Rotating shaft

Abstract

To change the mass of a rotating shaft according to rotation speed.SOLUTION: A rotating shaft includes a shaft body which has an oil storage chamber for storing oil, an oil introduction port communicating with the oil storage chamber, and an oil delivery port communicating with the oil storage chamber. The rotating shaft includes a valve mechanism which has a valve element movable between an open position at which the oil delivery port is opened and a close position at which the oil delivery port is closed. The valve element is moved to the open position or the close position by centrifugal force produced when the shaft body rotates.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a rotating shaft. [Background technology]

[0002] 2. Description of the Related Art Vehicles such as automobiles have engines incorporating a camshaft and a crankshaft (see Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-130161 A [Patent Document 2] Japanese Utility Model Application Publication No. 60-128933 [Patent Document 3] Japanese Patent Application Publication No. 8-270418 [Patent Document 4] Patent No. 6076840 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when designing a rotating shaft such as a camshaft or a crankshaft, it is necessary to optimize the natural frequency and moment of inertia by appropriately designing the mass of the rotating shaft. However, since the natural frequency and moment of inertia required for a rotating shaft are not uniquely determined but change depending on the rotation speed, it has been difficult to set the mass of the rotating shaft that can accommodate a wide range of rotation speeds. For this reason, it is necessary to change the mass of the rotating shaft depending on the rotation speed. [Means for solving the problem]

[0005] According to the present disclosure, the rotating shaft is a rotating shaft used in an engine, and has a shaft body including an oil storage chamber in which oil is stored, an oil inlet port communicating with the oil storage chamber, and an oil discharge port communicating with the oil storage chamber, and a valve mechanism including a valve body movable between an open position that opens the oil discharge port and a closed position that closes the oil discharge port, and the valve body moves to the open position or the closed position by centrifugal force when the shaft body rotates. Effect of the Invention

[0006] According to the present disclosure, the mass of the rotating shaft can be changed according to the rotation speed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a vehicle equipped with an engine. [Diagram 2] FIG. 1 is a diagram illustrating an example of an engine. [Diagram 3] FIG. 3 is a diagram showing the engine along line III-III in FIG. 2. [Figure 4] 4 is a diagram showing a part of the intake camshaft taken along line IV-IV in FIG. 3. [Diagram 5] 5 is a diagram showing an intake camshaft along line VV in FIG. 4. [Figure 6] 5 is a diagram showing an intake camshaft along line VV in FIG. 4. [Figure 7] 5 is a diagram showing an intake camshaft along line VV in FIG. 4. [Figure 8] 5 is a diagram showing an intake camshaft along line VV in FIG. 4. [Figure 9] FIG. 13 is a diagram showing a portion of an intake camshaft equipped with another oil housing. [Figure 10A] FIG. 10 is a diagram showing an intake camshaft along line XX in FIG. 9. [Figure 10B] FIG. 10 is a diagram showing an intake camshaft along line XX in FIG. 9. [Figure 11A] FIG. 10 is a diagram showing an intake camshaft along line XX in FIG. 9. [Figure 11B]FIG. 10 is a diagram showing an intake camshaft along line XX in FIG. 9. [Figure 12] FIG. 13 is a diagram showing a portion of an intake camshaft equipped with another oil housing. [Figure 13A] FIG. 13 is a diagram showing an intake camshaft along line XIII-XIII in FIG. 12. [Figure 13B] FIG. 13 is a diagram showing an intake camshaft along line XIII-XIII in FIG. 12. [Figure 14A] FIG. 13 is a diagram showing an intake camshaft along line XIII-XIII in FIG. 12. [Figure 14B] FIG. 13 is a diagram showing an intake camshaft along line XIII-XIII in FIG. 12. [Figure 15] FIG. 2 is a diagram showing a crank journal of a crankshaft and its vicinity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or substantially same configurations and elements will be designated by the same reference numerals and will not be described repeatedly.

[0009] <Embodiment 1> <Power unit> Fig. 1 is a diagram showing an example of a vehicle 11 equipped with an engine 10. As shown in Fig. 1, the vehicle 11 has a power unit 13 consisting of the engine 10 and a transmission 12. An output shaft 14 of the power unit 13 is connected to wheels 17 via a propeller shaft 15 and a differential mechanism 16. In addition, the engine 10 shown in the figure is a horizontally opposed engine, but is not limited to this and may be, for example, an in-line engine, a V-type engine, or a single-cylinder engine.

[0010] <Engine> Fig. 2 is a diagram showing an example of an engine 10. As shown in Fig. 2, the engine 10 has a cylinder block 20 that constitutes one cylinder bank, a cylinder block 21 that constitutes the other cylinder bank, and a crankshaft 22 supported by the pair of cylinder blocks 20, 21. A piston 24 is housed in a cylinder bore 23 of each of the cylinder blocks 20, 21, and the piston 24 is connected to the crankshaft 22 via a connecting rod 25.

