DE10347683A1 - Automatic idling control unit for stopping and starting a motor vehicle engine during idling, e.g. at a traffic lights, has device for monitoring the temperature of semiconductor switching elements to prevent their overheating - Google Patents

Abstract

An automatic control unit for stopping an idling motor vehicle engine and restarting it using an A.C. motor or generator (21), where the temperature of semiconductor switching elements (220) of A.C. to D.C. converter (22) that drive the motor or generator during a restart are measured or estimated automatic engine operation is prevented if the temperature exceeds a threshold, in order to prevent overheating of the switching elements during a subsequent restart.

Description

BACKGROUND OF THE INVENTION 1 , Field of the Invention

The present invention relates to an automatic control device to stop idling, to achieve economical fuel consumption, and by automatically stopping and then starting again an internal combustion engine of a vehicle when the vehicle is currently is stopped.

2. Description of the stand of the technique

Types are from the state of the art of devices known to automatically stop the engine of a vehicle and then start again if the vehicle is temporarily is stopped, such a type of device in general as an automatic control device to stop idling referred to as. Such a device the vehicle engine stops when the vehicle is stopped, at traffic lights, for example, and then starts the machine again if the vehicle is to move again (e.g. based on detecting an action by the vehicle driver that the intention to move the vehicle indicates). The use of such a device creates the possibility, reduce fuel consumption and exhaust emissions. An example of such a device is described in Japanese Patent 2000-192830.

With the help of such a conventional one automatic idle stop control unit is used instead a conventional one DC starter motor to restart the machine AC motor / generator used, which both the machine for one again Starting can drive and which is also driven by the machine can to generate electrical energy. Such a device also contains an AC / DC power converter for rectification the AC power from the AC motor / generator to a DC power supply to charge the vehicle battery obtained, and taking the DC voltage of the battery into an AC power supply is converted to the AC motor / generator during machine restart drive. Such a device can simple and reliable accomplished become.

• (a) während die Maschine wieder gestartet wird, wird nachfolgend einer automatischen Maschinenstopoperation ein hoher Wert des Stromes von der Fahrzeugbatterie in Wechselstromenergie durch den Umrichter umgesetzt, und
• (b) während die Batterie unmittelbar nach dem Maschinenwiederstart wieder aufgeladen wird, wobei ein hoher Wert eines Gleichstroms von dem Umrichter der Batterie zugeführt wird.

With such a type of automatic idle stop control device, as with any other type of power semiconductor device, it is necessary to design the device in such a way that the temperature of the semiconductor switch elements of the AC / DC power converter does not exceed a predetermined maximum value. More specifically, in an automatic idle stop control device, high values of current flow through the semiconductor switch elements are realized and thus there are high values of heat generation in these elements that occur under the following two conditions, that is:

• (a) while the machine is restarting, following an automatic machine stop operation, a high value of the current from the vehicle battery is converted into AC power by the converter, and
• (b) while the battery is being recharged immediately after the machine is restarted, a high value of a direct current being supplied from the converter to the battery.

In the state of the art Size of the semiconductor switch elements and the scale of the devices used for cooling of these switch elements are used based on the maximum Temperature set, which is expected for the semiconductor switch elements is achieved under any of the above conditions. As one result is the traditional one Types of automatic idle stop control devices have the disadvantage that she in size or are large in size and cause high manufacturing costs.

There is therefore a requirement the possibility to create such an automatic idle stop control unit more compact and to be able to manufacture at lower costs.

SUMMARY THE INVENTION

It is an object of the present invention problems inherent in the prior art as set forth above have been overcome by an improved automatic idle stop control unit for an internal combustion engine a vehicle is created, which is smaller in size accomplished and can be manufactured at a lower cost than this is possible with the prior art was.

In order to achieve the above object, according to a first aspect, the present invention provides an automatic idle stop control device that includes an AC motor / generator that is powered by the vehicle battery to power the vehicle engine in an engine restart operation, and the electric one Energy for charging the battery is generated when the machine is in operation. The apparatus also includes an AC / DC power converter with a plurality of semiconductor switch elements controlled in such a manner that the battery voltage is converted to an AC supply voltage for driving the AC motor / generator during an engine restart operation and the AC output voltage from the AC motor / Generator in a DC chip convert voltage to charge the battery during a battery charging operation. The apparatus is characterized in that it includes an inverter temperature detector section to derive an inverter temperature related signal indicative of the temperature of the semiconductor switch elements and a fuel economy operation control section that applies control to perform automatic machine stop operation or perform automatic machine restart operation following an automatic machine stop operation in accordance with vehicle status information and the converter temperature related signal.

The converter temperature-related Signal can be generated with the help of a temperature sensor Part of the automatic idle stop control unit itself is or can be off a signal, such as an engine cooling water temperature signal consist of or consist of an ambient air temperature signal, which is available from any other control device of the vehicle. It should thus be noted that the term "converter temperature detector section" as used in the following Description and the attached claims used has a broad meaning in the sense of "device for deriving a temperature indication signal, the fuel economy operation control section directly receives the temperature of the semiconductor switch elements or this appreciates ".

After performing an automatic machine stop operation and a subsequent machine restart operation Fuel economy operation control section repeated an operation according to a Judging by whether the temperature of the semiconductor switch elements has exceeded a predetermined threshold. If found will that the Threshold exceeded was (so that then if an automatic machine stop operation at this time perform is the temperature, soon followed by an engine restart operation of the semiconductor switch elements excessively high would be), the system then prevents an automatic machine stop operation from being performed at this time.

As a result, the automatic idle stop control device in the Size can be made more compact and can also be manufactured at a lower cost than the prior art be achieved, however, a high reliability of operation becomes.

More specifically, let The basic advantages that are achieved can be summarized as follows. If the machine is following an automatic machine stop operation is started again, and then if it is determined that the temperature of the semiconductor switch elements of the AC / DC power converter has exceeded a predetermined threshold, the execution another automatic machine stop operation at this time prevented. This ensures that the temperature the semiconductor switch elements do not exceed a permissible value, because of the high current values in the switch elements while of a machine restart, and subsequently one automatic machine stop operation and also during battery recharge, which follows immediately after the machine restart operation.

Because of the prevention of such an automatic machine stop operation based on the temperature, through the semiconductor switch elements of the AC / DC power converter is achieved, it is not necessary to base the whole system to be designed at a maximum temperature value that of the semiconductor switch elements can be achieved as a result of repeated execution a machine restart within a relatively short time interval, what is called "worst Case "of the design parameter applies. As a result, the system can be designed in such a way be that the Size and the AC / DC power converter cost reduced can be there the semiconductor switch elements and also the cooling devices, such as for example a heat sink and cooling fins executed smaller can be like that that the Overall size and the Total cost of the automatic idle stop control unit can be reduced can. The size reduction also simplifies the assembly of the AC / DC power converter inside the engine room of a vehicle.

Even if in practice the vehicle under extreme conditions, such as high traffic while a summer heat, leads to the prevention described above automatic machine stop operation based on temperature The semiconductor switch elements only cause fuel consumption increases only insignificantly and the exhaust emission values only insignificantly rise so this is not a serious disadvantage.

Thus, in the present invention, by adding only a device to monitor a signal serving as an indication of the temperature of the semiconductor switch elements of the AC / DC power converter, the converter can be made small, and less expensive semiconductor switch elements can be used, and thus the entirety of the automatic idle stop control device can be made much more compact and less expensive, which creates a larger free space within the engine room of a vehicle and the manufacturing costs can be reduced. These advantages are achieved without adversely affecting the driving characteristics of the vehicle.

