JP2014007173A - Terminal rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal rod capable of avoiding a fault of increase in electric resistance caused by oxidation of a contact point, in connection between an aluminum wire from a motor side and an aluminum terminal for being connected with a power supply.SOLUTION: A terminal rod comprises: a flange part 15b provided between one end and the other end; a pressure-bonded part 15e provided to the other end; a shaft part 15a provided on an opposite side to the pressure-bonded part 15e of the flange part 15b; and a screw part 15f provided to an opposite side to the flange part 15b of the shaft part 15a. A recessed part 15d is formed on an end surface of the pressure-bonded part 15e so as to be surrounded by the pressure-bonded part 15e. The pressure-bonded part 15e is made of pure aluminum. The flange part 15b, the shaft part 15a, and the screw part 15f are made of an aluminum alloy having a tensile strength larger than that of the pure aluminum.

Description

  The present invention relates to a terminal rod suitable for crimping an aluminum wire of a winding of a motor that drives a screw compressor main body using ammonia gas as a compression medium.

  From the viewpoint of preventing ozone depletion and global warming, natural refrigerants that have the properties of refrigerants, which are naturally existing substances, have been reviewed, rather than artificially created refrigerants such as HCFC refrigerants and HFC refrigerants. Yes. This natural refrigerant has zero ozone depletion coefficient, low global warming coefficient, and a large amount of ammonia existing in nature. However, the ammonia refrigerant has corrosiveness, toxicity, and flammability to copper.

  Therefore, in order to employ a screw compressor in a refrigeration apparatus using ammonia as a refrigerant, measures against ammonia are required. Conventionally, as a countermeasure, an ammonia screw compressor in which the winding of a motor is changed from copper to aluminum is known (see, for example, Patent Document 1 and Patent Document 2).

  When starting up a screw compressor that compresses ammonia, after all the air in the circulation passage including the inside of the motor and the screw compressor is removed, the circulation passage is filled with ammonia gas. Has been. However, it is difficult to completely remove air from the circulation flow path inside the motor, and a part of the air remains in the ammonia gas in the circulation flow path. In addition, when the screw compressor is operated, depending on the operation state, the suction side of the screw compressor becomes a negative pressure (vacuum state, etc.). Intrusion may occur.

  On the other hand, a compressor motor or the like used for compressing ammonia has a core wire formed by twisting a plurality of aluminum strands from the end face to a certain length or a core wire consisting of a single aluminum strand. , Several are used. In order to connect the core wire to the terminal of the compressor, Patent Document 3 discloses that a fitting hole extending in the axial direction is formed in the main body of the rod-shaped energizing terminal made of aluminum, and is fitted to a part of the outer peripheral portion. Form a notch communicating with the joint hole, insert the core wire into the fitting hole, heat from above the notch, melt at least the edge of the notch, and fix the core wire and the main body by welding A method of connecting is disclosed.

  However, in this method, since the connection between the aluminum element wire and the terminal body is insufficient at the inner peripheral portion radially opposite to the notch portion of the terminal body, the conductivity is poor. In addition, the electrical resistance increases at the portion where both are in contact with each other, and as a result of increasing the amount of heat generation, the motor may be burned out.

  In Patent Document 4, an electric wire core portion is inserted into an electric wire insertion hole provided in an electric wire connection portion of a connection terminal, and the electric wire connection portion is uniformly crimped in a radial direction over the entire circumference by an entire circumference caulking means. And a method of connecting the connection terminal.

  At the contact portion between the aluminum wire connected in this way and the aluminum connection terminal, oxidation is caused over time due to the air remaining in the motor and the oxygen contained in the external air entering from the suction side. In some cases, a film is formed, and the electrical resistance at the contact portion increases.

JP 2005-171943 A Japanese Patent No. 3357607 JP-A-9-180770 JP 2003-36898 A

  In view of the above problems, the present invention provides a terminal bar that can avoid the problem of increased electrical resistance caused by contact oxidation in the connection of an aluminum wire from the motor side and an aluminum terminal for connection to a power source. Is an issue.

