Variable valve system

Abstract

To switch a connection state and a release state of a plurality of locker arms by a simple constitution even if resilient springs are not arranged at the locker arms.SOLUTION: A variable valve device (20) comprises: a plurality of locker arms (31, 41) which can oscillate around an axis of a locker shaft (27); a connection pin (36) in a locker arm accommodation hole (33) which is close to one side; a release pin (46) in a locker arm accommodation hole (43) which is close to the other side; a pressing member (55) located closer to one side than the locker arm which is close to one side; a transmission member (58) located closer to the other side than the locker arm which is close to the other side; and a push-return member (59) for push-returning the transmission member from the other side. The pressing member pushes the connection pin into the accommodation hole of the locker arm which is close to the other side to connect the plurality of locker arms, and the transmission member push-returns the connection pin into the accommodation hole of the locker arm which is close to one side to release the connection of the plurality of locker arms.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a variable valve operating device. [Background technology]

[0002] Conventionally, a variable valve mechanism is known that switches valve operation by connecting multiple rocker arms (see, for example, Patent Document 1). The variable valve mechanism described in Patent Document 1 has a pair of rocker arms arranged adjacent to each other, and a connecting pin is inserted into a housing hole of one of the rocker arms. When part of the connecting pin enters the housing hole of the other rocker arm, the pair of rocker arms are connected and a pair of valves are operated simultaneously. When part of the connecting pin comes out of the housing hole of the other rocker arm, the pair of rocker arms are released from their connected state and only the valves on one side are operated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5907552 Summary of the Invention [Problem to be solved by the invention]

[0004] A repulsion spring for pushing back the connecting pin is disposed in the accommodation hole of the other rocker arm described in Patent Document 1. However, depending on the type of engine, etc., it may not be possible to dispose a repulsion spring inside the rocker arm, and even in such cases, a configuration is required that allows multiple rocker arms to be easily switched between a connected state and a released state.

[0005] The present invention has been made in consideration of these points, and aims to provide a variable valve mechanism that can switch between the connected and disconnected states of multiple rocker arms with a simple configuration, even when a repulsion spring is not arranged in the rocker arm. [Means for solving the problem]

[0006] A variable valve device according to one aspect of the present invention is a variable valve device capable of changing valve operation in a cylinder head, and includes a rocker shaft extending from one side to the other within the cylinder head, a plurality of rocker arms capable of swinging around the axis of the rocker shaft, a connecting pin arranged in an accommodation hole of the rocker arm closer to one side in the axial direction, a release pin arranged in an accommodation hole of the rocker arm closer to the other side in the axial direction, a pressing member arranged on one side of the rocker arm closer to the one side, a transmission member arranged on the other side of the rocker arm closer to the other side, and a push-back member arranged to push back the transmission member from the other side, wherein the pressing member pushes the release pin to the other side while pushing the connecting pin into the accommodation hole of the rocker arm closer to the other side to connect the plurality of rocker arms, and the transmission member is pushed back by the push-back member to push the connecting pin back into the accommodation hole of the rocker arm closer to the one side via the release pin, thereby releasing the connection of the plurality of rocker arms. The central axes of the connecting pin and the release pin are closer to the rocker shaft than the central axes of the pressing member and the transmission member. This solves the above problem. Effect of the Invention

[0007] According to a variable valve mechanism of one aspect of the present invention, when the connecting pin is pushed to the other side, the connecting pin partially enters from the accommodation hole of the rocker arm closer to one side into the accommodation hole of the rocker arm closer to the other side, connecting the multiple rocker arms via the connecting pin. When the connecting pin is released from being pushed in, the push-back member pushes the connecting pin back to the one side via the transmission member and the release pin, disconnecting the multiple rocker arms. In this way, even if no repulsion spring is provided in the rocker arms, the multiple rocker arms can be switched between connected and released states with a simple configuration. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic cross-sectional view of a cylinder head and a head cover according to the first embodiment. [Diagram 2]FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 2 is a schematic diagram of a connecting structure of a pair of rocker arms according to the first embodiment. [Figure 4] FIG. 11 is a schematic diagram of a connecting structure of a pair of rocker arms according to a second embodiment. [Diagram 5] FIG. 11 is a schematic diagram of a connecting structure of a pair of rocker arms according to a third embodiment. [Figure 6] FIG. 13 is a schematic diagram of a connecting structure of a pair of rocker arms according to a fourth embodiment. [Figure 7] FIG. 13 is a schematic diagram of a connecting structure of a pair of rocker arms according to a fifth embodiment. [Figure 8] FIG. 13 is a schematic diagram of a connecting structure of a pair of rocker arms according to a sixth embodiment. [Figure 9] FIG. 13 is a schematic diagram of a connecting structure of a pair of rocker arms according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A variable valve mechanism according to one aspect of the present invention changes valve operation in a cylinder head. A rocker shaft extends from one side to the other inside the cylinder head, and a plurality of rocker arms are supported on the rocker shaft so as to be pivotable about the axis. A connecting pin is disposed in a housing hole of the rocker arm closer to one side in the axial direction, and a release pin is disposed in a housing hole of the rocker arm closer to the other side in the axial direction. A pressing member is disposed on one side of the rocker arm closer to one side, and a transmission member is disposed on the other side of the rocker arm closer to the other side. A push-back member is disposed so as to push back against the transmission member from the other side. While the release pin is pushed out to the other side, the pressing member pushes the connecting pin into the housing hole of the rocker arm closer to the other side. The connecting pin partially enters from the housing hole of the rocker arm closer to one side into the housing hole of the rocker arm closer to the other side, and the plurality of rocker arms are connected via the connecting pin. The transmission member is pushed back by the push-back member, and the connecting pin is pushed back into the housing hole of the rocker arm closer to the one side via the release pin, and the connection of the plurality of rocker arms is released. In this way, even if no repulsion spring is provided in the rocker arm, the multiple rocker arms can be switched between the connected state and the released state with a simple configuration. EXAMPLES

[0010] <First Example> Hereinafter, a variable valve gear of a first embodiment will be described with reference to the accompanying drawings. Fig. 1 is a schematic cross-sectional view of a cylinder head and a head cover of the first embodiment. Fig. 2 is a schematic cross-sectional view taken along line AA in Fig. 1.

[0011] 1 and 2, a cylinder head 10 is provided with a pair of intake valves 12 (only one is shown) that open and close an intake port 11, and a single exhaust valve 15 that opens and closes an exhaust port 14. The pair of intake valves 12 are pressed in a valve closing direction by a valve spring 13, and the exhaust valve 15 is pressed in a valve closing direction by a valve spring 16. A cylinder head cover 17 is attached to the top surface of the cylinder head 10, and a valve train chamber 18 is formed by the cylinder head 10 and the cylinder head cover 17. A variable valve train mechanism 20 that varies the valve operation in the cylinder head 10 is mounted in the valve train chamber 18.

[0012] The variable valve mechanism 20 is provided with a camshaft 21 that is common to the intake and exhaust sides, and intake and exhaust side rocker shafts 27, 28 that are parallel to the camshaft 21. The camshaft 21 is rotatably supported by bearings 22, 23 in the cylinder head 10. The camshaft 21 is disposed between the intake valve 12 and the exhaust valve 15, and a pause cam 24, an intake cam 25, and an exhaust cam 26 are attached to the outer circumferential surface of the camshaft 21. The pause cam 24 is formed in a substantially circular plate shape with only a base circle, and the intake cam 25 and exhaust cam 26 are formed in a plate shape with cam lobes protruding from part of the base circle.

[0013] The intake-side and exhaust-side rocker shafts 27, 28 are attached to the cylinder head 10 above the camshaft 21. A pair of rocker arms 31, 41 are swingably supported on the intake-side rocker shaft 27, and a single rocker arm 51 is swingably supported on the exhaust-side rocker shaft 28. The pair of intake-side rocker arms 31, 41 and the exhaust-side rocker arm 51 are each a seesaw-type rocker arm. One end of each rocker arm 31, 41, 51 serves as a force point that receives input from the camshaft 21, and the other end of each rocker arm 31, 41, 51 serves as a point of action that actuates a valve.

[0014] A roller 32 that rolls in contact with the pause cam 24 is rotatably supported at one end of the rocker arm 31, and the intake valve 12 is connected to the other end of the rocker arm 31. A roller (not shown) that rolls in contact with the intake cam 25 is rotatably supported at one end of the rocker arm 41, and the intake valve (not shown) is connected to the other end of the rocker arm 41. A roller 52 that rolls in contact with the exhaust cam 26 is rotatably supported at one end of the rocker arm 51, and the exhaust valve 15 is connected to the other end of the rocker arm 51. The pair of rocker arms 31, 41 are adjacent to each other, and are formed so as to be connectable.

