Patent Description:
A unitized ignition coil (hereinafter referred to as "ignition coil unit") is employed in an engine widely used as a power source for a handheld working machine such as a sprayer, a spreader, and a mower. For example, the ignition coil unit including: a generator coil configured to generate an induced voltage in synchronization with the rotation of the engine; an ignition circuit including a primary coil and a secondary coil; and an ignition control circuit configured to supply an ignition voltage to the primary coil at a predetermined ignition timing based on the voltage induced by the generator coil, which are unitized, for example, by resin-molding, has been disclosed in <CIT>.

<CIT> discloses an ignition time controlling system for light duty combustion engines. The system comprises the features of the preamble of claim <NUM> herein.

<CIT> describes a system for analyzing an operation of a hand-held processing device having a processing tool and a drive system for driving the processing tool. The system comprises an optical recording device, which is designed to record a time sequence of images of a machining of a machining piece with the machining tool, a capturing device adapted to capture a time sequence of operating data values of the drive system during the recording of the time sequence of images, and at least one output device, which is designed to output in each case at least one of the recorded images with at least one operating data value of the drive system operating data value time-assigned thereto.

In addition, for example, a time totaling meter configured to calculate a cumulative operating time of an engine and a working machine using an ignition pulse has been proposed in <CIT>.

This time totaling meter can count, store, and display the cumulative time of the engine from the starting of operation, and a user can conduct maintenance and repair of the engine and the working machine based on data of the cumulative time.

The ignition coil unit can obtain the data of the cumulative time for maintenance of the engine and the working machine by installing the above-described time totaling meter. However, it is not possible to specifically know the operating states of the engine and the working machine only by cumulating the operating time, and therefore not possible to conduct a precise evaluation for the maintenance.

Moreover, the knowledge of the operating states of the individual engine and working machine when used allows understanding of the operating characteristics or habits of users. The operating characteristics of the users are different for each of the users, and there is demand to provide proper service to each of the users after understanding the operating characteristics of the individual users.

The present invention is proposed to address the above-described problem. It is therefore an object of the present invention to provide an ignition coil unit capable of conducting precise maintenance of an engine and a working machine with a proper evaluation index, and providing proper service to each of the users after knowing the operating state of the individual engine or working machine and understanding the operating characteristic of the user.

Said object is solved by an ignition coil unit according to claim <NUM>.

According to the present invention, it is possible to conduct precise maintenance of an engine and a working machine with an appropriate evaluation index, and provide proper service to each of the users after knowing the operating state of the individual engine or working machine and understanding the operating characteristic of the user.

The same reference numbers in the different drawings indicate the same functional sections, and therefore repeated description for each of the drawings is omitted.

In <FIG>, an ignition coil unit <NUM> includes an ignition circuit <NUM>, a power generator <NUM>, a controller <NUM> and a sensor <NUM>, which are unitized.

The ignition circuit <NUM> includes a primary coil <NUM>, a secondary coil <NUM>, a capacitor <NUM>, diodes <NUM> and <NUM>, and a thyristor <NUM>. The primary coil <NUM> is supplied with an ignition voltage of electricity stored in the capacitor <NUM>, and a spark plug <NUM> is connected to the secondary coil <NUM>. An induced voltage generated by the generator coil <NUM> of the power generator <NUM> is rectified by the diode <NUM> and stored in the capacitor <NUM>. When the thyristor <NUM> is controlled to be conductive by the controller <NUM>, the capacitor <NUM> discharges to flow a current to the primary coil <NUM>. When the current is flowed to the primary coil <NUM>, a high voltage is induced in the secondary coil <NUM> accordingly, and then a spark is generated by the spark plug <NUM> connected to the secondary coil <NUM>.

The power generator <NUM> includes the above-described generator coil <NUM>, and also includes a waveform shaping circuit <NUM>. The power generator <NUM> accumulates electricity in the capacitor <NUM> with the induced voltage of the generator coil <NUM>. The waveform shaping circuit <NUM> shapes the waveform of the induced voltage of the generator coil <NUM>. The waveform shaping circuit <NUM> shapes the waveform of the induced voltage generated by the generator coil <NUM> as illustrated in <FIG> into two waveforms as illustrated in <FIG>. The waveform shaped by the waveform shaping circuit <NUM> can be treated as a pulse signal having period T as illustrated in <FIG>, which becomes an input signal to the controller <NUM>.

