JP2006125359A - Cylinder block - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an open deck type cylinder block increasing strength when a bore part is expanded. <P>SOLUTION: The cylinder block 100 is provided with the bore part 12 surrounding a bore zone 15, and a main body part 11 arranged in the outer periphery of the bore part 12 forming a water jacket space 7 between bore part 12 and the same. The water jacket space 7 opens at a deck surface 211 of the cylinder block 100. The cylinder block 100 is provided with a plurality of coil springs 152 fitted in a space between the bore part 12 and the main body part 11 in proximity of the deck surface 211. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cylinder block, and more particularly to a cylinder block having a water jacket space for flowing cooling water.

Conventionally, the structure of a cylinder block is disclosed in, for example, Japanese Patent Laid-Open No. 2004-218447 (Patent Document 1) and Japanese Patent Laid-Open No. 7-103064 (Patent Document 2).
JP 2004-218447 A JP-A-7-103064

  Patent Document 1 discloses a technique for fixing a reinforcing material by welding between a bore portion and an outer wall of a water jacket on the top surface of a deck of an open deck cylinder block.

  Patent Document 2 discloses a technique for fixing a reinforcing material by brazing between a bore portion and an outer wall of a water jacket on the deck surface of a cylinder block of an open deck.

  However, in the conventional technique, first, a process of completely fixing the additional parts to the bore portion and the outer wall of the water jacket space is necessary, and there is a problem that the manufacturing process increases. In the above-described prior art, by using another piece, the bore part and the main body part are completely integrated, so that it is created based on the concept of improving rigidity as a part called a cylinder block.

  The purpose of adding parts to the open deck type as a base to obtain rigidity equivalent to the closed deck type is to suppress bore diameter expansion due to in-cylinder pressure, and in particular to suppress movement of the gasket seal surface. However, the movement of the gasket seal surface becomes so large that it becomes a problem only in some situations when the cylinder pressure is high and the load is high. That is, it is only necessary that the rigidity equivalent to the closed deck can be exhibited only when the in-cylinder pressure is large and the expansion of the bore diameter becomes larger than the allowable value. However, in the conventional structure, the rigidity is always ensured, and it can be said that it is in an excessive quality state.

  From the viewpoint of making it easier to make, it is preferable to simplify the manufacturing process by using a structure equivalent to a closed deck only when necessary.

  Further, the conventional technique has problems such as deformation of the bore after fixing the additional parts, generation of residual stress, and reduction in material strength. The reason for this is that when additional parts are joined by welding, they are adversely affected by heat reception. In the case of pressure bonding or the like, there is no problem with heat reception, but due to the pressing and fixing to the bore side, stress is generated on the bore side, causing deformation.

  Accordingly, the present invention has been made to solve the above-described problems, and can prevent an increase in the manufacturing process and can increase the rigidity when necessary without affecting the bore portion. The purpose is to provide.

  A cylinder block according to one aspect of the present invention is a cylinder block of an internal combustion engine, and is provided on a bore portion surrounding a bore region and an outer periphery of the bore portion, and forms a water jacket space between the bore portion. A main body. The water jacket space is opened at the deck surface of the cylinder block. The cylinder block includes a plurality of elastic bodies fitted between the bore portion and the main body portion in the vicinity of the deck surface.

  In the cylinder block configured as described above, a plurality of elastic bodies are fitted between the bore portion and the main body portion in the vicinity of the deck surface. Normally, an elastic body generates a large repulsive force as the deformation becomes large. That is, as the bore portion expands, a force that prevents the expansion of the bore portion acts on the elastic body, and the bore portion is pushed by the plurality of elastic bodies. As a result, the rigidity of the cylinder block is improved. Furthermore, the rigidity can be realized only by fitting a plurality of elastic bodies between the bore portion and the main body portion, and the rigidity can be increased without affecting the bore portion as compared with the case where the elastic bodies are joined by welding. .

  More preferably, the elastic body is a coil spring. In this case, the coil spring does not act as a resistance to water flow, and therefore does not block the water flow in the water jacket space on the deck surface.

