JP5959136B1 - Seeds heater, load test equipment - Google Patents

Abstract

To provide a sheathed heater that can easily maintain the connection between the heater terminal and the resistance wire. The sheathed heater (resistor R) includes a cylindrical portion 67, a resistance wire 61 disposed inside the cylindrical portion 67, and heater terminals 63 connected to both ends of the resistance wire 61. The heater terminal 63 has a male thread shape for screwing with the nut 66, a first end portion 63 a that is partially exposed from the cylindrical portion 67, and a columnar shape that is partially wrapped around the resistance wire 61. A flat surface portion 63a2 perpendicular to one of the radial directions of the first end portion 63a is provided on the side surface of the distal end portion of the first end portion 63a and exposed from the cylindrical portion 67, which has two end portions 63b. .

Description

  The present invention relates to a sheathed heater and a load test apparatus including the sheathed heater.

  Conventionally, as in Patent Document 1, a sheathed heater used in a load test apparatus or the like has been proposed.

JP 2010-255752 A

  Since the heater terminal of the sheathed heater is usually formed in a substantially cylindrical shape including the male screw part, if the nut is tightened too much, the male screw part may rotate and the connection state between the heater terminal and the resistance wire may be broken. is there.

  Accordingly, an object of the present invention is to provide a sheathed heater or the like that can easily maintain a connection state between a heater terminal and a resistance wire.

  The sheathed heater according to the present invention includes a cylindrical portion, a resistance wire disposed inside the cylindrical portion, and a heater terminal connected to both ends of the resistance wire, and the heater terminal is for screwing with a nut. A first end portion having a male screw shape and a part thereof exposed from the cylindrical portion; a second end portion having a columnar shape and a portion of the resistance wire wound thereon; In the portion exposed from the cylindrical portion, at least one of a hole or a recess extending in a direction parallel to one of the radial directions of the first end portion and a plane portion perpendicular to one of the radial directions is provided.

When the tip of the first end is sandwiched with a tool such as a pliers or a spanner so that at least the flat surface is in contact with the tool, and the tool is held, the held tool serves as a detent. In addition, even if the nut is turned too much, the heater terminal is difficult to rotate, and it is possible to prevent the resistance wire and the heater terminal from being disconnected (the connection state between the heater terminal and the resistance wire can be easily maintained).
In addition, since the heater terminal is difficult to rotate, there is an advantage that the user can easily recognize whether or not the nut is turned too much.

  In addition, if a rod-shaped object is inserted into the hole (or dent) and held, the held rod-shaped object serves as a detent, and even if the nut is turned too much during screwing with the nut, the heater It becomes difficult for the terminal to rotate, and it is possible to prevent the resistance wire and the heater terminal from being disconnected (to easily maintain the connection state between the heater terminal and the resistance wire).

  Preferably, the tip portion of the first terminal is provided with a cylindrical portion having a diameter equal to or less than the diameter of the valley of the male screw constituting the male screw-shaped portion, and a flat portion is provided at the tip of the cylindrical portion.

  The flat portion can be smoothly screwed into the nut without being caught by the nut.

  Preferably, at least one set of two plane portions in parallel positional relationship is provided on a side surface of the distal end portion of the first end portion and exposed from the cylindrical portion.

  Preferably, the tip portion of the first terminal is provided with a cylindrical portion having a diameter equal to or less than the diameter of the valley of the male screw constituting the male screw-shaped portion, and a hole or a dent is provided at the tip of the cylindrical portion. Provided.

  It is possible to smoothly screw the nut without the hole or dent being caught in the nut.

  Also preferably, the heater terminal further includes an insulating powder filled in the cylindrical portion, and the heater terminal includes a first end portion, a second end portion, and an intermediate portion sandwiched between the first end portion and the second end portion. The first end, the intermediate portion, and the second end portion are integrally configured, and the intermediate portion includes a portion having a cross-sectional shape other than a circular shape, and the centers of the first end portion and the second end portion. It includes at least one of portions having a cross-sectional shape in which the center of gravity is located at a position away from the extension line of the shaft.

