JPH0626851Y2 - Eddy current instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an eddy current instrument such as a vehicle speedometer.

(Prior Art) In a vehicle speedometer, etc., a magnet is rotated by rotation of a rotating shaft, an induction plate is rotated by an eddy current generated by this rotation, and a vortex that indicates a speed by a pointer linked to this induction plate. Current meters are widely used.

FIG. 5 shows a conventional speedometer of this type. A rotary shaft 2 is rotatably supported on the frame 1 via a bearing (not shown), and the rotational force from the transmission is transmitted to the rotary shaft 2 via a flexible shaft (not shown). At the upper end of the rotary shaft 2 in the figure, a charcoal plate 3, a bush 4, a magnet 5 and a magnetic compensating plate 6 for temperature correction of the magnet 5.
Are fixed concentrically in sequence. A concave hole 2a is formed in the upper end portion of the rotating shaft 2, and a lower end 8a of a pointer shaft 8 is rotatably and concentrically supported in the concave hole 2a via a mortise receiver 7. Further, a bowl-shaped guide plate 9 is concentrically fixed to an intermediate portion of the pointer shaft 8, and the charcoal plate 3
The outer wall of the magnet surrounds the outer periphery of the guide plate 9 and regulates the magnetic flux of the magnet 5. Further, the vicinity of the upper end of the pointer shaft 8 is rotatably supported by a bridge 11 originally provided on the upper part of the case 10, and one end of a spiral spring 12 is fixed to a portion where the pointer shaft 8 projects from the bridge 11. ing. It is fixed to a part of the other end body case 10 of the spiral spring 12 and gives a predetermined braking force to the rotation of the pointer shaft 8, and a pointer (not shown) is provided at the tip of the pointer shaft 8. It is installed.

On the other hand, a worm gear 13 is concentrically fixed to the rotary shaft 2 below the charcoal plate 3, and rotation of the rotary shaft 2 is carried out through gear trains 14, 15 and 16 by means of a numeral wheel 1 of an integrating meter.
7 is transmitted.

With the above configuration, the rotation speed proportional to the traveling speed of the vehicle is transmitted from the transmission to the rotating shaft 2, and the magnet 5 is driven to rotate, so that the torque proportional to the rotation speed of the magnet 5 due to the eddy current action on the guide plate 9. Occurs, the pointer shaft 8 is rotated to a position where the braking force of the spiral spring 12 is balanced, and the speed on a scale plate (not shown) is indicated.

(Problems to be Solved by the Invention) In the conventional eddy current instrument configured as described above,
A means for fixing the charcoal plate 3, the bush 4, the magnet 5 and the magnetic shunt plate 6 to the upper end of the rotary shaft 2 is shown in an enlarged manner in FIG. That is, the upper end of the rotary shaft 2 has a reduced diameter, and has a tubular shape with a concave hole 2a formed in the center. The charcoal plate 3 is sequentially attached to the tubular mounting portion 2b,
The bush 4, the magnet 5, and the magnetic shunt 6 are sequentially inserted and laminated concentrically, and the upper end of the mounting portion 2b is caulked and pushed out to the outer peripheral side, and the upper surface of the magnetic shunt 6 is pressed and fixed. However, according to such a fixing structure, when the upper end of the mounting portion 2b of the rotary shaft 2 is caulked, metal powder is generated and falls into the hollow receiver 7, so that the rotary shaft 2 and the hollow receiver 7 are together.
There is a problem that when the needle rotates, the pointer shaft 8 is shaken or an abnormal noise is generated.

The present invention has been made in view of this point, and an eddy current type instrument capable of preventing the generation of metal powder during assembly and preventing the movement of the pointer shaft and the generation of abnormal noise when the rotating shaft rotates. The purpose is to provide.

[Constitution of device]

(Means for Solving the Problems) In order to achieve the above object, the present invention is directed to a magnet fixed concentrically to a rotating shaft, a guide plate for driving a pointer by generating torque due to the rotation of the magnet, and the rotating member. A mortar holder that is fixed to the shaft and rotatably supports this pointer,
In a eddy current instrument equipped with a rectifying plate that covers the surface of the magnet, and a gear that is concentrically fixed to the rotary shaft and that transmits the rotation of the rotary shaft to an integrator, It is characterized in that it is fitted and locked to the boss portion, and that the magnet and the magnetic shunt plate are pressed and locked to the surface of the gear by this mortar holder.

(Operation) According to the above configuration, the gear is fitted and fixed to the rotary shaft, and the hoso receiver is fitted and locked to the boss portion of the gear. Therefore, no metal powder is generated when the gear is assembled. Absent. Further, the magnet and the magnetic shunting plate are provided with a flange portion on the upper end of the mortar holder, and are pressed and fixed to the gear surface via the flange portion. At this time, the magnet can be surely pressed and fixed to the gear surface by providing the magnetic compensating plate with the function of the leaf spring. No metal powder is generated even when the magnet and the magnetic shunt plate are fixed to the rotating shaft via a gear.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention. In the figure, the same or equivalent parts as those of the conventional example shown in FIGS. 5 and 6 are designated by the same reference numerals, and the description thereof will be omitted.

