JPH037642A - Rubber for wiper blade - Google Patents

Abstract

PURPOSE:To enhance the wear resistance while maintaining softness at the tip, and secure good wiping performance for a long period of time by providing a hardened layer consisting of a rubber material, which has a higher S content than the base, on both sides of the tip which performs wiping-off over the glass surface. CONSTITUTION:The wiping part 4 of a rubber 1 as a blade for wiper has a shoulder 5 in approx. triangular profile and a lip 6 in the form of thin plate, wherein surface hardened layers 7, 8 are formed on both sides of this lip 6 over the whole longitudinal of the rubber 1. Besides the surface hardened layers 7, 8, the rubber 1 is formed from a base of rubber material with softness such as natural rubber, synthetic rubber, etc., while the surface hardened layers 7, 8 are formed from a hard rubber material with higher S content than the base. This enables enhancement of the wear resistance of the lip 6 while sufficient softness is secured for the wiping part 4, and also prevents crack initiation which ensures that good wiping performance is maintained for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Field of Application)] The present invention relates to an improvement in a wiper blade rubber used for wiping a glass surface of a vehicle windshield or the like.

<Conventional technology> Conventionally, wiper blade rubber was mainly made of NR5SB.
It is made of diene rubber such as R, CR, EPDM, etc., and although it has excellent flexibility, it has poor abrasion resistance and the lip edge wears and becomes rough quickly, so it maintains good wiping performance over a long period of time. could not be maintained.

Furthermore, if the blade rubber is made of a rubber material containing a large amount of filler, the hardness will increase and the wear resistance can be improved. However, the flexibility required for good wiping performance cannot be secured in the lip part, and there is also the problem that aggregated filler particles may fall off from the lip part during use, resulting in streaks of residue. . For this reason, it has been difficult to achieve both flexibility and wear resistance.

<Problems to be Solved by the Invention> Therefore, the purpose of the present invention is to improve the abrasion resistance while ensuring the flexibility of the tip portion for wiping the glass surface, and to maintain good wiping performance over a long period of time. To provide a wiper blade rubber with excellent durability.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, the above-mentioned object is to provide a wiper blade rubber that is integrally formed using a rubber base material,
A wiper blade rubber, characterized in that a hardened layer made of a rubber material with a higher sulfur content than the base material is formed on both sides of at least the tip portion that wipes the glass surface.
− is achieved by frying and offering.

<Function> By doing this, by forming hardened layers on both sides of the tip by increasing the amount of sulfur compounded in the rubber material, the flexibility necessary to maintain the wiping performance can be maintained. Abrasion resistance can be improved.

<Example> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in cross section in FIG. 1, the wiper blade rubber 1 according to the present invention has a wiping part 4 integrally formed with a neck 3 on the lower side of a holding part 2 which is formed in one collar. has been done. The wiping part 4 has a shoulder part 5 having a generally triangular cross section and a lip part 6 having a thin plate shape. A thin surface hardening layer 7.8 is formed on both side surfaces of the lip portion 6 along the entire length of the blade rubber 1.

The blade rubber 1 is formed from a flexible rubber material such as natural rubber or synthetic rubber as a base material, similar to conventional blade rubber, except for the surface hardening layer 7.8. On the other hand, the surface hardening layer 7.8 is formed of a hard rubber material with a high sulfur content to which a larger amount of sulfur is added than the base material. Therefore, while ensuring sufficient flexibility in the wiping part 4,
The abrasion resistance of the lip portion 6 that comes into contact with the glass surface can be improved, and the occurrence of cracks and the like can be prevented.

Moreover, since it is not necessary to contain a large amount of filler, uneven wiping due to lack of filler does not occur, and good wiping performance is maintained over a long period of time.

In the modified blade rubber 1-1 shown in FIG. 2, hardened surface layers 15 and 16 are formed over the entire surface including the lip portions 13 and shoulder portions 14 on both sides of the wiping portion 12. As a result, not only the lip portion 13 but also the entire wiping portion 12 can improve its wear resistance and prevent the occurrence of cracks and the like. In addition, in the embodiments of Fig. 1 and Fig. 2,
It is also possible to reduce the coefficient of friction by chlorinating the hardened layers 7.8.15.16 or applying an antifriction agent such as molybdenum disulfide to prevent the occurrence of so-called chatter.

As shown in FIG. 3, the play rubber-1 is manufactured using a split mold consisting of a mold 21 and a lower mold 22, similar to the conventional blade rubber. Recesses 23 and 24 are respectively formed in the molding surfaces of both molds 21 and 22 facing each other so as to define cavities corresponding to the shape of two blade rubbers joined together at the tips of their lip parts. There is.

A base material 28 in which thick portions 27 are connected to both ends of a thin center portion 26 is formed by extrusion molding of blade rubber or roll portioning. Next, thin surface layer materials 29 and 30 having a predetermined width are placed on both upper and lower surfaces of the central portion 26 corresponding to the lip portion after molding.

