JP6293324B1 - Electronic circuit device and vehicle using electronic circuit device - Google Patents

Abstract

An electronic circuit device capable of estimating the outside air temperature in a short time with high accuracy and low cost without disposing a dedicated temperature sensor for detecting the outside air temperature in a place facing the outside that can be exposed to outside air, and the electronic circuit A vehicle using the apparatus is provided. A first temperature sensor 129 that is mounted on a circuit board 131 and detects a first temperature T1 using electric power supplied from a power supply 122, and is mounted on the circuit board 131 and supplied from a power supply 122. The estimated temperature Ta outside the circuit board on the straight line connecting the second temperature sensor 130 that detects the second temperature T2 using electric power in the external region of the circuit board is the first temperature T1 and the second temperature T2. From the temperature T2, the calculation unit calculates. [Selection] Figure 4

Description

  The present invention relates to an electronic circuit device, and more particularly to an electronic circuit device used in a control device for an internal combustion engine, and a vehicle using the electronic circuit device.

  Conventionally, an electronic control device for an internal combustion engine called an ECU (Engine Control Unit) is mounted on a vehicle. This ECU is mainly composed of a microcomputer, a power source, a power device, an input processing circuit, an output processing circuit, and the like, and controls operations related to driving of the vehicle. Various parameters are involved in such control. Outside temperature information is important as one of the parameters involved in the control.

  In general, the outside air temperature is most accurately measured by placing a dedicated temperature sensor in a place facing the outside where the outside air can be touched. On the other hand, a technique for indirectly estimating the outside air temperature without providing a dedicated temperature sensor is known in consideration of securing an arrangement location and cost reduction. For example, without providing a dedicated temperature sensor in an externally accessible place where outside air can be touched, a temperature sensor is placed in the intake pipe inside the system of an internal combustion engine that touches inhaled intake air, and is used as an intake air temperature sensor. A control device for an internal combustion engine to be estimated is known (for example, see Patent Document 1).

  In addition, a technique for estimating a temperature distribution in a plane using three or more temperature sensors is known, not limited to an internal combustion engine (see, for example, Patent Document 2).

JP 2008-45455 A JP-A-62-170826

  In the control apparatus for an internal combustion engine in Patent Document 1 described above, an intake air amount sensor is used in addition to the intake air temperature sensor for estimating the outside air temperature. That is, in the control device for an internal combustion engine of Patent Document 1, the outside air temperature is estimated from the relationship between the intake air temperature detected by the intake air temperature sensor and the intake air amount detected by the intake air amount sensor. Two different timing signals are required.

  In this case, there is a problem that, from the viewpoint of prediction accuracy and sensor accuracy, an interval is taken until the timing at which the difference between the two signal values becomes sufficiently large, or a sensor having high accuracy is required. Therefore, there is room for improvement with respect to the time required to estimate the outside air temperature or the cost of the sensor.

  In the in-plane temperature estimation method for estimating the temperature distribution of Patent Document 2 above, with respect to the estimation of the outside air temperature of the vehicle, where the temperature sensor is arranged in the vehicle, can an efficient estimation be realized? There was room for consideration. In addition, in the temperature estimation method of Patent Document 2, three or more temperature sensors are required for temperature estimation, and there is room for improvement in cost.

  The present invention has been made in view of the circumstances as described above, and without placing a dedicated temperature sensor for detecting the outside air temperature in a place facing the outside where the outside air can be touched, accurately in a short time, An object of the present invention is to provide an electronic circuit device capable of estimating the outside air temperature at low cost and a vehicle using the electronic circuit device.

In order to achieve the above object, an electronic circuit device according to the present invention is mounted on a circuit board on which an electronic circuit element is mounted , and a power source for supplying power, and the power source mounted on the circuit board and supplied from the power source A first temperature sensor that detects a first temperature using electric power; a second temperature sensor that is mounted on the circuit board and detects a second temperature using the electric power supplied from the power source; based on the first temperature and the second temperature, and a calculator for calculating the circuit board outside the estimated temperature in the outer region is an external mounting surface of the front SL circuit board, the second temperature sensor Is substantially on a straight line connecting the first temperature sensor and the external region, and the power source is mounted on the opposite side of the direction from the first temperature sensor to the second temperature sensor. .

