JP3894736B2 - Diesel engine vortex chamber combustion chamber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a vortex chamber combustion chamber of a diesel engine.
[0002]
[Prerequisite configuration]
  The vortex chamber combustion chamber of the diesel engine of the present invention is intended for the one having the following premise configuration as shown in FIGS. 1 and 2 (present invention) or FIGS. 11 to 12 (prior art), for example. .
[0003]
  FIG. 1A shows Embodiment 1 of the present invention.To explainFIG. 1B is a plan view of a piston in FIG. 1A, and FIG. 1C is a cross-sectional view taken along line CC in FIG. 1B. Figure. 2 (A) and 2 (B) are perspective views of the upper surface portion of the piston in FIG.
[0004]
  11A is a vertical side view of a vortex chamber type combustion chamber of a water-cooled vertical diesel engine showing the prior art 1, and FIG. 11B is a plan view of a piston in FIG. 11A. 12 is a perspective view of the upper surface portion of the piston in FIG.
[0005]
    [Prerequisite configuration]
  The vortex chamber (2) communicates with the main chamber (1) of the vortex chamber combustion chamber of the diesel engine via the nozzle hole (3), and the nozzle hole (3) is in front of the rear portion of the upper surface of the main chamber (1). Open in a downward sloping direction.
  On the piston upper surface (4) forming the lower surface of the main chamber (1), a pair of left and right disk-shaped concave chambers (5), (5), a front concave chamber (25), and a combustion gas flow diffusion guide groove (6) A diversion guide body (7) is provided.
[0006]
  The pair of left and right disk-shaped concave chambers (5) and (5) are arranged apart from each other in the left-right direction within an intermediate region in the front-rear direction of the piston upper surface (4). The front concave chamber (25) is disposed in the front central region of the piston upper surface (4).
  The combustion gas flow diffusion guide groove (6) is formed from the rear region in the front-rear direction to the intermediate region in the intermediate region in the left-right direction of the piston upper surface (4), and the groove of the diffusion guide groove (6). The bottom surface (8) is formed so as to be inclined forward, and the left and right groove side edges (9) and (9) of the diffusion guide groove (6) are formed so as to expand forward.
[0007]
  The injection hole (3) faces the groove start end (10) at the rear end of the diffusion guide groove (6), and the front end of the diffusion guide groove (6) near the end of the groove (11) is each disk-shaped concave chamber. (5) The piston is communicated with the concave portion on the piston center side in (5).
  The diversion guide body (7) is configured to protrude from the groove bottom surface (8) in the intermediate region of the groove width in the diffusion guide groove (6).
  The disk-shaped concave chambers (5) and (5) serve to promote combustion and may be formed exclusively for this combustion promotion, but may also serve as valve recesses for the intake and exhaust valves.
[0008]
    [Effects of prerequisite configuration]
  Near the compression top dead center of the piston (43), the combustion gas flow that has started to combust and expand in the vortex chamber (2) flows from the nozzle hole (3) to the combustion gas flow diffusion guide groove (6) in the main chamber (1). ) Is blown into the groove start end portion (10), and advances forward vigorously while expanding left and right in the diffusion guide groove (6).
[0009]
  The combustion gas flow flowing in the diffusion guide groove (6) rides on the momentum of the forward flow, and from the diffusion guide groove (6) and the left and right disk-shaped concave chambers (5) (5), the piston upper surface (4 ) On the front upper surface portion of the main chamber (1), and flows from the front partial region of the main chamber (1) to the left and right partial regions thereof in a large amount.
[0010]
  However, the combustion gas flow reverses from the left and right side partial areas of the main chamber (1) and tries to flow into the rear partial area of the main chamber (1). It is difficult to flow in a sufficiently large amount of time, resulting in a shortage, and the air utilization rate in the main room (1) tends to decrease.
[0011]
[Prior art]
  As the prior art to be compared with the present invention, there is the following one previously proposed by the present applicant.
  ○ Prior art See FIG. 11 and FIG. (FIG. 1 of JP-A-5-195783 and explanatory text in the specification).
[0012]
  11A is a vertical side view of a vortex chamber type combustion chamber of a water-cooled vertical diesel engine showing the prior art 1, and FIG. 11B is a plan view of a piston in FIG. 11A. 12 is a perspective view of the upper surface portion of the piston in FIG.
  This prior art 1 is obtained by adding the following configuration to the above premise configuration.
[0013]
  The groove end edge (12) of the combustion gas flow diffusion guide groove (6) is positioned to overhang forward from the respective disk-shaped concave chambers (5) and (5).
  The left and right guide body side surfaces (13) and (13) of the diversion guide body (7) extend to the groove end edge (12) in the diffusion guide groove (6).
  The upper surface (16) of the guide body (7) is a gently inclined surface that rises forward. The starting end face (15) of the diversion guide body (7) rises vertically.
[0014]
  ○ Prior art 2. See FIG. 13 and FIG. (FIG. 4 of Unexamined-Japanese-Patent No. 5-195783 and explanatory text in the specification).
  13A is a vertical side view of a vortex chamber type combustion chamber of a water-cooled vertical diesel engine showing the prior art 2, and FIG. 13B is a plan view of a piston in FIG. 13A. FIG. 14 is a perspective view of the upper surface portion of the piston in FIG.