  As means for solving the above-mentioned problems, the terminal rod of the present invention includes a flange portion provided between one end and the other end, a crimp portion provided at the other end, and the crimp portion of the flange portion. A shaft portion provided on the opposite side and a screw portion provided on the opposite side of the flange portion of the shaft portion are provided, and a recess is formed on the end surface of the pressure-bonding portion so as to be surrounded by the pressure-bonding portion. Thus, the crimping part is made of pure aluminum, and the flange part, the shaft part, and the screw part are made of an aluminum alloy having a tensile strength higher than that of pure aluminum.

  According to this configuration, when the aluminum wire to be crimped is made of pure aluminum, the crimping portion of the terminal rod and the aluminum wire are easily made of the same material, and the linear expansion coefficient is the same. Even if this occurs, it is possible to avoid loosening of the crimping between the terminal rod and the aluminum wire due to the rise in temperature. Further, since the flange portion, the shaft portion, and the screw portion are made of an aluminum alloy having a tensile strength larger than that of pure aluminum, it can be firmly fastened to the terminal block with a nut or the like.

  It is preferable that the pure aluminum of the crimping part and the aluminum alloy of the flange part are joined at the interface of these different aluminum materials.

  It is preferable that a communication portion that connects the outer peripheral surface of the crimping portion and the recess is provided.

  It is preferable that an aluminum wire made of pure aluminum is crimped to the crimping portion.

  It is preferable that a blocking material that blocks gas permeation is filled between the crimping portion and the aluminum wire.

  The aluminum wire is preferably composed of at least one or a plurality of aluminum wires, and a blocking material is applied to the outer surface of the aluminum wires.

  According to the terminal rod according to the present invention, when the aluminum wire to be crimped is made of pure aluminum, the crimping portion of the terminal rod and the aluminum wire are easily made of the same material and have the same linear expansion coefficient. Even if the temperature rises, it is possible to avoid loosening of the crimping between the terminal rod and the aluminum wire due to the temperature rise. Therefore, the oxygen contained in the air remaining inside the motor or the external air that has entered from the suction side at the contact portion between the aluminum wire and the aluminum connection terminal by crimping with the shielding material interposed. Due to the formation of the oxide film over time due to the above, it is possible to avoid the occurrence of a problem that the electrical resistance at the contact portion increases. Further, since the flange portion, the shaft portion, and the screw portion are made of an aluminum alloy having a tensile strength larger than that of pure aluminum, it can be firmly fastened to the terminal block with a nut or the like.

Sectional drawing of the screw compressor comprised using the terminal crimping method of the aluminum wire of the reference example 1. FIG. The enlarged view of the terminal rod assembled | attached by the terminal crimping method of the aluminum wire of the reference example 1, and the terminal block of a motor. FIGS. 3A to 3C are views showing a relationship between an aluminum wire and a terminal rod assembled by the terminal crimping method of the aluminum wire of Reference Example 1. FIG. IV-IV sectional view taken on the line of FIG. The fragmentary sectional view which shows the attachment procedure of the terminal block of the screw compressor of FIG. FIG. 6A is a diagram showing a part of a terminal rod in which aluminum wires are bonded by crimping at the crimping portion, and FIG. 6B is a cross-sectional view of the crimping portion whose outer periphery is crimped to a regular hexagon. The fragmentary sectional view which shows the attachment procedure of the terminal block of the screw compressor of FIG. The fragmentary sectional view which shows the attachment procedure of the terminal block of the screw compressor of FIG. The fragmentary sectional view which shows the attachment procedure of the terminal block of the screw compressor of FIG. The figure which shows the cross section of the aluminum wire assembled | attached by the terminal crimping method of the aluminum wire of the reference example 2, and a terminal rod. The figure which shows the investigation result of the connection state of an aluminum wire and a terminal rod. FIG. 12A is a partial cross-sectional view showing a seal portion between a terminal block and a terminal rod of a screw compressor motor, and FIG. 12B is a seal portion between the terminal block and the terminal rod of the screw compressor motor. FIG. The enlarged view of the terminal rod of this invention and the terminal block of a motor.

  Reference Example 1 will be described below with reference to the drawings.

  FIG. 1 shows a screw compressor 1 configured using the aluminum wire terminal crimping method of Reference Example 1. The screw compressor 1 includes a rotor casing 5 that forms a rotor chamber 4 that houses screw rotors (male rotor 2 and female rotor 3) that mesh with each other, and a motor rotor that shares a shaft with the motor stator 6 and the male rotor 2. A motor casing 9 that forms a motor chamber 8 that houses the motor 7 is integrally connected. In FIG. 1, the motor 10 is the right side portion of the drawing with respect to the connection portion between the rotor casing 5 and the motor casing 9.

