JP2015122161A - Terminal block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal block that reduces cost and improves quality.SOLUTION: A terminal block 1 includes a housing 2, a plate-like bus bar 3 and an adhesive 4. The housing 2 includes a resin molding part 21 formed from a resin. The bus bar 3 integrally includes an embedded part 32 that is embedded in the resin molding part 21, and a connection part 32 that protrudes outwards from an opening end 211 of the resin molding part 21. The adhesive 4 is arranged in a part of a gap 5 being present between the embedded part 32 and the resin molding part 21 and seals the gap 5. When a maximum temperature at which use is estimated is defined as T(°C) and a maximum use time estimated at the maximum temperature Tis defined as h(hours), viscosity of the adhesive 4 to which thermal processing is applied, to be maintained at the maximum temperature T°C for the time hhours at the maximum temperature Tis higher than 2100 Pa s.

Description

  The present invention relates to a terminal block.

  For example, a terminal block used for connecting an automobile wire harness or the like has a metal bus bar and a housing, and the bus bar is fixed to a resin portion of the housing by insert molding. The resin portion of the housing is usually difficult to adhere to metal, and easily undergoes dimensional changes due to molding shrinkage or the like. Therefore, a gap is inevitably formed between the housing and the bus bar. On the other hand, the terminal block may be required to liquid-tightly seal between the bus bar and the housing. In this case, usually, a sealing means for sealing the gap in a liquid-tight manner is provided between the housing and the bus bar.

  For example, Patent Document 1 discloses an example of a connector in which a metal bus bar and a resin connector housing are integrally formed by insert molding. In this connector, a seal portion is provided in advance in a portion of the bus bar embedded in the connector housing. Therefore, the resin portion and the seal portion of the housing are bonded during insert molding. Thereby, the clearance gap between a bus-bar and a connector housing is block | closed, and both are sealed liquid-tightly.

JP2013-45510A

  Generally, a resin-based adhesive is used for the seal portion of the terminal block. However, the resin-based adhesive has a problem that the viscosity decreases due to thermal deterioration during use. For this reason, there is a concern that the adhesive leaks from the connector housing when the terminal block is used for a long period of time.

  Therefore, various studies have been made to suppress leakage of the adhesive from the connector housing. However, in order to determine the presence or absence of leakage of the adhesive, there is no method other than actually preparing a test body and then heat-treating the test body itself to confirm the presence or absence of leakage.

  Further, in order to suppress the leakage of the adhesive, usually means for optimizing the shape of the connector housing is taken. Therefore, in order to obtain a connector housing that can suppress leakage of the adhesive, it is necessary to create a large number of test bodies in which the shape of the connector housing is changed. Therefore, there is a limit in reducing the cost required for trial production.

  The present invention has been made in view of such a background, and intends to provide a terminal block having low cost and excellent quality.

One aspect of the present invention is a housing having a resin molded portion made of resin,
A plate-like bus bar integrally provided with an embedded portion embedded in the resin molded portion and a connecting portion protruding outward from an opening end of the resin molded portion;
Arranged in a part of a gap existing between the embedded part and the resin molded part, and having an adhesive for sealing the gap,
The maximum temperature assumed to be used is T _max (° C),
When the maximum use time assumed at the maximum temperature T _max is h _max (hours),
The terminal block is characterized in that the adhesive that has been heat-treated at the maximum temperature T _max ° C for h _max time has a viscosity at the maximum temperature T _max greater than 2100 Pa · s.

The terminal block includes the adhesive configured to have a viscosity at the maximum temperature T _max of greater than 2100 Pa · s after being subjected to a heat treatment for h _max time at the maximum temperature T _max ° C. Yes. Therefore, the adhesive is unlikely to leak from the opening end after the heat treatment. As a result, the terminal block can prevent leakage of the adhesive after the heat treatment and has excellent quality.

  Moreover, as shown in the Example mentioned later, the said adhesive agent does not leak easily from an opening end, when changing the shape of a terminal block. Therefore, the use of the adhesive greatly simplifies the study of the housing shape. Therefore, the number of times of actually producing a test body including a housing, a bus bar, and an adhesive can be easily reduced, and as a result, the cost of trial production can be easily reduced.

  As described above, the terminal block has low cost and excellent quality.

The front view of the terminal block in Example 1. FIG. The top view of the terminal block in Example 1. FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. Sectional drawing which expanded the adhesive agent vicinity in FIG. The graph which shows the viscosity measurement result of the adhesive agent before heat processing in Example 1, and the viscosity measurement result of the adhesive agent after heat processing.