  This prior art 2 is obtained by changing a part of the premise configuration as follows.
[0015]
  Instead of the combustion gas flow diffusion guide groove (6) having the above-mentioned premise, a straight guide groove (91) is formed. Instead of the diversion guide body (7), a semicircular disk body (92) is formed. The linear guide groove (91), the semicircular disk body (92), and the pair of left and right disk-shaped concave chambers (5) and (5) form a cloverleaf combustion chamber.
  The upper surface (93) of the semicircular disk body (92) is a gently inclined surface that rises forward. The circumferential surface of the semicircular disk body (92) rises vertically.
[0016]
[Problems to be solved by the invention]
  The above prior art has the following problems.
  ○ Prior art See FIG. 11 and FIG.
  [ I. The combustion gas flow is difficult to flow in a sufficiently large amount from the front partial area and the left and right side partial areas of the main chamber (1) to the entire area of the rear partial area. The air utilization rate of ]
[0017]
  Near the compression top dead center of the piston (43), the combustion gas flow that has started to combust and expand in the vortex chamber (2) flows from the nozzle hole (3) to the combustion gas flow diffusion guide groove (6) in the main chamber (1). ) Is blown into the groove start end portion (10), and advances forward vigorously while expanding left and right in the diffusion guide groove (6).
[0018]
  The combustion gas flow flowing in the diffusion guide groove (6) rides on the momentum of the forward flow, and from the diffusion guide groove (6) and the left and right disk-shaped concave chambers (5) (5), the piston upper surface (4 ) On the front upper surface portion of the main chamber (1), and flows from the front partial region of the main chamber (1) to the left and right partial regions thereof in a large amount.
[0019]
  However, the combustion gas flow reverses from the left and right side partial areas of the main chamber (1) and tries to flow into the rear partial area of the main chamber (1). It becomes difficult to flow in a sufficiently large amount of time quickly, resulting in a shortage, and the air utilization rate in the main room (1) decreases.
  For this reason, it is not possible to sufficiently contribute to reducing unburned harmful components such as HC and CO in the exhaust gas I, improving the output of the II engine, and reducing the fuel consumption III.
[0020]
  [B. It is difficult to increase the combustion speed and contribute to the high-speed rotation of the engine by the amount that the remaining portion of the combustion gas flow does not flow quickly enough to the entire rear partial region of the main chamber (1). ]
[0021]
  As described in the above problem [A], the combustion gas flow is difficult to flow in a sufficiently large amount from the front partial region and the left and right partial regions of the main chamber (1) to the entire rear partial region. The combustion speed cannot be increased by the shortage and it is difficult to contribute to the high speed rotation of the engine.
[0022]
  ○ Prior art 2. See FIG. 13 and FIG.
  [ I. Air flow rate in the main chamber (1) is not sufficient because the combustion gas flow is difficult to flow quickly enough from the left and right side partial areas of the main chamber (1) to the entire rear partial area. Decreases. ]
[0023]
  Near the compression top dead center of the piston (43), the combustion gas flow that has started to combust and expand in the vortex chamber (2) passes from the nozzle hole (3) into the straight guide groove (91) of the main chamber (1). It goes straight and collides with the peripheral surface of the semi-disc body (92). Part of this combustion gas flow passes over the semi-disc body (92) and flows into the front partial region of the main chamber (1), and the remainder is divided into left and right disk-shaped concave chambers (5) (5 Turn in).
  However, it is difficult for the remaining part of the combustion gas flow to flow in a sufficiently large amount from the inside of each disk-shaped concave chamber (5) (5) to the entire rear partial region of the main chamber (1). The partial area becomes deficient, and the air utilization rate in the main room (1) decreases.
[0024]
  [B. It is difficult to increase the combustion speed and contribute to the high-speed rotation of the engine by the amount that the remaining portion of the combustion gas flow does not flow quickly enough to the entire rear partial region of the main chamber (1). ]
[0025]
  As described in the above problem [I], the remaining portion of the combustion gas flow is sufficiently large from the inside of each disk-shaped concave chamber (5) (5) to the entire rear partial region of the main chamber (1). Therefore, the combustion speed cannot be increased by an amount that is insufficient in the rear partial region, and it is difficult to contribute to the high-speed rotation of the engine.
[0026]
  An object of the present invention is to do as follows.
  (I). The left and right guidesSlopeWith this guiding action, the amount of combustion gas flowing in the diffusion guide groove is increased to a sufficiently large amount so as to flow into the entire rear partial region of the main chamber, thereby improving the air utilization rate in the main chamber.
  (B). By making the combustion gas flow quickly and sufficiently flow into the entire rear partial region of the main chamber, the combustion speed is increased and the engine is rotated at a high speed.
[0027]
  (C). The combustion gas flow is maintained at a high speed without receiving a large flow resistance, and is accelerated while being squeezed from a wide guide slope toward a narrow inner circumferential surface of a disk-shaped concave chamber. The time for flowing into the entire rear partial region is shortened, the mixing performance of air and fuel is improved, and the combustion performance is improved.
