JP2018123787A - Valve gear of direct-injection engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve gear of a direct-injection engine capable of reducing carrying-out of a fuel injected from an injector into a combustion chamber, to the outside of the combustion chamber, and suppressing dispersion of an air-fuel ratio.SOLUTION: A valve gear 40 of a direct-injection engine 1 has an intake valve 41 including a valve portion 41a for opening and closing an intake port 4a communicated to a combustion chamber 2, and a shaft portion 41b connected to the valve portion 41a and extended in an opening/closing direction of the valve portion 41a, a rotary cam 42 kept into contact with the other end portion of the shaft portion 41b and moving the shaft portion 41b in an axial direction, and springs 43, 53 for energizing the shaft portion 41b to a rotary cam 42 side. The intake valve 41 opens and closes an intake port 4a by sliding the valve portion 41a along an opening portion of the intake port 4a through the shaft portion 41b by the rotary cam 42.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a valve operating device for a direct injection engine that injects fuel from an injector into a combustion chamber.

  Conventionally, in order to improve fuel consumption, a direct injection engine that injects fuel into a combustion chamber from an injector and burns it has been put into practical use. In such a direct injection engine, in the fuel injection in the intake stroke, since the air-fuel mixture becomes poorly vaporized or non-uniform, for example, as described in Patent Document 1, the orientation of the injector nozzle is adjusted, By controlling the injection timing of the injector, the homogeneity of the air-fuel mixture is improved and uniform combustion is performed. Further, by controlling the injection timing of the injector and the opening / closing timing of the engine valve within a certain range, the adhesion of fuel to the engine valve is prevented.

JP 2005-256629 A

  However, in the above-described direct injection engine, when the engine valve is lowered into the combustion chamber, fuel injected from the injector into the combustion chamber may adhere to the umbrella portion of the engine valve and be taken out of the combustion chamber. There is. And if the fuel adhering to the umbrella part of the engine valve is taken away from the combustion chamber, the fuel used for the combustion is reduced, so that the air-fuel ratio varies and the intended combustion can be realized. It will disappear.

  Accordingly, the present invention has been made to solve the above-described problems, and can reduce the removal of fuel injected from the injector into the combustion chamber to the outside of the combustion chamber, thereby suppressing variations in the air-fuel ratio. An object of the present invention is to provide a valve operating device for a direct injection engine.

  One form of the present invention made to solve the above problems is a valve unit for opening and closing an intake / exhaust port communicating with the combustion chamber in a valve operating device for a direct injection engine that injects fuel from an injector into the combustion chamber of the engine. And an engine valve that is connected to the valve portion and extends in the opening / closing direction of the valve portion, and a rotation that contacts the other end portion of the shaft portion and moves the shaft portion in the axial direction. A cam and a spring that urges the shaft portion toward the rotating cam, and the valve portion of the engine valve extends along the opening portion of the intake / exhaust port through the shaft portion by the rotating cam. The intake and exhaust ports are opened and closed by being slid.

  In this valve operating device for a direct injection engine, when the shaft is reciprocated by the rotating cam, the valve is slid along the opening of the intake / exhaust port. The intake / exhaust port is opened and closed by the sliding movement of the valve portion. Thus, by driving the engine valve with the rotating cam, the valve portion can be slid along the opening of the intake / exhaust port to open / close the intake / exhaust port. Therefore, since the engine valve does not protrude into the combustion chamber, the fuel injected from the injector does not adhere to the engine valve and is not taken out of the combustion chamber. Further, the fuel hardly adheres to the side surface of the combustion chamber of the valve portion. Therefore, since almost all of the fuel injected from the injector is used for combustion, variations in the air-fuel ratio can be suppressed and good combustion can be realized.

  Further, since the fuel hardly adheres to the engine valve, it is not necessary to limit the injection timing of the injector and the opening / closing timing of the engine valve to a certain range as in the conventional case. Therefore, the control range of the injection timing of the injector and the opening / closing timing of the engine valve can be expanded as compared with the conventional case. Thereby, since the atomization of the fuel injected from the injector into the combustion chamber can be promoted, better combustion can be realized.

