JP2004044435A - Belt driven engine starter - Google Patents

Abstract

In an engine starting device that starts an engine by driving a belt, a belt that transmits a rotational motion of an engine is provided so that a tension exceeding a durability range is not applied to the belt. A circuit capable of changing the input current and the voltage supplied from the lead storage battery 26 is provided so that the output of the DC starter motor 32 that drives the power supply can be adjusted. Based on the rotation state of the engine 10 detected by the sensor 34, the controller 36 determines whether or not the resistor 38 should be included in the circuit, and issues an appropriate command to the first relay 40 and the second relay 42.
[Selection] Fig. 2

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a belt-driven engine starting device, and more particularly to an engine starting device using a DC starter motor (engine starting motor).
[0002]
[Prior art]
The start of the engine is generally performed by transmitting the rotational power of a starter motor to the engine. The starter motor is usually installed on the crankshaft portion of the engine, and drives the crankshaft directly or via a gear. However, while this means has the advantage of facilitating the transmission of rotational energy, it also has the disadvantage of being prone to vibration and noise. Therefore, in vehicles that incorporate the idling stop function that requires the engine to be restarted frequently during riding, a starter motor is installed to drive the belt that is stretched over the crankshaft of the engine to reduce silence. May be secured. However, in the device configured as described above, since the torque required for starting the engine is transmitted through the tension of the belt, there is a problem in that a heavy load is applied to the belt particularly at the initial stage of starting.
[0003]
One means for solving this problem is disclosed in Japanese Patent No. 3129268. That is, by using the auto tensioner in combination with a plurality of pulleys (pulleys), the belt tension is appropriately maintained, and both the durability of the belt and the quick start of the engine are achieved.
[0004]
[Problems to be solved by the invention]
However, in the means described in Japanese Patent No. 3129268, there is a problem that the size of the apparatus becomes large because an auto tensioner and a plurality of pulleys are used. In addition, there is a problem that it is difficult to precisely adjust the tension as compared with the control using an electric device because the control is performed mechanically.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, an engine starting device according to a first aspect of the present invention is an engine starting device that drives a belt that transmits a rotational motion of the engine to start the engine, and includes a DC starter motor that drives the belt. And a sensor for detecting a rotation state of the engine, and output control means for changing an output of the starter motor in accordance with a detection result of the sensor.
[0006]
According to a second aspect of the present invention, in addition to the features of the first aspect, the sensor detects a phase of the engine rotation.
[0007]
According to a third aspect, in addition to the features of the first aspect, the sensor detects an angular velocity of engine rotation.
[0008]
According to a fourth aspect of the present invention, in addition to the features of the first aspect, the output control means uses an electromagnetic relay so as to guide the output of the starter motor to an allowable range of belt durability and a quick startable range of the engine. Means for changing the input current and voltage to the starter motor.
[0009]
According to a fifth aspect of the present invention, in addition to the features of the first aspect, the output control means uses a starter by using a transistor so as to guide the output of the starter motor to an allowable range of belt durability and a quick startable range of the engine. It is a means for changing the input current and voltage to the motor.
[0010]
As for an attempt to control the output of the starter motor, Japanese Patent Application Laid-Open No. 61-200377 is known. Here, under a configuration using a starter motor that also serves as a generator, which is installed directly connected to the crankshaft of the engine, for the purpose of facilitating engine startup, an optimal startup torque corresponding to the engine speed is given. Means for adjusting are described. The motor is an AC motor, and the output is adjusted by adjusting the phase of the polyphase AC. On the other hand, an object of the present invention is to suppress a tension applied to a belt while securing a torque for driving an engine under a configuration using a belt-driven starter motor. The starter motor is a DC motor using a DC power supply, and its control means is naturally different.
[0011]
Further, Japanese Utility Model Laid-Open No. 1-88076 describes a starter control device that gives an optimum torque to an engine according to the engine temperature. However, the control means used in this control device switches the combination of gears when transmitting the rotational power of the starter motor to the crankshaft via gears, and adjusts the cranking rotation speed. It differs from the means of the invention.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, the same members are denoted by the same reference numerals, and description thereof is omitted.
[0013]
FIG. 1 is a block diagram showing an outline of the present invention, and shows a correspondence relationship with peripheral devices when an engine 10 is mounted on an automobile. The rotational motion generated by the engine 10 is transmitted from a crankshaft to a transmission 14 and further transmitted to a drive system (not shown). At the same time, the rotational movement is transmitted from the crankshaft to the belt 16. The belt 16 has an AC generator (alternator) 18 for converting rotational energy into electric energy, a water pump 20 for circulating cooling water for cooling the engine 10, and an air conditioner connected with a clutch 22a interposed therebetween. 22 and the like are installed. Further, the tensioner 24 plays a role of applying an appropriate tension to the belt 16 to suppress vibration.
[0014]
