JP5877519B2 - Valve control system for internal combustion engine and valve control method for internal combustion engine - Google Patents

Description

  The present invention relates to a valve operating control system and a valve operating control method for an internal combustion engine for driving intake valves and exhaust valves of the internal combustion engine.

  In order to increase the degree of freedom of control of an internal combustion engine, there is a hydraulic valve drive device that controls an intake valve and an exhaust valve using a hydraulic actuator, a hydraulic servo valve, and the like instead of a cam drive. For example, there has been proposed a valve driving device in which only the valve opening / closing operation (lift) is performed by an actuator (Patent Document 1). Further, Patent Document 2 describes a servo valve provided with a nozzle flapper mechanism.

JP 2009-257319 A JP 2010-060128 A

  By the way, in the valve drive device described in Patent Document 1, the valve drive piston is arranged so as to be interlocked with the valve rod of the intake valve or the exhaust valve during the reciprocating motion. The valve drive device is arranged with a clearance, which is a slight gap between the valve drive piston and the valve rod when the valve is closed. Thereby, although the influence of the thermal expansion of a structural member can be reduced, the setting of clearance is performed based on a clearance gauge, and adjustment work is complicated and requires work time.

  The present invention solves the above-described problems, and provides a valve control system for an internal combustion engine capable of adjusting a clearance, which is a slight gap between a valve drive piston and a valve rod when the valve is closed, and the operation of the internal combustion engine. An object is to provide a valve control method.

  In order to achieve the above object, a valve operating control system for an internal combustion engine according to the present invention includes a valve rod of an intake valve or an exhaust valve of an internal combustion engine, and an elastic force in a direction to close the intake valve or the exhaust valve on the valve rod. A valve spring that provides a valve, a valve drive piston that can drive the exhaust valve or the intake valve and reciprocates with a drive force in a valve drive cylinder, and a valve drive piston displacement detection that detects a displacement of the valve drive piston And a driving force control mechanism for controlling the driving force in the valve driving cylinder, and the driving force control mechanism operates the valve driving piston with a driving force smaller than an elastic force applied to the valve rod by the valve spring. The position at which the displacement change of the valve drive piston stops is detected as a reference position by the valve drive piston displacement detection means.

  Thereby, the reference position of the clearance, which is a slight gap when the valve is closed, can be grasped. For this reason, even if there is a deviation in the reference position due to the influence of changes in the external environment such as thermal expansion, or the influence of the position where the mount on which the valve drive cylinder is mounted is mounted on the internal combustion engine, Can be grasped again. Moreover, the adjustment of the clearance which was performed based on the clearance gauge becomes unnecessary, and the adjustment work can be automatically performed. As a result, the work time can be shortened.

  As a preferred aspect of the present invention, the reference position is stored as a position where the valve rod and the valve drive piston are in contact, the valve drive piston is moved from the reference position, and the valve rod, the valve drive piston, It is preferable to set a clearance between the two. As a result, the clearance, which is a slight gap when the valve is closed, is affected by either the influence of changes in the external environment such as thermal expansion of the valve or the influence of the position on which the mount on which the valve drive cylinder is mounted is mounted on the internal combustion engine. Even if it changes, the clearance can be adjusted to an appropriate distance. For this reason, since a clearance is maintained appropriately, the possibility of an operation delay of the valve drive piston can be reduced. Further, since the clearance is appropriately maintained, the clearance is lost due to the influence of thermal expansion, and the possibility that the exhaust valve and the intake valve that should have been closed will be reduced.

  In order to achieve the above object, the valve control method for an internal combustion engine of the present invention is a valve control that can drive an exhaust valve or an intake valve of an internal combustion engine by a valve drive piston that reciprocates with a drive force in a valve drive cylinder. A method of calculating a change in the displacement signal of the valve drive piston and stopping the change in displacement of the valve drive piston, storing the displacement of the valve drive piston as a reference position of the valve drive piston; Features.

  Thereby, the reference position of the clearance, which is a slight gap when the valve is closed, can be grasped. For this reason, even if there is a deviation in the reference position due to the influence of changes in the external environment such as thermal expansion, or the influence of the position where the mount on which the valve drive cylinder is mounted is mounted on the internal combustion engine, Can be grasped again. Moreover, the adjustment of the clearance which was performed based on the clearance gauge becomes unnecessary, and the adjustment work can be automatically performed. As a result, the work time can be shortened.

  As a desirable mode of the present invention, the reference position is a position where the valve rod and the valve drive piston are in contact with each other, and the valve drive piston is moved in a direction in which the valve drive piston is separated from the valve rod. It is preferable to calculate a change in the displacement signal of the valve and stop the valve drive piston at a position where a predetermined clearance is provided from the reference position between the valve rod and the valve drive piston. As a result, the clearance, which is a slight gap when the valve is closed, is affected by either the influence of changes in the external environment such as thermal expansion of the valve or the influence of the position on which the mount on which the valve drive cylinder is mounted is mounted on the internal combustion engine. Even if it changes, the clearance can be adjusted to an appropriate distance. For this reason, since a clearance is maintained appropriately, the possibility of an operation delay of the valve drive piston can be reduced. Further, since the clearance is appropriately maintained, the clearance is lost due to the influence of thermal expansion, and the possibility that the exhaust valve and the intake valve that should have been closed will be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the valve control system of the internal combustion engine which can adjust the clearance which is the slight clearance gap between the valve drive piston and valve rod at the time of valve closing, and the valve control method of an internal combustion engine can be provided.

