JP2012136968A - Driven valve tester of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driven valve tester of an internal combustion engine which can reduce valve operation delay due to operation delay of a hydraulic actuator.SOLUTION: A driven valve tester of an internal combustion engine consists of a valve drive device containing a valve drive piston and valve drive cylinder capable of driving an exhaust valve or feed valve of the internal combustion engine, a hydraulic unit for supplying oil pressure to a valve drive cylinder and a control device for controlling the valve drive device. The control device acquires a crank angle and rotation speed data of the internal combustion engine, stores a correction waveform for correcting the response amplitude attenuation and operation delay based on performance characteristics of the valve drive device, forms a drive waveform by adding a correction waveform to a target lift waveform to drive the valve drive piston, and control the valve drive device by the drive waveform.

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.

  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 valve operation delay due to operation delay of a hydraulic actuator.

  In order to achieve the above object, a valve operating test apparatus for an internal combustion engine according to the present invention comprises 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. A hydraulic unit that supplies hydraulic pressure to the cylinder; and a control device that controls the valve drive device, wherein the control device acquires crank angle and rotation speed data of the internal combustion engine, and operates characteristics of the valve drive device. A correction waveform for correcting response amplitude attenuation and operation delay based on the above is stored, a drive waveform is created by adding the correction waveform to a target lift waveform to drive the valve drive piston, and the valve drive device using the drive waveform It is characterized by controlling.

  Thereby, the response amplitude attenuation and the operation delay of the valve drive piston due to the 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. In addition, the mechanism for driving the camshaft by the crankshaft has a fixed cam phase, but the valve operating test apparatus for an internal combustion engine of the present invention does not have such a mechanism. Therefore, in the valve operating test apparatus for an internal combustion engine according to the present invention, 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 desirable mode of the present invention, in the valve operating test apparatus for an internal combustion engine according to the present invention, the correction waveform is preferably generated from the speed of the target lift waveform. As a result, it is possible to compensate for the response amplitude attenuation and operation delay of the valve drive device due to hydraulic pressure.

  As a desirable mode of the present invention, in the valve operating test apparatus for an internal combustion engine according to the present invention, it is preferable that the correction waveform is generated from an acceleration of a target lift waveform. As a result, it is possible to compensate for the response amplitude attenuation and operation delay of the valve drive device due to hydraulic pressure.

  As a desirable mode of the present invention, in the valve operating test apparatus for an internal combustion engine according to the present invention, a target lift waveform of the internal combustion engine is stored in advance, and the drive waveform is created by the correction waveform in accordance with the crank angle and the rotation speed data. To do. Thereby, it can be set as the valve operating test apparatus of the internal combustion engine with the high freedom degree which can change a valve operation profile arbitrarily.

  As a desirable mode of the present invention, in the valve operating test apparatus for an internal combustion engine according to the present invention, the control device drives the valve drive piston with the drive waveform to obtain response data, and if the target error is not reached, the drive It is preferable to further correct the waveform. 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, the valve operation delay due to the operation delay of the hydraulic actuator can be reduced.

FIG. 1 is a configuration diagram of the valve operating test apparatus for an internal combustion engine according to the first 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 illustrating a procedure for creating a correction waveform according to the first embodiment. FIG. 5 is an explanatory diagram illustrating an example of a correction waveform. FIG. 6 is an explanatory diagram illustrating an example of a correction waveform. FIG. 7 is a flowchart showing the operation of the valve operating test apparatus for the internal combustion engine according to the first 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 first embodiment. FIG. 9A is a diagram illustrating an example of the correction waveform generation of FIG. 8. FIG. 9B is a diagram illustrating an example of the correction waveform generation of FIG. FIG. 9C is a diagram illustrating an example of the correction waveform generation of FIG. FIG. 10 is a flowchart showing the operation of the valve operating test apparatus for an internal combustion engine according to the second embodiment. FIG. 11A is a diagram illustrating a comparison between the target lift and the response lift in the evaluation example. FIG. 11B is a diagram illustrating the deviation of FIG.

  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.

(Embodiment 1)
The first embodiment will be described with reference to the drawings. FIG. 1 is a configuration diagram of the valve operating test apparatus for an internal combustion engine according to the first 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 supply 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 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 air supply valve 4 b, a valve rod 5, and a valve spring 6. The exhaust valve 4 a and the air supply 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. Accordingly, when the valve drive piston 12 is driven, the exhaust valve 4 a and the air supply 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 air supply valve 4b is opened. Further, the valve drive piston 12 contracts when the hydraulic pressure is discharged from the valve drive cylinder 11 to close the exhaust valve 4a or the air supply 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.