[0015] At low and medium engine speeds, the pair of rocker arms 31, 41 on the intake side are not connected. Because the cam profile of the deactivation cam 24 is approximately circular, the rocker arm 31 does not swing even when the deactivation cam 24 rotates, and the operation of the intake valves 12 is paused. The rocker arm 41 swings in response to the rotation of the intake cam 25, and only the intake valves (not shown) on one side are opened and closed. At high engine speeds, the pair of rocker arms 31, 41 on the intake side are connected. The pair of rocker arms 31, 41 swing integrally in response to the rotation of the intake cam 25, and the pair of intake valves 12 are opened and closed simultaneously.

[0016] The variable valve mechanism 20 is formed with a structure that can switch between a connected state and a released state of the pair of rocker arms 31, 41. The pair of rocker arms 31, 41 are formed with accommodation holes, and a connecting pin 36 is disposed in the accommodation hole of the rocker arm 31. A part of the connecting pin 36 protrudes from the accommodation hole of the rocker arm 31 into the accommodation hole of the rocker arm 41, thereby connecting the pair of rocker arms 31, 41 via the connecting pin 36. A part of the connecting pin 36 is pushed back from the accommodation hole of the rocker arm 41 into the accommodation hole of the rocker arm 31, thereby releasing the connection between the pair of rocker arms 31, 41.

[0017] In the variable valve train 20, the repulsive force of the spring is used to push the connecting pin 36 back into the receiving hole of the rocker arm 31. In this case, if a spring is placed in the receiving hole of the rocker arm 41, the spring will swing together with the rocker arm 41, causing various problems. For example, the spring may be damaged due to resonance during engine operation, or the surrounding parts of the spring may wear out. In addition, if a spring is placed inside the rocker arm 41, the mass of the moving parts of the valve train may become large, making it unsuitable for a high-speed engine. Furthermore, the rocker arm 41 itself may become large, which may lead to an increase in size and weight of the variable valve train 20.

[0018] Therefore, the variable valve train 20 of this embodiment is configured so that a spring is arranged on the outside of the rocker arm 41 and the repulsive force of the spring is transmitted to the connecting pin 36 from the outside of the rocker arm 41. In this case, the location of the spring in the cylinder head 10 has been devised so that the structure of the variable valve train 20 is not complicated and the variable valve train 20 does not become large. As a result, even if a spring is not arranged on the rocker arm 41, the connected and released states of the rocker arms 31, 41 can be switched with a simple configuration. Because the spring does not swing together with the rocker arm 41, the above-mentioned problems do not occur.

[0019] Hereinafter, the connection structure of a pair of rocker arms of the first embodiment will be described with reference to Fig. 3. Fig. 3 is a schematic diagram of the connection structure of a pair of rocker arms of the first embodiment. Fig. 3(A) shows the pair of rocker arms in a released state, and Fig. 3(B) shows the pair of rocker arms in a connected state.

[0020] As shown in Fig. 3(A), a rocker shaft 27 extends from one side to the other inside the cylinder head 10. A pair of rocker arms 31, 41 are supported on the rocker shaft 27, and the pair of rocker arms 31, 41 are capable of swinging around the axis of the rocker shaft 27. The pair of rocker arms 31, 41 are disposed adjacent to each other on the rocker shaft 27, but the upper parts of the pair of rocker arms 31, 41 face each other with a small gap C1 between them. Accommodating holes 33, 43 parallel to the rocker shaft 27 are formed in the upper parts of the pair of rocker arms 31, 41.

[0021] A stopper 34 is formed at one end of the accommodating hole 33 of the rocker arm 31 by narrowing the hole diameter of the accommodating hole 33. An annular groove 35 is formed on the inner circumferential surface of the accommodating hole 33 on the other end side of the stopper 34. A stopper 44 is formed at approximately half of one side of the accommodating hole 43 of the rocker arm 41 by narrowing the hole diameter of the accommodating hole 43. An annular groove 45 is formed on the inner circumferential surface of the accommodating hole 43 on the other end side of the stopper 44. The hole diameter of the other end side of the accommodating hole 33 and the hole diameter of the one end side of the accommodating hole 43 match, and are formed coaxially so as to communicate when the pair of intake valves 12 (see FIG. 1) are in a closed state.

[0022] A connecting pin 36 is arranged in the receiving hole 33 of the rocker arm 31 so as to be movable in the axial direction. The connecting pin 36 is a stepped pin consisting of a large diameter portion and a small diameter portion, and the small diameter portion of the connecting pin 36 protrudes to one side from the rocker arm 31. A step 37 is formed on the outer circumferential surface of the connecting pin 36 at the boundary between the large diameter portion and the small diameter portion, and the step 37 of the connecting pin 36 abuts against the stopper 34 of the rocker arm 31, thereby restricting the movement of the connecting pin 36 to one side. In the released state of the pair of rocker arms 31, 41, the connecting pin 36 is positioned in an initial position (released position) where the step 37 and the stopper 34 come into contact.

[0023] A release pin 46 is disposed in the receiving hole 43 of the rocker arm 41 so as to be movable in the axial direction. The release pin 46 is a stepped pin consisting of a large diameter portion and a small diameter portion, and the other end of the large diameter portion of the release pin 46 protrudes from the rocker arm 41 to the other end side. A step 47 is formed on the outer circumferential surface of the release pin 46 at the boundary between the large diameter portion and the small diameter portion, and the step 47 of the release pin 46 abuts against the stopper 44 of the rocker arm 41, thereby restricting the movement of the release pin 46 to one side. In the released state of the pair of rocker arms 31, 41, the release pin 46 is positioned in an initial position where the step 47 and the stopper 44 come into contact.

[0024] A pressing member 55 is disposed on one side of the rocker arm 31 in the cylinder head 10. The pressing member 55 is formed of a solenoid pin, a push rod, a hydraulic plunger, or the like. The other end of the pressing member 55 contacts the connecting pin 36, and the connecting pin 36 is pushed to the other side by the pressing member 55. A guide hole 57 is formed on the other side of the rocker arm 41 in the cylinder head 10. A transmission member 58 is disposed in the guide hole 57. A straight pin is used as the transmission member 58. One end of the transmission member 58 contacts the release pin 46, and the release pin 46 is pushed back to the one side by the transmission member 58.

[0025] A repulsive spring (push-back member) 59 is disposed in the guide hole 57 of the cylinder head 10 so as to contact the transmission member 58 from the other side. A coil spring disposed coaxially with the transmission member 58 is used as the repulsive spring 59. One end of the repulsive spring 59 contacts the transmission member 58, and the other end of the repulsive spring 59 contacts the bottom wall of the guide hole 57. When the transmission member 58 is pressed into the guide hole 57 from one side, a repulsive force is stored in the repulsive spring 59, and when the pressing of the transmission member 58 is released, the transmission member 58 is pushed back to one side by the repulsive force of the repulsive spring 59. The repulsive force of the repulsive spring 59 automatically returns each pin 36, 46 via the transmission member 58.

[0026] Since the repulsion spring 59 is disposed in the cylinder head 10, the repulsion spring 59 does not swing together with the rocker arm 41. This prevents damage to the repulsion spring 59 due to resonance during engine operation and prevents wear on the parts surrounding the repulsion spring 59. The moving parts of the valve train around the rocker arm 41 are made smaller and lighter, making it possible to handle higher engine speeds compared to conventional engines. In addition, the rocker arm 41 does not become larger, and there is no need to add new parts for the arrangement of the repulsion spring 59. This prevents the variable valve train 20 from becoming larger and heavier.

[0027] The central axes O1 of the connecting pin 36 and the release pin 46 are closer to the rocker shaft 27 than the central axes O2, O3 of the pressing member 55 and the transmission member 58, and the upper parts of the multiple rocker arms 31, 41 are made smaller. The offset amount of the central axes O1, O2 of the connecting pin 36 and the pressing member 55 is preferably such that the contact area between the connecting pin 36 and the pressing member 55 is secured and axial wobble of the connecting pin 36 is suppressed. The offset amount of the central axes O1, O3 of the release pin 46 and the transmission member 58 is preferably such that the contact area between the release pin 46 and the transmission member 58 is secured and axial wobble of the release pin 46 is suppressed.