FIG. 4 illustrates a method of manufacturing two surface layer materials 30. A large amount of sulfur is mixed with the raw rubber forming the base material 30). Rubber material in the container 31 dissolved in a solvent such as luene is applied to the surface of a release paper 32 having a length ρ corresponding to the total length of the blade rubber 1. Apply it uniformly to the desired thickness using the spray gun 33. The thin sheet material formed by evaporating the solvent is then cut into a predetermined width d corresponding to the hardened surface layer 7.8 to form a tape-shaped surface material 29.30. paste.

Alternatively, a rubber compound containing high sulfur dissolved in a solvent may be directly applied to both the upper and lower surfaces of the central portion 26 with a brush or a stripe. In this case, since the surface of the center portion 26 of the base material 28 is slightly melted by the solvent, there is an advantage that the adhesiveness between the base material 28 and the two surface layer materials 30 is improved.

In this way, the surface material 29 is attached to the center portion 26 of the base material 28.
The molding material 25 with the molding material 30 arranged thereon is simultaneously vulcanized and molded within the mold 1-1.12. Then, after molding, the two blade rubbers 1 are completed by cutting in half along the length direction at the central portion 26.

Further, as a method for manufacturing the blade rubber, the base material 28 can be vulcanized and molded first, and the surface layer materials 29 and 30 can be vulcanized and bonded during post-vulcanization. Furthermore, the base material 28 and the surface layer material 2
After extruding 9.30 in two colors, it can be molded by simultaneous vulcanization using, for example, molds 21 and 22 shown in the third figure.

Example I NR rubber polymer 100 parts by weight sulfur
l // zinc oxide
5 Stearic acid 1
Carbon 60 Accelerator
2 // Process oil
A base material extruded from a rubber material consisting of 5 // and NR rubber polymer 100 parts by weight sulfur.
20 Zinc oxide
5 // Stearic acid l
// Carbon 20 Accelerator 1 A blade rubber was molded using a surface layer material made of a rubber material. This surface layer material is made by spraying the above-mentioned rubber composition dissolved in toluene onto release paper by the method shown in Figure 4, evaporating the toluene, forming a sheet with a thickness of 20 microns, and then forming it into a tape with a predetermined width. It was cut and integrally molded with the base material by the method shown in the third figure.

A 24-hour durability test was conducted in which the blade rubber thus formed was reciprocated on a glass surface in which the cycle of water sprinkling and water sprinkling stopped was repeated. Then, the blade rubber attached to the lever 34 shown in FIG.
J was selected and the cross-sectional dimensions were measured as shown in FIG.

From this measurement result, the amount of wear on the edge 36 can be calculated using the formula 1/
When calculated using the cross-sectional area expressed as 2.a1×b1+1/2.a2×b2, the calculation results shown in the following table were obtained.

As can be easily seen from this table, the amount of lip edge wear was significantly reduced compared to the conventional blade rubber integrally molded using only the base material described above. Furthermore, there is no damage to or loss of the lip part, and no residue left on the glass surface.
Good wiping performance and durability were confirmed.

[Effects of the Invention] As described above, according to the present invention, by forming a hardened layer with a high sulfur content on the surface of the lip portion that wipes the glass surface, the flexibility of the lip portion is maintained while maintaining the flexibility of the base material. 1. It can improve wear resistance. It is possible to maintain good wiping performance and significantly improve durability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a wiper blade rubber according to the present invention. FIG. 2 is a sectional view showing a modification of FIG. 1. FIG. 3 is a cross-sectional view schematically showing a method for manufacturing blade rubber according to the present invention. FIG. 4 is a perspective view schematically showing a method for manufacturing the surface layer material. FIG. 5 is a front view of the blade rubber showing the measurement positions of the test results. 6 is a partially enlarged sectional view taken along the line Vl--Vl in FIG. 5. FIG. 1... Blade rubber -2... Holding part 3... Neck 4... Wiping part 5... Shoulder part
6... Lip portion 7.8... Surface hardening layer 11...
Blade rubber 12... Wiping part 13... Lip part 14... Shoulder part 15.16... Surface hardening layer 21... Upper mold 22... Lower mold 23.
24... Recess 25... Molding material 26... Center part 27... Thick part 28... Base material
29.30... Surface layer 31... Container 3
2... Release paper 33... Spray gun 34... Lever 35... Blade rubber 36... Lip Edge Patent Applicant: Honda Motor Co., Ltd. 1

Claims (1)

[Scope of Claims] A wiper blade rubber integrally formed using a rubber material as a base material, wherein a hardened layer made of a rubber material with a higher sulfur content than the base material has a tip portion that wipes at least a glass surface. A wiper blade rubber characterized by being formed on both sides of.