JPS6237938Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a starting heating device for a direct injection internal combustion engine.

[Conventional technology and its problems]

Generally, if you double the diameter of the intake valve in an internal combustion engine, the area that allows intake air to flow will quadruple.
Filling efficiency is increased. Therefore, it was necessary to make the diameter of the intake valve as large as possible, so a three-valve type or
It is well known that four-valve type or overlapping valves are used. Such a three-valve engine consists of two intake valves and one exhaust valve, and although high engine output can be expected, the valve train is undeniably complicated.

On the other hand, some known internal combustion engines that have been developed as multi-fuel engines use a direct injection method for combustion and are equipped with glow plugs in the cylinder head to facilitate starting even at low temperatures.

By the way, based on these technical backgrounds, the present applicant is also developing a three-valve direct injection engine with a ribbon heater type intake air heating device of several hundred to 2.3KW attached to the intake manifold. In this case, since a starting motor is used, the ribbon heater type intake air heating device and the starting motor are powered by one power source, so simultaneous use of the starting motor and the intake air heating device at the time of starting requires a large current. This makes it difficult to use the ribbon heater, so we have taken measures to preheat the heating device for 20 to 30 seconds before switching to the starting motor and starting the engine. In such a case, the heating device does not heat after starting, and a large amount of irritating blue-white smoke is emitted during the period until warm-up, which is undesirable.

[Means for solving problems]

Therefore, the present invention was devised to solve this problem, and by providing a glow plug for starting assistance to a three-valve direct injection engine, it has good starting performance, high output, and a cylinder head. The objective is to provide an internal combustion engine that has a good balance of heat loads on both sides.

〔Example〕

This will be explained in detail with reference to embodiments shown in the accompanying drawings. Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 2 is a view taken along arrows A to A in Fig. 1, and Fig. 3 is a longitudinal sectional view of an embodiment of the present invention.
A cross-sectional plan view of the figure is shown.

1 having an inner diameter D1 of a valve seat opening into the cylinder 1
The cylinder head 5 is provided with an exhaust hole 3 and two intake holes 2A and 2B having an inner diameter D2 of the valve seat. In these exhaust holes 3 and intake holes 2A, 2B, an exhaust valve 6 as shown in FIG. 1 and an intake valve (not shown) slide up and down inside a valve guide in the cylinder head 5, The exhaust hole 3 and the intake holes 2A and 2B are opened and closed by the head 6A.

Next, the fuel injection valve 8 is inclined in the axial direction of the cylinder 1 and is installed outside the valve arm box 15 (partially shown).

Therefore, the two intake holes 2A, 2B and the exhaust hole 3
The arrangement relationship of the tip of the insertion hole 4 of the fuel injection valve 8 is as shown in FIG.
A. The insertion hole 4 of the fuel injector 8 and the intake hole 2B are arranged in this order, and the exhaust hole 3 is positioned on the substantially opposite side of the insertion hole 4, and the mutual arrangement angle of their center positions is In Figure 2, the angle connecting the centers of the exhaust hole 3, the intake hole 2B, and the insertion hole 4 = 55° ± 5° The angle connecting the centers of the intake hole 2B, the insertion hole 4, and the intake hole 2A = 170° ± 10゜ Connect the centers of the insertion hole 4, intake hole 2A, and exhaust hole 3 at an angle of 55° ± 5° Connect the centers of the intake hole 2A, exhaust hole 3, and intake hole 2B at an angle of 80° ± 5° The intake hole 2A, the insertion hole 4, the intake hole 2B, and the exhaust hole 3 are arranged so as to form a substantially triangular shape.

Next, regarding the intake ports, as shown in FIG.
The intersection angles between XY and the line connecting the center of cylinder 1 and the center of the opening of intake holes 2A and 2B relative to cylinder 1 are α1 = 90° to 140° and α2 = 70°, respectively.
These intake ports are formed so that the angle is between 100° and 100°, so that during intake, the cylinder 1
It generates a swirl inside.

Furthermore, the cooling water for cooling the cylinder head 5 is
The fuel enters the cylinder head 5 from the upward hole of the cylinder block via the inlet hole 10, flows through the through hole passage 11 provided between the exhaust hole 3 and the intake hole 2B, and then the fuel injection valve 8 is inserted. The V-shaped passage 12 provided between the walls of the intake hole 2B and the exhaust hole 3 collides with the front surface of the side wall of the exhaust hole 3 of the hole 4, and is then connected to the wall of the insertion hole 4 of the fuel injection valve 8. The flow is as shown by arrow W. An insertion hole 4 for the fuel injection valve 8 is provided between the intake holes 2A and 2B, and between this insertion hole 4 and the intake holes 2A and 2B, there is a common wall portion that is a component of the cylinder head 5, respectively. 5A and 5B, the fuel injection valve 8 is forcibly cooled by the intake air of the intake holes 2A and 2B, and the main flow of cooling water from the passage 11 is directed to the high heat load section between the exhaust hole 3 and the intake hole 2B. After cooling down, it collides with the front wall of the insertion hole 4,
This improves the cooling of the tip of the fuel injection valve 8 and further cools the high heat load area between the exhaust hole 3 and the intake hole 2A.

