JPH06100165B2 - Starter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a starter used for starting an engine, and more particularly to current control of a magnetic shift type starter.

[Conventional technology]

As is well known, a magnetic shift type starter used as an engine starter pushes a pinion of a starter motor to a ring gear side of an engine via a shift mechanism when a suction coil and a holding coil of a magnetic switch are excited. Be done. When the pinion and the ring gear are in mesh with each other from the beginning, the pinion meshes smoothly without colliding with the ring gear, the contacts are closed, and the motor rotates. If both gears are initially out of mesh, the pinion collides with the end face of the ring gear, and then the pinion is rotated while pressing it against the ring gear by the motor's rotational force or the thrust of the torsion spring, helical spline, etc. I am biting together.

In such a starter, when the pinion collides with the ring gear, a large impact force acts and causes wear and damage to the tooth end faces of the gear elements. Therefore, various measures have been conventionally taken.

For example, in the starter disclosed in Japanese Examined Patent Publication No. 61-48630, when the key switch (manual switch) enters the starting side, the current supply circuit of the starter motor is first energized for a short time to control the speed of the pinion. It is slowing down.

[Problems to be Solved by the Invention]

However, heretofore, sufficient consideration has not been given to the change in the impact coil current of the starter, and hence the impact force on the ring gear of the pinion, in response to changes in the operating environment of automobile parts.

That is, when the operating temperature of the starter changes, the resistance of the exciting coil of the magnetic switch changes and the exciting force also changes. Therefore, the magnetic attraction speed and force of the shift mechanism (plunger) for pushing out the pinion also change. Therefore, the pop-out energy of the pinion also changes, and the energy of collision with the ring gear also changes.

The problem here is that in order to prevent inactivation of the pinion, a predetermined magnetic attraction force is set at the upper limit of the temperature of the exciting coil, so when the starter is used at room temperature or low temperature. Is that the exciting coil current flows more than necessary and a large magnetic attraction force is generated, so that the collision energy of the pinion cannot be sufficiently suppressed.

The same can be said for the power supply voltage. That is, since the power supply voltage (battery voltage) changes depending on the charging state, the magnetic attraction force for pushing out the pinion is set under the assumption that the battery voltage is relatively low. A large magnetic attraction force is generated, and the collision energy of the pinion also increases.

The present invention has been made in view of the above points, and an object thereof is to always suppress the impact force of the pinion on the ring gear in the starter even if the operating temperature condition or the power supply voltage condition of the starter changes. , To improve the durability of the starter.

[Means for Solving the Problems]

In order to achieve the above object, the following problem solving means are proposed.

A first invention is a magnetic shift type starter for pushing a pinion to a ring gear side of an engine by a magnetic attraction force of an exciting coil of a magnetic switch, and a means for detecting a current of the exciting coil, converting the voltage, and outputting the voltage. Means for comparing a target set current value to be passed through the exciting coil with an actual detected value of the exciting coil current, and outputting a current command signal such that the exciting coil current amount flowing per unit time has a constant target value A means for oscillating a triangular wave voltage of a constant cycle to set the chopper frequency of the exciting coil current, and comparing the triangular wave oscillating voltage with the voltage of the current command signal to pass a pulse signal for chopper control. And a means for variably controlling the rate, and a means for controlling switching of the current supply circuit of the exciting coil by the pulse signal for controlling the chopper. Characterized by comprising Te.

In the embodiment described later, the exciting coil current detecting means is the exciting coil current detector 14 in FIGS. 2 and 3, the current command signal output means is the current command circuit 16, and the triangular wave voltage oscillating means is the triangular wave oscillator. 17, a chopper control pulse signal duty ratio variable control means is a deviation circuit 18, an exciting coil current supply circuit switching control means is a chopper circuit 19
Equivalent to.

A second invention is a magnetic shift starter for pushing out a pinion to a ring gear side of an engine by a magnetic attraction force of an exciting coil of a magnetic switch, a means for detecting the temperature of the exciting coil, and a power source for exciting coil current. A means for detecting the voltage and the change in the exciting coil resistance from the detected value of the exciting coil temperature, and the change in the state of the power supply voltage under this exciting coil resistance value to determine the constant amount of exciting coil current per unit time. And a means for controlling energization of the current supply circuit of the exciting coil.

