JP6645176B2 - Terminal block - Google Patents

Description

The present invention also relates to the terminal block.

  In recent years, hybrid vehicles and electric vehicles including a three-phase AC motor (hereinafter, also simply referred to as a motor) and an inverter have become widespread. In these vehicles, the current flowing through the motor is measured to appropriately control the rotation of the motor. The U-phase, V-phase, and W-phase terminals of the motor are respectively connected to the inverter via conductors (bus bars), and the magnitude of the current flowing through each bus bar is measured by a current sensor.

  The current sensor includes a magnetic core formed by laminating U-shaped magnetic materials, and a detection element (magnetic sensor) disposed in a gap provided at the tip of the magnetic core. In a current sensor, in a state where the bus bar is inserted into the internal space of the magnetic core, a magnetic flux generated around the bus bar is detected by a detecting element according to the magnitude of the current flowing through the bus bar, and the magnitude of the detected magnetic flux is detected. The magnitude of the current flowing through the bus bar is obtained by calculation based on. The magnetic core is used to concentrate the surrounding magnetic flux generated by energizing the bus bar inside the magnetic core, so that the magnetic sensor can efficiently detect the magnitude of the magnetic flux.

  In order to accurately measure the current value of the bus bar, the accuracy of the relative positional relationship between the bus bar and the current sensor is required. Therefore, usually, a terminal block in which a plurality of (for example, multiples of 3) bus bars and the same number of current sensors as the number of bus bars are housed in the main body and integrated is used (for example, see Patent Document 1).

JP 2014-006116 A

  The terminal block disclosed in Patent Document 1 is assembled by integrating six bus bars and a current sensor core (magnetic core) with a resin body by insert molding, and then mounting a Hall element (detection element). .

  As described above, since both ends of the bus bar are connected to the motor and the inverter, respectively, it is necessary to increase the positional accuracy of both end portions (hereinafter, also referred to as tip portions) of the bus bar on the terminal block. When the bus bar and the main body are integrated by insert molding, it is common to fill a molten resin into the mold while holding both ends of the bus bar in a molding mold (hereinafter, also simply referred to as a mold). is there. The holding of the bus bar in the mold continues until the body is formed and removed from the mold. Hereinafter, an assembly in which the bus bar taken out of the mold and the main body are integrated is also referred to as a main body with a bus bar. Heretofore, it has been considered that the positional accuracy of the end portion of the bus bar in the main body with the bus bar taken out of the mold is the same as the positional accuracy when the bus bar is held in the mold. However, in practice, it has been found that the positional accuracy of the tip portion of the bus bar in the main body with the bus bar is worse than the positional accuracy when the bus bar is held in the mold.

  In general, the degree of shrinkage of a resin product during curing is the smallest on the product surface, and is greater inside the product. Deterioration of positional accuracy in the body with the bus bar is caused by stress on the bus bar due to resin shrinkage inside the body integrated with the bus bar by insert molding, and when the body with the bus bar is removed from the mold due to this stress, the bus bar slightly It is considered that the movement and, as a result, the positional accuracy of the tip portion of the bus bar was deteriorated.

  As described above, when the bus bar and the main body are integrally formed by insert molding, the positional accuracy of the bus bar tip portion after the integral formation can be made substantially the same as the positional accuracy when the bus bar is inside the mold. A terminal block is required.

One embodiment of the terminal block according to the present invention includes a bus bar, and a resin body that is integrated with the bus bar and holds an intermediate portion of the bus bar, and the body is formed on both sides of the bus bar. And at least a part of the inner peripheral surface of each of the holes faces the bus bar, and the inner peripheral surface of one of the holes is formed on both of the two adjacent bus bars. is configured so as to face, the holes that have a extending direction formed along been recessed portions or convex portions of the bus bar.

