JP2016205268A - Cam changeover device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a cam changeover operation even if an angle range of a base circle is lack in respect to a cam changeover.SOLUTION: A cam profile of each of a standard intake cam 15 and a low speed cam 16 is defined in such a way that a first cam angle range [θ1-θ2] in which a valve lift amount of the standard intake cam 15 is larger than a valve lift amount of the low speed cam 16 and a second cam angle range [θ2-θ4] in which a valve lift amount of the low speed cam 16 is larger than a valve lift amount of the standard intake cam 15 may be formed. When a change-over is carried out from the standard intake cam 15 to the low speed cam 16, an opening or closing of the intake valve V1 is stopped by a cylinder deactivation mechanism 2 and an ECU 3 and at the same time a slide motion of an outer cam shaft 32 under operations of the cam shaft motion mechanism 1 and ECU 3 is started within the first cam angle range, and when a change-over is carried out from the low speed cam 16 to the standard intake cam 15, an opening or closing of the intake valve V1 is stopped and at the same time a slide motion of the outer cam shaft 32 is started within the second cam angle range.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a cam switching device, and in particular, a cam switching device that varies a valve characteristic of an intake / exhaust valve by selectively switching a pair of cams having different cam profiles provided corresponding to an intake / exhaust valve of an engine. About.

  Conventionally, two types of cams with different cam profiles are provided on the camshaft, and the camshaft is made to change the valve characteristics of the intake and exhaust valves by selectively switching the cam by sliding the camshaft in the axial direction with a hydraulic actuator. Devices are known (see, for example, Patent Documents 1 and 2).

  The intake / exhaust valve is normally urged in the valve closing direction by a valve spring, and is opened when a rocker arm that is swung by a cam presses the intake / exhaust valve against the restoring force of the valve spring. That is, when the cylinder in which the intake / exhaust valve is opened / closed is operating, a pressure contact force is always applied between the cam and the rocker arm. For this reason, cam switching is performed on the base circle of each cam where the intake and exhaust valves are not lifted.

JP 2002-4823 A JP 2001-123811 A

  Cam switching devices for switching cams must be provided on each of the intake side and the exhaust side. For this reason, when a cam switching device is provided for each cylinder, a device twice as many as the number of cylinders is required, and the configuration becomes complicated.

  Therefore, it is conceivable to provide a switching device on each of the intake side and the exhaust side and operate the intake side of the plurality of cylinders and the exhaust side of the plurality of cylinders collectively. However, since the valve opening / closing timing is determined for each cylinder, the angle range of the base circle may be insufficient for switching the cam depending on the number of cylinders and the cam profile. For example, when the intake / exhaust valve opening / closing timing corresponds to an angle range of 120 ° on the cam, the phase is 120 ° in a three-cylinder engine. In this case, since the intake / exhaust valves corresponding to any of the cylinders are lifted, it is difficult to switch the cams for the three cylinders together.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cam switching device that can perform cam switching even when the angle range of the base circle is insufficient for cam switching. It is to provide.

  In order to achieve the above-described object, a cam switching device according to the present invention is provided corresponding to an intake / exhaust valve of an engine, and selectively switches between a first cam and a second cam having different cam profiles, thereby enabling the intake and exhaust. A cam switching device capable of changing a valve characteristic of an exhaust valve, wherein the cam is rotated in conjunction with a crankshaft of the engine, and an outer periphery of the inner camshaft is spline-fitted, and the first cam and the cam An outer cam shaft on which the second cam is integrally rotatable; a cam shaft moving means for selectively switching the first cam and the second cam by sliding the outer cam shaft in the axial direction; Cylinder stopping means for stopping the cylinder by stopping the opening / closing operation of the exhaust valve, and the first cam and the second cam have a valve lift amount of the first cam that is the valve lift of the second cam. The cam profile is determined so that a first cam angle range larger than the first cam angle range and a second cam angle range where the valve lift amount of the second cam is larger than the valve lift amount of the first cam are formed. When switching from the first cam to the second cam, the cylinder pause means stops the intake / exhaust valve opening and closing operation, and the cam shaft moving means slides the outer cam shaft. When starting from the first cam angle range and switching from the second cam to the first cam, the cylinder resting means stops the intake / exhaust valve opening and closing operation, and the camshaft moving means causes the outer cam shaft to stop. Is started within the second cam angle range.

  According to the cam switching device of the present invention, the cam can be switched even if the angle range of the base circle is insufficient for the cam switching.

