JPS63105254A - Starter for engine - Google Patents

Abstract

PURPOSE:To enable an engine to be surely started, by changing a throttle valve opening of the engine during its cranking operation and generating a point of time for the throttle valve opening suitable for starting the engine, in case of the engine which connects its throttle valve to an actuator to be drivingly controlled. CONSTITUTION:An engine control unit 10 controls the opening of a throttle valve 1 through a stepping motor 5 so as to obtain a fixed engine speed on the basis of a detection signal from a crank speed sensor 19. Further the control unit performs various controls of a fuel valve 9, ignition timing, etc. on the basis of a detection value of cooling water temperature sensor 21, oil level sensor 22, etc. When an engine is started, first the throttle valve is fully opened thereafter fully closed, and the throttle valve, after its both opening positions are confirmed, is controlled to the optimum opening for starting the engine.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an engine starting device.

[Prior Art] Conventionally, when starting an engine, a throttle valve is often manually operated to start the engine, and the throttle valve is often constantly operated and controlled by an operator. Therefore, the throttle valve was connected to the operating handle by mechanical means.

In recent years, with advances in control technology, structures have been developed in which the throttle valve is operated by an actuator to control engine starting, operation, etc. from a remote location.

In this case, it is conceivable to operate the throttle valve using a stepping motor or the like that self-determines the amount of displacement as an actuator.

Incidentally, this type of actuator is constructed separately from the throttle valve, and the two are connected by some kind of connection means when used.

In this case, careful consideration is required because if the connecting portion shifts or plays, the premise for controlling the throttle valve will be impaired.

[Problems to be Solved by the Invention] Therefore, although careful consideration has been given to accuracy in connecting the two, it is difficult to completely eliminate backlash and deviation.

Minute gait. Even if it is a deviation, this deviation has a large effect on the intake passage area when the opening of the throttle valve is small, and when the engine is started, this deviation in the opening of the throttle valve is This greatly affects the reliability of engine starting.

[Means for solving problems]

Under such circumstances, this invention aims to ensure the reliability of engine starting, and in an engine in which a throttle valve of an engine is connected to an actuator to be driven and operated, the throttle valve opening during engine cranking is It is characterized by changing.

In this specification, the term "during engine cranking" refers to the period during which the engine is being energized and rotated to ignite the air-fuel mixture before the engine ignites the air-fuel mixture. Used in a concept that includes both continuous and intermittent rotation.

[Effect]

Since the opening of the throttle valve is changed during engine cranking in this way, even if there is some play, the point at which the opening of the throttle valve is appropriate for starting the engine is generated, so the engine can be started reliably. It can be done.

[Example] Hereinafter, the GHP (GAS ENGTNHE) of this invention will be described.
A first embodiment of the AT PUMP) system will be described with reference to FIGS. 1 to 6.

First, the configuration of the main parts of the GHP system will be explained with reference to Figure 3.The GHP system normally uses city gas as engine fuel to operate a heat pump, for example, for hot water supply or air conditioning.The power source for this device is the commercial power supply. is used.

The amount of water supplied to the engine 11 side is adjusted.

The city gas that has passed through the fuel valve 9 is mixed with air and E in the mixer 12.
It is mixed with exhaust gas components of a GR (exhaust gas recirculation system) and sent into the combustion chamber 14 of the engine 11 via the intake passage 13.

The mixed gas is combusted in the combustion chamber 14, and the exhaust gas is discharged from the exhaust passage 15 via the exhaust muffler 16.

In this way, the rotating engine 11 drives a compressor (not shown), and the refrigerant in the heat pump circuit is expanded and condensed to perform heating and cooling operations, heating of hot water, and the like.

Furthermore, if necessary, a heat exchanger may be installed in the exhaust muffler 16 or the like to recover heat from the exhaust gas of the engine 11, and a supply circuit to the above-mentioned destination may also be provided.

