JP2015176840A - Covered electric wire with terminal and wire harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a covered electric wire with a terminal and a wire harness in which generation of flaw, crack or peeling is suppressed in anticorrosive agent covering an electric connection part between a terminal metal fitting and an electric wire conductor.SOLUTION: An electric connection part 6 in which a terminal metal fitting 5 and an electric wire conductor 3 of a covered electric wire 2 are electrically connected is covered by anticorrosive agent 7 that consists of an insulating resin composition whose adhesive strength to the surface of the terminal metal fitting 5 is 0.1 MPa or more and hardness is 40 or more at Shore A hardness and 50 or less at Shore D hardness to constitute a covered electric wire 1 with a terminal. Further, a wire harness is constituted by including such a covered electric wire 1.

Description

  TECHNICAL FIELD The present invention relates to a coated electric wire with a terminal and a wire harness, and more particularly relates to a coated electric wire with a terminal excellent in corrosion resistance of an electric connection portion between an electric wire conductor and a terminal fitting, and a wire harness using the same.

  A terminal fitting is connected to the wire conductor at the end of the covered wire that is routed in a vehicle such as an automobile. It is required to prevent corrosion in the electrical connection portion where the terminal fitting and the wire conductor of the covered wire are electrically connected. In particular, for the purpose of reducing the weight of the vehicle, aluminum or an aluminum alloy may be used as the material for the wire conductor. On the other hand, copper or a copper alloy is often used as a material for the terminal fitting. Further, the surface of the terminal fitting is often subjected to plating such as tin plating. In other words, the wire conductor and the terminal fitting may be made of different materials. If the wire conductor and the terminal fitting are made of different materials, corrosion due to contact with different metals occurs at the electrical connection portion. For this reason, it is calculated | required that an electrical connection part should carry out corrosion prevention reliably.

  In order to achieve corrosion prevention in the electrical connection portion, attempts have been made to inject grease into the electrical connection portion or to cover the electrical connection portion with an adhesive resin. For example, Patent Document 1 discloses a polyamide-based resin composition for corrosion protection.

JP 2012-41494 A

  The anticorrosive which coat | covers the electrical-connection part between a terminal metal fitting and an electric wire conductor as described in patent document 1 forms the precise | minute film | membrane closely_contact | adhered to the terminal metal fitting surface, It is possible to prevent the intrusion and the like and fulfill the function of anticorrosion. However, when a connector is constructed by inserting a terminal fitting into a connector housing made of resin or the like, the anticorrosive layer is damaged, cracked or peeled off due to contact or friction between the connector housing and the anticorrosive agent. May occur. Then, there exists a possibility that the anticorrosion performance of an anticorrosive may fall.

  The problem to be solved by the present invention is to provide a coated electric wire with a terminal and a wire harness in which generation of scratches, cracks, and peeling is suppressed in an anticorrosive covering the electrical connection portion between the terminal fitting and the electric wire conductor. is there.

  In order to solve the above-mentioned problems, the covered electric wire with a terminal according to the present invention has an electrical connection portion in which the terminal fitting and the electric wire conductor of the covered electric wire are electrically connected, and the adhesive strength to the surface of the terminal fitting is 0.1 MPa or more. The gist is that it is coated with an anticorrosive agent comprising an insulating resin composition having a Shore A hardness of 40 or more and a Shore D hardness of 50 or less.

  Here, it is preferable that tin or a tin alloy is exposed on the surface of the terminal fitting.

  The insulating resin composition comprises at least one selected from olefin resin, polyamide resin, polyester resin, acrylic resin, epoxy resin, silicone resin, urethane resin, acrylic resin, phenol resin, and fluororesin. Good.

  The insulating resin composition may be a resin selected from a thermoplastic resin, a thermosetting resin, a moisture curable resin, an anaerobic curable resin, a two-component reaction curable resin, and an ultraviolet curable resin. .

  Moreover, the said terminal metal fitting is good to comprise copper or a copper alloy as a base material, and the said electric wire conductor is good to have a strand which consists of aluminum or an aluminum alloy.

  The wire harness concerning this invention makes it a summary to have said covered electric wire with a terminal.

