JPH0427375B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a device for raising the idle of an engine governor at the time of cold engine starting, and the governor spring is manufactured from a shape memory alloy, and the idle is raised by the shape memory action of the governor spring. By doing so, the idle compensator can be omitted and the structure can be simplified.

<Prior art> As a conventional technology for an engine idle-up device, there is a diaphragm-operated idle compensator. For example, the exhaust path and the diaphragm chamber are linked, and the diaphragm is retracted when starting a cold engine with a small displacement, thereby controlling the governor. The idle position of the fuel injection pump is moved up from the idling position to the increasing side (see Japanese Utility Model Publication No. 59-3161).

<Problems to be Solved by the Invention> However, the above-mentioned idle up device does not include a diaphragm type actuator, a transmission mechanism for swinging the governor with the diaphragm type actuator, a ventilation path communicating the diaphragm chamber with the exhaust path, etc. Each of them had to be provided, making the entire device complicated.

The technical problem of the present invention is to simplify the structure of the entire device.

<Means for Solving the Problems> The present inventors completed the present invention by focusing on the fact that the shape memory alloy can change the spring constant before and after the transformation temperature.

That is, in the present invention, the governor spring 1 of the governor G of the engine E is made of a shape memory alloy, the transformation temperature θ of the shape memory action of the governor spring 1 is set to the warm-up end temperature T of the engine E, and the governor spring 1 is made of a shape memory alloy. is configured such that when a temperature higher than the warm-up end temperature T of the engine E is detected, the tension is in the standard state, and when a temperature lower than the warm-up end temperature T is detected, the tension is increased. It is characterized by the fact that

<Function> Since the temperature at the time of cold start is lower than the temperature at the end of warm-up operation, the governor spring 1 made of shape memory alloy is shorter than the length during normal operation, and its tension increases.

Therefore, even when the speed regulating lever is set to the idling position, the governor spring 1 swings the governor lever more forcefully than during normal operation, and causes the rack of the fuel injection pump to slide toward the increase side compared to the idling position. , and achieve idol growth.

Further, when the engine temperature rises to the end temperature of warm-up due to cold start, the governor spring 1 is expanded beyond its length during warm-up and returns to its standard state, reducing its tension.

Therefore, the governor spring 1 swings the governor lever with a strength suitable for normal operation.

<Effects of the Invention> In the present invention, the idle up mechanism is achieved by changing the material of the governor spring to a shape memory alloy, so there is no need for an idle compensator with a complicated mechanism as in the past, and the idle up mechanism can be easily implemented. It can be made into something.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a front view of the main parts around the governor spring at the end of warm-up, FIG. 2 is a view equivalent to FIG. 1 at the time of cold start, and FIG. A pump housing chamber 2 is provided on the side of the cylinder block of the diesel engine E, a fuel injection camshaft 3 is mounted on the pump housing chamber 2, and the fuel injection camshaft 3 is connected to the crankshaft via a cam gear 4 and a crank gear 5. linked to.

A fuel injection pump 6 is housed in the pump housing chamber 2 and is linked to the fuel injection camshaft 3.

On the other hand, the governor G is connected to the main governor lever 8, the sub-governor lever 10, the governor spring 1 and the centrifugal weight 21.
Consists of.

That is, the main governor lever 8 and the sub-governor lever 10 are pivotably supported concentrically on a fulcrum 11 on the inner wall of the gear chamber 7 adjacent to the pump housing chamber 2 .

The main governor lever 8 has an L-shape, and its free end 12 is formed into a bifurcated shape, and the bifurcated portion 14 is fitted into a fuel injection rack pin 15 of the fuel injection pump 6 and is latched to an intermediate portion 16 thereof. A protrusion 17 is provided to protrude so as to receive a clockwise pushing force from the sub-governor lever 10.

The sub-governor lever 10 has a two-step bent shape, has a locking hole 19 in its free end 18, has a speed regulating lever 20 mounted above the gear chamber 7, and connects one end of the governor spring 1 to the locking hole 19 of the sub-governor lever 10. Stop hole 1
9, and the other end is attached to the speed regulating lever 20.

A ball-shaped centrifugal weight 21 is attached to the fuel injection camshaft 3.
The governor fork 22 is attached to be rotatable simultaneously, and the governor fork 22 is protruded from the centrifugal weight 21. The governor fork 22 is supported on the main governor lever 8 and is interlocked so that it can be pushed counterclockwise.The governor force GF generated from the centrifugal weight 21 is connected to the main governor lever. 8 to adjust the fuel injection amount of the fuel injection pump 6.

On the other hand, the governor spring 1 is made of a shape memory alloy, for example, a NiTi alloy that has durability even against 10 ⁷ times of repeated stress, and the transformation temperature θ of the shape memory action of the spring 1 is set to the temperature of the diesel engine E. Warm-up end temperature T, specifically 20
℃, and for a cold start below 20℃, the overall length of the governor spring 1 is shortened to increase its tension (see Figure 1), and when the engine E warms up to a temperature higher than 20℃, the governor spring 1 is 1 is stretched to the standard length, and its tension is reduced (see Figure 2).

The function of the idle up device thus constructed is as follows: When starting a cold engine, the tension of the governor spring 1 increases, the sub-governor lever 10 is strongly pulled and the main governor lever 8 is significantly swung in the direction of arrow P, and fuel injection is started. The rack pin 15 is slid to a position on the increase side compared to a normal warm-up start, that is, to an idle up position, and the engine speed is increased to quickly warm up the engine.

After that, when the engine warms up and reaches the warm-up end temperature T, the governor spring 1 that senses this temperature transforms the matrix of the alloy by its own shape memory effect, and the entire length returns to the standard state. is extended to reduce the tension of the sub-governor lever 10 compared to when the machine is cold.

Therefore, the main governor lever 8 is appropriately pushed back in the direction of the arrow Q, and the engine continues to operate normally.

FIG. 4 shows another embodiment of the present invention, with a right-handed spring section 30 and a left-handed spring section 31.
The entire governor spring 1 is constructed from the above, and the phase difference due to the shape memory effect of the governor spring 1 is absorbed by the combination of both spring parts, so that the rotary joint interposed between the governor spring 1 and the speed regulating lever 20 can be omitted. It is.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; Fig. 1 is a front view of the main parts around the governor spring at the end of warm-up operation, Fig. 2 is a view equivalent to Fig. 1 at the time of cold start, and Fig. 3 is a diagram of a diesel engine. FIG. 4, which is a longitudinal sectional front view of the vicinity of the governor, is a view corresponding to FIG. 1 showing another embodiment of the present invention. 1... Governor spring, E... Engine, G
...Governor, θ...Transformation temperature of 1, T...Temperature at the end of warm-up operation.

Claims (1)

[Claims] 1 Governor spring 1 of governor G of engine E
is made of a shape memory alloy, the transformation temperature θ of the shape memory effect of the governor spring 1 is set to the warm-up end temperature T of the engine E, and the governor spring 1 detects a temperature higher than the warm-up end temperature T of the engine E. The idle up device for an engine governor is characterized in that the tension is in a standard state in a state in which the temperature is increased, and the tension is in a state in which the tension is increased in a state in which a temperature lower than a warm-up end temperature T is detected.