  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, a procedure for creating a correction waveform will be described with reference to FIGS. FIG. 4 is a flowchart showing a procedure for creating a correction waveform according to the present embodiment. 5 and 6 are explanatory diagrams illustrating an example of a correction waveform.

  A procedure for creating a correction waveform will be described with reference to the flowchart shown in FIG. The control device 80 of the valve operating test device 100 acquires crank angle and rotation speed data from the measuring 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 (step S1).

  Next, the control device 80 drives the valve drive piston with the same drive waveform as the target lift waveform. The control device 80 detects the displacement of the valve drive piston 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 (step S2).

  Next, the control device 80 calculates the dynamic characteristics of the valve drive device. The one-cycle drive waveform and response waveform described above are stored together with the number of rotations with the crank angle as an index, and are converted into a time drive waveform and a time response waveform with the time as an index as time passes. The phase shift of the time response waveform with respect to the time drive waveform with respect to time is the operation delay characteristic of the valve drive device, and the amplitude attenuation of the time response waveform with respect to the time drive waveform is the response amplitude attenuation characteristic of the valve drive device. The operation delay and response amplitude attenuation are collectively referred to as a dynamic characteristic (operation characteristic) of the valve drive device. The control device 80 calculates the dynamic characteristics of the valve drive device from the time drive waveform and the time response waveform, and stores them in the storage unit 94 or the RAM 92 (step S3). The operating characteristics may be calculated in the form of a transfer function, for example.

  Next, the control device 80 calculates the reverse motion characteristic of the operation characteristic of the valve drive device. In calculating the reverse characteristics of the operating characteristics of the valve drive device, if the above-mentioned operating characteristics are calculated in the form of a transfer function, an inverse transfer function that is an inverse function of the transfer function of the operating characteristics may be calculated (step S4). ).

  Next, the control device 80 generates a deviation waveform obtained by subtracting the response waveform (time response waveform) from the target lift waveform (time target lift waveform). The controller 80 generates the time correction waveform by applying the above-described reverse motion characteristic to the deviation waveform. For example, a time correction waveform can be calculated by applying the inverse transfer function to a deviation waveform (step S5). From the above relationship, it can be seen that if the valve drive device is driven with the same time drive wave as the time correction waveform, the time response waveform of the valve drive piston matches the deviation waveform. Therefore, when the time correction waveform is added to the time drive waveform (A) and the valve drive device is driven as a new time drive waveform (B), the time response waveform matches the original time drive waveform (A). If the time target lift waveform and the time correction waveform are added together, a time drive waveform that reproduces the required target lift waveform can be generated. Next, a correction waveform can be generated by converting the time correction waveform into an index (crank angle index) for each rotation speed.

  The time drive waveform and the time response waveform described above have a causal relationship between cause and effect in terms of time. When the relationship is identified from moment to moment, it is identified as a causal relationship. Unlike this, the control device 80 temporarily stores both the drive waveform and response waveform for one cycle in the storage unit 94 or the RAM 92, and identifies the relationship between them, the reverse characteristics and time drive of the valve drive device. The time correction waveform for the waveform need not be causally related in time. In this case, the control device 80 can be identified as a non-causal relationship. For example, a time correction waveform identified as a non-causal relationship with respect to a time drive waveform having a value that is 0 until time T0 and that exceeds time T0 and is not 0 is represented as time T0− when τ is a positive value. It can be generated as a waveform having a certain value which is not zero after time T0-τ with zero value until τ.

  The control device 80 of the valve operating test apparatus 100 inputs a drive waveform obtained by adding the target lift waveform and the correction waveform to the servo valve 13, and controls the supply of hydraulic pressure or the discharge of hydraulic pressure from the valve drive cylinder 11. The drive piston 12 is driven to actually operate the valve drive device 10 (actuator). The control device 80 acquires an actual response waveform in which the valve drive device 10 (actuator) is operated for each crank angle and rotation speed of the internal combustion engine. The crank angle and the rotational speed are acquired via the measuring devices 20 and 21, and the response waveform is acquired via the displacement meter 15.