[0028] In this released state of the pair of rocker arms 31, 41, no pressing force is applied from the pressing member 55 to the connecting pin 36, and the spring force of the resilience spring 59 is applied to the release pin 46 via the transmission member 58. The step 37 of the connecting pin 36 abuts against the stopper 34 of the rocker arm 31, and the step 47 of the release pin 46 abuts against the stopper 44 of the rocker arm 41. At this time, the other end 38 of the connecting pin 36 contacts one end 48 of the release pin 46 at the non-connecting position P1 in the gap C1 between the pair of rocker arms 31, 41. The other end 38 of the connecting pin 36 is positioned outside the rocker arm 41, and the pair of rocker arms 31, 41 are separated.

[0029] 3(B), when the connecting pin 36 is pushed in by the pressing member 55, the connecting pin 36 moves the transmission member 58 to the other side via the release pin 46. The transmission member 58 is pushed into the guide hole 57 of the cylinder head 10, and the repulsive spring 59 is contracted by the transmission member 58, and a repulsive force is accumulated in the repulsive spring 59. The other end 38 of the connecting pin 36 is moved to the other side from the non-connecting position P1 to the connecting position P2 in the accommodation hole 43 of the rocker arm 41. A part of the connecting pin 36 enters the accommodation hole 43 of the rocker arm 41, and the pair of rocker arms 31, 41 are connected via the connecting pin 36.

[0030] 3(A), when the pressing of the connecting pin 36 by the pressing member 55 is released, the transmitting member 58 is pushed back by the repulsive force of the repulsive spring 59. The transmitting member 58 presses the release pin 46, and the releasing pin 46 pushes the connecting pin 36 back to one side. The other end 38 of the connecting pin 36 is moved to one side from the connecting position P2 to the non-connecting position P1, and the release pin 46 and the connecting pin 36 are returned to their original positions. A part of the connecting pin 36 comes out of the accommodation hole 43 of the rocker arm 41, and the connection between the pair of rocker arms 31, 41 is released.

[0031] When the pair of rocker arms 31, 41 are connected, the release pin 46 is pushed out to the other side against the repulsive force of the repulsive spring 59, while the pressing member 55 presses the connecting pin 36 into the accommodation hole 43 of the rocker arm 41. When the pair of rocker arms 31, 41 are released from the connection, the transmission member 58 is pushed back by the repulsive force of the repulsive spring 59, and the connecting pin 36 is pushed back into the accommodation hole 33 of the rocker arm 31 via the release pin 46 by the transmission member 58. The connecting pin 36 is moved between the non-connected position P1 and the connected position P2, switching between the connected state and the released state of the pair of rocker arms 31, 41.

[0032] As described above, according to the variable valve train 20 of the first embodiment, even when the repulsion spring 59 is disposed in the cylinder head 10, the pair of rocker arms 31, 41 can be switched between the connected and released states with a simple configuration. Also, damage to the repulsion spring 59 due to resonance during engine operation and wear on the members surrounding the repulsion spring 59 are suppressed, and the variable valve train 20 can be adapted to relatively high engine speeds. Also, the variable valve train 20 is prevented from becoming larger and heavier.

[0033] <Second Example> Next, a variable valve train of a second embodiment will be described with reference to Fig. 4. The variable valve train of the second embodiment differs from the variable valve train of the first embodiment in that a hydraulic cylinder is formed in one rocker arm as a pressing member, and a hydraulic cylinder is formed in the cylinder head as a pushing member. Therefore, a description of the same configuration of the second embodiment as that of the first embodiment will be omitted. Fig. 4 is a schematic diagram of the connecting structure of a pair of rocker arms of the second embodiment. Fig. 4(A) shows the pair of rocker arms in a released state, and Fig. 4(B) shows the pair of rocker arms in a connected state.

[0034] As shown in Fig. 4(A), a rocker shaft 62 extends from one side to the other inside a cylinder head 61, and a pair of rocker arms 71, 81 are supported on the rocker shaft 62 so as to be able to swing. An oil passage 63 is formed inside the rocker shaft 62, and a hydraulic chamber 73 is formed on one end side of the rocker arm 71. An oil hole 64 connecting the oil passage 63 and the hydraulic chamber 73 is formed in the peripheral wall of the rocker shaft 62 and the rocker arm 71, and oil is supplied from the oil passage 63 to the hydraulic chamber 73 via the oil hole 64. In this way, a hydraulic cylinder that pushes the connecting pin 75 to the other side is formed in the rocker arm 71.

[0035] The pair of rocker arms 71, 81 are formed with accommodation holes 72, 82 parallel to the rocker shaft 62. One end of the accommodation hole 72 of the rocker arm 71 forms a hydraulic chamber 73 into which oil enters, and a connecting pin 75 arranged in the accommodation hole 72 functions as a drive plunger. The accommodation hole 72 (hydraulic chamber 73) of the rocker arm 71 is formed in a bottomed cylindrical shape, and a protrusion 76 is formed on one end of the connecting pin 75. The protrusion 76 of the connecting pin 75 abuts against the inner bottom surface of the hydraulic chamber 73, restricting the movement of the connecting pin 75 to one side, thereby ensuring the minimum volume of the hydraulic chamber 73.

[0036] A hydraulic cylinder is formed in the cylinder head 61 on the other side of the rocker arm 81. A transmission member 96 is disposed in a guide hole 95 in the cylinder head 61, and an oil passage 97 is connected to the bottom surface of the guide hole 95. That is, the other end side of the guide hole 95 in the cylinder head 61 forms a hydraulic chamber 98 into which oil enters, and the transmission member 96 disposed in the guide hole 95 functions as a return plunger. A protrusion 99 is formed on the other end of the transmission member 96. The protrusion 99 of the transmission member 96 abuts against the inner bottom surface of the hydraulic chamber 98, thereby restricting the movement of the transmission member 96 to the other side, and the minimum volume of the hydraulic chamber 98 is ensured.

[0037] In this released state of the pair of rocker arms 71, 81, no hydraulic pressure is applied from the hydraulic chamber 73 of the rocker arm 71 to the connecting pin 75, and no hydraulic pressure is applied from the hydraulic chamber 98 of the cylinder head 61 to the transmission member 96. The protrusion 76 of the connecting pin 75 abuts against the inner bottom surface of the hydraulic chamber 73, and the step 86 of the release pin 85 abuts against the stopper 83 of the rocker arm 81. At this time, the other end 77 of the connecting pin 75 contacts one end 87 of the release pin 85 at the non-connecting position P1 of the gap C1 between the pair of rocker arms 71, 81. The other end 77 of the connecting pin 75 is positioned outside the rocker arm 81, and the pair of rocker arms 71, 81 are separated.

[0038] 4(B), when hydraulic pressure is applied to the connecting pin 75 from the hydraulic chamber 73 of the rocker arm 71, the connecting pin 75 moves the transmission member 96 to the other side via the release pin 85. The transmission member 96 is pushed into the guide hole 95 of the cylinder head 61, and the protrusion 99 of the transmission member 96 abuts against the inner bottom surface of the hydraulic chamber 98. The other end 77 of the connecting pin 75 is moved to the other side from the non-connecting position P1 to the connecting position P2 of the rocker arm 81. A part of the connecting pin 75 enters the accommodation hole 82 of the rocker arm 81, and the pair of rocker arms 71, 81 are connected via the connecting pin 75.

[0039] 4(A), when the hydraulic pressure applied to the connecting pin 75 is released, the transmission member 96 is pushed back by the hydraulic pressure in the hydraulic chamber 98 of the cylinder head 61. The transmission member 96 pushes in the release pin 85, which pushes the connecting pin 75 back to one side. The other end 77 of the connecting pin 75 is moved to one side from the connecting position P2 to the non-connecting position P1, and the release pin 85 and the connecting pin 75 are returned to their original positions. A part of the connecting pin 75 comes out of the accommodation hole 82 of the rocker arm 81, and the connection between the pair of rocker arms 71, 81 is released.

[0040] As described above, the variable valve device 60 of the second embodiment uses a simple hydraulic configuration to switch between the connected and released states of the pair of rocker arms 71, 81. Furthermore, since no repulsion spring is used, problems such as breakage of the repulsion spring do not occur.

