JP2014092094A - Cooling water surge tank structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling water surge tank structure of an internal combustion engine which separates air bubbles and impurities from cooling water by utilizing a reinforcing rib in a surge tank with respect to cooling water for cooling the internal combustion engine, and improves durability and reliability of the internal combustion engine.SOLUTION: A cooling water surge tank structure of an internal combustion engine includes: a flat-shaped and longitudinal outer shell part 31; a wall part 31 which is protruded to the inner side from an inner surface of the outer shell part 31, forms a plurality of surrounding spaces S and has a cutoff part 35 causing cooling water to circulate through the surrounding spaces; a first inflow port 31c through which cooling water from a water jacket 1c inflows; a second inflow port 31b through which cooling water from a radiator inflows; a cooling water outflow port 31a which is arranged on an under part of the outer shell part 31 and returns cooling water to the internal combustion engine 1 therethrough; and an impurity storage part which is provided on a position facing cooling water falling from the above side in the surrounding spaces S on the upstream side of the cooling water outflow port 31a and opens the upper side thereof so as to deposit the impurities.

Description

  The present invention relates to a coolant surge tank structure for removing impurities contained in surge tank type cooling water disposed in a cooling water system of an internal combustion engine.

A cooling system for an internal combustion engine is provided with a cooling water circulation system for circulating cooling water between the internal combustion engine and a radiator so as to cool the internal combustion engine. In addition, bubbles and impurities generated in the cooling water cause a reduction in cooling capacity.
Further, rust of metal corrosion due to the occurrence of cavitation, crystals of cooling water due to ultraviolet rays, etc. may impair the reliability and durability of the internal combustion engine.
Therefore, as described in Japanese Patent No. 2667317 (Patent Document 1), a surge tank system using a surge tank is known.

  In the surge tank type internal combustion engine cooling system, a surge tank is connected to the internal combustion engine and the radiator, bubbles generated in the cooling water are separated by the surge tank, and the cooling water from which the bubbles are removed is returned to the internal combustion engine. Further, the surge tank is maintained at a pressure equivalent to the pressure in the radiator, and the pressure drop of the cooling water sucked by the water pump can be prevented.

  According to Patent Document 1, a reservoir tank that is located higher than the cooling water level in the internal combustion engine and stores the replenishing cooling water is communicated with the pressure of the header tank (surge tank), so There is a technical disclosure in which the pressure increase can be moderated by absorbing the space in the expansion space, and the deterioration of each component constituting the cooling water system of the internal combustion engine can be prevented.

Japanese Patent No. 2667317

In Patent Document 1, the increase in the pressure of the cooling water system at the start of the internal combustion engine is moderated, the pressure fluctuation range of the cooling water system during operation of the internal combustion engine is reduced, and the opening / closing frequency of the pressure cap attached to the surge tank Is increased to extend the interval for supplying the preliminary cooling water to the reservoir tank.
Therefore, there is a problem that impurities contained in the cooling water flowing from the cooling water system to the reservoir tank cannot be separated and the impurities cannot be prevented from returning to the cooling water system of the internal combustion engine again.

  In view of the problems of the prior art, the present invention separates bubbles and impurities from cooling water using cooling ribs in a surge tank from cooling water that has cooled the internal combustion engine, thereby improving durability and reliability of the internal combustion engine. The purpose is to improve.

In order to achieve such an object, according to the present invention, a water jacket through which cooling water for cooling the internal combustion engine flows,
A radiator for cooling the cooling water heated through the water jacket;
In the surge tank structure of the internal combustion engine that is located above the water jacket and the radiator in the direction of gravity and stores the cooling water,
A vertically long outer shell portion having a substantially rectangular shape in plan view and a long gravity direction;
Projecting inward from the inner surface of the outer shell portion to form a plurality of surrounding spaces, and a wall portion having a cutout portion through which the cooling water flows in the surrounding space;
A first inlet into which the cooling water from the water jacket flows;
A second inlet through which the cooling water from the radiator flows;
A cooling water outlet disposed at a lower portion in the gravity direction of the outer shell portion, and cooling water flowing in from the first and second inlets flows through the surrounding space and returns to the internal combustion engine;
In the surrounding space on the upstream side of the cooling water flow path of the cooling water outlet, in the position facing the cooling water descending from above in the gravitational direction, the isolation wall and the wall standing up from the inner surface of the outer shell in the gravitational direction An internal combustion engine cooling water surge tank structure comprising: an impurity storage portion that is open at an upper portion that precipitates impurities mixed in the cooling water.