Further, in the vehicle according to the present invention, an intake passage for supplying outside air from the outside air intake to the internal combustion engine inside the vehicle housing, a signal generation unit for generating a control signal for the internal combustion engine,
The electronic circuit device according to any one of claims 1 to 12, wherein the signal generation unit is provided with the estimated temperature outside the circuit board estimated by the calculation unit, and the signal generation unit is outside the circuit board. The control signal is generated based on the estimated temperature.

  In the present invention, a first temperature sensor that detects a first temperature using power supplied from a power supply and mounted on a circuit board, and a second temperature sensor that uses power supplied from the power supply and mounted on the circuit board. The calculation unit is configured to calculate the estimated temperature outside the circuit board in a straight line connecting the second temperature sensor for detecting the temperature of the circuit board in the external region of the circuit board from the first temperature and the second temperature. Therefore, it is possible to predict the outside temperature of the circuit board in a short time with high accuracy and low cost without arranging a dedicated temperature sensor for detecting the outside air temperature at a place facing the outside where the outside air can be touched.

1 is a schematic diagram illustrating an entire control system of an internal combustion engine to which an electronic circuit device according to the present invention is applied. It is the schematic diagram which showed the Example of arrangement | positioning with the ECU main body incorporating the electronic circuit device which concerns on this invention, and the control system of an internal combustion engine. It is a top block diagram which shows the example of arrangement | positioning of the electronic circuit element in ECU main body incorporating the electronic circuit device which concerns on this invention. FIG. 4 is a graph showing a temperature distribution around an ECU main body shown in FIG. 3. It is a flowchart which shows a control algorithm when Embodiment 2 of the electronic circuit apparatus which concerns on this invention is applied to an internal combustion engine. It is a flowchart which shows a control algorithm when Embodiment 3 of the electronic circuit apparatus by this invention is applied to an internal combustion engine. It is a schematic diagram which shows Embodiment 4 of the vehicle which concerns on this invention. It is a schematic diagram which shows Embodiment 5 of the vehicle which concerns on this invention.

  Hereinafter, various embodiments of an electronic circuit device and a vehicle according to the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are merely examples, and the present invention is not limited to these embodiments.

<Electronic circuit device>
Embodiment 1 FIG.
FIG. 1 shows a configuration of an entire control system of a well-known internal combustion engine to which an electronic circuit device according to the present invention is applied. The internal combustion engine 100 is a four-cycle gasoline engine that is operated with four steps of intake, compression, expansion, and exhaust as one combustion cycle. An intake passage 101 of the internal combustion engine 100 is provided with an air filter 102, a throttle valve 103, and an intake pressure sensor 104 that detects the intake pressure of air in the intake passage 101 from the upstream side. The intake passage 101 is provided with a bypass passage 106 and an idle speed control valve 107 so that the upstream side and the downstream side of the throttle valve 103 communicate with each other.

  In the intake passage 101, an injector 110 is provided on the downstream side of the intake pressure sensor 104 to supply the fuel pumped up from the fuel tank 109 by the fuel pump 108 to the vicinity of the intake port.

  The internal combustion engine 100 has a combustion chamber 105. An intake valve 111 for intake is provided in the combustion chamber 105, and an ignition plug 112 with an electrode protruding is provided on the upper portion of the combustion chamber 105. A piston 113 that reciprocates up and down is provided below the combustion chamber 105. The piston 113 is connected to the crankshaft 115 through a connecting rod 114. The combustion chamber 105 is further provided with an exhaust valve 116, which is connected to the exhaust passage 117 via the exhaust valve 116.

A crank angle sensor 118 that detects a rotation angle of the crankshaft 115 is provided in the vicinity of the crankshaft 115 of the combustion chamber 105. A three-way catalyst 119 is provided on the downstream side of the exhaust passage 117. Further, an O ₂ sensor 120 is provided upstream of the three-way catalyst.

  The throttle valve 103 adjusts the opening of the throttle. The throttle valve 103 controls the flow rate of air supplied to the combustion chamber 105 of the internal combustion engine 100 through the intake passage 101 by adjusting the opening of the throttle for air from which dust has been removed by the air filter 102. From the viewpoint of the driver, the throttle valve 103 controls the throttle opening adjustment in accordance with the operation amount of an accelerator (not shown) operated by the driver.

  The idle speed control valve 107 provided in the bypass flow path 106 adjusts the flow rate of air flowing through the bypass flow path 106 so as to control the rotational speed of the internal combustion engine when the internal combustion engine 100 is idling.

