INSULATING SPACER

Abstract

An insulating spacer comprises a conical spacer body that supports a central conductor, is positioned around the central conductor, and has an axial direction identical to that of the central conductor. The spacer body includes a concave surface forming section, which creates a conical concave surface, and a convex surface forming section, which creates a conical convex surface. In the concave surface forming section, the relative permittivity is specified such that it gradually decreases in the direction of inclination from the side of the central conductor to the intermediate section within the conical shape, while the relative permittivity remains constant from the intermediate section to the outer circumferential edge.In the convex surface forming section, the relative permittivity is set such that it is constant from the side of the central conductor to the intermediate region in the inclination direction, while the relative permittivity is set such that it gradually increases from the intermediate region to the side of the outer circumferential edge.

Description

GENERAL STATE OF THE ART 1. TECHNICAL AREA The present invention relates to an insulating spacer. 2. DESCRIPTION OF THE STATE OF THE ART JP 2005-327580 A discloses a conical insulating spacer that is fixed inside a grounded tank filled with an insulating gas and divides the interior of the grounded tank. The insulating spacer of JP 2005-327580 A is formed from a conductor and an insulator. Since such an insulating spacer must exhibit high dielectric strength properties, it is necessary to reduce the electric field concentration near the triple connection of the insulator, the insulating gas, and the conductor or the grounded tank. BRIEF SUMMARY OF THE INVENTION In document JP 2005-327580 A, an insulating spacer insulator has multiple layers with different dielectric constants. These layers are stacked sequentially in descending order of dielectric constant from the through-tube to the grounded tank to create a compact gas insulation device and maintain insulation reliability. However, the insulating spacer offers potential for improvement in reducing the electric field strength near the aforementioned triple point to maintain favorable insulation reliability. The present invention was made in light of these circumstances, and one object of the present invention is to provide an insulating spacer that can maintain favorable insulation reliability. An insulating spacer according to one aspect of the present invention is an insulating spacer comprising a conical spacer body which supports a central conductor and is provided around the central conductor and has an axial direction identical to an axial direction of the central conductor, wherein the spacer body comprises a concave surface side-forming section forming a concave surface of the cone shape and a convex surface side-forming section forming a convex surface of the cone shape;wherein the concave surface-facing section has a relative permittivity that is set to gradually decrease from the side of the central conductor to an intermediate region in one inclination direction of the cone shape, while the relative permittivity is set to be constant from the intermediate region to one side of an outer circumferential edge; and the convex surface-facing section has a relative permittivity that is set to be constant from the side of the central conductor to the intermediate region, while the relative permittivity is set to gradually increase from the intermediate region to the side of the outer circumferential edge. According to the present invention, it is possible to reduce the electric field strength near the triple point of the spacer body, the insulating gas, the center conductor and the like, and to maintain favorable insulation reliability. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of a switchgear assembly according to one embodiment; Fig. 2 is a diagram showing the perimeter of an insulating spacer as a conceptual model; Fig. 3A is an explanatory view of a change in the relative permittivity in the insulating spacer of Example 1, and Fig. 3B is an explanatory view of a change in the relative permittivity in the insulating spacer of Example 2; Fig. 4A is an explanatory view of a change in the relative permittivity in the insulating spacer of Comparative Example 1, and Fig. 4B is an explanatory view of a change in the relative permittivity in the insulating spacer of Comparative Example 2; and Fig. 5 is a diagram showing results of the electric field strength analysis for each example and each comparative example. DETAILED DESCRIPTION Before describing an embodiment of the present invention, the background that led to the embodiment of the present invention will be described. It is known that a conventional gas-insulated switchgear uses a design in which a high-voltage conductor is arranged within a sealed metal container. In such a gas-insulated switchgear, a fixed insulator, referred to as an insulating spacer, is used to fix the high-voltage conductor in a predetermined position within the sealed container. Traditionally, the high-voltage