JP6542025B2 - Cylinder block - Google Patents

Description

  The present invention relates to a cylinder block constituting an internal combustion engine for vehicles and the like.

  The cylinder block is provided with a cooling water jacket through which the cooling water flows, and the cooling water jacket is generally formed in a closed loop shape surrounding the cylinder row. The cooling water jacket is supplied with cooling water from a cooling water inlet passage, and the cooling water inlet passage is generally open at one end surface to which a front cover covering the timing chain is fixed.

  Therefore, the cooling water inlet passage is in an attitude (horizontal attitude in the case of a vertical internal combustion engine) orthogonal to the axis of the cylinder. The reason why the cooling water inlet passage is provided on the side of the front cover is that the water pump is driven by the accessory drive belt disposed outside the front cover. The cooling water that has flowed into the cooling water jacket of the cylinder block generally flows into the jacket of the cylinder head via the cooling water jacket. For this reason, the cylinder head has a plurality of communication holes opened downward.

The cylinder head fixed to the top surface of the cylinder block has a higher temperature on the exhaust side than on the intake side. For this reason, the cylinder block also has a higher temperature on the side of the exhaust side than on the side of the intake side due to heat transfer from the cylinder head. Therefore, in order to suppress the thermal distortion of the cylinder, it may be highly necessary to cool the exhaust side more strongly than the intake side.

  Therefore, it has been proposed to control the flow direction of the cooling water flowing into the cooling water jacket to level the temperature gradient between the intake side and the exhaust side, and as an example, Patent Document 1 discloses A guide member made of a plate material is provided at a portion of the cooling water jacket to which the cooling water inlet passage is connected, so that a large portion of the cooling water flows in one direction and a portion of the cooling water flows in the other direction. Structure is disclosed.

Unexamined-Japanese-Patent No. 04-214951 gazette

  In Patent Document 1, the outlet of the cooling water inlet passage faces the axial center of the cylinder. Therefore, in the absence of the guide member, the cooling water flows through the cooling water jacket substantially equally in one direction and the other direction, and the amount of the cooling water flowing in the other direction is controlled by the guide member. It is possible to control the ratio between the amount flowing in one direction and the amount flowing in the other direction, but because it incorporates a guide member separate from the cylinder block, it not only increases the cost but also mixes with the cooling water if rusting occurs. There is a concern about problems that adversely affect water pumps and the like.

  In this respect, it is considered good to form guide parts such as projections and grooves on the cylinder block, but this method manufactures molds and cores if the actual flow is not as designed. Since it is necessary to rework, if the problem of fine adjustment takes time and the flow velocity of the cooling water changes due to the change of the engine specifications, the mold and core must be remanufactured, and the response to the change of the specifications is required. There is a problem that it takes time and money.

  The present invention has been made in view of such a current situation, and an object of the present invention is to provide a more improved cylinder block.

The cylinder block of the present invention is
"I have a cooling water jacket that surrounds the cylinder row, and a cooling water inlet passage that feeds water to the cooling water jacket,
While previous SL cooling water jacket is open to a top surface facing the cylinder head,
Before SL cooling water inlet passage is elongated in the crank axial direction, the inlet of the cooling water inlet passage is open to one end face facing the crank axial direction, the outlet of the cooling water inlet passage, the cooling water jacket And open to both the top surface and
In the configuration,
" The outlet of the cooling water inlet passage is formed by cutting out a film-like portion arranged to separate the outlet and the cooling water jacket with a drill in a posture parallel to the axis of the cylinder. The curved surface formed at the outlet by the drilling is formed as a straightening guide portion which makes a part of the cooling water U-turn to the cooling water jacket.
The configuration is added.

  If the cooling water jacket and the cooling water inlet passage are manufactured in communication with each other in advance, the core for forming the cooling water jacket and the core for forming the cooling water inlet passage must be brought into contact with each other. In addition, if the contact between the cores is incomplete, problems such as burrs may occur. On the other hand, in the present invention, since the core for forming the cooling water jacket and the core for forming the cooling water inlet passage are separated from each other, the structure of the mold can be prevented from being complicated and burrs can be prevented. There is no problem like the occurrence of

  And since it is what forms the rectification | straightening guide part which controls the flow of a cooling water using cutting out the film-like part which arose for the easiness and reliability of manufacture by drilling, it costs up. An appropriate flow of cooling water in the cooling water jacket can be realized without being invited. In addition, since no separate member is provided, problems such as rusting do not occur.

