KR100780325B1 - Shock Absorber with base shell using Thermoplastic - Google Patents

Abstract

The present invention provides a shock reduction device having an outer cylinder using a thermoplastic plastic that enables fuel economy and cost reduction of an automobile by using a thermoplastic material containing glass fiber and an impact resistant component as a material of the outer cylinder of an automobile impact damping device. I would like to.

Impact damping device having an outer cylinder using the thermoplastic of the present invention is a strut (Strut) is coupled to the piston, the outer cylinder coupled to stretch or stretch the strut in the axial direction while wrapping the piston, the outer side of the outer cylinder An impact damping device having a spring sheet for supporting a spring coil, comprising: a) 30 to 60 weight percent of a polyphthalamide; b) 20-50% by weight of glass fibers; c) an outer cylinder made of a material having a content of 5 to 20% by weight of ethylene propylene rubber and a plurality of ribs radially formed on the outer cylinder to support the spring sheet when the spring coil is compressed. It is done.

Shock Absorber, Outer Cylinder, Glass Fiber, Impact Resistant Components, Thermoplastic

Description

Shock absorber with outer cylinder using thermoplastics {Shock Absorber with base shell using Thermoplastic}

1 is a perspective view showing a vehicle suspension according to the prior art.

FIG. 2 is a perspective view illustrating an impact damping device used in the automobile suspension shown in FIG. 1.

Figure 3 is a perspective view showing an embodiment of an impact damping device having an outer cylinder using a thermoplastic according to the present invention.

FIG. 4 is a stress distribution diagram showing stress when a load of 1500 kgf is applied to a spring sheet of the impact damping apparatus shown in FIG. 3.

FIG. 5 is a deformation distribution diagram showing displacement when a load of 1500 kgf is applied to a spring sheet of the impact damping apparatus shown in FIG. 3.

FIG. 6 is a stress distribution diagram showing stress when a compressive load of 2500 kgf is applied to the bottom of the outer cylinder of the impact damping apparatus shown in FIG. 3.

FIG. 7 is a strain distribution diagram showing deformation when a compressive load of 2500 kgf is applied to the bottom of the outer cylinder of the impact damping device shown in FIG. 3.

<Description of the symbols for the main parts of the drawings>

100: outer cylinder 110: spring seat (Spring Seat)

120: triangle rib (122): first annular rib

124: second annular rib 126: third annular rib

130: first straight rib 132: second straight rib

The present invention relates to an impact damping device constituting a vehicle suspension device, and more particularly, to an impact damping device having an outer cylinder using a thermoplastic plastic containing glass fiber and an impact agent component as a material of the outer cylinder of the shock damping device. .

In general, a shock absorber (also referred to as a shock absorber) is one of the main components of the vehicle suspension, which is mounted between the vehicle body and the wheels and serves as a resistance to the shaking of the vehicle. to be.

The principle of such a shock absorbing device is to adjust the contraction of the spring, to prevent the spring shocked by the road surface to be repeatedly bounced up and down, thereby allowing the spring to return to its original state slowly.

In other words, the impact damping device weakens the stretching action of the spring, i.e. the vehicle body shakes or vibrates up and down.

1 is a perspective view showing a vehicle suspension according to the prior art. As shown in FIG. 1, the main parts of the vehicle suspension system include components for supporting a load on the vehicle body and wheels, and springs. In particular, the main component of the suspension device is the impact damping device 10 and the impact damping device. There is a spring 20 mounted on top of the spring sheet of the device 10.

The spring 20 absorbs the impact of the road surface, and serves to support the load applied to the vehicle body, and the impact attenuating device 10 acts as a function of the spring 20 to quickly shock and vibration from the road surface. It absorbs and buffers inside.

FIG. 2 is a perspective view illustrating an impact damping device used in the automobile suspension shown in FIG. 1. As shown in FIG. 2, the conventional shock absorbing device 10 is coupled to a strut (not shown) coupled to a piston (not shown), and expands or contracts the strut in an axial direction while surrounding the piston. The outer cylinder 12 and a spring seat 14 (Spring Seat) for supporting a spring coil (not shown, on the outside of the outer cylinder 12).