In addition, since smaller semiconductor switch elements can be used the amount of heat, which is emitted by this is reduced. It can therefore be a more compact or simpler device for cooling the semiconductor switch elements are used, such as a smaller heat sink, cooling fins etc. This enables it further that the Overall size and the Total cost of the automatic idle stop control unit reduced become.

There are preferably MOS transistors used as semiconductor switch elements. In this case, immediately ensure that a predetermined allowable Temperature through the semiconductor switch elements during a Machine restarts not exceeded which is carried out after an automatic machine stop process, or during the vehicle battery is charged, which is immediately after the machine is restarted takes place.

If such MOS transistors are used, can rectify the AC output energy of the AC motor / generator can be realized by using parasitic transition diodes (between drain and Source) of these transistors used during battery charging become. If such charging occurs immediately during an interval following a machine restart, high flows Current values in the MOS transistors, essentially continuously while this interval. However, there may be a limit on the current value can be achieved in a simple manner by using the parasitic junction diodes become. It becomes possible excessive warming of the MOS transistors during to avoid such a battery charging interval without the Need additional Must use diodes as rectifier diodes. So this is a configuration at the parasitic Junction diodes of the MOS transistors used, advantageous, compared to conventional Types of an AC / DC power converter that are used in generally a combination of IGBTs (Insulated Gate Bipolar Transistors = insulated gate bipolar transistors) and rectifier diodes are used, since the configuration of the present invention are the same elements while both electrical power generation (battery charging) and while the machine restart operations, so that the control circuit simply executed can be if the parasitic Junction diodes for the Rectification can be used.

With such a configuration, which only uses MOS transistors become the peak values the temperature of the semiconductor switch elements that then occur if the temperature increase results from the high current values, the during the electrical power generation flow (i.e. during the Battery charging), superimposed on the temperature rise resulting from a immediately preceding machine restart process results. This applies even if the MOS transistors are used to to synchronize electrical power generation in order to thereby minimizing the energy losses involved in rectification occur, that is in which the control of the switching of the MOS transistors with the Rotation of the AC motor / generator is synchronized. It However, the present invention ensures that the MOS transistors, used as switch elements, no predetermined exceed the maximum temperature value, namely during the machine restart after an automatic machine stop process or while battery charging, which immediately follows the machine restart he follows.

Furthermore, in the present Invention of the converter temperature detector section as at least a semiconductor temperature detector circuit can be configured (this means with a temperature sensor element), which is integrated, with at least one of the semiconductor switch elements. The The temperature of the semiconductor switch elements can thereby be determined exactly it can be reliability of the company increased and the temperature threshold can be as high as practical is sensible to be set.

By adding the MOS transistors the AC / DC power converter in rectification during of the electrical power generation operation of the AC motor / generator are used and the channel currents of these same MOS transistors be used when the battery voltage changes to an AC supply voltage is implemented to drive the motor generator, during a Machine restart operation, it is only necessary that Detect temperature of a single set of switch elements. However, in the case of a conventional type of AC / DC power converter, in which both power transistors and separate rectifier diodes used, the respective temperatures of the required To detect transistors and diodes, so that the temperature detection configuration is more complex.

Another aspect of the invention is as follows. The converter temperature detector section can be configured to estimate the temperature of the semiconductor switch elements based on the ambient temperature of the converter or based on the temperature of the machine cooling water in connection with a record of the current values flowing in the semiconductor switch elements, up to a recent one Time. That is, it is the conventional types of automatic idle stop control unit we essential to provide a means to directly detect the temperature of the semiconductor switch elements (and also generally of the rectifier diodes) of an AC / DC power converter. However, in the present invention, an equivalent circuit model of heat radiation can be created for these switch elements in advance and stored in a memory, and can then be used to estimate the temperature of the semiconductor switch elements based on the ambient temperature (which the current ambient temperature of the converter or the atmospheric temperature which is detected by an existing sensor), or the machine cooling water temperature can be used, i.e. values which are generally already measured by an existing machine control system of a vehicle, in connection with a history of the Current values that have flowed in the switch elements.

Since funds are generally provided, to detect the current values that are in the switch elements of a AC / DC power converter flow, and for the purpose of controlling the converter operation, and there is one Correlation between the amounts of heat exists, which is generated in the semiconductor switch elements, and the values of the current that exists in these switch elements flows (this means a relationship in the aforementioned equivalent circuit model is used), there is no longer any need for any additional To provide means to detect the values of the current, that flows in the semiconductor switch elements. Thus the temperature the switch elements are estimated with a sufficient degree of accuracy, using an equivalent Circuit model along with information through already existing sensor devices of the vehicle can be supplied. On this way the automatic idle stop control unit can continue can be simplified and thus manufacturing costs can also be reduced.

In the simplest case, the Time that has passed since the last occurrence of maximum Values of the current flowing in the semiconductor switch elements (the is called the time that has passed since the last machine restart) can be measured and it can perform an automatic machine stop operation be prevented at this time if the elapsed time is shorter as a predetermined minimum waiting interval under a condition at which the ambient temperature or the machine cooling water temperature exceeds a predetermined threshold.

Another aspect of the invention is as follows. As a cooling arrangement for one AC / DC power converters become devices like cooling fins and a heat sink typically used and these form an essential Part of the total weight and size of the converter. Since therefore the present invention the possibility creates the maximum amount of heat, radiated by the converter is significantly reduced, can such cooling devices be made smaller and less in weight.

According to another aspect, if Means are provided to convert the AC / DC power through a flow of machine cooling water to cool becomes the fuel economy operation control section configured to enable automatic machine stop operation prevent or prevent it from being executed, when the temperature of the engine cooling water is a predetermined one Threshold exceeded. This ensures that when the effectiveness the cooling of the AC / DC power converter has been excessively reduced, because of a high temperature of the machine cooling water (the is called the coolant, which is cooled in the radiator of the vehicle), damage or destruction of the semiconductor switch elements can be avoided. Because thus in in this case means for detecting the engine cooling water temperature is already installed on the vehicle, it is no longer necessary An additional To provide a sensor for detecting a condition in which the efficiency the cooling of the semiconductor switch elements excessively low has become.

In another aspect, the semiconductor switch elements of an AC / DC power converter of an automatic Idling stop control device according to the present Invention can be mounted on a circuit board and it can a sensor electrode for detecting the temperature of the semiconductor switch elements can be mounted on the same circuit board, i.e. in the near each of the switching elements. This way it is no longer necessary a separate temperature sensing device to be provided for each of the semiconductor switch elements so that the circuit configuration can be simplified.

By a suitable type of ceramic circuit board is used and by placing the temperature sensor close to the circuit board (e.g. using a synthetic resin adhesive), is the heat radiation of the switching elements effectively transferred to the temperature sensor. In this way it becomes possible in essentially exactly the temperature of the semiconductor switch elements assess using only one or a small one Number of temperature sensors.

Alternatively, each of the semiconductor switch elements may be close to a heat absorbing or Heat transferring heat sink are attached, with at least one temperature sensor being attached close to the heat sink. In this way, the temperature of all of the semiconductor switch elements can be estimated substantially exactly using a small number of temperature sensors since there is only a small amount of thermal resistance between the semiconductor switch elements and the heat sink to which they are attached. A temperature increase in the semiconductor switch elements can thus be detected very quickly by the temperature sensor or the temperature sensors.