  The screw rotors 2 and 3 are rotated by the rotational force of the motor rotor 7, suck in and compress the refrigerant (ammonia gas) from the suction passage 11a, and discharge the compressed refrigerant from the discharge passage 11b. Yes.

  An opening 9 a is provided on the end surface of the motor casing 9 opposite to the rotor chamber 4. A screw hole 9 b for attaching the terminal block 13 via the spacer 12 is provided at the periphery of the opening 9 a of the motor casing 9.

  The spacer 12 has a cylindrical shape, and a bolt hole 12a into which a mounting bolt 19 described later is inserted is formed in the wall in the axial direction. The spacer 12 closes a space continuous from the motor chamber 8 together with the terminal block 13. The spacer 12 is provided with O-rings 21 on the contact surface with the motor casing 9 and the contact surface with the terminal block 13, respectively, and hermetically seals the opening 9 a of the motor casing 9. The screw compressor 1 has a sealed structure in which the refrigerant flows from the rotor chamber 4 into the motor chamber 8, but since the motor chamber 8 is sealed, the refrigerant does not leak to the outside.

  The terminal block 13 is provided with an insertion hole 13 a at a position corresponding to the bolt hole 12 a of the spacer 12. As shown in FIG. 2, the terminal block 13 has a recess 13 b that fits into a flange portion 15 b of a terminal bar (aluminum terminal) 15 on a surface in contact with the inside of the motor casing 9, and the recess 13 b to the outside of the motor casing 9. A seal portion 13c having a reduced diameter in the direction of the head, and a through portion 13d having a size capable of penetrating the seal portion 13c and the outside of the motor casing 9 and accommodating a shaft portion 15a of the terminal rod 15 described later are provided. The terminal block 13 is made of polyphenylene sulfide (PPS) resin. The PPS resin has corrosion resistance against the gas (ammonia gas) inside the motor casing 9 and pressure resistance against the pressure inside the motor casing 9. In Reference Example 1, the motor casing 9 is designed to withstand even if the internal pressure is increased to about 2 MPa. Note that the pressure inside the motor casing 9 during normal operation is about 0.1 to 0.4 MPa, and that during stoppage is about 0.1 to 0.8 MPa, which is higher than atmospheric pressure in any case. The terminal block 13 fixes a plurality of terminal rods 15 to which aluminum wires 14 from the motor side are respectively connected. As shown in FIG. 3 (a), the aluminum wires 14 fixed to the individual terminal rods 15 by the crimping procedure described later are preliminarily gathered together by twisting or covering a plurality of aluminum strands. As shown in FIG. 3 (b), a plurality of aluminum wires may be fixed together in the terminal rod 15 as shown in FIG. Further, as shown in FIG. 3C, a plurality of aluminum wires in which a plurality of aluminum strands are gathered in advance may be prepared and crimped to a single terminal rod 15.

  The terminal rod 15 is provided on the opposite side of the flange portion 15b provided between one end and the other end of the terminal rod 15, the crimp portion 15e provided on the other end, and the crimp portion 15e of the flange portion 15b. The shaft portion 15a and the screw portion 15f provided on the opposite side of the flange portion 15b of the shaft portion 15a are provided. The end face 15c on the other end side of the terminal rod 15 is provided with a recess 15d formed so as to be surrounded by the crimping part 15e. At the back of the recess 15d, there is a conical gap 15j formed by the tip of the drill when processing the recess 15d. A communication portion 15h is provided for communicating the position corresponding to the depth of the recess 15d of the outer peripheral surface 15g of the crimping portion 15e with the recess 15d. The terminal rod 15 contains aluminum. That is, the terminal rod 15 is made of pure aluminum or aluminum alloy (for example, 5000 series such as A5056, 6000 series aluminum alloy such as A6061). Therefore, the terminal bar 15 is not easily corroded even when it comes into contact with ammonia gas having corrosiveness to copper. The terminal rod 15 is fixed to the terminal block 13 by screwing a plurality of nuts 17a and 17b to the screw portion 15f exposed to the outside of the motor casing 9 with the flange portion 15b fitted into the recess 13b of the terminal block 13. ing. In Reference Example 1, the nuts 17a and 17b are so-called double nuts. Between the nut 17b and the nut 17c that is screwed into the screw portion 15f adjacent to the nut 17b, a connection terminal 18 of a wiring for supplying power from a power source is sandwiched and fixed.