At this time, the outer cylinder 12 and the spring sheet 14 is made of steel (Steel) material that is most commonly used for mechanical parts due to its excellent rigidity, the outer cylinder 12 is welded by bending the steel plate round Is produced.

By the way, the conventional shock absorbing device having a steel material, despite the advantages of having excellent rigidity, due to the high specific gravity of the steel itself has a problem that the weight of the product is increased, thereby reducing the vehicle energy efficiency.

In addition, the conventional impact damping device having a steel material is manufactured in a manner of welding after bending the steel plate, there is a problem that the manufacturing cost of the impact damping device is increased by such welding and post-welding processing.

For this reason, in recent years, the mechanical strength and durability of the steel, but the weight is low, there is a situation that requires a shock absorbing device of a material that can simplify the manufacturing process.

Therefore, the object of the present invention, which solves the above mentioned problems and meets the above requirements, can be made by using a reinforced engineering plastic, which has mechanical strength and durability comparable to that of steel, is low in weight, and can be manufactured due to a simple process. An object of the present invention is to provide an impact damping apparatus having an outer cylinder using a thermoplastic resin.

An object of the present invention described above is a strut to which a piston is coupled, an outer cylinder coupled to stretch or stretch the strut in the axial direction while surrounding the piston, and a spring seat for supporting a spring coil on the outside of the outer cylinder. In the shock absorbing device provided with, the outer cylinder is a thermoplastic material as a base material, characterized in that it has a material further containing a glass fiber and an impact agent component to increase the strength and impact resistance to the thermoplastic plastic It is achieved by an impact damping device having an outer cylinder using a thermoplastic.

In this case, polyphthalamide (PPA, Polyphtalamide) is used as the thermoplastic plastic, and ethylene propylene rubber (EPDM, Ethylene Prophylene Dien Rubber) is used as the impact resistant component, and polyphthalamide 30 to 60 wt%; 20 to 50% by weight of glass fibers; And a material having a content of 5 to 20% by weight of ethylene propylene rubber. At this time, the polyphthalamide is a crystalline resin called aromatic nylon, and is a material excellent in high strength, high rigidity, high heat resistance, low absorption rate, dimensional stability, and the like. In addition, when the glass fiber is contained in the thermoplastic, tensile strength, modulus of elasticity and bending strength are increased. In addition, ethylene propylene rubber is an amorphous polymer material obtained by hybridization of ethylene and propylene, and when the ethylene propylene rubber is contained in the thermoplastic plastic, the impact resistance of the thermoplastic plastic is improved.

At this time, the compression of the spring coil, it is preferable to further include a plurality of ribs (Rib) disposed radially with respect to the outer cylinder to support the spring sheet. As a result, when the spring coil is compressed, the load is not concentrated on the spring sheet that supports the spring coil, and the load is distributed to a plurality of ribs to prevent bending or fracture of the spring sheet. do.

The plurality of ribs may further include a plurality of triangular ribs radially mounted to the outer cylinder between the surface of the spring sheet and the outer peripheral surface of the outer cylinder; A plurality of annular ribs mounted at ends of the triangular ribs and mounted at predetermined intervals along the longitudinal direction of the outer cylinder; And a plurality of straight ribs mounted between the annular ribs.

At this time, the bottom portion of the outer cylinder center rib mounted in a ring shape at the center of the bottom portion of the outer cylinder; And a plurality of comb-shaped ribs extending radially from the central rib to the outer circumferential surface of the outer cylinder.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings, Figure 3 is a perspective view showing an embodiment of an impact damping apparatus having an outer cylinder using a thermoplastic according to the present invention, Figure 4 is a prior art and shown in Figure 3 when applying a load of 1500kgf to the spring sheet It is a stress distribution diagram for comparing and explaining one embodiment. 5 is a strain distribution diagram for comparing and comparing the prior art and the embodiment shown in FIG. 3 when a load of 1500 kgf is applied to the spring sheet. 6 is a stress distribution diagram for comparing the prior art and the embodiment shown in FIG. 3 when a load of 2500 kgf is applied to the bottom of the outer cylinder. 7 is a variation distribution diagram for comparing the prior art and the embodiment shown in FIG. 3 when a load of 2500 kgf is applied to the bottom of the outer cylinder.