[0041] In the second embodiment, a hydraulic cylinder for pressing is formed on one rocker arm and a hydraulic cylinder for pushing back is formed on the cylinder head, but it is sufficient that a hydraulic cylinder is formed on at least one of them. That is, a hydraulic cylinder may be formed on one rocker arm instead of the pressing member, and a resilience spring may be disposed in a guide hole of the cylinder head as the pushing back member. Also, a solenoid pin or the like may be used as the pressing member, and a hydraulic cylinder may be formed on the cylinder head as the pushing back member.

[0042] <Third Example> Next, a variable valve train of a third embodiment will be described with reference to Fig. 5. The variable valve train of the third embodiment differs from the variable valve train of the first embodiment in that a sensor capable of detecting the connected and released states of a pair of rocker arms is provided. Therefore, a description of the configuration of the third embodiment that is similar to that of the first embodiment will be omitted. Fig. 5 is a schematic diagram of the connected structure of a pair of rocker arms of the third embodiment. Fig. 5(A) shows the released state of the pair of rocker arms, and Fig. 5(B) shows the connected state of the pair of rocker arms.

[0043] As shown in Fig. 5(A), a rocker shaft 102 extends from one side to the other inside a cylinder head 101, and a pair of rocker arms 111, 121 are supported by the rocker shaft 102 so as to be able to swing. A connecting pin 115 is disposed in a receiving hole 112 of the rocker arm 111, and a release pin 125 is disposed in a receiving hole 122 of the rocker arm 121. A pressing member 131 is disposed on one side of the rocker arm 111, and a guide hole 135 is formed in the cylinder head 101 on the other side of the rocker arm 121. A transmission member 136 and a repulsion spring 137 are disposed in the guide hole 135. A sensor 138 is disposed on the other side of the repulsion spring 137.

[0044] A rod 139 extending toward a sensor 138 is formed at the other end of the transmission member 136. The rod 139 passes through the inside of a coil-shaped repulsive spring 137 to the other side, and penetrates the portion of the cylinder head 101 where the guide hole 135 is formed. The sensor 138 is disposed near the tip of the rod 139, and the detection direction of the sensor 138 is perpendicular to the extension direction of the rod 139. The sensor 138 detects the connected and released states of the rocker arms 111, 121 from the movement of the tip of the rod 139. A command signal from a control unit (not shown) to the variable valve gear 100 and the detection signal of the sensor 138 are compared to detect a fault in the variable valve gear 100.

[0045] In the released state of the pair of rocker arms 111, 121, no pressing force is applied from the pressing member 131 to the connecting pin 115, and the spring force of the resilience spring 137 is applied to the release pin 125 via the transmission member 136. The step 116 of the connecting pin 115 abuts against the stopper 113 of the rocker arm 111, and the step 126 of the release pin 125 abuts against the stopper 123 of the rocker arm 121. At this time, the other end 117 of the connecting pin 115 contacts one end 127 of the release pin 125 at the non-connecting position P1 of the gap C1 between the pair of rocker arms 111, 121. The other end 117 of the connecting pin 115 is located outside the rocker arm 121, and the pair of rocker arms 111, 121 are separated.

[0046] 5(B), when the connecting pin 115 is pushed in by the pressing member 131, the connecting pin 115 moves the transmission member 136 to the other side via the release pin 125. The transmission member 136 is pushed into the guide hole 135 of the cylinder head 101, and the repulsive spring 137 is contracted by the transmission member 136, and a repulsive force is accumulated in the repulsive spring 137. The other end 117 of the connecting pin 115 is moved to the other side from the non-connecting position P1 to the connecting position P2 of the rocker arm 121. A part of the connecting pin 115 enters the accommodation hole 122 of the rocker arm 121, and the pair of rocker arms 111, 121 are connected via the connecting pin 115.

[0047] At this time, as the transmission member 136 moves to the other side, the tip of the rod 139 is positioned at the detection position of the sensor 138. When the tip of the rod 139 is detected by the sensor 138, the control unit determines that the variable valve train 100 is operating in accordance with the connection command. On the other hand, when the tip of the rod 139 is not detected by the sensor 138, the control unit determines that the variable valve train 100 is not operating in accordance with the connection command. A malfunction of the variable valve train 100, such as a lock of the connecting pin 115 or the release pin 125, is detected, and a malfunction warning light (MIL) is turned on to notify the driver of the malfunction.

[0048] 5(A), when the pressing of the connecting pin 115 by the pressing member 131 is released, the transmitting member 136 is pushed back by the repulsive force of the repulsive spring 137. The transmitting member 136 presses the release pin 125, and the releasing pin 125 pushes the connecting pin 115 back to one side. The other end 117 of the connecting pin 115 is moved to one side from the connecting position P2 to the non-connecting position P1, and the release pin 125 and the connecting pin 115 are returned to their original positions. A part of the connecting pin 115 comes out of the accommodation hole 122 of the rocker arm 121, and the connection between the pair of rocker arms 111, 121 is released.

[0049] At this time, as the transmission member 136 moves to one side, the tip of the rod 139 is removed from the detection position of the sensor 138. When the tip of the rod 139 is no longer detected by the sensor 138, the control unit determines that the variable valve train 100 is operating in accordance with the release command. On the other hand, when the tip of the rod 139 is detected by the sensor 138, the control unit determines that the variable valve train 100 is not operating in accordance with the release command. A malfunction of the variable valve train 100, such as a lock of the connecting pin 115 or the release pin 125, is detected, and a malfunction warning light is turned on to notify the driver of the malfunction.

[0050] As described above, according to the variable valve train 100 of the third embodiment, the pair of rocker arms 111, 121 can be switched between the connected and released states with a simple configuration. As with the first embodiment, there is no problem such as damage to the repulsion spring 137. Also, the repulsion spring 137 and the sensor 138 are compactly arranged, preventing the variable valve train 100 from becoming large. Furthermore, a malfunction warning light notifies the driver of a malfunction of the variable valve train 100, preventing the driver from continuing to drive with deteriorated exhaust gas.

[0051] Furthermore, in the third embodiment, a solenoid pin or the like is used as the pressing member, but as long as a sensor is provided, a hydraulic cylinder may be formed in one of the rocker arms instead of the pressing member.

[0052] In the third embodiment, the outer circumferential surface of the tip of the rod is formed straight, but the shape of the outer circumferential surface of the tip of the rod is not particularly limited. For example, the outer circumferential surface of the tip of the rod may be formed in a tapered shape, or the outer circumferential surface of the tip of the rod may be formed in a stepped shape.

[0053] In the third embodiment, the type of the sensor is not particularly limited, and may be, for example, a gap sensor, a contact switch, or a non-contact switch. The detection direction of the sensor may be parallel to the extending direction of the rod.

[0054] <Fourth Example> Next, a variable valve train of a fourth embodiment will be described with reference to Fig. 6. The variable valve train of the fourth embodiment differs from the variable valve train of the first embodiment in that the connecting pin and the pressing member are separated when the pair of rocker arms are in the released state. Therefore, a description of the configuration of the fourth embodiment that is similar to that of the first embodiment will be omitted. Fig. 6 is a schematic diagram of the connecting structure of the pair of rocker arms of the fourth embodiment. Fig. 6(A) shows the released state of the pair of rocker arms, and Fig. 6(B) shows the connected state of the pair of rocker arms.

[0055] As shown in Fig. 6(A), a rocker shaft 142 extends from one side to the other inside a cylinder head 141, and a pair of rocker arms 151, 161 are supported by the rocker shaft 142 so as to be able to swing. A connecting pin 155 is disposed in a housing hole 152 of the rocker arm 151, and a release pin 165 is disposed in a housing hole 162 of the rocker arm 161. A pressing member 171 is disposed on one side of the rocker arm 151, and a guide hole 185 is formed in the cylinder head 141 on the other side of the rocker arm 161. A transmission member 186 and a repulsion spring 187 are disposed in the guide hole 185.

[0056] The pressing member 171 is formed by a hydraulic plunger, and one end side of the pressing member 171 is disposed in an accommodation space formed in the cylinder head 141. When the pair of rocker arms 151, 161 are in a released state, a gap C2 is provided between the connecting pin 155 and the pressing member 171. A flange 172 is formed at one end of the pressing member 171, and the accommodation space in the cylinder head 141 is divided into first and second hydraulic chambers 173, 174 by the flange 172. A protrusion 175 is formed at one end of the pressing member 171, and the protrusion 175 abuts against the inner bottom surface of the first hydraulic chamber 173, thereby restricting the movement of the pressing member 171 to one side, and the minimum volume of the first hydraulic chamber 173 is ensured.