  Preferably, the elastic body is a coil spring having a predetermined contraction stroke, and when the bore portion expands beyond the stroke, each adjacent coil of the coil spring comes into close contact, and the coil spring connects the bore portion and the main body portion. Become. In this case, if the in-cylinder pressure at the bore portion is large and the expansion of the bore portion exceeds the allowable value, the coil spring comes into close contact, and the coil spring becomes a reinforcing member that connects the bore portion and the main body portion. As a result, the rigidity of the cylinder block can be increased.

  More preferably, the elastic body is a non-linear spring whose spring constant increases as it contracts. In this case, since the elastic constant of the elastic body increases as the elastic body contracts, a particularly large force is applied to the bore portion when the bore portion expands and the spring is contracted, thereby increasing the rigidity of the cylinder block. .

  A cylinder block according to another aspect of the present invention is a cylinder block of an internal combustion engine, and is provided in a bore portion surrounding a bore region and an outer periphery of the bore portion, and forms a water jacket space between the bore portion. A main body. The water jacket space is opened at the deck surface of the cylinder block, and the cylinder block includes a reinforcing member provided near the deck surface. When the internal combustion engine is stopped, a gap is generated between the reinforcing member and the bore portion. When the internal combustion engine is operated, the bore portion expands and the distal end portion of the reinforcing member comes into close contact with the bore portion.

  In the cylinder block configured as described above, since the gap is generated between the reinforcing member and the bore portion when the internal combustion engine is stopped, the reinforcing member does not adversely affect the bore portion. When the internal combustion engine is operated, the bore portion expands and the tip of the reinforcing member comes into close contact with the bore portion, so that the rigidity of the bore portion can be increased.

  According to the present invention, it is possible to provide a cylinder block capable of increasing rigidity when necessary.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a plan view of a cylinder block according to Embodiment 1 of the present invention. Referring to FIG. 1, a cylinder block 100 is a cylinder block of an internal combustion engine, and is provided with a bore portion 12 surrounding a bore region 15 and an outer periphery of the bore portion 12, and a water jacket space between the bore portion 12. 7 and a main body portion 11 that forms 7. The water jacket space 7 is opened at the deck surface 211 of the cylinder block 100. The cylinder block 100 has a plurality of coil springs 152 as elastic bodies fitted between the bore portion 12 and the main body portion 11 in the vicinity of the deck surface 211.

  The bore region 15 has a cylindrical shape, and a cylinder liner 151 is fitted on the outer periphery thereof. The cylinder liner 151 is made of iron and is a member having wear resistance. A plurality of cylinder liners 151 are arranged in a line. In this embodiment, an in-line engine is shown, but the present invention is not limited to this, and the present invention can be applied to engines of V type, W type, horizontally opposed type, and the like. Further, the present invention can be applied not only to an engine having a plurality of bore regions but also to a so-called single cylinder engine having only one bore region.

  The bore portion 12 is disposed so as to surround the bore region 15. The bore portion 12 is made of, for example, an aluminum alloy and has a shape in which a plurality of circular shapes are connected. A main body 11 is provided so as to face the bore 12. The main body 11 and the bore 12 are connected to each other at the bottom of the water jacket space 7 and are produced by casting using a mold. That is, the main body 11 and the bore 12 are made of the same material.

  A head bolt hole 14 is provided in the main body 11. The head bolt hole 14 is a hole for inserting a bolt for attaching the engine head to the cylinder block 100.

  A water jacket space 7 for flowing cooling water (long life coolant) is disposed between the main body 11 and the bore 12. The water jacket space 7 is a refrigerant passage and is open on the deck surface 211. That is, the cylinder block 100 is a so-called open deck type.

  A coil spring 152 is disposed so as to connect the bore portion 12 and the main body portion 11. One end of the coil spring 152 is in contact with the bore portion 12, and the other end is in contact with the main body portion 11. The coil spring 152 may be replaced with another elastic body such as a leaf spring. Further, the pitch of the coil springs 152 need not be constant, and coil springs 152 with unequal pitches may be used. Further, the coil spring 152 may be non-linear, and a spring constant that increases as the coil spring 152 contracts may be used.