conductor is provided in a central area of ​​a commonly used disc-shaped insulating spacer, which supports the conductor. The insulating spacer, inserted between the coupling flanges of the sealed container, is fitted with a metal flange and fixed to the sealed container by this flange. In recent years, higher demands have been placed on cost-effectiveness, leading to a desire for compact gas-insulated switchgear. With conventional insulating spacers, the electric field concentration in a gas space, due to differences in dielectric constant between an insulating gas containing SF6 as its main component and a solid insulator, compromises compactness. To achieve compactness, investigations have therefore been conducted to reduce the electric field of a creepage component on the surface of the conical insulating spacer by modifying the dielectric constant of the spacer along its axis. Since SF6 has an extremely high global warming potential (GWP) of 25,300, its replacement with compressed air (dry air, synthetic air), which contains no SF6, has recently begun.Since the insulating capacity in this case is only about 30% of that of SF6, the size of the device increases, so it is necessary to prevent such an increase in size. In such a conical insulating spacer, an insulator with a dielectric constant is used that decreases from the section in contact with the high-voltage conductor towards the grounding side. Simultaneously, the compactness of such an insulating spacer must be improved, and the reduction of the electric field strength at the interface between the insulator and the insulating gas must be further enhanced. With reference to the accompanying drawings, a gas-insulated switchgear assembly (hereinafter simply referred to as "switchgear") which uses an insulating spacer according to an embodiment of the present invention will be described in detail below. It should be noted that the present invention is not limited to the following embodiments, but can be suitably modified within a scope that does not deviate from its core. In the following drawings, some components may have been omitted for the sake of simplicity. Fig. 1 is a sectional view of a switchgear assembly according to one embodiment. As shown in Fig. 1, a switchgear assembly 1 comprises a sealed container 2, an insulating spacer 3 fixed in the sealed container 2, and high-voltage conductors 4 (shown by double-dotted lines) arranged on both sides of the center of the insulating spacer 3. The sealed container 2 is filled with dry air or SF6 gas as insulating gas G. A metal flange 6 is attached to an outer circumferential edge region of the insulating spacer 3, and the insulating spacer 3 is fixed to the sealed container 2 by inserting the metal flange 6 between coupling flanges 7 of the sealed container 2. The insulating spacer 3 has a central conductor 11, which is columnar in shape, and a spacer body 12, which supports the central conductor 11 and is provided around it. The spacer body 12 is conical in shape, with the direction of an axis A being the same as that of the central conductor 11. The axis A is the central axis position of the central conductor 11 and the spacer body 12, and the direction of the central axis and the direction of axis A are the same. Fig. 1 is a sectional view along a plane parallel to axis A, through which axis A passes. The spacer body 12 is designed in a conical shape such that, in the direction of axis A, one surface is formed as a convex surface C and the other surface as a concave surface R. The spacer body 12 has a chamfered shape on the concave surface R and the convex surface C. In the present description and the claims, the "direction of inclination" means the direction of the chamfered surface between the side of the spacer body 12 located on the central conductor 11 and the side of an outer circumferential edge 12a of the spacer body 12 in a sectional view as shown in Fig. 1. It should be noted that the shapes of the central conductor 11 and the spacer body 12 shown in the drawings are only schematic for ease of understanding, and the dimensions, thickness, and the like can be modified as needed in the direction of axis A, the radial direction, and the inclination. Furthermore, the design of the insulating spacer 3 of the present embodiment can be applied to an insulating manifold spacer for three phases, although the design of a single-phase type is shown here. In the insulating manifold spacer for three phases, the number of central conductors 11 is changed to three, and the passage area of ​​each of these three central conductors 11 in the spacer body is formed in a conical shape. The spacer body 12 has a concave surface forming section 13, which forms the concave surface R of the cone shape, and a convex surface forming section 14, which forms the convex surface C of the cone shape. The concave surface forming section 13 forms a region of predetermined thickness within the spacer body 12, extending from the concave surface R to the convex surface C, and encompasses the concave surface R. The convex surface forming section 14 forms a region of predetermined thickness within the spacer body 