JP6920248B2 - Ground child - Google Patents

Description

The present invention relates to a ground element and a method for manufacturing the same, for example, a ground element for detecting a train position of a railway and a method for producing the same.

The automatic train stop currently in use (hereinafter referred to as "ATS") is roughly classified into a variable frequency type and a transponder type. In the variable frequency ATS, when passing through a ground element having a resonance circuit, the ground element is detected by a phenomenon in which the signal frequency of the on-board element changes to the resonance frequency of the ground element. Safety can be ensured by operating the brake when a stop is indicated or the speed is exceeded. In the transponder type ATS, a lot of information can be transmitted because digital transmission is performed from the ground element, and efficient train control becomes possible by generating a speed pattern on the upper side of the vehicle. However, the transponder type ATS is more expensive than the variable frequency type ATS, and when the system is updated from the variable frequency type ATS to the transponder type ATS, it becomes necessary to replace all the on-board and ground elements.

Regarding the ground element used in both methods, the conventional ground element is made by winding an electric wire to make a coil, and assembling parts such as a coil, injecting a filler, casting resin for sealing, etc. Manufacture ground coils. As such a technique, a molding method is known in which a casting material, silicone rubber, is injected into a synthetic resin based on polypropylene and having strength to which glass fibers are added, and parts are fixed and integrated to form a ground element. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-127970

By the way, the conventional ground element requires a lot of man-hours as shown in the manufacturing process, and improvement is required from the viewpoint of manufacturing time and manufacturing cost, and the technique of Patent Document 1 also has the same problem. .. That is, the work of injecting the filler of the ground element using the thermosetting resin and the work of casting the sealing resin are all omitted, and the ground element molding process procedure is extremely simplified to start the ground element manufacturing. At the same time as reducing costs, it was required to reduce the weight of the ground element, improve maintainability by using all the parts used as passive parts, and reduce the burden on maintenance workers involved in construction and replacement. ..

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for solving the above problems.

The ground element of the present invention is a ground element having an LC circuit in which a coil and a capacitor are connected, and is provided with only an LC circuit in which a capacitor is mounted on a pattern coil substrate having a pattern coil, and the ground element substrate. The pattern coil has a spiral shape and is formed on the ground element substrate, and in the ground element substrate, the ground element substrate is located at the center of the spiral shape. A through hole is formed so as to penetrate the through hole in the thickness direction, and the outer shell member is formed on both side surfaces of the ground element substrate by embedding the through hole.

According to the present invention, it is possible to realize a technique for reducing the size and weight of a ground element at low cost.

It is a figure which shows the ground element which concerns on this embodiment. It is a figure which shows the ground element substrate which concerns on this embodiment. It is a figure which shows the manufacturing process of the ground element which concerns on this embodiment. It is a figure which shows the manufacturing process of the known ground element which is a comparative example which concerns on this embodiment. It is a figure which shows the ground element substrate which concerns on the modification of this embodiment.

Next, an embodiment for carrying out the present invention (hereinafter, simply referred to as “embodiment”) will be specifically described with reference to the drawings.

1A and 1B are views showing a ground element 1 according to the present embodiment, FIG. 1A shows a plan view, and FIG. 1B shows a front view. The ground element 1 has a rectangular parallelepiped shape, and is formed by an internal ground element substrate 10 and a resin outer shell 40 that covers the ground element substrate 10.

The resin outer shell 40 is formed as an outer shell structure of the ground element substrate 10 by compression molding (SMC molding) of the SMC sheets (first SMC sheet 41, second SMC sheet 42) used in the manufacturing process described later. The SMC sheet is a sheet in which chopped strands are impregnated with a resin paste mixed with a thermosetting resin such as an unsaturated polyester resin, a curing agent, a thickener, an internal mold release agent, a filler, etc., and both sides are covered with a film. This product is made into a sheet by heating it under a predetermined temperature condition to thicken it and improve its handleability. SMC molding is a molding method in which an SMC sheet is put into a mold for press molding and heated under pressure to be cured to obtain a molded product.

