JP2002276372A - Volute chamber type combustion chamber for diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the improvement in air using ratio in a main chamber, the higher-speed rotation of an engine, and the enhancement of combustion performance by the enhancement of mixing performance of air to fuel by sufficiently carrying a combustion gas flow to the rear part area of the main chamber. SOLUTION: The groove terminal edge 12 of a combustion gas flow diffusion guide groove 6 is located within each disc-like recessed chamber 5. A lateral pair of guide inclined surfaces 19 increased in height from both the lateral side parts to the center part is formed on the surface of a flow dividing guide body 7. Each guide inclined surface 19 is smoothly continued to the inside surface part closer to the center of a piston of the inside surface 14 of each disc- like recessed chamber 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swirl type combustion chamber of a diesel engine.

[0002]

[Premise Configuration] The swirl chamber type combustion chamber of the diesel engine of the present invention is, for example, shown in FIGS. 1 and 2 (the present invention) or FIG.
As shown in FIG. 12 (prior art), a device having the following premise configuration is targeted.

FIG. 1A is a longitudinal sectional side view of a swirl type combustion chamber of a water-cooled vertical diesel engine showing a first embodiment of the present invention, FIG. 1B is a plan view of a piston in FIG. 1A, FIG. 1C is a sectional view taken along line CC of FIG. 1B. Fig. 2 (A)
FIG. 2B is a perspective view of an upper surface portion of the piston in FIG.

FIG. 11 (A) is a longitudinal sectional side view of a swirl type combustion chamber of a water-cooled vertical diesel engine showing prior art 1, and FIG. 11 (B) is a plan view of a piston in FIG. 11 (A). Figure 1
FIG. 2 is a perspective view of an upper surface portion of the piston in FIG.

[Assumption] A swirl chamber (2) is connected to a main chamber (1) of a swirl chamber type combustion chamber of a diesel engine through an injection hole (3), and the injection hole (3) is connected to the main chamber (1). At the rear part of the upper surface of the upper surface in the downwardly inclined direction. A pair of left and right disc-shaped concave chambers (5), (5), a combustion gas flow diffusion guide groove (6), and a distribution guide body (7) are provided on a piston upper surface (4) forming a lower surface of the main chamber (1). Provide.

The pair of left and right disc-shaped concave chambers (5) and (5) are disposed apart from each other in the front-rear direction intermediate region of the piston upper surface (4). The combustion gas flow diffusion guide groove (6) is formed from the rear region to the intermediate region in the front-rear direction in the left-right intermediate region of the piston upper surface (4).
The groove bottom surface (8) of (6) is formed so as to be inclined upwardly 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.

The injection hole (3) faces the groove start end (10) at the rear end of the diffusion guide groove (6), and the groove end portion (11) located in front of the diffusion guide groove (6) is attached to each disk. The recessed chambers (5) are communicated with the recessed portion on the center side of the piston (5). Dividing guide body (7) is diffusion guide groove
(6) It is configured to be raised from the groove bottom surface (8) in the groove width middle region. The disc-shaped concave chambers (5) and (5) function to promote combustion, and may be formed exclusively for promoting combustion, but may also serve as valve recesses of the intake and exhaust valves.

[Operation of Premise Configuration] In the vicinity of the compression top dead center of the piston (43), the combustion gas flow which has started to burn and expand in the swirl chamber (2) flows from the injection hole (3) to the main chamber (1). Blows into the groove start end (10) of the combustion gas flow diffusion guide groove (6), and moves forward vigorously while expanding inside the diffusion guide groove (6) left and right.

The combustion gas flow flowing in the diffusion guide groove (6) rides on the force of the forward flow, and the piston flows from the diffusion guide groove (6) and the left and right disc-shaped concave chambers (5) and (5). Top surface (4)
Of the main room (1), and flows vigorously in a large amount from the front partial region of the main room (1) to the left and right partial regions thereof.

However, the combustion gas flow reverses from the left and right partial areas of the main chamber (1) and attempts to flow into the rear partial area of the main chamber (1). It is difficult to quickly flow in a large amount to the entire area quickly, and it tends to be short, and the air utilization rate in the main room (1) tends to decrease.

[0011]

2. Description of the Related Art Conventional technologies to be compared with the present invention include:
The followings have been proposed by the applicant earlier. ○ Conventional technology 1. See FIG. 11 and FIG. (Japanese Patent Laid-Open No. 5
1 of FIG.

FIG. 11 (A) is a longitudinal sectional side view of a swirl type combustion chamber of a water-cooled vertical diesel engine showing prior art 1, and FIG. 11 (B) is a plan view of a piston in FIG. 11 (A). Figure 1
FIG. 2 is a perspective view of an upper surface portion of the piston in FIG. The prior art 1 is obtained by adding the following configuration to the above-described premise configuration.

The groove end edge (12) of the combustion gas flow diffusion guide groove (6) is positioned so as to overhang forward of each of the disc-shaped concave chambers (5) (5). The left and right guide body side surfaces (13) and (13) of the diverting guide body (7) are in the diffusion guide groove (6),
It extends to the groove end edge (12). The upper surface (16) of the guide body (7) has a gentle upward slope. The starting end face (15) of the branch guide body (7) rises vertically.

○ Prior art 2. See FIG. 13 and FIG.
(FIG. 4 of JP-A-5-195873 and the description in the specification). FIG. 13A is a vertical sectional side view of a swirl-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. FIG. 14 is a perspective view of the upper surface of the piston in FIG. This prior art 2
Is a modification of the above-mentioned premise configuration, with a portion thereof changed as follows.