12, extending from the convex surface C to the concave surface R, and encompasses the convex surface C. The concave surface forming section 13 and the convex surface forming section 14 can be adjacent to each other within the thickness of the spacer body 12 or separated from each other by at least one intervening forming section. Here, the spacer body 12 has a relative permittivity that provides a predetermined electric field strength distribution in the concave surface forming section 13 and the convex surface forming section 14. The modeling and analysis for determining the relative permittivity were carried out as shown in Fig. 2. Fig. 2 is a diagram showing the perimeter of an insulating spacer as a conceptual model. In the model of Fig. 2, a cross-section of one half of the insulating spacer 3 is shown from axis A, with the outline of the area corresponding to the conical spacer body 12 represented by solid lines. A left end of the spacer body 12 in Fig. 2 extends straight in the vertical direction, and an area on the left side of the left end is a high-voltage region HV corresponding to the central conductor 11 and the high-voltage conductor 4, to which a predetermined voltage is applied. An outer circumferential edge 12a (the right end in Fig. 2)2) of the spacer body 12 also extends in a straight line in the vertical direction, and an area on the right side of the outer circumferential edge 12a is designated as the earth potential area GND, which corresponds to the sealed container 2 and is set to earth potential. Furthermore, the spacer body 12, in the cross-section through which the central axis (axis A) of the cone shape in Fig. 2 passes, is divided into a virtual boundary S in the inclination direction, located at the midpoint of the inclination direction, and a virtual boundary T in the thickness direction, located midway between the concave surface R and the convex surface C. More precisely, the spacer body 12 is formed such that it has a first to fourth region 21 to 24, which are separated by the virtual boundary S in the inclination direction and the virtual boundary T in the thickness direction. In the direction of axis A, a ratio h1:h2 is defined between a distance from the virtual boundary T in the thickness direction to the concave surface R of the spacer body 12 and a distance from the virtual boundary T in the thickness direction to the concave surface C. The ratio h1:h2 is set to 1:1 at the position shown in Fig. 2, but can be set to various other ratios, for example 4:1. Regarding the position of the virtual boundary S shown in Fig. 2 in the direction of inclination, the virtual boundary S is located at the midpoint between the interface with the central conductor 11 of the spacer body 12 and the outer circumferential edge 12 in the direction of inclination. Therefore, r1:r2, the ratio between the distance from the virtual boundary S in the direction of inclination to the outer surface of the high-voltage conductor 4 and the distance from the virtual boundary S in the direction of inclination to the inner surface of the sealed container 2, is fixed at 1:1 in the lateral direction of Fig. 2 (the radial direction of the spacer body 12). However, the virtual boundary S in the direction of inclination can be modified so that it is shifted towards the side of the central conductor 11 or towards the side of the outer circumferential edge 12a.It should be noted that the virtual limit S in the inclination direction and the virtual limit T in the thickness direction are virtual positions to determine a region in which the relative dielectric constant is fixed as described later, but the formation of an interface or the like is not necessarily required. Of the regions separated by boundaries S and T, a first region 21 forms the side of the concave surface R in the direction of axis A and the side of the central conductor 11 in the direction of inclination. Of the regions separated by boundaries S and T, a second region 22 forms the side of the concave surface R in the direction of axis A and the side of the outer circumferential edge 12a in the direction of inclination. Of the regions separated by boundaries S and T, a third region forms the side of the convex surface C in the direction of axis A and the side of the outer circumferential edge 12a in the direction of inclination. Of the regions separated by boundaries S and T, a fourth region 24 forms the side of the convex surface C in the direction of axis A and the side of the central conductor 11 in the direction of inclination. The first region 21 and the third region 23 in the spacer body 12 have a structure in which the relative permittivity changes (tilts) in the direction of inclination. Here, the relative change in the relative permittivity is shown in Fig. 2 and the subsequently described Figs. 3 and 4 by shading to facilitate understanding, and it is indicated that the relative permittivity is higher in a relatively darker shaded area than in a relatively lighter shaded area. In the first region 21, the relative permittivity is higher in a region represented by the dark shading, which is close to the central conductor 