  One of the recesses 15d of the terminal rod 15 is aluminum made of a plurality of aluminum wires 14c connected to the motor stator 6 inside the motor casing 9 (or the ends of the windings of the motor stator 6). In the state where the other end (tip portion 14b) of the wire 14 is inserted and the blocking material 25 is interposed between the aluminum wire 14 and the inner peripheral surface 15m of the crimping portion 15e and between the plurality of aluminum strands 14c and 14c, It is fixed to the crimping part 15e. The blocking material 25 blocks gas permeation, and contains a conductive powder in a substrate mainly composed of oil. The oil here is mineral oil, and the conductive powder is an aluminum powder. In Reference Example 1, the aluminum wire 14 is composed of 16 aluminum strands 14c, and is inserted into the recess 15d as illustrated in FIG. The aluminum wire 14 is made of pure aluminum (1000 series aluminum). Therefore, the aluminum wire 14 is not easily corroded even when it comes into contact with ammonia gas that is corrosive to copper. The aluminum wire 14 includes a fluororesin coating 14a that can more reliably prevent damage and corrosion, but the coating is peeled off at the tip 14b inserted into the recess 15d.

  In a state where the flange portion 15b of the terminal bar 15 is engaged with the recess 13b of the terminal block 13, the seal member 16 is a terminal on the side opposite to the crimping portion 15e of the flange portion 15b so as to be positioned on the seal portion 13c of the terminal block 13. The rod 15 is inserted and attached to the shaft portion 15a. In Reference Example 1, the seal member 16 is a ring-shaped elastic member. The seal member 16 is pressed by the shaft portion 15a of the terminal rod 15 and the flange portion 15b to be elastically deformed to block communication between the inside and the outside of the motor casing 9.

  A portion including the connection terminal 18 exposed to the outside of the terminal rod 15 is covered with an outer box 20 including a cover 22 fastened together with a mounting bolt 19 for attaching the terminal block 13 to the motor casing 9 together with the spacer 12.

  Subsequently, FIGS. 5 to 9 show a procedure for crimping the aluminum wire 14 and the terminal rod 15 and a procedure for attaching the terminal block 13 of the screw compressor 1. First, as shown in FIG. 5, the tip end portion 14 b of the aluminum wire 14 connected to the motor stator 6 is pulled out from the opening 9 a of the motor casing 9. Then, the coating of the tip end portion 14 b of the aluminum wire 14 is peeled by a length corresponding to the recess 15 d of the crimping portion 15 e of the terminal rod 15. Next, the blocking member 25 is filled in the recess 15 d of the crimping portion 15 e of the terminal rod 15. Thereafter, the aluminum wire 14 is inserted into the recess 15d of the crimping portion 15e of the terminal rod 15 from the end surface 15c side to the back. Then, as shown in FIG. 6A, the aluminum wire 14 is inserted into the concave portion 15d of the crimping portion 15e, and the caulking treatment (not shown) is applied to the outer circumferential surface 15g excluding the communication portion 15h of the crimping portion 15e over the entire circumference. Using a tool, pressure is applied evenly to fix the crimping portion 15e to the aluminum wire 14. The crimping jig may be a pair of opposed molding dies, for example, having a regular hexagonal cross section, even if the inner cross sectional shape is not circular. FIG. 6B shows the inside of the crimping portion 15e that is crimped by a jig whose inside cross-sectional shape is a regular hexagon.

  In addition, when pressing the outer peripheral surface 15g of the crimping portion 15e of the terminal rod 15 into which the tip end portion 14b of the aluminum wire 14 is inserted, the compression rate α defined by the following formula is added so as to be about 8 to 21%. It is preferable to be pressed.

