JP2015180155A - Drive controller of electric actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive controller of an electric actuator which achieves downsizing without sacrificing heat radiation performance.SOLUTION: A circuit board 20, on which various electronic components such as a micro computer 21 and a switching element 22 are mounted, is stored in an ECU housing 11 in which a bottom wall 12a is integrally formed with an actuator housing 5. Further, a mounting region of heating components, such as the switching element 22, on a rear surface 20b of the circuit board 20 is disposed contacting with a heat radiation pedestal 15 which is provided on an inner bottom surface of the ECU housing 11 in a protruding manner. The structure allows heat generated by the switching element 22 to be transmitted to the ECU housing 11.

Description

  The present invention relates to a drive control device for an electric actuator applied to, for example, a brake booster for an automobile.

  As a conventional drive control device for an electric actuator, for example, one described in Patent Document 1 below is known.

  This drive control device for an electric actuator drives a power module that constitutes an inverter circuit by mounting various electronic components such as a switching element inside a metal case from the bottom wall side, and the switching element. And a control module that constitutes a control circuit to be controlled, and are arranged in a stacked manner at a predetermined interval. For the power module, the switching element is placed on a block-shaped heat radiation base protruding from the bottom of the case. The contact arrangement dissipates heat generated in the switching element to the outside through the case.

JP 2013-62334 A

  However, in the case of the conventional drive control device for an electric actuator, sufficient heat dissipation cannot be achieved only with the case, and a heat dissipation path for the electric actuator is sufficiently secured from the configuration arranged on the tangential line with respect to the electric actuator. Since this is not possible, it is necessary to arrange the semiconductor drive element and the processing element that generate a relatively large amount of heat separately in the power module and the control module, and to dispose these modules as far apart as possible. As a result, there is a problem that the apparatus becomes large in the height direction.

  The present invention has been devised in view of such technical problems, and an object of the present invention is to provide a drive control device for an electric actuator that can realize downsizing of the device without sacrificing heat dissipation.

  The present invention provides an ECU housing in which a bottom wall is provided integrally with an actuator housing that houses an electric actuator, an arithmetic processing element that calculates a drive operation amount of the electric actuator, and a semiconductor drive that generates a drive signal for the electric actuator An element and a flat circuit board that is housed in the ECU housing and has the semiconductor driving element mounted on the front surface or the back surface thereof, and the semiconductor driving element or the mounting of the semiconductor driving element on the circuit board The opposite side surface of the region is arranged to be able to transfer heat to the ECU housing.

  According to the present invention, the semiconductor drive element can be dissipated through the ECU housing and the actuator housing. As a result, the power supply and control which have been separately configured in the related art are secured while ensuring good heat dissipation of the semiconductor drive element. The module can be integrated with the module, and the apparatus can be downsized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an entire automobile brake device to which an electric actuator drive control device according to the present invention is applied. It is a longitudinal cross-sectional view of the brake device shown in FIG. It is a disassembled perspective view of the drive control apparatus of the electric actuator shown in FIG. It is the front view showing the state which removed the cover member about the drive control apparatus of the electric actuator shown in FIG. It is the perspective view which looked at the circuit board simple substance shown in FIG. 3 from the surface side. It is the perspective view which looked at the circuit board simple substance shown in FIG. 3 from the back surface side. FIG. 6 is a perspective view showing a wiring pattern of the circuit board shown in FIG. 5. It is the sectional view on the AA line of FIG.

  Embodiments of an electric actuator drive control device according to the present invention will be described below in detail with reference to the drawings. In the embodiment described below, the apparatus is applied to an electric brake booster mounted on an automobile.

  That is, the brake booster 1 to which the drive control device for an electric actuator according to the present invention is applied is driven by three-phase AC power, particularly as shown in FIGS. 1 and 2, to control the hydraulic pressure of the brake fluid. An electric actuator unit 2 to be provided, and a motor control device 10 for driving and controlling an electric motor 7 described later that constitutes the electric actuator 2 based on a driver's brake operation and a driving state of the automobile, and a master described later. It is attached to a dash panel (not shown) of the vehicle body via a plurality of stud bolts 4 protruding from the rear end of the cylinder 5.