  (D). The above problem (ii) is achieved by allowing the combustion gas flow to spread over a sufficient amount quickly in a short period of time over the entire partial area of the front partial area, the left and right partial areas, and the rear partial area of the main chamber.・ Further increase the degree of achievement of (b) and (c).
[0028]
[Means for Solving the Problems]
  The vortex chamber type combustion chamber of the diesel engine according to the present invention is to solve the above-mentioned problems in the above premise configuration.In addition,The following feature configuration is added.
[0029]
[0030]
[0031]
[0032]
[0033]
  ○ Invention 1.See FIG. 1, FIG. 2 and FIG..
  The groove end edge (12) of the combustion gas flow diffusion guide groove (6) is located in each of the disk-shaped concave chambers (5) and (5).
[0034]
  On the surface of the diversion guide body (7), a pair of left and right guide slopes (19) and (19) are formed which become higher from the left and right sides to the center. Each of the pair of left and right guide slopes (19), (19) is an inner peripheral surface near the center of the piston among the respective inner peripheral surfaces (14), (14) of the respective disc-shaped concave chambers (5), (5). Make the parts smooth and continuous.
[0035]
  A stepped surface (26) is formed on the upper surface of the front central region of the diversion guide body (7) so as to be positioned lower than the piston upper surface (4). The step-down surface (26) is connected to the upper part of the left and right guide slopes (19), (19), and the front end (28) of the step-down surface (26) is lower than the piston upper surface (4). At least the upper peripheral surface portion of the indoor peripheral surface (29) of the concave chamber (25) is cut away so as to face the front concave chamber (25).
  As a result, the combustion gas flow introduction space (30) for allowing a part of the combustion gas flow flowing forward in the combustion gas flow diffusion guide groove (6) to flow into the front concave chamber (25) is reduced in the stepped surface (26). Form in the upper position.
  As illustrated in FIGS. 1 and 2,Forming the start end face (15) of the diversion guide body (7) into an upwardly inclined surfaceTo do.
[0036]
  As illustrated in FIG.The bottom surface (8) of the combustion gas flow diffusion guide groove (6) is formed in a slanted downward slope that becomes deeper from the left and right sides in the groove width direction toward the diversion guide body (7).
[0037]
【The invention's effect】
  The vortex chamber combustion chamber of the diesel engine of the present invention has the following effects.
  ○ Invention 1. Claim 1.See FIG. 1, FIG. 2 and FIG..
[0038]
  [ I. Due to the guiding action of the pair of left and right guide slopes (19), (19) on the surface of the diversion guide body (7), the remaining portion of the combustion gas flow flowing in the diffusion guide groove (6) is the rear partial region of the main chamber (1). The air utilization rate in the main room (1) is improved by the amount that the amount flowing into the entire area of the room can be increased sufficiently. ]
[0039]
  First, from the premise configuration, the combustion gas flow that has started to burn and expand in the vortex chamber (2) near the compression top dead center of the piston (43) is combusted from the nozzle hole (3) to the main chamber (1). It blows into the groove start end (10) of the gas flow diffusion guide groove (6), and moves forward vigorously while expanding in the diffusion guide groove (6) from side to side.
[0040]
  Part of the combustion gas flow flowing in the diffusion guide groove (6) rides on the momentum of the forward flow from the diffusion guide groove (6) and the left and right disk-shaped concave chambers (5) and (5) to the piston. It rides on the front upper surface portion of the upper surface (4) and flows in a large amount vigorously from the front partial region of the main chamber (1) to the left and right partial regions.
[0041]
  As a characteristic configuration of the first aspect of the present invention, the groove end edge (12) of the combustion gas flow diffusion guide groove (6) is positioned in each of the disk-shaped concave chambers (5) and (5).
  On the surface of the diversion guide body (7), a pair of left and right guide slopes (19) and (19) are formed which become higher from the left and right sides to the center. Each of the pair of left and right guide slopes (19), (19) is an inner peripheral surface near the center of the piston among the respective inner peripheral surfaces (14), (14) of the respective disc-shaped concave chambers (5), (5). Consists of smooth and continuous parts.
[0042]
  Due to this characteristic configuration, the remaining part of the combustion gas flow flowing in the diffusion guide groove (6) is a pair of left and right guide slopes (19) and (19) on the surface of the diversion guide body (7), and the left and right disc-shaped recesses. Both circles are smoothly guided along the inner peripheral surfaces (14) and (14) of the chambers (5) and (5), and vigorously U-turned in the respective disk-shaped concave chambers (5) and (5). Rides from the plate-like concave chambers (5) and (5) onto the rear upper surface portion of the piston upper surface (4) and (4), from the left and right side partial regions of the main chamber (1) to the entire rear partial region. , Flow in a large amount quickly and vigorously.
[0043]
  Thus, according to the present invention, the amount of the remaining portion of the combustion gas flow flowing in the diffusion guide groove (6) flowing into the entire rear partial region of the main chamber (1) is insufficient in the prior art. Then, the air utilization rate in the main chamber (1) is improved by the amount that can be increased sufficiently, reducing unburned harmful components such as HC and CO in the I exhaust gas, and the II engine It can contribute to improving output and reducing III fuel consumption.