FIG. 1 is a configuration diagram of a valve gear for an internal combustion engine according to the present embodiment. FIG. 2 is a schematic diagram of the valve drive device. FIG. 3 is a configuration diagram of the control device. FIG. 4 is an explanatory diagram illustrating an example of a hydraulic circuit according to the present embodiment. FIG. 5 is an explanatory view showing an example of a nozzle flapper mechanism. FIG. 6 is a flowchart showing control of the valve gear according to the present embodiment. FIG. 7 is an explanatory view showing the operation of the valve drive piston according to the present embodiment. FIG. 8 is an explanatory view showing the operation of the valve drive piston according to the present embodiment. FIG. 9 is an explanatory view showing the operation of the valve drive piston according to the present embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

  The present embodiment will be described with reference to the drawings. FIG. 1 is a configuration diagram of a valve gear for an internal combustion engine according to the present embodiment. FIG. 2 is a schematic diagram of the valve drive device. FIG. 3 is a configuration diagram of the control device. A valve operating apparatus 100 for an internal combustion engine according to the present embodiment is an apparatus that drives an exhaust valve 4a and an intake valve 4b as engine valves as the combustion piston 2 moves up and down in the cylinder block 3. The valve operating apparatus 100 for the internal combustion engine is also a valve operating control system for the internal combustion engine controlled by the control apparatus 80.

  As shown in FIG. 1, the valve operating apparatus 100 includes a valve driving device 10 installed in the internal combustion engine 1 (engine), measuring devices 20 and 21 that measure the state of the internal combustion engine 1, and a hydraulic pressure applied to the valve driving device 10. Is provided with a hydraulic unit 30 for supplying pressure, a control device 80 for controlling the valve driving device 10, signal lines I1, I2, I3, I4, and I5, and hydraulic lines O1 and O2. The dynamo 200 is a power conversion device. The dynamo 200 is not an essential component but an additional element, and is used, for example, when used as a test apparatus.

  As shown in FIG. 2, the valve drive device 10 includes a valve drive cylinder 11, a valve drive piston 12 movably accommodated in the valve drive cylinder 11, and a servo valve 13 for driving the valve drive piston 12. And a valve drive piston displacement meter 15 for measuring the position of the valve drive piston 12. As shown in FIG. 1, the internal combustion engine 1 includes a cylinder block 3, a crankcase 9, a combustion piston 2, a crankshaft 7, and a connecting rod 8. The combustion piston 2 and the crankshaft 7 are connected by a connecting rod 8. With such a structure, the reciprocating motion of the combustion piston 2 is converted into rotational motion by the crankshaft 7.

  As shown in FIG. 2, the internal combustion engine 1 includes an exhaust valve 4 a and an intake valve 4 b, a valve rod 5, and a valve spring 6. Each of the exhaust valve 4a and the intake valve 4b is fixed to the lower end of the valve rod 5, and is elastic in a direction (valve closing direction) in which the exhaust valve 4a or the intake valve 4b is closed by a valve spring 6 provided on the valve rod 5. Power is attached. The valve driving device 10 is fixed by mounting on the internal combustion engine 1 a gantry mounting side 300A of a gantry 300 on which the valve driving cylinder 11 shown in FIG. Further, the valve drive piston 12 is arranged so as to be interlocked with the valve rod 5 during the reciprocating motion. When the mount 300 is mounted on the internal combustion engine 1, the valve drive device 10 is disposed with a clearance L, which is a slight gap when the valve is closed, between the valve drive piston 12 and the valve rod 5. Thereby, the possibility that the exhaust valve 4a and the intake valve 4b are opened when the valve is closed due to thermal expansion is reduced. Further, when the valve drive piston 12 is driven, the exhaust valve 4 a and the intake valve 4 b are driven according to the valve rod 5.

  If the distance of the clearance L is too long, the valve drive piston 12 responding to the control command does not reciprocate with a desired profile, which may cause an unexpected delay. If the clearance L is too short, the clearance L is lost due to the effect of thermal expansion, and the exhaust valve 4a and the intake valve 4b that should have been closed may open. In the control system of the valve operating apparatus 100 according to the present embodiment, either due to the influence of changes in the external environment such as thermal expansion or the influence of the position where the gantry 300 on which the valve drive cylinder 11 is mounted is mounted on the internal combustion engine 1. Even when the clearance L, which is a slight gap when the valve is closed, changes, the clearance L can be adjusted to an appropriate distance. The distance of the clearance L may be adjusted when the gantry 300 on which the valve drive cylinder 11 is mounted is mounted on the internal combustion engine 1. Alternatively, the distance of the clearance L may be adjusted at the start of driving the internal combustion engine 1 with the valve gear 100.