  In the terminal block, a thermoplastic resin such as an aromatic nylon resin reinforced with glass fiber or a polybutylene terephthalate resin reinforced with glass fiber is used for the resin molding part. These resins satisfy the characteristics required for terminal blocks such as heat resistance and insulation, and by appropriately selecting the glass fiber content, the linear expansion coefficient of the thermoplastic resin is changed to the linear expansion coefficient of the bus bar. Can be approached. Then, by making the linear expansion coefficient of the thermoplastic resin close to the linear expansion coefficient of the bus bar, deformation such as warpage due to mismatch of the linear expansion coefficient is reduced when the terminal block is heated. As a result, it becomes easy to suppress that the said clearance gap spreads too much, and it becomes easier to suppress the leakage of an adhesive agent by extension.

  In addition, a part of the resin molded portion constitutes a flow path wall portion that covers a flow path from the opening end to the adhesive, and the thickness of the flow path wall portion in the thickness direction of the embedded portion. The dimension is preferably 3 mm or less, and more preferably 2 mm or less. In this case, since the amount of the resin constituting the flow path wall portion is reduced, deformation due to thermal expansion when the terminal wall portion is heated is reduced. As a result, it becomes easy to suppress that the said clearance gap spreads in the thickness direction of the said embedding part, and it becomes easier to suppress the leakage of an adhesive agent by extension.

  The said terminal block can be used conveniently as a terminal block for connecting the wire harness for motor vehicles. Terminal blocks used for such applications are required to have both extremely high quality and low cost as compared to general-purpose terminal blocks. On the other hand, the terminal block becomes low cost and excellent by using the adhesive. Therefore, the said terminal block is suitable as a terminal block for connecting the wire harness for motor vehicles.

Example 1
Examples of the terminal block will be described with reference to FIGS. As shown in FIGS. 1 to 4, the terminal block 1 includes a housing 2, a bus bar 3, and an adhesive 4. As shown in FIG.1 and FIG.2, the housing 2 has the resin molding part 21 which consists of resin. Further, as shown in FIG. 3, the bus bar 3 has a plate shape, and is embedded in the resin molding portion 21 and two locations protruding outward from the opening end 211 of the resin molding portion 21. The connection part 31 is integrally provided. Further, the adhesive 4 is arranged in a part of the gap 5 existing between the embedded portion 32 and the housing 2, and is configured to seal the gap 5.

Then, when the maximum temperature assumed to be used is T _max (° C.) and the maximum use time assumed at the maximum temperature T _max is h _max (hour), the maximum temperature T _max ° C. is held for h _max time. The heat-treated adhesive 4 is configured such that the viscosity at the maximum temperature T _max is greater than 2100 Pa · s. The details will be described below.

  As shown in FIGS. 1 to 4, the housing 2 of the terminal block 1 has a substantially flat plate shape, and a resin molding portion 21 is provided at the center thereof. Further, a plurality of bus bars 3 are disposed through the resin molding portion 21. The plurality of bus bars 3 are arranged in the width direction of the embedded portion 32. The bus bar 3 is arranged so that the longitudinal direction of the embedded portion 32 faces the thickness direction of the housing 2. In the following, the arrangement direction of the bus bars 3 is referred to as “lateral direction Y”. The longitudinal direction of the embedded portion 32 is referred to as “height direction Z”, and the thickness direction of the embedded portion 32 is referred to as “vertical direction X”.

  As shown in FIG.1 and FIG.2, the housing 2 has the resin molding part 21 which consists of thermoplastic resins. The resin molding part 21 has the flow-path wall part 212 which covers the embedding part 32 of the bus-bar 3, as shown in FIGS. The flow path wall 212 covers the flow path 51 of the adhesive 4, which is a region from the opening end 211 in the gap 5 to the adhesive 4, from four directions in the vertical direction X and the horizontal direction Y. Moreover, as shown in FIG. 4, the thickness dimension d of the said flow-path wall part in the thickness direction (vertical direction X) of the embedment part 32 is 3 mm. In addition, the resin molding part 21 of this example is formed from the aromatic nylon resin reinforced with glass fiber.

  The bus bar 3 is made of a plate-like metal and, as shown in FIGS. 1 to 3, penetrates the resin molding portion 21 and is fixed to the resin molding portion 21 by insert molding. The bus bar 3 of this example has a rectangular shape in which a cross section perpendicular to the longitudinal direction has a width of 12.5 mm and a thickness of 2.5 mm.

  As shown in FIG. 3, the bus bar 3 has connection portions 31 at both ends of an embedded portion 32 embedded in the resin molding portion 21. Each connecting portion 31 has a fastening hole 311 and a fastening nut 312 for fastening a wire harness or the like.

