CN220979593U

CN220979593U - Cam follower capable of adjusting valve timing

Info

Publication number: CN220979593U
Application number: CN202322566248.1U
Authority: CN
Inventors: 康纳新; 李文达; 牛军军
Original assignee: China Shipbuilding Power Engineering Institute Co Ltd
Current assignee: China Shipbuilding Power Engineering Institute Co Ltd
Priority date: 2023-09-20
Filing date: 2023-09-20
Publication date: 2024-05-17
Anticipated expiration: 2033-09-20

Abstract

The utility model relates to a cam follower capable of adjusting valve timing, which relates to the field of marine diesel engines and comprises a coupling body, eccentric follow-up shafts arranged on two sides of the coupling body, and covers sleeved with the eccentric follow-up shafts and detachably connected with the coupling body. The utility model realizes the adjustment of the valve timing by using the eccentric follow-up shaft, and simultaneously, the follow-up shafts of the cylinders are connected by the split type coupling, so that the valve timing of each cylinder can be respectively and independently adjusted.

Description

Cam follower capable of adjusting valve timing

Technical Field

The utility model relates to the field of marine diesel engines, in particular to a cam follower capable of adjusting valve timing.

Background

In order to obtain better intake and exhaust performance of the engine, the valve timing should be changed along with the change of the load and the rotating speed, and when the rotating speed and the load are higher, a larger valve overlap angle is needed to improve the output power; at lower speeds and loads, however, there is a need to reduce the valve overlap angle, thereby improving emissions performance.

In recent years, a variable valve timing technology is applied to the field of valve timing of marine internal combustion engines, and the valve timing is usually adjusted by using an eccentric follower shaft, and the contact point between a roller follower and an intake cam is changed by rotating the eccentric follower shaft, so that the opening time of the intake valve is changed, and the valve overlap angle is further adjusted.

In general, the follower shaft is installed inside the engine body, and is often integrated, and for a multi-cylinder engine, when the follower shaft rotates for a certain angle, the variation of the valve timing of each cylinder is different, and independent adjustment cannot be realized.

Disclosure of utility model

The purpose of the utility model is that: a cam follower is provided that can adjust valve timing for each cylinder separately.

In order to achieve the above purpose, the technical scheme of the utility model provides a cam follower capable of adjusting valve timing, which comprises a coupling body, eccentric follow-up shafts arranged on two sides of the coupling body, and a cover cap sleeved with the eccentric follow-up shafts and detachably connected with the coupling body.

Preferably, the roller follower swings about the eccentric follower shaft, which is stationary.

Preferably, a radial gap exists between the cover and the coupling body.

Preferably, the cover is connected with the coupling body by bolts.

Preferably, the bolts are vertically arranged.

Preferably, the cover cap is provided with a counter bore, and the coupling body is correspondingly provided with a bolt hole.

Preferably, the two eccentric follower shafts are respectively provided with the roller followers, and the two roller followers are respectively connected with the two cams.

Preferably, both of said cams are located on the same camshaft.

Preferably, the eccentric follow-up shaft and the coupling body are correspondingly provided with key grooves.

Preferably, the key groove may be provided with a flat key.

The utility model has the beneficial effects that: the valve timing adjustment is realized by using the eccentric follow-up shaft, and meanwhile, the follow-up shafts of the cylinders are connected through split couplings, so that the valve timing of each cylinder can be independently adjusted.

Drawings

FIG. 1 is a schematic side cross-sectional view of a cam follower with adjustable valve timing according to the present utility model;

FIG. 2 is a schematic perspective view of a cam follower with adjustable valve timing according to the present utility model;

FIG. 3 is a schematic illustration of the coupling body, eccentric follower shaft and cover connections in a cam follower with adjustable valve timing in accordance with the present utility model;

FIG. 4 is a schematic illustration of the connection of the coupler body, cover, bolts and flat keys in a cam follower with adjustable valve timing according to the present utility model;

fig. 5 is a schematic diagram showing the connection of the coupling body, the cover, the bolt and the flat key in the cam follower with adjustable valve timing according to the present utility model.

