JPS61139543A - Wiper device for vehicle - Google Patents

Abstract

PURPOSE:To provide a compact, vibration resisting, sufficiently exothermic wiper device for a vehicle by a plurality of PTC ceramics received in a groove formed on an arm head and fixed thereto with a press portion having elasticity. CONSTITUTION:An arm head 2 is formed on the back with an U-shaped groove 20. PTC ceramic 22 closely attached to the bottom surface of the groove 20 is pressed from the back surface by a spring 25 through a plus terminal 24. Then, the surface of PTC ceramic 22 contacting the arm head 2 has a graphite sheet 23 applied to improve the closely attaching condition and heat conduction to the arm head 2. Also, the spring 25 is provided with the same number of press portions 25a as that of PTC ceramics 22. And by supplying current from the plus terminal 24 side through a lead wire 26 to the earth electrode side of the arm head 2 is raised the temperature of PTC ceramic 22 to heat the arm head 2.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a wiper device for a vehicle.In winter, snow that falls in cold regions accumulates on the lower molding of the front window, and the snow is removed by the wind when driving. freezing,
This is intended to prevent problems such as idling of the arm head, deformation of the motor crank arm, and damage to the motor if the wiper is forcibly operated.

[Conventional technology]

A device of this type in which a resistance wire is provided on the wiper blade is known as Japanese Utility Model Application No. 107466/1983.

[Problem that the invention seeks to solve]

However, this type of wire has problems in that it is difficult to manufacture a wire with a large heat generation effect, and it is easily broken due to vibration or the like.

Therefore, an object of the present invention is to provide a wiper device for a vehicle that can be compactly stored in the wiper arm portion which is most easily affected by snow, has a large heat generation effect, and is less likely to be disconnected due to vibration or the like.

〔overview〕

The present invention heats the wiper by embedding a PTC (positive characteristic thermistor) ceramic that can be heated at a constant temperature in a part of the wiper.
The aim is to melt frozen snow and allow the wipers to operate normally.

In the embodiment of the present invention, a groove 20 is formed in the arm head 2 of the wiper, and a heating element is embedded in the groove. An insulating resin case 21 is placed in a groove 20 with good flatness. This case 21 has a hole in which the PTC element 22 is inserted. A graphite sheet 23 is pasted on one side of the PTC to aid in heat conduction. A positive terminal 24 is arranged on the back side of the PTC 22, and is further pressed by a spring 25 forming a pressing portion. The positive terminal has a lead wire 26 tied at its end, and the lead wire 26 is connected to an electric wire. The heat generating section has a seal structure, is covered with a resin cover 27, and is closed at a portion 30 of the arm head 2. Note that the lead wire extraction portion is sealed by a grommet 31.

Current flows from lead wire 26 to positive terminal 24 and to one side of each PTC 22. Each PTC is connected in parallel, and the current flows from the bottom surface to the top surface in FIG.
Flows through C22.

The minus side is the arm head 2, which is grounded to the body.

[Means for solving problems]

In order to achieve the above object, the present invention uses the arm head (2) of a vehicle wiper device as a ground electrode, and has a groove (2) in the arm head along the shape of the arm head (2).
20), a plurality of PTC ceramics (22) are disposed in the groove (26) so that the ceramics are in close contact with the bottom of the groove, and
2) The PTC ceramic is pressed from the back side of the arm head to the bottom of the groove of the arm head using an integrated electrode plate having the same number of pressing parts (25a) having spring properties as the PTC ceramic (22).

〔Example〕

FIG. 2 is a schematic cross-sectional view of a front window to which a wiper is attached. A wiper assembly 1 is composed of an arm head 2, a retainer 3, and a blade portion (not shown). This wiper assembly is fixed to a pivot 10 that moves in an arc. 6 is guide, 4,5
, 7, 8.9 are parts of the car body, 4 is the hood, and 5
is the front windshield, and 7 is the lower molding, and the purpose of the present invention is to melt the frozen snow that accumulates there. In addition, the cowl inner 8 and cowl outer 9 are each
The wiper storage room is separated from the vehicle interior and the engine room.

A wiper heating device is disposed on the arm head 2.

A U-shaped groove 20 is machined on the back surface of the arm head 2, and a PTC ceramic 22 is in close contact with the bottom surface of the groove and is pressed by a spring 25 from the back side via a positive terminal 24.

The side of the PTC ceramic 22 that comes into contact with the arm head has good adhesion to improve heat conduction to the arm head 2 (
Therefore, a graphite sheet 23 is attached. Further, as shown in FIG. 4, the spring 25 has the same number of pressing portions 25a (springs) as the number of PTC ceramics 22, and is integrally molded. It should be noted that, like the spring 25, the positive terminal 24 has the same number of contact parts as the PTC ceramic 22, and is integrally molded. The PTC ceramic 22 is housed in an insulating resin case 21 within the U-shaped groove of the arm head 2 to prevent it from shifting laterally.

Further, the end of the positive terminal 24 has a structure in which a power supply lead wire is caulked. The outside of the spring 25 is covered with a resin cover 27, which is fixed with adhesive.
Sealed. A hole is provided in the lead wire extraction portion, and a grommet 31 prevents water from entering.

[For production]

Current flows to the positive terminal by a lead wire 26 which is connected to a battery (not shown) via a relay. The PTC ceramic 22 is a rectangular sheet with silver electrodes coated on both sides, and current flows in the thickness direction from the positive terminal 24 side to the ground electrode side of the arm head 2. Thus, the temperature of the PCTC ceramic seat 22 is raised to a temperature of one Curtain, and the arm head 2 is heated. As a result, the snow that has frozen on the lower molding is melted, allowing the wiper to operate normally.

Incidentally, the PTC referred to in the present invention refers to a positive characteristic thermistor.

〔Effect of the invention〕

According to the present invention, a PTC (positive characteristic thermistor) is installed in the groove.
Since a large number of ceramic bodies are housed and fixed by a pressing part having spring properties, it is strong against vibrations and is compact, yet generates sufficient heat.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of essential parts of an embodiment of the present invention, Fig. 2 is a schematic external side view showing an embodiment of the wiper device of the present invention, Fig. 3 is a bottom view as seen from the arrow in Fig. 4 is a plan view and a side view of the pressing portion having spring properties used in FIG. 3. 2...Arm head, 20...Groove, 22...PT
C ceramic, 25a...pressing part.

Claims (1)

[Claims] An arm head (2) of a vehicle wiper device is used as a ground electrode, a groove (20) is provided in the arm head along the shape of the arm head (2), and a plurality of P are provided in the groove (20).
A TC ceramic (22) is disposed so that the ceramic is in close contact with the bottom of the groove, and a pressing portion (25a) having the same number of spring properties as the PTC ceramic (22) is inserted from the back side of the PTC ceramic (22). 1.) A wiper device for a vehicle, characterized in that the PTC ceramic is pressed against the bottom of the groove of the arm head by an integrated electrode plate having an electrode plate.