According to this invention, since the impurity reservoir is provided in the surrounding space on the upstream side of the flow path of the cooling water outlet by the isolation wall rising upward in the gravitational direction, rust generated in the circulating flow path of the cooling water, cooling Crystals of substances contained in water can be separated efficiently.
Therefore, the reliability of the internal combustion engine can be improved, and the cooling water filter disposed on the downstream side of the cooling water flow path of the water pump can be eliminated, and the cost can be reduced.

  In the present invention, preferably, a flow path changing wall having a horizontal plane portion is disposed above the isolation wall in the direction of gravity.

  By adopting such a structure, the cooling water descending from above in the surge tank directly collides with the deposits in the impurity reservoir and rises, and the deposits flow out from the cooling water outlet to the internal combustion engine side. Can be prevented.

  In the present invention, it is preferable that the flow path changing wall has a length extending in the longitudinal direction of the substantially rectangular shape at a position approximately 1.5 times the height of the isolation wall from the inner surface of the outer shell. It is good to have 1/2 length of the length of the said surrounding space of the same direction, and to arrange | position over the short side direction whole region of the said substantially rectangular shape.

  By adopting such a structure, the cooling water is changed by the flow path changing wall, and along the horizontal wall surface while being turbulent, and flowing while colliding with the upper part of the isolation wall, the impurities are isolated from the cooling water. In addition to being promoted, it is possible to prevent the impurities accumulated at the bottom of the impurity reservoir.

  In the present invention, it is preferable that the flow path changing wall has a first flow path changing wall on the upper surface on the downstream side of the cooling water flow path with respect to the first flow path changing wall having an I-shaped cross section. An inverted T-shaped second flow path changing wall having a wall surface standing in the direction of gravity for receiving the flow of cooling water from the path changing wall may be provided in the horizontal direction.

  With such a structure, the cooling water descending from above flows on the upper surface of the second flow path changing wall by the cooling water guided and flowing by the first flow path changing wall, and the second By preventing the impurities from being deposited in the impurity reservoir located below the flow path change wall, and colliding the cooling water descending with the cooling water flowing from the first flow path change wall side, The flow of cooling water is stagnated to promote precipitation of impurities and prevent the precipitation from rising.

  In the present invention, preferably, the flow cross-sectional area of the notch through which the cooling water flows in the surrounding space is mixed.

By adopting such a structure, the flow rate of the cooling water flowing in the surge tank is changed, thereby causing a disturbance in the flow of the cooling water and facilitating the separation of the mixed foreign matters.
Furthermore, the notch area of the portion where the surface rigidity of the outer shell is low can be reduced, and the rigidity of the entire surge tank can be improved.

  In the present invention, it is preferable that a drain device for discharging the precipitate out of the cooling water surge tank is disposed in the outer shell of the impurity reservoir.

  By adopting such a structure, the stored sediment is discharged, and it is ensured that impurities are prevented from entering the cooling water flowing out to the internal combustion engine.

  In the present invention, it is preferable that a communication hole that communicates between the impurity reservoirs is provided in a base portion of the isolation wall.

  By adopting such a structure, the sediment precipitated between the plurality of impurity isolation walls can be discharged with one drain device, and an increase in cost can be suppressed.

  According to the present invention, it is possible to improve the durability and reliability of the internal combustion engine by separating the air and impurities from the cooling water using cooling ribs in the surge tank. it can.

1 shows a cooling water system configuration diagram of an internal combustion engine mounted on a vehicle in which the present invention is implemented. The external appearance perspective view of the surge tank by which this invention is implemented is shown. The perspective view of the reinforcing rib and notch part inside the surge tank of this invention is shown. The principal part detail drawing of 1st Embodiment of this invention is shown. FIG. 6 shows an embodiment of the drain shape of FIG. 4. The principal part detail drawing of 2nd Embodiment of this invention is shown. The detailed explanatory view of the cooling water 1st channel in a 2nd embodiment is shown. The detailed explanatory view of the cooling water 2nd channel in a 2nd embodiment is shown.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.
In general, water or a liquid having antifreezing and rust prevention effects is used as the cooling medium. In the present embodiment, these are collectively referred to as “cooling water”.

