The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
The present invention will now be described in detail with reference to the accompanying drawings, wherein the same reference numerals will be used to identify the same or similar elements throughout the several views. It should be noted that the drawings should be viewed in the direction of orientation of the reference numerals.
First of all, in
Four cylinder bores 17A, 17B, 17C, 17D, which are arranged in parallel in the direction along an axis of the crankshaft 12, are provided to the cylinder block 14. A cylinder axis C of the respective cylinder bores 17A to 17D is inclined in the frontward and upward direction. Pistons 18 are slidably fitted in the respective cylinder bores 17A to 17D. The respective pistons 18 are connected to the crankshaft 12 by way of a connecting rods 19.
Combustion chambers 20, which top portions of the pistons 18 that are respectively slidably fitted in the cylinder bores 17A to 17D face, are formed for every cylinder between the cylinder block 14 and the cylinder head 15. Furthermore, in the cylinder head 15, intake ports 21 and discharge ports 22, which are in communication with the combustion chambers 20, are formed for every cylinder. The intake ports 21 are opened in a side surface of a rear portion of the cylinder head 15. The discharge ports 22 are opened in a side surface of a front portion of the cylinder head 15.
To explain the embodiment also in conjunction with
Cylinders at both ends along the arranging direction of the cylinders out of the in-line four cylinders are cylinders that are expected to assume the cylinder rest state. Two cylinders, which are arranged at the center along the cylinder arranging direction, are cylinders that are always operated during running of the engine. As shown in
Fuel injection valves 26 which inject fuel toward the intake ports 21 are respectively mounted on the respective throttle bodies 23A to 23D. The respective fuel injection valves 26 are connected to a common fuel rail 27.
Returning to
A valve operating device 34, which opens and closes the intake valves 30 and the discharge valves 31, is accommodated between the cylinder head 15 and the head cover 16. The valve operating device 34 includes an intake-side cam shaft 35 and a discharge-side cam shaft 36 to which a rotational force is transmitted from the crankshaft 12 by way of a timing transmission device (not shown in the drawing) at a reduction ratio of ½. Intake-side valve lifters 39 are interposed between intake-side valve-operating cams 37 mounted on the intake-side cam shaft 35 and intake valves 30 and are slidably fitted in the cylinder head 15. Discharge-side valve lifters 40 are interposed between discharge-side cams 38 mounted on the discharge-side cam shaft 36 and the discharge valves 31 and are slidably fitted in the cylinder head 15.
Furthermore, the hydraulic valve rest mechanisms 43, 43, which close and rest the intake valves 30 for bringing the cylinders into a rest state, are respectively mounted on the valve operating device 34 at portions thereof that correspond to the cylinders arranged at both ends along the arranging direction out of the in-line four cylinders.
In
To explain the embodiment also in conjunction with
An annular groove 49 is formed in an outer periphery of the pin holder 44, that is, in an outer periphery of the ring portion 44a. A bottom slide hole 50 is formed in the bridge portion 44b of the pin holder 44. The bottomed slide hole 50 has an axis thereof orthogonal to an axis along one diameter line of the ring portion 44a, that is, an axis of the intake-side valve lifter 39, and has one end thereof opened in the annular groove 49 and has another end thereof closed. Further, in a center lower portion of the bridge portion 44b, an insertion hole 52, through which a distal end portion of a valve stem 51 of the intake valve 30 biased in the valve closing direction by the valve spring 32 is passed, is formed in a state where the insertion hole 52 has an inner end thereof opened in the slide hole 50. In a center upper portion of the bridge portion 44b, an extension hole 53 that sandwiches the slide hole 50 with the insertion hole 52 is formed coaxially with the insertion hole 52 in a state where the extension hole 53 can accommodate the distal end portion of the valve stem 51 of the intake valve 30.
Furthermore, an accommodating sleeve portion 54, which has an axis thereof aligned with the axis of the extension hole 53, is integrally formed with a bridge portion 44b of the pin holder 44 at a position where the bridge portion 44b faces a closed end of the intake-side valve lifter 39. A portion of a disc-like shim 55, which closes an end portion of the extension hole 53, is fitted in the accommodating sleeve portion 54 on a closed-end side of the intake-side valve lifter 39. Furthermore, a projection 56 that is brought into contact with the shim 55 is integrally formed on a center portion of a closed-end inner surface of the intake-side valve lifter 39. A slide pin 46 is slidably fitted in the slide hole 50 of the pin holder 44. The hydraulic chamber 45, which is in communication with the annular groove 49, is defined between one end of the slide pin 46 and the inner surface of the intake-side valve lifter 39. The return spring 47 is accommodated in a spring chamber 57 that is defined between another end of the slide pin 46 and the closed end of the slide hole 50.