The heat sink is more preferred Made from a metal, with the chips (i.e. the dice) of the Semiconductor switch elements are closely attached to it on this Way the heat absorb, which is generated by the switching elements, or for the warmth on the external cooling device transferred to. It should be noted that a Electrode of the switching elements, which is formed from metal, a heat sink can represent how this for the present invention is established.

The temperature sensor can directly at the heat sink attached or it can be indirect over a layer of material be attached, which has a high efficiency in terms of heat transfer has. For example, if a temperature sensor on a circuit board can be mounted, which is made of a ceramic material the sensor firmly attached to the circuit board using a material be attached, which has a high efficiency of heat transfer has. Furthermore, a busbar, which the respective switch of the semiconductor switch elements connects as a heat transfer part serve.

There is a temperature difference between the respective heating part the heat sink (the is called, on which the semiconductor switch elements are attached) and one cooling source (for example, an external surface of the heat sink, that of an external Is exposed to air or immersed in a liquid, or a heat radiation surface, the through a motor housing is formed). It is therefore desirable that the Temperature sensor is attached in a place that is as dense as possible on the part with the highest Heat sink temperature is located. The whole point, however, is that the temperature sensor mounted on the circuit board of the semiconductor switch elements of the AC / DC power converter should be, since this simplifies the assembly of the temperature sensor and also creates the opportunity that the Wiring the printed circuit of the circuit board for this can be used to provide lead wires for the temperature sensor. So that can the construction and wiring layout are simplified.

In addition, a metal part, which consists of an electrode of the semiconductor switch elements, as a heat sink be used. In this case, one or more can Temperature sensors attached close to the respective electrode with the help of an electrically insulating material, such as a synthetic resin adhesive. Alternatively, if temperature sensor is formed by molding using an electrically insulating material, such as one synthetic resin, it may be possible be a synthetic resin section of the temperature sensor directly to be attached to the electrode.

In another aspect, can the AC / DC power converter is firmly attached to a housing of the AC motor / generator are attached. When this is done can the lengths the wiring between the AC motor / generator and the AC / DC power converters are briefly executed and the space occupied by such wiring can be reduced be, but at the same time or additional electrical losses can be lowered in the wiring and the emission of electrical noise due to high frequency currents in the wiring can also be reduced. Because the AC motor / generator even warmth generated in such a configuration, the maximum permissible temperature a sensor that measures the temperature of the AC motor / generator detected, exceeded become. However, if there is a temperature sensor on the circuit board of the AC / DC power converter is installed and the AC / DC power converter on the housing of the AC motor / generator is mounted, this temperature sensor can used to control the temperature of the AC motor / generator to monitor. Even if in this case the temperature by this temperature sensor is detected. within the maximum allowable temperature for the semiconductor switch elements of the AC / DC power converter, the system can can be configured to perform an automatic machine stop operation to prevent when the maximum permissible temperature of the AC motor / generator than exceeded is detected. Even if with such a configuration the Temperature sensor (or the temperature sensors) with the semiconductor switch elements is integrated or are integrated, namely by the AC / DC power converter, can reliably detect the temperature of the AC motor / generator This can be achieved if the temperature sensor is tight at a heat sink is attached by the heat efficient from the housing of the AC motor / generator can be transmitted.

In this way, the temperature sensors) used to reliably measure the temperature of both the semiconductor switch elements and the AC motor / generator to detect.

In another aspect, can the system can be configured in such a way that the fuel economy operation control section judges whether the temperature by the converter temperature detection section is detected, exceeds a first predetermined threshold value, when an engine restart is performed, subsequently an automatic machine stop operation, and the control section performing prevent automatic machine stop operation at this time, if the assessment is that the first threshold is exceeded and also makes an assessment as to whether the temperature is detected by the converter temperature detection section, exceeds a second predetermined threshold at this time, when a battery charging operation is to be performed, immediately following an engine restart process, and the control section then the level of the battery charging current is limited by the value the electrical energy is limited by the AC motor / generator is generated (that is by reducing the exciting current) when it is judged that the second Threshold exceeded has been.

The threshold value is preferably the Temperature at which energy generation limitation is carried out (while battery charge) higher set as the threshold temperature for which the automatic machine stop operation is prevented. In this way can be reliable ensure that a damage or destruction of semiconductor switch elements during of the machine restart does not occur, namely after one automatic machine stop.

As an alternative to a procedure the system may also use the DC starter motor to limit the charging current of the vehicle. In this case, the fuel economy operation control section performs control in such a way that when an engine restart perform following an automatic machine stop operation, and it is judged that the Temperature by the temperature detection section of the AC / DC power converter was detected, exceeds a second predetermined threshold value, the DC starter motor is driven to restart the machine perform, rather than by the AC motor / generator.

In other words, according to the above explained Aspect of the invention when the machine is stopped and then restarted, and if the system predicts (based on a surveillance of the inverter temperature-related signal) that the temperature of the semiconductor switch elements a permissible Exceed value when the machine restart operation is performed, at this time using the AC motor / generator, then the control executed like this which then uses the starter motor to restart the engine perform. If so, the temperature of the semiconductor switch elements an excessively high one Value, following an automatic machine stop operation, will damage of the semiconductor switch elements due to the supply of the driver current to the AC motor / generator at this time for machine restart prevented. However, since such a condition or condition does not occur frequently, leads this Using the starter motor does not cause excessive wear from it Engine.

In another aspect, the semiconductor switch elements each have MOS transistors, the fuel economy operation control section performs switching control on the MOS transistors to perform a synchronous rectification of the AC energy, the from the AC motor / generator during the electricity generation operation of the AC motor / generator is generated, and wherein the threshold the temperature is selected such that a maximum allowable predetermined one Temperature of the MOS transistors is not exceeded when the Machine restart operation is performed as follows on an automatic machine stop operation, and also not exceeded when the battery charging operation follows the engine restart operation carried out becomes.

In this case, instead of using the parasitic junction diodes of the MOS transistors for rectification, switching control is implemented to control the timing of the switching operations of the MOS transistors in accordance with the direction of current flow from the AC motor / generator, that is, in to control such that the current flow through the channel zones of the MOS transistors is exploited. This also serves to reduce the amount of energy loss in the MOS transistors, thereby reducing the temperature reached by the MOS transistors during machine restart. In addition, compared to the conventional use of IGBTs and the rectifier diodes to form the AC / DC power converter, this has the advantage that the same switch elements are used for both rectification and AC motor / generator voltage charging the battery and also for carrying it out the DC-to-AC conversion of the battery voltage to drive the AC motor / generator during an engine restart following an automatic engine stop operation.

SHORT DESCRIPTION THE DRAWINGS

1 Fig. 10 is a system block diagram of a first embodiment of an automatic idle stop controller;

2 FIG. 12 is a plan view illustrating a temperature sensor that is integral with an MOS transistor of an AC / DC power converter; FIG.

