JP2018098008A - Electronic control unit for electric power steering device - Google Patents

Abstract

An electronic control unit for an electric power steering apparatus capable of improving durability and reliability in an electrical connection portion is provided. A controller includes a metal case, a metal power board constituting a power module system, and a control system fixed to the case while being spaced apart above the power board. A control board 40 that constitutes the power board 30, a cover 70 that is fixed to the case 20 so as to cover the power board 30 and the control board 40 from above, and a connector that has terminals for input and output to wiring necessary for steering assistance by the electric motor 50 and 60, and the terminals of the connectors 50 and 60 that are erected on the power board 30 are electrically connected to the terminal mounting portion of the control board 40 by press-fitting or press-contact without using solder. ing. [Selection] Figure 3

Description

  The present invention relates to an electronic control unit used in an electric power steering apparatus.

  For example, Patent Documents 1 to 3 are disclosed as the internal configuration of the electronic control unit of the electric power steering apparatus. The electronic control units described in these documents have a configuration in which a plurality of substrates are stacked in the vertical direction. Generally, a metal power substrate constituting a power module system is provided on the lower side, and the control system is provided on the upper side. The control board which comprises is provided.

  In connection between these boards, terminals (multi-pole lead terminals arranged in a row) standing on the power board are inserted into through-hole portions of the control board and connected by solder. In addition, various connectors such as a sensor input system, a power input system, and an external communication system, which are arranged around these substrates, are similarly connected with solder.

JP 2008-4364 A JP 2013-65696 A CN202935424U (Chinese utility model)

  However, in the case of solder connection, when solder deterioration (solder crack) in the solder connection part is progressed due to repeated thermal stress such as thermal expansion / contraction of the solder joint part over a long period of time, an OPEN failure in the solder connection part, etc. There is a concern that it may cause

  In other words, when an electric power steering device in which this type of electronic control unit and electric motor are integrated is installed in the vehicle, the ambient temperature of the electronic control unit varies greatly due to heat from the engine room and heat from the external environment. To do. Furthermore, this type of electronic control unit uses a large number of heat generating components such as a semiconductor switching element for current control, a shunt resistor for detecting a control current, and a large capacity capacitor for absorbing ripple.

  Therefore, the heat generated from these heat generating components is added, and the temperature change width inside the electronic control unit is further increased. Therefore, as in the techniques described in Patent Documents 1 to 3, when a plurality of substrates are connected to each other by soldering using multipolar lead wires, a large thermal stress or the like is applied to the solder connection part, resulting in a solder crack. There is a potential problem that durability and impact resistance may be reduced.

  In addition, in an electronic control unit having a two-board configuration in which a power board and a control board are stacked up and down, the two boards are electrically connected to each other using a connection terminal (for example, a multipolar lead connector). In addition to improving the reliability of this connection part, simplification of assembly work is required.

  Therefore, the present invention has been made paying attention to such problems, and it is an object of the present invention to provide an electronic control unit for an electric power steering apparatus that can improve durability and reliability in an electrical connection portion. And

  In order to solve the above-mentioned problems, the invention according to the first aspect of the present invention is an electronic control unit used in an electric power steering apparatus having an electric motor for assisting steering, and is made of a metal case, A metal terminal fixed in the case and having a metal terminal standing on its upper surface and constituting a power module system necessary for driving the electric motor, and spaced above the power board A control board that is fixed to the case in a state where it is fixed and constitutes a control system necessary for controlling the electric motor, and a cover that is fixed to the case so as to cover the power board and the control board from above. A connector having a terminal for performing input / output to / from wiring necessary for steering assistance by the electric motor, or a terminal arranged upright on the power board or Terminal of the serial connector, without using the solder, characterized in that it is electrically connected by press-fitting or press the terminal mounting portion of the control board.

  In order to solve the above-mentioned problems, the invention according to the second aspect of the present invention is an electronic control unit used in an electric power steering apparatus having an electric motor for assisting steering, and is made of a metal case. And a power module unit fixed in the case and constituting a power module system necessary for driving the electric motor, and a control system stacked on the power module unit and necessary for controlling the electric motor. The control module unit is integrally formed with a multilayer resin substrate, a cover fixed to the metal case so as to cover the resin substrate from above, and wiring necessary for steering assistance by the electric motor. A connector having a terminal for performing output, and the terminal of the connector is press-fitted or pressed into the terminal mounting portion of the resin substrate without using solder. Characterized in that it is electrically connected to I.

