JP4466278B2 - Multi-cylinder engine intake system - Google Patents

Description

  The present invention relates to an intake device for a multi-cylinder engine, and more particularly to an intake device for a multi-cylinder engine provided with a pulse generator that generates a high-pressure wave in a cylinder.

  Conventionally, various technologies for increasing volumetric efficiency have been developed in an intake manifold of a multi-cylinder engine provided with a surge tank of an intake manifold and a branch pipe branched from the surge tank and connected to an intake port of each cylinder. .

  For example, Patent Document 1 discloses a technique in which a plurality of intake passages having different path lengths are provided for each intake port, and these intake passages are selectively communicated with a surge tank by a switching valve.

  On the other hand, Non-Patent Document 1 discloses a technique for increasing torque in a low rotation region by impulse. In that configuration, an electromagnetic valve that strokes in the direction of the path of the branch pipe is provided in the middle of the branch pipe of the intake manifold, and until the middle of the intake stroke, the solenoid valve is closed to form a negative pressure, and the bottom dead center of the intake stroke A configuration is disclosed in which air is rapidly supplied into a cylinder by opening a solenoid valve in the vicinity.

Non-Patent Document 2 discloses a device that generates a pulse using a flap valve as a device that generates an impulse.
JP 2003-41939 A Impulse charging boosts torque at low speed, Findlay Publications “European Automotive Design” February 2004 issue Development of an Actuator for a Fast Moving Flap for impulse Charging, Findlay Publications “European Automotive Design” January 2003 issue

  According to the configuration of Patent Document 1, by changing the intake passage between the low speed side and the high speed side of the engine, there is an excellent effect that the volume efficiency can be increased on each of the low speed side and the high speed side of the engine. However, since a plurality of intake passages are provided in each cylinder, there is a problem that the structure of the passage is complicated and expensive.

  In the configuration of Non-Patent Document 1, although the volume efficiency in the low rotation region can be increased, the electromagnetic valve is driven to control the opening and closing, so that the power consumption increases. Further, since the electromagnetic valve moves in the direction of the intake passage, the flow of intake air is hindered and the intake resistance becomes very large. Therefore, not only the volumetric efficiency is reduced, but also when a negative pressure is generated in the low rotation region and then the valve is opened momentarily, a tremendous pulsation occurs and a large noise is generated. Was difficult.

  On the other hand, in the configuration of Non-Patent Document 2, since the flap valve is configured to open and close, the resistance of air passing through the intake pipe is easily received. Even in the low-medium speed region, it has been extremely difficult to realize the opening / closing control in synchronization with the opening / closing timing of the intake valve, and it has not been put into practical use.

  The present invention has been made in view of the above-described problems, and can achieve reliable synchronization in a low, medium, and high speed rotation region, and can increase volumetric efficiency silently even in a low speed rotation region. It is an issue to provide.

In order to solve the above problems, the present invention is to provide an intake pipe for supplying air to a plurality of cylinders are provided in each intake port of the cylinder, the upstream end of the intake pipe of each cylinder, communicating with the intake pipe A surge tank as a collecting portion is provided, and a pulse generator that generates a high-pressure wave in the cylinder by opening the valve during the intake stroke in the valve opening period of the intake port corresponding to the intake stroke of each cylinder is provided. In a multi-cylinder engine intake device, the pulse generator is a rotary valve that rotates in synchronization with the crankshaft while being in sliding contact with the inner peripheral surface of the surge tank , and the diameter of the rotary valve is set to be larger than the intake pipe cross-sectional width. is Rutotomoni, the peripheral surface of the rotary valve, opening for communicating the interior and the intake pipes of the surge tank is formed, the upstream end of each intake pipe, selection facing the apertures of the rotary valve The ratio of the single independent intake passage volume from the downstream end of the intake port to the opening of the rotary valve to the single stroke volume of each cylinder is in the range of 70% to 130%. An intake device for a multi-cylinder engine characterized by being set.

In this aspect, a rotary valve that rotates in synchronization with the crankshaft is employed as the pulse generator, so that the crankshaft rotates in the low speed range even when the crankshaft rotates in the high speed range without receiving a large intake resistance. However, it is possible to generate a high-pressure wave in the cylinder at a desired timing by surely tuning the frequency. Further, since the diameter of the rotary valve is set larger than the intake pipe cross-sectional width, the intake pipe can be opened and closed at a high peripheral speed, and a strong pressure wave can be generated. Furthermore, since the intake passage can be opened and closed by a rotary valve provided inside the surge tank, the volume in the surge tank can be used effectively.

In addition, the rotary valve is configured such that the ratio of the single independent intake passage volume from the downstream end of the intake port to the opening of the rotary valve with respect to the single stroke volume of each cylinder is in the range of 70% to 130%. Is set. This setting range is a range found by simulation by the present inventors as a result of diligent research, and is a range in which the volumetric efficiency at 3500 rpm can be improved to about 90% or more as will be described in detail later. The ratio of the single intake passage volume from the downstream end of the intake port to the opening of the rotary valve with respect to the single stroke volume of each cylinder is referred to as “intake passage / stroke volume ratio” in this specification. Even if the intake passage / stroke volume ratio exceeds 130%, the volumetric efficiency is not necessarily lowered. However, in that case, since the intake passage becomes longer, the response to the torque improvement tends to decrease. Therefore, even if the torque during steady running can be increased, the torque may not necessarily be improved in a transient state during acceleration. On the other hand, when the intake passage / stroke volume ratio falls below 70%, the air amount necessary for the cylinder cannot be secured, so that the response is increased, but the volume efficiency is lowered. Therefore, in this aspect, the intake passage / stroke volume ratio is set from 70% to 130%. As a result, not only the torque at the steady state but also the torque in the transient state at the time of acceleration can be efficiently increased. The limitation of “70% to 130%” is not intended to exclude variations due to measurement errors and individual differences that are unavoidable in carrying out the invention.

  According to a second aspect of the present invention, there is provided the multi-cylinder engine intake device according to the first aspect, further comprising power transmission means for transmitting the power of the crankshaft of the engine to the rotary valve as a drive source. In this aspect, it is possible to perform the valve opening operation by physically synchronizing the crankshaft of the engine and the rotary valve. As the power transmission means, for example, a pulley and a timing belt are suitable.

  According to a third aspect of the present invention, in the intake device for a multi-cylinder engine according to the second aspect, the power transmission means rotates the rotary valve at a speed ½ of the rotational speed of the crankshaft. According to this aspect, the pressure wave can be propagated into the cylinder by mechanically synchronizing the valve opening cycle of the rotary valve with the valve opening cycle of the intake valve.

  According to a fourth aspect of the present invention, in the intake device for a multi-cylinder engine according to any one of the first to third aspects, the intake passage length of each intake pipe is set to be substantially the same. In this aspect, in any cylinder, the same volumetric efficiency can be obtained under the same conditions, so that torque variation does not occur in each cylinder.

According to a fifth aspect of the invention, an intake device for a multi-cylinder engine as claimed in any one of claims 1 4, wherein the surge tank, that incorporates the rotary valve concentrically. In this aspect, the diameter of the rotary valve can be set larger without increasing the size of the entire apparatus.

