JP2013002919A - Valve testing apparatus for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve testing apparatus for an internal combustion engine in which deviation of valve operation caused by a response characteristic of a displacement gauge can be reduced.SOLUTION: A valve testing apparatus for an internal combustion engine comprises a valve driving device including a valve drive piston and a valve drive cylinder capable of driving an exhaust valve or an intake valve of the internal combustion engine, a hydraulic unit which supplies oil pressure to the valve drive cylinder, a displacement gauge which measures displacement of the valve drive piston, and a control device which controls the valve driving device. The control device stores displacement gauge delay correction data for correcting delay of a displacement signal measured by the displacement gauge with respect to actual displacement of the valve drive piston, corrects a target lift waveform to drive the valve drive piston with the displacement gauge delay correction data and controls the valve driving device.

Description

  The present invention relates to a valve operating test apparatus for an internal combustion engine for experimentally driving an intake valve and an exhaust valve 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. 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).

JP 2009-257319 A

  By the way, although the valve drive device described in Patent Document 1 enables free valve control, a valve operation delay due to an operation delay of the hydraulic actuator occurs. Therefore, the displacement meter measures the valve drive piston, and the valve drive device feeds back displacement data of the displacement meter to the valve control. However, when the valve drive piston is rotated at a high speed, it is necessary to consider the response characteristics of the displacement meter for valve control.

  The present invention solves the above-described problems, and an object thereof is to provide a valve operating test apparatus for an internal combustion engine that can reduce a deviation in valve operation due to response characteristics of a displacement meter.

  In order to achieve the above-mentioned object, a valve operating test apparatus for an internal combustion engine according to the present invention includes a valve drive piston having a valve drive piston and a valve drive cylinder capable of driving an exhaust valve or an intake valve of the internal combustion engine, and the valve drive cylinder. In the valve operating test apparatus for an internal combustion engine, comprising: a hydraulic unit that supplies hydraulic pressure to the valve; a displacement meter that measures the displacement of the valve drive piston; and a control device that controls the valve drive device. Displacement meter delay correction data for correcting the delay of the displacement signal measured by the displacement meter with respect to the actual displacement of the valve drive piston is stored, and the target lift waveform to drive the valve drive piston is stored as the displacement meter delay correction data. And the valve driving device is controlled.

  Thereby, the shift | offset | difference of valve operation resulting from the response characteristic of a displacement meter can be reduced. In consideration of the response characteristics of the displacement meter, the drive wave formed by the target lift waveform is intentionally delayed so as to reduce the delay of the displacement meter signal. Thereby, the actual valve drive piston response is valve driven with a desired response.

  As a desirable aspect of the present invention, the control device acquires crank angle and rotation speed data of the internal combustion engine, and further stores a compensation waveform obtained by calculating response amplitude attenuation and operation delay based on operation characteristics of the valve drive device. Then, a compensation target lift waveform which is a compensated target lift waveform is created by adding the compensation waveform to the target lift waveform to drive the valve drive piston, and the compensation target lift waveform is converted into the displacement meter delay correction data. It is preferable that the valve drive device is controlled by generating a drive wave with the corrected compensation target lift waveform.

  Accordingly, in consideration of the response characteristics of the displacement meter, the compensated target lift waveform with high accuracy is intentionally delayed so as to reduce the delay of the displacement meter signal. Further, the response amplitude attenuation and operation delay of the valve drive piston due to hydraulic pressure are compensated, and the valve can be driven with a desired response. Further, the hydraulic actuator has a high output, and can follow high speed in the internal combustion engine. Further, the mechanism for driving the camshaft by the crankshaft has a fixed cam phase, but the valve operating test apparatus for the internal combustion engine of this embodiment does not have such a mechanism. For this reason, in the valve operating test apparatus for an internal combustion engine of the present embodiment, the valve operation profile such as the opening / closing timing of the intake / exhaust valve, the lift amount, the operating angle, or the overlap of the opening / closing timing of the exhaust valve and the intake valve can be arbitrarily changed. A valve operating test apparatus for an internal combustion engine having a high degree of freedom can be obtained. For example, in a valve operating test of an internal combustion engine, it is possible to find a lift pattern that can stabilize the operation of the internal combustion engine and increase the combustion efficiency even in a load region where the combustion becomes unstable. This contributes to making a high performance camshaft valve drive by feeding back to the design of the camshaft valve drive.

  As a preferred aspect of the present invention, the control device drives the valve drive piston with the corrected compensation target lift waveform to obtain an actual response waveform, and the corrected compensation target lift waveform and the actual response waveform are If the difference does not reach the target error, it is preferable to further correct the corrected compensation target lift waveform with the compensation waveform and the displacement meter correction delay data. Thereby, it can be set as a real response with high precision.

  According to the valve operating test apparatus for an internal combustion engine of the present invention, it is possible to reduce the deviation of the valve operation due to the response characteristic of the displacement meter.

FIG. 1 is a configuration diagram of a valve operating test apparatus 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 a flowchart showing the operation of the valve operating test apparatus for the internal combustion engine according to the present embodiment. FIG. 5 is an explanatory diagram illustrating an example of a compensation waveform according to the present embodiment. FIG. 6 is a flowchart for explaining the procedure of the inverse transfer function calculation according to the present embodiment. FIG. 7 is an explanatory diagram illustrating an example of a compensation target lift waveform according to the present embodiment. FIG. 8 is an explanatory diagram showing a block diagram of the valve operating test apparatus for the internal combustion engine according to the present embodiment. FIG. 9 is an explanatory diagram showing displacement signal comparison between the calibration displacement meter and the displacement meter. FIG. 10 is an explanatory diagram showing displacement signal comparison between the displacement meter for calibration and the displacement meter after compensation 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 operating test apparatus 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 used in an internal combustion engine valve operating test apparatus 100 (hereinafter referred to as a valve operating test apparatus) according to the present embodiment is an engine valve as the combustion piston 2 moves up and down in the cylinder block 3. This device drives the exhaust valve 4a and the intake valve 4b.

  As shown in FIG. 1, the valve operating test 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 the valve driving device 10. It has a hydraulic unit 30 that supplies hydraulic pressure, a control device 80 that controls 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 described later.

  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 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 FIGS. 1 and 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. The exhaust valve 4 a and the intake valve 4 b are each fixed to the lower end of the valve rod 5, and force is urged in the valve closing direction by a valve spring 6 provided on the valve rod 5. The valve drive device 10 is mounted on the internal combustion engine 1, and a valve drive piston 12 is connected to the valve rod 5. Alternatively, the valve driving device 10 is disposed with a slight gap when the valve is closed. Thus, 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. When the valve drive piston 12 is connected to the valve rod 5, the valve spring 6 is not necessary.

  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 an instruction of the signal line I2 from the control device 80. For example, the servo valve 13 includes a spool, an oil passage, an electromagnetic coil, and the like. The 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.

  For the displacement meter 15, for example, a non-contact type displacement sensor such as LVDT (Linear Variable Differential Transformer) is used. Here, the displacement meter 15 can measure the position of the valve drive piston 12. However, if the valve drive piston is driven at a high speed, there is a possibility that a response delay may occur. The displacement meter 15 of the valve drive piston 12 is connected to the control device 80 described above through a signal line I3. The transmission path of the signal line I3 may also cause a response delay.

  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 displacement meter 15 and the measuring 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 displacement meter 15 and the measurement devices 20 and 21 via the 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 operating test apparatus 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 an operation procedure of the valve operating test apparatus 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 test apparatus 100 using a dedicated hardware instead of a computer program.

  The operation procedure of the valve operating test apparatus 100 can also be realized by executing a prepared program on a computer system such as a personal computer, a workstation, or 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. .