  The injector 110 injects fuel into the air flowing through the intake passage 101 before the intake valve 111 to form an air-fuel mixture. The intake valve 111 supplies the formed air-fuel mixture to the combustion chamber 105. A spark plug 112 provided in the combustion chamber 105 ignites the air-fuel mixture supplied to the combustion chamber 105 with a discharge spark and burns the air-fuel mixture. Work is done outside by the combustion of the air-fuel mixture.

  Specifically, the crankshaft 115 rotates via the piston 113 and the connecting rod 114, and rotational energy is extracted from the combustion of the air-fuel mixture. The exhaust valve 116 discharges the exhaust gas generated by the combustion of the air-fuel mixture to the exhaust passage 117 by an opening operation. A plurality of protrusions provided at predetermined intervals are provided on the outer periphery of the rotor that rotates integrally with the crankshaft 115. The crank angle sensor 118 is rectangular when these protrusions cross the crank angle sensor 118. A crank signal with a shape is output. With the above-described configuration, the internal combustion engine 100 controls the timing of fuel injection and mixture ignition.

A three-way catalyst 119 provided in the exhaust passage 117 purifies NOx, HC, and CO of combustion exhaust gas. The O ₂ sensor 120 upstream of the three-way catalyst 119 changes the output value according to the oxygen concentration in the exhaust gas. Whether the air-fuel ratio is smaller or larger than the stoichiometric air-fuel ratio for the combustion of the air-fuel mixture That is, it is determined whether it is a rich state or a lean state, and is reflected in the combustion control conditions.

  FIG. 2 shows an example when the ECU main body 121 including the electronic circuit device according to the embodiment of the present invention is arranged in the control system of the internal combustion engine 100 shown in FIG. In this embodiment, the ECU main body 121 is disposed in the outside air intake port 133 of the internal combustion engine 100. A part of the components shown in FIG. 1 is not shown.

  FIG. 3 shows an arrangement example of electronic circuit elements in the ECU main body including the electronic circuit device according to the first embodiment of the present invention. The ECU main body 121 includes a power source 122, a microcomputer 123, an output processing circuit 124, an input processing circuit 125, an A / D conversion circuit 126, a power device 127, a communication IC 128, and the like disposed on the ECU board 131. The ECU main body 121 is an example in which the electronic circuit device according to the present invention is mounted, and the ECU board 131 is an example of a circuit board.

The ECU main body 121 takes in input signals from the intake pressure sensor 104, the crank angle sensor 118, the O ₂ sensor 120, and a vehicle speed sensor (not shown), and inputs them to the input processing circuit 125. Thereafter, the input signal is converted from an analog signal to a digital signal via the A / D conversion circuit 126 and input to the microcomputer 123. The microcomputer 123 performs combustion control of the internal combustion engine 100, such as fuel injection control by the injector 110 and ignition control processing by the spark plug 112, based on a control logic built in advance.

  That is, by sending a control value from the microcomputer 123 to the power device 127, the fuel injection interval (injection amount) of the injector 110 is controlled, or the timing at which a spark is generated at the electrode of the spark plug 112 is controlled. In the case of a spark plug, based on the control from the power device 127, control is performed such that a separately placed ignition coil is dielectrically generated to a high voltage to generate a spark.

  The microcomputer 123 mainly has functions of a CPU, a memory, an input / output system (I / O), a timer, and the like, and a basic control logic such as input / output to a data table and various operations is constructed. Is. A control signal to the control system of the internal combustion engine 100 can also be generated. Further, the microcomputer 123 calculates an estimated temperature outside the housing based on detection values of a first temperature sensor 129 and a second temperature sensor 130 described later, and outputs a signal for controlling the internal combustion engine 100 according to the calculation result. Generate. That is, the microcomputer 123 is an example of a calculation unit and a signal generation unit in the present embodiment.

  As described above, the ECU main body 121 has a configuration in which the microcomputer 123 performs calculation of the estimated temperature outside the housing and generation of a signal for controlling the internal combustion engine 100. However, the present invention is not limited to this example. The ECU main body 121 may be configured to include separately a component that calculates the estimated temperature outside the housing and a component that generates a signal for controlling the internal combustion engine 100. By providing the configuration separately, the degree of freedom in designing the ECU main body 121 is increased.

  Since the ECU main body 121 itself is an electronic circuit board, the ECU main body 121 is housed in a sealed ECU casing 121a to cope with rainfall or the like. That is, the ECU housing 121a is covered with the ECU board 131 with an appropriate space provided so as to protect the electronic components from rain or the like. The ECU body 121, the ECU board 131, and the ECU housing 121a may be considered as one circuit board. Therefore, the estimated temperature outside the casing is, in other words, the estimated temperature outside the circuit board in the external region of the circuit board, and is hereinafter referred to as the estimated temperature outside the circuit board.

