JPS6129923Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention is particularly useful for horizontally opposed internal combustion engines.
Regarding the oil tappet used in OHV type valve mechanism, which converts the rotational motion of the cam into horizontal linear motion,
More specifically, it relates to something that prevents oil from leaking in the oil tappet when the engine is stopped.

[Conventional technology]

In a horizontally opposed internal combustion engine, as shown in FIG. It is inserted into the installed cylinder 5 and moves reciprocatingly. Further, a camshaft 6 is provided under the crankshaft 1, and oil tappets 7 on the left and right sides of the camshaft 6 fit into holes 9 in the crankcase side support part 8, and are horizontally moved by the rotation of the cam 10 of the camshaft 6. These oil tappets 7 are connected to the valve 13 of the rocker arm 12 and the adjusting screw 14 on the opposite side through a push rod 11 extending substantially horizontally, and the movement of these oil tappets 7 and the push rod 11 causes The valve 13 is configured to open and close by swinging the rocker arm 12. Here, regarding oil tapets, for example,
The one described in Publication No. 52-24168 is known,
The conventional oil tappet, which is the issue of this invention, has been replaced with a second one.
To explain in detail with the drawings, the structure is exactly the same as that of a vertical internal combustion engine. That is, a plunger 16 is movably inserted into a horizontally installed cylindrical tappet body 15 with one end closed, and a pressure chamber 17 is formed between the cam 10 side in the tappet body 15 and the plunger 16. A tappet spring 18 is biased between the tappet body 15 and the plunger 16 within the pressure chamber 17. Further, an oil chamber 19 and a pressure chamber 17 in the plunger 16 are configured to communicate through a ball check valve 20, and the plunger 1
A rod seat 21 is connected to the opposite side of the pressure chamber 17 of the pressure chamber 6 and inserted so as to move together with the pressure chamber 17, and one end of the push rod 11 is in spherical contact with this seat 21. Tappet body 15 and plunger 16
Oil holes 22 and 23 are bored in the rod seat side of the peripheral wall of the main oil passage 24, and oil pumped by an oil pump (not shown) in the main oil passage 24 is passed through the oil holes 2.
The oil in the oil chamber 19 is injected into the pressure chamber 17 via the ball check valve 20. On the other hand, the oil in the oil chamber 19 is further leaked through the gap A between the tapepet body 15 and the rod seat 21, the passage 25 formed by bending in an L shape from the outer periphery of the seat 21 to the center, and the passage 26 inside the push rod 11.
The oil is supplied to the valve train including the rocker arm 12 and the like to lubricate it, and the rod seat 21 and the like are prevented from coming off with a snap spring 27. As a result, when the cam 10 lifts as shown in the figure, the ball check valve 20 is closed by first pushing the tappet body 15 and increasing the oil pressure in the pressure chamber 17, and thus the tappet body 15 and the plunger 16
and the rod seat 21 are integrated through the hydraulic pressure of the pressure chamber 17, and the push rod 11 is moved to one side to open the valve 13. Next, when the cam 10 passes the peak and descends, the tappet main body 15 returns to the left side in the figure and closes the valve 13, and at this time, the volume of the pressure chamber 17 is increased by the tappet spring 18 to perform suction. Ball check valve 2
0 is opened to supply oil from the oil chamber 19 to the pressure chamber 17. In addition, valve 13 and push rod 11
When the components thermally expand due to heating, the plunger 16 moves to the pressure chamber 17 side and absorbs the thermal expansion.

[Problem that the invention attempts to solve]

By the way, in the oil tappet 7 installed horizontally in such a horizontally opposed internal combustion engine, as the oil in the main oil passage 24 drains when the engine is stopped, the oil in the oil chamber 19 of the plunger 16 flows into the oil holes 23, 22. Furthermore, the oil in the pressure chamber 17 also leaks out from the gap between the tappet body 15 and the plunger 16 and decreases. Therefore, when the oil tappet is lowered when restarting the engine, the tappet spring 1
8, the volume of the pressure chamber 17 increases and air is sucked in when the ball check valve 20 is opened and a suction action is performed. This air is easily compressed when the oil tappet is lifted, making it impossible to move the plunger 16 and push rod 11 by a predetermined stroke, causing excessive valve clearance, causing noise such as valve seating noise, and output. There was a problem that led to a decline.

[Means to solve the problem]

