DE1480652A1 - Circuit arrangement for electric vehicles - Google Patents

Description

YaIe & Towne, Inc., Velbert / Rhld branch.

¹¹ Circuit arrangement for electric vehicles ¹¹

The invention is directed to a circuit arrangement for vehicles with at least one electric motor that by two batteries connected in series is fed, with the motor by means of a control element for the purpose of driving low speed first on a battery and then for the purpose of driving at higher speed on both Batteries is switchable.

Such a circuit arrangement is particularly suitable for vehicles in which, in addition to a drive motor, for the vehicle still has one or more electric motors for driving units arranged on the vehicle, such as one Lifting device, are provided, as it allows such an arrangement, for example, the drive motor with lower To operate voltage and thus low speed,

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by connecting only one of the two batteries to this motor while simultaneously using the electric motor to drive a hydraulic pump for the purpose of faster actuation of a lifting device with higher voltage and so that you can drive higher speed by connecting both ^ batteries to this motor or vice versa.

The aim of the invention is to ensure that no significant uneven discharge of the two Batteries can take place in such a circuit arrangement ο

According to the invention this is achieved in that the both batteries for the most even discharge possible with constant successive actuation of the ™ control element by electrical switching means alternately to supply a motor with low speed on the Motor can be switched. By alternately using the two batteries to power the motor in the low one Speed level, a largely uniform discharge of the two batteries is guaranteed in general.

A particularly advantageous arrangement is characterized in that the control element has two switches one after the other actuated, which in turn two each one of the two batteries

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Switch assigned contactors one after the other in such a way that first the battery assigned to the contactor that was switched on and then the other battery is switched to the motor, whereby a changeover relay that reverses the sequence of actuation of the two contactors when the switch that was first operated is switched on. M is seen, which is switched on when the switch operated first is switched on, remains switched on when this switch is subsequently switched off, and when this switch is subsequently switched on for the second time. Reversing the sequence of actuation of the two contactors is switched off again.

Regardless of this schematically working AC circuit, etc. or in conjunction with this one can, however, also measure is dependent on the charge state of gravity of the two batteries continuously and switching means provide that are · density difference actuated upon exceeding a predetermined Saur due to uneven discharging of the two batteries in such a way that to drive the motor at low speed only the less discharged battery is switched to the motor until the predetermined acid density difference is exceeded again.

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Each battery can have a measuring electrode pair which supplies an electrical voltage that is dependent on the acid density assign and one the electrical voltages of the two pairs of electrodes with each other Provide a comparative amplifier which, depending on which of the two batteries is more powerful or is less discharged, one of two relays assigned to each battery is operated for as long as the predetermined one Acid density difference is exceeded.

Such a circuit arrangement operating as a function of the acid density of the two batteries can be used as a additional device with particular advantage in connection with the electrical changeover circuit described above can be used to provide an additional guarantee that a uniform discharge actually occurs of the two batteries takes place.

This results in a particularly simple and expedient one Arrangement when the switching contacts of the two

Relays influenced by the acid density in such a way as the changeover relay of the one discussed above schematically working alternating circuit feeding circuit lie that this when one of the two is actuated by the Acid density-influenced relay is kept switched off, so that with each actuation the control

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organs for supplying the motor with low speed only those assigned to this relay, then less discharged Battery is switched to the motor and when the other relay influenced by the acid density is actuated the changeover relay is kept switched on so that every time the control element is actuated, it is supplied with power of the motor at low speed only uses the battery assigned to this other relay, which is then less discharged the motor is switched.

The invention is explained in more detail below with reference to the drawing, for example. This shows a circuit diagram for a circuit arrangement according to the invention.

The two batteries 17 and 18 provide the electrical i

Energy to operate a vehicle drive motor 14 and a motor 15 used to drive a hydraulic pump. The speed of the drive motor is controlled by operating a control mechanism in the form of a foot lever, while the pump motor 15 is controlled by the movement of a hand lever 21 which is located on the instrument panel in the Can be arranged near the steering wheel of a vehicle. The lever 21 has a switch 22 by means of which a higher speed level of the pump motor can be switched on *, for example if 909825/0500

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a faster lifting of a load by means of a lifting device is desired.