In this embodiment, a polyphthalamide (PPA, Polyphtalamide), which is a thermoplastic, is used as a base material of the outer cylinder. Polyphthalamide is generally a crystalline resin called an aromatic nylon. Since it has an aromatic structure in the molecular backbone, it is a thermoplastic resin having excellent high strength, high rigidity, high heat resistance, low water absorption, dimensional stability, and the like. In addition, these polyphthalamides are excellent in heat resistance, have high flexural modulus, excellent flexural fatigue characteristics, excellent melt stability, hardly cause burr, and have easy characteristics.

In addition, in the present embodiment, glass fibers are contained in the polyphthalamide which is a basic material in order to increase the strength of the outer cylinder. When the glass fiber is contained in the polyphthalamide, which is a thermoplastic, the tensile strength is increased, the elastic modulus is increased, the bending strength and the bending elastic modulus are increased, and thus it can be used as a good composite material in the aircraft, shipbuilding, and automobile industries. .

In addition, in the present embodiment, ethylene propylene rubber (EPDM, Ethylene Propylene Dien Rubber) is contained in polyphthalamide, which is a basic material, to increase impact resistance of the outer cylinder. It is an amorphous high molecular material obtained by hybridizing ethylene and propylene. It is chemically stable and vulcanized, and its physical properties show intermediate properties between natural rubber and SBR, and are widely used in automobile parts, machinery parts, and electrical parts. In fact, one example of the application to automobiles is that these ethylene propylene rubbers are used in automobile bumpers requiring impact resistance.

As described above, the outer cylinder used in the present embodiment uses a polyphthalamide, which is a thermoplastic, as a base material, contains glass fiber to increase strength thereof, and also contains ethylene propylene rubber to increase impact resistance thereto. Let's do it. At this time, the weight percentages of the polyphthalamide, glass fiber, and ethylene propylene rubber, which are preferable three components, are 30 to 60 polyphthalamide, 20 to 50 glass fiber, and 5 to 20 ethylene propylene rubber. The properties of the thermoplastic material formed by this weight% were performed by a conventional test apparatus, a data acquisition apparatus, and a test method, as shown in Table 1 below.

Figure 3 is a perspective view showing an embodiment of an impact damping device having an outer cylinder using a thermoplastic according to the present invention. In the present embodiment, a material composed of the weight% described above is used, and as shown in FIG. 3, the shock attenuator 100 having an outer cylinder using a thermoplastic plastic has a piston (not shown) coupled to its center. A strut (not shown), a cylindrical outer cylinder 105 coupled to expand and contract the axial direction of the strut while wrapping the piston, and a spring coil (not shown) outside the outer cylinder 105. A spring seat (110) for supporting a spring coil, and a plurality of ribs (120, 122, 124, 126, 130, 132, and ribs) disposed radially with respect to the outer cylinder to support the spring sheet (110). )

At this time, when comparing the impact damping device 10 used in the conventional vehicle suspension shown in Figure 2 and the impact damping device 100 having an outer cylinder using the thermoplastic plastic according to the present invention shown in Figure 3, the present invention Impact damping device 100 of the embodiment according to the thickness of the outer cylinder 105 is thickened to 2 to 2.5 times, the thickness of the spring sheet 110 is thickened to 1.5 to 2 times, the plurality of ribs 120, 122, 124, 126, 130, and 132 are characterized in that they are arranged radially with respect to the outer cylinder 105.

