CN211924268U - Camshaft structure for engine - Google Patents

Abstract

The utility model provides a camshaft structure for engine relates to vehicle engine technical field. The camshaft structure comprises a camshaft and a plurality of cam groups sleeved on the camshaft, wherein each cam group comprises a first cam, a third cam and a second cam which are sequentially sleeved on the camshaft, and the cam groups can be controlled to move along the axial direction of the camshaft so as to allow one of the first cam, the second cam and the third cam to be adjusted to a position corresponding to a valve of the engine; and the distance between the circle center of the first cam and the highest point of the first cam, the distance between the circle center of the second cam and the highest point of the second cam and the distance between the circle center of the third cam and the highest point of the third cam are different. The utility model provides a camshaft structure can reduce pollutant discharge and promote engine fuel economy.

Description

Camshaft structure for engine

Technical Field

The utility model relates to the technical field of engines, especially, relate to a camshaft structure for engine.

Background

In the prior art, the traditional engine adopting an Otto cycle combustion mode can meet the power demand of a vehicle under high-speed working conditions, but the traditional engine has poor fuel economy and more discharged pollutants, and the traditional engine is eliminated along with the strictness of various policies such as pollutant discharge and oil consumption regulations of the engine (internal combustion engine).

Therefore, it is a mainstream trend of current development to develop an engine that can meet the power demand of the vehicle at medium and high speeds, and can reduce pollutant emissions and improve fuel economy at low speed.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a can reduce pollutant emission and promote engine fuel economy's camshaft structure for engine.

A further object of the present invention is to provide a camshaft structure for an engine that is simple in structure.

The utility model provides a camshaft structure for engine, establish including camshaft and cover a plurality of cam groups on the camshaft, every the cam group all includes the first cam, third cam and the second cam that establish on the camshaft in proper order in the cover, wherein a plurality of the cam groups all can be controlled along the axial displacement of camshaft to allow one of the first cam, the second cam and the third cam to adjust to the position that corresponds with the valve of engine; and is

The distance between the circle center of the first cam and the highest point of the first cam, the distance between the circle center of the second cam and the highest point of the second cam and the distance between the circle center of the third cam and the highest point of the third cam are different.

Optionally, a distance between the center of the second cam and the highest point of the second cam is greater than a distance between the center of the first cam and the highest point of the first cam and is smaller than a distance between the center of the third cam and the highest point of the third cam.

Optionally, the camshaft structure further includes:

the number of the locking pins is the same as that of the cam groups;

the center of the camshaft penetrates through the camshaft along the axial direction of the camshaft to form an oil duct, the oil duct comprises a first end and a second end which are opposite, the first end is provided with a one-way valve, and the second end is provided with a pressure release valve;

the camshaft is also provided with a plurality of through holes which penetrate along the radial direction of the camshaft, and the locking pin is arranged in the through holes;

and the inner sides of the first cam, the second cam and the third cam are respectively provided with a first locking groove, a second locking groove and a third locking groove which are matched with the locking pin at positions corresponding to the through holes.

Optionally, the first locking groove, the second locking groove and the third locking groove are all hemispherical;

the shape of the position where the lock pin is fitted with the first lock groove, the second lock groove and the third lock groove is the same as the shape of the first lock groove, the second lock groove and the third lock groove.

Optionally, the camshaft structure further includes:

and the execution motor is connected with the cam group and used for providing power for the cam group to move along the axial direction of the cam shaft.

Optionally, the camshaft structure further includes:

and one end of the clamping jaw is connected with the execution motor, and the other end of the clamping jaw is connected with the cam group.

Optionally, a plurality of guide bosses are arranged on the outer wall of the cam shaft, and a plurality of guide grooves which are matched with the guide bosses and have the same number with the guide bosses are arranged on the inner walls of the first cam, the second cam and the third cam.

Optionally, the number of the guide grooves and the number of the guide bosses both exceed 1.

Optionally, the number of the guide grooves and the number of the guide bosses are both 6.

Optionally, the first cam is in the shape of a circular ring.

