JP2009255769A - Outboard motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To finely adjust the rotational speed of an engine by a simple constitution. <P>SOLUTION: An outboard motor 10 electrically controls the opening/closing operation of a throttle valve 53 so as to set the actual rotational speed Nr of an engine 14 for driving a propeller 18 to a target value. The outboard motor 10 comprises a low-speed mode changing unit 44 provided at a steering handle 41 to perform the manipulated operation, a turnable grip 42 provided at a fore end of the steering handle, a grip operational quantity detection unit 43 for detecting the operational quantity of the grip, and a control unit 51 which sets the target rotational speed according to an operational quantity detected by the grip operational quantity detection unit and controls the opening/closing operation of the throttle valve 53 so that the actual rotational speed Nr is set to the target value. The control unit 51 reduces the rate of a change of the target rotational speed according to the operational quantity when the changing signal is received from the low-speed mode changing unit 44 compared with the case that any changing signal is not received. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for controlling the rotational speed of an engine in an outboard motor.

In a small vessel, an outboard motor is mounted at the rear of the hull. The outboard motor includes a substantially horizontal bar-shaped steering handle. Various types of such outboard motors are known (see, for example, Patent Document 1-2).
JP 2005-319881 A Japanese Examined Patent Publication No. 2-014235

  The outboard motor known from this patent document 1-2 has a rotatable grip at the tip of the steering handle. The opening degree of the throttle valve can be adjusted by turning the grip. As a result, the rotational speed of the engine changes. The ship operator performs two operations simultaneously with one hand, while adjusting the opening degree of the throttle valve by further rotating the grip while grasping and gripping the grip.

  By the way, in the case of trolling (troll fishery), the speed of the ship is finely adjusted according to the situation. For this purpose, it is required that the engine speed can be finely adjusted. Fine adjustment of the rotation speed while the steering operator steers for a long time is a heavy burden on the operator and requires skill. In particular, for beginners, considerable training is required in order to make maneuvering easier.

  For this reason, the outboard motor known in Patent Document 1-2 is separately provided with an operation member that performs fine adjustment at a low speed. However, since the separate operation member is finely adjusted by the mechanical configuration, the configuration is complicated and there is room for further improvement.

  It is an object of the present invention to provide a technique capable of finely adjusting the rotational speed of an engine with a simple configuration and capable of maneuvering easily.

  In the invention according to claim 1, in the outboard motor that electrically controls the opening and closing of the throttle valve so that the actual rotational speed of the engine that drives the propeller matches the target rotational speed, the steering handle is provided and the manual operation is performed. A possible low-speed mode switching unit, a rotatable grip provided at the tip of the steering handle, a grip operation amount detection unit for detecting an operation amount of the grip, and the grip operation amount detection unit detected by the grip operation amount detection unit A control unit that sets the target rotational speed according to an operation amount and controls the opening and closing of the throttle valve so that the actual rotational speed matches the target rotational speed. When the switching signal is received from the low-speed mode switching unit, the rate at which the target rotational speed changes according to the operation amount compared to when the switching signal is not received , Characterized in that it is configured to control so as to reduce.

  According to a second aspect of the present invention, in the first aspect, when the control unit no longer receives the switching signal from the low speed mode switching unit, the control unit maintains the target rotation speed immediately before the switching signal is not received. It is the structure controlled to this.

  According to a third aspect of the present invention, in the second aspect, when the operation amount changes after the control unit has stopped receiving the switching signal from the low-speed mode switching unit, the control unit starts from the maintained target rotational speed. Further, the present invention is characterized in that the control is performed so as to gradually change the target rotational speed according to the changed operation amount.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the low-speed mode switching unit includes a manual operation switch disposed in the vicinity of the grip.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the steering handle includes a display unit that displays the actual rotational speed and the target rotational speed. And

  In the invention according to claim 1, the steering handle includes a rotatable grip and a low-speed mode switching unit. The control unit sets a target rotation speed in accordance with the grip operation amount detected by the grip operation amount detection unit, and controls opening and closing of the throttle valve so that the actual rotation speed matches the target rotation speed. The low speed mode switching unit issues an electrical switching signal in accordance with the operation of the vessel operator. When receiving the switching signal from the low-speed mode switching unit, the control unit reduces the rate at which the target rotational speed changes according to the operation amount, compared to when the control signal is not received.

  That is, the rate at which the target rotational speed changes according to the amount of grip operation is reduced by a simple operation that only operates the low-speed mode switching unit. Even if the amount of grip operation is maximum, the target rotational speed does not increase. For this reason, the target rotation speed can be finely adjusted. Since the engine speed can be finely adjusted in the low speed region, the speed of the ship can be finely adjusted in trolling (troll fishery) or the like. Even beginners can easily operate a ship. In addition, the low-speed mode switching unit can simply be configured because it only generates an electrical switching signal in response to the operation of the vessel operator.

  In the invention according to claim 2, the control unit does not receive the switching signal from the low speed mode switching unit when the operator operates to release the low speed mode switching unit. At this time, the control unit maintains the target rotational speed immediately before receiving the switching signal. For this reason, the target rotational speed does not change abruptly when the low-speed mode switching unit is released. Since the engine rotation speed does not change suddenly, the ship operator can perform more stable ship operation.