  According to the coated electric wire with a terminal according to the present invention, the anticorrosive agent has an adhesive strength of 0.1 MPa or more with respect to the surface of the terminal metal fitting, so that peeling of the anticorrosive agent from the terminal metal fitting surface is suppressed. The Moreover, when the anticorrosive has a hardness of 40 or more in Shore A hardness, formation of scratches such as tearing on the surface of the anticorrosive is suppressed. Furthermore, when the hardness of the anticorrosive is 70 or less in Shore D hardness, it is difficult for the anticorrosive to crack. Due to these effects, even when the terminal fitting portion of the covered electric wire with terminal is inserted into the connector housing, the anticorrosive agent is hardly damaged, peeled off, cracked, etc., and high anticorrosion performance is maintained.

  Here, when tin or a tin alloy is exposed on the surface of the terminal fitting, using a general-purpose tin-plated terminal, the connection portion with the wire conductor is used as an anticorrosive having high resistance to damage. A covered covered electric wire with a terminal can be formed.

  When the insulating resin composition contains at least one selected from olefin resin, polyamide resin, polyester resin, acrylic resin, epoxy resin, silicone resin, urethane resin, acrylic resin, phenol resin, and fluororesin High anticorrosion performance is easily exhibited. When the insulating resin composition is a resin selected from a thermoplastic resin, a thermosetting resin, a moisture curable resin, an anaerobic curable resin, a two-component reaction curable resin, and an ultraviolet curable resin. The electrical connection portion can be coated with the anticorrosive with high efficiency.

  In addition, when the terminal fitting is composed of copper or a copper alloy as a base material and the wire conductor has a strand made of aluminum or an aluminum alloy, a dissimilar metal is in contact with the electrical connection portion of the covered electric wire with a terminal. If the anticorrosion treatment is not applied, the probability of corrosion will increase, but it has a high resistance to damage and has a terminal-coated wire using the anticorrosive agent as described above that exhibits excellent anticorrosion performance. In addition, the corrosion resistance of the electrical connection portion is improved and the connection reliability is excellent.

  Since the wire harness according to the present invention has the above-described coated electric wire with a terminal, the anticorrosive agent that covers the electrical connection portion is less susceptible to damage such as scratches, peeling, and cracks, and the wire harness that maintains high anticorrosion performance Become.

It is an external appearance perspective view which shows an example of the covered electric wire with a terminal of this invention. FIG. 2 is a longitudinal sectional view taken along line AA in FIG. 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Coated wire with terminal>
(Overall configuration)
FIG. 1 is an external perspective view showing an example of a coated electric wire with a terminal according to the present invention, and FIG. 2 is a longitudinal sectional view taken along line AA in FIG. As shown in FIGS. 1 and 2, the coated electric wire with terminal 1 of the present invention includes an electric wire conductor 3 of a covered electric wire 2 in which an electric wire conductor 3 is covered with an insulator 4, and a terminal fitting 5 by an electric connection portion 6. It is electrically connected.

  The terminal fitting 5 has a tab-like connection portion 51 made of an elongated flat plate connected to the counterpart terminal, a wire barrel 52 extending at the end of the connection portion 51, and an insulation barrel 53. Part 54.

  In the electrical connection portion 6, the insulator 4 at the end of the covered electric wire 2 is peeled off to expose the electric wire conductor 3, and the exposed electric wire conductor 3 is crimped to one side of the terminal metal fitting 5. And the terminal fitting 5 are connected. The wire barrel 52 of the terminal fitting 5 is crimped and crimped from above the wire conductor 3 of the covered electric wire 2 so that the wire conductor 3 and the terminal fitting 5 are electrically connected. Further, the insulation barrel 53 of the terminal fitting 5 is crimped and crimped from above the insulator 4 of the covered electric wire 2.