Normally, when the bus bar and the main body are integrated, both ends of the bus bar are held. However, if the position accuracy of the end portion of the bus bar on the terminal block is not sufficient even if held in this manner, a pair of holes are formed on both sides of the bus bar in the main body, and a projection is inserted into the hole to insert the bus bar. Hold. As a result, the bus bar can be held with higher accuracy, and the positional accuracy of the end portion of the bus bar in the main body of the terminal block can be improved.
Also, the inner peripheral surface of one hole is configured to face both of the two adjacent bus bars, and the hole has a concave portion or a convex portion formed along the extending direction of the bus bar. In addition, it is possible to obtain a main body in which the creepage distance between adjacent bus bars is secured and the withstand voltage characteristics between the bus bars are satisfied.

  In one embodiment of the terminal block, when viewed from a direction perpendicular to both the extending direction of the bus bar and the depth direction of the hole, the holes forming the pair of holes are separated from each other. .

  If the holes constituting the pair of holes are separated from each other, the bus bar can be held over a wide range in the extending direction of the bus bar, so that the positional accuracy of the tip portion of the bus bar in the main body of the terminal block is improved. Can be done.

  One embodiment of the terminal block includes a plurality of the bus bars, and at least one pair of the holes is formed for each of the bus bars.

  Even if there are a plurality of bus bars, the main body has a pair of holes for each of the bus bars, so that the positional accuracy of the end portions of all the bus bars in the main body of the terminal block can be improved.

  One embodiment of the terminal block further includes a current sensor that detects a magnitude of a current flowing through the bus bar and is housed in the main body.

  By accommodating the current sensor in the terminal block, the magnitude of the current flowing through the bus bar can be detected by the current sensor.

It is a perspective view showing the composition of the terminal block concerning a 1st embodiment. It is a perspective view showing the structure of the lower mold | die which comprises a shaping | molding die, and showing the insertion process of a bus bar. FIG. 3 is a sectional view taken along the line III-III of FIG. 2 in a state where six bus bars are inserted into a lower mold. It is a perspective view showing the structure of the upper mold | die which comprises a shaping | molding die, and showing the mold closing process of an upper mold and a lower mold. It is a perspective view showing the lower mold in the state where the main body was formed by insert molding. It is a perspective view showing the process of inserting a magnetic sensor in a main body. It is a perspective view showing the process of inserting a magnetic core in a main body. 9 is a graph showing a difference in positional accuracy of a bus bar tip portion depending on the presence or absence of an intermediate restraint protrusion. It is sectional drawing showing the lower type | mold which has an intermediate | middle restraint projection for forming the main body of the terminal block which concerns on other embodiment (1). It is a top view showing the main part of the terminal block concerning other embodiment (1). It is sectional drawing showing the lower type | mold which has an intermediate | middle restraint projection for forming the main body of the terminal block which concerns on other embodiment (2). It is a top view showing the main part of the terminal block concerning other embodiment (2). It is sectional drawing showing the lower type | mold which has an intermediate | middle restraint projection for forming the main body of the terminal block which concerns on other embodiment (3). It is a top view showing the main part of the terminal block concerning other embodiments (3). It is sectional drawing showing the lower type | mold which has an intermediate | middle restraint projection for forming the main body of the terminal block which concerns on other embodiment (3). It is a top view showing the main part of the terminal block concerning other embodiments (3). It is sectional drawing showing the lower type | mold which has an intermediate | middle restraint projection for forming the main body of the terminal block which concerns on other embodiment (4). It is a top view showing the main part of the terminal block concerning other embodiment (4). It is sectional drawing showing the lower type | mold which has an intermediate | middle restraint projection for forming the main body of the terminal block which concerns on other embodiment (4). It is a top view showing the main part of the terminal block concerning other embodiment (4). It is sectional drawing showing the lower type | mold which has an intermediate | middle restraint projection for forming the main body of the terminal block which concerns on other embodiment (5). It is a top view showing the main part of the terminal block concerning other embodiments (5). It is a perspective view showing the shape of the bus bar used for the terminal block concerning other embodiment (5).

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

1. First embodiment [Terminal block structure]
As shown in FIG. 1, the terminal block 10 according to the first embodiment includes a main body 20, six bus bars 30, six magnetic cores 40, and six magnetic sensors 50. The main body 20 is made of resin, and is integrated with the bus bar 30 by insert molding. The configuration in which the magnetic core 40 and the magnetic sensor 50 are combined is an example of a current sensor. The method of assembling the terminal block 10 will be described later.