The circuit arrangement for actuating the drive motor 14 by means of the control member 20 has two speed settings, in one of the drive motor 14 only is connected to one of the two batteries 17 or 18 and in the other the drive motor to both batteries is connected in series. However, it is within the scope of the invention to also include other switches operated by the control element provide by means of which further speed levels by changing the circuit of the field windings of the drive motor and by switching resistors on or off are to be created from the drive motor circuit. "

In the position shown in the drawing, the drive motor 14 and the pump motor 15 are driven again. In this position, the two batteries 17 and 18 are connected in series by a line 25. As as will be seen in more detail below, this series connection between the batteries 17 and 18 can be maintained at all times stay.

To start the drive motor 14, the driver of the vehicle actuates the foot pedal 20, thereby creating a cam rod

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26 moved to the right in the direction of the arrow according to the drawing will. As a result of the initial movement of the cam rod 26 to the right, a switch 27 closes, as a result of which a contactor 29 is switched on via contacts 49c, 47b and 49b. At the same time a relay receives 48 Voltage through contacts 49c and 47b, attracts and closes contacts 48a and 48b and opens contacts 48c and 48d. Via contacts 48a and 49a, one is then explained in more detail below in its puncture as a changeover relay Relay 47 energized and switched on. The contactor 29 is now connected to the switch 27 and the contacts 48b and 49b, the relay 48 via switch 2? and contacts 48b and relay 47 through contacts 47a Voltage and are switched on. The drive motor 14 iet switched to the battery 18 by the closing of the contacts 29a when the contactor 29 is switched on, namely via a circuit from the positive side the battery 18, the contacts 29a, the drive motor 14, a rectifier 30 and in parallel therewith via the closed contacts 31a of a further contactor 31 leads to the negative side of the battery 18 the drive motor 14 runs in the low speed level.

By pressing the foot pedal 20 again, over the cam rod 26 another switch 32 is closed,

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whereby the contactor 31 is switched on in parallel with the contactor 29 and by what happens in the process Closing the contacts 31b via this also the battery 17 is switched to the drive motor 14, so that both batteries 17 and 18 now drive this with a higher voltage and thus at a higher speed.

By moving the foot pedal 20 back until it opens of the switch 32 does not change the switching state, except that the contactor 31 is switched off again, so that the motor 14 is switched back only to the battery 18 and accordingly again at a lower level Speed is running.

If the foot pedal 20 is now withdrawn so far that the switch 27 also opens again, so it can be seen that the contactor 29 and the relay 48 switch off and only the relay 47 remains switched on via the contacts 47a and 49a, whereby the next one Actuation of the foot pedal 20 until the switch 27 closes again, now initially via the contactor 31 contacts 48c, 47c and 48d are switched on «». At the same time, a relay 49 also receives via the contacts 48c and 47c voltage, attracts and closes the contact. 49d and opens contacts 49a, b and c. Dadurdh will be

Contacts 47c bridged and now relay 47 is removed

switches. Palls required, you can do that here Relay 47 drops out through a resistor 60 and delay a freewheeling diode 61 so that the contacts 49d are closed earlier than the contacts 47c open with certainty. The contactor 31 is now

via switch 27, contacts 49d and 48d to W

Voltage and the Heiais 49 via the switch 27 and the Contacts 49d. In this position, the drive motor 14 is connected to the battery 17, via a Circuit from the positive side of the battery 17 via a rectifier 36 and the parallel thereto lying contacts 29b, the drive motor 14 and the contacts 31b leads to the negative side of the battery 17