  Moreover, as shown in FIG. 4, the area | region between the adhesive agent 4 and the opening end 211 of the resin molding part 21 in the clearance gap 5 becomes the flow path 51 at the time of the adhesive agent 4 leaking out. That is, the flow path 51 is configured by a space between the surface 321 of the embedded portion 32 and the inner surface 213 of the resin molded portion 21. The length L of the flow path 51 is 1.55 mm from the opening end 211 to the adhesive 4.

  The adhesive 4 is provided in a part of the gap 5 and seals between the embedded portion 32 and the resin molded portion 21 in a liquid-tight manner. In this example, an adhesive 4 made of epichlorohydrin rubber (manufactured by Daiso Corporation, product name “Epichromer H”) is used, but the adhesive 4 is made of, for example, a polyester resin or the like. It may be configured. Moreover, the thickness of the adhesive 4 before insert molding is 0.1 mm.

The adhesive 4 used in this example has a viscosity at the maximum temperature T _max of greater than 2100 Pa · s after being heat-treated at the maximum temperature T _max ° C for h _max time. The heat treatment method and viscosity measurement method of the adhesive 4 are as follows.

  First, the test piece which shape | molded the adhesive agent 4 in the sheet form of thickness 2mm is created. The obtained test piece is subjected to heat treatment that is maintained at a temperature T for h hours using a heating furnace or the like. In this example, the heat treatment conditions were a temperature T of 150 ° C. and a holding time h of 1000 hours.

  The viscosity value of the heat-treated specimen is measured using a rheometer (“ARES rheometer” manufactured by TA Instruments). The measurement conditions of the rheometer are as follows.

Measurement mode: shear mode (Auto strain control)
Temperature increase rate: 3 ° C / min Measurement frequency: 1Hz
Measurement geometry: Parallel plate φ25mm
Measurement atmosphere: nitrogen atmosphere

  The results of measurement as described above are shown in FIG. The vertical axis in FIG. 5 is the value of viscosity (Pa · s) and is logarithmically displayed. Moreover, the horizontal axis of FIG. 5 is the value of the measurement temperature (° C.). As shown in FIG. 5, the viscosity of the adhesive 4 that was heat-treated at 150 ° C. for 1000 hours was 7500 Pa · s at 150 ° C.

  Next, the terminal block 1 having the above-described configuration was subjected to a heat treatment held at 150 ° C. for 1000 hours, and the presence or absence of leakage of the adhesive 4 after the heat treatment was visually observed. As a result, leakage of the adhesive 4 from the gap 5 was not observed in all of the plurality of bus bars 3. In addition, the heat processing to the terminal block 1 was performed in the state which faced the opening end 211 of the resin molding part 21 vertically downward.

Next, the function and effect of this example will be described. The terminal block 1 has an adhesive 4 configured so that the viscosity at the maximum temperature T _max is higher than 2100 Pa · s after the heat treatment for h _max time at the maximum temperature T _max ° C. Therefore, the terminal block 1 can prevent leakage of the adhesive 4 after being subjected to heat treatment, and has excellent quality.

  Further, a part of the resin molding portion 21 constitutes a flow path wall portion 212 that covers the flow path 51 from the opening end 211 to the adhesive 4. And the thickness dimension d of the flow-path wall part 212 in the thickness direction of the embedding part 32 is 3 mm or less. For this reason, it is easy to suppress the gap 5 from being excessively widened in the thickness direction (vertical direction X) of the embedded portion 32, and thus it is easier to suppress leakage of the adhesive 4. As a result, the terminal block 1 has better quality.

  As described above, the terminal block 1 has low cost and excellent quality. And since the terminal block 1 has low cost and outstanding quality, it can be used suitably for the use which connects the wire harness for motor vehicles.

(Example 2)
This example is an example in which the presence or absence of leakage of the adhesive 4 is evaluated when the shape of the housing 2 and the heat treatment conditions are changed. In this example, three types of terminal blocks 1 having different shapes of the housing 2 were produced as test bodies (test bodies 1 to 3). Below, the detail of the test bodies 1-3 is demonstrated.

-Specimen 1
This is the same as the terminal block 1 in the first embodiment.

-Specimen 2
In the terminal block 1 of Example 1, the number of bus bars 3 was changed from six to three. Further, the adhesive 4 was provided in the embedded portion 32 so that the length L of the flow path 51 was 4.5 mm. Others are the same as in the first embodiment.

-Specimen 3
In the terminal block 1 of Example 1, the number of bus bars 3 was changed from six to three. In addition, the adhesive 4 was provided in the embedded portion 32 so that the length L of the flow path 51 was 5.5 mm. Others are the same as in the first embodiment.