According to a sixth aspect of the invention, air upstream end on the intake pipe for supplying the respective intake ports of the plurality of cylinders, a surge tank as a collection portion communicating with the intake pipe is provided, the intake stroke of each cylinder Correspondingly, in an intake device of a multi-cylinder engine provided with a pulse generator that opens during the intake stroke of the intake port during a valve opening period and generates a high-pressure wave in the cylinder, the pulse generator includes the surge tank. inner sliding contact with the peripheral surface a rotary valve rotates synchronously with the crankshaft, Rutotomoni diameter of the rotary valve is set larger than the intake pipe cross-sectional width, the circumferential surface of the rotary valve, wherein the surge tank an opening communicating the interior of said intake pipes is formed, the upstream end of the intake pipes, characterized in that the is arranged to be selectively opened and closed so as to face the apertures of the rotary valve Multi-cylinder An intake system for engine.

Even in this mode, a rotary valve is used as the pulse generator, so it is possible to generate a large pressure wave by instantaneously opening the intake pipe at a large peripheral speed, and to increase volumetric efficiency and generate a high torque. become. Further, since the intake passage can be opened and closed by the rotary valve provided inside the surge tank, the volume in the surge tank can be effectively utilized.

  According to a seventh aspect of the present invention, in the intake device for a multi-cylinder engine according to the sixth aspect, the path length from the intake port to the opening of the rotary valve is set to be substantially the same length. Also in this aspect, since the same volumetric efficiency can be obtained under the same conditions in any cylinder, torque variation does not occur for each cylinder.

The invention according to claim 8 is the intake device for a multi-cylinder engine according to claim 6 or 7, wherein the engine includes first to fourth cylinders from one end side in the cylinder row direction and an intake stroke. The four-cylinder four-cycle engine is operated in the first, third, fourth, and second order with a phase difference of 180 ° in crank angle, and an upstream end opening of each intake pipe of the first and second cylinders is provided. It is connected to the surge tank so as to shift the phase by 90 ° to about 90 ° in the circumferential direction, and the opening at the upstream end of each intake pipe of the fourth and third cylinders is 90 ° to about 90 ° in the circumferential direction. It is connected to the surge tank so as to shift the phase, and the openings at the upstream ends of the intake pipes of the first cylinder and the fourth cylinder and the openings at the upstream ends of the intake pipes of the second cylinder and the third cylinder are rotary valves. Placed in the same phase in the circumferential direction The rotary valve rotates at half the rotational speed of the crankshaft, and 180 ° to approximately 180 ° in the circumferential direction so as to open the upstream end opening of each intake pipe in the above order. It has a pair of openings with a phase difference of °. In this aspect, by providing two openings in the rotary valve, the pressure wave can be propagated to the intake pipe of the four-cylinder engine at a desired timing, and it is possible to increase volumetric efficiency and obtain high torque. Become.

  According to a ninth aspect of the present invention, in the intake system for a multi-cylinder engine according to any one of the sixth to eighth aspects, a single unit from the downstream end of the intake port to the opening of the rotary valve for a single stroke volume of each cylinder. The ratio of one independent intake passage volume is set in the range of 70% to 130%. In this aspect, not only the torque at the steady state but also the torque in the transient state at the time of acceleration can be efficiently increased.

As described above, in the present invention, a rotary valve that can instantaneously open a valve in synchronism with the crankshaft is adopted for the intake pipe, and the intake passage / stroke volume ratio is changed from 70% to 130%. Set to percent. As a result, by using a rotary valve, it is possible to suppress the occurrence of pulsation, and it is possible to generate a pulse with a quiet sound, and the torque in the transient state during acceleration as well as the torque in the steady state is efficient. It becomes possible to increase well. Therefore, it is possible to reliably achieve synchronization in the low, medium, and high speed rotation regions, and there is a remarkable effect that volume efficiency can be increased with low noise even in the low speed rotation region. Further, since the intake passage can be opened and closed by the rotary valve provided inside the surge tank, the volume in the surge tank can be used effectively.

  In the invention according to claim 2, since it becomes possible to perform the valve opening operation by physically synchronizing the engine crankshaft and the rotary valve, the rotary valve and the phase of each cylinder are precisely synchronized. Therefore, it is possible to increase the volume efficiency by providing a more accurate pulse generation function.

  Furthermore, in the invention of claim 3, since the pressure wave can be propagated into the cylinder by mechanically synchronizing the valve opening cycle of the rotary valve with the valve opening cycle of the intake valve, the intake passage is made equal in length. It becomes easy to realize.

  In the invention according to claim 4, since the same volumetric efficiency can be obtained under the same conditions, torque variation does not occur between cylinders, and more stable torque generation characteristics can be obtained.

Further, in the fifth aspect of the present invention, instrumentation置全body without increasing the size of, it is possible to set a larger diameter of the rotary valve.

In the invention as set forth in claim 6, by incorporating the rotary valve in the surge tank , it is possible to efficiently increase the torque in a transient state during acceleration as well as the torque during steady state. Therefore, it is possible to reliably achieve synchronization in the low, medium, and high speed rotation regions, and there is a remarkable effect that volume efficiency can be increased with low noise even in the low speed rotation region. Moreover, the volume in the surge tank can be used effectively.

  Furthermore, according to the seventh aspect of the present invention, the same volumetric efficiency can be obtained under the same conditions in any cylinder, so that there is no variation in torque among the cylinders, and more stable torque can be generated. It becomes possible.

  Furthermore, in the configuration according to claim 8, by providing two openings in the rotary valve, the pressure wave can be propagated to the intake pipe of the four-cylinder engine at a desired timing, and the volume efficiency is increased and the torque is increased. Therefore, it is possible to achieve both the improvement of the torque generation characteristics by the equal length and the improvement of the response by shortening the intake passage.

  Furthermore, in the configuration of claim 9, the ratio of the single independent intake passage volume from the downstream end of the intake port to the opening of the rotary valve to the single stroke volume of each cylinder is in the range of 70% to 130%. Since the rotary valve is set at such a position, it is possible to efficiently increase the torque in the transient state during acceleration as well as the torque in the steady state.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a right side view of a four-cycle spark ignition engine employing an intake device 40 according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line AA of FIG.

  Referring to the drawings, the engine includes an engine body 10 having a cylinder block 11 and a cylinder head 12 integrated with the cylinder block 11. The engine body 10 is provided with first to fourth cylinders 12A to 12D, and a piston 4 connected to the crankshaft 3 is fitted into each of the cylinders 12A to 12D so as to burn above it. A chamber 15 is formed.

  A spark plug 16 is fixed to the cylinder head 12 for each combustion chamber 15 of each of the cylinders 12A to 12D. Each spark plug 16 is installed such that its tip faces the corresponding combustion chamber 15 from the top.

  The cylinder head 12 is formed with an intake port 17 and an exhaust port 18 that open toward the combustion chamber 15 for each of the cylinders 12A to 12D, and an intake valve 19 is provided at the ports 17 and 18, respectively. And an exhaust valve 20 are respectively provided.

