JPH0559972A - Manual starting diesel engine - Google Patents

Abstract

PURPOSE:To improve startability of a Diesel engine in a cold condition by pulling a recoil starter in a condition that a half-opened cam is switched to a half decompression position, repeatedly sliding a piston, and preheating a combustion chamber through compression heat generated thereby. CONSTITUTION:When an engine is started, a shaft shifting member 30 is switched and fixed to a half-decompression position Q, and a push rod 26 is engaged with a half-opened cam 15 through a tuppet 27. In such a condition, a recoil starter is pulled for operation. Pressure in a combustion chamber is increased to some extent by the operation of a half-opened intake valve. Compression heat is generated by the repetition of sliding, and the combustion chamber is preheated. The shaft shifting member 30 is next switched and fixed to a normal operation position P, and decompression operation is carried out by a preset decompression device. The recoil starter is pulled to start an engine E. Since the combustion chamber is preheated, the engine E is speedily started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recoil starter type, crank handle type, etc., hand-starting diesel engine which can improve cold start performance and prevent wasteful fuel consumption during preheating operation before starting. provide.

[0002]

2. Description of the Related Art The basic structure of a hand-starting diesel engine to which the present invention is applied is, as shown in FIG. 1 to FIG. 5 or FIG. 5, the valve camshaft 4 is used to open and close the open / close valve 3, and the speed control lever 50 is attached to the engine E so as to swing from the stop position A to the operation region B. The governor lever 52 is interlocked with the governor spring 51, and the governor lever 52 is interlocked with the injection rack 56 of the fuel injection pump 55.

Since a diesel engine has a high compression ratio,
In a recoil starter type or other hand-starting diesel engine, as shown in FIG. 6, a decompression device 6 is incorporated in the rocker arm chamber 1, the exhaust valve 3 is opened by the decompression device 6, and the combustion chamber is switched to a decompressed state to be light. It can be started by force.

[0004]

In the above conventional hand-starting diesel engine, since there is generally no preheating glow device unlike the cell starter starting diesel engine, there is a problem of poor cold startability. An object of the present invention is to improve the cold startability of a hand-start diesel engine.

[0005]

Means for achieving the above object will be described below with reference to the drawings illustrating an embodiment. That is, according to the present invention, in the hand-starting diesel engine having the basic structure, the half-open valve cam 15 is formed adjacent to the opening / closing driving cam 5 of the valve cam shaft 4, and the cam crest 1 of the half-open valve cam 15 is formed.
6 is formed so as to protrude over the entire circumference of the valve operating cam shaft 4 and is formed lower than the cam crest 17 of the opening / closing drive cam 5, and the opening / closing drive cam 5 and the half-open valve cam 15 are connected to the engine body 12 by the moving operation means 40. On the other hand, it is configured to be movable in the axial direction D to the normal operation position P and the half decompression position Q. At the normal operation position P,
The open / close drive cam 5 of the valve operating cam shaft 4 drives the open / close valve 3 to open / close, and at the half decompression position Q, the half open valve cam 15 of the valve operating cam shaft 4 moves the open / close valve 3 to an intermediate position between fully open and fully closed. The manual operation section 4 of the movement operation means 40 is configured so that it is always half-opened.
In the moving range C of 1, the receiving portion 53 of the speed control lever 50
When the speed control lever 50 is switched to the operating area B, the catching portion 53 advances so as to interfere with the movement range C of the manual operation portion 41 of the movement operation means 40, and the movement operation means 40 is moved. It is stopped at the normal operation position P and fixed to the half decompression position Q so that it cannot be switched.
When 0 is switched to the stop position A, the receiving portion 53 is configured to retreat with respect to the movement range C of the manual operation portion 41 and release the conflict.

The above-mentioned hand-start type diesel engine means a recoil starter type, rope starter type or crank handle type engine. The on-off valve 3 refers to either an intake valve or an exhaust valve.