  Another aspect of the present invention made to solve the above problems is a butterfly type that opens and closes an intake / exhaust port communicating with the combustion chamber in a valve operating device of a direct injection engine that injects fuel from an injector into the combustion chamber of the engine. An engine valve including a valve portion connected to the outer surface of the combustion chamber of the valve portion, and the shaft portion is moved in the axial direction by contacting the other end portion of the shaft portion to thereby move the valve portion. A rotating cam that rotates, and a spring that biases the shaft portion toward the rotating cam, and the engine valve is configured so that the outer surface of the combustion chamber is not directed toward the injection port of the injector. Thus, the intake / exhaust port is opened and closed by rotating the valve portion through the shaft portion.

  In this valve operating device for a direct injection engine, when the shaft portion is reciprocated by the rotating cam, the butterfly valve portion is rotated. The intake / exhaust port is opened and closed by the rotation of the valve. Thus, by driving the engine valve with the rotating cam, the valve portion can be rotated to open and close the intake / exhaust port.

  The butterfly valve portion is rotated within a range in which the outer surface of the combustion chamber is not directed toward the injection nozzle of the injector. For this reason, the amount of the valve portion protruding into the combustion chamber is small, and even if the fuel injected from the injector adheres to the engine valve, it adheres only to the side surface of the combustion chamber of the valve portion. Therefore, the fuel injected from the injector is not attached to the engine valve and taken away outside the combustion chamber. Therefore, since almost all of the fuel injected from the injector is used for combustion, variation in the air-fuel ratio can be suppressed and good combustion can be realized.

  Even in the valve operating device of this direct injection engine, since the fuel hardly adheres to the engine valve, the control range of the injection timing of the injector and the opening / closing timing of the engine valve can be expanded as compared with the conventional one. Thereby, since the atomization of the fuel injected into the combustion chamber from the injector can be promoted, better combustion can be realized.

  Another aspect of the present invention, which has been made to solve the above problems, is to open and close an intake / exhaust port communicating with the combustion chamber in a valve operating device for a direct injection engine that injects fuel from an injector into the combustion chamber of the engine. A valve portion, a rotating shaft that rotates the valve portion, a pinion provided on the rotating shaft, a rack that meshes with the pinion, and a shaft portion that is connected to the rack and extends in the moving direction of the rack An engine valve comprising: a rotating cam that contacts the other end of the shaft portion to move the shaft portion in the axial direction; and a spring that biases the shaft portion toward the rotating cam. The opening portion and the valve portion of the intake / exhaust port are shaped so that the valve portion and the opening portion are displaced when the valve portion is rotated from a closed state, and the engine valve is The pinion is rotated through the rack connected to the shaft by the rotation, and the valve unit is rotated along the opening of the intake / exhaust port through the rotation shaft provided with the pinion. And opening / closing the intake / exhaust port.

  In the valve operating device of this direct injection engine, when the shaft portion is reciprocated by the rotating cam, the rack is reciprocated. The reciprocating motion of the rack causes the rotating shaft to rotate through the pinion, thereby rotating the valve unit. And since the opening part and valve | bulb part of an intake / exhaust port have comprised the shape which the valve | bulb part and opening part shifted when the valve | bulb part rotated, an intake / exhaust port is opened and closed by rotation operation | movement of a valve | bulb part. In this way, by driving the engine valve with the rotating cam, the intake / exhaust port can be opened and closed by rotating the valve portion via the rack and pinion.

  When the intake / exhaust port is opened and closed, there is almost no protrusion of the valve portion in the combustion chamber (the amount of protrusion of the valve portion into the combustion chamber is very small), so that the fuel injected from the injector hardly adheres to the engine valve. Therefore, it is possible to reliably reduce the fuel that is injected from the injector and adheres to the engine valve and is taken out of the combustion chamber. Therefore, since almost all of the fuel injected from the injector is used for combustion, variation in the air-fuel ratio can be suppressed and good combustion can be realized.

