JPS6123809Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an eddy current type rotation speed indicating device, which reduces the number of parts and speeds up assembly work, and eliminates the need to improve the accuracy of finishing of the tip of the rotating shaft. It is an object of the present invention to provide an eddy current type rotation speed indicating device that can reduce manufacturing costs.

Generally, a conventional eddy current type rotational speed indicating device has a structure as shown in FIG. A gear 2 that transmits the rotation of the rotation shaft 1 to an integrating meter (not shown) is concentrically provided at the end of the rotation shaft 1, and a substantially cylindrical tip protrudes from the upper surface of the gear 2. A substantially U-shaped yoke 4, a magnet 5, and a magnetic shunt steel 6 are fitted into the gear 3 in a concentrically stacked manner, and are arranged on the upper surface of the gear 2. On the other hand, one end of the driven shaft 8 is supported by a bearing 7 provided in the substantially cylindrical tip 3, a pointer 9 is attached to the other end of the driven shaft 8, and the magnet 5 is attached to the driven shaft 8. One end of the guide plate 10 and the spiral spring 11 which are spaced and opposed to each other are fixed, and the driven shaft 8 is moved by the electromagnetic force caused by the eddy current generated in the guide plate 10 as the magnet 5 rotates and the elastic force by the spiral spring 11. The rotation speed of the rotary shaft 1 is indicated by the pointer 9 by counteracting the rotations of the rotary shaft 1.

In this conventional eddy current type rotational speed indicating device, the tip portion 3, yoke 4, magnet 5, and magnetic shunt steel 6 are fitted together by press fitting. However, the holes in the tip portion 3, yoke 4, etc. must be precisely finished on the order of 1/100 to 1/1000, which has the drawback of high manufacturing costs.

To improve this, it is possible to knurl the tip 3 protruding from the upper surface of the integrally formed gear 2, and to fit and fix the yoke 4 etc. to this tip 3, but as is well known, the knurling is ,
The top surface of the gear 2 cannot be completely cut, and if the yoke 4 is fitted to the tip 3, there will be a lot of backlash, which is inconvenient. Therefore, the rotating shaft 1 and the gear 2 are constructed separately, the entire end of the rotating shaft 1 is knurled, and the gear 2, the yoke 4, etc. are fitted and press-fitted into this end. There is. However,
Since gear 2 is subjected to a large load from the totalizer,
A mutual misalignment occurs between the gear 2 and the rotating shaft 1,
The knurling has the disadvantage that it wears out, causing the rotating shaft 1 to spin idly, and also has the disadvantage that the number of parts increases.

The present invention eliminates the above-mentioned drawbacks, and one embodiment thereof will be described below with reference to FIGS. 2 and 3A and 3B.

Fig. 2 is a vertical cross-sectional view of the rotating shaft side of an embodiment of the eddy current type rotational speed indicating device according to the present invention, Fig. 3A is a cross-sectional view of the tip of the same embodiment, and Fig. 3B is the same embodiment. It is a figure which shows the hole shape of a yoke, a magnet, and magnetic shunt steel of an example.

Reference numeral 2 denotes a gear integrally formed at the end of the aforementioned rotating shaft 1, and the rotation of the rotating shaft 1 is transmitted via this gear 2 to an integrating meter (not shown). This gear 2
The substantially cylindrical tip 12 protruding from the upper surface in the axial direction of the rotating shaft 1 has a yoke 13 and a magnet 1 as described above.
4. The magnetic shunt steels 15 are fitted and fixed in a stacked state, the upper end 12a of the tip part 12 is caulked, and the yoke 13, the magnet 14, and the magnetic shunt steel 15 are sandwiched between the upper end 12a and the upper surface of the tooth 2. The bearing 7 described above is provided within the substantially cylindrical tip portion 12.

The outer circumferential surface of the tip 12 does not require any special finishing, and is formed by simple cutting, and its cross section has a circular shape as shown in FIG. 3A. On the other hand, the yoke 1 fitted to this tip 3
3. The hole 16 of the magnet 14 and the magnetic shunt steel 15 is formed into a substantially circular shape as shown in FIG. . The hole 16 with the protrusion 16a can be easily formed by press working, which is easier than knurling the tip 12 side, and requires only changing the shape of the mold in the conventional punching operation. , the number of man-hours required can be reduced compared to conventional methods.

