JP5529622B2 - Engine driving method and apparatus - Google Patents

Description

  The present invention relates to an engine driving method and apparatus, and more particularly to a test apparatus for measuring engine behavior by hydraulically driving an engine piston.

  An engine bench is known as a test device for measuring the behavior of the engine. The engine bench has a transmission shaft connected to the crankshaft of the engine and a dynamometer connected to the transmission shaft. Then, the engine is tested by applying a predetermined load with the dynamometer.

  Such an engine bench requires a transmission system shaft and a dynamometer, which causes problems such as an increase in the size of the apparatus and an increase in cost. There are problems that it is difficult to measure accurately and that the behavior of the combustion chamber itself cannot be measured accurately.

  As a test apparatus for solving these problems, a test apparatus in which a hydraulic actuator is connected instead of the crankshaft can be considered. For example, in the test apparatus of Patent Document 1, a hydraulic actuator is connected to a piston (hereinafter referred to as a combustion chamber piston) disposed on the combustion chamber side of the engine. This hydraulic actuator includes a driving cylinder, a driving piston, a rod connecting them, and two ports provided at both ends of the driving cylinder. Then, by supplying and discharging pressure oil to and from the two ports, the driving piston is moved to drive the combustion chamber piston. According to the test apparatus of Patent Document 1 configured as described above, since the combustion chamber piston is driven by a hydraulic actuator, it is possible to perform tests by setting various phenomena such as temperature conditions and wet conditions independently. it can.

Japanese Patent Laid-Open No. 2001-21454

  By the way, in recent years, simulations by various modeling are performed in the engine development process, and there is a demand to accurately measure and model the behavior in the combustion chamber. For that purpose, it is necessary to perform various measurements while accurately displacing the combustion chamber piston (for example, while accurately displacing the combustion chamber piston).

  However, the test apparatus of Patent Document 1 has a problem that it is difficult to accurately displace the combustion chamber piston. That is, the internal pressure of the combustion chamber increases rapidly at the moment when the air-fuel mixture explodes, so that there is a problem that the driving force is insufficient at that moment and the displacement of the combustion chamber piston shifts from an accurate position. In order to solve this problem, it is necessary to secure a large driving force in accordance with the peak value of the internal pressure, and the pressure receiving surface of the driving piston must be enlarged. However, in this case, there are problems that the drive piston and the drive cylinder are increased in size and that a large amount of oil is required, which is difficult to implement in practice.

  The present invention has been made in view of the above circumstances, and provides an engine driving method and apparatus capable of accurately displacing a piston without increasing the size or requiring a large amount of oil. Objective.

In order to achieve the above object, the invention according to claim 1 is an engine driving method in which a combustion chamber piston forming a combustion chamber of an engine is driven by a hydraulic actuator having a driving cylinder and a driving piston. An engine driving method that performs first hydraulic drive control in which both surfaces of a driving piston are pressure receiving surfaces and second hydraulic drive control in which an end surface of a rod connected to the driving piston is a pressure receiving surface. Thus, a position of the combustion chamber piston is detected, and a second hydraulic drive control is performed according to the detected value .

According to the present invention, in addition to the first hydraulic drive control in which both surfaces of the drive piston are pressure receiving surfaces, the second hydraulic drive control is performed in which the end surface of the rod is the pressure receiving surface. Can be secured. Therefore, the driving force of the combustion chamber piston can be increased without increasing the size of the apparatus or requiring a large amount of oil, and the combustion chamber piston can be accurately displaced. According to the present invention, for example, the second hydraulic drive control can be performed at the ignition timing to increase the driving force. Thus, the driving force can be increased in accordance with the timing at which the internal pressure of the combustion chamber increases, and the combustion chamber piston can be accurately displaced.

  According to a second aspect of the present invention, in the first aspect, the first hydraulic drive control and the second hydraulic drive control are performed independently. According to the present invention, since the first hydraulic drive control and the second hydraulic drive control are performed independently, for example, the first hydraulic drive control is performed in addition to the first hydraulic drive control only for a short time when a large driving force is required. 2 can be performed, and the driving force can be temporarily increased. Note that “perform independently” means that the execution of the second hydraulic drive control can be set regardless of the execution of the first hydraulic drive control.