  Since the valve drive device 10 (actuator) is a hydraulic actuator, the actual value is determined from the command indicated by the drive waveform due to the influence of the viscosity of the hydraulic oil, the compressibility of the hydraulic oil, the inertia of the valve drive piston, the exhaust valve, or the air supply valve. The operation is delayed. It has been found that this delay increases as the rotational speed of the internal combustion engine 1 increases. For each rotation speed of the internal combustion engine 1, a correction waveform is generated by the above-described correction waveform generation procedure, and the obtained results are arranged and mapped for each rotation speed to obtain a correction waveform map.

  The correction waveform can also be obtained 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 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, and the hydraulic pressure to the valve drive cylinder 11. The servo valve 13 that switches between supply and discharge of oil and compression and supply and discharge of oil in the valve drive cylinder 11 is taken into consideration. In the model that can be analyzed, the response waveform when the valve drive device 10 (actuator) is driven by the drive waveform can be calculated. Using the created analysis model, an input of a drive waveform 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. Then, the correction waveform can be generated by the correction waveform generation procedure described above. Further, the obtained results are arranged and mapped for each number of rotations to obtain a corrected waveform map. The correction waveform map is a database for correcting response amplitude attenuation and operation delay.

  The correction waveform map created as described above can be easily generated by the following method without using the drive waveform, the response waveform, and the inverse characteristics of the valve drive device. The time correction waveform can be generated by adding the time target lift speed waveform obtained by differentiating the time target lift waveform by the first order time and the time target lift acceleration waveform obtained by differentiating the time target lift waveform by the second order time. As amplitude magnification correction, each value is multiplied by a correction coefficient, and each waveform is corrected for delay and added. For example, the correction coefficient is applied to each of the time target lift speed waveform and the time target lift acceleration waveform, and a correction coefficient may be set for each crank angle index section. Further, the correction coefficient and the delay correction amount are obtained by simulation using, for example, a minimum value search algorithm such as an experimental design method, using the correction coefficient and the delay correction amount as search values so that the response waveform matches the target lift waveform. be able to. The correction coefficient and the delay correction amount are determined for each speed waveform, acceleration waveform, and crank angle index section. FIG. 5 shows the time target lift speed subjected to amplitude magnification correction and delay correction, arranged for each rotation speed and mapped using the crank angle as an index, and FIG. 6 shows the time target lift acceleration waveform with amplitude magnification correction and delay correction. 1 shows an example of a corrected waveform component (corrected waveform map) that is arranged for each rotation speed and mapped with the crank angle as an index.

  The correction waveform component 41 shown in FIG. 5 performs an amplitude magnification correction and a delay correction on the speed component obtained by differentiating the target lift waveform with the correction coefficient and the delay correction amount determined by the above-described method, and arranges them for each rotation speed. It is a map with angle as an index.

  The correction waveform component 42 shown in FIG. 6 performs an amplitude magnification correction and a delay correction on the acceleration component obtained by second-order differentiation of the target lift waveform with the correction coefficient and the delay correction amount determined by the above-described method, and arranges it for each rotation speed. This is a map with the crank angle as an index.

  Next, the control device 80 stores each component of the correction waveform as shown in FIGS. 5 and 6 in the storage unit 94 or the RAM 92 (step S5). In the present embodiment, the control device 80 creates each component of the correction waveform. However, each component of the correction waveform is created by a computer system different from the control device 80, and data of each component of the correction waveform is transmitted to the storage unit. 94 or RAM 92 may be used. Moreover, in step S3 and step S4, although the correction waveform was created based on the dynamic characteristic (operation characteristic) of the actual valve drive device, the correction waveform may be created by simulation.

  Next, the operation procedure of the valve operating test apparatus 100 will be described with reference to FIGS. FIG. 7 is a flowchart showing the operation of the valve operating test apparatus according to the first embodiment. FIG. 8 is an explanatory diagram showing a block diagram of the valve operating test apparatus according to the first embodiment.

  The operation procedure of the valve operating test apparatus 100 will be described along the flowchart shown in FIG. The control device 80 of the valve operating test apparatus 100 acquires a target lift waveform and a correction waveform in which a target lift amount is given in advance for each crank angle of the internal combustion engine 1 and stores it in the storage unit 94 or the RAM 92. In addition, the control device 80 acquires the crank angle and rotation speed data of the internal combustion engine 1 from the measurement devices 20 and 21 in real time (step S10).