In the embodiment described later, the exciting coil temperature detecting means is the temperature sensor 20 shown in FIG. 6, the power supply voltage detecting means is the battery sensor 21, the energizing control means of the exciting coil current supply circuit is the microcomputer 22 and the chopper circuit 19. Equivalent to.

[Action]

According to the first aspect, the exciting coil current of the magnetic switch is directly detected, and the amount of the exciting coil current flowing per unit time becomes the target value due to the deviation between the detected current value and the target set current value. A current command signal is issued to the coil, and the exciting coil current supply circuit is chopper-controlled based on this current command signal.

By this chopper control, energization is controlled with good response so that the exciting coil current reaches the target value. According to this exciting coil current control, the exciting coil current of the magnetic switch can be directly detected and the exciting coil current can be controlled with a constant current, so that when the resistance value of the exciting coil changes due to temperature or when the exciting coil power source is changed. It is possible to effectively deal with the exciting coil current variation factor when the (battery voltage) changes in state.

As a result, even if one or both of the exciting coil temperature and the battery voltage (exciting coil power supply voltage) change, it is possible to control so that an optimum constant current always flows through the exciting coil of the magnetic switch.

According to the second invention, in addition to detecting the change in the exciting coil resistance from the temperature detection value of the exciting coil of the magnetic switch, the power supply voltage detecting means detects the state of the power supply voltage (battery voltage) of the exciting coil current.

Therefore, it becomes possible to accurately grasp the instantaneous value of the current flowing in the exciting coil based on the detection data of both of them, and in response to this, the energization control means causes the exciting coil current flowing in the exciting coil per unit time. The excitation coil current supply circuit is energized and controlled so that the amount becomes constant. The energization control means in this case is composed of, for example, a microcomputer, calculates the current to be passed through the exciting coil based on the above detection data, and energizes the exciting coil current supply circuit so as to reach the target set current. It can be realized by doing. Also in the present invention, even if one or both of the exciting coil temperature and the battery voltage (exciting coil power supply voltage) change, control can be performed so that an optimum constant current always flows through the exciting coil of the magnetic switch.

In the structure of the second aspect of the invention, the exciting coil temperature detecting means also serves as a conventionally used sensor for preventing the burning of the exciting coil, and the power supply voltage detecting means also serves as a voltage detecting sensor for battery charge diagnosis. Therefore, there is an advantage that the cost of the sensor can be reduced accordingly.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention, FIG. 2 is a block diagram of a starter current control circuit used in the above embodiment, and FIG. 3 is an explanatory diagram showing a specific circuit configuration thereof. .

In FIG. 1, 1 is a battery voltage used as a power source of a starter, 2 is a key switch, and 3 is a starter.

The starter 3 includes a magnetic switch 4, a motor 5, a shift mechanism 6, a pinion 7, a ring gear 8 on the engine side,
It is composed of a constant current control circuit 13 and the like.

The magnetic switch 4 has an exciting coil (suction holding coil) 10, a plunger 11, and an electric contact 12. The exciting coil in the present embodiment is a coil for magnetically attracting the plunger 11 and holding it thereafter.

The constant current control circuit 13 is a current supply circuit for the exciting coil 10,
The exciting coil 10 is located on the ground side and connected in series. The reason why the exciting coil is located on the ground side is that the constant current control circuit itself also serves as the ground. The constant current control circuit 13 has a function of controlling the current flowing through the exciting coil 10 to be constant, and in particular, the current control is performed so that the minimum necessary constant current for operating the pinion shift mechanism 6 flows through the exciting coil 10. To do. The constant current control circuit 13 of this embodiment is
A method is used in which the current of the exciting coil 10 is detected, the detected current value is fed back, and the energization is controlled so that the amount of exciting coil current per unit time becomes constant.

As shown in FIG. 2, the circuit configuration includes an exciting coil current detector 14, a constant voltage circuit 15, a current command circuit 16, a triangular wave oscillation circuit 17, a deviation circuit 18, and a chopper circuit 19. The functions of these circuits will be described together with the operation of the starter described below.

First, the operation outline of the starter will be described prior to the description of the constant current control.

