JP6010402B2 - Metal gasket - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a metal gasket that is attached to a joint surface between a cylinder block and a cylinder head constituting an internal combustion engine to prevent leakage of fluid such as combustion gas, cooling water, lubricating oil, etc. The present invention relates to a metal gasket coated with a microseal material comprising:

  Conventionally, in a metal gasket mounted on the joint surface between a cylinder block and a cylinder head formed of metal, in order to avoid direct contact between the metals and to improve the sealing performance against the joint surface, Generally, the outer surface is coated with a micro seal material made of rubber or the like.

  In recent years, the combustion gas has also been increased in pressure with the increase in output of the engine, so that a gasket with higher sealing performance has been demanded. Therefore, when the cylinder head and the cylinder block are tightened with the tightening bolts, the two metal plates with beads are used to increase the tightening pressure of the bead of the metal substrate provided so as to surround the cylinder bore of the cylinder block. There is an increasing use of a metal gasket having a three-layer structure in which a metal step adjustment plate is sandwiched between substrates. In order to use the above coating technology, in such a metal gasket having a three-layer structure, for example, an adhesive is applied to both surfaces of each metal substrate, and a micro seal material made of rubber or the like is further provided thereon. I try to apply.

  By the way, each of the cylinder block and the cylinder head is formed with a cooling water jacket for cooling them when the internal combustion engine is operated, and the metal gasket is provided with a cooling water hole corresponding to the cooling water jacket to cool the cylinder block and the cylinder head. The water jacket is filled with cooling water. When the water pump provided in the cylinder block is operated, the cooling water in the cooling water jacket of the cylinder block is fed into the cooling water jacket of the cylinder head through the cooling water hole of the metal gasket at a high speed.

  Under such circumstances, if the part coated with the micro-seal material is exposed to cooling water for a long time, the micro-seal material may peel off, and as a result of circulating with the cooling water, it adheres to the thermostat, radiator, etc. This may cause engine trouble such as overheating.

  As a metal gasket for solving such a problem, for example, as described in Patent Document 1, a technique is known in which a coating layer in a zone including a cooling water port is peeled off in advance by, for example, spraying ultra-high pressure water. It has been.

JP-A-64-73156

  By the way, although it is preferable that the step of peeling the micro seal material is as small as possible from the viewpoint of production efficiency and cost, in the metal gasket having the above three-layer structure, both surfaces of each metal substrate are coated. Therefore, in order to completely remove the possibility that the micro seal material is peeled off, it is necessary to peel off the micro seal materials for a total of four surfaces. For this reason, there has been a demand for a new metal gasket capable of minimizing the portion where the microseal material is removed in advance while reliably removing the possibility that the microseal material is exposed to cooling water and peeling off. .

  An object of the present invention is to provide a metal gasket capable of solving the above-described problems and improving production efficiency and suppressing cost.

The present invention is a cylinder block comprising two metal substrates each coated with a micro sealant on the outer surface thereof, and a step adjusting plate sandwiched between these metal substrates, and a cooling water jacket formed around the cylinder bore In a cylinder head metal gasket, which is mounted between a cylinder head having a cooling water jacket corresponding to the cooling water jacket,
The substrate on the cylinder head side has cooling water holes that have the same or wider opening width than the opening width of the cooling water jacket of the cylinder head,
The substrate on the cylinder block side includes a cooling water flow rate adjustment hole having an opening area smaller than the cooling water hole, and a region where the micro sealant is not coated on a contact surface in contact with the cylinder block is a cylinder. With uncoated areas formed identically or widely to the cooling water jacket of the block,
The step adjusting plate covers the cooling water flow rate adjusting hole, and an outer peripheral edge thereof is located outside an outer peripheral edge of an outer peripheral edge of the cooling water jacket of the cylinder block and an outer peripheral edge of the cooling water jacket of the cylinder head. Is a metal gasket for a cylinder head, which is provided with a step adjustment plate water hole which is located inside and has an opening area which is the same as or slightly larger than the opening area of the cooling water flow rate adjustment hole.

  Hereinafter, the background to the adoption of the above configuration will be described together with the operation. The inventor firstly has a three-layer structure as shown in FIGS. 8 to 9 in which a metal step adjustment plate 53 is sandwiched between a metal substrate 51 on the cylinder block CB side and a metal substrate 52 on the cylinder head CH side. The metal gasket 50 is examined. Both surfaces of the metal substrate 51 and the metal substrate 52 are coated with a micro sealant 54. The metal substrates 51 and 52 are provided with a full bead 55 for preventing high-pressure combustion gas from leaking from the cylinder bore of the cylinder block CB and a half bead 56 for preventing leakage of fluid such as cooling water or lubricating oil. Yes.

