JPS59145647A - Wiper apparatus - Google Patents

Abstract

PURPOSE:To facilitate the variation of press-contact force by installing an electromagnetic clutch onto a wiper shaft and adjusting the spring force of a tension spring which controls the press-contact force of a wiper blade, through a gear mechanism by utilizing the wiping force of the wiper in electric conduction state. CONSTITUTION:In the captioned apparatus in which, a wiper shaft 20 is moved in reciprocation by an arm 29 connected to a wiper motor (not shown in the figure), and a wiper blade is operated for wiping operation by swinging an arm head 32 fixed onto the wiper shaft 20, an electromagnet 25 which is brought into conduction when a car travels at a prescribed car speed or a certain wind speed is reached is provided. A clutch plate 28 equipped with a magnetic member 28b is attracted onto the electromagnet 25 against an elastic body 28a by the excitation of the electromagnet 25. Therefore, a spur gear 26 is fixed, and a spur gear 38 shifts, revolving around the spur gear 26 when the wiper operates in the wiping-up direction, and the spring force of a tension spring is increased through worm gear trains 36 and 37.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wiper device that can be used to wipe the window glass of an automobile or the like.

An example of a typical structure of a wiper device for wiping the window glass of an automobile or the like is shown in FIG. 1.

That is, an arm head 4 is fixed to a wiper shaft 3 which is rotatably supported by a pivot shaft 2 fixed to the vehicle body 1, and a wiper blade 5 is attached to the tip of the arm head 4.
A retainer 7 is connected to the arm 6 by a pivot pin 8.

Further, the retainer 7 is rotatable around a pivot pin 8, and tension springs 9 whose respective ends are hooked to the arm head 4 and the arm 6 are provided in the retainer 7. The wiper blade 5 is pressed against the glass surface 10 by the tension of the tension spring 9.

The wiper device described above reciprocates the wiper shaft 3 by a wiper motor (not shown) and a link connected to the wiper motor, and swings the arm head 4 fixed to the wiper shaft 3, thereby moving the wiper blade 5 to the glass surface 10. This is to dispel the

However, in the wiper device having only the above-described structure, the pressure force of the wiper blade 5 against the glass surface 10 is a force due to the almost constant tension of the tension spring 9. The lift force acting on the wiper blade 5 and the like increases due to the airflow, and the pressure force against the glass surface 10 decreases, resulting in insufficient wiping, which may impair safety.

Therefore, there is a need for a structure that can obtain a pressing force that can be used to counteract the lifting effect of the wiper blade 5. Here, as shown in FIG. 1, the pressing force P of the wiper blade 5 against the glass surface IO is influenced by the magnitude of the rotational moment M toward the vehicle body 1 about the pivot pin 8. , the moment M is 1, the product of the force T of the tension spring 9 and the length of the perpendicular line drawn from the mounting pin 8 to the tension spring 9, that is, M=
The moment M is expressed as TxI, and if the length from the pivot pin 8 to the fulcrum of the wiper blade 5 at the tip of the arm 6 is L, then the moment M is expressed as M=LXP. In other words, in order to change the contact force P, it is better to change the moment M. Specifically, the contact force P can be changed by changing either or both of the tension T of the tension spring and the length of the perpendicular line. It can be changed.

Therefore, in the past, there was a wiper device as shown in FIG. 2 having a mechanism for making the pressing force P variable.

FIG. 2 is a block diagram illustrating the above-mentioned mechanism. First, the vehicle speed or the airspeed measured by a wind turbine installed on the vehicle is detected by the detector 11, and the output obtained through the control circuit 12 is The control valve 13 is opened and closed, and the control valve 1 is connected to the drive pressure source 14.
By adjusting the pressure to the wiper 17 with the regulator 15 and operating the actuator 16, which has a built-in diaphragm or the like and converts pressure displacement into tension, the tension spring in the wiper 17 is expanded or contracted to increase or decrease the tension T, and the wiper The pressure force P of the blade was changed.

However, the conventional wiper device as described above requires a strong actuator that can directly pull the tension spring, and engine oil pressure is used as the drive pressure source for the actuator.