The utility model discloses a camshaft structure that scheme provided includes camshaft and a plurality of cam group. Each cam set includes a first cam, a second cam, and a third cam. Each cam set is controllably movable in an axial direction of the camshaft to allow one of the first, second and third cams to be adjusted to a position corresponding to a valve of the engine. And the distance between the circle center of the first cam and the highest point of the first cam, the distance between the circle center of the second cam and the highest point of the second cam and the distance between the circle center of the third cam and the highest point of the third cam are different. The lift of the valve is adjusted by adjusting the relative positions of the first cam, the second cam and the third cam and the valve, specifically, when the vehicle stops (or starts), the cam with the minimum distance between the highest point and the circle center is adjusted to the position corresponding to the valve, so that the lift of the valve is shortest, and the engine is stopped; when the vehicle runs at a low speed, the cam with the highest point and the center distance between the centers of circles is adjusted to the position corresponding to the valve, so that the valve lift is centered, and the engine runs at a low speed at the moment and adopts an Atkinson cycle; when the vehicle runs at a high speed, the cam with the maximum distance between the highest point and the circle center is adjusted to the position corresponding to the valve, so that the valve lift is the longest, and the engine runs at the high speed at the moment and adopts the Otto cycle. Therefore, the rotating speed of the engine can correspond to the actual power demand of the vehicle, and therefore pollutant emission is reduced and fuel economy is improved.

Further, the camshaft structure further includes a lock pin for locking the first cam, the second cam, or the third cam. The locking pin is pushed to move towards the direction of the cam group in a hydraulic mode, liquid (preferably oil) enters the oil channel through the one-way valve, and the pressure in the oil channel is larger than a first preset pressure, wherein the first preset pressure is capable of pushing the locking pin to move towards the direction of the cam group, but is not enough to trigger the pressure release valve. When it is necessary to switch from one cam to another cam, for example, from a first cam to a second cam, the control cam group moves in the axial direction of the cam shaft, specifically, moves leftwards or rightwards depending on the relative positions of the first cam, the second cam and the third cam, for example, when the first cam is placed at the right of the second cam, the control cam group moves leftwards, and conversely, moves rightwards, that is, which cam is necessary to switch to move the cam to the position corresponding to the locking pin. Along with the removal of cam group, the locking round pin receives the extrusion and removes to the center of camshaft, make the hydraulic pressure in the oil duct rise, along with the gradual rise of hydraulic pressure, the relief valve is triggered, hydraulic pressure reduces, the locking round pin continues to remove to the center of camshaft, then the disconnection of locking round pin and first locking groove, and then first cam just not spacing, the cam group continues to remove until the second cam removes to the position back corresponding with the locking round pin, the rethread increases the liquid in the oil duct and promotes hydraulic pressure, make the locking round pin move to the card second locking groove of going into to the direction of cam group, accomplish the switching promptly. The camshaft is simple in structure, few in parts and simple in transmission, and the fuel state of the engine can be switched only through movement of the locking pin.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present invention will be described in detail hereinafter, by way of illustration and not by way of limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

fig. 1 is a schematic structural view of a camshaft structure for an engine according to an embodiment of the present invention;

fig. 2 is a schematic sectional structure view of a camshaft structure for an engine according to an embodiment of the present invention;

fig. 3 is a schematic sectional structure view of a camshaft structure for an engine according to another embodiment of the present invention;

fig. 4 is a schematic structural view of a second cam of the camshaft structure for an engine according to an embodiment of the present invention;

fig. 5 is a schematic structural view of a camshaft structure for an engine according to an embodiment of the present invention.

Detailed Description

Fig. 1 is a schematic structural view of a camshaft structure for an engine according to an embodiment of the present invention. Fig. 2 is a schematic sectional structure view of a camshaft structure for an engine according to an embodiment of the present invention. As shown in fig. 1, the present invention provides a camshaft structure for an engine, which generally includes a camshaft 10 and a plurality of cam groups 20 sleeved on the camshaft 10. Each cam group 20 includes a first cam 21, a third cam 23 and a second cam 22 which are sequentially sleeved on the camshaft 10. The distance between the center of the first cam 21 and the highest point of the first cam 21, the distance between the center of the second cam 22 and the highest point of the second cam 22, and the distance between the center of the third cam 23 and the highest point of the third cam 23 are different. Wherein each of the plurality of cam groups 20 is controllably movable in the axial direction of the camshaft 10 to allow one of the first cam 21, the second cam 22, and the third cam 23 to be adjusted to a position corresponding to the valve 60 of the engine.