  Here, the size of the step adjustment plate 53 is preferably as small as possible in order to achieve the above-mentioned object as long as the width for stably sandwiching the entire bead is ensured, and to reduce the material cost. As shown in FIG. 9, the outer peripheral edge 53a is positioned so as to cover the entire joint surface between the cylinder block CB surrounding the cylinder bore B and the cylinder head CH, that is, the inner peripheral edge HW of the cooling water jacket HW of the cylinder head CH. The positions are almost the same. In addition, the opening area of the cooling water jackets BW and HW provided in the cylinder block CB and the cylinder head CH is an area where the required cooling water flow rate can be obtained so that the required cooling water flow rate can be easily adjusted. The cooling water hole 57 of the metal substrate 52 on the cylinder head CH side of the two metal substrates 51 and 52 is widened to increase the opening width of the cooling water jacket HW of the cylinder head CH. As for the metal substrate 51 on the cylinder block CB side, a cooling water flow rate adjusting hole 58 having an opening area smaller than the cooling water hole 57 of the metal substrate 52 is provided. A part of the cooling water hole provided in the metal substrate 51 is provided as a cooling water hole 59 having the same opening area as the cooling water hole 57 as shown in FIG.

  With such a configuration, the flow rate of the cooling water can be adjusted by changing only the size of the cooling water flow rate adjusting hole 58, and the outer surface of the metal substrate 52 provided with the cooling water hole 57 is provided with the cooling water. Since the micro sealant 54 is removed in advance, only the metal substrate 51 on the cylinder block CB side can be used. Further, the inventor also has a surface 51a where the metal substrate 51 contacts the cylinder block CB on the upstream side of the flow of the cooling water in order to reduce the portion of the metal substrate 51 on the cylinder block CB side where the micro sealant 54 is removed. Only the micro-seal material 54 was peeled to form an uncoated region 60, and the micro-seal material 54 was left on the surface 51b on the cylinder head CH side that was not exposed to the direct high-speed water flow from the upstream side.

  As a result of repeated studies on the metal gasket 50 having such a configuration, there was no problem in sealing properties such as combustion gas, cooling water, and lubricating oil, but the metal substrate 51 was left on the surface 51b on the cylinder head CH side. In some cases, the microseal material 54 was lifted from the surface 51b and swollen or peeled off. Further, a part of the step adjustment plate 53 may be deformed inward or outward in the radial direction as indicated by a broken line in FIG.

  Therefore, the inventor prevents the micro sealant 54 of the surface 51b on the cylinder head CH side of the metal substrate 51 from being directly exposed to the cooling water, and at the same time increases the rigidity to prevent the step adjustment plate 53 from being deformed. Based on the consideration that it is effective to increase the width of the step adjustment plate 53 to cover the micro sealant 54, the present invention has been completed by further studies.

  In the metal gasket of the present invention, the substrate on the cylinder head side has cooling water holes that have the same or wider opening width than the opening width of the cooling water jacket of the cylinder head. Therefore, it is not necessary to remove the micro-seal material from the cylinder head side substrate. In addition, the cylinder block side substrate is provided with a cooling water flow rate adjusting hole having an opening area smaller than the cooling water hole, and the step adjusting plate covers the cooling water flow rate adjusting hole and its outer periphery is the cylinder block. The outer peripheral edge of the cooling water jacket and the outer peripheral edge of the cooling water jacket of the cylinder head are located on the inner side of the outer peripheral edge located outside and the opening area is the same as or slightly larger than the opening area of the cooling water flow rate adjustment hole The flow rate of the cooling water only needs to be changed by changing the size of the cooling water flow rate adjustment hole and the level adjustment plate water hole, and in the substrate on the cylinder block side, Since the surface on the cylinder head side is covered with the step adjustment plate, the micro sealant on this surface is not directly exposed to the cooling water. Therefore, the part where the micro seal material is removed in advance can be only the cylinder block side surface of the cylinder block side substrate. At the same time, as a result of increasing the width of the step adjustment plate, the rigidity of the step adjustment plate is increased, and deformation of the step adjustment plate that may occur during use can be prevented.