2A and 2B are views showing the ground element substrate 10, FIG. 2A is a plan view, FIG. 2B is a front view, and FIG. 2C is a bottom view. The ground element substrate 10 includes a substrate main body 20 which is a plate-shaped printed circuit board, two sets of pattern coils 31 (first and second pattern coils 31a and 31b) provided on the substrate main body 20, and a chip capacitor 32 (first). And second chip capacitors 32a, 32b). The chip capacitor 32 is, for example, a monolithic ceramic capacitor, and has a performance that does not affect the characteristics even if it is left at a temperature of 150 degrees for 1000 hours. The chip capacitor 32 may be a non-chip type capacitor. The plate thickness of the substrate body 20 can be as thin as, for example, about 2 to 5 mm.

Specifically, in the substrate main body 20, two rectangular opening portions 21a and 21b penetrating vertically are formed symmetrically in a front view. In the figure, the first pattern coil 31a is formed in a spiral shape around the opening portion 21a on the right side of the surface 20a. A pair of first chip capacitors 32a is provided on the back surface 20b at a position facing the first pattern coil 31a. The ends of the first pattern coil 31a and the first chip capacitor 32a are connected to each other to form a so-called LC circuit. In the figure, the second pattern coil 31b is formed in a spiral shape around the opening portion 21b on the left side of the back surface 20b. A pair of second chip capacitors 32b are provided on the surface 20a at positions facing the second pattern coil 31b. The ends of the second pattern coil 31b and the second chip capacitor 32b are also connected to form a so-called LC circuit.

The component mounted on the ground element board 10, that is, the component inside the ground element 1, is only a passive component of the pattern coil 31 and the chip capacitor 32, and the failure rate of the ground element 1 can be significantly reduced. ..

FIG. 3 is a diagram showing a manufacturing process of the ground element 1, and the ground element 1 is manufactured by using a press-molded die including an upper die 51 and a lower die 52. First, as shown in the first SMC sheet arranging step of FIG. 3A, the first SMC sheet 41 is arranged in the cavity-shaped recess 54 formed on the upper surface of the lower mold 52.

Next, as shown in the ground element substrate arrangement step of FIG. 3B, the ground element substrate 10 is placed on the first SMC sheet 41. At this time, the recess 54 is formed with a positioning structure so that the ground element substrate 10 can be arranged at a predetermined position.

Subsequently, as shown in the second SMC sheet arranging step of FIG. 3C, the second SMC sheet 42 is arranged on the ground element substrate 10 so as to be sandwiched between the first SMC sheet 41 below the ground element substrate 10.

After the arrangement of the first SMC sheet 41, the second SMC sheet 42, and the ground element substrate 10 is completed, the upper die 51 is lowered to the lower die 52 as shown in the press molding step of FIG. 3 (d), and the convex portion of the upper die 51 is formed. The 53 is fitted into the recess 54 of the lower mold 52 and heated under pressure. The step of pressurizing and heating is a temperature of 140 degrees and a molding time of about 15 to 20 minutes. By this step, the first SMC sheet 41 and the second SMC sheet 42 are formed into a predetermined outer shape, and are fitted into the holes 21a and 21b of the ground element substrate 10, whereby the anchor effect is exhibited.

Finally, as shown in the demolding step of FIG. 3E, the upper die 51 is separated from the lower die 52, and the ground element 1 is taken out from the press molding die (that is, the lower die 52). By these steps, the molding of the ground element 1 is completed.

