Engine start control device

Abstract

To provide an engine start control device capable of preventing a starter motor from continuing to operate when an abnormality occurs in an electrification line of a starter relay.SOLUTION: An engine start control device includes: a first control section serving as a starter input detection section that generates a start signal until complete explosion of an engine when detecting a starting operation to a push start switch; and a control section that controls a first connection section and a second connection section on the basis of the start signal to control a starter relay to an on state or off state. When the state of the start signal is in the same state as that of before the complete explosion of the engine even after the complete explosion of the engine, the control section sets the starter relay 22 to the off state.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an engine starting control device.

Background Art

[0002] Patent Document 1 discloses a technique for suppressing accidental engine start when a push-type switch system fails in a control device for starting an engine by push-type switch operation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, unlike the method in which the driver continues to operate the ignition key until the completion of engine start is confirmed, in the method of starting the engine based on a push-type switch operation, when the switch operation is performed, the system needs to energize the starter relay until it is determined that the engine start has been completed. Therefore, it is necessary to consider abnormalities in the energization line of the starter relay.

[0005] Therefore, an object of the present invention is to provide an engine starting control device that can prevent the starter motor from continuously driving when an abnormality occurs in the energization line of the starter relay.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides an engine starting control device comprising: a start switch that accepts a starting operation by a driver; a starter motor that starts the engine; a starter relay that is controlled to supply power to the starter motor in an ON state and to cut off power to the starter motor in an OFF state; a first connection part that energizes or deenerges the upstream side of the starter relay in the energizing line through which the drive current of the starter relay flows; and a second connection part that energizes or deenerges the downstream side of the starter relay in the energizing line. The system comprises a first control unit for controlling the first connection and a second control unit for controlling the second connection, wherein the first control unit, upon detecting the start operation on the start switch, generates a start signal until the engine is fully ignited, transmits the start signal to the second control unit, and the second control unit controls the second connection based on the start signal. The aforementioned First control unit and the second If the state of the starting signal remains the same as before the engine was fully ignited, the control unit will: It was determined to be abnormal, The starter relay is characterized by being in the off state. [Effects of the Invention]

[0007] Thus, according to the present invention, it is possible to provide an engine starting control device that can prevent the starter motor from continuing to operate when an abnormality occurs in the energizing line of the starter relay. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a block diagram of an engine starting control device according to one embodiment of the present invention. [Figure 2] Figure 2 is a timing chart showing the changes in the vehicle state during the execution of the engine start control process of an engine start control device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0009] An engine start control device according to one embodiment of the present invention comprises: a push-start switch that accepts a start operation by a driver; a starter motor that starts the engine; a starter relay that is controlled to supply power to the starter motor in an ON state and to cut off power to the starter motor in an OFF state; a first connection part that energizes or deenerges the upstream side of the starter relay in the energizing line through which the drive current of the starter relay flows; and a second connection part that energizes or deenerges the downstream side of the starter relay in the energizing line. The control device further comprises: a starter input detection unit that generates a start signal until the engine is fully ignited when a start operation is detected on the push-start switch; and a control unit that controls the first connection part and the second connection part based on the start signal to control the starter relay to an ON state or an OFF state. The control unit is characterized in that, even after the engine has fully ignited, if the state of the start signal is the same as before the engine was fully ignited, it sets the starter relay to an OFF state. As a result, the engine starting control device according to one embodiment of the present invention can prevent the starter motor from continuing to operate in the event of an abnormality in the energizing line of the starter relay. [Examples]

[0010] Hereinafter, with reference to the drawings, an engine starting control device according to an embodiment of the present invention will be described in detail.

[0011] In Figure 1, a vehicle 1 equipped with an engine starting control device according to one embodiment of the present invention comprises an engine 2, a transmission 3, a battery 4, and a control unit 30.

[0012] Engine 2 has multiple cylinders. In this embodiment, engine 2 is configured to perform a series of four strokes for each cylinder, consisting of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke.

[0013] Engine 2 is connected to a starter motor 21. The starter motor 21 is connected to the crankshaft of engine 2 via gears (not shown). Power supplied from battery 4 causes the starter motor 21 to rotate, thereby rotating the crankshaft and providing the engine 2 with rotational force for starting. The upstream side of the starter motor 21 is connected to battery 4 via a starter relay 22. The downstream side of the starter motor 21 is connected to ground 33.

