KR20130025257A - Construction mechanical cylinder sealing up all style decompression - Google Patents

Abstract

PURPOSE: An integrated decompression seal for sealing a construction mechanical cylinder is provided to prevent the generation of heat degradation and fatigue around assembled portions by the concentrated tension. CONSTITUTION: An integrated decompression seal(4) for sealing a construction mechanical cylinder is formed of thermoplastic polyurethane. The decompression seal is obtained by inject-molding the thermoplastic polyurethane with the uniform value of tensile strength, oil resistance, hardness, resilience, and permanent transformation ratio. The integrated decompression seal determines the performance of a highly functional high-pressure cylinder which transfers the high pressure from a high-pressure cylinder rod sealing system to an oil packing on a rod seal after decompressing.

Description

Construction mechanical cylinder sealing up all style decompression}

The present invention relates to a one-piece pressure-reducing seal for sealing cylinders for construction machinery to improve the sealability and durability life by dispersing concentrated stress.

The conventional technology is that the main body 7-1 of the pressure reducing seal produces high pressure about 38MPa, temperature resistance of about -30 ℃ ~ 90 ℃ and high speed TPU material about 400 ~ 500mm by precision injection molding.

U-shaped circular ring and backup ring 7-2 Pressure, temperature and speed of the pressure reducing seal body 7-1 are backed up, so the physical properties of the backup ring 7-2 are 30 ~ 50% higher than the pressure reducing seal body 7-1. The assembly type pressure-sensitive seal made by assembling the product produced by the precision injection molding is the product produced by the precision injection molding process for both parts, so the degree of parallelism, flatness and squareness of the product's processing degree is 0.1 ~ 0.3mm. Due to the structural problem, when the high pressure is applied to the assembled pressure-sensitive seal 7, the concentrated load acts on the boundary of the assembly joint, which is the sliding surface 8, to promote thermal deterioration and fatigue due to friction and wear and tear. There is a problem of deterioration.

An object of the present invention is to provide an integrated pressure reducing seal that can improve the sealability and durability of the assembled fitting seal of a high performance cylinder.

The integrated fitting seal for sealing cylinder of construction machinery of the present invention is a one-piece TPU pressure reducing seal that reduces friction by reducing the contact pressure gradient peak value (Peack value) to 1/2 so that shaft contact does not occur up to 32 MPa. It is formed to have heat resistance and pressure resistance so that it can be used in the rod sealing system of high performance cylinders.

The integrated pressure reducing seal for construction machinery cylinder sealing according to the present invention has the following effects.

Technical effect:

It is highly contributing to the improvement of work efficiency of construction machinery by securing the shape design and design technology with the integral seal without backup and the durability life improved by 30%.

Economic effect:

The economic effect is that the conventional assembly type has the molding machine and the mold of the main body, and the backup molding machine and the mold should be respectively. Overall, facility costs and manufacturing costs

The economic effect is greatly reduced by about 30 to 50%.

1 is a cross-sectional view of the pressure-sensitive seal and the oil-packing, rod sealing of the present invention installed
2 is a sectional view of a state provided between members of the present invention.
Figure 3 is a cross-sectional view of the integral pressure-sensitive seal of the present invention.
Figure 4 is a product diagram of the integrated pressure reducing seal of the present invention.
5 is a endurance test cycle diagram of the rod sealing system of the present invention.
6 is a cross-sectional view of a conventional assembled pressure reducing seal.

Example 1;

Integrated pressure reducing seal without backing (4) As shown in Fig. -4, the approach angle β 4-6 is increased so that when the operating pressure is applied, the contact pressure gradient peak value is 1/2 of the assembled type so that no axial contact occurs. High-performance heat-resistant material TPU material with 30% or more heat resistance and pressure resistance than the assembled type with reduced shape. TPU material is a high-performance cylinder rod sealing system with an integrated seal that is precisely injection molded at 190 ~ 200 ℃ and 18 ~ 42MPa. As shown in Figs. 1 and 2, the pressure was set at 42 MPa, the temperature was 110 ° C., and the speed was 40 mm / sec, and the test cycle was tested for 500 hours for 1000 hours as shown in Fig. 5. Consists of shapes and materials with an improved lifespan of more than 30%.

Example 2;

As shown in Fig. 4, the shape of the integral pressure reducing seal 4 is 0.5 R at the tip of each 4-7 inner diameter, and the high heat resistance and high strength TPU material has an injection pressure of 28 MPa, an injection temperature of 200 ° C., and a crosslinking time of 0.5 minutes. Integral pressure-sensitive seal produced by precision injection molding under molding conditions was placed in the rod sealing system as shown in FIG. 1 as shown in FIG. It consists of a structure and modification of the shape which improved the sealability and durability life by about 30% compared with this assembly type pressure reduction seal.

The structure of the integrated pressure reducing seal 4 of the present invention has an integral shape in which the seal body and the backup are not separated. The improvement of the accumulator property and the shape without the backup ring prevent the extrusion at high pressure. Since the shape and material should be designed, the peak value β angle 4-6 (각 句 配 -6 値 Peak value 의) of the contact pressure gradient should be set so that the shaft contact of the HILL part 4-8 does not occur. Increase the pressure resistance by dispersing stress concentration by 2 times and increasing the pressure resistance, and low friction with inner hard tip angle of 4 to 0.2 ~ 0.5R, which is a new means of design of single shape and material design for integral extrusion prevention without backup. Precision injection molding with heat-resistant high-performance TPU improves the material properties by 30-40% compared to the assembled properties, and evenly distributes the concentrated stress. It is possible to form an integrated pressure reducing seal with improved lifespan.

1 Cylinder 7 Assembly Pressure Reducing Seal
2 Housing 7-1 Body
3 Mounting hole 7-2 Backup ring
4 Pressure Reducing Seal 7-3 Bore
4-1 Inner diameter 7-4 Outer diameter
4-2 Outer diameter 7-5 Height
4-3 Seal Width 7-6 Inner Lip
4-4 heel width 7-7 outer lip
4-5 α Angle 8 Sliding Surface
4-6 β angle
5 U-Packing (Rod Seal)
5-1 Rod Seal Backup Ring
6 dust seal

Claims (2)

A pressure reducing seal (4) of a rod sealing system for high performance cylinder sealing for construction machinery is formed by integrating a pressure reducing seal with an integral TPU material.
The method of claim 1, wherein
The material of the integral pressure reducing seal is TPU (Thermoplastic poly Urethan), and the integral pressure reducing seal for sealing a construction machine cylinder is characterized in that the physical property is injection molded to have a constant value of hardness, tensile strength, oil resistance, rebound elasticity and permanent strain.

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