JPS6330772B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of securing a linear motor ground-mounted coil to a ground structure.

The ground-mounted coil of a linear motor is a coil that is attached to a track laid on the ground and uses electromagnetic force to drive a vehicle. Since such ground-mounted coils are used while being attached to the track, they are exposed to all weather conditions and are also affected by electromagnetic forces generated by on-vehicle coils. Therefore, in order to withstand these harsh conditions, a molded coil whose exterior is robustly molded with a mode material is generally used as a ground-installed coil.

FIGS. 1 and 2 show the structure of such a conventional ground-installed coil. The ground-installed coil 1 includes a coil conductor 2 in which a conductor is wound in a rectangular shape with multiple turns, and an insulating structure material 3 that is coated around the coil conductor 2 and has excellent weather resistance, water resistance, and mechanical strength.
It is made up of. Note that this insulating structure material 3 has a tapered surface 4 on its side surface. As this insulating structure material 3, sheet molding compound (hereinafter referred to as SMC), resin concrete, or epoxy mold is used.

The above-mentioned SMC is a semi-cured sheet made by mixing a thermosetting resin, such as an unsaturated polyester resin, with rectangular glass fibers, powder filler, catalyst, internal mold release agent, pigment, thickener, etc. The resin concrete is a mixture of thermosetting resin, for example, unsaturated polyester resin, with gravel and sand. Furthermore, the above-mentioned epoxy mold is a mixture of an epoxy resin, a curing agent, and a powder filler.

Conventionally, the ground-installed coil 1 having such a structure is
As shown in FIG. 3, it was directly buried and fixed in an above-ground structure 5. However, since aluminum is often used as the material for the coil conductor 2 and the ground structure 5 is made of concrete, the linear expansion coefficients of the ground installed coil 1 and the ground structure 5 are different. For this reason, there was a high risk that the ground-installed coil 1 or the ground structure 5 would be destroyed due to thermal stress due to temperature changes or temperature increases due to solar radiation.

Therefore, a method has been proposed in which a spacer is inserted between the ground installed coil 1 and the ground structure 5 to alleviate the thermal stress generated between the ground installed coil 1 and the ground structure 5. However, with this method, it is necessary to taper the side surface of the insulating structure material 3 at an angle of 10 to 25 degrees, so the wall thickness of the insulating structure material 3 at the bottom becomes much larger than at the top (for example, when the coil height is 90 mm) In the case of , the difference in wall thickness between the top and bottom is 16~
42mm). Therefore, the wall thickness becomes extremely non-uniform, and cracks are likely to occur in the insulating structural material 3, and there are disadvantages in that the material of the insulating structural material 3 is wasted.

Here, the reason why the side surface of the insulating structure material 3 is tapered at an angle of 10 to 25 degrees is that in the event of an accident, the spacer is removed from the ground structure 5 and the ground installation coil 1 is attached to the ground structure 5. This is so that it can be taken out from the groove.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, an object of the present invention is to provide a method for fixing a coil installed on the ground, which prevents the occurrence of cracks in the insulating structural material and eliminates waste of materials.

The above object of the present invention is achieved by using a ground coil for levitation as a ground installation coil, since the operating voltage is low and the electromagnetic force that the coil receives is much smaller than that of a ground coil for propulsion and guidance. Focusing on the fact that the probability of this occurring is extremely low and it is almost impossible to take out the ground-mounted coil from the groove of the ground structure, we developed a flexible resin as a spacer material between the ground-mounted coil and the ground structure. This is achieved by using an impregnated laminate and by reducing the angle of the tapered portion provided on the side surface of the insulating structure material.

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

FIG. 4 is a cross-sectional view showing an embodiment of the ground-installed coil fixing method according to the present invention. However, similar or identical components to those in FIGS. 1 to 3 are indicated using the same reference numerals.

The ground-installed coil 1 includes a coil conductor 2 formed by winding a conductor into a rectangular shape with a plurality of turns, and an insulating structural material 3 having a tapered surface 4 on the side surface molded around the coil conductor 2. The ground-installed coil 1 having such a structure is buried between the above-ground structure 5 and a spacer 6 made of a flexible resin-impregnated laminate. Note that the flexible resin laminate is manufactured by using a polyester nonwoven fabric as a base material, impregnating it with a flexible epoxy resin, and then thermoforming it.

FIG. 5 shows another embodiment of the present invention, in which similar or identical components to those in FIG. 4 are indicated using the same reference numerals. The feature of this embodiment is that a protrusion 7 is provided on the spacer 6 in order to make it difficult for the spacer 6 to slip out from the ground structure 5, and the other configurations are the same as those of the previous embodiment.

The feature of the above embodiment is that the spacer 6 is made of a flexible resin-impregnated laminate having appropriate hardness and excellent wear resistance. I will explain why.

