JP3788112B2 - Speed control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speed control device for an internal combustion engine that controls the deviation between the speed of the internal combustion engine and an indicated speed to be within an allowable range.
[0002]
[Prior art]
As a speed control device that controls the rotational speed of the internal combustion engine, an electromagnetic actuator is used to operate the fuel supply amount adjustment unit of the internal combustion engine, and the actuator is controlled according to the deviation between the rotational speed of the engine and the indicated speed By doing so, a control is used in which the deviation between the rotational speed and the command speed of the internal combustion engine is controlled to be within an allowable range.
[0003]
An actuator used in this type of control device has an electromagnet (solenoid), an input end connected to a movable part of the electromagnet, and an output end connected to a fuel supply amount adjustment member of the internal combustion engine, and the movable of the electromagnet. An operation output transmission mechanism that transmits the displacement of the part to the fuel supply amount adjustment unit, and a spring that biases the movable part of the electromagnet to return to the original position.
[0004]
In this type of actuator, the output end is displaced in one direction by increasing the excitation current applied to the electromagnet, and the output end is displaced in the other direction by decreasing the excitation current. The position of the fuel supply amount adjustment unit is adjusted to adjust the fuel supply amount. Due to the influence of the hysteresis characteristics of the iron core, the output torque generated when the excitation current is increased and the excitation current is reduced. Since there is a difference between the generated driving torque, the characteristic that gives the relationship between the exciting current given to the electromagnet and the position of the movable part shows the hysteresis characteristic.
[0005]
FIG. 7 shows the relationship between the output torque of the electromagnet and the position of the movable part when the excitation current I applied to the electromagnet is increased. Curves a to d in the figure are cases where the excitation current is 1 [A], 2 [A], 3 [A], and 4 [A], respectively. When the excitation current of the electromagnet is decreased, the output torque for each excitation current is larger than the value shown in FIG. 7 due to the influence of the magnetism remaining in the iron core. The scale on the horizontal axis in FIG. 7 displays the displacement amount of the movable part of the electromagnet in%, with the position (maximum fuel supply amount position) Sf at which the fuel supply amount is maximized being 100 [%]. The position So when the displacement of the movable part of the electromagnet is 0 [%] is the original position of the movable part.
[0006]
In FIG. 7, a straight line e indicates the reaction force of the spring that urges the movable part of the electromagnet to return to the original position, and the movable part of the electromagnet stops at a position where the output torque and the reaction force of the spring balance. To do.
[0007]
As described above, in the electromagnet, since there is a difference between the output torque generated when the excitation current is increased and the output torque generated when the excitation current is decreased, the excitation current I of the electromagnet The characteristic that gives the relationship between the position of the movable part shows a hysteresis characteristic as shown in FIG. 8, and due to the hysteresis characteristic, a dead zone is generated in which the position of the movable part does not change even if the excitation current changes.
[0008]
In the example shown in FIG. 8, when the excitation current is increased to I2 and the position of the movable part is set to S1, the excitation current is decreased to move the position of the movable part to the original position So. The movable portion cannot be started toward the original position unless it is excessively changed by an amount corresponding to Ih shown and reduced to I1.
[0009]
In the above description, the characteristics of the actuator alone have been a problem. However, in the actual mechanical system of the control device including the actuator and the fuel supply amount adjusting member operated by the actuator, the sliding of each part of the operating force transmission mechanism The characteristic that gives the relationship between the excitation current applied to the actuator and the position of the fuel supply amount adjusting member under the influence of torque and the sliding resistance of the fuel supply amount adjusting member of the internal combustion engine is the hysteresis characteristic of the electromagnet alone Even greater hysteresis characteristics are exhibited.
[0010]
In this specification, the width of the hysteresis characteristic that the characteristic that gives the relationship between the excitation current of the actuator and the position of the fuel supply amount adjusting member when the output end of the actuator is connected to the fuel supply amount adjusting member A current value Ih ′ giving a current value (current value corresponding to Ih in FIG. 8) is called a dead band width of the excitation current.
[0011]
As described above, when the mechanical system of the control device that operates the fuel supply amount adjusting member by the actuator has a hysteresis characteristic, if the control for eliminating the influence of the dead zone caused by the hysteresis characteristic is not performed, the rotation of the engine The speed cannot be controlled accurately.
[0012]
In particular, in the case of a diesel engine that directly injects fuel from a fuel injection pump into a cylinder, the rotational speed of the engine changes in response to changes in the fuel injection amount. If the engine fuel supply amount adjustment member does not react even when the excitation current of the actuator is changed due to the influence of the dead zone caused by the above, the adjustment of the fuel supply amount is performed when the operation for correcting the rotation speed of the engine is performed. It is inevitable that the rotation will become unstable due to the delay. In particular, in the low speed region where the inertia energy of the engine is small, the influence of the presence of the mechanical system dead zone on the control of the engine speed becomes significant.
[0013]
Hereinafter, in this specification, a four-cycle three-cylinder diesel engine is taken as an example of an internal combustion engine to be controlled, and an electromagnetic actuator as described above is used to adjust the fuel supply amount to the diesel engine. By controlling the excitation current of the actuator, the engine speed, the command speed, and the deviation are controlled to be within an allowable range.
[0014]
As is well known, in a four-cycle diesel engine, a fuel injection pump is provided with a control rack, and the amount of fuel supplied is adjusted by the position of the control rack. Therefore, when controlling the rotational speed of the diesel engine, the output end of the actuator is coupled to the control rack (fuel supply amount adjusting member) of the fuel injection pump so that the deviation between the rotational speed of the engine and the indicated speed is within an allowable range. The excitation current supplied to the actuator is controlled so as to be within the range.
[0015]
FIG. 10 illustrates a control for eliminating a dead zone caused by a hysteresis characteristic of a mechanical system of a control device including an actuator and a fuel supply amount adjusting member when the rotational speed of a four-cycle diesel engine is controlled using an electromagnetic actuator. The control characteristics are shown when the excitation current of the actuator is changed by a control amount necessary to compensate for the deviation between the engine speed and the command speed.
[0016]
In FIG. 10, a curve a shows a temporal change in the rotational speed of the engine, and curves b and c show a temporal change in the excitation current flowing through the electromagnet of the actuator and a temporal change in the position of the control rack, respectively. In this example, the instructed speed of the engine is constant.
[0017]
In the example shown in FIG. 10, the dead zone caused by the hysteresis characteristic of the mechanical system of the control device causes a state in which the control rack does not move in the sections t1, t2 and t3 shown in the figure, and the excitation current has the dead zone width Ih '. Since the control rack starts to move after changing by more than the size, the engine rotation is unstable.
[0018]
In FIG. 10, the fine pulsation of the rotational speed of the engine is caused by the stroke change in each combustion cycle of the engine, and is a rotational fluctuation component that cannot be eliminated. The instantaneous rotational speed in each combustion cycle of the diesel engine is lowest when the piston reaches top dead center at the end of the compression stroke. The fuel is injected near the timing when the piston reaches top dead center in the compression stroke. Therefore, in the example shown in FIG. 10, the fuel injection timing is in the vicinity of each valley of the pulsation of the curve a indicating the rotational speed. The pulsation of the rotational speed accompanying the stroke change in each combustion cycle of the engine becomes particularly large at a low speed when the inertia energy of the engine is small.
[0019]
As disclosed in Japanese Patent Application Laid-Open No. 59-66719, in order to eliminate the dead zone caused by the hysteresis characteristic of the mechanical system including the actuator and the fuel supply amount adjusting member, the hysteresis characteristic of the actuator is stored in advance. It has been proposed to control the exciting current of the electromagnet so as to correct the stored hysteresis characteristics.
[0020]
However, since the hysteresis characteristics of the mechanical system of the control device are not uniform and differ for each product, the method of storing the hysteresis characteristics of the mechanical system in advance is to measure the characteristics for each individual product. Therefore, it was necessary to perform an operation for memorizing the measured characteristics, which was troublesome.
[0021]
In addition, since the hysteresis characteristics of the mechanical system of the control device are affected by the vibration of the engine, it is desirable to measure the characteristics while the engine is operating in order to perform the control to eliminate the dead band properly. Because the vibration in the engine operating state is not uniform and varies depending on the load state and the rotation speed, the hysteresis characteristic of the mechanical system of the control device in the engine operating state should be measured and stored accurately. Was difficult.
[0022]
As a technique to eliminate the dead zone caused by the hysteresis characteristic of the mechanical system of the control device, the pulsation component of the rotational speed that occurs with the stroke change in the engine combustion cycle is excited as a dither signal (vibrating current to eliminate the dead zone). A method of superimposing on an electric current is known.
[0023]
FIG. 11 shows the control characteristics when the pulsation component of the rotational speed generated with the engine stroke change is superimposed on the excitation current as a dither signal. In the figure, a curve a shows a temporal change in the rotational speed of the engine, and curves b and c show a temporal change in excitation current flowing through the electromagnet of the actuator and a temporal change in the position of the control rack, respectively. In this example as well, the instructed speed of the engine is constant.
[0024]
As described above, when the dither signal is superimposed on the excitation current of the actuator, the moving part of the electromagnet can immediately move following the change in the excitation current (dither effect is obtained), so excitation is performed at the fuel injection timing. It is possible to prevent a state in which the control rack does not respond when the current changes (control dead zone). However, when the pulsation component of the rotational speed is a dither signal, the dither effect at each fuel injection timing varies due to fluctuations in the peak value of the pulsation component, and the position at which the control rack starts to move at each fuel injection timing is made constant. Therefore, it has been unavoidable that the control rack varies with each injection timing due to the same variation in the excitation current, resulting in unstable control.
[0025]
That is, the fuel injection amount from the fuel injection pump is determined by the position of the control rack at the injection timing, but when the pulsation component of the rotational speed is a dither signal, the actual fuel injection amount is the curve c in FIG. As a result, it becomes like a broken line that connects the intersections with the vertical lines that indicate that the fuel injection amount varies greatly from one combustion cycle to the next. There wasn't.
[0026]
As the engine speed increases, the fuel supply amount adjustment member becomes easier to move due to engine vibration, and the dead zone width caused by the hysteresis characteristic of the mechanical system of the control device becomes narrower. The engine speed can be controlled stably without superimposing.
[0027]
[Problems to be solved by the invention]
As described above, the conventional speed control device for an internal combustion engine using an electromagnetic actuator as a means for operating the fuel supply amount adjusting member of the engine performs control for eliminating the dead zone caused by the hysteresis characteristic of the mechanical system. Since it could not be performed accurately, the rotation became unstable especially in the low speed region of the engine, and it was inevitable that the rotational speed giving the lower limit of the controllable region became high.
[0028]
Therefore, in the conventional speed control device for an internal combustion engine, the idling speed of the engine has to be set to a relatively high value, and it is inevitable that the fuel consumption in the idling state is deteriorated.
[0029]
In order to narrow the dead zone caused by the hysteresis characteristic of the mechanical system of the control device and reduce the influence of the dead zone on the control of the engine speed, the electromagnet is compared with the sliding resistance of the fuel supply amount adjusting member. Although it is conceivable to use a large one that generates a sufficiently large output torque, using a large electromagnet not only increases the weight of the actuator but also increases the power consumption of the electromagnet, which is not preferable. Even if a large electromagnet is used, the hysteresis characteristic of the actuator does not change, so the problem cannot be solved.
[0030]
An object of the present invention is to accurately control the rotational speed of an engine without being affected by a dead zone caused by a hysteresis characteristic of a mechanical system of a control device including an actuator and a fuel supply amount adjusting member, and Another object of the present invention is to provide a rotation speed control device for an internal combustion engine that can stably perform the operation in the above.
[0031]
[Means for Solving the Problems]
The present invention includes an electromagnet, an input end connected to the movable portion of the electromagnet, and an output end connected to a fuel supply amount adjustment member of the internal combustion engine, and the displacement of the movable portion of the electromagnet is controlled by the fuel supply amount adjustment portion. A characteristic that gives a relationship between the excitation current applied to the electromagnet and the position of the output end exhibits a hysteresis characteristic, and even if the excitation current changes due to the hysteresis characteristic An electromagnetic actuator that generates a dead zone where the position of the output end does not change, and a control unit that controls the deviation to be within an allowable range by applying an excitation current to the electromagnet according to the deviation between the rotational speed and the command speed of the internal combustion engine And a speed control device for an internal combustion engine including the above.
[0032]
In the present invention, the dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator has a constant phase relationship with the rotational speed pulsation caused by the combustion cycle of the internal combustion engine, and Dither signal superimposing means for generating integer cycles per pulsation period and superimposing the dither signal current on the excitation current is provided.
[0033]
As described above, when a dither signal having a constant phase relationship with the pulsation of the rotational speed generated by the combustion cycle of the internal combustion engine and generating an integer number of cycles per period of each pulsation is superimposed on the excitation current of the electromagnet Regardless of the width or height of the pulsation of the rotational speed, the dither effect can always be made constant, so that the position of the control rack can be made substantially the same at each fuel injection timing. Therefore, when the excitation current of the actuator is changed in order to correct the fuel injection amount at each fuel injection timing, the control rack can always start to move from substantially the same position, and the control rack can be controlled for the same amount of change in the excitation current. It is possible to prevent the variation from varying at each injection timing. As a result, the dead zone caused by the hysteresis characteristics of the electromagnet of the actuator can be eliminated, and the engine speed can be controlled stably.