[0044]
  [B. Combustion speed will be increased by the amount that the remaining part of the combustion gas flow has flowed into the entire rear part region of the main chamber (1) in a sufficiently large amount, contributing to high speed engine rotation. Can do. ]
[0045]
  As described in the above effect [A], the remaining part of the combustion gas flow flowing in the diffusion guide groove (6) is a pair of left and right guide slopes (19) and (19) on the surface of the diversion guide body (7). Are smoothly guided along the inner peripheral surfaces (14) and (14) of the disk-shaped concave chambers (5) and (5), and the U-turns are vigorously moved in the disk-shaped concave chambers (5) and (5). Then, it rides on the rear upper surface part of the piston upper surfaces (4) and (4) from both disk-shaped concave chambers (5) and (5), and from the left and right side partial regions of the main chamber (1) to the rear side. It flows into a large amount of the partial area quickly and sufficiently.
[0046]
  Thus, the combustion speed is increased and the engine is rotated at a high speed by the amount that the remaining portion of the combustion gas flow quickly and sufficiently flows into the entire rear partial region of the main chamber (1). Can contribute.
[0047]
  [C. The combustion gas flow is smoothly divided into left and right along both guide slopes (19, 19), and is maintained at a high speed without receiving a large flow resistance, and a wide guide slope (19) ( 19) from the disk-shaped concave chambers (5) and (5) toward the narrow inner peripheral surfaces (14) and (14) of the rear partial region of the main chamber (1) by the amount of acceleration while being throttled. The time for flowing into the entire area is shortened, the mixing performance of air and fuel is enhanced, and the combustion performance is enhanced. ]
[0048]
  The combustion gas flow that has started to burn and expand in the vortex chamber (2) is blown from the nozzle hole (3) into the groove start end (10) of the combustion gas flow diffusion guide groove (6) of the main chamber (1), and is divided. Since the surface of the guide body (7) is a pair of left and right guide slopes (19) and (19) when colliding with the guide body (7), both guide slopes (19) and (19) The flow is divided into left and right smoothly and no large flow resistance is generated, and the flow velocity is hardly lowered and is kept at a high velocity.
[0049]
  The combustion gas flow maintained at this high speed flows from the wide guide slopes (19), (19) toward the inner peripheral surfaces (14), (14) from the narrow disk-shaped concave chambers (5), (5). The amount of U-turn that is caused to make a U-turn in each disc-shaped concave chamber (5) (5) is accelerated by the amount of acceleration while gradually squeezing, and the left and right sides of the main chamber (1) Since the time required to flow in a large amount vigorously and quickly from the region to the entire rear partial region is shortened, the mixing speed of air and fuel is increased, so that the mixing performance is improved and the combustion performance is improved.
[0050]
  As a result, to reduce unburned harmful components such as HC and CO in I exhaust gas, to improve the output of II engine, to reduce III fuel consumption, and to make IV engine rotate at high speed, Can contribute.
[0051]
  [D. The above effect is achieved by allowing the combustion gas flow to spread over a large amount quickly in a short period of time over the entire area of the front partial area, the left and right partial areas, and the rear partial area of the main chamber (1). [I. Contributing to improvement of air utilization rate], effects [b. Contributing to high-speed engine rotation] and effects [c. [Improving combustion performance] is further improved. ]
[0052]
  The step-down surface (26) is positioned lower than the piston upper surface (4) on the upper surface of the front central region of the diversion guide body (7), and the formation speed is increased. The stepped surface (26) is continued to the upper part of the left and right guide slopes (19), (19). The front end portion (28) of the stepped surface (26) is lower than the piston upper surface (4), and at least the upper peripheral surface portion of the inner peripheral surface (29) of the front concave chamber (25) is cut away. It faces the concave chamber (25). As a result, the combustion gas flow introduction space (30) for allowing a part of the combustion gas flow flowing forward in the combustion gas flow diffusion guide groove (6) to flow into the front concave chamber (25) is reduced in the stepped surface (26). Form in the upper position.
[0053]
  From this configuration, first, a part of the combustion gas flow that has flowed from the vortex chamber (2) into the combustion gas flow diffusion guide groove (6) of the main chamber (1) is left and right of the branch guide body (7). Through the upper space of the guide slopes (19) and (19) and the combustion gas flow introduction space (30) on the stepped surface (26) into the front concave chamber (25) and the front of the cylinder (41) Guided by the inner peripheral surface of the door, it spreads to the left and right sides and makes a U-turn. For this reason, a part of the combustion gas flow spreads in a sufficiently large amount quickly in a short time over the entire region from the front side partial region to the left and right side partial regions of the main chamber (1).
[0054]
  Next, as described in the above effect [A], the remaining portion of the combustion gas flow flowing in the diffusion guide groove (6) is a pair of left and right guide slopes (19) and (19) on the surface of the diversion guide body (7). Then, it is guided smoothly along the inner peripheral surfaces (14), (14) of the left and right disc-shaped concave chambers (5), (5), and momentum is generated in the disc-shaped concave chambers (5), (5). It is made to make a U-turn and rides on the rear upper surface part of the piston upper surfaces (4) and (4) from both disk-shaped concave chambers (5) and (5). From there to the entire rear partial area, it flows quickly and sufficiently in a large amount.