It is a typical perspective view explaining the structure of the engine block upper part of the state which removed the head cover. It is a typical perspective view explaining the external appearance of a double cam shaft. (A) is a diagram for schematically explaining the periphery of the electromagnetic solenoid in the selected state of the standard intake cam, and (B) is a diagram for schematically explaining the positional relationship between the standard intake cam and the rocker roller. (A) is a figure which illustrates typically the circumference | surroundings of the electromagnetic solenoid in the selection state of a low speed cam, (B) is a figure which illustrates typically the positional relationship of a low speed cam and a rocker roller. It is typical sectional drawing explaining the structure of an intake / exhaust valve | bulb and its periphery. (A) is a diagram for schematically explaining the relationship between the cam angle of the intake cam and the cam lift amount, and (B) is a diagram for schematically explaining the relationship between the cam angle of the exhaust cam and the cam lift amount. (A) is a timing chart for explaining switching from a normal cam to a low speed cam provided in the intake cam, and (B) is a diagram for schematically explaining the positional relationship between the rocker roller and the cam during movement of the outer cam shaft. (A) is a timing chart explaining switching from a low-speed cam provided in the intake cam to a normal cam, and (B) is a diagram schematically explaining the positional relationship between the rocker roller and the cam during movement of the outer cam shaft.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. An engine 100 shown in FIG. 1 is, for example, an in-line three cylinder, and includes a cam switching mechanism 1 that selectively switches a pair of cams (described later) according to the operating state of the engine 100. Each cylinder of the engine 100 is provided with a cylinder deactivation mechanism 2 for deactivating the cylinder by stopping the opening / closing operation of the intake and exhaust valves. The set of the cam switching mechanism 1, the cylinder deactivation mechanism 2, and the ECU 3 (electronic control unit) that controls these operations is an example of the cam switching device according to the present invention.

  The cam switching mechanism 1 includes an intake side cam switching mechanism 10 and an exhaust side cam switching mechanism 20. The intake-side cam switching mechanism 10 includes an intake-side double cam shaft 12 provided with an intake cam 11, an intake-side slide groove 13 (see FIG. 3) for slidingly moving the intake-side double cam shaft 12, and an intake-side electromagnetic solenoid. 14. The exhaust side cam switching mechanism 20 includes an exhaust side double cam shaft 22 provided with an exhaust cam 21, an exhaust side slide groove 23 that slides the exhaust side double cam shaft 22, and an exhaust side electromagnetic solenoid 24. Yes.

  Among these, the set of the intake side slide groove 13 and the intake side electromagnetic solenoid 14 and the set of the exhaust side slide groove 23 and the exhaust side electromagnetic solenoid 24 are an example of the cam shaft moving means according to the present invention together with the ECU 3. Configure. The intake cam 11 provided on the intake-side double camshaft 12 includes two types of cams (standard intake cam 15 and low-speed cam 16) having different cam profiles, and is provided on the exhaust-side double camshaft 22. The exhaust cam 21 includes two types of cams (an early opening cam 25 and a standard exhaust cam 26) having different cam profiles. The standard intake cam 15 and the quick opening cam 25 are examples of the first cam according to the present invention, and the low speed cam 16 and the standard exhaust cam 26 are examples of the second cam according to the present invention.

  Note that the exhaust cam 21 to be switched with respect to each part included in the exhaust side cam switching mechanism 20, the exhaust side double cam shaft 22, the exhaust side slide groove 23, and the exhaust side electromagnetic solenoid 24 is referred to as the quick opening cam 25. Except for the provision of the standard exhaust cam 26, the configuration is the same as each part of the intake cam switching mechanism 10. Therefore, in the following, the intake side cam switching mechanism 10 will be described, and the description of the exhaust side cam switching mechanism 20 will be omitted.

  As shown in FIG. 2, the intake-side double camshaft 12 is spline-fitted to the inner camshaft 31 that rotates in conjunction with a crankshaft (not shown) of the engine 100 and the outer periphery of the inner camshaft 31. An outer cam shaft 32 that is slidable in the axial direction with respect to 31 is provided.

  A plurality of intake cams 11 are press-fitted into the outer cam shaft 32 and attached so as to be rotatable integrally with the outer cam shaft 32. As shown in FIG. 1, in the engine 100 of the present embodiment, since one cylinder includes two intake valves, a total of six intake valves and six intake cams 11 are provided. As shown in FIG. 2, each intake cam 11 includes a standard intake cam 15 and a low-speed cam 16. By sliding the outer cam shaft 32 in the axial direction of the inner cam shaft 31, One of the low speed cams 16 is selected. The two intake cams 11 corresponding to the same cylinder are attached so that the cam profiles have the same phase. Since there are three cylinders, the three sets of intake cams 11 are attached in a state where the phases are shifted by 120 ° for each cylinder.

  At the end of the outer cam shaft 32, two intake side slide grooves 13 (first slide groove 13A, second slide groove 13B) are provided. When the outer cam shaft 32 is slid in the axial direction of the inner cam shaft 31, switching pins 41A and 41B included in the intake-side electromagnetic solenoid 14 are fitted into these slide grooves 13A and 13B (FIG. 3 ( A) and FIG. 4 (A)).

  As shown in FIG. 3A, when the standard intake cam 15 is selected, the first switching pin 41A located on the left side in FIG. 3 moves downward, and the lower end of the first switching pin 41A is the first slide groove 13A. To fit. As a result, as shown in FIG. 3B, the outer cam shaft 32 slides in the right direction in the figure, and the standard intake cam 15 included in the intake cam 11 contacts the rocker roller 51A. As shown in FIG. 4A, when the low-speed cam 16 is selected, the second switching pin 41B located on the right side in the drawing moves downward, and the lower end of the second switching pin 41B becomes the second slide groove 13B. Mating. As a result, as shown in FIG. 4B, the outer cam shaft 32 slides to the left in the drawing, and the low-speed cam 16 provided in the intake cam 11 contacts the rocker roller 51A.