  The main body 20 has a central portion 202 into which the bus bar 30 is inserted, and ends 222 formed on both sides in the longitudinal direction of the central portion 202. The end 222 has a smaller thickness (the vertical direction in FIG. 1) than the center 202, and is formed parallel to the surface 204 with a step from the surface 204 of the main body 20. At each of the ends 222, a mounting hole 224 for mounting and fixing the terminal block 10 is formed.

  The shape of the end 222 is not limited to the shape shown in FIG. For example, end 222 may have no step with respect to surface 204 and may be coplanar with surface 204. Further, the end portion 222 has a step with respect to the surface 204, but may not be parallel to the surface 204, and may be curved or twisted. The end 222 can have any shape according to the shape of the portion where the terminal block 10 is fixed.

Six pairs (six pairs) of a pair of core holding holes 208 (see FIG. 7) formed at positions sandwiching each bus bar 30 are formed on the back surface 206 of the main body 20, and the U-shaped magnetic core 40 is formed therein. Is inserted. As shown in FIG. 1, six sensor holding holes 210 are formed on the surface 204 of the main body 20 so that the magnetic sensors 50 are arranged in the gaps between the magnetic cores 40. The six sets of core holding holes 208 and the six sensor holding holes 210 are all arranged in a staggered manner.
Further, from the front surface 204 to the back surface 206, six pairs (six pairs) of a pair of intermediate restraining holes 212 formed adjacent to the bus bar 30 and capable of facing the bus bar 30 from one inner peripheral surface thereof are formed. The six sets of intermediate restraining holes 212 are arranged in a straight line in parallel with the longitudinal direction of the main body 20. The intermediate restraining hole 212 is an example of a hole.

  The bus bar 30 has a rectangular plate shape and is made of a highly conductive metal such as copper or a copper alloy. One end of each of the six bus bars 30 is connected to U-phase, V-phase, and W-phase terminals of two three-phase AC motors (not shown), and the other end is connected to an inverter (not shown). You. As a result, the current flowing to the two three-phase AC motors flows through the six bus bars 30.

  The magnetic core 40 is configured by laminating a plurality of magnetic materials such as a U-shaped electromagnetic steel plate. The magnetic core 40 is inserted into a pair of core holding holes 208 of the main body 20 shown in FIG. 7, and is fixed to the main body 20 by a method such as bonding. Since the magnetic core 40 has a lower magnetic resistance than air, the magnetic flux generated around the bus bar 30 when a current flows through the bus bar 30 passes through the magnetic core 40 intensively.

  The magnetic sensor 50 is an element such as a Hall element that outputs a voltage (signal) according to the magnitude of the magnetic flux. The magnetic sensor 50 is inserted into a sensor holding hole 210 (see FIG. 1) of the main body 20 and fixed to the main body 20 by a method such as bonding. The magnetic sensor 50 is arranged such that its magnetic flux detecting portion is located in the gap of the U-shaped tip of the magnetic core 40 and faces the U-shaped tip.

[Operation of terminal block]
As described above, the terminal block 10 is used by connecting two three-phase AC motors and an inverter. When power is supplied to the three-phase AC motor, a current flows through the bus bar 30. When the current flows, a magnetic flux is generated around the bus bar 30. The magnitude of the generated magnetic flux is proportional to the magnitude of the flowing current. The generated magnetic flux is collected by the magnetic core 40 having a small magnetic resistance and passes through the magnetic core 40. Since the magnetic core 40 is U-shaped, the magnetic flux passes through the air between the gaps at the tip portions of the opposing U-shapes. Since the magnetic sensor 50 is disposed in the gap, the magnitude of the magnetic flux in the gap is detected by the magnetic sensor 50, and the magnitude of the current flowing through the bus bar 30 is determined based on the detected magnetic flux.

