JP2015078612A - Knocking detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a knocking detection device for facilitating to give a function for controlling an ignition timing to an internal combustion engine having no function for controlling an ignition timing to restrict occurrence of knocking.SOLUTION: There are provided a first wiring pattern 46A for electrically connecting an ignition timing calculation circuit 42 with a first common wiring pattern 44A to enable an energization control of an ignition coil to be carried out through an installation of an igniter 48A for performing an energization control on the basis of a correction ignition signal; and a second wiring pattern 46B for electrically connecting the ignition timing calculation circuit 42 with the first common wiring pattern 44A to enable ON/OFF signal generated by a switching element to be outputted to an external electronic control device through an installation of a switching element 48B controlled for ON/OFF on the basis of a correction ignition signal. Any one of the igniter 48A and the switching element 48B is installed on a circuit board to cause any one of the first wiring pattern 46A and the second wiring pattern 46B to be selectively connected.

Description

  The present invention relates to a knocking detection device that controls ignition timing according to the knocking state of an internal combustion engine (engine), for example, a general-purpose engine used for a small ship, a small generator, a lawn mower, etc. The present invention relates to a knocking detection device that can be applied to an engine or the like used in a construction machine.

  2. Description of the Related Art Conventionally, as a control technique for preventing engine knocking and suitably operating the engine, a technique for controlling ignition timing based on the output of a knocking sensor attached to the engine (ignition timing control) is known (Patent Document). 1).

  Generally, in the ignition timing control, when knocking is not detected by the knocking sensor, the ignition timing is advanced step by step, and when knocking is detected, the ignition timing is retarded. Yes. By performing this control, engine output can be maximized while preventing knocking.

  The above-described ignition timing control is generally performed in an engine mounted on a four-wheeled vehicle. However, in the present situation, for example, a general-purpose engine used for a small generator or an engine having a simple structure represented by an engine mounted on a two-wheeled vehicle does not perform the above ignition timing control.

  That is, when the engine structure is simplified, an electronic control device that performs engine control such as rotational speed control is used because it is highly necessary, but a device that is not so necessary, for example, a knocking sensor is not used. Therefore, ignition timing control that requires the output of a knocking sensor is often not applied to an engine with a simple structure.

JP 2008-215141 A

  In recent years, even for simple engines such as general-purpose engines and motorcycle engines, precise ignition control has begun to be demanded in order to improve fuel efficiency and optimize output. In order to meet this demand, it is conceivable that a knocking sensor is mounted on an engine having a simple structure and the above ignition timing control is performed.

  However, when ignition timing control is performed by attaching a knocking sensor to an engine with a simple structure, it is necessary to review various designs for performing ignition timing control, and labor (man-hours) for adapting to ignition timing control is required. And the cost becomes enormous. There has been a problem that this increase in labor and cost becomes an obstacle when responding to the above request.

  For example, there are the following two methods for controlling the ignition timing by attaching a knocking sensor to an engine having a simple structure. The first method is to provide an external electronic control circuit that corrects the ignition signal output from the electronic control device based on the output of the knocking sensor and controls the ignition of the engine itself. In this case, the electronic control unit originally provided in the engine outputs an ignition signal, but does not control ignition.

  The second method is a method of providing an external electronic control circuit that outputs a correction signal obtained by correcting the ignition signal output from the electronic control device based on the output of the knocking sensor to the electronic control device. In this case, the electronic control unit originally provided in the engine outputs an ignition signal and also controls ignition based on the correction signal.

  Since the first method and the second method have different advantages and disadvantages, it is difficult to adopt only one of them, and either method is selected in consideration of various circumstances. . As a result, it is necessary to prepare the above-described external electronic control circuit corresponding to the first method and the second method. Then, compared with the case where only one of the methods is adopted, there is a problem that the cost required for manufacturing and management further increases.

  The present invention has been made to solve the above-described problem, and can easily provide an ignition timing control function to an internal combustion engine that does not have an ignition timing control function for suppressing the occurrence of knocking. An object of the present invention is to provide a knocking detection device that can be used.

  A knocking detection device for solving the problems of the present invention is obtained from a knocking sensor for detecting knocking of an internal combustion engine, a knocking signal indicating the knocking state obtained from the knocking sensor, and an external electronic control device. And a circuit board on which an ignition timing arithmetic circuit for calculating a corrected ignition signal is mounted based on a signal related to the ignition timing of the internal combustion engine.

  Since the knocking detection device of the present invention includes the knocking sensor and the circuit board, it is possible to give an ignition timing control function to an internal combustion engine that does not have an ignition timing control function. Since the circuit board is equipped with an ignition timing calculation circuit, the knocking detection device calculates the ignition timing based on a knocking signal input from the knocking sensor and a signal related to the ignition timing input from an external electronic control device. It is possible to obtain a corrected ignition signal that is adjusted to an appropriate timing (for example, adjusting an advance angle or a retard angle). By controlling the ignition based on the corrected ignition signal, the internal combustion engine can be ignited at an optimal ignition timing.

