JP4583297B2 - Internal combustion engine - Google Patents

Description

The present invention comprises three or more N cylinders, a part of which is deactivated and only a predetermined number of cylinders of two or more are operated, and a single cylinder resting state in which all the N cylinders are operated. The present invention relates to an internal combustion engine capable of switching between all-cylinder operation states to be operated.

In a 2-cycle V-type 6-cylinder engine, when the number of cylinders that operate according to an increase in the accelerator opening is increased in order of 2 → 3 → 4 → 6, two cylinders are operated during 2-cylinder operation. Is ignited at regular intervals of 180 °, three cylinders are ignited at equal intervals of 120 ° during three-cylinder operation, and four cylinders are separated at 120 ° intervals and 60 ° intervals during four-cylinder operation. Japanese Patent Application Laid-Open Publication No. 2004-151561 discloses that a mixture is ignited and six cylinders are ignited at equal intervals of 60 ° during four-cylinder operation.
JP-A-8-114133

  By the way, at the time of cylinder resting operation in which the number of operating cylinders decreases, vibration and noise tend to increase as compared to the case of all cylinder operation in which all cylinders operate. In addition, if the ignition intervals of a plurality of cylinders are not uniform, vibration and noise tend to increase, and this tendency becomes prominent when the engine speed is low.

  In the above-mentioned conventional one, in order to reduce vibration and noise, it is necessary to adopt the two-cylinder operation or the three-cylinder operation when trying to make the cylinder ignition interval uniform during the idle cylinder operation. There is a problem that the output is insufficient because it is less than half of all cylinders. If the 4-cylinder operation is employed in order to eliminate this shortage of output, there is a problem that the ignition intervals of the four cylinders become non-uniform as described above, resulting in increased vibration and noise.

  The present invention has been made in view of the above circumstances, and provides an internal combustion engine capable of minimizing the occurrence of vibration and noise while arbitrarily setting the number of cylinders that are operated during cylinder resting operation. Objective.

In order to achieve the above object, according to the first aspect of the present invention, three or more N cylinders are provided, a part of which is deactivated and only a predetermined number of two or more cylinders are operated. In an internal combustion engine capable of switching between a single cylinder resting operation state and an all cylinder operation state in which all N cylinders are operated, the number of cylinders operating in the cylinder resting operation state is a divisor of 2 or more of N Except for the above, in the idle cylinder operation state, the ignition intervals of the operating cylinders are set at equal intervals, and in the all cylinder operation state, different ignition intervals are mixed in one cycle. An internal combustion engine is proposed.

  According to the first aspect of the present invention, since the ignition intervals of the cylinders operating during the cylinder resting operation are set at equal intervals, the vibrations and noises during the cylinder resting operation in which vibration and noise are likely to occur because the number of operating cylinders is small. Can be minimized. Also, even when different ignition intervals are mixed in one cycle during all cylinder operation due to equal interval ignition during cylinder rest operation, the number of cylinders operating during all cylinder operation is large and the engine speed is large. The increase in vibration and noise due to unequal interval ignition is not a problem in practice. Accordingly, it is possible to ensure the quietness of the internal combustion engine in both the idle cylinder operation state and the all cylinder operation state while arbitrarily setting the number of cylinders operating in the idle cylinder operation state.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 9 show an embodiment of the present invention. FIG. 1 is a top view of a cylinder head of a first bank of a V-type six-cylinder internal combustion engine (a view taken along the line 1-1 in FIG. 2). 2 is a sectional view taken along line 2-2 in FIG. 1, FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, FIG. 4 is a sectional view taken along line 4-4 in FIG. 6 is a sectional view taken along line 6-6 in FIG. 3, FIG. 7 is a sectional view taken along line 7-7 in FIG. 3, and FIG. 8 is a schematic diagram showing the cylinder arrangement of the first and second banks of the V-type six-cylinder internal combustion engine. FIG. 9 is a diagram showing ignition intervals of the # 1 to # 6 cylinders.