2 is a plan view of a metal gasket according to the present invention. FIG. It is sectional drawing in alignment with AA in FIG. 1 which shows the state which attached the metal gasket shown in FIG. 1 between the cylinder block and the cylinder head. It is sectional drawing in alignment with BB in FIG. 1 which shows the state which attached the metal gasket shown in FIG. 1 between the cylinder block and the cylinder head. It is a top view of a cylinder block of an engine according to the present invention. It is a top view of the metal substrate which comprises the metal gasket shown in FIG. 1, and is located in the cylinder block side. It is a top view of the metal substrate which comprises the metal gasket shown in FIG. 1, and is located in the cylinder head side. It is a top view of the level | step difference adjustment plate which comprises the metal gasket shown in FIG. It is a top view of the metal gasket used for examination before the completion of the present invention. It is sectional drawing which follows CC in FIG. It is a top view of the level | step difference adjustment plate which comprises the metal gasket shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 2 and 3, the metal gasket 1 shown in FIG. 1 includes a metal step adjustment plate 4 sandwiched between a metal substrate 2 on the cylinder block CB side and a metal substrate 3 on the cylinder head CH side. It is a metal gasket having a three-layer structure. A micro sealant 5 is coated on both surfaces of the metal substrate 2 and the metal substrate 3. In this embodiment, the micro seal material 5 made of rubber or the like is applied on the adhesive applied to the surfaces of the metal substrates 2 and 3. As shown in FIG. 3, in the metal substrate 2, an uncoated region 5 a that is not coated with the micro sealant 5 is provided on the contact surface 2 a that contacts the cylinder block CB. Further, in providing the non-coating region 5a, a necessary portion may be peeled off after coating the entire surface of the metal substrate 2 with the micro sealant 5, or the portion where the non-coating region 5a is provided may be masked in advance. Alternatively, the non-coating region 5a may not be coated with the micro sealant 5 from the beginning.

  As shown in FIG. 4, the cylinder block CB is provided with a plurality of cylinder bores B. On the outside of the cylinder bore B, a cooling water jacket formed so as to surround these cylinder bores B in a lump. BW is provided. Further, as shown in FIG. 3, the cylinder head CH is provided with a cooling water jacket HW corresponding to the cooling water jacket BW (formed in a hole shape at a position where a cooling water hole 8 described later is provided). Further, the opening shapes of the cooling water jacket HW and the cooling water jacket BW are formed so as to be larger than the area where the required cooling water flow rate can be obtained. The opening width of the cooling water jacket HW (the width from the inner peripheral edge HWa to the outer peripheral edge HWb of the cooling water jacket HW) is narrower than the opening width (the width from the inner peripheral edge BWa to the outer peripheral edge BWb of the cooling water jacket BW). Is formed. Note that, depending on the internal combustion engine, the cooling water jacket BW may be formed so that the opening width of the cooling water jacket BW is wider than the opening width of the cooling water jacket BW, or they may be the same opening width. Moreover, the non-coating area | region 5a mentioned above is formed so that it may become the same or wide with respect to the cooling water jacket BW which faces this.

  As shown in FIGS. 5 and 6, the metal substrates 2 and 3 are formed with at least one (three in this case) cylinder holes 6 and 7 corresponding to the cylinder bores B of the cylinder block CB. Has been. The metal substrates 2 and 3 are formed at positions corresponding to the cooling water jackets BW and HW, and have holes through which the cooling water passes from the upstream cooling water jacket BW to the downstream cooling water jacket HW. In the present embodiment, as shown in FIG. 3, the metal substrate 3 on the cylinder head CH side is formed with cooling water holes 8 having an opening width that is the same as or wider than the opening width of the cooling water jacket HW. Further, the metal substrate 2 on the cylinder block CB side is provided with a cooling water flow rate adjusting hole 9 smaller than the opening area of the cooling water hole 8. The cooling water holes provided in the metal substrate 2 do not have to be all smaller than the cooling water holes 8, and some of the holes have the same opening area as the cooling water holes 8 as shown in FIG. 5. The cooling water hole 10 may be provided. Further, the metal substrates 2 and 3 surround the cylinder holes 6 and 7 and surround the full bead 11 having a mountain-shaped cross section that prevents high-pressure combustion gas from leaking from the cylinder bore B, and the cooling water jacket HW. A half bead 12 for preventing leakage of cooling water is provided. A half bead 12 is also provided around the hole through which the lubricating oil flows.

