JP2012207626A - Engine start control device, and industrial vehicle mounted with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine start control device that can start an engine even when starting the engine under a condition of a low initial voltage of a battery caused by a cold atmosphere or an idling stop (including an autostart), and to provide an industrial vehicle mounted with the same.SOLUTION: The engine start control device 3 is mounted on a device having an engine and used to energize a starter motor 5 with the battery 1 by turning a starter input switch 2 on, driving the starter motor 5 to start the engine. When starting the engine under the condition of a low initial voltage of the battery 1, a voltage of starter input switch 2 generated by turning the starter input switch 2 on is detected, and the starter motor 5 is driven if the detected fed voltage is continued to be lower than a threshold voltage for less than a certain period of time, while the starter motor 5 is not driven if the detected fed voltage is continued to be lower than the threshold voltage for the certain period of time or more.

Description

  The present invention relates to an engine start control device used for starting an engine by energizing a starter motor from a battery by driving a starter input switch to drive the starter motor, and an industry equipped with the same. It relates to vehicles.

  An industrial vehicle or the like that uses an engine as a drive source is provided with an engine starting electric circuit 100 as shown in FIG. As shown in the figure, the engine starting electric circuit 100 is configured by connecting a battery 101, a starter input switch 102, an engine starting control device 103, a starter coil (relay) 104, and a starter motor 105.

  In the case of the key type, the starter input switch 102 is turned on when the ignition key is inserted and twisted by the driver. In the case of the button type, the starter input switch 102 is turned on when the start button is pressed by the driver. ). The engine start control device 103 (more specifically, a CPU provided in the engine start control device 103) detects energization of the starter input switch 102 when the starter input switch 102 is turned on as described above. Recognize by

  As described above, when the engine start control device 103 recognizes that the starter input switch 102 has been turned on, the engine start control device 103 turns on the starter coil (relay) 104 and starts from the battery 101 to the starter motor 105. Start energization. When the starter input switch 102 is continuously turned on, the starter motor 105 is driven to forcibly rotate an engine (not shown) physically connected to the starter motor 105. Along with this forcible rotation, the plug contact in the engine sparks and the engine starts when the fuel explosion starts.

  Here, the detection of the energization of the starter input switch 102 is performed when the energization voltage from the starter input switch 102 to the engine start control device 103 becomes a predetermined value (threshold). Value) or more. This is because when the energization voltage is less than a predetermined value (threshold value), the engine start control device 103 cannot recognize that the starter input switch 102 has been turned on. When the engine start control device 103 cannot recognize that the starter input switch 102 is turned on in this way, the result is the same as when the starter input switch 102 is not physically turned on. Since the starter coil (relay) 104 is not turned on, the starter motor 105 is naturally not driven.

JP-A-2005-351103

  By the way, the starter motor 105 has a characteristic that power consumption is maximized immediately after the start of driving. Therefore, the voltage of the engine starting electric circuit 100 decreases immediately after the start of driving. This is also described in Patent Document 1 (paragraph 0003). For example, as the waveform X1 shown in FIG. 6, this voltage drop first changes suddenly and then gradually increases with the passage of time thereafter.

  This voltage drop may cause a problem particularly when the engine is started in a cold atmosphere (so-called cold crank). That is, it is well known that the initial voltage of the battery 101 (the voltage of the battery 101 itself) is low in a cold atmosphere. However, when the starter input switch 102 is turned on in a state where the initial voltage is low, the waveform shown in FIG. Like X2, the voltage further decreases from the initial low voltage, and the energization voltage to the engine start control device 103 when the starter input switch 102 is turned on becomes lower than the predetermined value (threshold value) L for a short time. Sometimes.

  As described above, while the energization voltage to the engine start control device 103 is lower than the predetermined value (threshold value) L, the engine start control device 103 recognizes that the starter input switch 102 is turned on. No longer. That is, the engine start control device 103 erroneously recognizes that the starter input switch 102 has been disconnected, even though the starter input switch 102 has been physically turned on. Due to this misrecognition, the engine start control device 103 disconnects the starter coil (relay) 104 that has been in the on state immediately after the starter input switch 102 is turned on (in some cases even immediately after the starter input switch 102 is turned on) The starter coil (relay) 104 is not turned on due to misrecognition), and the power from the battery 101 is not supplied to the starter motor 105, so the starter motor 105 does not drive.