  Even in the valve operating device of this direct injection engine, since it is difficult for fuel to adhere to the engine valve, the control range of the injection timing of the injector and the opening / closing timing of the engine valve can be expanded as compared with the conventional one. Thereby, since the atomization of the fuel injected into the combustion chamber from the injector can be promoted, better combustion can be realized.

  In the valve operating device for another form of direct injection engine, it is desirable that the opening and the valve portion of the intake / exhaust port have an elliptical shape.

  By making the opening and the valve portion of the intake / exhaust port in such a shape, it can be easily manufactured, and the opening area of the intake / exhaust port can be increased when the valve portion is opened. Because.

  According to the valve operating apparatus for a direct injection engine according to the present invention, it is possible to reduce carry-out of fuel injected from the injector into the combustion chamber to the outside of the combustion chamber, and to suppress variations in the air-fuel ratio.

It is a schematic block diagram of a direct injection engine system. It is a schematic block diagram of the valve gear of 1st Embodiment. It is a figure which shows the positional relationship of an intake valve and a guide part. It is AA sectional drawing of FIG. It is a schematic block diagram of the valve gear of 2nd Embodiment. It is a schematic block diagram of the valve gear of 3rd Embodiment. It is a figure which shows the shape of the opening part of a valve part and an intake port, (a) is a valve closing state, (b) is a valve opening state.

<First Embodiment>
A direct injection engine system to which a valve operating apparatus according to an embodiment of the present invention is applied will be described in detail with reference to FIG. The direct injection engine system includes a reciprocating type multi-cylinder engine 1 having a well-known structure, and an injector 3 that directly injects fuel into the combustion chamber 2 is provided in each combustion chamber 2 of each cylinder of the engine 1. It has been. The engine 1 explodes and burns a combustible mixture of air sucked through the intake passage 4 and fuel injected from the injector 3 in the combustion chambers 2 of the respective cylinders, and exhausts the combusted gas to the outside through the exhaust passage 5. , The piston 6 is operated to rotate the crankshaft 7 to obtain power.

  A throttle valve 8 provided in the intake passage 4 is opened and closed to adjust the intake air amount (intake amount) taken into the combustion chamber 2 of each cylinder through the passage 4. A throttle sensor 21 is provided to detect the opening of the throttle valve 8 (throttle opening).

  Each injector 3 directly injects fuel into the corresponding combustion chamber 2. Each injector 3 is supplied with fuel at a predetermined pressure by a predetermined fuel supply device (not shown). The fuel supplied to each injector 3 is injected into the corresponding combustion chamber 2 when the injector 3 is operated. Air is taken into the intake passage 4 from the outside through the air cleaner 10. The air taken into the intake passage 4 forms a combustible mixture together with the fuel injected from each injector 3 in the combustion chamber 2 of each cylinder.

  The ignition plugs 11 provided in the combustion chambers 2 of the respective cylinders perform an ignition operation in response to an ignition signal output from the ignition coil 12. Each spark plug 11 and ignition coil 12 constitute an ignition device for igniting the combustible mixture formed in the combustion chamber 2.

  The catalytic converter 13 provided in the exhaust passage 5 incorporates a three-way catalyst for purifying exhaust exhausted from the combustion chamber 2. In the exhaust passage 5, an oxygen sensor 23 that detects the oxygen concentration Ox in the exhaust discharged from the combustion chamber 2 to the exhaust passage 5 is provided on the upstream side of the catalytic converter 13.

  Further, the engine 1 is provided with a water temperature sensor 24 that detects the temperature (cooling water temperature) of the cooling water flowing inside the engine 1, a rotation speed sensor 25 that detects the rotation speed of the crankshaft 7 as the engine rotation speed, and the like. Yes.

