JPH02211380A - Overrun preventing device for electric starter for engine - Google Patents

Abstract

PURPOSE:To prevent the breakage of a self-starter by installing an electricity supply cut-off device into an instruction input circuit and connecting an engine revolution speed detector of an engine and allowing the electricity supply cut-off device to cut off an instruction input circuit when the detected revolution speed becomes over a set revolution speed. CONSTITUTION:An electricity supply cut-off device 10 is formed from a relay 16, comparator, and an FV converter 18, and the relay 16 is connected with a part of an instruction input part circuit 2, and an electromagnetic revolution speed detector 11 is set close to a ring gear 8. Therefore, after the start of an engine E, the revolution speed detector 11 detects the increase of the revolution speed, and when the detected revolution speed becomes over a set revolution speed through the comparison by the comparator 17, the all-time closed contact point 19 of the relay 16 is opened to cut off the instruction input circuit 2, and the electricity supply to a self-starter S is cut off, and the driving force is reduced to zero, and the movement with a starting ring gear 8 is released. Therefore, the breakage of the self-starter S can be prevented, independently of the operation of a main switch 3 after start.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an overrun prevention device for an electric engine starter. To provide something that can prevent damage due to rotation.

<Prior Art> As shown in FIG. 1 or 2, the basic structure of an electric starter for an engine, which is the subject of the present invention, is that a command input terminal 1 of a cell starter S of an engine E is connected to a command input circuit 2 and a main While connecting to the battery 4 via the switch 3,
Connect the power input terminal 5 of the cell starter S to the power input circuit 6
By connecting the main switch 3 to the starting position A, the cell starter S is activated, and the pinion 7 of the cell starter S is pushed out and engaged with the starting gear 8 of the engine E. This is a push-in electric starter configured to rotate.

As shown in FIG. 2, this type of conventional technology includes attaching the pinion 7 directly to the armature shaft 13 of the cell starter S, or attaching the pinion 7 via an overrunning clutch 14 to the cell starter S. When a command input current flows from the command input circuit 2 to the magnet switch 12, the pinion 7 moves into the starting gear 8 against the return spring.
At the same time, the armature is energized and the cell starter S drives the engine E.

<Problems to be Solved by the Invention> In a general starting operation, an operator continuously puts the main switch 3 into the starting position A for a predetermined period of time to start the engine E, and after starting the engine E, the operator closes the main switch 3 as quickly as possible. The starting position A is returned to the on position B.

However, in the above-mentioned direct connection type conventional technology, if there is a delay in returning the main switch 3 from the starting position A to the on position B after starting due to operator carelessness or inexperience, the armature shaft 13 of the cell starter S There is a large risk that the engine will be driven at high speed by the side starting gear 8 and will be damaged.

In addition, in the conventional technology using an overrunning clutch 14, when the pinion 7 is reversely rotated by the starting gear 8, the transmission of rotation from the pinion 7 to the armature shaft 13 is cut off by the action of the clutch 14. , armature shaft 1
Overrun due to reverse rotation of 3 is prevented.

However, since the armature shaft 13 is driven without load by electric power and overruns, the risk of damage remains.

Incidentally, such damage to the armature shaft 13 also occurs when the main switch 3 is erroneously turned on to the starting position A while the engine E is operating.

The present invention can be used with or without an overrunning clutch.
The technical problem is to prevent the cell starter from being damaged during startup.

<Means for Solving the Problems> Means for solving the above problems will be described below using drawings corresponding to embodiments.

That is, the present invention provides an electric starting device for an engine having the basic structure described above, in which a power supply cutoff device 10 is interposed in the command input circuit 2, and the rotation speed of the engine E is configured to be detectable by the rotation speed detection device 11.
The rotation speed detection device 11 is connected to the power supply cutoff device 10, and when the rotation speed detected by the rotation speed detection device 11 exceeds the set rotation speed, the power supply cutoff device 10 cuts off the command input circuit 2 and stops power supply to the cell starter S. This is an overrun prevention device for an electric engine starting device, which is characterized by stopping the engine.

If the key is left in the starting position A of the main switch 3 for a long time even after starting the engine E due to operator carelessness, the engine speed will rapidly increase and the speed detection device 1 will
The detected rotation speed of 1 is equal to or higher than the set rotation speed.

As a result, the power supply cutoff device 1O that receives the signal from the rotation speed detection device 11 cuts off the command input circuit 2 connecting the command input terminal 1 of the cell starter S and the main switch 3, and stops the power supply to the cell starter S. At the same time, the pinion 7 is withdrawn by the return spring of the cell starter S and is no longer interlocked with the starting gear 8, and at the same time, the power supply to the armature shaft is cut off and the driving force is lost (that is, the cell starter S (stops by losing its function as a motor).