[0011] The engine 10 also has a cylinder head 26 provided on the cylinder block 20 and a cylinder head 27 provided on the cylinder block 21. Both cylinder heads 26, 27 have valve mechanisms 32 that open and close an intake port 30 and an exhaust port 31. That is, the cylinder heads 26, 27 have an intake valve 33 that opens and closes the intake port 30, and an intake camshaft (rotary shaft) 34 that drives the intake valve 33. Furthermore, the cylinder heads 26, 27 have an exhaust valve 35 that opens and closes the exhaust port 31, and an exhaust camshaft (rotary shaft) 36 that drives the exhaust valve 35. The cylinder heads 26, 27 each have a head main body 37 that is attached to the cylinder blocks 20, 21, and a rocker cover 38 that is attached to the head main body 37.

[0012] Fig. 3 is a diagram showing the engine 10 along the line III-III in Fig. 2. The structure of the cylinder head 26 will be described with reference to Fig. 3, but the structure of the cylinder head 27 is similar to that of the cylinder head 26 and therefore will not be described here. As shown in Fig. 3, the head body 37 of the cylinder head 26 has three support walls 37a that support the cam journals 34a to 34c of the intake camshaft 34. In addition, the head body 37 of the cylinder head 26 has three support walls 37b that support the cam journals 36a to 36c of the exhaust camshaft 36.

[0013] The intake camshaft 34 has an oil housing 41 with a cam sprocket 40 at one end. The exhaust camshaft 36 has an oil housing 43 with a cam sprocket 42 at one end. A timing chain 44 is wound around the cam sprockets 40, 42 of the oil housings 41, 43. The timing chain 44 is also wound around a crank sprocket (not shown) of the crankshaft 22. The oil housings 41, 43 and the timing chain 44 are housed in a chain chamber 46 in a chain cover 45.

[0014] <Camshaft> Fig. 4 is a diagram showing a part of the intake camshaft 34 taken along line IV-IV in Fig. 3. Figs. 5, 6, 7, and 8 are diagrams showing the intake camshaft 34 taken along line VV in Fig. 4. Figs. 5 and 6 show the intake camshaft 34 at low revolutions, and Figs. 7 and 8 show the intake camshaft 34 at high revolutions. Note that oil is indicated by cross-hatching in Figs. 6 and 8. The structure of the intake camshaft 34 will be described below, but the structure of the exhaust camshaft 36 will not be described because it is similar to the structure of the intake camshaft 34.

[0015] 3 and 4, the intake camshaft 34 used in the engine 10 has a shaft body 50 equipped with an oil housing 41. The shaft body 50 also has cam journals 34a to 34c, a cam lobe 51, and a mounting portion 52. As shown in Fig. 4, an internal flow passage 53 is formed radially inward of the cam journal 34a and the mounting portion 52, and an introduction port (oil introduction port) 54 communicating with the internal flow passage 53 is formed in the cam journal 34a.

[0016] 4, the support wall 37a of the cylinder head 26 supporting the cam journal 34a has an oil passage 55, and the oil passage 55 of the support wall 37a and the internal passage 53 of the shaft body 50 communicate with each other via an introduction port 54. The oil passage 55 of the support wall 37a provided in the cylinder head 26 is connected to the discharge port of the oil pump via an oil passage (not shown) of the cylinder block.

[0017] 4 and 5, the oil housing 41 has a disk 60 fixed to the mounting portion 52, a disk 61 arranged opposite to the disk 60, an outer peripheral wall 62 provided on the outer edges of the disks 60 and 61, and a partition wall 63 arranged radially inside the outer peripheral wall 62. An inner storage chamber 64 is defined inside the partition wall 63, and an outer storage chamber 65 is defined between the outer peripheral wall 62 and the partition wall 63.

[0018] The disk 60 has an opening 60a, and the internal flow passage 53 and the inner storage chamber 64 communicate with each other via the opening 60a. The partition wall 63 has a communication port 66, and the inner storage chamber 64 and the outer storage chamber 65 communicate with each other via the communication port 66. Furthermore, the outer peripheral wall 62 has a discharge port (oil discharge port) 67, and the outer storage chamber 65 and the chain chamber 46 communicate with each other via the discharge port 67.