  Various signals output from the throttle sensor 21, the intake pressure sensor 22, the oxygen sensor 23, the water temperature sensor 24, and the rotation speed sensor 25 are input to an electronic control unit (ECU) 30. The ECU 30 executes fuel injection control, ignition timing control, and the like based on these input signals, and controls each injector 3 and ignition coil 12 respectively.

  As is well known, the ECU 30 includes a central processing unit (CPU) 31, a read only memory (ROM) 32, a random access memory (RAM) 33, a backup RAM (BU RAM) 34, and the like. The ROM 32 stores in advance a predetermined control program related to the various controls described above. The ECU 30 (CPU 31) executes the various controls described above in accordance with these control programs.

  The engine 1 includes a cylinder block 15 and a cylinder head 16. The piston 6 is provided in the cylinder bore 17 provided in the cylinder block 15 so that a reciprocation is possible. The combustion chamber 2 is configured as a space surrounded by the cylinder bore 17, the piston 6, and the cylinder head 16. The cylinder head 16 is provided with an intake port 4a and an exhaust port 5a communicating with each combustion chamber 2. As shown in FIG. 2, an intake valve 41 and an exhaust valve 51 that open and close the intake port 4a and the exhaust port 5a, respectively. Are provided.

  The intake side valve operating device 40 urges the intake valve 41, a rotating cam 42 provided on a camshaft (not shown) that rotates in conjunction with the crankshaft 7, and the intake valve 41 toward the rotating cam 42. And a spring 43. And by this valve operating apparatus 40, the intake valve 41 is driven and the intake port 4a is opened and closed.

  The intake valve 41 includes a valve portion 41a and a shaft portion 41b. As shown in FIGS. 2 and 3, the valve portion 41a is a rectangular plate-like member capable of covering the opening of the intake port 4a (the communication portion with the combustion chamber 2), and the opening of the intake port 4a. And the intake port 4a is opened and closed. As shown in FIGS. 2 to 4, the valve portion 41 a is arranged in a guide portion 46 that is a concave space formed in the cylinder head 16, and slides in the guide portion 46. The guide portion 46 is provided so that the intake port 4a is located near the center thereof.

  The shaft portion 40b is a rod-like member connected to the side surface of the valve portion 41a by welding, and extends in the opening / closing direction of the valve portion 41a. At the other end of the shaft portion 41b, a flange portion 41c that projects in the radial direction is provided. The flange portion 41 c is in contact with the rotating cam 42. The shaft portion 40 b is biased toward the rotating cam 42 by the spring 43.

  In such a valve operating apparatus 40, when the rotary cam 42 rotates, the shaft portion 41b is reciprocated at a predetermined timing within a predetermined range according to the cam profile of the rotary cam 42. As the shaft portion 41b reciprocates, the valve portion 41a slides inside the guide portion 46 along the opening of the intake port 4a. Thereby, the intake port 4a is opened and closed by the intake valve 41 at a predetermined timing.

  Further, the exhaust side valve operating device 50 has basically the same configuration as the intake side valve operating device 40, and includes an exhaust valve 51 including a valve portion 51a, a shaft portion 51b, and a flange portion 51c, and an exhaust valve 51. A rotating cam 52 to be driven and a spring 53 for biasing the exhaust valve 51 toward the rotating cam 52 are provided. The valve portion 51a is disposed in the guide portion 56. And by this valve operating apparatus 50, the exhaust valve 51 is driven and the exhaust port 5a is opened and closed. Note that the opening / closing operation of the exhaust valve 51 is basically the same as the opening / closing operation of the intake valve 41, and thus detailed description thereof is omitted.

  As described above, in the valve gears 40 and 50, the intake valve 4a and the exhaust port 5a can be opened and closed by driving the intake valve 41 and the exhaust valve 51 using the rotating cams 42 and 52, as in the conventional art. . Therefore, it is possible to apply a variable valve mechanism that makes the opening and closing timings and movement amounts of the intake and exhaust valves 41 and 51 variable.