The present invention was developed to solve this problem, and the oil hole in the peripheral wall of the plunger is bypassed in the radial direction of the plunger by the oil groove on the outer periphery of the partition plate, and the oil passage and oil hole inside the partition plate. A check valve is provided that communicates with the internal oil chamber and only allows oil to flow into the oil passage, and the check valve and the configuration of the detour passage when the engine is stopped double prevent oil from leaking from the plunger's internal oil chamber. The summary is what we have done.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. First, in the embodiments shown in FIGS. 3 and 4, the tappet body 15, plunger 16, pressure chamber 17, ball check valve 20, rod seat 2
1. The oil holes 22, 23, etc. are constructed in the same manner as shown in FIG. A partition plate 28 having a thickness sufficient to cover the oil hole 23 is fitted in a liquid-tight manner at the end of the rod seat side of the plunger 16 at a position that coincides with the oil hole 23. Hole 23
An oil groove 29 is formed which communicates with the oil groove 29, and an oil passage 30 is formed in the radial direction passing through the center of the inside of the partition plate 28 from a position of the oil groove 29 substantially facing the oil hole 23. The opening of the oil passage 30 when drilling the hole is closed by a plug 31, and the oil passage 30 communicates with the oil chamber 19 in the plunger 16 through an oil hole 32 in the vicinity of the plug 31, which is farther away from the part communicating with the oil groove 29. As a result, the oil hole 23 has a detour structure in which the oil groove 29 and the oil passage 30 traverse the plunger 16 once in a reciprocating direction in a substantially radial direction and communicate with the oil chamber 19 via the oil hole 32. In addition, an orifice 33 is provided in the communication portion with the oil groove 29 in the oil passage 30, and a ball 3 for opening and closing the orifice 33 is provided.
4. A check valve 37 consisting of a retainer 35 and a spring 36 is provided to only allow oil to flow in from the oil groove 29. With this configuration, during engine operation, the oil flowing from the main oil passage 24 to the oil hole 23 via the oil hole 22 does not immediately flow into the oil chamber 19.
The oil flows in the oil groove 29 of the partition plate 28 to the side substantially opposite to the oil hole 23, and then flows into the oil passage 3 while opening the check valve 37.
The oil flows down through the oil chamber 19 through the oil hole 32, and is filled with the oil chamber 19. When the cam 10 rotates and descends, the volume of the pressure chamber 17 increases and oil in the oil chamber 19 is replenished into the pressure chamber 17, and oil is also supplied to the oil chamber 19 as described above. Become so. Next, when the main oil passage 24 stops pumping oil when the engine is stopped and the oil there flows out, the oil in the oil groove 29 also flows out, but the check valve 3
7 closes, the oil chamber 19 along with the oil passage 30
The inside remains filled with oil. Therefore, even if some oil in the pressure chamber 17 leaks out and a large amount of suction occurs when the engine is restarted, only oil is replenished from the oil chamber 19, and a predetermined oil pressure is generated in the pressure chamber 17 from the beginning, allowing normal operation. I do. On the other hand, at this time, the orifice 33 of the check valve 37
If dirt or the like gets caught between the oil hole 23 and the ball 34 and the sealing performance deteriorates, when the oil hole 23 faces downward and the oil passage 30 is made vertical as shown in the figure, the oil chamber should be closed to the level of the oil groove 29. Even in the worst case, when the plunger 16 turns 90 degrees and the oil passage 30 becomes approximately horizontal, oil remains in the oil chamber 19 up to approximately half the height where the orifice 33 is located. . Another embodiment of the present invention is shown in FIG.
According to this, the oil passage 30 of the partition plate 28 is bored to one side from the center, and the oil hole 23, the orifice 33 of the check valve 37, and the oil hole 32 are mutually arranged.
They are arranged at 120 degrees. As a result, in the case where the sealing performance of the check valve 37 deteriorates as described above, the oil can remain at a position higher than the center of the oil chamber 19 at any rotational position of the plunger 16, which is more effective.

[Effect of the idea]

As described above, according to the present invention, even if the oil in the main oil passage 24 is drained when the engine is stopped, the plunger 1
A large amount of oil remains in the oil chamber 19 of No. 6, and when the engine is restarted, air is not sucked into the pressure chamber 17 and the valve operates normally, so valve seating noise and output reduction do not occur. . Since oil leakage from the oil chamber 19 is double-prevented by the check valve 37 and the detour passage that crosses the plunger 16 in one reciprocation by the oil groove 29, oil passage 30, and oil hole 32, it is reliable and highly reliable.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a part of a horizontally opposed internal combustion engine to which the present invention is applied, Fig. 2 is a sectional view showing an example of a conventional oil tappet, and Figs. 3 and 4 are sectional views of the oil tappet of the present invention. A sectional view showing the first embodiment, a - sectional view in FIG. 3, and a sectional view showing the second embodiment in FIG. 7...Oil tappet, 10...Cam, 11...
... Push rod, 15 ... Tappet body, 16
... Plunger, 17 ... Pressure chamber, 18 ... Tappet spring, 19 ... Oil chamber, 20 ... Ball check valve, 21 ... Rod seat, 22, 23
... Oil hole, 28 ... Partition plate, 29 ... Oil groove, 30
...Oil passage, 32...Oil hole, 37...Check valve.

Claims (1)

[Scope of utility model registration request] A plunger is inserted into the tappet body which is installed horizontally and moves by the rotation of the cam, and a pressure chamber is formed in the tappet body on the side of the cam from the plunger, and the pressure chamber and the oil chamber in the plunger are connected to each other. They are communicated via a ball check valve, a tapepet spring is biased between the tappet body and the plunger in the pressure chamber, and an oil hole is communicated with the circumferential wall of the tappet body and the plunger to inject oil. In an oil tappet which is bored and further connected to a push rod via a rod seat on the side opposite to the pressure chamber of the plunger, a partition plate is fitted in the plunger at a position that coincides with the oil hole in the peripheral wall of the plunger. An oil hole is configured to communicate with the oil chamber in the plunger through an oil groove formed on the outer periphery of the partition plate, an oil passage inside the partition plate, and an oil hole, and only allow oil to flow into the oil passage. An oil tappet characterized by being equipped with a check valve.