Device for preventing oil gas leakage of cylinder cover

Abstract

The utility model discloses a device for preventing oil gas leakage of a cylinder cover, which belongs to the field of engine cylinder components and comprises a bolt screwed into a fixing hole of the cylinder cover, a 42crmo sealing washer arranged at the joint of the head of the bolt and the fixing hole of the cylinder cover, an external thread arranged at the tail end of the rod part of the bolt and capable of being externally meshed with the fixing hole, and a polished rod. A plurality of sealing structures are arranged on a polished rod of the bolt, the sealing structures are a plurality of sealing circular grooves which are formed in the polished rod and are consistent in specification, an O-shaped sealing ring is arranged in the bottommost sealing circular groove in a sleeved mode, and the outer diameter of the O-shaped sealing ring is larger than the outer diameter of an outer thread at the tail end of the bolt. According to the utility model, engine oil leakage during preassembling can be effectively prevented, and oil gas leakage faults caused by entering of external oil gas can be prevented.

Description

Technical Field

[0001] The utility model relates to the field of engine cylinder components, in particular to a device for preventing oil and gas leakage from a cylinder cover. Background Art

[0002] The engine cylinder head is one of the key parts in the engine. It has high precision requirements and complex processing technology. The quality of processing directly affects the overall performance and quality of the engine. The cylinder head is installed on the top of the cylinder body, sealing the cylinder from the top and forming a combustion chamber. It is often in contact with high-temperature and high-pressure gas. The cylinder head is installed with bolts. When installing, it is necessary to apply engine oil to the threaded fastening part. When the engine is working, there is a large amount of oil and gas in the combustion chamber. These oil and gas and excess oil will enter the threaded hole, resulting in oil and gas leakage. Under normal operation, in order to solve the oil and gas leakage problem in parts such as fuel lines, copper sealing washers are often set on the bolt heads. After the washers are installed, leakage may still occur. In order to ensure the sealing effect, the tightening strength needs to be increased. The cylinder head itself has high precision and has specified requirements for the tightening strength of the bolts. Because the material stiffness of the copper sealing washers is insufficient, the cylinder head position needs to withstand the strong impact generated by compression ignition, which requires a large bolt torque. The copper sealing washers are difficult to withstand the increased tightening torque, so this sealing method has certain limitations and the effect is average.

[0003] Document CN200320124469.3 discloses an aerator motor with a sealing structure, wherein a countersunk hole is added to each bolt hole connecting the aerator motor flange and the motor housing for installing an O-type sealing ring, the contact section between the bolt and the O-type sealing ring is bare, the O-type sealing ring clamps the bolt to seal the bolt shaft diameter, and the bolt presses the O-type sealing ring to the sealing plane at the bottom of the countersunk hole through the gasket, thereby preventing water outside the motor from penetrating into the reduction box through the bolt hole and preventing the oil in the reduction box from flowing out of the motor through the bolt hole. This sealing method of adding a countersunk hole under the gasket and arranging an O-type sealing ring in the countersunk hole has a good sealing effect, but it is difficult to use it in the cylinder head sealing. The cylinder head itself has high precision requirements, adding a countersunk hole, the process is complicated, and the cost is increased. Moreover, adding an O-type sealing ring under the gasket, because the cylinder head bolt has a large tightening strength, the O-type sealing ring is directly clamped, and the deformation is small, it still cannot withstand the tightening strength specified by the cylinder head bolt, and only one layer of O-type sealing ring is added, and the sealing effect is still not good. Therefore, in order to effectively avoid oil and gas leakage, a device with good sealing performance and capable of being used on a cylinder head with high tightening strength is needed. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a device for preventing oil and gas leakage from a cylinder head, which can be used on a cylinder head with high tightening strength and can effectively achieve sealing to prevent oil and gas leakage.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is: a device for preventing oil and gas leakage from a cylinder head, comprising a bolt screwed into a fixing hole of the cylinder head, a sealing gasket being arranged at the connection between the bolt head and the fixing hole of the cylinder head, an external thread being arranged at the rear end of the rod of the bolt and being able to externally engage with the fixing hole, and a plurality of sealing structures being arranged on the bare rod of the bare rod bolt, the sealing structure being a plurality of sealing circular grooves of the same specification arranged on the bare rod, an O-ring being sleeved in the sealing circular groove at the bottom, and an outer diameter of the O-ring being larger than an outer diameter of the external thread at the rear end of the bolt.

[0006] A further improvement of the technical solution of the utility model is that the sealing gasket is a gasket made of 42crmo material.

[0007] A further improvement of the technical solution of the utility model is that: there are two sealing structures, which are respectively arranged on the upper part and the lower part of the bolt polished rod.

[0008] A further improvement of the technical solution of the utility model is that the number of sealing circular grooves in each sealing structure is 4.

[0009] A further improvement of the technical solution of the utility model is that the O-type sealing ring is an oil-resistant and corrosion-resistant rubber ring.