  By the way, it is thought that the following two needs exist mainly in the knocking detection apparatus of this invention. First, there is a first need to provide the knock detection device of the present invention with an igniter to perform ignition control of the internal combustion engine. In addition, since ignition control is performed on the electronic control device side of the internal combustion engine, there is a second need not to provide the knock detection device of the present invention with an igniter. If two kinds of circuit boards having different wiring patterns are prepared to meet these needs, the manufacturing cost of the knocking detection device of the present invention may increase, and the versatility may be lost.

  In view of the above viewpoint, in the knocking detection device of the present invention, the circuit board is further provided with an igniter that performs energization control based on the corrected ignition signal, so that the ignition timing calculation circuit and the circuit board are mounted on the circuit board. A first wiring pattern that is electrically connected to the formed first common wiring pattern to enable energization control of an external ignition coil, and a switching element that is on / off controlled based on the corrected ignition signal The ignition timing calculation circuit and the first common wiring pattern are electrically connected to each other, and an on / off signal generated when the switching element is turned on / off is transmitted to the external electronic control device. A second wiring pattern that enables output, and by mounting either the igniter or the switching element on the circuit board, Against serial first common wiring pattern, it is adopted to selectively connect one of the first wiring pattern and the second wiring pattern.

  As described above, by providing the first common wiring pattern, the first wiring pattern, and the second wiring pattern on the circuit board, it is possible to meet the first and second needs described above with one type of circuit board. it can. That is, in order to meet the first need, the first common wiring pattern and the first wiring pattern are electrically connected by mounting the igniter on the circuit board. Thereby, ignition control of the internal combustion engine using the igniter mounted on the circuit board can be performed. When responding to the second need, the first common wiring pattern and the second wiring pattern are electrically connected by mounting the switching element on the circuit board. Thus, the electronic control device of the internal combustion engine can perform ignition control using the corrected ignition signal output from the circuit board.

  In the above invention, it is preferable that the circuit board has a ground potential portion, and the igniter or the switching element is connected to the ground potential portion via a second common wiring pattern formed on the circuit board. .

  In this way, by connecting the igniter or the switching element to the ground potential portion via the second common wiring pattern, it is possible to respond to the above first and second needs with one type of circuit board. it can. In other words, it is not necessary to separately provide a circuit board on which the igniter is mounted and a circuit board on which the switching element is mounted, and the igniter or the switching element can be mounted on the same circuit board.

  According to the knocking detection device of the present invention, the first common wiring pattern, the first wiring pattern, and the second wiring pattern are provided on the circuit board, whereby the knocking detection device is provided with the igniter on one type of circuit board. It is possible to meet the need for performing ignition control and the need for not providing an igniter in the knocking detection device. Therefore, there is an effect that the function of ignition timing control can be easily given to the internal combustion engine that does not have the function of ignition timing control for suppressing the occurrence of knocking.

It is explanatory drawing which shows the system configuration | structure of the internal combustion engine in which the ignition timing control apparatus by this invention is used. (A) is a plan view showing a partially broken ignition timing control device of Example 1, and (b) is a front view showing a partially broken ignition timing control device. It is a schematic diagram explaining the 1st common wiring pattern, the 1st wiring pattern, the 2nd wiring pattern, and the 2nd common wiring pattern which were provided in the ignition timing adjustment apparatus. It is a figure explaining the structure in the case of mounting an igniter in an ignition timing adjusting device. It is a figure explaining the relationship between a reference | standard ignition signal, a correction | amendment ignition signal, and the voltage of a center electrode. It is a graph explaining the state of adjustment by the advance angle or retard angle of the ignition timing. It is a flowchart explaining a correction ignition timing calculation process. It is a flowchart explaining a knocking detection process. It is a figure explaining the structure in the case of mounting a switching element in an ignition timing adjusting device.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The ignition timing control device 31 (knock detection device) according to the present embodiment is used for various engines (internal combustion engine 1) such as a general-purpose engine and a two-wheeled vehicle engine, and prevents knocking of the internal combustion engine 1. Therefore, it is a device for controlling the ignition timing. In the following description, a four-cycle engine for a two-wheeled vehicle will be described as an example.

