JPH07166824A - Tappet with valve clearance compensation mechanism - Google Patents

Abstract

PURPOSE: To cause suction of only a hydraulic medium into a center storage chamber by positioning the suction cross section of a suction conduit in an area located in the vicinity of the inner peripheral surface of a skirt and the lowest position of a ring-shaped oil storage chamber. CONSTITUTION: A center oil storage chamber 15 is provided between a clearance compensating member 12 an the underside 13 of a bottom 7 and a ring plate 16 having first and second additional parts 17a, 19 is provided around the oil storage chamber 15. A suction conduit 20 for a hydraulic medium is formed between the ring plate 16, the inner peripheral surface 11 of a skirt 3, and the underside of the bottom 7 by means of a passage machined in the ring plate 16. Next, the suction cross section of the passage, i.e., the suction conduit 20, is placed within an area in the vicinity of the inner peripheral surface 11 of the skirt 3 and in the lowest portion of a ring-shaped oil storage chamber 14 along gravity direction. Thus, since only the hydraulic medium is drawn into the center oil storage chamber 15, the hydraulic medium can be supplied in a sufficient amount to a tappet 8a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tappet for driving a valve of an internal combustion engine, which is provided with a hollow-cylindrical casing, the casing of which moves axially in a receiving hole of a cylinder head. Possibly guided, the end face of the casing facing the cam is closed by the bottom, and a coaxial guide sleeve for the hydraulic clearance compensating member is provided inside the tappet.
The guide sleeve is supported on the skirt by an annular web connected to the skirt, which, together with the bottom, the skirt and the guide sleeve, encloses the first ring-shaped oil reservoir, Second inside
A central oil storage chamber of the type, in which at least one suction conduit for oil leads from the ring-shaped oil storage chamber to the central oil storage chamber.

[0002]

2. Description of the Related Art Tappets of this type are disclosed in Japanese Examined Patent Publication No. 59-655.
It is known from Japanese Patent Publication No. 08-08. This tappet also has a cup-shaped casing, and the gap compensating member is coaxially arranged inside the casing. In the opposite direction to the bottom, the hydraulic medium from the outer ring-shaped oil storage chamber, which is confined by the web of the guide sleeve, is passed through the inlet provided at the bottom of the tappet bottom to the central oil storage. It is sucked into the room. It is known to the person skilled in the art that the air or air which may be present near the bottom of the ring-shaped oil storage chamber sucks in the bubbling oil, so that the oil from the deepest point of the oil storage chamber when viewed in the direction of gravity is used. Is being attempted to inhale. According to this solution, the suction point is realized in radial direction near the guide sleeve, that is to say near the axis of the tappet, and is realized by an additional sleeve extending axially from the bottom. For example, because a slight tappet rotation is desired for tribological reasons, the hydraulic medium is pressed against the skirt by the action of centrifugal force, and light components such as air or oil bubbles guide the guide sleeve in a ring shape. surround. This causes air or oil bubbles to be sucked into the high-pressure chamber of the clearance compensating member via the central oil storage chamber under adverse operating conditions, for example under the so-called "taxi operation" in which the engine is often shut off, which functions as a clearance compensation function. It causes the rattling noise of the tappet as well as reducing it.

[0003]

SUMMARY OF THE INVENTION The object of the invention is to eliminate the abovementioned disadvantages and to ensure with a high degree of certainty that a hydraulic medium with as little air content as possible is sucked into the central storage chamber. To make a tappet of the type described at the beginning.

[0004]

According to the structure of the present invention which has solved the above-mentioned problems, the suction cross section of the suction conduit is
It is located close to the inner peripheral surface of the skirt, which is also located in the region of the ring-shaped oil storage chamber, as viewed in the direction of gravity, near the lowest position.

By arranging the suction cross-section of the suction conduit and the oil inlet through the skirt of the tappet on opposite sides as claimed in claim 2, a reliable oil supply to the clearance compensating member is ensured. Another means is available. If both holes, that is to say the suction cross section and the oil inlet, are not arranged offset from each other, the hydraulic medium will be sucked directly into the suction conduit via the oil inlet, and under certain operating conditions. Therefore, unless pressure is applied to the hydraulic medium at the oil inlet via the supply conduit in the cylinder head, there is a risk of air inclusion.

According to the third to fifth aspects, the effective constitution of the present invention can be obtained. The lamella part which contacts the bottom or the guide sleeve forms a passage for the suction of the hydraulic medium from the desired deeper location without great construction costs. Furthermore, within the framework of the invention, this suction action is combined with the oil-diverting safety known per se or the chamber-like design of the ring-shaped oil reservoir. In yet another aspect of the invention, the suction conduit is machined on the inner peripheral surface of the skirt and / or on the underside of the bottom and is covered by the aforementioned lamella portion. According to a further development, the suction conduit from the ring-shaped oil storage chamber consists of a component of the casing itself.
In the structure according to claim 3, the web provided with the guide sleeve may be formed integrally with the additional portion of the ring plate.

