JPS6251710A - Device of feeding oil to hydraulic tappet - Google Patents

Abstract

PURPOSE:To reduce the volume of an oil pump, by a method wherein, through communication of a relief passage with a poppet valve device, oil discharged from a distributor to the reilief passage is fed to a lubricating part, and this reduces an amount of oil fed to the lubricating part with the aid of the oil pump. CONSTITUTION:With an engine started, an oil pump 31 is driven, and oil, fed with a pressure from a delivery port through a feed passage 32, is branched into a lubricating oil passage 34 and the downstream side of a feed passage 32 after flowing through an orifice j1. The oil fed to the downstream side of the feed passage 32 is branched into a distribution passage 28 and a communication passage 38 after flowing through second and third orifices J2 and J3. A part of the oil fed to the distribution passage 28 outgoes to a defoaming passage 40 togetherwith bubbles as a flow rate is regulated by a fourth orifice J4. In this case, when a pressure in the distribution passage 28 exceeds a specified value, with a relief valve 44 opened, a relief passage 43 is connected. This causes a part of oil in the distribution passage 28 to outgo in the relief passage 43 and be transferred to a lubricating oil passage 23.

Description

Detailed Description of the Invention A0 Object of the Invention (1) Industrial Field of Application The present invention relates to a system for supplying oil to a hydraulic tappet provided in a valve train of an internal combustion engine, in particular a system for supplying oil from a discharge port of an oil pump of an internal combustion engine. An extended supply passage, a distribution passage that communicates this supply passage with oil supply ports of a plurality of hydraulic tappets provided in the valve train, a relief passage connected to this distribution passage, and a distribution passage provided in this relief passage. This invention relates to an improvement in a device equipped with a relief valve that opens when the hydraulic pressure exceeds a specified value.

(2) Prior art The above-mentioned relief valve is used to keep the hydraulic pressure in the distribution passage constant regardless of changes in engine speed or temperature, and to ensure stable operation of the hydraulic valve and throat.

Therefore, the capacity of an oil pump is generally set so that a predetermined oil pressure can be applied to the distribution oil passage even when the oil pump is at its minimum discharge amount. A large amount of oil will be released into the relief passage.

(3) Problems to be Solved by the Invention However, in conventional oil supply systems, the relief passage is simply opened to the oil pan of the engine, so a large amount of oil released into the relief passage is returned to the oil pan. When the engine rotates at high speed, the amount of oil that is supplied can reach several times the amount of oil that is actually replenished to the hydraulic tappet, resulting in a large amount of waste.

The present invention has been made in view of the above circumstances, and uses the oil discharged into the relief passage to lubricate the valve gear, thereby suppressing unnecessary consumption of oil and thereby reducing the capacity of the oil pump. The purpose of the present invention is to provide a lubricating device for a hydraulic tappet.

B8 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention is characterized in that the relief passage communicates with the lubricating section of the valve train.

(2) Operation When the relief valve is pushed open, the oil released from the distribution passage into the relief passage is guided by the relief passage to the lubricating part of the valve gear and is effectively used for lubrication.

(3) Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a cylinder block 1 for an internal combustion engine has a plurality of cylinders 2 arranged in the front and back directions of the paper. A cylinder head 3 fixed to the upper end of the cylinder block 1 has a plurality of combustion chambers 4 corresponding to the plurality of cylinders 2, and an intake (exhaust) boat 5 opening into each combustion chamber 4.
The intake (exhaust) boat 5 is opened and closed by an intake (exhaust) valve 6. The valve 6 is supported by the cylinder head 3 via a valve guide 7 so as to be able to move up and down, and is driven by a valve train 8.

The valve train 8 includes a retainer 6a attached to two ends of the valve 6.
and a valve spring 9 which is compressed between the cylinder head 3 and the valve spring 9 and which attaches the valve 6 in the closing direction; and a support hole 10 of the cylinder head 3.
Hydraulic tappet 11 attached to this hydraulic tappet 1
a cam follower 12 whose base end is swingably supported by the operating end 11a of the valve 1 and whose distal end engages with the head of the valve 6; and a slipper surface 12a formed on the upper side of the cam follower 12.
and a cam shaft 13 that engages a cam 13a.