  The specific part which the anticorrosive 7 has coat | covered is the following parts. As shown in FIG. 1, the tip 2 a side of the covered electric wire 2 is covered with an anticorrosive 7 so as to protrude slightly from the tip of the wire conductor 3 to the connection portion 51 side of the terminal fitting 5. The tip 5 a side of the terminal fitting 5 is covered with the anticorrosive 7 so as to slightly protrude from the end of the insulation barrel 53 to the insulator 4 side of the covered electric wire 2. As shown in FIG. 2, the side surface 5 b of the terminal fitting 5 is also covered with the anticorrosive agent 7. The back surface 5 c of the terminal fitting 5 is not covered with the anticorrosive 7. In this way, the electrical connection portion 6 is covered with the anticorrosive agent 7 with a predetermined thickness along the outer peripheral shape of the terminal fitting 5 and the covered electric wire 2. The portion where the end of the covered wire 2 is peeled off and the wire conductor 3 is exposed is completely covered with the anticorrosive 7 and is not exposed to the outside. If the electrical connection is not affected, the back side of the wire fixing portion 54 of the terminal fitting 5 (including the back side of the wire barrel 52 and the insulation barrel 53) may be covered with the anticorrosive 7. .

  Accordingly, three of the peripheral ends of the anticorrosive agent 7 that covers the electrical connection portion 6 are in contact with the surface of the terminal fitting 5, and one is in contact with the surface of the insulator 4. That is, most of the peripheral edge of the anticorrosive 7 is in contact with the surface of the terminal fitting 5.

  Hereinafter, the specific structure of the covered electric wire 2, the terminal metal fitting 5, and the anticorrosive 7 which comprise the covered electric wire 1 with a terminal is demonstrated.

(Coated wire)
The electric wire conductor 3 of the covered electric wire 2 is made of a stranded wire formed by twisting a plurality of strands 3a. In this case, the stranded wire may be composed of one type of metal strand, or may be composed of two or more types of metal strand. Moreover, the strand wire may contain the strand etc. which consist of organic fibers other than a metal strand. Note that “consisting of one type of metal strand” means that all the metal strands constituting the stranded wire are made of the same metal material, and “consisting of two or more types of metal strands” This means that the wire contains metal wires made of different metal materials. The stranded wire may include a reinforcing wire (tension member) for reinforcing the covered electric wire.

  Examples of the material of the metal wire constituting the wire conductor 3 include copper, a copper alloy, aluminum, an aluminum alloy, or a material obtained by applying various platings to these materials. Examples of the material of the metal strand as the reinforcing wire include copper alloy, titanium, tungsten, and stainless steel. Examples of the organic fiber as the reinforcing wire include Kevlar.

  Examples of the material of the insulator 4 include rubber, polyolefin, PVC, and thermoplastic elastomer. These may be used alone or in combination of two or more. Various additives may be appropriately added to the material of the insulator 4. Examples of the additive include a flame retardant, a filler, a colorant and the like.

(Terminal bracket)
Examples of the material (material for the base material) of the terminal fitting 5 include various copper alloys and copper in addition to brass that is generally used. A part (for example, a contact) or the entire surface of the terminal fitting 5 may be plated with various metals such as tin, nickel, gold, or an alloy containing them.

  As described above, the wire conductor 3 and the terminal fitting 5 may be made of any metal material, but the terminal fitting 5 is made of a general terminal material in which a base material made of copper or a copper alloy is plated with tin. When the dissimilar metal is in contact with the electrical connection portion 6 as in the case where the wire conductor 3 includes the strand 3a made of aluminum or an aluminum alloy, the electrical connection portion 6 is brought into contact with moisture by contact with moisture. In particular, corrosion is likely to occur. However, the anticorrosive 7 as described below is in close contact with the surface of the electrical connection portion 6 and covers the electrical connection portion 6 so that such corrosion between different metals can be highly prevented. .

(Anticorrosive)
As described above, the anticorrosive 7 forms a dense film, and adheres to and covers the electrical connection portion 6 between the terminal fitting 5 and the wire conductor 3, thereby preventing intrusion of water or the like from the outside. . Thereby, it plays the role which prevents the corrosion by penetration | invasion of the water etc. to the electrical connection part 6. FIG.

  The anticorrosive 7 is made of an insulating resin composition and has an adhesive strength of 0.1 MPa or more with respect to the surface of the terminal fitting 5. Further, the anticorrosive 7 has a Shore A hardness of 40 or more and a Shore D hardness of 50 or less.

  The adhesion strength of the anticorrosive 7 can be measured as a tensile shear adhesion strength by conducting a tensile shear adhesion test in accordance with JIS K6850 at room temperature. Moreover, the hardness of the anticorrosive 7 can be measured at room temperature using a type A hardness meter or a type D hardness meter according to JIS K6253-3.