[0055]
  In this way, the combustion gas flow can be quickly and sufficiently distributed over a short period of time in all areas of the front partial area, the left and right side partial areas, and the rear partial area of the main chamber (1). Can do. As a result, the above-mentioned effect [I. Contributing to improvement of air utilization rate], effects [b. Contributing to high-speed engine rotation] and effects [c. The combustion performance can be further improved.
[0056]
  [F. The combustion gas flow is guided to be diverted to the left and right while easily climbing on the front rising surface of the start end face (15) of the diversion guide body (7), and smoothly flows into the diffusion guide groove (6). By eliminating the decrease in the flow velocity, the above effects [i. Contributing to improvement of air utilization rate], effects [b. Contributing to high-speed engine rotation], effects [c. Enhancing combustion performance] and effects [d. The combustion gas flow can be quickly and sufficiently distributed over all the region of the main chamber within a short period of time]. ]
[0057]
  The starting end face (15) of the flow dividing guide body (7) was formed as an upwardly inclined surface.
  From this configuration, the combustion gas flow that has started to combust and expand in the vortex chamber (2) blows into the groove start end (10) of the diffusion guide groove (6) from the nozzle hole (3), and the flow dividing guide body. When it collides with the start end surface (15) of (7), it is shunted to the left and right while being easily climbed on the inclined surface that rises forward of the start end surface (15), so that it is in the diffusion guide groove (6). It flows in smoothly.
[0058]
  For this reason, the combustion gas flow is rebounded from the start end face (15) of the diversion guide body (7) and reversed or reversely flowed so that the flow resistance does not increase, so that the combustion gas flow is within the diffusion guide groove (6). The flow velocity flowing through the flow is not reduced, and the flow velocity is increased.
  As a result, the effect of the invention 1 [i. Contributing to improvement of air utilization rate], effects [b. Contributing to high-speed engine rotation], effects [c. Enhancing combustion performance] and effects [d. It is possible to further improve the distribution of the combustion gas flow over the entire region of the main chamber in a sufficiently short amount of time.
[0059]
[H. The flow of combustion gas flowing in the diffusion guide groove (6)Guide slope (19) (19)The above-mentioned effect [I. is achieved by increasing the momentum of making a U-turn in the disk-shaped concave chambers (5) and (5) by the amount approaching the side. Contributing to improvement of air utilization rate], effects [b. Contributing to high-speed engine rotation] and effects [c. [Improving combustion performance] is further improved. ]
[0060]
  The bottom surface (8) of the combustion gas flow diffusion guide groove (6) is formed in a slanted downward slope that becomes deeper from the left and right sides in the groove width direction toward the diversion guide body (7).
  With this configuration, the flow center of the combustion gas flowing in the diffusion guide groove (6) has a flow center that is more than the groove side edge (9) (9).Guide slope (19) (19)As much as you get closer to the side,Guide slope (19) (19)Makes a large turn when guided along the inner circumferential surfaces (14) and (14) of the disk-shaped concave chambers (5) and (5), so that a U-turn is made in the disk-shaped concave chambers (5) and (5). Momentum will increase.
  As a result, the above-mentioned effect [I. Contributing to improvement of air utilization rate], effects [b. Contributing to high-speed engine rotation] and effects [c. The combustion performance can be further improved.
[0061]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of a vortex chamber combustion chamber of a diesel engine according to the present invention will be described below with reference to the drawings.
[0062]
  Embodiment 1 Fig. 1 Fig. 2FIG.reference.
  FIG. 1A shows Embodiment 1 of the present invention.It is a figure for explanation, and has a start end face of a diversion guide body, which is a constituent element of the first embodiment, which is an upwardly inclined surface.FIG. 1B is a plan view of a piston in FIG. 1A, and FIG. 1C is a cross-sectional view taken along line CC in FIG. 1B. Figure. 2 (A) and 2 (B) are perspective views of the upper surface portion of the piston in FIG.
  FIG. 6 (A) is a diagram for explaining the first embodiment of the present invention, and has a groove bottom surface of the combustion gas flow diffusion guide groove, which is a constituent element of the first embodiment, and has a downwardly inclined shape. The perspective view of the piston upper surface part of the vortex chamber type combustion chamber of a water-cooled vertical diesel engine, FIG.6 (B) is BB sectional drawing of FIG. 6 (A).
[0063]
  In FIG. 1A, reference numeral (41) is a cylinder block, (42) is a cylinder head block, (43) is a piston, (44) is an intake valve, (45) is a fuel injector, and (46) is a heat plug. , (1) is the main chamber of the vortex chamber type combustion chamber, (2) is the vortex chamber, (3) is the nozzle hole, and (4) is the piston upper surface (4).
[0064]
  As shown in FIGS. 1 and 2, the vortex chamber (2) is communicated with the main chamber (1) of the vortex chamber type combustion chamber of the water-cooled vertical multi-cylinder diesel engine through the nozzle hole (3). The nozzle hole (3) is opened forward and inclined toward the rear position on the upper surface of the main chamber (1).
  The horizontal dimension of the injection hole (3) is formed in a laterally expanded shape that gradually increases from the upper end of the hole toward the lower end of the hole. As a result, the combustion gas flow that has started to combust and expand in the vortex chamber (2) is gradually expanded to the left and right when passing through the nozzle hole (3), and expands to the left and right in the main chamber (1). Oriented to move forward.