[0019] In this way, the shaft body 50 of the intake camshaft 34 has an oil storage chamber 70 consisting of the internal flow passage 53, the inner storage chamber 64, and the outer storage chamber 65. The oil storage chamber 70 of the shaft body 50 is partitioned by the partition wall 63 into a first storage chamber 71 on the inlet port 54 side consisting of the internal flow passage 53 and the inner storage chamber 64, and a second storage chamber 72 on the discharge port 67 side consisting of the outer storage chamber 65.

[0020] The intake camshaft 34 has a valve mechanism 80 that is actuated by centrifugal force generated when the shaft body 50 rotates. The valve mechanism 80 has a valve body 81 and a spring member 82. The valve body 81 of the valve mechanism 80 is movable between an oil discharge position where the discharge port 67 is opened and the communication port 66 is closed, and an oil holding position where the discharge port 67 is closed and the communication port 66 is opened. The spring member 82 of the valve mechanism 80 biases the valve body 81 toward the oil discharge position. The oil discharge position of the valve body 81 is an open position where the discharge port 67 is opened, and the oil holding position of the valve body 81 is a closed position where the discharge port 67 is closed.

[0021] As shown in Fig. 5, when the rotation speed of the intake camshaft 34, i.e., the rotation speed of the shaft body 50, is low and falls below a threshold value, the centrifugal force acting on the valve body 81 falls below the spring force of the spring member 82, and the spring force causes the valve body 81 to move to the oil discharge position. When the valve body 81 moves to the oil discharge position, the valve body 81 moves away from the discharge port 67, opening the discharge port 67, and the oil in the second storage chamber 72 is discharged to the chain chamber 46, as shown by the arrow FL1 in Fig. 6. In addition, the communication port 66 is closed by the valve body 81, so that the oil in the first storage chamber 71 is retained in the first storage chamber 71. The oil discharged to the chain chamber 46 flows to the oil pan 47 below and is then sucked in again by an oil pump (not shown).

[0022] On the other hand, as shown in Fig. 7, when the intake camshaft 34 is rotating at a high speed and exceeds a threshold value, the centrifugal force acting on the valve body 81 exceeds the spring force of the spring member 82, and the valve body 81 moves to the oil retaining position due to the centrifugal force. When the valve body 81 moves to the oil retaining position in this manner, the discharge port 67 is closed and the communication port 66 is opened, so that the oil is retained in both the first storage chamber 71 and the second storage chamber 72, as shown in Fig. 8. In other words, when the intake camshaft 34 is rotating at a high speed, more oil is stored in the oil housing 41 than when the intake camshaft 34 is rotating at a low speed.

[0023] As described above, the amount of oil stored in the oil housing 41 decreases when the intake camshaft 34 is rotating at a low speed, but increases when the intake camshaft 34 is rotating at a high speed. In other words, the mass of the intake camshaft 34, including the oil, decreases when the intake camshaft 34 is rotating at a low speed, when the amount of oil decreases, but the mass of the intake camshaft 34, including the oil, increases when the intake camshaft 34 is rotating at a high speed, when the amount of oil increases. In this way, since the mass of the intake camshaft 34 can be changed according to the rotation speed, the natural frequency and moment of inertia of the intake camshaft 34 can be changed according to the rotation speed.

[0024] In this way, by changing the natural frequency of the intake camshaft 34 according to the rotation speed, it is possible to suppress vehicle vibration caused by resonance between the intake camshaft 34 and other parts. In other words, since the natural frequency of the intake camshaft 34 can be changed in the rotation speed range where the intake camshaft 34 resonates with other parts, it is possible to avoid resonance between the intake camshaft 34 and other parts, and it is possible to suppress vehicle vibration caused by resonance.

[0025] Furthermore, by changing the inertia, or moment of inertia, of the intake camshaft 34 according to the rotation speed, it is possible to suppress vibration of the intake camshaft 34 and thereby suppress vehicle vibration. That is, since the moment of inertia of the intake camshaft 34 can be increased in the rotation speed range where vibration of the intake camshaft 34 occurs, it is possible to suppress vibration of the intake camshaft 34 and thereby suppress vehicle vibration.

[0026] Moreover, because the mass of the intake camshaft 34 is increased by the oil, the mass of the intake camshaft 34 excluding the oil can be reduced. In other words, the amount of metal material used to form the intake camshaft 34 can be reduced, thereby lowering the manufacturing cost of the intake camshaft 34. In addition, when designing the intake camshaft 34, the mass of the intake camshaft 34 can be freely set by increasing or decreasing the volume of the oil accommodation chamber 70, thereby increasing the degree of freedom in designing the intake camshaft 34.