The feature of this embodiment lies in the mounting structure of the magnet 5 and the magnetic shunt plate 6 to the rotary shaft 2, and the structure of the other parts is the same as the conventional example. As shown in FIG. 1, the rotating shaft 2 is rotatably supported by the frame 1 via bearings 18.
A gear 19 is concentrically fixed to the upper end in the figure. As shown in FIG. 4, a flange portion 20 is integrally provided concentrically on the upper end of the gear 19 so as to project to the outer peripheral side.
The lower end of a substantially cylindrical charcoal plate 3 is fixed to the outer periphery of 0. In addition, a substantially cylindrical boss portion 21 is concentrically provided integrally with the upper portion of the gear 19, and locking holes 22 are formed in the bottom portion of the boss portion 21 at positions dividing the circumference into three equal parts. There is. The inner diameter of the annular magnet 5 is fitted to the outer periphery of the boss portion 21 and is supported on the surface of the collar portion 20 of the gear 19.

As shown in FIG. 2, the magnetic compensating plate 6 is formed of a plate member having elasticity in an annular shape, and a plurality of, for example, six notches 6a are radially provided on the inner peripheral portion. The magnetic shunt plate 6 is concentrically placed on the upper surface of the gear 5 in the figure.

The hoso receiver 23 is formed in a cylindrical shape with a bottom, and the outer circumference is fitted to the inner circumference of the boss portion 21 of the gear 19. As shown in FIG. 3 when viewed from the bottom, the outer periphery of the lower end of the mortise receiver 23 is provided with claw portions 24 projecting outward at positions where the circumference is divided into three equal parts. When it is fitted into the boss 21, the claw portion 24 elastically fits into the locking hole 22 provided in the boss portion 21, and the hook receiving member 23 is fitted into the boss portion 21.
It is designed to be positioned and fixed with respect to. Further, the flange portion 2 protruding outwardly is provided on the upper end surface of the hoso receiver 23.
5 are integrally provided concentrically, and the stepped lower surfaces of the flange portions 25 come into contact with the respective upper surfaces of the boss portion 21 of the gear 19 and the magnetic compensating plate 6. At this time, the magnetic shunt 6
Since the inner circumference of the magnet is elastically deformable via the notch 6a, the magnetic shunt plate 6 presses the magnet 5 elastically.
Further, the lower end 8 of the pointer shaft 8 is located at the center of the bottom surface of the hoso receiver 23.
A through hole 23a that rotatably supports a is provided, and a guide plate 9 is fixed to the middle of the pointer shaft 8 in the axial direction via a bush 26 as in the conventional example.

With the above configuration, the rotation speed proportional to the traveling speed of the vehicle is transmitted from the transmission to the rotary shaft 2 and further transmitted to the magnet 5 via the gear 19, and the magnet 5 is rotationally driven, whereby the guide plate 9 is rotated. Due to the overcurrent action, a torque proportional to the rotation speed of the magnet 5 is generated.
Then, the pointer shaft 8 is rotated 4 to a position where it is balanced with the braking force of the spiral spring 12 shown in FIG. 5 to indicate the speed on the scale plate (not shown). At the same time, the rotation of the gear 19 is transmitted to the accumulator to display the traveling distance of the vehicle.

According to this embodiment, when fixing the magnet 5 and the magnetic shunt plate 6 to the rotary shaft 2, there is no caulking step, so that the generation of metal powder can be prevented. Therefore, the metal powder does not drop into the hollow receiver 23, and it is possible to prevent the movement of the pointer shaft 8 and the generation of abnormal noise.

In the above embodiment, the case of the speedometer of the automobile has been described, but it can be applied to an eddy current type instrument used for other purposes and the same effect can be obtained.

Further, the structure of each part of this embodiment may be another structure without departing from the gist of the present invention.

[Effect of device]

As described above, according to the present invention, the magnet and the magnetic compensator provided in the eddy current type instrument are pressed and fixed to the gear fixed to the rotating shaft via the hosi receiver. The caulking step can be eliminated, the generation of metal powder can be prevented, and the movement of the pointer shaft and the generation of abnormal noise can be prevented.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an eddy current instrument according to the present invention, FIG. 2 is a plan view showing the magnetic compensating plate of FIG. 1, and FIG. 3 is a muller receiver of FIG. A rear view, FIG. 4 is a vertical sectional view showing the gear of FIG. 1, FIG. 5 is a partially sectional front view showing a conventional eddy current instrument, and FIG. 6 is an enlarged view of a main part of FIG. . 2 ... Rotary axis 5 ... Magnet 6 ... Magnetizing plate 7,23 ... Hoso receiver 8 ... Indicator shaft 9 ... Guide plate 13,19 ... Gear 21 ... Boss part

Claims (1)

[Scope of utility model registration request] 1. A magnet fixed concentrically to a rotary shaft, a guide plate for generating a torque by the rotation of the magnet to drive a pointer, and a hosi receiver fixed to the rotary shaft and rotatably supporting the pointer. An eddy current instrument comprising: a magnetizing plate that covers the surface of the magnet; and a gear that is concentrically fixed to the rotating shaft and that transmits the rotation of the rotating shaft to an integrator. An eddy current instrument, characterized in that the magnet and the magnetic shunt plate are pressed and locked on the surface of the gear by fitting and locking the boss portion of the gear.