FR2541198A1 - REGULATING DEVICE FOR HEATING A MOTOR VEHICLE - Google Patents

Abstract

THE INVENTION RELATES TO A REGULATING DEVICE FOR THE HEATING OF A MOTOR VEHICLE, COMPRISING A HEAT EXCHANGER, A MANEUVER SERVING TO CONTROL THE QUANTITY OF HEAT GIVEN BY THE HEAT EXCHANGER, AN ELECTRICAL CONTROL DEVICE SERVING TO ORDER THE MANEUVERING ORGAN, WHICH COMPRISES A CABIN TEMPERATURE SENSOR FI, A FHL TEMPERATURE SENSOR AFFECTED FOR THE HOT AIR DELIVERED, A SETPOINT VALUE TRANSMITTER AS WELL AS A COMPARISON UNIT WHICH IS COMPOSED OF 'AN OP1 OPERATIONAL AMPLIFIER TO THE NON-INVERTING INPUT TO WHICH THE CABIN TEMPERATURE SENSOR FI AND THE SETPOINT VALUE TRANSMITTER ARE CONNECTED, WHILE THE FHL TEMPERATURE SENSOR AFFECTING THE HOT AIR SUPPLIED IS CONNECTED TO THE BOTH TO THE INVERTER INPUT AND TO THE NON-INVERTER INPUT - OF THE OPERATIONAL AMPLIFIER.

Description

l 2541198

  The invention relates to a control device

  lation of the heating of a motor vehicle, comprising a heat exchanger, an operating member for controlling the heat given off by the heat exchanger, an electrical adjustment device for controlling

  the operating member, which includes a temperature sensor

  erasure of the passenger compartment, an affected temperature sensor

  with hot air supplied, a value transmitter

  gne, and a comparison unit which consists of

  an operational amplifier at the inverting input of the

  which the two temperature sensors and the transmitter

setpoint values are connected.

  In a device of this kind which is already con-

  naked (see for example the patent application of R F A. published under N O 28 49 275), the temperature sensor

  assigned to the hot air supplied is constituted by a cap-

  heat exchanger and it is connected to the

  reverse amplifier of the operational amplifier through

  towards a coupling capacitor We are trying to obtain

  by this means that, the temperature of the heat exchanger

  their, considered statically, has no influence on the regulator and that the heat exchanger sensor

  heat is only dynamically coupled This brings

  You certainly have advantages compared to another available

  sitive of the same kind intended for the regulation of the heating of a motor vehicle (patent application of the RF A. published under the born 25 31 015) in which one seeks to solve the problems of a transmitter of double real value thanks to a differentiated assessment of the effects of the passenger compartment temperature sensor and the

  the heat exchanger However, this solution presents

  You also have disadvantages, because, for example, only very fast dynamic phenomena can be captured in a correct measure and because with this

  device, we do not have certain other possibilities

correction skills.

2 2541198

  The object of the invention, on the contrary, is to improve

  operate a device of the kind mentioned at the beginning so as to ensure, in particular by a simple modification of the dimensions of a few components, the possibility of easily adapting the device to different wishes

  with regard to the appearance of the temperature, at different

  passenger compartment constructions of motor vehicles

  biles and, also with the differences in construction of the heating installation itself, for example with the installations regulated by action on the air or by action on water For this purpose, the device quoted at the beginning is characterized in that the affected temperature sensor

  to the supplied hot air is additionally connected to the

  non-inverting input of the operational amplifier Le

  temperature sensor is preferably connected to the

  non-inverting input of the operational amplifier through a resistor, which is connected through an additional resistor, at the junction point of

  two resistors which form a voltage divider

  connected to the on-board network voltage and is also connected to an on-board network voltage pole through a capacitor The antagonistic effects of the connection of the temperature sensor assigned to the hot air supplied to the inverting input and - at the entrance no

  inverting the comparator-allow to give the components

  health, as appropriate, values such as varia-

  conditions of the motor vehicle, or

  other influences exerted on the regulatory system

  tor, for example, solar radiation, rain, a sudden start or equivalent can be compensated

as desired.

  Other features and advantages of the

  vention will be better understood by reading the -descrip-

  tion which will follow from an exemplary embodiment and with reference to the accompanying drawing, which represents a diagram of a

  example of embodiment of the device produced in accordance with

ment to the invention.

