JPH0318668Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a speed limiting device on the low speed side of a diesel engine, and provides one that allows the speed regulating lever to be rotated to the rapid deceleration side without causing engine stall.

The diesel engine on which the present invention is based is, for example, as shown in FIG. 3 or FIG. 5.

That is, the speed regulating lever 3 is rotatably supported on a pedestal 2 attached to the crankcase 1, a high speed rotation limiter 4 and a low speed rotation limiter 5 are fixed to the pedestal 2,
When the speed regulating lever 3 rotates to the high speed side A, it contacts the high speed rotation limiter 4 and is positioned at the upper limit value, and when it rotates to the low speed side B, it contacts the low speed rotation limiter 5 and reaches the lower limit value. Positioned.

A governor lever 6 is swingably supported on the crankcase 1, the tip 6a of the governor lever is engaged with a fuel injection rack 7, and a fuel injection camshaft 10 linked to the crankshaft 8 is linked to a fuel injection pump 11. , a governor weight 1 is attached to the fuel injection camshaft 10.
2 is attached, and the speed regulating lever 3 is connected to the governor lever 6.
is connected to via a governor spring 14 to bias the governor lever 6 toward the high speed side A, and when the governor weight is displaced due to an increase in engine speed, a governor force F is applied to the governor lever 6 so that it swings toward the low speed side B. It is composed of

Conventionally, as a speed limiting device for a diesel engine, as shown in FIG. 5, and an operating rod 16 is suspended from the tip side of the speed regulating lever 3. According to this, when the speed control lever 3 is suddenly rotated to the low speed side B by operating the operating handle, the governor lever attempts to shift the fuel injection rack to a predetermined low speed injection position via the governor spring, but the engine speed Due to the delay in speed reduction, the governor force, which remains in a strong state, acts on the governor lever, pulling the fuel injection rack even lower than this predetermined position.

As a result, the rack position becomes lower than the minimum injection position required for engine rotation, causing the engine to stall, and the riding comfort of a working machine such as an agricultural machine equipped with the engine to be mounted to become poor.

This invention was proposed to solve the above problem, and to prevent engine stalling even when the speed regulating lever is suddenly decelerated, without dropping the easy fuel injection position to an excessively low injection position. and
To achieve this purpose, it is structured as follows.

That is, in the diesel engine having the basic configuration described above, a long hole 17 is formed in the speed regulating lever 3 in a state substantially along the pulling direction D of the operating rod 16,
The tip 16a of the operating rod 16 is loosely fitted into the elongated hole 17, and the low-speed rotation limiter 5 is fixed to the pedestal 2 via the elastic spring 15 so that it can move forward and backward, and the low-speed rotation limiter 5 is retracted. The end of the movement is set at the low speed lower limit position C, and the regulating lever 3 is configured to gradually move to the low speed lower limit position C.

Here, to describe the effects of the present invention brought about by the above configuration, a long hole is formed in the speed regulating lever approximately along the pulling direction of the operating rod, and the tip of the operating rod is loosely fitted into this long hole. Therefore, even if the operating rod is operated to the rapid deceleration side, the tip of the rod moves within the elongated hole without contact, and does not apply a rotational moment to the speed regulating lever.

However, even if the operating rod is suddenly decelerated, the reduction in engine speed will be delayed, so the governor lever will be biased toward the low speed side due to the governor force remaining in a strong state, and the governor lever will also be biased toward the low speed side. It rotates and comes into contact with the protruding end of the low-speed rotation limiter.

As the engine speed decreases in proportion to the reduction in fuel supply amount, the governor force also gradually decreases, so the governor force is also influenced by the low-speed rotation limiter due to the biasing force of this gradually decreasing governor force. While maintaining the stopped state, the low-speed rotation limiter gradually rotates to the end of its retraction movement.

Therefore, the fuel injection rack position remains at the predetermined low-speed lower limit injection position and can be prevented from being lowered below it, making it possible to prevent the engine from stalling even if an excessively rapid deceleration is performed. This makes it possible to maintain good riding comfort for agricultural machinery, construction machinery, etc. equipped with the engine.

In addition, the present invention has a simple structure in which a long hole is made in the speed control lever and the low-speed rotation limiter that the lever contacts can be moved forward and backward relative to the pedestal, so it can be implemented at low cost. , can be easily applied to existing diesel engines.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a schematic longitudinal sectional front view of the diesel engine, Fig. 2 is a longitudinal sectional side view of the main parts around the fuel injection pump, and Fig. 3 is a plan view of the main parts.Engine E has a cylinder arranged in the center. A piston 20 interlocking with the crankshaft 8 is fitted into the cylinder so as to be vertically slidable.

Further, a fuel injection nozzle 21 is arranged on the side of the head cover of the engine E, and a fuel injection pump 11 is arranged on the side of the crankcase 1, and these two are connected.
Attach the gear case 22 to a and crank case 1.
A fuel injection cam gear 23 is pivotally supported at the tip of the fuel injection camshaft 10 which is pivotally supported from the fuel injection camshaft 10 to the gear case 22, and the gear is housed in the gear case 22.

Then, the fuel injection camshaft 10 and the crankshaft 8 are interlocked via the gear 23, and the fuel injection camshaft 10 is interlocked with the fuel injection pump 11.

A governor lever 6 is attached to the crankcase end wall 1a.
The base end portion 6b of the fuel injection camshaft 10 is pivotably supported so that when the governor weight attached to the fuel injection camshaft 10 is displaced due to an increase in engine speed, a governor force F is applied to the governor lever 6 so that the governor lever 6 swings to the low speed side B. Configure.

