JPH0337373A - Engine starter - Google Patents

Abstract

PURPOSE:To secure the stable starting performance for the variation of the engine load by controlling the magnetic field of a shunt coil for control for the magnetic field of the series wound coil of a dc. compound-wound motor in the same or opposite direction on the basis on the basis of the magnitude of the engine load. CONSTITUTION:When an ST terminal is connected with a battery 5 by turning a key switch 6, a retaining coil 3b and a suction coil 3c electric-conduct, and a main contact point 3a is closed by the sum of these magnetic energizing forces, and an armature coil and a series wound coil conduct. Then, the voltage of the battery 5 is supplied into a starter motor 1, which is energized, and an engine is driven. In this case, the starter motor 1 is controlled by a motor control part 4 on the basis of the detection signal of a temperature sensor 2, etc. as the engine load detecting means. When the engine load is too heavy, the conduction direction of a shunt coil 1s is set to the same direction to the magnetic field of the series wound coil 1d.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a battery-powered engine starting device.

[Prior art 1 Japanese Utility Model Application Publication No. 58-31765 discloses a starter motor having a permanent magnet type field pole, a winding wound around the field pole, and a method in which the temperature of the starter motor is low when the engine is started. The present invention discloses an engine starting device including a temperature switch that energizes the winding to excite the field pole. - The above-mentioned energization compensates for the problem that the magnetic flux density of the permanent magnet type field pole fluctuates depending on the temperature.

On the other hand, engine starting devices for starting relatively large internal combustion engines, such as those used in automobiles, generally use DC series-wound type or DC compound-wound type starter motors.

[Problem to be Solved by the Invention 1] However, in the conventional DC series starter motor described above, when the engine load is a predetermined constant value (usually in accordance with the engine load at low temperature), the optimum starting Although each part is set up so that the characteristics will be the same, if the engine load fluctuates, the starting characteristics will vary greatly as a general characteristic of a DC series motor. In other words, the torque characteristics of the starter motor are set according to the engine load at low temperatures, and if the engine temperature rises and the oil viscosity decreases, the engine load becomes too light, and the There were problems such as the engine speed decreasing compared to the torque setting.

On the other hand, the DC series-wound type starter motor described above has a high rotational speed in the no-load operating state after engine startup due to its series-wound characteristic. It was necessary to provide a mechanism to prevent the rotor from increasing its rotation excessively.

The two problems described above similarly exist in a DC compound-wound starter motor having a series coil.

The first invention and the second invention have been made in view of the above-mentioned problems, and the object of the first invention is to provide an engine starting VJ device having stable starting characteristics against fluctuations in engine load. The object of the second invention is to provide an engine starting device that has excellent braking performance against an excessive increase in engine speed after starting the engine.

[Means for Solving the Problems] A first invention provides a DC compound-wound starter motor having a series coil and a control shunt coil, an engine load detecting means for detecting the magnitude of an engine load, and an engine load detecting means for detecting the magnitude of an engine load. When the load is too heavy, the shunt coil is energized in the summation direction, and when the engine load is too light, the shunt coil is energized in the differential direction, and when the engine load is within the normal range 1Y11, the shunt coil is energized. The device is characterized by being equipped with a motor control section that shuts off the motor.

The second charging method includes a DC compound-wound starter motor having a series coil and a shunt coil for control, and when the starter motor is braked, the shunt coil is energized in the harmonic direction to generate electricity.
It is characterized by comprising a motor control section that performs I motion.

Here, the sum direction refers to the current direction in which the magnetic fields of the shunt-wound coil and the series-wound coil are in the same direction, and the differential direction refers to the current direction in which the two magnetic fields are in opposite directions.

[Operation 1] In the first light, the motor control section 111 performs the following operations depending on the magnitude of the engine load detected by the engine load detection means.
If the engine load is too heavy, the shunt coil will be energized in the summation direction, if the engine load is too light, the shunt coil will be energized in the differential direction, and if the engine load is within the normal range, the shunt coil will be energized in the differential direction. Do not energize the winding coil. The torque increases by applying current in the sum direction, and the torque decreases by applying current in the differential direction, and as a result, the engine starting characteristics remain constant regardless of engine load fluctuations.