  A cabin temperature sensor FI is

  connected through a resistor Rl to the inverting input

  se of an operational amplifier O Pi For its part, the FHL temperature sensor assigned to the hot air supplied

  born is also connected to the inverting input of the am-

  operational planner OP 1, through a resistor

  R 2 In addition, the setpoint transmitter cons-

  the potentiometer Pl is also connected to the inverting input of the operational amplifier O Pl through resistors R 3 and R 4 The junction point

  between resistors R 3 and R 4 is connected to the negative pole

  tif of the on-board network voltage across a conden-

  sator Cl, which serves to delay the action of a modifier

  specification of the set value, and thus avoid a

suddenly brutal regulation.

  The two sensors FI and FHL are connected, on the one hand, to the negative pole of the on-board network voltage and, on the other hand, through resistors R 5 and

  R 6 respectively, at the positive pole of the voltage of the

  on-board bucket The potentiometer Pl is also connected

  at the two poles of the on-board network voltage Two au-

  very resistances R 7 and R 8 constituting a voltage divider

  are connected between the two voltage blades

  of the on-board network, the VP junction point of these resistances

  tances being connected through a resistor 9 to the

  non-inverting input of the operational amplifier OP 1.

  The non-inverting input of the operational amplifier

  is thus thus maintained at a voltage potential deter-

mine.

  In addition, the non-inverting input of the am-

  operational planner O Pl and the temperature sensor

  re assigned to hot air routed FHL are connected

  to each other through a resistance Rl O Par ail-

  their, the non-inverting input is still connected-to the negative pole of the on-board network voltage across

4 2541198

  a capacitor C 2 The temperature sensor FHL can therefore act on the non-inverting input of the operational amplifier O Pl through the resistor R 10 while

  that it can act on the inverting input through the re-

  sistance R 2. Between the positive pole and the negative pole of the

  on-board network voltage, there is still a resistance

  tance R Ul and a capacitor C 3 connected in series and at the junction point of which the base of a

  transistor Tl which can short-circuit the resistance R 9.

  In addition, another capacitor C 4 is connected in

  be the inverting input and the output of the amplifier

  operational OP 1 It is used to lower the parasitic voltage

you.

  The mode of action of the circuit described is as follows

  Before Normally, the capacitor C 2 is charged to a determined value, which is essentially given by the network R 6, R 7, R 8, R 9 and R 10 This means that the non-inverting input of the operational amplifier

  O Pl is maintained at the value which is determined by this-

  charges you The inverting input of the operating amplifier

  tional O Pl is on the contrary influenced by actions

  the cabin temperature sensor FI and the transmitter

  setpoint value P1, which are exerted one in the opposite direction to the other and, in this way, it is the same for the output of the operational amplifier OP 1,

  which acts on the operating member, for example by l Vin-

  through an amplifier and / or trans-

  training According to these considerations, the regulator is therefore only influenced by the temperature sensor

  cockpit and by the setpoint transmitter.

  We can calculate the resistances R 2 and R 10, by

  cooperation with resistance <R 9, so that the in-

  fluences of the sensor assigned to the hot air supplied FHL

  at the inverting and non-inverting inputs cancel each other out

2541198

  tally, and that the model of principle which has just been described also acts in practice, that is to say

  so that the temperature regulation of the

  tackle is actually only determined by the passenger compartment temperature sensor and the

setpoint.

  However, this is only valid for phe-

  very slow nomenes, that is to say for the phenomena of

  the order of magnitude of the minute or the hour, in the-

  which the charge of the capacitor C 2 can follow the influence

  this exerted via the temperature sensor FHL and o, consequently, the effects on R 2 and R 10 compensate each other On the contrary, in the case of very rapid phenomena, as, for example, in the case

  of the well-known heat wave, which occurs at the

  ment of starting after a brief stop, for example, a stop at a red light, the charge of capacitor C 2 cannot follow these rapid phenomena, for example from

  the order of a second or a few fractions of a second

  and the non-inverting input of the operating amplifier

  tional O Pl is therefore fixed, i.e. the influence

  exercised by the FHL temperature sensor through

diary of R 10 is deleted.

