CN107401436B - Engine and cam shaft, cam device and control cam thereof - Google Patents

Abstract

An engine, a cam shaft thereof, a cam device and a control cam, wherein the control cam is provided with a first driving surface facing one axial end, a second driving surface facing the other axial end and a spacing part positioned between the first driving surface and the second driving surface, and the first driving surface and the second driving surface are opposite to each other and are separated by the spacing part; the first driving surface and the second driving surface are respectively used for being matched with an actuating mechanism so that the cam device can be driven to move along different directions along the axial direction. The control cam has simpler structure and shape, more controllable shape and precision of the driving surface, and can be formed by one-step processing by adopting means of powder metallurgy, forging and the like, thereby simplifying the processing technology and being beneficial to reducing the cost.

Description

Engine and cam shaft, cam device and control cam thereof

Technical Field

The invention relates to the field of automobiles, in particular to an engine, a cam shaft, a cam device and a control cam thereof.

Background

Camshafts are important components in engines that are used to control the opening and closing actions of the valves. In a traditional cam shaft, a plurality of cams are uniformly distributed on the cam shaft, the cams and the cam shaft are of an integrated structure, and the cams cannot move axially.

With the development of technology, in order to make the lift of the valve variable, a new camshaft in which several cams of each cylinder are integrated on one sleeve and mounted on the camshaft through the sleeve has emerged. Each cam has two different lifts arranged in the axial direction, and the sleeve is movable in the axial direction relative to the camshaft to switch the lifts of the cams.

The sleeve is provided with two grooves which are respectively matched with the two lock pins and have opposite rotation directions, each sleeve is provided with a set of actuating mechanism which is arranged on the cylinder cover, and the actuating mechanism comprises the lock pins which can extend into the grooves. When the lock pin extends into the corresponding groove, the sleeve is driven to move axially with rotation of the cam shaft, so that the lift of the cam is switched.

The disadvantage of the above scheme is that, firstly, the structural form of the groove is complex, the processing difficulty is high, the shape and the precision of the groove are difficult to be molded at one time, and the groove is usually required to be finished, so that the cost is high. Second, for in-line multi-cylinder engines, such as in-line four-cylinder or six-cylinder engines, a plurality of sleeves are correspondingly required, and the length of the camshaft is limited, resulting in a very limited space for axial movement of each sleeve.

Disclosure of Invention

The invention solves the problems that in the existing engine camshaft, the structural form of a groove is complex, the processing is complicated, and the axial movement space of each sleeve is limited.

In order to solve the above-mentioned problems, the present invention provides a control cam for an engine cam device, the control cam being provided with a first driving surface facing one end in an axial direction, a second driving surface facing the other end in the axial direction, and a spacing portion located between the first driving surface and the second driving surface, the first driving surface and the second driving surface being opposite to each other and being spaced apart by the spacing portion; the first driving surface and the second driving surface are respectively used for being matched with an actuating mechanism so that the cam device can be driven to move along different directions along the axial direction.

Optionally, the first driving surface and the second driving surface respectively include an entry section, a switching section and an exit section which are sequentially connected along the circumferential direction of the control cam, and the cam device is driven when the switching section is matched with the actuating mechanism.

Optionally, the switching section of the first driving surface and the switching section of the second driving surface are mirror symmetrical to each other.

Optionally, the entering section and the exiting section are straight sections and perpendicular to a central axis of the control cam, as seen in a radial direction of the control cam.

Optionally, when viewed from a radial direction of the control cam, the switching section is a straight line section and is not perpendicular to a central axis of the control cam; or, the switching section is an arc section or a spiral section.

Optionally, the spacer is provided with a lightening hole or a groove.

Optionally, a position detecting device is disposed in the spacer portion, and is configured to detect an axial position of the engine cam device.

Optionally, the position detecting device is a magnetic element and is used in cooperation with the magnetic sensor.

Optionally, an annular groove is formed in the spacer, and the magnetic member is annular and is fixedly sleeved in the annular groove.