The present embodiment provides a camshaft structure including a camshaft 10 and a plurality of cam groups 20. Each cam set 20 includes a first cam 21, a second cam 22, and a third cam 23. Each cam group 20 is controllably movable in the axial direction of the camshaft 10 to allow one of the first cam 21, the second cam 22, and the third cam 23 to be adjusted to a position corresponding to the valve 60 of the engine. And the distance between the center of the first cam 21 and the highest point of the first cam 21, the distance between the center of the second cam 22 and the highest point of the second cam 22, and the distance between the center of the third cam 23 and the highest point of the third cam 23 are different. Adjusting the lift of the valve 60 by adjusting the relative positions of the first cam 21, the second cam 22 and the third cam 23 and the valve 60, specifically, when the vehicle is stopped (or in a starting state), adjusting the cam with the minimum distance between the highest point and the circle center at the position corresponding to the valve 60 to make the lift of the valve 60 the shortest, and at the moment, stopping the engine; when the vehicle runs at a low speed, the cam with the highest point and the center distance between the centers of circles is adjusted to the position corresponding to the valve 60, so that the lift of the valve 60 is centered, and at the moment, the engine runs at a low speed and adopts an Atkinson cycle; when the vehicle runs at a high speed, the cam with the maximum distance between the highest point and the circle center is adjusted to the position corresponding to the valve 60, so that the lift of the valve 60 is the longest, and at the moment, the engine runs at the high speed and adopts the Otto cycle. Therefore, the rotating speed of the engine can correspond to the actual power demand of the vehicle, and therefore pollutant emission is reduced and fuel economy is improved.

The free switching of the engine among the cylinder deactivation mode, the Atkinson cycle and the Otto cycle can be realized by controlling the axial movement of the cam group 20 along the camshaft 10, and the requirements of customers on driving dynamic property can be met by using the Atkinson cycle at low speed, the Otto cycle at high speed and the cylinder deactivation mode at partial rotating speed, and the fuel economy of the engine can be greatly improved and the pollutant emission can be reduced. Of course, those skilled in the art will understand that the solution provided by the present embodiment can also make the engine have more operation modes by increasing the number of cams in the cam group 20, and the concept formed by this way should fall within the protection scope of the present invention.

Preferably, the plurality of cam groups 20 arranged on the same camshaft 10 can be controlled individually in a specific manner, for example, each cam group 20 is connected with a control mechanism individually, so that the plurality of cam groups 20 can be controlled separately, the lift of the plurality of valves 60 corresponding to the same camshaft 10 can be made different, for example, the first cam 21 in one or some of the cam groups 20 can be controlled to adjust to the position of the corresponding valve 60, at this time, the intake and exhaust of one or some of the valves 60 are closed, and the fuel injection and ignition of the engine are controlled by the engine controller of the vehicle, so that the number of working cylinders can be reduced, the displacement of the engine is reduced, and the fuel economy is further improved.

Specifically, the number of the cam groups 20 may be increased or decreased according to the actual condition of the engine, and the present invention is not limited to the number thereof, and the number thereof preferably corresponds to the number of the valves 60 of the engine.

In a specific embodiment, the distance between the center of the second cam 22 and the highest point of the second cam 22 is greater than the distance between the center of the first cam 21 and the highest point of the first cam 21 and less than the distance between the center of the third cam 23 and the highest point of the third cam 23.

As shown in fig. 2, the camshaft structure further includes locking pins 30, the same number as the cam blocks 20. The center of the camshaft 10 penetrates through the oil passage 11 along the axial direction thereof, the oil passage 11 comprises a first end and a second end which are opposite to each other, the first end is provided with a one-way valve 12, and the second end is provided with a pressure release valve 13. The camshaft 10 is further provided with a plurality of through holes 14 penetrating in the radial direction of the camshaft 10, and the lock pins 30 are provided in the through holes 14, and the number of the through holes 14 is the same as the number of the cam groups 20. First, second, and third lock grooves 211, 221, and 231 that engage with the lock pin 30 are formed in positions corresponding to the through-holes 14 on the inner sides of the first, second, and third cams 21, 22, and 23, respectively.