Since the middle part of the heater terminal is provided with a part with a shape different from the cylindrical shape, the insulating powder filled around the part serves as a detent, and the nut is turned too much when screwing with the nut. However, it becomes difficult for the heater terminal to rotate, and it becomes possible to prevent the resistance wire and the heater terminal from being disconnected (to easily maintain the connection state between the heater terminal and the resistance wire).
In addition, since the heater terminal is difficult to rotate, there is an advantage that the user can easily recognize whether or not the nut is turned too much.

  More preferably, the intermediate portion includes a portion having a cross-sectional shape other than a circular shape, and the portion having a cross-sectional shape other than a circular shape has a polygonal column shape, and crosses the polygonal shape. All line segments from the center of gravity of the surface to the side forming the outer shape of the polygonal cross section are longer than the radius of the circle forming the cross section of the second end.

  More preferably, a portion corresponding to the first end portion and the second end portion is cut out from a columnar object having the same cross-sectional shape as that of the polygonal column shape and having a height longer than the polygonal column shape. Thus, a heater terminal is formed.

  Preferably, the intermediate part includes a part having a shape other than circular in cross section, and the intermediate part has a cylindrical part having a diameter larger than that of the first end part and the second end part, The portion having a cross-sectional shape other than circular is formed by cutting or deforming a part of the cylindrical portion.

  More preferably, the portion having a cross-sectional shape other than circular has a polygonal column shape.

  Preferably, the portion having a cross-sectional shape other than circular has a shape in which a part of the cylindrical portion is crushed.

  Preferably, the intermediate portion includes a portion having a cross-sectional shape in which the center of gravity is located at a position away from the extension line of the central axis of the first end portion and the second end portion. A portion having a cylindrical section having a diameter larger than that of the first end and the second end, and having a cross-sectional shape centered at a position away from the extension line of the central axis of the first end and the second end. Is formed by bending a part of a cylindrical portion.

  Preferably, the cylindrical portion holds the first end portion of the heater terminal via a first insulating member fitted in the opening portion, and the insulating powder includes a part of the first end portion and the first end portion. The filling is performed so as to cover all of the two end portions and all of the intermediate portion, and the portion of the insulating powder facing the first insulating member is subjected to caulking.

  The load test apparatus according to the present invention includes a plurality of sheathed heaters having a cylindrical portion, a resistance wire disposed inside the cylindrical portion, and heater terminals connected to both ends of the resistance wire, The heater terminal is used as a resistor for a dry load test. The heater terminal has a male screw shape and a first end portion that is partially exposed from the cylindrical portion, and a columnar shape and a part of the resistance wire is wound around the first end portion. A portion having two end portions, which is a side surface of the tip portion of the first end portion and exposed from the cylindrical portion, has a hole or a recess extending in a direction parallel to one of the radial directions of the first end portion, and a radial direction At least one of the plane portions perpendicular to one of the two is provided.

  Preferably, the cylindrical portion further includes an insulating powder, and the heater terminal has a first end, a second end, and an intermediate portion sandwiched between the first end and the second end. The first end portion, the intermediate portion, and the second end portion are integrally configured, and the intermediate portion includes a portion having a cross-sectional shape other than a circular shape, and central axes of the first end portion and the second end portion. It includes at least one of portions having a cross-sectional shape in which the center of gravity is located at a position away from the extension line.

  As described above, according to the present invention, it is possible to provide a sheathed heater that can easily maintain the connection state between the heater terminal and the resistance wire.