The present invention also provides an engine cam apparatus comprising: the sleeve is sleeved on the mandrel and can be pushed by the actuating mechanism to move along the axial direction of the mandrel; the cam pair is sleeved on the sleeve and used for controlling the valve to be opened and closed, and comprises at least two cams or convex peaches which are axially arranged and have different lifts; the control cam is sleeved on the sleeve.

Alternatively, the cam pairs have a plurality of cam pairs, each two cam pairs forming a group, each group of cam pairs being used for controlling the valve of one cylinder, and the plurality of cam pairs being divided into at least two groups.

Optionally, each group of cams is respectively arranged at two axial sides or the same side of the control cam.

The invention also provides a camshaft for an engine, comprising a mandrel and the cam device of any one of the above; the cam device is sleeved outside the mandrel through the sleeve.

The invention also provides an engine, which comprises the cam shaft and an actuating mechanism; the actuating mechanism comprises an electromagnetic driver and a lock pin part which is connected with and driven by the electromagnetic driver, wherein the lock pin part can extend or retract along the radial direction of the control cam and can extend to be matched with the first driving surface or the second driving surface so as to push the cam device to move along different directions along the axial direction.

Optionally, the lock pin part comprises a first lock pin and a second lock pin, and the first lock pin and the second lock pin are respectively used for being matched with the first driving surface and the second driving surface; the first lock pin and the second lock pin are connected to and driven by the same electromagnetic driver; alternatively, the first lock pin and the second lock pin are respectively connected to and driven by different electromagnetic drivers.

The invention also provides an engine, which comprises a mandrel, a sleeve sleeved on the mandrel, a cam pair sleeved on the sleeve, a control cam and an actuating mechanism, wherein the cam pair is used for controlling the opening and closing of a valve and comprises at least two cams or convex peaches with different lift ranges, and the control cam can be pushed by the actuating mechanism to move along the axial direction of the mandrel; the control cam is the control cam; the actuating mechanism comprises an electromagnetic driver and a lock pin part which is connected with the electromagnetic driver and driven by the electromagnetic driver, wherein the lock pin part can extend or retract along the radial direction of the control cam and can extend to be matched with the first driving surface or the second driving surface so as to push the cam device to move along different directions along the axial direction; the locking pin portion having been fully extended upon contact with the terminus of the entry section; alternatively, the detent portion may not fully extend upon contact with the end of the entry section and may extend fully during contact with the switching section.

Compared with the prior art, the technical scheme of the invention has the following advantages:

compared with the existing groove structure, the control cam has simpler structure and shape, more controllable shape and precision, can be formed by one-step processing by adopting means such as powder metallurgy, forging and the like, does not need post-finishing, simplifies the processing technology and is beneficial to reducing the cost.

Further, the sleeve is integrated with a plurality of groups of cam pairs which respectively correspond to different cylinders, and the same control cam is used for controlling the switching of the lift, so that the number of executing mechanisms can be reduced, the arrangement difficulty is reduced, and the cost is reduced.

Drawings

Fig. 1 is a perspective view of a camshaft according to a first embodiment of the present invention;

fig. 2 is a front view structural diagram of a camshaft according to a first embodiment of the present invention;

FIG. 3 shows a half-section of one of the sleeves and the mandrel of the camshaft of the first embodiment of the present invention in an exploded state;

FIG. 4 shows a cross-sectional view of one of the sleeves of the camshaft of the first embodiment of the present invention in an assembled state with the mandrel;

fig. 5 shows a perspective structure of a control cam according to a first embodiment of the present invention;

FIG. 6 shows a schematic cross-sectional view of a control cam of a first embodiment of the present invention;

fig. 7 shows an expanded schematic view of the control cam of the first embodiment of the present invention as seen in the radial direction;

fig. 8 is a perspective view showing a camshaft according to a modification of the first embodiment;

fig. 9 is a perspective view showing a camshaft according to another modification of the first embodiment;

fig. 10a to 10d are perspective view showing the structure of a camshaft according to still another modification of the first embodiment;

fig. 11 shows a perspective structure of a control cam according to a second embodiment of the present invention;

fig. 12 shows a front view of a control cam of a second embodiment of the present invention;

fig. 13 shows an expanded schematic view of a control cam of a second embodiment of the present invention as seen in a radial direction;

fig. 14 is a schematic perspective view showing a control cam in which a position detecting device is installed according to a second embodiment of the present invention;

fig. 15 is a front view showing a control cam in which a position detecting device is installed in a second embodiment of the present invention.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