First, the whole internal combustion engine 1 provided with the ignition timing control device 31 of the present embodiment will be described.
As shown in FIG. 1, an internal combustion engine 1 includes an engine body 3, an intake pipe 5 for introducing air into the engine body 3, an air flow meter 7 for detecting the intake air amount, and a throttle valve 9 for adjusting the intake air amount. A throttle opening sensor 11 for detecting the opening of the throttle valve 9, an intake manifold 15 for introducing air into the combustion chamber 13, a fuel injection valve 17 for injecting fuel into the intake manifold 15, and an engine body 3 An exhaust manifold 19 for discharging air (after combustion) from the exhaust, an air-fuel ratio sensor (or oxygen sensor) 21 for detecting an air-fuel ratio from the exhaust discharged from the exhaust manifold 19, and the like.

  A spark plug 25 is attached to the cylinder head 23 of the engine body 3. The engine body 3 has an engine speed sensor 27 for detecting the engine speed (rotation speed) and a crank angle sensor for detecting the crank angle. 29 is attached.

  Further, an ignition timing control device 31 described later is attached to the engine body 3. An ignition coil 35 is connected to the ignition timing control device 31, and the ignition coil 35 is connected to the spark plug 25.

  The internal combustion engine 1 includes an internal combustion engine control device (external electronic control) that comprehensively controls the operating state of the engine body 3 and the like (for example, air-fuel ratio feedback control based on the engine speed and the output of the air-fuel ratio sensor 21). Control device) 37 is provided. The internal combustion engine control device 37 is an electronic control device (ECU) including a microcomputer having a well-known RAM, ROM, CPU and the like, although not shown. Hereinafter, a system including the ignition timing control device 31 and the internal combustion engine control device 37 is referred to as an ignition timing control system 38.

  An air flow meter 7, a throttle opening sensor 11, an air-fuel ratio sensor 21, an engine speed sensor 27, a crank angle sensor 29, and an ignition timing control device 31 are connected to an input port (not shown) of the internal combustion engine control device 37. The signals (sensor signals, etc.) from these devices are input to the input port.

  On the other hand, the fuel injection valve 17 and the ignition timing control device 31 are connected to an output port (not shown) of the control device 37 for the internal combustion engine. A control signal for controlling the operation of each device is output.

  Next, the ignition timing control device 31 of this embodiment will be described. As shown in FIG. 2, in the ignition timing control device 31 of the present embodiment, the knocking sensor 41 and the ignition timing adjustment device 43 (circuit board) cannot be electrically and mechanically separated via the connection cable 45. It is comprised integrally.

  The knocking sensor 41 is a non-resonant type knocking sensor using a known piezoelectric element 65, and has a structure in which a mounting bolt (not shown) is inserted into the shaft hole 47 a of the metal shell 47. It is fixed to a cylinder block 49 (see FIG. 1) of the engine body 3.

  Specifically, the knocking sensor 41 is almost entirely molded by a resin molded body 51, and includes a substantially cylindrical main body portion 53 and a substantially rectangular parallelepiped connector portion 55 protruding from the side surface of the main body portion 53.

  Among these, the main body 53 includes a metal shell 47 including a cylindrical tubular portion 57 and an annular flange portion 59 provided on one end side (downward in FIG. 2B). The cylindrical portion 57 includes, from the flange portion 59 side, an annular first insulating plate 61, an annular first electrode plate 63, an annular piezoelectric element 65, an annular second electrode plate 67, and an annular second insulating plate 69. An annular weight 71, an annular disc spring 73, and an annular nut 75 are arranged. Also, a first output terminal 81 and a second output terminal 83 for taking out an output signal generated between the electrode plates 63 and 67 are connected to the first electrode plate 63 and the second electrode plate 67, respectively. ing.

  The ignition timing adjusting device 43 is a control device that adjusts the ignition timing. Like the internal combustion engine control device 37, the ignition timing adjustment device 43 is an electronic control device that includes a microcomputer (not shown) having a known RAM, ROM, CPU, and the like. is there. The CPU also functions as an ignition timing calculation circuit 42 described later (see FIG. 3 and the like).

  Further, the ignition timing adjusting device 43 includes a first common wiring pattern 44A, a first wiring pattern 46A, a second wiring pattern 46B, a second common wiring pattern 44B, as shown in FIG. Is provided. The first common wiring pattern 44A, the first wiring pattern 46A, the second wiring pattern 46B, and the second common wiring pattern 44B are wirings formed on a wiring board that constitutes the ignition timing adjusting device 43. It is formed from the well-known material which forms.

  The first common wiring pattern 44A enables energization control of the ignition coil 35 via the igniter 48A when the igniter 48A is mounted, and the switching element 48B when the switching element 48B is mounted. This wiring enables the on / off signal generated in accordance with the on / off control of 48B to be output to the control device 37 for the internal combustion engine.