In this embodiment, a glow plug G for assisting starting is provided as shown in FIGS. 1, 2, 3, and 4. That is, the glow plug G is connected to the insertion hole 4 of the fuel injection valve 8 and the intake hole 2A.
(The intake hole 2A is the one on the side closer to the intake inlet hole 9), and its tip faces the concave combustion chamber 13 provided at the top of the piston, and also faces the piston tip surface of the cylinder head 5. It faces a recess 20 recessed in the. Further, as shown in FIG. 1, the structure of the glow plug G is inclined at a slight angle θ1 of 15° to 30° with respect to the horizontal plane A to A of the cylinder head 5, and the intake inlet hole 9 It is arranged below the passage 14 of the intake hole 2B on the far side. Further, as shown in FIG. 4, the glow plug G is inclined at an angle θ2 of 0° to 30° in the downstream direction of the intake swirl with respect to the spray center line B of the fuel injection valve 8. Note that the directions Z to Z indicate the crankshaft direction, and the arrow S indicates the swirl direction.

Since this embodiment has such a configuration, the engine is operated by the vertical movement of the piston and the intermittent injection of the fuel injection valve 8 in conjunction with the vertical movement of the piston. glow plug G
A concave combustion chamber 13 provided on the top surface of the piston
This heats the scattered fuel that spreads due to the collision of the injected fuel on the outer peripheral wall of the engine, and continues to supply electricity for a certain period of time during and after starting the engine, thereby improving the startability of the engine. Therefore, Dumar. It can also be applied to fuel engines (gas intake, diesel spray ignition engines).

[Function and effect of the idea]

In summary, since the present invention adopts the structure described in the claims for utility model registration, it achieves the following effects.

Because it is a three-valve direct injection type, the valve train on the cylinder head is complicated, but
With this cylinder head, place the tip of the starting aid glow plug G facing the concave combustion chamber 13 provided at the top of the piston at an angle of about 15° to 30° below the passage 14 of the intake hole 2B on the side far from the intake inlet hole 9. Since the glow plug G is arranged at an angle, even if the cross section of the passage 14 is narrowed due to the insertion of the glow plug G and the intake flow is slightly affected, the passage 14 can be made longer, so that effect is eliminated. It does not affect the intake swirl, and the data established using the 3-valve direct injection engine can be followed as is.

The intake hole 2A, which is always cooled by intake air, and the insertion hole 4 for the fuel injection valve 8 on the side closer to the intake inlet hole 9
Since the glow plug G has been inserted between the cylinder head and the cylinder head, this glow plug can be inserted in the cylinder head where it is particularly cooled, i.e. where the heat load is minimal and therefore where the possibility of cracking in the worst case is low. Since G is protruded, the reliability of the engine can be improved.

The tip of the glow plug G collides with the outer circumferential wall within the outer peripheral wall of the concave combustion chamber 13 provided at the top of the piston, and faces directly into contact with the fuel spreading along the outer peripheral wall. Recess 2 formed in the end surface of the head 5 on the piston side
0, the sprayed fuel is difficult to burn and has a short reach during fuel spraying, the injected fuel does not generate a swirl, or the fuel collides with the outer circumferential wall of the concave fuel chamber and spreads along the outer circumferential wall. The atomized fuel directly surrounds and contacts the glow plug, which not only improves ignition and engine startability, but also suppresses the production of blue-white smoke with a pungent odor.

Since the fuel injector 8 can be inserted from the valve arm chamber at a slight incline, the injector is easy to maintain, and not only does maintenance such as fuel leakage at the fuel injection pipe joint become easier, but it It does not cause any hindrance.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 2 is a view taken along arrows A to A in Fig. 1, Fig. 3 is a plan sectional view of Fig. 1, and Fig. 4 is a fuel chamber in Fig. 1. The state diagram of the spray is shown in the top view of the figure. 2A, 2B...Intake hole, 3...Exhaust hole, 4...
Insertion hole, 5...Cylinder head, 8...Fuel injection valve, 9...Intake inlet hole, 13...Concave combustion chamber, 1
4... Passage, G... Glow plug for starting aid.

Claims (1)

[Scope of Claim for Utility Model Registration] In a cylinder head of a three-valve direct injection internal combustion engine consisting of two intake valves and one exhaust valve, in which the two intake valves and the insertion hole for the fuel injection valve are arranged approximately in a straight line, Between the insertion hole 4 and the intake hole 2A on the side closer to the intake hole 9, and under the passage leading to the intake hole 2B on the side farther from the intake hole 9, a piston-side end surface of the cylinder head 5 is provided. Insert the glow plug G for starting aid, which is arranged at an angle of approximately 15° to 30° to the piston, and place the tip of the glow plug G within the outer circumferential wall of the concave combustion chamber 13 provided at the top of the piston. The cylinder head 5 faces the part that directly contacts the fuel that collides and spreads along the outer peripheral wall.
A heating device for starting a direct injection internal combustion engine, which faces a recess 20 formed in a piston side end surface of the engine.