JPS6181529A - Starter for engine - Google Patents

Abstract

PURPOSE:To make throttle opening large to some extent in time of starting small in intake negative pressure and thereby improve a starting characteristic, by connecting negative pressure actuator, which operates with suction negative pressure at the downstream of a throttle valve, to the throttle valve of a carburetor of an engine provided with a manual starter. CONSTITUTION:In case of a starter for an engine provided with a recoil type starter R and a decompression device operating so as to open an exhaust valve in order to decompress internal pressure inside a cylinder in time of engine cranking, a negative pressure actuator V is connected to a throttle lever 45 coupled with a throttle valve shaft 47 of a carburetor via an interlocking device 46. Suction negative pressure in a suction manifold M at the downstream of a throttle valve is led into a negative pressure chamber 58 of this negative pressure actuator V. With this constitution, when the intake negative pressure of the negative pressure chamber 58 is less than the specified value, the throttle valve is opened to the starting opening being somethat larger than the idle opening, and when the negative pressure becomes more than the specified value, the starting opening is restored to the idle opening so that a starting characteristic is improved and starting operation is made so easy.

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Application Field The present invention is useful for starting f[' of engines used in outboard motors, power lawn mowers, etc., and particularly for starting carrots. A manual starter for ranking, and a pressure reducing device that opens the exhaust valve to reduce the pressure inside the cylinder when cranking carrots! :Relating to a starting device equipped with.

(2) Prior Art According to this type of starting device, when starting the carrot, the cranking load of the carrot is reduced by the operation of the pressure reducing device, so that manual operation of the starter can be performed easily. However, in general engines, the intake stroke and the compression stroke overlap each other, so in order to effectively reduce the pressure inside the cylinder, if the pressure reduction IT is activated from the beginning of the compression stroke,
This forces the exhaust valve to open before the intake valve closes.
As a result, the intake action is weakened and the amount of air-fuel mixture sucked into the engine becomes insufficient, leading to a decrease in starting performance.

Therefore, in the past, when starting an engine, the throttle valve of the carburetor was operated in order to prevent the intake C-leg aikido from being insufficient. Controlling the starting opening of the throttle valve is not only troublesome, but also requires some skill.

Industrial invention i4 was made in view of such circumstances,
When starting the engine, there is no need for any special manual operation.
The throttle valve of the carburetor is kept at a predetermined starting opening, and after starting, the throttle valve is automatically returned to the idle opening, thereby simplifying operation and improving engine O fluidity at the same time. It is an object of the present invention to provide a starting device for the carrot that can be achieved.

B1 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention connects a negative pressure actuator to a throttle valve of a carburetor installed in an engine, and operates the negative pressure actuator. The device has a negative chamber for introducing intake negative pressure downstream of the throttle valve, and when the negative pressure introduced into the chamber is less than a predetermined value, the throttle valve is opened to a starting opening slightly larger than the idle opening, and the throttle valve is opened to a starting opening slightly larger than the idle opening. The throttle valve is characterized in that it is configured to allow the throttle valve to return to the idle opening degree when the introduced negative pressure exceeds a predetermined value.

(2) Effect Before starting the engine, that is, when the engine is stopped, the negative pressure of the negative pressure actuator is under atmospheric pressure, so the negative pressure actuator causes the throttle valve of the carburetor to open slightly larger than the idle opening. It is held at the open position.

When the engine completely explodes, the intake negative pressure that rises to half a degree and above a predetermined value is introduced into the negative pressure chamber of the negative pressure actuator.
The negative pressure actuator operates to allow the throttle valve to return to its idle opening.

(3) Embodiment Hereinafter, an embodiment in which the present invention is applied to an outboard motor engine will be explained with reference to the drawings. The crankshaft 1 is arranged vertically, and the financial shaft 2
The signal is then transmitted to the horizontally disposed propeller shaft 4 via the forward/reverse switching device 3, thereby rotationally driving the propeller 5.

A tension case 7 that accommodates the drive shaft 2 is attached to the lower surface of the engine E, and a gear case 8 that accommodates the front and reverse switching device 3 in an oil-tight manner is attached to the lower surface of the case. A pair of upper and lower tension brackets 9°9' projecting forward are attached to the extension 7 case 7 via elastic support members io and to, and these extension brackets 9°9' are arranged approximately vertically. It is steerably connected to a swivel case 12 via an arranged swivel shaft 11 . Further, the swivel case 12 is connected via a horizontal pivot 15 to the upper part of a pair of right and left nutan brackets 14, 14 which are detachably fixed to the stern plate Sα of the hull S by a clamper 13 so as to be tiltable in the vertical direction.