In addition, in Fig. 2, 1 is a throttle valve, 5 is a stepping motor, 17 is an intake valve, 18 is an exhaust valve, 23 is an ignition coil, 2
4 is a spark plug.

By the way, as shown in FIGS. 3 and 4, the throttle valve 1 consists of a valve body 1a and a valve shaft 2, both of which are fixed together, and this valve shaft 2 is attached to a bearing part of an intake passage 3. 4 is rotatably supported.

This valve shaft 2 is connected to a stepping motor 5 which is an actuator.
One end of the valve shaft 2 is connected to an output shaft 6 of a stepping motor 5, which is constructed separately from the valve shaft 2.

The opening control range of the throttle valve 1 is from a fully open position (horizontal two-dot chain line position) to a fully closed position (two-dot chain line inclined position), and is normally set to about 70 degrees.

A fully open stopper 7 and a fully closed stopper 8 are arranged at the fully open position and the fully closed position to restrict and prevent further rotation of the throttle valve 1.

The amount of the mixed gas is controlled by the throttle valve 1 and supplied to the engine 11. In the normal operating state of this GHP system, the opening degree of the throttle valve 1 maintains the rotation speed of the engine 11 constant. be controlled to the best of its ability.

That is, fluctuations in the engine speed due to load fluctuations, disturbances in the intake air amount, etc. are detected via the signal line 20 using a detection signal from the crank rotation speed sensor 19.

Based on this detection signal, the engine control unit IO controls the stepping motor 5 as a driving means (actuator) for the throttle valve 1.

In addition to controlling to maintain a constant engine speed, the engine control unit 10 receives outputs from a cooling water temperature sensor 21 and an oil level sensor 22 from the engine 11, and controls various engine systems.

For example, engine control unit 10 sends an optimum ignition signal to spark plug 24 via ignition coil 23 .

Figures 5 and 6 show engine control unit 1.
0 and a stepping motor 5. FIG.

The engine control unit 10 receives DC +12V converted from commercial Nm as an input power source, and a power supply circuit 101 and 1' outputs a 13V DC power supply for operating a CPU (for example, an 1-chip 8-bit microcomputer), and detects the engine rotation speed. an engine pulse input circuit 103 that receives an output from a crankshaft rotation sensor 19 (engine pulse pickup coil) and supplies a rotation speed signal indicating the engine rotation speed to the CPU 102; and a cooling water temperature sensor 21 that indicates the engine engine temperature. Upon receiving various status output signals such as the output and the output of the engine oil level sensor 22, the C
It has a sensor input circuit 104 that inputs input to the PU 102.

The CPU 102 operates sequentially in response to a clock signal of a predetermined frequency from the oscillation circuit 105.

- The CPU 102 compares the current engine speed N with a predetermined reference speed Nref, and if a difference occurs between the two engine speeds, the CPU 102 controls the stepping motor 5 via the stepping motor drive circuit 106 in order to make the difference zero. to control the rotation.

The stepping motor 5 is a 4-phase motor with excitation+n tea
Taking an example with four wires, the input terminal 51 to each excitation winding
, 52, 53, and 54, the stepping motor drive circuit 10
6, pulses in different pulse sequence formats are sequentially sent out.

In FIG. 6, a timing chart of signals supplied to each terminal 51 to 54 in order to rotate the stepping motor 5 at a constant speed is shown in chronological order in response to the clock from the oscillation circuit 105.

In Figure 6, the numbers 1 to 9 at the top indicate the number of clocks (
n), and a pulse sequence is determined for each numerical state.

In order to determine the absolute position of the stepping motor 5, which is the relative position change control means, a stopper is provided corresponding to the fully open position and the fully closed position of the throttle valve 1, so that the stepping motor 5 when the throttle valve is fully open and fully closed is provided. The state is set as an initial state, the pulse sequence in this initial state is set as a reference value of the angle, and thereafter, the opening angle of the throttle valve 1 is controlled from this reference value.