Ｄ_１：圧着前の状態におけるアルミニウム製端子の圧着部の外径
Ｄ_２：圧着前の状態におけるアルミニウム製端子の圧着部の内径
ｄ：アルミニウム素線の直径
ｎ：アルミニウム素線の本数

D ₁ : Outer diameter of the crimped portion of the aluminum terminal before crimping D ₂ : Inner diameter of the crimped portion of the aluminum terminal before crimping d: Diameter of the aluminum strand n: Number of aluminum strands

  By pressurizing the outer peripheral surface 15g of the crimping portion 15e of the terminal rod 15 into which the tip end portion 14b of the aluminum wire 14 is inserted so that the compression rate α is about 8 to 21%, excessive pressure is applied during crimping. It is possible to avoid the disconnection of the aluminum wire 14 and the cracking of the crimping portion 15e of the terminal rod 15 due to the pressurization. Further, it is possible to avoid occurrence of loosening (relaxation) of contact between the aluminum wire 14 and the terminal rod 15 and uneven contact due to insufficient pressurization. Therefore, problems such as poor connection between the aluminum wire 14 and the terminal rod 15 and an increase in electrical resistance can be avoided.

  Further, the blocking member 25 is interposed between at least one of the plurality of aluminum wires 14c, or between the plurality of aluminum wires 14 and the terminal rod 15, and between the plurality of aluminum wires 14c and 14c. Since the terminal rod 15 is crimped to the aluminum wire 14 and the blocking member 25 blocks the permeation of oxygen, it is possible to avoid the occurrence of an oxidized contact between the aluminum wire 14 and the terminal rod 15. Therefore, it is possible to avoid the problem of increase in electrical resistance due to contact oxidation. Since the shielding material 25 is made of conductive powder, more specifically, oil containing aluminum powder, it is possible to realize good energization between the aluminum wire 14 and the terminal rod 15. Since the conductive powder contained in the shielding material 25 interposed between the aluminum wire 14 and the terminal rod 15 and between the plurality of aluminum wires 14c, 14c is all made of aluminum, corrosion due to contact of different materials ( Electrolytic corrosion) can be suppressed, and furthermore, good current conduction between the aluminum wire 14 and the terminal rod 15 can be realized.

  Then, as shown in FIG. 7, after the aluminum wire 14 is coupled to the terminal rod 15, the seal member 16 is inserted from the screw portion 15f side of the terminal rod 15 toward the shaft portion 15a until it contacts the flange portion 15b. . However, the sealing member 16 may be inserted in advance before the aluminum wire 14 is coupled to the terminal rod 15.

  Then, as shown in FIG. 8, the motor casing that surrounds the opening 9 a with the spacer 12 having the O-ring 21 disposed on the contact surface with the motor casing 9 and the contact surface with the terminal block 13, respectively. 9 is arranged on the outer wall of the peripheral edge. Then, as shown in FIG. 9, the terminal block 13 is arranged outside the spacer 12 while passing the terminal rod 15 from the flange portion 13 b of the terminal block 13 through the through portion 13 d, and the spacer 12, the terminal block 13, and the outer box 20. Is attached to the motor casing 9 with mounting bolts 19. Then, the flange portion 15b of the terminal rod 15 is fitted into the recess 13b, and the nuts 17a and 17b are screwed into the screw portion 15f to fix the terminal rod 15 to the terminal block 13 with a double nut. Thereafter, the connection terminal 18 is sandwiched and fixed between the nut 17b on the distal end side of the screw portion 15f and the nut 17c further screwed into the screw portion 15f of the double nut. Then, a lid 22 is attached to the outer box 20. With this attachment, the seal member 16 is elastically deformed by the seal portion 13c of the terminal block 13 and blocks communication between the inside and the outside of the motor casing 9. In addition, after the terminal block 13 is attached to the screw compressor 1 according to the above attachment procedure, when the screw compressor 1 is in a normal operation / stop state, the pressure inside the motor casing 9 is atmospheric pressure. Higher than. Therefore, the flange portion 15b of the terminal rod 15 is pressed in the direction toward the seal portion 13c, and the sealing effect in the seal portion 13c is also improved by this action. Further, the opening 9a of the motor casing 9 is hermetically sealed by O-rings 21 disposed on the contact surface with the motor casing 9 and the contact surface with the terminal block 13, respectively.

  In the screw compressor 1, the screw rotors 2 and 3 are rotated by the rotational force of the motor rotor 7, the refrigerant (ammonia gas) is sucked and compressed from the suction passage 11a, and the compressed refrigerant is discharged from the discharge passage 11b. To do.