  The intake valve 19 and the exhaust valve 20 open and close the intake port 17 and the exhaust port 18 in synchronism with a predetermined phase difference by a camshaft for an unillustrated intake valve and exhaust valve supported by the engine body 10. It is configured. The camshaft is connected to a cam sprocket gear (not shown), and this cam sprocket gear receives power from the cam pulley 30 via a timing belt (not shown) (see FIG. 3). The cam pulley 30 is attached to the front surface of the engine body 10 so as to be rotatable about an axis parallel to the crankshaft 3. On the other hand, an output pulley 32 attached to the front side of the engine body 10 is fixed to the crankshaft 3, and both pulleys 30 and 32 are configured to be synchronized and interlocked by a timing belt 34.

  Each camshaft is provided with variable valve timing mechanisms 21 and 22 that change the opening and closing timing by adjusting the rotation phase. As a result, the intake valve 19 can change the phase with respect to the crank angle.

  The intake device 40 according to the present invention includes an intake manifold 41 fixed to a side portion of the engine body 10 and a rotary valve 50 built in the intake manifold 41.

  The intake manifold 41 is fixed to the engine main body 10 via a support member (not shown), and a surge tank as a collective portion extending horizontally in the front-rear direction of the engine main body 10 (the direction in which the cylinders 12A to 12D are arranged). 42 and the first to fourth branch pipes 43A to 43D as intake pipes that are connected to the surge tank 42 and form separated intake passages PH1 to PH4. A throttle body 44 is fixed to the rear end portion of the surge tank 42, and a throttle valve (not shown) is built in the throttle body 44.

  The surge tank 42 is a substantially cylindrical member, and by communicating with the branch pipes 43A to 43D, absorbs the differential pressure of each branch pipe 43A to 43D, and functions to prevent abnormal noise and sensor malfunction. It is. In the present embodiment, the length SL of the surge tank 42 in the cylinder row direction is set to be shorter than the distance DL on the downstream end side in the cylinder row direction of the branch pipes 43A to 43D described below. (See FIG. 1).

  Each of the branch pipes 43A to 43D is provided for each of the cylinders 12A to 12D, and communicates the corresponding cylinders 12A to 12D with the surge tank 42 while being curved in a substantially L shape when viewed from the front. In the illustrated embodiment, each branch pipe 43A to 43D has a path length of its intake passage PH1 to PH4 (in this embodiment, the length from the intake port 17 to the peripheral surface 51 of the rotary valve 50 in the surge tank 42). ) Are set to the same length. The lengths of the intake passages PH1 to PH4 are set within 500 mm, thereby improving the response to torque by the rotary valve 50 described later. Further, the “intake passage / stroke volume ratio” (the ratio of the single intake passage volume from the downstream end of the intake port 17 to the openings 52 and 53 of the rotary valve 50 with respect to the single stroke volume of each cylinder) is 70 percent. It is set in the range of 130% or less (the length of the intake passage is 500 mm or less). This volume is determined so as to correspond to the natural frequency at which the intake air tunes and resonates in the high-speed rotation region (4500 rpm or more) of the engine. As a result, the natural frequency tunes and resonates at high speed, so that the opening time of the intake valve 19 can be secured in that region, and the inertia supercharging effect by setting the path length can be obtained in the high rotation region of the engine. It is possible to increase the volume efficiency.

  In addition, in this embodiment, the fuel injection valve 45 is provided in each branch pipe 43A-43D. The fuel injection valve 45 includes a needle valve and a solenoid, and is driven to open for a time corresponding to the pulse width of the pulse signal input from the ECU 60 of the engine, and an amount of fuel corresponding to the valve opening time is opened. It is configured to inject toward the vicinity of the electrode of the spark plug 16.

  The rotary valve 50 is a cylindrical member, and is rotatably disposed in a state where the outer peripheral surface 51 is in sliding contact with the inner peripheral surface of the surge tank 42.

  FIG. 3 is a perspective view schematically showing a main part of the present embodiment.

  Referring to the figure, an input gear 54A is provided concentrically at the front end of the rotary valve 50. The input gear 54A meshes with an output gear 54B provided concentrically with the cam pulley 30 so that power is transmitted from the crankshaft 3 at a ratio of 1: 0.5 via the output gear 54B. It has become. In other words, the rotary valve 50 is synchronized with the cam pulley 30 at a ratio of 1: 1. A pair of openings 52 and 53 are formed on the peripheral surface of the rotary valve 50 to communicate the inside of the surge tank 42 and the branch pipes 43A to 43D. The openings 52 and 53 are 180 degrees out of phase in the circumferential direction, and the front opening 52 is shifted upstream in the rotational direction with respect to the rear opening 53 in the axial direction. In the figure, 55 is an idler.

  In the illustrated embodiment, a rotary valve advance mechanism 56 is provided between the rotary valve 50 and the input gear 54A. The rotary valve advance mechanism 56 basically uses an input gear 54A and a rotary valve by using a rotation phase control device (see JP-A-11-107718) previously proposed by the present applicant. This is a mechanism for changing the valve opening timing of the rotary valve 50 by forming a phase between the rotary valve 50 and the rotary valve 50.

  The illustrated engine is an in-line four-cylinder engine, and when the cylinders are first to fourth cylinders 12A to 12D in order from the front of the engine body 10, the order of reaching the intake stroke is the first cylinder 12A, the third cylinder The cylinder 12C, the fourth cylinder 12D, and the second cylinder 12A are set. As a result, when the first cylinder 12A reaches the intake stroke, the relationship between each cylinder and the stroke is as shown in Table 1.

 Therefore, in the present embodiment, the first branch pipe 43A and the second branch pipe 43B are disposed so as to be opposed to each other with respect to the opening 52 of the rotary valve 50 with the phase shifted upstream in the rotational direction, The fourth branch pipe 43 </ b> D and the third branch pipe 43 </ b> C are arranged so as to face the opening 53 so as to be opposed to each other with a phase shifted to the upstream side in the rotational direction.

  More specifically, in order from the upstream side, the first branch pipe 43A connected to the first cylinder 12A and the second branch pipe 43B connected to the second cylinder 12B can be opposed to the front opening 52 in order from the upstream side. The fourth branch pipe 43D connected to the fourth cylinder 12D and the third branch pipe 43C connected to the third cylinder 12C are fixed to the surge tank 42 with the phase shifted by 90 °, and the rear opening It is fixed to the surge tank 42 in a state where the phase is shifted by 90 ° in order from the upstream side, at a position that can face 53. Further, the first branch pipe 43 </ b> A and the fourth branch pipe 43 </ b> D (therefore, the second branch pipe 43 </ b> B and the third branch pipe 43 </ b> C) are arranged in the same phase in the circumferential direction of the surge tank 42. Therefore, in this configuration, the branch pipes 43A to 43D can be opened and closed at a predetermined timing regardless of the engine speed, and the branch pipes 43A to 43D can be made equal in length and compact. Will do. As a result, the intake passages PH1 to PH4 can be shortened as much as possible, and an intake structure with high response to torque improvement can be configured. Further, as described above, the length SL of the surge tank 42 in the cylinder row direction is set to be shorter than the interval DL on the downstream end side in the cylinder row direction of the branch pipes 43A to 43D described below. (See FIG. 1), the upstream ends of the branch pipes 43A to 43D are converged in the cylinder row direction as compared with the downstream ends. For this reason, in this embodiment, it has the structure where the response with respect to a torque improvement becomes very high.

