Abstract:
Measuring equipment is equipped with: a measurement container having formed therein a chamber to be measured, into which a gas to be measured enters, and an inlet passage, through which the gas to be measured is introduced into the chamber to be measured; and a connection structure which, when a plug is not mounted to a plughole that opens into a combustion chamber in an internal combustion engine, connects the inlet passage to the plughole. The measurement container may be provided with a plasma generation device, which generates plasma in the chamber to be measured, or a mounting structure for mounting a heating device, which heats the gas to be measured in the chamber to be measured.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to measuring implement that is used for measurement for analyzing an internal combustion engine. 
       BACKGROUND ART 
       [0002]    There are various measuring implements for analyzing an internal combustion engine. For example, “Flame Structure in In-Cylinder Flow Field Controlled by Opposed Jets”, K. Kuwahara et. al. 11 th  Internal Combustion Symposium (1993) pp. 109-114 (In Japanese) discloses a measuring chamber having interior space that serves as a sub-combustion chamber of the internal combustion engine. The sub-combustion chamber is connected to a main combustion chamber of the internal combustion engine via a connection hole in the side wall of the main combustion chamber. A strong jet stream is introduced into the sub-combustion chamber by movement of a piston and a flow field accompanied by the strong flow is then formed inside the sub-combustion chamber. The flow field of the gas inside the sub-combustion chamber can be measured by visualization techniques. 
         [0003]    However, the conventional measuring implement needs to be installed in the lateral side of the main combustion chamber which has a large spatial limitation among the outside space of the internal combustion engine. Therefore, it was difficult to attach the measuring implement to the internal combustion engine. 
       THE DISCLOSURE OF THE INVENTION 
       [0004]    A measuring implement of the present disclosure comprises a measuring chamber including a measurement room to where a target measurement gas flows in, and an introductory passage that introduces the target measurement gas to the measurement room; and a connection structure that connects the introductory passage to a plughole, where the plughole is opened in a combustion chamber of an internal combustion engine and a plug is not installed in the plughole. 
         [0005]    A measuring method of the present disclosure relates to a measuring method using a measuring chamber including a measurement room to where a target measurement gas flows in, and an introductory passage that introduces the target measurement gas to the measurement room. This method comprises: a preparation step that connects the introductory passage of the measuring chamber to a plughole, where a plug is not installed in the plughole of an internal combustion engine, and connects a combustion chamber of the internal combustion engine and the measurement room via the plughole and the introductory passage; and a measuring step that operates the internal combustion engine after the preparation step and measures the target measurement gas, wherein the target measurement gas is the gas in the combustion chamber which is introduced into the measurement room via the plughole and the introductory passage. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a schematic structure diagram of a measuring implement of a measuring system of an embodiment. 
           [0007]      FIG. 2  is a longitudinal sectional view of a measuring chamber of an embodiment at the spark plug position. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    In the following, a detailed description will be given by an embodiment of the present invention with reference to the accompanying drawings. It should be noted that the following embodiments are merely preferable examples, and do not limit the scope of the present invention, applied field thereof, or application thereof. 
         [0009]    The present embodiment relates to measuring system  10  equipping measuring implement  30  of the present invention. Measuring implement  30  is an example of the present invention. Prior to the discussion of measuring implement  30  and measuring system  10 , internal combustion engine  20  will be explained hereafter.  FIG. 1  is a schematic structure diagram of measuring implement  30  of measuring system  10  when it is viewed from the front side.  FIG. 2  is a longitudinal sectional view of a measuring chamber  31  of measuring implement  30  in the position of spark plug  45 .  FIG. 2  is a longitudinal sectional view of measuring chamber  31  that is sectioned in the vertical direction of measurement room  34 . 
       Internal Combustion Engine 
       [0010]    Internal combustion engine  20  is a reciprocating type internal combustion engine as shown in  FIG. 1 . Internal combustion engine  20  includes cylinder head  21 , cylinder  22 , and piston  23 . Cylinder  22  is formed on a cylinder block (not illustrated). Piston  23  is formed inside cylinder  22  and reciprocates freely. Cylinder head  21 , cylinder  22 , and piston  23  define the combustion chamber  24 . When piston  23  reciprocates in cylinder  22  in the axial direction of cylinder  22 , a reciprocation movement of piston  23  is converted to a rotational movement by a connecting rod (not illustrated). 