[0015] The combustion gas flow diffusion guide groove according to the above-mentioned premise.
Instead of (6), a linear guide groove (91) is formed. A semi-disc body (92) is formed instead of the flow dividing guide body (7). A cloverleaf combustion chamber is formed by the straight guide groove (91), the semi-disc body (92), and the pair of left and right disc-shaped concave chambers (5) (5). The upper surface (93) of the semi-disc body (92) has a gentle upward slope. The peripheral surface of the semi-disc (92) rises vertically.

[0016]

The above prior art has the following problems. ○ Conventional technology 1. See FIG. 11 and FIG. [ I. Since it is difficult for the combustion gas flow to quickly and sufficiently flow from the front partial area and the right and left partial areas of the main chamber (1) to the entire area of the rear partial area, the combustion gas flow becomes insufficient. The air utilization of the car decreases. ]

In the vicinity of the compression top dead center of the piston (43),
The combustion gas flow that has begun to burn and expand in the vortex chamber (2)
From (3), it blows into the groove start end (10) of the combustion gas flow diffusion guide groove (6) of the main chamber (1), and moves forward vigorously while expanding inside the diffusion guide groove (6) from side to side.

The combustion gas flowing in the diffusion guide groove (6) rides on the momentum of the forward flow, and the piston flows from the diffusion guide groove (6) and the left and right disk-shaped concave chambers (5) and (5). Top surface (4)
Of the main room (1), and flows vigorously in a large amount from the front partial region of the main room (1) to the left and right partial regions thereof.

However, the combustion gas flow reverses from the left and right partial regions of the main chamber (1) and tries to flow into the rear partial region of the main chamber (1). It is difficult to quickly and sufficiently flow into the whole area, and it becomes insufficient, and the air utilization rate in the main room (1) decreases. For this reason,
In addition to reducing unburned harmful components such as HC and CO in exhaust gas, it cannot sufficiently contribute to improving engine output and reducing fuel consumption.

[B. Since it is difficult for the remaining portion of the combustion gas flow to quickly and sufficiently flow into the entire rear partial region of the main chamber (1), it is difficult to increase the combustion speed and to contribute to increasing the speed of the engine. ]

As described in the above problem [A], the combustion gas flow quickly and sufficiently flows from the front partial region and the left and right partial regions of the main chamber (1) to the entire rear partial region. It is difficult to increase the combustion speed by the amount of the shortage, and it is difficult to contribute to increasing the speed of the engine.

○ Prior art See FIG. 13 and FIG. [ I. Since it is difficult for the combustion gas flow to quickly and sufficiently flow from the left and right partial areas of the main chamber (1) to the entire area of the rear partial area and becomes insufficient, the air utilization rate in the main chamber (1) is insufficient. Decrease. ]

In the vicinity of the compression top dead center of the piston (43),
The combustion gas flow that has begun to burn and expand in the vortex chamber (2)
From (3), the vehicle goes straight in the straight guide groove (91) of the main chamber (1) and collides with the peripheral surface of the semi-disc body (92). A part of this combustion gas flow passes over the semi-disc body (92) and flows into the front partial area of the main chamber (1), and the remainder is divided into right and left disc-shaped concave chambers on the left and right.
(5) Turn inside (5). However, it is difficult for the remainder of the combustion gas flow to quickly and sufficiently flow from each of the disc-shaped concave chambers (5) and (5) to the entire rear partial area of the main chamber (1).
In the rear partial area, shortage occurs, and the air utilization rate in the main chamber (1) decreases.

[B. Since it is difficult for the remaining portion of the combustion gas flow to quickly and sufficiently flow into the entire rear partial region of the main chamber (1), it is difficult to increase the combustion speed and to contribute to increasing the speed of the engine. ]

As described in the above problem [A], the remainder of the combustion gas flow is separated from the disc-shaped concave chambers (5) and (5) by the main chamber.
(1) It is difficult to quickly and sufficiently flow into the entire rear partial area, and the combustion speed cannot be increased by the shortage in the rear partial area. It is difficult to contribute to.

An object of the present invention is as follows. (I). By the guide action of the left and right guide bodies on the left and right sides of the diverter guide body, the amount of the combustion gas flowing in the diffusion guide groove flowing into the entire rear part area of the main chamber is increased in a sufficiently large amount. Improve air utilization. (B). By allowing the combustion gas flow to flow in a sufficiently large amount and quickly into the entire rear partial region of the main chamber, the combustion speed is increased, which contributes to the high-speed rotation of the engine. (C). The combustion gas flow is maintained at a high speed without receiving a large flow resistance, and is accelerated while narrowing from the wide guide slope toward the narrow inner peripheral surface of the disc-shaped concave chamber, thereby accelerating the combustion gas flow. By shortening the time of flowing into the entire rear partial region, the mixing performance of air and fuel is enhanced, and the combustion performance is enhanced.

[0027]

The swirl type combustion chamber of a diesel engine according to the present invention has the following characteristic configuration in order to solve the above-mentioned problems in the above-described premise configuration, for example, as shown in FIGS. Is added.