According to the electronic control unit for an electric power steering apparatus according to any one aspect of the present invention, the terminal is connected to the terminal mounting portion without using solder connection as an electrical connection means between the boards or between the board and the connector. Are electrically connected to each other by press fitting or pressure welding. Therefore, it is possible to prevent an OPEN failure due to solder deterioration (solder crack) due to thermal expansion and contraction at the connection portion.
Furthermore, with such a configuration, the point dip soldering process (flux application), which has been performed as a solder connection process, can be realized simply by a pressing process. Therefore, it contributes to reduction and shortening of process tact. Furthermore, since the amount of solder used in the manufacturing process can be reduced, a product that is friendly to the global environment can be provided.

  As described above, according to the present invention, durability and reliability in the electrical connection portion can be improved.

1 is a schematic diagram illustrating a basic structure of an electric power steering apparatus including a controller that is an embodiment (first embodiment) of an electronic control unit for an electric power steering apparatus according to the present invention. It is a block diagram which shows the control system of the controller of the electric power steering apparatus shown in FIG. It is a disassembled perspective view of the controller of the electric power steering apparatus shown in FIG. 2A and 2B are enlarged views of a press-fit terminal portion of the controller shown in FIG. 1, in which FIG. 1A shows a single terminal portion and FIG. It is a disassembled perspective view which shows 2nd embodiment of the electronic control unit which concerns on this invention. It is a disassembled perspective view which shows 3rd embodiment of the electronic control unit which concerns on this invention. It is A arrow line view of the metal case part in FIG. FIG. 7 is a B arrow view of the connector portion in FIG. 6 ((a)), and an enlarged view of a C portion in FIG. It is a figure explaining the structure of the press-contact part of the terminal used for the electronic control unit for electric power steering devices concerning the present invention, the figure (a) is the perspective view, (b) is a front view, (c) is the right side FIG. It is a figure explaining the structure of the press-contact part of the press fit terminal used for the electronic control unit for electric power steering devices concerning the present invention, the figure (a) is the perspective view, (b) is a front view, (c). Is a right side view. It is a disassembled perspective view which shows 4th embodiment of the electronic control unit which concerns on this invention. It is a D arrow line view of the metal case part in FIG. It is the figure ((a)) which looked at the connector part in FIG. 11 from the D direction, and the E section enlarged view ((b)) of the same figure (a).

  Hereinafter, an embodiment of an electric power steering apparatus including an electronic control unit for an electric power steering apparatus according to the present invention will be described with reference to the drawings as appropriate. The drawings are schematic. For this reason, it should be noted that the relationship between the thickness and the planar dimension, the ratio, and the like are different from the actual ones, and the dimensional relationship and the ratio are different between the drawings. Each embodiment or modification shown below exemplifies an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention is the material and shape of the component parts. The structure, arrangement, etc. are not specified in the following embodiments or modifications.

  In the electric power steering apparatus according to the first embodiment, as shown in FIG. 1, the column shaft 2 to which the steering handle 1 is attached is steered from the reduction gear 3 via the universal joints 4 </ b> A and 4 </ b> B and the pinion rack mechanism 5. It is connected to the tight rod 6 of the wheel. The column shaft 2 is provided with a torque sensor 7 that detects the steering torque of the steering handle 1, and an electric motor 8 that assists the steering force of the steering handle 1 is connected to the column shaft 2 via the reduction gear 3. It is connected.

  A controller 10 is attached to the electric motor 8. The controller 10 is an electronic control unit that controls the electric power steering apparatus. The controller 10 calculates a steering assist command value serving as an assist (steering assist) command based on the steering torque Ts detected by the torque sensor 7 and the vehicle speed V detected by the vehicle speed sensor 9, and the calculated steering assist is calculated. Based on the command value, the current supplied to the electric motor 8 is controlled. The mechanism and configuration of the controller 10 are shown in FIG.

  Electric power is supplied to the controller 10 from a battery (not shown), and an ignition key signal IGN is input via an ignition key (not shown) as shown in FIG. The ignition signal IGN from the ignition key is input to the ignition voltage monitor unit 18 and the power supply circuit unit 19, and the power supply voltage Vdd is input from the power supply circuit unit 19 to the control arithmetic unit 11, and a reset for stopping the apparatus is performed. The signal Rs is input to the control arithmetic device 11.

  The steering torque Ts detected by the torque sensor 7 and the vehicle speed V detected by the vehicle speed sensor 9 are input to the control arithmetic device 11. The current command value calculated by the control calculation device 11 is input to the gate drive circuit 12. The gate drive circuit 12 forms a gate drive signal based on the current command value and the like, and the gate drive signal is input to the motor drive unit 13 having a FET bridge configuration. The motor drive unit 13 drives the electric motor 8 constituted by a three-phase brushless motor through the emergency stop circuit 14. The interruption | blocking apparatus 14 is comprised by the relay contacts 141 and 142 which interrupt | block two phases.