For example, after detecting the fully closed position, use that position as the reference position and set the opening degree to 0 degrees, and set the clock number i to 0 to create the pulse sequence in chronological order. After checking the full opening stopper and performing an initial check of the operation, control to stabilize the engine speed N is started.

That is, the control signal is obtained based on the current engine speed N and a predetermined reference speed Nref.

This control signal Vref is usually determined by the following formula based on so-called PID control.

Vref=P+I+D+offset Here, P is a proportional term (Nr e f −N:l ・
Kpl is an integral term [Σ(Nref-N)) ・Ki D is a differential term (N-N (p a s t)] ・K
d (Kd, Ki, Kp are coefficients) The control signal thus obtained is supplied to the stepping motor drive circuit 106 in order to adjust the opening angle of the corresponding throttle valve 1.

In this way, the stepping motor 5 uses the position regulated by the fully open stopper 7 and the fully closed stopper 8 as the reference position for controlling the opening of the throttle valve 1, and the opening angle e is set as shown in equation (1) below. The stepping motor rotation angle is changed by Δθ.

θ=Δθ·n−(1) Here, n is a signal (number of steps) given to the stepping motor 5 from the reference position to instruct sequential rotation.

Incidentally, when the engine 11 is started, the throttle valve 1 and the starter motor of the engine are controlled by the engine control unit 10 according to the flowchart shown in FIG. 7, and the operations are performed as shown in the timing chart of FIG. 1.

When the power is turned on (time point TI), the throttle valve 1 located at an arbitrary position is first operated in the fully closed direction and brought into contact with the fully open stopper 8 (step 1), and a predetermined time elapses from this contact time point T2. At point T3, rotation in the opposite direction to the fully open direction is started and brought into contact with the fully open stopper 7 in the fully open position (step 2, time point T4).

This is done by bringing the throttle valve 1 into contact with the fully open position.
You can check the operation of the actuator and whether the throttle valve is fully open or fully closed.

At this time, in order to always accurately contact and regulate the position of the twill valve 1 at the fully open or fully closed position, the control signal that supports the rotation range of the throttle valve 1 is set to the above-mentioned range of about 70 degrees or more, for example, 90 degrees. It is set to a certain degree.

Thereafter, at time point T5, the throttle valve 1 is again rotated in the fully closed direction and brought into contact with the fully closed stopper 8 (step 39, time point T6).

This opening/closing movement of the throttle valve 1 at T3 to T6 is controlled by an exhaust gas reburning system (EGR) in this engine.
There is a possibility that carbon may be attached to the valve stem 1a, and this opening/closing movement may be performed multiple times in order to try to remove this carbon.

Then, the fully closed position is regulated until time point T7, and it is confirmed that T3 to T6 of this throttle valve 1 have been operated once (step 4), and that position (fully closed position) is set as the reference position. From this point on, the throttle valve 1 is driven by the stepping motor 5 and reaches the opening set as the opening for starting the engine (step 52, time point T8).

Thereafter, at time point T9, the engine ignition circuit starts operating at the same time as the starter (not shown) is driven (step 6). These drives and operations continue for TL time thereafter.

Thereafter, the signal from the crankshaft rotation speed sensor 19 is compared with a preset engine start completion signal to determine whether or not the engine start has been completed (step 7).

When the engine air-fuel mixture is ignited, the signal from the crank rotation speed sensor 19 becomes larger than the set signal, so at this point (T12), the starter drive is stopped, and at the same time, the process proceeds to step 8, where normal engine rotation is resumed. Number control begins.

On the other hand, the air-fuel mixture does not ignite for a predetermined period of time (Ta, for example, 4
seconds) have elapsed (step 9), and when the time point TIO is reached, the throttle valve 1 is further opened by Δe (for example, 2 degrees) by the stepping motor (step 11).

Then, this state of opening of the throttle valve is maintained again for a predetermined time Ta, and the air-fuel mixture is ignited (step 6.7).

