Multi-stage sealing structure suitable for sensor

Abstract

The multistage sealing structure comprises a metal shaft body and a plastic hole body, the metal shaft body comprises a first shaft body and a second shaft body which are integrally connected, a plurality of annular steps are arranged on the periphery of the second shaft body in the axis direction of the second shaft body, and the first shaft body and the second shaft body are connected through the plastic hole body. A plurality of grooves are formed in the inner wall of the plastic hole body in the hole diameter direction of the plastic hole body, the first shaft body and the inner wall of the hole body are in interference fit to form a first sealing structure, and the annular steps and the corresponding grooves are connected in a clamped mode to form a second sealing structure. The shaft body is in interference fit with the hole wall, a liquid permeation path is blocked, the annular step and the groove are arranged at the tail end of the shaft body to form a multi-stage sealing structure, leakage path resistance is increased, and the problems that a sensor is prone to leakage and excessively depends on sealing of a sealing ring are solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to mechanical seal technical field, and particularly relates to a multistage sealing structure suitable for sensor. BACKGROUND

[0002] In prior art, the sealing structure of automobile sensor mostly adopts rubber sealing ring (such as butyronitrile rubber, fluorine rubber, etc.) to realize the sealing of metal parts and plastic parts, as shown in the drawing. Figure 1 However, such sealing scheme has the following defects:

[0003] 1. High cost: the sealing ring needs to be purchased separately, and special equipment (such as press-fitting tool) is needed in the installation process, which increases the material and manufacturing cost; 2. Poor environmental adaptability: the rubber material is prone to embrittlement or aging under extreme temperature (such as below-40℃ or above 125℃), resulting in sealing failure; in addition, the rubber may swell or corrode after long-term contact with fuel, lubricating oil and other media; 3. Complex structure: the sealing ring needs to be designed with a sealing groove, which occupies additional space and limits the miniaturization design. CONTENT OF UTILITY MODEL

[0004] The utility model aims at providing a multistage sealing structure suitable for sensor, which blocks the liquid penetration path through the interference fit between the shaft body and the hole wall, and forms a multistage sealing structure through the annular step at the end of the shaft body and the groove, thereby increasing the leakage path resistance and solving the problems of easy leakage and excessive dependence on sealing ring sealing of the sensor.

[0005] The utility model is implemented as follows: a multistage sealing structure suitable for sensor, comprising a metal shaft body and a plastic hole body, the metal shaft body comprises a first shaft body and a second shaft body which are integrally connected, the outer periphery of the second shaft body is provided with a plurality of annular steps along the axial direction thereof, the inner wall of the plastic hole body is provided with a plurality of grooves along the hole diameter direction thereof, the first shaft body and the inner wall of the hole body are interference fitted to form a first sealing structure, and the annular steps and the corresponding grooves are clamped and connected to form a second sealing structure.

[0006] When the utility model is installed, no special equipment is needed for press-fitting, the inner wall of the plastic hole body and the interference surface of the first shaft body are directly contacted to form a first sealing structure, the liquid penetration path is blocked, and the plurality of annular steps on the second shaft body and the grooves form a second sealing structure, thereby increasing the leakage path resistance. Compared with the prior art, the utility model has the beneficial effects that: the first sealing structure and the second sealing structure form a multistage sealing structure, which solves the problems of easy leakage and excessive dependence on sealing ring sealing of the sensor; through the optimization of material and structure design, the sealing ring and its supporting tooling requirements are eliminated, thereby reducing the sealing cost; through the multistage sealing strategy to replace the traditional sealing ring, the number of parts and the assembly process are reduced, the structure design is simplified, and the cost is saved.

[0007] As a further improvement of the utility model, the second sealing structure is a reverse buckle type sealing structure.

[0008] As a further improvement of the utility model, the annular step comprises an outwardly expanding guide part and a closed part.

[0009] As a further improvement of the utility model, the first shaft body end part is provided with a chamfer.

[0010] As a further improvement of the utility model, the interference amount between the first shaft body and the hole body inner wall is 0.03-0.05mm.

[0011] As a further improvement of the utility model, the metal shaft body is made of H62 brass material.

[0012] As a further improvement of the utility model, the plastic hole body is made of glass fiber reinforced POM material.

[0013] As a further improvement of the utility model, the metal shaft body outer surface is provided with a nickel plating layer and a tin plating layer.

[0014] As a further improvement of the utility model, the thickness of the nickel plating layer is 1μm, and the thickness of the tin plating layer is 3μm.