[0010] Due to the adoption of the above technical scheme, the technical progress achieved by the utility model is: by setting a sealing circular groove on the bolt rod, the O-type sealing ring is set in the sealing circular groove, so that the O-type sealing ring is not directly squeezed by the tightening bolt, ensuring the fixed position, while ensuring the sealing performance, it is more durable and convenient for assembly and use, and will not affect the tightening strength of the bolt. By setting multiple sealing circular grooves, the O-type sealing ring is set in the sealing circular groove at the bottom during assembly. In the process of screwing the bolt with the O-type sealing ring into the fixing hole, due to the friction during the assembly process, the O-type sealing ring may be squeezed out of the initial sealing circular groove, but because there are still multiple spare sealing circular grooves on the top, the O-type sealing ring will fall into the spare sealing circular groove, and the sealing can still be achieved, and the fixing hole will not be blocked due to the change of the position of the O-type sealing ring, causing the situation that it is difficult to deeply assemble the bolt. By setting a sealing gasket made of 42crmo material under the bolt head, the 42crmo material has high temperature resistance, can withstand large torque, and can cooperate with the bolt to achieve sealing. By setting up multiple sealing devices and multiple oil-resistant and corrosion-resistant rubber rings, the oil leakage during pre-installation can be effectively prevented, and at the same time, the entry of external oil and gas can be blocked to cause oil leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 It is a schematic diagram of the cylinder head structure;

[0013] Figure 2 It is a schematic diagram of the structure of the utility model;

[0014] Figure 3 It is an enlarged schematic diagram of the sealing structure of the utility model;

[0015] Among them, 1. bolt, 11. external thread, 2. sealing gasket, 3. cylinder head, 4. sealing structure, 41. O-ring, 42. sealing groove, 5. crankcase. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with the embodiments:

[0017] Embodiment 1

[0018] like Figure 1 As shown in FIG. 1 , it is a schematic diagram of the structure of the cylinder head of the engine, and a plurality of bolts 1 are screwed into the fixing holes of the cylinder head 3 to fasten the cylinder head 3 to the crankcase 5. Figure 2 The figure shows a schematic diagram of the structure of a device for preventing oil and gas leakage in a cylinder head, comprising a plurality of bolts 1 passing through sealing washers 2 made of 42crmo material, the bolts 1 being screwed into the interior of the fixing holes of the cylinder head 3, that is, a sealing washers 2 made of 42crmo material being provided at the connection between the head of the bolt 1 and the fixing hole of the cylinder head 3, a portion of the tail end of the rod of the bolt 1 being provided with an external thread 11, and the rest of the rod being a bare rod, the external thread 11 at the tail end being matched with the internal thread of the fixing hole of the cylinder head 3 and being able to mesh with each other, so that the bolt 1 is tightened and screwed into the fixing hole of the cylinder head 3.

[0019] A sealing structure 4 is provided on the bare rod of the bolt 1 at a distance of 6 mm from the bottom of the 42crmo material sealing gasket 2, and a sealing structure 4 is also provided at a distance of 126 mm from the bottom of the 42crmo material sealing gasket 2, that is, two sealing structures 4 of the same specifications are provided on the bare rod, one above and one below, each sealing structure 4 specifically includes four sealing circular grooves 42 of the same specifications provided on the bare rod, and an O-type sealing ring 42 is sleeved in the sealing circular groove 42 at the bottom of each sealing structure 4. The O-type sealing ring 42 is an oil-resistant and corrosion-resistant rubber ring, and its outer diameter is larger than the outer diameter of the external thread at the tail end of the bolt 1, so as to achieve the effect of blocking the entry of external oil and gas. During the actual assembly, apply engine oil to the external threaded part of the tail end of the bolt 1, pass the bolt 1 through the 42crmo material sealing gasket 2, and penetrate into the fixing hole of the cylinder head 3. Because the two sealing structures 4 of the bolt 1 are sleeved with O-rings 42 with large outer diameter, during the penetration process, the O-rings 42 will touch the hole wall, and may be displaced due to friction and squeezed out of the initial sealing circular groove. However, because multiple spare sealing circular grooves are still set above the initial groove, the O-rings 42 will fall into the spare sealing circular groove during displacement, and the sealing effect can still be achieved. It will not block the fixing hole during displacement deformation and affect the assembly of the bolt 1. After the bolt 1 is inserted into the fixing hole, it is pre-tightened by 50Nm according to the tightening requirements, and then tightened at multiple angles of 120°, 120°, and 60° to achieve tightening. The utility model can effectively prevent the leakage of engine oil during pre-installation, and at the same time, it can block the entry of external oil and gas to cause oil and gas leakage.

[0020] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for preventing oil and gas leakage from a cylinder head, comprising a bolt (1) screwed into a fixing hole of a cylinder head (3), a sealing gasket (2) being arranged at the connection between the head of the bolt (1) and the fixing hole of the cylinder head (3), an external thread (11) being arranged at the rear end of the rod of the bolt (1) and being capable of externally meshing with the fixing hole, and the rest of the rod being a bare rod, characterized in that: A plurality of sealing structures (4) are arranged on the polished rod of the bolt (1), the sealing structures (4) being a plurality of sealing circular grooves (42) of the same specification arranged on the polished rod, an O-type sealing ring (41) is sleeved in the bottommost sealing circular groove (42), and the outer diameter of the O-type sealing ring (41) is larger than the outer diameter of the external thread at the rear end of the bolt (1).

2. The device for preventing oil and gas leakage from a cylinder head according to claim 1, characterized in that: The sealing gasket (2) is a 42crmo gasket.

3. The device for preventing oil and gas leakage from a cylinder head according to claim 1, characterized in that: There are two sealing structures (4), which are respectively arranged at the upper part and the lower part of the bare rod of the bolt (1).

4. The device for preventing oil and gas leakage from a cylinder head according to claim 3, characterized in that: The number of the sealing circular grooves (42) in each sealing structure (4) is four.

5. A device for preventing oil and gas leakage from a cylinder head according to any one of claims 1 to 4, characterized in that: The O-type sealing ring (41) is an oil-resistant and corrosion-resistant rubber ring.

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