[0034]
Further, in the present invention, since the amplitude of the dither signal may be set to be large, it is generated by the hysteresis characteristic of the mechanical system without being influenced by the characteristic variation due to the individual difference of the mechanical system of the control device. The controllability can be improved by eliminating the influence of the dead zone.
[0035]
When the engine speed is high, the dead zone due to the hysteresis characteristics of the mechanical system of the control device is narrowed due to the vibration of the engine, and the increase in the inertia energy of the engine affects the delay in adjusting the fuel injection amount on the engine speed. Therefore, the engine can be operated stably without superimposing the dither signal current on the excitation current of the actuator. Therefore, the dither signal current may be superimposed on the excitation current only when the engine speed is equal to or lower than the set speed.
[0036]
The vibration width of the dither signal current is a value that is slightly larger than the maximum width of the variation range of the dead band width of the excitation current caused by individual differences in the mechanical system including the actuator and the fuel supply amount adjusting member operated by the actuator. It is preferable to set to.
[0037]
The vibration width of the dither signal is preferably set to an appropriate value according to the rotational speed of the internal combustion engine, or set to an appropriate value according to the indicated speed of the internal combustion engine.
[0038]
Further, the control unit is configured to detect an internal combustion engine from a rotation sensor that generates a rotation detection pulse each time the internal combustion engine rotates by a unit angle, and an average value of rotation detection pulse generation intervals obtained over a period of one cycle of the pulsation of the rotation speed. Rotation speed calculation means for calculating the rotation speed of the engine, deviation calculation means for calculating the deviation between the rotation speed calculation means and the command speed, and a control amount of the excitation current necessary to keep the deviation below an allowable value A control amount calculation unit and an excitation circuit that applies an excitation current to the actuator according to the control amount calculated by the control amount calculation unit can be provided.
[0039]
As described above, if the rotational speed calculation means is configured, the pulsation component of the rotational speed of the engine can be prevented from being included in the calculated value of the rotational speed, and the rotational speed can be controlled stably.
[0040]
When the internal combustion engine is an n-cylinder (n is an integer equal to or greater than 1) four-cycle diesel engine or an n-cylinder four-cycle gasoline engine, the rotation sensor outputs a rotation detection pulse per rotation of the internal combustion engine (n / 2) × m (m is an integer of 2 or more). In this case, the dither signal superimposing means is configured to generate an integer number of dither signal currents having a fixed phase relationship with respect to the pulsation of the rotation speed while m rotation detection pulses are generated.
[0041]
When the internal combustion engine is an n-cylinder (n is an integer equal to or greater than 1) two-cycle diesel engine or an n-cylinder two-cycle gasoline engine, the rotation sensor sends a rotation detection pulse to each engine revolution n. Xm (m is an integer of 2 or more) is generated. In this case, the dither signal superimposing means is configured to generate an integer number of dither signal currents having a fixed phase relationship with respect to the pulsation of the rotation speed while m rotation detection pulses are generated.
[0042]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of an electromagnetic actuator used in the present invention and an example of a fuel injection pump of a four-cycle diesel engine in which a control rack is operated by the actuator.
[0043]
In FIG. 1, 1 is a fuel injection pump, and 2 is an actuator arranged side by side on one side of the fuel injection pump 1 to operate a fuel supply amount adjusting unit of the pump.
[0044]
The fuel injection pump 1 includes a pump main body (not shown) that is driven by an engine to inject fuel, a control rack 101 as a fuel supply amount adjusting member, and a pinion gear meshed with the teeth of the control rack. An injection amount adjustment mechanism (not shown) that adjusts the injection amount of fuel from the pump body by rotation is housed in the housing 102.
[0045]
The illustrated fuel injection pump 1 supplies fuel to a four-cycle three-cylinder diesel engine, and a connector 103 for connecting pipes for supplying fuel to the three cylinders of the engine is provided above the housing 102. Yes. A rotating shaft 104 that drives a pump is provided at a lower portion in the housing 1 so as to extend in parallel with the control rack 101, and is supported on a side wall portion of the housing 102 via a bearing 105.
[0046]
One end of the rotating shaft 104 is led out to the opposite side of the actuator 2, and a gear 106 is attached to the end of the rotating shaft 104 led out from the housing 102. The internal combustion engine has a drive shaft (for example, a camshaft) that rotates at a rotational speed that is half the rotational speed of the crankshaft, separately from the crankshaft, and a gear attached to the drive shaft is connected to the gear 106. The rotating shaft 104 is rotationally driven by meshing.
[0047]
The other end of the rotating shaft 104 is led out to the actuator 2 side, and a rotor 301 made of a ferromagnetic material such as iron is attached to the end of the rotating shaft 104 led out to the actuator 2 side. The rotor 301 is provided with a ring gear-shaped reluctator 301a on the outer periphery thereof, and constitutes a rotation sensor (signal generator) together with a signal generator 303 described later.
[0048]
The control rack 101 is supported by support members 107 and 108 fixed to the side wall of the housing 102 so as to be linearly displaced in a direction parallel to the axial direction of the rotary shaft 104, and one end 101a and the other end 101b thereof are supported. Are respectively led to the actuator 2 side and the opposite side of the actuator 2. In the illustrated example, the fuel injection amount (fuel supply amount) increases when the control rack 101 is displaced to the side away from the actuator 2, and the fuel injection amount decreases when the control rack 101 is displaced to the actuator 2 side. It is supposed to be.
[0049]
The other end 101 b of the control rack 101 led out on the side opposite to the actuator 2 is covered with a cap 4.
[0050]
The actuator 2 includes a frame 201 that also serves as a case, and each part of the actuator is accommodated in the frame 201. The illustrated frame 201 is formed so as to open to the opposite side of the fuel pump, and a hollow first frame half 201A whose bottom is fixed to the side surface of the housing 102 of the fuel pump 1 by screws 202, and The second frame half 201B is provided in such a manner as to close the opening of the frame half 201A and is fastened to the half 201A by a bolt (not shown).