  As shown in FIG. 8, the # 1 cylinder C1, the # 2 cylinder C2, and the # 3 cylinder C3 are provided in the first bank B1 of the V-type six-cylinder internal combustion engine, and the # 4 cylinder C4 and # 5 cylinder are provided in the second bank B2. C5 and # 6 cylinder C6 are provided. Of the # 1 cylinder C1, # 2 cylinder C2 and # 3 cylinder C3 of the first bank B1, only the # 3 cylinder C3 can be deactivated, and the # 4 cylinder C4, # 5 cylinder C5 and # 6 of the second bank B2 Of cylinder C6, only # 4 cylinder C4 can be deactivated. The structure of the valve mechanism of the # 3 cylinder C3 and the # 4 cylinder C4 that can be deactivated is different from the structure of the valve mechanism of the # 1 cylinder C1, # 2 cylinder C2, # 5 cylinder C5, and # 6 cylinder C6 that cannot be deactivated. ing. The structure of the valve mechanism of the # 3 cylinder C3 and the # 4 cylinder C4 that can be stopped is the same, and the structure of the valve mechanism of the # 3 cylinder C3 will be described as a representative example. The structure of the valve operating mechanisms of the # 1 cylinder C1, the # 2 cylinder C2, the # 5 cylinder C5 and the # 6 cylinder C6, which cannot be stopped, is a well-known general structure, and the description thereof is omitted.

  As shown in FIGS. 1 to 7, an intake port 12 and an exhaust port 13 connected to the combustion chamber 11 are formed in the cylinder head 10, and the intake valve hole 14 is guided by the valve guide 15 so that the stem 16 a is slidable. The exhaust valve hole 17 is opened and closed by the umbrella portion 19b of the exhaust valve 19 slidably guided by the valve guide 18 through the stem 19a. The intake valve 16 and the exhaust valve 19 are urged in the valve closing direction by valve springs 61 and 62, respectively, and are controlled to open and close by a valve mechanism 21 driven by a camshaft 20 rotatably supported by the cylinder head 10. The

  A rocker shaft holder 22 is fastened to the cylinder head 10 by a plurality of bolts 23, and an intake side rocker shaft 24 and an exhaust side rocker shaft 25 are supported by the rocker shaft holder 22 along the cylinder arrangement direction.

  An intake-side drive rocker arm 26 and an intake-side free rocker arm 27 are swingably supported on the intake-side rocker shaft 24, and the intake-side drive rocker arm 26 abuts an adjustment screw 28 on the upper end of the stem 16 a of the intake valve 16. As a result, the intake valve 16 is always linked and connected. One intake side drive rocker arm 26 and one intake side free rocker arm 27 are provided for each of the pair of intake valves 16, 16, and the intake side drive rocker arm 26 drives the pair of intake valves 16, 16. Therefore, the tip is formed to be bifurcated.

  An exhaust-side drive rocker arm 29 and an exhaust-side free rocker arm 30 are swingably supported on the exhaust-side rocker shaft 25. The exhaust-side drive rocker arm 29 applies an adjustment screw 31 to the upper end of the stem 19a of the exhaust valve 19. By being in contact, the exhaust valve 19 is always linked and connected. One exhaust side drive rocker arm 29 and one exhaust side free rocker arm 30 are provided for each of the pair of exhaust valves 19, 19.

  The camshaft 20 includes an intake side valve cam 33 (see FIG. 5) that makes a roller 32 that is pivotally supported by the intake side free rocker arm 27 in rolling contact, and a roller that is pivotally supported by the exhaust side free rocker arms 30 and 30. A pair of exhaust side valve cams 35 and 35 (see FIG. 7) that are in rolling contact with 34 and 34, respectively, and a raised portion 37 (see FIG. 4) that is in sliding contact with a roller 36 provided on the intake side drive rocker arm 26; A pair of raised portions 39, 39 (see FIG. 6) are provided which are in sliding contact with the rollers 38, 38 provided on the exhaust side drive rocker arms 29, 29.

