Sealing device for diesel engine block

Description

1 / 7 Sealing device for diesel engine block - Technical sector

[001] This utility model relates to the technical field of mechanical engineering, more specifically to the sector of sealing systems applied to internal combustion engines, with a focus on diesel engines. It is a solution aimed at improving the functional seal between the engine block and cylinder head, through a new vertical arrangement of O-rings housed in machined cavities, which aims to eliminate coolant leaks, increase sealing and extend the engine's service life. State of the art

[002] In the internal combustion engine sector, especially diesel engines, the seal between the engine block and the cylinder head is traditionally achieved using metal or composite gaskets, with or without additional elastomeric elements. These gaskets play a fundamental role in containing the engine's internal fluids, such as coolant and combustion gases, preventing leaks that could compromise the engine's operation and durability.

[003] Currently there are several cylinder head gasket solutions for diesel engines, especially aimed at the Scania brand, EURO2, EURO3 and EURO5 models. These conventional solutions perform the sealing in a predominantly horizontal manner, using flat gaskets which, in many cases, do not effectively prevent coolant leakage, which can lead to overheating and internal corrosion of the engine.

[004] US patent 20140097575A1 (Cylinder head gasket) describes a cylinder head gasket with multiple layers and reinforcements, but does not contemplate the vertical sealing by localized compression of an o-ring in a machined housing, as proposed in the model for which protection is sought.

[005] Document CN210483907U (Cylinder head sealing gasket and cylinder) presents a gasket with integrated sealing, but without the application of specific machining in the engine block for dedicated housing, which limits Petition 870250089662, dated 02 / 10 / 2025, page 9 / 19 2 / 7 its adaptability and effectiveness in engines with a high rate of thermal deformation.

[006] Furthermore, the commercial product identified under code 36001468, disclosed by the manufacturer Diesel Technic on the Ronichaves website on March 24, 2021, anticipates a gasket with multiple integrated seals, including around the cylinder liner, but without the proposed independent vertical seal by compressed o-ring between the block and cylinder head. This absence of localized compression and dedicated machining represents a functional limitation compared to the solution now proposed.

[007] Therefore, although there are similar objects on the market and patent documents that address cylinder head gaskets with additional reinforcements and seals, none of them equivalently overcomes the problems of tightness and durability solved by the present utility model. Novelty and objective of the proposed model.

[008] The present Utility Model presents a novelty by proposing a new form of vertical sealing between the block and the cylinder head of diesel engines, by means of the localized compression of an o'ring inserted into a housing machined directly into the engine block.

[009] Unlike conventional solutions that achieve horizontal sealing using flat gaskets, the proposed model introduces a novel functional arrangement that significantly improves the tightness of the cooling system, reduces the risk of leaks, and increases engine durability.

[010] The main objective of the model is to solve the recurring sealing failure problems observed in Scania engines of the EURO2, EURO3 and EURO5 models, offering a simple, effective and easy-to-apply technical alternative that can be implemented with conventional machining and assembly tools, without the need for complex structural changes to the original engine. Functional improvement of the proposed model Petition 870250089662, dated 02 / 10 / 2025, page 10 / 19 3 / 7

[011] The functional improvement provided by the present utility model lies in altering the shape and arrangement of the sealing system between the block and the cylinder head of diesel engines, replacing the traditional horizontal seal with a vertical seal obtained by compressing an o-ring housed in a cavity machined in the engine block.

[012] This new configuration allows for more efficient and localized sealing, significantly reducing the risk of coolant leakage, which is common with conventional gaskets.

[013] As a result, the model increases the reliability of the cooling system, prevents failures due to overheating and corrosion, and contributes to engine longevity, without requiring complex structural modifications or additional components that are difficult to obtain. It is, therefore, a functionally superior solution, easy to implement and with a direct impact on the performance and durability of the powertrain. List of attached drawings

[014] In order for the present model to be fully understood and put into practice by any technician in this technological sector, it is described in a clear, precise and sufficient manner, based on the attached drawings listed below. Figure 1 - Partial view of the motor with the O-ring. Figure 2 - Cutaway view of the motor with the O-ring. Figure 3 - Cutaway view of the housing with the O-ring. Model description

[015] The main approach of the present utility model consists of a sealing device for a diesel engine block, designed to be applied at the interface between the engine block and the cylinder head, specifically around the cylinder liner region, in order to promote vertical sealing and prevent coolant leaks.

[016] The vertical sealing system consists of a technical assembly applied to diesel engines, especially the Scania 124 EURO2 models, Petition 870250089662, dated 02 / 10 / 2025, page 11 / 19 4 / 7 EURO3 and EURO5, with the aim of solving recurring sealing failures between the engine block and cylinder head.

[017] Unlike conventional gaskets that operate with transverse sealing, the model introduces a new functional arrangement based on the compression of an o'ring (02) positioned vertically in a housing (06) machined into the engine block (01).

[018] This housing (06) is produced by means of a cutting tool driven by a manual boring machine, with dimensions highlighted in table 1 and preferably containing approximately 151x155x1.5 mm, and receives an o-ring which may be made of 70 Shore A nitrile rubber, round profile, with preferably dimensions of 150x154x2.00 mm (02). Each engine cylinder receives a housing and o-ring assembly, totaling six units in six-cylinder engines. Table 1: Housing dimensions in the engine block MODEL Internal Diameter External Diameter Height EURO2 150mm 154mm 2mm EURO3 151mm 155mm 2mm EURO5 152mm 156mm 2mm

[019] After machining on the block (01), the ring is inserted into the housing as specified (02), followed by assembly of the cylinder head gasket and the cylinder head itself, which is secured with bolts and torque as per the manufacturer’s specifications.

