DE20013477U1 - Mechanical starter for internal combustion engines - Google Patents

Description

Willi Lieh, Dipl.-Ing.
Im Schelmbohl 47a
64665 Aisbach

Mechanical starter for combustion engines

The invention relates to a mechanical starter for internal combustion engines with a small displacement, which, after being triggered, starts the internal combustion engine, discharges itself in the process and then recharges itself independently.

Many small machines, such as lawn mowers, compressors, generators, etc., are equipped with small-displacement internal combustion engines. These engines are started with starters by rotating the engine drive shaft. Pull-cord starters, crank starters and electric starters are known as starters for such engines.

Rope starters are very common in the field of small machines. However, they have significant disadvantages. The starting attempt is inconsistent depending on the operator and is therefore not optimal for a start that is as short and successful as possible. There are frequent failed attempts and, in extreme cases, an unwanted fuel oversaturation in the piston chamber, which means that the engine must first be ventilated before it can be started - all in all, a strenuous affair. The uniformity and reliability of the start process with an electric starter cannot be achieved with the rope starter. Furthermore, each new start attempt must be carried out by the operator using muscle power.

Crank starters are hardly used anymore and have the same disadvantages as pull-cord starters.

Electric starters are the most reliable in this range, but they are rarely used in small work machines with combustion engines due to cost reasons and the need for a battery.

The object of the invention is to start an internal combustion engine of a small work machine with a mechanical starter without the use of muscle power and with the reliability of an electric starter, whereby the mechanical starter transfers its stored energy to the internal combustion engine for the starting process and is recharged by the internal combustion engine after the start.

This object is achieved according to the invention by a starter according to claims 1 - 5.

Further details and further embodiments can be found in the following description and the drawing of the embodiment.

Fig. 1 shows a schematic view of the mechanical self-recharging starter for internal combustion engines

The invention relates to a mechanical starter that receives its energy from a spring accumulator (1). The spring accumulator is a self-encapsulated unit with a spiral spring with a rectangular cross-section, which is dimensioned according to the size of the energy required. The spiral spring is tensioned by turning the shaft in the center to the left several times. On the primary side, the spring accumulator has a shaft stub with an external hexagon (2) for initial charging and/or for any necessary intermediate charging. In the tensioned state, the spiral spring is held by a disengageable pawl. On the secondary side of the spring accumulator there is a drive shaft (3) with a disengageable clutch with freewheel (4), a drive shaft (6) that has a positive connection to the motor drive shaft. The drive shaft (6) is connected via a gear transmission (11) to the shaft for the accumulator charge (7), which acts on the shaft (3) as required via a disengageable slip clutch with torque limitation (8) and a gear transmission (10).

At the beginning, the spring accumulator (1) is charged with a hand crank by turning the shaft stub (2). To start the combustion engine, the clutch (4) and the pawl that keeps the spring in the spring accumulator tensioned are released via the actuating elements (5). The shaft (6) transfers the torsional energy to the engine drive shaft until the engine starts. During the start-up process, the clutch (8) is disengaged. As soon as the engine is running independently, the clutch (4) goes into freewheel mode and is then disengaged via the actuating element (5).

To charge the spring accumulator, the clutch (8) is engaged via the actuating element (9). The clutch (4) remains disengaged. The drive shaft (3) is now rotated in the opposite direction via the shaft (6), the gears (11) and (10), thus tensioning the spring of the spring accumulator until the torque limit of the clutch (8) triggers the slip effect. The clutch (8) is then disengaged via the actuating element (9).

Claims (5)

1. Mechanical starter for internal combustion engines with small displacement, characterized in that the mechanical energy storage required for the starting process is recharged by the internal combustion engine. 2. Mechanical starter for internal combustion engines according to claim 1, characterized in that a spring accumulator is used as the mechanical energy accumulator, the energy size of which is dimensioned according to the requirements and the spring of which is designed as a spiral spring with a rectangular cross-section. 3. Mechanical starter for internal combustion engines according to claim 1 or 2, characterized in that both discharge and recharging of the mechanical energy storage device are controlled via gear transmissions and mechanical clutches. 4. Mechanical starter for internal combustion engines according to claims 1-3, characterized in that both discharge and recharging of the mechanical energy storage device are triggered via mechanical actuating elements. 5. Mechanical starter for internal combustion engines according to claims 1-4, characterized in that the mechanical energy storage device can also be charged with a hand crank.