To explain the embodiment also in conjunction with
The slide pin 46 is configured to be slidable in the axial direction in a state where hydraulic power that acts on one end side of the slide pin 46 by an oil pressure of the hydraulic chamber 45 and a spring force that acts on another end side of the slide pin 46 by the return spring 47 are balanced. In a non-operable state in which the oil pressure in the hydraulic chamber 45 is low, the slide pin 46 is moved rightwardly in
Furthermore, when the slide pin 46 is moved to a position where the accommodating hole 58 of the slide pin 46 is coaxially in communication with the insertion hole 52 and the extension hole 53, the pin holder 44 and the slide pin 46 are also moved to an intake-valve-30 side together with the intake-side valve lifter 39 along with the sliding of the intake-side valve lifter 39 due to a pushing force applied from the intake-side valve operating cam 37. However, the distal end portion of the valve stem 51 is merely accommodated in the accommodating hole 58 and the extension hole 53. A pushing force in the valve opening direction is not applied to the intake valve 30 from the intake-side valve lifter 39 and the pin holder 44. Hence, the intake valve 30 is held in a rest state. Furthermore, when the slide pin 46 is moved to a position where the distal end portion of the valve stem 51 is brought into contact with the contact surface 59, the intake-side valve lifter 39 is slid by a pushing force that is applied from the intake-side valve operating cam 37. Therefore, the pin holder 44 and the slide pin 46 are moved in the direction toward intake-side valve lifter 39 along with the sliding of the intake-side valve lifter 39, and a pushing force in the valve opening direction is applied to the intake valve 30 along with the movement toward the intake valve 30 side of the pin holder 44 and the slide pin 46. Hence, the intake valve 30 is opened or closed corresponding to the rotation of the intake-side valve operating cam 37.
When the slide pin 46 is rotated about an axis thereof in the inside of the pin holder 44, the axis of the accommodating hole 58 is offset from the axes of the insertion hole 52 and the extension hole 53 and, at the same time, it becomes impossible to bring the distal end portion of the valve stem 51 into contact with the contact surface 59. Hence, the rotation of the slide pin 46 about the axis is interrupted by the stopper pin 48.
The stopper pin 48 is configured to be fitted in mounting holes 60 that are coaxially formed in the bridge portions 44b of the pin holder 44 so as to sandwich one end-side portion of the slide hole 50 therebetween. The stopper pin 48 penetrates a slit 61 that is formed in one end side of the slide pin 46 and opens toward a hydraulic-chamber-45 side. That is, by mounting the stopper pin 48 in the pin holder 44 and to penetrate the slide pin 46, while allowing movement of the slide pin 46 in the axial direction, the stopper pin 48 is brought into contact with an inner-end closed portion of the slit 61. Hence, a moving end of the slide pin 46 on the hydraulic-chamber-45 side is also restricted.
A coil spring 62 is provided for biasing the pin holder 44 in the direction to bring a shim 55 mounted on the pin holder 44 into contact with the projection 56 mounted on a center portion of an inner surface of a closed-end of the intake-side valve lifter 39. Such a coil spring 62 is arranged between the pin holder 44 and the cylinder head 15 in a state where the coil spring 62 surrounds the valve stem 51 at a position that can prevent an outer periphery of the coil spring 62 from being brought into contact with an inner surface of the intake-side valve lifter 39. On a bridge portion 44b of the pin holder 44, a pair of projections 63, 63, which position an end portion of the coil spring 62 in the direction orthogonal to an axis of the valve stem 51, is integrally mounted in a projecting manner.
Furthermore, both projections 63, 63 are integrally formed on the pin holder 44 in a projecting manner with a projection quantity equal to or below a wire diameter of the coil spring 62. The projections 63, 63 are formed in an arcuate shape about an axis of the valve stem 51. Furthermore, on one of the projections 63, 63, a stepped portion 63a is formed. The stepped portion 63a comes into contact with an intake-valve-33R-side end portion of a stopper pin 48 and prevents the movement of the stopper pin 48 toward an intake-valve-30 side.
A communication hole 64 is formed in the slide pin 46 for allowing the spring chamber 57 to be in communication with the accommodating hole 58. This prevents the pressurizing and depressurizing of the spring chamber 57 attributed to the axial movement of the slide pin 46. A communication hole 65 for allowing the space to be in communication with the spring chamber 57 is formed in the pin holder 44. This prevents a pressure in a space defined between the pin holder 44 and an intake-side valve lifter 39 from being changed due to a temperature change.