  Each phase current of the electric motor 8 is detected by the current detection circuit 15, and the detected three-phase motor currents ia to ic are input to the control arithmetic device 11 as feedback currents. In addition, a rotation sensor 16 such as a hall sensor is attached to the electric motor 8, and a rotation signal RT from the rotation sensor 16 is input to the rotor position detection circuit 17, and the detected rotation position θ is a control arithmetic unit. 11 is input.

  In the motor drive unit 13, FETTr1 and Tr2, FETTr3 and Tr4, and FETTr5 and Tr6 connected in series to the power supply line 81 are connected in parallel to each other. Then, FETTr1 and Tr2, FETTr3 and Tr4, and FETTr5 and Tr6 connected in parallel to the power supply line 81 are connected to the ground line 82, thereby configuring an inverter circuit.

  Here, the FETTr1 and Tr2 are configured such that the source electrode S of the FETTr1 and the drain electrode D of the FETTr2 are connected in series to form a c-phase arm of a three-phase motor, and a current is output from the c-phase output line 91c. In addition, the FETTr3 and Tr4 are configured such that the source electrode S of the FETTr3 and the drain electrode D of the FETTr4 are connected in series to form an a-phase arm of a three-phase motor, and a current is output from the a-phase output line 91a. Further, the FETTr5 and Tr6 are configured such that the source electrode S of the FETTr5 and the drain electrode D of the FETTr6 are connected in series to form a b-phase arm of a three-phase motor, and a current is output from the b-phase output line 91b.

FIG. 3 is an exploded perspective view of the controller 10 of the first embodiment.
As shown in the figure, the controller 10 is coated with a metal case 20 (for example, aluminum die-cast), a power board 30 constituting a power module system including the motor drive unit 13, and a heat conductive paste. A heat dissipation sheet 39, a control board 40 constituting a control system including the control arithmetic unit 11 and the gate driving circuit 12, a power and signal connector 50, a three-phase output connector 60, and a sealing cover 70 With. When mounted on the vehicle, the power board 30 and the control board 40 are fixed in a state in which they are stacked in a vertical orientation.

  The case 20 is formed in a substantially rectangular shape in plan view, and has a flat plate-like substrate placement portion 21 for placing the power substrate 30, and power and power provided at the longitudinal ends of the substrate placement portion 21. Three-phase output for mounting a power / signal connector mounting portion 22 for mounting the signal connector 50 and a three-phase output connector 60 provided at the width direction end of the substrate mounting portion 21 The connector mounting part 23 is provided.

  A plurality of screw holes 21 a into which mounting screws 38 for mounting the power substrate 30 are screwed are formed in the substrate mounting portion 21. A plurality of posts 24 for mounting the control board 40 are erected on the upper surface of the case 20. Each post 24 is formed with a screw hole 24a into which a mounting screw 41 for mounting the control board 40 is screwed from above. Further, the three-phase output connector mounting portion 23 is formed with a plurality of screw holes 23a into which the mounting screws 61 for attaching the three-phase output connector 60 are screwed.

  The power / signal connector 50 has a plurality of terminals 102 for performing input to wiring necessary for steering assistance by the electric motor 8, and inputs DC power from a battery (not shown) to the power board 30. At the same time, it is used to input various signals including signals from the torque sensor 7 and the vehicle speed sensor 9 to the control board 40. The power / signal connector 50 includes a resin frame 50f made of a heat-resistant resin material, and the resin frame 50f is attached to the power / signal connector mounting portion 22 of the case 20 from the back side of the case 20 by a mounting screw 50n. It is attached.

The three-phase output connector 60 has an output terminal 62 that outputs to wiring necessary for assisting steering by the electric motor 8, and the output terminal 62 and the three-phase output unit 90 are connected by resistance welding. The current from the phase output terminal 92a, the b-phase output terminal 92b, and the c-phase output terminal 92c is output to the electric motor 8.
The three-phase connector 60 includes a resin frame 60f made of a heat-resistant resin material. A plurality of through holes 60a through which the mounting screws 61 are inserted are formed in the resin frame 60f. The resin frame 60 f is attached to the three-phase output connector mounting portion 23 provided on the plurality of attachment screws 61.

  The cover 70 covers the power board 30 and the control board from above the control board 40 with respect to the case 20 with the power board 30, the control board 40, the power / signal connector 50, and the three-phase output connector 60 attached thereto. It is attached so that 40 may be covered.

  The power board 30 includes a board body 31, and a plurality of through holes 31 a through which mounting screws 38 for attaching the power board 30 to the case 20 are inserted at appropriate positions around the board body 31. Yes. The substrate main body 31 is mounted with other surface mount components necessary for the power module system including components and capacitors necessary for the circuit of the motor drive unit 13 described above. Further, the substrate body 31 of the first embodiment includes an a-phase output terminal 92a connected to the a-phase output line 91a, a b-phase output terminal 92b connected to the b-phase output line 91b, and a c-phase output line 91c. A three-phase output unit 90 including a connected c-phase output terminal 92c is mounted.