It is a front view of the load test apparatus in this embodiment. It is a side view of the load test apparatus in this embodiment. It is a schematic diagram which shows the structure of the load test apparatus in this embodiment. It is a figure which shows one side surface of a resistance part. It is a figure which shows the other side surface of a resistance part. It is a perspective view which shows the circumference | surroundings of the terminal of a resistor. It is a cross-sectional block diagram which shows the positional relationship of a resistor and a frame containing the heater terminal which has the intermediate part in which one part was formed in prismatic shape. It is a perspective view of the heater terminal which has the intermediate part in which a part of column-shaped part was formed in prismatic shape. It is a perspective view of the heater terminal which has the intermediate part deform | transformed so that a part of cylindrical part may be crushed. It is a perspective view of the heater terminal which has the intermediate part containing the prism shape formed by shaving. It is a perspective view of the heater terminal which has the intermediate part in which one part was bent. It is a cross-sectional block diagram which shows the positional relationship of a resistor and a frame containing the heater terminal which has the intermediate part comprised only with the cylinder. It is a perspective view of the heater terminal which has the intermediate part comprised only with the cylinder. It is a section lineblock diagram of a resistor in a filling process. It is a section lineblock diagram of a resistor after a diameter reduction process. It is a section lineblock diagram of a resistor after a heating process. It is a section lineblock diagram of a resistor after an embedding process. It is a section lineblock diagram of a resistor after a screwing process. It is a cross-sectional block diagram which shows the positional relationship of a resistor and a frame containing the heater terminal which has the 1st edge part in which the cylindrical part containing a plane part was provided. It is a perspective view of the heater terminal which has the 1st end part in which the cylindrical part containing a plane part was provided. It is a perspective view of the 1st terminal and intermediate part in which the cylindrical part containing a plane part in a heater terminal was provided. It is a perspective view of the 1st terminal and intermediate part in which the cylindrical part containing a hole was provided in a heater terminal.

  Hereinafter, the present embodiment will be described with reference to the drawings. The dry load test apparatus 1 in the present embodiment includes a frame 10, a resistance unit 20, a cooling unit 30, and a connection switching unit 40 (see FIGS. 1 to 11 and FIGS. 14 to 22).

  In order to describe the direction, the horizontal direction in which the connection switching unit 40 and the frame 10 are arranged is the x direction, the horizontal direction perpendicular to the x direction is the y direction, and the vertical direction perpendicular to the x direction and the y direction is the z direction. explain.

  The frame 10 accommodates the resistance part 20 in the upper stage and accommodates the cooling part 30 in the lower stage. Further, a connection switching unit 40 is provided on the side of the frame 10, and a caster is provided on the lower part.

The side surface of the frame 10 (the surface where the heater terminal 63 of the resistor R constituting the resistor unit 20 can be seen) is the heater terminal 63, a cable connected to the heater terminal 63, a short-circuit bar, and a frame 21 that holds the resistor R. Is provided with a cover 11 (see FIG. 2).
The cover 11 is made of a conductive material such as iron or aluminum.

  The resistor section 20 is a terminal connection section 43 in which a plurality of resistor arrays in which a plurality of rod-shaped resistors R parallel to the y direction are arranged at predetermined intervals in the x direction are arranged in a plurality of stages in the z direction. It is used to perform a load test of a power source to be tested such as a generator connected via the. The resistor R is supplied with power from the power source to be tested.

  In the present embodiment, the resistor R includes nine resistor rows arranged in the x direction and arranged in 13 stages in the z direction. However, the number of resistors R arranged in each resistor row and the number of stages where the resistor rows are stacked are not limited to this.

  Note that the resistor R in at least one resistor row (the uppermost resistor row in the examples shown in FIGS. 4 and 5) is used for spare purposes such as replacement when another resistor R fails. It is desirable that the resistor R constituting the resistor row of the first stage is used as the resistor R constituting the first resistor group G1 to the twelfth resistor group G12.

  In the resistor R constituting the resistor unit 20, the 6 or 12 resistors R adjacent to each other are set as one resistor group, and the load is applied while changing the number of resistor groups to which a voltage is applied from the power source to be tested. Perform the test.

  Further, the connection in the resistor group (the connection state of the resistor R in the resistor group) is changed according to the type of the power source to be subjected to the load test.

  The resistor unit 20 includes a first resistor group G1 to a twelfth resistor group G12. In the present embodiment, a first resistor group G1 (rated capacity: 1 kW) having six resistors R having a rated voltage of 400 V and a rated capacity of 1.67 kW, a resistor R having a rated voltage of 116 V and a rated capacity of 334 W Second resistor group G2 (rated capacity: 2 kW, third resistor group G3 is the same), rated resistor: 116V, rated resistor: 4th resistor group G4 having six resistors R (rated 834W) Rated capacity: 5 kW), rated voltage: 116 V, rated capacity: fifth resistor group G5 having six resistors R of 1.67 kW (rated capacity: 10 kW, sixth resistor group G6 is the same), rated voltage: An example in which a seventh resistor group G7 having 12 resistors R with 116V and a rated capacity of 1.67 kW (rated capacity: 20 kW, the same applies to the eighth resistor group G8 to the twelfth resistor group G12) is provided. Indicates. However, the number of resistor groups G and the rated voltages and rated capacities thereof are not limited to the above-described configuration.