  The valve drive piston 12 movably accommodated in the valve drive cylinder 11 shown in FIG. 2 is a hydraulic actuator, and the valve drive piston 12 extends when the hydraulic pressure is supplied to the valve drive cylinder 11 and extends to the exhaust valve 4a or The intake valve 4b is opened. Further, the valve drive piston 12 contracts when the hydraulic pressure is discharged from the valve drive cylinder 11, and closes the exhaust valve 4a or the intake valve 4b. The servo valve 13 is attached to the outer side surface of the valve drive cylinder 11. The servo valve 13 is connected to a later-described hydraulic unit 30 through a hydraulic line O1 that is a hydraulic supply line and a hydraulic line O2 that is a return line. The servo valve 13 controls the supply of hydraulic pressure to the valve drive cylinder 11 or the discharge of hydraulic pressure from the valve drive cylinder 11 based on the instruction of the signal line I <b> 2 from the control device 80. For example, the servo valve 13 includes a spool, an oil passage, a nozzle flapper mechanism, and the like, which will be described later. The valve drive piston displacement meter 15 measures the position of the valve drive piston 12 in the valve drive cylinder 11 and outputs the measured position data to the control device 80.

  A measuring device 20 shown in FIG. 1 is an encoder that measures the rotational speed of the internal combustion engine 1. The measuring device 21 is a crank angle sensor that measures the crank angle of the internal combustion engine 1. The rotational speed information and crank angle information of the internal combustion engine 1 measured by the measuring devices 20 and 21 are output to the control device 80. Here, the number of rotations refers to a rotation speed that is an angle change per unit time at each crank angle.

  The control device 80 is a device that controls the valve driving device 10. As shown in FIG. 1, the control device 80 performs control to start or stop the hydraulic unit 30 via the signal line I1. Further, the control device 80 can control the servo valve 13 via the signal line I2. The control device 80 is connected to the valve drive piston displacement meter 15 and the measurement devices 20 and 21 via signal lines I3, I4, and I5. Next, the control device 80 will be described with reference to FIG.

  The control device 80 illustrated in FIG. 3 includes an input processing circuit 81, an input port 82, a processing unit 90, a storage unit 94, an output port 83, and an output processing circuit 84. The processing unit 90 includes, for example, a CPU (Central Processing Unit) 91, a RAM (Random Access Memory) 92, and a ROM (Read Only Memory) 93. The control device 80 may be accompanied by a display device 85 and an input device 86. A display device 85 and an input device 86 can be connected to the control device 80 as necessary. Further, the control device 80 can operate without the display device 85 and the input device 86.

  The processing unit 90, the storage unit 94, and the input port 82 and the output port 83 are connected via a bus 87, a bus 88, and a bus 89. By the bus 87, the bus 88, and the bus 89, the CPU 91 of the processing unit 90 is configured to exchange control data with the storage unit 94, the input port 82, and the output port 83 and to issue commands to one side. The

  An input processing circuit 81 is connected to the input port 82. For example, measurement data is is connected to the input processing circuit 81. The measurement data is is converted into a signal that can be used by the processing unit 90 by a noise filter, an A / D converter, or the like provided in the input processing circuit 81, and then sent to the processing unit 90 via the input port 82. Thereby, the processing unit 90 can acquire necessary information. The measurement data is is, for example, displacement data, crank angle data, and rotation speed data acquired from the valve drive piston displacement meter 15 and the measurement devices 20 and 21 via signal lines I3, I4, and I5.

  An output processing circuit 84 is connected to the output port 83. The output processing circuit 84 is connected to a display device 85 and an external output terminal. The output processing circuit 84 includes a display device control circuit, a control signal circuit such as a valve drive device, a signal amplification circuit, and the like. The output processing circuit 84 outputs the signal data to the servo valve 13 calculated by the processing unit 90 as a display signal to be displayed on the display device 85 or outputs it as an instruction signal id to be transmitted to the servo valve 13. As the display device 85, for example, a liquid crystal display panel, a CRT (Cathode Ray Tube), or the like can be used. The instruction signal id is transmitted to the servo valve 13 via the signal line I2.

  The storage unit 94 stores a computer program including an operation procedure of the valve gear 100. Here, the storage unit 94 can be configured by a volatile memory such as a RAM, a nonvolatile memory such as a flash memory, a hard disk drive, or a combination thereof.

  The computer program may execute the operation procedure of the valve gear 100 in combination with a computer program already recorded in the processing unit 90. Moreover, this control apparatus 80 may perform the operation | movement procedure of the valve operating apparatus 100 using dedicated hardware instead of a computer program.

  The operation procedure of the valve operating apparatus 100 can also be realized by executing a program prepared in advance on a personal computer, a workstation, or a computer system such as a control computer. The program is recorded on a computer-readable recording medium such as a recording device such as a hard disk, a flexible disk (FD), a ROM, a CD-ROM, an MO, a DVD, or a flash memory, and is read from the recording medium by the computer. Can also be implemented. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  In addition, the “computer-readable recording medium” dynamically stores the program for a short time, such as a communication line when the program is transmitted via a network such as the Internet or a communication line network such as a telephone line. What is held, and what holds a program for a certain period of time, such as volatile memory inside a computer system serving as a server or client in that case, are included. Further, the program may be for realizing a part of the above-described functions, and may be capable of realizing the above-described functions in combination with a program already recorded in the computer system. .