  FIG. 4 is an enlarged cross-sectional view of the main part of FIG.

  With reference to the figure, the diameter D of the rotary valve 50 is set larger than the cross-sectional width of each branch pipe 43A-43D. By rotating the rotary valve 50 in synchronization with the crankshaft 3, the time for opening the branch pipes 43A to 43D corresponding to the openings 52 and 53 is shortened. In addition, since the rotary valve 50 is rotated to supply air to the branch pipes 43A to 43D facing the peripheral surface through the openings 52 and 53 formed on the peripheral surface, air pulsation can be suppressed. The occurrence of abnormal noise is also reduced.

  Furthermore, the opening angle θ of each of the openings 52 and 53 formed in the rotary valve 50 is set in a range that can be opened from the latter half of the intake stroke to the latter half of the compression stroke based on a simulation described later. As a result, in the first half of the intake stroke, even if the intake valve 19 opens the intake port 17, the rotary valve 50 is in a state of shielding the surge tank 42. A negative pressure is generated in the branch pipe 43A (˜43D).

  Further, the engine body 10 is provided with two crank angle sensors 61 and 62. Each of the crank angle sensors 61 and 62 is disposed around the crankshaft 3 with a predetermined phase difference. While detecting the rotation speed of the engine based on the detection signal output from one of the crank angle sensors 61, The rotation direction and the rotation angle of the crankshaft 3 are detected based on detection signals output from both the crank angle sensors 61 and 62.

  Next, the engine ECU 60 will be described with reference to FIGS. 2 and 5.

  FIG. 5 is a block diagram showing a configuration of the ECU 60 of the present embodiment.

  As shown in the figure, the ECU 60 includes an operating state determination means 60A for determining whether or not the engine is at a high load, a valve opening timing control means 60B for controlling the valve opening timing of the rotary valve 50, The fuel injection control means 60C for controlling the fuel injection timing of the fuel injection valve 45 is functionally provided.

  The crank angle sensors 61 and 62 and the accelerator opening sensor 63 are connected to the ECU 60. The operating state determination means 60A of the ECU 60 is configured to determine the engine speed and the engine load status based on the detection signals of the sensors 61 to 63.

  The valve opening timing control means 60B of the ECU 60 is configured to control the variable valve timing mechanisms 21 and 22 and the rotary valve advance mechanism 56 in accordance with the engine speed based on the detection signals of the crank angle sensors 61 and 62. ing.

  FIG. 6 is a graph showing the relationship between the valve lift amount and the crank angle CA.

  Referring to FIG. 6 in detail, regarding the control of the variable valve timing mechanism 21, the valve opening timing is delayed as indicated by the curves V 1 to V 5 as the engine rotation region goes to the high speed side. Is set. On the other hand, with respect to the valve opening timing of the rotary valve 50, the valve opening timing control means 60B, as shown by LV1 in FIG. 6, has a relatively slow timing (at the intake stroke) in the low engine speed range (about 2500 rpm or less). The piston 4 of the cylinder in question is set to open at a timing of about 120 ° CA), and the valve opening timing is advanced as it goes to the high speed side, and the engine high speed range (about 4000 rpm or more) Then, as shown by LV2 in FIG. 6, it is set so that the overlap with the valve opening period of the intake valve 19 is maximized.

  Further, the fuel injection control means 60C of the ECU 60 is set to inject fuel in the intake stroke at least on the high load side according to the valve opening timing of the rotary valve 50 determined by the valve opening timing control means 60B. Yes.

  Specifically, the injection is set to start just before the rotary valve 50 is opened. As a result, the fuel injected into the high-pressure wave generated by the rotary valve 50 can ride and efficiently supply the fuel into the cylinder. Further, by injecting fuel into the cylinder in the intake stroke on the high load side, the temperature in the cylinder is lowered by the injected fuel, so that self-ignition can be prevented and occurrence of knocking can be suppressed. However, the timing “just before the rotary valve 50 opens” may be the intake stroke at the latest, and when the rotary valve 50 needs to be advanced in the high-speed rotation region, the timing is not limited to the intake stroke. The fuel may be injected in the exhaust stroke of the previous stroke.

  Further, the amount of fuel to be injected is adjusted as appropriate according to the running state of the vehicle, similarly to the known control means, but as the amount increases, the injection timing is determined by opening the rotary valve 50. It sets so that it may inject earlier than valve timing. As a result, even when more fuel is injected when the air-fuel ratio is made rich and burned, it is possible to efficiently supply the fuel into the cylinder by placing the fuel on the high-pressure wave generated by the rotary valve 50. become.

  Next, a control procedure of the ECU 60 in this embodiment will be described.

  FIG. 7 is a flowchart showing a control procedure of the ECU 60 according to the embodiment of FIG.

  Referring to the figure, when the engine is started from a stopped state (step S1), ECU 60 sets operation state determining means 60A, valve opening timing control means 60B, and fuel injection control means 60C to the PGV mode (step). S2). In this PGV mode, the intake valve 19 opens and closes with the characteristics of V1 to V5 in FIG. 6 according to the engine speed Ne, and the rotary valve 50 opens at the timing from LV1 to LV2 in FIG. As a result, in the low-speed rotation region, the opening timing of the intake valve 19 is accelerated, while the opening timing of the rotary valve 50 is delayed, so that the surge tank 42 and the cylinder are not the first time when the piston 4 reaches near the bottom dead center. It becomes possible to generate a large pressure wave, and on the medium and high speed side, it is possible to obtain a high volumetric efficiency while appropriately suppressing the generation of the pressure wave by the rotary valve 50. Further, when the engine rotation speed Ne reaches a predetermined high-speed rotation region (for example, 4500 rpm or more), the control mode of each means 60A-60C is shifted to the high-speed rotation region mode (step S3, step S4). In this high-speed rotation region mode, the intake valve 19 opens and closes with the characteristic of V5 in FIG. 6, and the rotary valve 50 opens at the timing up to LV2 in FIG. As a result, it is possible to suppress an excessive increase in intake pressure in a high-speed rotation region where intake is sufficiently obtained.

  Next, the opening / closing timing of the rotary valve 50 in the PGV mode will be described with reference to FIGS. 2, 8 to 10, and 11. 8 to 10 are schematic cross-sectional views illustrating states from the intake stroke to the exhaust stroke in the PGV mode. FIG. 11 is a graph showing the relationship between the crank angle (CA) of the first cylinder 12A, the in-cylinder pressure P, and the lift amount of the intake valve.

  First, referring to FIGS. 2 and 8, for example, when the first cylinder 12A shifts to the intake stroke (CA1 to CA2 in FIG. 11), the intake valve 19 immediately before shifting from the exhaust stroke to the intake stroke (FIG. 11). Since the opening 52 of the rotary valve 50 is closed at this stage, as the piston 4 moves toward the bottom dead center, as indicated by L1 and L4 in FIG. Thus, a negative pressure is formed in the branch pipe 43A and the first cylinder 12A.