  Next, the operation of the valve operating test apparatus for an internal combustion engine will be described with reference to FIGS. FIG. 4 is a flowchart showing the operation of the valve operating test apparatus for the internal combustion engine according to the present embodiment.

  As shown in FIG. 4, the control device 80 acquires the crank angle and rotation speed data of the internal combustion engine 1 from the measuring devices 20 and 21 in real time (step S1). 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 2 reciprocates twice. The control device 80 generates a target lift waveform for one cycle (step S2).

  Next, the control device 80 generates the same drive wave as the target lift waveform (step S3). The control device 80 drives the valve drive piston 12 with a drive wave, detects the displacement of the valve drive piston 12 with the displacement meter 15, and stores it in the storage unit 94 or the RAM 92 as a response waveform for each crank angle. The control device 80 feeds back displacement data, calculates the deviation from the drive wave, and performs PID control (step S4).

  The control device 80 acquires response waveform data of the valve drive piston 12 (step S5), and calculates a difference (error) between the target lift waveform and the response waveform. FIG. 5 is an explanatory diagram illustrating an example of a compensation waveform according to the present embodiment. FIG. 5 shows an example of a target lift waveform with the horizontal axis representing the crank angle and the vertical axis representing the lift amount, and a compensation waveform thereof. For example, the control device 80 calculates the difference between the target lift waveform Tr shown in FIG. 5 and the response waveform Res. If the difference calculated by the control device 80 is not less than or equal to the target error (for example, within a range of ± 0.1 mm) (step S6, No), the control device 80 reverses in order to calculate the compensation waveform Tx shown in FIG. The transfer function calculation procedure is performed (step S7).

  FIG. 6 is a flowchart for explaining the procedure of the inverse transfer function calculation according to the present embodiment. The control device 80 of the valve actuation test apparatus 100 stores the drive wave (x) and the response waveform Res in the storage unit 94 or the RAM 92 (step S81).

  Next, the control device 80 calculates the dynamic characteristics of the valve drive device 10 (step S82). Since the target lift waveform Tr and the response waveform Res for one cycle described above are stored together with the rotation speed with the crank angle as an index, this is converted into a time drive wave and a time response waveform with the time as an index as time passes. Convert. The phase shift of the time response waveform with respect to the time drive wave with respect to time is the operation delay characteristic of the valve drive device 10, and the amplitude attenuation of the time response waveform with respect to the time drive wave is the response amplitude attenuation characteristic of the valve drive device 10. The operation delay and response amplitude attenuation are collectively referred to as a dynamic characteristic (operation characteristic) of the valve drive device 10. The control device 80 calculates the dynamic characteristics of the valve drive device 10 from the time drive wave and the time response waveform, and stores them in the storage unit 94 or the RAM 92. The operating characteristics are calculated in the form of a transfer function Res = G (x).

Next, the control device 80 performs the reverse motion characteristic calculation of the operation characteristics of the valve drive device 10 (step S84). As the reverse dynamic characteristic calculation, for example, an inverse transfer function is calculated. That is, in the calculation of the reverse movement characteristic of the operation characteristic of the valve drive device 10, when the above-described operation characteristic is calculated in the form of a transfer function, the reverse transfer function x = G ⁻¹ which is an inverse function of the transfer function of the operation characteristic. (Res) may be calculated.

  Next, the control device 80 generates a deviation waveform E obtained by subtracting the response waveform (time response waveform) Res from the target lift waveform (time target lift waveform) Tr. The control device 80 generates the compensation waveform Tx by applying the above-described reverse characteristics to the deviation waveform. For example, the compensation waveform Tx can be calculated by applying the inverse transfer function to the deviation waveform (step S85). In this embodiment, the control device 80 creates each component of the compensation waveform Tx. However, each component of the compensation waveform is created by a computer system different from the control device 80, and data of each component of the compensation waveform is transmitted. The data may be stored in the storage unit 94 or the RAM 92.