  The resistor (seeds heater) R includes a coiled resistance wire 61 such as a nichrome wire, a heater terminal (bobbin) 63 electrically connected to the resistance wire 61 and provided at both ends of the resistance wire 61, and a first insulating member 65a. And a cylindrical portion (heater pipe) 67 that holds the heater terminal 63 and covers the side surfaces of the resistance wire 61 and a part of the heater terminal 63 (the portion that is not exposed to the outside from the wall constituting the frame 21) (FIGS. 6 to 6). 8).

  7 and cross-sectional configuration diagrams of FIGS. 12 and 14 to 19 described later show cross sections of members other than the resistance wire 61, the heater terminal 63, and the nut 66, and the resistance wire 61, the heater terminal 63, and the nut 66. Indicates the side.

  A heat radiating fin 69 is provided on the side surface of the cylindrical portion 67.

  The heater terminal 63 has a male thread shape for screwing with the nut 66, a first end portion 63 a partially exposed from the cylindrical portion 67, a substantially columnar shape, and a part of the resistance wire 61 is wound around the first end portion 63 a. 2 end part 63b, it has the intermediate part 63c pinched | interposed into the 1st end part 63a and the 2nd end part 63b, and the 1st end part 63a, the intermediate part 63c, and the 2nd end part 63b are comprised integrally. .

  The first end 63a may be configured by only the male screw-shaped part, but is the tip part of the male screw-shaped part and the portion exposed from the cylindrical part 67 equal to the diameter of the male screw valley? A cylindrical portion 63a1 having a diameter smaller than that is provided, and a configuration in which a flat surface portion 63a2 perpendicular to one of the radial directions is provided on the side surface at the tip of the cylindrical portion 63a1 by cutting or the like (FIG. 19 to FIG. 19). 21), or a form (see FIG. 22) in which a hole (or a recess) 63a3 extending in a direction parallel to one of the radial directions is provided on the side surface of the tip of the cylindrical portion 63a1.

  The tip of the first end 63a is sandwiched with a tool such as a pliers or a spanner so that at least a part of the flat surface 63a2 is in contact, and when the tool is held, the held tool serves as a detent, When the nut 66 is screwed, the heater terminal 63 becomes difficult to rotate even if the nut 66 is turned too much, and the disconnection between the resistance wire 61 and the heater terminal 63 is prevented (the connection state between the heater terminal 63 and the resistance wire 61 is maintained). Easy to do).

  Therefore, it is desirable to provide one or more sets of two plane portions 63a2 that are in a parallel positional relationship so that they can be sandwiched steadily. FIG. 21 shows an example in which one set of two plane portions 63a2 having a parallel positional relationship is provided.

  Further, when a rod-shaped object is inserted into the hole (or recess) 63a3 and the rod-shaped object is held, the held rod-shaped object serves as a detent, and when the nut 66 is screwed, the nut 66 is turned too much. However, it becomes difficult for the heater terminal 63 to rotate, and it is possible to prevent the resistance wire 61 and the heater terminal 63 from being disconnected (the connection state between the heater terminal 63 and the resistance wire 61 can be easily maintained).

  In addition, since the heater terminal 63 becomes difficult to rotate, there is also an advantage that the user can easily recognize whether or not the nut 66 is turned too much.

  In addition, at least one of the flat surface portion 63a2 and the hole (or dent) 63a3 may be provided on the side surface of the distal end portion of the male screw-shaped portion and exposed from the cylindrical portion 67, but the flat surface portion 63a2 or the hole may be provided. In order to smoothly engage the nut 66 without the 63a3 being caught by the nut 66, a cylindrical portion 63a1 having a diameter equal to or smaller than the diameter of the valley of the male screw is provided, and the planar portion 63a2 and a hole ( Alternatively, it is desirable to provide at least one of the recesses 63a3.