If ignition is not achieved even with this opening, the opening of the throttle valve is similarly maintained in a further open state, and the same operation is repeated once (for example, four times) (step 10).

If the air-fuel mixture is not ignited even after operating the throttle valve this number of times, turn off the starter and ignition circuit.
Then, in step 12), the throttle valve 1 is fully closed, and in step 13), the engine starting operation is stopped. Note that an abnormality display may be displayed together with this stop.

In this way, we decided to change the opening degree of the throttle valve while the starter motor is driving, so even if there is play in the connecting part between the throttle valve and the stepping motor, the opening degree of the throttle valve will be appropriate for starting the engine. This makes it possible to ensure the reliability of engine starting.

Next, a second embodiment of the present invention will be described. The device configuration of this second embodiment is the same as that of the first embodiment, and only the throttle valve control method is different. Therefore, the flow chart and timing of the throttle valve control are as follows. The charts are shown in FIGS. 8 and 9, and only the differences from the first embodiment will be explained.

That is, in the first embodiment, the elapse of the opening degree maintenance time Ta of the throttle valve l was determined in step 9, but in this embodiment, in a similar step 9, the elapse of the starter drive time Ts (for example, 7 seconds) is determined. We will judge the progress.

This is to avoid continuation of the driving time of the starter and to dissipate the heat generated by driving the starter motor in order to improve the durability of the starter motor.

Therefore, after the predetermined time Ts has elapsed in step 9, the scooter is stopped in step 12, and thereafter the same control method as in the first embodiment is used.

In addition, since time is required for the above-mentioned heat dissipation after the starter is stopped, the time Tb(
For example, after 3 seconds have elapsed, the process proceeds to step 10.

Therefore, the driving and stopping conditions of the starter are as shown in the timing chart shown in FIG.

In the first embodiment described above, the operation of the ignition circuit was also stopped when the starter was stopped in step 12, but in this second embodiment, even if the operation of the ignition circuit is not stopped in step 12, no actual damage will occur. There isn't.

In this way, in the second embodiment as well, since the opening degree of the throttle valve changes during engine cranking, which is the time when the scooter operates, there is no backlash or the like in the connection between the throttle valve and the stepping motor. Even if the engine is running, the engine can be started with certainty because it is adjusted.

〔Effect of the invention〕

As explained above, the present invention relates to an engine throttle valve connected to an actuator for driving operation.
The throttle valve opening degree is changed during engine cranking.

Therefore, since the opening of the throttle valve is changed during cranking of the engine, even if there is some play at the connection between the actuator and the throttle valve, the opening of the throttle valve is adjusted to the appropriate opening for starting the engine. Since the ignition operation is performed at this point, the engine can be started with certainty.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the present invention in a GHP system, and FIG. 1 is a timing chart of the first embodiment;
Figure 2 is a configuration diagram of the main parts of the GHP system, Figure 3 is an illustration of the connection between the throttle valve and actuator, Figure 4 is an illustration of the throttle valve fully open and fully closed stopper, and Figure 5 is the engine control unit. and a control block diagram of the stepping motor, FIG. 6 is an operation signal time chart of the stepping motor, FIG. 7 is a flowchart when starting the engine in the first embodiment, FIG. 8 is a flowchart when starting the engine in the second embodiment, FIG. 9 is a timing chart of the second embodiment. 1--throttle valve, 5--actuator, 11-engine. Patent Applicant: Yamaha Motor Co., Ltd. Engraving of page 8 (no changes to the contents) Figure 3 Figure 4 Figure 61''6 Procedural amendment (method) Display Patent Application No. 248208 of 1986 2, Name of the invention Engine starting device 3, Person making the amendment Relationship to the case Patent applicant 4, Date of the amendment order 6, Contents of the amendment

Claims (1)

[Scope of Claims] An engine starting device for driving and operating a throttle valve of an engine by connecting it to an actuator, characterized in that the opening degree of the throttle valve is changed during cranking of the engine.