When the hole 16 having the protrusion 16a is press-fitted into the tip 12, the press force forces the protrusion 16a to be bent and crushed by the outer surface of the tip 12, resulting in a tightly fitted state, and the yoke 13 and the magnet 1
4. The magnetic shunt steel 15 is completely fixed to the tip portion 12.

By forming this protrusion 16a, the outer diameter of the tip 12 and the yoke 13, magnet 14, magnetic shunt steel 15
The fitting tolerance between the diameter of the hole 16 formed in the hole 16 and the diameter of the hole 16 can be set more roughly than in the past. Also, especially yoke 1
This has the advantage of eliminating the looseness of 3.

In addition, the magnetic shunt steel 15 described above is used for the guide plate (first
(see figure) and the magnet 14, and even if there is no magnetic shunt steel 15,
It goes without saying that it functions as an eddy current type rotational speed indicating device.

As described above, the eddy current type rotational speed indicating device according to the present invention has a gear concentrically provided at the end of the rotating shaft for transmitting the rotation of the rotating shaft to the totalizer, and a gear that transmits the rotation of the rotating shaft to the totalizer. A substantially U-shaped yoke and a magnet are fitted concentrically in a stacked state to a substantially cylindrical tip portion protruding in the axial direction, and arranged on the upper surface of the gear, and provided within the substantially cylindrical tip portion. One end of the driven shaft is supported by a bearing, and a guide plate facing away from the upper surface of the magnet is fixed to the driven shaft, and an inner end of a spiral spring is fixed to the driven shaft, so that the rotation of the magnet is caused by the rotation of the magnet. The rotation of the driven shaft is counterbalanced by the electromagnetic force caused by the eddy current generated in the guide plate and the elastic force caused by the spiral spring, and the rotational speed of the rotating shaft is controlled by a pointer attached to the other end of the driven shaft. In an eddy current type rotation angle indicating device, the gear is integrally formed at the end of the rotating shaft, and the yoke and the magnet, which are fitted to the tip, respectively extend in the direction of the shaft center and By providing a plurality of protrusions surrounding the hole and press-fitting and fixing the yoke and the magnet to the tip, the gear is integrally formed with the rotating shaft, so the number of parts is small and assembly work is easy. It is easy to use, and the rotation of the rotating shaft can be reliably transmitted to the totalizer. Also, since the holes of the yoke and magnet are provided with protrusions, when they are fitted to the tip, these protrusions are crushed to ensure a tight fit. state,
The yoke and magnet are firmly fixed and follow the rotation of the rotating shaft without any deviation.
The tip requires only cutting and does not require precision finishing, and the protrusion can be formed by simply changing the punching die, eliminating the need for additional processing man-hours, which is an excellent tool that can reduce manufacturing costs. It has characteristics.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of an example of a conventional eddy current type rotation speed indicating device, FIG. 2 is a vertical sectional view of the rotating shaft side of an embodiment of the eddy current type rotation speed indicating device of the present invention, and FIG. Figure A is a cross-sectional view of the tip of the same embodiment, and Figure 3B is a diagram showing the hole shapes of the yoke, magnet, and magnetic shunt steel of the same embodiment. 1... Rotating shaft, 2... Gear, 3, 12... Tip, 4, 13... Yoke, 5, 14... Magnet,
6, 15... Magnetic shunt steel, 7... Bearing, 8... Driven shaft, 9... Pointer, 10... Guide plate, 11... Spiral spring.

Claims (1)

[Scope of utility model registration request] A gear for transmitting the rotation of the rotating shaft to the totalizer is provided concentrically at the end of the rotating shaft, and a substantially U-shaped tip is provided at the substantially cylindrical tip protruding from the upper surface of the gear in the axial direction of the rotating shaft. A yoke and a magnet are fitted in a stacked state concentrically and arranged on the top surface of the gear, a bearing provided within the substantially cylindrical tip part supports one end of the driven shaft, and is spaced apart and opposed to the top surface of the magnet. A guiding plate is fixed to the driven shaft, and an inner end of a spiral spring is fixed to the driven shaft, so that electromagnetic force due to eddy current generated in the guiding plate as the magnet rotates and elastic force due to the spiral spring are combined. In an eddy current type rotational speed indicating device that counteracts the rotation of the driven shaft by using A plurality of protrusions are formed integrally with the end portion and extend in the axial center direction of the holes of the yoke and the magnet that are fitted into the tip portion, respectively, and cover the holes, so that the yoke and the magnet are An eddy current type rotation speed indicator that is press-fitted into the tip.