(First embodiment)
An overall configuration in which the present invention is applied to an internal combustion engine mounted on a vehicle will be described with reference to FIGS.
FIG. 1 is a configuration diagram of a cooling water system of an internal combustion engine mounted on a vehicle. 1 is an internal combustion engine mounted on the vehicle, 2 is a radiator that cools cooling water discharged from the internal combustion engine 1, and 3 is a surge according to the present invention. The surge tank 3 is located above the water jacket 1a and the radiator 2 through which the cooling water for cooling the internal combustion engine 1 flows in order to separate bubbles and impurities mixed in the cooling water. A pressure cap 10 is installed to maintain the same pressure as that of the cooling water system. 7 is a thermostat that senses the temperature of the cooling water and changes the flow path of the cooling water, and 8 is a water pump that is driven along with the operation of the internal combustion engine 1 to flow the cooling water in the cooling water system. Reference numeral 9 denotes a radiator fan that sucks air, which has been heated by heat exchange between cooling water and air in the radiator 2, from the heat exchange section of the radiator 2.
Impurities are rust generated in the cooling water system, or substances generated by chemical reaction of additives contained in cooling water when the cooling water is exposed to ultraviolet rays while the vehicle is in use for a long time. Etc.

When the internal combustion engine 1 is started and the internal combustion engine 1 is not sufficiently warmed up (when cold), the cooling water flows from the internal combustion engine 1 to the thermo stud 7 via the pipe P4, and from the thermo stud 7 through the pipe P6. The water pump 8 is reached, and the water pump 8 is again pumped into the water jacket 1a of the internal combustion engine 1, and the circulation is repeated until the internal combustion engine 1 is sufficiently warmed up.
When the warm air of the internal combustion engine 1 advances and the temperature of the cooling water rises above a specified level, the thermo stud 7 stops the cooling water from the pipe 4 from flowing to the pipe 6 side, and flows to the pipe 7 side, so that the radiator The cooling water is cooled by 2, and is pumped into the water jacket 1 a of the internal combustion engine 1 by the water pump 8 through the pipe 5 to cool the internal combustion engine 1.

Further, when the internal combustion engine 1 is operated at a high speed, a high load, etc., the temperature of the cooling water rises as the temperature rises. The expanded amount of cooling water flows into the surge tank 3 via the pipe P1 and the pipe P2.
The cooling water flowing into the surge tank 3 is cooled in the surge tank 3 and air bubbles mixed in the cooling water are removed and sucked into the water pump 8 via the pipe P3. The pump 8 is pumped to the water jacket 1a and circulates in the cooling water system in a state where the occurrence of cavitation is suppressed.

Further, the pressure cap 10 always maintains the pressure of the cooling water system in an appropriate state.
This is maintained above atmospheric pressure in order to raise the boiling temperature of the cooling water and enhance the cooling effect of the cooling water.
As the cooling water temperature in the cooling water system rises, the pressure also rises. When the pressure in the surge tank 3 exceeds a specified value, the pressure cap 10 communicates with the outside air to lower the pressure.
On the other hand, when the cooling water temperature decreases, the inside of the surge tank 3 and the radiator 2 become negative pressure, the pressure cap 10 introduces outside air, and the pressure in the surge tank 3 is increased to keep it at a specified value. .

FIG. 2 is an external perspective view of the surge tank 3. The surge tank 3 is manufactured separately from a first outer shell portion 31 and a second outer shell portion 32 with a dividing line Z extending in the vertical direction (gravitational direction) as a boundary, As a result of welding, a surge tank 3 having a sealed inside is formed.
In particular, the surge tank 3 has a structure in which a floor surface (not shown) of the driver's seat is arranged above the internal combustion engine 1 such as a cab-over type truck, and a sufficient space cannot be secured between the internal combustion engine 1 and the floor surface. In order to adapt to the vehicle, a substantially rectangular parallelepiped having a substantially rectangular shape in a plan view and a long gravitational direction is formed on the back surface of the cabin.
When the direction of the surge tank is indicated, for the sake of easy explanation, the long side direction of the rectangle is described as “longitudinal direction”, the short side direction is described as “thickness direction”, and the gravity direction is described as “vertical direction”.

