DESCRIPTION

PORTABLE ENGINE UNIT

Technical Field

An aspect of the present invention relates to a portable engine unit used to perform required works by driving an engine .

Background Art In a portable engine unit for performing required works by using an engine as a driving source, a rotation speed of the engine is controlled by actuating a trigger to open or close a throttle valve of a throttle device through a throttle wire.

An exemplary throttle control device of a conventional portable engine unit will be described with reference to Figs. 5 to 7.

Fig. 5 is a side, view illustrating a hand grip of a conventional throttle control device, Fig. 6 is a partially cross-sectional side view illustrating a fully-opened condition of the throttle control device, and Fig. 7 is a partially cross-sectional side view illustrating a fully-closed condition of a throttle control device.

Referring to Figs. 6 and 7, a trigger 109 is pivotably actuated with respect to an axis 108 inside the hand grip 107. A fingering portion 109a of the trigger 109 is extended from

the hand grip 107 as shown in Figs. 5 and 6 when the throttle is fully closed. An end of the throttle wire 110 is connected to a distal end of an arm 109b of the trigger 109 extending towards the inside of the hand grip 107, while the other end of the throttle wire 110 is connected to a throttle device (not shown) . A claw 109c is protruded from the trigger 109 around an axis 108.

In the hand grip 107, the control lever 111 is pivotably supported by an axis 112. As shown in Fig. 5, the control lever 111 has a latch Ilia monolithically formed with the control lever 111 to outwardly extend in a radial direction. An engagement 111b to be engaged with the claw 109c of the trigger 109 is protruded from the control lever 111 to face toward the inside of the hand grip 107. When the trigger 109 is released as shown in Fig. 6, the throttle valve of the throttle is fully closed, so that the engine is rotated in an idle rotational frequency of low speed. However, when the fingering portion 109a of the trigger 109 is pulled, and the trigger 109 is pivoted with respect to an axis 108 in an arrow direction a (i.e., counterclockwise), the throttle wire 110 provided in the arm 109b of the trigger 109 is pulled towards an arrow direction b of Fig. 7, so that the throttle valve of the throttle is opened, and the rotation speed of the engine increases. When the trigger 109 is fully pulled as shown in Fig. 7, and the throttle wire 110 is fully pulled

towards an arrow direction b, the throttle valve of the throttle is fully opened, so that the rotation speed of the engine reaches its maximum RPM. In addition, since the throttle wire 110 is biased to a fully-closed condition (in an arrow direction b' of Fig. 6) , the fingering portion 109a of the trigger 109 is protruded in maximum from the hand grip 107 in the fully-closed condition as shown in Fig. 6.

The control lever 111 is pivotably mounted near the trigger 109 to have a frictional force in a pivoting direction. The frictional force is set so that the trigger 109 can be held against an urging force to return toward a fully-closed condition through engagement between the claw 109c and the engagement 111b.

Accordingly, since the trigger 109 is biased to return to a fully-closed condition through the throttle wire 110, the trigger 109 is pivoted in an arrow direction a' of Fig. 7 (i.e., clockwise) and automatically returns to a fully-closed condition A of Fig. 6 when an operator's index finger is released from the fingering portion 109a of the trigger 109. In addition, an operator may use his/her thumb to actuate the latch Ilia of the control lever 111 to adjust a rotation speed of the engine by pivoting the control lever 111 with respect to an axis 112 within an angle range between a fully-closed position A and a fully-opened position B, which engages the engagement 111b of the control lever 111 with the

claw 109c of the trigger 109 and pivots the trigger 109 with respect to an axis 108 in synchronization to adjust the throttle position. In this case, as described above, the control lever 111 have a fictional force enough to be held against the throttle-closing force from the trigger 109 biased to return toward a fully-closed position through the engagement of the claw 109c and the engagement 111b. Therefore, even when an operator's index finger is released, it is possible to hold the control lever 111 at any position by the frictional force in a rotational direction, and also possible to maintain the rotation speed of the engine at a desired value.