The controller <NUM> controls the ignition timing of the ignition circuit <NUM>, that is, the timing at which the thyristor <NUM> becomes conductive by the input signal from the waveform shaping circuit <NUM> which is generated by the induced voltage of the generator coil <NUM>. For this timing control, the controller <NUM> includes a speed computation part <NUM> and an ignition timing calculation part <NUM>.

The speed computation part <NUM> computes an engine rotational speed or frequency as operating information, based on the input signal from the waveform shaping circuit <NUM>. The input signal can be treated as a pulse signal having the period T as described above, and therefore it is possible to obtain the engine rotational speed by calculating the reciprocal of the period T (<NUM>/T).

The ignition timing calculation part <NUM> calculates and outputs the ignition timing according to the engine rotational speed obtained by the speed computation part <NUM>. The ignition timing is calculated for each rotation of the engine, and a signal to make the thyristor <NUM> conductive is outputted at a predetermined timing.

The sensor <NUM> of the ignition coil unit <NUM> detects load information and inputs the load information to the controller <NUM>. The load information is temperature information and provides knowledge of the load state of the engine with the ignition coil <NUM>, or the working machine equipped with this engine during the operation. Thus, the sensor <NUM> is a temperature sensor used to detect the temperature information. Hereinafter, the temperature sensor is used as the sensor <NUM> and the temperature in the unit is detected as the load information will be described.

The controller <NUM> includes a temperature measurement part <NUM> configured to measure the temperature from a detection signal of the sensor <NUM>. The controller <NUM> also includes a memory <NUM> configured to store the engine rotational speed as the operating information outputted from the speed computation part <NUM> and the temperature in the unit as the load information outputted from the temperature measurement part <NUM> in chronological order by using a time stamp function of the controller <NUM>. Moreover, the controller <NUM> includes a timer <NUM> configured to allow the memory <NUM> to store working time information corresponding to the engine rotational speed as the operating information and the temperature in the unit as the load information described above.

The controller <NUM> includes a matrix determination part <NUM> configured to allow the memory <NUM> to store the working time information corresponding to the engine rotational speed (hereinafter "speed") as the operating information and the temperature in the unit (hereinafter "temperature") as the load information, as matrix data composed of the operating information, the load information, and the time data.

<FIG> illustrates a constitutional example of the matrix data produced by the matrix determination part <NUM>. Here, two axes of the sections of the matrix constituting the matrix data indicate speed (r/min) and temperature (°C), respectively.

The matrix determination part <NUM> determines which of <NUM> sections of the matrix (An, Bn) {(A1, B1), (A1, B2),. , (A1, B5), (A2, B1),. , (A2, B5),. , (A5, B5)} corresponds to the speed and the temperature of the engine during the operation. The timer <NUM> measures the working time of the corresponding section to obtain a cumulation of the working time of each of the sections. Then, the controller <NUM> causes the memory <NUM> to store the obtained cumulative time.

In addition, the controller <NUM> also causes the memory <NUM> to store operating status data. This operating status data includes at least one of the total operating time of the working machine, the maximum value of the operating information such as the engine rotational speed, the maximum value of the load information such as the temperature in the unit, the number of times of trying recoil to start the engine, the number of times of starting (number of start) of the engine, and the number of times the engine rotational speed exceeds a set value. The controller <NUM> updates the operating status data as needed, and causes the memory <NUM> to store the data.

The operation of the controller <NUM> described above will be explained in detail with reference to the flowchart of <FIG>. First, when the waveform of the input signal (pulse signal) generated by a waveform shaping part <NUM> of the power generator <NUM> is inputted (step S01), the controller <NUM> causes the speed computation part <NUM> to compute the engine rotational speed with the period T of the input signal (the time difference from the previous input) (step S02), and determines whether the computed speed exceeds a set value (step S02A). When determining that the computed speed exceeds the set value (step S02A; YES), the controller <NUM> counts up the number of times the computed speed exceeds the set value (step S02B).

Then, the controller <NUM> determines whether to update the maximum speed by comparison between the presently obtained speed and the maximum speed previously obtained (step S03). When determining to update the maximum speed (step S03; YES), the controller <NUM> causes the memory <NUM> to store the presently obtained speed as the maximum speed (step S04). In the step S03 of the comparative determination, when the waveform is inputted the first time, the presently obtained speed is stored as is in the memory <NUM> as the maximum speed.

On the other hand, when determining not to update the maximum speed (step S03; NO) or after the maximum speed is saved in the memory <NUM>, the controller <NUM> causes the ignition timing calculation part <NUM> to calculate the ignition timing with the presently obtained speed (step S05).

