CN213711135U - Variable timing cam follower and valve group and engine provided with same - Google Patents

Abstract

The utility model relates to a variable timing cam follower and be equipped with its valve group, engine belongs to the variable timing technical field of valve. The cam follower comprises a follower body, the follower body is arranged between a tappet and a camshaft, the follower body moves between the tappet and the camshaft, one side, close to the camshaft, of the follower body slides on a cam surface of the camshaft, a curved surface track is arranged on one side, close to the tappet, of the follower body, the tappet slides on the curved surface track, and the position between the tappet and the axis of the camshaft is kept unchanged. The valve group comprises the variable timing cam follower, a tappet and a rocker arm valve group. The engine also includes a camshaft on which a side of the follower body adjacent the camshaft slides. The utility model discloses can adjust in right time the valve of engine, valve clearance remains unchanged in the valve adjustment in right time process, guarantees the reliability and the stationarity of engine in service.

Description

Variable timing cam follower and valve group and engine provided with same

Technical Field

The utility model belongs to the technical field of the variable timing of valve, a variable timing cam follower and be equipped with its valve group, engine is related to.

Background

The application market has higher and higher requirements on the performance of different working conditions, and the emission regulations have stricter and stricter requirements on the emission of the engine. In order to adapt the engine to market demands and to comply with legislative requirements, major engine design and manufacturing companies have in the past introduced high power engines including variable valve technology.

As shown in fig. 1, currently, the valve timing of an engine is usually adjusted by using an engine cam follower, when the engine normally operates, a camshaft 1 rotates, the camshaft 1 drives a tappet 5 to move along a lift direction through a follower body 2, and the tappet 5 realizes the opening and closing of a valve 11 through a push rod 7, a rocker arm 8, a valve bridge 9 and a spring 10. When the valve timing is adjusted, as shown in fig. 2, the eccentric shaft group 6 drives the driven member from a point a around the point O as the rotation center₀Move to a₁The roller 3 is driven by the driven member b₀Move to b₁While the contact point of the push rod 7 is also formed by c₀Move to c₁. After the valve timing is adjusted, the valve opening angle is changed from the angle alpha to the angle beta, the valve timing of beta-alpha is changed, the position of the cam follower in the push rod lifting direction is changed by delta, and the contact point height of the push rod 7 is changed by delta₂And (6) changing. With consequent occurrence of valve lash by₁A change in (c). The variation of the valve clearance influences the reliability and the smoothness of the engine in operation.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model aims at providing a variable timing cam follower and be equipped with its valve group, engine can adjust the valve of engine in right time, and valve clearance keeps unchangeable in the valve adjustment in right time process, guarantees the reliability and the stationarity of engine in service.

In order to achieve the above purpose, the utility model provides a following technical scheme:

the variable timing cam follower comprises a follower body, wherein the follower body is arranged between a tappet and a camshaft, the follower body moves between the tappet and the camshaft, one side, close to the camshaft, of the follower body slides on a cam surface of the camshaft, a curved surface track is arranged on one side, close to the tappet, of the follower body, the tappet slides on the curved surface track, and the position between the tappet and the axis of the camshaft is kept unchanged.

Optionally, the curved track is disposed along a direction of motion of the follower body.

Optionally, a roller is disposed on a side of the follower body that engages with the camshaft, and the follower body slides on the cam surface of the camshaft via the roller.

Optionally, the curved track is disposed at one end of the driven member body, and an eccentric rotating shaft is disposed at the other end of the driven member body, and the eccentric rotating shaft is rotatably connected to an eccentric end of an eccentric shaft group, and the eccentric shaft group drives the driven member body to move between the tappet and the camshaft.

The valve group provided with the variable timing cam follower comprises the variable timing cam follower, a tappet and a rocker arm valve group, wherein one end of the tappet is connected to the rocker arm valve group, and the other end of the tappet slides on a curved track of the variable timing cam follower.

Optionally, a roller is disposed at one end of the tappet close to the curved track, and the tappet slides on the curved track through the roller.

An engine provided with a variable timing cam follower comprises the variable timing cam follower, a tappet and a cam shaft, wherein the variable timing cam follower is arranged between the tappet and the cam shaft, one end of the tappet, which is close to the cam shaft, slides on a curved track, and one side of a follower body, which is close to the cam shaft, slides on a cam surface of the cam shaft.