  In the intake stroke of the engine 1, the valve gear 40 slides the valve portion 41a of the intake valve 41 along the opening of the intake port 4a within the guide portion 46 to open the intake port 4a. Therefore, when fuel is injected from the injector 3 into the combustion chamber 2, the intake valve 41 does not protrude into the combustion chamber 2. Therefore, the fuel injected from the injector 3 does not adhere to the intake valve 41 and is taken away from the combustion chamber 2. Further, the fuel hardly adheres to the side of the combustion chamber of the valve portion 41a.

  Accordingly, since almost all of the fuel injected from the injector 3 is used for combustion, variations in the air-fuel ratio can be suppressed and good combustion can be realized. Further, since the fuel hardly adheres to the valve portion 41a, there is no need to limit the injection timing of the injector 3 controlled by the ECU 30 and the opening / closing timing of the intake valve 41 to a certain range as in the prior art. Therefore, the control range of the injection timing of the injector 3 and the opening / closing timing of the intake valve 41 controlled by the ECU 30 can be expanded as compared with the conventional case. Thereby, since the atomization of the fuel injected into the combustion chamber 2 from the injector 3 can be promoted, better combustion can be realized.

  As described above in detail, according to the valve gear 40 according to the present embodiment, the intake valve 41 slides to open and close the intake port 4a. Therefore, when fuel is injected from the injector 3, the intake valve 41 does not protrude into the combustion chamber 2, so that the fuel injected from the injector 3 may adhere to the intake valve 41 and be taken out of the combustion chamber 2. Absent. Therefore, since almost all of the fuel injected from the injector 3 is used for combustion, variation in the air-fuel ratio can be suppressed and good combustion can be realized.

Second Embodiment
Next, a second embodiment will be described. In the valve gears 60 and 70 of the second embodiment, butterfly type intake and exhaust valves 61 and 71 are used as shown in FIG. First, the intake side valve gear 60 will be described. The valve gear 60 includes an intake valve 61, a rotating cam 62 that drives the intake valve 61, and a spring 63 that biases the shaft portion 61b of the intake valve 61 toward the rotating cam 62.

  Here, the intake valve 61 includes a valve portion 61a and a shaft portion 61b. The valve portion 61a is a butterfly valve disposed near the opening of the intake port 4a, and opens and closes the intake port 4a when the valve portion 61a rotates. The valve portion 61a is urged in the valve opening direction or the valve closing direction by a spring (not shown). In the present embodiment, the valve portion 61a is urged in the valve closing direction, and comes into contact with convex members 65a and 65b provided in part in the circumferential direction at the opening of the intake port 4a so as to be fully closed. It has become.

  The shaft portion 61b is a rod-like member connected to the combustion chamber outer surface (surface disposed on the intake port 4a side) 61ao of the valve portion 61a via a connecting member 64 such as a hinge, and the other end of the shaft portion 61b is connected to the other end of the shaft portion 61b. A flange portion 61c that projects in the radial direction is provided. The flange portion 61 c is in contact with a rotating cam 62 provided on a camshaft (not shown) that rotates in conjunction with the crankshaft 7. The shaft portion 61 b is biased toward the rotating cam 62 by the spring 63.

  In such a valve gear 60, when the rotary cam 62 rotates, the shaft portion 61b is reciprocated within a predetermined range at a predetermined timing (interval) according to the cam profile of the rotary cam 62. As the shaft portion 61b reciprocates, the valve portion 61a connected to the shaft portion 61b via the connection member 64 is alternately rotated in the opening direction and the closing direction. That is, the valve portion 61 a rotates in the opening direction when the shaft portion 61 b moves against the biasing force of the spring 63, and rotates in the closing direction when the shaft portion 61 b moves by the biasing force of the spring 63. Thereby, the intake port 4a is opened and closed by the intake valve 61 at a predetermined timing. The rotation of the valve portion 61a is within a range where the combustion chamber outer surface 65ao is not directed toward the injection port of the injector 3 (when the fully closed state is 0 °, the opening is within a range of 0 ° to 45 °). Done.