  The control device 80 described above acquires crank angle and rotation speed data from the measurement devices 20 and 21. In the present embodiment, it is assumed that the control device 80 stores a target lift waveform to which a lift amount is originally given for each desired crank angle in the storage unit 94 or the RAM 92. For example, in a 4-stroke engine, one cycle is completed by performing four strokes of intake, compression, expansion, and exhaust while the combustion piston reciprocates twice. The control device 80 generates a target lift waveform for one cycle, and sends a control command as a control signal to the servo valve so that the valve drive piston can be driven with the same drive waveform as the target lift waveform.

  Next, the hydraulic circuit according to the present embodiment will be described. FIG. 4 is an explanatory diagram illustrating an example of a hydraulic circuit according to the present embodiment. The hydraulic circuit 10A shown in FIG. 4 drives the valve drive cylinder 11 of the valve drive device 10 shown in FIG. 2, the valve drive piston 12 movably accommodated in the valve drive cylinder 11, and the valve drive piston 12. The hydraulic circuit with the servo valve 13 is shown.

  The hydraulic circuit 10A includes a valve drive cylinder 11, a valve drive piston 12, a direction switching control valve mechanism 18 having a spool 17, a nozzle flapper mechanism 60, oil passages 41, 42, 43, 44, 45, 46, 47, 48 and apertures 68 and 69 are included. The stroke (displacement) of the spool 17 is measured by a non-contact type spool displacement meter 19 such as an LVDT (Linear Variable Differential Transformer). The spool displacement meter 19 is connected to the control device 80 described above through a signal line I6. Similarly, the stroke (displacement) of the valve drive piston 12 is measured by a non-contact type valve drive piston displacement meter 15. Moreover, piping 71, 72, 73, 74, 75, 76, 77 is provided as needed. The oil passages 41, 42, 44, 45, 47, 48, 77 are connected to the oil ports 51, 52, 53, 54, 55, 56, 57.

  The hydraulic circuit 10A is connected to a reduced pressure hydraulic circuit 110 that is a driving force control mechanism. The pressure reducing hydraulic circuit 110 includes a pressure reducing valve 111 and oil passages 121, 122, 123, 124, 125. Further, the valve mechanism of the pressure reducing valve 111 is connected to the above-described control device 80 through the signal line I2 shown in FIG. The oil passages 122, 123, 124, and 125 are connected to the oil ports 53, 54, 52, and 57.

  The direction switching control valve mechanism 18 is a three-way switching control valve that can switch in three directions. The direction switching control valve mechanism 18 can switch the oil passages 45 and 48 connected to the oil passage 46 communicating with the valve drive cylinder 11 by the movement of the spool 17. Thereby, the supply target of the hydraulic oil pressure supplied to the oil passage 46 can be switched.

  The nozzle flapper mechanism 60 is a mechanism that changes the pressure by reducing the flow area of the nozzle. As shown in FIG. 4, a nozzle flapper mechanism 60 is interposed in the oil passage 41. The oil passage 41 includes an oil passage 41A on the side of the pipe connection 43a from the nozzle flapper mechanism 60 to the oil passages 42 and 43, and an oil passage 41B on the side of the oil port 51 from the nozzle flapper mechanism 60.

  FIG. 5 is an explanatory view showing an example of a nozzle flapper mechanism. As shown in FIG. 5, the nozzle flapper mechanism 60 is disposed between the oil passage 41A and the oil passage 41B. The nozzle flapper mechanism 60 includes a pipe 41 a of the oil passage 41, a nozzle 63, a flapper 61, and a nozzle flapper driving means 62. The nozzle flapper mechanism 60 is connected to the tank 79 through the oil port 51. A nozzle 63 is provided in the pipe 41 a of the oil passage 41. The flapper 61 is a member that can restrict or open the flow path area of the nozzle 63. The nozzle flapper driving means 62 can be constituted by an electromagnetic coil such as a piezoelectric body or a solenoid. The nozzle flapper driving means 62 is connected to the control device 80 described above via a signal line I2.

  The control device 80 described above transmits a control signal command, and the nozzle flapper driving means 62 shown in FIG. 5 expands and contracts in accordance with the control signal command. Along with the expansion and contraction of the nozzle flapper driving means 62, the pressure of the oil passage 41A can be changed by the flapper 61 restricting or opening the flow passage area of the nozzle 63.

  The oil passage 42 shown in FIG. 4 is connected to the hydraulic unit 30 via the oil port 52, and a pilot pressure is applied. The restrictor 68 is an orifice and is a pressure restrictor for adjusting the pilot pressure.

  The oil passage 43 is connected to the oil passage 41 </ b> A and the oil passage 42 by a pipe connection 43 a. The oil passage 43 is also a pressing portion that presses the spool 17 of the direction switching control valve mechanism 18. The oil passage 44 is connected to the hydraulic unit 30 via the oil port 53, and a pilot pressure is applied thereto.