[0051]
The rotor 301 is provided so as to be positioned in the first frame half 201A, and the magnetic pole portion of the signal generator 303 supported by the first frame half 201A via the support member 302 is provided. It is made to oppose to the ring-gear-shaped relaxer 301a provided in the outer periphery of the rotor 301. FIG. The signal generator 303 is a well-known one that has an iron core having a magnetic pole portion facing the relaxor 301a at the tip, a signal coil wound around the iron core, and a permanent magnet that causes a magnetic flux to flow through the iron core. When the teeth of 301a start facing the magnetic pole at the tip of the iron core, and when the facing ends, pulse signals having different polarities are induced in the signal coils. This pulse signal is used as a rotation detection pulse for obtaining information on the rotation angle position of the rotation shaft of the internal combustion engine and rotation speed information.
[0052]
In the example shown in the figure, the ring gear-shaped reluctator 301a has 15 teeth at equal angular intervals, and the signal generator 303 generates a positive polarity pulse and a negative polarity pulse during one revolution of the engine crankshaft. 30 are generated each time.
[0053]
In the control device according to the present invention, either positive polarity pulses or negative polarity pulses generated 30 times per rotation of the crankshaft are used as rotation detection pulses.
[0054]
An electromagnet 205 is fixed to the lower portion of the second frame half 201B, and a mover 206 is disposed on the side of the electromagnet 205. The electromagnet 205 is made of a laminate of steel plates, and has a substantially E-shaped iron core 207 having a shape in which three magnetic pole portions 207b to 207d protrude from the yoke 207a, and a central magnetic pole portion 207c wound around a bobbin. It comprises an excitation coil 208 fitted and a mover 206.
[0055]
The mover 206 has a substantially comb-like shape including an I-shaped yoke 206a and three magnetic pole portions 206b to 206d protruding from the yoke 206a on one side.
[0056]
A hole is provided at one end of the yoke 206a of the mover 206, and the support shaft 210 is rotatably fitted in the hole. The support shaft 210 is disposed at a substantially central portion of the frame half 201B in a state where the axis thereof is orthogonal to the axis of the control rack 101, and both ends thereof are fixed to the frame half 201B. Thereby, the mover 206 is rotatably supported by the frame 201. The magnetic pole portions 206b to 206d of the mover 206 are provided so as to correspond to the magnetic pole portions 207b to 207d of the iron core, respectively, and when the exciting coil 208 is excited, the magnetic pole portions 206b to 206d of the mover 206 are respectively The mover 206 is rotated toward the iron core 207 by being attracted by the magnetic pole portions 207b to 207d.
[0057]
A stopper 211 is attached to the lower portion of the frame half portion 201B by screwing a stopper 211 that abuts the distal end of the movable element 206 to regulate the rotation range of the movable element 206 when the movable element 206 rotates away from the iron core 207. Has been. In the illustrated example, the position of the movable element (the position shown in FIG. 1) when the tip of the movable element 206 is in contact with the stopper 211 is defined as the first position of the movable element. The mover 206 is displaced between this original position and the second position at which the magnetic pole portions 206b to 206d are completely attracted to the magnetic pole portions 207b to 207d of the iron core 207 and contact the electromagnet. The rotation range is determined so as to obtain.
[0058]
A return spring 213 is disposed between a spring receiving portion provided at the tip of the movable element 206 and a spring receiving member 212 fixed to the lower portion of the frame half portion 201B, and the movable element 206 is always the first by the return spring. It is biased to the position side. Therefore, the mover 206 is held at the first position shown when the electromagnet 205 is in a non-excited state.
[0059]
An output lever 215 is also rotatably supported on the support shaft 210. The output lever 215 is made of a metal plate punched into a predetermined shape, and the output lever 215 and the mover 206 are arranged with their positions shifted in the axial direction of the support shaft 210. The output lever 215 is configured so that the rotation center of the output lever 215 coincides with the rotation center of the movable element 206 (the central axis of the support shaft 210) by fitting the support shaft 210 in a hole formed in the middle thereof. In this state, it is supported so that it can be rotated in a state in which relative rotational displacement is allowed to occur between the movable element 206 and the movable element 206.
[0060]
The output lever 215 has a first portion 215 a that extends from the portion supported by the support shaft 210 to the opposite side of the movable element 206 and a second portion 215 b that extends on the same side as the movable element 206. Thus, a protrusion 215 c that protrudes on the opposite side of the iron core 207 is provided in a portion of the second portion 215 b near the support shaft 210. One end of a connection spring 216 made of a tension spring is connected to the protrusion 215c, and the other end of the connection spring 216 is fixed to a protrusion 206e provided near the tip of the movable element 206. The spring 216 connects the mover 206 and the output lever 215 so that the mover 206 is attracted by the iron core 207 and rotated from the first position to the second position and when the iron core 207 is excited. When the current is decreased and the movable element 206 rotates from the second position toward the first position, the output lever 215 rotates following the rotation of the movable element 206. .
[0061]
At the end of the second portion 215b of the output lever 215, an upright part 215d is formed standing on the movable element 206 side, and a screw 217 screwed into a screw hole provided in the upright part 215d is provided. The yoke 206a is in contact with the side surface. In this example, the screw 217 constitutes a position adjustment mechanism that adjusts the position of the output lever 215 when the mover 206 is in the first position, and adjusts the amount of protrusion of the screw 217 to the mover 206 side. Thus, the position of the output lever 215 when the mover 206 is in the first position can be adjusted as appropriate. The screw 217 is held in contact with the mover 206 by the biasing force of the spring 216.
[0062]
One end of the link 218 is connected to the first portion of the output lever 215 via the first pin P1, and the other end of the link 218 is connected to the one end 101a of the control rack 101 via the second pin P2. Yes. A first collar 221 and a second collar 222 are attached to the first pin P1 and the second pin P2, respectively.
[0063]
In this example, the second portion 215b of the output lever 215 is the output end of the actuator 2, and the output lever 215 is moved when the electromagnet movable element 206 rotates from the first position toward the second position. However, the control rack 101 is displaced to the fuel supply amount increase side.
[0064]
A position sensor 5 composed of a potentiometer is attached to the outside of the second half 201B of the frame 201. The position sensor 5 has a movable shaft 5a biased by a spring on the side protruding from the main body of the sensor, and outputs an electrical signal proportional to the amount of linear displacement of the movable shaft 5a. . The movable shaft 5a of the position sensor 5 is inserted into the frame 201, and the distal end of the movable shaft 5a is provided at the distal end of a protruding portion 215e that protrudes from the intermediate portion of the output lever 215 to the electromagnet 205 side. It is in contact with the portion 215f. Accordingly, the movable shaft 5 a of the position sensor 5 is displaced with the rotation of the output lever 215, and an electric signal corresponding to the rotation position of the output lever 215 is obtained from the position sensor 5.