  As shown in FIGS. 3A and 4A, the vertical movement of the first switching pin 41A and the second switching pin 41B is controlled by the intake-side electromagnetic solenoid. Specifically, it is controlled by energizing the first electromagnetic solenoid 42A positioned above the first switching pin 41A and the second electromagnetic solenoid 42B positioned above the second switching pin 41B.

  A first iron core 43A is disposed at the center of the first electromagnetic solenoid 42A, and the lower end of the first iron core 43A becomes the N pole when the first electromagnetic solenoid 42A is energized. A first permanent magnet 44A having an N pole on the top surface is provided at the upper end of the first switching pin 41A. Similarly, the second iron core 43B is disposed at the center of the second electromagnetic solenoid 42B, and the lower end of the second iron core 43B becomes the S pole when the second electromagnetic solenoid 42B is energized. A second permanent magnet 44B whose upper surface is an S pole is provided at the upper end of the second switching pin 41B. In addition, the upper ends of the first iron core 43A and the second iron core 43B are connected by a yoke 45 made of a plate-like magnetic permeable material.

  As shown in FIG. 3A, when the first electromagnetic solenoid 42A is energized and the second electromagnetic solenoid 42B is de-energized, the lower end of the first iron core 43A becomes the N pole and the first permanent magnet 44A. Therefore, the first switching pin 41A moves downward. On the other hand, although the second electromagnetic solenoid 42B is in a non-energized state, the lower end of the second iron core 43B is magnetized to the N pole by the magnetic field from the first iron core 43A and attracts the second permanent magnet 44B. Therefore, the second switching pin 41B is attracted to the lower end of the second iron core 43B.

  As shown in FIG. 4A, when the second electromagnetic solenoid 42B is energized and the first electromagnetic solenoid 42A is de-energized, the lower end of the second iron core 43B becomes the S pole and the second permanent magnet 44B In order to repel, the second switching pin 41B moves downward. On the other hand, the first electromagnetic solenoid 42A is in a non-energized state, but the lower end of the first iron core 43A is magnetized to the south pole by the magnetic field from the second iron core 43B and attracts the first permanent magnet 44A. The pin 41A is attracted to the lower end of the first iron core 43A.

  Accordingly, by selectively energizing the first electromagnetic solenoid 42A and energizing the second electromagnetic solenoid 42B, the first switching pin 41A and the second switching pin 41B are selectively moved to the first slide groove 13A and the second The standard intake cam 15 and the low speed cam 16 can be selectively brought into contact with the rocker roller 51A.

  Next, the cylinder deactivation mechanism 2 will be described. The cylinder deactivation mechanism 2 is a mechanism for deactivating the cylinder by closing the intake / exhaust valves, and constitutes an example of the cylinder deactivation means according to the present invention together with the ECU 3. As shown in FIG. 5, the cylinder deactivation mechanism 2 includes a rocker arm 51, a bracket 52, a hydraulic tappet 53, a needle 54, and a deactivation electromagnetic solenoid 55.

  The rocker arm 51 is swung by the intake cam 11 (standard intake cam 15, low speed cam 16) and exhaust cam 21 (standard exhaust cam 26, quick opening cam 25) to open the intake valve V1 and the exhaust valve V2 in the valve opening direction. It is a member to be operated. One end of the rocker arm 51 is attached to the bracket 52 so as to be rotatable about the rocker shaft 51B. The other end of the rocker arm 51 is in contact with the upper ends of the intake valve V1 and the exhaust valve V2 from above. A rocker roller 51 </ b> A that contacts the intake cam 11 or the exhaust cam 21 is formed in the middle of the rocker arm 51 in the longitudinal direction.

  The bracket 52 is a member that is pin-connected to the rocker arm 51 by a rocker shaft shaft 51B, and is moved up and down in accordance with the rocking of the rocker arm 51 in a cylinder rest state. Inside the bracket 52, a needle storage space 52 </ b> A that stores the needle 54 and is filled with engine oil is formed. A lower portion of the bracket 52 is a bottomed cylindrical piston portion 52 </ b> B that is advanced and retracted with respect to the hydraulic tappet 53. An oil hole 52C, which serves as an engine oil passage and into which the tip of the needle 54 is inserted, is formed in the center of the bottom surface of the piston portion 52B in a state of penetrating in the plate thickness direction. In addition, a communication hole 52D is formed on the side surface of the piston portion 52B to communicate the oil passage OL filled with engine oil and the needle housing empty portion 52A.

  The hydraulic tappet 53 is a member that supports the bracket 52 (piston portion 52B) from below while the piston portion 52B of the bracket 52 is inserted so as to be able to advance and retreat, and a cylindrical body 53A and a check ball spring (not shown). The check ball 53B urged upward by the bottom, a bottomed cylindrical storage portion 53C for contacting the lower end surface of the piston portion 52B and storing the check ball 53B and the check ball spring, and a storage portion 53C Piston spring 53D etc. supported from the lower side are provided.