Reference numerals: 1. a cam; 2. an eccentric follower shaft; 3. a roller follower; 4. a bolt; 5. a flat key; 6. a coupling body; 7. a cover cap; 9. a split coupling.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Aiming at a valve mechanism of a marine diesel engine, the embodiment of the utility model discloses a cam follower capable of adjusting valve timing.

As shown in fig. 1, the marine diesel engine adopts a lower camshaft type, a valve mechanism of the marine diesel engine comprises a cam 1, an eccentric follower shaft 2 and a roller follower 3, and when the engine works normally, a transmission chain of the valve mechanism is a camshaft-roller follower 3-tappet-rocker arm-valve spring-valve, wherein the roller follower 3 swings around the eccentric follower shaft 2, and the eccentric follower shaft 2 is fixed.

When the valve timing is adjusted, the eccentric follower shaft 2 rotates from a0 point to a1 point, the contact point of the roller follower 3 and the cam 1 moves from a b0 point to a b1 point, and the valve timing changes by an angle delta, so that the valve timing adjustment is realized. However, the respective cylinder cams 1 have a phase difference due to the difference in ignition timing. The eccentric follower shaft 2 rotates by the same angle, and the change angle delta of the valve timing of each cylinder is different. For independently adjusting the valve timing of each cylinder, each cylinder is provided with a follow-up shaft, and the follow-up shafts of adjacent cylinders are connected through split couplings 9, and the specific structure is shown in fig. 2.

The two-half coupling comprises a coupling body 6 and two covers 7, countersunk holes are formed in the covers 7, bolt holes matched with the countersunk holes are formed in the coupling body 6, the coupling body 6 is connected with the covers 7 through bolts 4, and key grooves are formed in the eccentric follow-up shaft 2 and the coupling body 6 and used for installing the flat keys 5. When the engine works normally, the bolts 4 are screwed down, the two covers 7 respectively compress the eccentric follow-up shafts 2 of the adjacent cylinders, and a radial gap exists between the covers 7 and the coupling body 6 during compression. When the valve timing needs to be adjusted, the bolt 4 is loosened, and the eccentric follower shaft 2 can freely rotate.

Finally, it should be noted that: the foregoing description of the preferred embodiments of the present utility model is not intended to be limiting, but rather, although the present utility model has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof, and any modifications, equivalents, improvements or changes may be made without departing from the spirit and principles of the present utility model.

Claims

1. The cam follower capable of adjusting the valve timing is characterized by comprising a coupler body (6), eccentric follow-up shafts (2) arranged on two sides of the coupler body (6), and covers (7) sleeved on the eccentric follow-up shafts (2) and detachably connected with the coupler body (6).

2. A cam follower with adjustable valve timing according to claim 1, characterized in that the roller follower (3) swings around the eccentric follower shaft (2), the eccentric follower shaft (2) being stationary.

3. A cam follower with adjustable valve timing according to claim 2, characterized in that a radial gap exists between the cover (7) and the coupling body (6).

4. A cam follower with adjustable valve timing according to claim 3, characterized in that the cover (7) is connected with the coupling body (6) with bolts (4).

5. A cam follower with adjustable valve timing according to claim 4, characterized in that the bolt (4) is arranged vertically.

6. The cam follower with adjustable valve timing according to claim 5, wherein the cover (7) is provided with a countersunk hole, and the coupling body (6) is correspondingly provided with a bolt hole.

7. A cam follower with adjustable valve timing according to claim 3, characterized in that two of said eccentric follower shafts (2) are provided with said roller followers (3) respectively, and that two of said roller followers (3) are connected to two cams (1) respectively.

8. A cam follower with adjustable valve timing according to claim 7, characterized in that both cams (1) are located on the same camshaft.

9. A cam follower with adjustable valve timing according to claim 3, characterized in that the eccentric follower shaft (2) and the coupling body (6) are provided with keyways, respectively.

10. A cam follower with adjustable valve timing according to claim 9, characterized in that said key way is provided with a flat key (5).