  A first temperature sensor 129 and a second temperature sensor 130 are provided on the ECU board 131 of the ECU main body 121. The first temperature sensor 129 and the second temperature sensor 130 are, for example, IC temperature sensors, and are one or more digits cheaper than a dedicated sensor for measuring the outside air temperature that requires a thermoelectric converter or the like. .

  Since the ECU main body 121 does not require an intake air amount sensor as described above, cost improvement is expected. In addition, since the first temperature sensor 129 and the second temperature sensor 130 are directly mounted on the ECU board 131 without using a cable, the ECU main body 121 has the first temperature sensor 129 and the second temperature sensor 130. A cable connecting the ECU body 121 and the ECU main body 121 becomes unnecessary, thermoelectric converters for converting the sensor inputs of the first temperature sensor 129 and the second temperature sensor 130 become unnecessary, and cost improvement is expected. Furthermore, the first temperature sensor 129 and the second temperature sensor 130 having the same configuration are used, so that the work efficiency for the assembly process can be improved.

  The first temperature sensor 129 is disposed adjacent to the power supply 122, while the second temperature sensor 130 is disposed far from the first temperature sensor 129 in the vicinity of the outer periphery of the ECU housing 121a. Has been.

  The first temperature sensor 129 is arranged on a straight line in the X direction connecting the power source 122 and the second temperature sensor 130, and on the straight line connecting the first temperature sensor 129 and the second temperature sensor 130. Are arranged so that there is no heating element. At the same time, the first temperature sensor 129 and the second temperature sensor 130 are arranged so that there is no local heat sink. That is, the ECU main body 121 is configured such that a region on the ECU board 131 between the first temperature sensor 129 and the second temperature sensor 130 is exposed.

  In other words, the ECU main body 121 is configured such that there is a space between each temperature sensor 129, 130 and the ECU housing 121a, and the space on the straight line in the X direction and the space between the temperature sensors 129-130. Is assumed to be the same. As a result, even when the temperature indicated by the first temperature sensor 129 and the temperature indicated by the second temperature sensor 130 are considered to be substantially linear, temperature estimation at a set position on the straight line is performed. Can be made as small as possible.

  Here, since the power source 122 is a power source that covers the entire ECU main body 121, there is little temperature variation over time with respect to the operating state of the internal combustion engine 100, that is, the operating state of the ECU main body 121. Therefore, it can be handled as a relatively stable heating element.

  On the other hand, the power device 127 or the like, for example, performs pulse generation of the injector 110, so that the amount of heat generation varies greatly depending on the operating state of the internal combustion engine 100, etc. Become. Therefore, it is desirable that the first temperature sensor 129 be installed in the vicinity of a component having a small temperature variation such as the power supply 122 rather than a component having a large temperature variation such as the power device 127.

  Note that the arrangement of the first temperature sensor 129, the second temperature sensor 130, and other elements shown in FIG. 3 is an example, and is not limited to this.

Figure 4 shows the temperature distribution curve C _T around the ECU body 121 having an electronic circuit device according to the first embodiment, when considering the heat transfer from the wall surface to the atmosphere, essentially This shows the physical phenomenon of the interface. The first temperature sensor 129 and the second temperature sensor 130 are installed on the ECU board 131, and the estimated outside air temperature is separated by an ECU container side wall 132 that is a part of the ECU housing 121a.

  In FIG. 4, the X direction shown in FIG. 3 is the horizontal axis, the vertical axis is the temperature, the temperature of the first temperature sensor 129 is T1 (K), the temperature of the second temperature sensor 130 is T2 (K), The temperature at a position outside the housing 121a is assumed to be an outside circuit board estimated temperature Ta (K).