  Since the anticorrosive 7 has an adhesive strength of 0.1 MPa or more with respect to the surface of the terminal fitting 5, the anticorrosive 7 strongly adheres to the surface of the terminal fitting 5. Thereby, it is suppressed that the anticorrosive 7 peels from the surface of the electrical connection part 6 including the surface of the terminal metal fitting 5. Thus, the effect which suppresses peeling of the anticorrosive 7 is exhibited also when it receives the thermal shock exposed repeatedly to high temperature and low temperature. The adhesion strength of the anticorrosive 7 to the surface of the terminal fitting 5 is preferably 3 MPa or more, more preferably 10 MPa or more.

  Moreover, when the hardness of the anticorrosive agent 7 is 40 or more in Shore A hardness, the anticorrosive agent 7 is difficult to form scratches such as tears on the surface of the anticorrosive agent 7 when subjected to friction or scratching. Yes. On the other hand, when the hardness of the anticorrosive agent 7 is 50 or less in Shore D hardness, it is difficult for the anticorrosive agent 7 to crack. Thus, the effect of suppressing the formation of cracks and scratches in the anticorrosive 7 is also exhibited when subjected to thermal shock. The hardness of the anticorrosive 7 is preferably 50 or more in Shore A hardness. Moreover, it is preferable that it is D40 or less in Shore hardness.

  Thus, the anticorrosive agent 7 has a predetermined adhesive strength and hardness, and thus is less susceptible to damage such as peeling, scratching, and cracking during handling and use. The covered electric wire 1 with a terminal is often used as a connector by inserting a portion of the terminal metal fitting 5 into a connector housing (not shown) made of resin or the like. Or when the terminal fitting 5 is removed from the connector housing for replacement of the connector housing or the like. With such an insertion / extraction operation of the terminal fitting 5 with respect to the connector housing, a force such as friction or scratching is applied between the anticorrosive 7 covering the surface of the terminal fitting 5 and the wall surface of the connector housing. is there. Since the coated electric wire with terminal 1 has the above-described adhesive strength and hardness, damage such as peeling, scratching, and cracking occurs in the anticorrosive 7 even when such a force is applied. It is difficult to form a dense film and is in close contact with the terminal fitting 5 and the wire conductor 3. If the anticorrosive agent 7 is damaged as described above, it becomes difficult to prevent the entry of water or the like into the region covered with the anticorrosive agent 7, and the anticorrosion performance cannot be maintained.

  As a resin component which comprises the anticorrosive 7, what kind of thing may be used as long as it provides the above adhesive strength and hardness. Specifically, olefin resin, polyamide resin, polyester resin, acrylic resin, epoxy resin, silicone resin, urethane resin, acrylic resin, phenol resin, fluorine resin, and the like can be given. These may be used alone or in combination of two or more. Additives such as coloring pigments, viscosity modifiers, anti-aging agents, inorganic fillers, storage stabilizers, and dispersants may be appropriately added to the anticorrosive agent 7.

  The resin material constituting the anticorrosive 7 is preferably a thermoplastic resin or a curable resin. Examples of the curable resin include a thermosetting resin, a moisture curable resin, an anaerobic curable resin, a two-component reaction curable resin, and an ultraviolet curable resin. Each curing method may be used in combination. When the anticorrosive 7 consists of curable resin, it is used in the state finally made into hardened | cured material.

  When the anticorrosive agent 7 includes a thermoplastic resin or a curable resin, the electric connection portion 6 is coated with the anticorrosion agent 7 with high efficiency to form a dense film of the anticorrosive agent 7 in close contact with the electric connection portion 6. can do. In the case where the anticorrosive 7 contains a thermoplastic resin, it may be cooled after being applied to the electrical connection portion 6 while being plasticized by heating. When the anticorrosive agent 7 contains a curable resin, it may be applied to the electrical connection portion 6 in an uncured and highly fluid state, and then a curing operation corresponding to each curing method may be performed. For example, in the case of a thermosetting resin, the anticorrosive agent 7 may be applied and then heated, and in the case of an ultraviolet curable resin, the anticorrosive agent 7 may be applied and then irradiated with ultraviolet rays. Which curing method resin is used may be selected according to the site to which the anticorrosive 7 is applied, the use environment, or the like. Application | coating of the anticorrosive 7 can use well-known means, such as a dripping method, the apply | coating method, and the extrusion method. Further, when the anticorrosive agent 7 is applied, the temperature of the anticorrosive agent 7 may be adjusted by heating, cooling, or the like. Furthermore, in order to improve the permeability (coating property) of the anticorrosive agent 7, the anticorrosive agent 7 may be diluted with a solvent to form a liquid when applied.

