JPH05862Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a contact device for a warning device that notifies the outside of a vehicle's speed by flashing lights, etc., and particularly relates to a contact device for warnings that uses a tachograph. be.

[Conventional technology]

Various types of warnings using tachographs have been carried out in the past, and the speed sensors used for these are generally of the overcurrent type. By the way, an overcurrent type speed sensor uses a rotating body that rotates according to the speed to rotate a magnet to form a rotating magnetic field, and during this rotation time, the overcurrent generated in a dielectric (conductive plate) placed on it causes the dielectric to rotate. It is a device that applies force, and generates a large torque when rotating at high speeds, but less torque when rotating at low speeds.
If a mechanical load is applied to the inductor at low speeds, it tends to affect the tachograph indication and mechanical properties.

Figures 4 and 5 show the main parts of a conventional warning contact device using a tachograph, in which the pointer shaft 1, which is the driven side of the overcurrent type speed sensor, has meshing, frictional force, etc. The guide shaft 3 guides the guide shaft 3 and moves the slide board 2 in a linear direction (vertical direction in FIG. 5) according to the rotation angle of the pointer shaft 1. A contact base 4 made of an electrically insulating material is fixed on the guide plate 2, and two conductive parts 5 and 6 made of copper foil are formed on the contact base 4. The conductive parts are arranged substantially straight in parallel, and one conductive part 6 has a hook part 6a so as to surround the other conductive part 5. A pair of contacts 7 and 8, which are insulated and fixed to the chassis, are disposed facing each other on the conductive parts 5 and 6, and each contact is normally in contact with one of the conductive parts.

In this device, when the speed is below a predetermined speed, one contact 7 contacts the conductive part 5 and the other contact 8 contacts the conductive part 6, and the contacts 7 and 8 are not short-circuited. The awning device (not shown) is switched off. As the speed increases, the slide plate 2 gradually moves upward, and when a predetermined speed is exceeded, one contact 7 separates from the conductive part 5 and comes into contact with the key part 6a of the conductive part 6. Therefore, since both contacts 7 and 8 come into contact with the conductive part 6, they are short-circuited and the warning device is turned on.

[Problem that the invention attempts to solve]

However, in the case of the above device, since the two contacts and the conductive part are always in contact even if the speed is low below a predetermined value, the sliding friction force between the contacts and the conductive part is If the overcurrent speed sensor is a load resistance and has a small torque in a low speed range, this load resistance has the disadvantage of deteriorating the indicating accuracy and mechanical characteristics of the speedometer and tachograph.

This invention was made in view of the above drawbacks,
The purpose of the present invention is to provide a warning contact device that can reliably perform a warning without deteriorating the accuracy and mechanical characteristics of the tachograph even when using a tachograph using an overcurrent type speed sensor.

[Means to solve the problem]

In order to achieve the above object, the present invention has a configuration in which a tapered part is formed on a slide plate on which a conductive part is formed, and the conductive part and the contact are maintained in a non-contact state below a predetermined speed, and when the speed exceeds a predetermined speed, the taper part is It is characterized by a contact that slides on the surface and comes into contact with the conductive part.

〔Example〕

Embodiments of the present invention will be described below based on FIGS. 1 to 3.

FIG. 1 is a side view of the main parts of the embodiment, and FIG. 2 is a plan view thereof. In the figure, the pointer shaft 1 is connected to the slide plate 2 by gear engagement, and the slide plate 2
is held movably in the vertical direction by a guide shaft 3 as in the conventional example, and an electrically insulating contact base 4 forming a part of the slide plate 2 is fixed on top of the slide plate 2. A conductive part 9 is placed on one side of the contact block 4.
is formed, and the contact block 4 is connected from one end of the conductive part 9
As shown in FIG. 1, the other side has a tapered portion 4a.
, and a part of the contact base 4 is removed. A pair of contacts 7 and 8 that are to contact the conductive portion 9 are spaced apart from the tapered portion 4a so as to face the surface of the tapered portion 4a.

FIG. 3 is a front sectional view of a speedometer using an overcurrent type speed sensor that operates the contact device,
A hole 12 is provided at the center of the closed surface of the box 11 with one end open, and a rotary shaft 13 is rotatably supported in the hole 12. A small-diameter cylindrical body 14 is fixed to the tip of the rotating shaft 13 coaxially with the rotating shaft 13, and the lower end of the pointer shaft 1 passing through the cylindrical body 14 rotates with respect to the rotating shaft 13 inside the cylindrical body 14. freely supported. A tub-shaped holder 15 having a relatively large diameter is coaxially fixed to the connecting portion between the cylindrical body 14 and the rotating shaft 13, and a yoke 16 made of a magnetic material is attached to the inner peripheral wall of the holder 15. It's worn. Between this yoke 16 and the cylindrical body 14,
A ring-shaped magnet 17 is fixed to the outer periphery of the cylindrical body 14, and a ring-shaped magnetic gap is formed between the outer periphery of the magnet 17 and the yoke 16. A guide plate 18 having an inverted bucket shape is fixed to the pointer shaft 1 above the cylindrical body 14.
A ring-shaped depending wall is located in the magnetic gap.

