Bottom oil port sealing structure of plastic oil tank
By embedding pre-embedded parts inside the plastic fuel tank and adopting a multi-seal structure, the problem of poor sealing caused by uneven joint surfaces between the plastic fuel tank and the metal pre-embedded parts was solved, thereby improving sealing reliability and mechanical strength.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2026-03-10
AI Technical Summary
The mating surfaces of plastic fuel tanks and metal embedded parts are difficult to keep flush. Due to thermal expansion and contraction and vibration, gaps are easily generated, leading to poor sealing and oil leakage.
Pre-embedded inserts are installed inside the plastic fuel tank, and the transition joint is connected to the oil pipe joint by thread. A multi-seal structure is adopted, including O-rings, combination gaskets and sealing gaskets, to enhance mechanical strength and sealing effect.
It effectively prevents oil leakage, extends the service life of the whole machine, enhances the mechanical strength of the interface, and avoids cracking of plastic materials.
Smart Images
Figure CN223984625U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of plastic hydraulic tank technology, specifically to a bottom oil port sealing structure for a plastic oil tank. Background Technology
[0002] Currently, all types of power machinery still rely on engines as their power source, and the combustion material of engines is mainly liquid fuel. In the current era, design technology is advancing rapidly, and various types of machinery with different shapes and functions are emerging. Traditional iron fuel tanks are gradually being replaced by plastic fuel tanks due to limitations such as the cost of design and mold investment. Plastic fuel tanks have the huge advantage of being able to be molded into any shape.
[0003] However, plastic fuel tanks themselves cannot provide reliable fastening threads. Metal parts need to be placed in the designated positions of the plastic fuel tank mold during manufacturing. The fuel tank can be integrated with the metal during manufacturing to form a fuel tank assembly.
[0004] like Figure 1 The diagram shows the existing fuel tank sealing structure, which involves embedding an existing pre-embedded insert II during the production of the existing plastic fuel tank I. The lower surface of the existing pre-embedded insert II is aligned with the lower surface of the plastic fuel tank I. During assembly, the existing fuel pipe connector IV is installed using the existing fixed hollow bolt VI through the existing pre-embedded insert II, and existing sealing gaskets I III and II V are used for sealing. During installation, the existing sealing gasket I III is pressed tightly against the surfaces of the existing plastic fuel tank I and the existing pre-embedded insert II to achieve a seal. However, during the manufacturing process, it is difficult to ensure that the surface of the existing pre-embedded insert II is completely flush with the surface of the existing plastic fuel tank I. In addition, due to the influence of thermal expansion and contraction, the shrinkage ratios of plastic and metal parts are different. Furthermore, during the assembly and use of the fuel tank, external forces and vibrations may cause gaps to form between the plastic and metal parts of the fuel tank, leading to oil leakage at the joint surface. Utility Model Content
[0005] The purpose of this utility model is to provide a reasonably designed bottom oil port sealing structure for a plastic oil tank, which can solve the above-mentioned defects and deficiencies of the existing technology.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: it includes a pre-embedded insert embedded in a plastic oil tank, a transition joint connected to the lower part of the pre-embedded insert by a thread, an oil pipe joint installed at the lower end of the transition joint by a fixing hollow bolt, an O-ring seal between the pre-embedded insert and the transition joint, a combined gasket between the upper part of the transition joint and the plastic oil tank, a sealing gasket one between the transition joint and the oil pipe joint, and a sealing gasket two at the installation location of the fixing hollow bolt.
[0007] Preferably, the pre-embedded insert is completely embedded inside the plastic fuel tank by injection molding, and the bottom surface of the pre-embedded insert is higher than the bottom surface of the plastic fuel tank.
[0008] Preferably, the combined gasket, sealing gasket one, and sealing gasket two are all composed of a metal gasket and a rubber sealing ring.
[0009] Preferably, the O-ring and the combination gasket are both installed on the transition joint.
[0010] Preferably, the fixed hollow bolt has a channel inside, which communicates with the inner cavities of the transition joint and the oil pipe joint respectively.