According to a third aspect of the present invention, in order to achieve the above object, an engine drive device for driving a combustion chamber piston forming a combustion chamber of an engine by a hydraulic actuator, wherein the hydraulic actuator includes: a drive cylinder; A driving piston disposed in the driving cylinder, two piston-side hydraulic chambers provided in the driving cylinder and having the driving piston as a pressure receiving surface, and a rod connected to the driving piston. An end face side hydraulic chamber having the end face of the rod as a pressure receiving surface, a hydraulic circuit for supplying and discharging pressure oil to and from the piston side hydraulic chamber and the end face side hydraulic chamber, and supply and discharge of pressure oil from the hydraulic circuit a control device for controlling the, comprising a position sensor for detecting the position of the piston for said combustion chamber, said controller, in response to the detection value of the position detection sensor, wherein To provide a driving device for an engine and controls the supply and discharge of pressure oil to the surface side hydraulic chamber.

According to the present invention, since the rod side hydraulic chamber is provided in addition to the piston side hydraulic chamber, the end surface of the rod can be used as a pressure receiving surface, and the driving force can be increased. Therefore, the driving force of the combustion chamber piston can be increased without increasing the size of the device or greatly increasing the amount of oil, and the combustion chamber piston can be accurately displaced. According to the present invention, the pressure oil is supplied to and discharged from the end face side hydraulic chamber according to the position of the combustion chamber piston. Supply to the end face side hydraulic chamber to increase the driving force. As a result, the driving force can be increased in accordance with the timing at which the internal pressure of the combustion chamber increases during fuel combustion, and the combustion chamber piston can be driven smoothly.

According to a fourth aspect of the present invention, the control device according to the third aspect is characterized in that the end surface side hydraulic chamber and the piston side hydraulic chamber are independently controlled. According to the present invention, since the end surface side hydraulic chamber and the piston side hydraulic chamber are controlled independently, for example, the driving force is supplied by supplying pressure oil to the end surface side hydraulic chamber only for a short time when a large driving force is required. Can be temporarily increased.

  According to the present invention, since not only the both surfaces of the piston but also the end surface of the rod is used as the pressure receiving surface, the driving force of the combustion chamber piston can be increased without increasing the size of the device or greatly increasing the amount of oil. Can be increased.

1 is a schematic configuration diagram showing an engine drive device according to a first embodiment of the present invention. Explanatory drawing explaining the effect | action of the drive device of the engine in this invention The schematic block diagram which shows the drive device of the engine of 2nd Embodiment in this invention. The schematic block diagram which shows the drive device of the engine of 3rd Embodiment in this invention. The figure which shows schematic structure of the drive device of the conventional engine

  Hereinafter, preferred embodiments of an engine driving method and apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a schematic configuration of a test apparatus 10 to which the driving method of the present invention is applied.

  A test apparatus 10 shown in FIG. 1 is an apparatus that tests a combustion chamber piston 14 by hydraulic pressure, and is mainly disposed in a combustion chamber cylinder 12 having a combustion chamber 12 </ b> A and the combustion chamber cylinder 12. The combustion chamber piston 14 and a hydraulic actuator 20 that drives the combustion chamber piston 14 are configured.

  The combustion chamber 12A is a space surrounded by the inner wall of the combustion chamber cylinder 12 and the combustion chamber piston 14, and includes an intake valve 16, an exhaust valve 18, an ignition device 19, and the like. By controlling the intake valve 16, the exhaust valve 18, and the ignition device 19 at predetermined timing, the fuel-containing gas is supplied from the intake valve 18 to the combustion chamber 12A and burned in the combustion chamber 12A. Is exhausted from the exhaust valve 18. The combustion chamber piston 14 is driven by this combustion.

  The combustion chamber piston 14 is connected to a hydraulic actuator 20, and a driving force is applied by the hydraulic actuator 20. The hydraulic actuator 20 is mainly composed of a driving cylinder 22, a driving piston 24, a rod 26, a hydraulic circuit 30, a control device 44, and a position sensor 46.