  The control board 40 includes a microcomputer including a power supply circuit, a sensor input circuit, a signal processing circuit, an external communication circuit (CAN), a PWM circuit, and the like. In the control board 40, a plurality of electronic components are mounted on a multilayer board body 43 to constitute a control circuit including the control arithmetic device 11 and the gate drive circuit 12. The control board 40 is formed with a plurality of through holes 40 a through which the mounting screws 41 are inserted at appropriate positions around the control board 40, and a plurality of the control boards 40 erected on the upper surface 24 s of the case 20 in a state of being spaced apart above the power board 30. A plurality of mounting screws 41 are mounted on the post 24 of the head.

  Here, a multi-pole lead connector 101 as a connection terminal is mounted on the power board 30 at a plurality of positions (in this example, two places). The multi-pole lead connector 101 controls the power board 30. The substrate 40 is connected to each other.

  Specifically, each multipolar lead connector 101 has a plurality of pin-shaped terminals 110. The plurality of pin-shaped terminals 110 are arranged at a predetermined pitch in a line in a direction orthogonal to the connection direction. Each pin-shaped terminal 110 is formed by punching and bending a metal plate, and is erected so as to extend in the connecting direction.

  In the present embodiment, the pin-shaped terminal 110 has two types of overall shapes, one in which the press-fit connection portion 112 extends linearly upward in the connection direction of the holding member 111 and one bent from the upper end in the connection direction of the holding member 111 to the front side. Some of them extend upward through the bent portion.

  The holding member 111 is a member having a rectangular cross section, and is formed by molding an insulating resin. The holding member 111 is formed by insert molding together with the plurality of pin-shaped terminals 110. Thereby, the multipolar lead connector 101 can be manufactured by a simple manufacturing process. The holding member 111 holds a plurality of pin-shaped terminals 110 at a predetermined pitch. By holding the plurality of pin-shaped terminals 110 by the holding member 111, the press-fit connection portion 112 and the surface mount connection portion 113 in each pin-shaped terminal 110 can be positioned.

  In the plurality of press-fit connection portions 112, pin-like terminals 110 extending in a straight line and pin-like terminals 110 extending through bent portions are alternately arranged in the terminal arrangement direction. As a result, the press-fit connection portions 112 are alternately arranged in the alignment direction between the ones extending in a straight line and the ones extending through the bent portions, so that the plurality of press-fit connection portions 112 are staggered along the terminal alignment direction. Arranged and high density arrangement is possible.

  Here, each pin-shaped terminal 110 is a press-fit terminal having a press-fit connection portion 112 extending to the upper end in the connection direction and a surface mount connection portion 113 on the lower end side in the connection direction. The surface mounting connection portion 113 in each pin-like terminal 110 is surface mounted on a conductive pad (not shown) on the substrate body 31 in the power substrate 30. When the multipolar lead connector 101 is mounted on the power board 30, the surface mounting connection portions 113 of the plurality of pin-shaped terminals 110 are electrically connected to the conductive pads on the board body 31 of the power board 30 by press-fitting or press-contacting. Is done.

As shown in an enlarged view in FIG. 4, the press-fit connecting portion 112 of the first embodiment has a pointed-shaped introduction portion 112d at the tip of the press-fit connecting portion 112 and is formed along the press-fitting direction. A pair of elastically deformable elastic pressure contact portions 112t disposed opposite to each other with a slit 112s serving as a bending space interposed therebetween.
The press-fit connecting portion 112 is inserted from the introduction portion 112d side into a through hole 42 that is a terminal mounting portion formed at a position facing the control board 40, and the outer surface of the pair of elastic pressure contact portions 112t is the through hole 42. It is a press-fit part that is press-fit connected to the inner wall surface.

Next, a method for attaching the power board 30 and the control board 40 to the case 20 will be described.
First, as shown in FIG. 3, the power board 30 on which the multipolar lead connector 101 is mounted is mounted on the board mounting portion 21 of the case 20 with a plurality of mounting screws 38. Prior to mounting the power substrate 30 on the substrate mounting portion 21, a heat dissipation sheet 39 coated with a heat conductive paste is mounted on the substrate mounting portion 21, and the power substrate 30 is mounted on the heat dissipation sheet 39. . The heat generated in the power board 30 is radiated to the case 20 through the heat dissipation sheet 39 by the heat dissipation sheet 39.

  Then, after mounting the power board 30 on which the multipolar lead connector 101 is mounted on the board mounting part 21, the control board 40 is mounted on the board mounting part 21 and the power / signal connector mounting part from above the power board 30. A plurality of mounting screws 41 are attached to a plurality of posts 24 erected on 22. Thereby, the power board 30 and the control board 40 can be attached to the case 20.