A steering wheel bracket 16 is integrally formed on the upper extension bracket 9, and a steering handle 17 is pivotally attached to the steering wheel bracket 16.

As shown in FIG. 3, the engine E has the crankshaft 1
The cylinder block 22 is connected to the crankshaft 1 and holds nine cylinders 21, and the seven-cylinder head 23 is connected to the end face of the cylinder block 22. It is formed integrally with the crankcase 20 at a position facing toward the rear of S. Incidentally, 26 is an engine cover which is fixed to the extension case 27 over the engine E.

In order to start the engine E, a throttle control system and a pressure reducing device for the coil starter R1 carburetor C as a manual starter are provided, and these will be explained in sequence.

About the recoil starter R> As shown in Fig. 3, the recoil starter R is installed near the crankcase 20 in order to drive the ring gear 25 fixed to the underside of the flywheel 24 at the upper end of the crank@1. It will be placed in front of it.

The starter R board 27 is fixed to the front surface of the crankcase 20, and a support shaft 30 parallel to the crankshaft 1 is erected on the -C board 27, and a rope reel 31 is rotatably fitted onto this. be done. Boss 31 of this rope reel 31
A pinion gear 33 is slidably fitted to the upper outer periphery of a through a helical spline 32. This pinion gear 33i-If is in an operating position where it meshes with the gear 25, and a position where the pinion gear 33i-If is disengaged downward from the ring gear 25 and reeled into the rope reel 3.
1 and an inactive position supported on the top surface of the device.

A pinching spring 35 is installed in the outer peripheral groove 34 of the boss of the pinion gear 33.
is frictionally engaged to provide a light rotational resistance to the pinion gear 33, and this dependent spring 35 is engaged with a detent piece 36 provided at the upper end of the support @30 so as to be freely slidable in the vertical direction.

A starter rope 38 is wound around the annular rope groove 37 of the rope reel 31 . Of this starter corporation 38,
The end is connected to the rope reel 31, and the outer end is pulled out from a drawer 028 on the front wall of the engine cover 26 and connected to a rope handle 39.

The rope handle 39 is supported by a boss 29 fixed to the front wall of the engine cover 26 to define the pull-out opening, and its inoperative position is restricted.

This is attached to the underside of the rope reel 31.
A mainspring spring 41 is attached that biases B in the winding direction.

Then, in order to start the engine E, the rope handle 39 is
When the starter rope 38 is pulled by the operator, the rope reel 31 is rotated. At this time, since the pinion gear 33 is receiving rotational resistance from the pinch spring 35, the rotating cope reel 31 applies an upward thrust to the pinion gear 733 via the helical spline 32.
This thrust causes the pinion gear 33 to rise and mesh with the ring gear 25 of the carrot E. Since the pinion gear 33 is prevented from rising after meshing, the pinion gear 33 slides between the pinion spring 35 and the rope reel 3.
1 and drives the ring gear 25. In this way, the crankshaft 1 is cranked and the engine E is started.

When the pinion gear 33 is driven from the ring gear 25 with the start of the engine E, the pinion gear 33 receives a downward thrust from the helical spline 32 and descends, and is released from engagement with the ring gear 25. Then, when the rope handle 39 is released, the rope reel 31
The torsional force of the spring spring 41 causes the starter rope 38 to be wound into the rope groove 37 in the reverse direction.

Regarding the control system of the carburetor c'y) P2 Te control system As shown in Figure 1, the steering handle 17
A throttle pulley 44 rotated by a throttle grip 43 attached to the tip is accommodated, and an interlocking device is connected to the throttle lever 45 of the carburetor C attached to the cylinder bend 23 via the intake manifold Af. 46. The lever 45 is connected to the zero valve field 47 of the throttle valve in the carburetor C, and a return spring 48 is connected to the lever 45 to bias it in the closing direction of the throttle valve.

Figure 1 and 1. - In Figure 1, the interlocking device 46 includes a wire 49 connected to the 20 sottle pulley 44, a link 50 connected to the throttle lever 45, and a lever assembly 51 interconnecting the wire 49 and link 50. The lever assembly 51 includes a shaft 53 rotatably supported at both ends by fixed supports 52 and 52' within the engine cover 26, and a shaft 53 fixed to the lower part of the shaft 53 and connected to the wire 49. second lever 54.
and a second lever 54 . fixed to the upper part of the same thread 53 and connected to the link 50 . It consists of therefore,
If the wire 49 is pulled or pulled by the rotation of the throttle pulley 44, the first. Second lever 54. ．． 54□ rotates counterclockwise in Figure 1, and by pulling the link 50, the throttle lever 45 can be rotated in the opening direction of the throttle valve.