3 11 is a cross-sectional view of an AC / DC power converter of the first embodiment;

4 Fig. 14 is a flowchart showing a control routine periodically executed by the fuel economy operation control section of the first embodiment;

5 Fig. 10 is a timing diameter for describing the control operation performed in the first embodiment to prevent excessive temperature rise of the AC / DC power converter;

6 FIG. 14 shows a cross-sectional view of an example of a conventional type of AC / DC power converter; FIG.

7 FIG. 14 is a cross-sectional view of an alternate configuration of the AC / DC power converter shown in FIG 3 is shown;

8th Fig. 11 shows a system block diagram of a sixth embodiment in which a DC starter motor can be used for engine restart under a high temperature condition of the AC / DC power converter;

9 10 is a cross-sectional view of an embodiment of FIG 1 wherein the AC / DC power converter is configured to be mounted within the housing of the AC motor / generator;

10 Fig. 3 is an oblique view showing the construction of the AC / DC power converter of 9 illustrated;

11 shows a cross-sectional view accordingly 9 , showing an alternative construction for the AC / DC power converter;

12 FIG. 10 is a flow diagram of an alternative control routine to that of FIG 4 used in the sixth embodiment;

13 FIG. 10 is a flow diagram of an alternative control routine to that of FIG 4 used in a seventh embodiment;

14 FIG. 10 is a flow diagram of an alternative control routine to that of FIG 4 , a period of time that has elapsed from a previous engine restart operation being used as a parameter in judging whether to prevent an automatic engine stop operation; and

15 Fig. 10 is a general system block diagram of the seventh embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

1 FIG. 10 shows a conceptual system block diagram of an embodiment of an automatic idle stop control device installed in a vehicle, the device being from a fuel economy operation control section 1 and an AC motor / generator device 2 is formed, which is an AC motor / generator 21 and an AC / DC power converter 22 incorporated with the AC motor / generator device 2 through the fuel economy operation control section 1 is controlled to a DC power supply voltage for charging a battery 3 to generate and convert the battery voltage to an AC supply voltage to the AC motor / generator 21 to restart the vehicle engine (not shown in the drawing) after an automatic engine stop operation has been performed. In the following description, the term "converter" when used alone means an AC / DC power converter.

The fuel economy plant control section 1 determines when to perform an automatic engine stop operation or engine restart based on vehicle status information such as vehicle speed, braking condition (eg, the amount of brake pedal actuation) and information indicating the temperature of a set of MOS transistors 220 of the converter 22 relate to a temperature detector section or circuit 27 (described below), and using the status information or externally supplied commands (not shown in the drawing) based, for example, on an action by the vehicle driver that indicates the intention that the vehicle should begin to move after an automatic machine stop operation has occurred. When it is judged that an automatic engine stop operation or an automatic engine restart operation is to be performed, the fuel economy operation control section generates 1 Off commands performs this operation and sends these commands to the AC motor / generator device 2 (and in the case of stopping the engine to a control device such as an engine ECU, which is not shown in the drawings). A detailed description of the control processing performed by the fuel economy operation control section 1 performed to cause the machine to stop and restart is not relevant to the present invention and is therefore omitted here.

In addition to the AC motor / generator 21 contains the AC motor / generator device 2 a gate driver circuit 23 that in combination with the MOS transistors 220 essentially the converter 22 forms, with the gate driver circuit 23 works in accordance with an angular position signal, which is from a rotation sensor 26 is fed. The AC motor / generator device 2 also includes the aforementioned temperature detector circuit 27 , an electricity generation and control circuit 24 , the operating commands of the gate driver circuit 25 supplies, and contains an excitation driver circuit 25 , The converter 22 consists of a three-phase converter, each of the MOS transistors 220 has an internal parasitic junction diode between the drain and source electrodes, and these diodes are used to perform rectification operation, as will be described below.

The AC motor / generator 21 consists of a field winding type of a synchronous machine which has stator windings which are connected to supply electrical energy from the converter 22 in a machine restart operation to receive electrical energy to the converter 22 while charging the battery 3 supply. The excitation current for the field winding of the converter 22 is powered by the excitation driver circuit 25 supplied which is turned on to a DC power supply voltage from the AC motor / generator device 2 to receive or an output DC voltage from the converter 22 to receive as shown.

The electricity generation and control circuit 24 sends operating commands to the gate driver circuit 23 in accordance with the instructions for performing an automatic engine stop operation or an engine restart operation issued by the fuel economy operation control section 1 can be supplied in the manner described above. When a command to perform an automatic machine stop operation by the gate driver circuit 23 is received, this sets all MOS transistors 220 in the switch-off state (that is, in the non-conductive state). When a command to effect machine restart is subsequently given by the gate driver circuit 23 is received, this begins to perform a synchronous control of the switching operations by the MOS transistors 220 be realized, based on the angular position signal from the rotation sensor 26 , which then causes the converter 22 3-phase electrical AC power to drive the AC motor / generator 21 supplies.

In this embodiment, the AC motor / generator performs 21 is set in rotation by the machine and thereby electrical 3-phase energy to the converter 22 feeds the converter 22 rectification to a DC power supply voltage for charging the battery 3 to be obtained, using the parasitic junction diodes of the MOS transistors explained above 220 , This has the advantage of a simple circuit arrangement for performing such rectification. As an alternative, however, although details are not in 1 are shown, the gate driver circuit 23 with the MOS transistors 220 connected so that not only the gate electrode voltage of each transistor is controlled, but also the voltage that appears on an electrode of each transistor is detected, or the level or value of the current is detected that is generated by each of the MOS transistors 220 flows through. In this case, the gate driver circuit 23 can be configured in such a way that when the AC motor / generator 21 driven by the vehicle engine, the gate driver circuit 23 the voltage or current flow information for each of the MOS transistors 220 used to synchronously rectify the 3-phase AC electrical energy from the AC motor / generator 21 to perform the DC power supply voltage to charge the battery 3 to obtain.

In this embodiment, as in the simplified top view of FIG 2 is illustrated, a temperature sensor element 271 on part of the semiconductor chip from one of the MOS transistors 220 educated. The temperature detector circuit 27 is from this temperature sensor element 271 formed, which consists of a PN junction diode, in conjunction with a current control circuit (not shown in the drawings), a voltage amplifier circuit (not shown in the drawings), an A / D converter circuit (not shown in the drawings) etc. A fixed current value is caused to flow through the temperature sensor element 271 flows through, and that a voltage drop across the diode resulting from the current flow is amplified and converted into a digital signal, the value of which is the temperature of the MOS transistors 220 displays.

As will be described hereinafter, the invention is not limited to using such an arrangement to obtain information regarding the temperature of the MOS transistors 220 display, and it becomes a signal by the fuel economy operation control section according to the appended claims 1 used to maintain the temperature of the semiconductor switch elements, such as a digital signal based on the temperature sensor element 271 is derived and which is also referred to as a "converter temperature-related signal".

The digital signal periodically becomes the fuel economy operation control section 1 transferred the temperature of the MOS transistors 220 obtained by processing this signal.

As an alternative to using the temperature sensor element 271 it is equally possible to use various other types of temperature sensing devices and circuitry that are at least partially associated with one or more of the MOS transistors 220 can be integrated to derive a converter temperature-related signal.

As in 1 are shown are three pairs of MOS transistors 220 present, the pairs each with one of the stator windings of the AC motor / generator 21 for the three phases are connected, one transistor from each pair (in an upper position in 1 shown) with the positive connection of the battery 3 is connected and the other transistor of each pair (in a lower section or position in 1 shown) with the negative connection of the battery 3 connected is. As in the cross-sectional view of the converter 22 in 3 is illustrated, the three MOS transistors 220 that at the top position in 1 shown. are, according to the respective phases, on the upper surface of a circuit board 221 mounted, which is made of an electrically insulating material. The remaining three MOS transistors 220 (in 3 not shown) are on the lower surface of the circuit board 221 assembled.

As described above, it is possible to use only a single temperature detector circuit 27 to use with one of the MOS transistors 220 is integrated, in connection with circuits for deriving a single digital temperature display signal. However, it may be preferable to have the same arrangement for each of the MOS transistors 220 to provide a variety of digital temperature display signals and to the fuel economy operation control section 1 transmitted or sent.