  The drive cylinder 22 is formed in a substantially cylindrical shape and is provided inside the combustion chamber cylinder 12. A driving piston 24 is slidably provided inside the driving cylinder 22, and the driving piston 24 divides the inside of the driving cylinder 22 into two hydraulic chambers (hereinafter referred to as piston-side hydraulic chambers 22 </ b> A and 22 </ b> B). It is separated.

  A rod 26 is connected to the driving piston 24, and the driving piston 24 is connected to the combustion chamber piston 14 via the rod 26. Therefore, when the driving piston 24 moves up and down, the combustion chamber piston 14 also moves up and down, and a driving force is applied.

  The rod 26 is attached in a state of penetrating the driving piston 24, and a lower end portion thereof is slidably provided in a small diameter portion inside the driving cylinder 22. Thus, a hydraulic chamber (hereinafter referred to as an end surface side hydraulic chamber 22C) is formed by the end surface 26C of the rod 26 and the inner wall of the driving cylinder 22.

  Ports 28A, 28B, and 28C are provided in each of the hydraulic chambers (piston side hydraulic chambers 22A and 22B and end face side hydraulic chamber 22C), respectively. The port 28A is provided at the upper end position of the piston side hydraulic chamber 22A, the port 28B is provided at the lower end position of the piston side hydraulic chamber 22B, and the port 28C is provided at the lower end position of the end face side hydraulic chamber 22C of the piston 22. It has been.

  The hydraulic circuit 30 is a circuit for supplying pressure oil to these ports 28 </ b> A to 28 </ b> C and discharging pressure oil from the ports 28 </ b> A to 28 </ b> C, and includes a servo valve 32, a switching valve 34, a pump 36, and an accumulator 38. The recovery unit 40 and the pipes 42A to 42G are provided.

  The pipes 42A to 42C are connected to the ports 28A to 28C, respectively. Among these, the piping 42B and the piping 42C are connected to the switching valve 34. The switching valve 34 is connected to the servo valve 32 via the piping 42D and is connected to the recovery unit 40 via the piping 42E. . The switching valve 34 is configured to switch between a first position that communicates the piping 42B and the piping 42D, and a communication between the piping 42C and the piping 42E, and a second position that communicates the piping 42D, the piping 42B, and the piping 42C. The The switching valve 34 is switch-controlled by a control device 44 described later.

  On the other hand, the pipe 42A is connected to the servo valve 32 together with the pipe 42D, and a pipe 42F and a pipe 42G are connected to the servo valve 32. The pipe 42F is connected to the pump 36 and the accumulator 38, and pressure oil is supplied from these. The pipe 42G is connected to the collection unit 40. The servo valve 32 includes a first position that blocks all the pipes 42A, 42D, 42F, and 42G, a second position that communicates the pipe 42A and the pipe 42F, the pipe 42D and the pipe 42G, a pipe 42A, the pipe 42G, and a pipe 42D. It is configured to switch between the third position that communicates the pipe 42F. The servo valve 32 is connected to the control device 44 and is controlled to be switched by the control device 44.

  A position sensor 46 is connected to the control device 44. The position sensor 46 is provided at the bottom of the drive cylinder 22 so that the position of the rod 26 can be detected. For example, a magnetic linear guide is used as the position sensor 46 and is disposed so as to be inserted into the hole 26 </ b> D of the rod 26. The position sensor 46 detects the position of the rod 26, that is, the position of the combustion chamber piston 14. In the present embodiment, the position of the rod 26 is detected, but the position of the combustion chamber piston 14 itself may be detected by, for example, an optical sensor.

  A detection signal of the position sensor 46 is output to the control device 44. The control device 44 controls the servo valve 32 and the switching valve 34 according to the detection value of the position sensor 46. Hereinafter, control examples of the servo valve 32 and the switching valve 34 will be described.

