JP2015009713A - Wiper blade rubber, and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce friction resistance between a lip part and a wiping surface.SOLUTION: In a wiper blade rubber 10, a tip surface 26 of a lip part 24 is constituted of a hardened layer 34 which is hardened by being thermally melted. Therefore, hardness on a tip surface 26 of the lip part 24 becomes higher. This makes a contact area with a windshield glass W at a tip part of the lip part 24 smaller. Further, the tip surface 26 of the lip part 24 is constituted of the hardened layer 34 which is hardened by being thermally melted, so that rubber properties in the hardened layer 34 is reduced. Therefore, friction state with the windshield glass W on the tip surface 26 of the lip part 24 can be brought to a low friction state. This can reduce friction resistance between the lip part 24 and (wiping surface of) the windshield glass W.

Description

  The present invention relates to a wiper blade rubber and a manufacturing method thereof.

  In the method of manufacturing a wiper blade rubber (wiper blade rubber) described in Patent Document 1 below, the tip surface of the lip portion is formed using a cutting tool. Specifically, a pair of wiper blade rubbers joined at the lip portion is cut by a pair of cutting tools on both side surfaces of the lip portion. And the front end surface of a lip | rip part is formed by tearing this cut | notched part.

Japanese Patent No. 3134209

  However, in the wiper blade rubber, a rubber material that has not been surface-treated is exposed at the front end surface of the lip portion cut by the cutting tool. For this reason, there is a problem that the frictional resistance (sliding resistance) between the lip portion and the wiping surface when the windshield glass (wiping surface) is wiped by the tip portion of the lip portion becomes relatively high.

  In view of the above facts, an object of the present invention is to provide a wiper blade rubber capable of reducing the frictional resistance between the lip portion and the wiping surface and a method for manufacturing the wiper blade rubber.

  The wiper blade rubber of the present invention is provided on the wiping surface side with respect to the base portion held by the holding member constituting the wiper blade, and is connected to the base portion by the connecting portion and is thermally melted and cured. And a wiping portion that has a lip portion including a tip surface constituted by the hardened layer and wipes the wiping surface with the lip portion.

  According to the wiper blade rubber having the above configuration, the base portion of the wiper blade rubber is held by the holding member constituting the wiper blade. A wiping portion is provided on the wiping surface side of the base portion, and the wiping portion is connected to the base portion by a connecting portion. That is, the wiping part protrudes from the base part to the wiping surface side via the connection part. Thereby, the wiper blade connected to the wiper arm swings, so that the lip portion of the wiping portion wipes the wiping surface. When the wiper arm swings, the connecting portion is bent and the wiping portion and the lip portion are inclined, so that the corner portion at the tip portion of the lip portion contacts the wiping surface.

  Here, the front end surface of the lip portion is constituted by a hardened layer that is thermally melted and hardened. For this reason, compared with the case where the hardened layer is not formed on the front end surface of the lip portion (that is, when the material such as rubber is exposed on the front end surface of the lip portion without being surface-treated), Hardness on the surface increases. Thereby, since the contact area of the front-end | tip part of a lip | rip part and a wiping surface becomes small compared with said case, the frictional resistance between a lip | rip part and a wiping surface can be reduced.

  In the wiper blade rubber of the present invention, the hardened layer is formed by a laser.

  According to the wiper blade rubber having the above configuration, since the hardened layer is formed by the laser, for example, by irradiating the tip of the lip with a laser, the tip of the lip can be cut while being melted. And while making the cut | disconnected surface into a front end surface, the said front end surface can be comprised with the hardened layer formed by being heat-melted.

  Moreover, the wiping performance of the lip | rip part with respect to windshield glass can be improved by cut | disconnecting the front-end | tip part of a lip | rip part with a laser, and forming a front end surface. That is, as compared with the case of cutting the tip portion of the lip portion with a pair of cutting tools as in the prior art, the cutting accuracy is not affected by the sharpness of the cutting tool or the like, and variations in the cutting shape on the tip surface of the lip portion can be suppressed. As a result, since the generation of wiping lines and the like when the windshield glass is wiped by the lip portion is suppressed, the wiping performance of the lip portion with respect to the windshield glass can be improved.

  In the wiper blade rubber of the present invention, the tip surface of the lip portion is inclined with respect to the protruding direction from the wiping portion in a side view.

  According to the wiper blade rubber having the above configuration, the tip end portion of the lip portion is formed so as to become narrower toward the tip end in a side view. For this reason, the frictional resistance between a wiping surface and the front-end | tip part of a lip | rip part can be reduced further.

