JPH0662677U - Drive mechanism for wiper unit - Google Patents

Abstract

(57) [Summary] [Purpose] When the wiper blade freezes on the transparent window of the camera case, the motor idles to protect the drive mechanism of the wiper unit. A rotating plate 9 rotatably attached to a motor rotating shaft 10 is rotated, and the wiper rotating shaft 7 rotatably attached to one end of a link arm B19 is reciprocated from the rotating plate 9 through a link arm A18 at a constant rotation angle. In the wiper drive mechanism in which the wiper blade 4 is swung in a fan shape via the wiper arm 3 attached to the wiper rotating shaft 7, the rotating plate 9
An annular groove 11 is formed in the hole, and a hole 12 having a step in the axial direction is bored from the peripheral edge of the rotary plate 9, and the tip of the hole 12 is moved in the direction of the groove 11 by urging a spring 14 in the hole 12. A moving pin 13 that slides in and out freely is provided, and
The link transmission pin 17 fixed to one end of the link arm A18 is inserted into the groove 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a drive mechanism for a wiper unit mounted on a camera case of a surveillance camera used outdoors.

[0002]

[Prior art]

 Generally, a surveillance camera is housed in a camera case equipped with a wiper unit in order to protect the camera from rainwater and dust. The mechanism of this wiper unit is shown in front of the camera case 1 as shown in FIG. The wiper unit 2 is attached to the upper part, and as shown in FIG. 5, the rotary plate 34 is rotated via the friction clutch plate 33 which is fixed to the rotary shaft 32 of the motor 31, and the transmission fixed to the side surface of the rotary plate is transmitted. By rotating the pin 35 so as to draw a circular arc, one end of a link arm A36 rotatably attached to the transmission pin 35 draws a circular arc in the same manner as the transmission pin 35, and One end of a link arm 38B pivotally attached to a pin 37 fixed to the other end of A36 is pivotally attached to a fixed shaft 39 fixed to a motor mount (not shown). Swings in a crank shape and the other end is the fulcrum. By this swinging, the wiper rotary shaft 40, which is fixed to the other end of the link arm B38, reciprocates at a constant rotation angle, and the wiper arm 3 attached to the wiper rotary shaft 40 is swung in a fan shape. Thus, the wiper blade 4 drops raindrops attached to the surface of the see-through window 5 to maintain the field of view.

According to such a conventional technique, since this kind of camera case is usually installed outdoors, the wiper blade 4 is fixed in close contact with the surface of the see-through window 5 during snowfall or freezing. Sometimes. When the motor 31 for operating the wiper is energized in order to maintain the field of view at this time, the wiper blade 4 is in a restrained state, and the rotation plate 34 is also restrained, so that the motor 31 also restrains rotation. To be done. Therefore, when the rotation of the motor 31 is suppressed, the load is increased, which may cause a burnout of the wire wheel due to an overcurrent or a failure such as a reduction of the speed reduction mechanism or the wiper mechanism built in the motor 31. . In order to prevent these obstacles, when the rotating plate 34 is fixed and does not rotate, the rotation is transmitted through the friction clutch plate 33, and when a certain load is applied to the friction clutch plate 33, the motor 31 rotates idly. A method that does not apply overload is used. However, according to this method, the wear on the surface contacting the friction clutch plate 33 and the rotating plate 34 is increased every time the wiper is used more frequently, so that the load during idling varies, and as a result, the wiper operation is disturbed. There were problems such as the need for maintenance.

[0004]

[Problems to be solved by the device]

 The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a drive mechanism for a wiper unit that prevents a failure caused by the wiper blade being constrained during snowfall or freezing.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention solves the above-mentioned problems by rotating a rotating plate attached to a rotating shaft of a motor, thereby reciprocating the rotating shaft of the wiper at a constant rotation angle via a link arm. In a wiper drive mechanism in which a wiper blade is oscillated in a fan shape from a wiper rotary shaft via a wiper arm, an annular groove is formed in the rotary plate, and a hole having a step in the axial direction from the peripheral edge of the rotary plate. Of the wiper unit, in which a moving pin whose front end is biased so as to be retractable in the direction of the groove is provided in the hole, and one end of the link arm is linked to the groove. It features a drive mechanism.