  For example, when the combustion chamber piston 14 reaches bottom dead center, the servo valve 32 is switched to the third position to supply pressure oil to the piston side hydraulic chamber 22B via the pipes 42D and 42B. The pressure oil in the chamber 22A is discharged to the recovery unit 40 through the pipes 42A and 42G. At that time, the switching valve 34 is set to the first position, and the rod-side hydraulic chamber 22C is communicated with the recovery unit 40 via the pipes 42C and 42E to suck up the atmospheric pressure oil from the recovery unit 40. As a result, the drive piston 24 is raised, and the combustion chamber piston 14 is raised.

  When the combustion chamber piston 14 reaches the top dead center, the servo valve 32 is switched to the second position to supply pressure oil to the piston side hydraulic chamber 22A via the pipes 42F and 42A. The pressure oil in the chamber 22B is discharged to the collection unit 40 via the pipes 42B, 42D, and 42G. As a result, the driving piston 24 descends, and the combustion chamber piston 14 descends. By repeating such an operation, the combustion chamber piston 14 can be moved up and down.

  Furthermore, in the present embodiment, when the rising combustion chamber piston 14 reaches a predetermined position (for example, a position where the internal pressure of the combustion chamber 12A rapidly increases), the switching valve 34 is switched to the second position. As a result, the pressure oil in the pipe 42D is supplied not only to the pipe 42B but also to the pipe 42C, and the pressure oil is supplied to the rod-side hydraulic chamber 22C. Therefore, the force that presses the rod 26 can be increased, and the driving force can be temporarily increased. Note that when the movement of the combustion chamber piston 14 is stopped, the servo valve 32 may be switched to the first position.

  Next, the operation of the test apparatus 10 configured as described above will be described using an example of a four-cycle engine. FIG. 2A shows the change over time of the displacement amount of the combustion chamber piston 14 in the engine, and FIG. 2B shows the change over time in the internal pressure of the combustion chamber 12A at the same time.

  In the figure, times α1, α3, and α5 are times when the combustion chamber piston 14 becomes a top dead center, times α2 and α4 are times when a bottom dead center is reached, and time α6 is an ignition timing. Further, α1 to α2 are intake strokes, in which the combustion chamber piston 14 is lowered and the air-fuel mixture is sucked into the combustion chamber 12A. α2 to α3 are compression strokes, in which the combustion chamber piston 14 is raised and the air-fuel mixture is compressed. α3 to α4 are explosion strokes, which are states in which the combustion chamber piston 14 is pushed down by the combustion and expansion of the ignited mixture. α4 to α5 are exhaust strokes, in which the combustion chamber piston 14 rises due to inertia and the combustion gas is pushed out of the combustion chamber cylinder 12. The engine is driven by repeating these intake stroke, compression stroke, explosion stroke, and exhaust stroke.

  As shown in FIG. 2 (b), when ignited at α6, the internal pressure of the combustion chamber 12A increases slightly after igniting (that is, at α7), and the internal pressure rapidly increases, and further, when the flame propagates (that is, The internal pressure reaches a peak (with α8). Thereafter, the internal pressure gradually decreases, and the increase in internal pressure due to combustion disappears at α9.

  Thus, the internal pressure of the combustion chamber 12A increases due to combustion at α7 to α9 immediately after ignition. For this reason, since the conventional test apparatus temporarily lacks the driving force during this period, the combustion chamber piston 14 cannot be accurately displaced in a sine wave form.

  On the other hand, unlike the conventional test apparatus, the test apparatus 10 of the present embodiment includes an end face side hydraulic chamber 22C in addition to the piston side hydraulic chambers 22A and 22B. Therefore, the driving force of the combustion chamber piston 14 can be temporarily increased. Hereinafter, it will be specifically described in comparison with a conventional test apparatus.

  FIG. 5 shows a schematic configuration of a conventional test apparatus 50 as a comparative example. As shown in the figure, the conventional test apparatus 50 is different from the test apparatus 10 shown in FIG. 1 in that there is no hydraulic chamber 22C. That is, only the piston side hydraulic chambers 22A and 22B separated by the driving piston 24 are formed inside the driving cylinder 22 of FIG. The port 28B of the piston-side hydraulic chamber 22B is connected to the servo valve 32 via a pipe 42B.