  The intake side valve cam 33 is formed to have a cam profile for opening and closing the intake valve 16, and the exhaust side valve cam 35 is formed to have a cam profile for opening and closing the exhaust valve 19. The portions 37 and 39 are formed so that the intake valve 16 and the exhaust valve 19 are substantially closed. Therefore, the intake valve 16 opens and closes when the intake side drive rocker arm 26 is connected to the intake side free rocker arm 27, but the connection of the intake side drive rocker arm 26 to the intake side free rocker arm 27 is released. In some cases, the valve is substantially closed. The exhaust valve 19 opens and closes when the exhaust side drive rocker arm 29 is connected to the exhaust side free rocker arm 30, but the connection of the exhaust side drive rocker arm 29 to the exhaust side free rocker arm 30 is released. In some cases, the valve is substantially closed.

  The intake-side drive rocker arm 26 and the intake-side free rocker arm 27 are provided with an intake-side switching mechanism 40 that switches connection and release of the intake-side drive rocker arm 26 to and from the intake-side free rocker arm 27 by hydraulic pressure.

  The intake side switching mechanism 40 has one end facing the first hydraulic chamber 41 formed in the intake side drive rocker arm 26 and the other end facing the second hydraulic chamber 42 formed in the intake side free rocker arm 27. And a connection pin 43 slidably fitted to the intake-side drive rocker arm 26 and the intake-side free rocker arm 27, and an intake-side free rocker arm 27 and the connection pin 43 housed in the second hydraulic chamber 42. And a return spring 44 provided therebetween.

  In the intake side switching mechanism 40, when hydraulic pressure is applied to the first hydraulic chamber 41, the connecting pin 43 moves to the second hydraulic chamber 42 side, and the intake side free rocker arm 27 and the intake side drive rocker arm 26 are connected. Is released. Conversely, when the hydraulic pressure acting on the first hydraulic chamber 41 is removed, the connecting pin 43 moves to the first hydraulic chamber 41 side by the elastic force of the return spring 44, and the intake-side free rocker arm 27 and the intake-side drive rocker arm 26. Are concatenated. In this way, the intake-side switching mechanism 40 switches the connection and release of the intake-side free rocker arm 27 to the intake-side drive rocker arm 26 by supplying the hydraulic pressure to the first hydraulic chamber 41, thereby operating the intake valve 16. Can be changed.

  A split member 45 that divides the intake side rocker shaft into two parts is fitted in the intake side rocker shaft 24, and the first hydraulic chamber 41 is provided in the intake side rocker shaft 24 by the split member 45. A first hydraulic oil passage 46 communicating with the second hydraulic fluid passage 47 and a second hydraulic oil passage 47 communicating with the second hydraulic chamber 42 are formed independently of each other.

  Further, the exhaust-side drive rocker arm 29 and the exhaust-side free rocker arm 30 that are adjacently arranged in pairs on the exhaust valve 19 side are connected to and disconnected from the exhaust-side free rocker arm 30. An exhaust side switching mechanism 48 that switches hydraulically is provided.

  The exhaust side switching mechanism 48 has one end facing the first hydraulic chamber 49 formed in the exhaust side drive rocker arm 29 and the other end of the second hydraulic chamber 50 formed in the exhaust side free rocker arm 30. A connection pin 51 slidably fitted to the exhaust side drive rocker arm 29 and the exhaust side free rocker arm 30 and a space between the exhaust side drive rocker arm 29 and the connection pin 51 accommodated in the first hydraulic chamber 49. And a return spring 52.

  In the exhaust side switching mechanism 48, when the hydraulic pressure acting on the second hydraulic chamber 50 is released, the connecting pin 51 moves to the second hydraulic chamber 50 side by the elastic force of the return spring 52, and the exhaust side free rocker arm 30 and The exhaust side drive rocker arm 29 is connected. Conversely, when hydraulic pressure is applied to the second hydraulic chamber 50, the connecting pin 51 moves to the first hydraulic chamber 49 side against the elastic force of the return spring 52, and the exhaust-side free rocker arm 30 and the exhaust-side drive rocker. The connection of the arm 29 is released. In this way, the exhaust-side switching mechanism 48 switches the connection and release of the exhaust-side free rocker arm 30 to the exhaust-side drive rocker arm 29 by supplying the hydraulic pressure to the second hydraulic chamber 50 to operate the exhaust valve 19. Can be changed.