  In the operation state of the cylinder, in the hydraulic tappet 53, the check ball 53B is urged upward, and the oil hole 52C of the piston portion 52B is closed by the check ball 53B. In a state where the oil hole 52C is closed, the engine oil that fills the lower side of the piston portion 52B cannot flow. For this reason, the bracket 52 (piston part 52B) cannot move downward, and the position in the height direction is fixed.

  On the other hand, in the cylinder tap state, the check tap 53B of the hydraulic tappet 53 is moved downward by the needle 54, and the oil hole 52C of the piston 52B is opened. In a state where the oil hole 52C is opened, the engine oil that fills the lower side than the piston part 52B can flow into the needle housing empty part 52A through the oil hole 52C. Then, the engine oil in the needle housing empty portion 52A can flow into the oil passage OL from the communication hole 52D formed on the side surface of the piston portion 52B. For this reason, when the oil hole 52C is opened, the bracket 52 (piston portion 52B) can move downward. That is, if the pressing force by the cams 11 and 21 is higher than the restoring force of the piston spring 53D, the piston spring 53D contracts and the bracket 52 moves downward. When the pressing force by the cams 11 and 21 is lower than the restoring force of the piston spring 53D, the bracket 52 moves upward by the restoring force of the piston spring 53D.

  The needle 54 is a rod-like member for moving the check ball 53B downward. The needle 54 is stored in the needle storage space 52A of the bracket 52 in a state of being movable in the axial direction, and the lower end is brought into contact with the check ball 53B. ing. The upper end portion of the needle 54 is housed inside the inactive electromagnetic solenoid 55 and is moved in the vertical direction by a plunger 55C provided in the inactive electromagnetic solenoid 55.

  The resting electromagnetic solenoid 55 includes a guide shaft 55A, a resting coil 55B, and a plunger 55C.

  The guide shaft 55A is a cylindrical member whose upper end is closed, and a plunger storage space 55D for storing the plunger 55C in a state in which the plunger 55C can move in the axial direction of the needle 54 is formed inside the upper end portion. A needle housing empty portion 55E is formed below the needle housing 52 so that the needle 54 can be moved in the axial direction. Further, a guide empty portion 55F is formed at the lower end portion of the guide shaft 55A so that the upper end portion of the bracket 52 can be slidably moved in the axial direction of the needle 54.

  The resting coil 55B is disposed at the upper end of the guide shaft 55A, and generates a magnetic field by energization to bias the plunger 55C downward. The plunger 55C is in contact with the upper end of the needle 54 from above, and pushes the needle 54 downward by a magnetic field generated from the resting coil 55B. When the energization of the resting coil 55B is stopped, the generation of the magnetic field is stopped, so that the check ball 53B is moved upward by the restoring force of the check ball spring, and the needle 54 and the plunger 55C are also moved accordingly. Moved upwards.

  In the cylinder deactivation mechanism 2 configured as described above, the deactivation electromagnetic solenoid 55 (deactivation coil 55B) is de-energized in the cylinder operation state, and the deactivation electromagnetic solenoid 55 is de-energized in the cylinder deactivation state. Is done.

  When the electromagnetic solenoid 55 for rest is not energized, the check ball 53B is moved upward to close the oil hole 52C of the piston portion 52B. Thereby, the height position of the bracket 52 is fixed. When the rocker roller 51A is pressed along the cam profile of the intake cam 11 or the exhaust cam 21, one end of the rocker arm 51 rotates about the rocker shaft 51B and the other end of the valve spring SP. It swings against the restoring force and opens and closes the intake valve V1 and the exhaust valve V2.

  In the energized state of the electromagnetic solenoid 55 for rest, the check ball 53B is moved downward to open the oil hole 52C of the piston portion 52B. As a result, the bracket 52 becomes movable in the vertical direction (the axial direction of the needle 54). When the rocker roller 51A is pressed along the cam profile of the intake cam 11 or the exhaust cam 21, the restoring force of the valve spring SP is strong, so the other end of the rocker arm 51 is the upper end of the intake valve V1. And the upper end of the exhaust valve V2 is pivoted about a fulcrum, and one end of the exhaust valve V2 swings up and down with the bracket 52 via the rocker shaft 51B. For this reason, even if the rocker arm 51 swings, the exhaust valve V2 is maintained in the closed state.

  Next, the cam profiles of the intake cam 11 and the exhaust cam 21 will be described with reference to FIG.

As shown in FIG. _6A , in the intake cam 11 of the first cylinder # 1, the cam profile # 1 _instd of the standard intake cam 15 has a lower speed cam 16 in the angle range from the cam angle θ1 to the cam angle θ2. The cam lift amount is larger than cam profile # 1 _inLow . On the contrary, in the angle range from the cam angle θ2 to the cam angle θ4, the cam profile # 1 _inLow of the low-speed cam 16 has a larger cam lift amount than the cam profile # 1 _instd of the standard intake cam 15.