  In the conventional test apparatus 50 configured as described above, only the upper and lower surfaces of the driving piston 24 act as pressure receiving surfaces, so that the obtained driving force is small. For this reason, during the period in which the internal pressure of the combustion chamber 12A is remarkably increased (α7 to α9 in FIG. 2), the driving force is insufficient, and the movement of the combustion chamber piston 24 is delayed when ascending and is accelerated when descending. Therefore, the conventional test apparatus 50 cannot accurately displace the combustion chamber piston 24 in a sine wave form. As a method for solving this problem, a method of ensuring a large driving force by designing the upper and lower surfaces of the driving piston 24 to be large can be considered. However, in this case, there is a problem that the hydraulic actuator 20 is enlarged or a large amount of pressure oil is required, so that it is difficult to actually implement it.

  On the other hand, the test apparatus 10 of the present embodiment is provided with an end surface side hydraulic chamber 22C in addition to the piston side hydraulic chambers 22A and 22B, and uses the end surface 26C of the rod 26 as a pressure receiving surface. Therefore, during the period in which the internal pressure of the combustion chamber 12A is significantly increased (α7 to α9 in FIG. 2), the pressure oil can be supplied to the end face side hydraulic chamber 22C and the driving force can be temporarily increased. As a result, the temporary shortage of driving force can be eliminated, and the combustion chamber piston 14 can be accurately displaced in a sine wave shape. Moreover, since the end surface side hydraulic chamber 22C utilizes the space behind the end surface 26C of the rod 26, it is possible to prevent the hydraulic actuator 20 from increasing in size.

  Particularly, in the present embodiment, the pressure oil is supplied to the end face side hydraulic chamber 22C according to the position of the combustion chamber piston 14 (specifically, at a position corresponding to α7 to α9 in FIG. 2). Therefore, it is possible to increase the driving force only during the period in which the internal pressure of the combustion chamber 12A increases, and it is possible to prevent unnecessary generation of a large driving force during other periods.

  Further, in the present embodiment, the hydraulic circuit 30 is configured such that the piston-side hydraulic chambers 22A, 22B and the rod-side hydraulic chamber 22C are driven independently, and the control device 46 further includes the piston-side hydraulic chambers 22A, 22B. The first hydraulic drive control for driving the second hydraulic drive control for driving the rod side hydraulic chamber 22C is performed independently. Therefore, the timing for performing the second hydraulic drive control can be freely changed, and various test conditions can be handled. For example, when the ignition timing (α6) is changed, the period α7 to α9 in which the increase in the internal pressure of the combustion chamber 12A is also changed, but according to the present embodiment, the second hydraulic drive control is performed. Since the timing can be changed independently, it can be easily handled.

  In the above-described embodiment, the pressure oil is supplied to the end face side hydraulic chamber 22C only during a period (α7 to α9) in which an increase in internal pressure due to combustion is seen. However, the present invention is not limited to this. The pressure oil may be supplied to the end face side hydraulic chamber 22C at the timing of, for example, α2 to α4 as a whole. Further, time control based on, for example, an ignition timing may be performed regardless of the position of the combustion chamber piston 14.

  In the above-described embodiment, the pressure oil is separately supplied to and discharged from the piston side hydraulic chambers 22A and 22B and the end face side hydraulic chamber 22C. However, the present invention is not limited to this. You may make it discharge | emit.

  In the above-described embodiment, the end face side hydraulic chamber 22C is provided inside the drive cylinder 22. However, the present invention is not limited to this, and a hydraulic chamber may be formed outside the drive cylinder 22.

  Further, the configuration of the hydraulic circuit 30 is not limited to the above-described embodiment, and the pressure oil supply destination and the discharge destination can be switched with respect to the piston side hydraulic chambers 22A and 22B and the end face side hydraulic chamber 22C. It only has to be configured. For example, FIG. 3 is an example provided with a hydraulic circuit 60 having a configuration different from that of the hydraulic circuit 30 of FIG.

