JP4305175B2 - Three-sided seal structure - Google Patents

Description

  The present invention relates to a seal structure for a three-sided joint portion of a structure in which a first member to a third member are coupled to each other.

  A structure in which the first member to the third member are coupled to each other, for example, as shown in FIG. 11, a cylinder head 100 and a cylinder block 110 below the cylinder head 100 are joined via a first seal surface f1, and these There is known an engine body E in which a chain case 120 is joined to projecting wall portions 101 and 102 extending in the vertical direction on one side of both via a second seal surface f2.

In such an engine body E, a gasket 130 is interposed between the cylinder head 100 and the cylinder block 110 to ensure the sealing performance of the first seal surface f1, and the protruding wall portions 101, 102 extending vertically from the chain case 120. The liquid gasket 140 is adhered between the two to ensure the sealing performance of the second sealing surface f2.
Here, in the three-surface mating portion m where the first seal surface f1 and the second seal surface f2 are abutted, the tip of the gasket 130 on the first seal surface f1 and the liquid gasket 140 on the second seal surface f2 are in abutment state. Opposed.

In this case, the sealing performance at the three-surface mating portion m is ensured by joining the tip portion of the gasket 130 and the end surface of the liquid gasket 140.
In Japanese Patent Laid-Open No. 10-274098 (Patent Document 1), a cylinder head and a cylinder block are integrally coupled with a gasket interposed therebetween, and a driving device case is integrally coupled to one side of these three surfaces. A seal structure in an engine provided with a mating portion is disclosed. Here, when the corners of the cylinder head and the cylinder block facing the three-surface mating part are assembled with machining burrs and relative steps, the machining burrs and corners are displaced by engine vibration and thermal deformation, Accordingly, the liquid gasket adhering along the seal surface on the drive device case side is prevented from being cut by a relief groove formed on the drive device case side, and the seal against the outside of the chain housing chamber inside the drive device case is avoided. It avoids the problem of reduced performance.

Japanese Patent Laid-Open No. 10-274098

  By the way, in the three-surface mating portion m shown in FIG. 11, in the initial stage of engine assembly, the tip portions of the cylinder head 100, the cylinder block 110, and the gasket 130 are located on the second seal surface f2 that is on the same plane. The two seal surfaces f2 are joined in a butted manner to the liquid gasket 140, and the sealability between the inner chamber in the chain case 120 and the outside at the three-surface mating portion m is ensured.

  However, due to differences in the materials and shapes of the cylinder head 100, cylinder block 110, and gasket 130, there is a relative difference in the amount of expansion and contraction when these thermal displacements occur. For example, there is a relative difference in expansion and contraction between the aluminum alloy cylinder head and cylinder block and the plate-like metal gasket 130. When such a thermal deformation difference occurs, the liquid gasket 140 that is relatively thinly attached to the second seal surface f2 extends to the maximum value of the elongation deformation amount, and then is detached from the gasket tip or the liquid gasket is cut. May occur, and a gap α may be formed between the gasket tip and the liquid gasket on the second seal surface f2. When the gap α is generated in this way, the sealing performance between the inner chamber R in the chain case 120 and the outside may be deteriorated.

  As described above, in the structural body such as the engine main body and the various storage boxes in which the first to third members are integrally coupled, the first member and the second member are joined via the first seal surface. When the third member m is joined to the protruding wall of the first member and the second member disposed along the second seal surface against which the seal surface abuts, the three-surface mating portion m is formed by thermal deformation or the like. The leading edge of the sealing material on the first sealing surface side is separated from the liquid sealing agent on the second sealing surface side or the liquid gasket is cut off, so that a gap α is generated. There is a problem that the sealing performance is lowered, and the improvement is desired.

  The present invention has been made on the basis of the above-described problems, and an object of the present invention is to provide a seal structure having a three-surface mating portion, on the second seal surface side where the front end of the seal material on the first seal surface side abuts. An object of the present invention is to provide a seal structure for a three-sided joint that can prevent a gap from being formed between the liquid sealant.

According to a first aspect of the present invention, there is provided a seal structure for a three-surface mating portion, wherein a cylinder head and a cylinder block of an engine that overlap with each other across the first seal surface, and a cylinder head and a cylinder block that are overlapped with each other. In the seal structure of the three-surface mating part with the chain case joined via the liquid sealant to the two seal surfaces, an inner chamber sandwiched between the inner wall of one end of the cylinder block and the inner wall of the chain case is formed, the corners of at least one of a corner portion above the chamber side of the cylinder head or the cylinder block at a site and the cylinder head and the cylinder block is polymerized in the second sealing surface, filled with the liquid sealant A recess for sealing is formed by cutting out the same corner in a substantially triangular pyramid shape, and the seal recess is on the inner chamber side. And a junction-side opening mouth and the clamping side opening, characterized in that it is formed at a predetermined depth from the inner chamber side opening to the outside direction.