Alternatively, a temperature sensor element 271 and associated circuits only for each of the MOS transistors 220 be provided on the top surface of the circuit board 221 are mounted, and the resulting digital temperature indication signals can then be transmitted or sent to the fuel economy operation control section.

As in 3 is shown is the circuit board 221 with a heat sink 223 equipped, which is attached in close contact with this. The heat sink 223 is with cooling fins 222 equipped, which are formed from a metal such as aluminum, an aluminum alloy or copper. An edge section 224 , which is made of a synthetic resin material, is around the entire outer periphery of the heat sink 223 over the cooling fins 222 formed, the upper portion of the edge portion 224 through a cover plate 225 is bordered. It can thus be understood that the construction described in 3 is shown in a manner similar to how the conventional type of power semiconductor device can be manufactured.

The drive shaft of the AC motor / generator 21 is coupled so that it can drive and be driven by the crankshaft of the vehicle machine (not shown in the drawings). The way in which a motor generator is used to drive a machine to effect a machine restart and that is driven to generate electrical power by the machine and to control the electrical power generation operation of the AC motor / generator device 2 are well known, so a detailed description is omitted here.

4 Fig. 14 is a flowchart of a control routine periodically executed by the fuel economy operation control section 1 of this embodiment is executed to control the AC motor / generator device 2. First, at step 1, a decision is made based on the vehicle status information explained above that goes to the fuel economy operation control section 1 whether an automatic machine stop operation should be performed at this time. If the result is "YES", then the temperature of the MOS transistors 220 based on the digital signal or the digital signals obtained from the temperature detector circuit 27 is supplied (step S2). When a plurality of the temperature display digital signals go to the fuel economy operation control section 1 are supplied in the manner described above, then the highest temperature value derived from these is taken as the converter temperature, that is the temperature of the MOS transistors 220 ,

Next, a decision is made as to whether the converter temperature exceeds a predetermined threshold, such as 110 ° C (step S3). If this threshold is exceeded, then a command is sent to the electricity generation and control circuit 24 of the AC motor / generator device 2 ge is sent to prevent any execution of an automatic machine stop operation at this time (step S4), and the control routine is then ended. If the threshold value is not exceeded, then a command is sent, for example to an engine ECU of the vehicle, which causes an engine stop to be carried out (step SS).

A waiting phase is then carried out until it is judged that the machine has to be started again (step S6). When this takes place, a command is sent to the electricity generation and control circuit 24 sent, indicating that the AC power should be supplied from the converter to the AC motor / generator 21 to drive (step S7). Next, a decision is made as to whether the engine restart has been completed (step S8) based on the status information such as the engine speed, etc. When it is judged that the engine start has been completed, a command to the electricity generation and control circuit 24 is sent to end the restart operation, that is, thereby supplying the AC power to supply the AC power to the AC motor / generator 21 by controlled switching of the MOS transistors 220 to end.

A 3-phase AC power supply is then started or by the AC motor / generator 21 generated and a 3-phase rectification is automatically by the parasitic junction diodes of the MOS transistors 220 performed to generate a DC voltage. When the engine speed rises to a sufficiently high level, the level of the DC voltage exceeds the voltage of the battery 3 so that the battery charging 3 starts. The battery 3 whose state of charge has decreased as a result of the machine restart operation is thereby renewed again, namely to its normal state.

Alternatively, as described above, it is also possible for the converter 22 the control of the MOS transistors 220 is carried out in order to achieve synchronous rectification during this battery charging operation, in order to reduce the energy losses as a result.

During the subsequent electrical power generation, the excitation driver circuit controls 25 the value of the excitation current, which is in the excitation winding of the AC motor / generator 21 flows in accordance with the voltage of the battery, for example by varying the duty cycle for controlling a switching element (not shown in the drawings) in such a way to the output voltage from the converter 22 to control the battery 3 to keep at a suitable loading value. Such a method of control is well known.

As a result of the control of the AC motor / generator device explained above 2 If the temperature of the AC / DC power converter exceeds a predetermined value, any embodiment of the automatic machine stop operation is prevented. So the requirements for cooling the MOS transistors 220 much lower than is required in the prior art, so that the AC motor / generator device 2 can be made more compact and lighter in weight.

The operation of this embodiment will now be described below with reference to 5 which represents the respective corresponding timing diagrams for the converter current (i.e. the value of the current generated by the AC / DC power converter of the battery 3 is supplied) for the converter temperature (that is, the temperature value determined by the fuel economy operation control section 1 is obtained in the manner described above), and for the vehicle speed. In 5 the vehicle speed becomes zero at times t1 and t3, while at time t1 the converter temperature, which is indicated as T1, is below the above-mentioned threshold value (eg 110 ° C.), so that an automatic machine stop operation is carried out at this time.

Subsequent to time t2, the fuel economy operation control section receives 1 Status information or a command that indicates that the vehicle is starting to move so that an engine restart operation is performed at that time. Due to the large amount of electrical energy supplied by the inverter during the machine restart operation, the temperature of the inverter rises above the threshold value at this time and also remains above the threshold value for a certain time afterwards, and then gradually decreases as this is indicated by the line segment T2.

If another automatic machine stop operation is now to be carried out, namely before the converter temperature has reached the threshold value, for example such an operation is to be carried out at time t3 and a machine restart is also to be carried out shortly thereafter, so that a large amount of electrical energy is again generated would be supplied via the converter, for example at time t4, then, as is shown by a broken line section of the converter temperature characteristic curve, the maximum permissible temperature for the MOS transistors 220 exceeded. This can damage the MOS transistors 220 likely to occur. However, in connection with the embodiment explained above, by preventing the execution of an automatic machine stop operation while the inverter temperature is above a predetermined threshold, such a damage damage can be avoided.

6 FIG. 14 shows a simplified cross-sectional view of an example of a conventional AC / DC power converter used in the AC motor / generator device 2 could be used in the same way as the drive 22 the embodiment explained above is used. As in 3 is shown, it is according to a comparison with the converter 22 the above-described embodiment for the conventional converter required that this with a heat sink 223 and with cooling fins 222 is equipped, which would then lead to approximately twice the weight and would also require approximately twice the volume than that which the converter 22 needed.

It should be noted that the system block diagram of 1 and the flow chart of 4 is also used in the description of other embodiments hereinafter, which differ from the first embodiment only in the manner of deriving a converter temperature related signal which is in the fuel economy operation control section 1 is used to change the converter temperature at step S2 of 4 to get, for example, by the function of the temperature detector circuit 27 is performed by a sensor leading to the motor-generator device 2 is arranged externally.

Second embodiment

A second embodiment will now be described. In the first embodiment, the temperature of the MOS transistors 220 detected directly and is used as the basis for the assessment in order to put the automatic machine stop operation function on standby. However, if air cooling is used to cool the MOS transistors 220 is used, the ambient temperature of the converter can be used as an assessment parameter. Here the "ambient temperature" characterizes the assessment parameter. Here, the “ambient temperature” can also identify the actual ambient temperature of the converter or a temperature that is related to the actual ambient temperature, such as, for example, the atmospheric temperature or the machine temperature. In this case, refer to the flow chart of 4 pointed out, in which the ambient temperature is detected in step S2 and a decision is made in step S3 whether the ambient temperature exceeds a predetermined threshold value. If this threshold is exceeded, step S4 is carried out to prevent the automatic machine stop operation from being carried out.