  The oil passage 45 is connected to the hydraulic unit 30 via the oil port 54, and the first hydraulic oil pressure of the valve drive piston 12 is applied thereto. The direction switching control valve mechanism 18 switches the connection between the oil passage 45 and the oil passage 46 according to the position of the spool 17.

  The oil passage 46 connects the direction switching control valve mechanism 18 and the valve drive cylinder upper chamber 11 a of the valve drive cylinder 11. Here, the valve drive cylinder upper chamber 11a is a space in the valve drive cylinder 11, and is a space surrounded by the valve drive piston 12 and the valve drive cylinder 11 on the opposite side of the valve rod 5 shown in FIG. . A pipe 71 is connected to the valve drive cylinder upper chamber 11a, and the pipe 71 acts to vent air as necessary.

  The valve drive cylinder lower chamber 11b is a space surrounded by the valve drive piston 12 and the valve drive cylinder 11 on the valve rod 5 side shown in FIG. The oil passage 47 is connected to the hydraulic unit 30 via the oil port 57, and the second hydraulic oil pressure of the valve drive piston 12 is applied thereto. The oil passage 47 is provided with a throttle 69. The restrictor 69 is an orifice and is a pressure restrictor for adjusting the second hydraulic oil pressure. It is preferable that the second hydraulic oil pressure is set to be smaller than the first hydraulic oil pressure described above by the throttle 69. The oil passage 47 has a pipe connection 47a to which a pipe 72 is connected. The pipe 72 acts to remove air as necessary.

  The oil passage 48 is a return pipeline from the direction switching control valve mechanism 18 and is connected to the oil tank via the oil port 55.

  The pipes 73, 74, 75, 76 and 77 are drain pipes, and moisture is discharged through the oil port 56. The oil ports 51, 52, 53, 54, 55, 56, and 57 are openings that carry oil or moisture that are opened to the servo valve 13.

  The decompression hydraulic circuit 110 is configured to supply the hydraulic pressure supplied from the hydraulic unit 30 to the oil ports 52 and 53, the first hydraulic oil pressure and the second hydraulic oil pressure supplied to the oil ports 54 and 57, This is a hydraulic circuit that divides the pressure into two. The pressure reducing valve 111 has an oil passage 121 as a primary side and an oil passage 124 as a secondary side. Then, the valve is opened and closed according to the control signal of the control device 80. The pressure reducing valve 111 can select an operation for transmitting the hydraulic pressure supplied from the hydraulic unit 30 through the oil passage 121 to the oil passage 124 and an operation for transmitting the pressure as the pressure reducing hydraulic oil pressure equal to or lower than the set pressure by opening and closing the valve. It is a control valve.

  The oil passage 121 branches off from the oil passage 122 at a pipe connection 121a. The oil passage 122 branches off from the oil passage 123 through a pipe connection 122a. The oil passage 122 is connected to the oil passage 44 via the oil port 53. The oil passage 123 is connected to the oil passage 42 through the oil port 52. The oil passage 124 branches off from the oil passage 125 at a pipe connection 124a. The oil passage 124 is connected to the oil passage 45 through the oil port 54. The oil passage 125 is connected to the oil passage 47 through the oil port 57.

  Next, control of the valve gear according to the present embodiment will be described with reference to FIGS. FIG. 6 is a flowchart showing control of the valve gear according to the present embodiment. 7, 8 and 9 are explanatory views showing the operation of the valve drive piston according to the present embodiment.

  As shown in FIG. 6, the control device 80 of the valve gear 100 transmits a command of a control signal to the hydraulic unit 30 and starts the hydraulic unit 30 (step S1). As shown in FIG. 1, the control signal command from the control device 80 is transmitted to the hydraulic unit 30 via the signal line I1. The hydraulic unit 30 supplies hydraulic pressure to the hydraulic line O1.

  When starting the hydraulic unit 30, only the pilot pressure is first supplied to the hydraulic circuit 10A. Thereby, careless operation of the valve operating piston can be prevented. For this reason, the pressure reducing valve 111 of the pressure reducing hydraulic circuit 110 shown in FIG. 7 is operated, and the oil pressure of the oil passage 124 is set to a pressure reducing hydraulic oil pressure equal to or lower than the set pressure.

  Next, as shown in FIG. 6, the control device 80 of the valve gear 100 drives the nozzle flapper (step S2). Specifically, as shown in FIGS. 1 and 2, the control signal command from the control device 80 is transmitted to the servo valve 13 via the signal line I2. In the servo valve 13, the nozzle flapper driving means 62 of the nozzle flapper mechanism 60 shown in FIG. 5 expands and contracts according to the command of the control signal.

  When the nozzle flapper driving means 62 shown in FIG. 5 is driven and the flow rate of the oil passage 41A is changed by reducing the flow passage area of the nozzle 63, the pilot pressure is not reduced in the oil passage 42 as shown in FIG. And applied to the oil passage 43. The pressure PPB is applied to the oil passage 43. As described above, the pilot pressure is also applied to the oil passage 44. Here, the pressure applied to the oil passage 44 is defined as a pressure PPA.