  In the present embodiment, the control device 80 stores the target list waveform in the storage unit 94 or the RAM 92 as described above. Therefore, the control device 80 performs a procedure for reading the target lift waveform stored in the storage unit 94 or the RAM 92 into the work area of the RAM 92 as described above. (Step S11). Next, the control device 80 performs a procedure for confirming whether the correction waveform stored in the storage unit 94 or the RAM 92 is stored as described above (step S12). When the correction waveform stored in the storage unit 94 or the RAM 92 is stored (step S12, Yes), the CPU 91 of the control device 80 performs a procedure for reading the correction waveform into the work area of the RAM 92, and then the control device 80. Advances to the procedure of the next drive waveform generation (step S14).

  The case where the correction waveform is stored includes the case where the correction waveform is stored in the above-described correction waveform map. Further, the case where the correction waveform is stored includes the case where the control device 80 stores the above-described reverse characteristics in the storage unit 94 or the RAM 92. As a result, the control device 80 generates a deviation waveform obtained by subtracting the time response waveform from the target lift waveform, outputs the correction waveform by applying the above-described reverse motion characteristic to the deviation waveform, and then the control device 80 performs the next drive. Proceed to waveform generation (step S14).

  In the present embodiment, correction waveforms stored in the storage unit 94 or the RAM 92 are stored. On the other hand, the correction waveform stored in the storage unit 94 or the RAM 92 may not be stored. When the correction waveform stored in the storage unit 94 or the RAM 92 is not stored (step S12, No), the control device 80 proceeds to the procedure of the correction waveform generation (step S13). For example, in the procedure of the correction waveform generation (step S13), the control device 80 can generate the correction waveform by creating the correction waveform according to the flowchart shown in FIG. Further, the correction wave can be generated by the control device 80 obtaining the correction waveform map described above by simulation. Alternatively, the correction waveform map can be generated by the control device 80 obtaining the above-described time target lift speed waveform or the above-described time target lift acceleration waveform. When the correction waveform is generated by the procedure of the correction waveform generation (step S13), the control device 80 proceeds to the procedure of the next drive waveform generation (step S14).

  The CPU 91 of the control device 80 generates a correction waveform at the corresponding rotational speed based on the crank angle index (step S13). The control device 80 of the valve operating test apparatus 100 performs a procedure for generating a drive wave (step S14). The drive wave is generated from the target lift waveform and the correction waveform based on the crank angle and rotation speed data of the internal combustion engine 1 acquired in real time in step S10. The control device 80 adds the correction waveform to the target lift waveform and generates a drive waveform. Note that the number of revolutions in one cycle of the internal combustion engine was constant, and the correction waveform was organized as a map at each number of revolutions. However, even if the rotation speed fluctuates during one cycle, the correction waveform corresponding to the rotation speed at that time is referred to. Therefore, if the fluctuation in the rotation speed is continuous and small, it corresponds to the rotation speed fluctuation during one cycle. A correction waveform can be generated.

  In this embodiment, when a target lift waveform is corrected with a correction waveform to generate a drive waveform, correction is performed with two types of correction waveform components. Referring to the block diagram of the valve operating test apparatus 100 in FIG. 8, the control device 80 stores the correction waveform component 41 and the correction waveform component 42 in the storage unit 94 or the RAM 92. The signal P of the drive waveform generation block 51 is added at the addition point 53 with the signal Q of the first gain correction block 52 that adds a predetermined (0 to 1) gain to the output of the correction waveform component 41. The signal R after the addition is added at the addition point 55 with the signal S of the second gain correction block 54 that adds a predetermined (0 to 1) gain to the output of the correction waveform component 42. The correction gains of the gain correction block 52 and the gain correction block 54 may be 1, but a variable value of 0 to 1 is taken in consideration of apparatus characteristics change and overcompensation due to repetition.