  The hydraulic circuit 60 in FIG. 3 is an example in which the circuit of pressure oil is switched by two servo valves 62 and 64, and mainly the servo valve 62, the servo valve 64, the pump 66, the accumulator 68, the recovery unit 70, and the respective pipes 72A to 72G. Is provided.

  The pipes 72A to 72C are connected to the ports 28A to 28C, respectively. Among these, the pipe 72A and the pipe 72B are connected to the servo valve 62, and the pipe 72F and the pipe 72G are connected to the servo valve 62. The pipe 72F is connected to a pump 76 and an accumulator 78, from which pressure oil is supplied. The pipe 72G is connected to the collection unit 70. The servo valve 62 includes a first position that blocks all the pipes 72A, 72B, 72F, and 72G, a second position that communicates the pipe 72A and the pipe 72F, the pipe 72B and the pipe 72G, a pipe 72A, a pipe 72G, and a pipe 72B. It is configured to switch between the third position where the pipe 72F communicates. The servo valve 62 is connected to the control device 74 and is controlled to be switched by the control device 74.

  On the other hand, the pipe 72C is connected to the servo valve 64, and pipes 72D, 72E, 72H are connected to the servo valve 64. The pipe 72D is connected to the pipe 72F, and the pipe 72E is connected to the pipe 72G. Further, the pipe 72H has its tip closed. The servo valve 64 includes a first position that blocks all the pipes 72C, 72D, 72E, and 72H, a second position that communicates the pipe 72C and the pipe 72D, and the pipe 72E and the pipe 72H, a pipe 72C, a pipe 72E, and a pipe 72D. It is configured to switch between the third position where the pipe 72H communicates. The servo valve 64 is connected to the control device 74 and is controlled to be switched by the control device 74.

  The control device 74 is connected to a position sensor 76 for detecting the position of the combustion chamber piston 14. The servo valves 62 and 64 are controlled according to the position of the combustion chamber piston 14 detected by the position sensor 76. Do. Hereinafter, control examples of the servo valves 62 and 64 will be described.

  For example, when the combustion chamber piston 14 reaches bottom dead center, the servo valve 62 is switched to the third position to supply the pressure oil to the piston side hydraulic chamber 22B via the pipes 72F and 72B. The pressure oil in the chamber 22A is discharged to the collection unit 40 through the pipes 72A and 72G. At that time, the servo valve 64 is set to the third position, and the rod-side hydraulic chamber 22C is connected to the recovery unit 70 via the pipes 72C, 72E, 72G, and the atmospheric oil is sucked up from the recovery unit 70. As a result, the drive piston 24 is raised, and the combustion chamber piston 14 is raised.

  When the combustion chamber piston reaches top dead center, the servo valve 62 is switched to the second position, whereby pressure oil is supplied to the piston side hydraulic chamber 22A via the pipes 72F and 72A. The pressure oil of 22B is discharged to the collection unit 70 through the pipes 72B and 72G. As a result, the driving piston 24 descends, and the combustion chamber piston 14 descends. By repeating such an operation, the combustion chamber piston 14 can be moved up and down.

  Furthermore, in the present embodiment, when the rising combustion chamber piston 14 reaches a predetermined position (for example, a position where the internal pressure of the combustion chamber 12A rapidly increases), the servo valve 64 is switched to the second position. Thereby, the pressure oil in the pipe 72F is supplied not only to the servo valve 62 but also to the servo valve 64, and is supplied to the rod side hydraulic chamber 22C via the pipe 72C. Therefore, the force for pressing the rod 26 can be increased, and the driving force can be temporarily increased. In addition, what is necessary is just to switch the servo valves 62 and 64 to a 1st position, when stopping the movement of the piston 14 for combustion chambers.

  According to the second embodiment configured as described above, the supply and discharge of pressure oil to and from the piston-side hydraulic chambers 22A and 22B and the end-face-side hydraulic chamber 22C are controlled by switching the servo valves 62 and 64. It can be controlled independently.