[0057] The first hydraulic chamber 173 is connected to an oil control valve 179 via a first oil passage 176, and the second hydraulic chamber 174 is connected to the oil control valve 179 via a second oil passage 177. Oil is supplied to the oil control valve 179 via a third oil passage 178. When oil is supplied from the oil control valve 179 to the first hydraulic chamber 173, the hydraulic pressure in the first hydraulic chamber 173 causes the pressing member 171 to jump out towards the connecting pin 155. When oil is supplied from the oil control valve 179 to the second hydraulic chamber 174, the hydraulic pressure in the second hydraulic chamber 174 causes the pressing member 171 to retract from the connecting pin 155.

[0058] In the released state of the pair of rocker arms 151, 161, the pressing member 171 and the connecting pin 155 are separated with a gap C2 therebetween, and the transmission member 186 pushed out by the repulsion spring 187 is in contact with the release pin 165. The step 156 of the connecting pin 155 abuts against the stopper 153 of the rocker arm 151, and the step 166 of the release pin 165 abuts against the stopper 163 of the rocker arm 161. At this time, the other end 157 of the connecting pin 155 abuts against one end 167 of the release pin 165 at the non-connecting position P1 of the gap C1 between the pair of rocker arms 151, 161. The other end 157 of the connecting pin 155 is located outside the rocker arm 161, and the pair of rocker arms 151, 161 are separated.

[0059] As shown in FIG. 6B, when oil is supplied from the oil control valve 179 to the first hydraulic chamber 173, the pressing member 171 is ejected toward the connecting pin 155 facing it across the gap C2. When the pressing member 171 collides with the connecting pin 155, the impact causes the transmission member 186 to be quickly moved to the other side via the release pin 165. The transmission member 186 is pressed into the guide hole 185 of the cylinder head 141, and the impact between the pressing member 171 and the connecting pin 155 is absorbed by the repulsion spring 187 via the transmission member 186. In this way, the repulsion spring 187 not only pushes back the transmission member 186, but also functions as a buffer.

[0060] Then, the other end 157 of the connecting pin 155 is moved to the other side from the non-connecting position P1 to the connecting position P2 of the rocker arm 161. A part of the connecting pin 155 enters the accommodation hole 162 of the rocker arm 161, thereby connecting the pair of rocker arms 151, 161 via the connecting pin 155. The pair of rocker arms 151, 161 are quickly connected by the impact of the pressing member 171 and the connecting pin 155, which makes it possible to cope with high engine speeds. Note that the gap C2 between the pressing member 171 and the connecting pin 155 is preferably set to a size equal to or greater than 25% of the stroke of the connecting pin 155.

[0061] 6(A), when oil is supplied from the oil control valve 179 to the second hydraulic chamber 174, the pressing member 171 is retracted from the connecting pin 155, and the transmitting member 186 is pushed back by the repulsive force of the repulsive spring 187. The transmitting member 186 pushes in the release pin 165, and the connecting pin 155 is pushed back to one side by the release pin 165. The other end 157 of the connecting pin 155 is moved to one side from the connecting position P2 to the non-connecting position P1, and the release pin 165 and the connecting pin 155 are returned to their original positions. A part of the connecting pin 155 comes out of the accommodation hole 162 of the rocker arm 161, and the connection between the pair of rocker arms 151, 161 is released.

[0062] As described above, according to the variable valve mechanism 140 of the fourth embodiment, the pair of rocker arms 151, 161 can be switched between the connected and released states with a simple configuration. As in the first embodiment, there is no problem such as damage to the repulsion spring 187. Furthermore, by quickly connecting the multiple rocker arms 151, 161, it is possible to accommodate higher engine speeds.

[0063] In addition, in the fourth embodiment, a hydraulic plunger connected to the oil control valve is used as the pressing member, but a solenoid pin or the like may be used as the pressing member as long as there is a gap between the pressing member and the connecting pin.

[0064] <Fifth Example> Next, a variable valve train of a fifth embodiment will be described with reference to Fig. 7. The variable valve train of the fifth embodiment differs from the variable valve train of the first embodiment in that the connecting pin and the release pin are straight pins. Therefore, a description of the same configuration of the fifth embodiment as that of the first embodiment will be omitted. Fig. 7 is a schematic diagram of the connecting structure of a pair of rocker arms of the fifth embodiment. Fig. 7(A) shows the pair of rocker arms in a released state, and Fig. 7(B) shows the pair of rocker arms in a connected state.

[0065] As shown in Fig. 7(A), a rocker shaft 182 extends from one side to the other inside a cylinder head 181, and a pair of rocker arms 191, 201 are supported by the rocker shaft 182 so that they can swing. A connecting pin 195 is disposed in the accommodation hole 192 of the rocker arm 191, and a release pin 205 is disposed in the accommodation hole 202 of the rocker arm 201. A pressing member 211 is disposed on one side of the rocker arm 191, and a guide hole 215 is formed in the cylinder head 181 on the other side of the rocker arm 201. A transmission member 216 and a repulsion spring 217 are disposed in the guide hole 215.

[0066] The accommodating holes 192, 202 of the pair of rocker arms 191, 201 are formed straight, and straight pins are used as the connecting pin 195 and the release pin 205. The connecting pin 195 is formed longer than the accommodating hole 192 of the rocker arm 191, but the release pin 205 is formed to be approximately the same length as the accommodating hole 202 of the rocker arm 201. In this case, the transmission member 216 is abutted against the rocker arm 201, and the connecting pin 195 and the release pin 205 are sandwiched between the transmission member 216 and the pressing member 211, so that the connecting pin 195 and the release pin 205 are positioned in their initial positions.

[0067] In this released state of the pair of rocker arms 191, 201, no pressing force is applied from the pressing member 211 to the connecting pin 195, and the spring force of the resilience spring 217 is applied to the release pin 205 via the transmission member 216. The transmission member 216 abuts against the rocker arm 201, and the release pin 205 is completely accommodated in the accommodation hole 202 of the rocker arm 201. At this time, the other end 197 of the connecting pin 195 contacts one end 207 of the release pin 205 at the non-connecting position P1 in the gap C1 between the pair of rocker arms 191, 201. The other end 197 of the connecting pin 195 is positioned outside the rocker arm 201, and the pair of rocker arms 191, 201 are separated.

[0068] 7(B), when the connecting pin 195 is pushed in by the pressing member 211, the connecting pin 195 moves the transmission member 216 to the other side via the release pin 205. The transmission member 216 is pushed into the guide hole 215 of the cylinder head 181, and the repulsive spring 217 is contracted by the transmission member 216, and a repulsive force is accumulated in the repulsive spring 217. The other end 197 of the connecting pin 195 is moved to the other side from the non-connecting position P1 to the connecting position P2 of the rocker arm 201. A part of the connecting pin 195 enters the accommodation hole 202 of the rocker arm 201, and the pair of rocker arms 191, 201 are connected via the connecting pin 195.

[0069] 7(A), when the pressing of connecting pin 195 by pressing member 211 is released, transmitting member 216 is pushed back by the repulsive force of repulsive spring 217. Release pin 205 is pressed in by transmitting member 216, and connecting pin 195 is pushed back to one side by release pin 205. The other end 197 of connecting pin 195 is moved to one side from connecting position P2 to non-connecting position P1, and transmitting member 216 hits rocker arm 201, and release pin 205 and connecting pin 195 are returned to their original positions. A part of connecting pin 195 comes out of accommodation hole 202 of rocker arm 201, and the connection between the pair of rocker arms 191, 201 is released.

[0070] As described above, according to the variable valve device 180 of the fifth embodiment, the pair of rocker arms 191, 201 can be switched between the connected state and the released state with a simpler configuration. As in the first embodiment, there is no problem such as damage to the repulsion spring 217. Furthermore, the pin shapes of the connecting pin 195 and the release pin 205 are simplified, allowing costs to be reduced.

[0071] In the fifth embodiment, the connecting pin and the release pin are straight pins, but at least one of the connecting pin and the release pin may be a straight pin. For example, a straight pin may be used as the connecting pin and a stepped pin as the release pin, or a stepped pin may be used as the connecting pin and a straight pin as the release pin.