  In this embodiment, the coil spring 152 has a predetermined contraction stroke. When the bore portion 12 expands beyond the stroke, adjacent coils of the coil spring 152 are brought into close contact with each other, and the coil spring 152 serves as a reinforcing member that connects the bore portion 12 and the main body portion 11. The bore portion 12 expands according to the output state of the engine. The coil spring 152 is contracted by this expansion, and when the limit of the contraction stroke is reached, the coil spring 152 is fully contracted. In that case, the main body 11, the coil spring 152, and the bore 12 are integrated in a pseudo manner in the radial direction, and the rigidity in the radial direction increases. This provides rigidity equivalent to a closed deck.

  In the present invention, the cylinder block 100 employs a structure having both high productivity of the open deck and high rigidity of the closed deck. In the present invention, a coil spring 152 is incorporated between the bore portion 12 and the main body portion 11 on the deck surface 211 of the open deck type cylinder block 100. Thereby, the in-cylinder pressure at the time of high load (when the pressure in the bore region 15 is high, the coil spring 152 is brought into close contact with the deformation of the bore portion 12. As a result, the main body portion 11 (water jacket outer wall) is integrated in a pseudo manner. It is possible to create a state and exhibit rigidity equivalent to a closed deck.

  FIG. 2 is a cross-sectional view taken along the line II-II in FIG. With reference to FIG. 2, the cylinder block 100 includes a crankcase portion 51, a main body portion 11 on the crankcase portion 51, and a bore portion 12 provided inside the main body portion 11. A cylinder liner 151 is provided on the inner peripheral surface of the bore portion 12. A cylinder liner 151 surrounds the bore region 15.

  A space between the bore portion 12 and the main body portion 11 is a water jacket space 7, and the water jacket space 7 is filled with cooling water 120. In this embodiment, the structure in which the bore portion 12 is cooled using water is shown. However, the present invention is not limited to this, and oil, other fluids, etc. can be poured into the water jacket space 7. . In order to adjust the flow of the cooling water 120 in the water jacket space 7, a water jacket spacer may be provided.

  In the present invention, a coil spring 152 as a part for bridging the bore portion 12 and the main body portion 11 is added to the open deck type cylinder block 100. The coil spring 152 is positioned when installed in the cylinder block 100, but is not fixed (integrated) to the cylinder block 100 by welding or the like. When the pressure in the bore region 15 (in-cylinder pressure) increases and a predetermined deformation occurs, the three parts of the bore part 12, the coil spring 152, and the main body part 11 are brought into close contact with each other, and the rigidity equivalent to the closed deck is exhibited.

  This eliminates the need for a joining step such as welding at the additional portion forming the bridge portion of the closed deck.

  Due to the design of the closed deck only when the deformation amount of the bore portion 12 becomes too large, complete fixing to the bore side and the main body side becomes unnecessary. Moreover, when attaching the coil spring 152 as an additional part, the opportunity of receiving heat, such as welding, can be eliminated, and the occurrence of stress in the bore part such as crimping to the bore side can be eliminated. As a result, the deformation of the bore portion 12 after the additional parts are assembled can be prevented.

  The coil spring 152 is configured by a general compression spring, and is fitted into the grooves 111 and 112 by being compressed and deformed when being mounted on the cylinder block 100. The grooves 111 and 112 are simultaneously formed by casting when the cylinder block 100 is cast. In the process in which the in-cylinder pressure increases and the expansion of the bore portion 12 increases and the coil spring 152 is compressed, the coil spring 152 comes into close contact when the expansion amount exceeds a predetermined value. If a non-linear spring is used as the coil spring 152 and the required amount of elasticity (rigidity in the expansion direction: spring constant) can be secured when the deformation amount of the bore portion 12 exceeds a predetermined value, the coil spring 152 is not necessarily provided. It does not have to be in close contact.

  In the cylinder block 100 according to the present invention as described above, rigidity equivalent to a closed deck can be obtained only when necessary. Further, the bore portion 12 is not adversely affected.