  As shown in FIG. 9, when the piston 4 approaches the vicinity of the bottom dead center (in the illustrated embodiment, CA4 in FIG. 11: about 120 ° CA), the rotary valve 50 opens instantaneously with a large peripheral speed. For this reason, the air in the surge tank 42 generates a pulse (pressure wave) due to the negative pressure generated in the first cylinder 12A, and is aspirated rapidly into the first cylinder 12A. The fuel injection control means 60C performs fuel injection by the fuel injection valve 45 for a predetermined time (CA6 to CA7 in FIG. 11) immediately before the rotary valve 50 is opened. As a result, the injected fuel is rapidly aspirated into the first cylinder 12A together with fresh air by a pulse (pressure wave) generated in the first cylinder 12A. Accordingly, even when rich combustion is performed, the fuel does not adhere to the passage wall, and a desired amount of fuel can be efficiently supplied into the cylinder.

  Further, as shown in FIG. 10, at the timing when the piston 4 reaches the bottom dead center (CA2 in FIG. 11), the “intake passage / stroke volume ratio” is 70% or more and 130% or less (the path length of the intake passage is 500 mm). The air from the surge tank 42 is rapidly charged into the first cylinder 12A in combination with the setting of the following range. Immediately thereafter (in the illustrated embodiment, CA3: about 225 ° CA), the intake valve 19 is closed, so that extremely high volumetric efficiency can be obtained in a wide rotational speed range (2000 rpm or more).

  Thereafter, the piston 4 reaches the compression stroke and the expansion stroke, and the spark plug is ignited after fuel injection, whereby the air-fuel mixture is combusted, and after the combustion, the exhaust is exhausted by the exhaust stroke. Further, the opening 52 of the rotary valve 50 closes the branch pipe 43A at a predetermined timing (CA5 in FIG. 11: about 270 ° CA) after the intake valve 19 closes the intake port 17.

  Next, the relationship between the opening / closing timing of the rotary valve 50 and the opening / closing timing of the intake valve 19 will be described.

  FIG. 12 is a graph showing an example in which the opening / closing timing of the intake valve 19 and the opening timing of the rotary valve 50 are varied and simulated.

  As shown in the figure, the inventor obtains volumetric efficiency from simulation by changing the opening / closing timings L21 to L23 of the intake valve 19 and the opening timings L31 to L35 of the rotary valve 50, and the opening / closing timings L21 L23 and opening timings L31 to L35 are selected.

  Next, for each of the valve timings L31 to L35, a high-speed engine suitable for a sports car in which the valve opening period (crank angle) of the intake valve 19 is large and the volume efficiency in the high-speed region closed with a crank angle slower than the CA3 is emphasized (4 cylinders) and low / medium speed suitable for general passenger cars that place importance on volume efficiency in the low / medium speed region where the valve opening period (crank angle) of the intake valve 19 is relatively small (approximately 25 ° to 30 ° CA small) The volume efficiency with the type engine (4 cylinders) was examined.

  FIG. 13 is a graph showing the relationship between the volume efficiency of the high speed engine and the engine speed, and FIG. 14 is a graph showing the relationship between the volume efficiency of the low and medium speed engine and the engine speed. The opening / closing timing of the intake valve 19 is adjusted to increase the volumetric efficiency according to the engine speed.

  Referring to these figures, the volumetric efficiency was 100% or more in the range of the rotational speed Ne from 3200 rpm to 4500 rpm, regardless of which vehicle was used for measurement.

  FIG. 15 is a graph in which the maximum values at the respective opening timings L31 to L35 in FIGS.

  In the figure, F10 indicates the volume efficiency of the high speed engine, and F11 indicates the maximum volume efficiency of the low / medium speed engine. F21 and F22 indicate the volumetric efficiency when no rotary valve is used for each of the high-speed engine and the low-medium-speed engine.

  As can be seen from FIG. 15, when the rotary valve is not used, the volumetric efficiency is greatly reduced when the rotational speed is in the range of 2000 rpm to 3000 rpm, whereas when the rotary valve is used as in the above embodiment, It can be seen that even when the rotational speed is in the range of 2000 rpm to 3000 rpm, the volumetric efficiency is secured around 100%. Thus, in the aspect of this embodiment, it was confirmed that good volume efficiency can be obtained even in the low and medium speed rotation region where volume efficiency tends to drop.

  Next, the relationship between the stroke volume and the intake passage volume will be described.

  The present inventor performed a simulation on the relationship between the stroke volume of the cylinder and the volume of the branch pipe in the cylinder of the specification shown in Table 2 when configuring the intake device 40 of the above-described embodiment.

  In Table 2, the intake passage length is the sum of the path lengths of the intake port 17 and the branch pipe 43A (43B, 43C, 43D). Specifically, the intake end of the intake port 17 with respect to the combustion chamber 5 (downstream end) ) To the opening 52 (53) of the rotary valve 50 (see FIG. 2). The stroke volume Vh is a volume from the piston top dead center to the piston bottom dead center of the cylinder 14, and the intake passage volume V is the volume of the intake port 17 formed in the cylinder head 12 and the branch pipe 43A (43B, 43C, 43D).

  FIG. 16 is a graph showing the relationship between the volumetric efficiency ηv and the rotational speed Ne in this specification.

  The measurement result of FIG. 16 is based on the case where the intake passage length is 200 mm (in the case of R3), and the opening / closing range of the intake valve when the rotary valve is opened at 115 ° CA is 50 ° CA / 30 ° CA to 10 °. The maximum value at CA / 70 ° CA is shown. As shown in the figure, when the intake passage / stroke volume ratio is low and the intake passage / stroke volume ratio falls below 70%, the overall volume efficiency ηv decreases as shown by R1 in the figure, particularly 3500 rpm. The volumetric efficiency ηv is greatly reduced. This is because the intake passage volume V is too small, so that a sufficient amount of air cannot be secured even by the pulse generation action by the rotary valve, and the low rotation region (2500 rpm range) and the high speed rotation region (4500 rpm) at the time of pulse generation. ~ 5500rpm) becomes peaky, and it is considered that a valley is formed at 3500rpm. On the other hand, when the intake passage length is longer than the base length (when the intake passage / stroke volume ratio is 96% or more), the peak in the high-speed rotation region is relaxed, resulting in a volumetric efficiency ηv in the low-speed rotation region. It was found that the valley at 3500 rpm tends to be small even when it is high. However, if the intake passage length is increased, the response of intake air is also deteriorated, so that the transient torque during acceleration may be reduced. From these viewpoints, when the intake passage / stroke volume ratio is 70% or more and 130% or less (the intake passage length is 500 mm or less), a high torque can be obtained both in the steady state and in the transient state. It was found that the response was improved.

  As described above, according to the present embodiment, since the rotary valve 50 that rotates in synchronization with the crankshaft 3 is employed as the pulse generator, the crankshaft 3 can be operated at a high speed without receiving a large intake resistance. Whether rotating in the rotation region or in the low speed region, it is possible to reliably tune the frequency and generate high-pressure waves in the cylinders 12A to 12D at a desired timing. As a result, although it is a spark ignition type engine, it becomes possible to ensure the output equivalent to a diesel engine. In addition, since the diameter of the rotary valve 50 is set larger than the cross-sectional width of the branch pipes 43A to 43D, the branch pipes 43A to 43D can be opened and closed at a high peripheral speed to generate a strong pressure wave. it can.