  The wiper blade rubber manufacturing method of the present invention is applied to the wiper blade rubber having the above-described configuration, and a laser cutting process is performed to form a base, a connecting portion, and a wiping portion, and a lip portion for wiping the wiping surface of the wiping portion. A cutting step of forming a tip surface of the lip portion and forming a hardened layer that is melted and hardened at the time of cutting on the tip surface.

  According to the wiper blade rubber manufacturing method of the present invention, the tip surface of the lip portion can be formed by laser cutting the tip portion of the lip portion, and a hardened layer is formed on the tip surface when cutting the tip portion of the lip portion. it can.

It is the expanded sectional side view which shows the wiper blade rubber which concerns on this Embodiment. It is explanatory drawing for demonstrating the manufacturing method of the wiper blade rubber shown by FIG. (A) is typical sectional drawing which shows the state in which the front-end | tip part in the lip | rip part of the wiper blade rubber shown by FIG. 1 wipes a windshield glass, (B) is the lip | rip part of the wiper blade rubber of a comparative example It is typical sectional drawing which shows the state in which the front-end | tip part wipes off a windshield glass. (A) is a graph which shows the relationship between the moving speed and friction coefficient in this invention and a comparative example when a wiper blade rubber wipes the windshield glass of a WET state, (B) is the windshield of a DRY state It is a graph which shows the relationship between the moving speed and friction coefficient in this invention and the comparative example at the time of wiping off glass with a wiper blade rubber. It is the expanded side cross section which shows the other example of the front end surface in the lip | rip part of the wiper blade rubber which concerns on this Embodiment.

  Hereinafter, the wiper blade rubber 10 according to the present embodiment will be described with reference to the drawings. The wiper blade rubber 10 is used in a wiper device (not shown) of a vehicle (automobile), and the windshield glass W (wiping surface thereof) is wiped by the wiper blade rubber 10.

  FIG. 1 shows a wiper blade rubber 10 in a side sectional view. As shown in this figure, the wiper blade rubber 10 includes a base portion 12, a connecting portion 18, and a wiping portion 20, and is formed in a substantially long shape. That is, FIG. 1 is described as a cross-sectional view of the wiper blade rubber 10 as viewed from the longitudinal direction.

  The wiper blade rubber 10 is made of rubber (for example, natural rubber (NR), chloroprene rubber (CR), synthetic rubber of natural rubber (NR) and chloroprene rubber (CR), nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR). , Synthetic rubber of styrene butadiene rubber (SBR) and natural rubber (NR), synthetic rubber of styrene butadiene rubber (SBR), natural rubber (NR) and butadiene rubber (BR), ethylene propylene diene rubber (EPDM), ethylene It is composed of a synthetic rubber of propylene diene rubber (EPDM) and butyl rubber (IIR), butyl rubber (IIR), chlorosulfonated polyethylene rubber (CSM), or the like, or a thermoplastic elastomer.

  The base 12 is held by a holding member 40 that constitutes a wiper blade (not shown) of the wiper device. Specifically, a pair of first groove portions 14 are formed in the base portion 12, and the first groove portions 14 are opened to the outer side in the width direction of the wiper blade rubber 10 (the arrow A direction and the arrow B direction in FIG. 1). Yes. A holding claw 42 of the holding member 40 is engaged in the first groove portion 14, whereby the base 12 is held by the holding member 40. A wiper arm (not shown) to which the wiper blade is connected is reciprocally swung by a driving force of a motor (not shown), so that the wiper blade rubber 10 together with the holding member 40 (wiper blade) is windshield glass W ( The wiping surface is reciprocally swung.

  A pair of second groove portions 16 are formed in the base portion 12 above the pair of first groove portions 14 (in the direction of arrow C in FIG. 1). The second groove portion 16 is opened outward in the width direction of the wiper blade rubber 10, and a substantially long plate-like backing 44 made of a spring material is accommodated in the second groove portion 16. In the natural state of the backing 44, the backing 44 is slightly curved so that the central portion in the longitudinal direction thereof is convex to the side opposite to the windshield glass W (the direction of the arrow C in FIG. 1). The wiper blade rubber 10 and the holding member 40 follow the wiping surface of the windshield glass W by the spring force of the backing 44, and the pressing force from the wiper arm via the holding member 40 is dispersed in the longitudinal direction of the wiper blade rubber 10. It is configured to let you.

  The connecting portion 18 is formed integrally with the base portion 12 and is formed in a substantially rectangular plate shape in a side sectional view, and is from the center in the width direction of the base portion 12 to the windshield glass W side (the arrow D direction side in FIG. 1). It is protruded to.