[0072] <Sixth Example> Next, a variable valve train of a sixth embodiment will be described with reference to Fig. 8. The variable valve train of the sixth embodiment differs from the variable valve train of the first embodiment in that the connecting pin, release pin, pressing member, transmission member, and repulsion spring are coaxially arranged. Therefore, a description of the configuration of the sixth embodiment that is similar to that of the first embodiment will be omitted. Fig. 8 is a schematic diagram of the connecting structure of a pair of rocker arms of the sixth embodiment. Fig. 8(A) shows the pair of rocker arms in a released state, and Fig. 8(B) shows the pair of rocker arms in a connected state.

[0073] As shown in Fig. 8(A), a rocker shaft 222 extends from one side to the other inside the cylinder head 221, and a pair of rocker arms 231, 241 are supported by the rocker shaft 222 so as to be able to swing. A connecting pin 235 is disposed in the accommodation hole 232 of the rocker arm 231, and a release pin 245 is disposed in the accommodation hole 242 of the rocker arm 241. A pressing member 251 is disposed on one side of the rocker arm 231, and a guide hole 255 is formed in the cylinder head 221 on the other side of the rocker arm 241. A transmission member 256 and a repulsion spring 257 are disposed in the guide hole 255.

[0074] The accommodating holes 232, 242 of the pair of rocker arms 231, 241 are formed straight, and straight pins are used as the connecting pin 235 and the release pin 245. The connecting pin 235 is formed longer than the accommodating hole 232 of the rocker arm 231, but the release pin 245 is formed to be approximately the same length as the accommodating hole 242 of the rocker arm 241. In this case, the transmission member 256 is abutted against the rocker arm 241, and the connecting pin 235 and the release pin 245 are sandwiched between the transmission member 256 and the pressing member 251, so that the connecting pin 235 and the release pin 245 are positioned in their initial positions.

[0075] The outer diameter of the pressing member 251 is larger than the outer diameter of the connecting pin 235, and the outer diameter of the transmission member 256 is larger than the outer diameter of the release pin 245. When the pair of intake valves 12 (see FIG. 1) are in a closed state, the central axes O2, O3 of the pressing member 251 and the transmission member 256 and the central axes O1 of the connecting pin 235 and the release pin 245 are arranged coaxially, suppressing axial wobble during movement of the connecting pin 235 and the release pin 245. The transmission member 256 is formed in a bottomed cylindrical shape, and one end side of the repulsion spring 257 enters the inside of the transmission member 256. By entering the repulsion spring 257 inside the transmission member 256, the installation space of the transmission member 256 and the repulsion spring 257 is saved.

[0076] In this released state of the pair of rocker arms 231, 241, no pressing force is applied from the pressing member 251 to the connecting pin 235, and the spring force of the resilience spring 257 is applied to the release pin 245 via the transmission member 256. The transmission member 256 abuts against the rocker arm 241, and the release pin 245 is completely accommodated in the accommodation hole 242 of the rocker arm 241. At this time, the other end 237 of the connecting pin 235 contacts one end 247 of the release pin 245 at the non-connecting position P1 in the gap C1 between the pair of rocker arms 231, 241. The other end 237 of the connecting pin 235 is positioned outside the rocker arm 241, and the pair of rocker arms 231, 241 are separated.

[0077] 8(B), when the connecting pin 235 is pushed in by the pressing member 251, the connecting pin 235 moves the transmission member 256 to the other side via the release pin 245. The transmission member 256 is pushed into the guide hole 255 of the cylinder head 221, and the repulsive spring 257 is contracted by the transmission member 256, and a repulsive force is accumulated in the repulsive spring 257. The other end 237 of the connecting pin 235 is moved to the other side from the non-connecting position P1 to the connecting position P2 of the rocker arm 241. A part of the connecting pin 235 enters the accommodation hole 242 of the rocker arm 241, and the pair of rocker arms 231, 241 are connected via the connecting pin 235.

[0078] 8(A), when the pressing of connecting pin 235 by pressing member 251 is released, transmitting member 256 is pushed back by the repulsive force of repulsive spring 257. Release pin 245 is pressed in by transmitting member 256, and connecting pin 235 is pushed back to one side by release pin 245. The other end 237 of connecting pin 235 is moved to one side from connecting position P2 to non-connecting position P1, and transmitting member 256 hits rocker arm 241, and release pin 245 and connecting pin 235 are returned to their original positions. A part of connecting pin 235 comes out of accommodation hole 242 of rocker arm 241, and the connection between the pair of rocker arms 231, 241 is released.

[0079] As described above, according to the variable valve device 220 of the sixth embodiment, the pair of rocker arms 231, 241 can be switched between the connected state and the released state with a simpler configuration. As in the first embodiment, there is no problem such as damage to the repulsion spring 257. Also, the pin shapes of the connecting pin 235 and the release pin 245 are simplified, which allows costs to be reduced. Furthermore, axial wobble of the connecting pin 235 and the release pin 245 when they move is suppressed, and locking of the connecting pin 235 and the release pin 245 is suppressed.

[0080] In the sixth embodiment, a configuration in which a part of the repulsion spring is inserted into the cylindrical transmission member with a bottom is illustrated, but the shape of the transmission member is not particularly limited as long as the connecting pin, the release pin, the pressing member, the transmission member, and the repulsion spring are arranged coaxially. For example, the transmission member may be formed in a straight pin shape.

[0081] <Seventh Example> Next, a variable valve train of the seventh embodiment will be described with reference to Fig. 9. The variable valve train of the seventh embodiment differs from the variable valve train of the first embodiment in that flanges are formed on the connecting pin, release pin, pressing member, and transmission member. Therefore, a description of the configuration of the seventh embodiment that is similar to that of the first embodiment will be omitted. Fig. 9 is a schematic diagram of the connecting structure of a pair of rocker arms of the seventh embodiment. Fig. 9(A) shows the pair of rocker arms in a released state, and Fig. 9(B) shows the pair of rocker arms in a connected state.

[0082] 9(A), a rocker shaft 262 extends from one side to the other inside a cylinder head 261, and a pair of rocker arms 271, 281 are supported by the rocker shaft 262 so as to be able to swing. A connecting pin 275 is disposed in a housing hole 272 of the rocker arm 271, and a release pin 285 is disposed in a housing hole 282 of the rocker arm 281. A pressing member 291 is disposed on one side of the rocker arm 271, and a guide hole 295 is formed in the cylinder head 261 on the other side of the rocker arm 281. A transmission member 296 and a repulsion spring 297 are disposed in the guide hole 295.

[0083] The accommodating holes 272, 282 of the pair of rocker arms 271, 281 are formed straight, and flange pins are used as the connecting pin 275 and the release pin 285. A flange 276 is formed at one end of the connecting pin 275 protruding from one side from the rocker arm 271, and a flange 286 is formed at the other end of the release pin 285 protruding from the other side from the rocker arm 281. In this case, the flange 276 of the connecting pin 275 abuts against the rocker arm 271 to restrict the pushing of the connecting pin 275, and the flange 286 of the release pin 285 abuts against the rocker arm 281 to restrict the pushing back of the release pin 285.

[0084] Flange pins are also used for pressing member 291 and transmission member 296. A flange 292 is formed at the other end of pressing member 291 that contacts connecting pin 275, and a flange 298 is formed at one end of transmission member 296 that contacts release pin 285. Since flanges 276, 292 are formed on connecting pin 275 and pressing member 291, the contact area between connecting pin 275 and pressing member 291 is increased. Since flanges 286, 298 are formed on release pin 285 and transmission member 296, the contact area between release pin 285 and transmission member 296 is increased. The increased contact area suppresses axial wobble when connecting pin 275 and release pin 285 move.

[0085] In this released state of the pair of rocker arms 271, 281, no pressing force is applied from the pressing member 291 to the connecting pin 275, and the spring force of the resilience spring 297 is applied to the release pin 285 via the transmission member 296. The flange 286 of the release pin 285 abuts against the rocker arm 281, and the release pin 285 is positioned at the initial position. At this time, the other end 277 of the connecting pin 275 contacts one end 287 of the release pin 285 at the non-connecting position P1 in the gap C1 between the pair of rocker arms 271, 281. The other end 277 of the connecting pin 275 is positioned outside the rocker arm 281, and the pair of rocker arms 271, 281 are separated.

[0086] 9(B), when the connecting pin 275 is pushed in by the pressing member 291, the connecting pin 275 moves the transmission member 296 to the other side via the release pin 285. The transmission member 296 is pushed into the guide hole 295 of the cylinder head 261, and the repulsion spring 297 is compressed by the transmission member 296. The other end 277 of the connecting pin 275 is moved to the other side from the non-connecting position P1 to the connecting position P2 of the rocker arm 281, and the flange 276 of the connecting pin 275 abuts against the rocker arm 271, restricting the movement of the connecting pin 275. A part of the connecting pin 275 enters the accommodation hole 282 of the rocker arm 281, and the pair of rocker arms 271, 281 are connected via the connecting pin 275.