In the second cylinder # 2 of the intake cam 11, the angle range of the cam angle θ3 to the cam angle .theta.5, cam lift than cam profile _{# 2 InLow} cam profiles _# who _{2 INSTd} slow cams 16 of the standard intake cam 15 Is getting bigger. On the contrary, in the angle range from the cam angle θ5 to the cam angle θ7, the cam profile # 2 _inLow of the low-speed cam 16 has a larger cam lift amount than the cam profile # 2 _instd of the standard intake cam 15.

Third the intake cam 11 of the cylinder # 3, in the angle range of the cam angle θ6 until cam angle .theta.8, cam lift than cam profile _{# 3 InLow} cam profiles _{# 3 INSTd} towards slow cams 16 of the standard intake cam 15 Is getting bigger. On the contrary, in the angle range from the cam angle θ8 to the cam angle θ9, the cam profile # 3 _inLow of the low speed cam 16 has a larger cam lift amount than the cam profile # 3 _instd of the standard intake cam 15.

  6A, in the intake cam 11 of the present embodiment, the intake valve V1 of any cylinder is lifted regardless of which cam angle is selected, and the angle range of the base circle provided in the intake cam 11 is standard. It can be seen that the switching between the intake cam 15 and the low speed cam 16 is insufficient.

  In the example of FIG. 6A, the angle range from the cam angle θ1 to the cam angle θ2, the angle range from the cam angle θ3 to the cam angle θ5, and the angle range from the cam angle θ6 to the cam angle θ8 are the present invention. Corresponds to the first angle range. The angle range from the cam angle θ2 to the cam angle θ4, the angle range from the cam angle θ5 to the cam angle θ7, and the angle range from the cam angle θ8 to the cam angle θ9 correspond to the second angle range of the present invention. .

As shown in FIG. 6B, in the exhaust cam 21 of the first cylinder # 1, the cam profile # 1 _exfst of the quick-open cam 25 is the standard exhaust cam in the angle range from the cam angle θ11 to the cam angle θ12. The cam lift amount is larger than 26 cam profile # 1 _exstd . Conversely, in the angle range from the cam angle θ12 to the cam angle θ14, the cam profile # 1 _exstd of the standard exhaust cam 26 has a larger cam lift amount than the cam profile # 1 _exfst of the quick-open cam 25.

In the exhaust cam 21 of the second cylinder # 2, in the angle range from the cam angle θ13 to the cam angle θ15, the cam profile # 2 _exfst of the quick-open cam 25 is more cam _lifted than the cam profile # 2 _exstd of the standard exhaust cam 26. The amount is getting bigger. On the contrary, in the angle range from the cam angle θ15 to the cam angle θ17, the cam profile # 2 _exstd of the standard exhaust cam 26 has a larger cam lift amount than the cam profile # 2 _exfst of the quick-open cam 25.

In the exhaust cam 21 of the third cylinder # 3, in the angle range from the cam angle θ16 to the cam angle θ18, the cam profile # 3 _exfst of the fast-open cam 25 is more cam _lifted than the cam profile # 3 _exstd of the standard exhaust cam 26. The amount is getting bigger. On the other hand, in the angle range from the cam angle θ18 to the cam angle θ19, the cam profile # 3 _exstd of the standard exhaust cam 26 has a larger cam lift amount than the cam profile # 3 _exfst of the quick-open cam 25.

  From FIG. 6B, in the exhaust cam 21 of the present embodiment, the exhaust valve V2 of any cylinder is lifted regardless of which cam angle is selected, and the angle range of the base circle provided in the exhaust cam 21 is fast. It can be seen that the switching between the open cam 25 and the standard exhaust cam 26 is insufficient.

  In the example of FIG. 6B, an angle range from the cam angle θ11 to the cam angle θ12, an angle range from the cam angle θ13 to the cam angle θ15, and an angle range from the cam angle θ16 to the cam angle θ18 are defined in the present invention. Corresponds to the first angle range. Further, the angle range from the cam angle θ12 to the cam angle θ14, the angle range from the cam angle θ15 to the cam angle θ17, and the angle range from the cam angle θ18 to the cam angle θ19 correspond to the second angle range of the present invention. .

  Next, cam switching control by the ECU 3 will be described. Here, the switching control between the standard intake cam 15 and the low-speed cam 16 included in the intake cam 11 and the switching control between the standard exhaust cam 26 and the quick-open cam 25 included in the exhaust cam 21 have the same contents. Therefore, the switching control at the intake cam 11 will be described, and the description of the switching control at the exhaust cam 21 will be omitted.

  First, the switching control from the standard intake cam 15 to the low speed cam 16 will be described with reference to FIG. In the timing chart of FIG. 7A, the horizontal axis is time. The switching Req is a timing signal indicating a switching request from the standard intake cam 15 to the low speed cam 16. CAM1x is a timing signal indicating the start of each cycle when the control for the three cylinders is one cycle. CAM3x is a timing signal indicating the start of control for each cylinder in one cycle period.