Another B _e make the Pusspedals 20 to g

Closing the switch 32 only has the effect that the contactor 29 is also switched on in parallel with the contactor 31 is, whereby both batteries 17 and 18 in series to drive the drive motor with higher Speed can be switched. Releasing the foot pedal 20 until the switch 32 opens again switches the battery 18 again «,

If the foot pedal 20 is now completely withdrawn, then 909825/0500

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that the switch 27 opens again, it can be seen that the contactor 31 and the relay 49 drop out, whereby the original switching state shown in the drawing is restored, so that with the next actuation of the foot pedal 20 until the switch 27 closes to drive the drive motor 14 at low speed again the first Battery 18 is used. So iet achieved that with constant successive actuation of the foot pedal 20, the drive motor for driving is alternately switched to the two batteries 17 and 18 with rLedriger speed.

The rectifiers 30 and 36 prevent a power interruption during the switching time of the contactors and 31 · Without the rectifier, the batteries were initially switched off when the second battery was switched on completely disconnected from the motor circuit, then connected in series and reconnected to the motor circuit causing a heavy load on the contacts due to switching arcs and jerking Work of the drive motor 14 would result.

The circuit arrangement for the pump motor 15 is 909825/0500

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essentially speaks in its basic structure of the above-described arrangement for the drive motor 14, so that a more detailed explanation is dispensed with. The switches 38 and 22a correspond to the switches 27 and 32, the contactors 40 and 42 the contactors

29 and 31 and the relays 51, 50 and 52 with correspondingly assigned contacts with the relays 48, 47 and 49 correspondingly assigned contacts. The rectifiers and 46 correspond in their effect to the rectifiers

30 and 36 in the circuit arrangement for the drive motor 14.

With successive actuation of the switching lever 21 for the purpose of closing the switch 38 the battery 17 or 18 is alternately connected to the motor 15 for driving at low speed, a subsequent switching off and on of the switch 22a exactly like switching the on and off Switch 32 in the above-described circuit arrangement only switches it on or off again causes the second battery to drive the motor 15 at a higher speed.

In the circuit arrangement for the pump motor 15, an additional circuit is built which is independent

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from the schematically operating one previously described Changeover circuit always shows the actual state of charge of the two batteries monitored and when a predetermined difference in state of charge is reached causes the Driving the motor 15 at low speed as long as only the less discharged battery is connected to the motor is until the predetermined difference in the state of charge is undershot again.

For this purpose, each battery 17 and 18 has an additional pair of measuring electrodes 55 and 56 in a cell assigned. The electrode pairs behave in exactly the same way as the normal electrodes of a battery cell. she are either separately charged or electrically charged together with the battery by appropriate switching means and deliver a voltage that, with a suitable choice of the immersed materials, corresponds to the electrolyte density is equivalent to. In order to largely avoid a discharge of the measuring electrode pairs 55 and 56, the ones supplied by them Voltages supplied to an amplifier 57, which amplifies the difference between the two voltages and at a predetermined voltage difference a relay 53 or 54 turns on. In the arrangement shown the relay 53 is switched on when the drink density in the battery 18 is greater than in the battery 17,

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while the relay 54 is actuated when the acid density in the battery 17 is higher than that in the Battery 18,

As can be seen, the switching contacts 53a and 54a are located the relays 53 and 54 in such a way in the circuit feeding the changeover relay that this upon actuation of the Relay 53 due to corresponding acid density differencesζ or different state of charge of the two batteries is kept constantly switched off, because by opening the contacts 53a of the positive side of the batteries via the contacts 53a, 51a, 52a and the relay 50 to Negative side of the batteries leading to the switching on of the changeover relay 50 circuit interrupted so that this can not come into action to change the order in each case in the manner described above the actuation of the two batteries 17 and 18 to drive the motor 15 at low speed to reverse. Rather, only the battery 18 is switched to the motor 15 via the contactor 40. Will the predetermined If the acid density difference falls below again, the relay 53 drops out again and the batteries 17 and 18 are switched on again alternately by switching on the changeover relay 50 accordingly.