[0087] 9(A), when the pressing of connecting pin 275 by pressing member 291 is released, transmitting member 296 is pushed back by the repulsive force of repulsive spring 297. Release pin 285 is pressed in by transmitting member 296, and connecting pin 275 is pushed back to one side by release pin 285. The other end 277 of connecting pin 275 is moved to one side from connecting position P2 to non-connecting position P1, and flange 286 of release pin 285 abuts against rocker arm 281, and release pin 285 and connecting pin 275 are returned to their original positions. A part of connecting pin 275 comes out of accommodation hole 282 of rocker arm 281, and the connection between the pair of rocker arms 271, 281 is released.

[0088] As described above, according to the variable valve device 260 of the seventh embodiment, the pair of rocker arms 271, 281 can be switched between the connected state and the released state with a simple configuration. As in the first embodiment, there is no problem such as damage to the repulsion spring 297. Furthermore, axial wobble of the connecting pin 275 and the release pin 285 when they move is suppressed, and locking of the connecting pin 275 and the release pin 285 is suppressed.

[0089] In the seventh embodiment, the connecting pin, the release pin, the pressing member, and the transmission member are flange pins, but at least one of the connecting pin, the release pin, the pressing member, and the transmission member may be a flange pin. For example, a flange pin may be used as the connecting pin, and a straight pin may be used as the release pin, the pressing member, and the transmission member.

[0090] In the seventh embodiment, a stepped pin may be used as the connecting pin, a flange pin may be used as the release pin, and a straight pin may be used as the pressing member and the transmitting member.

[0091] In the seventh embodiment, stepped pins may be used as the connecting pin and the releasing pin, a straight pin may be used as the pressing member, and a flange pin may be used as the transmitting member.

[0092] In the seventh embodiment, a stepped pin may be used as the connecting pin, a flange pin may be used as the release pin and the transmission member, and a straight pin may be used as the pressing member.

[0093] In the seventh embodiment, straight pins may be used as the connecting pin, the pressing member, and the transmitting member, and a flange pin may be used as the release pin.

[0094] In the seventh embodiment, straight pins may be used as the connecting pin, the release pin and the pressing member, and a flange pin may be used as the transmitting member.

[0095] In the above embodiments, the transmission member and the resilience spring are disposed in the cylinder head, but the transmission member and the resilience spring may be disposed in the cam housing that supports the camshaft, or may be disposed on a member fixed to the cylinder head and the cam housing.

[0096] In addition, in each of the above embodiments, a seesaw type rocker arm is exemplified, but the type of rocker arm is not particularly limited, and a finger follower type rocker arm may also be used.

[0097] In addition, in each of the above embodiments, a pair of rocker arms is provided on the intake side of the variable valve device, but it is sufficient if multiple rocker arms are provided on the intake side of the variable valve device. For example, three or more rocker arms may be provided on the intake side of the variable valve device.

[0098] In addition, in each of the above embodiments, a single rocker arm is provided on the exhaust side of the variable valve device, but multiple rocker arms may be provided on the exhaust side of the variable valve device. In this case, the multiple rocker arms on the exhaust side may also be configured to be switchable between a connected state and a released state.

[0099] Further, in each of the above embodiments, the rocker arms are adjacent to each other, but the rocker arms may be spaced apart.

[0100] In addition, in some embodiments, a configuration has been illustrated in which the central axes of the pressing member and the transmission member and the central axes of the connecting pin and the release pin are misaligned, but the central axes of the pressing member and the transmission member and the central axes of the connecting pin and the release pin may be arranged coaxially.

[0101] In addition, in some of the embodiments, a resilient spring or a hydraulic cylinder is exemplified as the pushing-back member, but the pushing-back member may be any member arranged to push back the transmission member from the other side. For example, the pushing-back member may be formed of an elastic member such as rubber.

[0102] The exhaust system of the present embodiment may be used not only in the engine of the saddle-ride vehicle but also in the engine of other vehicles. The saddle-ride vehicle is not limited to a motorcycle but may be any vehicle equipped with an engine. The saddle-ride vehicle is not limited to vehicles in general on which the rider sits astride the seat, but also includes scooter-type vehicles on which the rider does not sit astride the seat.

[0103] As described above, the variable valve device (20) is a variable valve device capable of changing valve operation in the cylinder head (10), and includes a rocker shaft (27) extending from one side to the other within the cylinder head, a plurality of rocker arms (31, 41) that can swing about the axis of the rocker shaft, a connecting pin (36) arranged in a receiving hole (33) of the rocker arm that is closer to one side in the axial direction, a release pin (46) arranged in a receiving hole (43) of the rocker arm that is closer to the other side in the axial direction, and a release pin (47) arranged on one side of the rocker arm that is closer to the one side. The device includes a pressing member (55) arranged on the other side of the rocker arm closer to the other side, a transmission member (58) arranged on the other side of the rocker arm closer to the other side, and a push-back member (rebound spring 59) arranged to push back the transmission member from the other side, and the pressing member pushes the release pin to the other side while pushing the connecting pin into the accommodation hole of the rocker arm closer to the other side to connect the multiple rocker arms, and the transmission member is pushed back by the push-back member and pushes the connecting pin back into the accommodation hole of the rocker arm closer to the one side via the release pin to release the connection of the multiple rocker arms. According to this configuration, when the connecting pin is pushed to the other side, the connecting pin partially enters from the accommodation hole of the rocker arm closer to the one side into the accommodation hole of the rocker arm closer to the other side, and the multiple rocker arms are connected via the connecting pin. When the pushing of the connecting pin is released, the push-back member pushes the connecting pin back to one side via the transmission member and the release pin, and the connection of the multiple rocker arms is released. In this way, even if a rebound spring is not arranged on the rocker arm, the multiple rocker arms can be switched between the connected state and the released state with a simple configuration.

[0104] In the variable valve train, the push-back member is a repulsive spring arranged to contact the transmission member from the other side, and the pressing member pushes the release pin to the other side against the spring force of the repulsive spring while pushing the connecting pin into the accommodation hole of the rocker arm closer to the other side to connect the multiple rocker arms, and the transmission member is pushed back by the repulsive force of the repulsive spring and pushes the connecting pin back into the accommodation hole of the rocker arm closer to the one side via the release pin to release the connection of the multiple rocker arms. According to this configuration, when the connecting pin is pushed to the other side, the connecting pin partially enters from the accommodation hole of the rocker arm closer to the one side into the accommodation hole of the rocker arm closer to the other side, and the multiple rocker arms are connected via the connecting pin. When the pushing of the connecting pin is released, the repulsive force of the repulsive spring pushes the connecting pin back to the one side via the transmission member and the release pin, and the connection of the multiple rocker arms is released. In addition, the repulsive spring does not swing together with the rocker arm, and damage to the repulsive spring due to resonance during engine operation and wear of the peripheral members of the repulsive spring are suppressed.

[0105] In the variable valve mechanism, the transmission member and the push-back member are disposed in the cylinder head or the cam housing that supports the camshaft. With this configuration, there is no need to add new parts for arranging the rebound spring, and the variable valve mechanism can be prevented from becoming large.

[0106] In the variable valve mechanism, the central axes (O1) of the connecting pin and the release pin are closer to the rocker shaft than the central axes (O1, O2) of the pressing member and the transmission member. With this configuration, the central axes of the connecting pin and the release pin are closer to the rocker shaft, making it possible to reduce the size of the multiple rocker arms.

[0107] In the variable valve device, when the rocker arms are in the released state, the connecting pin and the pressing member are separated. With this configuration, the pressing member quickly connects the rocker arms due to the impact of the connecting pin, making it possible to accommodate higher engine speeds.

[0108] The variable valve train is provided with a sensor (138) disposed on the other side of the push-back member, and the sensor detects the connected and released states of the multiple rocker arms. With this configuration, it is possible to detect malfunctions in the variable valve train, such as a locked connecting pin. In addition, because the sensor is disposed on the other side of the push-back member, the valve train components can be made compact.

[0109] In the variable valve mechanism, a rod (139) extending toward a sensor is formed on the transmission member, and the sensor detects the connected and disconnected states of the multiple rocker arms from the movement of the rod. With this configuration, by extending the rod from the transmission member, it is possible to improve the degree of freedom in arranging the sensor on the other side of the push-back member.