  In the present embodiment, the throttle 68 is set so that the pressure PPA is approximately half of the pressure PPB when the nozzle flapper driving means 62 shown in FIG. It is preferable. As a result, when the nozzle flapper driving means 62 shown in FIG. 5 is driven and the flow area of the nozzle 63 is reduced by a predetermined amount or more, the pressure PPB becomes larger than the pressure PPA and the spool 17 moves. When the spool 17 moves, the spool displacement meter 19 reads the displacement of the spool, and the spool displacement meter 19 sends the displacement information of the spool to the control device 80 through the signal line I6.

  Next, as shown in FIG. 6, the control device 80 of the valve gear 100 drives the nozzle flapper (step S2), thereby causing the valve drive piston 12 to move (step S3). Specifically, the direction switching control valve mechanism 18 connects the oil passage 45 and the oil passage 46 with the movement of the spool 17 described above. As a result, the valve drive cylinder upper chamber 11a becomes the reduced first hydraulic oil pressure and becomes larger than the reduced second hydraulic oil pressure in the valve drive cylinder lower chamber 11b. 7 moves in the direction of the valve rod 5 shown in FIG. 7 and in the direction of the arrow Z1 shown in FIG. The displacement of the valve drive piston 12 is measured by the valve drive piston displacement meter 15 shown in FIG. 2, and the valve drive piston displacement meter 15 sends piston displacement information to the control device 80 through the signal line I3.

  Here, the valve rod 5 shown in FIG. 7 is pressed to a predetermined position by the spring pressure (elastic force) of the valve spring 6. The elastic force that the valve spring 6 applies to the valve rod 5 in the direction of closing the exhaust valve 4a or the intake valve 4b is defined as F0. Further, the reduced first hydraulic oil pressure P1, the pressure receiving area A1 of the first hydraulic oil pressure P1 of the valve drive piston 12, the reduced second hydraulic oil pressure P2, and the first pressure of the valve drive piston 12 Assuming that the pressure receiving area A2 of the hydraulic oil pressure P2 is 2, the driving force Fp applied to the valve driving piston 12 is Fp = P1 × A1−P2 × A2. The pressure reducing valve 111 of the pressure reducing hydraulic circuit 110 is set to be depressurized so that the driving force Fp is smaller than the elastic force F0.

  The control device 80 of the valve gear 100 measures the movement of the valve drive piston 12 with the valve drive piston displacement meter 15 and determines whether or not the piston displacement has changed (step S4). When there is a change in piston displacement (No in step S4), the valve drive piston 12 continues to measure the movement of the valve drive piston 12 while the valve drive piston 12 is moved (step S3).

  As shown in FIG. 8, when the valve rod 5 and the valve drive piston 12 come into contact with each other, the drive force Fp is smaller than the elastic force F0, so that the movement of the valve drive piston 12 stops. The control device 80 of the valve operating device 100 measures the movement of the valve drive piston 12 with the valve drive piston displacement meter 15, and when there is no change in the piston displacement (step S4, Yes), the control device 80 detects the valve drive piston displacement. The position information of the valve drive piston 12 measured by the total 15 is stored in the storage unit 94 or the RAM 92 as a reference position (step S5).

  Next, as shown in FIG. 6, the control device 80 of the valve gear 100 performs the reverse movement of the valve drive piston 12 (step S6). Specifically, when the nozzle flapper driving means 62 shown in FIG. 5 is driven and the flow rate of the oil passage 41A is changed by opening the restriction of the flow passage area of the nozzle 63, the oil passage 42 of the oil passage 42 is changed as shown in FIG. The pilot pressure is reduced. For this reason, the pressure applied to the oil passage 43 is also reduced. As a result, the pressure PPB applied to the oil passage 43 is smaller than the pressure PPA applied to the oil passage 44.

  That is, the pressure PPA is driven by the nozzle flapper driving means 62 shown in FIG. 5, and when the restriction of the flow passage area of the nozzle 63 is opened more than a predetermined amount, the pressure PPA becomes larger than the pressure PPB and the spool 17 moves. When the spool 17 moves, the spool displacement meter 19 reads the displacement of the spool 17, and the spool displacement meter 19 sends displacement information of the spool 17 to the control device 80 through the signal line I 6.

  As the spool 17 moves, the direction switching control valve mechanism 18 switches the connection between the oil passage 45 and the oil passage 46 to the connection between the oil passage 48 and the oil passage 46. As a result, the valve drive cylinder upper chamber 11a becomes the pressure of the return line, and becomes smaller than the second hydraulic oil pressure in the valve drive cylinder lower chamber 11b, so that the valve drive piston 12 is connected to the valve rod 5 shown in FIG. It moves in the opposite direction, the direction of the arrow Z2 shown in FIG. The displacement of the valve drive piston 12 is measured by the valve drive piston displacement meter 15 shown in FIG. 2, and the valve drive piston displacement meter 15 sends piston displacement information to the control device 80 through the signal line I3.

