JPH0536971Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a fuel injection cam lubrication device for an engine, and in particular, to an engine that can simplify the structure for lubricating the cam peripheral surface of the fuel injection cam. The present invention relates to a fuel injection cam lubricating device.

<Prerequisite configuration> To explain in more detail, the present invention includes, for example, as shown in FIGS. 1 to 3, a camshaft 3 is provided in the crank chamber 2 of the engine 1, and a tappet support wall 4 is provided above the camshaft 3. A valve operating cam 5 for an intake valve and a valve operating cam 6 for an exhaust valve are formed on the camshaft 3 at appropriate intervals, and a tappet 7 for an intake valve driven by each valve operating cam 5, 6 is formed. The exhaust valve tappet 8 is slidably fitted into each of the tappet holes 9 and 10 of the tappet support wall 4, and a fuel injection cam 11 is formed in the middle of both valve cams 5 and 6. Cam circumference 1
The present invention relates to a fuel injection cam lubricating device for an engine, which has a prerequisite configuration that lubricating oil is supplied to the engine by an injection cam lubricating means.

<Prior Art> Conventionally, the injection cam lubrication means of the fuel cam lubrication system of an engine having the above-mentioned prerequisite configuration includes a splash lubrication device such as an impeller or spoon that splashes oil into the crank chamber 2, and a droplet lubrication device such as an impeller or spoon that splashes oil into the crank chamber 2, and a droplet lubrication device from an oil pump. There is a forced lubrication device configured to supply pressure-fed lubricating oil to the cam peripheral surface through a lubricating oil passage formed in a camshaft in which a fuel cam is formed.

<Problems to be solved by the invention> In the above-mentioned splash lubrication device, the cam circumferential surface is lubricated by attaching the oil mist that fills the crank chamber to the cam circumferential surface, so the cam circumferential surface is sufficiently lubricated. In order to do this, it is necessary to increase the amount of lubricating oil in order to fill the crank chamber with a large amount of oil mist, which increases the volume of the oil pan that stores the lubricating oil, which is a disadvantage when trying to downsize the engine. be.

Although forced lubrication devices can eliminate these drawbacks, it is necessary to form a lubrication hydraulic pressure path from the oil pump to the camshaft's lubricating oil path, making the structure for lubricating the cam circumferential surface complicated. There's a problem.

The present invention has been made in consideration of the above circumstances, and is capable of simplifying the structure for lubricating the cam peripheral surface of the fuel injection cam in a fuel injection cam lubrication device for an engine having the above-mentioned prerequisite configuration. It is an object of the present invention to provide a fuel cam lubrication device for an engine as described above.

<Means for Solving the Problems> In the fuel cam lubrication device for an engine according to the present invention, in order to achieve the above object, the fuel injection pump 26 is tilted and the fuel injection pump 26 is inserted from above the fuel injection cam 11. A lubricating oil return path 14 is vertically provided in the middle between both tappets 7 and 8 of the tappet support wall 4, and an outlet 15 of the lubricant return path 14 is provided on the lower surface 13 of the tappet support wall 4. The lubricating oil return path 14 is opened to face the cam peripheral surface 12 of the fuel injection cam 11 from above, so that the lubricating oil return path 14 also serves as the injection cam lubrication means.

<Function> According to the present invention configured as described above, the oil returned to the crank chamber flows down in the lubricating oil return passage provided vertically through the tappet support wall. Then, the lubricating oil released from the outlet 15 of the lubricating oil return path 14 into the crank chamber 2 naturally flows into the cam peripheral surface 1 of the fuel injection cam 11.
2 and lubricates the cam peripheral surface 12. Therefore, it is possible to simplify the configuration for lubricating the cam circumferential surface by omitting the lubricating oil passage in the camshaft 3 and the lubricating oil pressure feed path from the lubricating oil pump to the lubricating oil passage in the camshaft 3. can.