  Moreover, although the compensation waveform was created based on the dynamic characteristic (operation characteristic) of the actual valve drive device 10, the compensation waveform may be created by simulation. First, an analysis model of the valve drive device 10 (actuator) is created in advance. The analysis model is described by a high-order ordinary differential nonlinear equation, and the displacement of the valve drive piston 12 can be obtained as a solution by numerical calculation using a computer. The analysis model of the valve drive device 10 (actuator) includes the mass of the valve drive piston 12, the stroke, the friction coefficient between the valve drive piston 12 and the valve drive cylinder 11, the spring constant of the valve spring 6, It is created in consideration of the delay in the operation of the servo valve 13 for switching between supply and discharge of hydraulic pressure and compression, supply and discharge of oil in the valve drive cylinder 11. In the model that can be analyzed, the response waveform when the valve drive device 10 (actuator) is driven by a drive wave can be calculated. Using the created analysis model, an input of a drive wave is given to the analysis model of the valve drive device 10 (actuator) for each rotation speed of the internal combustion engine 1 (engine), and a response to the input is simulated by a computer. The compensation waveform can be created by the above-described compensation waveform creation procedure. After the CPU 91 of the control device 80 performs the procedure of reading the compensation waveform into the work area of the RAM 92, the control device 80 proceeds to the next compensation target lift waveform generation (step S8) procedure.

  The control device 80 of the valve operating test apparatus 100 performs a procedure for generating a compensated target lift waveform (step S8). In step S8, the above-described compensation target lift waveform is set as a new target lift waveform. FIG. 7 is an explanatory diagram illustrating an example of a compensation target lift waveform according to the present embodiment.

  As shown in FIG. 7, the compensation target lift waveform Tr2 should be more approximate to the response waveform Res described above. However, when the operation of the valve drive piston 12 is measured by, for example, a laser displacement meter other than the displacement meter 15, a response waveform Res2 is obtained, and there may be a delay m. This delay m is often easily reproduced when the valve drive piston 12 is rotated at a high speed. FIG. 8 is an explanatory diagram showing a block diagram of the valve operating test apparatus for the internal combustion engine according to the present embodiment. FIG. 9 is an explanatory diagram showing displacement signal comparison between the calibration displacement meter and the displacement meter. FIG. 10 is an explanatory diagram showing displacement signal comparison between the displacement meter for calibration and the displacement meter after compensation according to the present embodiment.

  The valve operating test apparatus for an internal combustion engine according to the present embodiment shown in FIG. 8 includes, for example, a displacement meter 15A for calibration such as a high-precision laser displacement sensor in addition to the displacement meter 15. The calibration displacement meter 15 </ b> A measures the displacement of the measurement unit 12 </ b> A that is driven together with the valve drive piston 12. Thereby, the displacement meter 15 and the displacement meter 15A for calibration measure the valve drive piston 12 which is driving the same. When comparing the LVDT sensor of the displacement meter 15 and the laser displacement sensor of the calibration displacement meter 15A, the laser displacement sensor of the calibration displacement meter 15A has a faster response speed. Therefore, as shown in FIG. 9, if the displacement meter 15 and the calibration displacement meter 15A simultaneously measure the displacement of the valve drive piston 12, the displacement signal of the displacement meter 15 may be delayed. For this reason, the control device 80 calculates the delay by the CPU 91 and calculates the difference data so that the displacement signal between the displacement meter 15 shown in FIG. 10 and the displacement meter 15A for calibration does not have a time delay. . The control device 80 stores the difference data in the storage unit 94 or the RAM 92 as displacement meter delay correction data. Thereby, the displacement meter delay correction data becomes information for correcting the delay of the displacement signal measured by the displacement meter 15 with respect to the actual displacement of the valve drive piston 12. The displacement meter delay correction data may be a constant. Further, the displacement meter delay correction data may be a function of the rotational speed driven by the valve drive piston 12. The control device 80 calculates the displacement meter delay correction data from the characteristic data of the displacement meter 15 instead of the difference data between the displacement meter 15 and the calibration displacement meter 15A, and stores it in the storage unit 94 or the RAM 92. Good.