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If the relay 54 "is now actuated, because the acid density in the battery 17 is higher than the predetermined amount than in the battery 19, it is over the closed contacts 53a of the relay 53 and the at the actuation of the relay 54 closing contacts 54a kept the changeover relay 50 constantly switched on, regardless of the otherwise provided switching elements, so that again the changeover circuit described above except Puncture is set and via the contactor 42 only the battery 17 to drive the motor 15 with lower Speed is switched to this until the acid density difference falls below the predetermined value again is.

Of course, the circuit, which works as a function of the acid density, could also be used in the same way Circuit arrangement for the drive motor 14 can be switched on or without the described changeover circuit work, in which case the switching relays 53 and 54 would have to be followed by corresponding switching elements, which in each case only the less discharged battery as long as on a motor for the purpose of driving the same with lower Switch speed as the predetermined difference in charge level is exceeded.

Patent claims:

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Claims (5)

Patent claims: 1. Circuit arrangement for vehicles with at least one electric motor, which is connected by two in series Batteries are fed, with the motor by means of a control mechanism for the purpose of drive with low speed first on a battery and then for the purpose of driving at higher speed both batteries is switchable, characterized in that the two batteries (17, 18) for the purpose of uniform unloading with constant, successive actuation of the control element (20 or 21) by electrical switching means alternately to supply the motor (14 or 15) with lower Speed can be switched to the motor. 2. Circuit arrangement according to claim 1, characterized in that the control member (20 or 21) one after the other two switches (27, 32 or 38, 22a) actuated, which in turn have two each of one of the two batteries (17, 18) associated switch support (31, 29 or 42, 40) switch one after the other in such a way that first the the contactor that was switched on first 9 09825/0500 . ■ β, - 1430652 Battery and subsequently also the other battery is switched to the motor (14 or 15), with when the switch that was operated first is switched on, the sequence of Actuation of the two contactors reversing changeover relay (47 or 50) is provided, which in a first Switching on the first operated switch (27 or 38) is switched on, with subsequent switching off this switch remains switched on and when this switch is switched on a second time is switched off again after the sequence of actuation of the two contactors has been reversed. 3. Circuit arrangement for vehicles with at least one Electric motor that is fed by two batteries connected in series, the motor by means of a Control organ for the purpose of driving at low speed initially on a battery and then for the purpose of driving can be switched to both batteries at a higher speed, in particular according to claim 1 or 2, characterized in that that the acid density of the two batteries (17, 18), which depends on the state of charge, is measured continuously and when a predetermined acid density difference is exceeded due to uneven discharge ' of the two batteries switching means (53, 54) actuated 909825/0500 U80652 Λ? are used to drive the motor (15) at low speed as long as only the less discharged Switch the battery on to the engine "until the acid density difference falls below the predetermined value again is. 4. Circuit arrangement according to claim 3 »characterized in that each battery (17, 18) is assigned a measuring electrode pair (55» 56) which supplies a voltage dependent on the acid density and that an amplifier (57) comparing the electrical voltages of the two electrode pairs. Depending on which of the two batteries is more or less discharged, one of two relays (53, 54) assigned to each battery is actuated for as long as the predetermined acid density difference * is exceeded. 5. Circuit arrangement according to Claim 2 and 4, characterized in that the switching contacts (53a, 54a) of the two relays (53, 54) influenced by the acid density in the one that feeds the changeover relay (50) Circuit lie that this influenced by the acid density when one (53) of the two was actuated Relay (53, 54) is kept switched off so that each time the control 909825/0500 organs (21) for supplying the motor (15) with low speed only this relay (53) assigned, then less discharged battery (18) is switched to the engine and when the other relay (54) influenced by the acid density, the changeover relay (50) is kept switched on is, so that with each actuation of the control member (21) to feed the motor (15) with lower Speed of this other relay (54) assigned, then less discharged battery (17) to the engine is switched. 9 09825/0500