First embodiment

Referring to fig. 1 to 4, an embodiment of the present invention provides an engine and a camshaft thereof, a cam apparatus 1, a control cam 13, wherein the control cam 13 is used in the cam apparatus 1 of the engine camshaft. The cam device 1 is used for being sleeved on the mandrel 2 and forms an engine camshaft together with the mandrel 2. The cam device 1 and the mandrel 2 may be connected by a spline or other structure so that the cam device 1 may move in the axial direction of the mandrel 2.

The actuator 3 is arranged outside the cam shaft, is fixed on a cylinder or a cylinder cover and is used as a driving component for driving the cam device 1 to axially move, and the actuator 3 can act on the control cam 13 when the cam device 1 needs to move, so that the cam device 1 is pushed to axially move along the mandrel 2.

The cam device 1 includes a sleeve 11 and a cam pair 12 provided on the sleeve 11 in addition to a control cam 13, and the cam device 1 controls valve opening and closing of a cylinder by the cam pair 12. Wherein the cam pair 12 has at least two cams or lobes arranged in an axial direction and having different lift. The cam device 1 is sleeved on the mandrel 2 through the sleeve 11, and can realize axial movement along the mandrel 2 through interaction between the actuating mechanism 3 and the control cam 13, so that cams or convex peaches with different lifts can be switched and used according to different working conditions, and the valve lift is adjusted.

As shown in fig. 1 to 4, the control cam 13 is located in the cam device 1 and sleeved on the sleeve 11. As shown in fig. 5, 6, and 7, the control cam 13 is provided with a first driving surface 13a facing one end in the axial direction, a second driving surface 13b facing the other end in the axial direction, and a spacer portion 13c located between the first driving surface 13a and the second driving surface 13b, and the first driving surface 13a and the second driving surface 13b are opposite to each other and are separated by the spacer portion 13 c.

The first driving surface 13a and the second driving surface 13b are respectively used for being matched with the actuating mechanism 3 so that the cam device 1 can be driven to move along different directions along the axial direction. When the actuator 3 is engaged with the first driving surface 13a, the cam device 1 can be driven to move toward one axial end; when the actuator 3 is engaged with the second driving surface 13b, the cam device 1 can be driven to move toward the other end in the axial direction.

Compared with the existing groove structure, the control cam has simpler structure and shape, more controllable shape and precision, can be formed by one-step processing by adopting means such as powder metallurgy, forging and the like, does not need post-finishing, simplifies the processing technology and is beneficial to reducing the cost.

The control cam 13 may be integrally formed with the sleeve 11 or may be secured to the sleeve by a press-fit process or a connecting structure. In addition, in order to reduce the weight of the control cam 13, a lightening hole or a groove may be opened in the spacer portion 13 c.

The actuator 3 includes an electromagnetic driver 31, and a lock pin portion 32 connected to the electromagnetic driver 31 and driven by the electromagnetic driver 31. As shown in fig. 1 and 2, the electromagnetic actuator 31 has two actuators, a first actuator 31a and a second actuator 31b, respectively; accordingly, the locking pin portion 32 also includes two locking pins, defined as a first locking pin 32a and a second locking pin 32b, respectively. The first lock pin 32a and the second lock pin 32b are respectively connected to and driven by different electromagnetic drivers. As shown in fig. 1 and 2, the first lock pin 32a is connected to the first driver 31a and driven by the first driver 31a, and the second lock pin 32b is connected to the second driver 31b and driven by the second driver 31 b.

In use, the first detent 32a is adapted to engage the first drive surface 13a to urge the cam device 1 to move in one direction in an axial direction, and the second detent 32b is adapted to engage the second drive surface 13b to urge the cam device 1 to move in the other direction in an axial direction.

In other embodiments, as shown in fig. 8, the first and second locking pins 32a, 32b may be connected to the same electromagnetic driver 31, driven by the same electromagnetic driver 31.