FIG. 1 (A) is a vertical sectional side view of a swirl type combustion chamber of a water-cooled vertical diesel engine showing a first embodiment of the present invention, FIG. 1 (B) is a plan view of a piston in FIG. 1 (A), FIG. 1C is a sectional view taken along line CC of FIG. 1B. Fig. 2 (A)
FIG. 2B is a perspective view of an upper surface portion of the piston in FIG.

FIG. 3A is a perspective view of an upper surface portion of a piston of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a second embodiment of the present invention, and FIG. 3B is a view taken along the line III-III of FIG.
3 (C) and 3 (D) are sectional views showing a modification of FIG. 3 (B). FIG. 4A is a perspective view of an upper surface portion of a piston of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a third embodiment of the present invention, and FIG.
FIG. 4A is a cross-sectional view taken along the line BB, and FIG.
FIG. 4 is a sectional view taken along line C of FIG.

FIG. 5A is a perspective view of an upper surface of a piston of a swirl type combustion chamber of a water-cooled vertical diesel engine according to a fourth embodiment of the present invention, and FIG. 5B is a view taken along the line BB of FIG. 5A. It is a line sectional view. FIG. 6A is a perspective view of an upper surface portion of a piston of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a fifth embodiment of the present invention, and FIG. 6B is BB of FIG. 6A.
It is a line sectional view.

FIG. 7 (A) is a vertical sectional side view of a swirl type combustion chamber of a water-cooled vertical diesel engine showing a sixth embodiment of the present invention, FIG. 7 (B) is a plan view of a piston in FIG. 7 (A), FIG. 7C is a cross-sectional view taken along line CC of FIG. 7B. Fig. 8 (A)
FIG. 8B is a perspective view of the upper surface of the piston in FIG. FIG. 9A is a longitudinal sectional side view of a swirl-type combustion chamber of a water-cooled vertical diesel engine showing a seventh embodiment of the present invention.
9B is a plan view of the piston in FIG. 9A, and FIG.
FIG. 10 is a sectional view taken along line CC of FIG. 10 (A) and 10
(B) is a perspective view of the piston upper surface part in FIG. 9.

○ Invention 1 Claim 1. 1 and 2,
See FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. 7 / FIG. 8, or FIG. A groove end edge (12) of the combustion gas flow diffusion guide groove (6) is located in each of the disc-shaped concave chambers (5) (5).

A pair of left and right guide slopes (19) (19) are formed on the surface of the flow dividing guide body (7) as the distance from the left and right sides to the center increases. The pair of left and right guide slopes (19) and (19) are the inner peripheral surfaces of the inner peripheral surfaces (14) and (14) of the left and right disk-shaped concave chambers (5) and (5) near the center of the piston. It is constructed so as to be smoothly continued to the part.

○ Invention 2 Claim 2. See FIG. The invention 2 is characterized in that the following features are added to the invention 1 described above. Of the ridge streaks (22) of the pair of left and right guide slopes (19) and (19) of the branch guide body (7), the ridge portion (23) closer to the start end is closer to the piston upper surface (4) than the piston upper surface (4). It is formed in a substantially horizontal shape which is substantially parallel to the piston upper surface (4) at a low position. On the other hand, the ridge portion (24) located near the end of the ridge streak (22)
Was formed in an upward slope gradually rising from the ridge portion (23) near the beginning.

○ Invention 3. Claim 3. 1 and 2,
Or see FIG. The invention 3 is characterized in that the following features are added to the invention 1 or 2. Dividing guide body
The starting end face (15) of (7) was formed on a slope rising forward.

○ Invention 4. Claim 4. See FIG. The invention 4 is characterized in that the following features are added to the invention 1, 2, or 3. The groove bottom end (20) located at the end of the groove bottom (8) of the combustion gas flow diffusion guide groove (6) is located lower than the concave chamber bottom (21) of the disc-shaped concave chamber (5). Let it. This groove bottom end (20) and concave chamber bottom (21)
Were smoothly continued through the spiral upward slope (37).

○ Invention 5 Claim 5. See FIG. The invention 5 is the invention according to the invention 1, 2, 3, or 4,
The following feature configuration is added. The groove bottom surface (8) of the combustion gas flow diffusion guide groove (6) was formed so as to be inclined downward from the right and left sides in the groove width direction so as to become deeper as approaching the diversion guide body (7).

[0038]

The swirl type combustion chamber of the diesel engine according to the present invention has the following effects. ○ Invention 1. Claim 1. 1, 2, 3, 4,
See FIG. 5, FIG. 6, FIG. 7, FIG. 8, or FIG.

[A. The guide action of the pair of left and right guide slopes (19) and (19) on the surface of the diversion guide body (7) causes
(6) Utilization of air in the main chamber (1) to the extent that the remaining amount of the combustion gas flow flowing into the entire rear part of the main chamber (1) can be increased sufficiently. The rate is improved. ]

First, from the above premise, the combustion gas flow which started to burn and expand in the swirl chamber (2) near the compression top dead center of the piston (43) flows from the injection hole (3) through the main chamber (1). ) Blows into the groove start end (10) of the combustion gas flow diffusion guide groove (6), and moves forward vigorously while expanding inside the diffusion guide groove (6) left and right.

A part of the combustion gas flow flowing in the diffusion guide groove (6) rides on the forward flow, and
(6) and from the left and right disk-shaped concave chambers (5) and (5), ride on the front upper surface portion of the piston upper surface (4), and form the main chamber (1).
Flows vigorously in a large amount from the front partial area of the first part to the right and left partial areas.