  The first common wiring pattern 44A is provided with a branch wiring connected to the igniter 48A branched from the common wiring portion and a branch wiring connected to the switching element 48B. In the first common wiring pattern 44A, as shown in FIG. 3B, an igniter 48A for performing energization control based on the corrected ignition signal mounted in the ignition timing adjusting device 43 can be mounted so as to be electrically connectable. As shown in FIG. 3C, a switching element 48B that is on / off controlled based on a corrected ignition signal mounted on the ignition timing adjusting device 43 can be mounted so as to be electrically connectable.

As shown in FIG. 3B, the first wiring pattern 46 </ b> A electrically connects an igniter 48 </ b> A that performs energization control based on a corrected ignition signal mounted on the ignition timing adjusting device 43 and the lead wire 105. As shown in FIG. 3C, the second wiring pattern 46B, which is a wiring, includes a switching element 48B that is on / off controlled based on a corrected ignition signal mounted on the ignition timing adjusting device 43, a lead wire 99, Is a wiring for electrically connecting the two.

  The second common wiring pattern 44 </ b> B is a wiring that electrically connects the igniter 48 </ b> A or the switching element 48 </ b> B mounted on the ignition timing adjusting device 43 and the ground potential portion 44 </ b> C provided on the ignition timing adjusting device 43.

  The second common wiring pattern 44B is provided with a branch wiring connected to the igniter 48A branched from the common wiring portion extending from the ground potential portion 44C and a branch wiring connected to the switching element 48B. As shown in FIG. 3B, an igniter 48A can be mounted on the second common wiring pattern 44B so as to be electrically connectable, and as shown in FIG. 3C, it can be electrically connected to the switching element 48B. Can be installed.

  As shown in FIGS. 2 (a) and 2 (b), the connection cable 45 is provided with respective electrical wirings (not shown) connected to the first output terminal 81 and the second output terminal 83 therein. A first connector 85 and a second connector 87 connected to both electrical wirings are provided at both ends of the connection cable 45.

  That is, the first connector 85 is fitted into the opening 55 a of the connector portion 55 of the knocking sensor 41, and each electrical wiring is connected to the first and second output terminals 81 and 83. The second connector 87 is fitted into the concave connector portion 89 of the ignition timing adjusting device 43, and each electrical wiring is connected to an internal wiring (not shown) in the ignition timing adjusting device 43.

  In particular, in the present embodiment, the first connector 85 of the connection cable 45 is fitted into the connector portion 55 of the knocking sensor 41 and is fixed by an adhesive or the like and is integrally configured so as not to be separated. Similarly, the second connector 87 of the connection cable 45 is fitted into the connector portion 89 of the ignition timing adjusting device 43 and is integrally formed so as not to be separated by being fixed by an adhesive or the like.

  Next, an electrical configuration and the like related to the ignition timing control device 31 when the igniter 48A is mounted on the ignition timing adjusting device 43 will be described. FIG. 4A is a schematic diagram for explaining an electrical configuration when the igniter 48A is mounted on the ignition timing adjusting device 43, and FIG. 4B schematically shows an electric circuit.

  As shown in FIG. 4A, power is supplied from the battery 91 to the ignition timing adjusting device 43 of the ignition timing control device 31. The ignition timing adjusting device 43 is detachably connected to the internal combustion engine control device 37 via a pair of lead wires (signal lines) 97 and 99. The lead wires 97 and 99 are detachable from both the ignition timing adjusting device 43 and the internal combustion engine control device 37.

  The ignition timing adjusting device 43 receives an ignition signal (A), which will be described later, from the internal combustion engine control device 37, and the ignition timing adjusting device 43 will not be described in detail with respect to the internal combustion engine control device 37. A signal indicating failure (abnormality) of the knocking sensor 41 or the ignition timing adjusting device 43 is output. Further, the ignition timing adjusting device 43 is connected to the ignition coil 35 via one lead wire 105.

  Specifically, as shown in FIG. 4B, the ignition coil 35 includes a primary winding 35a and a secondary winding 35b, and the positive electrode of the battery 91 is connected to one end of the primary winding 35a. The other end is connected to the collector of an igniter 48A which is an npn type power transistor. The igniter 48A is a switching element that switches energization / non-energization to the primary winding 35a. The emitter of the igniter 48A is connected to a ground potential portion 44C having the same potential as the negative electrode of the battery 91, as shown in FIG.

  On the other hand, one end of the secondary winding 35 b is connected to the negative electrode of the battery 91, and the other end is connected to the center electrode 25 a of the spark plug 25. The ground electrode 25 b of the spark plug 25 is grounded to the ground having the same potential as the negative electrode of the battery 91.

  In this embodiment, the control device 37 for the internal combustion engine and the ignition timing adjusting device 43 are connected, and an ignition signal (B) is sent from the ignition timing calculating circuit 42 of the ignition timing adjusting device 43 to the base of the igniter 48A. Is output, and the igniter 48A performs a switching operation based on the ignition signal (B), and the energization / non-energization of the primary winding 35a of the ignition coil 35 is switched.