  The wiping portion 20 is provided on the windshield glass W side of the base portion 12 and the connecting portion 18. The wiping portion 20 is formed in a substantially triangular shape in cross section, and is set so that the width dimension of the wiping portion 20 becomes smaller toward the windshield glass W side. And the wiping part 20 is couple | bonded with the connection part 18 in the center part of the width direction in the upper part of the wiping part 20. FIG.

  Shoulder portions 22 are formed at both ends in the width direction of the upper portion of the wiping portion 20, and the shoulder portions 22 are inclined toward the base portion 12 toward the outer side in the width direction of the wiping portion 20. When the windshield glass W is wiped by the wiping portion 20, the connecting portion 18 is bent and the wiping portion 20 is tilted (see FIG. 3A), so that the shoulder portion 22 comes into contact with the lower surface of the base portion 12, thereby wiping. The inclination of the part 20 is limited.

  A lip portion 24 extending in the vertical direction with a constant width dimension in a side sectional view is formed at the distal end portion (lower end portion) of the wiping portion 20, and the distal end surface 26 of the lip portion 24 is in a natural state (no load state). ) Is formed along a direction orthogonal to the protruding direction of the lip portion 24 from the wiping portion 20. Thereby, a pair of corner | angular part 28 in the lower end of the front-end | tip part of the lip | rip part 24 is formed at right angle.

  Further, the outer peripheral surface excluding the front end surface 26 of the lip portion 24 is subjected to chlorine treatment, and an anti-friction layer 32 is formed on the surface of the side surface 30 of the lip portion 24 (see FIG. 3A). . Thereby, it is comprised so that the frictional resistance between the side surface 30 of the lip | rip part 24 and the windshield glass W may be reduced.

  Further, a hardened layer 34 (see FIG. 3A) is formed on the tip surface 26 of the lip portion 24. The hardened layer 34 is formed by hardening after the front end surface 26 is melted by heat. And the hardness in the hardened layer 34 is comprised higher than the hardness in the general part 36 (part except the hardened layer 34 and the antifriction process layer 32) of the wiping part 20. FIG.

  Next, a method for manufacturing the wiper blade rubber 10 will be described.

  First, the base portion 12, the connecting portion 18, and the wiping portion 20 of the wiper blade rubber 10 are formed by a conventionally known extrusion molding or the like (forming step). In this step, the pair of wiper blade rubbers 10 are formed in a coupled state. Specifically, the front end surfaces 26 of the lip portion 24 in the wiping portion 20 of the wiper blade rubber 10 are abutted and joined to each other.

  In this state, the surfaces of the pair of wiper blade rubbers 10 are chlorinated to form the anti-friction layer 32 on the surface of the side surface 30 of the lip portion 24 (surface treatment step).

  Next, as shown in FIG. 2, the pair of wiper blade rubbers 10 is set on the guide jig 50 mounted on the laser cut table. In this set state, the lip portions 24 coupled to each other in the pair of wiper blade rubbers 10 are exposed from the guide jig 50.

  In this state, by irradiating the laser R from the side of the lip portion 24 (direction perpendicular to the side surface 30 of the lip portion 24), a part of the lip portion 24 of the wiper blade rubber 10 is cut while being melted. Is done. Then, by moving the laser R in the longitudinal direction of the wiper blade rubber 10, the lip portion 24 of the wiper blade rubber 10 is continuously cut along the longitudinal direction of the wiper blade rubber 10, and the tip of the wiper blade rubber 10. A surface 26 is formed. At this time, the heat-melted front end surface 26 is cured, and a hardened layer 34 is formed on the front end surface 26 (cutting step).

  When the lip portion 24 of the wiper blade rubber 10 is cut by the laser R, the position of the laser R is fixed, and the guide jig 50 is moved relative to the laser R in the longitudinal direction of the wiper blade rubber 10. It may be.

  Next, the operation and effect of the present embodiment will be described.

  When the wiper blade rubber 10 wipes the windshield glass W, the connecting portion 18 bends, and the lip portion 24 of the wiping portion 20 moves away from the wiping direction (outside in the width direction) with respect to the connecting portion 18. The wiping portion 20 is inclined so as to be disposed. For this reason, the wiper blade rubber 10 wipes the windshield glass W in a state where the corner portion 28 of the lip portion 24 of the wiping portion 20 is in contact with the windshield glass W. In other words, the side surface 30 (anti-friction layer 32) portion and the front end surface 26 (hardened layer 34) portion of the lip portion 24 of the wiping portion 20 are in contact with the windshield glass W (see FIG. 3A). ).