  In the block diagram shown in FIG. 8, the target lift waveform generation block 51, the compensation waveform generation block 71, the displacement meter delay correction data block 59, the PID control block 55, the servo valve 13, the valve drive piston 12, and the valve A drive cylinder 11, a displacement meter 15, and a response waveform block 54 are included. The signal P of the target lift waveform Tr of the target lift waveform generation block 51 is added to the signal Q of the output of the compensation waveform generation block 71 at the addition point 52 to become the signal R of the compensation target lift waveform Tr2. If it is not necessary to compensate the target lift waveform Tr, the signal Q in the compensation waveform generation block 71 is eliminated, and the signal R becomes the same as the signal P of the target lift waveform Tr. The added signal R is further added at the addition point 52A with the signal S output from the displacement meter delay correction data block 59 to become a signal T. In the displacement meter delay correction data block 59, the control device 80 reads the displacement meter delay correction data described above from the storage unit 94 or RAM 92 to the work area of the RAM 92, corrects the compensation target lift waveform Tr2, and compensates the compensation target shown in FIG. Let it be a lift waveform Ra. That is, the control device 80 performs displacement meter delay correction shown in FIG. 4 with respect to the compensation target lift waveform Tr2 (step S9).

  Here, in the response waveform block 54, the CPU 91 feeds back displacement data of the valve drive piston 12 driven by the displacement meter 15 in the valve drive cylinder 11, and converts it into a signal U of the response waveform Res. The signal T, which is the compensation target lift waveform Ra of the displacement meter delay correction data block 59, is added (feedback connection) to the signal U at the addition point 53 to become a deviation signal V. That is, the control device 80 calculates a deviation of the fed back displacement data to obtain a compensated drive wave. Then, a deviation signal V that is a compensated drive wave is sent to the PID control block 55. In the PID control block 55, the deviation control signal V is converted into a control signal W for the servo valve 13. Thereby, the control device 80 shown in FIG. 1 controls the servo valve 13. The servo valve 13 controls the hydraulic pressure Op, and controls the valve drive piston 12 that is driven in the Z direction in the valve drive cylinder 11, for example. A correction gain may be appropriately added at the above-described addition point. The correction gain may be 1, but it is preferable to take a variable value of 0 to 1 in consideration of overcompensation due to device characteristic changes and repetition.

  Further, the procedure for calculating the inverse transfer function (step S7) and the procedure for generating the compensation target lift waveform (step S8) shown in FIG. 4 are omitted, and the displacement shown in FIG. You may perform the procedure (step S9) of a meter delay correction | amendment. Thereby, the shift | offset | difference of valve operation resulting from the response characteristic of the displacement meter 15 can be reduced. In addition, in consideration of the response characteristics of the displacement meter 15, the target lift waveform Tr can be intentionally delayed so as to reduce the delay of the signal from the displacement meter 15.

  Further, the displacement meter delay correction procedure (step S9) shown in FIG. 4 may be performed before the inverse transfer function calculation procedure (step S7). Accordingly, the target lift waveform Tr can be intentionally delayed so as to reduce the delay of the signal of the displacement meter 15 in consideration of the response characteristics of the displacement meter 15.

  As shown in FIG. 4, the control device 80 generates a drive wave compensated by the compensated target lift waveform Ra in which the displacement meter delay is corrected by the displacement meter delay correction procedure (step S9) (step S3). The control device 80 performs PID control using the compensated drive wave (compensated drive wave) (step S4). That is, the control device 80 drives the valve drive piston 12 with the compensated drive wave, detects the displacement of the valve drive piston 12 with the displacement meter 15, and stores it in the storage unit 94 or the RAM 92 as a response waveform for each crank angle.

