JPS6353153A - Pressing force variable wiper - Google Patents

Abstract

PURPOSE:To reduce the operating force of a wiper by installing one end of a tension spring the other end of which is engaged with the fixed point of a wiper arm, on an arm head via a lever, and placing said fixed point on the bisector of the rotation angle of said lever. CONSTITUTION:One end of a tension spring 7 is engaged with a wiper arm 3 by means of a hook, while the other end is engaged with an L-shaped lever 11. And, a fixed point 13 is positioned on the bisector of the rotation angle phiof the lever 11. In this structure, the pressing force of a wiper can be adjusted by applying an operating force in a defined direction to, and rotating, the lever 11. In this case, a force corresponding to the angle phi/2 suffices for the required operating force. Thereby, the operating force for rotating the wiper arm 3 at the time of adjusting a pressing force can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a wiper device for wiping the windshield of an automobile, for example, which applies a force that urges a wiper arm supporting a wiper blade toward the windshield. It is related to a device that changes.

[Prior art]

FIG. 4 is a perspective view of the wiper device. An arm head 2 is fixed to a pivot shaft 1, and a wiper arm is pivotally supported on the arm head. 4 is a pivot shaft. A wiper blade 5 is attached to the tip of the wiper arm 3.

In order to bring the wiper blade 5 into close contact with the windshield 6, a spring is provided to apply rotational force to the wiper arm 3. FIG. 5 shows a V-V cross section of FIG. 4.

A tension spring 7 is installed between a hook 8 fixed to the wiper arm 3 and a pin 9 fixed to the arm head 2.
is attached with an intervention.

The turning force (that is, the pressing force of the wiper blade) arrow P received by the wiper arm 3 is proportional to the product of the tension T of the tension spring 4 and the length Q of a perpendicular line drawn from the pivot shaft 4 to the arrow T.

Therefore, in order to change the rotation urging force of the wiper arm 3, it is sufficient to change the length Q mentioned above.

A technique for changing the rotating force of the wiper 7-m 3 by changing the length Q as described above is disclosed in Japanese Patent Application Laid-Open No. 59-16734.
No. 9 is known.

FIG. 6 is a schematic diagram for explaining the above-mentioned known technique.

A lever 10 is interposed and engaged between the pin 9 and the tension spring 7.

When a pressing force in the direction of arrow P' is applied by a pressing means (not shown) to move the lever 10 to the 10' position and the tension spring 7 to the 7' position, the length Q' of the perpendicular line shown in the figure increases and the wiper arm The rotation urging force of 3 becomes larger. In this case, the tension spring at the 7' position is expanded compared to the tension spring at the 7 position, so the tension T' is increased, but this increase in tension is greater than the increase in the length Q' of the perpendicular line. There are only a few. Therefore, it can be seen that the rotation biasing force of the wiper arm 3 is approximately proportional to the length Q' of the perpendicular line.

FIG. 7 is an operational explanatory diagram showing a conventional example based on the same principle as the conventional example shown in FIG.

The L-shaped lever 11 is pivotally connected to an arm head (not shown) by a lever shaft 12, and rotates within an angle φ in response to the operating force f1, and accordingly, the tension spring rotates within an angle θ. It cannot be rotated and gets wet. This figure depicts a posture when the wiper arm 3 operates as a wiper (referred to as a normal posture). In this state (Fig. 7), the fixing point 13, which engages the tension spring 13 with respect to the wiper arm 3, the lever shaft 12, and the pivot shaft 4 are positioned on the same straight line m-m. It is configured.

When the L-shaped lever 11 and the tension spring 7 coincide with the line m-m as shown by the solid line, that is, the angle φ=○,
In the state where the angle θ=O, the rotation biasing force of the wiper arm 3 becomes zero.

The L-shaped lever 11 rotates downward in the figure and clockwise in the figure.
When the illustrated angle φ is increased, the illustrated angle θ is also increased (approximately, the angle O and the angle φ are directly proportional), and the rotation biasing force of the wiper arm (3) increases accordingly. .

[Problem that the invention seeks to solve]

In the configuration shown in FIG. 7, when an operating force indicated by an arrow f is applied to the L-shaped lever 11 in order to adjust the rotational force of the wiper arm 3, the operating force f1 changes in accordance with the rotation angle φ of the L-shaped lever 11. do.

That is, when the angle φ and the angle 0 are zero, the operating force f1 is also almost zero, and as the angle φ and the angle θ increase, the operating force f1 increases in a sinusoidal manner. When the clockwise rotation of the L-shaped lever 11 reaches the stroke end (indicated by a chain line) 11',
The operating force f1 becomes maximum.

When configuring the variable pressing force type wiper device of this conventional example (FIG. 7), the capacity of the operating means (not shown) is set so as to be able to apply the operating force f1 corresponding to the maximum rotation angle φ. Must.

The purpose of the present invention is to make it possible to change the suppressing force so that the operating force corresponding to the angle φ is not necessary, and the operating force corresponding to the angle φ/2 is sufficient, that is, the suppressing force can be significantly reduced compared to the prior art. The wiper device is to be provided.