Here, as a preferred embodiment of the present invention, to describe the form in which the plurality of ribs (120, 122, 124, 126, 130, 132) is disposed in the outer cylinder 105, first, a spring coil (not shown) is supported Between the opposite side of the surface of the spring seat 110 and the outer peripheral surface of the outer cylinder 105, eight triangular ribs 120 are mounted radially with respect to the outer cylinder 105. The first annular rib 122 having a width of approximately 3 mm is mounted along the outer diameter of the outer cylinder 105 at the end portion of the inclination of the triangular rib 120. The second annular rib 124 is spaced apart from the first annular rib 122 by a predetermined interval, and the second annular rib 124 is spaced apart by a predetermined interval from the third annular shape. Ribs 126 are mounted. At this time, the shape and width of the second annular rib 124 and the third annular rib 126 is preferably the same as the first annular rib 122.

Meanwhile, a first straight rib 130 and a second straight rib 132 are disposed between the first annular rib 122, the second annular rib 124, and the third annular rib 126. Inserted and mounted.

The first straight rib 130 is a member having a shape of a straight plate having a height of about 3 mm and extends from an end of eight triangular ribs 120 radially mounted with respect to the outer cylinder 105. It is inserted between and supports the annular rib 122 and the second annular rib 124.

The second straight rib 132 is a member having the same shape and width as the first straight rib 130, and extends from the first straight rib 130 to extend the second annular rib 124. It is inserted between and supports the third annular rib 126.

Thus, the triangular rib 120, the first annular rib 122, the first straight rib 130, the second annular rib 124, the second straight rib 132 and the first The tricyclic rib 126 is disposed radially along the outer circumferential surface of the outer cylinder 105 at regular intervals. When the spring coil (not shown) is compressed, the stress generated in the spring sheet 110 supporting the spring coil 110 is dispersed so that the spring sheet 110 is not bent or broken on the outer cylinder 105. It plays a role of preventing.

In addition, a bottom portion of the outer cylinder 105 extends radially from the center rib 140 mounted in a ring shape at the center of the outer cylinder 105 to the outer circumferential surface of the outer cylinder 105 from the central rib 140. Eight comb-shaped ribs 142 are additionally mounted. Because of this, when receiving a compressive load at the bottom of the outer cylinder 105, it serves to disperse it.

In another embodiment, the shape, size and arrangement of the ribs may be changed little by little.

On the other hand, the impact damping device 100 having an outer cylinder 105 using a thermoplastic according to an embodiment of the present invention has the advantage of selecting a variety of easy and simple plastic molding method such as injection, compression, etc. according to the characteristics of the material There is this.

Such, the impact damping device 100 having an outer cylinder 105 using a thermoplastic according to an embodiment of the present invention has the same rigidity and durability as the impact damping device having an outer cylinder using conventional steel, This is illustrated in Table 2.

As shown in [Table 2], the impact damping device 100 having an outer cylinder 105 using a thermoplastic according to an embodiment of the present invention is obtained by each of the stress, strain and safety factor according to two conditions In this experiment, MSC / Nastran was used as the solver. In this case, condition 1 is to measure the stress and strain when the spring coil (not shown) in the direction of pushing the spring sheet 110 during compression, when a load of 1500kgf (ie, 14700N) is applied to the spring sheet 110 Condition 2 is to measure the stress and strain when applying a compressive load of 2500kgf (ie 24500N) at the bottom of the outer cylinder (105).

Referring to [Table 2], in the case of an impact damping device 100 having an outer cylinder 105 using a thermoplastic plastic containing 30 to 60 polyphthalamide, 20 to 50 glass fibers, and 5 to 20% by weight of ethylene propylene rubber. In the present embodiment in which a plurality of ribs 120, 122, 124, 126, 130, and 132 are added and the thickness of the outer cylinder 105 and the spring sheet 110 is reinforced, the stress is dispersed as a whole so that the tensile strength is increased. Beyond the generated stress, the safety rate was 1.5 to 1.8.

4 is a stress distribution diagram showing stress when a load of 1500 kgf (that is, 14700 N) is applied to the spring sheet of the impact damping apparatus shown in FIG. 3. As shown in Figure 4, it can be seen that the stress concentrated in the spring sheet is distributed throughout the outer cylinder along the plurality of ribs.