A support hole 66 is formed in the cylinder head 15 for allowing the fitting of an intake-side valve lifter 39 therein in a state that the intake-side valve lifter 39 is slidably supported by the cylinder head 15. An annular recessed portion 67 that surrounds the intake-side valve lifter 39 is formed in an inner surface of the support hole 66. Furthermore, a communication hole 68 and a release hole 69 are formed in the intake-side valve lifter 39. The communication hole 68 and the release hole 69 are provided for allowing the annular recessed portion 67 to be in communication with the annular groove 49 of the pin holder 44 irrespective of the slide movement of the intake-side valve lifter 39 in the inside of the support hole 66. The release hole 69 is formed at a position which allows the annular recessed portion 67 to be in communication with the inside of the intake-side valve lifter 39 below the pin holder 44 when the intake-side valve lifter 39 is moved to an uppermost position in
To focus on
To explain the embodiment also in conjunction with
A bottomed slide hole 79 that closes one end thereof and opens another end thereof is formed in the valve housing 75. A cap 80 that closes another end opening portion of the slide hole 79 is fitted in the valve housing 75. Furthermore, spool valve element 76 is slidably fitted into the slide hole 79. A spring chamber 81 is defined between the spool valve element 76 and an one-end closing portion of the slide hole 79, while a pilot chamber 82 is defined between another end of the spool valve element 76 and the cap 80. A spring 83, which biases the spool valve element 76 toward a side which decreases a capacity of the pilot chamber 82, is accommodated in the spring chamber 81.
The inlet port 77 and the outlet port 78 are formed in the valve housing 75 at positions that are sequentially spaced apart along an axis of the slide hole 79 from one end to another end side in a state that the inlet port 77 and the outlet port 78 opens in an inner surface of the slide hole 79. An annular recessed portion 84, which allows the inlet port 77 and the outlet port 78 to communicate with each other, is formed in the spool valve element 76. As shown in
An oil filter 85 is fitted in the inlet port 77, and an orifice hole 86, which allows the inlet port 77 and the outlet port 78 to be in communication with each other, is formed in the valve housing 75. Accordingly, even when the spool valve element 76 is arranged at a position where the communication between the inlet port 77 and the outlet port 78 is interrupted as shown in
Furthermore, in the valve housing 75, a release port 87, which is in communication with the outlet port 78 through an annular recessed portion 84 only when the spool valve element 76 is arranged at the position where the communication between the inlet port 77 and the outlet port 78 is interrupted, is formed. The release port 87 opens into a space defined between the cylinder head 15 and the head cover 16.
A passage 88, which is normally in communication with the inlet port 77, is formed in the valve housing 75. The passage 88 is connected with a connection hole 89, which is formed in the valve housing 75 and is in communication with a pilot chamber 82 by way of the solenoid-operated valve 73. Accordingly, when the solenoid-operated valve 73 is operated to open the valve, oil pressure is supplied to the pilot chamber 82, and a hydraulic force of the oil pressure introduced into the inside of the pilot chamber 82 drives the spool valve element 76 in the direction toward a side which increases a capacity of the pilot chamber 82. Hence, the inlet port 77 and the outlet port 78 are in communication with each other through the annular recessed portion 84 formed in the spool valve element 76.
In the inside of the crankcase 13, an oil pump (not shown in the drawing), which is interlockingly operated with the crankshaft 12, is housed. A working oil supplied from the oil pump is supplied to an oil passage 91 formed in the head cover 16 by way of a hydraulic hose 90. The oil passage 91 is in communication with the inlet ports 77 in both hydraulic control devices 71, 71.
Furthermore, in the head cover 16, an oil passage 92A, which is in communication with the outlet port 78 of one hydraulic control device 71, is formed in a state where the oil passage 92A extends toward one end side in the cylinder arranging direction. An oil passage 92B, which is in communication with the outlet port 78 of another hydraulic control device 71, is formed in a state where the oil passage 92B extends toward another end side in the cylinder arranging direction. Oil passages 93 (see
To explain the manner of operation of this embodiment, the hydraulic valve rest mechanisms are mounted on the valve operating device 34. The valve operating device 34 performs open-close driving of the intake valves 30 of the respective cylinders of the in-line four-cylinder internal combustion engine. The hydraulic valve rest mechanisms 43 are operated with oil pressure that is controlled by the hydraulic control devices 71 so as to close and rest one or more intake valves 30 of one or more cylinders for bringing the cylinders into a rest state. The hydraulic control devices 71 are arranged on the engine body 11 directly above a portion thereof corresponding to the cylinder that is expected to assume the cylinder rest state. Accordingly, the entire internal combustion engine can be miniaturized along the axis of the crankshaft 12 and, at the same time, it is possible to shorten lengths of the oil passages 92A, 92B. 93 that connect the hydraulic valve rest mechanism 43 and the hydraulic control devices 71 with each other.
Furthermore, the hydraulic control devices 71 are directly mounted on the head cover 16, which constitutes a portion of the engine body 11 and is joined to the cylinder head 15. Hence, parts that are exclusively used for supporting the hydraulic control devices 71 become unnecessary. Therefore, the number of parts is reduced to reduce manufacturing costs. It is also possible to shorten lengths of the oil passages 92A, 92B, 93 that connect the hydraulic valve rest mechanisms 43 and the hydraulic control devices 71 with each other.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Number | Date | Country | Kind |
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2006-270021 | Sep 2006 | JP | national |