  Next, the basic operation of the ignition timing control using the ignition timing control device 31 shown in FIG. 4 will be described. The internal combustion engine control device 37 determines a reference ignition timing as a reference for the ignition timing based on, for example, the engine speed and the intake air amount. The reference ignition timing is an ignition timing that is set with a sufficient margin so that the internal combustion engine 1 is not damaged even in consideration of variations among the internal combustion engines 1 and climate changes. A plurality of maps set for each state are used, and the ignition timing as a base set by associating (collating) this map with the current operating state (that is, the target to be adjusted by the ignition timing adjusting device 43) Ignition timing).

  The signal indicating the reference ignition timing is a reference ignition signal (that is, ignition signal (A): see FIG. 5A) as a signal related to the ignition timing. The reference ignition signal (A) is output to the ignition timing adjusting device 43.

  The ignition timing calculation circuit 42 of the ignition timing adjustment device 43 that receives the reference ignition signal (A) receives a signal (knocking signal) from the knocking sensor 41 and generates knocking (knock) based on the knocking signal. The presence or absence of is detected. For example, the presence or absence of knocking is determined based on the magnitude of the peak value of the knocking signal.

  Then, the ignition timing calculation circuit 42 adjusts (corrects) the ignition timing in accordance with the knocking occurrence state and the like to determine the corrected ignition timing. A signal indicating the corrected ignition timing is a corrected ignition signal (that is, ignition signal (B): see FIG. 5B).

  Specifically, as shown in FIG. 6, when knocking does not occur, the ignition timing is gradually advanced until reaching the maximum advance angle every predetermined period, and when knocking occurs, the reference ignition timing is reached. The corrected ignition timing is set so that it returns. As shown in FIG. 5, the process for correcting the ignition timing is not performed when the fluctuation of the engine speed is large, such as during the operation transition period such as when the engine is started or during acceleration.

  Next, when the corrected ignition timing is determined as described above, the corrected ignition signal (B) is output from the ignition timing calculation circuit 42 to the igniter 48A as shown in FIG. 4B. When the corrected ignition signal (B) is given to the base of the power transistor that is the igniter 48A, the igniter 48A performs a switching operation in accordance with the on / off of the corrected ignition signal (B).

  Specifically, when the corrected ignition signal (B) is off (low level: generally ground potential), the base current does not flow and the igniter 48A is turned off (shut off), and a current (primary current) flows through the primary winding 35a. i1) never flows. When the corrected ignition signal (B) is on (high level: a state where a positive voltage is supplied from the ignition timing adjusting device 43), the base current flows and the igniter 48A is on (energized state). Thus, a current (primary current i1) flows through the primary winding 35a. By energizing the primary winding 35a, magnetic flux energy is accumulated in the ignition coil 35.

  Further, when the corrected ignition signal (B) becomes low level while the corrected ignition signal (B) is at high level and the primary current i1 flows through the primary winding 35a, the igniter 48A is turned off, and the primary winding The energization of the primary current i1 to 35a is cut off (stopped). Then, the magnetic flux density in the ignition coil 35 changes abruptly to generate an ignition voltage in the secondary winding 35b, which is applied to the ignition plug 25, whereby the center electrode 25a and the ground electrode 25b of the ignition plug 25 are applied. Spark discharge occurs between (see FIG. 5C). At this time, the current flowing through the secondary winding 35b is the secondary current i2.

  Note that the reference ignition signal (A) and the corrected ignition signal (B) described above include information about the timing when the low level changes to the high level and the timing when the high level changes to the low level. Among these, the timing from the high level to the low level is a desired ignition timing (ignition timing). In addition, a predetermined period is set in the high level period so that necessary magnetic flux energy is accumulated.

  Next, a corrected ignition timing calculation process performed by the ignition timing calculation circuit 42 of the ignition timing adjustment device 43 will be described. This process is a process for calculating the corrected ignition timing based on the reference ignition signal (A) and calculating the engine speed using the reference ignition signal (A).

  As shown in the flowchart of FIG. 7, in step (S) 100, the timer storage variable N is reset (set to 0). In the following step 110, the rotation speed storage / knock window (Window) variable S is reset. The rotational speed storage / knock window variable S is a variable indicating a time series when the engine rotational speed is sequentially stored in step 240, and a value of a crank angle window for detecting knocking in step 250. It is a variable indicating the time series when stored sequentially.

  In the following step 120, the initial value T (0) of the timer T is set to zero. In the following step 130, the initial value KNW (0) of the knock detection window KNW is set to zero. The knock detection window KNW indicates a region where knocking may occur (a predetermined rotation angle), corresponds to a specific period set with the ignition timing as a starting point, and analyzes the knocking signal. It corresponds to a section.