  In the first and second embodiments described above, the rod 26 is configured as one component, but may be configured by a plurality of components. In the first and second embodiments described above, the actuator 20 is directly fixed. However, the present invention is not limited to this, and the actuator 20 may be attached via another member. For example, FIG. 4 is a schematic configuration diagram showing a test apparatus including those configurations.

  The test apparatus of the third embodiment shown in FIG. 4 is different from the test apparatus 10 shown in FIG. 1 in that the rod 26 is composed of a plurality of parts. 4, the rod 26A is connected to the combustion chamber piston 14, the rod 26B is connected to the drive piston 24, and the flange 26C of the rod 26A and the flange 26D of the rod 26B are connected by screws or the like. Are detachably connected. Therefore, according to the present embodiment, the rod 26A, the actuator 20, and the like can be exchanged, and for example, the stroke amount can be easily changed.

  A connecting member 80 is detachably connected to the lower end of the driving cylinder 22, and the connecting member 80 is detachably connected to the combustion chamber cylinder 12. Therefore, the connecting member 80 can be easily replaced. For example, the moving range of the combustion chamber piston 14 can be changed by replacing the connecting member 80 with a connecting member 80 having a different length.

  In the first to third embodiments described above, the position control of the combustion chamber piston 14 (that is, the control for accurately displacing the combustion chamber piston 14) is performed. Load control (that is, control so that the combustion chamber piston 14 has a predetermined load) may be performed. In that case, for example, the load may be measured by attaching a load cell to the rod 26, and the hydraulic actuator may be controlled so that the load becomes a set value.

  In the first to third embodiments described above, the present invention is applied to a device for driving the combustion chamber piston 14. However, the present invention may be applied to a drive device for the intake valve 16 or the exhaust valve 18. .

DESCRIPTION OF SYMBOLS 10 Test apparatus 12 Combustion chamber cylinder 14 Combustion chamber piston 16 Intake valve 18 Exhaust valve 20 Hydraulic actuator 22 Drive cylinder 22A, 22B Piston side hydraulic chamber 22C End surface side hydraulic chamber 24 Drive piston 26 Rod 28A-28C Port 30 Hydraulic circuit 32 Servo valve 34 Switching valve 36 Pump 38 Accumulator 40 Recovery part 42A-42G Piping 44 Controller 46 Position sensor 60 Hydraulic circuit 62 Servo valve 64 Switching valve 66 Pump 68 Accumulator 70 Recovery part 72A-72H Piping 74 Controller 76 Position Sensor

Claims (4)

In a driving method of an engine in which a combustion chamber piston forming a combustion chamber of an engine is driven by a hydraulic actuator having a driving cylinder and a driving piston,
First hydraulic drive control in which both surfaces of the drive piston are pressure receiving surfaces;
A second hydraulic drive control in which an end face of a rod connected to the drive piston is a pressure receiving surface;
An engine driving method for performing
Detecting the position of the combustion chamber piston;
A second hydraulic drive control is performed according to the detected value .   2. The engine driving method according to claim 1, wherein the first hydraulic drive control and the second hydraulic drive control are performed independently. 3. In an engine drive device for driving a combustion chamber piston forming a combustion chamber of an engine by a hydraulic actuator,
The hydraulic actuator is
A driving cylinder;
A driving piston disposed in the driving cylinder;
Two piston-side hydraulic chambers provided in the driving cylinder and having the driving piston as a pressure receiving surface;
A rod connected to the drive piston;
An end face side hydraulic chamber having the end face of the rod as a pressure receiving surface;
A hydraulic circuit for supplying and discharging pressure oil to the piston-side hydraulic chamber and the end surface-side hydraulic chamber;
A control device for controlling supply / discharge of pressure oil in the hydraulic circuit;
A position detection sensor for detecting the position of the combustion chamber piston;
The engine drive device according to claim 1, wherein the control device controls supply / discharge of pressure oil to / from the end face side hydraulic chamber according to a detection value of the position detection sensor . The engine control device according to claim 3 , wherein the control device controls the end face side hydraulic chamber and the piston side hydraulic chamber independently.

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