  In the invention according to claim 3, the target rotation speed changes according to the operation amount of the grip by turning the grip after the ship operator releases the low-speed mode switching unit. In this case, the control unit performs control so as to gradually change from the maintained target rotation speed to the target rotation speed corresponding to the changed operation amount. Thus, the target rotational speed changes only when the operator consciously turns the grip after releasing the low-speed mode switching unit. Moreover, the target rotational speed changes gradually. For this reason, the ship operator can perform ship operation more stably.

  In the invention which concerns on Claim 4, since the low speed mode switch part was comprised by the manual operation switch arrange | positioned in the vicinity of a grip, the structure of a low speed mode switch part can be simplified.

  In the invention according to claim 5, since the steering handle is provided with a display unit for displaying the actual engine speed and the target engine speed, the engine speed is always easy to visually check when the operator is steering. Can be confirmed.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a side view of an outboard motor according to the present invention. FIG. 2 is a plan view of the steering handle shown in FIG. As shown in FIG. 1, the outboard motor 10 includes a mount case 11, an extension case 12, a gear case 13, an engine 14, a drive shaft 15, a gear mechanism 16, a propeller shaft 17, a propeller 18, and an outboard motor mounting mechanism 19. Become.

  The mount case 11 is a so-called engine support case in which the engine 14 is attached to the upper surface. The extension case 12 is attached to the lower part of the mount case 11. The gear case 13 is attached to the lower part of the extension case 12. The engine 14 is a vertical engine (for example, a single cylinder engine), in which the axis of the cylinder 21 is oriented horizontally (substantially horizontal) and the crankshaft 22 is oriented vertically. The drive shaft 15 is housed in the extension case 12, extends downward from the crankshaft 22, and transmits the power of the engine 14 to the propeller 18 via the gear mechanism 16 and the propeller shaft 17.

  The engine 14 is covered with a lower undercase 31 and an upper engine cover 32. The engine cover 32 has a fresh air inlet 32a at the top. Outside air is taken into the engine cover 32 from the fresh air inlet 32a. Further, the engine cover 32 houses therein a throttle valve 53 for the engine 14.

  The outboard motor mounting mechanism 19 fixes the outboard motor 10 to the hull Si, swings the outboard motor 10 left and right in plan view around the swivel shaft 19a, and swivels around the tilt shaft 19b. The outboard motor 10 including the shaft 19a can be flipped up in the clockwise direction in the figure.

  Incidentally, the undercase 31 includes a substantially horizontal bar-shaped steering handle 41 on the side of the front portion (the hull Si side). The steering handle 41 (tiller handle 41) can be set to a substantially horizontal use position indicated by a solid line and a substantially vertical storage position by swinging counterclockwise from the use position.

As shown in FIGS. 1 and 2, the steering handle 41 includes a grip 42, a grip operation amount detection unit 43, a low speed mode switching unit 44, and a display unit 45.
The grip 42 is disposed at the tip of the bar-like steering handle 41 and is attached to be rotatable around the axis CL of the steering handle 41. The grip operation amount detection unit 43 detects an actual operation amount θr (not shown) when the grip 42 is turned, and is disposed inside the steering handle 41. The grip operation amount detection unit 43 includes a variable resistor that emits a voltage signal proportional to the operation amount θr (operation angle θr) of the grip 42.

  The low speed mode switching unit 44 is set when the operator wants to switch the rotational speed control mode of the engine 14 to a predetermined low speed mode (a control mode for finely adjusting the rotational speed of the engine 14; a trolling mode). It consists of a manual operation switch operated by the operator. Since the low speed mode switching unit 44 is configured by the manual operation switch disposed in the vicinity of the grip 42, the configuration of the low speed mode switching unit 44 can be simplified.

  This manual operation switch consists of a rocker switch, for example. This rocker switch is also called a seesaw switch or a tumbler switch. More specifically, the low-speed mode switching unit 44 including a rocker switch is a switch for switching the connection circuit by pressing one side of the operation knob 44a that performs a seesaw operation. The operation knob 44a is configured to switch between two positions, an OFF position OFF and an ON position ON that tilts by performing a seesaw operation from the OFF position OFF, and can be switched even if the operation force is removed after the operation. Self-holding in a different position.

  The switch signal generated by the low-speed mode switching unit 44 includes two signals, an off signal and an on signal. Specifically, when the operation knob 44a is positioned at the OFF position OFF, the low speed mode switching unit 44 issues an OFF signal (release signal). When the operation knob 44a is located at the ON position ON, the low speed mode switching unit 44 issues an ON signal (switching signal). Hereinafter, the low speed mode switching unit 44 is appropriately referred to as a “low speed mode switch 44”.

  The low speed mode switching unit 44 is provided at a position different from the grip 42 in the steering handle 41. For example, the low speed mode switching unit 44 is fixed to the distal end surface of the steering handle 41. For this reason, for example, the low speed mode switching unit 44 can be operated by the thumb of the hand holding the grip 42.

  As shown in FIG. 1, it is preferable to arrange the low-speed mode switching unit 44 so that the operation knob 44a performs a seesaw operation up and down when the steering handle 41 is in a substantially horizontal use position. With this arrangement, the operation of the operation knob 44a does not change regardless of whether the operator is positioned on the left or right (front and back of the paper in FIG. 1) with respect to the steering handle 41. For this reason, the operability of the operation knob 44a is further enhanced.