  On the contrary, the influence of the temperature sensor

  ture FHL, which would otherwise be compensated, and which is exerted via the resistor R 2 on the inverting input of the operational amplifier O Pl fully enters into action and immediately neutralizes this heat wave in the direction desired If this were not the case, the heat wave would not be felt in

  the passenger compartment and, consequently, on the temperature sensor

  ture of the cabin that when it is already felt

  tie unpleasantly by the occupants of the vehicle.

  The device constructed in accordance with the invention

  tion therefore ensures regulation in the desired direction,

  that is, in the case of slow phenomena, it is

6 2541198

  performs the regulation in the same way as if the sensor

  FHL temperature was uncoupled and that if the cap-

  cabin temperature sensor FI was the only determinant

  while while in the presence of rapid phenomena, which would manifest themselves in the form of discomfort, it highlights

  clearance to the desired extent, and so to speak with anti

  cipation, the temperature sensor assigned to the hot air supplied This desired measurement now shifts very clearly in favor of the FHL sensor which, on the contrary,

  must see its action suppressed in the installations

I have known.

  In the case of phenomena that occur

  with an average pace, neither slow nor fast, the charge-

  capacitor C will not accompany the action of the cap-

  FHL temperature sensor only to a lesser extent and, therefore, it is also only to this weaker extent that it will exert on the non-inverting input

  antagonistic to the action that the temperature sensor

  erasure FHL exerts on the inverting input through the

  resistance R 2 This also acts in the direction of

  lation desired for the comfort of the passengers of the motor vehicle. In total, the device according to the invention acts in the manner of a real PD regulator. Slow phenomena such as, for example, the variation of the outside temperature or equivalent, are only taken into account via the temperature sensor. cockpit FI

  while rapid phenomena, which are essential-

  to be charged to the heat exchanger, are quickly compensated for by the regulation, * and namely with a very slight oscillation In this case, there is no shift in the adjustment scale as in the case of a

  pure P regulator equipped with two real value transmitters

  The It is not necessary to correct the setpoint transmitter, even on long journeys. A decisive fact is that

  can choose the ratio of the ac-

  the cabin temperature sensor FI and the cap-

  FHL temperature sensor substantially by acting on the resistors Rl and R 2 since the false effects of the FHL temperature sensor can once again be compensated

  through the second coupling carried out through

  towards Rl O Conversely, it is also possible to obtain directly, by the dimensioning of R 9 and Rl O, that the action of the temperature sensor FHL acts

  more strongly, as desired, on the to-

  tal-of the two temperature sensors, which can be used

  For example, to raise the temperature of the home.

  key when the outside temperature decreases, without

  have to make a correction on the va transmitter

  their set point Pl This is frequently felt as

  physiologically more pleasant by occupants of the vehicle

  Normally this requires a temperature sensor.

  re external while, in the case of the device se-

  lon invention, this result can be achieved by a-

  tre dimensioning of the resistance Rl O,

  The essential advantage of the device according to the

  vention consists in its ability to adapt easily-

  lie in a variety of wishes and circumstances.

  Heating systems for motor vehicles

  including the use of a heat exchanger

  which uses the waste heat from the engine for heating

  the interior of the vehicle are mainly classified

  sées in installations with regulation by action on water and with regulation by action on air, that is to say that, in installations in which, in the first case, the heated cooling water is controlled by

  an operating member, for example by displacement

  continuous or by impulse action, in the form of a re-

  two-point regulator, while the air flow follows

  other laws, for example, dynamic pressure

  while walking, or the fan on stage, tan-

  say that in the second case the heated cooling water flowing through the heat exchanger is left

  unchanged and one determines, by means of a organ of ma-

  operation, a different mixing ratio between the cold air supplied and the air heated via the heat exchanger In both cases, the FHL temperature sensor assigned to the hot air supplied presents measurement results not only from its mounting point, but also, in particular, from the differences in response speed and oscillation between installations regulated by action on water and those regulated by action on air L here provides ease of adaptation

  from the action of the FHL temperature sensor to the regulation

  tion in the sense that one has practically only to realize one

  modification of the three components constituted by the re-

  Sistances R 9 and R 10 and the capacitor C 2 We can see in this easy adaptation to different conditions a

  particular advantage of the invention.