[0065]
An exciting coil 208 of the electromagnet 205 is connected to a controller (not shown) through an electric cord 6 having a connector 6a at the tip, and an exciting current is applied to the exciting coil 208 from the controller. The output of the position sensor 5 is provided to a controller (not shown) through a lead wire 7 having a connector 7a at the tip.
[0066]
In the above example, the displacement of the electromagnet movable element 206 is controlled by the control rack 101 (fuel supply amount adjusting member) by the output lever 215, the connecting spring 216, the position adjusting mechanism including the screw 217, and the connecting means including the link 218. An operation output transmission mechanism for transmitting to is configured.
[0067]
In the illustrated example, a drive shaft 223 extending on the side of the link 218 in parallel with the rotation shaft (support shaft 210) of the output lever 215 is rotatably supported by the frame 201. One end of the drive shaft 223 is led out of the frame 201, and one end of the manual operation lever 224 is fixed to one end of the drive shaft 223. The manual operation lever 224 is provided so that the other end extends to a position where it can be manually operated. By rotating the manual operation lever clockwise and counterclockwise in FIG. 1, the drive shaft 223 is rotated clockwise. And can be rotated counterclockwise.
[0068]
One end of a rotating plate 225 constituting a forced drive member is fixed to the other end of the drive shaft 223 located in the frame 201. The rotating plate 225 is disposed so as to intersect the link 218 in a non-contact manner at a position between the first pin P1 and the second pin P2, and the first pin P1 and the second pin P2. The neutral position of the forcible drive member (rotating plate) 225 is set at a position between the two. In the state shown in the drawing, the rotating plate 225 is disposed at the neutral position, and the rotating plate 225 is placed between the pin 226 fixed to the rotating plate 225 and the pin fixed to the frame 201. A holding spring (a tension spring) 227 that is urged so as to be held is attached. The rotating plate 225 is urged by the holding spring 227 and held at the neutral position shown in the figure when no external force is applied from the manual operation lever 224 side.
[0069]
When the rotating plate 225 is rotated to the output lever 215 side by the manual operation lever 224, the rotating plate 225 comes into contact with the first collar 221 and the control rack 101 is urged by the connecting spring 216. The output lever 215 is rotated so as to be displaced against the fuel supply amount decreasing side, and when the rotating plate 225 is rotated to the control rack 101 side, the rotating plate 225 becomes one end 101a of the control rack 101. The control rack 101 is configured to displace to the fuel supply amount increase side in contact with (see FIG. 2).
[0070]
In the fuel supply device described above, when the exciting coil 208 of the electromagnet 205 is energized, the magnetic pole portions 206b, 206c and 206d of the mover 206 are attracted to the magnetic pole portions 207b, 207c and 207d of the iron core 207, respectively. 206 rotates from the illustrated first position toward the second position which is the limit position on the iron core 207 side. When the movable element 206 is rotated, the output lever 215 connected to the movable element via the spring 216 is rotated in the same direction as the movable element 206. As a result, the control rack 101 of the fuel injection pump 1 is displaced toward the side where the fuel supply amount is increased. The mover 206 stops at a position where the attractive force of the iron core 207 and the biasing force of the return spring 213 are balanced. The stop position of the mover 206 can be appropriately adjusted according to the magnitude of the current flowing through the exciting coil 208.
[0071]
When the control rack 101 comes into contact with a stopper portion (not shown), the movement of the control rack 101 is stopped and the increase in the fuel supply amount is stopped. The position of the control rack 101 at this time is the fuel supply amount maximum position.
[0072]
In the electronic governor fuel supply apparatus described above, when the electromagnet 205 cannot drive the output lever 215 due to some reason and the control rack 101 cannot be operated, the manual operation lever 224 is manually operated. The forced drive member 225 is rotated by holding and rotating, and the output lever 215 and the control rack 101 can be manually operated.
[0073]
In the example shown in FIG. 1, the output lever 215 is supported by the support shaft 210 common to the mover 206 so that the rotation center of the output lever 215 coincides with the rotation center of the mover 206. 215 is rotatably supported by the frame in a state in which it can be rotated relative to the mover about an axis common to the rotation center axis of the mover or an axis parallel to the rotation center axis. It only has to be. Therefore, the rotation center of the output lever 215 is not necessarily coincident with the rotation center of the movable element 206, and the output lever 215 is rotatably supported by a shaft different from the shaft that supports the movable element 206. It may be.
[0074]
In the example shown in FIG. 1, the position sensor 5 for detecting the rotational position of the output lever 215 is provided, but the position control for controlling the actuator 2 so as to keep the position of the control rack at the target position is not performed. In this case, the position sensor 5 can be omitted.
[0075]
FIG. 2 shows a controller 12 that controls the actuator 2 together with a four-cycle three-cylinder diesel engine 10 to be controlled, a load 11 of the engine, and the like. The controller 12 shown in FIG. 2 has an input processing circuit 12a that receives an output of the rotation sensor 3 and an output of an accelerator sensor 13 that outputs an instruction speed signal that gives an instruction rotation speed of the engine, and an input processing circuit 12a. The microcomputer 12b to which the output of each sensor is input, the excitation circuit 12c that converts the output of the microcomputer 12b into the excitation current to be applied to the electromagnet of the actuator and is applied to the excitation coil of the electromagnet 205, and the output of the battery 13 are input. And a power supply circuit 14 that outputs a voltage necessary for driving each part of the controller.
[0076]
The microcomputer 12b, along with the rotation sensor 3, the rotation speed instruction means 13, and the excitation circuit 12c, gives an excitation current to the electromagnet 205 according to the deviation between the rotation speed and the instruction speed of the internal combustion engine, and the rotation speed and the instruction speed. The control part which controls so that the deviation of this may fall within an allowable range is comprised.
[0077]
The configuration of this control unit is, for example, as shown in FIG. In FIG. 3, the rotational speed calculation means 21 calculates the rotational speed of the internal combustion engine from the average value of the rotation detection pulse generation intervals obtained over one period of the pulsation of the rotational speed of the engine (the engine of one combustion cycle). The deviation calculating means 23 calculates the deviation between the rotation speed calculated by the rotation speed calculating means and the instruction speed given from the rotation speed instruction means 13.
[0078]
Further, the operation amount calculation unit 24 calculates, as the operation amount, the magnitude of the excitation current that needs to be given to the electromagnet 205 of the actuator in order to keep the deviation calculated by the deviation calculation means 23 below the allowable value. The excitation circuit 12 c supplies an excitation current to the electromagnet 2 according to the operation amount calculated by the operation amount calculation unit 24. As a result, the output end of the actuator 2 is displaced, the control rack 101 is moved to a predetermined position, and the rotational speed of the engine is corrected so that the deviation between the rotational speed of the engine and the command speed falls within an allowable range.