At this time, the press-fit connection portions 112 of the pin terminals 110 of the multipolar lead connector 101 mounted on the power board 30 are inserted into the through holes 42 of the control board 40 and press-fit connected by press-fitting.
As shown in FIG. 4B, this press-fit connection is made by connecting a pair of elastic pressure contact portions 112t wider than the through-hole diameter to the through-hole 42 having a conductive inner wall surface 42h opened in the control board 40. Thus, the pressure contact surfaces of the pair of elastic pressure contact portions 112t are pressure contacted with the compressive stress remaining on the conductive inner wall surface 42h of the through hole 42.

Each pin-shaped terminal 110 of the multipolar lead connector 101 is held by the holding member 120 at a predetermined pitch. Therefore, the press-fit connection part 112 in each pin-shaped terminal 110 can be reliably positioned in the predetermined through-hole 42 facing each other.
Therefore, the press-fit connection part 112 of each pin-shaped terminal 110 is inserted into each through-hole 42 of the control board 40 appropriately and smoothly. Therefore, the press-fit connection of the press-fit connection portion 112 can be stably performed, and the electric conductivity variation in each pin-shaped terminal 110 can be suppressed.

  As described above, in the first embodiment, the pin-like terminals 110 of the multipolar lead connector 101 are used as predetermined through-holes without using solder connection as electrical connection means between the control board 40 and the power board 30. Since it is electrically connected to the hole 42 by press-fitting, an OPEN failure due to solder deterioration (solder crack) due to thermal expansion and contraction at the connection portion can be prevented.

  Furthermore, with such a configuration, the point dip soldering process (flux application), which has been performed as a solder connection process, can be realized simply by a pressing process. Therefore, it contributes to reduction and shortening of process tact. Furthermore, since the amount of solder used in the manufacturing process can be reduced, a product that is friendly to the global environment can be provided.

  As mentioned above, although 1st embodiment of this invention was described, this invention can be variously changed and improved without being limited to said 1st embodiment. For example, the plurality of pin-like terminals 110 arranged in a direction orthogonal to the connection direction of the press-fit connection portion is not limited to a single row, and may be arranged in a plurality of rows.

  Further, for example, in the first embodiment, an example in which the multilayer control board 40 and the power board 30 are configured from two boards having separate components is shown, but the present invention is not limited to this. In the first embodiment, the example in which the press-fit connection is used without using the solder connection as the electrical connection means between the control board 40 and the power board 30 has been described. It can electrically connect also to the terminal connection part of another connector by press-fitting or press-contact. Such a mode is shown in the second embodiment.

  As shown in FIG. 5, the controller 10 of the second embodiment is different from the control board 40 and the power board 30 in the first embodiment in that the board is limited to one multilayer resin board 80. Is different. In the figure, the same or corresponding components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be appropriately omitted except for differences (the same applies to other embodiments below).

  In the resin substrate 80 according to the second embodiment, a power module part constituting a power module system and a control module part constituting a control system are integrated. In the second embodiment, the plurality of terminals 102 of the power and signal connector 50 and the output terminal 62 of the three-phase output connector 60 are arranged at the tips of the respective pin-like terminals as in the first embodiment. Having a press-fit connection.

  Then, in the terminal mounting portion of the resin substrate 80, a through hole having a predetermined shape corresponding to each pin-shaped terminal arranged opposite to each other at the position facing the tip of each pin-shaped terminal, as in the first embodiment. 42 is provided. That is, in the three-phase output connector 60 of the second embodiment, the output terminal 62 is connected by press-fit connection to the through hole 42 corresponding to the three-phase output portion instead of resistance welding.

In the second embodiment, the resin substrate 80 is formed with a plurality of through holes 40a through which the mounting screws 41 are inserted at appropriate positions around the resin substrate 80, and on the plurality of posts 24 erected on the upper surface 24s side of the case 20. Are attached by a plurality of mounting screws 41.
In the second embodiment, first, the power and signal connector 50 is attached to the three-phase output connector mounting portion 23 with a plurality of mounting screws 61, and the three-phase output connector 60 is mounted with a plurality of mounting screws 50n. Attach to the power / signal connector mounting portion 22. Thereafter, the resin substrate 80 is mounted on the case 20 with a plurality of mounting screws 41.

Here, in the second embodiment, the mounting direction of the connectors 50 and 60 and the connection direction of the press-fit connection portion of each pin-shaped terminal are the same direction. Accordingly, the press-fit connection portions of the pin terminals 102 of the power / signal connector 50 and the output terminals 62 of the three-phase output connector 60 are connected to the through holes when the resin substrate 80 is mounted. The press-fit connection can be surely made by inserting through 42 and press-fitting with a predetermined pressure.
Thus, according to the controller 10 of the second embodiment, the power / signal connector 50 and the three-phase output connector 60 each have the press-fit connection portion at the tip of each pin-like terminal. Each terminal can be electrically connected to each terminal mounting portion of the resin substrate 80 by press-fitting or press-contact without using solder.