The low speed mode switching unit 44 may be configured to be disposed in the vicinity of the grip 42 in the steering handle 41. For example, the low speed mode switching unit 44 may be disposed on the swing base 41 a side of the steering handle 41 with respect to the grip 42.
Since the low speed mode switching unit 44 is provided not on the outboard motor 10 itself but on the steering handle 41, the position of the low speed mode switching unit 44 is closer to the operator. For this reason, it is easy for the operator to operate the low speed mode switching unit 44.

The display unit 45 is disposed on the steering handle 41 closer to the swing base 41a than the grip 42 and on the upper surface of the handle.
As described above, since the grip operation amount detection unit 43, the low speed mode switching unit 44, and the display unit 45 are provided not on the outboard motor 10 itself but on the steering handle 41, they are not easily covered with water.

  FIG. 3 is a schematic system diagram of the outboard motor according to the present invention. As shown in FIG. 3, the outboard motor 10 is characterized by mounting an electronic governor 50 (also referred to as an electric governor or an electronic governor). The electronic governor 50 controls the rotational speed of the engine 14 by automatically adjusting the opening of the throttle valve 53 with the electric motor 52 based on the control signal of the control unit 51. The electronic governor 50 includes a combination of a control unit 51, an electric motor 52, a throttle valve 53, a throttle opening sensor 54, and an engine rotation sensor 55. The throttle opening sensor 54 detects the opening α of the throttle valve 53. The engine rotation sensor 55 detects an actual rotation speed Nr of the engine 14.

  The control unit 51 receives signals from the grip operation amount detection unit 43, the low speed mode switching unit 44, the throttle opening sensor 54, the engine rotation sensor 55, and the main switch 56, and controls the engine 14 to perform predetermined control. This is an electronic control unit controlled in a mode, and is composed of a microcomputer, for example. That is, the control unit 51 controls the ignition device 57 and further sets the target rotation speed Ns according to the operation amount θr (operation angle θr) of the grip 42 detected by the grip operation amount detection unit 43. The throttle valve 53 is electrically opened and closed via the electric motor 52 so that the actual rotational speed Nr matches the target rotational speed Ns.

  FIG. 4 is a conceptual diagram illustrating a concept in which the control unit illustrated in FIG. 3 increases or decreases the target rotation speed. The conceptual diagram of FIG. 4 represents the characteristic of the target rotation speed Ns with respect to the operation amount θr, with the horizontal axis being the actual operation amount θr of the grip 42 and the vertical axis being the target rotation speed Ns of the engine.

  A straight line MN indicated by a thick line rising to the right in the figure is a target rotational speed characteristic line in the normal mode, and indicates that the target rotational speed Ns changes according to the operation amount θr. According to the target rotational speed characteristic line MN in the normal mode, when the operation amount θr is 0 which is the minimum value, the target rotation speed Ns is 0 which is the minimum value, and the operation amount θr is 100% (maximum angle). Sometimes it can be seen that the target rotational speed Ns is the maximum value Nmax1. The target rotational speed characteristic line MN in the normal mode can be used as a “normal mode map MN” when the control unit 51 obtains the target rotational speed Ns according to the operation amount θr in the normal mode.

  On the other hand, a straight line ML indicated by a thin line rising to the right in the figure is a target rotational speed characteristic line in the low speed mode, and indicates that the target rotational speed Ns changes according to the operation amount θr. According to the target rotational speed characteristic line ML in the low speed mode, when the operation amount θr is 0 which is the minimum value, the target rotation speed Ns is 0 which is the minimum value, and the operation amount θr is 100% (maximum angle). Sometimes it can be seen that the target rotational speed Ns is the maximum value Nmax2. The maximum value Nmax2 in the low speed mode is a value smaller than the maximum value Nmax1 in the normal mode, and is set to, for example, 1/3. The target rotational speed characteristic line ML in the low speed mode can be used as a “low speed mode map ML” when the control unit 51 obtains the target rotational speed Ns according to the operation amount θr in the low speed mode.

Further, the control unit 51 shown in FIG. 3 is configured to perform the following three controls.
In the first control, when the electrical switching signal (ON signal) is received from the low-speed mode switching unit 44, the rate at which the target rotational speed Ns changes according to the operation amount θr is compared to when the electrical switching signal (ON signal) is not received. It is to control to reduce.
The second control is to perform control so that the target rotational speed Ns immediately before the switching signal is not received is maintained as it is when the switching signal is not received from the low speed mode switching unit 44.
In the third control, when the operation amount θr of the grip 42 changes after the switching signal is not received from the low speed mode switching unit 44, the target corresponding to the changed operation amount θr is determined from the maintained target rotation speed Ns. Control is to gradually change the rotation speed to Ns.

  The electric motor 52 (electric actuator 52) consists of a step motor, for example. The throttle valve 53 is provided in an intake passage 58 for supplying combustion air to the engine 14. The amount of combustion air can be adjusted by the throttle valve 53. The main switch 56 includes an ignition switch for turning on and off the power supply system of the engine 14 and starting the engine 14.

