JPH0315409Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a constant number wiping device suitable for various wipers for automobiles, such as headlamp wipers and rear wipers.

[Prior art]

As a constant number of times wiping device for a wiper motor, a reduction gear is meshed with a worm wheel which is the final rotating gear of the wiper motor, a cam is integrally molded on the final stage gear of the reduction gear, and the cam is used to wipe the outer periphery of the gear. It is known to actuate a fixed position stop switch by pressing a located contact piece, whereby by simply turning on the wiper switch for a short time, after the wiper has wiped a predetermined number of times,
The wiper would stop at a predetermined position. However, the problem with this method is that when the reduction ratio of the reduction gear is increased to increase the number of times of wiping, the ratio of the wiping speed of the wiper to the rotational speed of the final stage gear becomes large, resulting in a decrease in the accuracy of the wiper's stopping position. It was hot. Therefore, Japanese Utility Model Application Publication No. 50-3233 proposed using a Geneva mechanism instead of a reduction gear, and providing a conductive disk constituting a fixed position stop switch on a disk rotating together with the Geneva gear. However, in the device using the Geneva mechanism, the Geneva gear is rotated when the Geneva pin provided on the output gear meshes with the tooth groove of the Geneva gear, and during this time the power supply line of the motor is connected to stop the wiper at a predetermined position. Since the fixed position stop switch operates to open, when the wiper stops, the Geneva pin is in a position where it is about to come out of the tooth groove of the Geneva gear, and the conductive plate provided on the disc is
The notch has a certain width in consideration of coasting of the motor, so when trying to operate the wiper, the Geneva pin is cut out with a certain width until it meshes with the tooth groove of the next Geneva gear. In the device disclosed in Publication No. 3233, unless the wiper switch is kept on until the wiper makes one reciprocation, the contact piece in contact with the conductive disk cannot come out of the notch, and the wiper stops at the position where the wiper switch is turned off. This will result in

[Problem that the invention attempts to solve]

The present invention starts the motor by operating the wiper switch for a short time, reduces the variation in the stop position after wiping a predetermined number of times, and keeps the wiper in a predetermined position to ensure visibility to the outside world.

[Means to solve the problem]

The present invention consists of a worm wheel that is the final rotating gear of a wiper motor, a Geneva pin fixed to the worm wheel, a Geneva gear meshed with and driven by the Geneva pin, and coupled on the same axis to rotate together with the Geneva gear. and a cam disk having a cutout in a portion thereof, and a grounded disk-shaped relay plate fixed on a side surface of the worm wheel opposite to the cam disk and having a portion cut out;
A ground contact and a contact plate fixed to the motor case are provided, and when the cam disc comes to a part other than the notch during rotation of the cam disc, the contact plate and the ground contact are connected, When the notch is reached, the contact plate is provided with an S contact that connects the contact plate and the relay plate, the contact plate is connected to the off-side terminal of the wiper switch, and the Geneva pin is inserted into the notch of the relay plate. This is a constant number of times wiping device provided near the rear end in the rotation direction.

[Effect]

After turning on the wiper switch for a short time, the motor continues to rotate as the contact plate is connected to the earth contact via the S contact by the cam disc.
Eventually, after the contact plate comes into contact with the relay plate provided on the worm wheel through the notch in the cam disc, it reaches the notch in the relay plate and the motor stops, causing the wiper to auto-stop. The variation in position is extremely small, and the Geneva pin is located near the rear end of the notch in the relay plate in the rotational direction, so when the wiper is at rest, the Geneva pin tends to engage with the tooth groove of the Geneva gear. When the wiper is started, the Geneva gear is immediately rotated to rotate the cam disc, and the disc part of the cam disc contacts the contact plate with the ground contact via the S contact, so the wiper switch The turn-on operation will only take a short time.

〔Example〕

An example of implementing the present invention will be described below based on the drawings. The shapes of the worm wheel relay plate, short circuit plate, and cam disc shown in FIG. 1C and FIGS. 3A and 3B are the perspective view of FIG. 1A.

Reference numeral 1 denotes a drive shaft rotatably supported by a case of a wiper motor (not shown), and a worm wheel 2 that meshes with a worm formed at one end of an armature shaft of the motor is fixed thereto. A lock plate 3 is fixed to the worm wheel 2, and a joint pin 4 is fixed to the lock plate 3.
is provided. The joint pin 4 is rotatably connected to one end of a connecting rod (not shown), converts rotation of the worm wheel 2 into reciprocating movement of the connecting rod, and connects the connecting rod to the other end via a link. The wiper is oscillated, and as before, the worm wheel 2 is the final rotating gear of the wiper motor. Reference numeral 5 denotes a Geneva pin provided on the worm wheel 2, which together with the Geneva gear 7 constitutes a Geneva mechanism. A cam disk 8 having a notch in a part is coupled to the Geneva gear 7 so as to rotate together, and the Geneva gear 7 and the cam disk 8 are connected to a driven shaft rotatably supported by a case of a wiper motor (not shown). It is fixed at 6. Reference numeral 9 denotes a partially cutout disc-shaped relay plate, which is provided on the side surface of the worm wheel 2 facing the cam disc 8, and is grounded through the drive shaft 1. A shorting plate 12 is provided in the notch of the relay plate 9, and the position where the Geneva pin is planted is located near the rear end of the notch in the rotational direction (the rotational direction of the worm wheel 2). It is arranged like this. 10
and 11 are a ground contact and a contact unit fixed to the wiper motor case, respectively, as shown in FIG. 2, and the contact unit 11 is a contact plate 11B connected to one end of the motor M.
and a contact plate 11S connected to the off terminal of the wiper switch. The contact plate 11B is arranged so as to contact only the shorting plate 12 through the notch of the cam disk 8. The contact plate 11S is provided with an S contact, which contacts the relay plate 9 and the short circuit plate 12 through the notch of the cam disc 8 via the S contact, and is further pushed by the disc part of the cam disc 8 to contact the S contact. The ground contact 10 is disposed so as to be in contact with the ground contact 10 through the ground contact 10 . SW is an automatic reset type switch that serves as a wiper switch. Its contact piece is connected to the motor, and the normally open on terminal is grounded. Note that the battery is connected to the side of the motor M opposite to the wiper switch.