  In the first and second embodiments, the control board 40 or the multilayer resin board 80 is fixed using a plurality of mounting screws. However, the present invention is not limited to this. In the present invention, the press-fit connection also serves as a mechanical connection means, thereby eliminating the need for mounting screws for these substrates. As such aspects, third and fourth embodiments will be described below.

  As shown in FIG. 6, the controller 10 of the third embodiment is not provided with a plurality of through holes 40a in the control board 40B. Instead, two mounting reference holes 40k are used for positioning. It is provided in the vicinity of two corners of the substrate body 43 in the diagonal direction. On the case 20 side, as shown in FIGS. 6 and 7, posts 25 serving as positioning pins are erected at two positions facing the two mounting reference holes 40k, and a plurality of posts 24 The upper surface is different from the first embodiment in that it is a flat mounting surface 24m.

  In the third embodiment, as in the first embodiment, the power board 30 has two multipolar lead connectors 101 and the tips of pin-shaped terminals such as the positive terminal 81a and the negative terminal 82a as press-fit connecting portions. Yes. In the third embodiment, the output terminal 62 of the three-phase output connector 60 has a press-fit connection portion at the tip of each pin-like terminal.

  Furthermore, in the third embodiment, as shown in FIG. 8, as in the second embodiment, the plurality of terminals 102 of the power / signal connector 50 are respectively connected to the tips of the respective pin-shaped terminals. It has a press-fit connection with the same configuration. The terminal mounting portion of the control board 40B is provided with a predetermined through hole 42 corresponding to the press-fit connection at each position facing the tip of each pin-like terminal.

  In the third embodiment, the power board 30 is attached to the case 20 as in the first embodiment. The power / signal connector 50 and the three-phase output connector 60 are attached to the case 20. Thereafter, the two mounting reference holes 40k of the control board 40B are inserted into the two positioning posts 25 formed in the case 20, and the control board 40B is maintained along the positioning post 25 while maintaining the horizontal posture of the control board 40B. 40B is pressed toward the case 20 with a set pressure.

  Thereby, the control board 40B is connected to the press-fit connection part 112 of each pin-shaped terminal 110 of the multipolar lead connector 101 mounted on the lower power board 30 and the press-fit connection part of each pin-shaped terminal such as the negative electrode terminal 82a. These through holes 42 are inserted and press-fit connected by press-fitting.

  At this time, in the press-fit connection in the third embodiment, the connection state is set in consideration of the mechanical strength necessary for holding the control board 40 as well as the electrical connection of each connection portion. . Therefore, according to the third embodiment, the press-fit connection at each terminal of the control board 40B allows the control board 40B itself to be mechanically fixed simultaneously, and the control board 40B mounting screw 41 and the mounting board 41 are attached. Tapping can be eliminated.

  Furthermore, in the third embodiment, as shown in FIG. 8, the plurality of terminals 102 of the power / signal connector 50 and the output terminals 62 of the three-phase output connector 60 are also press-fit connection portions. Therefore, the mechanical fixing state of the control board 40B itself can be further stabilized.

Here, in the present invention, as a means for electrically connecting the terminal mounting portion by press-fitting or press-contacting, a spring contact structure can be adopted in addition to the press-fit connecting portion. For example, various terminal connection structures can be applied to the terminal connection structure in the resin frame of the power / signal connector 50.
Specifically, as a means for electrically connecting the terminal mounting portion by press-fitting or press-contacting, as shown in FIG. 9, a bellows-like spring connection terminal structure 102b folded back in a plurality of stages can be used. In the figure, the spring connection terminal structure 102b has one end surface 102t and the other end surface 102c on the opposite side as pressure contact surfaces. Moreover, as shown in FIG. 10, it is good also as a terminal structure which combined the bellows-like spring connection terminal structure 102b folded in multiple steps, and the press fit connection part 102d provided with the slit 102s. Although detailed description of the connection structure with the one end surface 102t of the bellows-like spring connection terminal structure 102b corresponding to the surface facing the press-fit connection portion 102d is omitted, for example, a metal connection pad is provided on the power substrate 30 side, With this portion and one end face 102t of the bellows-like spring connection terminal structure 102b receiving an appropriate compressive stress, metal contact is made with the connection pad on the power board 30 side.

  Also by using such a spring contact structure, the terminal mounting portion can be pressed from above and below without using solder, and can be electrically connected by press-fitting or press-contacting. In particular, in the electric power steering apparatus, the ambient temperature of the electronic control unit such as the controller 10 varies greatly due to heat from the engine room or heat from the external environment, and a semiconductor switching element for current control, a large-capacitance capacitor, Many heat generating parts are used.