[0110] In the variable valve system, the repulsive spring is a coil spring, and the rod passes through the inside of the repulsive spring and extends to the other side. With this configuration, the repulsive spring and the transmission member can be arranged compactly, preventing the variable valve system from becoming large.

[0111] In another variable valve device, a variable valve device (60) capable of changing valve operation in a cylinder head includes a rocker shaft (62) extending from one side to the other within the cylinder head, a plurality of rocker arms (71, 81) capable of swinging around the axis of the rocker shaft, a connecting pin (75) arranged in an accommodation hole (72) of the rocker arm closer to one side in the axial direction, a release pin (85) arranged in an accommodation hole (82) of the rocker arm closer to the other side in the axial direction, a transmission member (96) arranged on the other side of the rocker arm closer to the other side, and a push-back member (98) arranged so as to push back against the transmission member from the other side, wherein the rocker arm closer to the one side is formed with a hydraulic cylinder that pushes the connecting pin to the other side, and the hydraulic cylinder pushes the release pin to the other side while pushing the connecting pin into the accommodation hole of the rocker arm closer to the other side, connecting the multiple rocker arms, and the transmission member is pushed back by the push-back member to push the connecting pin back into the accommodation hole of the rocker arm closer to the one side via the release pin, thereby releasing the connection of the multiple rocker arms. According to this configuration, when the hydraulic cylinder pushes the connecting pin to the other side, the connecting pin partially enters from the accommodation hole of the rocker arm closer to one side into the accommodation hole of the rocker arm closer to the other side, connecting the multiple rocker arms via the connecting pin. When the pushing of the connecting pin is released, the push-back member pushes the connecting pin back to the one side via the transmission member and the release pin, disconnecting the multiple rocker arms. In this way, even if no repulsion spring is arranged in the rocker arms, the multiple rocker arms can be switched between the connected state and the released state with a simple configuration.

[0112] Although the present embodiment has been described, other embodiments may be made by combining the above-described embodiments and modifications in whole or in part.

[0113] In addition, the technology of the present invention is not limited to the above examples, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to the progress of technology or a different technology derived therefrom, the invention may be implemented using that method. Therefore, the claims cover all embodiments that may be included within the scope of the technical idea. [Explanation of symbols]

[0114] 10, 61, 101, 141, 181, 221, 261: Cylinder head 20, 60, 100, 140, 180, 220, 260: Variable valve gear 27, 62, 102, 142, 182, 222, 262: Rocker shaft 31, 71, 111, 151, 191, 231, 271: One-sided rocker arm 33, 72, 112, 152, 192, 232, 272: One-sided storage hole 36, 75, 115, 155, 195, 235, 275: Connecting pin 41, 81, 121, 161, 201, 241, 281: Rocker arm on the other side 43, 82, 122, 162, 202, 242, 282: Other side receiving hole 46, 85, 125, 165, 205, 245, 285: Release pin 55, 131, 171, 211, 251, 291: Pressing members 58, 96, 136, 186, 216, 256, 296: Transmission parts 59, 137, 187, 217, 257, 297: Rebound springs (push-back members) 98: Hydraulic room 138: Sensor 139: Rod

Claims

1. A variable valve mechanism capable of changing valve operation in a cylinder head, a rocker shaft extending from one side to the other within the cylinder head; A plurality of rocker arms that are pivotable about the axis of the rocker shaft; A connecting pin disposed in a receiving hole of the rocker arm on one side in the axial direction; A release pin disposed in a receiving hole of the rocker arm on the other side in the axial direction; a pressing member disposed on one side of the one-side rocker arm; a transmission member disposed on the other side of the other-side rocker arm; a push-back member arranged to push back the transmission member from the other side, The pressing member presses the connecting pin into the receiving hole of the rocker arm closer to the other side while pushing the release pin to the other side, thereby connecting the plurality of rocker arms together, the transmission member is pushed back by the push-back member, and pushes back the connecting pin into the accommodation hole of the rocker arm closer to the one side via the release pin, thereby releasing the connection between the plurality of rocker arms; A variable valve operating device, wherein the transmission member and the push-back member are disposed in a cam housing that supports the cylinder head or a camshaft.

2. A variable valve mechanism capable of changing valve operation in a cylinder head, a rocker shaft extending from one side to the other within the cylinder head; A plurality of rocker arms that are pivotable about the axis of the rocker shaft; A connecting pin disposed in a receiving hole of the rocker arm on one side in the axial direction; A release pin disposed in a receiving hole of the rocker arm on the other side in the axial direction; a pressing member disposed on one side of the one-side rocker arm; a transmission member disposed on the other side of the other-side rocker arm; a push-back member arranged to push back the transmission member from the other side, The pressing member presses the connecting pin into the receiving hole of the rocker arm closer to the other side while pushing the release pin to the other side, thereby connecting the plurality of rocker arms together, the transmission member is pushed back by the push-back member, and pushes back the connecting pin into the accommodation hole of the rocker arm closer to the one side via the release pin, thereby releasing the connection between the plurality of rocker arms; a central axis of the connecting pin and the release pin being closer to the rocker shaft than a central axis of the pressing member and the transmission member is.

3. the pushing back member is a resilient spring disposed so as to contact the transmission member from the other side, The pressing member pushes the release pin to the other side against the spring force of the resilience spring, while pressing the connecting pin into the receiving hole of the rocker arm closer to the other side to connect the plurality of rocker arms, 3. The variable valve mechanism according to claim 1, wherein the transmission member is pushed back by the repulsive force of the repulsive spring, and pushes the connecting pin back into the accommodation hole of the rocker arm on the one side via the release pin, thereby releasing the connection between the multiple rocker arms.

4. 4. The variable valve mechanism according to claim 1, wherein the connecting pin and the pressing member are spaced apart from each other when the rocker arms are in a released state.

5. A sensor is provided on the other side of the push-back member, 5. The variable valve mechanism according to claim 1, wherein the sensor detects a connected state and a disconnected state of the rocker arms.

6. The transmission member is formed with a rod extending toward the sensor, 6. The variable valve system according to claim 5, wherein the sensor detects the connected and released states of the rocker arms from the movement of the rod.

7. The push-back member is a coil-shaped resilience spring, 7. The variable valve mechanism according to claim 6, wherein the rod passes inside the rebound spring and extends to the other side.

8. A variable valve mechanism capable of changing valve operation in a cylinder head, a rocker shaft extending from one side to the other within the cylinder head; A plurality of rocker arms that are pivotable about the axis of the rocker shaft; A connecting pin disposed in a receiving hole of the rocker arm on one side in the axial direction; A release pin disposed in a receiving hole of the rocker arm on the other side in the axial direction; a transmission member disposed on the other side of the other-side rocker arm; a push-back member arranged to push back the transmission member from the other side, A hydraulic cylinder is formed in the rocker arm on one side to push the connecting pin to the other side, The hydraulic cylinder pushes the release pin to the other side while pushing the connecting pin into the receiving hole of the rocker arm closer to the other side to connect the multiple rocker arms, the transmission member is pushed back by the push-back member, and pushes back the connecting pin into the accommodation hole of the rocker arm closer to the one side via the release pin, thereby releasing the connection between the plurality of rocker arms; A variable valve operating device, wherein the transmission member and the push-back member are disposed in a cam housing that supports the cylinder head or a camshaft.

9. A variable valve mechanism capable of changing valve operation in a cylinder head, a rocker shaft extending from one side to the other within the cylinder head; A plurality of rocker arms that are pivotable about the axis of the rocker shaft; A connecting pin disposed in a receiving hole of the rocker arm on one side in the axial direction; A release pin disposed in a receiving hole of the rocker arm on the other side in the axial direction; a transmission member disposed on the other side of the other-side rocker arm; a push-back member arranged to push back the transmission member from the other side, A hydraulic cylinder is formed in the rocker arm on one side to push the connecting pin to the other side, The hydraulic cylinder pushes the release pin to the other side while pushing the connecting pin into the receiving hole of the rocker arm closer to the other side to connect the multiple rocker arms, the transmission member is pushed back by the push-back member, and pushes back the connecting pin into the accommodation hole of the rocker arm closer to the one side via the release pin, thereby releasing the connection between the plurality of rocker arms; A variable valve mechanism, characterized in that central axes of the connecting pin and the release pin are closer to the rocker shaft than a central axis of the transmission member.

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