Furthermore, the control unit 51 issues a display command to the display unit 45 to display the above-described target rotation speed Ns and actual rotation speed Nr. 5A and 5B are diagrams illustrating the display unit illustrated in FIG.
The display unit 45 shown in FIG. 5A has a bar-code-like display pattern 45b formed by arranging a plurality of bar-like display segments 45a (including indicator lights) in a horizontal row. Ns and Nr are displayed. The display unit 45 shown in FIG. 5B is configured to display each rotational speed Ns, Nr by a display pattern 45d formed by arranging a plurality of circular display segments 45c (including display lamps) in a horizontal row. To display. These display patterns 45b and 45d are display systems in which the leftmost display segments 45a and 45c display the lowest speed in FIG.

  Further, the display unit 45 includes a control mode display unit 46. The control mode display unit 46 displays the control mode in which the throttle valve 53 is controlled by the control unit 51 shown in FIG. When the control unit 51 is controlling the throttle valve 53 in the above-described low speed mode (control mode for finely adjusting the rotational speed of the engine 14; trolling mode), the lighting is displayed. Since the ship operator can easily know the current control mode by viewing the control mode display unit 46, an erroneous operation can be prevented.

  Next, a control flow when the control unit 51 (see FIG. 3) is a microcomputer will be described based on FIGS. 6 to 10 with reference to FIG. FIG. 6 is a control flowchart (main routine) showing an example of throttle valve control executed by the control unit shown in FIG. When the ship operator operates the main switch 56 to the start position and starts the engine 14 by operating the ignition device 57, and then operates the main switch 56 to the on position, the control unit 51 performs the control flow of FIG. Start controlling. Then, the control part 51 complete | finishes control by switching the main switch 56 to an OFF position. This control flow is a closed-loop control flow that is repeatedly executed every predetermined time, for example, every 20 msec (milliseconds). Hereinafter, the control flow will be described.

  Now, the low speed mode switch 44 is in an OFF state. In this state, the boat operator switches the main switch 56 to the on position. When the main switch 56 is turned on, the control unit 51 first performs initial setting and then starts control (step ST01). That is, the system is reset, all the flags (first flag Fa, second flag Fb, third flag Fc, fourth flag Fd) are set to 0, and the reference operation amount θL is set to 0.

  Next, the actual operation amount θr of the grip 42 is read (step ST02). The actual operation amount θr of the grip 42 is detected by the grip operation amount detection unit 43. Next, the actual rotational speed Nr of the engine 14 is read (step ST03). The actual rotation speed Nr (actual rotation speed Nr) is detected by the engine rotation sensor 55. Next, the switch signal of the low speed mode switch 44 is read (step ST04).

Next, it is determined whether or not the switch signal of the low speed mode switch 44 is off (step ST05). If it is determined in step ST05 that the switch signal is OFF, it is determined whether or not the third flag Fc = 0 (step ST06).
If the switch signal is off in step ST05 and the third flag Fc = 0 in step ST06, it is determined that the normal mode has been entered, and the speed control in the normal mode by the operator is executed (step ST05). ST07). FIG. 7 shows detailed control contents of the normal mode speed control (step ST07).

  FIG. 7 is a control flowchart showing a subroutine for executing the normal mode speed control (step ST07) shown in FIG. In the subroutine shown in FIG. 7, first, “normal mode map MN” is selected from the map shown in FIG. 4 (step ST101). Next, based on the normal mode map MN, the target rotational speed Ns of the engine 14 is obtained from the actual operation amount θr of the grip 42 (step ST102).

  Next, normal speed control by the operator is executed (step ST103). That is, in step ST103, the ship operator appropriately turns the grip 42 in accordance with the state of maneuvering, and the actual rotation with respect to the target rotation speed Ns corresponding to the operation amount θr (the speed Ns obtained in step ST102). The control unit 51 controls opening / closing of the throttle valve 53 so that the speed Nr matches. Specifically, the opening and closing of the throttle valve 53 is controlled by driving the electric motor 52 by PID control or the like. The signal of the opening α detected by the throttle opening sensor 54 is sent to the control unit 51 as a feedback signal. Thereafter, the subroutine shown in FIG. 7 is terminated, and the process returns to the main routine shown in FIG.

Since the normal mode is entered as described above, the first flag Fa is inverted from 0 to 1 (step ST08) and the second flag Fb is inverted from 0 to 1 as shown in FIG. 6 (step ST08). ST09). Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.
Thus, when a series of steps ST02 to ST10 are repeated, the control unit 51 maintains the speed control in the normal mode.

  Thereafter, when the boat operator turns on the low speed mode switch 44, the switch signal of the low speed mode switch 44 is inverted to on. For this reason, in step ST05, it is determined that the switch signal of the low speed mode switch 44 is turned on, that is, a switching signal is received, and as a result, it is determined that the low speed mode has been entered. Next, it is determined whether or not the first flag Fa = 0 (step ST11). In step ST08, the first flag Fa has already been inverted from 0 to 1. Therefore, in step ST11, it is determined that the first flag Fa is inverted from 0 to 1, and as a result, it is determined that the initial stage for shifting to the low speed mode has been entered. Then, the transition control to the low speed mode is executed (step 12). FIG. 8 shows the detailed control contents of the transition control to the low speed mode (step ST12).

  FIG. 8 is a control flowchart showing a subroutine for executing the transition control to the low speed mode (step ST12) shown in FIG. In the subroutine shown in FIG. 8, it is first determined whether or not the second flag Fb = 1 (step ST201). In step ST09 (see FIG. 6), the second flag Fb has already been inverted from 0 to 1. For this reason, in step ST201, it is determined that the second flag Fb is inverted from 0 to 1.