FIG. 5 is a deformation distribution diagram showing displacement when a load of 1500 kgf is applied to a spring sheet of the impact damping apparatus shown in FIG. 3. As shown in FIG. 5, it can be seen that the stress concentrated only on the spring sheet is dispersed throughout the outer cylinder along the plurality of ribs, thereby reducing the bending generated in the spring sheet.

FIG. 6 is a stress distribution diagram showing stress when a compressive load of 2500 kgf is applied to the bottom of the outer cylinder of the impact damping apparatus shown in FIG. 3. As shown in FIG. 6, it can be seen that the stress concentrated at the bottom of the outer cylinder is distributed along the central rib and eight comb-shaped ribs extending therefrom.

FIG. 7 is a strain distribution diagram showing deformation when a compressive load of 2500 kgf is applied to the bottom of the outer cylinder of the impact damping device shown in FIG. 3. As shown in FIG. 7, it can be seen that the stress concentrated at the bottom of the outer cylinder is distributed along the central rib and eight comb-shaped ribs extending therefrom, thereby reducing the deformation of the bottom of the outer cylinder. .

On the other hand, by using the thermoplastic plastic having such a content, it has a large mechanical rigidity and durability compared to the low weight, it is possible to manufacture the inner cylinder to be inserted into the outer cylinder in addition to the outer cylinder, furthermore many parts of the impact damping device It can be made of thermoplastics. In the case where many parts of the inner cylinder and the impact damping device are made of the thermoplastic plastic, it may be preferable to additionally install the reinforcing ribs in the weak parts of the parts, for example, the parts where the stress is concentrated.

It has been described above the impact damping device having an outer cylinder using the thermoplastic according to the present invention. Such a technical configuration of the present invention will be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the following claims rather than the foregoing description, and the meanings of the claims and All changes or modifications derived from the scope and the equivalent concept should be construed as being included in the scope of the present invention.

As described above, the impact damping device having an outer cylinder using the thermoplastic plastic of the present invention uses polyphthalamide, glass fiber, and ethylene propylene rubber as the outer cylinder material, and has a low mechanical rigidity and durability comparable to that of steel. Has a weight, it is effective to bring fuel economy of the car equipped with it.

In addition, the impact damping device having an outer cylinder using the thermoplastic plastic of the present invention using a polyphthalamide, glass fiber and ethylene propylene rubber as the material of the outer cylinder, a simple injection or compression than the method of manufacturing the outer cylinder from a conventional steel material It is possible to use a molding method, etc., which has the effect of reducing the price of the part.

Claims (5)

delete delete A shock absorbing device having a strut coupled to a piston, an outer cylinder coupled to expand or contract the strut in an axial direction while surrounding the piston, and a spring sheet for supporting a spring coil on the outside of the outer cylinder. In a) 30 to 60 weight percent of polyphthalamide; b) 20-50% by weight of glass fibers; c) 5 to 20% by weight of ethylene propylene rubber An outer cylinder made of a material having a content of? When compressing the spring coil, the shock absorbing device having an outer cylinder using a thermoplastic, characterized in that it comprises a plurality of ribs (Rib) formed radially in the outer cylinder to support the spring sheet. The method of claim 3, wherein The plurality of ribs, A plurality of triangular ribs radially mounted to the outer cylinder between the surface of the spring sheet and the outer peripheral surface of the outer cylinder; A plurality of annular ribs mounted at ends of the triangular ribs and mounted at predetermined intervals along the longitudinal direction of the outer cylinder; And Impact damping device having an outer cylinder using a thermoplastic, characterized in that it comprises a plurality of straight ribs mounted between each annular rib. The method according to claim 3 or 4, Bottom portion of the outer cylinder, A center rib mounted in a ring shape at the center of the bottom of the outer cylinder; And And a plurality of comb-shaped ribs extending radially from the central rib to the outer circumferential surface of the outer cylinder.

Images