         [0011]    Plughole  25  is formed in cylinder head  21  for attaching a spark plug. Inner end of plughole  25  is opened toward combustion chamber  24 . Inlet port  26  and exhaust port  27  that are formed in cylinder head  21  so as to open toward combustion chamber  24 . Intake valve  28  and an injector (not illustrated) are provided in inlet port  26 . In contrast, exhaust valve  29  is formed in exhaust port  27 . 
       Measuring System 
       [0012]    Measuring system  10  equips measuring implement  30  and measuring device  50 . Measuring system  10  is for providing the measuring environment that is close to a condition in combustion chamber  24  of internal combustion engine  20 . 
         [0013]    Measuring implement  30  equips measuring chamber  31  and connection structure  32 . Measuring chamber  31  forms therein a measuring room  34  to where the measurement gas flows inside, and an introductory passage  35  that introduces the measurement gas into measuring room  34 . On the contrary, connection structure  32  has a structure that connects introductory passage  35  to plughole  25  where the spark plug is not attached in internal combustion engine  20 . Measuring implement  30  will be detailed later. 
         [0014]    Measuring device  50  is for measuring a flow field of a gas. Measuring device  50  is a measuring device that uses a PIV (Particle Image Velocimetry) method. The measuring device that is applicable to measuring system  10  shall not be limited to measuring device  50  of the present embodiment. As shown in  FIGS. 1 and 2 , measuring device  50  equips a particle feed unit  51  that supplies a tracer particle, a lighting installation  52  that forms a laser sheet, a capturing device  53  (a high speed camera) that photos measuring room  34 , and an analysis device  54  that analyzes the images captured by capturing device  53 . 
         [0015]    Particle feed unit  51  supplies a tracer particle to the intake air that flows through inlet port  26  of internal combustion engine  20 , for example. Lighting device  52  forms a laser sheet in measuring room  34  of measuring chamber  31 . The photography device  53  photos the flow field of the measuring room  34 . Analysis device  54  executes the analysis of flow field in measuring room  34  based on the image data acquired by the photo of capturing device  53 , and then outputs the analysis result. 
       Measuring Implement 
       [0016]    Measuring implement  30  will be detailed hereafter. 
         [0017]    Measuring chamber  31  is so called an optical chamber, as shown in  FIGS. 1 and 2 . Measuring chamber  31  is constituted by connecting a pair of facing components  41  mutually using a bolt, for example. In measuring chamber  31 , circular measurement windows  39 , e.g. fused quartz are provided respectively for each of the pair of facing components  41 . Measuring room  34 , having a circular section, is formed between measurement windows  39  in measuring chamber  31 . Measuring room  34  is a cylindrical space surrounded by a flat measurement window  39 . As shown in  FIG. 1 , optical introduction window  38  for introducing a laser sheet in measuring room  34  is formed on the side surface of measuring chamber  31 . The geometries of measuring room  34  and measurement window  39  are not limited to the geometries of the present embodiment. 
         [0018]    Tubular component  42 , whose inner space is introductory passage  35 , is provided between a pair of facing components  41  in measuring chamber  31 . In this embodiment, two tubular components  42  are formed in measuring chamber  31 . However, the numbers of tubular components  42  can be one, or can be three or more. 
         [0019]    Each tubular component  42  is a straight piping. One end of each tubular component  42  opens toward measuring room  34  and the other end connect to a connection passage of connection structure  32 . As shown in  FIG. 1 , each tubular component  42  is prolonged downward from measuring room  34 , and is projected from the bottom surface of measuring chamber  31 . The extension direction of each tubular component  42  coincides substantially in the tangential direction of the inner circumference wall of measuring room  34  at the upper edge position of tubular component  42 . Two tubular components  42  are provided symmetrically against the center of measuring room  34 . 
         [0020]    In measuring room  34 , a countering jet stream is formed by measurement gas emitted from two tubular components  42 . The measurement gas that flowed from each tubular component  42  flows inside along the inner circumference wall of measuring room  34 . The measurement gas that flowed from each tubular component  42  then collides in the upper part of measuring room  34 . 
         [0021]    In this embodiment, the cross-sectional channel size of introductory passage  35  is constant along the longitudinal direction of tubular component  42  for each tubular component  42 . The cross-sectional channel size of introductory passage  35  is same for two tubular components  42 . This allows a formation of a flow field ruled by a pair of strong vortex as a flow field that is similar to the flow field of tumble collapse process. 
         [0022]    The cross-sectional channel size of introductory passage  35  can be designed differently between two tubular components  42 . The flow field ruled by one strong vortex such as right revolution or left revolution can be formed in measuring room  34 , as a flow field similar to a swirl, by setting appropriately the cross-sectional channel size of each introductory passage  35 . 