  9A, 9B, and 9C are diagrams illustrating an example of the correction waveform generation of FIG. FIG. 9A, FIG. 9B, and FIG. 9C are correction waveforms that are arranged and mapped every rotation speed of 1000 rpm to 1800 rpm. The correction waveform component 43 shows an actual detailed waveform of the correction waveform component 41. The correction waveform component 44 shows an actual detailed waveform of the correction waveform component 42. Since the first gain correction block 52 and the second gain correction block 54 are connected, the signal P of the target lift waveform is a correction waveform component 45 in which the correction waveform component 43 and the correction waveform component 44 are added. Waveform correction is performed. The control device 80 may store the correction waveform component 45 in advance and perform correction using one type of map (correction waveform component). The correction waveform component 45 is corrected so that the rising side is larger than the falling side when compared with the rising crank angle section of the target lift waveform and the falling crank angle section of the target lift waveform. Thereby, the operation delay of the valve drive piston 12 caused by the delay in transmitting the hydraulic pressure from the valve drive cylinder 11 to the valve drive piston 12 during the lift operation of the valve drive piston 12 can be eliminated.

  Next, as shown in the flowchart of FIG. 7, the CPU 91 feeds back displacement data (step S15). In FIG. 8, the signal T (corrected drive waveform) after addition is added (feedback connection) at the addition point 57 using the displacement data 56 of the valve drive piston 12 as a signal U from the displacement meter 15 shown in FIG.

  Next, as shown in the flowchart of FIG. 7, the control device 80 sends the deviation between the drive wave and the displacement data fed back to the PID control block (step S16). The deviation control signal V shown in FIG. 8 is sent to the PID control block 58. Thereby, the control device 80 shown in FIG. 1 controls the servo valve 13.

  As described above, in the valve operating test apparatus of the present embodiment, the valve driving device includes a valve driving cylinder and a valve driving piston that can drive an exhaust valve or an air supply valve of an internal combustion engine, and a servo that drives the valve driving piston. And a control device for controlling the servo valve. The control device drives the target lift waveform to drive the valve drive piston by adding a correction in consideration of the operation characteristics of the valve drive device. A waveform is created and the valve drive device is controlled by the drive waveform.

  Thereby, the response amplitude attenuation and the operation delay of the valve drive piston due to the 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 is arbitrarily changed. It is possible to provide a valve operating test apparatus for an internal combustion engine with a high degree of freedom. 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.

  In the valve operating test apparatus according to the present embodiment, the correction waveform is preferably generated from the speed of the target lift waveform. As a result, it is possible to compensate for the response amplitude attenuation and operation delay of the valve drive device due to hydraulic pressure.

  In the valve operating test apparatus according to the present embodiment, the correction waveform is preferably generated from the acceleration of the target lift waveform. As a result, it is possible to compensate for the response amplitude attenuation and operation delay of the valve drive device due to hydraulic pressure.

  In the valve operating test apparatus according to the present embodiment, it is preferable that the control device stores a target lift waveform of the internal combustion engine in advance and creates a drive waveform based on the correction waveform matched to the crank angle and rotation speed data. Thereby, it can be set as the valve operating test apparatus of the internal combustion engine with the high freedom degree which can change a valve operation profile arbitrarily.

  The internal combustion engine of the present embodiment includes a cylinder block, a combustion piston that moves up and down in the cylinder block, an exhaust valve and an intake valve, and the valve operating test device that drives the exhaust valve and the intake valve, respectively. It is preferable to have. 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.

(Embodiment 2)
FIG. 10 is a flowchart showing the operation of the valve operating test apparatus according to the second embodiment. The valve operating test apparatus according to the present embodiment is the same as that of the first embodiment, but is characterized by further correcting the drive waveform obtained by the valve operating test apparatus of the first embodiment. In the following description, the same components as those described in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

  As shown in FIG. 10, the control device 80 acquires the crank angle and rotation speed data of the internal combustion engine 1 from the measurement devices 20 and 21 in real time (step S21). It is assumed that the control device 80 stores a target lift waveform in 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 (step S22).

  Next, the control device 80 generates the same drive waveform as the target lift waveform. (Step S23). The control device 80 drives the valve drive piston with a drive waveform, detects the displacement of the valve drive piston 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 a deviation from the drive waveform, and performs PID control (step S24).

  The control device 80 acquires displacement data of the valve drive piston 12 that is a response waveform (step S25), and calculates a difference (error) from the target valve lift amount. If the calculated difference is not within a target error (for example, within a range of ± 0.1 mm) (No in step S26), the control device 80 checks whether the correction waveform stored in the storage unit 94 or the RAM 92 is stored. The procedure to perform is performed (step S27). When the correction waveform stored in the storage unit 94 or the RAM 92 is stored (step S27, Yes), the CPU 91 of the control device 80 performs a procedure for reading the correction waveform into the work area of the RAM 92, and then the control device 80. Advances to the procedure of the next drive waveform generation (step S29).