According to the first aspect of the present invention, since the capacity of the liquid sealant in the sealing recess can be secured, a relative displacement in the direction of the first seal surface occurs due to thermal fluctuations, and the cylinder head and the cylinder block. Even if the gap between the end of the chain and the chain case via the second seal surface fluctuates greatly, a sealing recess notched in a substantially triangular pyramid shape is formed at the corner on the inner chamber side. Since the liquid sealant is filled in the recess for liquid , the liquid sealant easily expands and contracts to prevent the opening of the gap, and the three-sided joint between the cylinder head and the end of the cylinder block and the chain case is provided. It can be surely sealed. In particular, the cross section of the liquid sealant in the recess for sealing forms a wedge-shaped cross section with respect to the outside, so even if the liquid seal material hardens over time, it is sure to shift to the outside with an increase in the internal pressure of the inner chamber. In this respect, a stable sealing function can be exhibited.

Furthermore, since the sealing recess is formed in a substantially triangular pyramid shape, the processing is facilitated and the cost can be reduced.

FIG. 1 and FIG. 2 show a structure to which a seal structure of a three-surface mating portion as one embodiment of the present invention is applied.
A structure 1 in FIGS. 1A and 1B includes a rectangular outer shell member 4 having a front opening 2 and a side opening 3, and thick plate-like first members 5 and second members that close the front opening 2. 6 and a thick plate-like third member 7 for closing the side opening 3. This structure 1 is a structure 1 in which the inner chamber 8 of the outer shell member 4 is partitioned from the outer space 9, and the sealing performance of the inner chamber 8 is secured against heat fluctuation, and the main member is aluminum. It is made of an alloy material and is used as a box that houses various devices in a sealable manner.

  Here, the front opening 2 is closed by a first member 5 and a second member 6 that sandwich a plate-shaped sealing material 10 (see FIG. 2) provided along the lateral first sealing surface f1 from above and below. Are coupled to each other by fastening means 11 and their peripheral edges are fixed to the concave edge 12 of the outer shell member 4 by fixing means (not shown). The protruding wall portions 14 and 15 of the upper and lower first members 5 and the second member 6 are formed along the vertical second seal surface f2 where the first seal surface f1 is abutted orthogonally.

The side opening 3 is closed by a third member 7 joined to the concave edge portion 12 of the outer shell member 4 and the protruding wall portions 14 and 15 aligned in the vertical direction Z. Here, the peripheral portion of the third member 7 is fixed to the concave edge portion 12 of the outer shell member 4 by a fixing means (not shown), and the opposite portions of the protruding wall portions 14 and 15 are interposed via the second seal surface f2. Tightened by the fastening means 13.
A liquid sealant is formed along the vertical second seal surface f2 in which the first seal surface f1 is abutted orthogonally to the vertical joint wall 17 of the third member 7 facing the protruding wall portions 14, 15. 16 is applied and joined to the protruding wall portions 14 and 15 of the first member 5 and the second member 6 via the liquid sealing agent 16.

The liquid sealing agent 16 is attached in advance to the joining wall 17 of the third member 7 (see FIG. 4A), and then the first member 5 and the second member 6 arranged along the second sealing surface f2. Are pressed against the protruding wall portions 14 and 15 (see FIG. 4B), and the joining process is performed. The liquid sealing agent 16 has a heat resistance and an oil resistance, and a sealing material that can maintain the sealing performance even when elastically extended to about twice the coating thickness is selectively used.
As shown in FIG. 5, the seal line (application region) of the liquid sealant 16 having a predetermined width q is disposed at a position overlapping a seal recess 21 and a seal bead on the liquid sealant 16 and a notch 24 described later. The Further, the first member 5 and the second member 6 have substantially the same shape in plan view, and the plate-like sealing material 10 provided along the first sealing surface f1 is sandwiched therebetween.

  As shown in FIGS. 5 and 10, the plate-like sealing material 10 includes a metal plate-like main portion 101 and rubber coating 101 </ b> A and sealing beads 101 </ b> B on the upper and lower surfaces of the main portion 101. The elastic sealing agent 22 uses silicon rubber as a base material, and a material whose hardness, viscosity, and adhesive force are adjusted so as to ensure sealing performance is employed.