[0065]
  On the piston upper surface (4) forming the lower surface of the main chamber (1), a pair of left and right disk-shaped concave chambers (5), (5), one disk-shaped front concave chamber (25), and a combustion gas flow A diffusion guide groove (6) and a diversion guide body (7) are provided.
  The pair of left and right disk-shaped concave chambers (5) and (5) are arranged apart from each other in the left-right direction within an intermediate region in the front-rear direction of the piston upper surface (4). One disk-shaped front concave chamber (25) is arranged in the front central region of the piston upper surface (4). The pair of left and right disk-shaped concave chambers (5) and (5) and one disk-shaped front concave chamber (25) serve as valve recesses for two intake valves (44) and valve recesses for one exhaust valve. ing.
[0066]
  The combustion gas flow diffusion guide groove (6) is formed from the rear region in the front-rear direction to the intermediate region in the intermediate region in the left-right direction of the piston upper surface (4). The groove bottom surface (8) of the diffusion guide groove (6) is formed so as to be inclined upward. The left and right groove side edges (9) and (9) of the diffusion guide groove (6) are formed so as to expand forward.
[0067]
  The injection hole (3) faces the groove start end (10) at the rear end of the diffusion guide groove (6). The groove end portion (11) near the front of the diffusion guide groove (6) is communicated with the piston center side recessed chamber portion of each disk-shaped recessed chamber (5) (5).
  The diversion guide body (7) is raised from the groove bottom surface (8) in the intermediate region of the groove width in the diffusion guide groove (6).
[0068]
  The groove end edge (12) of the combustion gas flow diffusion guide groove (6) is located in each of the disk-shaped concave chambers (5) and (5). The portion of the terminal edge (12) located on the left side of the diversion guide body (7) is located in the middle of the disc-shaped concave chamber (5), whereas the portion located on the right side thereof is a circle. It is made to correspond with the indoor peripheral surface (14) of a plate-shaped recessed chamber (5).
[0069]
  On the surface of the diversion guide body (7), a pair of left and right guide slopes (19) and (19) are formed which become higher from the left and right sides to the center. Each of the pair of left and right guide slopes (19), (19) is an inner peripheral surface near the center of the piston among the respective inner peripheral surfaces (14), (14) of the respective disc-shaped concave chambers (5), (5). Make the parts smooth and continuous.
  Each of the pair of left and right guide slopes (19) (19) is formed in a flat plane. The guide slopes (19) and (19) are formed such that the slope angle is gradually increased at the end slope side than the slope part at the intermediate part in the length direction.
[0070]
  A step-down surface (26) is formed on the upper surface of the front central region of the diversion guide body (7) so as to be positioned lower than the piston upper surface (4). The stepped surface (26) is positioned at the same height or a little higher than the bottom surface of the front concave chamber (25). The stepped surface (26) is continued to the upper part of the left and right guide slopes (19), (19).
[0071]
  The front end portion (28) of the step-down surface (26) is lower than the piston upper surface (4), and the entire inner peripheral surface (29) of the front concave chamber (25) in the height direction or around the upper portion. Face the front concave chamber (25) in the form of excising the face.
  As a result, the combustion gas flow introduction space (30) for allowing a part of the combustion gas flow flowing forward in the combustion gas flow diffusion guide groove (6) to flow into the front concave chamber (25) is reduced in the stepped surface (26). Form in the upper position.
[0072]
  AndAs shown in FIG. 1 and FIG.The start end face (15) of the diversion guide body (7) is formed in a forwardly inclined surface. The start end portion (31) of the diversion guide body (7) is shifted in the start end side region (32) in the diffusion guide groove (6) and just before the lower end opening (33) of the nozzle hole (3). It has been made.
  In the first embodiment, the combustion gas flow diffusion guide groove ( 6 ) Groove bottom ( 8 ) FIG. 6 shows a diversion guide body from the left and right sides in the groove width direction as shown in FIG. ( 7 ) It is formed in an inclining downward slope that becomes deeper as it approaches.
[0073]
  Embodiment 2 See FIG.
  FIG. 3A shows a second embodiment of the present invention.To explain3B is a cross-sectional view taken along the line III-III of FIG. 3A, and FIGS. 3C and 3D are diagrams. It is the same sectional view showing the modification of 3 (B).
In the second embodiment, a part of the configuration of the first embodiment is changed as follows.To do.
  As shown in FIGS. 3A and 3B, each of the pair of guide slopes (19) and (19) is formed in a concave shape.To do.
[0074]
  In addition, the shape of the guide slopes (19) and (19) shown in FIG. 3 (B) is that the cross-sectional shape of the ridge streak is changed to a double parallel convex curved surface as shown in FIG. 3 (C). Alternatively, as shown in FIG. 3D, it is conceivable to change the cross-sectional shape of the ridge streak into an arc or elliptical arc shape (48) having a large curvature radius.
[0075]
  Embodiment 3 See FIG.
  FIG. 4A shows a third embodiment of the present invention.To explain4B is a cross-sectional view taken along the line BB of FIG. 4A, and FIG. 4C is a view of C of FIG. 4A. FIG.