When using such a procedure may be when the vehicle is in a condition or condition is operated in which the converter can be overheated (for example then, when the vehicle is driven in summer, at one Traffic jam), ensure that an automatic machine stop operation carried out and that the Semiconductor switch elements of the converter are not damaged, as a result of overheating in a subsequent machine restart operation or when charging the battery, which is performed immediately after the machine restart operation. Consequently the converter can also be compact in size.

In general, the atmospheric temperature is measured as an ordinary control parameter of a vehicle, so that it is not necessary to provide an additional temperature sensor when the atmospheric temperature is controlled by the fuel economy operation control section 1 is used to estimate the ambient temperature of the converter.

Alternatively, a history of the values of the current flow of the converter would be possible 22 record up to the current point in time and then use this record to estimate the converter temperature at the current point in time. This can be done using calculation methods. In this case, a decision is then made as to whether the automatic machine stop operation should be enabled or prevented, depending on whether the temperature that is estimated in this way exceeds a predetermined threshold value.

Third execution form

As a further alternative to directly detecting the temperature of the semiconductor switch elements of the converter by using one or more temperature sensors, which are integrated with the respective switch element, and using the detected temperature as a judgment parameter for determining whether the automatic machine stop operation should be released, such as this has been described above using the first exemplary embodiment, it is also possible to use a temperature sensor which is adjacent to and on the same substrate as the MOS transistors 220 is mounted. This is in 7 illustrated in which a temperature sensor element 371 is formed from a material such as ceramic, and on the circuit board 221 is mounted on which each of the MOS transistors 220 is mounted in this way the temperature of the MOS transistors 220 to detect.

As an alternative to using the temperature value directly using the temperature sensor element 371 it would be detected possible that the fuel economy operation control section 1 uses this detected temperature value in conjunction with fluctuations in this detected temperature value to more accurately determine the current temperature of the MOS transistors 220 to calculate.

As another alternative configuration (see the 3 or 7 ) the temperature sensor element 371 firmly on the heat sink 223 be attached and provided with a surface which is coated with an electrically insulating material such as synthetic resin and which is fixed in close contact with an aluminum part (not shown in the drawings) which is in close contact with the surface of the heat sink 223 is appropriate. In this way, the heat from the MOS transistors 220 on the heat sink 223 are transmitted and thus also via the aluminum part to the temperature sensor element 371 ,

If the temperature sensor element 371 on the circuit board 221 is mounted like this in 7 is shown, the sensor can be close to the MOS transistors 220 be located so that the temperature of these transistors can be obtained with a relatively high degree of accuracy. In addition, a temperature detector circuit for amplifying and adjusting the output signal of the temperature sensor element can also be used 371 on the circuit board 221 be mounted so that the wiring arrangement can be simplified. Furthermore, the temperature of the MOS transistors 220 can be obtained as a temperature value by the temperature sensor element 371 is detected, namely incremented by a predetermined amount.

As a further alternative, it is possible to detect the temperature of bus bars on which the MOS transistors 220 are mounted, or to detect the temperature of the air at the heat sink 223 flows past, or to detect the temperature of the air coming from the cooling fins 222 flows here in order to obtain an inverter temperature-related signal.

Whatever alternative is realized, the converter temperature-related signal is always by the fuel economy operation control section 1 used directly or in a calculated form to give a value of the temperature of the MOS transistors 220 which is compared to a predetermined threshold, the result of this comparison being used as a basis for judging whether execution of the automatic machine stop operation should be released, as described above with reference to the flow chart of FIG 4 is described.

Fourth embodiment

It will now be a fourth embodiment described. In the second and third embodiments, that are described above will use air cooling to cool the semiconductor switch elements is used, however, according to the fourth embodiment the machine cooling water (the is called, which is cooled by the radiator of the vehicle) is used for this purpose. It is noted that the Expression "cooling water" here in a general Sinn is used to identify any type of liquid coolant.

As an alternative form of the fourth embodiment then when the cooling water exclusively for cooling the semiconductor switch elements of the converter is fed, a temperature sensor is provided by which the temperature of this cooling water is detected to obtain the inverter temperature related signal.

In the fourth embodiment, according to the flowchart of FIG 4 at step S2, the cooling water temperature is detected and becomes the fuel economy operation control section 1 supplied as an inverter temperature-related signal. Thus, at step S3, a temperature value obtained based on the cooling water temperature (or the cooling water temperature itself) is compared with a predetermined threshold, and the result of this judgment determines whether an automatic engine stop operation should be prevented, that is, whether step S4 or S5 is then executed. In the same way as in the second embodiment, this embodiment is advantageous if the vehicle is driven under opposite conditions so that the converter can be overheated immediately. In other words, it can be ensured that the MOS transistors 220 not be damaged due to high current flow values during a machine restart operation that follows the automatic machine stop operation when this automatic machine stop operation is to be performed while the inverter temperature is high.

This embodiment has the further advantage that when the machine cooling water for cooling the MOS transistors 220 it is not necessary to provide an additional temperature sensor since the engine cooling water temperature is detected as a standard parameter for vehicle control, so that a water temperature signal is generally available for use as an inverter temperature related signal.

modified configuration

To derive the accuracy of the actual temperature of the MOS transistors 220 Increasing when air cooling is used and the ambient temperature is detected, or the cooling water is used and the cooling water temperature is detected can be a history of the values of the current flow of the converter 22 recorded up to the current time. In this case, the history of the converter current values can be combined with the detected temperature information, for example by calculation using a predetermined algorithm, in order to estimate the converter temperature in a more precise manner. The values of the current flow of the converter can be obtained directly by using a current sensor or by estimation based on such factors as the engine speed, the battery voltage, the motor-generator voltage or the previously mentioned duty cycle, which is caused by excitation of the driver circuit 25 is applied.

It is also possible to use the time that has elapsed from the very last machine restart operation as a judgment parameter. This elapsed time can be measured from the start time or from the end time of the machine restart. More specifically, the temperature of the MOS transistors reaches 220 their highest values when the vehicle is operated under a condition in which the air temperature (and thus the ambient temperature of the MOS transistors 220 ) is high, and the machine restart operations must be performed frequently. Furthermore, the maximum temperature of the MOS transistors occurs 220 then when machine restart is performed, and then gradually decreases. These facts can be used to configure an alternative form of the third embodiment in the following manner. The fuel economy plant control section 1 performs control in such a manner that when the ambient temperature exceeds a predetermined threshold, any automatic machine stop operation is prevented up to a predetermined wait interval Δt which has then passed since the very last machine restart operation, e.g. since the end this machine restart operation. In this way, it becomes possible to achieve the advantages described above in connection with the first embodiment, overheating the MOS transistors 220 is prevented while the inverter 22 can be made compact in size without the need to use one or more temperature sensors to measure the temperature of the MOS transistors 220 to detect directly.

A flowchart of a control routine performed periodically by the fuel economy operation control section 1 is executed, in the case of such an alternative configuration, is in 14 shown. In this case, the ambient temperature of the converter is obtained in step S2 (the ambient temperature or the ambient temperature value can consist of an air temperature value which is detected as a standard control parameter in the manner described above) and is compared with a threshold value in step S3. If the threshold value is not exceeded, then a machine stop is carried out in step SS, but in the other case a decision is made as to whether the aforementioned waiting interval Δt has elapsed since the end of the very last machine restart operation. If this has passed, the machine stop operation is carried out, but otherwise the machine stop operation is prevented.

