JPS6349541Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field of the invention This invention relates to a pre-chamber device for a diesel engine.

Technical background of the invention Traditionally, diesel engines have been equipped with a main combustion chamber and an auxiliary chamber, and typical examples include:
There are those shown in Figures 1 to 3.

First, one conventional example shown in FIGS. 1 and 2 will be explained. A cylinder head 3 is fastened to the upper end of the cylinder block 1 with a bolt 4 through a gasket 2, and the cylinder head 3 has a sub-chamber forming hole 5 and a glow plug mounting hole 6 formed therein. A cylindrical body 8 having a pre-combustion chamber 7 formed therein as a auxiliary chamber is attached to the auxiliary chamber forming hole 5 via a gasket 9, and a fuel injection nozzle 10 is further attached to press the cylindrical body 8. ing. A glow plug 11 is mounted in the glow plug mounting hole 6, and the tip of the glow plug 11 passes through the cylinder 8 and faces into the pre-combustion chamber 7.

Next, another conventional example shown in FIG. 3 will be explained. Note that the same parts as those described in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted.
A lower cylindrical body 12 and an upper cylindrical body 13 are installed in the sub-chamber forming hole 5 while facing each other with a gasket 14 in between.
A pre-combustion chamber 15, which is a sub-chamber, is defined by the inner peripheral surface of the lower cylinder 12 and the inner peripheral surface of the upper cylinder 13.

Problems with the Background Art In the case shown in FIGS. 1 and 2, the cylindrical body 8 is a single member, so its shape is complicated and it takes time and effort to manufacture. In addition, the entire structure must be made of heat-resistant steel, which is expensive.

In the case shown in FIG. 3, when the glow plug 11 is installed, the gasket 14 and the glow plug 11 intersect, making it difficult to seal the gas at the intersecting portion. For this reason, the glow plug 11 is not installed, and therefore the startability at low temperatures is poor.

Purpose of the invention This invention was devised in view of the above points, and the purpose of this invention is to obtain a pre-chamber device for a diesel engine that is easy to manufacture, low in cost, and allows easy installation of glow plugs. That is.

Summary of the invention In this invention, a sub-chamber forming hole and a glow plug mounting hole are formed in the cylinder head fixed to the cylinder block, and a lower cylinder and an upper cylinder are installed in the sub-chamber forming hole with a predetermined distance apart. and forms a subchamber surrounded by the inner circumferential surface of the lower cylinder, the inner circumferential surface of the upper cylinder, and the inner circumferential surface of the subchamber forming hole located between the lower cylinder and the upper cylinder. , by making the tip of the glow plug installed in the glow plug mounting hole face into the sub-chamber from the inner peripheral surface of the sub-chamber forming hole, which forms a part of the sub-chamber, thereby forming a lower cylindrical body that forms a part of the sub-chamber. The upper cylindrical body and the lower cylindrical body are made with an open end structure to facilitate their manufacture, and only the lower cylindrical body, which requires the most heat resistance, is made of heat-resistant steel to reduce costs.
The glow plug is arranged so as to face the subchamber at a position that does not affect the gas seal of the upper cylinder, so that the glow plug can be easily installed.

Embodiment of the invention An embodiment of the invention will be described based on FIGS. 4 and 5. Note that the same parts as those explained in FIG. 1 and FIG. 2 are indicated by the same reference numerals, and the description thereof will be omitted. A lower cylindrical body 16 and an upper cylindrical body 17 formed of heat-resistant steel are attached to the sub-chamber forming hole 5.
They are installed at a predetermined distance apart along the axial direction of the. The lower cylinder body 16 has a main combustion chamber 1.
A communication hole 19 communicating with the lower cylinder 16 is formed, and a caulking protrusion 20 for positioning the lower cylinder 16 and preventing it from coming off is formed. A fuel injection nozzle 10 is connected to the upper end of the lower cylindrical body 17, and the lower edge of the upper cylindrical body 17 is pressed into contact with a stepped portion 21 formed on the inner peripheral surface of the sub-chamber forming hole 5 via a gasket 22. ing. The inner peripheral surface of the lower cylindrical body 16, the inner periphery of the upper cylindrical body 17, and the inner periphery of the auxiliary chamber forming hole 5 located in an exposed state between the lower cylindrical body 16 and the upper cylindrical body 17. A pre-combustion chamber 23, which is an auxiliary chamber, is formed by being surrounded by the surfaces. A glow plug 11 is installed in the glow plug installation hole 6,
The tip of the glow plug 11 faces into the pre-combustion chamber 23 from the inner peripheral surface of the sub-chamber forming hole 5 that constitutes a part of the pre-combustion chamber 23.

In such a configuration, the lower cylinder 16 and the upper cylinder 17 both have a shape with one end opened, and are easy to manufacture. Moreover, only the lower cylindrical body 16, which requires the most heat resistance, needs to be formed of heat-resistant steel, thereby reducing product costs. In addition, when the glow plug 11 is installed, the tip thereof faces into the pre-combustion chamber 23 from the inner peripheral surface of the sub-chamber forming hole 5 located between the lower cylinder 16 and the upper cylinder 17. There is no problem in attaching the gasket 22, the glow plug 11 can be easily attached, and starting performance at low temperatures can be improved.

Effects of the invention As described above, this invention consists of a sub-chamber consisting of a lower cylinder, an upper cylinder, and the inner peripheral surface of the sub-chamber forming hole located between the lower cylinder and the upper cylinder. This makes it easy to manufacture the lower cylinder and upper cylinder, and only the lower cylinder, which requires the most heat resistance, is made of heat-resistant steel, reducing product costs. By having the tip part facing into the subchamber from the inner peripheral surface of the subchamber forming hole, the glow plug can be easily installed without interfering with the gas seal in the upper cylinder, making it easier to start at low temperatures. This has effects such as being able to improve sexual performance.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing a conventional example, Fig. 2 is a sectional view taken along the line A-A, Fig. 3 is a longitudinal sectional front view showing another conventional example, and Fig. 4 shows an embodiment of this invention. FIG. 5 is a longitudinal sectional front view and a sectional view taken along the line B--B. DESCRIPTION OF SYMBOLS 1... Cylinder block, 3... Cylinder head, 5... Sub-chamber forming hole, 6... Glow plug mounting hole, 10... Fuel injection nozzle, 11... Glow plug, 16... Lower cylinder body, 17... ...Upper cylinder, 1
8... Main combustion chamber, 19... Communication hole, 23... Pre-combustion chamber (auxiliary chamber).

Claims (1)

[Scope of utility model registration request] A sub-chamber forming hole and a glow plug mounting hole are formed in the cylinder head fixed to the cylinder block,
A lower cylindrical body in which a communication hole communicating with the main combustion chamber is formed in the auxiliary chamber forming hole and an upper cylindrical body to which a fuel injection nozzle is connected are installed with a predetermined distance apart, and the inner circumferential surface of the lower cylindrical body forming a subchamber surrounded by the inner circumferential surface of the upper cylinder and the inner circumferential surface of the subchamber forming hole located between the lower cylinder and the upper cylinder;
A subchamber for a diesel engine, characterized in that a tip end of a glow plug mounted in the glow plug mounting hole faces into the subchamber from an inner circumferential surface of the subchamber forming hole that constitutes a part of the subchamber. room equipment.