JPH0669360U - diesel engine - Google Patents

Abstract

(57) [Summary] [Objective] To provide a low-cost diesel engine in which the injection nozzle can be easily replaced. A holding portion 5a that engages with a flange portion 4a of the injection nozzle 4 is provided on one end side, and a support portion 5b that engages with an upper portion of the outer peripheral surface of the rocker shaft 2 is provided on the other end side, and the holding portion 5a. The diesel engine is equipped with the nozzle bridge 5 in which the mounting portion 5c into which the fixing bolt 6 that is screwed into the screw hole 1a of the cylinder head 1 is fitted between the nozzle bridge 5 and the supporting portion 5b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a diesel engine equipped with a nozzle bridge for fixing an injection nozzle to a cylinder head.

[0002]

[Prior art]

 Diesel engines obtain power by highly compressing the air in the cylinder to a high temperature, then highly compressing and supplying fuel such as light oil with an injection nozzle, and causing it to spontaneously ignite and explode. For this reason, it has higher thermal efficiency and lower fuel cost than gasoline engines, and is therefore widely used not only in industrial vehicles such as buses and trucks but also in passenger cars for personal use.

FIG. 3 shows an upper surface of a peripheral portion of the injection nozzle of such a conventional diesel engine, and FIG. 4 shows a cross section taken along the line IV-IV in FIG. 4, and the structure thereof will be described below.

As shown in FIGS. 3 and 4, a rocker shaft 22 is provided above the cylinder head 21. A plurality of rocker arms 23 are swingably fitted to the rocker shaft 22. An injection nozzle 24 fitted in the cylinder head 21 is provided on the right side between the adjacent rocker arms 23 in the drawing. A nozzle bridge 25 for fixing the injection nozzle 24 to the cylinder head 21 is provided above the cylinder head 21 between the injection nozzle 24 and the rocker shaft 22.

A holding portion 25 a that engages with a flange portion 24 a of the jet nozzle 24 is formed on the jet nozzle 24 side of the nozzle bridge 25. On the rocker shaft 22 side of the nozzle bridge 25, a support portion 25b that engages with the upper surface of the cylinder head 21 is formed. At the central portion of the nozzle bridge 25 between the holding portion 25a of the nozzle bridge 25 and the support portion 25b, a mounting portion 25c into which a fixing bolt 26 screwed into the screw hole 21a of the cylinder head 21 is fitted is formed. Has been done. A plurality of spring washers 27 are interposed between the upper portion of the mounting portion 25c and the head portion of the fixing bolt 26.

That is, the holding portion 25 a of the nozzle bridge 25 is engaged with the injection nozzle 24, the support portion 25 b of the nozzle bridge 25 is engaged with the cylinder head 21, and the mounting portion 25 c of the nozzle bridge 25 is fixed with the fixing bolt 26. By fixing to the head 21, the injection nozzle 24 is fixed to the cylinder head 21.

[0007]

[Problems to be solved by the device]

 In the conventional diesel engine using the nozzle bridge 25 shown in FIGS. 3 and 4, when the injection nozzle 24 is replaced for maintenance or inspection, since the nozzle bridge 25 is located below the rocker shaft 22, The injection nozzle 24 must be replaced by removing the rocker shaft 22 and then the nozzle bridge 25. For this reason, the replacement work of the injection nozzle 24 is very complicated.

Therefore, as shown in FIGS. 6 and 7, by using a nozzle bridge 27, one end of which is rotatably fitted to the rocker shaft 31 and the other end of which is engaged with the flange portion 24 b of the injection nozzle 24. It has been proposed that the injection nozzle 33 can be replaced without removing the rocker shaft 22.

However, since one end of the nozzle bridge 27 as described above has to be processed so as to be rotatably fitted to the rocker shaft 22, the manufacturing of the nozzle bridge 27 becomes complicated, which causes a cost increase. ing.

[0010]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention is provided with a holding part that engages above the injection nozzle at one end side and a support part that engages with the upper part of the outer peripheral surface of the rocker shaft at the other end side. Further, the diesel engine is configured by including the nozzle bridge in which the mounting portion fixed to the cylinder head is provided between the holding portion and the supporting portion.

[0011]

[Action]

 In the diesel engine having the above-described configuration, when the holding portion engages above the injection nozzle and the mounting portion is fixed to the cylinder head, the nozzle bridge fixes the injection nozzle to the cylinder head above the rocker shaft. . Further, since the mounting portion is located above the rocker shaft, the nozzle bridge can be removed from the cylinder head and the injection nozzle can be removed from the cylinder head without removing the rocker shaft.

[0012]

【Example】

 FIG. 1 shows the upper surface of the injection nozzle peripheral portion of one embodiment of the diesel engine of the present invention, and FIG. 2 is a sectional view taken along the line II-II in FIG. 2, the structure of which will be described below.