  Next, the exhaust-side valve operating device 70 will be described. This valve operating device 70 has basically the same configuration as the valve operating device 60 on the intake side, and an exhaust valve 71, a rotary cam 72 that drives the exhaust valve 71, and an exhaust valve 71 are attached to the rotary cam 72 side. And a spring 73 to be energized. The exhaust valve 71 includes a butterfly valve portion 71a urged in a valve closing direction by a spring (not shown), and a shaft portion connected to a combustion chamber outer surface 71ao of the valve portion 71a via a connecting member 74 such as a hinge. 71b and a flange portion 71c provided at the other end of the shaft portion 71b and in contact with the rotating cam 72. And by this valve operating apparatus 70, the valve part 71a of the exhaust valve 71 is alternately rotated in the opening direction and the closing direction, and the exhaust port 5a is opened and closed. Note that the opening / closing operation of the exhaust valve 71 is basically the same as the opening / closing operation of the intake valve 61, and thus detailed description thereof is omitted.

  As described above, also in the valve gears 60 and 70, the intake valves 4a and the exhaust ports 5a are opened and closed by driving the intake valves 61 and the exhaust valves 71 using the rotating cams 62 and 72, as in the prior art. Therefore, it is possible to apply a variable valve mechanism that makes the opening / closing timings and movement amounts of the intake and exhaust valves 61 and 71 variable.

  In the intake stroke of the engine 1, the valve gear 60 rotates the valve portion 61 a of the intake valve 61 within a range where the combustion chamber outer surface 61 ao is not directed to the injection port of the injector 3 (opening within 45 °). Open the intake port 4a. For this reason, the amount of the valve portion 61a protruding into the combustion chamber 2 is small, and even if the fuel injected from the injector 3 adheres to the intake valve 61, it adheres only to the combustion chamber side surface 61ai of the valve portion 61a. Therefore, the fuel injected from the injector 3 is not attached to the intake valve 61 and taken away from the combustion chamber 2. Therefore, since almost all of the fuel injected from the injector 3 is used for combustion, variation in the air-fuel ratio can be suppressed and good combustion can be realized.

  Further, since the fuel hardly adheres to the valve part 61a, it is not necessary to limit the injection timing of the injector 3 controlled by the ECU 30 and the opening / closing timing of the intake valve 60 within a certain range as in the conventional case. Therefore, the control range of the injection timing of the injector 3 and the opening / closing timing of the intake valve 61 controlled by the ECU 30 can be expanded as compared with the conventional case. Thereby, since the atomization of the fuel injected into the combustion chamber 2 from the injector 3 can be promoted, better combustion can be realized.

<Third Embodiment>
Finally, a third embodiment will be described. In the valve gears 80 and 90 of the third embodiment, screw type intake and exhaust valves 81 and 91 are used as shown in FIG. First, the intake side valve operating device 80 will be described. The valve operating device 80 includes an intake valve 81, a rotating cam 82 that drives the intake valve 81, and a spring 83 that biases a shaft portion 81 b included in the intake valve 81 toward the rotating cam 82.

  Here, the intake valve 81 is a screw type valve that rotates while moving slightly. Such an intake valve 81 is connected to a valve portion 81a that opens and closes the intake port 4a, a rotary shaft 81s having a pinion 81p, and a rack 81r that meshes with the pinion 81p, and extends in the moving direction of the rack 81r. Part 81b.