  Next, as shown in FIG. 6, the control device 80 of the valve gear 100 stops the valve drive piston 12 at a predetermined position from the reference position stored in the storage unit 94 or the RAM 92 (step S7). Specifically, the control device 80 of the valve operating device 100 measures the movement of the valve drive piston 12 with the valve drive piston displacement meter 15 and monitors the displacement of the piston from the reference position to a predetermined clearance L. When the piston displacement reaches a predetermined clearance L from the reference position, the valve drive piston 12 is stopped, the position of the valve drive piston 12 is stored in the storage unit 94 or the RAM 92, and between the valve drive piston and the valve rod when the valve is closed. It is set as a clearance L which is a slight gap.

  When the normal valve driving device 10 is driven after the clearance adjustment is completed, the control device 80 of the valve operating device 100 transmits a control signal to the pressure reducing valve 111 to recover the pressure reduction of the oil passage 124. Thereby, the hydraulic unit 30 can supply the operating hydraulic pressure to the hydraulic circuit 10A.

  As described above, the valve operating control system for the internal combustion engine 1 according to the present embodiment has the valve rod 5 of the exhaust valve 4a or the intake valve 4b and the valve rod 5 in the direction to close the exhaust valve 4a or the intake valve 4b. A valve spring 6 that gives an elastic force, a valve drive piston 12 that can drive the exhaust valve 4a or the intake valve 4b and reciprocates with a drive force in the valve drive cylinder 11, and a displacement of the valve drive piston 12 It includes a valve drive piston displacement meter 15 that is a valve drive piston displacement detection means for detecting, and a pressure reducing hydraulic circuit 110 that is a drive force control mechanism that controls the drive force in the valve drive cylinder 11. The valve drive piston 12 is operated with a drive force Fp smaller than the elastic force F0 applied by the valve spring 6 to the valve rod 5 by the pressure reducing hydraulic circuit 110 which is a drive force control mechanism, and the valve drive piston displacement meter 15 The position where the displacement change is stopped is detected as a reference position.

  As a result, the reference position of the clearance L, which is a slight gap when the valve is closed, can be grasped. For this reason, even if there is a deviation in the reference position due to either the influence of changes in the external environment such as thermal expansion or the influence of the position at which the mount 300 on which the valve drive cylinder 11 is mounted is mounted on the internal combustion engine 1. The reference position can be grasped again. In addition, the adjustment of the clearance L, which has been performed based on the gap gauge, is unnecessary, and the adjustment work can be automatically performed, thereby shortening the work time.

  In the valve operating control system for the internal combustion engine 1 according to the present embodiment, the reference position is stored in the storage unit 94 or the RAM 92 as storage means as the position where the valve rod 5 and the valve drive piston 12 are in contact, and the valve drive piston 12 is used as a reference. It is preferable to set the clearance L between the valve rod 5 and the valve drive piston 12 by moving from the position.

  Thereby, a slight gap at the time of valve closing is caused by either the influence of a change in the external environment such as thermal expansion or the influence of the position at which the mount 300 on which the valve drive cylinder 11 is mounted is mounted on the internal combustion engine 1. Even when the clearance L changes, the clearance L can be adjusted to an appropriate distance. For this reason, since the clearance L is maintained appropriately, the possibility of the operation delay of the valve drive piston can be reduced. Further, since the clearance L is appropriately maintained, the clearance L is eliminated due to the influence of thermal expansion, and the possibility that the exhaust valve 4a and the intake valve 4b that should have been closed will be reduced.

  As described above, the valve control method for an internal combustion engine is a valve control method capable of driving an exhaust valve or an intake valve of an internal combustion engine by a valve drive piston that reciprocates with a drive force in a valve drive cylinder, When the change in the displacement signal of the valve drive piston is calculated and the change in displacement is constant, the displacement of the valve drive piston is stored as the reference position of the valve drive piston.

  As a result, the reference position of the clearance L, which is a slight gap when the valve is closed, can be grasped. For this reason, even if there is a deviation in the reference position due to either the influence of changes in the external environment such as thermal expansion or the influence of the position at which the mount 300 on which the valve drive cylinder 11 is mounted is mounted on the internal combustion engine 1. The reference position can be grasped again. In addition, the adjustment of the clearance L, which has been performed based on the gap gauge, is unnecessary, and the adjustment work can be automatically performed, thereby shortening the work time.

  In the valve operating control method for an internal combustion engine according to the present embodiment, the reference position is set to a position where the valve rod and the valve drive piston are in contact with each other, and the displacement signal of the valve drive piston is separated from the valve rod. It is preferable to calculate a change and set a clearance between the valve rod and the valve drive piston.

  Thereby, a slight gap at the time of valve closing is caused by either the influence of a change in the external environment such as thermal expansion or the influence of the position at which the mount 300 on which the valve drive cylinder 11 is mounted is mounted on the internal combustion engine 1. Even when the clearance L changes, the clearance L can be adjusted to an appropriate distance. For this reason, since the clearance L is maintained appropriately, the possibility of the operation delay of the valve drive piston can be reduced. Further, since the clearance L is appropriately maintained, the clearance L is eliminated due to the influence of thermal expansion, and the possibility that the exhaust valve 4a and the intake valve 4b that should have been closed will be reduced.