Because air pumps, engine suction negative pressure, etc. were used,
The accompanying equipment such as regulators and control valves made the whole vehicle larger and increased the weight of the vehicle. Further, since pressure-resistant piping is required between each device 4, there are problems such as high cost.

This invention was made in view of the above-mentioned problems, and aims to provide a wiper device that eliminates devices such as actuators, simplifies the structure, and is lightweight and low cost. The structure of the device is such that a first gear is rotatably fitted to a pivot that supports a wiper shaft and can be fixed by a fixing means, and a second gear coaxial with a worm gear pivoted to an arm head and the first gear. and hooking one end of the tension spring to a worm wheel that meshes with the worm gear at a position removed from the rotational axis of the worm wheel, so that the tension of the tension spring can be varied while the first gear is fixed. This is considered a #sign.

The present invention will be explained below based on the drawings.

FIGS. 3 and 4 are diagrams for explaining the structure of a wiper device according to an embodiment of the present invention.

In the wiper device shown in the figure, a pivot 21 having a cylindrical hollow part 21a into which a wiper shaft 20 is inserted has a plurality of ports 22 in a two-run 9 part 21b integrally molded on its outer periphery.
is provided, and is fixed to the vehicle body 24 by tightening a nut 23 that is threaded onto the bolt 22 from the back side of the vehicle body 24. Also, the shaft portion 2 of the pivot 21. In the lc, a ring-shaped electromagnet 25 consisting of an iron core 25a and a coil 25b is fitted and fixed, and a stepped portion 21d is formed on the upper side of the electromagnets 2 and 5, where the shaft portion 21c has a smaller diameter. , the shaft portion 21c
After the first spur gear 26 is rotatably fitted into the stepped portion 21d, a stomp ring 27 is fitted to prevent the first spur gear 26 from coming off. Further, on the lower surface of the first spur gear 26, an elastic body 28a, ? A plurality of clutch plates 28, which are constructed by overlapping the ignition body 28b and the brake shoes 280 in this order, are fastened by rivets 75, and at this time, between the lower surface of the clutch plates 28 and the two surfaces of the electromagnet 25, The structure is such that there is a slight gap between the two.

The wiper shaft 20 has a link mechanism arm 29 fixed to its lower end, which is connected to a wiper motor (not shown).
After being inserted into the hollow part 21a via a wafer washer 30 between it and the lower end surface of the pivot 21, it is supported by the pivot 21 by fitting a stomp ring 31 into the upper end surface position of the pivot 21. Further, an arm head 32 is fixed to the upper end. Note that the arm 32 can be attached to the wiper shaft 20 by having a tapered vertical protrusion 20a on the wiper shaft 20 side, which is engaged with a tapered mounting hole 32a of the arm head 32 to attach the wiper shaft 20 to the wiper shaft 20. It is fixed by tightening a nut 33 from the upper end of the
As the wiper @20 rotates, the arm head 32 also rotates. .

The wiper shaft 20 is located inside the tip side of the arm head 32.
A worm gear 36 supported by upper and lower flat bearings 34 and 35 in the same axial direction as the worm gear 36 and a worm wheel 37 that engages with the worm gear 36 are provided at the lower end of the worm gear 36. A second spur gear 38 is arranged coaxially with the first spur gear 26 at a position where it engages with the first spur gear 26 when the rad 32 is picked up. Further, on the side surface of the worm wheel 37, a connecting metal fitting 40 is rotatably attached at a position separated from the central support shaft 39, and this connecting metal fitting 40 and the worm wheel 37 constitute a link mechanism. Further, a non-retainer 42 that constitutes a part of the wiper arm is connected to the tip of the arm head 32 by a pivot pin 41, and one end of an arm piece (not shown) that also constitutes the wiper arm together with the retainer 42 and the A tension spring 43 is tensioned between the connecting fitting 40 and the connecting fitting 40.

The wiper arm and wiper blade, which are composed of the retainer 42 and the arm piece, have the same structure as the conventional structure,
The wiper blade is pressed against the glass surface IO by the tension of the tension spring 43.