[0014] Transmission 3 takes the rotation input from engine 2, changes the gear ratio according to one of several gear stages, and outputs it to the main shaft.

[0015] A clutch (not shown) is provided between the engine 2 and the transmission 3, and the clutch connects or disconnects the power transmission between the engine 2 and the transmission 3.

[0016] Transmission 3 is configured as an AMT (Automated Manual Transmission) in which gear shifting and clutch engagement and disengagement are performed by actuators.

[0017] Battery 4 is made up of, for example, a lead-acid battery. Battery 4 supplies power to the electrical loads of vehicle 1, such as the starter motor 21.

[0018] A starter relay 22 is provided between the battery 4 and the starter motor 21. The starter relay 22 is configured to take on either an ON state, which electrically connects the battery 4 and the starter motor 21, or an OFF state, which electrically disconnects the battery 4 and the starter motor 21.

[0019] The starter relay 22 is turned on when a drive current is supplied. Specifically, the starter relay 22 includes a movable contact 22A, a drive coil 22B, and a power supply line 22C. When a drive current is supplied to the power supply line 22C of the starter relay 22, the movable contact 22A is closed by the magnetic force generated by the drive coil 22B, turning on the relay, and power is supplied to the starter motor 21. On the other hand, when the drive current to the power supply line 22C is cut off, the movable contact 22A opens, turning off the relay, and power to the starter motor 21 is cut off.

[0020] The control unit 30 includes a first control unit 5 and a second control unit 6, and detects and controls the states of each part of the vehicle 1 through the cooperative control of the first control unit 5 and the second control unit 6. The first control unit 5 mainly detects and controls the state of the vehicle body (body). The second control unit 6 mainly detects and controls the state of the transmission 3.

[0021] A first connection part 23 is provided on the upstream side in the direction in which the drive current flows in the power supply line 22C through which the drive current flows. A second connection part 24 is provided on the downstream side in the direction in which the drive current flows in the power supply line 22C through which the drive current flows. The first connection part 23 and the second connection part 24 are composed of semiconductor switches such as transistors.

[0022] The upstream side of the first connection part 23 is connected to the battery 4. Therefore, the first connection part 23 connects or disconnects the battery 4 and the starter relay 22. The downstream side of the second connection part 24 is connected to the ground 33. Therefore, the second connection part 24 connects or disconnects the starter relay 22 and the ground 33.

[0023] The first connection part 23 is provided in the first control unit 5, and is configured to take either an on state (power supply state) in which a drive current is supplied or an off state (non-power supply state) in which a drive current is not supplied according to the control of the first control unit 5.

[0024] The second connection unit 24 is provided in the second control unit 6 and, in accordance with the control of the second control unit 6, takes on either an ON state (energized state) in which drive current is supplied or an OFF state (non-energized state) in which drive current is not supplied.

[0025] When both the first connection part 23 and the second connection part 24 are turned ON, drive current flows to the power line 22C, and the starter relay 22 is turned ON.

[0026] The first control unit 5 and the second control unit 6 are each composed of a computer unit equipped with a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), flash memory for storing backup data, an input port, and an output port.

[0027] The ROM of these computer units stores various constants and maps, along with programs that allow the computer unit to function as the first control unit 5 and the second control unit 6, respectively.

[0028] In other words, the CPU executes a program stored in ROM using RAM as a working area, thereby enabling these computer units to function as the first control unit 5 and the second control unit 6 in this embodiment, respectively.

[0029] The first control unit 5 and the second control unit 6 are connected by a communication line 31 for the in-vehicle LAN (Local Area Network) that conforms to standards such as CAN (Controller Area Network), and can mutually send and receive signals such as control signals.

[0030] Furthermore, the first control unit 5 and the second control unit 6 are connected by a hardwire 32 capable of transmitting a predetermined high-voltage high-level signal and a predetermined low-voltage low-level signal. This hardwire 32 transmits the start signal generated by the first control unit 5 to the second control unit 6. When a start signal is generated, a high-level signal is transmitted as a start signal via the hardwire 32, and when a start signal is not generated, a low-level signal is transmitted via the hardwire 32.