[0027] As described above, since the intake camshaft 34 and the exhaust camshaft 36 have the same structure, the exhaust camshaft 36 can also achieve the same effect as the intake camshaft 34. In other words, by increasing or decreasing the amount of oil in the oil housing 43 according to the rotation speed, the mass of the exhaust camshaft 36 can be changed according to the rotation speed, and the natural frequency and moment of inertia of the exhaust camshaft 36 can be changed. In this way, since the natural frequency of the exhaust camshaft 36 can be changed according to the rotation speed, vehicle vibration caused by resonance between the exhaust camshaft 36 and other parts can be suppressed. In addition, since the inertia, i.e., the moment of inertia, of the exhaust camshaft 36 can be changed according to the rotation speed, the vibration of the exhaust camshaft 36 can be suppressed, thereby suppressing vehicle vibration.

[0028] 3, the oil housing 41 is provided on the intake camshaft 34, and the oil housing 43 is provided on the exhaust camshaft 36, but the present invention is not limited to this. In other words, if the influence of the intake camshaft 34 on vehicle vibrations is small, the oil housing 41 may be omitted from the intake camshaft 34, and the oil housing 43 may be provided on the exhaust camshaft 36. Also, if the influence of the exhaust camshaft 36 on vehicle vibrations is small, the oil housing 43 may be omitted from the exhaust camshaft 36, and the oil housing 41 may be provided on the intake camshaft 34.

[0029] <Embodiment 2> In the example shown in FIG. 5, the oil housing 41 has the partition wall 63, but this is not limiting, and the partition wall 63 may be omitted from the oil housing 41.

[0030] FIG. 9 is a diagram showing a part of an intake camshaft 91 having another oil housing 90. FIG. 9 shows a cross-sectional portion similar to that shown in FIG. 4. FIG. 10A, FIG. 10B, FIG. 11A, and FIG. 11B show the intake camshaft 91 along the line XX in FIG. 9. FIG. 10A, FIG. 10B, FIG. 11A, and FIG. 11B show the intake camshaft 91 without the cam sprocket 40. FIG. 10A and FIG. 11A show the intake camshaft 91 at low revolutions, and FIG. 10B and FIG. 11B show the intake camshaft 91 at high revolutions. In FIG. 9, FIG. 10A, FIG. 10B, FIG. 11A, and FIG. 11B, the same members and parts as those shown in FIG. 5 are denoted by the same reference numerals, and the description thereof will be omitted.

[0031] 9 and 10A, an intake camshaft (rotary shaft) 91 used in engine 10 has a shaft body 50 equipped with an oil housing 90. The oil housing 90 has a disk 60 fixed to a mounting portion 52, a disk 61 disposed opposite to the disk 60, and an outer peripheral wall 62 provided on the outer edges of the disks 60 and 61. A storage chamber 92 for storing oil is defined inside the outer peripheral wall 62. The storage chamber 92 and the internal flow path 53 communicate with each other via an opening 60a of the disk 60, and the storage chamber 92 and the chain chamber 46 communicate with each other via a discharge port 67 of the outer peripheral wall 62.

[0032] The shaft body 50 of the intake camshaft 91 has an oil storage chamber 93 consisting of an internal flow path 53 and a storage chamber 92. The intake camshaft 91 also has a valve mechanism 96 that is actuated by centrifugal force generated when the shaft body 50 rotates. The valve mechanism 96 has a valve body 94 and a spring member 95. The valve body 94 of the valve mechanism 96 is movable between an open position that opens the exhaust port 67 and a closed position that closes the exhaust port 67. The spring member 95 of the valve mechanism 96 urges the valve body 94 toward the open position.

[0033] As shown in Fig. 10A, when the rotational speed of the intake camshaft 91, i.e., the rotational speed of the shaft body 50, is low and falls below a threshold value, the centrifugal force acting on the valve element 94 is less than the spring force of the spring member 95, and the spring force causes the valve element 94 to move to the open position. When the valve element 94 moves to the open position in this manner, the valve element 94 moves away from the drain port 67, opening the drain port 67, and the oil in the oil storage chamber 93 is discharged into the chain chamber 46, as shown by arrow FL2 in Fig. 11A. The oil discharged into the chain chamber 46 flows into the oil pan 47 below, and is then sucked in again by an oil pump (not shown).

[0034] On the other hand, as shown in Fig. 10B, when the intake camshaft 91 is rotating at a high speed and exceeds a threshold value, the centrifugal force acting on the valve body 94 exceeds the spring force of the spring member 95, and the valve body 94 moves to the closed position due to the centrifugal force. When the valve body 94 moves to the closed position in this manner, the discharge port 67 is closed, and the oil in the oil storage chamber 93 is retained in the oil storage chamber 93, as shown by the cross-hatching in Fig. 11B. In other words, when the intake camshaft 91 is rotating at a high speed, more oil is stored in the oil housing 90 than when the intake camshaft 91 is rotating at a low speed.