[020] The resulting vertical seal prevents coolant leaks, protecting the engine against overheating and corrosion. The system was tested on a Scania model 440 engine, subjected to pressurization with hot water at 95 °C and a pressure of 4.0 Bar, demonstrating effectiveness both with the original gasket without a seal and with the conventional seal maintained.

[021] The functional assembly also includes the cylinder liner (03), the piston (04) and the connecting rod (05), which operate in synergy with the proposed sealing system, guaranteeing the thermal and mechanical performance of the engine. Petition 870250089662, dated 02 / 10 / 2025, page 12 / 19 5 / 7

[022] In its preferred configuration, the sealing device comprises an o-ring (02), made of elastomeric material resistant to high temperatures and chemical agents present in the coolant, such as, for example, nitrile rubber (NBR), Viton® or silicone, according to the engine requirements, in the gasket with the seal a polymer known as TPV could be used. The o-ring (02) has a round profile, with an outer diameter and cross-section dimensioned according to the cylinder liner diameter and the depth of the machined housing.

[023] The o-ring (02) is housed in a machined housing (01), made directly in the engine block, around the region corresponding to the cylinder liner (03) of each cylinder. The housing (01) is made using a manually operated cutting tool, such as a hand mill, countersink or similar tool, allowing the precise creation of the circular groove around the liner, without the need for complete disassembly of the block or the use of CNC machinery. The housing (01) has a depth and width compatible with the o-ring (02), ensuring its perfect seating and preventing displacement during cylinder head assembly.

[024] The typical depth of the housing (01) varies between 2 mm and 4 mm, while the width is dimensioned to accommodate the diameter of the o-ring (02), for example, from 3 mm to 5 mm, depending on the cylinder liner diameter and engine specifications. The surface finish of the housing is important to ensure the integrity of the o-ring and to prevent damage during operation.

[025] During assembly, the o-ring (02) is inserted into the housing (01) machined around the cylinder liner (03). When the cylinder head is positioned on the engine block and the specified torque is applied to the fixing bolts, the o-ring (02) is compressed vertically between the surfaces of the block and the cylinder head, providing an effective seal and preventing coolant from escaping to the outside or inside of the cylinder.

[026] The device is applied individually to each cylinder of the engine, i.e. each liner (03) receives its own o'ring (02) and housing (01), Petition 870250089662, dated 02 / 10 / 2025, page 13 / 19 6 / 7 providing modularity to the sealing system. In case of failure or wear of the o-ring in a given cylinder, it is possible to replace only the corresponding element, without the need to replace the entire gasket or intervene in the other cylinders, reducing costs and maintenance time.

[027] The constructive configuration of the device also allows for compensation of small dimensional variations resulting from machining, seating or thermal deformations, since the o-ring (02) has sufficient elasticity to adapt to the contact surface, maintaining tightness even under pressure and temperature variations typical of diesel engine operation.

[028] The choice of a round profile for the o-ring (02) provides uniform distribution of the compression force and superior resistance to coolant leakage, compared to flat or irregular profile seals. The selected elastomeric material must exhibit resistance to temperatures above 120°C, chemical compatibility with the coolant and low permanent compression deformation.

[029] The execution of the housing (01) by hand tool provides flexibility to the process of adapting the device to different engine models and facilitates field repairs, without the need for specialized equipment. The procedure can be carried out by qualified technicians, using portable cutting and measuring tools, ensuring the dimensional accuracy required for sealing.

[030] The present sealing device is particularly advantageous in heavy-duty diesel engines, such as trucks, buses, tractors and industrial equipment, where sealing failures can result in serious engine damage and high repair costs. The proposed solution allows for quick and localized interventions, increasing the operational availability of the equipment.

[031] In summary, the sealing device for diesel engine blocks of the present utility model is characterized by its constructive simplicity, ease of installation and maintenance, modularity and high efficiency in containing the coolant, overcoming the limitations of the solutions Petition 870250089662, dated 02 / 10 / 2025, page 14 / 19 7 / 7 conventional systems based on integrated joints and non-individualized seals. Petition 870250089662, dated 02 / 10 / 2025, page 15 / 19

Claims

1 / 1 CLAIMS 1. SEALING DEVICE FOR DIESEL ENGINE BLOCK, characterized by comprising an o'ring (02) configured to be housed in a machined housing (01) disposed in the engine block, the housing (01) being dimensioned to receive the o'ring (02) in order to perform the vertical seal between the engine block and the cylinder head, preventing coolant leaks.

2. SEALING DEVICE FOR DIESEL ENGINE BLOCK, according to claim 1, characterized in that the machined housing (01) is made by means of a manually operated cutting tool.

3. SEALING DEVICE FOR DIESEL ENGINE BLOCK, according to claim 1, characterized in that the o'ring (02) has a round profile.

4. SEALING DEVICE FOR DIESEL ENGINE BLOCK, according to claim 1, characterized in that the machined housing (01) is arranged around the region corresponding to the cylinder liner (03) of the engine.

5. SEALING DEVICE FOR DIESEL ENGINE BLOCK, according to claim 1, characterized by being applied individually to each cylinder of the engine. Petition 870250089662, dated 02 / 10 / 2025, pp. 16 / 19

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