  The misrecognition described above is that the initial voltage of the battery 101 increases to such an extent that the energization voltage to the engine start control device 103 due to the starter input switch 102 being turned on does not become lower than a predetermined value (threshold value) L. It will continue to happen unless you do it. For this reason, engine startup may be impossible in a cold atmosphere, which is a serious problem.

  In Patent Document 1, in order to prevent malfunction or error in the vehicle control system, the engine is started from the input / output signals of the engine start control device 103 (described as “controller” in Patent Document 1). The method of invalidating the data for a predetermined period is described (paragraph 0033) except for the input / output signals necessary for the above (for input / output signals for vehicle control systems, meters, auxiliary machines, etc.). That is, in the invention according to Patent Document 1, the input / output signal necessary for starting the engine is not controlled by the engine start control device 103 at all.

  In addition to the cold atmosphere, the decrease in the initial voltage of the battery 101 is caused by the idling stop function that has been adopted in various vehicles from the recent demand for environmental protection (specifically, emission gas reduction). The idling stop function also reduces the initial voltage because it can occur even when the engine is automatically stopped while power is supplied to the electrical system (for example, electrical circuits such as instruments, control devices, and lighting). It is necessary to consider as a cause.

  The decrease in the initial voltage of the battery 101 due to the idling stop function can occur when the engine automatically stops and the time elapses, but an auto start function often provided in industrial vehicles in combination with the idling stop function. It becomes more remarkable by working frequently.

  The auto-start function is a function for automatically starting the engine by detecting that a driver (operator) of an industrial vehicle such as a forklift is sitting on the driver's seat with a sensor provided on the seat. is there.

  In a forklift, etc., the driver (operator) often works away from the driver's seat, such as adjusting the position of the load to be lifted and adjusting the fork width, and repeatedly returns to the driver's seat after the work is completed. If the idling stop function and the auto start function are activated each time, the battery 101 is heavily burdened. In other words, in an industrial vehicle provided with a combination of the idling stop function and the auto start function, the possibility that the initial voltage of the battery 101 will decrease is higher than in other vehicles.

  Accordingly, the present invention provides an engine start control device capable of reliably starting the engine even in a situation where the initial voltage of the battery is lowered due to the above causes (cold atmosphere, idling stop (including auto start)) and an industry equipped with the engine start control device. It is an object to provide a vehicle.

  The engine start control device of the present invention is mounted on a device equipped with an engine, and when the starter input switch is turned on, the starter motor is energized from the battery, and the starter motor is driven to start the engine. In the engine start control device to be used, the battery is in a cold atmosphere or the engine is automatically stopped while the electric system of the device including the engine is energized. When starting the engine in a state where the initial voltage of the battery is low, the energization voltage of the starter input switch due to the starter input switch being turned on is detected, and the value of the detected energization voltage is reduced. If the continuation of the state below the threshold is less than a certain time, the starter motor is driven. , In the case of a predetermined time or more is an engine start control device characterized by not driving the starter motor.

  Moreover, it is preferable that the engine start control device of the present invention recognizes the continuation of the state of being less than the threshold value by continuously detecting the energized voltage a plurality of times at predetermined time intervals.

  The industrial vehicle equipped with the engine start control device of the present invention is used to start the engine by energizing the starter motor from the battery and driving the starter motor by turning on the starter input switch. In an industrial vehicle equipped with an engine start control device, the battery is in a cold atmosphere, or the engine is automatically stopped while the electrical system of the industrial vehicle is energized. When the engine is started in a state where the initial voltage of the battery is lowered, the engine start control device detects the energization voltage of the starter input switch due to the starter input switch being turned on, and the detected When the continuation of the state where the value of the energization voltage is less than the threshold is less than a certain time Serial The starter motor is driven, in the case of more than the predetermined time of industrial vehicle equipped with the engine start control device characterized by not driving the starter motor.

  According to each of the above-described configurations, since the starter motor is driven on condition that the state where the value of the energization voltage detected by the engine start control device is less than the threshold value continues for a certain time or more, When starting the engine in a situation where the voltage has dropped, the starter motor can be driven even if the value of the energization voltage detected by the engine start control device becomes less than the threshold value for a short time due to the voltage drop. it can.