With continued reference to fig. 5, 6 and 7, the first driving surface 13a and the second driving surface 13b respectively include an entry section p1, a switching section p2 and an exit section p3 sequentially connected in the circumferential direction of the control cam 13, and the cam device 1 is driven when the switching section p2 is engaged with the actuator 3. In other words, when the actuator 3 is in contact with the entering section p1 or the exiting section p3, the cam device 1 cannot be pushed to move in the axial direction.

It should be noted that, when the switching section p2 is engaged with the lock pin, the cam device 1 can be moved axially, so that the switching section p2 must have a certain inclination angle with respect to the radial plane of the control cam 13, and the inclination directions of the switching section p2 of the first driving surface 13a and the switching section p2 of the second driving surface 13b are opposite. In the present embodiment, the switching section p2 of the first driving surface 13a and the switching section p2 of the second driving surface 13b are mirror images of each other.

The reason for setting the entry segment p1 will be explained in detail here. When the cam device 1 does not need to be pushed to move along the axial direction, the first lock pin 32a and the second lock pin 32b of the actuating mechanism 3 are in a retracted state, and neither the first lock pin 32a nor the second lock pin 32b is in contact with the corresponding driving surface. When it is necessary to push the cam gear 1 to move in the axial direction, for example, when it is necessary to push the cam gear 1 to move toward the right as viewed in fig. 2, the first lock pin 32a is extended and reaches a predetermined position in contact with the first drive surface 13 a. The force provided by the pin, which is related to the length of its extension, is less than the required thrust force F required to push the cam means 1 into motion, and if the pin is in contact with the switching section p2 when it is not fully extended, it is possible to cause damage to the pin. The present embodiment thus sets up: the locking pin should be in the fully extended state at the latest in the end position of the entry section p1, i.e. when in contact with the start of the switching section p2, the locking pin is already at its maximum extension.

The exit segment p3 is provided for the same reason. In addition, the arrangement of the entering section p1 and the exiting section p3 can also provide a certain buffer for the matching and the disengaging of the lock pin and the corresponding driving surface, so that the impact between the lock pin and the driving surface caused by abrupt change of force is avoided.

As shown in fig. 7, the entry section p1 and the exit section p3 are straight sections and perpendicular to the central axis of the control cam 11 as viewed in the radial direction of the control cam 13. That is, the points of entry segment p1 are all located on the same radial plane of the control cam, and the points of exit segment p3 are all located on the same radial plane of the control cam 13. The radial plane here means a plane perpendicular to the central axis of the control cam 13.

The switching segment p2 is a straight segment as viewed in the radial direction of the control cam 13, and is not perpendicular to the central axis of the control cam 13. When the locking pin of the actuator 3 contacts the switching section p2, the switching section p2 will push the cam device 1 to move axially at a constant speed. In other embodiments, the switching section p2 may be an arc section or a spiral section, and when the lock pin of the actuator 3 contacts the switching section p2 and pushes the cam device 1 to move axially, the movement of the cam device 1 will present a certain acceleration.

When the cam device 1 moves to the specified position and no further movement is required, the lock pin moves to the end of the switching section 2, i.e. the start of the exit section p 3. As shown in fig. 5 and 6, the control cam 13 includes a main body cam 13f, and the first driving surface 13a, the second driving surface 13b, and the spacer 13c are provided on the outer peripheral surface of the main body cam 13f and in the middle region of the main body cam 13 f. Wherein, the circumferential surfaces of the parts of the body cam 13f extending out of the first driving surface 13a and the second driving surface 13b along the axial direction are respectively provided with an exit convex peach 13g, and the circumferential position of the exit convex peach 13g corresponds to the exit section p 3. When the lock pin moves to the start of the exit section p3, the bottom of the lock pin contacts the exit lobe 13g, and as the lock pin moves along the exit section p3, the exit lobe 13g can push the lock pin toward the retraction direction to push it radially out of the drive surface.