  The plate-like sealing material 10 is formed so as to have substantially the same length and width with respect to the downward holding surface 5df and the upward holding surface 6uf of each of the holding walls 18 and 19 of the first member 5 and the second member 6, and will be described later. A portion opposed to the sealing recess 21 is cut out to form a notch 24. A rubber coating 101A and a sealing bead 101B are applied to the entire upper and lower surfaces of the plate-shaped sealing material 10 in the longitudinal direction, and in particular, one end of the sealing line is set to overlap the central portion of the notch 24.

  As shown in FIGS. 3 and 5, the second member 6 protrudes from the holding wall portion 19 and the portion where the wall portion 15 overlaps, that is, the three-sided alignment in which the first horizontal seal surface f <b> 1 abuts the second vertical seal surface f <b> 2. The edge portion 23 of the inner chamber side wall surface iw, which is a portion facing the three-surface mating portion A and is opposed to the inner chamber 8 and is one side wall surface, is notched in a triangular pyramid shape and is used for sealing. A recess 21 is formed. Note that the sealing recess 21 here is a triangular pyramid-shaped notch that facilitates processing, which can contribute to a reduction in processing costs.

  As shown in FIGS. 3 and 5, the sealing recess 21 includes an inner chamber side opening a formed on the inner chamber side wall surface iw, a sandwiching side opening b formed on the first seal surface f1, and a second seal surface. a junction-side opening c formed at f2. The sealing recess 21 is formed with a depth h in the outer direction Y from the inner chamber side opening a, is formed with a lateral width i in a direction away from the second sealing surface f2 from the bonding side opening c, and the first seal from the sandwiching side opening b. It is formed with a vertical width j in a direction away from the surface f1.

As shown in FIG. 5, the notch 24 of the plate-shaped sealing material 10 is notched in substantially the same planar view shape as the sandwiching side opening b of the sealing recess 21 to substantially increase the capacity of the sealing recess 21 and It is formed so that the liquid sealing agent 16 can be surely filled in the gap portion (t: hatched portion in FIG. 4 (c)) between the first member 5 and the second member 6.
The depth h of the recess 21 for sealing easily overlaps with the seal line composed of the rubber coating 101A of the plate-shaped sealing material 10 and the sealing bead 101B, and the seal line of the width q of the liquid sealant 16 on the second seal surface f2. Is set to just the width.

As a result, the liquid sealing agent 16 in the sealing recess 21 and the notch 24 and the elastic sealing agent 22 bonded to the end face of the plate-like sealing material 10 are securely attached during the bonding treatment (see FIG. 4B). The first seal surface f1 in the vicinity of the three-surface mating portion A is continuous and can be reliably continued with the liquid sealant 16 on the second seal surface f2 without interruption.
The vertical width j of the sealing recess 21 is such that the liquid sealing agent 16 on the second sealing surface f2 side is pressed against the protruding wall portions 14 and 15 of the wall portions 14 and 15 from the state of FIG. When reaching the state of b), the liquid sealing agent 16 is set to a value that can be easily pushed and filled into the sealing recess 21 side.

The lateral width i of the sealing recess 21 is appropriately set in consideration of regulating the volume of the liquid sealing agent 16 in the sealing recess 21.
Conversely, the liquid sealant 16 must be applied in an amount sufficient to fill the sealing recess 21 and the cutout 24.
Changes when such a structure 1 of FIG. 1 undergoes thermal deformation during use will be described with reference to FIGS.

  First, prior to assembly, the plate-like sealing material 10 is provided between the sandwiching wall portions 18 and 19 of the first member 5 and the second member 6, both of which are integrally fastened by the fastening means 11, It is integrally attached to the outer shell member 4. Further, the liquid sealing agent 16 is applied to the joining wall 17 of the third member 7 and set to the pre-assembly state shown in FIG.

  Next, as shown in FIG. 4B, the joining wall 17 of the third member 7 is pressed against the protruding wall portions 14 and 15 of the first member 5 and the second member 6 and held at the assembly position P0. Are integrally fastened by the fastening means 13 and are integrally attached to the outer shell member 4. At this time, the opposite end side of the plate-shaped sealing material 10 to the second sealing surface f2 is brought into contact with the joining wall 17 of the third member 7 with a thickness of the liquid sealing agent 16 on the second sealing surface f2. is there. In particular, a part of the liquid sealing agent 16 applied to the joining wall 17 relatively thickly is pressed into the sealing recess 21 and the notch 24 from the joining side opening c side during the assembly, Almost the entire area was filled, and the state was shown as a hatched area within a two-dot chain line.