  The present invention relates to an engine start control device in a situation where the initial voltage of the battery has decreased due to either that the battery is in a cold atmosphere or the engine has been automatically stopped while the electrical system is energized. Since the starter motor can be driven even if the value of the energization voltage detected in (2) is less than the threshold value for a short time, the engine can be reliably started even in such a situation.

It is the schematic which shows the structure of the electric circuit for engine starting which concerns on one Embodiment of this invention. It is a block diagram which shows the relationship between an engine starting control apparatus, a starter input switch, a starter coil (relay), and a starter motor among the electric circuits. It is a graph which shows the correlation of each state of the same electric circuit. It is a flowchart at the time of driving a starter motor. It is the schematic which shows the structure of the conventional electric circuit for engine starting. It is a graph which shows the example of the voltage fall at the time of a drive start of a starter motor.

  The present invention will be described below by taking one embodiment.

  The main mounting target of the engine start control device of the present invention is an industrial vehicle. Examples of such industrial vehicles include construction vehicles (bulldozers, power shovels, road rollers, etc.), transport vehicles (forklifts, crane vehicles, etc.), agricultural vehicles (combiners, etc.), but various other vehicles are intended for installation. be able to. In addition to industrial vehicles, the engine start control device of the present invention can be mounted on various devices including an engine, such as a stationary generator.

  The configuration of the engine starting electric circuit 10 of the present embodiment is shown in FIG. The engine start electric circuit 10 is configured by connecting a battery 1, a starter input switch 2, an engine start control device 3, a starter coil (relay) 4, and a starter motor 5.

  The battery 1 supplies DC power to the electrical system of the industrial vehicle, and in particular supplies power to the engine starting electric circuit 10 to drive the starter motor 105. The engine start control device 3 is also supplied with power for input / output processing described later. In the present embodiment, a battery having a voltage of 12V is used.

  The starter input switch 2 is artificially operated by a driver of an industrial vehicle and can be exemplified by a key type and a button type as main methods, but various other methods can be adopted. In the case of the key type, the ignition key is inserted and twisted by the driver. In the case of the button type, the starter input switch 2 is turned on by pressing the start button by the driver. Thus, when the starter input switch 2 is turned on, the circuit in the starter input switch 2 can be energized.

  Normally, while the starter input switch 2 is artificially turned on (when the ignition key is twisted for the key type, or while the start button is pressed for the button type), the starter input switch However, the starter input switch 2 is configured so that the artificial input is performed instantaneously, and then the input state is maintained for a certain period of time even if the driver releases the starter input switch 2. May be.

  The starter coil (relay) 4 is provided to operate energization from the battery 1 to the starter motor 5. The starter motor 5 is driven (rotated) by energization from the battery 1, and the drive shaft of an engine (not shown) physically connected to the rotation shaft of the starter motor 5 is forcibly rotated to Start the engine.

  In this embodiment, the engine start control device 3 is configured as a part of a vehicle control controller (VCM / Vehicle Control Module) mounted on an industrial vehicle. The engine start control device 3 is connected to each of a battery 1, a starter input switch 2, and a starter coil (relay) 4 as shown in the figure. The engine start control device 3 includes a CPU, and can perform input / output processing for the connection destination. In the present embodiment, this CPU has functions of a switch-on signal detection means 31, a detection presence determination means 32, a detection absence determination means 33, and a starter coil control means 34, which will be described later.

  Next, regarding the engine start control device 3, input / output processing for the starter input switch 2 and starter coil (relay) 4 connected to the engine start control device 3 will be described with reference to FIGS. 1 and 2 (block diagrams). The following will be described with reference to FIG.

  When the starter input switch 2 is turned on, a current related to energization of the starter input switch 2 (hereinafter, this current will be referred to as a “starter input switch input signal”) passes from the battery 1 through the starter input switch 2 to the engine. Input to the start control device 3. The switch-on signal detecting means 31 in the engine start control device 3 detects the input of this starter input switch-on signal.

  As described above, when the switch-on signal detecting unit 31 detects the input of the starter input switch-on signal, the starter coil control unit 34 in the engine start control device 3 applies the starter coil (relay) 4 to the starter coil (relay) 4. A current for turning on the coil (relay) 4 (hereinafter, this current is referred to as a “starter coil turning signal”) is output. The starter coil (relay) 4 is turned on by the output of the starter coil turning signal, and the starter motor 5 is energized from the battery 1. Then, the starter motor 5 is driven, and accordingly, the engine is forcibly rotated to start the engine.