The magnitudes of the central angles of the first and second drive surfaces 13a, 13b corresponding to the circumferential direction of the control cam 13 are set according to the axial distance the sleeve 11 needs to move when switching the lift, the switching time requirement, and the like. In this embodiment, the central angles corresponding to the first driving surface 13a and the second driving surface 13b are not greater than 360 degrees. And, the central angle corresponding to the switching section p2 is smaller than 360 degrees. That is, the first and second driving surfaces 13a and 13b do not extend beyond one circumference of the control cam 13 in the circumferential direction.

In this embodiment, the plurality of cam pairs 12 provided on one sleeve 11 is divided into at least two groups, and generally, each two cam pairs form a group, and each group corresponds to a cylinder of an engine and is used for controlling the valve opening and closing of the corresponding cylinder.

As shown in fig. 1, the plurality of cam pairs 12 on each sleeve 11 are equally divided into two groups, i.e., a first group of cam pairs 12a, a second group of cam pairs 12b. The first cam pair 12a corresponds to one cylinder and is used for controlling the opening and closing of the valve; the second cam pair 12b corresponds to another cylinder and is used to control the opening and closing of its valve. In other embodiments, the cam pairs 12 may be divided into three or more groups, each group corresponding to a cylinder of an engine, for controlling valve opening and closing of the corresponding cylinder.

It can be seen that in the present invention, only the axial movement of one sleeve 11 needs to be controlled to change the valve lift of a plurality of cylinders. When the sleeve 11 of the present invention is applied to a camshaft, the number of sleeves 11 on the camshaft can be reduced for an in-line engine having the same number of cylinders, whereby the axial movement space of each sleeve can be increased.

Moreover, when one sleeve 11 correspondingly controls a plurality of cylinders, as the control cam 13 is arranged on the sleeve 11, the control of the valve lift of the plurality of cylinders can be realized by only one control cam 13 and one set of actuating mechanism corresponding to the control cam 13, so that the number of the actuating mechanisms can be reduced, the arrangement difficulty of the actuating mechanisms is reduced, and the cost is reduced.

Further, when the sleeve 11 is integrated with a plurality of sets of cam pairs corresponding to different cylinders respectively, the control cam 13 may be provided at either axial end of the sleeve 11 or in the middle. That is, the plurality of cam pairs 12 may be provided on both sides of the control cam 13, or on the same side of the control cam 13, respectively. As shown in fig. 1 to 4, the present embodiment adopts the latter arrangement in which each set of cam pairs 12a, 12b is provided on both axial sides of the control cam 13, respectively. In other embodiments, each set of cam pairs 12a, 12b may be provided on the same side of the control cam 13, as shown in fig. 9.

It should be noted that, in the engine camshaft according to the embodiment of the present invention, the number of cam devices 1 sleeved on the same mandrel 2 may be one or more. Taking two cam pairs 12a, 12b distributed on each sleeve 11 as an example, for an in-line six-cylinder engine, at most three cam devices 1 can be sleeved on each mandrel 2, as shown in fig. 1 to 4, 8 and 9. For an in-line four-cylinder engine, at most two cam devices 1 can be sleeved on each mandrel 2, as shown in fig. 10a to 10 d. In summary, the number of sleeves 11 on each mandrel 2 is determined by the number of in-line cylinders and the number of sets of cam pairs on each sleeve 11. Wherein different sleeves 11 on the same spindle 2 may have different sets of cam pairs.

As shown in fig. 10a to 10d, similarly, in the case of the in-line four-cylinder engine, the cam pairs 12a and 12b of each group may be provided on both axial sides of the control cam 13 (fig. 10a and 10 c), or may be provided on the same side of the control cam 13 (fig. 10b and 10 d). The first lock pin 32a and the second lock pin 32b may be connected to different electromagnetic drivers 31 and driven by the respective electromagnetic drivers 31 (fig. 10a and 10 b), or may be connected to the same electromagnetic driver 31 and driven by the same electromagnetic driver 31 (fig. 10c and 10 d).

Wherein, as shown in fig. 1 and 2, the sleeve 11 is provided with at least one journal 15 and is arranged between two cam pairs 12 of the same group. This embodiment is only partially labeled in fig. 1. The journal 15 serves as a support point, and the camshaft is supported on the cylinder head of the cylinder at the location of the journal 15.