  In the third embodiment, as in the first embodiment, the flow dividing guide body ( 7 ) Start face of (15) Are formed on an inclined surface that rises forward.
In the third embodiment, the following configuration is added to the configuration of the first or second embodiment.To do.
[0076]
The groove bottom end portion (20) located at the end portion of the right half portion of the groove bottom surface (8) of the combustion gas flow diffusion guide groove (6) is the bottom surface (21) of the concave chamber (5). Lower than. The groove bottom surface end portion (20) and the concave chamber bottom surface (21) are smoothly and continuously connected through the spiral upward inclined surface (37).The
[0077]
  Embodiment 4 See FIG.
  FIG. 5A shows a fourth embodiment of the present invention.To explainThe perspective view of the piston upper surface part of the vortex chamber type combustion chamber of a water-cooled vertical diesel engine, FIG.5 (B) is BB sectional drawing of FIG. 5 (A).
In the fourth embodiment, the following configuration is added to the configuration of the first, second, or third embodiment.To do.
[0078]
  Of the ridge lines (22) of the pair of left and right guide slopes (19) and (19) of the diversion guide body (7), the ridge portion (23) closer to the start end is closer to the piston upper surface (4). It is positioned low and formed in a substantially horizontal shape substantially parallel to the upper surface (4) of the piston.
  On the other hand, the end ridge portion (24) located near the end of the ridge streak (22) is formed in an upward slope gradually increasing from the ridge portion (23) near the start end.To do.
[0079]
[0080]
[0081]
  ○ Embodiment5. See FIG. 7 and FIG.
  FIG. 7A shows an embodiment of the present invention.For explaining 5FIG. 7B is a plan view of the piston in FIG. 7A, and FIG. 7C is a cross-sectional view taken along line CC in FIG. 7B. Figure. 8A and 8B are perspective views of the upper surface portion of the piston in FIG.
Embodiment5Is the above-mentioned embodiment 1, 2, 3Or 4A part of the configuration is changed as followsTo do.
[0082]
  Embodiment 1 described above (FIGS. 1 and 2)reference), The start end portion (31) of the flow dividing guide body (7) is located in the start end side region (32) in the diffusion guide groove (6) immediately before the lower end opening (33) of the nozzle hole (3). The position was shifted. This configuration is this embodiment5Then, change as follows.
[0083]
  That is, the starting end portion (31) of the diversion guide body (7) is located in the lower end opening (33) of the nozzle hole (3) in the starting end side region (32) in the diffusion guide groove (6). In a configuration that overlaps only at the front part ofTo do.
[0084]
  ○ Embodiment6. See FIG. 9 and FIG.
  FIG. 9A shows an embodiment of the present invention.6 to explainFIG. 9B is a plan view of the piston in FIG. 9A, and FIG. 9C is a cross-sectional view taken along line CC in FIG. 9B. Figure. 10 (A) and 10 (B) are perspective views of the upper surface portion of the piston in FIG.
Embodiment6Is the above-mentioned embodiment 1, 2, 3Or 4A part of the configuration is changed as followsTo do.
[0085]
  The start end portion (31) of the above-mentioned diversion guide body (7) is positioned in an intermediate region (34) between the start end side region (32) and the end end side region (35) in the diffusion guide groove (6). At the same time, it is biased toward the nozzle hole (3) with respect to the imaginary line (36) connecting the center points of the pair of left and right disc-shaped concave chambers (5) and (5), and the lower end opening of the nozzle hole (3) ( It is configured to be positioned closer to the virtual line (36) than 33).
[Brief description of the drawings]
FIG. 1A shows Embodiment 1 of the present invention.It is a figure for explanation, and has a start end face of a diversion guide body, which is a constituent element of the first embodiment, which is an upwardly inclined surface.FIG. 1B is a plan view of a piston in FIG. 1A, and FIG. 1C is a cross-sectional view taken along line CC in FIG. 1B. Figure.
2 (A) and 2 (B) are perspective views of the upper surface portion of the piston in FIG.
FIG. 3 (A) shows a second embodiment of the present invention.To explain3B is a cross-sectional view taken along the line III-III of FIG. 3A, and FIGS. 3C and 3D are diagrams. Sectional drawing which shows the modification of 3 (B).
FIG. 4 (A) shows a third embodiment of the present invention.To explain4B is a cross-sectional view taken along the line BB of FIG. 4A, and FIG. 4C is a view of C of FIG. 4A. -C sectional view.
FIG. 5 (A) shows a fourth embodiment of the present invention.To explainThe perspective view of the piston upper surface part of the vortex chamber type combustion chamber of a water-cooled vertical diesel engine, FIG.5 (B) is a BB sectional drawing of FIG. 5 (A).
FIG. 6 (A) shows the present invention.It is a figure for describing Embodiment 1, and has a groove bottom face of a combustion gas flow diffusion guide groove which is a component which is Embodiment 1, and is in the shape of sloping downward,The perspective view of the piston upper surface part of the vortex chamber type combustion chamber of a water-cooled vertical diesel engine, FIG.6 (B) is the BB sectional drawing of FIG.6 (A).