[0006]

[Action]

 With the above-described structure, according to the drive mechanism of the wiper unit of the present invention, when the motor is energized to rotate the rotating shaft, the moving pin is attached to the link transmission pin mounted in the groove of the rotating plate. By abutting and rotating the moving pin in an arc shape, the other end of the link arm A to which one end of the link transmission pin is fixed is rotatably attached to one end of the link arm B. The crank-like swing is repeated through the fixed shaft at the other end of the link arm B as a fulcrum. Therefore, the wiper rotary shaft attached to the other end of the link arm B reciprocates at a constant angle, and the wiper arm attached to the wiper rotary shaft is swung in a fan shape so that the wiper blade attaches water droplets to the transparent window. To remove.

[0007] When the wiper blade freezes on the transparent window and is constrained during snowfall or freezing, the link transmission pin is also constrained and stopped at a fixed position, so that the rotating plate rotates. When the hemispherical surface at the one end of the moving pin comes into contact with the side surface of this link transmitting pin by a certain amount of pressure, the moving pin is pushed in the outer peripheral direction of the groove, and the rotating plate is moved. Slide toward the outer edge of. On the other hand, since the other end of the moving pin is biased in the direction of the groove by the spring, it returns to the direction of the groove when the hemispherical surface of the moving pin comes off the side surface of the link transmission pin. Therefore, the rotating plate will idle while the link transmission pin is blocked, and prevent the motor wheel ring from burning due to overcurrent and the speed reduction mechanism or wiper mechanism built into the motor from being damaged. You can

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing a drive mechanism of a wiper unit of a camera case applied to the present invention, FIG. 2 is a perspective view of an essential part of FIG. 1, FIG. 4) is a side sectional view of a main part thereof, FIG. 4 is a diagram showing the operation of FIG. 3, FIG. 4A is a plan sectional view of the main part, and FIG. In the figure, reference numeral 1 denotes a camera case. A wiper unit 2 is attached to an upper front part of the camera case 1, and a wiper rotating shaft 7 is rotatably attached to a fixed shaft 6 fixed to a motor mount (not shown). The wiper blade 4 removes raindrops adhering to the see-through window 5 via the wiper arm 3 attached to the wiper rotating shaft 7. Reference numeral 8 is a motor with a built-in reduction mechanism, which is fixed to a motor mount (not shown) and rotates in a fixed direction when energized. Reference numeral 9 is a disc-shaped rotating plate having a predetermined thickness, and the center of the rotating plate 9 is fixed to the motor rotating shaft 10 of the motor 8. Reference numeral 11 denotes an annular groove having a predetermined width and depth, and a hole 12 having a step is formed from the outer edge direction at one location between the outer periphery of the groove 11 and the outer edge. Reference numeral 13 denotes a moving pin having a hemispherical projection formed at one end and a cylindrical flange formed at the other end. The moving pin 13 is inserted into the hole 12 so that the projection of the moving pin 13 projects into the groove 11. For example, the flange-formed portion of the moving pin 13 is engaged with the step-forming portion of the hole 12. Reference numeral 14 denotes a coil-shaped spring having a predetermined elasticity. By sandwiching the spring 14 between the other end of the moving pin 13 and the fixed plate 15 and fixing it with a screw 16, the moving pin 13 is It is designed to be biased in the direction of the groove 11.

Reference numeral 17 denotes a link transmission pin having a cylindrical side surface. The side surface of the link transmission pin is mounted on the groove 11 of the rotating plate 9, and one end thereof is caulked to one end of the link arm A 18. It is fixed by etc. Reference numeral 19 denotes a link arm B. One end of the link arm B 19 is rotatably attached to the other end of the link arm A 18 via a support pin 20, and the other end of the link arm B 18 has a wiper rotating shaft 7 And is rotatably supported by the fixed shaft 6 described above.