When the sleeve 11 is mounted on the mandrel 2, two conditions need to be met, namely, the requirement that the sleeve 11 can move axially along the mandrel 2, namely, axial guiding is ensured; secondly, the sleeve 11 and the mandrel 2 are prevented from relative rotation, namely, torsion resistance is required. The sleeve 11 is thus connected to the spindle 2 by a form fit (not shown) with splines or slide-grooves.

Further, an axial limiting part is further arranged between the mandrel 2 and the sleeve 11 to limit the space for axially moving the sleeve 11, and the limiting position of the sleeve 11 in the axial movement is controlled.

In this embodiment, referring to fig. 3 in combination with fig. 4, the axial limiting portion includes: a first limit groove 51 located on the outer peripheral surface of the spindle 2, a second limit groove 52 located on the inner peripheral surface of the sleeve 11, and an elastic locking portion 53. One of the first and second limiting grooves 51, 52 is located on the outer circumferential surface of the mandrel 2, and the other is located on the inner circumferential surface of the sleeve 11. The elastic locking portion 53 is installed in the first limiting groove 51, and one end of the elastic locking portion extending out of the first limiting groove 51 is used for extending into the second limiting groove 52 and being locked in the second limiting groove 52 so as to axially limit the sleeve 11.

In this embodiment, the first limiting groove 51 is located on the outer peripheral surface of the mandrel 2, and the second limiting groove 52 is located on the inner peripheral surface of the sleeve 11. In fig. 3 and 4, the first limiting groove 51 is provided in the form of a counterbore on the mandrel 2 and extends in the radial direction of the mandrel 2 in the depth direction, and the second limiting groove 52 is provided in the form of an annular groove surrounding the sleeve 11 on the inner peripheral surface of the sleeve 11. In other embodiments, the positions of the first limit groove and the second limit groove can be interchanged.

The elastic locking portion 53 is always in a compressed state. That is, the elastic locking portion 53 always has a tendency to move toward the second limiting groove 52 in the radial direction. In this embodiment, the elastic locking portion 53 includes a spring 53a and a steel ball 53b that are connected to each other, one end of the spring 53a is fixed in the first limiting groove 51, the other end is connected to the steel ball 53b, and the steel ball 53b is always pushed by the spring 53 b.

When the sleeve 11 moves axially relative to the spindle 2, the second limit groove 52 also moves axially relative to the first limit groove 51. When the sleeve 11 moves axially to the set position, the first limit groove 51 and the second limit groove 52 overlap in the radial direction, i.e., when the second limit groove 52 moves to be aligned with the first limit groove 51 in the radial direction, the elastic locking portion 53 extends into the second limit groove 52 to prevent the sleeve 11 from moving further.

It will be appreciated that the sleeve 11 may be moved in different directions in the axial direction to effect switching between the different cams. Then, in order to achieve the limitation in both directions in the axial direction, the second limitation groove 52 has two and is arranged in the axial direction, and the elastic locking portion 53 moves between the two second limitation grooves 52 in the axial direction.

The number of the first limiting grooves 51 and the elastic locking portions 53 may be one or two. When the two first limiting grooves 51 are provided, each first limiting groove 51, the elastic locking portion 53 thereof and the corresponding second limiting groove 52 form a group of limiting structures, and the two groups of limiting structures are respectively used for limiting the movement of the sleeve 11 along two directions. The two sets of limit stops may be axially arranged along the sleeve 11.

In the present embodiment, only one first limit groove 51 is provided, and two second limit grooves 52 are axially adjacent to each other. When the sleeve 11 moves in the axial direction, the elastic locking portion 53 can be switched only between the two second limiting grooves 52.

In other embodiments, the axial distance between the two second limiting grooves 52 may be set according to the distance that the sleeve 11 needs to move along the axial direction, and the two limiting grooves are in a proportional relationship. Alternatively, if the number of cams to be switched is large for each valve, and a plurality of setting positions are required for the movement of the sleeve 11, the number of the second limiting grooves 52 may be increased.