When starting the engine 10 for the first time, an initial starter motor 26 attached to the transmission 14 is used. The rotation of the starter motor 26 for initial startup is transmitted from the crankshaft to the engine 10, and the engine 10 is started. After the engine 10 is started, the starter motor 26 for initial startup is separated by a relay 28 from a lead storage battery (battery) 30 which is a power supply source. Power is supplied to the lead storage battery 30 by the AC generator 18.
[0015]
The movement of the engine 10 may be stopped when the vehicle is stopped at a red light or the like, or when the vehicle is running only by electric energy. After that, when the power of the engine 10 is required, it is desirable to restart the engine 10 promptly and smoothly. Therefore, unlike the initial start-up, a belt-driven engine starter is provided which drives the belt 16 using the starter motor 32 and transmits the rotation of the belt 16 to the engine 10 from the crankshaft. As a result, the engine 10 can be restarted without generating unnecessary vibration or noise.
[0016]
However, on the other hand, when the engine 10 is driven using the starter motor 32, there is a problem that a very large tension is applied to the belt 16 particularly immediately after the start of driving. If the output of the starter motor 32 is simply reduced to solve this, the torque required to quickly restart the engine 10 cannot be provided. In addition, if the width of the belt 16 is widened to extend the allowable durability range, a problem in mounting space occurs. Therefore, in the present invention, the output of the starter motor 32 is controlled by installing the controller 36 in the engine starting device. The starter motor 32 is assumed to be a DC motor in consideration of the ease of using the power supplied by the lead storage battery 30 which is a DC power supply.
[0017]
Here, the engine starting device will be described in detail with reference to the block diagram of FIG. The engine 10 is driven by a starter motor 32 to which electric energy of a lead storage battery 30 is supplied. As will be described later, the tension of the belt 16 at this time suddenly reaches a maximum immediately after the start of driving, and gradually decreases thereafter. The value also depends on the piston position of the engine 10. Therefore, a sensor 34 for detecting the rotational angular velocity or rotational phase of the engine 10 is provided, and the detection information is transmitted to the controller 36. The controller 36 determines how to change the output of the starter motor 32 based on this information. If it is determined that the output should be suppressed, a command to connect the first electromagnetic relay 40 and disconnect the second relay 42 is issued, and the resistor 38 is inserted into the circuit. If it is determined that the output should be increased, a signal for connecting the second relay 42 is issued. In addition, as a matter of course, by providing a plurality of circuits including the electromagnetic relay and the resistor, multi-stage control can be performed.
[0018]
The flowchart of FIG. 3 shows an output control process of the starter motor 32 when the sensor 34 detects the rotational angular velocity of the engine 10. First, the first relay 40 and the second relay 42 are in a disconnected state, but when the start of the engine 10 is started, the first relay 40 is connected, and the starter motor 32 starts to start the belt. At this time, since a part of the electric energy is consumed by the resistor 38, the output of the starter motor 32 is suppressed. This state is maintained while the rotational angular velocity of the engine detected by the sensor 34 is less than an appropriate threshold. If the rotational angular velocity becomes equal to or greater than this threshold value and thereafter, it is recognized that the amount of change over time in the rotational angular velocity of the engine has decreased, it is considered that the period in which the tension of the belt 16 is excessive has ended, and the second relay 42 is turned off. Connected. As a result, the current flows into the starter motor 32 through a circuit that does not pass through the resistor 38, and the rotational output increases. Eventually, when the engine finishes starting, the first relay 40 and the second relay 42 are both disconnected, and the starter motor 32 ends its operation.
[0019]
FIG. 4 shows the relationship between the rotational angular velocity of the starter motor 32 and the rotational output. The horizontal axis represents the rotation of the motor in terms of the rotational angular speed of the engine (unit: rpm), and the vertical axis represents the output torque (unit: Nm) measured at the crankshaft. This torque is proportional to the tension applied to the belt 16. In the conventional example shown by the broken line, the output torque is slightly less than 150 (Nm) when the rotational angular velocity is 0 (rpm), monotonically decreases as the rotational angular velocity increases, and when the rotational angular velocity approaches 1000 (rpm). It is almost 0 (Nm). From this, it can be seen that a very large torque is output immediately after starting the rotation. On the other hand, the solid line shows the output torque when the input power to the starter motor 32 is suppressed using the resistor 38 in FIG. Since the threshold value of the engine rotation angular velocity in the flowchart of the output control means of FIG. 3 is set to 160 (rpm), the input power is suppressed and the torque output is reduced during the rotation angular velocity from 0 (rpm) to 160 (rpm). Have been. The value is slightly less than 90 (Nm) when the rotational angular velocity is 0 (rpm), and slightly greater than 50 (Nm) when the rotational angular velocity is 160 (rpm). When the rotational angular velocity exceeds 160 (rpm), the restriction on the input power is removed, and the output torque increases to about 90 (Nm), which is the same as the conventional example. Accordingly, the output torque is maintained at about 90 (Nm) or less throughout the entire rotation angular velocity, and the corresponding belt tension can be suppressed. Here, the threshold is set to 160 (rpm), but an appropriate threshold varies depending on the characteristics of the starter motor and the engine.
[0020]