The exciting coil 10 is excited by the current supplied from the battery 1 when the key switch 2 is turned to the start side. Due to this excitation, the plunger 11 is magnetically attracted to the left side of the drawing against the force of the return spring, and the operation of the lever 9 of the shift mechanism 6 causes the pinion 7 to slide on the motor output shaft together with the pinion sleeve 7a, and the ring gear. It is pushed to the 8 side. In this case, if the teeth of the pinion face the ring gear 8 so as to be meshed with each other from the beginning, the pinion 7 and the ring gear 8 directly mesh with each other. Otherwise, the teeth of the pinion 7 do not. The end face collides with the tooth end face of the ring gear 8.

Further, when the plunger 10 is magnetically attracted to the end, the movable contact 12A arranged at one end of the plunger 10 becomes fixed contact 12B.
, The electric current is also supplied from the battery 1 to the motor 5, and the motor 5 starts rotating. At this time, when the pinion 7 interferes with the tooth end surface of the ring gear 8 and is not in mesh with each other, the interference is released by the rotation torque of the motor 5, and the pinion 7 moves forward and meshes with the ring gear 8 by the attracting action of the exciting coil. . Then, the motor 5 fully rotates and the engine is started via the ring gear 8.

When performing the above operation, the constant current control circuit 13 performs the constant current control of the exciting coil as follows.

When the key switch 2 is put in the starting side, a current is supplied from the battery 1 to the exciting coil 10 of the magnetic switch 4 of the starter 3. At the same time, the drive signal is also sent to the constant current control circuit 13.

The constant current control circuit 13 is activated by this drive signal, and the current is controlled so that the amount of the exciting coil current of the magnetic switch 4 per unit time becomes constant. In this case, the constant current control circuit 13 controls so that the minimum necessary current necessary for the operation of the pinion shift mechanism 6 is flown.
Even if the resistance of the exciting coil changes due to the temperature change and the charge state of the battery voltage changes, the current does not flow in the battery 10 more than the battery 1.

Here, the circuit configuration of the constant current control circuit 13 of FIG. 2 will be described.

When the starting side of the key switch 2 is input, the constant voltage circuit 15
Supplies the power supply voltage to each circuit element of the constant current control circuit 13 at a constant value. The current detector 14 detects the current flowing through the exciting coil 10 of the magnetic switch, converts this detection signal into a voltage, and feeds it back to the current command circuit 16.

The current command circuit 16 compares the target set current value to be passed through the exciting coil with the actual detected value of the exciting coil current, and the current increase / decrease command such that the exciting coil current amount flowing per unit time becomes a constant target value. Is output. The signal of the current command circuit 16 is sent to the deviation circuit 18.

The deviation circuit 18 inputs, in addition to the command signal of the current command circuit 16, a triangular wave of a constant cycle output from the oscillation circuit 17. This triangular wave is the fundamental frequency of the chopper that controls the exciting coil current. Then, these input signals are compared and the conduction ratio of the pulse signal for chopper control is variably controlled.

The chopper circuit 19 is connected in series to the ground side of the exciting coil 10 and is switching-controlled by the chopper control pulse signal output from the deviation circuit 18. In the chopper control in this case, energization control of the exciting coil current is intermittently performed so that the exciting coil current amount per unit time becomes constant corresponding to the increase or decrease in the detected value of the exciting coil current. here,
The amount of exciting coil current per unit time to be controlled is based on the charging state of the battery, which is a factor of fluctuations in the power supply voltage, the increase / decrease in the resistance of the key switch circuit, the resistance change of the exciting coil due to temperature change, and the key switch circuit resistance change. In consideration of,
The exciting coil current required to generate the minimum magnetic attraction force required for pinion meshing (driving the pinion shift mechanism) is set.

However, according to the present embodiment, even if there are various environmental changes such as a change in battery voltage and a change in resistance due to a change in temperature of the exciting coil and the like, these changes are not affected and an excessively large change is caused to the engine ring gear of the pinion. The generation of collision energy can be prevented. Therefore, when the pinion and the ring gear mesh with each other, wear of the tooth end surface can be significantly reduced, and damage to the tooth end surface can be eliminated to improve the durability of the starter.