  Furthermore, by changing the position and depth of drilling, or the drill diameter, etc., appropriate flow conditions can be obtained, so that fine adjustment can be performed easily and at low cost to match actual products, and the cylinder block It is easy to cope with the case where the model or specifications are changed while making the same.

As described above, since the temperature of the cylinder block rises higher on the side of the exhaust side than on the side of intake, it is highly necessary to strongly cool the side of the exhaust side in order to suppress the thermal distortion of the cylinder. In this respect, in the present invention, the cooling water discharged from the cooling water inlet passage can be U-turned and efficiently guided to the side of the exhaust side, so the side of the exhaust side is properly cooled to contribute to the suppression of thermal distortion. it can.

  Also, by adjusting the drilling depth, the depth of the cooling water discharged from the cooling water inlet passage can also be adjusted into the cooling water inlet passage, so that the cooling water stagnates at the bottom of the cooling water jacket. Can be easily prevented.

(A) is a top view of the partial before drill processing of the cylinder block concerning a 1st embodiment, (B) is an important section plane sectional view of (A). (A) is a cross-sectional view taken along line IIA-IIA in FIG. 1 (A), and (B) is a cross-sectional view taken along line IIB-IIB in FIG. 1 (A). It is a plane sectional view of an important section after drilling processing.

Next, an embodiment of the present invention will be described based on the drawings . Direction In the description follows, the use of the left and right wording front and rear for specifying the direction, the front-rear direction is the crank axial direction, the lateral direction is orthogonal to both the crank axis and the cylinder axis It is.

  In the cylinder block 1, a plurality of cylinders 3 and 4 opened to a top surface (upper surface) 2 and a crank chamber (not shown) are formed in series in the direction of the crank axis O. Further, an open loop cooling water jacket 5 surrounding the cylinder row is formed to open toward the top surface 2. The cooling water jacket 5 makes the distance between the cylinders 3 and 4 as uniform as possible, so the distance between the bores 6 is narrowed.

  Of the outer periphery of the cylinder block 1, the side surface on one side across the row of cylinders 3 is an intake side surface 7, and although not shown, the other side is an exhaust side surface. The "intake side" and "exhaust side" indications are given in FIG. 1 just in case. Needless to say, the cylinder head overlapped and fixed to the cylinder block 1 also has the same intake side and exhaust side as the cylinder block 1, the intake manifold is fixed to the intake side, and the exhaust side is the exhaust side The manifold is fixed.

A front cover 9 covering a timing chain (not shown) is fixed to one end face 8 of the outer periphery of the cylinder block 1 facing the direction of the crank axis O, and the crank shaft O is sandwiched in the front cover 9 A water pump 10, which is driven by an accessory drive belt (not shown), is disposed at a position shifted to the intake side 7 side.

A return pipe (not shown) is connected to the water pump 10, and the cooling water pressurized in the pump chamber passes through the passage provided in the front cover 9, and the cooling water inlet passage 11 formed in the cylinder block 1 Flow into Accordingly, the cooling water inlet passage 11 has a long attitude in the direction of the crankshaft axis O, and the inlet is open toward one end surface 8 of the cylinder block 1.

In FIG. 1, two cylinders 3 and 4 are displayed, and for convenience, the cylinder close to one end face 8 of the cylinder block 1 is referred to as a first cylinder 3 and the cylinder adjacent thereto is referred to as a second cylinder 4. The cooling water inlet passage 11 is located closer to the intake side 7 than the cooling water jacket 5 across the first cylinder 3, and the end portion (outlet) 11 a is the transverse center line 12 of the first cylinder 3. It is located on the side of the second cylinder 4 slightly more than that.

  The portion of the cooling water jacket 5 located in the vicinity of the end 11 a of the cooling water inlet passage 11 is a slightly wide bulge portion 5 a, and when casting the cylinder block 1, the portion of the bulge portion 5 a The cooling water jacket 5 and the cooling water jacket 5 are manufactured in a state of being separated by the film-like portion 13. That is, although the end 11a of the cooling water inlet passage 11 and the swelling portion 5a of the cooling water jacket 5 communicate with each other in principle, they are cast in a state of being separated by the membrane 13.

The film-like portion 13 is curved so as to be convex in a direction opposite to the crank axis O in a plan view (a view in the cylinder axis direction), and is a vertically long wall in a front cross-sectional view . Therefore, the film-like portion 13 is in a state of entering the side of the cooling water jacket 5 (the film-like portion 13 is formed in a state of dividing the end of the cooling water jacket 5 into two). . As shown in FIG. 2, the cooling water jacket 5 has a cross-sectional shape close to a square (trapezoid) in a front view.