[0079]
Since the 4-cycle diesel engine performs four strokes of intake, compression, explosion and exhaust while the crankshaft rotates twice, in the case of three cylinders, three explosion strokes are performed per two rotations. Therefore, in a three-cylinder four-cycle diesel engine, as shown in FIG. 4 (A), the width of the pulsation of the rotational speed is a width corresponding to 2/3 rotation of the crankshaft. Assuming that 30 rotation detection pulses are generated per one rotation of the shaft, the width corresponding to 20 pulses is the pulsation width of the rotation speed.
[0080]
In this case, as shown in FIG. 4B, an average value of pulse intervals for 20 pulses (average value of time required for 2/3 rotation) is obtained, and the rotational speed is calculated from the average value. If so, the engine speed can be obtained without being affected by the pulsation component of the engine speed.
[0081]
Further, when each pulse is generated, the pulse interval between the previous pulse is obtained, the average value of the pulse intervals for 20 pulses is sequentially obtained, and the rotational speed is calculated from the average value. The rotational speed can be detected without being affected by the pulsation component for each pulse.
[0082]
Note that the excitation current shown in FIG. 10 is an excitation current that does not include a component that compensates for pulsation, and the pulsation-free curve superimposed on the rotation speed in FIG. 11 is the rotation speed detected by the above method. . If there is no dead zone in the actuator, a compensation amount (control amount) of the excitation current necessary to compensate for the fluctuation in the rotational speed is obtained based on the rotational speed detected in this way, and the compensation amount is stored in the actuator. By adding to the exciting current that flows, it is possible to stably perform control for maintaining the rotational speed of the engine at the indicated speed.
[0083]
However, because there is actually a dead zone caused by the hysteresis characteristics of the mechanical system including the actuator and control rack, simply calculating the compensation for the excitation current using the rotation speed detected without being affected by the pulsation component, The rotation speed cannot be controlled stably.
[0084]
Therefore, in the present invention, the dither signal current that vibrates with a vibration width greater than the dead band width of the excitation current of the actuator is given a constant phase relationship with the rotational speed pulsation caused by the combustion cycle of the internal combustion engine. And a dither signal superimposing means for generating an integer cycle per period of each pulsation and superimposing the dither signal current on the excitation current.
[0085]
FIGS. 5A to 5C show signal processing performed by the dither signal superimposing means. FIG. 5A shows the pulsation component of the rotation speed, and FIG. 5B shows the rotation detection pulse generated by the rotation sensor. Show. The generation interval of the rotation detection pulse changes according to the instantaneous value of the pulsation component of the rotation speed. FIG. 5C shows the dither signal voltage superimposed on the control voltage Q applied to the excitation coil of the electromagnet in order to superimpose the dither signal current on the excitation current of the actuator. In this example, the dither signal voltage is composed of a vibration voltage that vibrates with a vibration width equal to the width of the dead band around the level that gives the center of the dead band width of the excitation current. One cycle of the dither signal voltage is generated per period.
[0086]
In the example shown in the figure, 20 rotation detection pulses are generated per cycle of the pulsation of the rotation speed. Therefore, a period in which 20 rotation detection pulses are generated is defined as one cycle of the dither signal. And the dither signal is generated with a constant phase relationship with the pulsation of the rotational speed.
[0087]
In the example shown in the figure, a voltage corresponding to the half-wave amplitude of the dither signal voltage is added to or subtracted from the control voltage Q applied to the exciting coil of the electromagnet at intervals of 10 rotation detection pulses, so that 1 per pulsation cycle. The dither signal voltage of the cycle is generated in a state in which the zero point is matched with the valley of the pulsation of rotation speed (fuel injection timing).
[0088]
The cycle of the dither signal does not necessarily have to be equal to the cycle of the pulsation of the rotational speed and may be shorter than the cycle of the pulsation of the rotational speed. It is necessary to generate them one by one.
[0089]
The vibration width of the dither signal current is preferably set to be slightly larger than a value that gives a lower limit of the range of variation in the dead zone width Ih ′ of the excitation current due to individual differences in the mechanical system of the control device.
[0090]
When the excitation current of the actuator is PWM-controlled, the magnitude of the dither signal current is set in the form of a duty ratio, and the magnitude of the dither signal current is set to the duty ratio that gives the magnitude (average value) of the excitation current. By adding or subtracting the given duty ratio, the dither signal current can be superimposed on the excitation current.
[0091]
In the control unit shown in FIG. 3, the rotation speed calculation unit 21, the deviation calculation unit 23, the control amount calculation unit 24, and the dither signal superimposing unit 26 can be realized by causing the microcomputer 12b to execute a predetermined program. .
[0092]
FIG. 6 shows a rotation detection pulse interruption routine that is executed every time the rotation sensor 3 generates a rotation detection pulse in order to realize the dither signal superimposing means 26. When the rotation detection pulse is generated, the count value of the interrupt counter is incremented in step 1, and then it is determined in step 2 whether the count value of the interrupt counter is 20 or less. As a result, if the count value is 20 or less, it is next determined in step 3 whether the count value of the interrupt counter is 10 or less. If the count value is 10 or less, the dither data is output from the PWM output. Is returned to the main routine.
[0093]
If it is determined in step 3 that the count value of the interrupt counter exceeds 10, the process proceeds to step 5 to add dither data to the PWM output and then returns to the main routine.
[0094]
Here, the “PWM output” is a control amount (excitation current necessary for keeping the deviation within the allowable range) obtained by performing PID calculation on the deviation between the engine speed and the command speed. It is calculated by the control amount calculation means realized.
[0095]
“Dither data” is an amount that gives the half-wave amplitude of the dither signal, and is stored in the ROM in the form of a duty ratio when the excitation current of the electromagnet is subjected to PWM control.
[0096]
When it is determined in step 2 that the count value of the interrupt counter exceeds 20, the process proceeds to step 6 to clear the interrupt counter and return to the main routine.
[0097]
When the dither signal current that vibrates is superimposed on the excitation current of the actuator 2, the movable part of the electromagnet vibrates with the vibration of the dither signal. In this way, if the moving part of the electromagnet is constantly vibrating, the moving part of the electromagnet can move immediately when the excitation current changes at the fuel injection timing. There is no longer a situation where the rack does not move (dither effect is obtained). However, if the position at which the movable part of the electromagnet starts to move at each injection timing varies, the amount of fuel supplied cannot be accurately changed with respect to the change in the excitation current, so that the rotation speed can be controlled stably. I can't.