  Furthermore, as a result of the intake passage / stroke volume ratio being set at a position that is in the range of 70% to 130%, the torque in the transient state during acceleration as well as the steady state torque can be efficiently increased. This makes it possible to reliably achieve synchronization in the low, medium, and high speed rotation regions, and achieves a remarkable effect that volumetric efficiency can be increased with low noise even in the low speed rotation region. In addition, by setting this range, the intake passage can be set short, so the distance that the fuel injected from the fuel injection valve 45 reaches the cylinder is also shortened, and the fuel can be put on a high intake flow velocity. Combined with the action, the fuel does not adhere to the wall surface of the port and the fuel supply efficiency increases.

  In this embodiment, the fuel injection valve 45 injects fuel in the vicinity of the opening of the rotary valve 50. Therefore, fuel is injected immediately before the pressure wave is generated, and this fuel rides on the intake air. In other words, the cylinder is pushed into the cylinder. As a result, the fuel is also efficiently introduced into the cylinder and mixed with the fresh air, so that the mixed state is promoted and the fresh air is cooled by the latent heat of vaporization of the fuel. Therefore, even when the air-fuel ratio is enriched in a high load state, it is possible to suppress the fuel from adhering to the passage wall surface and enhance the function of preventing knocking due to vaporization latent heat.

  In addition, since the fuel is injected first as the air-fuel ratio is made richer, it is possible to achieve both vaporization atomization performance by the fuel and knocking suppression.

  In particular, in this embodiment, power transmission means for transmitting the power of the crankshaft 3 of the engine to the rotary valve 50 as a drive source is provided. Therefore, the crankshaft 3 of the engine and the rotary valve 50 are physically synchronized. The valve opening operation can be performed. Accordingly, it is possible to precisely synchronize the rotary valve 50 and the phases of the cylinders 12A to 12D and to increase the volume efficiency by providing a more accurate pulse generation function.

  Further, in the present embodiment, the power transmission means rotates the rotary valve 50 at a speed ½ of the rotational speed of the crankshaft 3, so that the valve opening cycle of the rotary valve 50 is set to the intake valve 19. The pressure wave can be propagated into the cylinders 12A to 12D in mechanical synchronization with the valve opening cycle.

  Further, in this embodiment, the pressure wave can be propagated into the cylinders 12A to 12D by mechanically synchronizing the valve opening period of the rotary valve 50 with the valve opening period of the intake valve 19, so that the intake passages have the same length. It becomes easy to realize.

  Furthermore, in this embodiment, since the intake passage lengths of the branch pipes 43A to 43D are set to substantially the same dimension, the same volume efficiency can be obtained under the same conditions in any of the cylinders 12A to 12D. Torque variation does not occur for each of the cylinders 12A to 12D, and more stable torque generation characteristics can be obtained.

  Further, in the present embodiment, a surge tank 42 is provided at the upstream end of the branch pipes 43A to 43D as a collecting portion communicating with the branch pipes 43A to 43D. The surge tank 42 includes the rotary valve 50 concentrically. Therefore, the intake passages PH1 to PH4 can be opened and closed inside the surge tank 42, and the volume in the surge tank 42 can be used effectively. Therefore, the diameter of the rotary valve 50 can be set larger without increasing the size of the entire apparatus.

  In the above-described aspect, the intake passage / stroke volume ratio is set to a position in the range of 70% to 130%. However, even if the intake passage / stroke volume ratio is out of this range, the rotary valve 50 is placed in the surge tank 42. When the built-in configuration is adopted, the branch pipes 43A to 43D are instantaneously opened at a large peripheral speed to generate a large pressure wave, and torque in a transient state during acceleration as well as torque in a steady state. Can also be increased efficiently. Accordingly, synchronization in the low, medium, and high speed rotation regions can be ensured, and volumetric efficiency can be increased with low noise even in the low speed rotation regions.

  In particular, in this embodiment, the branch pipes 43A to 43D are connected to a 4-cylinder 12A to 12D engine, and the path lengths of the branch pipes 43A to 43D are set to be substantially the same length. In any of the cylinders 12A to 12D, the same volumetric efficiency can be obtained under the same conditions, and torque variation does not occur between the cylinders 12A to 12D. As a result, more stable torque can be generated.

  In the present embodiment, the engine includes the first to fourth cylinders 12A to 12D from one end in the cylinder row direction, and the intake strokes are performed in the order of the first, third, fourth, and second. The four-cylinder four-cycle engine is operated with a phase difference of 180 ° in crank angle, and the rotary valve 50 rotates at a speed half that of the crankshaft 3 and is spaced apart in the axial direction. Two openings 52 and 53 that are 180 ° to substantially 180 ° out of phase in the circumferential direction, and the openings at the upstream ends of the branch pipes 43A and 43B of the first cylinder 12A and the second cylinder 12B are 90 in the circumferential direction. It is connected to the surge tank 42 so as to shift the phase by about 90 ° to about 90 °, and the opening at the upstream end of the branch pipes 43D, 43C of the fourth cylinder 12D and the third cylinder 12C is 90 ° to about 9 ° in the circumferential direction. ° It is connected to the surge tank 42 so as to shift the phase, the opening at the upstream end of the branch pipes 43A and 43D of the first cylinder 12A and the fourth cylinder 12D, and the branch pipe 43B of the second cylinder 12C and the third cylinder 12D, The opening at the upstream end of 43C is arranged in the same phase in the circumferential direction of the rotary valve 50.

  Therefore, by providing two openings in the rotary valve 50, it is possible to propagate pressure waves to the branch pipes 43A to 43D of the 4-cylinder 12A to 12D engine at a desired timing, and to increase the volume efficiency ηv and increase the torque. Therefore, it is possible to achieve both the improvement of the torque generation characteristics by the equal length and the improvement of the response by shortening the intake passage.

  Further, in the present embodiment, in the low / medium speed rotation region of the engine, first, the intake stroke is performed with the intake valve 19 opened and the rotary valve 50 closed, so that until the middle of the intake stroke, the inside of each cylinder 12A-12D A negative pressure is formed in Thereafter, the rotary valve 50 as a pulse generator is opened, so that fresh air is introduced into the cylinders 12A to 12D with a high-pressure wave. Therefore, in the medium speed rotation region, sufficient air can be introduced into the cylinder in the intake stroke by the pressure wave generated by the rotary valve 50. Furthermore, in the high rotation region, the valve opening timing of the rotary valve 50 is advanced and the valve opening timing of the intake valve 19 is delayed, so that both valve opening timings overlap. Therefore, in the high-speed rotation region where the intake air flow rate is high, it is possible to secure the intake charge time and obtain sufficient volume efficiency. As a result, when the high pressure wave is introduced into each of the cylinders 12A to 12D by the rotary valve 50, the timing for closing the introduced high pressure wave (fresh air) within each of the cylinders 12A to 12D is optimized in a wide rotation range, and the high speed wave is made high speed. In the rotation region, it is possible to secure the intake filling time by the intake valve 19 and obtain high volumetric efficiency in a wide operation region.

  In this embodiment, the volume of the intake passage from the openings 52 and 53 of the rotary valve 50 to the intake valve 19 is set to a natural frequency that tunes and resonates in the high engine speed region, and the valve opening timing control means 60B Since the valve opening period of the intake valve 19 and the rotary valve 50 is controlled to be maximized in the high rotation region, the path length is set even in the high rotation region where the impulse action by the rotary valve 50 cannot be obtained. It is possible to increase the volumetric efficiency by exerting the inertial supercharging effect. Therefore, it is possible to increase volumetric efficiency in a wide range of rotation.