A cooling water outlet 31a for returning the cooling water of the surge tank 3 to the water pump 8 through the pipe P3 and cooling water from the radiator 2 and the like flow into the first outer shell portion 31 of the surge tank 3 through the pipe P2. A first inlet 31b and a second inlet 31c into which cooling water from the water jacket 1a of the internal combustion engine 1 flows in via the pipe P1 are provided in the lower part in the vertical direction.
A pressure cap 10 that maintains the pressure of the cooling water system at a specified value is attached to the upper portion of the first outer shell portion 31 of the surge tank 3 in the vertical direction.
In addition, a replenishing port 31d for replenishing when the cooling water is insufficient is provided in the middle portion in the vertical direction of the first outer shell portion 31.
Further, two mounting holes 31e for fitting a total of four fastening members (not shown) for mounting the vehicle body are formed in the middle portion in the vertical direction of the surge tank 3 and two in the lower portion.
31f is a level sensor mounting hole for detecting the minimum necessary amount of cooling water in the surge tank 3.

FIG. 3 shows the internal structure of the surge tank 3 on the first outer shell portion 31 side.
The first outer shell portion 31 of the surge tank 3 has an outer peripheral wall 31m that protrudes in the thickness direction in a circumferential shape (substantially rectangular shape), and a flat wall 31n that closes the outer peripheral wall 31m is disposed. The center has a space-like pan shape.
In the central space portion, a plurality of reinforcing ribs 31p, which are continuous wall portions between the opposing outer peripheral walls 31m having a rectangular shape (a grid shape), are provided to form a large number of surrounding spaces S surrounded by a rectangular shape. doing.
The reinforcing rib 31p is formed so that the base portion is connected to the planar wall 31n and the height (thickness direction) is flush with the dividing line Z of the outer peripheral wall 31m.
The reinforcing rib 31p that forms the surrounding space S is provided with large and small notches 35 (35a, 35b, 35c) so that the cooling water can flow through the surrounding space S.

Although not shown, the second outer shell portion 32 is formed in the same manner as the first outer shell portion 31.
However, the second outer shell portion 32 is not provided with the cooling water outlet 31a, the first and second inlets 31b, 31c, and the level sensor attachment hole 31f.
That is, it is formed so that the outer peripheral shape of the dividing line Z and the arrangement position of the reinforcing rib continuous between the outer peripheral walls 31m face each other.
Therefore, by welding the first outer shell 31 and the second outer shell 32 along the dividing line Z, the closed surrounding space S is in communication with the cooling water through the notch.

The reinforcing rib 31p is for increasing the rigidity of the surge tank 3 in the thickness direction, and has a cutout portion 35 for circulating cooling water.
The cutout portion 35 is provided with a small cutout portion 35a, an intermediate cutout portion 35b, and a large cutout portion 35c.
Many large notches 35c are provided around the periphery of the mounting hole 31e.
This is because the first outer shell portion 31 and the second outer shell portion 32 are continuously arranged in the thickness direction of the surrounding member forming the attachment hole 31e, so that rigidity in the thickness direction is easy. This is because it can be secured.
Moreover, many small notches 35a are provided in the upper part (gravity direction) of the surge tank 3 in which the attachment hole 31e and the inlet / outlet of a cooling water are not arrange | positioned.
Many intermediate notches 35b are provided in a portion located between the attachment hole 31e in the vertical middle part of the surge tank 3 and the lower attachment hole 31e.
This is an arrangement in which both sides are supported by attachment holes 31e having high rigidity in the thickness direction.