Second embodiment

As shown in fig. 11 to 13, the present embodiment differs from the first embodiment in that the control cam structure is different, and in the control cam 13 of the present embodiment, the first driving surface 13a and the second driving surface 13b are designed in the same manner as in the first embodiment, and as shown in fig. 13, the first driving surface 13a and the second driving surface 13b respectively include an entry section p1, a switching section p2, and an exit section p3, which are sequentially connected in the circumferential direction of the control cam 13, and the cam device 1 is driven when the switching section p2 is engaged with the actuator 3. In other words, when the actuator 3 is in contact with the entering section p1 or the exiting section p3, the cam device 1 cannot be pushed to move in the axial direction.

As shown in fig. 11 to 13, the control cam of the present embodiment differs from the control cam of the first embodiment in that an annular groove 13d is provided in a spacer portion 13c of the control cam 13. The annular recess 13d separates the first drive face 13a from the second drive face 13 b.

Wherein the annular groove 13d may serve as a weight-reducing groove of the control cam 13. Alternatively, the annular groove 13d may also serve as a mounting portion for mounting other components.

In this embodiment, the annular groove 13d is provided with a position detecting device 14, and as shown in fig. 14 and 15, the detecting device 14 is annular and sleeved in the annular groove 13d for detecting the axial position of the sleeve 11, i.e. the axial position of the engine cam device.

In this embodiment, the position detecting device 14 is a magnetic member for use with a magnetic sensor. Wherein the magnetic sensor may be generally fixedly mounted on the cylinder or cylinder head, and detecting whether the sleeve 11 is axially moved by sensing a magnetic field generated by the magnetic member.

For example, if the magnetic element is radially aligned with the magnetic sensor when no axial movement of the sleeve 11 occurs, the magnetic sensor is able to sense the magnetic element; when the sleeve 11 moves axially, the magnetic element is staggered with the magnetic sensor in the radial direction, and when the magnetic sensor cannot sense the magnetic element, the sleeve 11 is judged to move axially.

In other embodiments, the shape of the magnetic member is not limited, and may be a block, a bar, an arc, or other shapes.

Third embodiment

The present embodiment provides another engine which differs from the engine of the first embodiment in that the mating relationship of the actuator 3 and the control cam 13 is different.

In this embodiment, the pins of the pin portion 32 (i.e., the first pin 32a, the second pin 32 b) are not fully extended when in contact with the end of the entry section p1, and are fully extended during contact with the switching section p 2.

That is, when the locking pin of the locking pin portion 32 needs to extend to engage with the corresponding driving surface, the locking pin extends and enters the entry segment p1, and the locking pin is in the process of extending continuously during the movement of the locking pin from the start point to the end point of the entry segment p 1.

But when the lock pin moves to the end of the entry segment p1, the lock pin has not yet fully extended, i.e., not to the maximum length. At this time, the lock pin enters the switching section p2 and continues to be extended, and the extending action is completed in the switching section p2, extending to the maximum length in the switching section.

As in the first embodiment, a certain thrust force F is required to push the cam device 1 into motion, and the force provided by the lock pin is related to its extended length. In addition, the force that the locking pin can provide is also related to its diameter, as well as the strength of the material. If the diameter of the locking pin is sufficiently large, or if the strength of the material is sufficiently large, then the locking pin is not damaged even if it is in contact with the switching section p2, as long as it is not fully extended, for example to the second position, which can provide a thrust force F which can be reached or even exceeded.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims (16)

1. A control cam for an engine cam device, characterized in that the control cam is provided with a first driving surface facing one axial end, a second driving surface facing the other axial end, the first driving surface and the second driving surface facing axially outward, respectively, and a spacing portion between the first driving surface and the second driving surface, the first driving surface and the second driving surface being opposite to each other and being spaced apart by the spacing portion; the first driving surface and the second driving surface are respectively used for being matched with an actuating mechanism so that the cam device can be driven to move along different directions along the axial direction;

the first driving surface and the second driving surface respectively comprise an entering section, a switching section and an exiting section which are sequentially connected along the circumferential direction of the control cam, and the cam device is driven when the switching section is matched with the executing mechanism;

the control cam is provided with a body cam, the first driving surface, the second driving surface and the spacing part are all arranged on the outer peripheral surface of the body cam and are arranged in the middle area of the body cam, the body cam axially extends out of the peripheral surfaces of the first driving surface and the second driving surface, and the circumferential positions of the withdrawing convex peaches correspond to the withdrawing sections.