In addition, upon receiving the input signal described above, the controller <NUM> causes the temperature measurement part <NUM> to obtain a detection signal from the sensor <NUM> to measure the temperature (step S06). Then, the controller <NUM> determines whether to update the maximum temperature by comparison between the presently obtained temperature and the maximum temperature previously obtained (step S07). When determining to update the maximum temperature (step S07; YES), the controller <NUM> causes the memory <NUM> to store the presently obtained temperature as the maximum temperature (step S09).

On the other hand, when determining not to update the maximum temperature (step S07; NO), the controller <NUM> determines whether to update the minimum temperature by comparison between the presently obtained temperature and the minimum temperature previously obtained (step S08). When determining to update the minimum temperature (step S08; YES), the controller <NUM> causes the memory <NUM> to store the presently obtained temperature as the minimum temperature (step S10). In the step S07 and the step S08 of the comparative determination, when the waveform is inputted the first time, the presently obtained temperature is stored as is in the memory <NUM> as the maximum temperature and the minimum temperature.

After determining to update the maximum temperature and the minimum temperature, the controller <NUM> causes the matrix determination part <NUM> to perform matrix determination, based on the presently obtained speed and temperature (step S11).

In the matrix determination, the controller <NUM> determines which of the preset matrix sections (An, Bn) corresponds to the presently obtained speed and temperature; obtains the timer value from the timer <NUM> having counted the period T of the input signal (step S12); and cumulates the obtained timer value for each of the corresponding matrix sections (step S13). After that, the controller <NUM> outputs an output signal to the ignition circuit <NUM> at the ignition timing obtained in the step S05 to make the thyristor <NUM> of the ignition circuit <NUM> conductive, and performs ignition for each of the input signals (step S14).

The controller <NUM> discriminates the continuity of the input signals to obtain the number of times of trying recoil and the number of times of starting the operating status data, and saves the data in the memory <NUM> as needed (not illustrated in the flowchart of <FIG>). Here, the controller <NUM> determines the starting when the engine continues to be rotated a set number of times at an engine rotational speed equal to or higher than a set value, and counts up the number of times of the starting, and determines the recoil when the input signals continue to be inputted after the controller <NUM> is powered on before the engine is started.

Moreover, the controller <NUM> sums the cumulative time for each of the matrix sections stored as the matrix data to obtain the total operating time as the operating status data.

The controller <NUM> can cause the memory <NUM> to save log data of the speed and the temperature obtained for each of the input signals by adding a step to the flowchart of <FIG>. In this case, for example, the controller <NUM> causes the memory <NUM> to continuously save the log data every several seconds for several minutes, and after a set period of time has elapsed, overwrites the old data to save new log data. By this means, the controller <NUM> can cause the memory <NUM> to save significant log data such as the log data just before the engine stop with a limited memory capacity.

According to this ignition coil unit <NUM>, it is possible to precisely determine the time for maintenance or replacement and diagnose failure by an appropriate evaluation index, by referring to the matrix data and the operating status data stored in the memory <NUM> which is built in the ignition coil unit <NUM>. In addition, it is possible to understand the operation characteristic of the user of the individual engine or working machine, and the status of use of the working machine by analyzing the data stored in the memory <NUM> built in the ignition coil unit <NUM> of the individual engine, and therefore to provide service to each user with the personalized menu for the user. Moreover, the memory function of the ignition coil unit <NUM> essential to the engine is enriched, and therefore it is possible to solve the problems with precise maintenance and so forth at lower cost.

Hereinafter, an example of practical use of this ignition coil unit <NUM> will be specifically described. For example, at the time for maintenance, the user of the working machine brings the working machine to a dealer or store. Then, the ignition coil unit <NUM> is removed from the engine, and the memory <NUM> of the ignition coil unit <NUM> is connected to a diagnostic system. The diagnostic system includes, for example, a display device configured to display the matrix data and the operating status data stored in the memory <NUM>.

In this case, the memory <NUM> has already stored user information such as user ID, and therefore it is possible to refer to or analyze the matrix data and the operating status data retrieved from the memory <NUM> in association with the user information. By employing this diagnostic system, the dealer can provide the individual user with service corresponding to the characteristic of the user.

Understanding the status of use from the matrix data can be used as a material for determining how the user is using the engine. When the matrix data of the engine rotational speed and the temperature indicates that the engine is operated within a predetermined range of rotational speeds and a predetermined range of temperatures, it can be information to understand that the user ideally uses the engine, and, on the other hand, when the matrix data of the engine rotational speed and the temperature indicates that the engine is operated out of the predetermined range of rotational speeds and the predetermined range of temperatures, it can be information to understand that the user does not ideally use the engine.

