CN211174260U

CN211174260U - Camshaft starting pressure reducing mechanism

Info

Publication number: CN211174260U
Application number: CN201921463349.3U
Authority: CN
Inventors: 刘丽美; 王雪雁; 张立鹏
Original assignee: Tianjin Internal Combustion Engine Research Institute (tianjin Motorcycle Technical Center)
Current assignee: Tianjin Internal Combustion Engine Research Institute (tianjin Motorcycle Technical Center)
Priority date: 2019-09-04
Filing date: 2019-09-04
Publication date: 2020-08-04
Anticipated expiration: 2029-09-04

Abstract

The utility model discloses a camshaft starting pressure reducing mechanism, which comprises a camshaft, an air inlet cam, a disc, a pressure reducing transmission assembly and a pressure reducing piece, wherein the pressure reducing piece is arranged on the air inlet cam, an air inlet valve can be opened or closed, and the pressure of an air cylinder is reduced by opening the air inlet valve, thereby being beneficial to starting an engine; after the engine is started, the normal work of the engine is not influenced by closing the inlet valve; the pressure reduction transmission assembly comprises an inner column, a throwing plate and an elastic piece, wherein the throwing plate and the elastic piece drive the inner column to rotate; the cam shaft is provided with a disc which can drive the throwing plate to rotate; the throwing plate and the disc can keep relatively static at a certain rotating speed by arranging the elastic piece; the utility model discloses simple structure, the part is less, easily assembly.

Description

Camshaft starting pressure reducing mechanism

Technical Field

The utility model belongs to the technical field of engine starting device, especially, relate to a camshaft starts mechanism of decompressing.

Background

When the engine is started, the piston moves upwards to compress air in the cylinder under the condition that the intake valve and the exhaust valve are closed, and the gas pressure in the cylinder is very high near the compression end point, so that the starting is very difficult and laborious. If the pressure of the gas in the cylinder cannot be overcome, the phenomenon of rebounding and wrecking can occur, and even the personal safety of a user is endangered. Therefore, there is a need for a pressure reducing mechanism for engine starting, which is used to reduce the cylinder pressure and the pressure reducing function can be automatically eliminated after the engine is started, without affecting the normal operation of the engine.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a camshaft starts mechanism of decompressing can reduce the jar and press, and after the engine start was accomplished, the decompression function can disappear automatically, does not influence the engine and normally works.

A camshaft starting decompression mechanism comprises a camshaft and an air inlet cam arranged on the camshaft, and further comprises:

the disc is arranged on the camshaft;

the decompression transmission assembly comprises an inner column, a throwing plate and an elastic piece, wherein an axial inner hole is formed in the center of the camshaft, the inner column is arranged in the inner hole, one end of the throwing plate is hinged with the surface of the disc, one end of the elastic piece is installed on the surface of the disc, the other end of the throwing plate is connected with the other end of the elastic piece, and the throwing plate is connected with the inner column through a pin and used for driving the inner column to rotate;

the decompression piece is arranged on the base circular surface of the air inlet cam and can extend out or into the base circular surface of the air inlet cam under the driving of the inner column.

Preferably, in the above technical scheme, the pressure reduction part is a ball, a limit hole communicated with the inner hole is arranged on the base circle surface of the intake cam, the axis of the limit hole and the axis of the camshaft incline at a certain angle, the ball is arranged in the limit hole, and one end of the limit hole, which is far away from the inner hole, can limit the ball to be separated from the limit hole from one end, which is far away from the inner hole.

Above technical scheme is preferred, the inner prop is cylindricly, on the inner prop with the position that spacing hole corresponds is equipped with the grooving, the grooving includes two relative cell walls and connect in the tank bottom between the groove wall, two the cell wall all with the terminal surface of inner prop is parallel, the tank bottom of grooving with the axis of inner prop is parallel.

Above technical scheme is preferred, be equipped with on the camshaft with the spout of hole intercommunication, the spout with the axis of camshaft is perpendicular, the one end of pin with get rid of the board and be connected, the other end of pin passes the spout with interior post link.

Preferably, in the above technical solution, the elastic member is a tension spring.