[0035] In this way, even if the partition wall 63 is omitted from the oil housing 90, the amount of oil in the oil housing 90 can be increased or decreased according to the rotation speed, so the mass of the intake camshaft 91 can be changed according to the rotation speed. In other words, the natural frequency and moment of inertia of the intake camshaft 91 can be changed according to the rotation speed, and vehicle vibration can be suppressed.

[0036] <Embodiment 3> 4 and 9, the amount of oil in the oil housing 41 is reduced at low revolutions and increased at high revolutions, but the present invention is not limited to this. In other words, the amount of oil in the oil housing 41 may be increased at low revolutions and decreased at high revolutions.

[0037] FIG. 12 is a diagram showing a part of an intake camshaft 101 having another oil housing 100. FIG. 12 shows a cross-sectional portion similar to that shown in FIG. 4. FIG. 13A, FIG. 13B, FIG. 14A, and FIG. 14B show the intake camshaft 101 along the line XIII-XIII in FIG. 12. FIG. 13A, FIG. 13B, FIG. 14A, and FIG. 14B show the intake camshaft 101 without the cam sprocket 40. FIG. 13A and FIG. 14A show the intake camshaft 101 at low revolutions, and FIG. 13B and FIG. 14B show the intake camshaft 101 at high revolutions. In FIG. 12, FIG. 13A, FIG. 13B, FIG. 14A, and FIG. 14B, the same members and parts as those shown in FIG. 5 are denoted by the same reference numerals, and the description thereof will be omitted.

[0038] 12 and 13A, intake camshaft (rotary shaft) 101 used in engine 10 has shaft body 50 equipped with oil housing 100. Oil housing 100 has a disk 60 fixed to mounting portion 52, a disk 61 arranged opposite disk 60, an outer peripheral wall 62 provided on the outer edges of disks 60 and 61, and a partition wall 63 arranged radially inward of outer peripheral wall 62.

[0039] An inner storage chamber 64 is defined inside the partition wall 63, and an outer storage chamber 65 is defined between the outer peripheral wall 62 and the partition wall 63. The internal flow path 53 and the inner storage chamber 64 communicate with each other through an opening 60a of the disk 60, and the inner storage chamber 64 and the outer storage chamber 65 communicate with each other through a communication port 66 of the partition wall 63. Furthermore, the outer storage chamber 65 and the chain chamber 46 communicate with each other through a discharge port 67 of the outer peripheral wall 62.

[0040] The shaft body 50 of the intake camshaft 101 has an oil storage chamber 70 consisting of an internal flow passage 53, an inner storage chamber 64, and an outer storage chamber 65. The oil storage chamber 70 of the shaft body 50 is partitioned by a partition wall 63 into a first storage chamber 71 on the inlet port 54 side consisting of the internal flow passage 53 and the inner storage chamber 64, and a second storage chamber 72 on the outlet port 67 side consisting of the outer storage chamber 65.

[0041] The intake camshaft 101 has a valve mechanism 104 that is actuated by centrifugal force generated when the shaft body 50 rotates. This valve mechanism 104 is composed of a valve unit 102 and a valve unit 103. The valve unit 102, which opens and closes the exhaust port 67, has a valve body (first valve body) 102a and a spring member 102b. Moreover, the valve unit 103, which opens and closes the communication port 66, has a valve body (second valve body) 103a and a spring member 103b.

[0042] The valve element 102a of the valve unit 102 is movable between an open position that opens the exhaust port 67 and a closed position that closes the exhaust port 67. The spring member 102b of the valve unit 102 biases the valve element 102a toward the closed position. In addition, the valve element 103a of the valve unit 103 is movable between an open position that opens the communication port 66 and a closed position that closes the communication port 66. The spring member 103b of the valve unit 103 biases the valve element 103a toward the open position.

[0043] As shown in Fig. 13A, when the rotation speed of the intake camshaft 101, i.e., the rotation speed of the shaft body 50, is low and below a threshold value, the centrifugal force acting on the valve body 102a is less than the spring force of the spring member 102b, so that the spring force causes the valve body 102a to move to the closed position. Also, when the rotation speed of the intake camshaft 101 is low and below a threshold value, the centrifugal force acting on the valve body 103a is less than the spring force of the spring member 103b, so that the spring force causes the valve body 103a to move to the open position. In this way, when the valve body 102a moves to the closed position and the valve body 103a moves to the open position, the discharge port 67 is closed and the communication port 66 is opened, so that the oil is retained in both the first storage chamber 71 and the second storage chamber 72, as shown in Fig. 14A.