2. The control cam of claim 1, wherein the switching segment of the first drive face and the switching segment of the second drive face are mirror images of each other.

3. The control cam of claim 1 wherein the entry and exit sections are straight sections and perpendicular to a central axis of the control cam as viewed in a radial direction of the control cam.

4. A control cam according to any one of claims 1-3, characterized in that the switching section is a straight section, seen in the radial direction of the control cam, and is non-perpendicular to the central axis of the control cam; or, the switching section is an arc section or a spiral section.

5. The control cam of claim 1, wherein the spacer is provided with a lightening hole or slot.

6. The control cam of claim 1, wherein a position detecting means is provided in the spacer for detecting an axial position of the engine cam gear.

7. The control cam as recited in claim 6 wherein said position sensing means is a magnetic member for use with a magnetic sensor.

8. The control cam of claim 7, wherein the spacer has an annular groove formed therein, and the magnetic member is annular and is fixedly received in the annular groove.

9. An engine cam device comprising: the sleeve is sleeved on the mandrel and can be pushed by the actuating mechanism to move along the axial direction of the mandrel; the cam pair is sleeved on the sleeve and used for controlling the valve to be opened and closed, and comprises at least two cams or convex peaches which are axially arranged and have different lifts; the control cam is characterized by further comprising the control cam of any one of claims 1-8, wherein the control cam is sleeved on the sleeve.

10. The cam apparatus of claim 9 wherein said cam pairs are plural, each two cam pairs forming a group, each group of cam pairs for controlling a valve of a cylinder, said plural cam pairs being divided into at least two groups.

11. The cam device according to claim 10, wherein each of said cam groups is provided on both or the same axial sides of said control cam, respectively.

12. A camshaft for an engine, comprising a core shaft, and the cam apparatus of any one of claims 9 to 11; the cam device is sleeved outside the mandrel through the sleeve.

13. An engine comprising the camshaft of claim 12, and an actuator; the actuating mechanism comprises an electromagnetic driver and a lock pin part which is connected with the electromagnetic driver and driven by the electromagnetic driver, wherein the lock pin part can extend or retract along the radial direction of the control cam and can extend to be matched with the first driving surface or the second driving surface so as to push the engine cam device to move along different directions along the axial direction.

14. The engine of claim 13, wherein the detent portion includes first and second detents for mating with the first and second drive surfaces, respectively; the first lock pin and the second lock pin are connected to and driven by the same electromagnetic driver; alternatively, the first lock pin and the second lock pin are respectively connected to and driven by different electromagnetic drivers.

15. An engine comprises a mandrel, a sleeve sleeved on the mandrel, a cam pair and a control cam sleeved on the sleeve, and an actuating mechanism, wherein the cam pair is used for controlling the opening and closing of a valve and comprises at least two cams or convex peaches with different lifts, and the control cam can be pushed by the actuating mechanism to move along the axial direction of the mandrel; characterized in that the control cam is a control cam according to any one of claims 1-4; the actuating mechanism comprises an electromagnetic driver and a lock pin part which is connected with and driven by the electromagnetic driver, wherein the lock pin part can extend or retract along the radial direction of the control cam and can extend to be matched with the first driving surface or the second driving surface so as to push the cam device to move along different directions along the axial direction; the detent portion having been fully extended upon contact with the terminus of the entry section; alternatively, the detent portion may not fully extend upon contact with the end of the entry section and may fully extend during contact with the switching section.

16. The engine of claim 15, wherein the detent portion includes first and second detents for mating with the first and second drive surfaces, respectively; the first lock pin and the second lock pin are connected to and driven by the same electromagnetic driver; alternatively, the first lock pin and the second lock pin are respectively connected to and driven by different electromagnetic drivers.