11, than in a region represented by the light shading, which is close to the virtual boundary S in the direction of inclination. Therefore, the relative permittivity of the first region 21 is arranged such that it gradually decreases from the side of the central conductor 11 (the high-voltage region HV) to the virtual boundary S in the direction of inclination. In the third region 23, the relative permittivity is higher in a region represented by the dark shading, which lies close to the outer circumferential edge 12a of the spacer body 12, than in a region represented by the light shading, which lies close to the virtual boundary S in the inclination direction. Therefore, the relative permittivity of the third region 23 is arranged such that it gradually decreases from the side of the outer circumferential edge 12a (the earth potential) to the virtual boundary S in the inclination direction. The second region 22 and the fourth region 24 have a structure in which the shading in white (the paper color) in Fig. 2 does not change and the relative permittivity remains constant. The relative permittivity of the second region 22 corresponds to the relative permittivity of the virtual boundary S in the inclination direction in the first region 21. The relative permittivity of the fourth region 24 corresponds to the relative permittivity of the virtual boundary S in the inclination direction in the third region 23. By adjusting the relative permittivity of the first to fourth regions 21 to 24 as described above, the relative permittivity of the spacer body 12 on the side of the central conductor 11 on the side of the concave surface R is relatively higher than on the side of the convex surface C. Furthermore, the relative permittivity of the spacer body 12 on the side of the outer circumferential edge 12a on the side of the convex surface C is relatively higher than on the side of the concave surface R. In the model of the insulating spacer 3 in Fig. 2, the concave surface-facing section 13 can be formed by the first region 21 and the second region 22, and the convex surface-facing section 14 can be formed by the third region 23 and the fourth region 24. Therefore, the relative permittivity of the concave surface-facing section 13 of the spacer body 12 is such that it gradually decreases from the side of the central conductor 11 to the virtual boundary S in the inclination direction, which is the intermediate region in the inclination direction, while the relative permittivity is constant from the virtual boundary S in the inclination direction to the side of the outer circumferential edge 12a.Furthermore, the relative dielectric constant of the convex surface forming section 14 is set such that it is constant from the side of the central conductor 11 to the virtual boundary S in the inclination direction, which is the intermediate region in the inclination direction, while the relative dielectric constant gradually increases from the virtual boundary S in the inclination direction to the side of the outer circumferential edge 12a. Regarding the model of Fig. 2, in the construction of the insulating spacer 3, the positions of the spacer body 12 indicated by the dashed lines can represent the virtual boundary S in the inclination direction and the virtual boundary T in the thickness direction. Thus, the spacer body 12 can be formed such that it has the first to fourth regions 21 to 24, which are separated by the virtual boundary S in the inclination direction and the virtual boundary T in the thickness direction. Therefore, in the spacer body 12 of Fig. 2, the concave surface forming section 13 can be formed by the first region 21 and the second region 22, and the convex surface forming section 14 can be formed by the third region 23 and the fourth region 24. As an example of a method for manufacturing the insulating spacer 3, the manufacturing method disclosed in JP 2024-31901 A can be cited. In this manufacturing method, the spacer body 12 is formed such that it has a lattice section, which is configured in a three-dimensional mesh shape, and a solid section, which is arranged in a solid state within an interior space of the lattice section. The solid section is formed by injecting an insulating resin into the interior space of the lattice section, and the relative dielectric constant of the solid section is significantly lower than that of the lattice section.Therefore, the relative dielectric constants of the concave surface-face formation section 13 and the convex surface-face formation section 14 can be changed by changing the ratio of the lattice section and the solid section per unit volume in the spacer body 12 as described above. As another example of a method for manufacturing the insulating spacer 3, a method disclosed in JP 2024-31261 A can be cited. In this manufacturing method, the conical spacer body 12 is formed by winding a prepreg in a ribbon form around the central conductor 11. The prepreg before winding consists of a nonwoven fabric as the base material and is formed by applying an insulating resin containing a filler material to the nonwoven fabric by means of a coating device or the