  The adhesive strength and hardness of the anticorrosive 7 can be appropriately selected depending on the resin type. It can also be adjusted to some extent by the type and amount of additives such as inorganic fillers. Furthermore, when the anticorrosive 7 contains a curable resin, the hardness can be adjusted depending on the degree of curing.

<Wire harness>
The wire harness concerning this invention consists of a some covered electric wire containing the covered electric wire 1 with a terminal concerning the said invention. All of the covered electric wires constituting the wire harness may be the covered electric wires with terminals 1 according to the present invention, or only a part thereof may be the covered electric wires 1 with terminals according to the present invention.

  Examples of the present invention and comparative examples are shown below. In addition, this invention is not limited by these Examples.

1. Preparation of test piece <Adhesion test piece>
In order to perform a tensile shear adhesion test in accordance with JIS K6850, an adhesion test piece was prepared. That is, the anticorrosive agent which consists of various curable resin shown in following Table 1 with a thickness of 0.1 mm was apply | coated to the tin plating copper board, and it bonded together with the acrylic board. Here, the acrylic resin (Example 1, Comparative Examples 1 and 3) is an ultraviolet curable resin and is irradiated with ultraviolet rays using a mercury xenon lamp (500 mW / cm ² × 6 seconds) from the acrylic plate side. Cured. The epoxy resin (Example 2) is a thermosetting resin, and was cured by heating at 100 ° C. for 30 minutes. The silicone resin (Comparative Example 2) is a moisture curable resin, and was cured by leaving it in the air at room temperature for 7 days.

<Hardness test piece>
In order to measure the hardness of JIS K6253-3, an anticorrosive sheet was prepared. That is, by performing curing in the same manner as described above, each anticorrosive was cured into a sheet shape to produce a sheet having a thickness of 2 mm.

<Scratch specimen>
In order to perform a scratch test of JIS K5600-5-5, each anticorrosive agent was applied on an aluminum plate at a thickness of 0.5 mm, and the anticorrosive agent was cured by performing a curing operation in the same manner as described above.

2. Production of covered electric wire with terminal For 100 parts by mass of polyvinyl chloride (degree of polymerization 1300), 40 parts by mass of diisononyl phthalate as plasticizer, 20 parts by mass of calcium bicarbonate as filler, 5 parts by mass of calcium zinc-based stabilizer as stabilizer A polyvinyl chloride composition was prepared by mixing the parts with an open roll at 180 ° C. and forming them into pellets with a pelletizer. Next, using a 50 mm extruder, the polyvinyl chloride composition obtained above was 0.28 mm thick around a conductor (cross-sectional area 0.75 mm) made of an aluminum alloy twisted wire in which seven aluminum alloy wires were twisted together. And extrusion coated. This produced the covered electric wire (PVC electric wire).

  After stripping the end of the coated wire produced above to expose the wire conductor, a brass male crimp terminal fitting (tab width 0.64 mm), commonly used for automobiles, is crimped onto the end of the coated wire Crimped. Next, each anticorrosive agent shown in Table 1 was applied to the electrical connection portion between the wire conductor and the terminal fitting in a thickness of 0.5 mm to cover the exposed wire conductor and the barrel of the terminal fitting. And the anticorrosive was hardened similarly to the above, and the covered electric wire with a terminal was obtained.

3. Evaluation method <Measurement of adhesive strength>
A tensile shear adhesion test was performed on the adhesion test piece prepared above at room temperature in accordance with JIS K6850. The anticorrosive is peeled from the tin-plated copper plate side, and Table 1 shows the value of the adhesive strength (tensile shear adhesive strength) obtained at that time.