  The control device 80 acquires displacement data of the valve drive piston 12 that is a response waveform (step S5), and calculates a difference (error) between the target lift waveform and the response waveform. If the calculated difference is not less than or equal to the target error (for example, within a range of ± 0.1 mm) (step S6, No), the control device 80 calculates a reverse transfer function to calculate the compensation waveform Tx shown in FIG. (Step S7).

  The control device 80 of the present embodiment acquires response waveform data of the valve drive piston 12 (step S5), calculates a difference (error) between the target lift waveform and the response waveform, and the calculated difference is the target error (for example, ± The compensation target lift waveform compensated by the above-described compensation waveform Tx is generated (step S8) until it is within 0.1 mm. Since the procedure from step S3 to step 9 is repeated until it is within a target error (for example, within a range of ± 0.1 mm), the valve testing apparatus of the present embodiment generates a drive wave that responds to achieve the target error. Can be generated. Thereby, it can be set as a highly accurate response.

  If the calculated difference is equal to or less than a target error (for example, within a range of ± 0.1 mm) (step S6, Yes), the response amplitude attenuation and the operation delay are compensated, and the compensation is terminated.

  As described above, the valve operating test apparatus 100 for an internal combustion engine has the valve drive piston 12 and the valve drive cylinder 11, and can drive at least one of the exhaust valve 4 a or the intake valve 4 b of the internal combustion engine 1. And a hydraulic unit 30 that supplies hydraulic pressure to the valve drive cylinder 12, a displacement meter 15 that measures the displacement of the valve drive piston 12, and a control device 80 that controls the valve drive device 10. The control device 80 stores displacement meter delay correction data for correcting the delay of the displacement signal measured by the displacement meter 15 with respect to the actual displacement of the valve drive piston 12, and the target lift waveform Tr that attempts to drive the valve drive piston 12. Is corrected by the displacement meter delay correction data, and the valve drive device 10 is controlled.

  Thereby, the shift | offset | difference of valve operation resulting from the response characteristic of the displacement meter 15 can be reduced. Further, in consideration of the response characteristics of the displacement meter 15, the target lift waveform Tr is intentionally delayed so as to alleviate the delay of the signal from the displacement meter 15. As a result, the actual response of the valve drive piston 12 is valve driven with a desired response.

  Further, in the valve operating test apparatus 100 for an internal combustion engine, the control device 80 acquires the crank angle and rotation speed data of the internal combustion engine 1, and the response amplitude attenuation and the operation delay based on the operation characteristics of the valve drive device 10 are expressed by an inverse transfer function. The calculated compensation waveform Tx is further stored, and a compensated target lift waveform Tr2 is created by adding the compensation waveform Tx to the target lift waveform Tr that is to drive the valve drive piston 12, and the compensated compensated target lift waveform It is preferable that Tr2 is corrected with displacement meter delay correction data, and a drive wave is generated with the corrected compensation target lift waveform Ra to control the valve driving device 10.

  As a result, in consideration of the response characteristics of the displacement meter 15, the compensated target lift waveform Tr <b> 2 with high accuracy is intentionally delayed so as to reduce the delay in the signal of the displacement meter 15. For this reason, the accuracy in which the response amplitude attenuation and the operation delay of the actual valve drive piston 12 are compensated is further increased, and the valve can be driven with a desired response.

  Further, the hydraulic actuator has a high output, and can follow high speed in the internal combustion engine. Further, the mechanism for driving the camshaft by the crankshaft has a fixed cam phase, but the valve operating test apparatus for the internal combustion engine of this embodiment does not have such a mechanism. For this reason, in the valve operating test apparatus for an internal combustion engine of the present embodiment, the valve operation profile such as the opening / closing timing of the intake / exhaust valve, the lift amount, the operating angle, or the overlap of the opening / closing timing of the exhaust valve and the intake valve can be arbitrarily changed. A valve operating test apparatus for an internal combustion engine having a high degree of freedom can be obtained. For example, in a valve operating test of an internal combustion engine, it is possible to find a lift pattern that can stabilize the operation of the internal combustion engine and increase the combustion efficiency even in a load region where the combustion becomes unstable. This contributes to making a high performance camshaft valve drive by feeding back to the design of the camshaft valve drive.