  It is assumed that the structure 1 shown in FIG. 1 is thermally deformed over time. In this case, relative displacement between the sandwiching wall portions 18 and 19 facing each other on the first seal surface f1, and between the joining walls 17 to the protruding wall portions 14 and 15 aligned in the vertical direction Z on the second seal surface f2. The relative displacement is relatively small and airtightness is maintained.

  On the other hand, in the direction X of the first sealing surface f1, the opposing end of the plate-shaped sealing material 10 with respect to the holding wall portions 18 and 19 of the first member and the second members 5 and 6 is as shown in FIG. Furthermore, it shifts by a shift width t and changes to a change position P1 after thermal deformation. The shift width t at this time is more than three times the thickness of the liquid sealant 16 on the second seal surface f2, but the seal recess 21 and the notch 24 in the notch 24 are bonded to the opposing end e of the plate-like seal material 10. Since the liquid sealing agent 16 has a sufficient capacity and a sufficient thickness, the liquid sealing agent 16 can be extended and displaced sufficiently to absorb the elastic extending displacement of the shift width t. In addition, at this time, it is possible to prevent the liquid sealing agent 16 from being detached from the opposing end e while the end of the plate-like sealing material 10 is bonded to the liquid sealing agent 16 in the sealing recess 21 and the notch 24. For this reason, after the plate-shaped sealing material 10 and the liquid sealing agent 16 in the sealing recess 21 and the notch 24 are thermally deformed, the opposing end e of the plate-shaped sealing material 10 is displaced from the second seal surface f2. In spite of the movement by the width t, it is possible to stably maintain both the adhesion state of the facing end e and the joint surface 17sf of the third member 7 and stably maintain the sealing performance of the three-surface mating portion. For this reason, cutting of the sealing material in the direction X of the first seal surface f1 in the vicinity of the three-surface mating portion can be prevented, and the gap between the inner chamber side wall surface iw and the other side wall surface ow, which is one side wall surface, That is, it is possible to reliably prevent a decrease in airtightness of the inner chamber 8 with respect to the outer space 9. Further, the sealing recess 21 and the notch 24 here are formed on the inner chamber 8 side, and the liquid sealing material 16 filled in the same is cured with time, so that the cross section has a wedge-shaped cross section with respect to the outside. Therefore, even if there is an increase in the internal pressure of the inner chamber 8, the displacement to the outside is surely prevented, and a stable sealing function can be exhibited in this respect. Further, since the sealing recess 21 has a simple structure, it can be easily formed when the second member 6 is cast, and the notch 24 can be easily formed when the plate-shaped sealing material 10 is manufactured. No additional machining is required, and cost increases can be suppressed.

Next, the engine main body 30 to which the seal structure of the three-surface mating portion as the second embodiment of the present invention is applied will be described with reference to FIGS.
The engine body 30 here is a chain case 33 (a cylinder block 31 and a cylinder head 32 above the cylinder block 31 that simultaneously covers one side surface in the longitudinal direction X1 of the cylinder head 32 (first member) and the cylinder block 31 (second member)). A third member), an upper head cover 34, and a lower oil pan 35, which are integrally coupled to each other by bolts (not shown). The engine main body 30 constitutes a main part of a multi-cylinder engine in which a plurality of cylinders S are arranged in series at predetermined intervals along the engine longitudinal direction X1.

  The engine body 30 has a well-known structure in which a crank mechanism (not shown) is provided in the cylinder block 31 and thereby a piston 36 that moves up and down in each cylinder S is connected to the crankshaft 37 side to output a rotational force. A main part of a four-cycle engine in which a valve operating device (not shown) in the head 32 is driven in synchronization with the rotation of the crankshaft 37 so as to supply an air-fuel mixture to each cylinder S and discharge exhaust as appropriate. Constitute. Here, a chain accommodating chamber (hereinafter referred to as an inner chamber 38) is formed as a space sandwiched between the inner wall at one end of the cylinder block 31 and the inner wall of the chain case 33. The inner chamber 38 accommodates a chain drive system (not shown) for synchronously rotating the valve operating device on the cylinder head 32 side by the rotational force of the crankshaft 37.