[0007]

[Operation] (1) The opening / closing drive cam 5 of the valve cam shaft 4 and the half-open cam 15 are configured to be movable in the axial direction D between the normal operation position P and the half decompression position Q. Since the half open valve cam 15 is configured to always open the open / close valve 3 halfway, the half open valve cam 15 is switched and fixed to the half decompression position Q, and when the recoil starter is pulled in this state, for example, the half open valve 3 opens the combustion chamber. Since the pressure of No. 2 increases to some extent, compression heat is generated by repeated piston sliding. This compression heat plays a so-called glow substitute function and preheats the combustion chamber, so that the cold startability is improved. Since the opening / closing valve 3 is not fully closed but half opened, there is no problem in the manual starting operation of the recoil starter or the like. Then, when the combustion chamber is preheated by the compression heat, the opening / closing drive cam 5 is switched to the normal operation city P and the diesel engine E is started by a manual start operation.

(2) When the speed control lever 50 is switched and fixed in the operation area B, the receiving portion 53 of the speed control lever 50 advances into the movement range C of the manual operation portion 41 of the movement operation means 40, and the movement operation means 40 Is locked at the normal operating position P, and the opening / closing drive cam 5 drives the opening / closing valve 3 to open / close. On the contrary, when the speed control lever 50 is switched and fixed to the stop position A, the receiving portion 51 is retracted, and the switching operation between the normal operation position P and the half decompression position Q by the movement operation means 40 becomes free.
That is, the engine E is switched to the above position by switching to the half decompression position Q.
When the preheating operation by the compression heat as in (1) is performed, the speed control lever 50 is positioned and fixed at the stop position A, and there is no excessive fuel consumption.

[0009]

[Effects of the Invention] (1) The cam surface of the valve operating camshaft is moved and fixed by switching the camshaft to the half decompression position, and when manually started in this state, it is compressed into the combustion chamber by the action of the half-open on-off valve. Since heat is generated and this functions as a substitute for glow to preheat the combustion chamber, the cold startability of the diesel engine can be improved satisfactorily.

(2) When the operation of moving the cam surface of the valve operating cam shaft is interlocked with the rocking operation of the speed control lever and the engine is preheated by compression heat as described in (1) above, the speed control lever is used. Since it is positioned and fixed at the stop position, excess fuel consumption can be eliminated during preheating before starting. Therefore, it is possible to prevent the difficulty of starting due to the rich mixture and the ignition during the preheating.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a schematic perspective view of a valve operating mechanism, FIG. 2 is a schematic plan view of a speed control lever, FIG. 3 is a schematic vertical sectional view of a valve operating cam shaft, and FIG. 4 is a schematic of a recoil starter type vertical air-oil cooled diesel engine. FIG. 5 is a vertical cross-sectional view of the vicinity of the pump chamber of the engine.

As shown in FIG. 4, the cooling fan 14 is fixed to the front end of the crankshaft 13 of the recoil starter type vertical air-oil cooled diesel engine E, and the cooling fan 14 is covered with a wind guide case 18 to guide the wind. The recoil starter 20 is arranged in front of the case 18. The recoil starter 20 is connected to the cooling fan 14 via a transmission pulley 19.
Further, an oil cooler 22 is arranged above the air guide case 18 via the ventilation port 21, and the oil cooled in the auxiliary combustion chamber (not shown) of the diesel engine E is replaced by the oil cooler 22.
It is configured to radiate heat.

As shown in FIG. 5, the fuel injection pump 55 is housed in the pump chamber 10 of the diesel engine E, the fuel injection pump 55 is interlocked with the fuel injection cam shaft 57 supported in the pump chamber 10, and the fuel injection cam is connected. The governor weight 54 is attached to the shaft 57. A speed governing lever 50 is attached to the upper side wall 42 of the diesel engine E so that the position can be switched from a stop position A to an operating region B, and a governor lever 52 is provided.
Is swingably supported in the pump chamber 10. A two lever type governor lever 52 is interlocked with the speed control lever 50 via a governor spring 51, and a governor weight 54 is interlocked with the governor lever 52 so that thrust can be transmitted.
Is engaged with the injection rack 56 of the fuel injection pump 55, and the governor lever 52 is swung by an unbalanced force between the governor force G of the governor weight 54 and the spring force S of the governor spring 51, so that the rack of the fuel injection pump 55 is swung. The position is adjustable to match the engine speed.