Another aspect of the present invention is described in claim 5. This pipe, which has plunged into the oil storage chamber, is fixed in the bore of the hollow cylindrical appendage, for example by simple frictional engagement,
And optionally it can consist of a lightweight material as embodied in claims 6 and 7 for the further tappet component. In order to improve the strength of the tappet of the invention, in a further embodiment of the invention, the casing of the cam follower, which is also provided as a lightweight tappet, is reinforced by embedded fibers and / or particles or is resistant to It is also possible to provide a separate bottom plate of wear-resistant material or a coated wear protection layer.

According to the structure described in claim 8, a simple structure capable of deep drawing the guide sleeve provided with the hopper-shaped web can be obtained.

According to a further configuration within the framework of the invention,
The tappet comprises a web extending radially towards the skirt from a hollow cylindrical addition for guiding the clearance compensating member, which web comprises at least one suction conduit to the clearance compensating member. At the same time, the web is designed to reinforce the entire tappet, or at least partially to fill the oil reservoir in the circumferential direction, resulting in a compact construction. This configuration can also be made of a lightweight material.

[0010]

The structure of the invention makes it possible to manufacture a tappet in a simple manner and without any component which significantly increases the mass. According to this tappet, only the hydraulic medium is sucked into the central oil storage chamber under all operating conditions and with high reliability. In so-called "taxi operation", there is a risk that the tappet will not be supplied with sufficient hydraulic medium to operate the engine for a short time, and / or the high-pressure chamber of the gap compensation member will be decompressed due to the necessary leakage. A reliable and short-time gap compensation function for tappets can be obtained.

[0011]

EXAMPLE A tappet 1 is shown in FIG. This tappet 1 comprises a hollow cylindrical casing 2, which is arranged axially movable in a receiving hole 4 of a cylinder head 5 by means of its skirt 3. The end face 6 of the casing 2 is closed by a bottom 7. This bottom 6 is loaded by a cam 8. A coaxial guide sleeve 9 is arranged inside the tappet 8a. The guide sleeve 9 comprises a web 10, which is supported on the inner peripheral surface 11 of the skirt 3. A clearance compensating member 12 (not shown in detail) is provided in the guide sleeve 9.
Are arranged so as to be movable in the axial direction. The web 10, the guide sleeve 9, the lower side 13 of the bottom part 7 and the inner peripheral surface 11 of the skirt 3 surround a first ring-shaped oil storage chamber 14. A second central oil storage chamber 15 is provided between the gap compensating member 12 and the lower side 13 of the bottom portion 7 in the axial direction. A clearance compensating member 12 is provided in the oil storage chamber 15.
A specified leak amount of oil is pumped from the high pressure chamber (not shown) during the high pressure state of the tappet. At the same time, the required amount of hydraulic medium is sucked into the high pressure chamber via the tappet to be replenished during the basic circle state.

A ring plate 16 is arranged on the lower side 13 of the bottom portion 7. A first additional portion 17a extends from the outer edge 17 of the ring plate 16 toward the inside 8a of the tappet. The additional portion 17a is in contact with the inner peripheral surface 11 of the skirt 3. From the inner edge 18 of the ring plate 16, the second edge is formed in the axial direction.
The additional portion 19 of is extended. This second addition 19 surrounds the central oil storage chamber 15. A suction conduit 20 for the hydraulic medium is formed between the ring plate 16 and the inner peripheral surface 11 of the skirt 3 and the underside of the bottom 7 by means of a passage machined in the ring plate 16. The suction cross-section of the passage or suction conduit 20 is, according to the invention, in the region of the skirt 3 near the inner circumferential surface 11 and also at the lowest point of the ring-shaped oil reservoir 14 when viewed in the direction of gravity. It is located in.

FIG. 2 shows a configuration similar to that of FIG. However, in this case, the gap compensating member 12 is surrounded by the thin plate portion 22. From the first end face 23 of the thin plate portion 22, a radial additional portion 24 is formed on the lower side 13 of the bottom portion 7.
Extends along. The second additional portion 25 starts from the second end surface 26 of the thin plate portion 22 and the inner peripheral surface 27 of the web 10.
Extends up. A suction conduit 28 which extends from the ring-shaped oil storage chamber 14 into the central oil storage chamber 15 is formed by a passage formed in the thin plate portion 22 along the inner peripheral surface 27 of the web 10 and the outer peripheral surface 29 of the guide sleeve 9. Has been done.

According to the configuration shown in FIG. 3, the thin plate portion described so far is omitted. In this case, a coaxial hollow cylindrical addend 30 extends from the underside of the bottom 7, which cooperates with the guide sleeve 9 to close the central oil reservoir 15. A hole 32 penetrating the additional portion 30 is provided in the area of the additional portion 30 near the bottom portion 7. A tube is inserted into this hole 32 as a suction conduit 33, the suction cross section of which is shown in FIGS.
As in the above embodiment, the opening is made in the ring-shaped oil storage chamber 14.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a tappet according to an embodiment of the present invention having a ring plate in contact with a bottom portion.