Next, the operation of the drive mechanism of the wiper unit according to the present invention will be described. When the motor 8 is energized, the motor rotating shaft 10 rotates, and at the same time the rotating plate 9 rotates, so that the side surface of the link transmission pin 17 contacts the hemispherical surface of the moving pin 13 protruding from the outer circumference of the groove 11 to the inner circumference. By moving in an arc shape and swinging in a crank shape via the link arm A18 with the other end of the link arm B19 as a fulcrum, the wiper rotation shaft 7 axially attached to the other end of the link arm B19 is moved. The wiper blade 4 reciprocates in a fan shape through the wiper arm 3 attached to the wiper rotating shaft 7 by reciprocating around the fixed shaft 6 at a constant rotation angle. Next, when the wiper blade 4 is frozen on the transparent window and is restrained, the link transmission pin 17 is also restrained at the restrained position. Therefore, when the rotary plate 9 rotates, the wiper blade 4 is linked to the hemispherical surface of the moving pin 13. The side surface of the transmission pin 17 comes into contact, slides the movable pin 13 toward the outer edge of the rotary plate 9, and is disengaged. At the disengaged stage, the spring 14 biases the movable pin 13 toward the groove 11. Therefore, even if the wiper blade 4 frosts on the see-through window, the rotary plate 9 idles and the rotation of the motor 8 continues.

[0011]

[Effect of device]

 As described above, according to the drive mechanism of the wiper unit of the present invention, the rotation of the motor is suppressed when the wiper blade is constrained and an excessive load is applied to the moving pin provided on the rotating plate. When the wiper blade is no longer restrained, the sweep operation is restarted. Therefore, it is possible to eliminate the load fluctuation at the start of operation due to wear, which is a drawback of the conventional friction clutch plate, and reduce the load applied to the entire drive mechanism to prevent damage to each part.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a drive mechanism of a wiper unit according to the present invention.

FIG. 2 is a perspective view of an essential part showing an embodiment of a drive mechanism of a wiper unit according to the present invention.

FIG. 3 is a view showing an embodiment of a drive mechanism of a wiper unit according to the present invention, in which (A) is a plan sectional view of an essential part,
(B) is a side sectional view of the relevant part.

4A and 4B are views showing an operation of an embodiment of a drive mechanism of a wiper unit according to the present invention, FIG. 4A is a plan sectional view of a main part, and FIG. 4B is a side sectional view of the main part.

FIG. 5 is a perspective view of an essential part showing an embodiment of a drive mechanism of a conventional wiper unit.

[Explanation of symbols]

 1 Camera Case 2 Wiper Unit 3 Wiper Arm 4 Wiper Blade 5 Transparent Window 6 Fixed Shaft 7 Wiper Rotation Shaft 8 Motor 9 Rotating Plate 10 Motor Rotating Shaft 11 Groove 12 Hole 13 Moving Pin 14 Spring 15 Fixing Plate 16 Screw 17 Link Transmission Pin 18 Link arm A 19 Link arm B 20 Support pin

Claims (1)

[Scope of utility model registration request] 1. A rotating plate rotatably attached to a rotating shaft of a motor causes the wiper rotating shaft to reciprocate from the rotating plate through a link arm at a fixed rotation angle, and the wiper arm moves from the rotating wiper shaft. In a wiper drive mechanism in which a wiper blade is oscillated in a fan shape through, an annular groove is formed in the rotary plate, and a hole having a step in the axial direction is formed from the peripheral edge of the rotary plate, and the hole is formed. A drive mechanism for the wiper unit, in which a moving pin whose tip is biased so as to be retractable in the direction of the groove is provided, and one end of the link arm is linked to the groove.