And the upper part of the surge tank 3 with many small notches 35a is a part in which the steam stays contained in the cooling water, and there is almost no circulation of the cooling water.
Accordingly, the rigidity of the surge tank 3 can be ensured without increasing the flow resistance of the cooling water.
In addition, by mixing the middle notch 35b and the large notch 35c, changing the flow rate of the cooling water causes turbulence in the cooling water and makes it easy to separate impurities mixed in the cooling water. Has an effect.
Cooling water from the radiator 2 side is introduced into the surging tank 3 from the first inflow port 31b, flows upward through the small cutouts 35a, and passes through the cutouts 35 as shown by the broken line A1. To flow.
On the other hand, the cooling water from the water jacket 1a of the internal combustion engine 1 is introduced into the surge tank 3 from the second inlet 31C, flows upward through the small notch 35a as shown by the broken line A2, and passes through each notch 35. Passes and flows downward.
Therefore, the water level of the cooling water is usually up to the B line position, and the vapor separated from the cooling water is filled above the B line.

FIG. 4 shows an enlarged view of the lower portion of the surge tank 3 in the vertical direction (gravity direction).
In FIG. 4, an isolation wall 31 g erected upward from the outer peripheral wall 31 m at the lower part of the first outer shell 31 is disposed in the surrounding space S. The isolation wall 31g, the reinforcing rib 31p, and the outer peripheral wall 31m form an impurity storage portion 36 that opens upward.
A communication hole 31h through which precipitated impurities can flow is formed at the base of the isolation wall 31g that separates the impurity storage part 36g and the impurity storage part 36j.
Further, a drain device 37 is attached to the outer peripheral wall 31m which is the bottom of the impurity reservoir 36j.

The drain device 37 includes a wing-like rotation operation portion 37a, a screw portion 37b that is screwed into a screwing hole 31g disposed in the outer peripheral wall 31m that is the bottom of the impurity storage portion 36j of the surge tank 3, and a rotation operation portion. It is comprised with the water-tight seal ring 38 clamped by the connection part of 37a and the screw part 37b, and the outer peripheral wall 31m.
The screw portion 37b is connected to a joint portion of the screw portion 37b with the rotation operation portion 37a. The screw portion 37b communicates with the through hole 37d in the radial direction through the screw portion 37b, and opens to the impurity storage portion 36. And an impurity discharge hole 37c provided along the axis of the screw portion 37b.
In the impurity discharging method, the rotation operation portion 37a is rotated to expose the through hole 37d outward from the outer peripheral wall 31m, whereby the impurities flow in the order of the impurity discharge hole 37c → the through hole 37d and are discharged out of the surge tank 3. The

In the state of FIG. 4, the cooling waters W1, W2, and W3 descending from above are introduced into the impurity reservoir 36 (three in FIG. 4) from the three intermediate notches 35b. The cooling water introduced into the impurity reservoir 36 is discharged from the cooling water outlet 31a to the water pump 8 side through the isolation wall 31g.
However, since the clearance L between the upper end of the isolation wall 31g and the surrounding member that can form the mounting hole 31e is smaller than that of the large notch 35c, the cooling water stagnates in the impurity reservoirs 36h, 36j, and 36k. The impurities are deposited at the bottom of each impurity reservoir 36h, j, k.
Impurities deposited on the bottom of the impurity reservoir 36 flow to the impurity reservoir 36j provided with the drain device 37 through the communication hole 31h, and are discharged out of the surge tank 3 by the drain device 37.
In this way, the impurities mixed in the coolant are positively precipitated in the impurity reservoir 36 so as not to enter the water jacket 1a of the internal combustion engine 1, thereby making the internal combustion engine 1 reliable and durable. The effect which improves property is acquired.

(Second Embodiment)
The embodiment of the present invention is the same as the first embodiment except that the storage structure of the impurity storage portion 36 in the lower part (gravity direction) of the surge tank is different, so only that portion will be described and the rest will be omitted.
Note that members having the same shape and the same action are denoted by the same reference numerals and description thereof is omitted.