To explain the operation of the device configured as described above, first, when the wiper is stopped, the respective positional relationships are as shown in Figure 1, and the Geneva pin 5
is about to enter the tooth space of the Geneva gear 7. Here, when the wiper switch SW is pressed and the contact piece is turned on to the ON terminal side, current flows through the motor M from the battery to the terminal (B) to the motor M to the terminal (Lo) to the wiper switch SW contact piece to the ON terminal to ground. Motor M starts and wiper starts wiping. At the same time, the Geneva pin 5 enters the tooth groove of the Geneva gear 7, and the Geneva gear 7 is driven and rotated, and the cam disk 8 also rotates. When the worm wheel 2 rotates in the direction of the arrow in FIG. 3A until the Geneva pin 5 comes out of the tooth space of the Geneva gear 7, the second
The state will be as shown in Figure B and Figure 3A. That is, the cam disk 8
The S contact rides on the disc part of the , and the S contact comes into contact with the ground contact. In this state, there is no need to keep pressing the wiper switch SW. This is because battery → terminal (B) → motor (M) → terminal Lo) → wiper switch SW contact, off terminal →
This is because a power supply path to the motor M is formed from the terminal (S) to the contact plate 11S to the S contact to the ground contact to the ground. In this way, when starting the wiper motor, if the wiper switch SW is pressed for a short period of time until the Geneva pin 5 comes out of the tooth space of the Geneva gear 7, and then released to bring the contact piece into contact with the off terminal, the motor M is supplied with power and continues to rotate, but when the worm wheel 2 starts its fifth rotation, that is, when the wiper starts wiping for the fifth time, the Geneva pin 5 comes out of the fifth tooth groove of the Geneva gear, and the second The state will be as shown in Figure A and Figure 3B. That is, the notch of the cam disk 8 returns to the S contact position. Then, the S contact comes into contact with the relay plate 9 through the notch of the cam disk 8, and the sequence is as follows: Battery → Terminal (B) → Motor (M) → Terminal (Lo) → Terminal (S) Contact plate 11S → S contact → Relay plate 9→
A new power supply path to the motor M from the drive shaft to the ground is formed, and the motor M continues to rotate, and the worm wheel 2 continues to rotate for the fifth time.
When the wiper finishes the fifth round trip and approaches the stop position, the S contact comes into contact with the notch of the relay plate 9, and the power supply path to the motor M is cut off. Then, the contact plates 11S and 11B are connected via the short circuit plate 12, and the motor M, in which a short circuit is formed, stops, and the wiper stops at a predetermined stop position. In this way, since the auto-stop position is detected by the relay plate 9 provided on the worm wheel 2, when the wiper stops, the Geneva pin 5 is placed at the rear end of the notch in the relay plate 9 in the rotational direction. Since the wiper is located near the edge of the wiper, it is at a position where it is about to enter the tooth groove of the Geneva gear 7, that is, the position shown in FIG. 1A, and is ready for the next wiper activation.

[Effect of idea]

(1) The wiper stop position is determined by a relay plate installed on the worm wheel, which is the final rotating gear of the wiper motor, so the accuracy of the wiper stop position is high even though the wiper wipes a constant number of times. It is extremely high, ensuring visibility, etc.

(2) Since the stop position is determined by the relay plate installed on the worm wheel, which is the final rotating gear of the wiper motor, a Geneva pin can be installed near the rear end of the notch in the relay plate in the rotational direction. When the wiper motor is stopped, the Geneva pin is in a position where it is about to enter the tooth groove of the Geneva gear, and the wiper motor can be started with a short operation of the wiper switch, providing good operability.

[Brief explanation of drawings]

FIGS. 1A, 1B, and 1C are a plan view, a front view, and a perspective view of the plan view showing an example of the implementation of the present invention.
2A and 3B and 3A and 3B are explanatory diagrams and circuit diagrams showing the operation of the present invention. In the drawings, each reference numeral indicates the following member.
1: Drive shaft, 2: Worm wheel, 3: Lock plate, 4: Joint pin, 5: Geneva pin, 6: Driven shaft, 7: Geneva gear, 8: Cam disc, 9: Relay plate, 10: Earth contact, 1
1: Contact unit, 11S: Contact plate, 11B: Contact plate, 12: Short circuit plate.

Claims (1)

[Scope of utility model registration request] A worm wheel that is the final rotating gear of the wiper motor, a Geneva pin fixed to the worm wheel, a Geneva gear that meshes with and is driven by the Geneva pin, and a part that is coaxially connected to the Geneva gear so as to rotate together. a cam disk having a notch, and a grounded relay plate in the form of a disk, which is fixed on the side surface of the worm wheel facing the cam disk and has a portion cut out; and a grounded relay plate fixed to the motor case. Further, during rotation of the cam disc, when a disc part other than the notch comes, the contact plate and the ground contact are connected, and the notch is connected to the ground contact. When this happens, an S contact is provided on the contact plate to connect the contact plate and the relay plate, the contact plate is connected to the off-side terminal of the wiper switch, and the Geneva pin is connected to the rear of the rotation direction of the notch of the relay plate. A constant number of times wiping device for a wiper, characterized in that it is provided near an end.