  The possibility of short-circuiting the resistance R 9 ensures a further improvement in the comfort provided by the device. In parallel with this resistance,

  is the transistor Tl which, in the example of reali-

  station, is a PNP transistor whose base is connected

  at the junction point between resistance R Ul and con-

  densifier C 3 The adjustment processes described above take place without disturbance in the normal case, where it is tacitly assumed that either the capacitor C 2 is

  discharged, or we are in a situation of

  overload in which the engine, not yet warmed up, does not supply heat to the heat exchanger and o,

  therefore, the capacitor C 2 has time to charge

  manage before intervening in the desired direction in pro-

discontinued regulation.

  However, there may be a situation in which, after a short stop, for

  which the vehicle engine has been switched off, it remains

  you still have a sufficient amount of heat in the

  heat changer but o the capacitor C 2 has

  charged in the meantime, for example because the device

  heating control has been switched off simultaneously

  especially when the engine of the motor vehicle is stopped, because it is connected to the ignition switch in this direction. The simplest countermeasure would be to

  leave the electrical part at least constantly energized

  door of the device which is assigned to the control of the

  heating, so that this part is always pre-

  -Te for regulation However, this measure is inde-

  sirable for well known reasons such as, for example, the fact that the battery would discharge at

  during extended downtime.

  If the measure described above is abandoned and the circuit shown in the drawing is switched off

  circuit simultaneously with the engine stopping at each stop

  stopping the vehicle, there could be a disturbance

  tion resulting from the discharge of the capacitor C 2, in the sense that, due to the fact that the heat exchanger is still hot, the regulating device would introduce

  in the passenger compartment of the vehicle a quantity of heat

  less than that which is necessary and o, therefore

  quent, the temperature would rise unpleasantly

  in this case, the attack of the transistor Tl through the resistance

  this Rll and the capacitor C 3 acts and intervenes in the opposite direction to this process, so that the disturbance does not occur. Due to the charging of the capacitor C 3 produced during operation, this counter-command, which is only necessary during a short time, is eliminated and it does not intervene in the normal regulation activity Naturally, it is possible to bring to the circuit described above different variants which do not depart from the principle of the invention Thus,

  for example, there is the possibility of providing, in lieu of

  placement of the capacitor C 2 which is connected to the ne pole

  gative of the vehicle's on-board network, another condensa-

  tor which is connected to the positive pole of the on-board network and which, in this way, also determines a maintenance

  potential at the non-inverting input of the amplifier

  operational operator OP 1 Also in this case, the components

  Tl, Rll and C 3 can be deleted.

  Of course, various modifications may be made by those skilled in the art to the device which

  has just been described only by way of non-binding example

  mitative without departing from the scope of the invention.

Claims (4)

R E V E N D I C A T I O N S   1 device for regulating the heating of a motor vehicle comprising a heat exchanger,   an operating member for controlling the heat   provided by the heat exchanger, an electrical adjustment device used to control the operating member, which includes a cabin temperature sensor, a temperature sensor assigned to the hot air supplied,   a setpoint transmitter and a comparison unit   reason which is constituted by an operation amplifier-   nel at the inverting input from which the two sensors   temperature and the setpoint transmitter are con-   nectés, characterized in that the temperature sensor   assigned to the supplied hot air (FHL) is connected in sup-   to the non-inverting input of the amplifier rational (O Pl).   2 Device according to claim 1, charac-   terized in that the temperature sensor (FHL) is con-   connected through a resistor (R 10) at the input not in-   jug (+) of the operational amplifier (OPI) la-   which is itself connected through a resistor   additional (R 9) at the junction point (VP) of two re-   sistances (R 7, R 8) which form a voltage divider   connected to the on-board supply voltage, and is connected   moreover at a pale line voltage   edge through a capacitor (C 2).   3 Device according to claim 1, charac terized in that the cabin temperature sensor (Fl) and the temperature sensor assigned to the supplied hot air (FHL) are connected to the inverting input of the operational amplifier ( OP 1), each through a resistor (Rl or R 2 respectively)   4 Device according to claim 2, charac-   terized in that the capacitor (C 2) is connected to the pole   the negative of the on-board network voltage, and in this   that it is planned, connected in parallel with the resistance   ce (R 9), a transistor (Tl) whose base is connected   at the junction point between a resistor (Rll) connected   light on positive of the on-board network voltage and a capacitor (C 3) connected to the negative pole of the voltage on-board network.