In the second aspect of the invention, the motor control section performs dynamic braking by energizing the shunt coil in the harmonic direction when braking the starter motor after starting the engine, thereby preventing the rotational speed of the starter motor from increasing excessively.

[Example 1 An embodiment of the first and second inventions will be described with reference to FIG.

Start this engine! 11 is a DC compound-wound starter motor 1 having a series-wound coil 1d and a shunt-wound coil 1S, a temperature sensor 2 that constitutes engine load detection means in the present invention, and an armature current of the starter motor 1 that is connected intermittently. The motor II 611 section 4 drives the shunt coil IS.

One end of the armature coil (not shown) of the starter motor 1 is grounded via the series coil 1d, and the other end of the armature coil is connected to the main contact 3 of the magnetic switch 3.
It is connected to the positive electrode of the battery 5 via a. The coil of the magnetic switch 3 consists of a holding coil 3b and a suction coil 3C that are connected in series to each other, and the holding coil 3b
The independent end of the attraction coil 3C is connected to the connection point 8 between the armature coil and the main contact 3a,
A common end of the holding coil 3b and the attraction coil 3C is connected to the ST' end of the key switch 6.

The IG terminal of the key switch 6 is connected to the high-level power supply terminal of the motor control section 4, and the movable side contact of the key switch 6 is connected to the positive electrode of the battery 5.

On the other hand, a tachometer 7 that detects the engine speed is connected to one input terminal of the motor control section 4, and a temperature sensor 2 that detects the engine temperature is connected to the other input terminal of the motor control section 4. . Furthermore, another input terminal of the motor control section 4 is connected to a connection point 8, and the motor control section 4 is connected to a connection point 8.
Both ends of the shunt coil 1S are connected to the pair of output ends of the shunt coil 1S.

The operation of this engine starting device will be explained.

When the key switch 6 is turned and the ST end is connected to the battery 5, the holding coil 3b and the attraction coil 3C are energized, and the main contact 3a is closed by the sum of the magnetic forces of the holding = 1 coil 3b and the attraction coil 3C. The armature coil and the series coil 1d are energized. When the main contact 3a closes, the main contact 3a short-circuits the attraction coil 3C, but the closed state of the main contact 3a is sufficiently maintained by the magnetic force of the holding coil 3b.

When the main contact 3a is closed, battery voltage is supplied to the starter heater 1, the starter motor 1 is started, and the engine (not shown) connected to the rotating shaft of the starter motor 1 is activated.
is driven. After starting the engine, turn key switch 6 to fJ.
l <As a result, the power supply to the starter moder 1 is stopped.

Next, the operation of the motor control section 4 will be explained using the flowcharts of FIGS. 2 and 3.

When the key switch 6 is turned on to the 8th position, the routine starts, and in order to improve the meshing PL of the binion gear built in the starter -91, the shunt coil 1s is applied to the shunt coil 1s until the main contact 3a closes. (S1
0), it is checked whether the main contact 3a of the magnet switch 3 is closed or not based on the potential change at the connection point 8 (S12). If the main contact 3a is not closed, the process returns to S10, and if the main contact 3a is closed, the engine m1M detected by the temperature sensor 2 is at the high temperature side threshold tl (t1=for example, 80
It is checked whether it is equal to or greater than 'C) (S14), and if it is equal to or greater than 11, the shunt coil 1S is differentially energized (322>), and if it is lower than tl, the procedure proceeds to S16. At 316, it is checked whether the engine temperature is below a low temperature side threshold t2 (t2 = for example -10°C) (316), and if it is below t2, the shunt coil 1S is
1, ``Do not energize the current 31B) If it is higher than t2, do not energize the shunt coil 1S (320>.

Next, it is determined whether or not the cranking state is established (826).

The cranking state refers to a state in which the engine speed detected by the tachometer 7 is in the range of 50 to 50 rpm.

If it is in the cranking state, the process returns to S14, and if it is out of the cranking state, it is checked whether it is in the locked state (32B>).

Whether the engine is in the locked state or not is determined by checking whether the engine speed detected by the tachometer 7 is 50 rDm or less. It happens again
In order to prevent an excessively low-speed rotation state immediately after J from being mistakenly determined as a locked state at step 328, an average value of rotation fluctuations within a certain period of time is used.