  On the other hand, when the starter input switch 2 is disconnected, the starter input switch input signal is not detected by the switch input signal detection means 31, so the starter coil input signal from the starter coil control means 34 to the starter coil (relay) 4. Output also stops. As a result, the starter coil (relay) 4 is disconnected and the drive of the starter motor 5 is stopped.

  Here, as described above, in the situation where the initial voltage of the battery 1 is lowered due to the cold atmosphere and idling stop (including auto start), the engine start control device is controlled from the starter input switch 2 corresponding to the starter input switch input signal. 3 may be lower than a threshold that can be detected by the switch-on signal detecting means 31 of the engine start control device 3. In this case, although the starter input switch 2 is physically turned on, the switch-on signal detecting means 31 does not detect the input of the starter input switch-on signal. That is, the engine start control device 3 may erroneously recognize that the starter input switch 2 is disconnected.

  Therefore, in this embodiment, when the state where the starter input switch input signal is not detected continues for 50 ms (milliseconds), the no-detection determination means 33 in the engine start control device 3 recognizes the disconnection of the starter input switch 2. I am doing so. That is, when the duration of the state where the value of the energized voltage detected by the switch-on signal detection unit 31 is less than the threshold is less than 50 ms, the starter coil control unit 34 holds the output of the starter coil input signal. When the starter motor 5 is driven and the continuation of the same state is 50 ms or longer, the starter coil control means 34 stops the output of the starter coil input signal so that the starter motor 5 is not driven. As a result, even when the starter input switch 2 is physically turned on and the energized voltage drops below the threshold value for a short time, the engine start control device 3 It is possible to suppress erroneous recognition of cutting.

  Even when the starter input switch 2 is disconnected by an artificial operation, the non-detection determining means 33 recognizes the disconnection with a time lag of 50 ms as described above, but this time lag is very short. Since it is time, there is no practical influence such as giving the driver a sense of incongruity.

  Further, in the present embodiment, the time for the no-detection judging means 33 to recognize the disconnection of the starter input switch 2 is set to 50 ms as described above. This voltage is determined assuming a time when the voltage drops as the waveform X2 shown in FIG. However, in the present invention, this time is not limited to 50 ms, and can be set at various times according to the type (capacity, etc.) of the battery 1 or the starter motor 5. This time setting may be performed by rewriting the software in the engine start control device 3, or by providing hardware for setting the time in the engine start control device 3 and adjusting the hardware.

  Further, in the present embodiment, the 50 ms continuous recognition is performed by continuously detecting 5 times every 10 ms.

  In the engine start control device 3 of the present embodiment, a time for the detection determining means 32 in the engine start control device 3 to recognize the continuation of the input of the starter input switch 2 is also set. This time is 30 ms. That is, in the detection presence determination means 32 of the present embodiment, the starter coil control means 34 outputs a starter coil input signal to the starter coil (relay) 4 after the starter input switch input signal has been input for 30 ms. Then, the starter motor 5 is driven to start the engine. With this configuration, the engine start control device 3 causes an error in the starter input switch input signal even though the starter input switch 2 is physically disconnected due to the influence of noise from the outside of the engine start electric circuit 10 or the like. It is possible to suppress the occurrence of malfunction that causes the engine to start. The detection presence determination means 32 of the present embodiment performs the above-described recognition of 30 ms continuation by continuously detecting three times every 10 ms.

  The time settings are summarized in FIG. In the figure, the first stage from the top indicates the input status of the starter input switch 2 (“1” is in the on state, “0” is in the disconnected state). The second stage shows the state of the energization voltage in the engine start control device 3 (the two-dot chain line in the figure indicates the threshold value). The third row shows the input detection status of the starter input switch input signal in the switch input signal detection means 31 of the engine start control device 3 (“1” is detected, “0” is not detected). The fourth level (bottom level) indicates the drive status of the starter motor 5.