As a result, an operator may ^' control the fingering portion 109a of the trigger 109 with his/her index finger when performing work such as intermittently changing the throttle position, that is, engine RPM. Also, an operator may adjust and fix the latch Ilia of the control lever 111 at any position with his/her thumb, and then easily perform works without need to hold the latch Ilia with his/her thumb when performing work at any fixed throttle position, that is, engine RPM. In the throttle control device of the conventional portable engine unit shown in Figs. 5 and 7, an operator is allowed to easily perform works without need to manually hold the latch Ilia of the control lever 111 when working at any fixed throttle position, that is, engine RPM, as described above. However, it has some shortcomings as follows.

That is, since the position of the latch Ilia of the control lever 111 is significantly varied between the fully-closed position A and the fully-opened position B as shown in Fig. 5, it is uneasy for an operator to use the thumb pad when the position of the control lever 111 is changed from the fully-opened position B to the fully-closed position A. In this case, the operator needed to use his/her thumb nail, which is difficult to put strength into, or use the other hand. For this reason, it is difficult to use a single hand to control the control lever 111 when finely adjusting the throttle position near the fully-opened position B, or returning the control lever 111 to the fully-closed position A after completing work, and resulted in deterioration of work efficiency. As a method for solving the aforementioned problems, in respect to the fully-opened position B, the existing location of the latch Ilia may be offset counterclockwise from its original location in Fig. 5 in order to allow the latch Ilia of the control lever 111 to be controlled by the operator's thumb pad. However, this configuration may generate another problem that the thumb may not reach the latch Ilia in a fully-closed position A.

Disclosure of Invention The present invention is contrived to solve the

aforementioned problems, and its object is to provide a portable engine unit having a control lever easily controlled with a single hand within a full range of a throttle position. According to an aspect of the present invention, there is provided a portable engine unit including: an engine functioning as a driving source; a throttle device which controls a rotation speed of the engine; a trigger for actuating a throttle wire extending from the throttle device; a control lever having an engagement for engaging the trigger and a latch for pivotably actuating the control lever with a finger; and a hand grip for pivotably holding the control lever and the trigger, wherein a location of at least part of the latch is higher than a central axis of the hand grip whenever the control lever is positioned at a throttle fully-opened position or a throttle fully-closed position.

According to such configuration, since the location of at least part of the latch of the control lever is higher than a central axis of the hand grip whenever the control lever is positioned at a throttle fully-opened position or a throttle fully-closed position, it is possible to easily rotate the latch of the control lever that is located higher than the central axis of the hand grip with one hand whenever the control lever is positioned at a throttle fully-opened position or a throttle fully-closed position, thus adjusting the controllability of the engine rotation speed including fine

adjustment within a full range of the throttle position.

The latch of the control lever may have a concave portion .

According to such configuration, since the latch of the control lever has a concave portion, an operator' s thumb may be inserted into the concave portion to piviotably actuate the control lever with ease.

According to another aspect of the present invention, there is provided a portable engine unit including: an engine functioning as a driving source; a throttle device which controls a rotation speed of the engine; a trigger for actuating a throttle wire extending from the throttle device; a control lever having an engagement for engaging the trigger and a latch for pivotably actuating the control lever with a finger; and a hand grip for pivotably holding the control lever and the trigger, wherein the latch of the control lever includes a first latch used to actuate the control lever toward a fully-opened position and a second latch used to actuate the control lever toward a fully-closed position.

According to such configuration, since there is provided a latch used for rotating the control lever to a fully-opened throttle and another latch for rotating the control lever to a fully-closed throttle, the latch for a fully-opened position still remains within a convenient location for adjusting the control lever to a fully-opened position even when the latch for a fully-closed position is used to actuate the control lever

to a fully-opened position. Accordingly, it is possible to pivotably actuate the control lever with ease from a fully-opened position toward a throttle closing direction, thus adjusting the controllability of the engine rotation speed including fine adjustment within a full range of the throttle position.

Brief Description of the Drawings

Fig. 1 is a side view illustrating a portable engine unit according to an embodiment of the present invention.

Fig. 2 is a side view illustrating a hand grip having a throttle control device of a portable engine unit according to the embodiment.

Fig. 3 is a diagram illustrating a variation of a control lever used in a portable engine unit according to the embodiment.

Fig. 4 is a diagram illustrating a variation of a control lever used in a portable engine unit according to the embodiment . Fig. 5 is a side view illustrating a hand grip of a conventional throttle control device.