<Effects of the Invention> When there is a delay in returning the main switch after starting due to operator carelessness, etc., the power supply cutoff device immediately cuts off the power supply to the cell starter due to the increase in engine speed, causing the pinion to retreat. At the same time, since the armature shaft of the cell starter is stopped, overrun of the cell starter can be eliminated and damage to it can be prevented.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic explanatory diagram of an overrun prevention device of an electric starting device for an engine. It is composed of a rotation speed detection device 11.

A starting ring gear 8 is formed on a flywheel 15 at the rear of the engine E, and a cell starter S is configured to be interlocked with the starting ring gear 8.

The cell starter S has an armature shaft 1 that serves as a rotating shaft.
3, a pinion 7 that meshes with the ring gear 8, an overrunning clutch 14 that is interposed between the armature shaft 13 and the pinion 7, and a magnetic switch 12 that issues power supply and commands to insert and remove the pinion 7.

The command input terminal 1 of the magnetic switch 12 is connected to the starting position A of the main switch 3 through the command input circuit 2, and the power input terminal 5 of the magnetic switch 12 is connected to the main switch 3 through the power input circuit 6 and the battery 4. .

Note that the symbol B indicates the on position of the main switch 3, and the symbol C indicates the off position.

In addition, when a command current is applied to the cell starter S from the command input terminal l, the binion 7 is pushed out against a return spring (not shown) built into the cell starter S and is engaged with the starting ring gear 8. At the same time, the magnet The contactor of switch 12 is energized and the armature is driven.

On the other hand, the power supply cutoff device 10 consists of a relay 16, a comparator 17, and an FV converter 18.
is interposed in a part of the command input circuit 2, and an electromagnetic pick-up nut rotation speed detection device 11 is installed in the ring gear 8.
A comparator 17, an FV converter 18, and a rotational speed detecting device 11 are connected in series to this relay 16 in this order.

Therefore, the functions of the above-mentioned overrun prevention device will be described.

When the operator turns the main switch 3 to the starting position A,
A command current flows through the command input terminal 1, and the magnet switch 12 pushes out the binion 7 against the return spring, and by meshing with the starting ring gear 8, the crankshaft 20 is driven via the flywheel 15. Then engine E starts.

In this case, even after the engine E has started, if there is a delay in returning it from the starting position A to the on position B due to operator carelessness, the pinion 7 of the cell starter S will be rotated at high speed by the ring gear 8. However, the rotation speed detection device 11
detects this increase in rotational speed.

That is, when the rotation speed detected by the comparator 17 exceeds the set rotation speed, the normally closed contact 19 of the relay 16 opens to cut off the command input circuit 2, and the power supply to the cell starter S is cut off. At the same time that the driving force of the armature shaft 13 disappears, the binion 7 moves out due to the action of the return spring built into the cell starter S, and the interlocking with the starting ring gear 8 is released.

Therefore, even if the operator is careless in operating the main switch 3, the power supply to the cell starter S will be cut off immediately after starting the engine E, so the cell starter S will be cut off immediately after the engine E starts. Damage to the data S can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an overrun prevention device for an electric engine starter according to an embodiment of the present invention, and FIG. 2 is a schematic explanatory diagram of an electric engine starter according to the prior art. ■...Command input terminal, 2...Command input circuit, 3...
... Main switch, 4... Battery, 5... Power input terminal, 6... Power input circuit, 7... Binion, 8... Starting gear, 10... Power supply cutoff device, 1
1... Rotation speed detection device, 12... Magnetic switch, A... Starting position, S... Cell starter, E...
·engine. Patent applicant Kubota Iron Works Co., Ltd.

Claims (1)

[Claims] 1. The command input terminal 1 of the cell starter S of the engine E is connected to the battery 4 via the command input circuit 2 and the main switch 3.
By connecting the power input terminal 5 of the cell starter S to the battery 4 via the power input circuit 6 and turning the main switch 3 to the starting position A, the cell starter S is activated. In an electric starting device for an engine configured so that the pinion 7 of the engine E is pushed out and engaged with the starting gear 8 of the engine E to rotate, a power supply cutoff device 10 is interposed in the command input circuit 2, and the rotation of the engine E is controlled. The rotation speed detection device 11 is configured to be detectable by the rotation speed detection device 11, and the rotation speed detection device 11 is connected to the power supply cutoff device 10, and when the rotation speed detected by the rotation speed detection device 11 exceeds the set rotation speed, the power supply cutoff device 10 is configured to detect the rotation speed. An overrun prevention device for an electric starter for an engine, characterized by cutting off a command input circuit 2 and stopping power supply to a cell starter S.