The beneficial effects of the utility model reside in that: (1) the curved surface track is arranged on one side, close to the tappet, of the driven element, when the valve is adjusted in timing, the driven element body slides relative to the tappet, the tappet slides on the curved surface track, and the curved surface track absorbs displacement of the driven element body in the tappet lift direction, so that the position between the tappet and the axis of the camshaft is kept unchanged, and further, the valve clearance of the engine is kept unchanged in the valve timing adjusting process. (2) The roller is arranged on one side of the driven piece body matched with the cam shaft, the roller is arranged on one end of the tappet matched with the driven piece body, the roller and the roller can reduce friction of the driven piece body when the driven piece body moves between the cam shaft and the tappet, abrasion of the cam shaft, the driven piece body and the tappet is reduced, and valve timing adjustment is more sensitive.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and/or combinations particularly pointed out in the appended claims.

Drawings

For the purposes of promoting a better understanding of the objects, features and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram of a conventional cam follower;

FIG. 2 is a schematic illustration of a conventional cam follower adjusting valve timing process;

FIG. 3 is a schematic structural diagram of a cam follower in this embodiment;

fig. 4 is a schematic diagram of the process of the cam follower adjusting the valve timing in the present embodiment.

Reference numerals: the cam shaft comprises a cam shaft 1, a driven part body 2, a roller 3, a roller 4, a tappet 5, an eccentric rotating shaft 6, a push rod 7, a rocker arm 8, a valve bridge 9, a spring 10, a valve 11, an eccentric shaft group 12 and a curved track 21.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in any way limiting the scope of the invention; for a better understanding of the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc., indicating directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for convenience of description and simplification of description, but it is not intended to indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore, the terms describing the positional relationships in the drawings are only used for illustrative purposes and are not to be construed as limiting the present invention, and those skilled in the art can understand the specific meanings of the terms according to specific situations.

Referring to fig. 3, the valve train with the variable timing cam follower includes the variable timing cam follower, a tappet 5 and a rocker arm valve train. The variable timing cam follower comprises a follower body 2, the follower body 2 is arranged between a tappet 5 and a camshaft 1, and a curved track 21 is arranged on one side of the follower, which is close to the tappet 5. One end of the tappet 5 is connected to the rocker valve group, and the other end of the tappet 5 acts on the curved track 21 of the follower body 2. The follower body 2 moves between the tappet 5 and the camshaft 1, and the curved track 21 is provided along the moving direction of the follower body 2. One side of the follower body 2 close to the camshaft 1 slides on the cam surface of the camshaft 1, the tappet 5 slides on the curved track 21, and the position between the tappet 5 and the axis of the camshaft 1 is kept constant by the curved track 21.

In this embodiment, a roller 4 is disposed at one end of the tappet 5 close to the curved track 21, a roller 3 is disposed at one side of the driven member body 2 matched with the camshaft 1, and the driven member body 2 slides on the cam surface of the camshaft 1 through the roller 3. The tappet 5 slides on the curved track 21 by means of the roller 4. In this embodiment, an eccentric rotating shaft 6 is disposed at an end of the driven member body 2 away from the curved track 21, the driven member body 2 is rotatably connected to an eccentric end of the eccentric shaft group 12 through the eccentric rotating shaft 6, and the eccentric shaft group 12 drives the driven member body 2 to move between the tappet 5 and the camshaft 1 during valve timing adjustment. Be provided with roller 3 on follower body 2 and camshaft 1 complex one side, tappet 5 and follower body 2 complex one serve and be provided with gyro wheel 4, and the friction of follower body 2 when moving between camshaft 1 and tappet 5 can be reduced to gyro wheel 4 and roller 3, reduces the wearing and tearing between camshaft 1, follower body 2 and the tappet 5, makes the valve timing adjust more sensitive.