As a modified embodiment of the construction explained above, the waiting interval Δt can be set in accordance with the ambient temperature, that is, if the ambient temperature is high, the duration of Δt can be increased. In this way, more effective protection against the effects of a temperature rise of the MOS transistors can be achieved 220 can be obtained, which arises as a result of the high values of the current flow, during the very last machine restart operation and during the generation of electrical energy (immediately after the machine restart operation) for recharging the battery. Conversely, when the ambient temperature is low, the duration of Δt can be shortened.

Fifth embodiment

A fifth embodiment will now refer to the cross-sectional view of FIG 9 described. In this embodiment, the components of the converter 22 firmly on the AC motor / generator 21 appropriate. The AC motor / generator 21 who in 9 shown consists of a common type of synchronous machine with a stator 210 that is fixedly attached to a drive shaft that rotates within the housing 214 is held. With 211 is a stator winding of the stator 210 designated and 212 denotes an excitation winding on the rotor 213 is trained. With 216 is a centrifugal fan designated at one end of the rotor 213 is mounted, and 215 denotes a pulley that is fixedly attached to the front end of the drive shaft.

The converter 22 is fixed to a rear end wall of the housing 214 appropriate. In this example, the converter is 22 out of a shit ben-shaped heat sink 223 , the MOS transistors 220 that are directly attached to the heat sink 223 are mounted, and a circuit board 325 formed, which has a printed wiring layer that is fixed to the heat sink 223 is appropriate. A control IC (integrated circuit) 226 and a temperature sensor element 371 (in this example a thyristor) are on the circuit board 325 assembled. The control IC 226 serves the MOS transistors 220 to control to set a temperature detection output signal generated by the temperature sensor element 371 is generated, that is, functions of the electricity generation control circuit 24 and the gate driver circuit 23 of the AC motor / generator device 2 which in 1 is shown to perform. With 224 is an edge portion designated around the entire outer circumference of the heat sink 223 is appropriate, and 227 denotes an edge section that extends around the entire inner circumference of the heat sink 223 is appropriate. The heat sink 223 is on the case 214 through the edge section 224 attached, on the inside of the rear end wall of the housing 214 , A concave annular zone that is between the heat sink 223 and the edge sections 224 and 227 is formed with injected synthetic resin material 228 filled. This material 228 serves to seal the MOS transistors 220 , the tax IC 226 and the temperature sensor element 371 within this concave zone.

A cover part 229 , which is made of a synthetic resin material, is fixed to the edge portion 224 attached so that it is the heat sink 223 covers. The fan 216 directs a flow of cooling air from the air intake openings 2291 from that in the cover part 229 are formed in the interior of the cover part 229 , This flow of cooling air cools the heat sink 223 and also runs inside the case 214 to thereby remove the stator winding 211 and the rotor winding 212 to control, and then leaves the case 214 ,

10 illustrates the construction of the converter 22 of 9 if this is from the AC motor / generator 21 is separated. The synthetic resin material 228 and the control IC 226 are omitted from the drawing.

With such a configuration, the temperature sensor element 371 which is on the circuit board 325 is mounted, close to the heat sink 223 placed, separately from the heat sink 223 through the circuit board 235 , The heat sink 223 contains MOS transistors mounted on it 220 so that the temperature sensor element 371 effectively the temperature of the MOS transistors 220 can detect. Because the six MOS transistors 220 are mutually thermally coupled, namely at the same heat sink 223 are mounted, and since the heat sink 223 With such a configuration, all MOS transistors can have a high thermal transfer efficiency 220 are cooled to substantially the same temperature. The temperature sensor element 371 is firmly on the circuit board 325 attached, which is formed from a ceramic substrate, which is attached with the aid of an adhesive material, for example on the heat sink 223 , The temperature sensor element thus reaches 371 essentially the same temperature as the heat sink 223 and can exactly the temperature of the MOS transistors 220 detect.

With such a configuration, it is not possible to reliably detect the highest temperature caused by the MOS transistors 220 is achieved, however, as is possible with the configuration of the first embodiment shown in FIG 1 is shown, in which a temperature sensor element 271 with one of the MOS transistors 220 is integrated or directly on one of the MOS transistors 220 is mounted. In the in the 8th and 10 The configuration shown is the temperature generated by the temperature sensor element 371 is detected, substantially equal to the average temperature by the MOS transistors 220 is achieved. However, in the manner described above, each of the MOS transistors 220 Reaching approximately the same temperature, a satisfactory quality can be achieved by using the temperature obtained with the temperature sensor element 371 is detected for comparison with a predetermined threshold for the purpose of judging whether the automatic machine stop operation should be prevented as long as the effects of the manufacturing variations between the MOS transistors 220 be considered or taken into account when the threshold is set. Such an arrangement offers the advantage that the temperature detection can be carried out using a simple configuration.

In the 9 The configuration shown can be modified as shown by the cross-sectional view of FIG 11 is illustrated. In this case there is an aluminum part 400 in close contact with the surface of the edge portion 227 arranged (around the entire inner circumference of the heat sink 223 is appropriate, as described above and also in 10 is illustrated) and is also in close contact with the surface of a molded synthetic resin material in which the temperature sensor or element 371 is wrapped or embedded. If the MOS transistors 220 Generate heat and the heat increases accordingly, the heat is very quickly through the heat sink 223 , the aluminum part 400 and the edge section 227 to the temperature sensor element 371 transferred so that the rise in temperature of the MOS transistors 220 directly through the temperature sensor element 371 can be detected can.

Sixth embodiment

In connection with the above-described embodiments, the execution of the automatic machine stop operation is prevented when the temperature of the MOS transistors 220 of the converter 22 exceeds a predetermined limit, thereby causing an excessive temperature increase of the MOS transistors 220 to prevent when machine restart is performed shortly after an automatic machine stop operation has occurred. However, in some cases, when an automatic engine stop operation is performed at a time when the vehicle engine was operated under a high value of a load, the flow of the cooling air into the engine room can be stopped or reduced when the engine is stopped , the temperature inside the machine room increases significantly, due to the heat emitted by the machine. As a result, after an automatic machine stop operation has been performed (that is, at a time when the converter temperature is estimated to be above the threshold value, it becomes possible that the maximum allowable temperature of the converter is exceeded when a machine restart is performed becomes.

However, in a sixth embodiment, which is in the form of a general system block diagram in FIG 8th a conventional type of engine starter motor 300 (that is, a DC motor) installed on the vehicle, and is with the machine 100 coupled to the vehicle and can be used to start the machine 100 to be controlled. In this embodiment, when an engine restart is to be performed following an automatic engine stop operation, the fuel economy operation control section judges 1 whether the converter temperature exceeds the threshold at this time. If it is determined that the threshold is exceeded, the fuel economy operation control section performs 1 Instead of using the AC motor / generator to restart the machine, a control is performed, which makes the starter motor 300 with the DC supply voltage from the battery 3 is supplied to the machine 100 to start.

In this way, if the above-mentioned adverse operating condition of the vehicle should occur (that is, the vehicle engine is stopped at a time when the engine has been operated under a high load condition), it is ensured that the MOS transistors are not damaged 220 occurs due to the heat generated as a result of performing a machine restart operation using the inverter 22 to the AC motor / generator 21 drive.

12 Fig. 14 is a flowchart showing a control routine periodically executed by the fuel economy operation control section 1 of this embodiment is carried out to achieve the effects described in connection with this embodiment above.