  FIG. 10 shows a terminal crimping method of the aluminum wire 14 of Reference Example 2. About the screw compressor 1 comprised using the method of this reference example 2, since the component is the same as the screw compressor 1 comprised using the method of the reference example 1, description is abbreviate | omitted.

  As for the aluminum wire 14 of the reference example 2, the shielding material 25 is apply | coated to the outer surface (the outer peripheral surface and end surface of the front-end | tip part 14b) of the aluminum strand 14c. The blocking material 25 is applied after removing the oxide film on the surface of the aluminum wire 14 and the inner surface 15d of the terminal rod 15 with sandpaper, for example.

  According to the method of Reference Example 2, the terminal rod 15 is pressure-bonded to at least one of the plurality of aluminum strands 14c coated with the blocking material 25 on the outer surface, or the tip portions 14b of the plurality of aluminum wires 14. Since the blocking member 25 blocks the permeation of oxygen, it is possible to avoid an oxidized contact between the aluminum wire 14 and the terminal rod 15. Therefore, it is possible to avoid the problem of increase in electrical resistance due to contact oxidation.

  The inventor of the present application conducted the following experiment in order to ascertain whether there is a defect in the connection between the aluminum wire 14 and the terminal rod 15 due to the difference in the compression ratio α.

FIG. 11 shows the result of investigating the connection state between the aluminum wire 14 and the terminal rod 15. In the investigation, the outer diameter D ₁ and the inner diameter D ₂ of the crimping part 15e, the diameter d of the aluminum strand 14c, and the number n of the aluminum strands 14c were changed to various numerical values. Whether or not the electrical resistance between the aluminum wire 14c outside the terminal rod 15 and the end of the terminal rod 15 opposite to the crimping portion 15e is stable at a low level (a plurality of aluminum wires As a result of investigating the presence or absence of cracks occurring in the crimping portion 15e of the terminal rod 15, as shown in FIG. 11, the compression rate α is 7.78. %, 15.11%, 20.61%, etc., confirming that good results (a state where the electrical resistance is stable at a low level and the crimping part 15e is not cracked) are obtained. did it.

  In the above Reference Examples 1 and 2, the blocking material 25 is a substrate whose main component is oil, but the substrate whose main component is oil is semi-solid by dispersing a thickener in the raw material base oil. So-called grease may be used. According to this configuration, since the grease has an appropriate viscosity, it is easy to handle and the recess 15d can be easily filled with the blocking material 25, or the blocking material containing grease at the tip portion 14b of the aluminum wire 14 can be used. 25 can be easily applied.

  Further, the blocking material 25 may be made of conductive grease containing powder of silicon carbide engineering ceramics. By interposing the powder of silicon carbide-based engineering ceramics between the aluminum wire 14 and the terminal rod 15, the crimping of the aluminum wire 14 and the terminal rod 15 can be held more firmly, and loosening (relaxation) is achieved. Can be avoided.

  In the above reference examples 1 and 2, the screw compressor 1 has been described as an example, but a compressor other than the screw compressor 1 may be used. Further, the present invention can also be applied to a device such as a screw expander in which ammonia gas is in contact with a motor winding.

  Further, the terminal block 13 may be attached to the side portion of the motor casing 9 instead of the end portion via the spacer 12. Further, when there is a large space in the motor casing 9 where it is easy to dispose the aluminum wire 14, it is not essential to provide the spacer 12, and the motor casing 9 and the terminal block 13 are directly coupled. May be configured. The rotor casing 5 and the motor casing 9 are not separated by structural integrity. The portion that forms the rotor chamber 4 is the rotor casing 5, and the portion that forms the motor chamber 8 is the motor casing 9. Must be understood.

  Further, the seal portion may be as shown in FIGS. 12 (a) and 12 (b).

  In the case shown in FIG. 12A, an annular recess is provided on the surface of the terminal block 13 facing the surface of the flange portion 15b opposite to the crimping portion 15e, and the sealing member 16 is provided in the annular recess. Is inserted to form the seal portion 13e.

  In the case shown in FIG. 12B, the seal portion 13f is formed with the surface of the terminal block 13 facing the surface of the flange portion 15b opposite to the crimp portion 15e as a smooth surface. Here, an annular recess 15k is provided on the surface of the flange portion 15b opposite to the crimping portion 15e, and the seal member 16 is fitted into the annular recess 15k.