In addition, in the case of understanding the status of use of the engine by the operating status data, the maximum rotational speed, the number of times the rotational speed exceeds the set value, and the maximum temperature and the minimum temperature in use can be information for the dealer to determine whether the user ideally uses the engine. In particular, in the case of analyzing the cause of a failure, when the number of times of rotation exceeds a value equal to or higher than the set value, it is possible to analyze that the failure is caused by a high rotational speed. In addition, it is possible to analyze that the failure is caused by the temperature, by inspecting from the maximum or minimum temperature in use whether the engine is used under a condition in conformity to the requirement of the service temperature of electronic parts in the ignition coil unit <NUM>. Moreover, in particular, when the engine fails many times, the matrix data and the operating status data presented from the dealer to the user, can be used as information to teach the user about the operation getting close to the ideal use.

In the case of understanding the status of use of the engine by another operating status data, it is possible to evaluate the starting capability of the working machine by the number of times of trying recoil and the number of times of starting. The starting capability of the working machine can be information for the dealer to know the state of the working machine, for example, the deterioration of the working machine. In addition, the starting capability of the working machine has a cause-and-effect relationship with the operating environment, and therefore the dealer can understand the effect of the operating environment on the starting capability of the working machine, by analyzing the correlation of the number of times of trying recoil or the number of times of starting with the matrix data or the maximum temperature and the minimum temperature.

As described above, by employing the ignition coil unit <NUM> according to the embodiment of the invention, it is possible to understand the operating characteristic (operating status) of the user, and the state and the operating environment of the working machine, by the matrix data and the operating status data (total operating time, the maximum temperature in use, the maximum rotation frequency, the number of times of trying recoil, and the number of times of starting). Therefore, the dealer can propose the next time for maintenance to the individual users, based on the operating characteristic of each of the users.

Moreover, the dealer can determine whether the user is a heavy user who frequently uses the working machine or a light user who infrequently uses the working machine, based on the operating status data such as the total operating time. Therefore, when introducing a new product or article to the user, the dealer can provide the product or article corresponding to the status of use of the user, and after that, provide maintenance corresponding to the status of use of the user.

As described above, the ignition coil unit <NUM> according to the embodiment of the invention allows understanding the status of use of the user, the cause of failure, and the state and the operating environment of the working machine, by the matrix data and the operating status data. Therefore, it is possible to provide precise evaluation for the maintenance of the engine and the working machine, and consequently to provide service to the individual users which corresponds to the operating characteristic of each of the users.

Claim 1:
An ignition coil unit (<NUM>) comprising:
an ignition circuit (<NUM>) including a primary coil (<NUM>) and a secondary coil (<NUM>);
a power generator (<NUM>) including a generator coil (<NUM>) ;
a controller (<NUM>) configured to control an ignition timing of the ignition circuit (<NUM>) by an input signal generated by an induced voltage of the generator coil (<NUM>) and to compute an engine rotational speed based on said input signal; and
a temperature sensor (<NUM>) configured to input a temperature in the ignition coil unit (<NUM>) to the controller (<NUM>),
characterized in that the controller (<NUM>) includes a memory (<NUM>) with matrix data stored therein;
wherein the matrix data is a cumulation of the working time information as a function of said engine rotational speed and said temperature in the ignition coil unit (<NUM>) which is obtained for each of the matrix sections;
wherein two axes of the sections of a matrix constituting the matrix data indicate speed (r/min) and temperature (°C), respectively;
wherein the controller (<NUM>) is configured to determine which of the sections of the matrix corresponds to the current engine rotational speed and the current temperature of the engine during an operation;
wherein the controller (<NUM>) is configured to measure a working time of a corresponding section to obtain a cumulation of the working time of each of the sections;
wherein the controller (<NUM>) is configured to cause the memory (<NUM>) to store an obtained cumulative time in the determined section;
wherein the memory (<NUM>) is also configured to store user information;
wherein the controller (<NUM>) is configured to update operating status data as needed and to store it into the memory (<NUM>);
wherein the operating status data includes at least one of the total operating time of the working machine, the maximum value of operating information such as the engine rotational speed, the maximum value of load information such as the temperature in the ignition coil unit, the number of times of trying recoil to start the engine, the number of times of starting of the engine, and the number of times the engine rotational speed exceeds a set value; and
wherein the ignition coil unit is comprising means to connect the memory to a diagnostic system in order to analyse the matrix data and the operating status data in association with the user information.