The utility model has the advantages and positive effects that: the utility model provides a camshaft starting pressure reducing mechanism, which comprises a camshaft, an air inlet cam, a disc, a pressure reducing transmission assembly and a pressure reducing piece, wherein the pressure reducing piece is arranged on the air inlet cam, an air inlet valve can be opened or closed, and the pressure of an air cylinder is reduced by opening the air inlet valve, thereby being beneficial to starting an engine; after the engine is started, the normal work of the engine is not influenced by closing the inlet valve; the pressure reduction transmission assembly comprises an inner column, a throwing plate and an elastic piece, wherein the throwing plate and the elastic piece drive the inner column to rotate; the cam shaft is provided with a disc which can drive the throwing plate to rotate; the throwing plate and the disc can keep relatively static at a certain rotating speed by arranging the elastic piece; the utility model discloses simple structure, the part is less, easily assembly.

Drawings

Fig. 1 is a half-sectional view of a camshaft starting decompression mechanism according to an embodiment of the present invention;

fig. 2 is a left side view of a camshaft activated pressure relief mechanism provided in accordance with an embodiment of the present invention;

FIG. 3 is a cross-sectional view B-B of FIG. 1 prior to priming;

fig. 4 is a cross-sectional view B-B of fig. 1 after priming.

Wherein: 1. a camshaft; 2. an intake cam; 3. a disc; 4. a pressure reduction member; 5. an inner column; 6. throwing the plate; 7. an elastic member; 8. riveting; 9. a pin; 10. macropores; 11. a small hole; 12. grooving; 13. a chute.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The embodiment provides a camshaft starting pressure reducing mechanism, as shown in fig. 1-4, which comprises a camshaft 1, an intake cam 2, a disc 3, a pressure reducing transmission assembly and a pressure reducing part 4, wherein the intake cam 2 and the disc 3 are both arranged on the camshaft 1 and can rotate together with the camshaft 1. The decompression transmission assembly comprises an inner column 5, a throwing plate 6 and an elastic piece 7, an axial inner hole is formed in the center of the camshaft 1, the inner column 5 is arranged in the inner hole, and one end of the throwing plate 6 is hinged with the surface of the disc 3 and is connected with the surface of the disc 3 through a rivet 8 for example; one end of the elastic part 7 is arranged on the surface of the disc 3, the other end of the throwing plate 6 is connected with the other end of the elastic part 7, and the throwing plate 6 is connected with the inner column 5 through a pin 9 and used for driving the inner column 5 to rotate; in this embodiment, the throwing plate 6 is crescent-shaped, the outer portion of the other end of the throwing plate 6 is connected with the other end of the elastic member 7, and the inner portion of the other end of the throwing plate 6 is connected with the pin 9. The decompression piece 4 is arranged on the base circle surface of the intake cam 2, and the decompression piece 4 can extend out or into the base circle surface of the intake cam 2 under the driving of the inner column 5, so that the intake valve is opened or closed.

The decompression spare 4 is the ball, is equipped with the spacing hole with the hole intercommunication on the base circle of the cam 2 that admits air, and the axis in spacing hole and the certain angle of camshaft 1's axis slope, the ball is located spacing downtheholely, and the one end that the hole was kept away from in spacing hole can restrict the ball and deviate from spacing hole by the one end of keeping away from the hole. The specific limiting hole comprises a large hole 10 and a small hole 11. The size of the big hole 10 is larger than or equal to the diameter of the ball, and the big hole 10 is communicated with the inner hole. The size of the small hole 11 is smaller than the diameter of the ball, so that the small hole 11 can limit the ball to be separated from the limiting hole outwards.

The inner column 5 is cylindric, and the position that corresponds with spacing hole on the inner column 5 is equipped with grooving 12, and grooving 12 includes two relative cell walls and connects the tank bottom between the groove wall, and two cell walls all are parallel with the terminal surface of inner column 5, and the tank bottom of grooving 12 is parallel with the axis of inner column 5. The depth of the slot 12 ensures that the ball will not protrude from the base circle surface of the intake cam 2 when the ball is dropped into the slot 12.

The camshaft 1 is provided with a sliding groove 13 communicated with the inner hole, the sliding groove 13 is vertical to the axis of the camshaft 1, one end of a pin 9 is connected with the throwing plate 6, and the other end of the pin 9 penetrates through the sliding groove 13 to be connected with the inner column 5. The elastic member 7 is a tension spring and can apply tension to the flail plate 6.