  The case where the correction waveform is stored includes the case where the correction waveform is stored in the correction waveform map described above in the first embodiment. In addition, the case where the correction waveform is stored includes the case where the control device 80 stores the reverse motion characteristics described in the first embodiment in the storage unit 94 or the RAM 92. As a result, the control device 80 generates a deviation waveform obtained by subtracting the time response waveform from the target lift waveform, outputs the correction waveform by applying the above-described reverse motion characteristic to the deviation waveform, and then the control device 80 performs the next drive. Proceed to waveform generation (step S29).

  When the correction waveform stored in the storage unit 94 or the RAM 92 is not stored (No at Step S27), the control device 80 proceeds to the procedure of generating a correction waveform (Step S28). For example, in the procedure of generating a correction waveform (step S28), the control device 80 can generate a correction wave by creating a correction waveform according to the flowchart shown in FIG. 4 described above in the first embodiment. Further, the control device 80 can generate a correction wave by obtaining the correction waveform map described above in the first embodiment by simulation. Alternatively, the correction waveform map can be generated by obtaining the time target lift speed waveform described in the first embodiment or the time target lift acceleration waveform described above in the first embodiment. When the correction waveform is generated by the procedure of the correction waveform generation (step S28), the control device 80 proceeds to the procedure of the next drive waveform generation (step S29).

  The control device 80 of the valve actuation test apparatus 100 performs a procedure for generating a drive wave (step S29). In step S29, the drive waveform generated in step S23 is set as the target lift waveform. The control device 80 adds the correction waveform to the target lift waveform (the drive waveform generated in step S23) to generate a drive waveform.

  The control device 80 drives the valve drive piston with a drive waveform, detects the displacement of the valve drive piston 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 a deviation from the drive waveform, and performs PID control (step S24).

  The control device 80 acquires displacement data of the valve drive piston 12 that is a response waveform (step S25), and calculates a difference (error) from the target valve lift amount. If the calculated difference is not within a target error (for example, within a range of ± 0.1 mm) (No in step S26), the control device 80 checks whether the correction waveform stored in the storage unit 94 or the RAM 92 is stored. The procedure to perform is performed (step S27).

  The control device 80 of the present embodiment acquires displacement data of the valve drive piston 12 that is a response waveform (step S25), calculates a difference (error) from the target valve lift amount, and the calculated difference is a target error (for example, The drive waveform is generated (step S29) using the above-described correction waveform until it falls within the range of ± 0.1 mm. Since the procedure from step S24 to step 29 is repeated until the target error (for example, within a range of ± 0.1 mm) or less is reached, the valve operating test apparatus of the present embodiment generates a drive waveform that responds to achieve the target error. Can be generated. Thereby, it can be set as a highly accurate response.

  When the correction waveform stored in the storage unit 94 or the RAM 92 is not stored (step S27, No), for example, in the procedure of the correction waveform generation (step S28), the control device 80 is configured as described above with reference to FIG. A correction waveform is created according to the flowchart shown in FIG. Here, when the correction wave is repeatedly generated, for example, the control device 80 generates an i-th deviation waveform from the deviation between the time target lift waveform and the i-th time response waveform, and from the deviation waveform and the reverse motion characteristic ( The i + 1) th correction waveform is generated (step S28). Accordingly, the control device 80 generates the (i + 1) th drive waveform from the ith drive waveform and the (i + 1) th correction waveform (step S29).

  If the calculated difference is equal to or smaller than a target error (for example, within a range of ± 0.1 mm) (Yes in step S26), the response amplitude attenuation and the operation delay are compensated, and the compensation is terminated.

  As described above, in the valve operating test apparatus of the present embodiment, it is preferable that the control device obtains actual response data of the drive waveform and further corrects the drive waveform when the target error is not reached. Thereby, it can be set as a highly accurate response.

(Evaluation)
Evaluation was performed using the valve operating test apparatus 100 described in the first embodiment. The internal combustion device (engine) used in the evaluation is a diesel engine, which is a 4 cylinder 16 valve. The rated output of the internal combustion device (engine) is 40.9 kW, and the rated rotational speed is 1800 rpm.