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 located in each of the disc-shaped concave chambers (5) (5). A pair of left and right guide slopes (19) (19) are formed on the surface of the diverting guide body (7) so as to increase from the left and right sides to the center. The pair of left and right guide slopes (19) and (19) correspond to the left and right disk-shaped concave chambers.
(5) The inner peripheral surfaces (14) and (14) of (5) are smoothly connected to the inner peripheral surface portion near the center of the piston.

From this characteristic configuration, the remainder of the combustion gas flow flowing in the diffusion guide groove (6) is formed by a pair of left and right guide slopes (19) and (19) on the surface of the branch guide body (7). Plate-shaped concave chamber
(5) Smoothly guided along the inner peripheral surface (14) (14) of (5), the U-turn is made vigorously in each disk-shaped concave chamber (5) (5), and both disks Piston upper surface (4) (4) from concave chamber (5) (5)
Of the main chamber (1), and quickly and sufficiently flow into a large amount from the left and right side partial areas of the main chamber (1) to the entire rear partial area.

As described above, the amount of the remaining portion of the combustion gas 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. In the present invention 1, the air utilization rate in the main chamber (1) is improved by the amount that can be increased in a sufficiently large amount, and the HC in the exhaust gas is increased.
In addition to reducing unburned harmful components such as CO and CO, it can also contribute to improving engine output and reducing fuel consumption.

[B. The combustion speed is increased by the amount that the remainder of the combustion gas flow quickly and sufficiently flows into the entire rear part of the main chamber (1), contributing to the high speed rotation of the engine. Can be. ]

As described in the above effect [A], the remainder of the combustion gas flow flowing in the diffusion guide groove (6) is divided by the split flow guide body.
The pair of left and right guide slopes (19) and (19) on the surface of (7) are smoothly guided along the inner peripheral surfaces (14) and (14) of the left and right disk-shaped concave chambers (5) and (5). Then, the U-turn is made vigorously in each of the disk-shaped concave chambers (5) and (5), and the rear side of the piston upper surfaces (4) and (4) is moved from the disk-shaped concave chambers (5) and (5). Ride on the upper part, the main room
From (1) both right and left partial regions to the entire rear partial region, a large amount of fluid flows quickly and vigorously.

As described above, the remainder of the combustion gas flow is the main chamber.
(1) The combustion speed is increased by a sufficiently large amount that quickly flows into the entire rear part region, which can contribute to the high-speed rotation of the engine.

[C. The combustion gas flow is controlled by both guide slopes (1
9) (19) It is smoothly divided into left and right along the (19), it is maintained at a high speed without receiving a large flow resistance, and in addition to the wide guide slope (19) (19), the disc-shaped concave chamber ( 5) (5)
The time required to flow into the entire rear part of the main room (1) is reduced by the amount of acceleration while being throttled toward the narrow inner peripheral surfaces (14, 14) of The mixing performance with fuel is enhanced, and the combustion performance is enhanced. ]

The combustion gas flow which has begun to burn and expand in the swirl chamber (2) flows from the injection hole (3) to the groove start end (10) of the combustion gas flow diffusion guide groove (6) in the main chamber (1). When the air blows and collides with the diversion guide body (7), since the surface of the guide body (7) is a pair of left and right guide slopes (19), (19), both guide slopes (19) (19) The flow is smoothly divided into right and left along the line (19), and no large flow resistance is generated. The flow speed is hardly reduced and the flow speed is maintained at a high speed.

The combustion gas flow maintained at the high speed flows from the wide guide slopes (19) and (19) to the inner peripheral surfaces (14) and (14) of the disk-shaped concave chambers (5) and (5) because of the narrow width. The U-turn speed, which is vigorously U-turned in each of the disc-shaped concave chambers (5) and (5), is also accelerated as much as it gradually accelerates while being throttled,
Since the time required for a large amount of water to flow quickly and vigorously from the right and left partial areas of the main chamber (1) to the entire area of the rear partial area is reduced, the mixing speed of air and fuel is increased, and the mixing performance is improved. And combustion performance.

As a result, it further contributes to reducing unburned harmful components such as HC and CO in the exhaust gas, improving the output of the engine, reducing fuel consumption, and increasing the speed of the engine. can do.

○ Invention 2 Claim 2. See FIG. The invention 2 provides the effects [a], [b] and.
In addition to [c], the following effect is obtained.

[D. The combustion gas flow vigorously passes at a high velocity along the guide slopes on both sides of the low starting ridge part (23), and the rising slope-end ridge part
Since the guide is quickly guided to the left and right along the guide slopes on both sides of (24), the U-turn speed in the disk-shaped concave chambers (5) and (5) is accelerated to form the main chamber (1). The above-mentioned effect [a. Contributing to the improvement of the air utilization rate] and effects [b. Contributing to high-speed rotation of the engine] and effects [c. Enhancing combustion performance]. ]

Of the pair of left and right guide slopes (19) of the diverting guide body (7), the ridge streak portion (23) located closer to the start end thereof is located near the start end thereof. ) And is formed in a substantially horizontal shape substantially parallel to the piston upper surface (4). On the other hand, the ridge portion (24) closer to the end of the ridge streak (22) is formed in an upwardly sloped shape that gradually becomes higher from the ridge portion (23) near the start end.