[0044] 13B, when the rotation speed of the intake camshaft 101 is high and exceeds the threshold value, the centrifugal force acting on the valve body 102a exceeds the spring force of the spring member 102b, and the centrifugal force moves the valve body 102a to the open position. Also, when the rotation speed of the intake camshaft 101 is high and exceeds the threshold value, the centrifugal force acting on the valve body 103a exceeds the spring force of the spring member 103b, and the centrifugal force moves the valve body 103a to the closed position.

[0045] In this manner, when the valve body 102a moves to the open position and the drain port 67 is opened, the oil in the second housing chamber 72 is discharged to the chain chamber 46, as shown by arrow FL3 in Fig. 14B. When the valve body 103a moves to the closed position and the communication port 66 is closed, the oil in the first housing chamber 71 is retained in the first housing chamber 71. In other words, when the intake camshaft 101 is rotating at high speed, less oil is contained in the oil housing 100 than when the intake camshaft 101 is rotating at low speed. The oil discharged to the chain chamber 46 flows below into the oil pan 47, and is then sucked in again by an oil pump (not shown).

[0046] As described above, the amount of oil stored in the oil housing 100 increases when the intake camshaft 101 is rotating at a low speed, but decreases when the intake camshaft 101 is rotating at a high speed. In other words, the mass of the intake camshaft 101 increases when the intake camshaft 101 is rotating at a low speed, when the amount of oil increases, but decreases when the intake camshaft 101 is rotating at a high speed, when the amount of oil decreases. In this way, since the mass of the intake camshaft 101 can be changed according to the rotation speed, the natural frequency and moment of inertia of the intake camshaft 101 can be changed according to the rotation speed. In addition, since the natural frequency and moment of inertia of the intake camshaft 101 can be changed according to the rotation speed, vehicle vibration can be suppressed.

[0047] <Embodiment 4> In the above description, the oil storage chamber 70 is provided in at least one of the intake camshaft 34 and the exhaust camshaft 36, but this is not limiting, and the oil storage chamber 110 may be provided in the crankshaft (rotating shaft) 22 of the engine 10. Here, Figure 15 is a diagram showing the crank journal 111 of the crankshaft 22 and its vicinity.

[0048] 15, the crankshaft 22 has a shaft body 113 equipped with an oil housing 112. The oil housing 112 has a crank sprocket 114 around which the timing chain 44 is wound. The shaft body 113 has a crank pin 115, a crank journal 111, and an attachment portion 116. An internal flow passage 117 is formed radially inward of the crank journal 111 and the attachment portion 116, and an introduction port (oil introduction port) 118 communicating with the internal flow passage 117 is formed in the crank journal 111.

[0049] 15, a support wall 119 of the cylinder blocks 20, 21 that supports the crank journal 111 has an oil passage 120. The oil passage 120 in the support wall 119 and an internal passage 117 of the shaft body 113 communicate with each other via an introduction port 118. The oil passage 120 in the support wall 119 provided in the cylinder blocks 20, 21 is connected to a discharge port of an oil pump (not shown).

[0050] The oil housing 112 of the crankshaft 22 has a disk 121 fixed to the mounting portion 116 and a disk 122 arranged opposite to the disk 121. The oil housing 112 also has an outer peripheral wall 123 provided on the outer edges of the disks 121 and 122, and a partition wall 124 arranged radially inside the outer peripheral wall 123. An inner storage chamber 125 is defined inside the partition wall 124, and an outer storage chamber 126 is defined between the outer peripheral wall 123 and the partition wall 124.

[0051] The disk 121 has an opening 121a, and the internal flow path 117 and the inner storage chamber 125 communicate with each other via the opening 121a. The partition wall 124 has a communication port 127, and the inner storage chamber 125 and the outer storage chamber 126 communicate with each other via the communication port 127. Furthermore, the outer peripheral wall 123 has a discharge port (oil discharge port) 128, and the outer storage chamber 126 and the chain chamber 46 communicate with each other via the discharge port 128.

[0052] In this way, the shaft body 113 of the crankshaft 22 has the oil storage chamber 110 consisting of the internal flow passage 117, the inner storage chamber 125, and the outer storage chamber 126. The oil storage chamber 110 of the shaft body 113 is partitioned by the partition wall 124 into a first storage chamber 131 on the inlet port 118 side consisting of the internal flow passage 117 and the inner storage chamber 125, and a second storage chamber 132 on the discharge port 128 side consisting of the outer storage chamber 126.