[0011] The beneficial effects of this utility model after adopting the above structure are:
[0012] The structure designed in this utility model enhances the mechanical strength of the interface by fully embedding the metal pre-embedded insert into the plastic oil tank through injection molding, avoids the problem of cracking of the plastic material at the installation location of the pre-embedded insert under high pressure or repeated load, and adds a transition joint as a connecting transition part and adopts a multi-seal structure to effectively prevent oil from leaking out of the oil tank and significantly extend the service life of the whole machine. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the sealing structure of the oil inlet at the bottom of an existing plastic fuel tank;
[0014] Figure 2 This is a schematic diagram of the structure of this utility model.
[0015] Explanation of reference numerals in the attached figures:
[0016] Ⅰ. Existing plastic fuel tank; Ⅱ. Existing embedded inserts; Ⅲ. Existing sealing gasket 1; Ⅳ. Existing oil pipe joint; Ⅴ. Existing sealing gasket 2; Ⅵ. Existing fixed hollow bolts;
[0017] 1. Plastic fuel tank; 2. Embedded inserts; 3. O-ring seals; 4. Combination gaskets; 5. Transition joints; 6. Sealing gasket one; 7. Oil pipe joint; 8. Sealing gasket two; 9. Fixing hollow bolts. Detailed Implementation
[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0019] See Figure 2As shown, it includes a pre-embedded insert 2 embedded in a plastic oil tank 1. A transition joint 5 is threadedly installed below the pre-embedded insert 2. An oil pipe connector 7 is installed at the lower end of the transition joint 5 via a fixing hollow bolt 9. The fixing hollow bolt 9 has a channel for oil flow, which communicates with the inner chambers of both the transition joint 5 and the oil pipe connector 7 to ensure smooth oil transfer. An O-ring seal 3 is provided between the pre-embedded insert 2 and the transition joint 5 to achieve a sealed connection. Furthermore, a combination gasket 4 is provided above the transition joint 5 and between it and the plastic oil tank 1. Both the O-ring seal 3 and the combination gasket 4 are installed on the transition joint 5, forming a multi-layered seal. Structure: A sealing gasket 6 is provided between the transition joint 5 and the oil pipe joint 7, while a sealing gasket 8 is provided at the installation location of the fixed hollow bolt 9 to further enhance the sealing effect of each connection. The pre-embedded insert 2 is completely embedded in the interior of the plastic oil tank 1 by injection molding, and its bottom surface is higher than the bottom surface of the plastic oil tank 1, thereby providing space for the connection of the structure below. At the same time, the connection position is located inside the plastic oil tank 1, and the mechanical strength of the connection point of the plastic oil tank 1 is greater than that of the bottom surface position. The combined gasket 4, sealing gasket 6, and sealing gasket 8 are all composed of metal gaskets and rubber sealing rings, which have both rigid support and flexible sealing functions, ensuring the reliability and sealing performance of the overall structure.
[0020] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A bottom filler seal structure for a plastic fuel tank, characterized by: It contains the pre-embedded insert (2) buried in the plastic oil tank (1), the pre-embedded insert (2) is completely embedded in the plastic oil tank (1) by injection molding, the bottom surface of the pre-embedded insert (2) is higher than the bottom surface of the plastic oil tank (1); The transition joint (5) is connected below the pre-embedded insert (2), the oil pipe joint (7) is installed at the lower end of the transition joint (5) through the fixed hollow bolt (9), the O-shaped sealing ring (3) is arranged between the pre-embedded insert (2) and the transition joint (5), the combined gasket (4) is arranged between the upper portion of the transition joint (5) and the plastic oil tank (1), the sealing gasket one (6) is arranged between the transition joint (5) and the oil pipe joint (7), and the sealing gasket two (8) is arranged at the fixed hollow bolt (9) installation position.
2. The bottom filler neck seal for a plastic fuel tank of claim 1, wherein: The combined gasket (4) is composed of a metal gasket and a rubber sealing ring.
3. The bottom filler neck seal for a plastic fuel tank of claim 2, wherein: The O-shaped sealing ring (3) and the combined gasket (4) are both installed on the transition joint (5).
4. The bottom filler neck seal for a plastic fuel tank of claim 1, wherein: The fixed hollow bolt (9) is provided with a hole, and the hole is in communication with the inner cavities of the transition joint (5) and the oil pipe joint (7).