[Production method of terminal block]
Next, a method for manufacturing the terminal block 10 will be described with reference to FIGS. As shown in FIG. 2, a slit 604 for holding both ends of the bus bar 30 is formed in a lower die 62 of a molding die (hereinafter, also simply referred to as a die) 60. The depth of the slit 604 in the insertion direction of the bus bar 30 (the direction of the arrow in FIG. 2) is larger than the width of the bus bar 30. In the center of the lower mold 62, a concave portion 602 that becomes the main body 20 by being filled with a resin and cured is formed. At the bottom of the concave portion 602, a pair of prism-shaped core holding hole protrusions 608 (rectangular in cross section perpendicular to the standing direction) are provided so as to sandwich the bus bar 30 with a gap from the bus bar 30. Six sets (six pairs) of a pair of intermediate constraining protrusions 612 of a prismatic shape (a cross section perpendicular to the erecting direction is rectangular) standing in contact with the bus bar 30 and sandwiching the bus bar 30 are provided. Six pairs) are formed. Further, mounting hole protrusions 624 are formed at both ends in the longitudinal direction of the concave portion 602.
The intermediate restraining projection 612 is an example of a projection.

  The manufacturing process of the terminal block 10 will be described below. First, as shown in FIGS. 2 and 3, six bus bars 30 are inserted into the lower mold 62. Both ends of each bus bar 30 are held by the slits 604 and also by the intermediate restraining projections 612. Since the intermediate restraining projection 612 has a prism shape, the bus bar 30 can be held in a large area by abutting one side surface on the bus bar 30.

  Next, as shown in FIG. 4, the upper mold 64 of the mold 60 is fitted into the lower mold 62 and the mold is closed, and at least a middle restraining projection 612 inside the mold 60 is filled with a thermoplastic resin from a gate (not shown). Fill the area containing. The upper die 64 is formed with a plate-like projection 606 that fits into the slit 604 to prevent the resin from leaking to both ends of the bus bar 30 and six sensor holding hole projections 610.

  In FIG. 4, the upper mold 64 is inclined and opposed to the lower mold 62 for the sake of description of the plate-like projections 606 and the sensor holding hole projections 610. Are arranged to face each other so that the surfaces contacting each other are parallel.

  Next, after the mold 60 is cooled and the thermoplastic resin filled in the mold 60 is cured, the upper mold 64 is removed and the mold is opened (see FIG. 5). By this curing, the thermoplastic resin in the mold 60 becomes the main body 20. After hardening of the thermoplastic resin, six bus bars 30 are integrated with the main body 20 in a state of being inserted.

  Next, the main body 20 in which the bus bar 30 is inserted is taken out from the lower mold 62. On the main body 20, the shape of the core holding hole 208 formed by transferring the shape of the core holding hole projection 608, the shape of the sensor holding hole 210 to which the shape of the sensor holding hole projection 610 is transferred, and the shape of the intermediate restraining projection 612 are transferred. The mounting holes 224 to which the shapes of the formed intermediate restraining holes 212 and the mounting hole protrusions 624 are transferred are formed.

  As described above, the main body 20 is formed in a state where the intermediate restraining projection 612 is in contact with the bus bar 30, so that the contact surface 612 a of the intermediate restraining projection 612 with the bus bar 30 and the bus bar 30 are between the four side faces. Almost no resin flows into. Therefore, among the inner peripheral surfaces of the intermediate restraining holes 212 formed in the main body 20, there is almost no resin on the contact surface 212a formed by the contact surface 612a, and the bus bar 30 can be directly faced.

  Next, as shown in FIG. 6, the six magnetic sensors 50 are inserted into the six sensor holding holes 210, respectively, and as shown in FIG. The cores 40 are respectively inserted. Thus, the terminal block 10 was completed.

  FIG. 8 shows all the end portions of the six bus bars 30 in the case where the main body 20 is formed by providing the intermediate restraining projection 612 on the lower mold 62 and in the case where the main body 20 is formed without providing the intermediate restraining projection 612. The figure shows the results of measuring the average value of the positional accuracy (total 12 locations) for nine terminal blocks 10. In the graph of FIG. 8, the closer the vertical axis is to “0”, the more accurate the position accuracy of the front end portion of the bus bar 30 after the main body 20 is removed from the mold 60 is when the lower end 62 holds the front end of the bus bar 30. This indicates that the position accuracy is close to that of the part. As shown in FIG. 8, the provision of the intermediate restraining protrusion 612 maintains the positional accuracy of the distal end portion of the bus bar 30 in a state where the positional accuracy of the distal end portion of the bus bar 30 is held by the lower mold 62. I understand. By providing the intermediate restraining projection 612 in this manner, the positional accuracy of the end portion of the bus bar 30 in the main body 20 of the terminal block 10 can be improved.