  A split member 53 that divides the exhaust side rocker shaft 28 into two parts is fitted in the exhaust side rocker shaft 25, and the first hydraulic chamber is placed in the exhaust side rocker shaft 25 by the split member 53. A first hydraulic oil passage 54 leading to 49 and a second hydraulic oil passage 55 leading to the second hydraulic chamber 50 are formed independently of each other.

  The intake side for biasing the intake-side free rocker arm 27 to the intake-side valve cam 33 of the camshaft 20 in a state where the intake-side switching mechanism 40 releases the connection of the intake-side free rocker arm 27 to the intake-side drive rocker arm 26. A lost motion spring 56 is provided between the rocker shaft holder 22 and the intake side free rocker arm 27. Further, the exhaust side switching mechanism 48 urges the exhaust side free rocker arm 30 to the exhaust side valve cam 35 of the camshaft 20 in a state where the connection of the exhaust side free rocker arm 30 to the exhaust side drive rocker arm 29 is released. A side lost motion spring 57 is provided between the rocker shaft holder 22 and the exhaust side free rocker arm 30.

  On the base end side of the intake-side free rocker arm 27, a roller 32 that contacts the intake-side valve cam 33 and a spring contact portion 27b that contacts the intake-side lost motion spring 56 are provided. An adjustment screw 28 that comes into contact with the upper end of the stem 16 a of the intake valve 16 is provided on the distal end side, and the intake side switching mechanism 40 is located closer to the intake side drive rocker arm 26 and the intake side free rocker arm 27 than the intake side rocker shaft 24. It is arranged on the base end side. Similarly, on the base end side of the exhaust-side free rocker arm 30, a roller 34 that contacts the exhaust-side valve cam 35 and a spring contact portion 30b that contacts the exhaust-side lost motion spring 57 are provided, and an exhaust-side drive rocker An adjustment screw 31 that abuts the upper end of the stem 19a of the exhaust valve 19 is provided on the distal end side of the arm 29, and the exhaust side switching mechanism 48 is located on the exhaust side drive rocker arm 29 and the exhaust side free rocker rather than the exhaust side rocker shaft 25. It is arranged on the proximal end side of the arm 30.

  Next, the operation of this embodiment will be described.

  As shown in FIG. 8, the firing order of # 1 cylinder C1 to # 6 cylinder C6 is as follows: # 1 cylinder C1 → # 4 cylinder C4 → # 2 cylinder C2 → # 5 cylinder C5 → # 3 cylinder C3 → # 6 cylinder C6 It is. All cylinders # 1 to C6 operate during full cylinder operation, but # 3 cylinder C3 in the first bank B1 and # 4 cylinder C4 in the second bank B2 deactivate during idle cylinder operation. The stop control of the # 3 cylinder C3 and the # 4 cylinder C4 is performed by the valve operating mechanism 21 described with reference to FIGS.

  As shown in FIG. 9, since the internal combustion engine of the present embodiment has a four-stroke cycle, two rotations of the crankshaft (crank angle of 720 °) are one cycle. During idle cylinder operation, four cylinders (# 1 cylinder C1, # 2 cylinder C2, # 5 cylinder C5 and # 6 cylinder C6) other than the # 3 cylinder C3 and # 4 cylinder C4, which are idle cylinders, operate. The ignition interval is set to a uniform 180 °. In other words, during cylinder idle operation, # 1 cylinder C1, # 2 cylinder C2, # 5 cylinder C5 and # 6 cylinder C6 are ignited at intervals of 180 °.

  In general, during the idle cylinder operation (during low speed rotation including idle operation), the number of cylinders that operate is small, and vibration and noise are likely to occur. However, the # 1 cylinder C1, the # 2 cylinders C2, and # 2 that operate during idle cylinder operation. Since the 5-cylinder C5 and # 6 cylinder C6 ignition intervals are set at equal intervals (180 °), vibration and noise can be minimized.