  Therefore, if the spring contact structure is used for the terminal connection portion of the electronic control unit, a through hole is not required and assembly is easy, and electrical connection can be achieved by pressure contact that does not require solder or wires. In addition, by effectively releasing stress along the terminal connection direction by a plurality of springs folded in a bellows shape, it is possible to absorb warpage deformation of the substrate due to external vibration or thermal stress. Therefore, the heat dissipation is improved and the thermal stress mitigating effect is obtained with a simple configuration, which is particularly suitable for dealing with a large thermal stress at the terminal connection portion of the power system.

  Further, as illustrated in FIG. 10, if the spring contact structure and the press-fit connection structure are integrated, stress or the like due to thermal stress can be released by the spring contact structure. Therefore, it is suitable for preventing or mitigating adverse effects such as stress concentration due to vibration and thermal stress at the press-fit connection part.

  Further, the example in which the mechanical fixing of the substrate itself shown in the third embodiment is also performed by press-fit connection can be applied to the single substrate mode shown in the second embodiment. That is, as shown in FIG. 11, the fourth embodiment is an example in which the resin substrate 80B is mechanically fixed to the multilayer resin substrate 80B by press-fit connection without using mounting screws.

As shown in the figure, the controller 10 of the fourth embodiment is not provided with the plurality of through holes 40a in FIG. 5 in the resin substrate 80B, and instead of this, two mountings are used for positioning. The reference holes 80k are provided in the vicinity of two corners of the substrate body 83 in the diagonal direction. In the fourth embodiment, the output terminal 62 of the three-phase output connector 60 and the plurality of terminals 102 of the power and signal connector 50 are connected to the first terminals of the respective pin-shaped terminals. A press-fit connection similar to the embodiment is provided.
On the case 20 side, as shown in FIGS. 11 and 12, positioning posts 25 are provided at two positions facing the two mounting reference holes 80k, and the upper surfaces of the plurality of posts 24 are flat. The mounting surface is 24 m.

  When assembling the controller 10 of the fourth embodiment, the connector 50 for power and signal and the connector 60 for three-phase output are mounted in advance on the case 20 side. Thereafter, the two mounting reference holes 80k of the resin substrate 80B are inserted into the two positioning posts 25 formed in the case 20, and along the positioning posts 25 while maintaining the horizontal posture of the resin substrate 80B. The resin substrate 80B is pressed toward the case 20 with a set pressure.

  As a result, the through-holes of the resin substrate 80B are connected to the press-fit connecting portions of the output terminals 62 of the three-phase output connector 60 and the pin-like terminals 102 of the power and signal connector 50 that are mounted in advance. 42 is inserted, and press-fit connection is performed by press-fitting with a predetermined pressure.

  At this time, in the press-fit connection in the fourth embodiment, the connection state is set in consideration of the mechanical strength necessary for maintaining the mounting state of the resin substrate 80B as well as the electrical connection of each connection portion. Has been. Therefore, according to the fourth embodiment, the resin substrate 80B itself can be mechanically fixed by press-fit connection at each terminal of the resin substrate 80B at the same time, and the mounting screw and the attachment of the resin substrate 80B are attached. The tapping process can be made unnecessary.

Here, in the fourth embodiment, it is preferable to use the terminal integrated with the spring contact structure and the press-fit connection structure shown in FIG. 10 as the output terminal 62 of the three-phase output connector 60.
That is, in the electric power steering apparatus, as shown in FIG. 11, a plurality of FETs that generate a large amount of heat and flow a high current are mounted on the power device mounting portion 80j on the resin substrate 80B. Therefore, there exists a problem that the circumference | surroundings of the power device mounting part 80j are easy to thermally deform. And in 4th embodiment, since the periphery of the through hole 42 which is a terminal mounting part formed in the position facing the output terminal 62 of the three-phase output connector 60 is the power device mounting part 80j, this The problem becomes noticeable.

  On the other hand, the fourth embodiment employs a press-fit connection structure for the output terminal 62, which is suitable for preventing or mitigating adverse effects such as stress concentration due to thermal stress. By providing the spring contact structure shown inside the resin case side, the stress caused by thermal stress can be relieved by the spring contact structure, thus preventing or mitigating adverse effects such as vibration at the press-fit connection and stress concentration due to thermal stress. This is even more preferable.