FIG. 2 is a vertical cross-sectional view of another embodiment of the tappet of the present invention including a thin plate portion surrounding a guide sleeve.

FIG. 3 is a longitudinal sectional view of a tappet according to still another embodiment of the present invention, which includes a separate tube as a suction conduit.

[Explanation of symbols]

1 tappet, 2 casings, 3 skirts,
4 receiving hole, 6 end face, 7 bottom part, 8 cam,
8a Inside of tappet, 9 Guide sleeve, 10 Web, 11 Inner peripheral surface, 12 Gap compensating member, 13
Lower side, 14 and 15 oil storage chamber, 16 ring plate, 17 outer edge, 17a addition part, 18 inner edge,
19 additional part, 20 suction conduit (passage), 21
Suction cross section, 22 thin plate part, 23 end face,
24, 25 additional portion, 26 end surface, 27 inner peripheral surface,
28 suction conduit, 29 outer peripheral surface, 30 additional portion, 31 region, 32 hole, 33 suction conduit (pipe), 34 oil inflow hole

Claims (8)

[Claims] 1. A tappet for driving a valve of an internal combustion engine, which is provided with a hollow cylindrical casing (2), the casing (2) of the cylinder head (5) being provided by its skirt (3). The cam (8) of the casing (2) is guided so as to be axially movable in the receiving hole (4).
The end face (6) facing in the direction of is closed by the bottom (7) and the tappet interior (8a) is provided with a coaxial guide sleeve (9) for a hydraulic clearance compensating member (12). The guide sleeve (9) is supported on the skirt (3) by an annular web (10) connected to the guide sleeve (9), which is attached to the bottom (7) and the skirt (3). Along with the guide sleeve (9) surrounds the first ring-shaped oil reservoir (14), inside the guide sleeve (9) a second central oil reservoir (15).
In which at least one suction conduit (20, 33) for oil leads from the ring-shaped oil storage chamber (14) to the central oil storage chamber (15). The suction cross-section (21) of (20, 33) corresponds to the inner peripheral surface (1) of the skirt (3).
A tappet with a valve clearance compensation mechanism, characterized in that it is arranged in the region near 1), also in the direction of gravity, near the lowest position of the ring-shaped oil storage chamber (14) . 2. An oil inlet hole (21) in which the suction cross section (21) of the suction conduit (20, 33) leads into the ring-shaped oil storage chamber (14) through the skirt (3) of the tappet (1). 35. The tappet according to claim 1, wherein the tappet is formed so as to be shifted by 180 degrees with respect to 35). 3. A thin ring plate (16) is coaxially arranged on the lower side (13) of the bottom part (7), the ring plate being axially oriented at its outer edge (17). The additional portion (17a) is in contact with the inner peripheral surface (11) of the skirt (3) and is directed axially from the inner edge (18) of the ring plate (16). A protruding additional part (19) projecting, which limits the central oil storage chamber (15) and radially surrounds a part of the guide sleeve (9), and
The suction conduit (20) is connected to the inner peripheral surface (1) of the skirt (3).
Tappet according to claim 1, characterized in that it is formed by at least one passage formed in the ring plate (16) and in the additional part (17a) along with 1) and the underside (13) of the bottom part (7). 4. The clearance compensating member (12) and / or the guide sleeve (9) are surrounded by a cylindrical sheet part (22), both end faces (2) of which are provided.
Radial ring-shaped additional parts (24, 25) extend from the respective (3, 26), and the first radial ring-shaped additional part (24) is provided on the lower side (13) of the bottom part (7). The second radial addition (25) is in contact with the inner peripheral surface (27) of the web (10) and the suction conduit (20) is inside the web (10). Perimeter (27)
2. The tappet according to claim 1, characterized in that it is formed by at least one passage formed in the thin plate part (22) along the outer peripheral surface (29) of the guide sleeve (9). 5. A hollow cylindrical addendum (30) cooperating with a guide sleeve (9) extends from the underside (13) of the bottom part (7) towards the inside of the tappet (8a), At least one suction conduit (33) formed as
2. The tappet according to claim 1, wherein the tappet extends from the central oil storage chamber (15) as a starting point through the addition portion (30) and into the lower region of the ring-shaped oil storage chamber (14). 6. Guide sleeve (9), ring plate (16)
Tappet according to claim 1, 3 or 4, wherein the thin plate portion (22) is made of a lightweight material. 7. The tappet according to claim 1, wherein the casing (2) of the tappet (1) is made of a lightweight material. 8. Tappet according to claim 1, wherein the guide sleeve (9) with the web (10) is formed in the shape of a hopper.