[0031] A push-start switch 7 is connected to the input port of the first control unit 5, which serves as a start switch. The push-start switch 7 is a momentary push-type switch that receives instructions from the driver regarding transitions in the power state of the vehicle 1, as well as starting and stopping the engine 2.

[0032] The push-start switch 7 is in the ON state while it is pressed and outputs an ON signal to the first control unit 5. On the other hand, the push-start switch 7 is in the OFF state when it is not pressed and outputs an OFF signal to the first control unit 5.

[0033] The first control unit 5 controls, for example, the power status of the vehicle 1, the starting and stopping of the engine 2, etc., based on the output signal from the push-start switch 7.

[0034] The second control unit 6 controls, for example, the transmission 3. The second control unit 6 controls, for example, the actuators of the transmission 3 to switch gears and engage and disengage the clutch.

[0035] The second control unit 6 determines whether the engine 2 can be started, for example, based on the state of the transmission 3 or the state of the brake pedal (not shown) operated by the driver.

[0036] The second control unit 6 switches the gear of the transmission 3 according to the position of the shift lever (not shown) operated by the driver.

[0037] The second control unit 6 receives selector position information, which is information about the operating position of the shift lever; gear position information, which is information about the actual gear stage formed in the transmission 3 (so-called actual gear stage); and brake switch information, which is information about whether or not the brake pedal is pressed down.

[0038] In this embodiment, the transmission 3 is not mechanically connected to the shift lever, and employs a shift-by-wire system in which the gear position is changed by an actuator. Therefore, there may be cases where the gear position based on the selector position information does not match the actual gear position based on the gear position information. For example, even if the shift lever is in the neutral position (N position), the actual gear position may not be neutral due to some malfunction.

[0039] In this embodiment, when the first control unit 5 detects that a start operation has been input to the push start switch 7, it determines whether the conditions for starting the engine 2 have been met. The conditions for starting the engine 2 that are determined to be met by the first control unit 5 are called the first starting conditions. The first starting conditions are met when all of several conditions are satisfied, such as the push start switch 7 being pressed and the brake pedal being pressed. The first control unit 5 constitutes a starter input detection unit. If the first starting conditions have been met, the first control unit 5 controls the first connection unit 23 to be in the ON state.

[0040] Furthermore, when the first control unit 5 detects that a start operation has been input to the push-start switch 7, it sends a start request signal to the second control unit 6. This start request signal includes a request for the second control unit 6 to determine whether the conditions for starting the engine 2 have been met. This request is transmitted from the first control unit 5 to the second control unit 6 via the communication line 31 for the in-vehicle LAN (Local Area Network).

[0041] Furthermore, the first control unit 5 generates a start signal when it detects that a start operation has been input to the push start switch 7. The start signal is a latch operation signal that ensures that the starter motor 21 continues to drive until the engine 2 is fully ignited, even after the driver has stopped pressing the push start switch 7. When the first control unit 5 detects a start operation, it generates a signal consisting of a predetermined high voltage as the start signal. The starter motor 21 is started when predetermined start conditions are met in both the first control unit 5 and the second control unit 6.

[0042] The first control unit 5 generates a start signal until it detects that the engine 2 has fully combusted. This start signal is transmitted from the first control unit 5 to the second control unit 6 via a hardwire 32.

[0043] When the second control unit 6 receives a request from the first control unit 5 to determine whether the engine 2 starting conditions are met, it determines whether the engine 2 starting conditions are met. The engine 2 starting conditions that are determined to be met by the second control unit 6 are called the second starting conditions. The second starting conditions are met when all of the following conditions are satisfied: the selector position is in parking or neutral, the brake pedal is depressed, and the actual gear is in neutral. The second control unit 6 determines whether the second starting conditions are met based on selector position information, brake switch information, gear position information, etc. If the second starting conditions are met, the second control unit 6 controls the second connection unit 24 to the ON state.

[0044] In this way, the control unit 30, which has a first control unit 5 and a second control unit 6, controls the first connection unit 23 and the second connection unit 24 based on the start signal to control the starter relay 22 to an ON state or an OFF state. Specifically, when the first start condition is met, the first control unit 5 turns on the first connection unit 23, and when the second start condition is met, the second control unit 6 turns on the second connection unit 24, causing the starter relay 22 to turn ON and the starter motor 21 to drive.