The valve operating device 8 is housed in a valve operating chamber 14 formed above the cylinder throat 3, and the upper opening of the chamber 14 is closed by a head cover 15.

As the camshaft 13 rotates, when the cam 13a applies a pressing force to the slipper surface 12a of the cam follower 12 due to its lifting action, the hydraulic tappet 11 is pressed down by the hydraulic pressure generated in the internal hydraulic chamber. As a result of supporting the base end of the cam follower 12, the cam follower 12 is swung downward by the cam 13a using the operating end 11a of the hydraulic tappet 11 as a fulcrum, and opens the valve 6 against the elastic force of the valve spring 9.

During this time, hydraulic oil slightly leaks from the hydraulic chamber within the hydraulic tappet 11. Next, when the cam 13a releases its lifting action on the cam follower 12, the valve spring 9 pushes up the valve 6 together with the cam follower 12 to return it to the closed position. At this time, the hydraulic tappet 11 exhibits an extension function to eliminate the valve head gap. When the hydraulic chamber inside the hydraulic tappet 11 is depressurized due to the expansion of the hydraulic tappet 11, the distribution passage 22 described later is
Hydraulic oil is supplied to the hydraulic chamber from.

In FIG. 2, the camshaft 13 is arranged horizontally along the direction in which the plurality of cylinders 2 are arranged. To support the camshaft 13, a plurality of bearing stands 16. 163 are integrally formed, and the bearing surface 17a is also semicircular.
A plurality of cam holders 17. ~17. is prepared,
The cam holder 17° to 17
3 is the bearing stand 16. -163, respectively, by bolts 18 (FIG. 4). At that time, the bearing stands 16. ．． 1.6. and cam holder 17, i7. The position of joining is defined by the positioning pin 19 and positioning collar 20 (FIG. 4) fitted therein.

As shown in FIGS. 2 and 3, a plurality of cam holders 17
．． -173 are a pair of cross members 21 having a cross-sectional shape
．． Both end portions are integrally connected to each other by a pipe-shaped cross member 21, and the intermediate portion is integrally connected to each other by a pipe-shaped cross member 22. The hollow part of the pipe-shaped cross member 22 is used as a lubricating oil passage 23, and the core oil passage 23 is connected to the cam holders 17, to 17.
The oil supply hole 24 communicating with each bearing surface 17a of each cam holder 171-17. Further, an oil injection hole 25 is formed in the cross member 22 and opens from the lubricating oil passage 23 toward the plurality of cams 13a of the camshaft 13 into the valve operating chamber 14.

The hydraulic tappets 11 and cam followers 12 are arranged horizontally in the same number as the number of valves 6 used, and a horizontally extending distribution passage 28 is bored in the cylinder head 3 so as to communicate with the oil supply port 27 of each hydraulic tappet 11. established,
A blind plug 29 is placed in the perforation.

In addition, the cylinder block 1 and cylinder head 3 include
A supply passage 32 extending upward from the discharge port of the oil pump 31 of the engine and reaching the distribution passage 28 is bored, and also rises from the vicinity of the connecting portion between the supply passage 32 and the distribution passage 28 to form the lubricating oil passage 23. The communication path 38 that reaches the bearing stand 16. is located at the right outer position. and is bored in the cam holder 171. A first orifice J++ is provided in the middle of the supply path 32, and a second orifice J2 is provided at the entrance of the distribution path 28, and a third orifice J is provided in the middle of the communication path 38. The third orifice J3 is formed to have a smaller or equivalent hole diameter than the second orifice J2.

A lubricating oil path 34 branches from a supply path 32 on the upstream side of the first orifice J (that is, on the oil holder 31 side) and reaches a lubricating section 35 around the crankshaft of the engine.

Further, a defoaming passage 40 rising from the back of the distribution passage 28 and reaching the lubricating oil passage 23 is bored in the bearing stand 163 and the cam holder 17 located on the left outer side, and a fourth orifice J4 is provided in this passage 40. It will be done.