  If it is determined in step ST201 that the second flag Fb = 1, the value of the reference operation amount θL of the grip 42 is set to the value of the actual operation amount θr at the current time (step ST202). In step ST202, the reference operation amount θL is a value serving as a reference for determining whether or not the grip 42 has been operated after the ship operator has turned on the low speed mode switch 44. In step ST202, the actual operation amount θr at the present time is the target at the time when the switch signal of the low-speed mode switch 44 is reversed from off to on by turning on the low-speed mode switch 44. This is the rotation speed Ns.

  Next, the second flag Fb is set to 0 (step ST203), and the process proceeds to step ST204. On the other hand, if it is determined in step ST201 that the second flag Fb = 0, the process proceeds to step ST204 while maintaining the original reference operation amount θL. In step ST204, it is determined whether or not the actual operation amount θr matches the reference operation amount θL. If it is determined in step ST204 that they match (θL = θr), “normal mode map MN” is selected from the map shown in FIG. 4 (step ST205).

  Next, based on the normal mode map MN, the target rotational speed Ns of the engine 14 is obtained from the actual operation amount θr of the grip 42 (step ST206). The actual operation amount θr in step ST206 is the same value as the reference operation amount θL (θr = θL).

  Next, the normal mode speed control is maintained as it is (step ST207). That is, the control unit 51 controls the opening and closing of the throttle valve 53 so that the actual rotational speed Nr matches the target rotational speed Ns corresponding to the operation amount θr (the speed Ns obtained in step ST206). In this way, the control unit 51 performs control so that the maintained target rotational speed Ns is maintained as it is when the switch signal of the low speed mode switch 44 is reversed from off to on. . Thereafter, the subroutine shown in FIG. 8 is terminated, and the process returns to the main routine shown in FIG. Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.

  Thus, when a series of steps ST02 to ST05, ST11 to ST12, and ST10 are repeated, the control unit 51 continues to maintain the speed control in the normal mode as it is. In other words, the control unit 51 performs control so as to maintain the actual operation amount θr immediately before starting to receive the ON signal when starting to receive the ON signal (switching signal) from the low speed mode switch 44. As a result, the control unit 51 performs control so as to maintain the target rotational speed Ns immediately before starting to receive the ON signal.

  When the boat operator turns on (switches) the low speed mode switch 44, the low speed mode switch 44 receives an on signal (switching signal) issued to the control unit 51. At this time, the control unit 51 continues to maintain the maintained target rotation speed Ns as it is. For this reason, the target rotational speed Ns does not change suddenly when the low speed mode switch 44 is switched. Since the rotation speed Nr of the engine 14 does not change suddenly, the boat operator can perform more stable boat maneuvering.

  By the way, when the operator operates the grip 42 after turning on the low speed mode switching unit 44 as described above, the actual operation amount θr changes. Therefore, in step ST204, it is determined that the actual operation amount θr does not match the reference operation amount θL (θL ≠ θr), and as a result, it is determined that the low-speed mode has been entered. Therefore, next, the “low speed mode map ML” is selected from the map shown in FIG. 4 (step ST208). Next, a new target rotational speed Ns of the engine 14 is obtained from the actual operation amount θr of the grip 42 based on the low speed mode map ML (step ST209).

  Next, the throttle valve 53 is controlled to open and close so that the actual rotational speed Nr matches the new target rotational speed Ns (the speed Ns obtained in step ST209) (step ST210). By the way, in this step ST210, the target rotational speed Ns maintained is gradually changed to a new target rotational speed Ns. The “degree of change” in which the target rotational speed Ns gradually changes is determined by setting a small amount of change (ΔNs / Δt, acceleration / deceleration) of the target rotational speed Ns per unit time Δt. That is, the speed of change is slower than when the normal mode speed control is executed. The response of the change in the target rotational speed Ns is dull with respect to the operating speed at which the grip 42 is operated. For this reason, the control unit 51 performs control so as to gradually change from the maintained target rotational speed Ns to the target rotational speed Ns corresponding to the changed operation amount θr.

  Thus, the target rotational speed Ns changes only when the operator turns the grip 42 consciously after turning on the low speed mode switch 44 (switching operation). In addition, the target rotational speed Ns gradually changes. For this reason, the ship operator can perform ship operation more stably.

  Next, it is determined whether or not the actual rotational speed Nr matches the target rotational speed Ns (step ST211). If it is determined in step ST211 that they do not match, the first flag Fa is left as it is, the subroutine shown in FIG. 8 is terminated, and the process returns to the main routine shown in FIG. Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.

  On the other hand, if it is determined in step ST211 that they match, the first flag Fa is inverted from 1 to 0 (step ST212), the subroutine shown in FIG. 8 is terminated, and the process returns to the main routine shown in FIG. Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.

  Thereafter, in step ST11 shown in FIG. 6, it is determined that the first flag Fa is inverted from 1 to 0, and the speed control in the low speed mode is executed (step ST13). FIG. 9 shows the detailed control contents of the speed control (step ST13) in the low speed mode.

  FIG. 9 is a control flowchart showing a subroutine for executing the speed control (step ST13) in the low speed mode shown in FIG. In the subroutine shown in FIG. 9, first, the “low speed mode map ML” is selected from the map shown in FIG. 4 (step ST301). Next, based on the low speed mode map ML, the target rotational speed Ns of the engine 14 is obtained from the actual operation amount θr of the grip 42 (step ST302).

  Next, speed control in the low speed mode by the operator is executed (step ST303). That is, in step ST303, the boat operator appropriately turns the grip 42 in accordance with the boat maneuvering state, and the actual rotation with respect to the target rotation speed Ns corresponding to the operation amount θr (the speed Ns obtained in step ST302). The control unit 51 controls opening / closing of the throttle valve 53 so that the speed Nr matches. Thereafter, the subroutine shown in FIG. 9 is terminated, and the process returns to the main routine shown in FIG.

Since the low-speed mode has been entered as described above, the third flag Fc is inverted from 0 to 1 (step ST14) and the fourth flag Fd is inverted from 0 to 1 as shown in FIG. 6 (step ST14). ST15). Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.
Thus, when a series of steps ST02 to ST05, ST11, ST13 to ST15, and ST10 are repeated, the control unit 51 maintains the speed control in the low speed mode.

  Thereafter, when the boat operator returns the low-speed mode switch 44 to OFF again, the switch signal of the low-speed mode switch 44 is inverted to OFF. For this reason, in step ST05, it is determined that the switch signal of the low-speed mode switch 44 has been turned off, that is, the release signal has been input. Next, it is determined whether or not the third flag Fc = 0 (step ST06). In step ST14, the third flag Fc has already been inverted from 0 to 1. Therefore, in step ST06, it is determined that the third flag Fc is inverted from 0 to 1, and as a result, it is determined that the initial stage for returning to the normal mode speed control is entered. Then, transition control to the normal mode is executed (step ST16). FIG. 10 shows detailed control contents of the transition control to the normal mode (step ST16).

  FIG. 10 is a control flowchart showing a subroutine for executing the control for shifting to the normal mode (step ST16) shown in FIG. In the subroutine shown in FIG. 10, first, it is determined whether or not the fourth flag Fd = 1 (step ST401). In step ST15 (see FIG. 6), the fourth flag Fd has already been inverted from 0 to 1. For this reason, in step ST401, it is determined that the fourth flag Fd is inverted from 0 to 1.

  If it is determined in step ST401 that the fourth flag Fd = 1, the value of the reference operation amount θL of the grip 42 is set to the value of the actual operation amount θr at the current time (step ST402). In step ST402, the reference operation amount θL is a value serving as a reference for determining whether or not the grip 42 has been operated after the ship operator has turned off the low speed mode switch 44. In step ST402, the actual operation amount θr at the present time is the target at the time when the switch signal of the low-speed mode switch 44 is reversed from on to off when the low-speed mode switch 44 is turned off. This is the rotation speed Ns.

  Next, the fourth flag Fd is set to 0 (step ST403), and the process proceeds to step ST404. On the other hand, when it is determined in step ST401 that the fourth flag Fd = 0, the process proceeds to step ST404 while maintaining the original reference operation amount θL. In step ST404, it is determined whether or not the actual operation amount θr matches the reference operation amount θL. If it is determined in step ST404 that they match (θL = θr), “low speed mode map ML” is selected from the map shown in FIG. 4 (step ST405).

  Next, the target rotational speed Ns of the engine 14 is obtained from the actual operation amount θr of the grip 42 based on the low speed mode map ML (step ST406). The actual operation amount θr in step ST406 is the same value as the reference operation amount θL (θr = θL).

  Next, the speed control in the low speed mode is maintained as it is (step ST407). That is, the control unit 51 controls the opening and closing of the throttle valve 53 so that the actual rotational speed Nr matches the target rotational speed Ns corresponding to the operation amount θr (the speed Ns obtained in step ST406). As described above, the control unit 51 performs control so that the maintained target rotational speed Ns is maintained as it is when the switch signal of the low-speed mode switch 44 is reversed from on to off. . Thereafter, the subroutine shown in FIG. 10 is terminated, and the process returns to the main routine shown in FIG. Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.

  Thus, when a series of steps ST02 to ST06, ST16 and ST10 are repeated, the control unit 51 continues to maintain the speed control in the low speed mode. That is, when the control unit 51 starts to receive an off signal (release signal) from the low speed mode switch 44, the control unit 51 performs control so as to maintain the actual operation amount θr immediately before starting to receive the off signal. As a result, the control unit 51 performs control so as to maintain the target rotational speed Ns immediately before starting to receive the off signal.

  When the boat operator turns off (releases) the low-speed mode switch 44, an off signal (release signal) issued from the low-speed mode switch 44 to the control unit 51 is received. At this time, the control unit 51 continues to maintain the maintained target rotation speed Ns as it is. For this reason, the target rotational speed Ns does not change suddenly when the low-speed mode switch 44 is released. Since the rotation speed Nr of the engine 14 does not change suddenly, the boat operator can perform more stable boat maneuvering.

  By the way, when the operator operates the grip 42 after turning off the low-speed mode switching unit 44 as described above, the actual operation amount θr changes. For this reason, in step ST404, it is determined that the actual operation amount θr does not match the reference operation amount θL (θL ≠ θr), and as a result, it is determined that the mode has shifted to the normal mode. Therefore, next, “normal mode map MN” is selected from the map shown in FIG. 4 (step ST408). Next, a new target rotational speed Ns of the engine 14 is obtained from the actual operation amount θr of the grip 42 based on the normal mode map MN (step ST409).