  In addition, by setting this range, the intake passage can be set short, so the distance that the fuel injected from the fuel injection valve 45 reaches the cylinder is also shortened, and the fuel can be put on a high intake flow velocity. Combined with the action, the fuel does not adhere to the wall surface of the port and the fuel supply efficiency increases.

  Furthermore, in this embodiment, the ratio of the volume of the single branch pipes 43A to 43D from the downstream end of the intake port 17 to the opening of the rotary valve 50 with respect to the single stroke volume of each cylinder 12A to 12D is 70% or more and 130%. Since it is set within the following range (the path length of the intake passage is 500 mm or less), it is possible to efficiently increase the torque in the transient state during acceleration as well as the torque during steady state.

  Further, in this embodiment, a surge tank 42 as a collecting portion communicating with each branch pipe 43A to 43D is provided on the upstream side of the branch pipes 43A to 43D along the cylinder row direction. Is set to be shorter than the distance DL on the downstream end side in the cylinder row direction of the branch pipes 43A to 43D, so that the response to the torque improvement of the rotary valve 50 is improved.

  Furthermore, in this embodiment, when starting the engine in the so-called cold stop state, the valve opening timing control means 60B determines that the rotation region of the engine is the low speed side, the rotary valve 50, the variable valve timing mechanism 21, and the like. Therefore, when the engine is started, the overlap portion between the intake valve 19 and the valve opening period of the rotary valve 50 becomes as short as possible. Therefore, when a large negative pressure is generated, a new high-pressure wave is suddenly generated. Qi is introduced into the cylinder in the intake stroke. As a result, the adiabatic compression action in each of the cylinders 12A to 12D is increased and the temperature in each of the cylinders 12A to 12D is increased, so that the engine starting performance is improved.

  Further, in the present embodiment, the variable valve timing mechanism 21 changes the phase with respect to the crank angle and opens the intake valve 19, so that the intake pressure is adjusted while using the intake valve 19 that is opened and closed by full lift. Can be adjusted, and the combination with the rotary valve 50 becomes easy. Accordingly, it is possible to adjust the appropriate intake pressure from the low speed rotation region to the high speed rotation region. In particular, in the high-speed rotation region, the valve opening lift amount of the intake valve 19 can be set to full lift. Therefore, when adjusting the valve opening timing of the rotary valve 50 by advancing, the high-pressure wave generated by the rotary valve 50 is appropriately It becomes easy to adjust to the correct intake pressure.

  Further, in this embodiment, power transmission means (input pulleys 32, 54, timing belt 34, etc.) for transmitting the power of the crankshaft 3 of the engine to the rotary valve 50 as a drive source is provided. 3 and the rotary valve 50 can be physically synchronized to perform the valve opening operation.

  The above-described embodiments are merely preferred specific examples of the present invention, and the present invention is not limited to the above-described embodiments.

  FIG. 17 is a schematic cross-sectional view of an engine showing another embodiment of the present invention, and FIG. 18 is a block diagram according to the embodiment of FIG.

  As shown in the figure, an electric motor 156 may be employed as means for driving the rotary valve 50. In that case, the valve opening timing control means 60B provided in the ECU 60 can adjust the phase of the rotary valve 50 by controlling the rotational speed of the electric motor 156.

  19 is a schematic cross-sectional view of an engine showing still another embodiment of the present invention, and FIG. 20 is a flowchart of the embodiment of FIG.

  Referring to FIG. 19, in the embodiment according to FIG. 19, a turbocharger 58 is provided. The turbocharger 58 includes a turbine section 58a connected to the exhaust port 18 via an exhaust pipe 18a, and a compressor section 58b driven by the turbine section 58a, and a fan built in the turbine section 58a is exhausted. The fan built in the compressor section 58b sucks outside air by rotating by the exhaust gas discharged from the port 18, and supercharges fresh air into the surge tank 42 of the intake manifold 41. Yes. The turbine section 58a of the turbocharger 58 is provided with a waste gate 58c whose intercept point is a medium speed rotation region (for example, between 2000 rpm and 3000 rpm), and the engine speed is higher than that of the medium speed rotation region. If this happens, the waste gate 58c is opened to bypass the exhaust.

  Next, referring to FIG. 20, in the embodiment of FIG. 19, the engine is started (step S11), and after each control means 60A-60C shifts to the PGV mode (step S12), the engine rotation speed is set to the turbocharger 58. Whether or not the intercept point is exceeded (step S13). After exceeding the intercept point, the mode immediately shifts to the high-speed rotation region mode, and the intercept point is monitored until the engine stops ( Step S14, Step S15). In the aspect of this embodiment, in the rotation region up to the intercept point of the turbocharger 58, the rotary valve 50 can introduce pressure waves into the respective cylinders 12A to 12D, and the medium and high speed rotation after the intercept point. In the region, the opening period of the intake valve 19 and the rotary valve 50 is overlapped to prevent an excessive pressure difference from occurring, and fresh air is introduced into each cylinder 12A to 12D at a desired intake pressure. It becomes possible. Therefore, the intake in the low-speed rotation region can be supplemented by the rotary valve 50, while the supercharging pressure by the turbocharger 58 can effectively exert the supercharging effect at the intercept point and increase the charging efficiency.

  FIG. 21 is a graph showing the relationship between the valve lift amount and the crank angle according to still another embodiment of the present invention, and FIG. 22 is a flowchart of the embodiment of FIG.

  Referring to these drawings, when the variable valve timing mechanism is adopted, the valve lift amount (valve opening period) can also be adjusted. In the low speed rotation region, as shown by V6 in FIG. 21, a low lift (short valve opening period) is possible. ) To open and close the intake valve to obtain boost pressure. That is, in the middle and high speed rotation region, as shown in FIG. 21 as in the case of FIG. 6, when the intake valve is configured to open and close with a high lift, in the low speed rotation region, On the contrary, there is a possibility that the time for increasing the filling efficiency may be lengthened. Therefore, as shown in FIG. 22, in the case of adopting a configuration in which the intake valve is opened and closed with low lift to obtain boost pressure in the low speed rotation region, each control is performed after the engine is started (step S21). The means is set to the low speed rotation region mode (step S22). In this low speed rotation region mode, in the rotation region where the valve lift is set to low lift, the valve opening timing of the rotary valve 60 is set to LV2 shown in FIG. 21 to synchronize with the valve opening timing of the intake valve 19. In the case where the boost pressure is obtained exclusively by adjusting the valve lift amount and the engine rotation area is shifted beyond the medium speed rotation area, the engine rotation area depends on the engine rotation area as in the control mode described in FIG. The control mode of each of the control means 60A to 60C is switched to the PGV mode or the high speed rotation area mode (steps S23 to S27).

  In this aspect, in a low rotation region where high followability to engine load is required, the intake valve 19 is opened and closed with a low lift to supply high pressure fresh air into each cylinder 12A to 12D in a short time. In addition, in the middle speed rotation region, the intake valve 19 can be opened and closed with a high lift that can suppress the high-pressure wave generated by the rotary valve 50 by changing the phase of the intake valve 19. Further, in a high-speed rotation region where intake can be sufficiently secured, it is possible to suppress the occurrence of excessive pressure by overlapping the opening period of the intake valve 19 and the opening period of the rotary valve 50.