[0053] The crankshaft 22 has a valve mechanism 135 that is actuated by centrifugal force generated when the shaft body 113 rotates. The valve mechanism 135 has a valve body 133 and a spring member 134. The valve body 133 of the valve mechanism 135 is movable between an oil discharge position where the discharge port 128 is opened and the communication port 127 is closed, and an oil holding position where the discharge port 128 is closed and the communication port 127 is opened. The spring member 134 of the valve mechanism 135 biases the valve body 133 toward the oil discharge position. The oil discharge position of the valve body 133 is an open position where the discharge port 128 is opened, and the oil holding position of the valve body 133 is a closed position where the discharge port 128 is closed.

[0054] As described above, the crankshaft 22 equipped with the oil housing 112 can increase or decrease its mass depending on the rotation speed, similar to the above-mentioned intake camshaft 34. That is, when the rotation speed of the crankshaft 22, i.e., the rotation speed of the shaft body 113, is low and falls below a threshold value, the centrifugal force acting on the valve body 133 falls below the spring force of the spring member 134, and the spring force moves the valve body 133 to the oil discharge position.

[0055] In this way, when the valve body 133 moves to the oil discharge position, the valve body 133 moves away from the drain port 128, opening the drain port 128, and the oil in the second housing chamber 132 is discharged into the chain chamber 46. In addition, the communication port 127 is closed by the valve body 133, so the oil in the first housing chamber 131 is retained in the first housing chamber 131. The oil discharged to the chain chamber 46 flows into the oil pan 47 below, and is then sucked in again by an oil pump (not shown).

[0056] On the other hand, when the rotation speed of the crankshaft 22 is high and exceeds the threshold value, the centrifugal force acting on the valve body 133 exceeds the spring force of the spring member 134, and the valve body 133 moves to the oil retaining position by the centrifugal force. When the valve body 133 moves to the oil retaining position in this manner, the discharge port 128 is closed and the communication port 127 is opened, so that oil is stored in both the first storage chamber 131 and the second storage chamber 132. In other words, when the intake camshaft 34 is rotating at high speed, more oil is stored in the oil housing 112 than when the intake camshaft 34 is rotating at low speed.

[0057] As described above, the amount of oil stored in the oil housing 112 decreases when the crankshaft 22 is rotating at a low speed, but increases when the crankshaft 22 is rotating at a high speed. In other words, the mass of the crankshaft 22 decreases when the crankshaft 22 is rotating at a low speed and the amount of oil decreases, but the mass of the crankshaft 22 increases when the crankshaft 22 is rotating at a high speed and the amount of oil increases. In this way, since the mass of the crankshaft 22 can be changed according to the rotation speed, the natural frequency and moment of inertia of the crankshaft 22 can be changed according to the rotation speed.

[0058] In this way, by changing the natural frequency of the crankshaft 22 according to the rotation speed, it is possible to suppress vehicle vibration caused by resonance between the crankshaft 22 and other parts. In other words, since the natural frequency of the crankshaft 22 can be changed in the rotation speed range in which the crankshaft 22 resonates with other parts, it is possible to avoid resonance between the crankshaft 22 and other parts, and it is possible to suppress vehicle vibration caused by resonance.

[0059] Furthermore, by varying the inertia, or moment of inertia, of the crankshaft 22 according to the rotation speed, it is possible to suppress vibration of the crankshaft 22 and thereby suppress vehicle vibration. That is, since the moment of inertia of the crankshaft 22 can be increased in the rotation speed range where vibration of the crankshaft 22 occurs, it is possible to suppress vibration of the crankshaft 22 and thereby suppress vehicle vibration.

[0060] Moreover, since the mass of the crankshaft 22 is increased by the oil, the mass of the crankshaft 22 excluding the oil can be reduced. In other words, the amount of metal material used to form the crankshaft 22 can be reduced, so the manufacturing cost of the crankshaft 22 can be reduced. In addition, when designing the crankshaft 22, the mass of the crankshaft 22 can be freely set by increasing or decreasing the volume of the oil storage chamber 110, so that the degree of freedom in designing the crankshaft 22 can be increased. Note that the oil housing 90 shown in FIG. 9 may be applied to the crankshaft 22, and the oil housing 100 shown in FIG. 12 may be applied to the crankshaft 22.

[0061] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. The illustrated engine 10 is an engine mounted on a vehicle 11, but is not limited thereto. For example, the intake camshaft 34, exhaust camshaft 36, crankshaft 22, etc. of the present disclosure may be applied to an engine used as a power source for other devices. The illustrated engine 10 is a gasoline engine, but is not limited thereto. For example, the intake camshaft 34, exhaust camshaft 36, crankshaft 22, etc. of the present disclosure may be applied to a diesel engine or a hydrogen engine.