In this embodiment, the camshaft structure further includes a lock pin 30 for locking the first cam 21, the second cam 22, or the third cam 23. By hydraulically pushing the locking pin 30 in the direction of the cam pack 20, a fluid (preferably oil) enters the oil channel 11 through the check valve 12, so that the pressure in the oil channel 11 is greater than a first predetermined pressure, which is sufficient to push the locking pin 30 in the direction of the cam pack 20, but is insufficient to trigger the relief valve 13. When it is necessary to switch from one cam to another, such as from the first cam 21 to the second cam 22, the control cam group 20 moves in the axial direction of the camshaft 10, specifically, moves to the left or to the right depending on the relative positions of the first cam 21, the second cam 22 and the third cam 23, for example, when the first cam 21 is placed at the right of the second cam 22, it moves to the left, and conversely, it moves to the right, that is, it is necessary to switch to which cam to move the cam to the position corresponding to the locking pin 30. Along with the movement of the cam group 20, the locking pin 30 is squeezed to move towards the center of the camshaft 10, so that the hydraulic pressure in the oil passage 11 rises, along with the gradual rise of the hydraulic pressure, the relief valve 13 is triggered, the hydraulic pressure decreases, the locking pin 30 continues to move towards the center of the camshaft 10, then the connection between the locking pin 30 and the first locking groove 211 is disconnected, further the first cam 21 is not limited, the cam group 20 continues to move until the second cam 22 moves to the position corresponding to the locking pin 30, then the hydraulic pressure is increased by increasing the liquid in the oil passage 11, so that the locking pin 30 moves towards the cam group 20 to be clamped into the second locking groove 221, and the switching is completed. The camshaft has the advantages of simple structure, less parts and simple transmission, and can realize the switching of the fuel state of the engine only by the movement of the locking pin 30.

Fig. 3 is a schematic sectional structure view of a camshaft structure for an engine according to another embodiment of the present invention. Fig. 2 shows the camshaft structure when the engine is in the otto cycle, and fig. 3 shows the camshaft structure when the cam group 20 is in the moving state, as shown in fig. 3, and at this time, the locking pin 30 is completely pushed into the through hole 14, and the connection with the cam group 20 is disconnected, and the cam group 20 can freely move in the axial direction of the camshaft 10.

Referring to fig. 2 or 3, in a preferred embodiment, the first, second and third locking grooves 211, 221 and 231 are all hemispherical, and the positions where the locking pin 30 is engaged with the first, second and third locking grooves 211, 221 and 231 have the same shape as the first, second and third locking grooves 211, 221 and 231, that is, the end of the locking pin 30 contacting the cam block 20 has the hemispherical shape, so that the locking pin 30 can be smoothly moved toward the center of the camshaft 10 when the cam block 20 is controlled to move in the axial direction of the camshaft 10. In other embodiments, the shapes of the lock pin 30 and the first, second, and third lock grooves 211, 221, and 231 may be other shapes, for example, an arch shape, and any shape may be used to lock the cam group 20 without restricting the movement of the lock pin 30.

With continued reference to fig. 2 or 3, in one particular embodiment, the camshaft arrangement further includes an actuator motor 40 coupled to the cam pack 20 for powering axial movement of the cam pack 20 along the camshaft 10. The number of the actuating motors 40 can be one or more, one actuating motor 40 can be connected with all the cam groups 20, one actuating motor 40 can be connected with part of the cam groups 20, and the latter mode can realize the separate control of a plurality of cam groups 20. When the working mode of the engine needs to be switched, the actuating motor 40 controls the cam group 20 to move along the axial direction of the camshaft 10.

With continued reference to fig. 2 or 3, in one particular embodiment, the camshaft arrangement further includes a pawl 50 connected at one end to the actuator motor 40 and at the other end to the cam pack 20. The number of the claws 50 may be one or more, one actuator 40 may correspond to one claw 50, one actuator 40 may correspond to a plurality of claws 50, one claw 50 may correspond to all the cam groups 20, and one claw 50 may correspond to one connecting part cam group 20. In this embodiment, the actuator motor 40 is coupled to the cam pack 20 via the pawl 50. Preferably, the pawl 50 is fitted over the outer wall of the cam block 20.

Fig. 4 is a schematic structural diagram of the second cam 22 of the camshaft structure for an engine according to an embodiment of the present invention. Fig. 5 is a schematic structural view of the camshaft 10 of the camshaft structure for an engine according to an embodiment of the present invention.