Further, as shown in FIG. 4, a rotation detector 44 connected to the support shaft 39 of the worm wheel 37 is built in the position of the worm wheel 37 on the side surface of the arm rad 32, and is located on the outside. Power.

A bar 32a is fitted.

Although the first and second gears are spur gears in this embodiment, they may be helical gears, bevel gears, or the like.

The wiper device configured as described above includes an arm 29 connected to a wiper motor (not shown) provided inside the vehicle body 24.
The wiper shaft 20 is reciprocated by
By swinging the arm head 32 fixed at zero, the wiper blade performs a wiping operation. In addition, the wiper device has a structure in which the pressure contact force of the wiper blade against the glass surface, that is, the tension of the tension spring 44, is made variable according to the vehicle speed or wind speed, and the wiper device is configured to vary the pressure force of the wiper blade against the glass surface, that is, the tension of the tension spring 44, and receives signals from the vehicle speed detector and the vehicle speed detector or from the wind power detector. A control circuit and the like are attached to the electromagnet 25 to turn on/off the energization of the electromagnet 25 according to the signal.

Hereinafter, the case will be explained based on vehicle speed, but the use of wind speed will have the same effect and effect, so the use of wind speed will be omitted.

As shown in the graph of FIG. 5(a), this wiper device changes the pressure contact force of the wiper blade in proportion to the vehicle speed when the vehicle speed exceeds a preset value. For example, when the vehicle speed is 8.
The pressure contact force is set to 700 g at 0 km/h, and then the potentiometer output from the rotation detector 44, which becomes a pressure contact signal when the pressure contact force is 700 g, is set to 3
If the voltage is set to v, the output of the f-■ conversion circuit by the vehicle speed sensor when the vehicle speed is 80 km/h is also set to 3 v, as shown in FIG. 5(C). In other words, the control may be performed so that the same 13 voltage as the output voltage of the f-v conversion circuit as the vehicle speed signal is outputted as the potentiometer output as the pressure contact force signal.

FIG. 6 is a logic circuit showing a circuit for controlling the above output, in which 50 is a vehicle speed sensor, 51 is a waveform shaping circuit, 52 is an f-v conversion circuit, 53 is a filter, and 54
is a potentiometer output of the rotation detector 44, 55 is an error detection circuit, 56 is a correction start point detection circuit in the pressure contact force jfJ4th direction, 57 is a correction start point detection circuit in the pressure contact force weakening direction, 58 is a correction completion detection circuit, 59 is a signal holding circuit for increasing pressure contact force, 60 is a signal holding circuit for reducing pressure contact force, 61 is a stop position detection circuit, 62 is an auto stop play 63 is a wiper reciprocating operation detection circuit, 64 and 65 are electromagnets 25 (third 66 is a switch circuit for turning on/off the energization of the electromagnet 25.

Next, to explain the operation, first, the error detection circuit 55
generates an output obtained by subtracting the voltage of the potentiometer output 54 from the output voltage of the f-v conversion circuit obtained from the vehicle speed sensor 50. Since the system is a single power supply, as shown in FIG. The operating point A is set so that the output voltage of the error detection circuit 55 becomes Vcc/2 when the difference in output voltage is "0". Therefore, in Fig. 7, in the region where the output voltage is +A, it is detected that the vehicle speed is high relative to the pressure contact force of Kuipab 1/D, and a correction signal is issued in the direction of increasing the pressure contact force, and in the region of -A, it is detected that the vehicle speed is low. is detected and outputs a correction signal in the direction of weakening. However, since the vehicle speed always fluctuates, if the pressure correction signal is issued when the pressure force is moved away from the operating point A, the control will be performed frequently. Correction start detection circuits 56 and 57 are provided respectively, and the pressure contact force is not corrected when the output voltage of the error detection circuit is within a preset range B. Then, correction is performed when the error detection circuit output voltage exceeds the +A area correction starting point C1 or falls below the -A area correction starting point C2.

The auto stop plate 62 is fixed to a worm wheel that constitutes a deceleration mechanism for the wiper motor 67.
It rotates once with respect to the wiper reciprocation, and between the fixed contact pieces 68a, 68b and the fixed Contact piece 68b, 6
Three rotary contact plates 69a, 69b, and 69c, which connect between 8c and 111j alternately every half rotation, are available.