Fig. 6 is a partially cross-sectional side view illustrating a conventional throttle control device in a fully-opened position. Fig. 7 is a partially cross-sectional side view

illustrating a conventional throttle control device in a fully-closed position.

Best Mode for Carrying out of the Invention Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings .

Fig. 1 is a side view illustrating a portable engine unit according to an embodiment of the present invention, and Fig. 2 is a side view illustrating a hand grip including a throttle control device of a portable engine unit.

The portable engine unit 1 of Fig. 1 is a blower which intakes or exhausts air by rotatably driving a fan (not shown) using an engine 2. Air is input from the intake duct 3b and output to the exhaust duct 3a. A throttle device 4 and an air cleaner 5 are connected to the intake duct of the engine 2, and a silencer 6 is connected to the exhaust duct of the engine 2.

In addition, on the upper side of the portable engine unit 1, a hand grip 7 to be gripped when the operator holds the portable engine unit 1 with a single hand is provided horizontally. One end of the hand grip 7 internally has a trigger 9 pivotably actuated with respect to an axis 8. A fingering portion 9a of the trigger 9 is downwardly extended from the hand grip 7 as shown in Figs. 1 and 2 when the throttle is fully closed. While an end of the throttle wire 10 is

connected to a distal end of an arm 9b extending toward the inside of the hand grip 7, the other end of the throttle wire 10 is connected to a throttle device 4. A claw 9c is protruded from the trigger 9 near the axis 8. A control lever 11 is pivotably supported on the hand grip 7 by an axis 12 near the trigger 9 (within a distance where a thumb of an operator' s hand grasping the hand grip 7 can reach) . As shown in Fig. 2 in detail, the control lever 11 has two latches HA and HB monolithically formed with the control lever 11 to outwardly extend in a radial direction. The locations of both latches HA and HB of the control lever 11 are higher than the center of the axis 12. While one latch HA is used to pivotably actuate the control lever 11 toward a fully-closed position, the other latch HB is used to pivotably actuate the control lever 11 toward a fully-opened position. Other components except for the control lever 11 of the throttle control device are similar to those shown in Figs. 5 to 7, and their description will be omitted.

According to the present embodiment, even when an operator holds the hand grip 7 and rotates the latch HB of the control lever 11 with his/her thumb to a fully-opened position B as shown as a dashed line in Fig. 2, the position of the other latch HA is still within a range allowing the operator' s thumb pad to pivotably actuate the control lever 11 with ease. Therefore, it is possible for an operator to

pivotably actuate the control lever 11 with ease from the fully-opened position B toward a throttle closing direction (i.e., counterclockwise from Fig. 2) by rotating the latch HA with his/her thumb pad. In this case, when the latch HA of the control lever 11 approaches the fully-closed position A, and an operator fails to reach the latch HA with his/her thumb, the control lever 11 can be pivotably actuated to a fully-closed position Aby controlling the other latch HB with an operator' s thumb. Also, when the throttle position is finely adjusted near the fully-opened position B, an operator may rotate the latch HA of the control lever 11 with his/her thumb pad.

According to the embodiment, since either of the latches HA or HB of the control lever 11 is selectively used depending on a throttle position, it is possible to control the rotation speed of the engine 2 by easily actuating the control lever 11 with a single hand even when the throttle position is finely adjusted near a fully-opened position B, or when the control lever 11 is returned to a fully-closed position A after completing work. Alternatively, the control lever 11 may have variations such as a control lever 11' of Fig. 3 obtained by combining the latches HA and HB, or a control lever H'' of Fig. 4 obtained by forming a concave portion Ha' ' in outer periphery of the control lever 11' of Fig. 3. When the control lever H'' of Fig. 4 is used, an operator's thumb may be inserted

into the concave portion 11a' ' to pivotably actuate the control lever ll ^{f /} with more ease.

This application claims priority from Japanese Patent

Application No. 2007-260473 filed on October 4, 2007, the entire contents of which are incorporated herein by reference .

Industrial Applicability

According to the present invention, there is provided a portable engine unit having a control lever easily controlled with a single hand within a full range of a throttle position.