FIG. 6 is the same as the first embodiment except that a cooling water flow path changing wall is provided above the impurity reservoir 36.
An isolation wall 31g stands upward from an outer peripheral wall 31m at the lower part of the surge tank 30. The isolation wall 31g, the reinforcing rib 31p, and the outer peripheral wall 31m form a plurality of impurity reservoirs 36 that open upward.
The plurality of impurity reservoirs 36 include a first impurity reservoir 36a, a second impurity reservoir 36b, and a third impurity reservoir 36c from a corner (left side in FIG. 6) where the outer peripheral wall 31m rises upward in the gravity direction from the bottom. The fourth impurity reservoir 36d, the fifth impurity reservoir 36e, the sixth impurity reservoir 36f, and the seventh impurity reservoir 36g are formed in this order.
The first and second flow path changing walls 51 and 52 for changing the flow path of the cooling water are disposed above the impurity reservoir 36.
Since the cooling water passes through the notches 35 and descends through a number of paths, the first flow path Q1 and the second flow path Q2 shown in FIG. 6 will be described as a representative example.

The first flow path Q1 for the cooling water will be described.
A large cutout portion 35c formed in the reinforcing rib 31p that separates the first impurity storage portion 36a and the second impurity storage portion 36b has a flow path of cooling water across the first impurity storage portion 36a and the second impurity storage portion 36b. A first flow path changing wall 51 is provided to change the above.
As shown in FIG. 7, the first flow path changing wall 51 is continuous from the notch end edge of the large notch 35c to the second outer shell 32 side (opposite to the front side in FIG. 7).
The vertical position of the first flow path changing wall 51 is approximately H / 2 above the lower end of the large notch 35c with respect to the height H from the inner peripheral surface of the outer peripheral wall 31m to the lower end of the large notch 35c of the reinforcing rib 31p. The first flow path changing wall 51 is disposed such that the lower surface 51a, which is a horizontal plane portion, is located there.
The length of the first flow path changing wall 51 in the width direction (longitudinal direction of a substantially rectangular shape in plan view) is approximately ½ of the impurity storage portion 36 in the same direction.

This is because if the distance between the isolation wall and the flow path changing wall is large, the turbulent flow of the cooling water is not rectified, and the cooling water flows into the first impurity reservoir 36a and the second impurity reservoir 36b, Soar.
On the other hand, if the distance between the isolation wall and the flow path changing wall is small, the flow resistance of the cooling water that passes between them increases, the flow velocity increases, and the substance to be precipitated together with the cooling water flows from the cooling water outlet to the internal combustion engine side. Spill to
Further, in the case of FIG. 7, since the sum in the width direction of the first impurity reservoir 36a and the second impurity reservoir 36b is W, W / 2 is the first impurity reservoir 36a and the second impurity reservoir 36b. It becomes approximately ½ of the width direction of each.
Even in this case, if the length W in the width direction of the first flow path changing wall 51 is longer than approximately ½ of the impurity storage portion 36 in the same direction, the surrounding reinforcing ribs 31p and the first flow path changing wall 51 The distance to the edge in the width direction (cooling water flow cross-sectional area) is reduced, and the flow resistance of the cooling water is increased.
When the length W in the width direction becomes shorter than about ½, the cooling water is not clarified, and the cooling water flows into the first impurity storage part 36a and the second impurity storage part 36b, and the precipitate is soared.

In the case of the first flow path Q1 of the cooling water having such a structure, the first flow path Q1 flows through the upper surface of the first flow path changing wall 51 to the first impurity storage section 36a side and the second impurity storage section 36b. Shunt to the side.
The cooling water that has flowed into the first impurity reservoir 36a becomes a spiral turbulent flow in the first impurity reservoir 36a.
However, since the gap H / 2 between the first flow path changing wall 51 and the lower end of the large cutout portion 35c is substantially half of the height H to the lower end of the large cutout portion 35c of the reinforcing rib 31p, it is within the first impurity storage portion 36a. The cooling water flow becomes slower, and the separation of impurities and the precipitation of the impurities at the bottom of the first impurity reservoir 36a are promoted.
In addition, since the cooling water descending from above does not directly collide with the precipitated impurities, the rising of the precipitate is prevented.
Thereafter, the lower surface 51a of the first flow path changing wall 51 flows toward the second impurity reservoir 36b.
On the other hand, the cooling water that has flowed into the second impurity reservoir 36b side merges with the cooling water that has flowed through the lower surface 51a of the first flow path changing wall 51 at the upper part of the second impurity reservoir 36b. The inflow speed (inflow momentum) into 36b is inhibited, and the rise of impurities that have settled at the bottom of the second impurity reservoir 36b is suppressed. Then, it flows to the third impurity reservoir 36c side.
Impurities precipitated in the first and second impurity reservoirs 36a and 36b flow to the third impurity reservoir 36c via the communication holes 31h.
The height of the lower surface 51A of the first flow path changing wall 51 is 1.5H (height H to the lower end of the notch 35c + the gap H / 2), and the length in the width direction of the first flow path changing wall 51 is an impurity. Although described as the widthwise length W / 2 of the reservoir 36, the height of the lower surface 51A of the first flow path changing wall 51 is 1.5 ± 0.2H,
It has been confirmed that good results can be obtained even if the width direction lengths are appropriately combined within the range of W / 2 ± W / 5.