[0045] When the engine speed of the engine 2 reaches a predetermined engine speed threshold, the first control unit 5 determines that the engine 2 has fully ignited, changes the first starting condition to not met, and switches the first connection unit 23 to the off state. As the first connection unit 23 is switched to the off state, the starter relay 22 turns off, and the starter motor 21 stops. Furthermore, when the first control unit 5 determines that the engine 2 has fully ignited, it terminates the generation of the start signal.

[0046] When the first control unit 5 finishes generating the start signal, the second control unit 6 changes the second start condition to not met and switches the second connection unit 24 to the off state.

[0047] In this embodiment, a first connection part 23 and a second connection part 24 are provided on the energizing line 22C of the starter relay 22, and the first connection part 23 and the second connection part 24 are controlled by the first control unit 5 and the second control unit 6, respectively.

[0048] Therefore, abnormalities in the energizing line 22C of the starter relay 22 include abnormalities in the first connection part 23, the second connection part 24, the first control unit 5, and the second control unit 6. Furthermore, abnormalities in the energizing line 22C of the starter relay 22 may include an abnormality in which the first connection part 23 remains in the ON state even after the first starting condition has been changed to not being met (an abnormality in the operation of the first connection part 23 itself), or an abnormality in which the first control unit 5 continues to generate a starting signal even after the engine 2 has fully ignited (an abnormality related to the generation of the starting signal).

[0049] In this embodiment, even if the first connection unit 23 remains ON due to an abnormality after the first starting condition is changed to not being met, the second control unit 6 switches the second connection unit 24 to the OFF state in response to the termination of the starting signal, so that the starter relay 22 turns OFF and the starter motor 21 stops.

[0050] On the other hand, even if the first connection unit 23 operates normally, if the first control unit 5 continues to generate a start signal due to an abnormality after the engine 2 has fully ignited, the starter motor 21 will continue to drive.

[0051] Therefore, in this embodiment, the control unit 30, which has a first control unit 5 and a second control unit 6, turns off the starter relay 22 if the state of the start signal after the engine 2 has fully combusted is the same as before the engine 2 had fully combusted. In other words, it is normal for the start signal to be generated while the engine 2 is starting and to be non-generated after the engine 2 has fully combusted. Contrary to this, if the start signal is still being generated after the engine 2 has fully combusted, the control unit 30 determines that an abnormality has occurred and turns off the starter relay 22 to stop the starter motor 21.

[0052] The control unit 30 turns off the starter relay 22 by de-energizing the second connection part 24. Specifically, the second control unit 6 of the control unit 30 determines that it is abnormal that the start signal is still being generated even after the engine 2 has fully ignited, and the second control unit 6 de-energizes the second connection part 24.

[0053] Furthermore, the control unit 30 may turn off the starter relay 22 by de-energizing the first connection part 23. Specifically, the first control unit 5 of the control unit 30 determines that it is abnormal for the start signal to still be generated even after the engine 2 has fully ignited, and the first control unit 5 de-energizes the first connection part 23.

[0054] The engine start control process by the engine start control device according to this embodiment, configured as described above, will be explained with reference to Figure 2. In Figure 2, the vertical axis represents the success or failure of the first start condition, the success or failure of the second start condition, the state of the first connection part 23, the state of the second connection part 24, the state of the start signal, and the engine speed, while the horizontal axis represents time. Furthermore, the engine start control process when there is no abnormality in the energizing line 22C of the starter relay 22 (hereinafter referred to as "normal case") is represented by a solid line, and the engine start control process when there is an abnormality in the energizing line 22C of the starter relay 22 (hereinafter referred to as "abnormal case") is represented by a dashed line.

[0055] First, let's explain the engine start control process under normal conditions. At time t0, engine 2 is stopped, the first and second start conditions are not met, and the first connection part 23 and the second connection part 24 are in the OFF state (indicated as OFF in the figure).

[0056] At time t0, the push-start switch 7 is pressed as a starting operation, causing the first control unit 5 to raise the start signal to a high level. In other words, a start signal is generated.

[0057] Subsequently, at time t1, the first starting condition is met, and at time t2, the second starting condition is met. Then, at time t3, the first connection unit 23 is turned on, and at time t4, the second connection unit 24 is turned on.

[0058] When both the first connection part 23 and the second connection part 24 are turned on, the starter relay 22 is turned on, the starter motor 21 starts cranking the engine 2, and the engine speed increases.