like, thereby impregnating it. The insulating resin is in a liquid or semi-cured state at the time of winding and can be a thermosetting resin containing a filler material. Furthermore, before winding the ribbon-shaped prepreg, at least one of the composition and quantity of the filler material contained in the thermosetting resin is regulated such that a region is formed in which the relative dielectric constant of the spacer body 12 increases, decreases, or remains constant as described above. In the spacer body 12, which is formed by winding the prepreg in a conical shape, the relative dielectric constants of the concave surface-facing section 13 and the convex surface-facing section 14 can be modified as described above. As a further example of the method for manufacturing the insulating spacer 3, a manufacturing process can be mentioned in which the spacer body 12 is produced using a 3D manufacturing device. The 3D manufacturing device is also referred to as a 3D printer or the like and is a device that produces a three-dimensional object by layering cross-sectional shapes based on 3D data. The manufacturing process of the 3D manufacturing device can be any method, such as a fused deposition modeling process, in which a resin material is ejected from a nozzle and stacked and shaped, or an optical manufacturing process, in which a liquid resin is solidified by means of UV radiation.By adjusting the data structure of the 3D data, the relative dielectric constants of the concave surface forming section 13 and the convex surface forming section 14 in the spacer body 12 can be changed as described above. EXAMPLES Next, with reference to Fig. 3 and Fig. 4, Examples 1 and 2, in which different setup conditions were established in the above embodiment and an electric field analysis was carried out, and comparative Examples 1 and 2 are described below. Fig. 3A is an explanatory view of a change in the relative permittivity in the insulating spacer of Example 1, and Fig. 3B is an explanatory view of a change in the relative permittivity in the insulating spacer of Example 2. Fig. 4A is an explanatory view of a change in the relative permittivity in the insulating spacer of Comparative Example 1, and Fig. 4B is an explanatory view of a change in the relative permittivity in the insulating spacer of Comparative Example 2. In Fig. 3A, Fig. 3B, Fig. 4A, and Fig. 4B, a spacer body 12, modeled in the same way as in Fig. 2, is shown, and a diagram is shown below the spacer body illustrating the relationship between the position of the spacer body 12 in the direction of inclination and the relative permittivity.In the diagram of each drawing, the horizontal axis represents the position in the inclination direction of the spacer body 1, and the vertical axis represents the relative permittivity. It should be noted that in the models of comparative examples 1 and 2 in Fig. 4A and Fig. 4B, the setups corresponding to the respective examples are labeled with the same reference numerals. [Example 1] In the spacer 12 shown in Fig. 3A, the relative permittivity was varied (tilted) in the first region 21 and the third region, similar to the setup shown in Fig. 2 of the embodiment described above. The maximum and minimum values ​​of the relative permittivity were set to 12 and 4, respectively. In the second region 22 and the fourth region 24, the relative permittivity was kept constant at 4. In Example 1, the distance r from the outer surface of the high-voltage conductor 4 of the spacer body 12 to the inner surface of the sealed container 2 was set to 65 mm, and the position of the virtual boundary S in the inclination direction was set such that r1:r21:1. The thickness t of the spacer body 12 in the direction of axis A was set to 65 mm, 85 mm, and 105 mm, and the position of the virtual boundary t in the thickness direction was set such that h1:h21:1. A voltage of 100 kV was applied between the high-voltage area HV and the earth potential area GND. Since the electric field strength is particularly high in the areas of the ellipses indicated by dashed lines in Fig. 2, the positions at which the electric field strength analysis is performed are the analysis points P1 and P2 shown in Fig. 2. More precisely, analysis point P1 was positioned a distance d along axis A from the triple point where the concave surface R, the insulating gas G, and the high-voltage region HV overlap, while the concave surface R of the spacer body 12 forms an acute angle with the high-voltage region HV. Analysis point P2 was positioned a distance d along axis A from the triple point where the convex surface C, the insulating gas G, and the ground potential region GND overlap, while the convex surface C of the spacer body 12 forms an acute angle with the ground potential region GND.At each of the analysis points P1 and P2, a stable analysis result was obtained by setting the distance d to 1 mm, while approaching the triple point where the electric field strength was maximum. Under the conditions described above, a general three-dimensional electric field analysis was performed using the finite element method (FEM) as an example to determine the