The fixed contact pieces 68a, 68b, and 68c are provided in parallel on the auto-stop plate 62, which rotates, so as to draw trajectories of different radii. 69a, 69b.

Two rotating contact plates 69a and 69c of 69c are 180
Since they are provided at different positions, it is possible to detect when the wiper is wiping up and down by rotating the auto-stop plate 62. Therefore, in this invention, the fixed contact piece 68a.

68c for every half rotation, and a signal holding circuit 59 for increasing pressure contact force or a signal holding circuit 60 for decreasing pressure contact force.
The pressing force of the arm is changed depending on the relationship between the duck signal and the vehicle speed.

That is, a signal passing through each fixed contact piece 68a, 68b, 68c which is intermittent on the auto-stop plate 62 is transmitted to the wiper reciprocating motion detection circuit 63 as a signal indicating the reciprocating motion of the wiper.

The correction signal from the error detection circuit 55 and the reciprocating operation signal from the wiper reciprocating operation detection circuit 63 are transmitted to the electromagnet 25.
The switch circuit 66 enters the switch circuit 66 via the energizing circuits 64 and 65, and these signals are used to energize the wiper during acceleration and turn it off when the wiper is wiped down, and to cut off the energization when decelerating. The wiper is controlled to be energized when wiping down and cut off when wiping up.

Therefore, for example, when acceleration is performed from a speed that has been kept constant and the magnitude of the acceleration exceeds the correction start point C1 of the correction start detection circuit 56 in the direction of increasing the pressure contact force, the output of the correction start detection circuit 56 changes to the pressure contact force. Energizing cables 1 and 6 in the direction of increasing force
4, as shown in Figure 8, the wiper wiping direction (
In the direction of arrow X in the figure), the switch circuit 66 energizes the electromagnet 25 (see FIG. 3). Since the electromagnet 25 is excited by this energization, the clutch plate 28 having the magnetic body 28b is attracted to two surfaces of the electromagnet 25 due to the expansion of the elastic body 28a. In other words, the first spur gear 26
is fixed by suction of the flange plate 28 fixed to the lower surface, so as shown in FIGS. 8 and 9(a)
As shown in (b), when the wiper moves in the wiping direction, the second spur gear 38 moves while rotating around the fixed first spur gear 26, and is coaxial with the second spur gear 38. The rotation of the worm gear 36 causes the worm wheel 37 to rotate. At this time, tension spring 4
The connecting fitting 40 that hooks one end of 3 was originally shown in Fig. 9 (
As shown in a), the worm wheel 37 is moved closer to the wiper tip, but as the worm wheel 37 rotates, the tension spring is moved downward as shown in FIG. 9(b). 43 and distance #
Increase the pressure of the wiper brake 1 against the glass surface.

Further, when moving in the wiping down direction, the electricity to the electromagnet 25 is cut off, so the electromagnet 25 is demagnetized and the -
The spur gear 26 returns to its rotatable state. Therefore, since the first spur gear 26 merely rotates idly with respect to the movement of the second spur gear 38, the second spur gear 38 also does not rotate, and the pressure contact force of the wiper blade remains maintained. Then, when the acceleration is finished and the amount of change in speed decreases, the energization to the electromagnet 25 is stopped, and the wiper continues to swing while maintaining the same pressure contact force.

Furthermore, since the transmission configuration is made up of the worm wheel 37 and the worm gear 36, the worm wheel 37 will not rotate in the opposite direction even if the first spur gear 26 is in a rotatable state.Next, when J decelerates Since the electromagnet 25 is energized when the wiper is moving in the downward direction, contrary to when accelerating, the fixed first spur gear 26 causes the second spur gear 38 . The worm wheel 36 and the worm wheel 37 all rotate in reverse,
Since the tension spring 43 is loosened and the distance NL is reduced at the same time, the pressure force of the wiper blade against the glass surface is reduced. Note that when the wiper is in the wiping direction, the -t+z tooth group 26 idles, so there is no change in the pressure contact force. Then, when the amount of change in speed becomes even smaller, the energization of the electromagnet 25 is stopped, and the wiper continues to swing with the same pressing force.