  The intermediate part 63c has the same central axis as the central axis LX of the first end part 63a and the second end part 63b, and has a substantially cylindrical part 63c1 having a diameter larger than that of the first end part 63a and the second end part 63b. And a portion 63c2 having a cross-sectional shape other than circular.

  For example, a portion 63c2 having a shape other than a circular cross section in the intermediate portion 63c is obtained by cutting out portions corresponding to the first end portion 63a and the second end portion 63b from a columnar object (column) having a circular cross section. Alternatively, the heater terminal 63 is formed in a state before the portion 63c3 having a cross-sectional shape with the center of gravity located at a position away from an extension line of the center axis LX described later.

  As shown in FIGS. 7 and 8, the portion 63c2 having a cross-sectional shape other than a circle has a substantially polygonal column shape in which a part of the intermediate portion 63c is formed by cutting or pressing (the cross-section is polygonal). As shown in FIG. 9, a configuration in which a part of the intermediate portion 63c is crushed by pressing or the like (the cross section is substantially elliptical) is conceivable.

  In this case, at least some of the line segments from the center of gravity in the shape other than the circle to the side or arc forming the outer shape of the shape are shorter than the radius of the circle forming the cross section of the substantially cylindrical portion 63c1. In addition, shapes other than the circle are formed.

  Further, the shape other than the circle is a polygon, and all the line segments from the center of gravity of the polygon to the side forming the outer shape of the shape are cross sections of the second end portion 63b and the substantially cylindrical portion 63c1. A shape other than the circle may be formed so as to be longer than the radius of the circle to be formed (see FIG. 10).

  In this case, the entire heater terminal 63 including the upper and lower substantially cylindrical portion 63c1 and the portion 63c2 having a cross-sectional shape other than circular is formed by cutting out from a columnar object (polygonal column) having a polygonal cross section. I can do it.

  Specifically, it has the same cross-sectional shape as that of the polygonal column shape, and has a height (the height of the first end portion 63a, the second end portion 63b, and the intermediate portion 63c) longer than the polygonal column shape. A portion corresponding to the substantially cylindrical portion 63c1 of the first end portion 63a, the second end portion 63b, and the intermediate portion 63c is cut out from the columnar object to form the heater terminal 63.

  For example, if a portion corresponding to the substantially cylindrical portion 63c1 of the first end portion 63a, the second end portion 63b, and the intermediate portion 63c is cut out from a regular hexagonal column member, the portion 63c2 having a cross-sectional shape other than a circular shape. Can obtain a heater terminal 63 having a regular hexagonal prism shape.

  Further, instead of or in addition to the portion 63c2 having a cross-sectional shape other than circular, the intermediate portion 63c is formed by bending a part of the substantially cylindrical portion 63c1, and the first end portion 63a and the second end portion 63a. A form including a portion 63c3 having a cross-sectional shape in which the center of gravity is located at a position away from the extension line of the central axis LX of the end 63b may be used (see FIG. 11).

A part of the resistance wire 61 is wound around the second end 63b and fixed by spot welding or the like.
The inside of the cylindrical portion 67 is filled with an insulating powder 64 such as magnesia and is hardened by compression and heat.

The insulating powder 64 is filled so as to cover a part of the first end part 63a, the whole second end part 63b, and the whole intermediate part 63c.
A portion of the insulating powder 64 facing the first insulating member 65a (a boundary portion between the insulating powder 64 and the first insulating member 65a) and a part of the male screw-shaped portion of the first end 63a are subjected to caulking 62 with silicone or the like. Is done.
A part of the male thread shape portion of the first end 63a and the insulating powder 64 are fixed via the caulking 62.

  The nut 66 is screwed into the first end 63a with the first insulating member 65a and the cylindrical portion 67 sandwiched therebetween.

  In an embodiment where the intermediate portion 63c of the heater terminal 63 is not provided with a shape different from a substantially cylindrical shape such as a prismatic shape (see FIGS. 12 and 13), if the nut 66 is turned too much during screwing with the nut 66, the heater There is a possibility that the terminal 63 slips and rotates, and the connection state between the resistance wire 61 and the heater terminal 63 is broken.