Therefore, using the constant U (W / K) (multiplying a plurality of constants obtained from the heat balance) and the coefficient h (W / K), the estimated temperature Ta (K) outside the circuit board is expressed by the following formula ( It is defined in 1). Using the following equation (1), the microcomputer 123 calculates an estimated temperature Ta (K) outside the circuit board.
Ta = T2-U / h (T1-T2) (1)

  In this equation (1), the amount of heat transferred is determined by the temperature difference between T1 and T2 and the thermal conductivity, and the amount of heat transfer determined by the temperature difference between T2 and the estimated temperature Ta outside the circuit board and the heat conductivity. The curved temperature distribution on the left side of the side wall 132 shown in FIG. 4 shows a strict distribution between the wall surface and the atmosphere, and generally the atmospheric temperature is approximated as being unrelated to the distance from the wall. Therefore, also in the present embodiment, the distance at which the curved temperature distribution is formed approximates zero. The constant U includes position information of the first temperature sensor 129 and the second temperature sensor 130. Since these position information is fixed information, the constant U is measured in advance and is used as a microcomputer as a calculation unit. 123 may be stored.

  The ECU body 121 is provided in an environment in which ambient air is not easily affected by the flowing air when the vehicle travels. For example, in a two-wheeled vehicle, both are in the area surrounded by a panel at the bottom of the seat. In the case of a passenger car, an engine room that is not affected by outside air flow or the inside of the vehicle can be considered. In an internal combustion engine for a vehicle, the arrangement as described above is desirable in order to prevent rainwater from entering the combustion chamber from the outside air intake, particularly under an environment such as rain. Furthermore, it is desirable that the outside air intake is in the direction opposite to the forward direction of the vehicle because rainwater is difficult to enter.

  From the above results, in order to obtain the outside air temperature information, the outside air temperature is easily estimated by an inexpensive temperature sensor directly mounted on the ECU board 131 without using a dedicated temperature sensor, wiring, thermoelectric converter, or the like. It becomes possible. Further, the first temperature sensor 129 and the second temperature sensor 130 are arranged in the control system of the internal combustion engine 100, and are provided on the ECU board 131 in the vicinity of the power source 122 that is relatively small in thermal time variation. Therefore, the temperature can be estimated with high accuracy. Therefore, an electronic control system for the internal combustion engine can be realized at low cost.

  Here, in the embodiment of FIG. 2, the ECU main body 121 is provided in the vicinity of the outside air inlet 133 provided with the air filter 102 of the internal combustion engine 100, and further, the first temperature sensor 129 and the second temperature sensor 130. Are arranged so that the −X direction is generally directed to the outside air inlet 133. As a result, the estimated outside air temperature and the intake air temperature taken in from the outside air inlet 133 coincide in position.

  As described above, since the outside air intake port 133 is provided in the −X direction of the ECU main body 121, for example, even when there is a temperature distribution in the outside air around the internal combustion engine 100, the outside air temperature taken into the internal combustion engine 100 can be more accurately determined. Predictable.

  Further, by combining the estimated temperature outside the circuit board and the intake pressure data of the intake pressure sensor 104 provided in the intake passage 101, it is possible to know more accurately the state of the outside air introduced into the combustion chamber 105, and the like. High combustion control can be realized.

Embodiment 2. FIG.
In the second embodiment, the temperature of the internal combustion engine 100 is estimated using the estimated value of the outside air temperature obtained in the first embodiment. The microcomputer 123 estimates the outside air temperature from the first temperature sensor 129 and the second temperature sensor 130 provided in the ECU main body 121, estimates the main body temperature of the internal combustion engine 100 using this result, and uses these results. This is applied to combustion control.

First, the microcomputer 123 calculates the outside air temperature Ta estimated from the first temperature sensor 129 and the second temperature sensor 130 provided on the ECU board 131, and the energy balance Q _IN -Q _OUT of the main body of the internal combustion engine 100. calculate. When the temperature of the internal combustion engine body is T _ENG , the following equation (2) is established.
M · C _P · ΔT _ENG / Δt = Q _IN −Q _OUT (2)

Furthermore, the sum total of the energy output from the internal combustion engine can be expressed by the following equation (3).
Q _OUT = Σ (Qj) + β (T _ENG −Ta) (3)
Note that the two items on the right side of Equation (3) indicate the amount of heat released, and the first item on the right side indicates other output energy. Where M is the weight of the internal combustion engine body (kg), C _{P is} the specific heat of the internal combustion engine body (J / (kg · K)), and Q _IN is the total energy input to the internal combustion engine body (J / S), Q _OUT : Total energy output from the internal combustion engine body (J / s), Qj: Output energy of individual element j from the internal combustion engine body, t: Time (s), β: Constant ( W / K).

