JPS6236086Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detection coil mounted on an annular core in which two coils are concentratedly wound at intervals on the circumference.

In a device such as the detection part of an induction potentiometer that utilizes the difference in voltage induced in two coils wound around the circumference of an annular iron core, it is necessary to improve the balance of the voltage induced in the two coils. , generally both coils are wound in exactly the same way,
Moreover, it is preferable that the winding direction is always continuous from the circumference of the annular core toward the center of the ring.

FIG. 1 shows an outline of a detection coil of an annular core used in a detection section of an induction potentiometer. In FIG. 1, two annular cores 2 and 3 having different diameters are arranged concentrically with a gap 4 in between, centering on a rotation shaft 1 that is rotationally driven by the rotational displacement to be measured. 5. An excitation coil 6 is wound around the yoke 5, and an AC power source is applied to the excitation coil 6. Bobbins 7 and 7' are provided on the inner annular core 2 so as to sandwich the yoke 5 therebetween, and detection coils 8 and 8' are wound around each bobbin 7 and 7'. Furthermore, a short circuit ring 9 is provided on the annular core 2 so that the core magnetic flux interlinks with the short circuit ring 9, and this short circuit ring 9 is mechanically coupled to the rotating shaft 1 via an arm 10. Therefore, the shorting ring 9 is rotated on the circumference of the annular iron core 2 in accordance with the amount of rotational displacement to be measured.

When an excitation current is applied to the excitation coil 6, the generated magnetic flux is distributed from the yoke 5 to the left and right sides of the iron core 2, evenly distributed in the gap 4, gathers in the outer iron core 3, and returns to the yoke 5. Here, if the short circuit ring 9 is provided on the circumference of the iron core 2, both the counterclockwise magnetic flux and the clockwise magnetic flux are evenly distributed in the gap 4 along the iron core 2 and gradually decrease, and the short circuit ring 9 It becomes zero at the position. In this way, the flow of magnetic flux differs with the position of the short-circuiting ring 9 as a branching point, so the short-circuiting ring 9 is connected to the yoke 5 on the circumference of the iron core 2.
If they are exactly 180 degrees opposite to each other, the magnetic flux of the yoke 5 will be equally divided into left and right parts of the iron core 2 and distributed in the air gap 4, so the number of magnetic fluxes interlinked between the two detection coils 8 and 8' will be equal to each other. Similarly, the voltages induced in the coils 8 and 8' are also equal. However, if the shorting ring 9 is shifted to one side by the Q angle from this position, the number of magnetic fluxes that divide the iron core 2 into left and right sides is different, so the number of magnetic fluxes interlinked with the two detection coils 8 and 8' is also different, and the detection coil The voltages induced at 8 and 8' are also different. This induced voltage is proportional to the position Q of the different short circuit rings 9.
Therefore, by differentially connecting the two detection coils 8, 8', the position of the short-circuit ring 9, that is, the rotational displacement to be measured, can be determined from the voltage across both ends.

Conventionally, two detection coils provided on such an annular core are provided by providing two bobbins 7 and 7' on the core 2, respectively, as shown in FIG.
Either the detection coils 8 and 8' are fixed in a fan shape so that the end face of the frame 7' includes the center of the ring of the iron core 2 as much as possible, and the detection coils 8, 8' are wound thereon, or grooves are formed at both ends of one frame so as to surround each frame. is provided so that the two surfaces containing this groove each include the center of the ring of the iron core 2 as much as possible, and the detection coils 8, 8' are wound around this groove. However, in order to wind coils on these two bobbins or grooves, the directions of the wires to be wound are two directions as shown by the arrows R and R', respectively, and they intersect with each other. That is, there is a drawback that the winding work requires two steps. Moreover, when the diameter of the iron core is small, there is a drawback that the angle at which the two coils intersect in the conductor direction becomes large. These drawbacks are a major obstacle to streamlining winding using automatic winding machines.

The present invention aims to eliminate the above-mentioned drawbacks and provide a balanced toroidal core detection coil by winding two coils in one step.

The purpose of this is to create a detection coil for a ring-shaped core in which two coils are concentratedly wound around the circumference at regular intervals, and the ribs of the parts corresponding to the inside of the core are flexibly connected to each other with exactly the same shape. This is achieved by superimposing two bobbins on the same axis, fitting them onto the iron core, winding the detection coils around the bobbins, and then separating the outer sides of both bobbins from the iron core at a constant distance. In other words, according to the present invention, the two detection coils are wound by overlapping the two bobbins on which they are wound, fitting them onto the annular core, winding them in the same direction in one step, and then winding both detection coils onto the core. Fixed in place. Therefore, the two detection coils have exactly the same shape and are balanced.
Moreover, since the wrapping is done in one step, it is easy to automate the wrapping.

The two bobbins are integrally molded from plastic, for example polypropylene, and are joined together at one end. This joint portion is located on the inner peripheral side of the annular core.

Next, embodiments of the present invention will be described in detail based on the drawings. In FIGS. 2A and 2B, the end surfaces of two bobbins 7 and 7' having rectangular flanges on the end surfaces are arranged in parallel, one side of the opposing flanges are brought into contact with each other, and one of the flanges of both end surfaces is connected to each other. Two bobbins 7, 7' are arranged in a large rectangular shape with notches 7a, 7a' formed on one side, respectively.Bobbins 7, 7' are integrally molded from plastic such as polypropylene, and these bobbins 7, 7' are made of plastic such as polypropylene. As shown by the P arrow, bend at the connecting part 7c and overlap the end faces, and as shown in FIG. ’. At this time, the conductor winds a coil 8 from the Q end of the bobbin 7 in the direction of the S arrow, and upon completion of this winding, continues to wind the coil 8' around the bobbin 7' in the direction of the S' arrow parallel to the S arrow, and finally Pull it out from the R end. Therefore, the wrapping work is completed in one step. Moreover, since the shapes of the coils are exactly the same, the balance between both coils is good. Thereafter, as shown in FIG. 4, the outer peripheries of the bobbins 7, 7' are separated in a fan shape around the connecting portion 7c of the bobbins 7, 7' to form a distance d. When forming the bobbins 7, 7', cutouts 7 are made on the opposing outer sides of the bobbins 7, 7' that are connected side by side as shown in FIG.
Even if the bobbins b and 7b' are provided, both bobbins 7 overlapped,
The iron core 2 can be inserted into 7', and the winding work will not be hindered at all.

As described above, according to the present invention, the annular iron core is inserted into two stacked bobbins and the conducting wire is wound continuously from one side, so that the winding work is completed in one step, which is convenient for automatic winding. Moreover, since both detection coils are wound in exactly the same manner, the balance between the two coils is good, and the coil is excellent as a detection coil for an annular iron core for determining the difference in voltage induced in two coils.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the configuration of the detection section of the induction potentiometer, Figs. A is a front view;
B is a plan view, FIG. 3 is a plan view showing how to wind the detection coil of the annular core according to the present invention, and FIG. 4 is a completed perspective view of FIG. 3. 2: Annular iron core, 7, 7': Detection coil bobbin, 8, 8': Detection coil.

Claims (1)

[Scope of utility model registration request] In a detection coil that is provided on an annular core and is made of two coils that are concentratedly wound around the circumference at a constant interval, the flanges of parts that have the same shape and correspond to the inside of the core are flexibly connected to each other. An annular shape characterized in that two bobbins are superimposed on the same axis and fitted onto the iron core, and after the detection coil is wound around each of the bobbins, the outer sides of the bobbins with respect to the iron core are separated at a constant interval. Iron core detection coil.