  In the present embodiment, the intermediate portion 63c of the heater terminal 63 has a portion 63c2 having a shape other than a circular cross section, such as a polygonal column shape, or an extension of the central axis LX of the first end portion 63a and the second end portion 63b. Since a portion 63c3 having a cross-sectional shape in which the center of gravity is located at a position away from the line, that is, a portion having a shape different from the substantially cylindrical shape is provided, the insulating powder 64 filled around the portion serves as a detent. When the nut 66 is screwed, even if the nut 66 is turned too much, the heater terminal 63 is difficult to rotate and prevents the resistance wire 61 and the heater terminal 63 from being disconnected (the connection state of the heater terminal 63 and the resistance wire 61). Can be easily maintained).

  In addition, since the heater terminal 63 becomes difficult to rotate, there is also an advantage that the user can easily recognize whether or not the nut 66 is turned too much.

  Further, since a part of the substantially cylindrical shape in the intermediate portion 63c of the heater terminal 63 is cut or deformed by cutting or pressing, it is possible to easily form a portion having a shape different from the substantially cylindrical shape.

  Further, in the case of machining, a heater including a portion 63c2 having a cross-sectional shape other than a circle without concentrating stress on a part of the intermediate portion 63c of the heater terminal 63 as compared with pressing or bending. A terminal 63 can be formed.

  The manufacturing procedure of the resistor R will be described later.

  The heater terminal 63 of the resistor R is connected to the heater terminal 63 of another resistor R by a short-circuit bar, or is connected to the terminal connection part 43 or a relay via a cable.

  The side surface of the resistor R is covered with a frame 21 composed of four walls.

  A portion of the resistor R that is not electrically connected to the heater terminal 63 (such as the vicinity of both ends of the cylindrical portion 67 that holds the heater terminal 63 via the first insulating member 65a) is connected to the frame 21 via the second insulating member 65b. It is held on the wall that constitutes it.

  FIG. 6 shows the end portions of the four resistors R held by the frame 21, and two of them are the ones (the first end portion 63 a is not provided with the cylindrical portion 63 a 1 including the flat portion 63 a 2). The heater terminals 63 are connected to each other through a short-circuit bar.

  Further, the upper surface and the lower surface of the frame 21 are opened in order to allow the cool air from the cooling unit 30 provided in the lower part to flow upward.

  In order to efficiently perform the cooling by the cooling unit 30, the resistor array adjacent in the z direction is positioned at a middle position between the resistor R constituting the resistor array and the resistor R adjacent to the resistor R in the x direction. The resistors R of each resistor row are arranged so that the resistors R are arranged.

  A cooling unit 30 having a cooling fan is provided below the resistance unit 20 (lower stage of the frame 10).

  The relay provided for each resistor group in the cooling unit 30 or the resistor unit 20 and controlling the power supply from the test target power source to any one of the resistor groups is a power source (load test device drive) different from the test target power source. (Refer to FIG. 3).

  The connection switching unit 40 includes an operation unit 41 and a terminal connection unit 43 (see FIGS. 2 and 3). The terminal connection unit 43 may be arranged at a position away from the operation unit 41 (for example, the back surface of the operation unit 41).

  The operation unit 41 includes a mode switch 41a and a resistance switch 41b.

  The mode changeover switch 41a is a rotary operation switch and is used to turn on / off the load test apparatus 1 and to select the type of power supply to be tested (mode changeover).

The resistance changeover switch 41b is a slide type (or toggle type or push button type) operation switch, and is a switch for performing on / off control of the relays of the first resistor group G1 to the twelfth resistor group G12.
When the first operation switch S1 is turned on, the relay of the first resistor group G1 is turned on (conducting state), and the first resistor group G1 is connected to the load test apparatus 1 via the terminal connection portion 43. The current from the connected power source to be tested can be made to flow.
The same applies to the second operation switch S2 to the twelfth operation switch S12. When the second operation switch S2 to the twelfth operation switch S12 are turned on, the relay of the corresponding resistor group is turned on (conductive state), and the terminal connection portion 43 is connected to the resistor group. Thus, a current from the power supply to be tested connected to the load test apparatus 1 can flow.