As indicated by the alternate long and short dash line in FIG. 2B, the membrane 13 is cut away by the drill 14 in the same posture as the axis 16 of the cylinder 3. Accordingly, the end 11 a of the cooling water inlet passage 11 is open to both the cooling water jacket 5 and the top surface 2.
Then, as shown in FIG. 3, the axial center 15 of the drill 14 is shifted by a certain size E3 toward the intake side 7 side with respect to the inner side surface 11 b of the cooling water inlet passage 11 to cut off the membrane 13 and At the same time, at the back of the cooling water inlet passage 11, there is formed a straightening guide portion 17 curved in a concave state toward the cooling water jacket 5 when viewed from the direction of the cylinder axis 16.

In this embodiment, the axis 15 of the drill 14, (forward) in the side one end face 8 than the axis 16 of the first cylinder 3 is slightly dimensions E1 deviation. Further, the rear end of the straightening guide portion 17 is deviated toward the second cylinder 4 by a certain size E 2 with respect to the axial center 16 of the cylinder 3.

(2 ). Summary In the above configuration, the cooling water flowing into the cooling water inlet passage 11 flows into the cooling water jacket 5, but since the cooling water is provided with a rectilinearity in the cooling water inlet passage 11, the cooling water inlet Part of the cooling water discharged from the passage 11 flows in the cooling water jacket 5 in the direction of the second cylinder 4 as indicated by the arrow 18.

On the other hand, since the straightening guide portion 17 is concave toward the outlet side of the cooling water inlet passage 11, a part of the cooling water discharged from the cooling water inlet passage 11 is subjected to a direction changing action by the straightening guide portion 17. Then, as shown by the arrow 19, the cooling water jacket 5 flows toward the front side and flows toward the exhaust side.

  The ratio between the amount of cooling water going straight and the amount of cooling water reversing can be adjusted by shifting the processing position of the drill 14 in the front-rear direction or in the left-right direction. That is, when the position of the drill 14 is shifted in the direction away from the cooling water jacket 5, the curved surface of the straightening guide portion 17 becomes large and the action of inhibiting the straightness of the cooling water becomes high, so the amount of reversal of the cooling water increases.

  On the other hand, when the drill 14 is shifted rearward, the cooling water slides in the cooling water jacket 5 and the amount of the cooling water flowing to the side of the intake side 7 increases. Therefore, by adjusting the back and forth position and the left and right position of the drill 14, a desired diversion function can be realized. When the swelling portion 5a is provided in the cooling water jacket 5 as in the cooling water jacket 5, since the swelling portion 5a exhibits a buffer function, there is an advantage that the cooling water can be diverted stably.

  Control of the flow of cooling water can also be realized by changing the outer diameter of the drill 14. Generally, when the outer diameter of the drill 14 is increased, the reverse guiding action of the cooling water is increased to increase the flow rate flowing to the exhaust side. By adjusting the processing depth of the drill 14, the height of the center of the water flow can be changed. For this reason, a strong water flow can be generated at the bottom of the cooling water jacket 5 to prevent the stagnation of the cooling water.

  In the embodiment, the upper end of the membrane 13 is not exposed to the top, but it is also possible to expose the upper end of the membrane 13 to the top. In this case, the front end of the end portion of the cooling water inlet passage 11 opens upward, and is divided into right and left portions by the membrane 13.

  The present invention is practically applicable to a cylinder block. Therefore, it can be used industrially.

O Crankshaft line 1 cylinder block 2 top surface of cylinder block (upper surface)
3 1st cylinder 4 2nd cylinder 5 cooling water jacket 6 end face of cylinder block 7 intake side of cylinder block 10 water pump 11 cooling water inlet passage
11a end (outlet)
13 membrane part 14 drill 15 axis of drill 16 axis of cylinder 17 straightening guide part (guide surface)

Claims (1)

A cooling water jacket surrounding the cylinder row, and a cooling water inlet passage for supplying water to the cooling water jacket;
While previous SL cooling water jacket is open to a top surface facing the cylinder head,
Before SL cooling water inlet passage is elongated in the crank axial direction, the inlet of the cooling water inlet passage is open to one end face facing the crank axial direction, the outlet of the cooling water inlet passage, the cooling water jacket And the top surface, wherein
The outlet of the cooling water inlet passage is formed by cutting out a membrane-like portion arranged to separate the outlet and the cooling water jacket with a drill in a posture parallel to the axis of the cylinder, The curved surface formed at the outlet by the above-mentioned drilling forms a straightening guide portion which makes a part of the cooling water U-turn to the cooling water jacket.
Cylinder block.

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