JPH0633752B2 - Engine cell start and stop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application> The present invention starts an engine by interlockingly connecting a starting gear to a crankshaft of an engine and rotating the crankshaft via a pinion and a starting gear with a cell starter. The present invention also relates to an engine cell starting and stopping device configured to stop after the engine causes an engine braking action due to the stop operation of the engine stopping device and the engine speed is rapidly reduced.

<Prior Art> Conventionally, in stopping a diesel engine, fuel is cut by manual operation or actuation of an actuator such as a solenoid or an electric motor, and compression of a cylinder causes an engine braking action to rapidly lower the rotation and stop the engine. It is common.

<Problems to be Solved by the Invention> When the engine is stopped by the fuel cut, the crankshaft stops due to compression of the cylinder at a fixed rotation phase determined corresponding to the number of cylinders. At the time of starting, the position where the pinion of the cell starter starts to mesh with the starting gear (generally attached to the flywheel) linked to the crankshaft is determined. When the engine is started, the pinion rotates and approaches the starting gear, so that the pinion initially comes into sliding contact with the side surface of the starting gear, and wear occurs there.

Therefore, as the pinion meshing start point is determined as described above, wear is concentrated on a specific part of the starting gear, and pinion meshing failure occurs during long-term use.

Therefore, we have taken measures such as changing the mounting phase of the starting gear when the wear has progressed to a certain degree, but since the starting gear is generally shrink-fitted and fixed to the flywheel provided at the crankshaft end, it is not possible to change the mounting phase. It took a lot of time and effort.

The present invention was made by paying attention to the actual situation,
By making improvements to the engine stop device, the stop position of the crankshaft is made indefinite, thereby avoiding specifying the start position of meshing with the pinion and preventing local wear of the start gear. It was something I tried to do.

<Means for Solving Problems> A characteristic configuration of the present invention for achieving the above object is to provide a decompression device for a combustion chamber, a decompression operating device, and a pre-stop low rotation detection device in an engine, and the engine is an engine stop device. When the low rotation speed just before the rotation stops is approached while the rotation speed is being reduced while the engine is being stopped by the engine, the low rotation speed before the stop detects this low rotation speed. The point is that the device is operated to bring the combustion chamber into the decompression state.

<Operation> According to the above configuration, when the engine stop operation is performed and the engine rotation speed is rapidly reduced to the set low rotation speed immediately before the rotation stop, this is detected by the rotation detection device, and the decompression device is detected based on this detection. The combustion chamber becomes decompressed by working. Therefore, immediately before the engine is stopped, there is no compression in the combustion chamber, and the crankshaft freely rotates inertially and stops at an unspecified position.

<Effects of the Invention> Therefore, according to the device of the present invention, although the engine causes an engine braking action due to the stop operation of the engine stop device to promptly lower the rotation and stop, the start gear is stopped every time the engine is stopped. The rotation phase is different and the meshing start position of the pinion of the cell starter is changed. As a result, local wear of the starting gear due to sliding contact with the pinion was avoided, and the durability of the starting gear was improved.

<Example> FIG. 1 shows a four-cylinder diesel engine 1 to which the present invention is applied.
A schematic side view of is shown.

A flywheel 3 is fixed to the rear end (left end in the figure) of the crankshaft 2 supported horizontally in the front-rear direction, and a start gear 4 is connected and fixed to the outer periphery thereof. A cell starter 6 having a pinion 5 capable of meshing with the starting gear 4 is attached to a rear portion on one lateral side of the engine 1, and the pinion 5 is rotationally advanced.
Is configured so that the engine is started by meshing with the starting gear 4 and rotating the crankshaft 2.

In addition, a speed governor 7 for adjusting the amount of fuel supplied from the fuel injection pump via a governor is provided at the front of the other side of the engine 1, and an engine stop lever 8 provided on the speed governor 7 is provided.
An engine stop device 10 that cuts fuel and stops the engine 1 by driving and operating a solenoid 9
Is provided.

Further, the engine head portion is provided with a decompressor (decompression device) 11 for opening the combustion chamber of each cylinder and a solenoid 12 as a decompression operation device for driving and operating the decompression device. In addition, the rotation of a gear (not shown) interlocked with the crankshaft 2 was measured in the gear case portion of the front of the engine 1 using a rotary encoder or the like, and the engine rotation reached the set low rotation speed immediately before the stop. A pre-stop low rotation speed detection device 13 for detecting this is provided.

The operation of the engine stop solenoid 9 and the decompression operation solenoid 12 is controlled by the circuit shown in FIG. 2. The engine stop operation will be described with reference to FIG.

When an engine stop button or the like is operated to output an engine stop signal, the contact S ₁ is closed and the relay R ₁ and the timer relay TR are activated.

Upon activation of relay R ₁ , its normally open relay contact r ₁
a ′, r ₁ a ″ are closed, the solenoid 9 of the engine stopping device 10 is energized, the stop lever 8 is operated against the biasing force in the fuel supply direction, and the fuel supply is cut off.

Due to the fuel cut, the engine speed drops rapidly.
Then, when the engine rotation reaches the set low rotation speed n ₀ (for example, 100 rpm) immediately before the stop, this is the rotation detection device 13.
Is detected, a signal is emitted based on this detection, the contact S ₂ is closed, and thereby the relay R ₂ is activated.

With the activation of the relay R ₂ , its normally open relay contact r ₂
a is closed, the decompression operation solenoid 12 is energized, and each combustion chamber is opened.

When the combustion chamber is opened, the crankshaft 2 rotates by free inertia and finally stops.

After that, the timer relay TR times up and its normally-open relay contacts tr ', tr "are opened, and the energization of both solenoids 9 and 12 is cut off.
The time-up time t of R is about 30 seconds, and FIG. 3 shows an operation time chart of the engine rotation and the respective solenoids 9 and 12.

An electric motor may be used instead of the solenoid 9 of the engine stop device 10 and the solenoid 12 as a decompression operation. Further, the engine stopping device 10 may be of a manually operated type.

[Brief description of drawings]

FIG. 1 is a schematic side view of an engine equipped with a cell starting and stopping device according to the present invention, FIG. 2 is an electric circuit diagram for controlling the engine stopping device, and FIG. 3 is an operation time chart. 1 ... Engine, 2 ... Crankshaft, 4 ... Starting gear,
5 ... Pinion, 6 ... Cell starter, 10 ... Engine stop device, 11 ... Decompression device, 12 ... Decompression operation device, 13 ... Low speed detection device before stop.

Claims (1)

[Claims] 1. A starting gear for a crankshaft (2) of an engine (1)
(4) are linked and connected, and the engine (1) is started by rotating the crankshaft (2) via the pinion (5) and the starting gear (4) by the cell starter (6), and The engine is stopped by stopping the engine (10).
In a cell starting and stopping device of an engine configured such that (1) causes an engine braking action to rapidly decrease its rotation and then stops, the engine (1) includes a decompression device (11) and a decompression operating device (12) for a combustion chamber in the engine (1). ) And a pre-stop low rotation speed detection device (13) are provided, and while the engine (1) is stopped by the engine stop device (10) and the engine speed is reduced while engine braking is being performed, a low rotation speed immediately before the rotation stop is approached. When the low rotation speed is detected by the low rotation speed detection device before stop (13), the decompression operation device (12) activates the decompression device (11) to bring the combustion chamber into the decompression state. The engine cell start and stop device.