  12 (a) and 12 (b) can exhibit a sealing effect equivalent to or greater than that of the seal portion 13c of the reference examples 1 and 2 described above. However, the seal part 13c of the reference examples 1 and 2 described above is easier to process the seal part than the one shown in FIGS. 12A and 12B, and the seal member is attached to the seal part. It is advantageous in terms of ease of work.

  In the above example, the terminal rod 15 is made of pure aluminum or an aluminum alloy. However, the terminal rod 15 is made of a single material as exemplified by the terminal rod of the present invention below. It doesn't have to be. For example, in the terminal rod of the present invention, as shown in FIG. 13, an interface 15n is formed in a portion adjacent to the flange portion 15b of the crimping portion 15e of the terminal rod 15, and the interface 15n on the left side of the interface 15n in FIG. Is made of pure aluminum, and aluminum alloy (5000 series, 6000 series, etc. aluminum alloy) whose right side from the interface 15n in the drawing, that is, the flange portion 15b, the shaft portion 15a, and the screw portion 15f has a higher tensile strength than pure aluminum. It is comprised so that it may consist of. At the interface 15n, different aluminum materials are joined by brazing or welding. According to such a terminal rod 15, when the aluminum wire 14 to be crimped is made of pure aluminum, the crimping portion 15 e of the terminal rod 15 and the aluminum wire 14 are easily made of the same material and have the same linear expansion coefficient. Even if the temperature around the terminal rod 15 rises, it is possible to avoid loosening of the crimping between the terminal rod 15 and the aluminum wire 14 due to the temperature rise. Therefore, by crimping in a state where a blocking material is interposed, the contact portion between the aluminum wire 14 and the aluminum connection terminal 15 is further subjected to air remaining inside the motor 10 or external air entering from the suction side. By forming an oxide film over time due to oxygen contained, it is possible to avoid the occurrence of a problem that the electrical resistance at the contact portion increases. Further, since the flange portion 15b, the shaft portion 15a, and the screw portion 15f are made of an aluminum alloy having a high tensile strength, the flange portion 15b, the shaft portion 15a, and the screw portion 15f can be firmly fastened to the terminal block 13 with a nut or the like.

DESCRIPTION OF SYMBOLS 1 Screw compressor 2 Male rotor 3 Female rotor 4 Rotor chamber 5 Rotor casing 6 Motor stator 7 Motor rotor 8 Motor chamber 9 Motor casing 9a Opening part 9b Screw hole 10 Motor 12 Spacer 13 Terminal block 13a Insertion hole 13b Depression 13c, 13e, 13f Sealing part 13d Penetration part 14 Aluminum wire 14b Tip part 14c Aluminum element wire 15 Terminal bar (aluminum terminal)
15a Shaft portion 15b Flange portion 15c End surface 15d Recessed portion 15e Crimped portion 15f Screw portion 15g Outer peripheral surface 15h Communication portion 15j Clearance portion 15k Recessed portion 15m Inner peripheral surface 15n Interface 16 Seal member 17 Nut 18 Connection terminal 25 Blocking material

Claims (6)

A flange portion provided between one end and the other end; a crimping portion provided at the other end; a shaft portion provided on the opposite side of the flange portion from the crimping portion; and the shaft portion A screw portion provided on the opposite side of the flange portion,
A concave portion is formed on the end surface of the crimp portion so as to be surrounded by the crimp portion,
The terminal bar, wherein the crimping portion is made of pure aluminum, and the flange portion, the shaft portion, and the screw portion are made of an aluminum alloy having a higher tensile strength than pure aluminum.   2. The terminal rod according to claim 1, wherein the pure aluminum of the crimping portion and the aluminum alloy of the flange portion are joined at an interface between these different aluminum materials.   The terminal bar according to claim 1, wherein a communication portion that communicates the outer peripheral surface of the crimping portion and the concave portion is provided.   The terminal rod according to any one of claims 1 to 3, wherein an aluminum wire made of pure aluminum is crimped to the crimping portion.   The terminal bar according to claim 4, wherein a blocking material that blocks gas permeation is filled between the crimping portion and the aluminum wire.   The terminal rod according to claim 4, wherein the aluminum wire is composed of at least one or a plurality of aluminum wires, and a shielding material is applied to an outer surface of the aluminum wires.

Images