  During all cylinder operation (at high speed), the # 4 cylinder C4 is ignited between the # 1 cylinder C1 and the # 2 cylinder C2, and the # 3 cylinder C3 is between the # 5 cylinder C5 and the # 6 cylinder C6. Ignite. Therefore, between # 1 cylinder C1 and # 4 cylinder C4, between # 4 cylinder C4 and # 2 cylinder C2, between # 5 cylinder C5 and # 3 cylinder C3, and between # 3 cylinder C3 and # 6 cylinder C6. The ignition interval is 90 °, the ignition interval is 180 ° between the # 2 cylinder C2 and the # 5 cylinder C5, and between the # 6 cylinder C6 and the # 1 cylinder C1, and the ignition interval is not constant during one cycle. It becomes uniform.

  Thus, even if different ignition intervals are mixed in one cycle during all-cylinder operation, the number of cylinders operating during all-cylinder operation is large and the engine speed is large. The increase in noise is not a problem in practice. In particular, when the engine speed is low and the load is high (when switching from the closed cylinder operation state to the all cylinder operation state in the low rotation range), the automatic shift is performed to bring the internal combustion engine closer to the high rotation range where high output can be obtained earlier By performing the control of sliding the torque converter of the machine, it is possible to simultaneously suppress the vibration caused by the unequal-interval ignition of the internal combustion engine during all cylinder operation from being transmitted to the vehicle body.

  Therefore, according to the present embodiment, only two cylinders out of the six cylinders are deactivated and the four cylinders are operated during the idle cylinder operation, so that compared with the cylinders deactivating three or four cylinders out of the six cylinders. In addition, the output during the idle cylinder operation can be ensured, and the quietness of the internal combustion engine can be ensured in both the idle cylinder operation state and the all cylinder operation state.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, the V-type 6-cylinder internal combustion engine is exemplified in the embodiment, but the present invention can be applied to an arbitrary type of internal combustion engine having three or more cylinders. However, when the number of cylinders is a natural number N of 3 or more, the present invention is not applied to the case where the number of cylinders operating in the cylinder resting state is a divisor of 2 or more of N. The reason for this is that, in the case described above, even if the ignition interval is set to be equal in the all-cylinder operation state, the ignition interval can be made equal in the non-cylinder operation state, and the problem of the present invention does not occur in the first place. Because.

  The present invention can be applied not only to a 4-stroke cycle internal combustion engine but also to a 2-stroke cycle internal combustion engine. Since one cycle of a two-stroke cycle internal combustion engine has a crank angle of 360 °, different ignition intervals are set between 360 ° of the crank angle during all cylinder operation.

Top view of the cylinder head of the first bank of the V-type 6-cylinder internal combustion engine (viewed along line 1-1 in FIG. 2) 2-2 sectional view of FIG. 3-3 sectional view of FIG. Sectional view taken along line 4-4 in FIG. Sectional view along line 5-5 in FIG. 6-6 sectional view of FIG. Sectional view along line 7-7 in FIG. Schematic diagram showing the cylinder arrangement of the first and second banks of the V-type six-cylinder internal combustion engine The figure which shows the ignition interval of # 1-# 6 cylinder

C1 # 1 cylinder (working cylinder)
C2 # 2 cylinder (working cylinder)
C3 # 3 cylinder (stop cylinder)
C4 # 4 cylinder (stop cylinder)
C5 # 5 cylinder (working cylinder)
C6 # 6 cylinder (working cylinder)

Claims (1)

One cylinder resting state in which three or more N cylinders (C1 to C6) are provided, and a part of them is deactivated to operate only a predetermined number of cylinders of two or more, and all the N cylinders In the internal combustion engine capable of switching between the all-cylinder operation state in which (C1 to C6) is operated,
Except for the case where the number of cylinders operating in the idle cylinder operation state is a divisor of 2 or more of N, in the idle cylinder operation state, the ignition intervals of the cylinders (C1 to C6) to be operated are set at equal intervals. In the all-cylinder operation state, the internal combustion engine is set so that different ignition intervals are mixed during one cycle.

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