[0015] As a further improvement of the utility model, the number of annular steps and grooves is two. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a sealing structure schematic view of a traditional sealing ring.

[0017] Figure 2 It is a three-dimensional structure schematic view of the metal shaft body of the utility model.

[0018] Figure 3 It is a multi-stage sealing structure schematic view of the utility model.

[0019] Among them, 1 metal shaft body, 101 first shaft body, 102 second shaft body, 103 annular step, 103a guide part, 103b closed part, 104 chamfer, 2 plastic hole body, 3 first sealing structure, 4 second sealing structure. CONCRETE IMPLEMENTATION

[0020] As Figure 2 And 3As shown, it is a multi-stage sealing structure suitable for sensor, comprising a metal shaft body 1 and a plastic hole body 2, the metal shaft body 1 comprises a first shaft body 101 and a second shaft body 102 which are integrally connected, the second shaft body 102 is provided with two annular steps 103 along the axial direction of the outer periphery, the inner wall of the plastic hole body 2 is provided with two grooves along the hole diameter direction, the first shaft body 101 and the inner wall of the hole body are in interference fit to form a first sealing structure 3, and the two annular steps 103 and the corresponding grooves are clamped and connected to form a second sealing structure 4.

[0021] Specifically, the first shaft body 101 is provided with a chamfer 104 at the end, the interference amount of the first shaft body 101 and the inner wall of the hole body is controlled within the range of 0.03-0.05mm, an initial sealing force is formed by elastic deformation, and micro gaps are filled by plastic deformation; the annular step 103 comprises an outwardly expanding guide portion 103a and a closed portion 103b, and the guide portion 103a and the closed portion 103b are in close contact with the groove to form a reverse locking type sealing structure.

[0022] The metal shaft body 1 is made of H62 brass material, and the outer surface is plated with a 1μm nickel layer and a 3μm tin layer, which has corrosion resistance and high hardness, and ensures the anti-deformation ability during assembly; the plastic hole body 2 is made of glass fiber reinforced POM (polyoxymethylene) material, which has high creep resistance (long-term interference amount decay <0.01mm), and avoids the influence of environmental humidity by low moisture absorption.

[0023] In use, the shaft hole and the interference surface directly contact to form the first sealing structure 3, and the liquid penetration path is blocked, the annular step 103 is arranged at the end of the shaft body and forms a reverse locking type second sealing structure 4 with the groove in the hole, and the leakage path resistance is increased.

[0024] The utility model is not limited to the above embodiment, on the basis of the technical scheme disclosed in the utility model, those skilled in the art can make some substitutions and deformations to some technical features according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the utility model.

Claims

1. A multi-stage sealing structure suitable for sensors, characterized in that, The metal shaft body comprises a first shaft body and a second shaft body which are integrally connected, and the outer periphery of the second shaft body is provided with a plurality of annular steps along the axial direction; the inner wall of the plastic hole body is provided with a plurality of grooves along the hole diameter direction; the first shaft body is in interference fit with the inner wall of the hole body to form a first sealing structure; and the annular steps are in clamping connection with the corresponding grooves to form a second sealing structure.

2. A multi-stage seal structure suitable for a sensor according to claim 1, wherein, The second sealing structure is a reverse buckle type sealing structure.

3. A multi-stage seal structure suitable for a sensor according to claim 1, wherein, The annular steps comprise an outwardly expanding guide part and a closed part.

4. A multi-stage seal structure suitable for a sensor according to claim 1, wherein, The end of the first shaft body is provided with a chamfer.

5. A multi-stage seal structure suitable for a sensor according to claim 1, wherein, The interference amount between the first shaft body and the inner wall of the hole body is 0.03-0.05 mm.

6. A multi-stage seal structure suitable for a sensor according to claim 1, wherein, The metal shaft body is made of H62 brass material.

7. A multi-stage seal structure suitable for a sensor according to claim 1, wherein, The plastic hole body is made of glass fiber reinforced POM material.

8. A multi-stage seal structure suitable for use with a sensor according to claim 1, wherein, The outer surface of the metal shaft body is provided with a nickel plating layer and a tin plating layer.

9. A multi-stage seal structure suitable for use with a sensor according to claim 1, wherein, The thickness of the nickel plating layer is 1 μm, and the thickness of the tin plating layer is 3 μm.

10. A multi-stage seal structure suitable for use with a sensor according to claim 1, wherein, The number of the annular steps and the grooves is two.

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