[0098]
However, as in the present invention, the dither signal current that vibrates with a vibration width greater than the dead band width of the excitation current of the actuator 2 has a constant phase relationship with the rotational speed pulsation caused by the combustion cycle of the internal combustion engine. If the dither signal current is superimposed on the excitation current by generating an integer number of cycles per each pulsation, the dither effect is always constant regardless of the width or height of the pulsation of the rotational speed. Therefore, at each fuel injection timing, the position at which the control rack 101 starts to move in response to a change in the excitation current can be made the same.
[0099]
Therefore, when the excitation current of the actuator is changed to correct the fuel injection amount at each fuel injection timing, the control rack can always start to move from the same position, and the change of the control rack with respect to the same change amount of the excitation current. It is possible to prevent the amount from varying at each injection timing. For this reason, the influence of the dead zone caused by the hysteresis characteristic of the mechanical system of the control device on the control can be eliminated, and the rotation speed of the engine can always be controlled stably.
[0100]
In the present invention, the dither signal current is oscillated symmetrically around the center level of the dead zone width of the excitation current of the actuator, so there is no problem even if the amplitude of the dither signal current is increased. Therefore, as described above, the vibration width of the dither signal current can be set larger than a value that gives the lower limit of the range of the variation of the dead band width Ih ′ of the excitation current due to individual differences in the mechanical system of the control device. By setting the amplitude of the dither signal current in this manner, it is possible to perform favorable control without being affected by variations in actuator characteristics and without being affected by the dead zone.
[0101]
Actually, when the rotational speed of the same engine as the diesel engine shown in FIGS. 10 and 11 is controlled, as shown in FIG. 5C, the dither signal voltage of one cycle per cycle of the pulsation of the rotational speed. Was applied to the electromagnet of the actuator and the dither signal current was superimposed on the excitation current, and good control characteristics as shown in FIG. 9 could be obtained.
[0102]
In the example shown in FIG. 9, the dither signal component causes a current ripple greater than the hysteresis width (dead band width) in the excitation current of the actuator, which eliminates the dead band and causes the control rack to respond quickly to the excitation current and cause the fuel to flow. The supply amount is adjusted.
[0103]
Further, when the rotational speed of the engine starts to decrease due to the application of a load, the excitation current of the actuator starts to increase, but the control rack operates without any response delay due to the dead zone to adjust the engine fuel.
[0104]
In the present invention, it is preferable that the vibration width of the dither signal is set to an appropriate value according to the rotational speed of the internal combustion engine, or set to an appropriate value according to the indicated speed of the internal combustion engine.
[0105]
The appropriate value of the dither signal varies depending on the rotational speed of the engine. In general, it is preferable to increase the vibration width of the dither signal as the rotational speed is lower. Therefore, as described above, the vibration width of the dither signal is set to an appropriate value according to the rotational speed of the internal combustion engine, or the vibration width of the dither signal is set to an appropriate value according to the indicated speed of the internal combustion engine. By doing so, it is possible to always obtain the optimum dither effect.
[0106]
In the above example, it is generated based on the rotation detection pulse obtained from the rotation sensor. However, the method of generating the dither signal is not limited to the above example. For example, the frequency of the pulsation component of the rotational speed of the engine The dither signal may be obtained by shaping the waveform so that the crest values of the signal obtained by multiplying the frequency are equal.
[0107]
In the above example, the diesel engine is taken as an example, but the present invention is also applied to the case where the rotational speed is controlled using an electromagnetic actuator to adjust the fuel supply amount of a gasoline engine or a gas engine. Can do. When controlling the rotational speed of a gasoline engine or a gas engine, the control system is stabilized by a response delay of a vaporizer that vaporizes fuel or a mixer that mixes fuel and air. Therefore, stable rotation speed control can be performed by appropriately setting the amplitude of the dither signal without expecting the stability factors due to these response delays.
[0108]
In the above example, a four-cycle three-cylinder internal combustion engine is taken as an example. However, in the case of a four-cycle four-cylinder internal combustion engine, the rotation speed pulsation period is a period corresponding to 1/2 rotation of the crankshaft. When the sensor generates 30 rotation detection pulses per rotation, the rotation speed pulsation period is equal to a period of 15 pulses. In the case of a 4-cycle 6-cylinder internal combustion engine, the period of the pulsation of the rotational speed is a period corresponding to 1/3 rotation of the crankshaft, and the rotation sensor generates 30 rotation detection pulses per rotation. The period of the pulsation of the rotational speed becomes equal to the period of 10 pulses.
[0109]
The present invention can also be applied when controlling the rotational speed of a two-cycle engine. When the rotational speed of an m-cylinder two-cycle engine is controlled, the period of one cycle of rotational speed pulsation is equal to the period corresponding to 1 / m rotation of the crankshaft.
[0110]
【The invention's effect】
As described above, according to the present invention, a dither signal having a constant phase relationship with the pulsation of the rotational speed generated by the combustion cycle of the internal combustion engine and generating an integer number of cycles per period of each pulsation is generated by the electromagnet. Since it is superimposed on the excitation current, the dither effect can be kept constant regardless of the width or height of the pulsation of the rotational speed, and in response to changes in the excitation current at each fuel injection timing The starting position of the control rack can be made the same. Therefore, when the excitation current of the actuator is changed to correct the fuel injection amount at each fuel injection timing, the control rack can always start to move from the same position, and the change of the control rack with respect to the same change amount of the excitation current. It is possible to prevent the amount from varying at each injection timing. Therefore, it is possible to eliminate the influence of the dead zone caused by the hysteresis characteristic of the mechanical system of the control device on the control, and to stably control the engine speed.
[0111]
Further, according to the present invention, since the amplitude of the dither signal may be set to be large, it is not affected by variations in actuator characteristics or variations in the sliding resistance of the engine fuel supply amount adjustment unit. Further, the controllability can be improved by eliminating the influence of the dead zone caused by the hysteresis characteristic of the actuator of the mechanical system of the control device.
[Brief description of the drawings]
FIG. 1 is a side view showing a partial cross section of an example of the configuration of an actuator and a fuel injection pump used in an internal combustion engine speed control apparatus according to the present invention.
FIG. 2 is a block diagram showing a configuration of a controller used in the speed control device according to the present invention.
FIG. 3 is a block diagram showing a configuration example of a control unit used in the speed control device according to the present invention.
FIG. 4 is a waveform diagram showing a pulsation component of rotation speed and a rotation detection pulse of an internal combustion engine to be controlled by the present invention.
FIG. 5 is a waveform diagram showing a pulsation component of a rotation speed of an internal combustion engine, a rotation detection pulse, and a dither signal that are controlled by the present invention.