         [0023]    Spark plug  45 , which is a plasma generating device, is attached to measuring chamber  31  as shown in  FIGS. 1 and 2 . Chamber side plughole  46  is formed in measuring chamber  31  as an attachment structure for attaching spark plug  45 . Chamber side plughole  46  is formed in the upper part of measuring chamber  31 . The tip part of spark plug  45  is exposed above measuring room  34  in measuring chamber  31 . 
         [0024]    Connection structure  32  will be discussed hereafter. Connection structure  32  includes two connecting pipes  47 , which are connection components for plughole  25  side, and pillar component  48  which is a connection component for measuring chamber  31  side. The numbers of the connection components shall not be limited to those in this embodiment. Connection structure  32  can be a single connection component that has a connection passage formed therein. 
         [0025]    As shown in  FIG. 1 , two connecting pipes  47  are connected directly to the outer end (upper end in  FIG. 1 ) of plughole  25 . Two connecting pipes  47  are connected to plughole  25  using a seal component or a welding so that the gas came from combustion chamber  24  does not leak at the jointing section with plughole  25 . Two connecting pipes  47  spread upper ward and stretches near the upper surface of cylinder head  21 . The interior space of each connecting pipe  47  becomes a part of connection passage that connects plughole  25  and introductory passage  35 . 
         [0026]    Pillar component  48  is a pillar-shaped component that has two penetration holes  44  corresponding to two connecting pipes  47 . Each penetration holes  44  becomes a part of the connection passage. Pillar component  48  is attached to the upper surface of cylinder head  21  so that each penetration holes  44  is connected directly to each connecting pipe  47 . Each penetration holes  44  is connected directly to each tubular component  42  of measuring chamber  31 . Instead of designing the cross-sectional channel size of introductory passage  35  differently for forming a flow field similar to a swirl flow, the cross-sectional channel size of each penetration holes  44  can be made different between the two tubular components  42 . Multiple flow fields such as left revolution and right revolution can be formed easily by preparing multiple species of pillar components  48  without changing a design of the body of measuring implement  30 . 
         [0027]    In this embodiment, a plate-like pedestal  49  is provided on the upper surface of cylinder head  21  for installing measuring chamber  31  as shown in  FIG. 1 . Penetration hole  37  that accommodates pillar component  48  is formed in pedestal  49 . Seal components  40 , e.g. O-ring, seals respectively the upper end and lower end of penetration hole  37  in pedestals  49 . The undersurface of pedestal  49  has a geometry corresponding to the upper surface of cylinder head  21 . The upper surface of pedestal  49  is a flat surface. Measuring chamber  31  is fixed on the upper surface of pedestal  49 . 
       Measuring Method 
       [0028]    A measuring method using measuring system  10  will be discussed. The measuring method comprises a preparation step and a measuring step. 
         [0029]    In the preparation step, two connecting pipes  47  are connected directly to plughole  25 , where the spark plug is not attached, in internal combustion engine  20 . Pillar component  48  is then attached to the upper surface of cylinder head  21  so that each penetration hole  44  of pillar component  48  is connected to each connecting pipe  47 . Pedestal  49 , to which seal component  40  is attached, is then installed on the upper surface of cylinder head  21  so as to surround pillar component  48 . Thereafter, measuring chamber  31  is fixed to the upper surface of pedestal  49  so that each tubular component  42  is connected to each penetration hole  44  of pillar component  48 . Through these operations, measuring chamber  31  is attached to internal combustion engine  20 . 
         [0030]    In the preparation step, an installation of measuring device  50  is performed in addition to the operations mentioned above. Specifically, operations such as (i) connecting particle feed unit  51  to inlet port  26  of internal combustion engine  20 ; (ii) installing lighting device  52  so as to form a laser sheet in measuring room  34 ; or (iii) installing capturing device  53  for capturing measuring room  34  through measurement window  39  are executed. When the installation of the measuring device  50  is completed, the settings in measuring devices  50  such as an irradiation timing of laser of lighting device and a capturing timing of capturing device  53 . 
         [0031]    First, the measuring step for measuring a flow field of the gas in the measuring room  34  will be discussed. 
         [0032]    At this measuring step, the operation internal combustion engine  20 , i.e. motoring operation is activated and a tracer particle is then supplied from particle feed unit  51  to intake air flowing inlet port  26  in the intake stroke of internal combustion engine  20 . The tracer particle flows into combustion chamber  24  together with the intake air. Then, in the compression stroke, the tracer particle flows into measuring room  34  via plughole  25 ; connecting pipes  47 ; and penetration holes  44  and tubular component  42  of pillar component  48 ; together with the gas in combustion chamber  24  compressed by piston  23 . The pressure of measuring room  34  becomes almost equal to the pressure of combustion chamber  24 , and the pressure changes synchronously with the pressure of combustion chamber  24 . Under this pressure condition, the flow field of gas is formed inside measuring room  34  by the target measurement gas that has flowed into measuring room  34  from two tubular components  42 . 