The 2nd flow path Q2 of a cooling water is demonstrated.
An isolation wall 31g stands in the gravitational direction from the inner peripheral surface of the outer peripheral wall 31m in the middle portion in the longitudinal direction of the rectangular (cell-shaped) surrounding space S surrounded by the reinforcing ribs 31p.
A large notch 35cu formed in the reinforcing rib 31pu is disposed above the isolation wall 31g.
As shown in FIG. 8, an inverted T-shaped second flow path changing wall 52 is disposed at an intermediate portion between the large notch 35cu and the isolation wall 31g.
The inverted T-shaped second flow path changing wall 52 has a shape having a horizontal surface 52a on the lower side and a protruding portion 52b that protrudes in the direction perpendicular to the horizontal surface at the upper middle portion of the horizontal surface 52a on the upper side. doing.
The second flow path changing wall 52 is disposed by connecting the first outer shell portion 31 and the second outer shell portion 32.
The vertical position of the lower surface 52a of the second flow path change wall 52 is such that the height H of the isolation wall 31g from the inner peripheral surface of the outer peripheral wall 31m is the plane of the second flow path change wall 52 from the upper edge of the isolation wall 31g. It arrange | positions so that the clearance gap to the horizontal surface 52a which is a part may become a position of substantially H / 2.
The length of the second flow path changing wall 52 in the longitudinal direction is substantially W / 2 in the same direction of the impurity reservoir 36.

In the case of the second flow path Q2 of the cooling water having such a structure, the second flow path Q2 contacts the upper surface of the second flow path changing wall 52. The flow is divided into the sixth impurity storage part 36f side and the seventh impurity storage part 36g side by the protrusion 52b of the second flow path changing wall 52.
The cooling water that has flowed into the sixth impurity storage portion 36f side merges with the cooling water that has flowed from the fifth impurity storage portion 36e side, so that the flow velocity becomes slow.
Therefore, the cooling water flowing into the sixth impurity reservoir 36f becomes a spiral turbulent flow but has a low flow rate.
The cooling water in the sixth impurity reservoir 36f promotes impurity separation and precipitation.
The protrusion 52b of the second flow path changing wall 52 causes a large amount of cooling water to flow from the upper side to the seventh impurity storage part 36f side by cooling water flowing from the fifth impurity storage part 36e side. Prevents uneven flow.

Furthermore, since the gap H / 2 between the flat portion 52a of the second flow path changing wall 52 and the upper edge of the isolation wall 31g is substantially half of the height H of the isolation wall 31g, the cooling in the first impurity storage portion 36a is performed. The flow of water is further slowed, promoting the separation of impurities and the precipitation of the impurities at the bottom of the first impurity reservoir 36a.
In addition, since the cooling water descending from above does not directly collide with the precipitated impurities, the rising of the precipitate is prevented.
Then, the lower surface 52a of the second flow path changing wall 52 flows toward the seventh impurity reservoir 36g.
On the other hand, the cooling water that has flowed into the seventh impurity storage portion 36g merges with the cooling water that has flowed through the lower surface 52a of the second flow path changing wall 52 at the upper portion of the seventh impurity storage portion 36g. The inflow speed into 36f is hindered, and the rise of impurities deposited on the bottom of the second impurity reservoir 36b is suppressed.
Thus, by using the I-shaped first flow path change wall 51 and the inverted T-shaped second flow path change wall 52 on the downstream side of the cooling water path of the first flow path change wall 51 in combination, Impurity separation from the cooling water can provide a more effective action.
Further, an impurity storage portion in which a drain device 37 is disposed for draining impurities precipitated in each impurity storage portion 36 by a separation hole 31g forming each impurity storage portion 36 and a communication hole 31h provided in a base portion of the reinforcing rib 31p. 36 g and can be discharged to the outside of the reserve tank 3 by the drain device 37. In this way, an increase in the cost of the reserve tank 3 can be suppressed.
In the present embodiment, the first flow path changing wall 51 and the second flow path changing wall 52 are used in combination, but each may be used separately, or a plurality may be used in appropriate combination. It becomes possible.