<Measurement of hardness>
The hardness test piece prepared above was measured at room temperature in accordance with JIS K6253-3. For the measurement, a type A hardness meter or a type D hardness meter was used according to the hardness of each anticorrosive agent. Table 1 shows the hardness values obtained.

<Scratch test>
In order to simulate the process of forming scratches on the anticorrosive agent by inserting and removing the connector, a scratch test was performed at room temperature in accordance with JIS K5600-5-5 using the scratch test piece created above. At this time, the scratching speed was 30 mm / s and the load applied to the scratching needle was 1 g. After scratching, the anticorrosive agent was visually observed, and a scratch (tear) penetrating the anticorrosive film was defined as a pass “◯”, and a scratch penetrating the anticorrosive film was formed. Things were rejected as “x”.

<Thermal shock test>
A thermal shock test (temperature change test) was performed in accordance with JIS C0025 in a state where the coated electric wires with terminals created above were inserted into the connector housing. Specifically, the cycle in which the covered electric wire with terminal was left at 125 ° C. for 1 hour and then left at −40 ° C. for 1 hour was repeated five times. Then, the electric wire with a terminal was taken out from the connector housing, and the external appearance was observed visually. The anticorrosive agent in which cracking or peeling did not occur was regarded as acceptable “◯”, and the one in which cracking or peeling occurred was regarded as unacceptable “x”.

<Results and discussion>
Table 1 shows the results of the scratch test and the thermal shock test for the test samples according to the examples and comparative examples, together with the adhesive strength and hardness.

  In Comparative Example 1, the anticorrosive has a high hardness exceeding 50 in Shore D hardness. For this reason, the anticorrosive agent is in a state of being easily cracked, and cracks are observed in the anticorrosive agent when subjected to a thermal shock test. In Comparative Example 2, the hardness of the anticorrosive agent is a low value of less than 40 in Shore A hardness. For this reason, the anticorrosive agent is damaged in the scratch test. In Comparative Example 3, the adhesion strength of the anticorrosive agent is a small value of less than 0.1 MPa. For this reason, adhesion of the anticorrosive agent to the electrical connection portion becomes insufficient, and peeling occurs in the anticorrosive agent when subjected to thermal shock.

  On the other hand, in Examples 1 and 2, no scratch was formed in the anticorrosive agent in the scratch test, and neither peeling nor cracking occurred in the anticorrosive agent even after the thermal shock test. This is because the anticorrosive agent has a Shore A hardness of 40 or more and a Shore D hardness of less than 50 and an adhesive strength of 0.1 MPa or more, so that it is damaged by scratches, cracks, peeling and the like. Indicates that it is difficult.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Coated electric wire with terminal 2 Coated electric wire 3 Electric wire conductor 4 Insulator 5 Terminal metal fitting 52 Wire barrel 53 Insulation barrel 54 Electric wire fixing part 6 Electrical connection part 7 Anticorrosive

Claims (6)

  The electrical connection portion in which the terminal fitting and the wire conductor of the covered electric wire are electrically connected has an adhesive strength to the surface of the terminal fitting of 0.1 MPa or more, a hardness of 40 or more in Shore A hardness and 50 in Shore D hardness. A coated electric wire with a terminal, which is coated with an anticorrosive comprising the following insulating resin composition.   The covered electric wire with a terminal according to claim 1, wherein tin or a tin alloy is exposed on a surface of the terminal fitting.   The insulating resin composition comprises at least one selected from olefin resin, polyamide resin, polyester resin, acrylic resin, epoxy resin, silicone resin, urethane resin, acrylic resin, phenol resin, and fluororesin. The covered electric wire with a terminal according to claim 1 or 2, characterized by the above-mentioned.   The insulating resin composition is a resin selected from a thermoplastic resin, a thermosetting resin, a moisture curable resin, an anaerobic curable resin, a two-component reaction curable resin, and an ultraviolet curable resin. The covered electric wire with a terminal according to any one of claims 1 to 3.   The said terminal metal fitting is comprised using copper or a copper alloy as a base material, and the said electric wire conductor has a strand which consists of aluminum or an aluminum alloy, The covering with a terminal of any one of Claim 1 to 4 characterized by the above-mentioned. Electrical wire.   A wire harness comprising the covered electric wire with a terminal according to any one of claims 1 to 5.

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