FIG. 4 schematically shows a manufacturing process of a known ground element as a comparative example. Here, the manufacturing process is shown by the cross-sectional structure of the ground element. In this manufacturing process, as shown in FIG. 4A, first, the resin outer shell (outer shell member) 101 is prepared by press molding or the like. Next, as shown in FIG. 4 (b), the substrate 102 is arranged in the cavity (recess) of the resin outer shell (outer shell member) 101, and as shown in FIG. 4 (c), the filler 103 of the insulating synthetic resin. Inject. The filler 103 is required to cure for about 24 hours. Then, as shown in FIG. 4D, the cured filler 103 is covered with the epoxy resin 104 and sealed. Curing of the epoxy resin 104 requires about 12 hours for the primary curing and about 6 hours for the secondary curing. Finally, as shown in FIG. 4 (e), the epoxy resin 104 is covered with the glass cloth 105 to strengthen the sealing.

As described above, with a known ground element, it takes about two days to manufacture one unit. On the other hand, in the ground element 1 of the present embodiment, as described above, the injection work of the filler and the adhesive is unnecessary, and it takes only about 15 to 20 minutes to manufacture one unit. That is, it is possible to significantly reduce the manufacturing time and to cope with mass production.

Further, in the known ground element, when the same mechanical performance is realized, for example, the size is 280 × 510 × 40 mm and the weight is 5.2 kg, and the size is 250 × 445 × 40 mm and the weight is 6.3 kg. It has been confirmed that the ground element 1 of the present embodiment can be realized as a prototype with a size of 242 x 380 x 15 mm and a weight of about 2.6 kg. In this way, it is possible to significantly reduce the weight and size (particularly thinning the plate). As a result, the degree of freedom in installing the ground element 1 is improved as compared with the conventional case. For example, it can be installed so as to be fitted into a wall surface and integrated. In addition, installation work, replacement / maintenance work can be facilitated, maintenance work load can be reduced, maintenance cost can be reduced, and safety assurance of workers involved in maintenance work can be improved.

The present invention has been described above based on the embodiments. This embodiment is an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of each of these components and processing processes, and that such modifications are also within the scope of the present invention.

For example, instead of the SMC sheet (1st SMC sheet 41, 2nd SMC sheet 42), a mixture of a thermosetting resin such as an unsaturated polyester resin or a filler such as BMC (Bulk Molding Compound) is bulked. The resin outer shell 40 may be formed by press molding using a material.

Further, the LC circuit is not limited to two sets, and may be one set or three or more sets. FIG. 5 shows a ground element substrate 210 of a modified example. 5 (a) is a plan view, FIG. 5 (b) is a front view, and FIG. 5 (c) is a bottom view. As shown in the figure, in this ground element substrate 210, the pattern coil 231 and the chip capacitor 232 are only one set, and the other structures are the same. Specifically, the pattern coil 231 is spirally formed around the surface 220a side of the rectangular opening portion 221 formed in the center of the substrate main body 220. The back surface 220b is provided with a chip capacitor 232 in the left region of the hole 221. This structure forms a set of LC circuits.

1 Ground element 10, 210 Ground element substrate 20, 220 Substrate body 20a, 220a Front surface 20b, 220b Back surface 21a, 21b, 221 Holes (through holes)
31,231 Pattern coil 31a 1st coil pattern 31b 2nd coil pattern 32, 232 Chip capacitor 32a 1st chip capacitor 32b 2nd chip capacitor 40 Resin outer shell (outer shell member)
41 1st SMC sheet 42 2nd SMC sheet 51 Upper die 52 Lower die 53 Convex part 54 Concave part

Claims (1)

A ground element having an LC circuit in which a coil and a capacitor are connected.
A ground element board provided only with an LC circuit in which a capacitor is mounted on a pattern coil board having a pattern coil,
The outer shell member of the resin molding member that covers the ground element substrate and
Have,
The pattern coil has a spiral shape and is formed on the ground element substrate.
In the ground element substrate, a through hole penetrating the ground element substrate in the thickness direction is formed at the center of the spiral shape.
The outer shell member is a ground element formed on both side surfaces of the ground element substrate by embedding the through hole.

Images