As shown in FIGS. 1 and 3, the intake cam 5a and the exhaust cam 5b are attached to the valve operating cam shaft 4 of the diesel engine E.
The intake cam 5a is linked to the intake push rod 26 and the intake tappet 27 to open and close the intake valve 3. As shown in FIG. 3, a semi-open valve cam 15 is provided adjacent to the intake cam 5a of the valve operating cam shaft 4, and a valve closing cam 28 is provided adjacent to the exhaust cam 5b, and these cams and a bifurcated flange type receiving flange 29 are provided. Are integrally formed with the shaft shift member 30, and the shaft shift member 30 is configured to be switchable between the normal operation position P and the half decompression position Q along the axial direction D on the valve camshaft 4. That is, the cam lobe 16 of the half-open valve cam 15 projects in a cam shape over the entire circumference of the valve cam shaft 4 and is formed lower than the cam lobe 17 of the intake cam 5a. The valve closing cam 28 is formed as a "mountainless" cam. At the half decompression position Q, the half open valve cam 15 is configured to always open the intake valve 3 halfway between the fully open and fully closed positions via the intake tappet 27 and the push rod 26.

As shown in FIGS. 1 and 2, the shaft shift member 30 is constructed so that it can be manually operated in the axial direction D by the movement operation means 40, and the movement operation means 40 is provided with the vertically oriented support shaft 37.
A manual operation lever 41 fixed to the upper end portion thereof, and a push-pull arm 35 fixed to the lower end portion thereof and engaged with the receiving flange 29. As shown in FIG. 2, the receiving portion 53 of the speed control lever 50 is brought into contact with the movement range C of the manual operation lever 41 of the movement operation means 40. That is, the pressing pin 43 is vertically projected to the tip of the manual operation lever 41, the bevel-shaped projection 44 and the cove-shaped recess 45 are provided adjacent to the disc-shaped speed control lever 50, and the bevel-shaped projection 44 The outer edge is formed on the receiving portion 53, and the receiving portion 53 is made to face the pressing pin 43 of the manual operation lever 41 so as to be able to be received. (1) As shown in FIG. 2A, when the speed control lever 50 is switched to the operation area B, the receiving portion 53 of the speed control lever 50 comes into contact with the movement range C of the manual operation portion 41 of the movement operation means 40. As described above, the movement operation means 40 is stopped at the normal operation position P and the switching to the half decompression position Q is disabled. (2) As shown in FIG. 2B, when the speed control lever 50 is switched to the stop position A, the recess 45 of the speed control lever 50 advances to the pressing pin 43 of the manual operation lever 41, and the speed control lever 50. Is released so that the movement operation means 40 can be freely switched between the normal operation position P and the half decompression position Q.

The operation procedure for cold starting of the diesel engine according to this embodiment will be described. (1) As shown in FIG. 3B, when the shaft shift member 30 is switched and fixed to the half decompression position Q and the recoil starter 20 is pulled in this state, the pressure of the combustion chamber is increased to some extent by the action of the half open intake valve 3. Since it increases, the compression heat is generated by repeating the vertical movement of the piston. This heat of compression plays a so-called glow substitute function and preheats the combustion chamber. In this case, since the intake valve 3 is not fully closed but half opened, the recoil starter 20
There is no hindrance to the hand starting operation. Note that the exhaust tappet is in contact with the valve closing cam 28 having no ridges, so that the exhaust valve remains closed. (2) Next, as shown in A of FIG. 3, the shaft shift member 30
Is fixed to the normal operating position P, and the existing (that is, FIG.
While performing the decompression operation by the decompression device 6, the recoil starter 20 is pulled to start the engine E. At this time, since the combustion chamber is preheated by the above (1) and the cold startability is improved, the diesel engine E can be started quickly.