  A lower side opening of the inner chamber 38 is covered by an end protruding wall 39 of the cylinder block 31, and an upper portion communicates with a valve system accommodating space 341 in the head cover 34.

  As shown in FIG. 7, in the engine main body 30 as such a structure, the cylinder head 32 as the first member, the cylinder block 31 as the second member, and the chain case 33 as the third member are in the engine lateral width direction. Three-surface mating portions A1 and A2 are formed in the vicinity of both ends in Y1, respectively.

The cylinder block 31 has a large number of inner and outer walls that cover all the cylinders S and the water jacket 41, and the upper wall 42 functions as a clamping member that faces the first seal surface f1.
Here, the cylinder block 31 has a pair of left and right protruding wall portions 44 protruding further in the engine longitudinal direction X1 from the inner wall 43 covering the cylinder S on one end side, and the pair of protruding wall portions 44 are the first seal surface f1. Are formed so as to be along the second seal surface f2 that abuts at right angles.

  The cylinder head 32 has an outer wall continuous with the cylinder block 31, inner and outer walls forming a water jacket (not shown), and a lower wall 45 that forms a clamping wall portion facing the upper wall 42 of the cylinder block 31. It forms so that it may join to the gasket 46 arrange | positioned along the 1st sealing surface f1. Moreover, like the cylinder block 31, it has a pair of projecting wall portions 48 projecting further in the engine longitudinal direction X 1 from the end inner wall 47 on one end side. The pair of protruding wall portions 48 are formed along the second seal surface f2 with which the first seal surface f1 abuts at right angles.

  In addition, the joining wall part 49 of the periphery of the chain case 33 formed along the 2nd seal surface f2 joins to the protruding wall parts 48 and 44 arranged in the up-down direction Z. Thereby, as shown in FIGS. 7 and 8, a pair of the three-surface mating portions A1 and A2 where the first seal surface f1 and the second seal surface f2 come into contact with each other are formed.

  As shown by a two-dot chain line in FIG. 7, the upper and lower cylinder heads 32 and the cylinder block 31 sandwich a plate-like gasket 51 disposed along the lateral first seal surface f1. The gasket 51 is formed so as to ensure the sealing performance between the upper wall 42 and the lower wall 45 surrounding the entire cylinder S and the water jacket 41 formed by the cylinder head 32 and the cylinder block 31, and through holes are formed according to the necessary portions. A rubber coating agent 52 (see FIGS. 8A and 8B) is applied with a predetermined width r on the upper and lower surfaces near the periphery of each through hole as appropriate. In particular, between the protruding wall portions 44 and 48 aligned in the vertical direction Z, the end portion bent extension portion 511 of the gasket 51 extends and is provided. A cutout portion 24a is formed on the inner chamber 38 side of the end bent extension portion 511. Moreover, the rubber coating agent 22a is applied to the end bent extension 511 of the gasket 51 with a predetermined width, and a seal bead (not shown) is disposed.

As shown in FIGS. 7, 8 (a) and 8 (b), the edge of the end 23 a facing the chain case 33 of the protruding wall portion 44 of the cylinder block is a portion where the three-surface mating portions A 1 and A 2 are formed. The part is formed with a sealing recess 21a cut out in a triangular pyramid shape.
The sealing recess 21a is formed in the same manner in consideration of the same requirements as the sealing recess 21 shown in FIG. That is, it has an inner chamber side opening a, a sandwiching side opening b, and a bonding side opening c, and is formed with a depth h in the external direction Y from the inner chamber side opening a. The second sealing surface f2 is formed from the bonding side opening c. It is formed with a lateral width i in the direction away from it, and is formed with a longitudinal width j in a direction away from the first seal surface f1 from the holding side opening b.

The horizontal width i and the vertical width j are set based on the filling amount of the liquid sealing agent 16 that can ensure the sealing performance. The depth h is set so as to overlap with a seal bead (seal line) formed in the gasket 51.
As shown in FIGS. 8 (a) and 8 (b), the notch 24a of the gasket 51 is notched so as to have substantially the same plan view shape as the sandwiching side opening b of the sealing recess 21a, and is directly attached to the gasket end e1. Is formed.

  Even when the engine main body 30 of FIG. 7 is thermally deformed during driving, the liquid sealing agent 16 in the sealing recess 21a and the notch 24a is not contained in the same manner as described above with reference to FIGS. 4 (a) to 4 (c). It functions to maintain airtightness with respect to the outside of the chamber 38, and the same effect as the structure 1 of FIG. 1 can be obtained.