  First, simultaneously with the starter input switch 2 being turned on, a starter input switch turning-on signal is detected by the switch-on signal detecting means 31 of the engine start control device 3. When the detection presence determining means 32 determines that the state where the starter input switch input signal is detected continues for 30 ms, the starter coil control means 34 starts driving the starter motor 5. When the drive of the starter motor 5 is started, the energization voltage decreases, and in the illustrated case, becomes less than the threshold value. When this happens, the starter input switch input signal cannot be detected by the switch input signal detection means 31. However, since the voltage drop continues for less than 50 ms, the starter motor continues to drive.

  Thereafter, when the starter input switch 2 is disconnected and the state continues for 50 ms, the starter motor 5 stops. In the stop state, even if an erroneous starter input switch-on signal is detected by the switch-on signal detection unit 31 due to the influence of noise, the continuation of this state is less than 30 ms. Therefore, the starter motor 5 is not driven.

  Finally, together with FIG. 4 which is a flowchart, input / output processing in the engine start control device 3 of the present embodiment will be summarized.

  First, the switch input signal detecting means 31 detects a starter input switch input signal due to the starter input switch 2 being in the input state (step S1). When the starter input switch input signal is detected, it is determined whether the detection presence determination means 32 is detected three times continuously every 10 ms (step S2). When the starter input switch input signal is detected three times continuously every 10 ms, the starter coil control means 34 turns on the starter coil (relay) 4 (step S3) and supplies power from the battery 1 to the starter motor 5. Then, the starter motor 5 is driven (step S4). Then, the engine starts (step S5).

  On the other hand, if the starter input switch input signal is not detected three times every 10 ms in step S2, the process returns to step S1.

  If the starter input switch input signal is not detected in step S1, the non-detection determining means 33 determines whether this non-detection state continues five times every 10 ms (step S6). If it is determined to be continuous, the process is terminated (that is, the starter motor 5 is not driven). On the other hand, if it is determined in step S6 that the non-detection state does not continue five times every 10 ms, the starter coil control means 34 turns on the starter coil (relay) 4 (step S3), and the battery 1 Electric power is supplied to the starter motor 5 to drive the starter motor 5.

  In addition, after the starter motor 5 is driven in step S4, the value of the energization voltage detected by the engine start control device 3 falls below a threshold value, so that the starter motor 5 stops and the engine start fails. Even in the case (step 7), the process returns to step S1 and the series of processes is performed.

  As described above, the present invention has been described with reference to one embodiment. However, the specific configuration of the engine start control device according to the present invention is not limited to the present embodiment and is within the scope not departing from the gist of the present invention. Various modifications are possible.

  For example, power for input / output processing of the engine start control device 3 may be supplied to the engine start control device 3 from a power source other than the battery 1 or a capacitor.

  Further, the engine start control device 3 may not be configured as a part of a vehicle control controller (VCM / Vehicle Control Module) as in the present embodiment, but may be configured independently or as a part of another control device. good.

1 Battery 2 Starter Input Switch 3 Engine Start Control Device 4 Starter Coil (Relay)
5 Starter motor 10 Engine starting electrical circuit

Claims (3)

In the engine start control device used for starting the engine by energizing the starter motor from the battery and driving the starter motor by turning on the starter input switch, which is mounted on a device equipped with an engine.
The initial voltage of the battery is reduced due to either the battery being in a cold atmosphere or the engine automatically shutting down while the electrical system of the device including the engine is energized. When starting the engine in
Detecting the energization voltage of the starter input switch due to the starter input switch being turned on;
The starter motor is driven when the duration of the state where the value of the detected energization voltage is less than a threshold is less than a certain time, and the starter motor is not driven when the continuation is longer than a certain time. Start control device.   2. The engine start control device according to claim 1, wherein the continuation of the state of being less than the threshold value is recognized by continuously detecting the energization voltage a plurality of times at predetermined time intervals. In an industrial vehicle equipped with an engine start control device that is used to start the engine by energizing the starter motor from the battery by driving the starter input switch to drive the starter motor,
In a situation where the initial voltage of the battery has decreased due to either that the battery is in a cold atmosphere or that the engine has been automatically stopped while the electrical system of the industrial vehicle is energized. When starting the engine,
The engine start control device detects the energization voltage of the starter input switch due to the starter input switch being turned on;
The continuation of the state where the value of the detected energization voltage is less than a threshold value is less than a certain time, the starter motor is driven, and if the continuation is longer than a certain time, the starter motor is not driven. Industrial vehicle equipped with an engine start control device.

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