  The electric actuator unit 2 is a master cylinder that is a hydraulic pressure generating means for generating a brake hydraulic pressure based on an axial movement of a piston member (not shown) that is slidably provided in the cylinder housing portion 5a of the actuator housing 5. 6, an electric motor 7 provided in the motor housing portion 5 b attached to the cylinder housing portion 5 a in the actuator housing 5, and a rotational force of the electric motor 7 is applied to the piston member. It comprises power transmission means (not shown) that converts the piston member into a linear moving force and transmits it, and a reservoir tank 8 that stores brake fluid used for generating the hydraulic pressure.

  With this configuration, in the brake booster 1, the push rod 9 extending coaxially with the piston is pressed in the axial direction via a brake pedal (not shown) by a driver's brake operation. The hydraulic pressure of the brake fluid is controlled by driving and controlling the electric motor 7 with an exciting current energized by the motor control device 10 based on the stroke amount and the vehicle operating state.

  As shown in FIGS. 2 to 4, the motor control device 10 is used to calculate the drive operation amount of the electric motor 7 in the ECU housing 11 in which a part of the bottom wall 12 a is provided integrally with the actuator housing 5. It is configured by housing a flat circuit board 20 on which various electronic components such as a microcomputer 21 as an arithmetic processing element and a switching element 22 as a plurality of semiconductor drive elements used for generating drive signals for the electric motor 7 are mounted. Has been.

  The ECU housing 11 is integrally formed with the actuator housing 5, and is made of a metal case 12 that is a bottomed rectangular tube-shaped housing body that opens toward the side of the actuator housing 5. A metal cover 13, which is a substantially plate-like cover member that closes the opening, is fastened by a plurality of screws S <b> 1. A seal member 14 is interposed. The case 12 is molded by a so-called aluminum die casting method, while the cover 13 is formed by press molding a metal plate.

  In addition, the inner bottom surface of the case 12 is used for heat dissipation of the electronic components 21 and 22 at positions facing the mounting area A1 of the microcomputer 21 and the mounting area A2 of the switching elements 22 on the circuit board 20, respectively. A rectangular block-shaped heat radiation pedestal 15 is formed so as to protrude, and the mounting regions A1 and A2 (see FIG. 6) of the circuit board 20 (back surface 20b) are attached to the upper surface of each heat radiation pedestal 15. By being arranged in contact with the heat transfer material 16, the heat generated in each of the electronic components 21 and 22 can be radiated through the case 12 and the actuator housing 5 formed integrally with the case 12.

  At this time, a plurality of heat dissipating fins 17 are provided on the outer bottom surface of the case 12 so that the heat dissipating fins 17 can effectively dissipate heat. Further, as the heat transfer material 16, in addition to an elastic sheet material made of, for example, silicon as shown in FIG. 3, liquid grease or the like may be adopted. It is good also as a structure which contacts each said switching element 22 directly to each heat radiation base 15 without interposing.

The circuit board 20 has first to fourth wiring patterns P1 to P1 that are a plurality of conductor patterns as shown in FIG. 7 on both the front and back surfaces and inside of a substrate made of a nonconductive resin material typified by glass epoxy resin. P4 is arranged in a stacked state, and each of the wiring patterns P1 to P4 constitutes an inverter circuit, and a plurality of pieces inserted through fastening holes 20c penetratingly formed in the outer peripheral edge portion (mainly corner portion) or the central portion. Each screw S2 is housed and fixed in the case 12 by being screwed to a fixing portion 12b provided in the case 12. And, on the surface 20a which is a component mounting surface of the circuit board 20, especially in FIG. As shown, a connector 23 is provided at one end for transmission and reception of signals and power with an external electronic device (not shown), and the microcomputer 21 and current interrupting means are provided at an intermediate portion. As the semiconductor relay 24, the switching elements 22 are mounted on the other end. The connector 23 is configured to face the outside through a connector insertion hole 13 a formed in the cover 13. In addition, 25 in FIG. 5 is a normal choke coil that functions as a noise filter component, 26 is a smoothing capacitor, and 27 is a shunt resistor as current detecting means.