  The valve portion 81a opens and closes the intake port 4a by rotating along the opening surface of the intake port 4a. In the present embodiment, the valve portion 81a rotates in the range of 0 to 90 °. Therefore, the shape of the valve part 81a and the intake port 4a is such that when the valve part 81a rotates from the closed state shown in FIG. 7A, the opening parts of the valve part 81a and the intake port 4a as shown in FIG. 7B. It has a shape that shifts, in other words, a shape other than a perfect circle. In this embodiment, since it can be manufactured easily and the opening area of the intake port 4a when fully opened can be increased, the shapes of the valve portion 81a and the intake port 4a are elliptical.

  The rotation shaft 81s includes a pinion 81p, and a male screw portion 85a is formed at an end thereof. The male screw portion 85 a meshes with a female screw portion 85 b formed in the cylinder head 16. Thus, when the rotation shaft 81s rotates, the rotation shaft 81s moves slightly in the axial direction.

  The shaft portion 81b includes a rack 81r, and is a member that rotates the rotation shaft 81s via the pinion 81p by moving the rack 81r. At the other end of the shaft portion 81b, a flange portion 81c projecting in the radial direction is provided. The flange portion 81c is in contact with a rotating cam 82 provided on a camshaft (not shown). The shaft portion 81 b is biased toward the rotating cam 82 by a spring 83.

  In such a valve operating device 80, when the rotating cam 82 rotates, the shaft portion 81 b is reciprocated within a predetermined range at a predetermined timing (interval) according to the cam profile of the rotating cam 82. As the shaft portion 81b reciprocates, the rotation shaft 81s is rotated via the rack 81r and the pinion 81p, and the valve portion 81a is alternately rotated in the opening direction and the closing direction. At this time, the rotating shaft 81s and the valve portion 81a are slightly moved by the male screw portion 85a and the female screw portion 85b. That is, when the shaft portion 81b moves against the biasing force of the spring 83, the valve portion 81a rotates in the opening direction while moving slightly away from the intake port 4a, and the shaft portion 81b is rotated by the biasing force of the spring 83. When it moves, it rotates in the closing direction while moving slightly in the direction approaching the intake port 4a. Thereby, the intake port 4a is opened and closed by the intake valve 81 at a predetermined timing.

  Next, the exhaust side valve gear 90 will be described. The valve operating device 90 has basically the same configuration as the valve operating device 80 on the intake side, and includes a valve portion 91a that opens and closes the exhaust port 5a, a rotary shaft 91s having a pinion 91p, and a rack 91r that meshes with the pinion 91p. The exhaust valve 91 includes a shaft portion 81b that is connected to the rack 91r and extends in the moving direction of the rack 91r, the rotary cam 92 that drives the exhaust valve 91, and the shaft portion 91b that is provided in the exhaust valve 91 is connected to the rotary cam 92 side. And a spring 93 that biases the spring. Then, by this valve operating device 90, the valve portion 91a of the exhaust valve 91 is alternately rotated in the opening direction and the closing direction to open and close the exhaust port 5a. Since the opening / closing operation of the exhaust valve 91 is basically the same as the opening / closing operation of the intake valve 81, detailed description thereof is omitted.

  As described above, also in the valve operating devices 80 and 90, the intake valves 81 and the exhaust valves 91 are driven using the rotating cams 82 and 92 to open and close the intake ports 4a and the exhaust ports 5a. Therefore, it is possible to apply a variable valve mechanism that makes the intake / exhaust valve open / close timing and movement amount variable.

  Then, in the intake stroke of the engine 1, the valve gear 80 opens the intake port 4a by rotating the valve portion 81a of the intake valve 81 while slightly moving the valve portion 81a away from the opening of the intake port 4a. Therefore, the amount of protrusion of the valve portion 81a into the combustion chamber 2 is small. Therefore, the fuel injected from the injector 3 becomes difficult to adhere to the intake valve 81. Therefore, the fuel that adheres to the intake valve 81 and is taken out of the combustion chamber 2 can be reliably reduced. Therefore, since almost all of the fuel injected from the injector 3 is used for combustion, variation in the air-fuel ratio can be suppressed and good combustion can be realized.