Equation (2) is a differential equation between the time t and the engine body temperature _{T ENG,} showing the variation [Delta] T _ENG of the engine temperature _{T ENG} with respect to time variation Delta] t. T _ENG at time t is obtained by discretizing the energy balance of equation (3) with respect to time, and T _ENG and ΔT _{ENG at} time t are discretized by discretizing the differential equation of equation (2). after Delta] t, that is, _{T ENG} time (t + Δt) is obtained from. By repeating this, the internal combustion engine temperature _TENG with respect to time is sequentially calculated. Note that initially, because that will calculate the T _ENG at time Δt from T _ENG at time t = 0, inputs the temperature of the internal combustion engine main body prior to combustion.

By substituting Ta in the equations (2) and (3) and the above equation (1) into the equation (3) and solving the simultaneous equations of the equations (2) and (3), An estimated temperature _TENG of the internal combustion engine body is calculated.

  Here, the time difference Δt indicates, for example, a fuel injection timing interval of the internal combustion engine. In the calculation, the initial temperature, that is, the initial temperature at the time when the internal combustion engine is started and combustion starts is input.

This initial temperature calculation method is, for example,
(1) A method of storing the temperature at the time of stopping, counting the elapsed time until the next operation start, and estimating the initial temperature from the elapsed time and the heat capacity of the estimation target,
(2) The resistance value of the existing resistor in the electronic control device or power device is measured, the temperature of the resistance is known from the relationship between the resistance value and the temperature associated in advance, and the resistance associated in advance. (3) Knowing the pressure value of the outside air sucked into the internal combustion engine, and determining the initial temperature from the relationship between the pressure value associated in advance and the temperature of the estimation target An estimation method can be considered. Note that this initial value estimation method is an example, and is not limited thereto.

  FIG. 5 shows a flowchart of the estimation of the outside air temperature from the ECU main body 121 provided with the electronic circuit device according to the second embodiment and the temperature estimation of the internal combustion engine main body. This is a case where the ECU body 121 is installed in an environment where the ambient temperature is not directly affected by the flowing air when the vehicle travels. Constants for estimation, such as constant U and coefficient h, are stored in the nonvolatile memory, and other necessary information is input when the vehicle is turned on.

Thereby, the estimated temperature Ta outside the circuit board according to the present invention is calculated from the input values from the first temperature sensor 129 and the second temperature sensor 130, and the result is used to calculate the temperature T _{ENG of the} internal combustion engine body. Can be estimated.

  That is, in FIG. 5, first, initial state information of the internal combustion engine, for example, information from various sensors and estimated initial values (U, h, β) are input to the microcomputer 123 when the vehicle is turned on before combustion. (Step S1).

  And after calculating | requiring the temperature of the internal combustion engine main-body part before combustion (step S2), each temperature T1 and T2 are input from the 1st temperature sensor 129 and the 2nd temperature sensor 130 (step S3). Then, the circuit board estimated temperature Ta of the above equation (1) is calculated from the above constants and the temperatures T1 and T2 (step S4).

At the same time, the internal combustion engine operating parameters are input to the microcomputer 123 (step S5). The microcomputer 123 obtains Q _IN and Q _OUT from the energy balance equation according to the above equations (2) to (3) using the estimated temperature Ta outside the circuit board and the internal combustion engine parameters (step S6), and the time difference Δt. The temperature T _ENG of the subsequent internal combustion engine body is estimated (step S7). Information on the estimated temperature Ta outside the circuit board is also used for subsequent combustion control (step S8).

Further, T _ENG after Δt is used again as T _ENG after time t for prediction of the temperature of the internal combustion engine main body after the next Δt (step S2). Predict temperature. The internal combustion engine operating parameter is a parameter determined by the operating state of the internal combustion engine, and includes, for example, the rotational speed and vehicle speed of the internal combustion engine.

Embodiment 3 FIG.
FIG. 6 shows a flowchart of the estimation of the outside temperature of the circuit board and the estimation of the internal combustion engine body temperature in the electronic circuit device according to the third embodiment.
This is a case where the ECU main body 121 is installed in an environment where the ambient temperature is directly affected by the flowing air when the vehicle travels. Constants for estimation, for example, constant U and constant α are stored in the nonvolatile memory, and other necessary information is input when the vehicle is turned on.

The estimated temperature Ta outside the circuit board according to the third embodiment is calculated from the input values from the first temperature sensor 129 and the second temperature sensor 130 and the coefficient h using the vehicle speed V as a parameter. Using the result, the temperature _TENG of the internal combustion engine main body can be estimated.