  The cooling water that has cooled the internal combustion engine is disposed in the cooling water system of the internal combustion engine to improve the durability and reliability of the internal combustion engine by separating bubbles and impurities from the cooling water using the reinforcing ribs in the surge tank. Available for the constructed surge tank structure.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 1a Water jacket 2 Radiator 3 Surge tank 8 Water pump 10 Pressure cap 31 1st outer shell (outer shell part)
31a Cooling water outlet 31b 1st inlet 31c 2nd inlet 31g Separation wall 31h Communication hole 31p Reinforcement rib (partition wall)
32 Second outer shell (outer shell)
35 Notch part 36 Impurity storage part 37 Drain device 51 1st flow path change wall (flow path change wall)
52 Second channel change wall (channel change wall)
S Go space

Claims (7)

A water jacket through which cooling water for cooling the internal combustion engine flows;
A radiator for cooling the cooling water heated through the water jacket;
In the surge tank structure of the internal combustion engine that is located above the water jacket and the radiator in the direction of gravity and stores the cooling water,
A vertically long outer shell portion having a substantially rectangular shape in plan view and a long gravity direction;
Projecting inward from the inner surface of the outer shell portion to form a plurality of surrounding spaces, and a wall portion having a cutout portion through which the cooling water flows in the surrounding space;
A first inlet into which the cooling water from the water jacket flows;
A second inlet through which the cooling water from the radiator flows;
A cooling water outlet disposed at a lower portion in the gravity direction of the outer shell portion, and cooling water flowing in from the first and second inlets flows through the surrounding space and returns to the internal combustion engine;
In the surrounding space on the upstream side of the cooling water flow path of the cooling water outlet, in the position facing the cooling water descending from above in the gravitational direction, the isolation wall and the wall standing up from the inner surface of the outer shell in the gravitational direction An internal combustion engine cooling water surge tank structure comprising: an impurity storage portion formed at a top portion, the upper portion being formed to precipitate impurities mixed in the cooling water.   2. A cooling water surge tank structure for an internal combustion engine according to claim 1, wherein a flow path changing wall having a horizontal plane portion is disposed above the isolation wall in the gravitational direction.   The flow path changing wall has a length extending in the longitudinal direction of the substantially rectangular shape at a position approximately 1.5 times the height of the isolation wall from the inner surface of the outer shell. The cooling water surge tank structure for an internal combustion engine according to claim 2, wherein the cooling water surge tank structure has a length of ½ of the length and is disposed over the entire area of the substantially rectangular short side direction.   The flow path changing wall includes a first flow path changing wall having an I-shaped cross section, and a cooling water flow from the first flow path changing wall on an upper surface on the downstream side of the cooling water flow path of the first flow path changing wall. 4. The cooling of an internal combustion engine according to claim 2, further comprising an inverted T-shaped second flow path changing wall having a wall surface standing in a gravitational direction for receiving a flow in the horizontal direction. Water surge tank structure.   The cooling water surge tank structure for an internal combustion engine according to any one of claims 1 to 4, wherein a flow cross-sectional area of the notch through which the cooling water flows through the surrounding space is mixed.   The cooling water surge of the internal combustion engine according to any one of claims 1 to 5, wherein a drain device for discharging the precipitate out of the cooling water surge tank is disposed in the outer shell of the impurity reservoir. Tank structure.   The cooling water surge tank structure for an internal combustion engine according to any one of claims 1 to 6, wherein a communication hole communicating between the impurity reservoirs is provided in a base portion of the isolation wall.

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