Further, since the exciting coil current set value can be set in consideration of various environmental conditions, the operation reliability of the starter can be improved. Especially, in the past, the operation reliability of the starter was affected by the change of the automobile over time.
In the present embodiment, a system that does not change semipermanently can be constructed by considering this change with time as a condition for setting the exciting coil current.

Next, a concrete configuration example of the constant current control circuit of FIG. 2 and its operation will be described with reference to FIGS. 3 and 4. Note that FIG. 4 is a signal waveform diagram of the circuit operation of FIG. 3, and as an example, when the exciting coil current detection value is in the standard state (normal state).
And the operation mode when the number is smaller than this.

The sensor 14 that detects the excitation coil current outputs the detection signal as a voltage.
Convert to V1 and output. As shown in FIG. 4, this voltage V1 detects an instantaneous value periodically at short time intervals. This voltage
V1 is sent to the current command circuit 16, and the resistor R1 and capacitor C5
Is smoothed by the integral action of to become voltage V2. On the other hand, the resistor R2 and the variable resistor VR1 set the target value of the exciting coil current by the signal of the voltage V3 according to the voltage division ratio. The voltage V3 is adjusted by the variable resistor VR1, and its set value is determined by the input / output characteristics of the current detector 14.

Then, the operational amplifier OP1 compares the current detection value V2 with the current setting value voltage V3, and outputs the command voltage V4 for increasing / decreasing the current. The output voltage V4 of the operational amplifier OP1 is given by the following equation if the resistors R3 and R4 are equal and the resistors R5 and R6 are equal.

Therefore, when the voltage V2 is larger than the voltage V3, the voltage (current command signal) V4 decreases, and when the voltage V2 is smaller, the voltage V4 increases. The current command voltage V4 is
The voltage V is integrated and smoothed by R11 and capacitor 7.
It will be 5.

The oscillator circuit 17 is for setting the chopper frequency as described above, and outputs a triangular wave at a constant cycle. The chopper frequency is governed by the values of capacitor 6 and resistor R9.

The operational amplifier OP3 of the deviation circuit 18 compares the current command voltage V5 with the triangular wave oscillation voltage V6 and outputs a command pulse voltage V7 for driving the chopper transistor T2. The pulse voltage 7 becomes "LOW" level when the current command signal V5 is larger than the triangular wave voltage V6, and "HIG level" when V6 is larger than V5.
H level.

The chopper circuit 19 finally controls the current flowing through the exciting coil 10 by turning on and off the transistor T2. That is, when the output V3 of the operational amplifier OP3 is "LOW", the first-stage PNP transistor T1 is turned on, the NPN transistor T2 is also turned on, and a current flows through the exciting coil. The Zener diode Z2 works together with the diode D2 to protect the transistor T2 from overvoltage.

As a result of such a series of circuit operations, as shown in FIG. 4, the exciting coil current conduction ratio is finally set to the V8 chopper command corresponding to the magnitude of the exciting coil current detection value V1. The amount of exciting coil current per unit time is controlled to be always constant by variably controlling it to be smaller or larger.

FIG. 5 is an overall block diagram of a starter showing a second embodiment of the present invention. In the figure, the same reference numerals as in the first embodiment indicate the same or common elements.

In the present embodiment, as the exciting coil 10 of the starter, the suction coil (series coil) 10A and the holding coil (shunt coil) 10B are separately provided, and the constant current control circuit 13 is incorporated in a branch connection type. It is a thing.

In this type of exciting coil 10, when the start switch is turned on, current flows through both the suction coil 10A and the holding coil 10B, and the plunger 11 is attracted. Therefore, in order to achieve the object of the present invention, it is necessary to control the coil current flowing through both the suction coil 10A and the holding coil 10B by constant current control. Therefore, the constant current control circuit 13 includes a suction coil 10A and a holding coil 10A.
It is connected in series upstream of B.

The constant current control of this embodiment is performed as in the first embodiment.

FIG. 6 is an overall configuration diagram showing a third embodiment of the present invention.

Here, differences between this embodiment and the first embodiment will be described.

In this embodiment, the temperature sensor 20 detects the temperature of the exciting coil 10 of the magnetic switch 4, and the battery sensor 21
The power supply voltage (battery voltage) of the exciting coil current is detected by and the detection data is input to the microcomputer 22.