FIG. 7A is an embodiment of the present invention.For explaining 5FIG. 7B is a plan view of the piston in FIG. 7A, and FIG. 7C is a cross-sectional view taken along line CC in FIG. 7B. Figure.
8A and FIG. 8B are perspective views of the upper surface portion of the piston in FIG.
FIG. 9A is an embodiment of the present invention.6 to explainFIG. 9B is a plan view of the piston in FIG. 9A, and FIG. 9C is a cross-sectional view taken along line CC in FIG. 9B. Figure.
10 (A) and 10 (B) are perspective views of the upper surface portion of the piston in FIG.
11A is a vertical side view of a vortex chamber type combustion chamber of a water-cooled vertical diesel engine showing prior art 1, and FIG. 11B is a plan view of a piston in FIG. 11A.
12 is a perspective view of an upper surface portion of a piston in FIG.
13A is a vertical side view of a vortex chamber type combustion chamber of a water-cooled vertical diesel engine showing prior art 2, and FIG. 13B is a plan view of a piston in FIG. 13A.
14 is a perspective view of an upper surface portion of a piston in FIG.
[Explanation of symbols]
  1 ... Main room. 2 ... Uzumuro. 3 ... nozzle hole. 4 ... The upper surface of the piston. 5 ... Disc-shaped concave chamber. 6 ... Combustion gas flow diffusion guide groove. 7 ... Branch guide body. 8 ... groove bottom surface. 9: groove side edge. 10 ... groove start end. 11: Near the groove end. 12 ... groove end edge. 14 ... Indoor peripheral surface. 15 ... Starting end surface of the guide body. 19 ... Guide slope. 20 ... groove bottom end portion. 21 ... bottom of the concave chamber. 22 ... ridge line. 23 ... Ridge line near the start. 24 ... ridge line near the end. 25. Front concave chamber. 26: Stepped surface. 28 ... front end. 29. Indoor peripheral surface. 30 ... Combustion gas flow introduction space, 37 ... Spiral upward inclined surface.

Claims (1)

The swirl chamber type combustion chamber of the main chamber of the diesel engine (1) to the swirl chamber (2) communicates through a nozzle hole (3), the nozzle hole (3) before the rear position of the upper surface of the main chamber (1) Open in the downward direction,
The upper surface of the piston (4) forming the lower surface of the main chamber (1), a pair of left and right circular-shaped recessed chamber (5) (5) and the front recess chamber (25) and the combustion gas flow diffusion guide groove (6) A diversion guide body ( 7 ) ,
The pair of left and right disk-shaped concave chambers ( 5 ) and ( 5 ) are disposed apart from each other in the middle region in the front-rear direction of the piston upper surface ( 4 ) , and the front concave chamber (25) is disposed on the piston upper surface ( 4 ). Placed in the front center area of
The combustion gas flow diffusion guide groove ( 6 ) is formed from the rear region in the front-rear direction to the intermediate region in the intermediate region in the left-right direction of the piston upper surface ( 4 ) , and the groove of the diffusion guide groove ( 6 ) . The bottom surface ( 8 ) is formed in an upwardly inclined shape, and the left and right groove side edges ( 9 ) ( 9 ) of the diffusion guide groove ( 6 ) are formed so as to expand forward.
The groove start end of the rear end of the diffusion guide groove (6) (10) is faced to the nozzle hole (3), the diffusion guide groove groove end nearer portion of the front portion (6) (11) of each disc-shaped recessed chamber ( 5 ) Communicate with the piston center concave chamber part of ( 5 ) ,
The shunt guide body ( 7 ) is raised from the groove bottom surface ( 8 ) in the middle region of the groove width in the diffusion guide groove ( 6 ) ,
In the vortex chamber combustion chamber of the diesel engine
A groove end edge (12) of the combustion gas flow diffusion guide groove ( 6 ) is located in each of the disk-shaped concave chambers ( 5 ) ( 5 ) ,
Shunt guide body (7) on the surface of the pair of guide slope becomes higher as it approaches the central portion from the left and right side portions (19) (19) is formed, the pair of the guide slope (19) (19) Is smoothly connected to the front inner peripheral surface portion of the indoor peripheral surfaces (14), (14) of the left and right disc-shaped concave chambers ( 5 ), ( 5 ) ,
A step-down surface (26) is formed on the upper surface of the front central region of the diversion guide body ( 7 ) so as to be positioned lower than the piston upper surface ( 4 ) , and the step-down surface (26) is formed on the left and right guide slopes (19). The front end (28) of the stepped surface (26) is lower than the piston upper surface ( 4 ) , and is continuous with the upper part of (19) , and at least the upper part of the inner peripheral surface (29) of the front concave chamber (25) Face the front concave chamber (25) in the form of excising the peripheral surface part ,
Thus, some front recessed chamber (25) combustion gas stream introduction space stage falling surface (30) to flow into the combustion gas stream diffusion guide groove (6) in a forward flow combustion gas stream (26) Formed in the upper position,
Forming the start end face (15) of the diversion guide body ( 7 ) in an upwardly inclined surface;
The bottom surface (8) of the combustion gas flow diffusion guide groove (6) is formed in a slanted downward slope that becomes deeper from the left and right sides in the groove width direction toward the diversion guide body (7). What to do.

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