  # 1 deactivation is a control signal that becomes H level over the cylinder deactivation period of the first cylinder # 1, and # 1 lift amount is the lift amount of the pair of intake valves V1 provided in the first cylinder # 1. This is a signal schematically shown. # 2 deactivation is a control signal that becomes H level over the cylinder deactivation period of the second cylinder # 2, and # 2 lift amount is the lift amount of the pair of intake valves V1 provided in the second cylinder # 2. This is a signal schematically shown. # 3 stop is a control signal that becomes H level during the cylinder stop period of the third cylinder # 3, and # 3 lift amount is the lift amount of the pair of intake valves V1 provided in the third cylinder # 3. This is a signal schematically shown.

  The first SOL is a signal indicating the magnitude of the energization current to the first electromagnetic solenoid 42A. The second SOL is a signal indicating the magnitude of the energization current to the second electromagnetic solenoid 42B. In the example of FIG. 7A, the second electromagnetic solenoid 42B is energized in order to switch from the standard intake cam 15 to the low speed cam 16.

  The ECU 3 monitors the switching request signal and recognizes that a cam switching request has occurred based on a change in the voltage level of the switching request signal. In the example of FIG. 7A, the ECU 3 recognizes that a switching request has been made at the falling timing (time t1) from the H level to the L level.

  When recognizing the cam switching request, the ECU 3 sequentially puts the cylinders # 1 to # 3 into a resting state. Therefore, the ECU 3 recognizes that the control start timing of the next cycle is based on the timing signal CAM1x (time t2), and based on the timing signal CAM3x immediately after that, the deactivation electromagnetic solenoid 55 corresponding to the first cylinder # 1. (Pause coil 55B) is energized (time t3). Thus, for the first cylinder # 1, the exhaust valve V2 is maintained in the closed state even if the rocker arm 51 swings.

  Next, the ECU 3 energizes the inactive solenoid solenoid 55 corresponding to the second cylinder # 2 based on the timing signal CAM3x (time t4). As a result, even for the second cylinder # 2, the exhaust valve V2 is maintained in the closed state even if the rocker arm 51 swings. Similarly, the ECU 3 energizes the inactive solenoid solenoid 55 corresponding to the third cylinder # 3 based on the timing signal CAM3x (time t5). As a result, even for the third cylinder # 3, the exhaust valve V2 is maintained in the closed state even if the rocker arm 51 swings. At this time t5, the cylinders # 1 to # 3 are brought into a resting state.

  The ECU 3 starts energizing the second electromagnetic solenoid 42B at time t5. When the second electromagnetic solenoid 42B is energized, the second switching pin 41B moves downward and the lower end is fitted in the second slide groove 13B. Thereby, the slide movement of the outer cam shaft 32 is started along the second slide groove 13B, that is, the slide movement is started in the angle range from the cam angle θ1 to θ2, and the relative position between the intake cam 11 and the rocker roller 51A is changed. Change. Specifically, the intake cam 11 is moved so that a part of the rocker roller 51A is positioned on the low-speed cam 16 from the contact state of the rocker roller 51A and the standard intake cam 15 so far.

  Here, as described with reference to FIG. 6A, the cam lift amount of the standard intake cam 15 is larger than the cam lift amount of the low speed cam 16 in the angle range from the cam angle θ1 to θ2. That is, as shown in FIG. 7B, the low speed cam 16 is at a position lower than the standard intake cam 15 (position close to the rotation center). Therefore, the step between the cam surface of the standard intake cam 15 and the cam surface of the low speed cam 16 does not become an obstacle, and the intake cam 11 can be smoothly slid. And since the opening / closing operation | movement of the intake / exhaust valve | bulb V2 with which each cylinder is provided is stopped, even if the rocker roller 51A falls the level | step difference of the standard intake cam 15 and the low speed cam 16, the rocker arm 51 goes up and down with the bracket 52 vertically. The rocker arm 51 is moved and absorbed. As a result, the cam can be switched while suppressing the occurrence of abnormal noise.

  As can be seen from FIG. 6A, the intake cams 11 of the second cylinder # 2 and the third cylinder # 3 have a cam lift amount of 0 in the angle range from the cam angle θ1 to θ2. That is, the base circle of the intake cam 11 is in contact with the rocker roller 51A. For this reason, the intake cams 11 of the second cylinder # 2 and the third cylinder # 3 can be smoothly switched from the standard intake cam 15 to the low-speed cam 16.

  As shown in FIG. 7A, thereafter, at time t6, the inactive solenoid solenoid 55 corresponding to the first cylinder # 1 is deenergized and the intake valve V1 is switched to the operating state. At least a part of the rocker roller 51 </ b> A is located on the low speed cam 16. Thus, the opening / closing operation of the intake valve V1 of the first cylinder # 1 starts smoothly according to the cam profile of the low-speed cam 16.

  Thereafter, at time t7, the deactivation electromagnetic solenoid 55 corresponding to the second cylinder # 2 is de-energized, and at time t8, the deactivation electromagnetic solenoid 55 corresponding to the third cylinder # 3 is de-energized. The intake valve V1 included in # 2 and # 3 is switched to the operating state. Also for these cylinders # 2 and # 3, at least a part of the rocker roller 51A is positioned on the low speed cam 16, so that the intake valve V1 starts to open and close smoothly according to the cam profile of the low speed cam 16. .