The working process of the embodiment: the decompression structure is mainly arranged at the intake cam 2. When the engine is started, the throwing plate 6 is kept relatively static with the camshaft 1 under the stretching action of the tension spring, as shown in figure 3, the surface outside the upper cutting groove 12 of the inner column 5 is contacted with the ball, the ball is jacked up and extends out of the base circle surface of the intake cam 2, the protruding ball on the profile surface of the intake cam 2 enables the intake valve to keep an opening state within a certain cam rotation angle range after the compression top dead center, and in this state, the inner column 5 and the ball are kept relatively static; along with the increase of the rotating speed of the engine, the centrifugal force of the throwing plate 6 is greater than the tension of the tension spring, the throwing plate 6 rotates along the sliding groove 13 by taking the hinged part with the disc 3 as the center of a circle, and the pin 9 drives the inner column 5 concentric with the camshaft 1 to rotate; when the rotating speed of the camshaft 1 reaches a certain value, the centrifugal force of the throwing plate 6 overcomes the pulling force of the tension spring and rotates to the maximum throwing position of the throwing plate 6, at the moment, the throwing plate 6 is limited by the sliding groove 13 and does not rotate along the sliding groove 13, at the moment, as shown in figure 4, the protruding ball on the base circular surface of the intake cam 2 moves downwards along with the cutting groove 12 on the inner column 5, the starting and the pressure reduction are completed, and the engine works normally; after the engine is stopped, the throwing plate 6 and the inner column 5 are restored to the previous state under the action of the tension spring, so that the ball extends out of the base circle surface of the air inlet cam 2 to wait for the next engine starting.

The starting decompression mechanism of the camshaft 1 provided by the embodiment comprises the camshaft 1, an air inlet cam 2, a disc 3, a decompression transmission assembly and a decompression piece 4, wherein the decompression piece 4 is arranged on the air inlet cam 2, so that an air inlet valve can be opened or closed, the air pressure of an air cylinder is reduced by opening the air inlet valve, and the starting of an engine is facilitated; after the engine is started, the normal work of the engine is not influenced by closing the inlet valve; the pressure reducing transmission assembly comprises an inner column 5, a throwing plate 6 and an elastic piece 7, wherein the throwing plate 6 drives the inner column 5 to rotate, and the inner column 5 can control the pressure reducing piece 4 to extend out of or into the air inlet cam 2; the camshaft 1 is provided with a disc 3 which can drive a throwing plate 6 to rotate; the elastic piece 7 is arranged, so that the throwing plate 6 and the disc 3 can keep relatively static at a certain rotating speed; the embodiment has the advantages of simple structure, fewer parts and easiness in assembly.

While one embodiment of the present invention has been described in detail, the description is only a preferred embodiment of the present invention, and should not be considered as limiting the scope of the present invention. All the equivalent changes and improvements made according to the application scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A camshaft starting decompression mechanism comprises a camshaft and an air inlet cam arranged on the camshaft, and is characterized by further comprising:

the disc is arranged on the camshaft;

2. The camshaft activated pressure relief mechanism of claim 1 wherein: the pressure reducing piece is a ball, a limiting hole communicated with the inner hole is formed in the base circle surface of the air inlet cam, the axis of the limiting hole and the axis of the cam shaft incline for a certain angle, the ball is arranged in the limiting hole, and one end, far away from the inner hole, of the limiting hole can limit the ball to be separated from the limiting hole from one end, far away from the inner hole.

3. The camshaft activated pressure relief mechanism of claim 2 wherein: the inner column is cylindrical, a cutting groove is formed in the position, corresponding to the limiting hole, of the inner column, the cutting groove comprises two opposite groove walls and a groove bottom connected between the groove walls, the two groove walls are parallel to the end face of the inner column, and the groove bottom of the cutting groove is parallel to the axis of the inner column.

4. The camshaft activated pressure relief mechanism of claim 1 wherein: the camshaft is provided with a chute communicated with the inner hole, the chute is perpendicular to the axis of the camshaft, one end of the pin is connected with the throwing plate, and the other end of the pin penetrates through the chute and is connected with the inner column.

5. The camshaft activated pressure relief mechanism of claim 1 wherein: the elastic piece is a tension spring.