If the engine is in the locked state, it is assumed that the engine has started normally (that is, the engine speed is 50 Orpm or more), and the shunt coil 1s is energized (S).
30). Note that the reason why the shunt coil 1S is energized in a harmonic manner is to reduce the no-load rotational speed of the starter and prevent damage to the commutator of the starter motor 1 due to an excessive increase in the rotational speed.

Next, check whether the main contact 3a is closed (S32
), if the main contact 3a is closed, it returns to 330, and if the main contact 3a is not closed, it waits for a certain period of time (33/
1) After that, stop energizing the shunt coil] S (S36)
, exit the routine.

The reason why the engine waits for a certain period of time in S34 is to sufficiently perform the power generation frill operation to the starter t1 and to properly perform the deceleration.

If the locked state is detected at 32B, after waiting for a certain period of time (338), check whether the re-locked state is reached 54
0), if the locked state has been released, proceed to S30;
If it is still in the locked state, the 1i notification signal is output to the outside (S42), and the process proceeds to S36.

Note that the outside temperature may be detected instead of the engine temperature.

The cranking state (i.e., starting rotation before engine ignition) and engine lock (i.e., engine rotation failure) can be electrically detected not only by using the tachometer 7 but also by, for example, a potential change at the connection point 8. I can do it.

As explained above, in this embodiment, the magnitude of the engine load is detected based on the engine temperature. In other words, when the engine temperature is high, the oil viscosity is low and the engine load is light; when the engine temperature is low, the oil viscosity is high and the engine load is heavy; and if the engine temperature is within a predetermined setting range, the oil viscosity is low. Assume that the condition is normal and the engine load is appropriate. By doing so, the engine load at the time of starting the engine can be easily estimated.

Further, in this embodiment, the torque characteristics of the starter motor 1 due to the energization of the shunt coil 1S are designed in accordance with the engine load when the engine temperature is within a predetermined setting range. In this way, it is only necessary to change the direction of current to the shunt coil 1S at high and low temperatures, and the absolute value of the current flowing to the shunt coil 1S does not have to be set in three scales. Three types of torque characteristics can be obtained by energization/cutoff control and energization direction switching control. Note that, as is well known, controlling the absolute value of the energizing current requires a complicated circuit configuration.

Further, after the engine is started, instead of energizing the shunt coil 1S in the wave direction for a certain period of time from the open state of the main contact 3a, the shunt coil 1S may be energized in the wave direction only while the starter motor 1 is rotating. As a means for detecting one rotation of the starter motor, an electromagnetic pickup, a Hall element, or the like can be used.

Furthermore, in this embodiment, after energizing the holding coil 3b and attraction coil 3G of the magnetic switch 3, the main contact 3
Since wave current is applied to the shunt coil IS until a closes, there is a starting shock and starting ' at the moment the main contact 3a closes.
There is an advantage that the i/1 current is small.

(Effects of the Invention) As explained above, the first invention has the following advantages:
Since the shunt coils are switched between differential energization, no energization, and differential energization depending on whether the coil is medium or small, the starting torque characteristics can be compensated for in response to engine load fluctuations through simple control.

In addition, in the second invention, when braking the starter motor after starting the engine, the shunt coil is energized in the harmonic direction to perform dynamic braking, so it is possible to prevent the rotational speed of the starter motor from increasing excessively. , it is possible to improve the reliability of the starter motor and reduce its size and weight.

4. ffi Q' Explanation of the Drawings FIG. 1 is a circuit diagram showing an embodiment of the first and second Brahmans.

Figures 2 and 3 show the motor iJI control section 9 in Figure 1.
70-chart showing the operation of FIG.

1...Starter motor 1d...Series coil 1S...Shunt coil 2...Temperature sensor (Engine load detection means) 4...Motor control section

Claims (2)

[Claims] (1) A DC compound-wound starter motor that has a series coil and a control shunt coil; an engine load detection means that detects the magnitude of the engine load; , a motor control unit that energizes the shunt coil in the differential direction when the engine load is too light, and cuts off the energization to the shunt coil when the engine load is within a normal range. Characteristic engine starting device. (2) a DC compound-wound starter motor having a series-wound coil and a shunt-wound coil for control; and a motor control unit that performs dynamic braking by energizing the shunt-wound coil in the harmonic direction when braking the starter motor. An engine starting device characterized by comprising the following.