  When the rotational position of the mode switch 41a is set to the rotational position (operation mode) corresponding to the type of power supply to be tested, the cooling fan of the cooling unit 30 is driven, and the first is based on the operating state of the resistance switch 41b. On / off control of each relay of the resistor group G1 to the twelfth resistor group G12 is performed.

  Note that when a main power switch is provided, the main power switch is turned on, and the rotation position of the mode changeover switch 41a is set to the rotation position (operation mode) corresponding to the type of power source to be tested, The form in which the on / off control of each of the first resistor group G1 to the twelfth resistor group G12 is performed may be employed.

  The terminal connection unit 43 is a terminal for connecting a power source to be tested, and the test target power source and the first resistor group G1 to the twelfth resistor group G12 can be connected via the terminal connection unit 43. Is done.

  Next, the manufacturing procedure of the resistor R will be described (see FIGS. 14 to 18).

A resistance wire 61 attached between the two heater terminals 63 is inserted into the cylindrical portion 67, held so that the opening in the cylindrical portion 67 faces the vertical direction, and the lower opening is closed with a rubber bushing 68. In this state, the insulating powder 64 is introduced into the cylindrical portion 67 so as to cover a part of the first end portion 63a, the entire second end portion 63b, and the entire intermediate portion 63c (see FIG. 14, filling). Process).
At this time, since a large amount of the insulating powder 64 is filled without any gaps, it is desirable that the sufficiently dried insulating powder 64 is put in a state where vibration is applied to the cylindrical portion 67 and the like.

  After the filling of the insulating powder 64 is completed, a diameter reducing process for compressing the side surface of the cylindrical portion 67 is performed in a state where the upper opening in the cylindrical portion 67 is closed with a rubber-like bushing 68 (see FIG. 15, the diameter reducing step). ).

  With the upper and lower bushings 68 removed, heat is applied to the cylindrical portion 67 (see FIG. 16, heating step).

  The insulating powder 64 is hardened into a sintered body by the diameter reduction process and the heating process.

  The portion exposed in the vicinity of the opening of the cylindrical portion 67 in the insulating powder 64 (the portion facing the bushing 68) is subjected to caulking 62 with silicone or the like, and then the first insulating member 65a is fitted (FIG. 17). Reference, inset process). Further, the heat radiation fin 69 is attached to the cylindrical portion 67.

The nut 66 is screwed into the first end portion 63a, and the first insulating member 65a and the cylindrical portion 67 are sandwiched between the nuts 66 to complete the resistor R (see FIG. 18, screwing step). .
When the first end portion 63a is provided with the flat surface portion 63a2, the tip end portion of the first end portion 63a is sandwiched with a tool such as a pliers or a spanner so that at least a part of the flat surface portion 63a2 is in contact with the first end portion 63a. Screwing is performed with the tool held.
When the hole (or dent) 63a3 is provided in the first end 63a, a rod-like object is inserted into the hole (or dent) 63a3, and screwing is performed in a state where the rod-like object is held.

  In the present embodiment, a form in which a resistor (seeds heater) R having a heater terminal 63 provided with a portion having a shape different from a substantially cylindrical shape is used in the dry load test apparatus 1 for a part of the intermediate portion 63c. As described above, the use of the sheathed heater is not limited to the dry load test apparatus, but may be a form used for other purposes such as an electric heating apparatus.

DESCRIPTION OF SYMBOLS 1 Load test apparatus 10 Frame 11 Cover 20 Resistance part 21 Frame 30 Cooling part 40 Connection switching part 41 Operation part 41a Mode change switch 41b Resistance change switch 43 Terminal connection part 61 Resistance wire 62 Caulking 63 Heater terminal 63a 1st end part 63a1 Cylinder Part 63a2 plane part 63a3 hole or recess 63b second end part 63c intermediate part 63c1 substantially cylindrical part 63c2 part having a cross-sectional shape other than circular 63c3 the center is located at a position away from the extension of the central axis of the first end part Part having cross-sectional shape located 64 Insulating powder 65a, 65b First insulating member, second insulating member 66 Nut 67 Cylindrical portion 68 Bushing 69 Heat radiation fin 70 Cap 71 Cylindrical portion 71a 襞 73 Lid portion 75 Bar cover portion 75a Bar Back cover G1-G12 1st resistor Vessel groups to twelfth resistor group R resistor (sheath heater)