Seventh embodiment

In the above-described embodiments, protection against overheating of the MOS transistors 220 of the converter 22 achieved because of the high level of electrical energy that must be supplied when a machine restart is performed following an automatic machine stop operation, that is, when the inverter 22 AC power to the AC motor / generator 21 supplies. However, it is possible. that the overheating of the MOS transistors 220 may occur as a result of the rectification that occurs during normal electrical power generation operation in certain circumstances, such as when there is insufficient air flow to cool the MOS transistors 220 occurs. In the seventh embodiment, the problem of overheating that occurs during normal electric power generation is alleviated or eliminated by controlling the MOS transistors 220 to perform synchronous rectification instead of using the parasitic junction diodes as described above to reduce the amount of resistance loss that occurs in the MOS transistors 220 occur. Since the way of performing such synchronous rectification using an AC / DC power converter such as the converter 22 , well known, detailed description is omitted here.

In addition, in the seventh embodiment, overheating of the MOS transistors 220 also prevented during normal electrical power generation operation by monitoring the temperature value determined by a sensor such as the temperature sensor 271 or 371 , which have been described above, and by controlling the value of the field current flowing in the rotor winding of the AC motor / generator in accordance with the detected temperature value. In other words, the value of the field current is interrupted or reduced when the detected temperature exceeds a predetermined threshold, called the second threshold (as opposed to the first threshold, which is used as a basis for judging whether the execution of an automatic machine stop ration should be prevented, and which can typically be at 110 ° C, as described above in connection with the preceding embodiments). The second threshold is chosen higher or higher than the first threshold and can typically be set to 130 ° C.

In the seventh embodiment, as in the general system block diagram of FIG 15 commands from the fuel economy operation control section are shown 1 to the excitation driver circuit 25 of the AC motor / generator device 2 are transmitted, via a connecting line 110 to determine whether the field current of the AC motor / generator 21 should be reduced by 50% or not.

In this way it can be ensured that the MOS transistors are damaged or destroyed 220 is avoided due to overheating during electrical power generation.

13 Fig. 14 shows a flowchart of a control routine periodically executed by the fuel economy operation control section 1 of the seventh embodiment is carried out to achieve the effects described above.

It should be noted that, although the invention in connection with the above specific embodiments various modifications have been described in these embodiments envisaged can be and also diverse other combinations of features are possible that are related with the respective embodiments have been described, but all fall within the scope of him through the attached Claims held is.

Claims (13)

Automatic idle stop control unit for an internal combustion engine a vehicle with: an AC motor / generator that is so operable to apply kinetic energy to the machine and to be driven by the machine to an AC supply voltage to create, an AC / DC power converter with a variety of semiconductor switch elements that are so operable are to convert a battery DC voltage into an AC supply voltage to convert the AC motor / generator, and while during an engine restart operation, and around the AC supply voltage, generated by the AC motor / generator into a DC supply voltage to charge the battery while a battery charging operation, and a fuel economy operation control section, that responds to vehicle status information that is supplied to it, to perform an automatic machine stop operation at which the machine is stopped, and subsequently the inverter to control to start the AC motor / generator again to drive the machine; in which the device further includes an inverter temperature detection section to derive a converter temperature related signal, which relates to a temperature of the semiconductor switch elements, and the fuel economy operation control section a temperature value of the semiconductor switch elements based on the converter temperature-related signal and a respective evaluation operation performs, whether the temperature obtained exceeds a predetermined threshold and about execution prevent the automatic machine stop operation when judging that the Threshold exceeded becomes. Automatic idle stop control device according to claim 1, in which the semiconductor switch elements MOS transistors (metal oxide semiconductor) each of which has a parasitic junction diode between the drain and source electrode, the parasitic junction diodes used to perform full wave rectification of the AC supply voltage by the AC motor / generator, and at which the threshold the temperature is determined in such a way that the temperature of the MOS transistors has a predetermined maximum permissible temperature does not exceed if the machine restart operation follows the automatic Machine stop operation performed and the maximum allowable Temperature value is not exceeded, if the battery charging operation is subsequent to the engine restart operation carried out becomes. Automatic idle stop control device according to claim 1 or 2, in which the converter temperature detection section is a or a variety of semiconductor temperature detection circuits comprises each of these circuits including a temperature sensor element and each Element contiguous formed with a corresponding one of the semiconductor switch elements is. Automatic idle stop control device according to claim 1, where the converter temperature related signal is based on at least one of a set of parameters can be derived, which an ambient temperature of the AC / DC power converter, an ambient temperature of the vehicle and a temperature of the cooling water included in the machine. Automatic idle stop control device according to claim 1, with an air cooling device for cooling the AC / DC power converter through air. Automatic idle stop control device according to claim 1, with a water cooling device for cooling the AC / DC power converter through a flow of machine cooling water, and in which the fuel economy operation control section execution the automatic machine stop operation prevents when a temperature of the machine cooling water exceeds a predetermined threshold. Automatic idle stop control device according to claim 1, in which the semiconductor switch elements on a circuit board are mounted, the inverter temperature detection section contains a temperature sensor element, which is mounted on the circuit board. Automatic idle stop control device according to claim 1, in which the semiconductor switch elements in close contact with a heat sink are positioned, which causes heat absorption or heat transfer causes, and in which the inverter temperature detection section has a temperature sensor element which is in close contact with the heat sink is arranged. Automatic idle stop control device according to claim 7 or claim 8, wherein the AC / DC power converter firmly on a housing of the AC motor / generator is attached. Automatic idle stop control device according to claim 1, in which the fuel economy operation control section judges whether received based on the converter temperature related signal Temperature exceeds after a first predetermined threshold the machine restart operation following the execution of a automatic machine stop operation has been performed and execution of the prevents automatic machine stop operation when judged will that the first threshold exceeded will, and assesses whether the based on the converter temperature-related Signal received temperature exceeds a second predetermined threshold that is higher than the first threshold when the battery charging operation is performed after the machine restart operation has been performed and limits the value of the battery charging current by a limitation the electrical power generation by the AC motor / generator carried out if it is judged that the second threshold exceeded becomes. Automatic idle stop control device according to claim 1, with a DC starter motor, which is used to start the machine can be operated, and when the machine is restarted, namely after the execution the automatic engine stop operation, the fuel economy operation control section assessed. whether that detected by the temperature detection section of the AC / DC power converter Temperature exceeds a predetermined threshold, and control applies to drive the DC starter motor to restart perform, if it was judged that the Threshold exceeded has been. Automatic idle stop control device according to claim 1, in which the semiconductor switch elements have respective MOS transistors (Metal oxide semiconductor), and in which the fuel economy operation control section performs switch control on the MOS transistors to a synchronous rectification the AC power to perform by the AC motor / generator during the electricity generation operation of the AC motor / generator is generated, and in which the Threshold value is selected in such a way that a predetermined maximum permissible Temperature of the MOS transistors is not exceeded when the machine restart operation following an automatic machine stop operation, and this threshold is not exceeded when the battery charging operation follows the machine restart operation is carried out. Automatic idle stop control device according to claim 1, where the converter temperature related signal is based on is derived from at least one of a set of parameters that an ambient temperature of the AC / DC power converter and contain an ambient air temperature of the vehicle, and wherein the fuel economy operation control section repeats an operational sequence according to judgments performs, whether the temperature based on the converter temperature-related Signal was received exceeds a predetermined threshold, in which when it is judged that the Threshold exceeded is judged whether a predetermined waiting interval has passed following the very last execution of the machine restart operation, and then when it is judged that the waiting interval is not yet the execution has passed an automatic machine stop operation is prevented.