Furthermore, a relief passage 43 is bored in the bearing stand 163 and the cam holder 173, which connects the distribution passage 28 and the lubricating oil passage 23 together with the oil supply hole 24. A relief valve 44 is provided which opens when this occurs.

Next, the operation of this embodiment will be explained. When the engine is started, the oil pump 31 is operated and the oil is pumped from its discharge port to the supply path 32, and is lubricated at an appropriate ratio by the first orifice J. The oil is divided into the oil passage 34 and the downstream side of the supply passage 32, and the oil sent to the lubricating oil passage 34 is supplied to a lubricating section 35 around the crankshaft.

The oil sent to the downstream side of the supply path 32 is passed through the second and third orifices J2. J, the flow is further divided into the distribution path 28 and the communication path 38 at a constant ratio. The oil sent to the distribution path 28 is supplied as hydraulic oil to the plurality of hydraulic tappets 11, 11, . . . , and the oil sent to the communication path 38 is transferred to the lubricating oil path 34.

Further, a part of the oil sent to the distribution passage 28 flows out to the defoaming passage 40 with the air bubbles contained therein while the flow rate is regulated by the fourth orifice J4, and then moves to the lubricating oil passage 23.

Further, when the pressure in the distribution passage 28 exceeds a specified value, the relief valve 45 opens and the relief passage 43 is made conductive, so that a part of the oil in the distribution passage 28 flows into the relief passage 43 and the lubricating oil passage. Move on to 23. When the pressure in the distribution path 28 drops to a specified value, the relief valve 44 closes. By opening and closing the relief valve 44 in this manner, the optimum hydraulic pressure for operating each hydraulic tappet 11 is maintained in the distribution passage 28.

A portion of the oil transferred from the communication passage 38, degassing passage 40, and relief passage 43 to the lubricating oil passage 23 passes through the oil supply hole 24.24 and lubricates the journal of the camshaft 13, and the remaining oil is transferred to a plurality of jets. A plurality of cams 13a, 13 from the oil holes 25, 25...
The cam 13a and the cam follower 12 form a pair.
Lubricate the sliding surfaces between. In this way, the valve train 8 is lubricated.

Oil leaking from each hydraulic tappet 11 and oil that has finished lubricating the valve train 8 flow down from the valve train chamber 14 through a return oil path (not shown), return to the oil pan at the bottom of the engine, and are discharged from the orifice holder 31 again. be done.

C6 Effects of the Invention As described above, according to the present invention, since the relief passage is communicated with the lubricating part of the valve train, the oil released from the distribution passage to the relief passage can be supplied to the lubricating part of the valve train. I can do it,
Therefore, the amount of oil originally directly supplied from the oil pump to the lubricating section of the valve train can be reduced accordingly, and the capacity of the oil pump can be reduced.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of the main parts of an internal combustion engine equipped with the device of the invention, FIG. 2 is a longitudinal sectional front view of the main parts of the engine, and FIG. 3 is a longitudinal sectional view of the main parts of the engine. is a bottom view of the cam holder assembly of the same engine, and Figures 4 and 5 are the TV-TV of Figure 3.
FIG. 8...Valve train, 11...Hydraulic tappet, 23...
- Lubricating oil passage as a valve train, 27... Hydraulic tappet oil supply port, 31... Oil pump, 32... Supply passage, 38... Communication passage, 40... Defoaming passage, 4・３・・
・Relief passage, 44...Relief valve Fig. 2 Fig. 1

Claims (1)

[Claims] A supply passage extending from a discharge port of an oil pump of an internal combustion engine, a distribution passage communicating this supply passage with oil supply ports of a plurality of hydraulic tappets provided in a valve train, and a relief passage connected to this distribution passage. In the oil supply device for the hydraulic tappet of an internal combustion engine, the relief passage is provided in the relief passage and is equipped with a relief valve that opens when the oil pressure in the distribution passage exceeds a specified value, and the relief passage is communicated with the lubricating part of the valve gear. A lubricating device for hydraulic tappets, which is characterized by: