JP2005214035A - Cylinder deactivation type internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily form, at low cost, a supercharging mechanism used in an internal combustion engine performing cylinder deactivation operation. <P>SOLUTION: This cylinder deactivation type internal combustion engine 10 comprises air communication passages 30 and 32 communicating from exhaust passages 22c and 22d on the downstream side of deactivation-capable cylinders 14c and 14d to intake passages 16a and 16b on the upstream side of normal operating cylinders 14a and 14b, open/close valves 34 and 36 installed in the exhaust passages 22c and 22d, and a controller 38 performing a switching operation between all cylinder operation and deactivation cylinder operation and the operation of open/close valves 34 and 36. The controller 38 stops the supply of a fuel from fuel injection valves 24c and 24d in a deactivation operation to act the deactivation-capable cylinders 14c and 14d as pumps and controls the open/close valves 34 and 36 so that air can be supplied from the exhaust passages 22c and 22d to the intake passages 16a and 16b via. the air communication passages 30 and 32. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cylinder deactivation type internal combustion engine including a cylinder deactivation mechanism that deactivates a part of a plurality of cylinders, and in particular, a cylinder deactivation including a supercharging mechanism that increases the intake amount of a cylinder in order to improve combustion efficiency. The present invention relates to an internal combustion engine.

  In order to improve the torque and power (hereinafter referred to as output) of the internal combustion engine, it is effective to increase the amount of air supplied into the cylinder bore. For this reason, a turbocharger that increases the intake air amount using a turbine that rotates by the flow of exhaust gas has been proposed (see, for example, Patent Document 1). For the same purpose, a device (so-called supercharger) that forcibly supplies air by a compressor connected to an engine crankshaft has been developed and put into practical use.

  On the other hand, some internal combustion engines mounted on vehicles perform a cylinder resting operation in which some of a plurality of cylinders are stopped under a predetermined condition for the purpose of improving fuel consumption (for example, patents). Reference 2).

JP-A-5-33667 JP 2003-176747 A

  By the way, the turbocharger requires a complicated drive mechanism such as a turbine or a compressor that rotates at high speed. Further, since sufficient supercharging cannot be performed until the turbine speed exceeds a predetermined number of revolutions, a delay may occur until the output of the internal combustion engine increases with respect to the accelerator depression operation.

  The supercharger also requires a dedicated compressor for supercharging, which complicates the structure of the internal combustion engine and increases costs.

  On the other hand, in an internal combustion engine that performs a cylinder resting operation, all cylinders are operated in an operating state at high output, and a cylinder resting operation in which some cylinders are deactivated under a predetermined condition is performed. The idle cylinder operation is performed for the purpose of reducing fuel consumption at the time of low output, but a slight shock may occur due to the reduction of the output when switching from the all cylinder operation. Accordingly, there may be a case where a relatively large output is desired at the time of switching from the all-cylinder operation even during the idle cylinder operation. The turbocharger and supercharger can be applied to improve the output, but it is reasonable to install these complicated and high-priced turbochargers only for the purpose of improving the output during idle cylinder operation. Not.

  The present invention has been made in consideration of such problems, and provides a cylinder deactivation type internal combustion engine that can easily and inexpensively configure a supercharging mechanism used in an internal combustion engine that performs a cylinder deactivation operation. With the goal.

  The cylinder deactivation type internal combustion engine according to the present invention is a cylinder deactivation type internal combustion engine comprising a deactivation-compatible cylinder that is stopped during a predetermined deactivation operation and a normal operation cylinder that is operated even during the deactivation operation. It has an air communication passage that communicates the exhaust passage of the corresponding cylinder and the intake passage side of the normal operation cylinder.

  In this way, the non-operating cylinder is operated as a pump during the cylinder deactivation operation, and air is supplied from the exhaust passage of the deactivation cylinder to the intake passage side of the normal operation cylinder via the air communication path. Moreover, the effect as a supercharging mechanism is produced at a low price.

  In this case, it is preferable to provide a control means for switching a deriving destination of the gas discharged from the deactivation-response cylinder between the exhaust passage and the air communication passage according to operating conditions. By doing so, air can be supplied to the intake passage of the normal operation cylinder more reliably.

  A pressure detector configured to detect a pressure in the exhaust passage, wherein the control means is configured to discharge gas discharged from the inactive cylinder so that the pressure detected by the pressure detector is a predetermined value or less; It may be led out to the air communication passage.

  Furthermore, the cylinder deactivation type internal combustion engine may be a four-stroke type, and the deactivation-response cylinder may have a combustion cycle phase delayed by 180 ° from the normal operation cylinder. Thereby, air can be supplied to the intake passage of the normal operation cylinder in accordance with the timing at which the normal operation cylinder intakes air.

  Furthermore, when the number of the normal operation cylinders and the number of cylinders corresponding to the stoppage are the same, and one air communication passage is provided from each of the normal operation cylinders to each of the cylinders corresponding to the stoppage, Balance is good.

  The normal operation cylinder and the stop corresponding cylinder are arranged in series, and when the air communication passage is provided between the adjacent normal operation cylinder and the stop corresponding cylinder, the air communication passage is set short. The supply delay time due to the passage of air is short. Moreover, the resistance of the pipe line can be reduced.

  When the intake passage is connected to a surge tank having a predetermined volume, the air communication passage may be connected to the surge tank.

  The cylinder deactivation type internal combustion engine according to the present invention causes air to be discharged from the exhaust passage of the deactivation correspondence cylinder to the intake passage of the normal operation cylinder through the air communication passage by operating the deactivation correspondence cylinder as a pump during the deactivation operation. Supply. Therefore, the cylinder deactivation type internal combustion engine can be realized simply and inexpensively, and the configuration can be reduced in size and weight.

  In the normal operation cylinder, air for combustion is sufficiently supplied into the combustion chamber, so that the volume efficiency and the combustion efficiency are improved and the fuel efficiency is improved.

  Hereinafter, a cylinder deactivation type internal combustion engine according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a cylinder deactivation type internal combustion engine 10 according to the present embodiment is mounted on a vehicle (not shown), and operates two cylinders out of four cylinders according to the driving situation of the vehicle. It is possible to perform a cylinder resting operation to be stopped. A state in which all the four cylinders are operated with respect to the idle cylinder operation is referred to as an all cylinder operation. Examples of the vehicle on which the cylinder deactivation type internal combustion engine 10 is mounted include a motorcycle.

  There are a plurality of methods for cylinder deactivation of the internal combustion engine. In the cylinder deactivation type internal combustion engine 10, the fuel injection to the deactivation-response cylinders 14c and 14d is stopped and the ignition of the ignition plug of the cylinder is stopped. To do.

  Specifically, the cylinder deactivation type internal combustion engine 10 has an in-line four-cylinder configuration, two normally operated cylinders 14a and 14b that are always operated, and deactivation corresponding cylinders 14c and 14d in which fuel supply is stopped during the deactivation operation. And have. The normal operation cylinders 14a and 14b are two cylinders on both ends, and the stop corresponding cylinders 14c and 14d are two cylinders on the inner side.

  The cylinder deactivation type internal combustion engine 10 is a four-stroke type, and the crankshaft rotates 720 ° per one combustion cycle (see FIG. 2). In addition, the cylinders 14c and 14d corresponding to the suspension are configured so that the phase of the combustion cycle is delayed by 180 ° from the normal operation cylinders 14a and 14b, and vibrations due to a piston and a balancer (not shown) are offset.

  The cylinder deactivation type internal combustion engine 10 is a four-stroke type, and the normal operation cylinders 14a and 14b take in a mixture of fuel and air from the intake passages 16a and 16b via the intake valves 18a and 18b, and take in the combustion chamber. Repeat the compression, ignition, expansion and exhaust combustion cycles. Exhaust gas generated by the combustion is discharged from the exhaust valves 20a and 20b to the exhaust passages 22a and 22b, and is guided to a muffler (not shown).

  Similarly, the inactive cylinders 14c and 14d inhale the fuel / air mixture from the intake passages 16c and 16d via the intake valves 18c and 18d, and repeatedly execute the combustion cycle. The exhaust gas is discharged from the exhaust valves 20c and 20d to the exhaust passages 22c and 22d.

  The intake valves 18a to 18d and the exhaust valves 20a to 20d are opened and closed by camshafts that are linked to the rotation of the crankshaft. In practice, two intake valves 18a to 18d and two exhaust valves 20a to 20d are provided for each cylinder to improve intake and exhaust efficiency.

  The intake passages 16a, 16b, 16c, and 16d are respectively provided with fuel injection valves 24a, 24b, 24c, and 24d that generate an air-fuel mixture (hereinafter simply referred to as an air-fuel mixture) by spraying the fuel. The air-fuel mixture is ignited by the spark plugs 26a to 26d in the combustion chambers of the normal operation cylinders 14a and 14b and the stop corresponding cylinders 14c and 14d, and combusts and expands.

  Throttle valves 28a to 28d are provided in the intake passages 16a to 16d, respectively, and their upstream sides are connected to a surge tank 29 having a predetermined volume. The surge tank 29 has a volume for performing functions such as smoothing the pressure fluctuation of the intake air and generating a pressure reversal wave.

  The cylinder deactivation type internal combustion engine 10 includes air communication passages 30 and 32 communicating from the exhaust passages 22c and 22d to the intake passages 16a and 16b, and on-off valves (control means) 34 provided in the exhaust passages 22c and 22d, respectively. 36 and a controller 38 as control means. The on-off valves 34 and 36 are opened / closed according to operating conditions under the action of the controller 38 and switch the destination of the gas discharged from the cylinders 14c and 14d corresponding to the suspension to the exhaust passages 22c and 22d and the air communication passages 30 and 32.

  A check valve 41a is provided in the middle of the air communication passage 30 so that air flows only in one direction from the exhaust passage 22c to the intake passage 16a. A check valve 41b is provided so that air flows only in one direction from the passage 22d to the intake passage 16b. The position of the connecting portion between the air communication passages 30 and 32 and the intake passages 16a and 16b is set slightly upstream from the position where the fuel injection valves 24a and 24b are provided. The air communication passages 30 and 32 are smooth pipelines through which air can easily flow.

  The controller 38 includes pressure detectors 40a to 40d that detect negative pressure downstream of the throttle valves 28a to 28d, and an oxygen concentration sensor 42 that detects the oxygen concentration in the exhaust passages 22a to 22d (typically in FIG. 1). The oxygen concentration sensor 42 of the exhaust passage 22a is shown), the rotation speed sensor 44 for detecting the rotation speed of the crankshaft, the pedal opening sensor 46 for detecting the depression amount of the accelerator pedal, the water temperature sensor 48 for detecting the temperature of the cooling water, etc. Sensors are connected. Based on the signals from these sensors, the controller 38 controls the fuel injection valves 24a to 24d, the spark plugs 26a to 26d, the on-off valves 34 and 36, and the throttle valves 28a to 28d. Judgment of switching to cylinder operation is performed. These controls by the controller 38 are executed based on a predetermined computer program.

  Next, the operation and action of the cylinder deactivation type internal combustion engine 10 configured as described above will be described.

  First, during the all-cylinder operation, the controller 38 intermittently operates all the fuel injection valves 24a to 24d and the spark plugs 26a to 26d at a predetermined timing, and all the normal operation cylinders 14a and 14b and the stop corresponding cylinders 14c and 14d are operated. Make it work. Further, during the all-cylinder operation, the on-off valves 34 and 36 are opened under the action of the controller 38 (the state shown by the solid line in FIG. 1), and the exhaust valves 20c and 20d of the inactive cylinders 14c and 14d are exhausted. The exhaust gas thus passed through the exhaust passages 22c and 22d is guided to the muffler.

  At this time, since the fuel injection valves 24a and 24b in the intake passages 16a and 16b are arranged slightly downstream of the connection portions with the air communication passages 30 and 32, the air-fuel mixture enters the air communication passages 30 and 32. Without entering, it is appropriately introduced into the normal operation cylinders 14a and 14b. Further, since the air communication passages 30 and 32 are provided with the check valves 41a and 41b, the air-fuel mixture is reliably prevented from flowing back from the intake passages 16a and 16c to the exhaust passages 22c and 22d. Of course, when it is verified and confirmed that the air-fuel mixture does not flow backward, the check valves 41a and 41b can be omitted.

  During the idle cylinder operation, the controller 38 stops fuel injection from the fuel injection valves 24c and 24d and ignition by the spark plugs 26c and 26d. At this time, since the intake valves 18c and 18d and the exhaust valves 20c and 20d of the stop corresponding cylinders 14c and 14d continue to open and close in conjunction with the rotation of the crankshaft, the stop corresponding cylinders 14c and 14d do not include fuel. Is sucked and compressed from the intake valves 18c and 18d and discharged from the exhaust valves 20c and 20d.

  Further, when switching from the all-cylinder operation to the non-cylinder operation, the on-off valves 34 and 36 are closed under the action of the controller 38 (the state of the broken line in FIG. 1), and the exhaust passages 22c and 22d are shut off. Therefore, the compressed air discharged from the exhaust valves 20c and 20d of the cylinders 14c and 14d corresponding to the suspension is supplied to the intake passages 16a and 16b through the air communication passages 30 and 32, respectively.

  The operation of the cylinder deactivation type internal combustion engine 10 during the cylinder deactivation operation will be described in detail with reference to FIG. FIG. 2 is a displacement chart of each piston in the normal operation cylinders 14a and 14b and the stop corresponding cylinders 14c and 14d with the rotation angle of the crankshaft as the horizontal axis. Is the bottom dead center. The ignition sequence during normal operation of the cylinder deactivation type internal combustion engine 10 is in the order of the normal operation cylinder 14a, the deactivation corresponding cylinder 14c, the normal operation cylinder 14b, and the deactivation corresponding cylinder 14d. To do.

  When the ignition timing P at the top dead center of the normal operation cylinder 14a is set to 0 ° as a reference, the piston descends to 180 ° by the expansion of the combustion gas. At this time, the exhaust valve 20a opens at a time slightly earlier than reaching 180 °, the combustion gas is discharged between 180 ° and 360 ° when the piston rises, and the exhaust valve 20a is slightly over 360 °. Closes.

  In addition, the intake valve 18a is opened slightly earlier than reaching 360 °, and the piston descends between 360 ° and 540 °. As the piston descends, the air-fuel mixture is sucked from the intake passage 16a through the intake valve 18a. The intake valve 18a is closed when a little over 540 °. The piston rises again between 540 ° and 720 °, and the air-fuel mixture sucked into the normal operation cylinder 14a is compressed and ignited at 720 °. Note that the ignition timing P does not necessarily coincide with the top dead center, and the ignition timing P can be changed under predetermined conditions.

  On the other hand, the stop corresponding cylinder 14c has a phase delay of 180 ° with respect to the normal operation cylinder 14a, and therefore exhausts when the normal operation cylinder 14a performs intake. By the way, during the idle cylinder operation, the fuel injection valve 24c does not inject the fuel, so the idle cylinder 14c acts as a pump and supplies compressed air to the exhaust passage 22c.

  At this time, the exhaust passage 22c is blocked by the on-off valve 34, and the intake passage 16c is in a negative pressure as the piston of the normal operation cylinder 14a descends. Therefore, the compressed air in the exhaust passage 22c is air It is supplied to the intake passage 16a through the communication passage 30, and the effect as a supercharging action is exhibited.

  Note that the normal operation cylinder 14b and the stop corresponding cylinder 14d perform the same operation with a phase delay of 360 ° with respect to the normal operation cylinder 14a and the stop corresponding cylinder 14c, respectively. Accordingly, the cylinder corresponding to the stop 14c acts as a pump, and the compressed air in the exhaust passage 22d is supplied to the intake passage 16b through the air communication passage 32 by blocking the exhaust passage 22d by the on-off valve 36.

  In FIG. 2, the supercharging action from the stop corresponding cylinder 14c to the normal operation cylinder 14a is schematically indicated by an arrow A, and the supercharging action from the stop corresponding cylinder 14d to the normal operation cylinder 14b is indicated by an arrow B.

  Due to such supercharging action, the normal operation cylinders 14a and 14b supplied with the air bypassed from the air communication passages 30 and 32 have sufficient air for combustion in the combustion chamber, and volume efficiency (or (Filling efficiency) and combustion efficiency are good. Further, fuel efficiency is improved by improving volumetric efficiency and combustion efficiency.

  As described above, according to the cylinder deactivation type internal combustion engine 10 according to the present embodiment, it is possible to perform the supercharging action on the normal operation cylinders 14a and 14b during the cylinder deactivation operation. A higher output can be obtained than when the cylinder is idled. Further, the output of the cylinder deactivation type internal combustion engine 10 during the cylinder deactivation operation can be adjusted by the opening degrees of the on-off valves 34 and 36 or the fuel injection amounts of the fuel injection valves 24a and 24b. Therefore, it is possible to gradually reduce the output when switching from all-cylinder operation to rest-cylinder operation, and to suppress a shock at the time of switching.

  The controller 38 may adjust the opening degree of the on-off valves 34 and 36 so that the pressure becomes a predetermined value or less while referring to the pressure detected by the pressure detectors 40a and 40b. As a result, the on-off valves 34 and 36 have an action similar to that of a so-called waste gate, and can suppress the occurrence of knocking and prevent excessive pressure from being applied to the intake passages 16a and 16b.

  Further, the cylinder deactivation type internal combustion engine 10 uses the deactivation-compatible cylinders 14c and 14d as a pump, and thus does not require a complicated drive mechanism such as a dedicated turbine or a compressor. Therefore, the cylinder deactivation type internal combustion engine 10 can be configured simply and inexpensively, and is small and lightweight.

  Further, unlike a turbocharger turbine, air corresponding to the displacement can be reliably supplied to the normal operation cylinders 14a and 14b even at a low speed, and there is no time delay until the output increases.

  Furthermore, the cylinder deactivation type internal combustion engine 10 is an in-line four cylinder, and the normal operation cylinder 14a and the deactivation corresponding cylinder 14c are adjacent to each other, so that the air communication passage 30 can be set short, and air passes through. There is little delay in time. Therefore, air can be reliably supplied from the stop corresponding cylinder 14c in synchronization with the intake timing of the normal operation cylinder 14a. Similarly, the normal operation cylinder 14b and the stop corresponding cylinder 14d are adjacent to each other, and the air communication passage 32 can be set short, so that air is supplied from the stop corresponding cylinder 14d in synchronization with the intake timing of the normal operation cylinder 14b. Can be supplied.

  Further, the non-operating cylinder 14 c corresponds to the normal operation cylinder 14 a via the air communication passage 30, and the non-operation cylinder 14 d corresponds to the normal operation cylinder 14 b via the air communication passage 32. That is, since the number of cylinders that perform normal operation and the number of cylinders that are deactivated are the same and symmetrically arranged, the balance of the forces applied to the crankshaft is good. Further, the air communication passages 30 and 32 may be connected to the surge tank 29. Also in this case, the compressed air passing through the air communication passages 30 and 32 is supplied to the intake passages 16a and 16b via the surge tank 29.

  The injection timing of the fuel injection valves 24a and 24b and the ignition timing of the spark plugs 26a and 26b may be changed between the all-cylinder operation and the idle cylinder operation.

  The on-off valves 34 and 36 are not limited to so-called butterfly valves as shown in FIG. 1, and may be any on-off valves that can block the exhaust passages 22c and 22d. Further, the number of cylinders of the cylinder deactivation type internal combustion engine 10 is not necessarily limited to four.

  Next, a cylinder deactivation type internal combustion engine 10a, which is a modification of the cylinder deactivation type internal combustion engine 10, will be described with reference to FIG. In the cylinder deactivation type internal combustion engine 10a, portions having the same configuration as the cylinder deactivation type internal combustion engine 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The cylinder deactivation type internal combustion engine 10 a includes switching on / off valves 34 a and 36 a instead of the on-off valves 34 and 36. The switching on / off valves 34a and 36a have a function of switching the communication direction of the exhaust passages 22c and 22d to the direction of the muffler (upward in FIG. 3) or the direction of the air communication passages 30 and 32.

  During the all-cylinder operation, the switching on-off valves 34a and 36a are set at the positions indicated by the solid lines in FIG. 3, and all the exhaust gas discharged from the exhaust valves 20c and 20d of the cylinders 14c and 14d corresponding to the stoppage is exhaust passage 22c. And 22d through the muffler. At this time, the air communication passages 30 and 32 are blocked by the switching on / off valves 34a and 36a, respectively, so that the exhaust gas exhausted from the stop-response cylinders 14c and 14d is reliably prevented from entering. Similarly, since the air-fuel mixture does not flow into the air communication passages 30 and 32, the valves corresponding to the check valves 41a and 41b need not be provided.

  Further, during the idle cylinder operation, the switching on / off valves 34a and 36a are set at the positions indicated by the broken lines in FIG. 3, and the passages from the exhaust passages 22c and 22d to the muffler are blocked. On the other hand, passages from the exhaust passages 22c and 22d to the air communication passages 30 and 32 are opened, respectively, and the compressed air supplied from the cylinders 14c and 14d corresponding to the suspension passes through the air communication passages 30 and 32 and the intake passages 16a and 16b. Led to.

  In this way, according to the cylinder deactivation type internal combustion engine 10a, it is possible to perform a supercharging action on the normal operation cylinders 14a and 14b, similarly to the cylinder deactivation type internal combustion engine 10.

  The cylinder deactivation type internal combustion engine according to the present invention is not limited to the above-described embodiment and its modifications, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

It is a schematic block diagram of the cylinder deactivation type internal combustion engine which concerns on this Embodiment. 7 is a displacement chart of each piston of a normal operation cylinder and a stop corresponding cylinder at the time of cylinder resting operation. It is a schematic block diagram of the cylinder deactivation type internal combustion engine which concerns on the modification of this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10a ... Cylinder deactivation type internal combustion engine 14a, 14b ... Normal operation cylinder 14c, 14d ... Deactivation corresponding cylinders 16a-16d ... Intake passage 18a-18d ... Intake valve 20a-20d ... Exhaust valve 22a-22d ... Exhaust passage 24a-24d ... Fuel injection valves 26a-26d ... Spark plugs 28a-28d ... Throttle valve 29 ... Surge tank 30, 32 ... Air communication passages 34, 36 ... Open / close valves 34a, 36a ... Switching on / off valve 38 ... Controller

Claims (7)

A cylinder deactivation type internal combustion engine comprising a deactivation-capable cylinder that is stopped during a predetermined deactivation operation and a normal operation cylinder that is also activated during the deactivation operation,
A cylinder deactivation type internal combustion engine having an air communication path that communicates an exhaust path of the cylinder corresponding to deactivation with an intake path side of a normal operation cylinder. The cylinder deactivation type internal combustion engine according to claim 1,
A cylinder deactivation type internal combustion engine comprising control means for switching a discharge destination of gas discharged from the deactivation-response cylinder between the exhaust passage and the air communication passage according to operating conditions. The cylinder deactivation type internal combustion engine according to claim 2,
A pressure detector for detecting the pressure of the exhaust passage;
The cylinder deactivation type internal combustion engine, wherein the control means guides the gas discharged from the deactivation corresponding cylinder to the air communication passage so that the pressure detected by the pressure detector becomes a predetermined value or less. . The cylinder deactivation type internal combustion engine according to claim 1,
The cylinder resting type internal combustion engine, which is a four-stroke type, wherein the resting corresponding cylinder has a combustion cycle phase delayed by 180 ° from the normal operation cylinder. The cylinder deactivation type internal combustion engine according to claim 1,
The number of the normal operation cylinders and the number of cylinders corresponding to the pause are the same,
A cylinder deactivation type internal combustion engine, wherein one air communication passage is provided from each normal operation cylinder to each deactivation corresponding cylinder. The cylinder deactivation type internal combustion engine according to claim 1,
The normal operation cylinder and the inactive cylinder are arranged in series,
The cylinder deactivation type internal combustion engine, wherein the air communication passage is provided between the adjacent normal operation cylinder and the deactivation corresponding cylinder. The cylinder deactivation type internal combustion engine according to claim 1,
The cylinder deactivation type internal combustion engine, wherein the intake passage is connected to a surge tank having a predetermined volume, and the air communication passage is connected to the surge tank.

Images