  Next, the throttle valve 53 is controlled to open and close so that the actual rotation speed Nr matches the new target rotation speed Ns (speed Ns obtained in step ST409) (step ST410). By the way, in this step ST410, the target rotational speed Ns maintained is gradually changed to a new target rotational speed Ns. The “degree of change” in which the target rotational speed Ns gradually changes is determined by setting a small amount of change (ΔNs / Δt, acceleration / deceleration) of the target rotational speed Ns per unit time Δt. That is, the speed of change is slower than when the normal mode speed control is executed. The response of the change in the target rotational speed Ns is dull with respect to the operating speed at which the grip 42 is operated. For this reason, the control unit 51 performs control so as to gradually change from the maintained target rotational speed Ns to the target rotational speed Ns corresponding to the changed operation amount θr.

  Thus, the target rotational speed Ns changes only when the operator intentionally turns the grip 42 after turning off the low-speed mode switch 44 (release operation). In addition, the target rotational speed Ns gradually changes. For this reason, the ship operator can perform ship operation more stably.

  Next, it is determined whether or not the actual rotational speed Nr matches the target rotational speed Ns (step ST411). If it is determined in step ST411 that they do not match, the third flag Fc is left as it is, the subroutine shown in FIG. 10 is terminated, and the process returns to the main routine shown in FIG. Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.

  On the other hand, if it is determined in step ST411 that they match, the third flag Fc is inverted from 1 to 0 (step ST412), the subroutine shown in FIG. 10 is terminated, and the process returns to the main routine shown in FIG. Next, the target rotation speed Ns and the actual rotation speed Nr are displayed on the display unit 45 shown in FIG. 5 (step ST10). Thereafter, the process returns to step ST02.

  Thereafter, in step ST06 shown in FIG. 6, it is determined that the third flag Fc is inverted from 1 to 0, and the speed control in the normal mode is executed again (step ST07).

As described above, when a series of steps ST02 to ST06, ST16, and ST10 are repeated, the control unit 51 executes control for gently returning to the speed control in the normal mode.
By turning the grip 42 after the ship operator releases the low-speed mode switch 44, the target rotational speed Ns changes according to the operation amount θr of the grip 42. In this case, the control unit 51 performs control so as to gradually change from the target rotation speed Ns maintained until now to the target rotation speed Ns corresponding to the changed operation amount θr. Thus, the target rotational speed Ns changes only when the operator consciously turns the grip 42 after releasing the low speed mode switch 44. In addition, since the target rotational speed Ns gradually changes, the ship operator can perform ship operation more stably.

  Next, the operation of the electronic governor 50 described in the control flowchart of FIG. 6 will be described based on FIG. 11 with reference to FIG. FIG. 11 is an explanatory diagram of the operation of the electronic governor and each part shown in FIG. 3, and shows the action of each part in a time chart with the horizontal axis as time. However, the actual operation amount θr has a relationship of “0 <θ1 <θ2 <θ3 <θ4”. The magnitudes of the target rotational speed Ns and the actual rotational speed Nr are in a relationship of “0 <N1 <N2 <N3 <N4”.

The target rotation speed Ns changes according to the operation amount θr of the grip 42. The actual rotational speed Nr changes so as to match the target rotational speed Ns.
Now, since the low-speed mode switch 44 is off, the control mode is in the normal mode. In this state, the normal mode map MN is selected from the map shown in FIG. When the ship operator increases the operation amount θr from the value 0 to the value θ2 from the time point 0 to the time point t1, the target rotation speed Ns and the actual rotation speed Nr are changed from the value 0 based on the characteristics of the normal mode map MN. Increase to value N3.

  Thereafter, when the operation amount θr maintains the value θ2, the target rotation speed Ns and the actual rotation speed Nr maintain the value N3. Thereafter, when the low speed mode switch 44 is turned on at time t2, the normal mode is shifted to the low speed mode. In this low speed mode, the low speed mode map ML is selected from the map shown in FIG. However, since the operation amount θr maintains the value θ2, the target rotation speed Ns and the actual rotation speed Nr maintain the value N3 as they are.

  Thereafter, when the vessel operator starts to decrease the operation amount θr from the value θ2 at time t3, the target rotation speed Ns and the actual rotation speed Nr start to gradually decrease from the value N3. For example, the boat operator decreases the operation amount θr from the value θ2 to the value θ1 over the elapsed time T1 from the time point t3 to the time point t4. At this time, the target rotation speed Ns and the actual rotation speed Nr gradually decrease from the value N3 to the value N1 over the elapsed time T2 from the time point t3 to the time point t5. The elapsed time T2 is longer than the elapsed time T1 (T2> T1).

  Thereafter, when the operation amount θr maintains the value θ1, the target rotation speed Ns and the actual rotation speed Nr maintain the value N1. Thereafter, when the ship operator increases the operation amount θr from the value θ1 to the value θ3 from the time point t6 to the time point t7, the target rotational speed Ns and the actual rotational speed Nr are based on the characteristics of the low speed mode map ML. Increase from N1 to the value N2. Thereafter, when the operation amount θr maintains the value θ3, the target rotation speed Ns and the actual rotation speed Nr maintain the value N2.