According to this configuration, the combustion gas flow vigorously flowing in the diffusion guide groove (6) flows along the guide slopes (19) on both sides of the low ridge portion (23) near the start end along the slope near the start end of the guide slopes (19) and (19). , Passing through at a high speed without receiving much resistance, and gradually along the slopes near the end of the guide slopes (19) and (19) on both sides of the ridge part (24) near the end of the upward slope. It is smoothly guided to the left and right and quickly flows into the inner peripheral surfaces (14) (14) of the disc-shaped concave chambers (5) (5).

For this reason, the combustion gas flow is accelerated at a U-turn speed at which the U-turn is vigorously made in each of the disk-shaped concave chambers (5) (5), and the left and right sides of the main chamber (1) are accelerated. It is further increased that a large amount of fluid flows quickly and quickly from the partial region to the entire rear partial region.

Thus, the effect of the above invention 1 [A. Contributing to the improvement of the air utilization rate] and effects [b. Contributing to high-speed rotation of the engine] and effects [c. Enhancing combustion performance] can be further improved.

○ Invention 3 Claim 3. 1 and 2,
Or see FIG. The third aspect of the present invention provides the effects [a], [b], and
In addition to [c], the following effect is obtained. [E. Starting end face (15) of combustion gas flow (7)
The above-mentioned effect can be obtained by eliminating the flow velocity drop by smoothly flowing into the diffusion guide groove (6) while being guided to the left and right while easily climbing on the front rising slope. Contributing to the improvement of the air utilization rate] and effects [b. Contributing to high-speed rotation of the engine] and effects [c. Enhancing combustion performance].
]

The start end face (15) of the flow dividing guide body (7) was formed as a slope rising forward. With this configuration, the combustion gas flow that has begun to burn and expand in the swirl chamber (2) blows into the groove start end (10) of the diffusion guide groove (6) from the injection hole (3), and flows therethrough. When colliding with the starting end face (15) of (7), the diverging guide groove (6) is guided to the right and left while easily climbing on the inclined surface rising forward of the starting end face (15). It smoothly flows into.

Therefore, the flow of the combustion gas is divided by the guide member (7).
The flow velocity of the combustion gas flowing through the diffusion guide groove (6) does not decrease, and the flow velocity increases as much as the flow resistance is not increased by being bounced back and reversing and backflowing at the starting end face (15) . Thereby, the effect of the first invention [A. Contributing to the improvement of the air utilization rate] and effects [b. Contributing to high-speed rotation of the engine] and effects [c. Increasing combustion performance] can be further improved.

○ Invention 4. Claim 4. See FIG. The invention 4 provides the effects [a], [b] and.
In addition to [c], the following effect is obtained. [F. The depth of the groove bottom end (20) is increased, and the combustion gas flow spirals up from the groove bottom end (20) to the concave chamber bottom (21) and is smoothly guided on the inclined surface (37). The above effect [A. Contributing to the improvement of the air utilization rate] and effects [b. Contributing to high-speed rotation of the engine] and effects [c. Enhancing combustion performance].
]

The bottom surface of the combustion gas flow diffusion guide groove (6)
The groove bottom end portion (20) located at the end portion of (8) is positioned lower than the concave chamber bottom surface (21) of the disk-shaped concave chamber (5). The groove bottom end portion (20) and the concave chamber bottom surface (21) are spirally inclined upward (3).
7) through to continue smoothly.

With this configuration, as the depth of the groove bottom end portion (20) increases, the cross-sectional area of the upper passage increases, and the combustion gas flow easily flows at a high speed. In addition, the remainder of the combustion gas flow flowing in the diffusion guide groove (6) is spirally raised from the groove bottom end portion (20) to the concave chamber bottom surface (21) and is smoothly guided by the inclined surface (37). The U-turn speed in the plate-shaped concave chambers (5) and (5) increases, and the amount and speed of vigorously flowing into the entire rear partial area of the main chamber (1) increase. As a result, the above effect [A. Contributing to the improvement of the air utilization rate] and effects [b. Contributing to high-speed rotation of the engine] and effects [c. Increasing combustion performance] can be further improved.

○ Invention 5 Claim 5. See FIG. The invention 5 provides the effects [a], [b] and.
In addition to [C], the following effects are obtained. [G. The combustion gas flow flowing in the diffusion guide groove (6) is
As the flow center approaches the guide body side surfaces (13) and (13), the momentum of making a U-turn in the disk-shaped concave chambers (5) and (5) becomes stronger, whereby the above-mentioned effect [A. Contributing to the improvement of the air utilization rate] and effects [b. Contributing to high-speed rotation of the engine] and effects [c. Enhancing combustion performance]. ]

The bottom surface of the combustion gas flow diffusion guide groove (6)
(8) is a diversion guide body from both right and left sides in the groove width direction
It was formed in a downwardly inclined shape that became deeper as approaching (7).
Due to this configuration, the flow of the combustion gas flowing in the diffusion guide groove (6) is such that its flow center is on the side of the guide body more than the groove side edges (9) and (9).
(13) As much as it approaches the (13) side, the guide body side (13) (1
When guided along the inner peripheral surfaces (14) and (14) of the disc-shaped concave chambers (5) and (5) from (3), a large turn is made. The momentum to turn becomes stronger. As a result, the above effect [A. Contributing to the improvement of the air utilization rate] and effects [b.
Contributing to high-speed rotation of the engine] and effects [c. Increasing combustion performance] can be further improved.

[0066]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a swirl type combustion chamber of a diesel engine according to the present invention will be described below with reference to the drawings.