  The test bodies 1 to 3 having the above-described configuration were subjected to a heat treatment for holding at the temperature T shown in Table 1 for h hours. Thereafter, the presence or absence of leakage of the adhesive 4 was confirmed visually. The results are shown in Table 1.

  Table 1 shows the viscosity of the adhesive 4 that has been heat-treated at the temperature T for h hours. The method for measuring the viscosity of the adhesive 4 is the same as in Example 1.

  As shown in Table 1, in any of the test bodies 1 to 3, no leakage of the adhesive 4 was observed under the heat treatment conditions in which the viscosity of the adhesive 4 was greater than 2100 Pa · s. On the other hand, under the heat treatment conditions where the viscosity of the adhesive 4 was 2100 Pa · s or less, the adhesive 4 leaked from any of the test bodies.

  As described above, the adhesive 4 having a viscosity after the heat treatment larger than 2100 Pa · s is not easily leaked from the opening end even when the shape of the terminal block is changed. Therefore, by using the adhesive 4, the study of the shape of the housing 2 is greatly simplified, and as a result, the trial production cost of the terminal block 1 can be easily reduced.

(Example 3)
In this example, the material of the adhesive 4 is changed. The test body 11 used for the test is the same as the test body 1 of Example 2 except that the adhesive 4 is changed to the adhesive 4 made of chlorosulfonated polyethylene resin. Similarly, the test body 12 is obtained by changing the adhesive 4 of the test body 2 to an adhesive 4 made of chlorosulfonated polyethylene resin, and the test body 13 is the adhesive 4 of the test body 3 that is chlorosulfonated polyethylene. The adhesive 4 is made of resin.

  Table 2 shows the result of visually confirming the presence or absence of leakage of the adhesive 4 after performing the heat treatment for holding at the temperature T for h hours. Table 2 also shows the viscosity of the adhesive 4 that has been heat-treated at the temperature T for h hours. The method for measuring the viscosity of the adhesive 4 is the same as in Example 1.

  As is known from Table 2, in any of the test bodies 11 to 13, no leakage of the adhesive 4 was observed under the heat treatment conditions in which the viscosity of the adhesive 4 was greater than 2100 Pa · s. On the other hand, under the heat treatment conditions where the viscosity of the adhesive 4 was 2100 Pa · s or less, the adhesive 4 leaked from any of the test bodies.

  As shown in Examples 1 to 3, the presence or absence of leakage of the adhesive 4 from the heat-treated terminal block 1 depends on the viscosity of the heat-treated adhesive 4 regardless of the shape of the housing 2. Determined. And the value of the viscosity of the adhesive 4 can be measured using only the adhesive that has been subjected to the heat treatment in advance, and it is not necessary to actually produce a test body including a housing, a conductor, and an adhesive. . Therefore, the trial production cost can be easily reduced.

In addition, the terminal block 1 is designed in advance so that the adhesive 4 does not leak out after the heat treatment for holding the maximum use time h _{max at} the maximum temperature T _max is performed by using the adhesive 4 having the above-described characteristics. Has been. That is, the terminal block 1 is designed in advance so that the adhesive 4 does not leak out under the severest use conditions among the assumed use conditions. Therefore, the terminal block 1 has excellent quality without the leakage of the adhesive 4 within the temperature range and period assumed for use.

DESCRIPTION OF SYMBOLS 1 Terminal block 2 Housing 21 Resin molding part 211 Open end 3 Conductor 31 Connection part 32 Embedding part 4 Adhesive 5 Crevice 51 Flow path

Claims (3)

A housing having a resin molded portion made of resin;
A plate-like bus bar integrally provided with an embedded portion embedded in the resin molded portion and a connecting portion protruding outward from an opening end of the resin molded portion;
Arranged in a part of a gap existing between the embedded part and the resin molded part, and having an adhesive for sealing the gap,
The maximum temperature assumed to be used is T _max (° C),
When the maximum use time assumed at the maximum temperature T _max is h _max (hours),
The terminal block characterized in that the adhesive at the maximum temperature T _max of the adhesive that has been heat-treated at the maximum temperature T _max ° C for h _max time is greater than 2100 Pa · s.   A part of the resin molded part constitutes a flow path wall part that covers the flow path from the opening end to the adhesive, and the thickness dimension of the flow path wall part in the thickness direction of the embedded part is The terminal block according to claim 1, wherein the terminal block is 3 mm or less.   The terminal block according to claim 1, wherein the terminal block is a terminal block for connecting an automobile wire harness.

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