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

FIG. 1 is a rear view of an oil-cooled engine according to an embodiment of the present invention, with main parts taken longitudinally, FIG. 2 is a rear view thereof, and FIG. 3 is a cross-sectional view taken along the line - , FIG. 4 is a plan view of the cylinder block.

As shown in FIG. 3, a crankshaft 16 and a camshaft 3 are arranged in parallel to each other in the crank chamber 2 of the engine 1, and are housed in a gear chamber 17 on the rear side of the crank chamber 2. The crankshaft 16 and the camshaft 3 are synchronized through a timing gear device 18. The lower part of the crank chamber 2 constitutes an oil storage chamber 19 for storing lubricating oil. crankshaft 1
6 is force-fed to a bearing part 23 that rotatably supports the bearing part 6.

A pressure setting valve 24 for setting the supply pressure of lubricating oil is branch-connected to the lubricating oil pressure feed line 22, and a drain chamber 25 of this pressure setting valve 24 is connected to a cooling oil jacket 28 formed in the cylinder block 27.
and is communicated with the crank chamber 2 via a return path 14. The terminal end 29 of the oil jacket 28 and the starting end 30 of the return path 14 are communicated through a communication path 32 formed of a groove formed on the lower surface of the cylinder head 31.

A valve operating cam 5 for the intake valve and a valve operating cam 6 for the exhaust valve are formed on the camshaft 3 at appropriate intervals in the longitudinal direction, and fuel is injected at an intermediate location between these valve operating cams 5 and 6. A cam 11 is formed. The fuel injection cam 11 is configured to drive a fuel injection pump 26, and the fuel injection pump 26 is disposed in an inclined manner so as to be displaced laterally outward from the upper side of the fuel injection cam 11. A tapepet support wall 4 is provided above the camshaft 3, and a push rod insertion chamber 33 is formed above the tapepet support wall 4.
As shown in FIG. 4, an intake valve push rod 34 and an exhaust valve push rod 35 are inserted into the push rod insertion chamber 33. Push rod insertion chamber 3
It is separated from 3. Above oil jacket 2
8 is formed on the cylinder chamber 37 side of the push rod insertion chamber 33 and the return path 14.

The intake valve tappet 7 and the exhaust valve tappet 8, which are driven by the respective valve driving cams 5 and 6, are supported by the tappet support wall 4 so as to be able to move up and down, and their lower end surfaces are connected to the corresponding valve driving cams. It is accepted by 5 and 6. The return path 14 is provided vertically through the tappet support wall 4 at a midpoint between both the tappets 7 and 8, and the outlet 15 at the lower end is connected to the fuel injection cam 11.
By opening the cam circumferential surface 12 from above, the lubricating oil return path 14 is also used as injection cam lubrication means.

In this way, if the lubricating oil return path 14 that returns lubricating oil from the cylinder block 27 to the crank chamber 2 is also used as the fuel injection cam lubrication means, there is no need to form a lubricating oil passage in the camshaft 3, and the oil pump There is also no need to form a pressure passage for pumping lubricating oil from 21 to the camshaft 3. Therefore, by omitting the lubricating oil passage in the camshaft 3 and the pressure feeding path to the camshaft, the structure for lubricating the cam circumferential surface 12 of the fuel injection cam 11 can be simplified and manufacturing costs can be reduced. .

FIG. 5 is a longitudinally sectional rear view of the essential parts of an oil-cooled engine in which a cylinder head 31 that is partially cooled with oil is installed in place of the cylinder head 31 that is not cooled with oil as described above.

Inside the cylinder head 31 of the engine 1, there is an oil jacket (not shown) and an introduction path 38 for supplying cooling oil to this oil jacket, and from this oil jacket, lubricating oil is sent to a return path 14 via an oil cooler (not shown). A lead-out path 39 for returning is formed. The introduction port 40 of the introduction passage 38 is connected to the oil jacket 28 formed in the cylinder block 27.
The outlet 41 of the lead-out passage 39 is opened at the lower end face of the cylinder head 31 facing the starting end 30 of the return passage 14.

