e,

(53) The second bistable valve unit 230 is formed by the relay valve of the trailer 230a, a solenoid valve 230b, a further solenoid valve 230c and also a throttle 230d.

(54) Here, the valve device 232 is formed solely by the relay valve of the trailer 230a and the throttle 230d.

(55) The solenoid valves, the pressure sensor and the throttle also serve to define and to ensure the bistable function, the switching characteristics and also the switching points here.

(56) FIG. 4 shows a schematic illustration of a further exemplary embodiment of an electronic parking brake device 316 which, in the exemplary embodiment according to FIG. 1, illustrates a possible embodiment of the electronic parking brake device 16 shown there.

(57) Here, the first bistable valve unit 326 is formed by the relay valve of the tractor vehicle 326a, a first solenoid valve 326b, a second solenoid valve 326c, a pressure sensor 326d and also a throttle 326e.

(58) The second bistable valve unit 330 is formed by the relay valve of the trailer 330a, a solenoid valve 330b, a further solenoid valve 330c and also a throttle 330d.

(59) The valve device 332 is formed by the relay valve of the trailer 330a and also a deaeration valve 332a.

(60) The parking brake device 316 according to FIG. 4 is a parking brake device comprising a pneumatic valve in the feedback line.

(61) FIG. 5 shows a further embodiment of an electronic parking brake device 416 which illustrates a possible embodiment of the electronic parking brake device 16 shown in FIG. 1.

(62) This embodiment is an embodiment with a pneumatic valve in the supply line.

(63) Here, the first bistable valve unit 426 is formed by the relay valve of the tractor vehicle 426a, a first solenoid valve 426b, a second solenoid valve 426c, a pressure sensor 426d and also a throttle 426e.

(64) The second bistable valve unit 430 is formed by the relay valve of the trailer 430a, a solenoid valve 430b, a further solenoid valve 430c and also a throttle 430d.

(65) The valve device 432 is formed by the relay valve of the trailer 430a and also a deaeration valve 432a.

(66) However, in contrast to the exemplary embodiment according to FIG. 4 where the pneumatic deaeration valve 332a is arranged in the feedback line for the relay valve 330a, the pneumatic deaeration valve 432a is located in the supply line for the relay valve of the trailer here.

(67) FIGS. 6 and 7 show embodiments of an electronic parking brake device 516 (FIG. 6) and also of an electronic parking brake device 616 (FIG. 7).

(68) In both cases, these embodiments can be a possible refinement of the electronic parking brake device 16 shown in FIG. 1.

(69) The two embodiments of an electronic parking brake device 516 and 616 are embodiments with bistable valve units without feedback.

(70) In the case of the electronic parking brake device 516 according to FIG. 6, the first bistable valve unit 526 is formed by the relay valve of the tractor vehicle 526a, a solenoid valve 526b, a further solenoid valve 526c, a control valve device 526d and also a pressure sensor 526e.

(71) The second bistable valve unit 530 comprises the relay valve of the trailer 530a, a solenoid valve 530b, a further solenoid valve 530c, a control valve 530d and also a pressure sensor 530e.

(72) The valve device 532 is formed by the relay valve of the trailer 530a, the solenoid valve 530c, the control valve 530d and also the pressure sensor 530e here.

(73) In the case of the electronic parking brake device 616 according to FIG. 7, the first bistable valve unit 626 is formed by the relay valve of the tractor vehicle 626a, a solenoid valve 626b, a further solenoid valve 626c, a control valve device 626d and also a pressure sensor 626e. In addition, the first bistable valve unit 626, as distinct from the embodiment shown in FIG. 6, further has a throttle 626f.

(74) The second bistable valve unit 630 comprises the relay valve of the trailer 630a, a solenoid valve 630b, a further solenoid valve 630c, a control valve 630d and also a pressure sensor 630e. Furthermore, the embodiment according to FIG. 7, as distinct from the embodiment according to FIG. 6, further has a throttle 630f.

(75) The valve device 632 is formed by the relay valve of the trailer 630a, the solenoid valve 630c, the control valve 630d, the pressure sensor 630e and also the throttle 630f here.

(76) FIG. 7 shows the parking brake device 616 in the parked state.

(77) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

LIST OF REFERENCE NUMERALS

(78) 10 Pneumatic brake device 12 Spring store 13 Brake cylinder 14 Compressor 16 Electronic parking brake device 18 Parking valve switching element 20 First switch 22 Second switch 24 Electronic control unit 26 First bistable valve unit 28 Air treatment arrangement 30 Second bistable valve unit 32 Valve device 34 First compressed-air container 36 Second compressed-air container 38 Foot brake valve 40 Tractor vehicle protection valve 42 Connection 44 Separate connection 46 Line 48 Line 50 Line 52 Line 54 Line 56 Line 58 Line 60 Line 62 First signal line 64 Second signal line 116 Electronic parking brake device 126 First bistable valve unit 126a Relay valve 126b Solenoid valve 126c Solenoid valve 126d Pressure sensor 126e Throttle 130 Second bistable valve unit 130a Relay valve of the trailer 130b First solenoid valve 130c Second solenoid valve 130d Pressure sensor 130e Throttle 132 Valve device 132a Solenoid valve 132b Pressure sensor 216 Electronic parking brake device 226 First bistable valve unit 226a Relay valve 226b Solenoid valve 226c Solenoid valve 226d Pressure sensor 226e Throttle 230 Second bistable valve unit 230a Relay valve of the trailer 230b First solenoid valve 230c Second solenoid valve 230d Throttle 232 Valve device 232a Solenoid valve 232b Pressure sensor 316 Electronic parking brake device 326 First bistable valve unit 326a Relay valve of the tractor vehicle 326b Solenoid valve 326c Solenoid valve 326d Pressure sensor 326e Throttle 330 Second bistable valve unit 330a Relay valve 330b Solenoid valve 330c Solenoid valve 330d Throttle 332 Valve device 332a Deaeration valve 416 Electronic parking brake device 426 First bistable valve unit 426a Relay valve of the tractor vehicle 426b Solenoid valve 426c Solenoid valve 426d Pressure sensor 426e Throttle 430 Second bistable valve unit 430a Relay valve 430b Solenoid valve 430c Solenoid valve 430d Throttle 432 Valve device 432a Deaeration valve 516 Electronic parking brake device 526 First bistable valve unit 526a Relay valve 526b Solenoid valve 526c Solenoid valve 526d Control valve device 526e Pressure sensor 530 Second bistable valve unit 530a Relay valve 530b Solenoid valve 530c Solenoid valve 530d Control valve 530e Pressure sensor 532 Valve device 616 Electronic parking brake device 626 First bistable valve unit 626a Relay valve 626b Solenoid valve 626c Solenoid valve 626d Control valve device 626e Pressure sensor 626f Throttle 630 Second bistable valve unit 630a Relay valve 630b Solenoid valve 630c Solenoid valve 630d Control valve 630e Pressure sensor 630f Throttle 632 Valve device