In a specific embodiment, the outer wall of the camshaft 10 is provided with a plurality of guide bosses 15, and the inner walls of the first cam 21, the second cam 22 and the third cam 23 are provided with a plurality of guide grooves 222 which are matched with the guide bosses 15 and have the same number with the guide bosses 15. In this way, the cam group 20 can be restricted from moving relative to the camshaft 10 in the circumferential direction of the camshaft 10, so that the cam group 20 and the camshaft 10 move synchronously in the circumferential direction of the camshaft 10.

Specifically, the number of the guide grooves 222 and the guide bosses 15 is each more than 1.

Preferably, the number of the guide grooves 222 and the guide bosses 15 is 6 each. So can satisfy the spacing to cam group 20, can satisfy the requirement of camshaft structure at weight again.

In a preferred embodiment, the first cam 21 is annular in shape.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been shown and described in detail herein, many other variations and modifications can be made, consistent with the principles of the invention, which are directly determined or derived from the disclosure herein, without departing from the spirit and scope of the invention. Accordingly, the scope of the present invention should be understood and interpreted to cover all such other variations or modifications.

Claims (10)

1. A camshaft structure for an engine, comprising a camshaft (10) and a plurality of cam sets (20) fitted over the camshaft (10), each cam set comprising a first cam (21), a third cam (23) and a second cam (22) fitted over the camshaft (10) in this order, wherein the plurality of cam sets are each controllably movable in an axial direction of the camshaft (10) to allow one of the first cam (21), the second cam (22) and the third cam (23) to be adjusted to a position corresponding to a valve (60) of the engine; and is

The distance between the circle center of the first cam (21) and the highest point of the first cam (21), the distance between the circle center of the second cam (22) and the highest point of the second cam (22) and the distance between the circle center of the third cam (23) and the highest point of the third cam (23) are different.

2. The camshaft structure according to claim 1, characterized in that a distance between the center of the second cam (22) and the highest point of the second cam (22) is greater than a distance between the center of the first cam (21) and the highest point of the first cam (21) and less than a distance between the center of the third cam (23) and the highest point of the third cam (23).

3. The camshaft structure according to claim 1 or 2, further comprising:

the number of the locking pins (30) is the same as that of the cam groups;

the center of the camshaft (10) penetrates through the camshaft in the axial direction to form an oil duct (11), the oil duct (11) comprises a first end and a second end which are opposite, the first end is provided with a one-way valve (12), and the second end is provided with a pressure release valve (13);

the camshaft (10) is also provided with a plurality of through holes (14) which penetrate through the camshaft (10) along the radial direction, and the locking pin (30) is arranged in the through holes (14);

the inner sides of the first cam (21), the second cam (22) and the third cam (23) are respectively provided with a first locking groove (211), a second locking groove (221) and a third locking groove (231) which are matched with the locking pin (30) at positions corresponding to the through hole (14).

4. The camshaft structure according to claim 3, wherein the first lock groove (211), the second lock groove (221), and the third lock groove (231) are all hemispherical;

the shape of the position where the lock pin (30) is fitted to the first lock groove (211), the second lock groove (221), and the third lock groove (231) is the same as the shape of the first lock groove (211), the second lock groove (221), and the third lock groove (231).

5. The camshaft structure according to claim 4, further comprising:

and the execution motor (40) is connected with the cam group and is used for providing power for the cam group to move along the axial direction of the cam shaft (10).

6. The camshaft structure according to claim 5, further comprising:

and the claw (50) is connected with the actuating motor (40) at one end and connected with the cam group at the other end.

7. A camshaft structure as claimed in claim 6, characterized in that a plurality of guide bosses (15) are provided on the outer wall of the camshaft (10), and a plurality of guide grooves (222) that are matched with the guide bosses (15) and are the same in number as the guide bosses (15) are provided on the inner walls of the first cam (21), the second cam (22) and the third cam (23).

8. The camshaft structure according to claim 7, wherein the number of the guide grooves (222) and the guide bosses (15) each exceeds 1.

9. The camshaft structure according to claim 8, wherein the number of the guide grooves (222) and the guide bosses (15) is 6 each.

10. A camshaft arrangement as claimed in any one of claims 4 to 9, characterized in that the first cam (21) is ring-shaped.

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