Claims (9)

A cylindrical portion;
A resistance wire disposed inside the cylindrical portion;
A heater terminal connected to both ends of the resistance wire;
An insulating powder filled in the cylindrical portion;
The heater terminal has a male screw shape for screwing with a nut, a first end portion that is partially exposed from the cylindrical portion, and a second end that has a columnar shape and a portion of the resistance wire is wound around the first end portion. And an intermediate portion sandwiched between the first end portion and the second end portion, and the first end portion, the intermediate portion, and the second end portion are configured integrally.
The intermediate portion has a cross-sectional shape in which the center of gravity is located at a position away from an extension line of the central axis of the first end portion and the second end portion, and a first portion having a cross-sectional shape other than circular. Including at least one of the second parts,
The intermediate portion has a cylindrical portion having a diameter larger than that of the first end portion and the second end portion,
When the first portion is included in the intermediate portion, the first portion is formed by cutting or deforming a part of the columnar portion,
When the second part is included in the intermediate part, the second part is formed by bending a part of the columnar part . A portion of the side surface of the distal end portion of the first end portion exposed from the cylindrical portion includes a hole or a recess extending in a direction parallel to one of the radial directions of the first end portion, and one of the radial directions. The sheathed heater according to claim 1, wherein at least one of the vertical plane portions is provided. A cylindrical portion having a diameter equal to or less than the diameter of the male screw valley constituting the male screw-shaped portion is provided at the distal end portion of the first end portion , and the flat surface portion is provided at the distal end of the cylindrical portion. The sheathed heater according to claim 2 , wherein Wherein the portion exposed from the cylindrical portion a side of the distal end portion of the first end, two of the flat portion in a parallel positional relationship, in claim 2, characterized in that provided at least one set The described sheathed heater. A cylindrical portion having a diameter equal to or smaller than the diameter of the male screw valley constituting the male screw-shaped portion is provided at the distal end portion of the first end portion, and the hole or dent is formed at the distal end of the cylindrical portion. sheath heater according to claim 2, characterized in that it is provided. The intermediate part includes the first part,
The first portion has a polygonal column shape,
All of the line segments from the center of gravity of the cross section of the polygonal column shape to the side forming the outer shape of the cross section of the polygonal column shape are longer than the radius of the circle forming the cross section of the second end portion. The sheathed heater according to claim 1 . The cylindrical portion holds the first end of the heater terminal via a first insulating member fitted in the opening,
The insulating powder is filled so as to cover a part of the first end part, the whole second end part, and the whole intermediate part,
The first insulating member and the portion opposite to the sheath heater according to claim 1, characterized in that coking is facilities in the insulating powder. A plurality of sheathed heaters having a cylindrical portion, a resistance wire disposed inside the cylindrical portion, and heater terminals connected to both ends of the resistance wire,
The plurality of sheathed heaters are used as resistors for a dry load test,
The heater terminal has a first end portion having a male screw shape and a part thereof exposed from the cylindrical portion, a second end portion having a columnar shape around which a part of the resistance wire is wound, and the first end portion And an intermediate portion sandwiched between the second end portions, the first end portion, the intermediate portion and the second end portion are integrally configured,
The intermediate portion has a cross-sectional shape in which the center of gravity is located at a position away from an extension line of the central axis of the first end portion and the second end portion, and a first portion having a cross-sectional shape other than circular. Including at least one of the second parts,
The intermediate portion has a cylindrical portion having a diameter larger than that of the first end portion and the second end portion,
When the first portion is included in the intermediate portion, the first portion is formed by cutting or deforming a part of the columnar portion,
Wherein when that contains the second portion to the intermediate portion, the second portion, the load test apparatus you being formed by bending a portion of the cylindrical portion. A portion of the side surface of the distal end portion of the first end portion exposed from the cylindrical portion includes a hole or a recess extending in a direction parallel to one of the radial directions of the first end portion, and one of the radial directions. load test apparatus according to claim 8, wherein at least one is provided Rukoto vertical planar portion.

Images