A control arm 55 is integrally formed with the second lever 542;
A negative pressure actuator V is installed corresponding to the control arm 55.

The negative pressure actuator V is connected to an I-crank 57 supported by a fixed placket 56 in the engine cover 26, a diaphragm 60 that partitions the inside of the housing 57 into a negative royal chamber 58 and an atmospheric chamber 59, and the diaphragm 60. The operating rod 61 extends through the atmospheric chamber 59 and has its tip opposed to one side of the control arm 55, and the valve opening spring 62 is contracted to the negative crown 58 and biases the diaphragm 60 toward the atmospheric chamber 59. be done. The negative pressure chamber 58 is communicated with the inside of the intake manifold through a negative pressure conduit 63, and the operating rod 61 is connected to the valve opening spring 6.
20 force is applied, the control arm 55 is pushed and the arithmetic lever 542 is rotated in the throttle valve opening direction, and the throttle valve opening at that time becomes the predetermined starting opening. like,
The amount of displacement of the diaphragm 60 is regulated by the end wall of the housing 57.

Further, the diaphragm 60 operates to move the operating rod 61 back from the control arm 55 when a negative pressure equal to or higher than a specified value is introduced into the negative pressure chamber 58 .

Regarding the pressure reducing device> As shown in Fig. 4, a cam shaft 67 driven from the crank @1 via timing gears 65 and 66 is disposed in the crankcase 20, and the cam shaft 67 is The intake valve 68 is opened by the rotation of the intake cam 67L and exhaust cam 67t (Military Figure 3)
and the exhaust valve 69 can be opened. exhaust cam 67
1fi between e and exhaust valve 69,) pet 70. The two are linked by the Puseon Yurosod 71 and the Nikka arm 72,
The same goes for the intake system.

The exhaust valve 69 is slightly opened by a pressure reducing device during the compression stroke when the engine is cranking.

The pressure reducing device is composed of a tappet lifter 73, a centrifugal weight 74, and a spring 75. The tappet lifter 73 is
It is formed into a bell crank shape consisting of first and second arms 73α and 73b, and the cam shaft 6 is adjacent to the exhaust cam 67tK.
The operating position is such that the tip of the first arm 73α is adjacent to the exhaust cam 67 and projects outward from its base circle by a height of 100 cm, and the first arm 73a is pivoted on the base circle 76. It is set to oscillate between a non-operating position in which it is retracted inwardly, and to fit together.

The centrifugal weight 74 and the timing gear 66 integrated with the camshaft 67
The base end is pivotally supported 77 on one side of the base. An actuating plate 74d extending toward the second arm 73b of the tappet lintuff 3 is connected to the free end of the centrifugal weight 74.
A driven claw 79 formed at the tip of the second arm 73b is engaged between a pair of driving claws 78 and 78 formed at 4α. Therefore, due to the swinging of the centrifugal weight 74, the actuating plate 74α
A spring 75 is connected to the centrifugal weight 74 to bias the centrifugal weight 74 toward the operating position.

When the engine E is in a stopped state or in a starting cranking state, the tappet lifter 73 is held in the operating position by the action of the spring 75, and the first arm 73. Protrude the tip of zO outward from the base circle of the exhaust cam 67g by a height h and
Ru. Therefore, when the engine E is cranked by the operation of the starter R, the tappet T
O is pushed up by the height of the first arm 73a by the tappet lifter 73, so the exhaust valve 69 opens slightly.

As a result, the compressed gas in the cylinder of the engine E is discharged to the exhaust port, thereby reducing the pressure in the cylinder and achieving a reduction in cranking load.

When the rotation speed of the camshaft 67 exceeds a predetermined value due to a complete explosion of the engine E, the centrifugal force acting on the centrifugal weight 74 is applied to the spring γ.
5, the centrifugal weight 74 swings outward, thereby rotating the IJ lid γ3 to the inoperative position. That is, since the tip of the first arm 73α is retracted inward from the base circle of the exhaust cam 67e, the exhaust valve 69 can be opened and closed normally only by the exhaust cam 67t.