(3) The moving operation means 40 for operating the valve camshaft 4 as described in (1) and (2) above is only available when the speed control lever 50 is at the stop position A as shown in FIG. It becomes operable. That is, when the speed control lever 50 is switched and fixed to the operation area B, the receiving portion 53 of the speed control lever 50 advances into the movement range C of the manual operation portion 41 of the movement operation means 40, and the movement operation means 40 is moved to the normal operation position. When locked to P, the open / close drive cam 5 drives the open / close valve 3 to open / close (that is, enters a normal operating state). On the contrary, when the speed control lever 50 is switched and fixed to the stop position A, the receiving portion 51 is retracted, and the switching operation between the normal operation position P and the half decompression position Q by the movement operation means 40 becomes free. Therefore, when the engine E is preheated by the compression heat as described in (1) by switching to the half decompression position Q, the speed control lever 50 is positioned at the stop position A and the injection of the fuel injection pump 55 is performed. Rack 5
Since No. 6 is fixed at the non-injection position, extra fuel consumption can be eliminated during preheating before starting. Therefore, it is possible to prevent the difficulty of starting due to the rich mixture and the ignition during the preheating. On the other hand, when the engine E is in a normal operation state, the movement operation means 40 is positioned and fixed in the normal operation position P due to the collision of the speed control lever 50, so that the shaft shift member 30 is switched to the half decompression position Q and cannot move. Therefore, malfunctions (during the preheating operation) during operation can be eliminated.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a valve operating mechanism of a diesel engine.

FIG. 2 is a schematic plan view of a speed control lever.

FIG. 3 is a schematic vertical sectional view of a valve operating cam shaft.

FIG. 4 is a schematic vertical sectional view of a recoil starter type vertical air-oil cooled diesel engine.

FIG. 5 is a vertical cross-sectional view around the pump chamber of the engine.

FIG. 6 is a vertical cross-sectional view around a rocker arm chamber showing a conventional technique.

[Explanation of symbols]

 1 rocker arm chamber 2 rocker arm 3 open / close valve 4 valve camshaft 5 open / close drive cam 15 half-open valve cam 16 cam mountain 17 15 cam mountain 40 moving operation means 41 40 manual operation part 50 governor lever 51 governor spring 52 governor lever 53 50 receiving part 55 fuel injection pump 56 55 injection rack E hand-start diesel engine A 50 stop position B 50 operating range C 41 swing range D 4 axis center P 4 normal operating position Q half decompression position

Claims (1)

[Claims] 1. A valve operating camshaft (5) having a valve operating camshaft (4) formed on a valve operating camshaft (4) of a hand-starting diesel engine (E).
The open / close valve (3) can be opened and closed by (4), and
The speed control lever (50) is swingably attached to the engine (E) from the stop position (A) to the operating range (B).
Governor lever (50) via governor spring (51)
Link the governor lever (52) with the fuel injection pump (52).
In a hand-starting diesel engine linked to the injection rack (56) of (55), a half-open cam (15) is formed adjacent to the opening / closing drive cam (5) of the valve camshaft (4), and the half-open cam The cam lobe (16) of (15) is projected over the entire circumference of the valve operating cam shaft (4) and is formed lower than the cam lobe (17) of the opening / closing drive cam (5). And the half open valve cam (15)
(40) is configured to be switchable between the normal operation position (P) and the half decompression position (Q) in the axial direction (D) with respect to the engine body (12). Open / close drive cam for valve cam shaft (4)
(5) drives the open / close valve (3) to open / close, and in the half decompression position (Q), the half open valve cam of the valve camshaft (4)
(15) is configured so that the on-off valve (3) is always half-opened at an intermediate position between fully open and fully closed, and the movement range of the manual operation part (41) of the above-mentioned movement operation means (40).
When the catching portion (53) of the speed control lever (50) is brought into contact with (C) so that the speed controlling lever (50) is switched to the operating region (B), the catching portion (53) moves the moving operation means ( 40) Manual operation part (41)
Of the semi-decompression position by stopping the movement operation means (40) at the normal operation position (P) while moving forward within the movement range (C) of
When the speed control lever (50) is switched to the stop position (A) while fixing the switch to (Q) so that it cannot be switched, the receiving portion (53) retracts with respect to the moving range (C) of the manual operation portion (41). A hand-start diesel engine characterized by being configured to release conflicts.