The valve operating control system and valve operating control method according to the present embodiment includes a driving force Fp that is smaller than the elastic force F0 that the valve spring 6 applies to the valve rod 5 with respect to the valve driving piston 12 by the pressure reducing hydraulic circuit 110 that is a driving force control mechanism. The valve drive piston displacement meter 15 detects the position where the displacement change of the valve drive piston 12 is stopped as a reference position. Also, a plurality of hydraulic units 30 are provided , and a pressure reducing hydraulic circuit 110 that is a driving force control mechanism is used as a relief valve mechanism that connects to each hydraulic unit 30, and a hydraulic circuit that independently supplies pilot pressure and hydraulic oil pressure. It may be replaced .

  The valve control system and the valve control method according to the present embodiment are also suitable for a test machine that opens and closes an intake valve or an exhaust valve of an internal combustion engine. The internal combustion engine of the present embodiment preferably drives the cylinder block, the combustion piston that moves up and down in the cylinder block, the exhaust valve and the intake valve, and the exhaust valve and the intake valve. Thereby, it is possible to contribute to the reduction of NOx and unburned HC emissions and the reduction of carbon dioxide emissions by clean exhaust and improved fuel efficiency.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Piston for combustion 3 Cylinder block 4a Exhaust valve 4b Intake valve 5 Valve rod 6 Valve spring 7 Crankshaft 8 Connecting rod 9 Crankcase 10 Valve drive device 11 Valve drive cylinder 11a Valve drive cylinder upper chamber 11b Valve drive cylinder bottom Chamber 12 Valve drive piston 13 Servo valve 15 Valve drive piston displacement meter 17 Spool 18 Direction switching control valve mechanism 19 Spool displacement meter 20, 21 Measuring device 30 Hydraulic unit 41, 42, 43, 44, 45, 46, 47, 48 Oil Road 60 Nozzle flapper mechanism 62 Nozzle flapper driving means 63 Nozzle 80 Control device 100 Valve operating device 110 Pressure reducing hydraulic circuit 111 Pressure reducing valve 121, 122, 123, 124, 125 Oil passage 300 Mounting base

Claims (2)

A valve rod of an intake valve or an exhaust valve of an internal combustion engine;
A valve spring that gives an elastic force in a direction to close the intake valve or the exhaust valve to the valve rod;
A valve driving piston capable of driving the exhaust valve or the intake valve and reciprocating with a driving force in a valve driving cylinder;
A valve drive piston displacement meter for measuring the position of the valve drive piston in the valve drive cylinder in a non-contact manner and detecting a displacement of the valve drive piston;
Including a driving force control mechanism for controlling the driving force in the valve driving cylinder;
The pressure reducing valve of the pressure reducing hydraulic circuit that is the driving force control mechanism is set to reduce pressure, and the upper chamber of the valve driving cylinder is set as a first hydraulic oil pressure, and the lower chamber of the valve driving cylinder is set as a second hydraulic oil pressure. Based on the pressure receiving area of the first hydraulic oil pressure and the pressure receiving area of the second hydraulic oil pressure, the driving force applied to the valve driving piston is expressed by the elastic force applied to the valve rod by the valve spring. also small to operate the valve driving piston Kushida state, detecting a position where the displacement change of the valve drive piston is stopped by the valve drive piston displacement meter as a reference position,
The reference position is stored as a position where the valve rod and the valve driving piston are in contact, and the valve driving piston is moved from the reference position to set a clearance between the valve rod and the valve driving piston. A valve operating control system for an internal combustion engine. A valve drive control method capable of driving an exhaust valve or an intake valve of an internal combustion engine by a valve drive piston that reciprocates with a drive force in a valve drive cylinder,
The internal combustion engine includes a valve rod for the intake valve or the exhaust valve, a valve spring for applying an elastic force to the valve rod in a direction for closing the intake valve or the exhaust valve, and driving the exhaust valve or the intake valve. A valve driving piston capable of reciprocating with a driving force in the valve driving cylinder and a valve for measuring the position of the valve driving piston in the valve driving cylinder in a non-contact manner and detecting the displacement of the valve driving piston. A driving piston displacement meter, and a driving force control mechanism for controlling driving force in the valve driving cylinder,
The pressure reducing valve of the pressure reducing hydraulic circuit that is the driving force control mechanism is set to reduce pressure, and the upper chamber of the valve driving cylinder is set as a first hydraulic oil pressure, and the lower chamber of the valve driving cylinder is set as a second hydraulic oil pressure. Based on the pressure receiving area of the first hydraulic oil pressure and the pressure receiving area of the second hydraulic oil pressure, the driving force applied to the valve driving piston is expressed by the elastic force applied to the valve rod by the valve spring. The valve drive piston is operated in a state where
When a change in displacement signal of the valve drive piston measured by the valve drive piston displacement meter is calculated and the displacement change of the valve drive piston stops, the displacement of the valve drive piston is stored as a reference position of the valve drive piston. And
The reference position is the position where the valve rod and the valve drive piston are in contact with each other, and the valve drive piston is moved in the direction away from the valve rod to calculate the change in the displacement signal of the valve drive piston. The valve drive piston is stopped at a position where a predetermined clearance from the reference position is established between the valve rod and the valve drive piston.

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