[0062] In the example shown in FIG. 3, the oil housing 41 is provided at the end of the intake camshaft 34, but the present invention is not limited thereto. For example, the oil housing 41 may be provided at the center of the intake camshaft 34 in the longitudinal direction. Similarly, in the example shown in FIG. 3, the oil housing 43 is provided at the end of the exhaust camshaft 36, but the present invention is not limited thereto. For example, the oil housing 43 may be provided at the center of the exhaust camshaft 36 in the longitudinal direction. Similarly, in the example shown in FIG. 15, the oil housing 112 is provided at the end of the crankshaft 22, but the present invention is not limited thereto. For example, the oil housing 112 may be provided at the center of the crankshaft 22 in the longitudinal direction. In addition, in the example shown in FIG. 15, the oil housing 112 is provided at the end on the crank sprocket 114 side, but the present invention is not limited thereto. The oil housing 112 may be provided at the end on the flywheel side, that is, the opposite end.

[0063] 13A and 13B, when transitioning from the low rotation region to the high rotation region, the exhaust port 67 is opened by the valve unit 102, and the communication port 66 is closed by the valve unit 103. In this way, during the process of transitioning from the low rotation region to the high rotation region, the exhaust port 67 may be opened by the valve unit 102, and then the communication port 66 may be closed by the valve unit 103. Also, during the process of transitioning from the low rotation region to the high rotation region, the communication port 66 may be opened by the valve unit 103, and then the exhaust port 67 may be closed by the valve unit 102.

[0064] The valve mechanisms 80, 96, 104, 135 are not limited to the structures shown in Figures 4, 9, 12, and 15. For example, the valve mechanisms 80, 96, 104, 135 may be configured by using a spool valve that operates by centrifugal force generated when the shaft body 50, 113 rotates. In addition, in the examples shown in Figures 4, 9, 12, and 15, one valve mechanism 80, 96, 104, 135 is provided, but this is not limited thereto, and a plurality of valve mechanisms 80, 96, 104, 135 may be provided. For example, a plurality of valve mechanisms 80 may be arranged at equal intervals in the circumferential direction for the intake camshaft 34 shown in Figure 4. [Explanation of symbols]

[0065] 10 Engine 22 Crankshaft (rotating shaft) 34 Intake camshaft (rotating shaft) 36 Exhaust camshaft (rotating shaft) 50 Shaft body 54 Inlet port (oil inlet port) 63 Bulkhead 66 Communication port 67 Drain port (oil drain port) 70 Oil Containment Chamber 71 Containment Cell No. 1 72 Containment Cell No. 2 80 Valve mechanism 81 Valve body 82 Spring material 91 Intake camshaft (rotating shaft) 93 Oil Containment Chamber 94 Valve body 96 Valve mechanism 101 Intake camshaft (rotating shaft) 102a Valve body (first valve body) 103a Valve body (second valve body) 104 Valve mechanism 110 Oil Containment Chamber 113 Shaft body 118 Inlet port (oil inlet port) 124 Bulkhead 127 Communication port 128 Drain port (oil drain port) 131 Containment Cell No. 1 132 Second Containment Cell 133 Valve body 135 Valve mechanism

Claims

1. A rotating shaft for use in an engine, a shaft body including an oil storage chamber in which oil is stored, an oil inlet port communicating with the oil storage chamber, and an oil outlet port communicating with the oil storage chamber; a valve mechanism including a valve body movable between an open position for opening the oil discharge port and a closed position for closing the oil discharge port; having The valve body moves to an open position or a closed position by centrifugal force when the shaft body rotates. Rotation axis.

2. 2. The rotating shaft according to claim 1, The valve body moves to a closed position by centrifugal force when the shaft body rotates. Rotation axis.

3. 2. The rotating shaft according to claim 1, The valve body moves to an open position by centrifugal force when the shaft body rotates. Rotation axis.

4. 2. The rotating shaft according to claim 1, the shaft body includes a partition wall that divides the oil accommodating chamber into a first accommodating chamber on the oil inlet port side and a second accommodating chamber on the oil discharge port side, and a communication port that is provided in the partition wall and that communicates between the first accommodating chamber and the second accommodating chamber, the valve body opens the communication port when moving to a closed position where the oil discharge port is closed, and closes the communication port when moving to an open position where the oil discharge port is opened. Rotation axis.

5. 2. The rotating shaft according to claim 1, the shaft body includes a partition wall that divides the oil accommodating chamber into a first accommodating chamber on the oil inlet port side and a second accommodating chamber on the oil discharge port side, and a communication port that is provided in the partition wall and that communicates between the first accommodating chamber and the second accommodating chamber, the valve mechanism includes a first valve body that is the valve body, and a second valve body that is movable between an open position that opens the communication port and a closed position that closes the communication port, The second valve body moves to an open position when the first valve body moves to a closed position, and moves to a closed position when the first valve body moves to the open position. Rotation axis.

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