FIG. 5 shows a measurement result of the time change of the belt tension and the engine rotation angular velocity after the engine starting device is started. The horizontal axis represents elapsed time (unit: ms), the left vertical axis represents belt tension (unit: N), and the right vertical axis represents rotational angular velocity (unit: rpm). The broken line schematically shows the conventional belt tension from the initial time to the elapsed time of about 160 (ms). The belt tension sharply increases after the start, and reaches a maximum value exceeding 3500 (N) around the elapsed time of 30 (ms). Further, the value again increases around the elapsed time 120 (ms). However, the value rapidly decreases during the subsequent elapsed time (not shown), and decreases while repeating the vibration accompanying the engine rotation phase. On the other hand, when the output control means of the present invention shown by the solid line is used, the belt tension is less than the maximum value of 1300 (N) near the elapsed time of 20 (ms), which is about one third of the conventional example. It can be seen that it has decreased to the value. Thereafter, the belt tension temporarily decreases, and then takes a value exceeding 1200 (N) again near the elapsed time 140 (ms), and after 300 (N), approximately 300 to 1100 (N) after the elapsed time 200 (ms). It attenuates while vibrating in the range. The corresponding engine rotation angular velocity in the case of the present invention shown by a thick solid line rises from 0 (rpm) while including vibration accompanying a change in the engine rotation phase, and reaches about 550 (rpm) near an elapsed time of 500 (ms). Has reached. During this period, the elapsed time exceeds 160 (rpm) near the elapsed time 190 (ms), and after the elapsed time 210 (ms), the rate of change with time continues to increase but decreases. In response, as shown in the flowchart of FIG. 3, the relay 42 is connected, and the output of the starter motor 32 is strengthened. As described above, the belt tension vibrates in the same range as that of the conventional example.
[0021]
Next, FIG. 6 shows an example in which the output control means of the present invention is realized by another method. This embodiment has substantially the same configuration as the invention shown in FIG. 2, but the output control means is realized using a transistor 44 instead of an electromagnetic relay. Although the type of the transistor 44 is not particularly limited, a case where a depletion type MOS FET is used as an example will be described here. In this case, by changing the gate voltage of the transistor 44 by the controller 36, the amount of drain current can be changed, and the input power to the starter motor 32 can also be changed. Since the amount of drain current changes steplessly in accordance with the change in gate voltage, precise control is possible. Therefore, in this case, finer control may be performed than in the flowchart of FIG.
[0022]
In the example described above, the sensor 34 detects the rotational angular velocity of the engine 10, but may detect another amount by which the rotational state of the engine 10 can be grasped. For example, a unit that measures the rotation angle of the crankshaft 12 and detects the rotation phase of the engine 10 can be incorporated in the output control unit. As shown in FIG. 5, the tension of the belt 16 greatly changes depending on the rotation phase of the engine 10, that is, the cylinder position of the engine 10. Therefore, by setting a reference that suppresses the output of the starter motor 32 during the phase in which the tension increases, and increases the output of the starter motor 32 during the phase in which the tension decreases, more precise control can be achieved. Become.
[0023]
Although the description given here has been made on the assumption that the engine 10 is mounted on an automobile, it is needless to say that the present invention can be applied to general motives equipped with a belt-driven engine starting device.
[0024]
【The invention's effect】
As described above, according to the first invention of the present application, it is possible to realize an engine starting device that can start the engine quickly without increasing the belt width and increasing the durability. As a result, it is possible to prevent the size of the entire apparatus from increasing.
[0025]
According to the second and third aspects of the present application, it is possible to perform fine output control based on the rotation phase rotation of the engine and the rotation angular velocity of the engine, respectively.
[0026]
According to the fourth and fifth aspects of the present application, the output of the starter motor can be easily controlled by using the electromagnetic relay and the transistor, respectively.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a circuit diagram illustrating an outline of an engine starting device using a relay.
FIG. 3 is a flowchart illustrating an operation of the engine starting device.
FIG. 4 is a diagram showing output characteristics of a starter motor.
FIG. 5 is a diagram showing a change over time of an engine rotation angular velocity and a belt tension.
FIG. 6 is a circuit diagram illustrating an outline of an engine starting device using a transistor.
[Explanation of symbols]
Reference Signs List 10 engine, 16 belt, 30 lead storage battery, 32 starter motor, 34 sensor, 36 controller, 40 first relay, 42 second relay, 44
Transistor.

Claims (5)

An engine starting device that drives a belt that transmits the rotational motion of the engine to start the engine,
A DC starter motor for driving the belt,
A sensor for detecting the rotation state of the engine,
An engine starting device comprising: output control means for changing an output of a starter motor according to a detection result of a sensor. The engine starting device according to claim 1, wherein
An engine starting device, wherein the sensor detects a phase of engine rotation. The engine starting device according to claim 1, wherein
An engine starting device, wherein the sensor detects an angular speed of engine rotation. The engine starting device according to claim 1, wherein
The output control means is a means for changing the input current and voltage to the starter motor using an electromagnetic relay so as to guide the output of the starter motor to the belt endurable range and the quick startable range of the engine. Characteristic engine starting device. The engine starting device according to claim 1, wherein
The output control means is means for changing the input current and the voltage to the starter motor using a transistor so as to guide the output of the starter motor to the belt endurable range and the rapid startable range of the engine. Engine starting device to do.

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