  The specification of the valve driving device 10 of the valve operating test apparatus 100 is that eight sets of one set of valve driving devices for driving the exhaust valve 4a and the air supply valve 4b are integrated, a maximum stroke of 14 mm, a maximum speed of 2.2 m / s, The maximum thrust is 1.1 kN, the outer diameter is 426 mm × 250 mm × 273 mm, and the mass is 75 kg. The valve drive device 10 was assembled in the internal combustion device (engine) described above, and the operation of the valve operating test device was performed according to the flowchart shown in FIG. In the evaluation method, the data of the displacement meter 15 and the data of the measuring device 21 which is a crank angle sensor are acquired by the control device 80. The target lift amount of the valve drive piston 12 and the response lift amount, which is actual response data, were compared with data for 10 cycles. The evaluation results are shown in FIGS. 11-1 and 11-2.

  FIG. 11A is a diagram illustrating a comparison between the target lift and the response lift in the evaluation example. FIG. 11B is a diagram illustrating a deviation between the target lift and the response lift in FIG. As shown in FIG. 11A, when the rotation speed of the internal combustion engine (engine) is 4000 rpm, the target lift amount of the valve drive piston 12 is a peak when the crank angle is taken on the horizontal axis and the lift amount is taken on the vertical axis. It can be seen that the curved line is drawn. When the response lift amount, which is the actual response data, is overlapped with the target lift amount for 10 cycles, they almost coincide with each other. FIG. 11-2 shows the deviation between the target lift amount and the response lift amount, but is within the range of ± 0.2 mm, and it can be seen that the valve operation delay is eliminated.

  In the valve operating test apparatus 100 that has been evaluated, 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 supply valve can be arbitrarily changed. For this reason, for example, when mounted in a test apparatus for an internal combustion engine, it is possible to find a lift pattern that can stabilize the operation of the internal combustion engine even in a load region where combustion becomes unstable and can increase the combustion efficiency. . This contributes to making a high performance camshaft valve drive by feeding back to the design of the camshaft valve drive.

  Further, the valve operating test apparatus according to the present embodiment or the valve operating apparatus for an internal combustion engine is related to waveform accuracy improvement using a compensation wave calculated from the speed of the lift waveform or the acceleration of the lift waveform. In order to compensate for actuator operation delay (response delay) or amplitude shortage, by applying a gain to the speed component of the lift waveform or the acceleration component of the lift waveform according to the rotational speed of the internal combustion engine (engine), and adding it to the input , Can improve the reproduction accuracy.

  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 device. A control device for controlling the internal combustion engine, wherein the control device acquires crank angle and rotation speed data of the internal combustion engine, and attenuates response amplitude and operation delay based on operating characteristics of the valve drive device A valve for an internal combustion engine that stores a correction waveform for correcting the valve, creates a drive waveform by adding the correction waveform to a target lift waveform to drive the valve drive piston, and controls the valve drive device with the drive waveform It can also be applied to devices.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 3 Cylinder block 2 Combustion piston 4a Exhaust valve 4b Supply 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 20, 21 Measuring device 30 Hydraulic unit 41, 42, 43, 44, 45 Correction waveform component 51 Drive waveform generation block 52 First gain correction block 53 Additional point 54 Second gain correction block 55, 57 Additional point 58 PID control Block 80 Control device 100 Valve train test device

Claims (5)

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;
In a valve operating test apparatus for an internal combustion engine having a control device for controlling the valve driving device,
The controller is
Obtaining the crank angle and rotation speed data of the internal combustion engine, storing a correction waveform for correcting response amplitude attenuation and operation delay based on the operation characteristics of the valve drive device,
A valve operating test apparatus for an internal combustion engine, wherein a drive waveform is created by adding the correction waveform to a target lift waveform to drive a valve drive piston, and the valve drive device is controlled by the drive waveform.   2. The valve operating test apparatus for an internal combustion engine according to claim 1, wherein the correction waveform is generated from a speed component of a target lift waveform.   The valve operating test apparatus for an internal combustion engine according to claim 2, wherein the correction waveform is generated from an acceleration component of a target lift waveform.   The said control apparatus memorize | stores the target lift waveform of the said internal combustion engine previously, and produces the said drive waveform by the said correction waveform matched with the said crank angle and the said rotation speed data. The valve operating test system for internal combustion engines.   The said control apparatus drives a valve drive piston with the said drive waveform, acquires real response data, and when it does not reach | attain a target error, the said drive waveform is further correct | amended. The valve operating test system for internal combustion engines.

Images