  As described above, in the valve operating test apparatus 100 of the present embodiment, the control device 80 acquires the actual response data of the corrected compensation target lift waveform Ra, and the difference between the corrected compensation target lift waveform Ra and the actual response waveform. If the target error does not reach the target error, it is preferable to further correct the compensation target lift waveform Ra with the compensation waveform Tx and the displacement meter correction delay data. Thereby, it can be set as a highly accurate response.

  As described above, the valve operating test apparatus according to the present embodiment is suitable for a testing machine that opens and closes an intake valve or an exhaust valve of an internal combustion engine. The present invention relates to a valve drive device having a valve drive piston and a valve drive cylinder capable of driving an exhaust valve or an intake valve of an internal combustion engine, a hydraulic unit for supplying hydraulic pressure to the valve drive cylinder, and the valve drive piston. A displacement meter that measures displacement; and a control device that controls the valve drive device, the control device correcting a delay of a displacement signal measured by the displacement meter with respect to an actual displacement of the valve drive piston. The displacement meter delay correction data to be stored is stored, the target lift waveform for driving the valve drive piston is corrected with the displacement meter delay correction data, and the valve drive device of the internal combustion engine for controlling the valve drive device can be applied. . Further, the control device acquires crank angle and rotation speed data of the internal combustion engine, further stores a compensation waveform obtained by calculating response amplitude attenuation and operation delay based on operation characteristics of the valve drive device, and storing the valve drive A compensation target lift waveform which is a compensated target lift waveform is created by adding the compensation waveform to the target lift waveform to drive the piston, and the compensation target lift waveform is corrected with the displacement meter delay correction data. More preferably, the valve operating device of the internal combustion engine generates a drive wave with the compensated target lift waveform and controls the valve driving device.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Combustion piston 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 12 Valve drive piston 13 Servo valve 15 Displacement meter 15A Displacement meter for calibration 20, 21 Measuring device 30 Hydraulic unit 80 Control device 100 Valve testing device

Claims (3)

A valve drive device having a valve drive piston and a valve drive cylinder capable of driving an exhaust valve or an intake valve of an internal combustion engine, a hydraulic unit for supplying hydraulic pressure to the valve drive cylinder, and a displacement meter for measuring the displacement of the valve drive piston And a control device for controlling the valve drive device, a valve operating test apparatus for an internal combustion engine,
The controller is
Storing displacement meter delay correction data for correcting a delay of a displacement signal measured by the displacement meter with respect to an actual displacement of the valve drive piston;
A valve operating test apparatus for an internal combustion engine, wherein a target lift waveform for driving the valve driving piston is corrected with the displacement meter delay correction data to control the valve driving apparatus. The controller is
Acquiring crank angle and rotational speed data of the internal combustion engine, further storing a compensation waveform obtained by calculating response amplitude attenuation and operation delay based on operation characteristics of the valve drive device;
A compensation target lift waveform which is a compensated target lift waveform is created by adding the compensation waveform to the target lift waveform to drive the valve drive piston, and the compensation target lift waveform is corrected with the displacement meter delay correction data. The valve operating test apparatus for an internal combustion engine according to claim 1, wherein a drive wave is generated with the corrected compensation target lift waveform to control the valve driving apparatus.   The control device drives the valve drive piston with the corrected compensation target lift waveform to obtain an actual response waveform, and a difference between the corrected compensation target lift waveform and the actual response waveform reaches a target error. 3. The valve operating test apparatus for an internal combustion engine according to claim 2, wherein if not, the corrected target lift waveform is further corrected by the compensation waveform and the displacement meter correction delay data.

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