[0059] Subsequently, at time t5, the engine speed reaches the engine speed threshold and continues to rise. The engine speed threshold is the engine speed threshold at which engine 2 fully ignites and becomes capable of self-sustaining rotation.

[0060] When the engine speed reaches the engine speed threshold, the start signal is set to a low level. In other words, the start signal is not generated. As a result, the first start condition is not met, and the first connection part 23 is turned off. Consequently, the starter relay 22 is turned off, and the starter motor 21 stops.

[0061] Subsequently, at time t6, the second starting condition is not met, the second connection unit 24 is turned off, and the starting signal is set to high level.

[0062] Thus, under normal circumstances, when engine 2 fully ignites, the start signal is set to a low level, which turns off the starter relay 22 and stops the starter motor 21.

[0063] Next, we will explain the engine start control process in the event of an abnormality. In the event of an abnormality, even after engine 2 has fully combusted at time t5, the start signal remains at a high level, and the starter motor 21 continues to crank engine 2.

[0064] In this case, the start signal is set to a low level at time t7. This turns off the first connection part 23 and the second connection part 24. As a result, the starter relay 22 turns off, and the starter motor 21 stops.

[0065] Thus, if the start signal remains at a high level even after engine 2 has fully ignited, the start signal is set to a low level. This causes the starter relay 22 to turn off, and the starter motor 21 to stop.

[0066] Furthermore, if a start request signal is transmitted from the first control unit 5 to the second control unit 6, and the start signal is in a non-generating state (low level), the first control unit 5 or the second control unit 6 can determine that an abnormality has occurred.

[0067] As described above, this embodiment includes a first control unit 5, which acts as a starter input detection unit and generates a start signal until the engine 2 is fully ignited when a start operation is detected on the push start switch 7, and a control unit 30 that controls the first connection unit 23 and the second connection unit 24 based on the start signal to control the starter relay 22 to an ON state or an OFF state. The control unit 30 then turns off the starter relay 22 if the state of the start signal remains the same as before the engine 2 was fully ignited after the engine 2 has fully ignited.

[0068] As a result, if the start signal, which should be at a low level after engine 2 has fully combusted, remains at the same high level as before engine 2 had fully combusted due to an abnormality, the starter relay 22 will be turned off and the starter motor 21 will stop. This prevents the starter motor 21 from continuing to drive if there is an abnormality in the power supply line 22C of the starter relay 22.

[0069] In this embodiment, the control unit 30 turns off the starter relay 22 by de-energizing the second connection unit 24.

[0070] In this embodiment, the control unit 30 turns off the starter relay 22 by de-energizing the first connection unit 23.

[0071] In this embodiment, the first control unit 5 generates a start signal consisting of a predetermined high voltage (high level) when it detects a start operation.

[0072] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of Symbols]

[0073] 1 vehicle 2 engines 5. First control unit (starter input detection unit) 6. Second Control Unit 7. Push-start switch (start switch) 21 Starter motor 22 Starter relay 22C power supply line 23. First connection section 24 Second Connection Section 30 Control Unit

Claims

1. A start switch that accepts the driver's operation to start the vehicle, The starter motor that starts the engine, A starter relay controlled to supply power to the starter motor in an ON state and to cut off power to the starter motor in an OFF state, A first connection part that energizes or deenerges the upstream side of the starter relay in the energized line through which the drive current of the starter relay flows, An engine starting control device comprising: a second connection part for energizing or de-energizing the downstream side of the starter relay in the energizing line, The system comprises a first control unit for controlling the first connection portion and a second control unit for controlling the second connection portion. When the first control unit detects the start operation on the start switch, it generates a start signal until the engine is fully ignited, transmits the start signal to the second control unit, and the second control unit controls the second connection unit based on the start signal. The engine starting control device is characterized in that the first control unit and the second control unit determine that an abnormality exists if the state of the starting signal remains the same as before the engine was fully ignited after the engine has fully ignited, and turn off the starter relay.

2. The engine starting control device according to claim 1, characterized in that the first control unit and the second control unit turn off the starter relay by de-energizing the first connection part or the second connection part.

3. The engine start control device according to claim 1 or 2, characterized in that the start signal is generated by the first control unit as a predetermined high-voltage signal and transmitted to the second control unit via a hardwire.

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