The curved surface track 21 is a fitting curved surface, and the track of the fitting curved surface is the motion track of the tappet 5 relative to the axis of the roller 4 when the eccentric shaft group 12 rotates. In the process of fitting the curved surface track 21, the axis O of the eccentric shaft group 12₁Axial center O of camshaft 1₂And the position between the tappets 5 remains unchanged. When the eccentric shaft group 12 rotates for a certain angle, the eccentric shaft group 12 drives the roller 4 of the driven member body 2 to slide on the cam surface of the camshaft 1. Since the profile of the cam surface is known and the relative position between the eccentric rotary shaft 6 and the axis of the roller 4 is known, an eccentric shaft can be obtainedWhen the group 12 rotates by a certain angle, the position of the axis of the roller 4 is maintained, and the position of the tappet 5 relative to the axis of the roller 4 can be obtained because the position of the tappet 5 is kept unchanged. The eccentric shaft group 12 rotates a plurality of angles in sequence to obtain the motion track of the tappet 5 relative to the axis of the roller 4, and the track is the track of the curved track 21.

Referring to fig. 4, when the valve timing is actually adjusted, the rotation angle γ of the eccentric shaft set 12 is determined, and the axial positions of the eccentric shafts 6 are sequentially a during the rotation of the eccentric shaft set 12₀、A₁、A₂The eccentric shaft group 12 drives the follower body 2 to move between the tappet 5 and the camshaft 1, and the roller 3 rolls in contact with the cam surface of the camshaft 1, thereby adjusting the phase angle of the valve timing by θ. During the rolling process of the roller 3, the axes of the roller 3 are sequentially F₀、F₁、F₂The displacement amount of the axial center of the roller 3 in the lifter 5 lift direction is Δ. The roller 4 on the tappet 5 slides on the curved track 21, and the contact points of the roller 4 and the curved track 21 are G in sequence₀、G₁、G₂. Because the curved surface track 21 is a fitting curved surface, the curved surface track 21 absorbs the displacement of the follower body 2 in the lift direction, so that the relative position between the tappet 5 and the axis of the camshaft 1 is kept unchanged, the distance between the axis of the roller 4 and the axis of the camshaft 1 in the lift direction of the tappet 5 is always H, and further, in the valve timing adjustment process, the valve clearance delta 1 of the engine is kept unchanged.

Meanwhile, the tappet 5 is in sliding connection with the curved track 21, and when the valve is adjusted in timing, the tappet 5 cannot move along with the driven part body 2, so that the swing range of the tappet 5 and the push rod 7 is reduced, the size of a push rod sealing sleeve can be reduced, and the simplification of the structure and the size of an engine is facilitated.

Finally, the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the scope of the claims of the present invention.

Claims (7)

1. The utility model provides a variable timing cam follower, includes the follower body, the follower body sets up between tappet and camshaft, its characterized in that: the tappet slides on the curved surface track, and the position between the tappet and the axis of the camshaft is kept unchanged.

2. A variable timing cam follower according to claim 1, wherein: the curved surface track is arranged along the motion direction of the driven member body.

3. A variable timing cam follower according to claim 1, wherein: and a roller is arranged on one side of the driven part body matched with the camshaft, and the driven part body slides on the cam surface of the camshaft through the roller.

4. A variable timing cam follower according to claim 1, wherein: the curved surface track is arranged at one end of the driven piece body, an eccentric rotating shaft is arranged at the other end of the driven piece body, the eccentric rotating shaft is rotatably connected to the eccentric end of the eccentric shaft group, and the eccentric shaft group drives the driven piece body to move between the tappet and the camshaft.

5. A valve train provided with a variable timing cam follower, characterized in that: comprising the variable timing cam follower according to any of claims 1-4, further comprising a tappet and a rocker arm valve set, one end of the tappet being connected to the rocker arm valve set, the other end of the tappet sliding on a curved track of the variable timing cam follower.

6. A valve train provided with a variable timing cam follower as claimed in claim 5, wherein: and one end of the tappet, which is close to the curved surface track, is provided with a roller, and the tappet slides on the curved surface track through the roller.

7. An engine provided with a variable timing cam follower, characterized in that: comprising the variable timing cam follower according to any one of claims 1 to 4, further comprising a tappet and a camshaft, the variable timing cam follower being disposed between the tappet and the camshaft, the tappet sliding on a curved track near one end of the camshaft, and a side of the follower body near the camshaft sliding on a cam surface of the camshaft.

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