FIG. 6 is a flowchart showing an example of an algorithm of a program executed by the microcomputer in the speed control device according to the present invention.
FIG. 7 is a diagram showing an example of the relationship between the position of the movable part of the electromagnet of the actuator used in the speed control device for an internal combustion engine according to the present invention and the output torque, using the excitation current as a parameter.
FIG. 8 is a diagram showing an example of a characteristic that gives a relationship between the position of the movable part of the electromagnet of the actuator used in the speed control device for an internal combustion engine according to the present invention and the excitation current.
FIG. 9 is a diagram showing an example of control characteristics obtained by a speed control device for an internal combustion engine to which the present invention is applied.
FIG. 10 is a diagram showing control characteristics when a dither signal is not superimposed on an excitation current of an actuator in a speed control device for a four-cycle three-cylinder diesel engine.
FIG. 11 is a diagram showing control characteristics when a pulsation component of engine rotational speed is superimposed as a dither signal on an excitation current of an actuator in a speed control device of a four-cycle three-cylinder diesel engine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fuel injection pump, 2 ... Actuator, 3 ... Rotation sensor, 12 ... Controller, 13 ... Rotation speed instruction | indication means.

Claims (8)

An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  The dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator has a constant phase relationship with the pulsation of the rotational speed generated by the combustion cycle of the internal combustion engine, and 1 of each pulsation Dither signal superimposing means for generating integer cycles per period and superimposing the dither signal current on the excitation current is provided,
  The speed control apparatus for an internal combustion engine, wherein the vibration width of the dither signal is set to an appropriate value according to the rotational speed of the internal combustion engine. An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  The dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator has a constant phase relationship with the pulsation of the rotational speed generated by the combustion cycle of the internal combustion engine, and 1 of each pulsation Dither signal superimposing means for generating integer cycles per period and superimposing the dither signal current on the excitation current is provided,
  The vibration width of the dither signal current is slightly larger than the maximum width of the range of the dead band width variation of the excitation current caused by individual differences in the mechanical system including the actuator and the fuel supply amount adjusting member operated by the actuator. Set to the value
  The speed control apparatus for an internal combustion engine, wherein the vibration width of the dither signal is set to an appropriate value according to the rotational speed of the internal combustion engine. An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  When the rotational speed of the internal combustion engine is equal to or lower than a set speed, a dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator is generated by the rotational speed pulsation caused by the combustion cycle of the internal combustion engine A dither signal superimposing means for superimposing the dither signal current on the excitation current by generating an integer number of cycles per period of each pulsation with a constant phase relationship with respect to
  The speed control apparatus for an internal combustion engine, wherein the vibration width of the dither signal is set to an appropriate value according to the rotational speed of the internal combustion engine. An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  When the rotational speed of the internal combustion engine is equal to or lower than a set speed, a dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator is generated by the rotational speed pulsation caused by the combustion cycle of the internal combustion engine A dither signal superimposing means for superimposing the dither signal current on the excitation current by generating an integer number of cycles per period of each pulsation with a constant phase relationship with respect to
  The vibration width of the dither signal current is slightly larger than the maximum width of the range of the dead band width variation of the excitation current caused by individual differences in the mechanical system including the actuator and the fuel supply amount adjusting member operated by the actuator. Set to the value
  The speed control apparatus for an internal combustion engine, wherein the vibration width of the dither signal is set to an appropriate value according to the rotational speed of the internal combustion engine. An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  The dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator has a constant phase relationship with the pulsation of the rotational speed generated by the combustion cycle of the internal combustion engine, and 1 of each pulsation Dither signal superimposing means for generating integer cycles per period and superimposing the dither signal current on the excitation current is provided,
The vibration width of the dither signal is set to an appropriate value according to the rotational speed of the internal combustion engine,
  An internal combustion engine speed control device, wherein the vibration width of the dither signal is set to an appropriate value in accordance with an instruction speed of the internal combustion engine. An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  The dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator has a constant phase relationship with the pulsation of the rotational speed generated by the combustion cycle of the internal combustion engine, and 1 of each pulsation Dither signal superimposing means for generating integer cycles per period and superimposing the dither signal current on the excitation current is provided,
  The vibration width of the dither signal current is a variation in the dead band width of the excitation current caused by individual differences in the mechanical system including the actuator and the fuel supply amount adjusting member operated by the actuator. Set to a value slightly larger than the maximum width of the
  An internal combustion engine speed control device, wherein the vibration width of the dither signal is set to an appropriate value in accordance with an instruction speed of the internal combustion engine. An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  When the rotational speed of the internal combustion engine is equal to or lower than a set speed, a dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator is generated by the rotational speed pulsation caused by the combustion cycle of the internal combustion engine A dither signal superimposing means for superimposing the dither signal current on the excitation current by generating an integer number of cycles per period of each pulsation with a constant phase relationship with respect to
  An internal combustion engine speed control device, wherein the vibration width of the dither signal is set to an appropriate value in accordance with an instruction speed of the internal combustion engine. An electromagnet having a movable portion that generates a displacement corresponding to the magnitude of the excitation current; an input end connected to the movable portion of the electromagnet; and an output end connected to a fuel supply amount adjusting member of the internal combustion engine. An operation output transmission mechanism for transmitting the displacement of the movable part of the electromagnet to the fuel supply amount adjusting unit, and the characteristic that gives the relationship between the excitation current applied to the electromagnet and the position of the output end is a hysteresis characteristic Due to the hysteresis characteristic, an electromagnetic actuator in which a dead zone in which the position of the output end does not change even if the excitation current changes, and the electromagnet according to the deviation between the rotational speed and the indicated speed of the internal combustion engine In a speed control device for an internal combustion engine provided with a control unit that controls the deviation to fall within an allowable range by applying an excitation current,
  When the rotational speed of the internal combustion engine is equal to or lower than a set speed, a dither signal current that vibrates with a vibration width equal to or greater than the dead band width of the excitation current of the actuator is generated by the rotational speed pulsation caused by the combustion cycle of the internal combustion engine A dither signal superimposing means for superimposing the dither signal current on the excitation current by generating an integer number of cycles per period of each pulsation with a constant phase relationship with respect to
  The vibration width of the dither signal current is slightly larger than the maximum width of the range of the dead band width variation of the excitation current caused by individual differences in the mechanical system including the actuator and the fuel supply amount adjusting member operated by the actuator. Set to the value
  An internal combustion engine speed control device, wherein the vibration width of the dither signal is set to an appropriate value in accordance with an instruction speed of the internal combustion engine.

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