  That is, in FIG. 6, when calculating the estimated temperature Ta outside the circuit board (step S4), in addition to the temperature from the first temperature sensor 129 and the second temperature sensor 130, a coefficient using the vehicle speed V as a parameter. The point of calculation using h (step S9) is different from the flowchart of FIG.

That is, when the vehicle speed V is higher than the threshold value, it can be expressed by the approximate expression shown in the following expression (4). That is, the microcomputer 123 can calculate the estimated temperature Ta (K) outside the circuit board using Expression (4).
h = αV ^0.8 ... Formula (4)
Here, α is a proportional constant, and V is the vehicle speed. The vehicle speed V is input from, for example, a vehicle speed sensor (not shown). Since the vehicle is originally provided with means for obtaining speed information, it can be used.

Conventionally, a temperature sensor is attached to an internal combustion engine body, and combustion conditions (for example, throttle opening adjustment for setting an air flow rate) are controlled in accordance with the temperature state of the internal combustion engine body.
In each of the above-described embodiments, the temperature of the internal combustion engine body can be estimated, and a dedicated temperature sensor for measuring the outside air temperature and wiring thereof can be eliminated. Can be eliminated, and further, it is possible to eliminate the processing of the internal combustion engine body accompanying the sensor mounting and the wiring. Therefore, an electronic circuit device system can be realized at a lower cost.

  Each of the above embodiments is not limited to the specific details described and described above and to the representative embodiments. Modifications and effects that can be easily derived by those skilled in the art are also included in the invention. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the claims and their equivalents.

  In the above-described embodiment, the power source 122 provided in the ECU main body 121 has been described in the calculation of the estimated temperature outside the circuit board. However, the present invention is not limited to this, and heat generation that shows a steady and stable temperature. Any body is acceptable. For example, the microcomputer 123 or the A / D converter is more preferable than the power device 127 or the like that has a large operation fluctuation during operation.

  In the above embodiment, the ECU is exemplified as the electronic circuit device. However, the electronic circuit device is not limited to this. For example, a hybrid control unit (HCU), an electronic control unit (ECU), a motor control unit is used. When a control unit such as an (MCU) or a transmission control unit (TCU) is provided and a part or all of the control units are separately provided, the same effect can be obtained in a circuit board applied to any control unit.

  In the above embodiment, the estimated temperature outside the circuit board is used to estimate the temperature of the internal combustion engine body. However, the temperature may be used for controlling an air conditioner or engine cooling, for example.

<Vehicle using electronic circuit device>
Embodiment 4 FIG.
FIG. 7 shows an example in which the electronic circuit device according to the first to third embodiments is applied to a motorcycle. In this case, the internal combustion engine 100 is mounted on the motorcycle 200. The ECU body with two temperature sensors installed in the motorcycle 200 was examined for the difference between the estimated temperature outside the circuit board and the actually measured outside air temperature under different operating conditions in different environments. The vehicle includes an automobile or a two-wheeled vehicle.

  As a result, in the case of this arrangement, it was found that the coefficient h and the U / h by the constant U used in the above equation (1) can be handled as a constant value and the temperature can be estimated. Thereby, the calculation for temperature estimation is simplified, and the load on the microcomputer 123 in the estimation process can be reduced.

Embodiment 5. FIG.
FIG. 8 shows a motorcycle 200 using the electronic circuit device according to the fifth embodiment. The configuration of the electronic circuit device is the same as that of the above-described first and second embodiments, but the ECU main body 121 of FIG. 8 is different from the motorcycle 200 of the first embodiment shown in FIG. Is different. That is, the ECU main body 121 of FIG. 8 is disposed in the front part of the motorcycle 200, and is provided at a site where the ambient temperature is affected by the flowing air when the vehicle travels.

  In this case, since heat transfer from the ECU container side wall 132 shown in FIG. 4 is promoted, the outside air temperature can be estimated by capturing the coefficient h shown in the above equation (1) as a function of the flow velocity. It becomes possible. For example, if the flow is turbulent, the heat transfer from the ECU container side wall 132 is considered to be proportional to the 0.8th power of the speed. Here, α is a proportionality constant.

When the vehicle speed is high, the outside air temperature Ta (K) can be estimated by the approximate expression shown in the above expression (4).
As a result, the ECU body 121 can be easily set in the external region of the circuit board by the inexpensive first temperature sensor 129 and the second temperature sensor 130 provided directly on the ECU board 131 and the vehicle speed without depending on the installation location. Can be estimated.