  Although not specifically shown, the fuel injection valve 45 may be attached to the intake port 17 formed in the cylinder head 12.

  It goes without saying that various modifications can be made within the scope of the claims of the present invention.

1 is a right side view of an intake device for a multi-cylinder engine according to an embodiment of the present invention. It is AA cross-section schematic of FIG. It is a perspective view which simplifies and shows the principal part of this embodiment. It is sectional drawing to which the principal part of FIG. 2 was expanded. It is a block diagram which shows the structure of ECU of this embodiment. It is a graph which shows the relationship between valve lift amount and a crank angle. It is a flowchart which shows the control procedure of ECU which concerns on embodiment of FIG. 6 is a schematic cross-sectional view showing a state from an intake stroke to an exhaust stroke in a PGV mode. 6 is a schematic cross-sectional view showing a state from an intake stroke to an exhaust stroke in a PGV mode. 6 is a schematic cross-sectional view showing a state from an intake stroke to an exhaust stroke in a PGV mode. It is a graph which shows the relationship between the crank angle of a 1st cylinder, cylinder pressure, and the lift amount of an intake valve. It is a graph which shows the example which simulated the opening-and-closing timing of an intake valve, and the timing which a rotary valve opens. It is a graph which shows the relationship between the volume efficiency of a high-speed type engine, and an engine speed. It is a graph which shows the relationship between the volume efficiency of a low and medium speed type engine, and an engine speed. The maximum values at the respective opening timings in FIGS. 13 and 14 are graphed and superimposed. It is the graph which showed the relationship between volumetric efficiency and rotation speed by this specification. 4 is a schematic cross-sectional view of an engine showing another embodiment of the present invention. FIG. 18 is a block diagram according to the embodiment of FIG. 17. 6 is a schematic cross-sectional view of an engine showing still another embodiment of the present invention. 20 is a flowchart of the embodiment of FIG. It is a graph which shows the relationship between the valve lift amount and crank angle which concern on another embodiment of this invention. It is a flowchart of FIG.

3 Crankshaft 4 Piston 10 Engine body 11 Cylinder block 12 Cylinder head 12A to 12D Cylinder 14 Cylinder 17 Intake port 19 Intake valve 30 Cam pulley 32 Output pulley 34 Timing belt 40 Intake device 41 Intake manifold 42 Surge tank 43A to 43D Branch pipe (intake Example of tube)
45 Fuel injection valve 50 Rotary valve (an example of a pulse generator)
52 Opening 53 Opening 60 ECU
60A Operating state determination means 60B Valve opening timing control means 60C Fuel injection control means D Diameter DL Distance SL on the downstream end side in the cylinder row direction of each branch pipe Length of the collecting portion in the cylinder row direction Ne Rotational speed PH1 to PH4 Intake passage V Intake passage volume Vh Stroke volume ηv Volume efficiency θ Opening angle

Claims (9)

With an intake pipe for supplying air to a plurality of cylinders are provided in each intake port of the cylinder, the upstream end of the intake pipe of each cylinder, a surge tank as a collection portion communicating with the intake pipes are provided, each cylinder In response to the intake stroke of the multi-cylinder engine equipped with a pulse generator that opens a valve in the middle of the intake stroke during the valve opening period of the intake port and generates a high-pressure wave in the cylinder,
Pulse generator, while in sliding contact with the inner peripheral surface of the surge tank is a rotary valve rotates synchronously with the crankshaft, the diameter of the rotary valve is set larger than the intake pipe cross-sectional width Rutotomoni, the rotary valve the peripheral surface, the opening communicating the interior and the intake pipes of the surge tank is formed, the upstream end of the intake pipe, the is arranged to be selectively opened and closed so as to face the apertures of the rotary valve ,
The ratio of the single independent intake passage volume from the downstream end of the intake port to the opening of the rotary valve to the single stroke volume of each cylinder is set in the range of 70% to 130%. Cylinder engine intake system. The intake device for a multi-cylinder engine according to claim 1,
An intake system for a multi-cylinder engine, comprising power transmission means for transmitting power from a crankshaft of the engine to the rotary valve as a drive source. The intake device for a multi-cylinder engine according to claim 2,
An intake system for a multi-cylinder engine, wherein the power transmission means rotates a rotary valve at a speed ½ of a rotational speed of a crankshaft. The intake device for a multi-cylinder engine according to any one of claims 1 to 3,
An intake device for a multi-cylinder engine, wherein the intake passage length of each intake pipe is set to be substantially the same size. The intake device for a multi-cylinder engine according to any one of claims 1 to 4,
An intake device for a multi-cylinder engine, wherein the surge tank contains the rotary valve concentrically. Air upstream end on the intake pipe for supplying the respective intake ports of the plurality of cylinders, a surge tank as a collection portion communicating with the intake pipe is provided, in correspondence with the intake stroke of each cylinder, opening of the intake port In an intake device of a multi-cylinder engine provided with a pulse generator that opens a valve in the middle of an intake stroke within a valve period and generates a high-pressure wave in the cylinder
Pulse generator is a rotary valve rotates synchronously with the crankshaft sliding contact with the inner peripheral surface of the surge tank, the diameter of the rotary valve is set larger than the intake pipe cross-sectional width Rutotomoni, the rotary valve on the peripheral surface, the opening communicating the interior and the intake pipes of the surge tank is formed, arranged so that the upstream end of the intake pipes are selectively opened and closed to face the open port of the rotary valve An intake device for a multi-cylinder engine, characterized in that The multi-cylinder engine intake device according to claim 6,
An intake device for a multi-cylinder engine, wherein the path length from the intake port to the opening of the rotary valve is set to be substantially the same length. The multi-cylinder engine intake device according to claim 6 or 7,
The engine includes first to fourth cylinders from one end in the cylinder row direction, and the intake stroke is performed in the first, third, fourth, and second order with a phase difference of 180 ° in crank angle. 4 cylinder 4 cycle engine
Openings at the upstream ends of the intake pipes of the first cylinder and the second cylinder are connected to the surge tank so as to shift the phase by 90 ° to approximately 90 ° in the circumferential direction, and the fourth and third cylinders The upstream end opening of each intake pipe is connected to the surge tank so as to shift the phase by 90 ° to about 90 ° in the circumferential direction, and the upstream end opening and the first end of the intake pipe of the first cylinder and the fourth cylinder are connected. Openings at the upstream ends of the intake pipes of the second and third cylinders are arranged in the same phase in the circumferential direction of the rotary valve,
The rotary valve rotates at a speed that is half the rotational speed of the crankshaft, and has a phase difference of 180 ° to approximately 180 ° in the circumferential direction so as to open the upstream end opening of each intake pipe in the above order. An intake device for a multi-cylinder engine having a pair of openings having The multi-cylinder engine intake device according to any one of claims 6 to 8,
The ratio of the single independent intake passage volume from the downstream end of the intake port to the opening of the rotary valve to the single stroke volume of each cylinder is set in the range of 70% to 130%. Cylinder engine intake system.

Images