Other parts are common to the above-mentioned first embodiment, so their explanation will be omitted to avoid duplication.

In this way, the cooling oil inlet 40 and the outlet 41 of the cylinder head 3 are opened at the lower end surface of the cylinder head 31 so as to face the terminal end of the oil jacket 28 and the starting end of the return path 14. The cylinder block 27 can be shared between the engine 1 (FIG. 5) in which at least a portion of the cylinder head 31 is oil-cooled and the oil-cooled engine 1 (FIG. 1) in which the cylinder head 31 is not oil-cooled.

(Effects of the invention) As described above, according to the invention, the lubricating oil return path to the cylinder chamber is also used as the fuel injection cam lubrication means, so the lubricating oil passage in the camshaft and the lubricating oil pressure thereto are Since there is no need to form a feed path and the lubricating oil return path is simply provided vertically through the tapepet support wall, the structure for lubricating the cam circumferential surface of the fuel injection cam can be extremely simplified.

Moreover, since the fuel injection pump is displaced laterally outward from the upper side of the fuel injection cam and the outlet of the lubricating oil return path is opened above the cam circumferential surface, the lubricating oil return path has a simple configuration, but the return oil By simply dropping it from this outlet, it can be efficiently supplied to the cam peripheral surface, improving lubrication performance.

[Brief explanation of the drawing]

FIG. 1 is a rear view of an oil-cooled engine according to an embodiment of the present invention, with main parts cut longitudinally; FIG. 2 is a rear view thereof;
Fig. 3 is a sectional view taken along the - line in Fig. 2, Fig. 4 is a plan view of the cylinder block, and Fig. 5 is an oil-cooled engine according to the present invention, in which a portion of the cylinder head is cooled with oil instead of the cylinder head which is not cooled with oil. FIG. 2 is a longitudinally sectional rear view of the main parts of an oil-cooled engine with a cylinder head assembled therein. 1... Engine, 2... Crank chamber, 3... Camshaft, 4... Tappet support wall, 5... Valve operating cam for intake valves, 6... Valve operating cam for exhaust valves, 7... For intake valves. Tappet, 8... Exhaust valve tappet, 9, 10
... Tappet hole, 11 ... Fuel injection cam, 12 ...
...Cam peripheral surface of fuel injection cam 11, 13... Lower surface of tapepet support wall 4, 14... Lubricating oil return path, 15
...Exit of the lubricating oil return path 14.

Claims (1)

[Scope of claim for utility model registration] A camshaft 3 is provided in the crank chamber 2 of the engine 1,
A tappet support wall 4 is formed on the upper side of the camshaft 3, and a valve operating cam 5 for an intake valve and a valve operating cam 6 for an exhaust valve are formed on the camshaft 3 at appropriate intervals, and each valve operating cam 5, The intake valve tappet 7 and the exhaust valve tappet 8 driven by the valve cams 6 and 6 are slidably fitted into the respective tappet holes 9 and 10 of the tappet support wall 4, and the dual valve cams 5 and
In the fuel injection cam lubricating device for an engine, the fuel injection cam 11 is formed in the middle part of the fuel injection cam 26 , and the lubricating oil is supplied to the cam circumferential surface 12 of the fuel injection cam 11 by an injection cam lubrication means. The fuel injection pump 26 is displaced laterally outward from the upper side of the fuel injection cam 11 by tilting the fuel injection cam 11, and a lubricating oil return path 14 is provided vertically and transparently at an intermediate location between both tappets 7 and 8 of the tappet support wall 4. Lubricating oil return path 1 on the lower surface 13 of the support wall 4
The outlet 15 of 4 is connected to the cam peripheral surface 12 of the fuel injection cam 11.
A fuel injection cam lubricating device for an engine, characterized in that the lubricating oil return path 14 is opened so as to face from above so that the lubricating oil return path 14 also serves as the injection cam lubricating means.