To explain the operation of this embodiment, before starting the engine E,
That is, in the stopped state, the negative pressure chamber 5B of the negative pressure actuator V is
Similar to the inside of the intake manifold AI ((since the pressure is at atmospheric pressure, use the force of the operating rod 611/'i valve opening spring 62 to push the control arm 55 to the specified position as shown by the solid line in Figure 1). The accompanying rotation of the second lever 542 pulls the link 50 and rotates the throttle lever 45 of the carburetor C to the starting opening position of the throttle valve.In this way, the throttle valve opens slightly larger than the idle opening position. It is held at the starting opening.

Therefore, if the starter R is operated to crank the engine E in order to start the engine E, even if the exhaust valve 69 is opened by the pressure reducing device before the intake valve 68 is closed, the throttle grip 43 will not be closed. Vaporizer C without operation
Supplying a rich and sufficient amount of mixture to carrot E from
You can quickly detonate Carrot E.

With the complete explosion of the carrot E (・When the intake negative pressure in the intake manifold M rises above a predetermined value, the negative pressure flows through the negative pressure conduit 6
3 into the negative pressure chamber 58 of the negative pressure actuator Il, the diaphragm 60 is drawn toward the negative pressure chamber 58 against the force of the valve opening spring 62, causing the operating rod 61 to retreat from the control arm 55. As a result, the throttle lever 45 can be returned to the idle opening position of the throttle valve by the force of the return spring 48.

C9 Effects of Invention As described above, according to the present invention, a negative pressure actuator is connected to a throttle valve of a carburetor installed in an engine, and the negative pressure actuator is
It has a negative pressure chamber that introduces intake negative pressure downstream of the throttle valve, and when the negative pressure introduced into the chamber is less than a predetermined value, the throttle valve is opened to a starting opening degree slightly larger than the idle opening degree, It is configured to allow the throttle valve to return to the idle opening when the introduced negative pressure exceeds a predetermined value, so the throttle valve of the carburetor can be maintained at the starting opening when the engine is started. Therefore, despite the operation of the pressure reducing device, a rich and sufficient amount of air-fuel mixture can be supplied to the engine, thereby improving the startability of the engine. After the engine is started, the restriction on the throttle valve is automatically released and the throttle valve is allowed to return to the idle opening, so manual operation of the throttle valve is not necessary at all until the engine starts.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to an outboard motor engine. Fig. 1 is a partially cutaway view of the engine section, and Fig. 1A is an enlarged longitudinal sectional side view of the main part of Fig. 1. , Figure 2 is a side view of the outboard motor, Figure 3 is a longitudinal side view of the carrot section, Figure 4 is a sectional view taken along the line IV-IV in Figure 3, Figure 5 is an enlarged view of the pressure reducing device in Figure 4. Planar section, Figure 6 is a sectional view taken along the line VT-Vl in Figure 5, Figure 7 is a view taken in the direction of
It is a sectional view taken along the l-v■ line. C... Carburizer, D... Pressure reducing device, E... Engine/1.
V... Intake manifold, R... Glue coil starter as manual starter, V... Negative pressure actuator 1...
Crankshaft, 43...Throttle grip, 45...
Throttle lever, 55... Fi control arm, 57.
・・Housing, 58・−・Negative pressure chamber, 59・・Atmospheric chamber,
60...Diaphragm, 61...Operating rod, 62...
・Valve opening spring, 63...Negative pressure conduit, 67...Camshaft,
67 otsu... intake cam, 67 e... exhaust cam, 68...
...Intake valve, 69...Exhaust fi valve, 70...Tappet, 71...Buso 7 euros, 72...Rocker arm, 73...Tappet lifter, 74...Centrifugal weight, 7
5... Spring, T8... Driving claw, 79... Driven claw Patent originator: Kida Giken Kogyo Special Co., Ltd. Figure 7φ≠ Figure 8 Figure 5 and Figure 6'

Claims (1)

[Claims] a manual starter for cranking the engine;
In an engine starting device including a pressure reducing device that operates to open an exhaust valve to reduce pressure in a cylinder when cranking the engine, a negative pressure actuator is connected to a throttle valve of a carburetor installed in the engine, The negative pressure actuator has a negative pressure chamber that introduces intake negative pressure downstream of the throttle valve, and when the negative pressure introduced into the chamber is less than a predetermined value, the throttle valve is opened at a starting opening slightly larger than the idle opening. 1. An engine starting device, characterized in that the throttle valve is configured to open at a certain time and allow the throttle valve to return to an idle opening degree when the introduced negative pressure reaches a predetermined value or more.