dielectric relaxation effect. This electric field analysis using the finite element method can be carried out, for example, with commercially available simulation software. Figure 5 shows the results of the electric field strength analysis at the analysis points P1 and P2 for thicknesses t set to 65 mm, 85 mm, and 105 mm. [Example 2] In the spacer body 12 of Example 2, shown in Fig. 3B, the position of the virtual boundary T in the thickness direction was changed from that in Example 1, and h1:h2 was set to 4:1, while the other conditions corresponded to those of Example 1. Fig. 5 is a diagram showing the result of the electric field strength analysis. [Comparison example 1] In comparison example 1, shown in Fig. 4A, the relative permittivity of the spacer body 12 was modified from that of example 1. In comparison example 1, the relative permittivity was kept constant at 4 in all four sections 21 to 24 from the first to fourth region, while the other conditions were the same as in example 1. Fig. 5 is a diagram showing the result of the electric field strength analysis. [Comparative example 2] In Comparative Example 2, shown in Fig. 4B, the relative permittivity values ​​of the second region 22 and the fourth region 24 in the spacer body 12 were modified (tilted) from those in Example 1. In the second region 22 of Comparative Example 2, the relative permittivity was set so that it gradually decreased towards the virtual boundary S in the direction of the tilt. In the fourth region 24 of Comparative Example 2, the relative permittivity was set similarly to the first region 21, so that it gradually decreased towards the virtual boundary S in the direction of the tilt. Also in the second region 22 and the fourth region 24 of Comparative Example 2, the maximum value of the relative permittivity was set to 12 and the minimum value to 4. The other conditions were the same as in Example 1. Fig. 5 is a diagram showing the result of the electric field strength analysis. Figure 5 is a diagram showing the results of the electric field strength analysis for each example and its respective comparison example. As shown in the diagram in Figure 5, it was confirmed for Example 1 that at analysis point P1, compared to comparison example 1, a dielectric relaxation effect of at most approximately 8.3% (thickness t: 105 mm) and at least approximately 4.0% (thickness t: 65 mm) was obtained. Furthermore, it was confirmed for Example 1 that at analysis point P2, compared to comparison example 1, a dielectric relaxation effect of at most approximately 11.9% (thickness t: 105 mm) and at least approximately 3.6% (thickness t: 65 mm) was obtained. In Example 1, it was confirmed that at analysis point P1, compared to comparison example 2, a dielectric relaxation effect of at most approximately 7.2% (thickness t: 105 mm) and at least approximately 0.5% (thickness t: 65 mm) was obtained. Furthermore, in Example 1, it was confirmed that at analysis point P2, compared to comparison example 2, a dielectric relaxation effect of at most approximately 15.2% (thickness t: 105 mm) and at least approximately 4.3% (thickness t: 65 mm) was obtained. The above analysis results show that by adjusting the relative dielectric constant of the spacer body 12 as in Example 1, compared with the individual comparison examples, it is possible to achieve a dielectric breakdown resistance in the insulating gas and maintain favorable insulation reliability. In particular, it was confirmed that an improved dielectric relaxation effect can be obtained with an increase in the thickness t of the spacer body 12. In example 2, at the analysis point P1, compared to comparison example 1, a dielectric relaxation effect of a maximum of approximately 16.4% (thickness t: 105 mm) and at least approximately 13.3% (thickness t: 65 mm) was obtained, and compared to comparison example 2, a dielectric relaxation effect of a maximum of approximately 15.4% (thickness t: 105 mm) and at least approximately 10.1% (thickness t: 65 mm) was obtained. On the other hand, the electric field strength at the analysis point P2 increased by about 8.4% to 11.6% compared to comparison example 1, and the electric field strength increased by about 4.5% to about 10.7% compared to comparison example 2. The above analysis results show that by adjusting the relative dielectric constant of the spacer body 12 as in Example 1, compared with the individual comparison examples, it is possible to produce a dielectric breakdown resistance in the insulating gas at analysis point P1 and maintain favorable insulation reliability. At analysis point P2, the electric field strength is lower in each comparison example than in Example 2. However, in Example 2, the electric field strength at analysis point P1 can be significantly reduced compared with each of the comparison examples, and if the potential applied to the central conductor 11 is the same, analysis point P1 generally exhibits a higher electric field than analysis point P2.Therefore, a reduction of the electric field at analysis point P1 on the high-voltage (HV) side is more necessary than at analysis point P2 on the ground potential (GND) side. Consequently, in a comprehensive evaluation compared to any other example, Example 2 can exhibit a dielectric breakdown resistance in the insulating gas and maintain favorable insulation reliability. It should be noted that the present invention is not limited to the embodiments and examples above, but can be implemented with various modifications. In the embodiments above and the like, the size, shape, orientation, and the like, illustrated in the accompanying drawings, are not limited to these, but can be modified appropriately within a scope that preserves the effects of the present invention. Other modifications can be made and implemented as appropriate without departing from the scope of the present invention. In the above embodiment, a case was described in which the analysis of the electric field was carried out using the finite element method; however, the analysis method is not limited to a specific method, but the analysis of the electric field can be carried out, for example, using a method such as the difference method or the surface charge density method. Furthermore, the values ​​of the relative permittivity εr, the thickness t and the distance d described above for Examples 1 and 2 are merely examples that can be changed as appropriate depending on the different conditions. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature JP 2005-327580 A [0002, 0003]JP 2024-31901 A

[0033] JP 2024-31261 A

[0034]

Claims

Insulating spacer comprising a conical spacer body supporting a central conductor and provided around the central conductor, having an axial direction identical to an axial direction of the central conductor, wherein the spacer body has a concave surface forming section forming a concave face of the cone shape and a convex surface forming section forming a convex face of the cone shape, wherein the concave surface forming section has a relative dielectric constant that is defined to gradually decrease from the side of the central conductor to an intermediate region in an inclination direction of the cone shape, while the relative dielectric constant is defined to be constant from the intermediate region to a side of an outer circumferential edge.and the convex surface forming section has a relative permittivity that is set to be constant from the side of the central conductor to the intermediate region, while the relative permittivity is set to gradually increase from the intermediate region to the side of the outer circumferential edge. Insulating spacer according to claim 1, wherein the side of the spacer body at the central conductor has a relative dielectric constant which is higher on the side of the concave surface than on the side of the convex surface, and the side of the spacer body at the outer circumferential edge has a relative dielectric constant which is relatively higher on the side of the convex surface than on the side of the concave surface. Insulating spacer according to claim 1 or 2, wherein the spacer body is formed such that it has, in a cross-section through which the central axis of the cone shape passes, a first to fourth region which are separated by a virtual boundary in an inclination direction, which is located at an intermediate region in the inclination direction, and a virtual boundary in a thickness direction, which is located at an intermediate region between the concave surface and the convex surface, wherein the first region in the axial direction forms the side of the concave surface and in the inclination direction the side of the central conductor and has a relative dielectric constant which gradually decreases from the side of the central conductor to the virtual boundary in the inclination direction.The second region forms the side of the concave surface in the axial direction and the side of the outer circumferential edge in the inclined direction, and has a relative permittivity that is constant at the virtual boundary in the inclined direction in the first region. The third region forms the side of the convex surface in the axial direction and the side of the outer circumferential edge in the inclined direction, and has a relative permittivity that gradually decreases from the side of the outer circumferential edge to the virtual boundary in the inclined direction. The fourth region forms the side of the convex surface in the axial direction and the side of the central conductor in the inclined direction, and has a relative permittivity that is constant at the virtual boundary in the inclined direction in the third region. Insulating spacer according to claim 3, wherein the ratio of the distance of the concave surface from the virtual boundary in the thickness direction and the distance of the convex surface from the virtual boundary in the thickness direction in the axial direction is set to 4:

1. Insulating spacer according to claim 3, wherein the ratio of the distance of the concave surface from the virtual boundary in the thickness direction and the distance of the convex surface from the virtual boundary in the thickness direction in the axial direction is set to 1:1.

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