(Embodiment 2)
FIG. 3 is a cross-sectional view of a cylinder block according to the second embodiment of the present invention. Referring to FIG. 3, in cylinder block 100 according to the second embodiment of the present invention, reinforcing member 154 as an additional part is fixed to body portion 11 by press fitting, and tip portion 1540 of reinforcing member 154 is bored. It is away from the part 12 and the distance of the gap is L.

  The cylinder block 100 according to the second embodiment includes a bore portion 12 that surrounds the bore region 15, and a main body portion 11 that is provided on the outer periphery of the bore portion 12 and forms a water jacket space 7 with the bore portion 12. Prepare. The water jacket space 7 is opened at the deck surface 211 of the cylinder block 100. The cylinder block 100 includes a reinforcing member 154 that protrudes toward the bore portion 12 in the vicinity of the deck surface 211. When the internal combustion engine is stopped, a gap is generated between the reinforcing member 154 and the bore portion 12 or the main body portion 11. When the internal combustion engine is operated, the bore portion 12 expands and the distal end portion 1540 of the reinforcing member 154 comes into close contact with the bore portion 12.

  In this embodiment, the spring in the first embodiment is replaced with a reinforcing member 154 for press-fitting and fixing. Further, the low rigidity portion until the spring is brought into close contact is replaced with a gap. The reinforcing member 154 is fixed to the main body portion 11 in this embodiment, but is not fixed to the main body portion 11, and the reinforcing member 154 has a gap with respect to both the main body portion 11 and the bore portion 12. It is good. Further, the reinforcing member 154 may be attached to the bore portion 12, and a gap may be provided between the main body portion 11 and the reinforcing member 154.

  For example, a hole may be provided in the main body 11, and a reinforcing member 154 may be fitted into the hole so that the reinforcing member 154 can be moved by sliding in the radial direction of the bore region 15. Even in this case, when the expansion amount of the bore portion 12 exceeds a predetermined amount, the bore portion 12, the reinforcing member 154, and the main body portion 11 are integrated.

  The cylinder block 100 according to the second embodiment configured as described above has the same effect as the cylinder block 100 according to the first embodiment.

  Although the embodiment of the present invention has been described above, the embodiment shown here can be variously modified. First, the engine of the present invention is not limited to one mounted on a vehicle, but may be an engine for a generator.

  Further, the present invention may be applied not only to gasoline engines but also to diesel engines as engine types.

  Further, the position and number of the reinforcing members 154 and the coil springs 152 are not particularly limited as long as they are in the vicinity of the deck surface 211.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be applied in the field of internal combustion engines.

It is a top view of the cylinder block according to Embodiment 1 of this invention. It is sectional drawing along the II-II line | wire in FIG. It is sectional drawing of the cylinder block according to Embodiment 2 of this invention.

Explanation of symbols

  7 Water jacket space, 11 body portion, 12 bore portion, 15 bore region, 100 cylinder block, 152 coil spring.

Claims (5)

A cylinder block of an internal combustion engine,
The cylinder block includes a bore portion surrounding the bore region;
A main body provided on the outer periphery of the bore and forming a water jacket space with the bore;
The water jacket space is open at the deck surface of the cylinder block,
Furthermore, the cylinder block includes a plurality of elastic bodies fitted between the bore portion and the main body portion on the deck surface.   The cylinder block according to claim 1, wherein the elastic body is a coil spring.   The elastic body is a coil spring having a predetermined contraction stroke, and when the bore portion expands beyond the stroke, adjacent coils of the coil spring are brought into close contact with each other so that the coil spring connects the bore portion and the main body portion. The cylinder block according to claim 1, which serves as a reinforcing member to be connected.   The cylinder block according to claim 1, wherein the elastic body is a non-linear spring having a spring constant that increases as the elastic body contracts. A cylinder block of an internal combustion engine,
The cylinder block includes a bore portion surrounding the bore region;
A main body provided on the outer periphery of the bore and forming a water jacket space with the bore;
The water jacket space is open at the deck surface of the cylinder block,
Furthermore, the cylinder block includes a reinforcing member provided in the vicinity of the deck surface,
When the internal combustion engine is stopped, a gap is generated between the reinforcing member and the bore portion. Cylinder block.

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