  Here, the front end surface 26 of the lip portion 24 is constituted by a hardened layer 34 that is thermally melted and hardened. For this reason, compared with the comparative example shown in FIG. 3B (the wiper blade rubber 10 ′ in which the hardened layer 34 is not formed on the tip surface 26 of the lip portion 24), the hardness of the tip surface 26 of the lip portion 24 is higher. Get higher. Thereby, as shown in FIGS. 3A and 3B, the width dimension W1 of the portion in contact with the windshield glass W (wiping surface thereof) at the tip of the lip portion 24 is smaller than that in the comparative example. Become. As a result, the contact area between the tip of the lip 24 and the windshield glass W (wiping surface thereof) is smaller than in the case of the comparative example.

  In addition, as described above, the tip surface 26 of the lip portion 24 is constituted by the hardened layer 34 that is thermally melted and hardened, so that the rubber property of the tip surface 26 (hardened layer 34) is higher than that of the comparative example. It is falling. For this reason, the friction state with the windshield glass W in the front end surface 26 of the lip portion 24 can be set to a lower friction state than in the case of the comparative example. As described above, the frictional resistance between the lip portion 24 and the windshield glass W (wiping surface thereof) can be reduced.

  This point will be described using the test results shown below. Note that the wiper blade rubber 10 of the present invention and the wiper blade rubber 10 'of the comparative example used in the following tests are composed of a synthetic rubber of 70% natural rubber and 30% chloroprene rubber. Further, in the wiper blade rubber 10 ′ of the comparative example, the tip surface 26 of the lip portion 24 is cut by the cutting tool, and as described above, the hardened layer 34 is not formed on the tip surface 26 of the lip portion 24 (FIG. 3 (B)).

  FIG. 4A shows the result of Test 1 in which the windshield glass W in a WET state (a state where water droplets are attached to the windshield glass W) is wiped by the wiper blade rubbers 10 and 10 ′. Specifically, FIG. 4A shows a movement speed of the wiper blade rubber 10, 10 ′ (wiper speed of the wiper blade), a friction coefficient μ between the wiper blade rubber 10, 10 ′ and the windshield glass W, Shows the relationship.

  FIG. 4B shows the result of Test 2 in which the windshield glass W in the DRY state (the windshield glass W is dry) is wiped with the wiper blade rubber 10, 10 '. Specifically, FIG. 4B shows the movement speed of the wiper blade rubber 10, 10 ′ (wiper speed of the wiper blade), the friction coefficient μ between the wiper blade rubber 10, 10 ′ and the windshield glass W, Shows the relationship. In Test 1 and Test 2, the pressing force F (see FIGS. 3A and 3B) of the wiper blade rubber 10, 10 'against the windshield glass W is set to 12 gf / cm. 4A and 4B, the horizontal axis represents the movement speed (wiper speed) (m / sec) of the wiper blade rubber 10, 10 ', and the vertical axis represents the windshield glass W and the wiper blade. The coefficient of friction between the rubbers 10 and 10 ′ is μ. And the test result by the wiper blade rubber 10 of the present invention is shown by a solid line, and the test result by the wiper blade rubber 10 'of the comparative example is shown by an alternate long and short dash line.

  As shown in FIG. 4A, in the WET state, when the wiper blade rubber 10, 10 ′ starts to move relative to the windshield glass W, the friction coefficient μ in the wiper blade rubber 10 of the present invention is The friction coefficient μ of the wiper blade rubber 10 ′ of the comparative example is reduced by about 1/3. That is, the static friction coefficient of the wiper blade rubber 10 with respect to the windshield glass W in the WET state is reduced as compared with the comparative example.

  Further, as shown in FIG. 4B, in the DRY state, the friction coefficient μ of the wiper blade rubber 10 of the present invention is the wiper of the comparative example over the entire moving speed of the wiper blade rubber 10, 10 ′. It is reduced by about 1/3 compared to the blade rubber 10 '. That is, the static friction coefficient and the dynamic friction coefficient of the wiper blade rubber 10 with respect to the windshield glass W in the DRY state are reduced as compared with the comparative example. As can be seen from the results of Test 1 and Test 2 above, according to the wiper blade rubber 10 of the present invention, the frictional resistance (sliding resistance) between the lip portion 24 and the windshield glass W can be reduced. .

  Further, the windshield glass W has a large operating load on the wiper arm (motor) when in the DRY state. As described above, according to the wiper blade rubber 10 of the present invention, the static friction coefficient and the dynamic friction coefficient of the wiper blade rubber 10 with respect to the windshield glass W in the DRY state are reduced as compared with the comparative example. For this reason, the power consumption of the motor that drives the wiper arm can be reduced, and the motor can be downsized.