  Thereafter, when the low speed mode switch 44 is turned off at time t8, the low speed mode is changed to the normal mode. In this normal mode, the normal mode map MN is selected from the map shown in FIG. However, since the operation amount θr maintains the value θ3, the target rotation speed Ns and the actual rotation speed Nr maintain the value N2 as they are.

  Thereafter, when the boat operator starts increasing the operation amount θr from the value θ3 at time t9, the target rotation speed Ns and the actual rotation speed Nr start to gradually increase from the value N2. For example, the boat operator increases the operation amount θr from the value θ3 to the value θ4 over the elapsed time T3 from the time t9 to the time t10. At this time, the target rotation speed Ns and the actual rotation speed Nr gradually increase from the value N2 to the value N4 over the elapsed time T4 from the time point t9 to the time point t11. The elapsed time T4 is longer than the elapsed time T3 (T4> T3).

  The above description is summarized as follows. The steering handle 41 includes a rotatable grip 42 and a low speed mode switching unit 44 (low speed mode switch 44). The control unit 51 sets the target rotation speed Ns according to the operation amount θr of the grip 42 detected by the grip operation amount detection unit 43, and the actual rotation speed Nr matches the target rotation speed Ns. The throttle valve 53 is controlled to open and close. Further, the low speed mode switching unit 44 issues an electrical switching signal (ON signal) according to the operation of the boat operator. When receiving the switching signal from the low speed mode switching unit 44, the control unit 51 reduces the rate at which the target rotational speed Ns changes according to the operation amount θr, compared to when not receiving it.

  That is, the rate at which the target rotational speed Ns changes according to the operation amount θr of the grip 42 is reduced by a simple operation that only operates the low-speed mode switching unit 44. Even if the operation amount θr of the grip 42 is the maximum, the target rotational speed Ns does not increase. For this reason, the target rotational speed Ns can be finely adjusted. Since the rotational speed Nr of the engine 14 can be finely adjusted in a low speed region, the speed of the ship can be finely adjusted in trolling (trolling fishery) or the like. Even beginners can easily operate a ship. In addition, the low-speed mode switching unit 44 only emits an electrical switching signal in accordance with the operation of the vessel operator, and thus a simple configuration is sufficient.

  In the present invention, the low-speed mode switching unit 44 is not limited to the configuration of the rocker switch, and may be, for example, a rotary switch or a push switch.

  The outboard motor 10 of the present invention is suitable for use in various types of hull Si from small to relatively large.

1 is a side view of an outboard motor according to the present invention. It is a top view of the steering handle shown in FIG. 1 is a schematic system diagram of an outboard motor according to the present invention. It is a conceptual diagram which shows the concept which the control part shown in FIG. 3 increases / decreases a target rotational speed. It is the figure which illustrated the display part shown in FIG. FIG. 4 is a control flowchart (main routine) showing an example of throttle valve control executed by the control unit shown in FIG. 3. FIG. It is a control flowchart which shows the subroutine for performing speed control (step ST07) of the normal mode shown by FIG. It is a control flowchart which shows the subroutine for performing the shift control (step ST12) to the low speed mode shown by FIG. It is a control flowchart which shows the subroutine for performing speed control (step ST13) of the low speed mode shown by FIG. FIG. 7 is a control flowchart showing a subroutine for executing control for shifting to a normal mode (step ST <b> 16) shown in FIG. 6. FIG. 4 is an operation explanatory diagram of the electronic governor and each unit shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Outboard motor, 14 ... Engine, 18 ... Propeller, 41 ... Steering handle, 42 ... Grip, 43 ... Grip operation amount detection part, 44 ... Low speed mode switching part (low speed mode switch, manual operation switch), 45 ... Display Reference numeral 51: Control unit 52: Electric motor 53: Throttle valve Nr: Actual rotational speed Ns: Target rotational speed

Claims (5)

In an outboard motor that electrically controls the opening and closing of the throttle valve so that the actual rotational speed of the engine that drives the propeller matches the target rotational speed,
A low-speed mode switching unit provided on the steering wheel and capable of manual operation;
A rotatable grip provided at the tip of the steering handle;
A grip operation amount detection unit for detecting the operation amount of the grip;
A control unit that sets the target rotation speed according to the operation amount detected by the grip operation amount detection unit and controls the opening and closing of the throttle valve so that the actual rotation speed matches the target rotation speed. And
The control unit is configured to control to reduce the rate at which the target rotational speed changes according to the operation amount when receiving a switching signal from the low speed mode switching unit compared to when not receiving the switching signal. An outboard motor characterized by   The control unit is configured to control to maintain the target rotation speed immediately before the switching signal is not received when the switching signal is not received from the low-speed mode switching unit. The outboard motor according to 1.   When the operation amount is changed after the control unit no longer receives the switching signal from the low speed mode switching unit, the control unit changes the maintained target rotation speed to a target rotation speed corresponding to the changed operation amount. The outboard motor according to claim 2, wherein the outboard motor is controlled to be gradually changed.   The outboard motor according to any one of claims 1 to 3, wherein the low-speed mode switching unit includes a manual operation switch disposed in the vicinity of the grip.   The outboard motor according to any one of claims 1 to 4, wherein the steering handle includes a display unit that displays the actual rotational speed and the target rotational speed.

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