Generally, when a spacer is buried between a ground-installed coil and a ground structure, the stress σ generated at the end of the coil can be approximated by the following equation.

σ=( _α1 − _α2 )×ΔT× _E1 /2× _A1 × _E1 ×t/ _A3 × _E3
×l+1……(1) However, α ₁ is the linear expansion coefficient of the coil, α ₂ is the linear expansion coefficient of the aboveground structure, ΔT is the amount of temperature change since the coil was buried, and E ₁ is the average longitudinal elastic modulus of the coil. , E ₃ is the longitudinal elastic modulus of the spacer in the thickness direction, A ₁ is the cross-sectional area of the coil,
A ₃ is the area of the spacer subjected to thermal stress, t is the thickness of the spacer, and l is the length of one side of the coil. The denominator value on the right side of equation (1) is always greater than 1, and the smaller E ₃ is compared to E ₁ or the larger the spacer value t, the larger the denominator value becomes. σ becomes smaller.

On the other hand, since the adhesive force between the ground structure 5 and the ground installation coil 1 and spacer 6 buried therein is extremely small, when a force is applied in the x direction in FIG. There is a risk that the ground-installed coil 1 will fall off the ground structure 5. Furthermore, even if θ≠0 degrees, there is a risk that the spacer 6 sandwiched between the ground-installed coil 1 and the ground structure 5 will deform and the coil will move relative to the ground structure 5. The amount of movement δ in the x direction can be expressed by the following equation.

δP×t×cosδ/2×L×h×E ₃ ×sin ² θ……(2) However, P is the force applied to the entire coil in the x direction, θ
is the angle of the tapered portion, L is the total length of the coil center line, and h is the height of the coil. As the angle θ of the tapered part increases in the range of 0 degrees < θ < 90 degrees, cos θ decreases and sin θ increases, so Equation (2)
It can be seen that the amount of movement δ shown in is smaller as θ becomes smaller. Furthermore, it can be seen that as E ₃ increases, δ decreases.

Therefore, if the taper angle is made smaller according to equations (1) and (2), the amount of movement δ will increase, causing an abnormality in the running system. Furthermore, if the elastic modulus E ₃ in the thickness direction of the spacer 6 is too large, the amount of movement δ becomes small, but the thermal stress σ generated in the coil becomes large. Conversely, if the spacer's elastic modulus E ₃ in the thickness direction is made smaller, the stress σ generated in the coil becomes smaller, but the amount of movement δ increases, so the longitudinal elastic modulus E ₃ of the spacer 6 in the thickness direction becomes a moderate value. There is a need to.

Based on the above considerations, rubber with a cushioning effect can be considered as the material for the spacer 6, but rubber is usually very soft with a longitudinal elastic modulus of about 0.2 kg/mm ² .
There is a concern that the repeated application of electromagnetic force will cause gradual wear. To prevent this wear,
It is possible to use hard rubber such as nitrile rubber or urethane rubber, but the former has poor ozone and acid resistance, and the latter has weak acid and alkali resistance, so it cannot be used in all weather conditions. For this reason, flexible resin-impregnated laminates have been used as spacer materials that have appropriate hardness and can be used in all weather conditions.

According to this embodiment, a spacer 6 made of a flexible resin-impregnated laminate having appropriate hardness and excellent wear resistance is sandwiched between the ground-installed coil 1 and the ground structure 5. The angle of the taper portion provided on the side surface of the insulating structure material 3 can be made smaller, which has the effect of improving crack resistance and reducing waste of the material of the insulating structure material 3.

As is clear from the above description, according to the present invention, by interposing a spacer made of a flexible resin-impregnated laminate between the ground-installed coil and the ground structure, cracks in the insulating structure material can be prevented. In addition, it is possible to provide a ground-installed coil fixing method that eliminates waste of materials.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional ground-mounted coil;
The figure is a cross-sectional view of FIG. 1, FIG. 3 is a cross-sectional view showing a state in which a ground-installed coil is fixed to a ground structure according to the prior art, and FIG. 4 is an implementation of the ground-installed coil fixing method according to the present invention. Cross-sectional view showing an example, No. 5
The figure is a cross-sectional view showing another embodiment of the method for fixing a ground-installed coil according to the present invention. 1...Ground installation coil, 2...Coil conductor, 3
...Insulating structural material, 4...Tapered surface, 5...Ground structure, 6...Spacer, 7...Protrusion.

Claims (1)

[Claims] 1. In a ground-installed coil fixing method in which a ground-installed coil for levitation of a linear motor in which a rectangular coil conductor is coated with an insulating structure material is fixed to a groove of a ground structure via a spacer, a flexible resin-impregnated laminate is used as a spacer material. A ground-installed coil fixing method characterized by using a plate.