[Means for solving problems]

FIG. 1 is an explanatory diagram of the principle of operation of the present invention, and is a schematic diagram depicting an improved state in which the present invention is applied to the conventional example shown in FIG. 7.

In Fig. 1, the rotation angle φ of the L-shaped lever is the same as in Fig. 7, but the bisector of this angle φ is the line m'-m'.
It is configured to match. As a result, the line m
'-m' is also the bisector of the angle θ.

To explain this configuration as an example of a specific design procedure,
A tension spring 7 for setting the wiper arm 3 supported on the pivot shaft 4 and applying a required rotational force to the wiper arm 3
, the position of the fixed point 13, and the operating angle range θ are set. Then, if the lever shaft 12 of the L-shaped lever is set on the bisector of the angle θ, the line m'-m' will become the angle θ.
and becomes the bisector of the angle φ.

In this configuration (Fig. 1), when the L-shaped lever 11 and the tension spring 7 are in the posture shown by the solid line, the rotation biasing force of the wiper arm 3 is minimum (almost zero),
L-shaped lever 11' shown with f1 gland.

The rotation urging force is maximum in the state of the tension spring 7'.

When no separate operating force is applied to the L-shaped lever, the L-shaped lever (more specifically, the arm on the side where the tension spring is attached to the L-shaped lever), and the tension spring are on the line m' - m'. (not shown) In this state, the pivot shaft 4 is at a distance of 118 with respect to the glands m'-m'.
Since they are separated by Q', a rotating torque corresponding to the tension of the tension spring x Ω' is applied.

[Effect]

When an operating force is applied to the L-shaped lever in the direction of arrow f2, and the L-shaped lever is rotated clockwise by an angle φ/2 as indicated by (dashed line) 11', the rotation urging force of the wiper arm 3 is maximized. However, the operating force f2 is sufficient to be a force corresponding to the angle φ/2.

Furthermore, when an operating force is applied to the L-shaped lever in the direction of arrow f3 and the L-shaped lever is rotated by an angle φ/2 counterclockwise as shown by (solid line) 11, the rotation urging force of the wiper arm 3 is minimized. However, a force corresponding to the angle φ/2 is sufficient as the operating force f3.

〔Example〕

FIG. 2 is a longitudinal sectional view showing one embodiment of the present invention, and FIG. 3 is a bottom view of the same.

A wiper arm 3 is pivotally connected to an arm head 2 fixed to a pivot shaft 1 by a pivot shaft 4.

8 is a hook serving as a fixing point for securing one end of the tension spring 7 to the wiper arm 3. The other end of the tension spring 7 is connected to an L-shaped lever 11 via a link 13.

The link 13 described above is a member for avoiding interference with the pivot shaft 4. 12 is the shaft of the L-shaped lever.

FIG. 1 depicts a state in which the L-shaped lever 11 has rotated all the way in the counterclockwise direction in the figure, and in this state, the spring attachment point A of the L-shaped lever, the pivot shaft 4, and the hook 8
are aligned on a straight line S, and the rotation biasing force of the wiper arm 3 is zero. The axis 12 of the L-shaped lever is offset downward in the figure compared to the line S mentioned above. To maintain this state (FIG. 2), it is necessary to apply the operating force of arrow f3. This operating force is applied to the L-shaped lever 11 through the bracket 16 by converting the rotational output of the motor 14 into reciprocating motion by the screw means 15 . However, the motor 14 is energized only when rotating the L-shaped lever 11.
The force for holding the L-shaped lever 11 in a fixed position is provided by the frictional force of the screw means 15 and other forces.

〔Effect of the invention〕

As detailed above, when the present invention is applied, the operating force required to adjust the pressing force of the variable pressure wiper can be significantly reduced (nearly half).

As explained above, when the present invention is applied, an excellent practical effect can be achieved in that the operating force required to adjust the suppressing force can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of one embodiment of the present invention, and FIG. 3 is a bottom view of the same. FIG. 4 is a perspective view of the wiper device, and FIG. 5 is a cross-sectional view taken along the line ■-■. FIGS. 6 and 7 are schematic diagrams of known variable pressing force wipers, respectively. 1... Pivot shaft, 2... Arm head, 3
...Wiper arm, 7,7'...Tension spring, 11.11'...L-shaped lever, 12...
Lever shaft, 13...fixing point to which the tension spring is attached.

Claims (1)

[Claims] 1. A wiper arm is pivotally supported by an arm head fixed to a pivot shaft, a wiper blade is attached to the tip of the wiper arm, and a tension spring is interposed and engaged between the arm head and the wiper arm to provide rotational force to the wiper arm. In the wiper device in which the wiper arm is energized, one end of the tension spring is engaged with a fixed point of the wiper arm, and the other end of the tension spring is attached to the arm head via an L-shaped lever, so that when the wiper arm is in a normal posture, . A variable pressing force wiper, characterized in that the fixed point is located on the bisector of the rotation angle of the tension spring engaging arm of the L-shaped lever.