  In the following step 140, based on the reference ignition signal (A) received from the internal combustion engine controller 37, the reference ignition timing (input ignition timing) TIGIN is set as the corrected ignition timing TIG. Here, the value of the corrected ignition timing TIG is a value that has not been corrected yet.

  In the following step 150, the ignition signal interval measurement timer T1 is reset. In the following step 160, it is determined whether or not the reference ignition signal (A) is input. If an affirmative determination is made here, the process proceeds to step 170, while if a negative determination is made, the process waits.

  In step 170, an ignition signal interval measurement timer T1 is started in order to measure the time from the input of the reference ignition signal (A). In the subsequent step 180, it is determined whether or not the reference ignition signal (A) is input again. If a positive determination is made here, the process proceeds to step 190, and if a negative determination is made, the process waits.

  In step 190, since the reference ignition signal (A) is input, the timer storage variable N is counted up. In the following step 200, the time when the reference ignition signal (A) is input this time (Nth time) is stored as a timer T (N). That is, the count value of the ignition signal interval measurement timer T1 is stored as the value of the timer T (N).

  In the subsequent step 210, the time (T (N)) when the reference ignition signal (A) is input this time (Nth), and the time (T (N-1) when the reference ignition signal (A) is input last time (N-1). N−1)) and a difference ΔT (N) is obtained. That is, the time between successive reference ignition signals (A) is obtained.

  In the following step 220, the engine speed (rpm) is calculated by the calculation of “2 rotations × 60 sec / ΔT (N)” (in the case of 1 ignition / 2 rotations in a 4-cycle engine). In the following step 230, the rotational speed storage / knock window variable S is counted up.

  In the following step 240, the engine speed obtained in step 220, that is, the engine speed corresponding to the rotational speed storage / knock window variable S is stored (stored) as RPN (S). In the following step 250, the knock detection window KNW (S) is calculated. That is, calculation of the knock detection window KNW (S) corresponding to the rotational speed storage / knock window variable S is performed by a known calculation method, and the value is stored.

  In the next step 260, it is determined whether or not the rotational speed storage / knock window variable S exceeds 2. If an affirmative determination is made here, the process proceeds to step 270, whereas if a negative determination is made, the process returns to step 180.

In step 270, knocking detection processing, which will be described later, is performed to detect knocking.
In the subsequent step 280, the engine speed “RPNS (S) / RPNS (S-1)” is calculated, that is, the current (S-th) engine speed RPNS (S) is changed to the previous (S-1) engine. By dividing by the engine speed RPNS (S-1), a deviation (engine speed deviation) ΔRPN of the engine speed indicating the magnitude of the fluctuation of the engine speed is calculated.

  In the subsequent step 290, it is determined whether or not the rotational speed deviation ΔRPN is below a predetermined determination value RPNs. If an affirmative determination is made here, the process proceeds to step 300, whereas if a negative determination is made, the process proceeds to step 310.

  In step 310, since the rotational speed deviation ΔRPN is large and it is not appropriate to advance the ignition timing, the reference ignition timing TIGIN itself is set as the corrected ignition timing TIG, and the routine returns to step 180.

  On the other hand, in step 300, whether or not knocking has occurred is determined based on whether or not a knock detection flag KNS set in a knocking detection process described later is 1. If an affirmative determination is made here, the process proceeds to step 320, while if a negative determination is made, the process proceeds to step 330.

  In step 320, since knocking has occurred, the ignition timing is retarded in order to prevent the occurrence of knocking. Specifically, the reference ignition timing TIGIN itself is set as the corrected ignition timing TIG (see FIG. 6), and the process returns to step 180.

  On the other hand, in step 330, since knocking has not occurred, it is determined whether or not the ignition timing (corrected ignition timing TIG) is the maximum advance angle TIGM. If an affirmative determination is made here, the process proceeds to step 340, while if a negative determination is made, the process proceeds to step 350.

In step 340, since the corrected ignition timing TIG is the maximum advance angle TIGM, the value of the maximum advance angle TIGM is set as the value of the corrected ignition timing TIG, and the process returns to step 180.
On the other hand, in step 350, since the corrected ignition timing TIG is not the maximum advance angle TIGM, the ignition timing is advanced by a predetermined value ΔTIG. Specifically, a predetermined value (corrected advance value) ΔTIG is subtracted from the corrected ignition timing TIG to set it as the current corrected ignition timing TIG, and the process returns to step 180.

The knocking detection process is a process for detecting knocking based on the knocking signal. This process is performed every predetermined period.
As shown in FIG. 8, at step 400, knock detection flag KNS is cleared (set to 0). In the following step 410, it is determined whether or not it is an ignition timing (whether or not the ignition signal is a timing when the ignition signal changes from a high level to a low level). If an affirmative determination is made here, the process proceeds to step 420, whereas if a negative determination is made, the present process is temporarily terminated.