The microcomputer 22 obtains the change of the exciting coil resistance from the detected value of the exciting coil temperature and energizes the exciting coil 10 so that the amount of current per unit time becomes constant from the change of the exciting coil resistance value and the state of the power supply voltage. The control signal is calculated (this energization control signal is calculated as, for example, a chopper control signal), and the energization control signal controls the conduction ratio of the exciting coil current supply control circuit via the chopper circuit 19.

In the present embodiment as well, even if one or both of the exciting coil temperature and the battery voltage change, it is possible to control so that the exciting coil current of the magnetic switch always has an optimum constant current.

In the present embodiment, a sensor for preventing the burning of the exciting coil is used as the temperature sensor 20, and a sensor for battery charge diagnosis is used as the battery sensor 21.

〔The invention's effect〕

As described above, according to the present invention, the exciting coil current of the magnetic switch of the starter is controlled so as to be always the optimum constant current. Therefore, even if the exciting coil temperature, the battery voltage, or the like changes, the exciting coil is excessively large. The current can be prevented from flowing. As a result, the collision energy of the pinion with respect to the ring gear can be suppressed as much as possible, the durability of the starter can be improved, and the operation reliability can be improved.

Furthermore, since the impact energy of the pinion on the ring gear is suppressed by electrical control without increasing the mechanical strength of the parts such as the pinion, it is possible to prevent the apparatus from becoming large and the weight from increasing.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a starter control circuit showing a first embodiment of the present invention, FIG. 2 is a block diagram of a constant current control circuit used in the first embodiment, and FIG. 3 is a specific example of the constant current control circuit. 4 is a schematic circuit diagram, FIG. 4 is an electrical signal waveform diagram showing an operating state of the first embodiment, FIG. 5 is an overall configuration diagram of a starter control circuit shown in the second embodiment of the present invention, and FIG. It is a whole block diagram of the starter control circuit which shows the 3rd Example of this invention. 1 ... Battery voltage, 2 ... Key switch, 3 ... Starter,
4 ... Magnetic switch, 5 ... Motor, 6 ... Shift mechanism, 7 ... Pinion, 8 ... Ring gear, 9 ... Shift lever, 10 ... Excitation coil, 10A ... Suction coil, 10B ... Holding coil, 11 ... Plunger, 12A ... Movable Contact, 12B ... Fixed contact,
13 ... Constant current control circuit, 14 ... Current detector, 15 ... Constant voltage circuit, 16 ... Current command circuit, 17 ... Oscillation circuit, 18 ... Deviation circuit,
19 ... Chopper circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyoshi Takahashi 2477 No. 2477 Kashima Yatsu, Katsuta City, Ibaraki Pref. 3 Hitachi Automotive Engineering Co., Ltd. (56) Bibliography 62-51987 (JP, U) Actual development Sho 51-328 (JP, U)

Claims (2)

[Claims] 1. A magnetic shift type starter for pushing out a pinion to a ring gear side of an engine by a magnetic attraction force of an exciting coil of a magnetic switch, a means for detecting a current of the exciting coil, converting the voltage, and outputting the voltage. Means for comparing a target set current value to be passed through the exciting coil with an actual detected value of the exciting coil current, and outputting a current command signal such that the exciting coil current amount flowing per unit time has a constant target value. , A means for oscillating a triangular wave voltage of a constant period to set the chopper frequency of the exciting coil current, and the triangular wave oscillating voltage and the voltage of the current command signal are compared, and the conduction ratio of the pulse signal for chopper control is compared. And a means for variably controlling the current supply circuit of the exciting coil with a pulse signal for controlling the chopper. Starter, characterized by comprising. 2. A magnetic shift starter for pushing out a pinion to a ring gear side of an engine by a magnetic attraction force of an exciting coil of a magnetic switch, a means for detecting a temperature of the exciting coil, and a power supply voltage of an exciting coil current. To detect the change in the exciting coil resistance from the detected value of the exciting coil temperature, and to detect the state change of the power supply voltage under this exciting coil resistance value, the exciting coil current amount per unit time becomes constant. A starter comprising means for controlling energization of the current supply circuit of the exciting coil.