Embodiment 1 Claims 1.3. Figure 1
・ See FIG. FIG. 1A is a vertical side view of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a first embodiment of the present invention.
FIG. 1B is a plan view of the piston in FIG.
FIG. 2 is a sectional view taken along line CC of FIG. FIG. 2 (A) and FIG.
FIG. 2B is a perspective view of an upper surface portion of the piston in FIG. 1.

In FIG. 1A, reference numeral (41) denotes a cylinder block, (42) denotes a cylinder head block, (43) denotes a piston, (44) denotes an intake valve, (45) denotes a fuel injector, and (46). Is a heat plug, (1) is the main chamber of the swirl chamber combustion chamber, (2) is the swirl chamber,
(3) is an injection hole, and (4) is a piston upper surface (4).

As shown in FIGS. 1 and 2, the main chamber (1) of the swirl-type combustion chamber of the water-cooled vertical multi-cylinder diesel engine
Then, the vortex chamber (2) is communicated through the injection hole (3). Orifice
In (3), the main chamber (1) is opened forward and downward at a rear position on the upper surface of the main chamber (1). The lateral width of the injection hole (3) is formed in a laterally expanding shape that gradually increases from the upper end of the injection hole toward the lower end of the injection hole. As a result, the combustion gas flow that has begun to burn and expand in the swirl chamber (2) gradually spreads left and right when passing through the injection hole (3), and spreads left and right in the main chamber (1). Orientated to move forward.

Upper surface of piston forming lower surface of main chamber (1)
(4), a pair of left and right disc-shaped concave chambers (5) and (5), one disc-shaped front concave chamber (25), a combustion gas flow diffusion guide groove (6), and a branch guide body ( 7) is provided. A pair of left and right disc-shaped concave chambers (5)
(5) are arranged apart from each other left and right in an intermediate region in the front-rear direction of the piston upper surface (4). One disc-shaped front recess (25)
Is located in the front central region of the piston upper surface (4). This pair of left and right disk-shaped concave chambers (5) and (5) and one disk-shaped front concave chamber
(25) doubles as a valve recess of two intake valves (44) and a valve recess of one exhaust valve.

The combustion gas flow diffusion guide groove (6) is formed in the middle area in the left-right direction of the piston upper surface (4) from the rear area to the middle area in the front-rear direction. The groove bottom surface (8) of the diffusion guide groove (6) is formed to be inclined forward. The left and right groove side edges (9) and (9) of the diffusion guide groove (6) are formed so as to extend forward.

The injection hole (3) faces the groove start end (10) at the rear end of the diffusion guide groove (6). The front end portion (11) of the diffusion guide groove (6) is communicated with each of the disc-shaped concave chambers (5) and (5) at the piston center side concave part. The diversion guide body (7) rises from the groove bottom surface (8) in the groove width intermediate region in the diffusion guide groove (6).

The end edge (12) of the combustion gas flow diffusion guide groove (6) is located in each of the disc-shaped concave chambers (5) (5). The portion of the terminal edge (12) located on the left side of the flow dividing guide (7) is located in the middle of the disk-shaped concave chamber (5), whereas the portion located on the right side is circular. It is made to correspond to the inner peripheral surface (14) of the plate-shaped concave chamber (5).

A pair of left and right guide slopes (19) (19) are formed on the surface of the diversion guide body (7) so as to increase from both left and right sides toward the center. The pair of left and right guide slopes (19) and (19) are the inner peripheral surfaces of the inner peripheral surfaces (14) and (14) of the left and right disk-shaped concave chambers (5) and (5) near the center of the piston. Continue smoothly over the part. This pair of left and right guide slopes (19) (1
9) is formed on an uneven plane. And this guide slope (19)
(19) is formed such that the inclination angle of the slope portion on the terminal end side becomes gradually larger than the slope portion of the middle portion in the longitudinal direction. And the branch guide body (7).
Is formed on an inclined surface rising forward.

Then, the starting end (31) of the branch guide body (7)
Is located in the starting end side region (32) in the diffusion guide groove (6) and is shifted just before the lower end opening (33) of the injection hole (3).

Embodiment 2 Claim 1. See FIG. FIG. 3A is a perspective view of an upper surface portion of a piston of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a second embodiment of the present invention, and FIG. 3B is a sectional view taken along line III-III of FIG. 3 (C) and 3 (D) are sectional views showing a modification of FIG. 3 (B). In the second embodiment, a part of the configuration of the first embodiment is changed as follows.
As shown in FIGS. 3A and 3B, the pair of guide slopes (19) and (19) are formed in a concave shape.

The guide slope (1) shown in FIG.
9) The shape of (19) can be changed by changing the cross-sectional shape of the ridge streak to a two-parallel parallel convex curved surface as shown in FIG. 3 (C), or as shown in FIG. 3 (D). It is conceivable to change the cross-sectional shape of the ridge streak into an arc or an elliptical arc (48) having a large radius of curvature.

Embodiment 3 Claims 1, 3, and 4.
See FIG. FIG. 4A is a perspective view of a piston upper surface portion of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a third embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along line BB of FIG. , FIG.
FIG. 5C is a cross-sectional view taken along line CC of FIG. In the third embodiment, the following configuration is added to the configuration of the first or second embodiment.