  In step 420, a knock detection window measurement timer is started. In the following step 430, whether or not it is within the period corresponding to the knock detection window KNW calculated in step 250 (in other words, whether or not it is in the knock detection window KNW) is based on the value of the knock window measurement timer. judge. If an affirmative determination is made here, the process proceeds to step 440. If a negative determination is made, the process returns to step 430 and the same processing is repeated.

  In step 440, the knocking signal obtained from the knocking sensor 41 is set to be valid. In the following step 450, whether or not the period corresponding to the knock detection window KNW calculated in step 250 has elapsed (in other words, whether or not the knock detection window KNW is outside) is based on the value of the knock window measurement timer. judge. If an affirmative determination is made here, the process proceeds to step 460. If a negative determination is made, the process returns to step 440 and the same processing is repeated.

  In step 460, the knock measurement timer is reset. In the following step 470, the peak value KninPk of the knocking signal is calculated. In the following step 480, it is determined whether or not the peak value KninPk of the knocking signal exceeds a predetermined determination value Th for determining the presence or absence of knocking, that is, whether or not knocking has occurred. If an affirmative determination is made here, the process proceeds to step 490, whereas if a negative determination is made, the present process is temporarily terminated. In step 490, since knocking has occurred, a knock detection flag KNS indicating that is set (set to 1), and this processing is terminated.

  As described above, in addition to the igniter 48A being mounted on the ignition timing adjusting device 43, the switching element 48B may be mounted. Next, an electrical configuration and the like related to the ignition timing control device 31 when the switching element 48B is mounted on the ignition timing adjusting device 43 will be described. FIG. 9A is a schematic diagram for explaining an electrical configuration when the switching element 48B is mounted on the ignition timing adjusting device 43, and FIG. 9B schematically shows an electric circuit.

  As shown in FIG. 9A, power is supplied from the battery 91 to the ignition timing adjusting device 43 of the ignition timing control device 31. The ignition timing adjusting device 43 is detachably connected to the internal combustion engine control device 37 via a pair of lead wires (signal lines) 97 and 99.

  The ignition timing adjustment device 43 receives the reference ignition signal (A) from the internal combustion engine control device 37 and knocks the ignition timing adjustment device 43 from the ignition timing adjustment device 43 to the internal combustion engine control device 37, although the detailed description is omitted. A signal indicating failure (abnormality) of the sensor 41 or the ignition timing adjusting device 43 is output. Further, the internal combustion engine control device 37 is connected to the ignition coil 35 via a single lead wire 105.

  Specifically, as shown in FIG. 5B, the ignition coil 35 includes a primary winding 35a and a secondary winding 35b, and the positive electrode of the battery 91 is connected to one end of the primary winding 35a. The other end is connected to the collector of an npn-type power transistor 33 mounted on the internal combustion engine controller 37. The power transistor 33 is a switching element that switches between energization and non-energization of the primary winding 35a. The emitter of the power transistor 33 is grounded to the ground potential portion 44C having the same potential as the negative electrode of the battery 91.

  On the other hand, one end of the secondary winding 35 b is connected to the negative electrode of the battery 91, and the other end is connected to the center electrode 25 a of the spark plug 25. The ground electrode 25 b of the spark plug 25 is grounded to the ground having the same potential as the negative electrode of the battery 91.

  Further, here, the internal combustion engine control device 37 and the ignition timing adjustment device 43 are connected, and an ignition signal (B) is transmitted from the ignition timing adjustment device 43 to the base of the power transistor 33 of the internal combustion engine control device 37. Is output, and based on the ignition signal (B), the power transistor 33 performs a switching operation to switch energization / non-energization to the primary winding 35a of the ignition coil 35.

  Next, the basic operation of the ignition timing control using the ignition timing control device 31 shown in FIG. 9 will be described. The description of the same operation as the ignition timing control using the ignition timing control device 31 shown in FIG. 4 is omitted.

  From the determination of the reference ignition timing in the internal combustion engine control device 37 to the determination of the corrected ignition timing in the ignition timing calculation circuit 42 is the same as the ignition timing control using the ignition timing control device 31 shown in FIG. When the corrected ignition timing is determined, a corrected ignition signal (B) is output from the ignition timing calculation circuit 42 to the internal combustion engine controller 37 as shown in FIG. 9B.

  In the internal combustion engine control device 37, the switching operation of the power transistor 33 mounted therein is performed in response to the on / off of the corrected ignition signal (B). Since the operation of the power transistor 33 with respect to the corrected ignition signal (B) is the same as the operation of the igniter 48A with respect to the corrected ignition signal (B), description thereof is omitted. The same applies to the corrected ignition timing calculation process performed by the ignition timing calculation circuit 42, and the description thereof is omitted.