DESCRIPTION OF SYMBOLS 1 Steering handle 2 Column shaft 3 Reduction gear 4A, 4B Universal joint 5 Pinion rack mechanism 6 Tight rod 7 Torque sensor 8 Electric motor 9 Vehicle speed sensor 10 Controller (electronic control unit)
DESCRIPTION OF SYMBOLS 11 Control arithmetic unit 12 Gate drive circuit 13 Motor drive part 14 Emergency stop circuit 15 Current detection circuit 16 Rotation sensor 17 Rotor position detection circuit 18 IGN voltage monitor part 19 Power supply circuit part 20 Case 21 Substrate mounting part 21a Screw hole 22 Power / Signal Connector Mounting Portion 23 Three-phase Output Connector Mounting Portion 23a, 24a Screw Hole 24 Post 25 Positioning Post 24a Screw Hole 30 Power Board 31 Board Body 31a Through Hole 39 Heat Dissipation Sheet 40 Control Board 40a Through Hole 40k Mounting Reference hole 41 Mounting screw 42 Through hole 42h Inner wall surface 43 Substrate body 50 Power / signal connector 51 Mounting screw 60 Three-phase output connector 60a Through hole 62 Output terminal 70 Cover 80, 80B Resin substrate 80k Mounting reference hole 81 Power supply Line 81 a positive terminal 82 ground line 82a negative terminal 90 three-phase output section 91a a-phase output line 91b b-phase output line 91c c-phase output line 101 multipolar lead connector 110 pin-shaped terminal 111 holding section 112 press-fit connection section 112d introduction section 112s Slit 112t Elastic pressure contact portion 120 Holding member

Claims (10)

An electronic control unit used in an electric power steering apparatus having an electric motor for assisting steering,
A metal case,
A metal power board that is fixed in the case and has a metal terminal standing on the upper surface thereof and that constitutes a power module system necessary for driving the electric motor,
A control board that is fixed to the case in a state of being spaced apart above the power board and that constitutes a control system necessary for controlling the electric motor;
A cover fixed to the case so as to cover the power board and the control board from above;
A connector having a terminal for performing input / output to the wiring necessary for steering assistance by the electric motor;
With
Electric power steering characterized in that terminals arranged upright on the power board or terminals of the connector are electrically connected to a terminal mounting portion of the control board by press-fitting or press-contact without using solder. Electronic control unit for equipment.   2. The electric power steering apparatus according to claim 1, wherein the control board is mechanically fixed in the case by press-fitting or press-contacting the terminal of the connector and the terminal mounting portion without using screw fastening. Controller unit. The terminals arranged upright on the power board or the terminals of the connector are
A press-fit terminal comprising: a terminal main body portion; and a press-fit portion that is provided at a distal end portion of the terminal main body portion and press-fitted into the through-hole of the control board to be electrically connected to the through-hole,
3. The electric power steering apparatus according to claim 1, wherein the press-fitting portion has a pair of elastically deformable elastic press-contact portions that are arranged to face each other with a slit serving as a bending space formed along the press-fitting direction. Electronic control unit.   4. The electronic control unit for an electric power steering apparatus according to claim 1, wherein the portion that is electrically connected by the press contact has a bellows-like spring connection terminal structure that is folded back in a plurality of stages. The power board has a plurality of pin-like terminals arranged in rows in a direction orthogonal to the connection direction with the control board and extending in the connection direction as terminals arranged upright on the power board. ,
The plurality of pin-shaped terminals are held mutually by holding members whose intermediate portions extend in a direction orthogonal to the connection direction and are held at a predetermined pitch.
5. The electric power steering apparatus according to claim 1, wherein each of the plurality of pin-shaped terminals is press-fit connected by being press-fitted into a through-hole formed in the control board disposed to face the terminal. Electronic control unit.   The electronic control unit for an electric power steering apparatus according to any one of claims 1 to 5, wherein the power board and the control board are fixed to each other in a vertical orientation when mounted on a vehicle.   The electronic control unit for an electric power steering apparatus according to any one of claims 1 to 6, wherein a heat conductive paste is applied between the power board and the case. An electronic control unit used in an electric power steering apparatus having an electric motor for assisting steering,
A metal case,
A power module unit fixed in the case and constituting a power module system necessary for driving the electric motor, and a control module layered on the power module unit and constituting a control system necessary for controlling the electric motor A multi-layer resin substrate integrally formed with
A cover fixed to the case so as to cover the resin substrate from above;
A connector having a terminal for inputting and outputting wiring necessary for steering assistance by the electric motor;
With
The electronic control unit for an electric power steering apparatus, wherein the terminal of the connector is electrically connected to the terminal mounting portion of the resin substrate by press-fitting or press-contacting without using solder.   The electric power steering apparatus according to claim 8, wherein the resin substrate is mechanically fixed in the case by press-fitting or press-contacting the terminal of the connector and the terminal mounting portion without using screw fastening. Electronic control unit.   10. The electronic control unit for an electric power steering apparatus according to claim 8, wherein the portion electrically connected by the press contact has a bellows-like spring connection terminal structure folded back in a plurality of stages.

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