  Next, switching control from the low speed cam 16 to the standard intake cam 15 will be described with reference to FIG. In the timing chart of FIG. 8A, the items on the horizontal axis and the vertical axis are the same as those in FIG.

  The ECU 3 monitors the switching request signal and recognizes that a cam switching request has occurred based on a change in the voltage level of the switching request signal. The ECU 3 recognizes that there has been a switching request at time t11.

  When recognizing the cam switching request, the ECU 3 sequentially puts the cylinders into a resting state. For this reason, the ECU 3 recognizes that it is the control start timing of the next cycle based on the timing signal CAM1x (time t12), and based on the subsequent timing signal CAM3x, the inactive electromagnetics corresponding to the cylinders # 1 to # 3. The solenoid 55 is energized (time t13 to t15).

  The ECU 3 starts energizing the first electromagnetic solenoid 42A at time t15. When the first electromagnetic solenoid 42A is energized, the first switching pin 41A moves downward and the lower end is fitted into the first slide groove 13A. Thereby, the slide movement of the outer cam shaft 32 is started along the first slide groove 13A, that is, the slide movement is started in the angle range from the cam angle θ2 to θ4, and the relative position of the intake cam 11 and the rocker roller 51A is Change. The intake cam 11 is moved so that a part of the rocker roller 51A is positioned on the standard intake cam 15 from the contact state of the rocker roller 51A and the low-speed cam 16 until then.

  Here, as described with reference to FIG. 6A, the cam lift amount of the low-speed cam 16 is larger than the cam lift amount of the standard intake cam 15 in the angle range from the cam angle θ2 to θ4. That is, as shown in FIG. 8B, the standard intake cam 15 is at a position lower than the low speed cam 16 (position close to the rotation center). Therefore, the step between the cam surface of the low speed cam 16 and the cam surface of the standard intake cam 15 does not become an obstacle, and the intake cam 11 can be smoothly slid. And since the opening / closing operation | movement of the intake / exhaust valve | bulb V2 with which each cylinder is stopped, even if the rocker roller 51A falls the level | step difference of the low speed cam 16 and the standard intake cam 15, the rocker arm 51 goes up and down with the bracket 52 up and down. The rocker arm 51 is moved and absorbed. As a result, the cam can be switched while suppressing the occurrence of abnormal noise.

  As can be seen from FIG. 6A, the intake cams 11 of the second cylinder # 2 and the third cylinder # 3 have a cam lift amount of 0 in the angle range from the cam angle θ2 to θ3. That is, the base circle of the intake cam 11 is in contact with the rocker roller 51A. Therefore, for the intake cams 11 of the second cylinder # 2 and the third cylinder # 3, if at least a part of the rocker roller 51A is positioned on the standard intake cam 15 by the cam angle θ3, the standard intake cam 15 can be switched smoothly.

  As shown in FIG. 8A, after that, at time t16, the inactive solenoid solenoid 55 corresponding to the first cylinder # 1 is deenergized and the intake valve V1 is switched to the operating state. At least a part of the rocker roller 51 </ b> A is located on the standard intake cam 15. As a result, the opening / closing operation of the intake valve V1 of the first cylinder # 1 starts smoothly according to the cam profile of the standard intake cam 15.

  After that, at time t17, the deactivation electromagnetic solenoid 55 corresponding to the second cylinder # 2 is de-energized, and at time t18, the deactivation electromagnetic solenoid 55 corresponding to the third cylinder # 3 is de-energized. The intake valve V1 included in # 2 and # 3 is switched to the operating state. Also for these cylinders # 2 and # 3, since at least a part of the rocker roller 51A is located on the standard intake cam 15, the intake valve V1 starts to open and close smoothly according to the cam profile of the standard intake cam 15 Is done.

  As described above, the engine 100 according to the present embodiment includes the cam switching mechanism 1 that selectively switches the pair of cams included in the intake cam 11 and the exhaust cam 21 according to the operating state of the engine 100. Each cylinder of the engine 100 is provided with a cylinder deactivation mechanism 2 that deactivates the cylinder by stopping the opening / closing operation of the intake / exhaust valve V2.

  A standard intake cam 15 provided in the intake cam 11 and an early opening cam 25 provided in the exhaust cam 21 (first cam), and a standard exhaust cam 26 provided in the low-speed cam 16 provided in the intake cam 11 and the exhaust cam 21 (second cam). The first cam angle range in which the valve lift amount of the standard intake cam 15 and the early opening cam 25 is larger than the valve lift amount of the low speed cam 16 and the standard exhaust cam 26, and the valve lift amount of the low speed cam 16 and the standard exhaust cam 26. The respective cam profiles are determined such that a second cam angle range is formed that is larger than the valve lift amount of the standard intake cam 15 and the quick-open cam 25.