  According to the ignition timing control device 31 configured as described above, since the knocking sensor 41 and the ignition timing adjustment device 43 are provided, the ignition timing control function is provided to the internal combustion engine 1 that does not have the ignition timing control function. Can do. Since the ignition timing adjusting device 43 is equipped with an ignition timing calculation circuit 42, the ignition timing control device 31 has a knocking signal input from the knocking sensor 41 and a reference ignition signal input from the control device 37 for the internal combustion engine ( Based on (A), a corrected ignition signal (B) for adjusting the ignition timing to an appropriate timing (for example, adjusting an advance angle or a retard angle) can be obtained. By controlling the ignition based on the corrected ignition signal (B), the internal combustion engine 1 can be ignited at an optimal ignition timing.

  Furthermore, by providing the first common wiring pattern 44A, the first wiring pattern 46A, and the second wiring pattern 46B on the ignition timing adjusting device 43, the igniter 48A is added to the ignition timing control device 31 by one type of ignition timing adjusting device 43. The first need to provide ignition control of the internal combustion engine 1 and the second need not to provide the ignition timing control device 31 with the igniter 48A can be met. In other words, when the first need is met, the first common wiring pattern 44A and the first wiring pattern 46A are electrically connected by mounting the igniter 48A in the ignition timing adjusting device 43. Thereby, the ignition control of the internal combustion engine 1 using the igniter 48A mounted on the ignition timing adjusting device 43 can be performed. In order to meet the second need, the first common wiring pattern 44A and the second wiring pattern 46B are electrically connected by mounting the switching element 48B in the ignition timing adjusting device 43. Thus, the internal combustion engine control device 37 of the internal combustion engine 1 can perform ignition control using the corrected ignition signal (B) output from the ignition timing adjusting device 43.

  By connecting the igniter 48A or the switching element 48B to the ground potential portion 44C via the second common wiring pattern 44B, the one kind of ignition timing adjusting device 43 can meet the above first and second needs. can do. In other words, it is not necessary to separately provide the ignition timing adjusting device 43 on which the igniter 48A is mounted and the ignition timing adjusting device 43 on which the switching element 48B is mounted, and the igniter 48A or the switching element is provided on the same ignition timing adjusting device 43. 48B can be mounted.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the knocking sensor 41 is not limited to a non-resonant type sensor, and is not limited to that type as long as it can use a resonance type sensor and can detect knocking.

  Further, the method for detecting knocking is not limited to the method for detecting from the peak of the knocking signal, and is not limited to that type as long as knocking can be detected, such as a method using an FFT or an integral value for a known knocking signal.

  Furthermore, the present invention can also be applied to a two-cycle engine. Further, when the operating state of the internal combustion engine is a state in which advance of the ignition timing is prohibited, the knocking signal may not be input to the ignition timing adjusting device 43 because the knocking signal is not used.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 31 ... Ignition timing control apparatus (knocking detection apparatus), 37 ... Control apparatus for internal combustion engines (external electronic control apparatus), 41 ... Knocking sensor, 42 ... Ignition timing arithmetic circuit, 43 ... Ignition timing adjustment apparatus (Circuit board), 44A ... first common wiring pattern, 44B ... second common wiring pattern, 44C ... ground potential part, 46A ... first wiring pattern, 46B ... second wiring pattern, 48A ... igniter, 48B ... switching element

Claims (2)

A knocking sensor for detecting knocking of the internal combustion engine;
Implementation of an ignition timing calculation circuit for calculating a correction ignition signal based on a knocking signal indicating the knocking state obtained from the knocking sensor and a signal relating to the ignition timing of the internal combustion engine obtained from an external electronic control unit A circuit board,
In the circuit board,
By mounting an igniter that controls energization based on the corrected ignition signal, the ignition timing calculation circuit and one first common wiring pattern formed on the circuit board are electrically connected, and an external ignition coil is connected. A first wiring pattern enabling energization control;
By mounting a switching element that is controlled to be turned on / off based on the corrected ignition signal, the ignition timing calculation circuit and the first common wiring pattern are electrically connected, and along with the on / off control of the switching element. A second wiring pattern capable of outputting the generated on / off signal to the external electronic control device, and
By mounting either the igniter or the switching element on the circuit board, either the first wiring pattern or the second wiring pattern is selectively connected to the first common wiring pattern. A knocking detection device characterized by:   The circuit board includes a ground potential part, and the igniter or the switching element is connected to the ground potential part via a second common wiring pattern formed on the circuit board. Item 4. The knocking detection device according to Item 1.

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