  In the present embodiment, the middle restraining hole 212 formed by the middle restraining projection 612 penetrates the central portion 202 of the main body 20, but is not limited to this. The length of the intermediate restraining projection 612 may be shortened as long as the required positional accuracy is obtained at the end of the bus bar 30. In this case, the intermediate restraining hole 212 is a non-through hole.

2. Other Embodiments (1) In the first embodiment, one set of intermediate restraining projections 612 is formed for each bus bar 30, but the present invention is not limited to this. As shown in FIG. 9, the main body 20 may be formed using the lower mold 62 in which two sets of the intermediate restraining projections 612 are formed for one bus bar 30. As a result, as shown in FIG. 10, two sets of intermediate restraining holes 212 are formed in the main body 20. As described above, by forming the main body 20 by increasing the number of sets of the intermediate restraining projections 612, the positional accuracy of the end portion of the bus bar 30 in the main body 20 of the terminal block 10 can be further improved.

  (2) In the first embodiment, the intermediate restraining projection 612 has a prismatic shape, but the invention is not limited to this. As shown in FIG. 11, the main body 20 may be formed using a lower mold 62 in which the intermediate restraining projection 612 is formed in a columnar shape (a cross section perpendicular to the standing direction is circular). As a result, as shown in FIG. 12, a columnar intermediate restraining hole 212 is formed in the main body 20. As described above, by forming the intermediate restraining projection 612 in a cylindrical shape, the intermediate restraining projection 612 can be configured using a general-purpose round pin, and the cost of the mold 60 can be reduced. Thereby, the cost of the terminal block 10 can be reduced. The “columnar shape” includes not only the case where the cross section perpendicular to the standing direction is a circle but also the case where the cross section is an ellipse or an ellipse.

  (3) In the first embodiment, the pair of intermediate restraining projections 612 are formed at positions that are line-symmetric with respect to the bus bar 30, but the present invention is not limited to this. As shown in FIGS. 13 and 15, the main body 20 is formed by using the lower mold 62 in which one of the intermediate constraint protrusions 612 facing each other across the bus bar 30 is shifted along the extending direction of the bus bar 30. Is also good. As a result, as shown in FIGS. 14 and 16, a pair of intermediate restraining holes 212 are formed in the main body 20, which are shifted along the extending direction of the bus bar 30.

  At this time, when viewed from a direction perpendicular to both the extending direction of the bus bar 30 and the extending direction of the intermediate restraining hole 212 (the horizontal direction in FIGS. 14 and 16), a set of the intermediate restraining holes 212 is formed. The two intermediate restraining holes 212 may be configured to partially overlap (FIG. 14), or may be configured to be separated without overlapping at all (FIG. 16). With such a configuration, the bus bar 30 can be held over a wide range in the extending direction of the bus bar 30, although the configuration is not as good as the configuration of FIG. 10, and therefore, the tip of the bus bar 30 in the main body 20 of the terminal block 10. The positional accuracy of the part can be improved.

  (4) In the first embodiment, the pair of intermediate restraining projections 612 holds one bus bar 30, but the present invention is not limited to this. For example, when the strength (the cross-sectional area perpendicular to the extending direction) of the intermediate restraining projection 612 is insufficient, or when the distance between the adjacent bus bars 30 is short and two intermediate restraining projections 612 cannot be provided. Alternatively, the main body 20 may be formed using a lower mold 62 configured to hold two adjacent bus bars 30 with one intermediate restraining projection 612.

