DE3049271C2 - Stop-start device for a vehicle internal combustion engine - Google Patents

Description

The invention relates to a stop-start device for a vehicle internal combustion engine.

From DE-AS 23 32 627 a generic stop start device is known, with the help of which the The engine can be switched off in a simple manner by simply pressing the stop button. If this is for example happens when the vehicle stops behind a traffic jam on a downhill road, there is a risk that the vehicle, when the stowed vehicles start moving, with the parked The engine is rolling. There is then no auxiliary energy for a brake booster or power steering available, which can lead to dangerous conditions.

From DE-AS 22 42 587 a starter device for motor vehicles with automatic transmission is known, which when the vehicle engine stops automatically starts the engine again, including speed and Speed monitoring are provided. This ensures that in automatic vehicles where when the accelerator pedal is not depressed, a freewheel is provided, the engine does not fail, which leads to a standstill of the Auxiliary units would lead.

The object of the invention is to develop a generic stop-start device that dangers are largely avoided during the operation of vehicles equipped with it, with the necessary Circuit measures are implemented as part of the circuit of the stop-start device.

This task is with the features of the main claim solved.

With the invention it is achieved that the engine starts automatically after A. shutdown via the stop button, as soon as the vehicle rolls. In this way, it is reliable for auxiliary-assisted units Energy available.

Claim 2 characterizes an advantageous embodiment of the device according to the invention.

The invention is illustrated below with the aid of a schematic Drawing for example and explained with further details.

The single figure shows a circuit diagram of an embodiment a stop-start device.

According to the figure, an ignition switch 4 connected to a positive terminal 2 of a vehicle battery is shown in FIG Series with a starter switch 6 and an electromagnet 8 of a starter relay 10 switched. When the electromagnet 8 is excited, a set of contacts 12 closes of the starter relay 10, a circuit in which a starter 14 is located, as long as a first contact set 16 an engine operation detection switch 20 is closed, which between the starter switch 6 and the Electromagnet 8 is arranged. The function of the engine operation detection switch 20 is such that below a predetermined speed of the internal combustion engine, for example 500 min- ', the first contact set 16 is closed and a second set of contacts 22 is open, while above the predetermined Speed of the first contact set 16 opened and the second contact set 22 of the motor operation detection switch 20 is closed. With the first set of contacts 16 it is achieved that the starter 14 is switched on automatically is as soon as the internal combustion engine has reached the predetermined speed.

The ignition switch 4 is connected downstream via normally closed contacts 26 of an interrupt relay 28 an ignition circuit 30 or fuel supply of the internal combustion engine. The ignition circuit 30 and the engine operation detection switch 20 are known in their construction and are therefore not used in the individually explained.

One of the contacts of the second Ko; wktsatzes 22 des Engine operation detection switch 20 is via the ignition switch 4 to the positive pole 2 of the battery connected, the other contact is via a line 32 with the electromagnet 34 of a readiness relay 36 connected to self-holding contacts 38 and a further set of contacts 40.

The contact set 40 is in a circuit 41, which is parallel to the starter switch and an oil pressure switch 42 and two further sets of contacts 43

so and 44, which are assigned to an accelerator pedal 45 and a clutch pedal 46, respectively.

The oil pressure switch 42 opens above a speed of the internal combustion engine of, for example, 50 min- ¹ , which is below the speed at which the engine operation detection switch 20 opens. The contact set 43 is closed when the accelerator pedal 45 is actuated. The contact set 44 is closed when the clutch pedal 46 is actuated.

To bypass the oil pressure switch 42, a bridging relay 50 is provided, its electromagnet 52 via a line 54 to the contact of the oil pressure switch facing away from the readiness relay 36 42 and connected to ground. A first set of contacts 56 closes when the electromagnet is energized

«5 52 a current path bypassing the oil pressure switch 42. A second set of contacts 58 closes a current path when the electromagnet 52 is energized. which the Electromagnet via a terminal 99 and a

similar to the contact set 16 below the predetermined speed closed third contact set 60 of the Motor operation detection switch 20 to the positive Pole 2 of the battery, not shown, connects.

When the ignition switch 4 is closed, a line 62 connects the positive pole 2 of the battery to a contact 64 of a stop button 66 and a contact 68 of a holder relay 70. Another contact 72 of the stop button 66 is connected to a further contact 74 of the holding relay 70 and a contact of another, the accelerator pedal 45 associated contact set 76 connected, which is closed in the non-actuated state of the accelerator pedal 45 From the contact set 76 leads a line 78 via a closed when the vehicle is stationary Switch 80 of known type for the electromagnet of the holding relay 70 and the interrupter relay 28. A lamp 82 is connected between line 78 and ground

To bridge the contact sets 43 and 44, a current path 86 is provided, which in series one at a vehicle speed z. B. 4 km / h closing switch 88 and a contact set 90 of a relay 92 contains The switch 88 advantageously closes at a higher vehicle speed than that Switch 80. The excitation winding of relay 92 is connected to contact 72 of the stop button and via self-holding contacts 94 and a contact 62 of the further contact set 60 of the motor operation detection switch 20 connected. The contact 61 is connected to the positive pole 2 of the battery (not shown) via a time switch 96 tied together. The timer 96 closes a connection between the contact 61 and the pole 2 for one predetermined period of time, e.g. B. 5 sea when its input 98 has positive voltage applied to it.