Also, while driving at high speed, that is, when the pressure contact force is stronger than usual M:
If the wiper inch is turned off at the same time, as shown in FIG.
This stop No. 4g is transmitted to the energizing gate 65 in the direction of weakening the pressure contact force. Therefore, since the pressure contact force correction signal during deceleration is input to the switch circuit 66 together with the wiper reciprocating operation signal, the pressure contact force of the wiper blade decreases as described above. Furthermore, at this time, the wiper motor 67 did not stop immediately, and the contact force decreased to the normal pressure due to a change in the resistance value of the rotation detector 44, that is, the potentiometer output 54, as the worm wheel 37 rotated. is detected by the stop position detection circuit 61 and the wiper off circuit 70 is reset. After that, the auto stop play 1/62 and the wiper reciprocating motion detection circuit 63 detect that the wiper has reached the predetermined stop position, and the wiper motor 67 is activated. make it stop.

As described above, according to the present invention, the first gear is rotatably fitted to the pivot supporting the wiper shaft and fixed by the fixing means, and the second gear is coaxial with the worm gear pivotally connected to the arm head. A gear and the first gear are meshed together, and one end of the tension spring is hooked to a worm wheel that meshes with the worm gear at a position away from the rotational axis of the worm wheel, so that the first gear is in a fixed state. Since the tension spring has a structure in which the tension is variable, devices such as actuators are not required, and the structure is greatly simplified, resulting in light weight and low cost.

[Brief explanation of drawings]

Figure 1 is a sectional view explaining the structure of an automobile wiper;
The figure is a block diagram illustrating the configuration of a conventional wiper lifting prevention structure, FIG. 3 is a partial sectional view illustrating a wiper structure according to an embodiment of the present invention, and FIG. 4 is a sectional view taken along line A-A in FIG. 3. , Fig. 5 (a), (b), and (c) are graphs showing the relationships between vehicle speed and pressure contact force, pressure contact force and potentiometer output, and vehicle speed and output of the f-v conversion circuit, respectively, and Fig. 6 is shown in Fig. 3. FIG. 7 is a logic circuit diagram of a circuit that controls wiper operation; FIG. 7 is a graph showing the error detection circuit output voltage with respect to the difference between the output voltage of the f-v conversion circuit and the potentiometer voltage; Fig. 8 is an explanatory plan view showing the movement of each gear during reciprocating upward movement of the wiper, and Figs. 9 (a) and (b) are sectional views before rotation and sectional views in the rotation state, also illustrating the movement of each gear. It is. 20... wiper shaft, 21... pivot, 25...
Electromagnet, 26...-th spur gear (first gear), 28...
・Clutch plate, 32... Arm head, 36... Worm gear, 37... Worm wheel, 38...
Second spur gear (second gear), 39... Support shaft, 40...
Connecting fittings, 42... Retainer, 43... Tension spring. Special T1 Applicant Jidosha Electric Industry Co., Ltd. Representative Patent Attorney Yutaka Oshio Figure 5 (°) (b) Σ (C) Dan

Claims (2)

[Claims] (1) One end of the wiper arm is pivotally attached to an arm head fixed to a wiper shaft that rotates back and forth, a wiper blade is pivotally attached to the other end of the wiper arm, and a tension spring is installed between the arm head and the wiper arm. In the wiper device, which wipes the wiping surface by reciprocating rotation of the wiper shaft while pressing the soipper blade against the wiping surface by the tension of the tension spring, the first gear is rotatable on a pivot that supports the wiper shaft. A second gear coaxial with the worm gear pivotally connected to the arm head is engaged with the first gear, and a worm wheel that engages with the worm gear is provided with a rotation support shaft of the worm wheel. A wiper device characterized in that one end of the tension spring is hooked at a position removed from the first gear, and the tension of the tension spring is variable when the first gear is fixed. (2) The fixing means is an electromagnetic clutch type structure consisting of a clutch plate provided on the lower surface of the first gear and an electromagnet provided on the pivot.
The wiper device described in section 1).