The starting end face (15) of the branch guide body (7) is formed as a slope rising forward. The combustion gas flow diffusion guide groove
The groove bottom end portion (20) located at the end of the right half of the groove bottom surface (8) of (6) is positioned lower than the recess bottom surface (21) of the disc-shaped recess (5). The groove bottom end portion (20) and the concave chamber bottom surface (21) are smoothly continuous with each other via a spiral upward slope (37).

Embodiment 4 Claims 1.2. FIG.
reference. FIG. 5A is a perspective view of an upper surface portion of a piston of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a fourth embodiment of the present invention, and FIG. 5B is a cross-sectional view taken along line BB of FIG. It is. The fourth embodiment is obtained by adding the following configuration to the configuration of the first, second, or third embodiment.

The ridge streak (23) of the pair of left and right guide slopes (19) (19) of the diverting guide body (7), which is closer to the start end, is located on the piston upper surface (4). ) And is formed in a substantially horizontal shape substantially parallel to the piston upper surface (4). On the other hand, the end ridge portion (24) located near the end of the ridge streak (22) is formed in an upwardly sloped shape gradually increasing from the ridge portion (23) near the start end.

Embodiment 5 Claims 1.5. FIG.
reference. FIG. 6A is a perspective view of an upper surface portion of a piston of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a fifth embodiment of the present invention, and FIG. 6B is a cross-sectional view taken along line BB of FIG. It is. In the fifth embodiment, the following configuration is added to the configuration of the first, second, third or fourth embodiment.

The bottom surface of the combustion gas flow diffusion guide groove (6)
(8) is a diversion guide body from both right and left sides in the groove width direction
It is formed in a downwardly inclined shape that becomes deeper as approaching (7).

Embodiment 6 Claim 1. See FIG. 7 and FIG. FIG. 7A is a longitudinal sectional side view of a swirl-type combustion chamber of a water-cooled vertical diesel engine according to a sixth embodiment of the present invention.
FIG. 7B is a plan view of the piston in FIG.
FIG. 8 is a cross-sectional view taken along line CC of FIG. 8 (A) and 8
FIG. 8B is a perspective view of the upper surface of the piston in FIG. 7. The sixth embodiment corresponds to the first, second, third, fourth or fifth embodiment.
In the above configuration, a part of the configuration is changed as follows.

In the first embodiment (FIGS. 1 and 2), the starting end (31) of the flow dividing guide (7) is located within the starting end side region (32) in the diffusion guide groove (6). It was shifted just before the lower end opening (33) of the hole (3). This configuration is referred to as the sixth embodiment.
Then, change as follows.

That is, the starting end of the branch guide body (7)
(31) is configured to overlap only in the forward portion of the lower end opening (33) of the injection hole (3) in the starting end side region (32) in the diffusion guide groove (6). Things.

Embodiment 7 Claim 1. See FIG. 9 and FIG. FIG. 9A is a longitudinal sectional side view of a swirl-type combustion chamber of a water-cooled vertical diesel engine showing a seventh embodiment of the present invention.
9B is a plan view of the piston in FIG. 9A, and FIG.
FIG. 10 is a sectional view taken along line CC of FIG. 10 (A) and 10
(B) is a perspective view of the piston upper surface part in FIG. 9. The seventh embodiment corresponds to the first, second, third, fourth or fifth embodiment.
In the above configuration, a part of the configuration is changed as follows.

The starting end (31) of the above-mentioned branch guide body (7)
The start side area (32) and the end side area (35) in the diffusion guide groove (6)
And is located closer to the injection hole (3) than an imaginary line (36) connecting the center points of the pair of left and right disc-shaped concave chambers (5) (5). At the same time, it is configured to be located at a position closer to the imaginary line (36) than the lower end opening (33) of the injection hole (3).

[Brief description of the drawings]

FIG. 1 (A) is a vertical side view of a swirl type combustion chamber of a water-cooled vertical diesel engine showing a first embodiment of the present invention,
FIG. 1B is a plan view of the piston in FIG.
(C) is a sectional view taken along line CC of FIG. 1 (B).

2 (A) and 2 (B) are perspective views of an upper surface portion of a piston in FIG. 1;

3 (A) is a perspective view of an upper surface portion of a piston of a swirl chamber type combustion chamber of a water-cooled vertical diesel engine according to a second embodiment of the present invention, and FIG. 3 (B) is a view III-A of FIG. 3 (A). 3 (C) and 3 (D) are cross-sectional views showing a modification of FIG. 3 (B).

4 (A) is a perspective view of an upper surface portion of a piston of a swirl type combustion chamber of a water-cooled vertical diesel engine showing a third embodiment of the present invention, and FIG. 4 (B) is a sectional view taken along line B- of FIG. 4 (A). FIG. 4C is a cross-sectional view taken along a line B-C of FIG. 4A.

5 (A) is a perspective view of an upper surface portion of a piston of a swirl chamber type combustion chamber of a water-cooled vertical diesel engine according to a fourth embodiment of the present invention, and FIG. 5 (B) is a sectional view taken on line B- of FIG. 5 (A). B sectional drawing.

FIG. 6 (A) is a perspective view of a piston upper surface portion of a swirl type combustion chamber of a water-cooled vertical diesel engine showing a fifth embodiment of the present invention, and FIG. 6 (B) is a sectional view taken along line B-B of FIG. B sectional drawing.

FIG. 7A is a vertical sectional side view of a swirl chamber type combustion chamber of a water-cooled vertical diesel engine showing a sixth embodiment of the present invention,
FIG. 7B is a plan view of the piston in FIG.
FIG. 8C is a cross-sectional view taken along line CC of FIG.