  Further, since the fuel hardly adheres to the valve portion 81a, there is no need to limit the injection timing of the injector 3 controlled by the ECU 30 and the opening / closing timing of the intake valve 81 to a certain range as in the prior art. Therefore, the control range of the injection timing of the injector 3 and the opening / closing timing of the intake valve 81 controlled by the ECU 30 can be expanded as compared with the conventional case. Thereby, since the atomization of the fuel injected into the combustion chamber 2 from the injector 3 can be promoted, better combustion can be realized.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described third embodiment, the shape of the valve portion 81a and the intake port 4a is an elliptical shape, but is not particularly limited as long as it is a shape other than a perfect circle, for example, a rhombus or the like Also good.

1 Engine 2 Combustion Chamber 3 Injector 4a Intake Port 5a Exhaust Port 30 Electronic Control Unit (ECU)
40, 60, 80 Valve train 41, 61, 81 Intake valve 41a, 61a, 81a Valve part 41b, 61b, 81b Shaft part 41c, 61c, 81c Flange part 42, 62, 82 Rotating cam 43, 63, 83 Spring 50 , 70, 90 Valve-operating devices 51, 71, 91 Exhaust valves 51a, 71a, 91a Valve portions 51b, 71b, 91b Shaft portions 51c, 71c, 91c Flange portions 52, 72, 92 Rotating cams 53, 73, 93 Spring 61ao Combustion Outdoor surface 71ao Combustion chamber outer surface 81p, 91p Pinion 81r, 91r Rack 81s, 91s Rotating shaft

Claims (4)

In a valve operating device for a direct injection engine that injects fuel from an injector into the combustion chamber of the engine,
An engine valve comprising: a valve portion that opens and closes an intake / exhaust port communicating with the combustion chamber; and a shaft portion that is connected to the valve portion and extends in an opening and closing direction of the valve portion;
A rotating cam that contacts the other end of the shaft and moves the shaft in the axial direction;
A spring for urging the shaft portion toward the rotating cam,
The engine valve opens and closes the intake / exhaust port when the valve portion is slid along the opening of the intake / exhaust port via the shaft portion by the rotating cam. Valve operating device. In a valve operating device for a direct injection engine that injects fuel from an injector into the combustion chamber of the engine,
An engine valve comprising a butterfly valve portion for opening and closing an intake / exhaust port communicating with the combustion chamber, and a shaft portion connected to an outer surface of the combustion chamber of the valve portion;
A rotating cam that contacts the other end of the shaft portion and moves the shaft portion in the axial direction to rotate the valve portion;
A spring for urging the shaft portion toward the rotating cam,
The engine valve opens and closes the intake / exhaust port by rotating the valve portion via the shaft portion by the rotating cam so that the outer surface of the combustion chamber is not directed to the injection port of the injector. A valve mechanism for a direct injection engine. In a valve operating device for a direct injection engine that injects fuel from an injector into the combustion chamber of the engine,
A valve portion that opens and closes an intake / exhaust port communicating with the combustion chamber, a rotating shaft that rotates the valve portion, a pinion provided on the rotating shaft, a rack that meshes with the pinion, and a rack that is coupled to the rack An engine valve including a shaft portion extending in a moving direction of the rack;
A rotating cam that contacts the other end of the shaft and moves the shaft in the axial direction;
A spring for urging the shaft portion toward the rotating cam,
The opening and the valve portion of the intake / exhaust port have a shape in which the valve portion and the opening are displaced when the valve portion rotates from a closed state,
In the engine valve, the pinion is rotated through the rack connected to the shaft portion by the rotating cam, and the valve portion is opened to the intake / exhaust port through the rotating shaft provided with the pinion. A valve operating device for a direct injection engine, wherein the intake and exhaust ports are opened and closed by being rotated along a portion. The valve operating device for a direct injection engine according to claim 3,
The valve operating device for a direct injection engine, wherein the opening and the valve of the intake / exhaust port have an elliptical shape.

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