The tip end 6a of the governor lever 6 is engaged with the fuel injection rack 7, and the middle part 6c is connected to the gear case 2.
The governor lever 6 is connected via a governor spring 14 to a speed regulating lever 3 pivotally supported on the upper wall of the controller 2, and urges the governor lever 6 toward the high speed side A.

The speed regulating lever 3 is rotatably supported on a rectangular plate-shaped pedestal 2 fixed to the upper wall of the gear case with bolts 24, and a governor spring is attached to a support 26 pivotally supported on the lower end of this pivot shaft 25. 14 is suspended.

Further, the speed regulating lever 3 is formed into a substantially dogleg shape, one bent piece 3a is made thin and stepped, and the other bent piece 3b is made thick, and the thick bent piece 3b is connected to the operating rod 16. It is connected to the operating lever 27 via.

That is, the tip 16a of the operating rod 16 is bent into an L-shape, and the L-shaped tip 16a is loosely inserted from below into the elongated hole 17 formed in the wide bent piece 3b while substantially following the pulling direction D of the operating lever. Fit this tip 16a
engage the stop piece 28 from above, and then press the operating rod 16.
is constructed such that it cannot be removed from the elongated hole 17.

On the other hand, a fixed wall 30 is provided protruding near the left end of the pedestal 2, and a bolt-shaped high-speed rotation limiter 4 is adjustably screwed into the lower part of the fixed wall 30, and the high-speed rotation limiter 4 is oriented so as to be inclined towards you. Attach the left edge 3 of the wide bent piece 3b
1 so that they can come into contact with each other.

Further, a low-speed rotation limiter 5 is adjustably screwed onto the upper portion of the fixed wall 30, and the low-speed rotation limiter 5 is oriented in a backward inclined manner so as to be able to come into contact with the left end edge 32 of the bending piece 3a.

As shown in FIG. 4, the low-speed rotation limiter 5 is fitted into a cylindrical bolt 33 so that it can move forward and backward, and the cylindrical bolt 33 is screwed into the fixed wall 30 and then tightened. It is tightened and fixed by a locking nut 34.

That is, the low-speed rotation limiter 5 is configured by integrally connecting a contact rod 5a and a piston 5b, and the piston 5b
is horizontally slidably fitted into the sliding chamber 35 of the cylindrical bolt 33, and the elastic spring 1 is inserted between the piston 5b and the stopper 36 that seals the opening of the sliding chamber 35.
5 is inserted to urge the contact rod 5a against the cylindrical bolt 33 in the advancing direction.

Then, the end of the compression movement of the elastic spring 15 is set at the low speed lower limit position C, and the speed regulating lever 3 is configured to be gradually moved to the low speed lower limit position C.

In the speed limiting device constructed in this manner, even if the operating lever 27 is suddenly decelerated, since the tip of the operating rod 16 is loosely fitted into the elongated hole 17, rotational moment is directly applied to the speed regulating lever 3. Instead, the speed regulating lever 3 gradually rotates to the low speed side B while responding to the governor force F which is decreasing with a delay.

That is, the governor lever 6 gradually swings toward the lower speed side and gradually reduces the fuel supply amount while maintaining balance with the gradually reduced governor force, thereby preventing the engine from stalling.

Therefore, the low-speed rotation limiter only needs to be one that gently receives the speed regulating lever, and the conventionally used bolt is supported on the receiver via a compression spring so that it can move forward and backward. It can also be used as a low speed rotation limiter.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a schematic vertical sectional view of a diesel engine, and FIG.
The figure is a vertical sectional side view of the main parts around the fuel injection pump.
4 is a sectional view taken along the line -- in FIG. 3, and FIG. 5 is a view corresponding to FIG. 3 showing a conventional example. DESCRIPTION OF SYMBOLS 1...Crank case, 2...Base, 3...Governing lever, 4...High speed rotation limiter, 5...Low speed rotation limiter, 6...Governor lever, 6a...Tip of 6, 7... Fuel injection rack, 8... crankshaft,
10... Fuel injection camshaft, 11... Fuel injection pump, 12... Governor weight, 15... Restriction spring, 16... Operation rod, 16a... Tip of 16, 17... Long hole, A... High speed Direction, B...low speed direction, C...low speed lower limit position, D...16 tension direction.

Claims (1)

[Scope of utility model registration request] A speed regulating lever 3 is rotatably supported on a pedestal 2 attached to the crankcase 1, a high speed rotation limiter 4 and a low speed rotation limiter 5 are fixed to the pedestal 2, and the speed regulating lever 3 is rotated at a high speed. When rotated to side A, high speed rotation limiter 4
When the governor lever 6 is rotated to the low speed side B, it comes into contact with the low speed rotation limiter 5 and is positioned at the lower limit value. A fuel injection camshaft 10 which is movably supported, has a governor lever tip 6a engaged with a fuel injection rack 7 and is linked to a crankshaft 8, is connected to a fuel injection pump 11, and a governor weight 12 is attached to the fuel injection camshaft 10. The governor lever 3 is connected to the governor lever 6 via the governor spring 14 to bias the governor lever 6 toward the high speed side A, and when the governor weight 12 is displaced due to an increase in engine speed, the governor force F is applied to the governor lever 6. In a diesel engine configured to swing to the low speed side B by giving a While loosely fitting into the long hole 17,
The low-speed rotation limiter 5 is fixed to the pedestal 2 via an elastic spring 15 so that it can move forward and backward, and the end of the retraction movement of the low-speed rotation limiter 5 is set at the low-speed lower limit position C, and the speed regulating lever 3 is gently moved. A speed limiting device for a diesel engine, characterized in that the speed limiting device is configured to shift to the low speed lower limit position C.