Further, a pointer 19 is fixed to the tip of the pointer shaft 1, and a scale plate 20 is arranged behind the pointer 19. A balance spring 21 is fixed to the middle portion of the pointer shaft 1, and the balance spring 21 provides a resistance to the rotational force of the pointer shaft 1.

Next, the operation of this embodiment will be explained.

Magnetic lines of force are generated from the magnet 17 that originates from its N pole and reaches its S pole, but most of them pass through the yoke 16 to form a closed magnetic path. It penetrates in the direction perpendicular to the Since magnetic poles are formed on the magnet 17, when the magnet 17 rotates, the lines of magnetic force passing through the guide plate 18 change, so that eddy currents are generated on the guide plate 18 in a direction that prevents the change in the lines of magnetic force. Regarding the component of this eddy current parallel to the rotation axis 13, since a magnetic field H perpendicular to the induction plate 18 exists at this position, the induction plate 18 has a direction perpendicular to both the eddy current and the magnetic field H. Electromagnetic force works. This electromagnetic force F is proportional to the rate of change of magnetic flux, that is, the number of rotations of the rotating shaft 13 per terminal time. This electromagnetic force F causes the guide plate 18 to rotate in a direction that follows the rotation of the rotating shaft 13 against the biasing force of the hairspring 21, and at a rotation angle that balances the electromagnetic force F and the biasing force of the hairspring 21. The pointer 19 stops and indicates the scale.

Further, the switch operation for warning depending on the speed is as follows.

When the pointer shaft 1 is rotated by the eddy current speed sensor as described above, the gear-coupled slide plate 2 is guided by the guide shaft 3 and moves linearly. When the speed increases and the slide plate moves to a certain position, the pair of contacts 7 and 8 move to the tapered portion 4a of the contact base 4.
come into contact with. In this state, since the contact base 4 is made of electrically insulating resin, the contacts 7 and 8 are not electrically conductive. When the speed increases further and reaches a predetermined speed, the contacts 7 and 8 ride on the upper surface of the contact base 4 while sliding on the tapered portion 4a due to the movement of the slide plate 2, and come into contact with the conductive portion 9. As a result, the contacts 7 and 8 are electrically connected, and the warning switch is turned on. At this time, the contacts 7 and 8 do not come into contact with the conductive part 9 at all until they reach a predetermined speed, and even just before they come into contact, they are in contact with the tapered part 4a of the contact base 4 made of synthetic resin, so the friction The resistance is extremely small and does not act as a load resistance to the rotational force of the pointer shaft 1.

In this embodiment, the warning contact device has only been described in terms of a pair of contacts, but if multiple warning display lamps are to be lit in stages according to the speed, the number of contacts can be increased according to the number of warning lamps. good.

[Effect of idea]

The present invention is as described above, and according to the present invention,
The tapered part of the slide plate keeps the conductive part and the contact in a non-contact state below a predetermined speed, so there is no need to apply more load than necessary to the induction plate of the eddy current speed sensor, and it can be connected to the speed sensor. The accuracy and mechanical properties of the tachograph can be maintained normally.
Furthermore, the warning can be performed reliably.

[Brief explanation of drawings]

Fig. 1 is a side view of the main parts of the embodiment of the invention, Fig. 2 is a plan view of the main parts of the embodiment of the invention, Fig. 3 is a front sectional view showing the overall structure of the embodiment of the invention, and Fig. 4 is the conventional FIG. 5 is a side view of the main part of the example, and FIG. 5 is a plan view of the main part of the conventional example. 1...Pointer shaft, 2...Slide plate, 4...Contact stand, 4a...Tapered part, 7, 8...Contact, 9...
Conductive part, 17... magnet, 18... guide plate.

Claims (1)

[Scope of utility model registration request] A rotating magnetic field is formed by a magnet that rotates according to the speed, and an eddy current speed sensor is connected to the guiding plate, and an eddy current type speed sensor is used which applies rotational force to the guiding plate by eddy current generated in the guiding plate arranged in the rotating magnetic field. A conductive part is formed on a slide plate that moves according to the speed, and as the slide plate moves, this conductive part contacts a pair of contacts and short-circuits between the contacts, thereby giving a warning according to the speed. In the slide plate, the slide plate and the contact are kept in a non-contact state when the speed is below a predetermined speed, and when the speed exceeds the predetermined speed, the contact contacts the conductive part of the slide plate,
A warning contact device characterized by having a tapered portion so as to slide.