  Further, a hardened layer 34 is formed on the tip surface 26 of the lip portion 24 by laser cutting. For this reason, by irradiating the lip 24 of the wiping unit 20 with the laser R, the lip 24 of the wiping unit 20 can be cut while being thermally melted. The cut surface can be used as the tip surface 26, and the tip surface 26 can be constituted by the hardened layer 34 formed by heat melting.

  Moreover, since the lip portion 24 of the wiping portion 20 is cut by the laser R, the wiping performance of the lip portion 24 with respect to the windshield glass W can be improved. That is, when the lip portion 24 of the wiping portion 20 is cut by a pair of cutting tools as in the prior art, if the positional deviation occurs in the pair of cutting tools, the front end surface 26 of the lip portion 24 in a sectional view is formed in a stepped shape. Is done. Further, when the lip portion 24 of the wiping unit 20 is cut by the cutting tool, the blade is brought into contact with the lip portion 24 of the wiping unit 20, so that pressure acts on the lip portion 24 from the cutting tool. Even in this case, there is a possibility that the front end surface 26 of the lip portion 24 is formed in a step shape in the cross-sectional view, and further, the angular variation of the corner portion 28 at the front end portion of the lip portion 24 in the cross-sectional view may be increased. is there. Then, when the windshield glass W is wiped by the lip portion 24, for example, wiping lines may remain.

  On the other hand, according to the wiper blade rubber 10 of the present invention, the tip of the lip portion 24 can be cut from one direction by the laser R. Further, the lip portion 24 can be cut by the laser R in a non-contact manner. Thereby, it can suppress or prevent that the front end surface 26 of the lip | rip part 24 is formed in a step shape in cross-sectional view, and the angle dispersion | variation of the corner | angular part 28 in the front-end | tip part of the lip | rip part 24 can be suppressed. Therefore, the shape of the front end surface 26 of the lip portion 24 can be stably formed, and as a result, the wiping performance in the lip portion 24 can be improved.

  In the present embodiment, the tip surface 26 of the lip portion 24 is disposed along a direction orthogonal to the protruding direction of the lip portion 24. Instead, as shown in FIG. 5, the tip surface 26 of the lip portion 24 may be formed so as to be inclined with respect to the protruding direction of the lip portion 24. In other words, in a side sectional view, one corner 28 of the lip portion 24 may be formed as an acute angle and the other corner 28 may be formed as an obtuse angle. In this case, the tip surface 26 can be easily formed by inclining the wiper blade rubber 10 with respect to the irradiation direction of the laser R and laser cutting the lip portion 24. Further, since the lip portion 24 of the wiping portion 20 is formed to become narrower toward the tip of the lip portion 24 in a side view, the frictional resistance between the windshield glass W and the lip portion 24 can be further reduced. .

  In the present embodiment, the pair of wiper blade rubbers 10 joined at the lip portion 24 are irradiated with the laser R to cut the tip portion of the lip portion 24. Alternatively, the lip portion 24 of the wiper blade rubber 10 formed as a single unit may be cut by the laser R to form the tip surface 26 and the hardened layer 34 of the lip portion 24. Alternatively, the hardened layer 34 may be formed by irradiating a laser R to the tip surface 26 formed in advance.

DESCRIPTION OF SYMBOLS 10 ... Wiper blade rubber, 12 ... Base part, 18 ... Connection part, 20 ... Wiping part, 24 ... Lip part, 26 ... Tip surface, 34 ... Hardened layer

Claims (4)

A base held by a holding member constituting the wiper blade;
The lip portion is provided on the wiping surface side with respect to the base portion, and is connected to the base portion by a connecting portion, and has a lip portion including a distal end surface constituted by a hardened layer that is melted by heat and is cured by the lip portion. A wiping portion for wiping the wiping surface;
Wiper blade rubber with   The wiper blade rubber according to claim 1, wherein the hardened layer is formed by a laser.   The wiper blade rubber according to claim 1 or 2, wherein, in a side view, a tip surface of the lip portion is inclined with respect to a protruding direction from the wiping portion. Applied to the wiper blade rubber according to any one of claims 1 to 3,
A molding step of molding the base, the connecting portion, and the wiping portion;
A cutting step of forming a distal end surface of the lip portion by laser cutting a lip portion that wipes a wiping surface in the wiping portion, and forming a cured layer that is thermally melted and cured at the time of cutting on the distal end surface;
A method for manufacturing a wiper blade rubber comprising:

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