  As described above, in the present invention, the estimated temperature outside the circuit board obtained by the electronic circuit device can be used, for example, as one of the control signals in the control device of the internal combustion engine of the vehicle. There is no need to arrange a temperature sensor.

DESCRIPTION OF SYMBOLS 100 Internal combustion engine, 101 Intake passage, 102 Air filter, 103 Throttle valve, 104 Intake pressure sensor, 105 Combustion chamber, 106 Bypass flow path, 107 Idle speed control valve, 108 Fuel pump, 109 Fuel tank, 110 Injector, 111 Intake valve , 112 Spark plug, 113 piston, 114 connecting rod, 115 crankshaft, 116 exhaust valve, 117 exhaust passage, 118 crank angle sensor, 119 three-way catalyst, 120 O ₂ sensor, 121 ECU body, 121a ECU housing, 122 power supply, 123 microcomputer, 124 output processing circuit, 125 input processing circuit, 126 A / D conversion circuit, 127 power device, 128 communication IC, 129 first temperature sensor, 130 second temperature sensor, 131 ECU board, 13 2 ECU container side wall, 133 outside air intake, 200 motorcycle.

Claims (14)

A power supply that is mounted on a circuit board on which electronic circuit elements are mounted and supplies power;
A first temperature sensor mounted on the circuit board and detecting a first temperature using the power supplied from the power source;
A second temperature sensor mounted on the circuit board and detecting a second temperature using the power supplied from the power source;
Based on the first temperature and the second temperature, and a calculator for calculating the circuit board outside the estimated temperature in the outer region is an external mounting surface of the front SL circuit board,
The second temperature sensor is substantially on a straight line connecting the first temperature sensor and the external region, and the power source is opposite to the direction from the first temperature sensor to the second temperature sensor. Electronic circuit device mounted on the side . When the first temperature is T1, the second temperature is T2, the constant is U, and the coefficient is h, the estimated temperature Ta (K) outside the circuit board is obtained from the following equation: Ta = T2-U / H (T1-T2)
The electronic circuit device according to claim 1. The electronic apparatus according to claim 2, wherein the constant U includes position information of the first temperature sensor and position information of the second temperature sensor, and the position information is stored in advance in the calculation unit. Circuit device. A signal generator for generating a control signal for the internal combustion engine;
The electronic circuit device according to claim 1, wherein the signal generation unit generates the control signal based on the estimated temperature outside the circuit board estimated by the calculation unit. The electronic circuit device according to claim 4, wherein the power source, the arithmetic unit, and the signal generation unit are arranged on the circuit board separated from the straight line. The electronic circuit device according to claim 1, wherein the first temperature sensor is provided in the vicinity of the power source. The said 1st temperature sensor and the said 2nd temperature sensor are arrange | positioned on the said straight line, and are arrange | positioned between the external area | region of the said circuit board, and the said power supply. The electronic circuit device according to 1. On the circuit board, the first temperature sensor and the second temperature sensor are sealed from the outside air,
The electronic circuit device according to claim 1, wherein the circuit board is exposed in a region between the first temperature sensor and the second temperature sensor on the straight line. The electronic circuit device according to claim 1, wherein an external region of the circuit board is located in a vicinity of an outer periphery of the circuit board. The electronic circuit device according to any one of claims 1 to 9, wherein the electronic circuit device is installed at a site that is not affected by a flow of outside air generated around the vehicle according to a vehicle speed. The calculation unit calculates, as the estimated temperature outside the circuit board, a first estimated temperature outside the circuit board when the internal combustion engine is in an initial state, and a second estimated temperature outside the circuit board after the initial state,
The signal generation unit generates the control signal according to an energy balance of the internal combustion engine based on the first estimated temperature outside the circuit board and the second estimated temperature outside the circuit board, and controls combustion of the internal combustion engine The electronic circuit device according to claim 4. The electronic circuit device according to claim 2, wherein, when the vehicle speed is higher than a threshold value, the calculation unit calculates the estimated temperature Ta (K) outside the circuit board by including the vehicle speed in the coefficient h. An intake passage for supplying outside air from the outside air intake to the internal combustion engine inside the vehicle housing;
A signal generator for generating a control signal for the internal combustion engine;
The electronic circuit device according to any one of claims 1 to 12, wherein the signal generation unit is provided with the estimated temperature outside the circuit board estimated by the arithmetic unit.
The signal generation unit generates the control signal based on the estimated temperature outside the circuit board. The vehicle according to claim 13, wherein an external region of the circuit board of the electronic circuit device is located at the outside air intake.

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