As shown in FIGS. 1 and 2, a rocker shaft 2 is provided above the cylinder head 1. A plurality of rocker arms 3 are swingably fitted to the rocker shaft 2. On the right end side of these rocker arms 3 in the figure, the upper ends of valves (not shown) fitted with valve springs 7 are engaged via branch arms 3a. Further, push rods (not shown) are engaged with the left ends of the rocker arms 3 in the figure. Therefore, the rocker arms 3 open and close the valves in accordance with the operation of the push rods to appropriately perform exhaust and intake in the cylinder in response to the reciprocating movement of the piston.

On the other hand, an injection nozzle 4 fitted in the cylinder head 1 is provided on the right side between the adjacent rocker arms 3 in the drawing. An injection pump (not shown) is connected to the injection nozzle 4, and the injection nozzle 4 injects the fuel sent from the injection pump into the cylinder from the tip end in accordance with the reciprocating motion of the piston. .

A nozzle bridge 5 for fixing the injection nozzle 4 to the cylinder head 1 is provided on the side of the rocker shaft 2 between the adjacent rocker arms 3 between the injection nozzle 4 and the rocker shaft 2. There is. A holding portion 5a that engages with the flange portion 4a of the jet nozzle 4 is formed on the jet nozzle 4 side of the nozzle bridge 5. On the rocker shaft 2 side of the nozzle bridge 5, a support portion 5b that engages with the upper portion of the rocker shaft 2 between the adjacent rocker arms 3 is formed. At the central portion of the nozzle bridge 5 between the holding portion 5a and the support portion 5b of the nozzle bridge 5, there is formed a mounting portion 5c into which a fixing bolt 6 screwed into the screw hole 1a of the cylinder head 1 is fitted. Has been done. A spring washer 7 is interposed between the upper portion of the mounting portion 5c and the head of the fixing bolt 6.

That is, the holding portion 5a of the nozzle bridge 5 is engaged with the injection nozzle 4, the support portion 5b of the nozzle bridge 5 is engaged with the upper portion of the rocker shaft 2, and the mounting portion 5c of the nozzle bridge 5 is fixed. The injection nozzle 4 is fixed to the cylinder head 1 by fixing it to the cylinder head 1 with the bolt 6.

Removal of the injection nozzle 4 from the cylinder head 1 in the diesel engine having the above structure is performed as follows.

That is, when the head of the fixing bolt 6 is turned with a wrench to remove the fixing bolt 6 from the screw hole 1 a and remove the nozzle bridge 5 from the cylinder head 1, there is no obstacle around the injection nozzle 4. Since the objects are gone, the injection nozzle 4 can be easily removed from the cylinder head 1.

When the injection nozzle 4 is attached to the cylinder head 1, the procedure reverse to the above-mentioned procedure may be performed, and similarly to the above, the rocker shaft 2 does not hinder the injection nozzle 4 on the cylinder head 1. 4 can be easily fixed.

In this embodiment, the fixing bolt 6 fitted to the mounting portion 5c of the nozzle bridge 5 is screwed directly into the screw hole 1a of the cylinder head 1 to be directly mounted. In order to reduce the load on the fixing bolt 6, the end faces of the nozzle bridge 5 correspond to the lower surface of the nozzle bridge 5 and the upper surface of the cylinder head 1, and a pipe having an inner diameter corresponding to the diameter of the fixing bolt 6 may be fitted to the fixing bolt 6. . Further, in the present embodiment, the mounting portion 5c is fixed to the cylinder head 1 by using the fixing bolt 6, but the present invention is not limited to this, and the same effect can be obtained as long as the mounting portion is fixed to the cylinder head. .

[0021]

[Effect of device]

 According to the diesel engine of the present invention, since the nozzle bridge is provided above the rocker shaft to fix the injection nozzle to the cylinder head, the nozzle bridge can be attached and detached without removing the rocker shaft, and the injection nozzle can be easily installed. Can be exchanged. Further, since the structure of the nozzle bridge is simple, the nozzle bridge can be manufactured easily, and a low-cost diesel engine can be produced.

[Brief description of drawings]

FIG. 1 is a top view of a peripheral portion of an injection nozzle according to an embodiment of a diesel engine of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a top view of a peripheral portion of an injection nozzle of a conventional diesel engine.

FIG. 4 is a sectional view taken along the line IV-IV.

FIG. 5 is a top view of the main part around the injection nozzle of another conventional diesel engine.

FIG. 6 is a side sectional view thereof.

[Explanation of symbols]

 1 Cylinder Head 1a Screw Hole 2 Rocker Shaft 4 Injection Nozzle 5 Nozzle Bridge 5a Holding Part 5b Supporting Part 5c Mounting Part 6 Fixing Bolt

Claims (1)

[Scope of utility model registration request] 1. A holding portion that engages above the injection nozzle is provided at one end side, and a support portion that engages with an upper portion of the outer peripheral surface of the rocker shaft is provided at the other end side, and the holding portion and the support portion are provided. A diesel engine, comprising: a nozzle bridge provided with an attachment portion fixed to the cylinder head.