  When switching from the standard intake cam 15 or the quick opening cam 25 to the low speed cam 16 or the standard exhaust cam 26, the opening / closing operation of the intake / exhaust valve V2 is stopped by the combination of the cylinder deactivation mechanism 2 and the ECU 3 (cylinder deactivation means). The sliding movement of the outer cam shaft 32 by the combination of the switching mechanism 1 and the ECU 3 (cam switching means) is started within the first cam angle range, and the low-speed cam 16 and the standard exhaust cam 26 are switched to the standard intake cam 15 and the fast-open cam 25. In this case, the opening / closing operation of the intake / exhaust valve V2 is stopped by the combination of the cylinder deactivation mechanism 2 and the ECU 3, and the sliding movement of the outer cam shaft 32 by the combination of the cam switching mechanism 1 and the ECU 3 is started in the second cam angle range. Yes.

  Thus, the intake cam 11 and the exhaust cam 21 can be slid without being affected by the step between the standard intake cam 15 and the low speed cam 16 or the step between the quick opening cam 25 and the standard exhaust cam 26. As a result, in the intake cam 11 and the exhaust cam 21, the cam can be switched even if the angle range of the base circle is insufficient for the cam switching.

  The above description of the embodiment is for facilitating the understanding of the present invention, and does not limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

  For example, the engine 100 is not limited to three cylinders as long as it has a plurality of cylinders. The present invention can be applied to any configuration in which the angle range of the base circle is insufficient for cam switching due to the cam profile. Further, the cylinder deactivation mechanism 2 is not limited to the example of the embodiment, and the present invention can be applied as long as each cylinder can be deactivated.

DESCRIPTION OF SYMBOLS 1 ... Cam switching mechanism, 2 ... Cylinder deactivation mechanism, 3 ... ECU, 10 ... Intake side cam switching mechanism, 11 ... Intake cam, 12 ... Intake side double cam shaft, 13 ... Intake side slide groove, 13A ... First slide Groove, 13B ... second slide groove, 14 ... intake side electromagnetic solenoid, 15 ... standard intake cam, 16 ... low speed cam, 20 ... exhaust side cam switching mechanism, 21 ... exhaust cam, 22 ... exhaust side double cam shaft, 23 ... exhaust side slide groove, 24 ... exhaust side electromagnetic solenoid, 25 ... fast open cam, 26 ... standard exhaust cam, 31 ... inner cam shaft, 32 ... outer cam shaft, 41A ... first switching pin, 41B ... second switching pin , 43A ... first iron core, 43B ... second iron core, 44A ... first permanent magnet, 44B ... second permanent magnet, 45 ... yoke, 51 ... rocker arm, 51A ... rocker roller, 51B ... rocker shaft shaft, 52 ... bracket , 52A ... Needle storage empty space, 52B ... Piston portion, 52C ... Oil hole, 52D ... Communication hole, 53 ... Hydraulic tappet, 53A ... Body, 53B ... Check ball, 53C ... Storage portion, 53D ... Piston spring, 54 ... Needle 55 ... Electromagnetic solenoid for pause, 55A ... Guide shaft, 55B ... Coil for pause, 55C ... Plunger, 55D ... Plunger storage space, 55E ... Needle storage space, 55F ... Guide space, 100 ... Engine, OL ... Oil path , V1 ... intake valve, V2 ... exhaust valve, SP ... valve spring

Claims (3)

A cam switching device that is provided corresponding to an intake / exhaust valve of an engine and that selectively switches between a first cam and a second cam having different cam profiles, thereby making the valve characteristics of the intake / exhaust valve variable,
An inner camshaft that rotates in conjunction with the crankshaft of the engine;
An outer camshaft that is spline-fitted to the outer periphery of the inner camshaft and that the first cam and the second cam are provided so as to be integrally rotatable;
A cam shaft moving means for selectively switching the first cam and the second cam by sliding the outer cam shaft in the axial direction;
Cylinder stopping means capable of stopping the cylinder by stopping the opening and closing operation of the intake and exhaust valves,
The first cam and the second cam have a first cam angle range in which a valve lift amount of the first cam is larger than a valve lift amount of the second cam, and a valve lift amount of the second cam is the first cam. Each cam profile is defined such that a second cam angle range larger than the cam valve lift amount is formed,
When switching from the first cam to the second cam, the cylinder pausing means stops the opening / closing operation of the intake / exhaust valve, and the sliding movement of the outer cam shaft by the cam shaft moving means is the first cam angle. Start with a range,
When switching from the second cam to the first cam, the cylinder pause means stops the opening / closing operation of the intake / exhaust valve, and the cam shaft moving means causes the outer cam shaft to slide to the second cam angle. Cam switching device that starts in range. A rocker arm that swings according to the cam profile of the first cam and the second cam and presses the intake and exhaust valves against a restoring force of a valve spring;
2. The cam switching device according to claim 1, wherein the cylinder deactivation means swings the rocker arm with a point of contact with the intake / exhaust valve as a fulcrum. The engine is an in-line cylinder engine in which a plurality of cylinders are arranged in series,
The first cam and the second cam are provided corresponding to the intake and exhaust valves of the plurality of cylinders,
When selectively switching the first cam or the second cam, the cylinder resting means stops the intake / exhaust valves provided in the plurality of cylinders, and the cam shaft moving means pivots the outer cam shaft. The cam switching device according to claim 1 or 2, wherein the cam switching device is slid in a direction.

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