         [0033]    Lighting device  52  forms a laser sheet on measuring room  34  by irradiating a laser for a predetermined timing, for example, around the TDC (Top Dead Centre), e.g. from 10 deg before TDC to 10 deg after TDC. Capturing device  53  captures measuring room  34  synchronously with the irradiation timing of the laser of lighting device  52 . Capturing device  53  photos a dispersion light from the tracer particle on the laser sheet. 
         [0034]    Multiple image data outputted from capturing device  53  are stored in a memory of analysis device  54 . Analysis device  54  divides each of the multiple image data stored in the memory to multiple inspection domains, and then calculates a local displacement vector of a tracer particle image statistically from a tracer particle image on each inspection domain of the image data at consecutive two capturing timings. The gas flow rate at the corresponding position is calculated from the local displacement vector. The partial flow velocity in each lattice point of measuring room  34  can be thus calculated using the PIV method. 
         [0035]    The measuring step for measuring the flame propagation condition in measuring room  34  will be discussed. 
         [0036]    At this measuring step, fuel is injected from the injector of internal combustion engine  20  in the intake stroke of internal combustion engine  20 . Air-fuel mixture flows into combustion chamber  24 . Air-fuel mixture of combustion chamber  24  compressed by piston  23  flows into measuring room  34  via plughole  25 , connecting pipes  47 , penetration holes  44  of pillar component  48 , and tubular component  42  during the compression stroke. A high-voltage pulse is supplied to spark plug  45  at the TDC timing of internal combustion engine  20 , and the target measurement gas is then ignited by spark plug  45 . The flame that is ignited near spark plug  45  expands in measuring room  34 . Capturing device  53  photos a propagation condition of the flame in a predetermined interval. Analysis device  54  analyzes the propagation condition of the flame based on multiple image data outputted from capturing device  53 , and then outputs the analysis result. 
       ADVANTAGE OF THE EMBODIMENT 
       [0037]    This embodiment allows an installation of measuring chamber  31  above the internal combustion engine  20  and in the outside space of internal combustion engine  20  where a spatial limitation is small. Therefore, measuring chamber  31  can be attached conveniently to internal combustion engine  20 . 
         [0038]    Capturing device  53  can be installed conveniently in the position where spatial restriction is small because measuring chamber  31  equipped with measurement window  39  can be formed above internal combustion engine  20 . 
         [0039]    Further, the condition in combustion chamber of internal combustion engine  20  can be reproduced realistically because measuring chamber  31  is installed above internal combustion engine  20  in this embodiment and the communication between combustion chamber  24 , which is the main combustion chamber, and measuring room  34  is not intercepted even when the piston reaches TDC. 
       OTHER EMBODIMENT 
       [0040]    The following embodiments can be contemplated further. 
         [0041]    The measuring device can be a device using LDV (Laser Doppler Velocity meter) in the above embodiment. 
         [0042]    The internal combustion engine can be a diesel engine that has a plughole for attaching a glow plug formed therein in the above embodiment. In this case, the connection structure of the measuring implement connects an introductory passage to the plughole where the glow plug is not attached in the internal combustion engine. The glow plug, i.e. heating device, can be attached to the measuring chamber. 
         [0043]    A plasma generating device for generating non-equilibrium plasma can be attached to the measuring chamber. The plasma generating device is, for example, a device that enlarges small plasma generated by a spark plug using microwave energy, and an antenna for radiating microwave is attached to the measuring chamber. A connection structure can be attached to the measuring chamber in the above embodiment, and the entrance of the introductory passage of the measuring chamber can be connected directly to the plughole. 
         [0044]    The measuring implement can have an adjustment component that adjusts a dead volume considering that the dead volume is increased when the measuring room is connected to the combustion chamber via the introductory passage in the above embodiment. The adjustment component is fixed to a piston head, for example. 
         [0045]    In the above embodiment, at least one of the multiple introductory passages can have a narrowing portion that narrows partially the cross-sectional channel size is. 
       INDUSTRIAL APPLICABILITY 
       [0046]    The present disclosure is applicable for measuring implements which are used for measurement for analyzing an internal combustion engine, for example.