  However, with such a configuration, the withstand voltage characteristics (especially the creepage distance) between the adjacent bus bars 30 may not satisfy the specifications. In such a case, as shown in FIGS. 17 and 19, the side of the intermediate restraining projection 612 extending in the direction intersecting with the bus bar 30 among the side faces of the intermediate restraining projection 612 is moved in the extending direction of the bus bar 30. The main body 20 may be formed by using the lower mold 62 having a concave portion 614 (FIG. 17) or a convex portion 616 (FIG. 19) protruded outward along the inside of the intermediate restraining protrusion 612. . As shown in FIG. 17, if the intermediate restraining projection 612 has the concave portion 614, the man-hour for processing the intermediate restraining projection 612 is reduced, and the intermediate restraining projection 612 can be easily machined. On the other hand, as shown in FIG. 19, if the intermediate restraining projection 612 has the convex portion 616, the amount of outward projection can be increased, so that a larger creepage distance can be easily secured.

  By forming the main body 20 using the lower mold 62 configured using the intermediate restraining projections 612 as shown in FIG. 17, a concave portion 214 is formed in the intermediate restraining hole 212 along the extending direction of the bus bar 30. (FIG. 18). Further, by forming the main body 20 using the lower mold 62 configured using the intermediate restraining projections 612 as shown in FIG. 19, the convex portion 216 is formed in the intermediate restraining hole 212 along the extending direction of the bus bar 30. Formed (FIG. 20). In the main body 20, the intermediate restraining hole 212 is configured to have the concave portion 214 or the convex portion 216, so that the adjacent two bus bars 30 are connected to one intermediate restraining protrusion due to insufficient strength of the intermediate restraining protrusion 612 and the like. Even if the lower die 62 configured to be held at 612 is used, it is possible to obtain the main body 20 having the intermediate restraining hole 212 that ensures the creepage distance and satisfies the specification of the withstand voltage characteristic between the adjacent bus bars 30. Can be.

  (5) As shown in FIGS. 21 and 22, the linear busbar 30 cannot be used due to the specifications of the terminal block 10, and the busbar 30 is bent in a crank shape near the outer surface 205 of the main body 20. May need to be used. In such a case, since the distance between the crank portion 302 of the bus bar 30 (see FIG. 22) and the outer surface 205 of the main body 20 is too short, there is no space near the outer surface 205 of the main body 20 for forming the intermediate restraining hole 212. There are cases.

  In such a case, as shown in FIG. 23, instead of bending the entire bus bar 30 in a crank shape, a part of the bus bar 30 is extended without cranking to form an extended portion 304, and as shown in FIG. As described above, the main body 20 may be configured using the lower mold 62 having the intermediate restraining projections 612 provided on both sides of the extension portion 304. As a result, as shown in FIG. 22, a set of intermediate restraining holes 212 is formed in the main body 20 so as to sandwich the extension portion 304. With such a configuration, even if the bus bar 30 is bent in the shape of a crank near the outer surface 205, the end portion of the bus bar 30 in the main body 20 of the terminal block 10 is held by holding the bus bar 30 with the extension portion 304. Position accuracy can be improved.

  The configurations of the embodiments described above can be combined as much as possible.

The present invention can be used for a terminal block .

DESCRIPTION OF SYMBOLS 10 Terminal block 20 Main body 30 Bus bar 40 Magnetic core (current sensor)
50 Magnetic sensor (current sensor)
60 Molding die 212 Intermediate restraining hole (hole)
214 concave portion 216 convex portion 612 intermediate restraining projection (projection)

Claims (4)

A busbar,
A resin body that is integrated with the bus bar and holds an intermediate portion of the bus bar,
The main body has a pair of holes formed on both sides of the bus bar,
At least a part of the inner peripheral surface of each of the holes faces the bus bar ,
An inner peripheral surface of one of the holes is configured to face both of the two adjacent bus bars, and the hole has a concave portion or a convex portion formed along the extending direction of the bus bar. Stand. When viewed from a direction perpendicular to both the depth direction of the extending direction and the bore of the bus bar, wherein each of said holes constituting a pair of holes are spaced apart, the terminal block according to claim 1 . 3. The terminal block according to claim 1, wherein a plurality of the bus bars are provided, and at least one pair of the holes is formed for each of the bus bars. 4. Detecting the magnitude of current flowing through the bus bar, and further comprises a current sensor housed in the body, the terminal block according to any one of claims 1 to 3.

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