8 (A) and 8 (B) are perspective views of an upper surface portion of a piston in FIG. 7;

FIG. 9 (A) is a longitudinal sectional side view of a swirl chamber type combustion chamber of a water-cooled vertical diesel engine showing a seventh embodiment of the present invention,
FIG. 9B is a plan view of the piston in FIG.
(C) is a sectional view taken along line CC in FIG. 9 (B).

10 (A) and FIG. 10 (B) are perspective views of an upper surface portion of a piston in FIG. 9;

FIG. 11A is a vertical sectional side view of a swirl-type combustion chamber of a water-cooled vertical diesel engine showing prior art 1, FIG.
1 (B) is a plan view of the piston in FIG. 11 (A).

FIG. 12 is a perspective view of an upper surface portion of the piston in FIG. 11;

FIG. 13 (A) is a longitudinal sectional side view of a swirl type combustion chamber of a water-cooled vertical diesel engine showing prior art 2, FIG.
FIG. 3B is a plan view of the piston in FIG.

FIG. 14 is a perspective view of an upper surface portion of the piston in FIG. 13;

[Explanation of symbols]

1. Main room. 2. Whirlpool. 3 ... Nozzle. 4: Upper surface of piston. 5 ... Disc-shaped concave chamber. 6: combustion gas flow diffusion guide groove. 7: Dividing guide body. 8 ... groove bottom. 9 ... groove side edge. 10 ... groove start end. 11: groove end portion. 12
... Gutter end edge. 14 ... Indoor peripheral surface. 15 ... Guide body start end face. 19: Guide slope. 20: Groove bottom end. 2
1… Bottom of concave room. 22 ... ridge streak. 23 ridge streaks near the beginning 24 ... ridge streak portion near the end. 37 ...
Spiral up slope.

Continued on the front page (72) Inventor Hiroshi Suzuki 3-8 Chikushinmachi, Sakai City, Osaka Inside Kubota Sakai Rinkai Plant (72) Inventor George George 3-8 Chikushinmachi, Sakai City, Osaka Prefecture Kubota Corporation Inside the Sakai Rinkai Plant (72) Inventor Sachiko Nakagawa 3-8 Chikushinmachi, Sakai-shi, Osaka F-term in the Kubota Sakai Rinkai Plant 3G023 AA07 AB05 AC05 AD22 AD27 AD27 AD29

Claims (5)

[Claims] 1. A swirl chamber (2) is communicated with a main chamber (1) of a swirl chamber type combustion chamber of a diesel engine through an injection hole (3), and the injection hole (3) is an upper surface of the main chamber (1). The upper surface (4) of the piston, which forms the lower surface of the main chamber (1), has a pair of left and right disc-shaped concave chambers (5) and (5) and a combustion gas flow diffusion guide groove. (6)
And a diversion guide body (7). A pair of left and right disc-shaped concave chambers (5) and (5) are arranged to be separated from each other left and right within an intermediate region of the piston upper surface (4) in the front-rear direction. The flow diffusion guide groove (6) is formed from the rear area to the intermediate area in the front-rear direction in the middle area in the left-right direction of the piston upper surface (4).
(8) is formed so as to be inclined forward and upward, the left and right side edges (9) and (9) of the diffusion guide groove (6) are formed so as to extend forward, and the groove at the rear end of the diffusion guide groove (6) With the injection hole (3) facing the starting end (10), the groove end portion (11) near the front of the diffusion guide groove (6) is recessed toward the center of the piston of each disk-shaped concave chamber (5) (5). In the swirl chamber type combustion chamber of the diesel engine, the branch guide body (7) is raised from the groove bottom surface (8) in the middle of the groove width in the diffusion guide groove (6). The groove end edge (12) of the combustion gas flow diffusion guide groove (6) is located in each of the disc-shaped concave chambers (5), (5). The pair of left and right guide slopes (19) (1
9), and this pair of left and right guide slopes (19) and (19)
The left and right disk-shaped concave chambers (5) and (5) are smoothly connected to the inner peripheral surface of the inner peripheral surface (14) (14) near the center of the piston. Whirlpool combustion chamber for diesel engine. 2. The swirl type combustion chamber of a diesel engine according to claim 1, wherein a pair of left and right guide slopes (19) (19) of the branch guide body (7) is provided.
Of the ridge streaks (22), the ridge portion (23) near the beginning is located lower than the piston upper surface (4) and is formed in a substantially horizontal shape substantially parallel to the piston upper surface (4). 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. Features. 3. The swirl chamber type combustion chamber of a diesel engine according to claim 1, wherein a start end face (15) of the branch guide body (7) is formed as a slope rising forward. What to do. 4. The swirl type combustion chamber of a diesel engine according to claim 1, 2 or 3, wherein a groove bottom end located at a terminal end of a groove bottom (8) of the combustion gas flow diffusion guide groove (6). The portion (20) is positioned lower than the bottom surface (21) of the disc-shaped concave chamber (5), and the groove bottom end portion (20) and the concave chamber bottom surface (21) are spirally upwardly inclined. (37) Smoothly continuous through and configured. 5. The swirl chamber type combustion chamber of a diesel engine according to claim 1, wherein the groove bottom surface (8) of the combustion gas flow diffusion guide groove (6) is formed in a width direction of the groove. It is formed so as to be inclined downward from the right and left sides as it approaches the branch guide body (7).