  That is, when the engine body 30 is thermally deformed by driving, in the engine longitudinal direction X, the opposed end e1 of the end bent extension portion 511 of the gasket 51 with respect to the upper wall 42 and the lower wall 45 that are the sandwiching wall portions. As shown in FIGS. 8A and 8B, the initial position P0 is shifted by a shift width t1 and is changed to a change position P1 after thermal deformation. At this time, the liquid sealant 16 in the recess 21a for sealing and the notch 24a to be bonded to the opposing end e1 of the end bent extension 511 has a sufficient capacity and a sufficient thickness. It is possible to extend and displace enough to absorb the elastic extension displacement, to prevent the liquid sealing agent 16 from being detached from the opposed end e1, and to stably maintain the adhesive state between the joining wall portion 49 of the chain case 33. it can. That is, it is possible to stably maintain the sealing performance of the three-surface mating portions A1 and A2, to reliably prevent a decrease in airtightness with respect to the outside of the inner chamber 38 due to the formation of a gap, and the structure 1 described in FIG. Similar effects can be obtained.

  In the above description, each of the sealing recesses 21 and 21a is formed at a portion facing the second member 6 and the three-surface mating portion A on the cylinder block 31 side, but instead of or in addition to this, A concave portion for sealing may be formed in a portion facing the one member 5 or the three-surface mating portion A on the cylinder head 31 side, and the same effect can be obtained in such a case.

  In the above description, in the seal structure of the three-surface mating portion of the present invention, the first seal surface is applied to the three-surface mating portion in which the first seal surface f1 and the second seal surface f2 are abutted orthogonally. The present invention can be similarly applied even when f1 and the second seal surface f2 are abutted at an intersection angle other than the orthogonal state and applied to the three-surface mating portion.

The structure to which the seal structure of the three-surface joining part as one embodiment of the present invention is applied is shown, (a) is a partially cutaway plan view, and (b) is a front view. FIG. 2 is an enlarged cutaway front view of the structure of FIG. 1 with a first member removed from a first seal surface f1. It is a principal part notch back view in the 1st seal surface f1 vicinity of the structure of FIG. FIG. 2 is a cutaway enlarged view of the first seal surface f1 of the structure of FIG. 1 in the vicinity of the three-surface mating portion of the first member, where (a) shows a state before assembly, (b) shows a fastening state, and (c) shows heat. It is a figure explaining a deformation | transformation state. FIG. 2 is a schematic perspective view in the vicinity of a three-surface mating portion of the structure of FIG. 1. It is the schematic of the engine main body to which the seal structure of the three-surface joining part as other embodiment of this invention was applied. FIG. 7 is a schematic enlarged plan view of a main part of the cylinder block in FIG. 6. The principal part expansion notch perspective view of the protrusion wall part of the cylinder block in FIG. 6 is (a) one side, (b) shows the other side. It is a perspective view of the cylinder block in FIG. It is sectional drawing of the plate-shaped sealing material in FIG. It is a schematic block diagram of the conventional engine main body.

Explanation of symbols

5 First member 6 Second member 7 Third member 9 Other side wall surface (external space)
DESCRIPTION OF SYMBOLS 10 Plate-shaped sealing member 14,15 Protruding wall part 16 Liquid sealing agent 17 Joining wall part 18, 19 Clamping wall part 21 Sealing recessed part 23 Edge part f1 1st sealing surface f2 2nd sealing surface iw Inner chamber side wall surface (one side) Wall)
ow Other side wall surface A Three-surface mating part X First seal surface direction Y Second seal surface direction X1 Engine longitudinal direction Y1 Engine lateral width direction

Claims (1)

The engine cylinder head and cylinder block that overlap with each other across the first seal surface, and the chain that is joined to the second seal surface located at the end of the cylinder head and cylinder block that are overlapped with each other via a liquid sealant In the seal structure of the three-sided joint with the case,
An inner chamber sandwiched between the inner wall of one end of the cylinder block and the inner wall of the chain case is formed,
The corners of at least one of a corner portion above the chamber side of the cylinder head or the cylinder block at a site and the cylinder head and the cylinder block is polymerized in the second sealing surface, filled with the liquid sealant A recess for sealing is formed by cutting out the same corner portion into a substantially triangular pyramid shape,
The sealing structure of a three-surface mating part, wherein the sealing recess has an inner chamber side opening, a sandwiching side opening, and a bonding side opening, and is formed at a predetermined depth outward from the inner chamber side opening.

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