  Moreover, as shown in FIG. 7, the level | step difference adjustment plate 4 is provided with the cylinder hole 13 formed corresponding to the cylinder bore B (three in this embodiment). Further, the step adjustment plate 4 is provided with a step adjustment plate water hole 14 having an opening area which is the same as or slightly larger than the opening area of the cooling water flow rate adjustment hole 9 at a position corresponding to the cooling water flow rate adjustment hole 9. By the way, from the viewpoint of protecting the micro seal material, it is preferable to make the opening area of the step adjustment plate water hole 14 smaller than the opening area of the cooling water flow rate adjustment hole 9, but in this case, the step adjustment plate water hole 14 is Since it is thin, the step adjustment plate water hole 14 that protrudes from the cooling water flow rate adjustment hole 9 may be deformed depending on the flow of the cooling water. Therefore, here, the step adjustment plate water is larger than the opening area of the cooling water flow rate adjustment hole 9. The opening area of the hole 14 is slightly increased. Note that the difference between these sizes is small, and even if the microsealing material around the cooling water flow rate adjusting hole 9 is exposed, peeling of the microsealing material is effectively prevented. Further, in the present embodiment, the outer peripheral edge 15 of the step adjusting plate 4 is outside the outer peripheral edge HWb of the cooling water jacket HW of the cylinder head CH, as shown in FIG. 3, and the cooling water jacket BW of the cylinder block CB. It is set so that it may be located inside the outer peripheral edge BWb. That is, since the level difference adjusting plate 4 covers a portion facing the cooling water jacket HW on the surface of the metal substrate 2 on the cylinder head CH side, the micro sealant 5 at this portion is not directly exposed to the cooling water. . Further, since the step adjustment plate 4 is not sandwiched between the joint surfaces located outside the cooling water jackets BW and HW, the step adjustment plate 4 has a function of increasing the tightening pressure of the full bead 11 surrounding the cylinder bore B of the step adjustment plate 4. There is no inhibition. When the cooling water jackets BW and HW have the same opening width, the outer peripheral edge of the step adjustment plate 4 is set so that the step adjustment plate 4 is not sandwiched between the joint surfaces of the cooling water jackets BW and HW. 15 is set so as to be located slightly inside from both the outer peripheral edge HWb and the outer peripheral edge BWb.

  The metal substrates 2 and 3 and the level difference adjusting plate 4 are coupled in a state where three are overlapped as shown in FIG. 2 by, for example, shear extrusion coupling as described in Japanese Patent No. 4783606 (coupling portion 16). In addition, in joining three sheets, it is not limited to a shear extrusion coupling | bonding, Various known methods, such as a rivet, eyelet, and spot welding, can be used. In addition, since the coupling part protrudes in the plate pressure direction with respect to the surrounding part, when the gasket is tightened, a gap is formed between the cylinder block and the cylinder head, causing the combustion gas and various liquids to leak. . For this reason, in this embodiment, the coupling | bond part 16 is provided in the cooling water jacket BW, as shown in FIG.

  When the metal gasket 1 having such a structure is mounted between the cylinder block CB and the cylinder head CH and examined by an actual machine test, there is no problem in sealing performance of combustion gas, cooling water, lubricating oil, etc. No swelling or peeling of the micro sealant 5 on the surface of the metal substrate 2 on the cylinder head CH side covered with the adjusting plate 4 was observed. Further, no deformation of the step adjustment plate 4 was observed. Therefore, according to the present invention, the non-coating region 5a in the metal substrates 2 and 3 can be formed by only one of the front and back surfaces (total of four surfaces) of each metal substrate 2 and 3, and the step adjusting plate can be used. 4 can be prevented from being deformed.

  According to the present invention, the micro-seal material coated on the metal gasket is exposed to the cooling water and is not likely to be peeled off, and the portion where the micro-seal material is removed in advance can be kept to a minimum. It became possible to provide a highly efficient metal gasket.

DESCRIPTION OF SYMBOLS 1 Metal gasket 2 Metal substrate 3 Metal substrate 4 Step adjustment plate 5 Micro seal material 5a Uncoated area 6, 7 Cylinder hole 8 Cooling water hole 9 Cooling water flow rate adjustment hole 10 Cooling water hole 11 Full bead 12 Half bead 13 Cylinder hole 14 Step adjustment Plate water hole 15 Outer peripheral edge 16 Joint portion CB Cylinder block CH Cylinder head BW Cooling water jacket HW Cooling water jacket

Claims (1)

A cylinder block having two metal substrates each coated with a micro sealant on each outer surface and a step adjusting plate sandwiched between the metal substrates, and a cooling water jacket formed around the cylinder bore, and the cooling water In the cylinder head metal gasket mounted between the cylinder head and the cooling water jacket corresponding to the jacket,
The substrate on the cylinder head side has cooling water holes that have the same or wider opening width than the opening width of the cooling water jacket of the cylinder head,
The substrate on the cylinder block side includes a cooling water flow rate adjustment hole having an opening area smaller than the cooling water hole, and a region where the micro sealant is not coated on a contact surface in contact with the cylinder block is a cylinder. With uncoated areas formed identically or widely to the cooling water jacket of the block,
The step adjusting plate covers the cooling water flow rate adjusting hole, and an outer peripheral edge thereof is located outside an outer peripheral edge of an outer peripheral edge of the cooling water jacket of the cylinder block and an outer peripheral edge of the cooling water jacket of the cylinder head. And a step adjustment plate water hole having an opening area that is the same as or slightly larger than the opening area of the cooling water flow rate adjustment hole.

Images