The function of the described arrangement is as follows:

It is initially assumed that the engine is stopped and the ignition is switched off, so that all relays are passive.

When the ignition switch 4 is closed, the ignition circuit JO via the closed contacts 26 of the Interrupt relay 28 put in readiness for operation

If the starter switch 6 is now closed, the closed contact set 16 of the operating detection switch 20 the electromagnet 8 of the starter relay 10 is energized, whereby its contact set 12 closes and the starter 14 starts up. Once the engine is ready to operate the engine operation detection switch 20 has reached the required speed, the contact set 16 opens, causing the starter 14 to stop. Simultaneously closes the contact set 22, whereby the electromagnet 34 of the readiness relay 36 is energized and this goes over the self-holding contacts 38 in self-holding. The contact set is also closed 40, so that the circuit 41 bridging the starter switch 6 becomes operational. the Latching of the readiness relay 36 continues until the ignition switch 4 is switched off.

If the engine is now to be switched off at a red traffic light, for example, it must be switched off when the traffic light is stationary Vehicle, ie closed switch 80 and non-actuated accelerator pedal 45, ie closed Contact set 76, the stop button 66 are printed. The interrupt relay 28 is energized, so that whose contacts 6 open and the ignition circuit 30 is switched off. At the same time, the holding relay 70 energized, whereby its contacts 68 and 74 are bridged and the stop button 66 bridged. The stop button 66 can thus be released again without the interrupt relay 28 dropping out. The lamp 82 lights up and indicates the operation of the engine which has been interrupted by means of the stop button 66.

When the engine speed drops below the speed at which the engine operation detection switch 20 is activated, the contact set 22 opens and the contact set 16 closes on the excitation of the electromagnet 34 of the readiness relay 36 this has no effect, since the readiness relay 36 via the self-holding contacts 38 is in self-holding.

When the speed of the engine drops to almost zero, the oil pressure switch 42 closes and is energized in the process the bypass relay 50, the contact sets 56 and 58 of which close.

If the engine is now to be started again, the clutch pedal 46 and the accelerator pedal 45 must be operated simultaneously. When the accelerator pedal 45 is operated, the contact set 76 opens, as a result of which the holding relay 70 and the interrupt relay ¹ ′ ″ 28 drop out and the ignition circuit 30 is activated.

When the clutch pedal 46 and accelerator pedal 45 are actuated, the starter relay is activated as when the starter switch is actuated 6 actuated via the oil pressure switch 42 or the contact set 56 and the contact sets 43 and 44. As soon as the motor has reached the predetermined speed and the contact sets 16 and 60 open, the ends Operation of the starter 14 and the self-holding of the

Bridging relay 50, which after opening the oil pressure switch 42 is excited via the contact set 58.

The starting process can be interrupted at any time by releasing the accelerator pedal 45 or the clutch pedal 46 will.

The function of the current path 86 is explained below:

If the stop button 66 is pressed while the engine is running, the relay 92 is energized and goes over the Self-holding contacts 94 and initially the time switch 96 in self-holding. The hold time of the timer 96 is long enough for the motor to come to a standstill so that contact 61 can be closed by closing the Contact set 60 is connected to the positive pole 2 and the self-holding continues.

If the vehicle is now set in motion, e.g. B. on a slope, the switch 80 opens, whereby the Ignition circuit 30 is activated. Then the switch 88 closes, whereby the starter 14 is actuated, until the engine operation detection switch 20 signals that the engine is running and the contact set 60 opens. As a result, the latching of the relay 92 is canceled. The contact 61 and thus the input 98 of the timer 96 are de-energized, the timer is already on, if the stop button 66 is pressed again for a to close a predetermined period of time.

It will be understood that the switch 88 mi. the switch 80 can be combined to form a Schmitt trigger with hysteresis.
The described function of the current path 86 ensures that uas vehicle cannot roll without the engine running after pressing the stop button 66, so that the energy supply z. B. for servo pumps and the like, is always guaranteed.

When the battery is empty, i.e. H. Inoperable starter after switching off with the stop button 66 can also be put into operation by pushing the vehicle, with only the accelerator pedal 43 being actuated must be for the ignition circuit 30 to operate

is set. It goes without saying that the switch 80 ciali so is carried out that it is closed when the battery is empty. It goes without saying that, for the sake of simplicity, the Self-holding relays or relays represented components by fully electronic components such as mono- and / or bistable flip-flops or similar circuits can be replaced.

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Claims (2)

Patent claims: 1. stop-start device for a vehicle internal combustion engine, with an ignition switch, a starter circuit and an engine operation detection switch, which the starter circuit in a predetermined operating state of the engine interrupts a stop button, the actuation of which a Engine operation interruption circuit in an engine operation interruption state offset, and a start button, which the engine operation interruption circuit resets and closes the starter circuit, characterized by a starter actuation circuit which after the engine has been switched off by means of the stop button (66) above a certain driving speed of the vehicle closes the starter circuit (10, 12), the starter actuation circuit contains a switching device (90,92,94) which can be excited by pressing the stop button (66), their then closing contact set (30) in series with one above a predetermined driving speed closing switch (88) is arranged, the series connection of the start button (43-46) is connected in parallel. 2. Stop-start device narh claim 1, characterized characterized in that the switching device (90, 92, 94) time switches (96) and / or self-holding devices having the closed position of the contact set (90) until the engine is restarted upright.