  Further, as shown in FIG. 6, a motor connection portion 28 that is electrically connected to the electric motor 7 is provided on the back surface 20 a of the circuit board 20. The motor connecting portion 28 is configured to be connected to the electric motor 7 through a wiring (not shown) that passes through the communication hole 12 c formed through the bottom wall 12 a of the case 12. In addition, A1 in FIG. 6 indicates a mounting area of the microcomputer 21, A2 indicates a mounting area of each switching element 22, and each of the mounting areas A1 and A2 passes through the heat transfer material 15 as described above. Thus, the heat generated in the microcomputer 21 and the switching elements 22 is transmitted to the heat radiating pedestals 15 through the case 12 and the actuator housing 5, respectively. It is supposed to be dissipated.

  Here, among the wiring patterns P1 to P4, the first and fourth wiring patterns P1 and P4 located in the vicinity of the fastening holes 20c include the fastening holes as shown in FIGS. By forming the screw insertion holes 35 corresponding to 20c, the hole edges of the respective screw insertion holes 35 are formed in a substantially annular shape, and heat transfer portions 36 for heat transfer to the respective fixing portions 12b are provided. It has been. That is, with respect to the first and fourth wiring patterns P1 and P4, the switching elements 22 and the smoothing capacitors are provided with the circuit board 20 in close contact with the fixing portions 12b based on the fastening with the screws S2. The heat transmitted to each of the wiring patterns P1 and P4 based on the heat generated by the circuit 26 can be transmitted to the fixed portions 12b via the heat transfer portions 36.

  In the present embodiment, the heat transfer portions 36 are illustrated in an annular shape. However, the heat transfer portions 36 are not limited to the endless ring shape, for example, a C-shape or the like. Any shape can be adopted as long as it overlaps with each of the fixed portions 12b in the vertical direction.

  From the above configuration, according to the motor control device 10, when the switching elements 22, the microcomputer 21, etc. generate heat in accordance with the energization control to the electric motor 7, this heat is applied to the back surface 20 b of the circuit board 20. Each of the switching elements 22 and the like is transmitted to the respective heat dissipation pedestals 15 that come into contact and dissipated from the respective heat dissipation pedestals 15 to the outside via the case 12 and the actuator housing 5 formed integrally with the case 12. As described above, the power module and the control module, which have been separately configured as described above, can be integrally configured as described above, and the motor controller 10 can be reduced in size. Can do.

  Further, in the present embodiment, since the heat transfer portions 36 are provided in the wiring patterns P1 and P4 to which the heat generating components are connected, heat generated in the switching elements 22 and the like is generated in the wiring patterns P1. , P4 can also be transmitted to the fixing portions 12b that are in close contact with the heat transfer portions 36 by the heat transfer portions 36, thereby further improving heat dissipation through the case 12 and the actuator housing 5 described above. Can be improved.

  In the case of the motor control device 10, in the circuit board 20, the switching elements 22 are not on the side of the motor housing 5 b that houses the electric motor 7 that generates heat by driving, but on the side of the cylinder housing 5 a that is unlikely to become high temperature. The cylinder housing portion 5a is arranged to be biased to the other end side, and in the cylinder housing portion 5a, the temperature rise of the cylinder housing portion 5a is suppressed based on the air flow generated along with the movement of the piston. It becomes possible to transmit heat of 22 etc. to the cylinder housing part 5a of comparatively low temperature, and more effective heat dissipation of the switching elements 22 can be achieved.

  Further, in the motor control device 10, since the connector 23 protrudes from the surface 20a of the circuit board 20 facing the cover 13, the connector is connected to each module in order to superimpose the power module and the control module. Compared to the conventional case in which it is forced to extend in parallel, the height of the ECU housing 11 can be reduced, which contributes to further miniaturization of the motor control device 10.

  In addition, in the motor control device 10, since the motor connection portion 28 protrudes from the back surface 20 b of the circuit board 20 facing the case 12 (bottom wall 12 a) continuous with the actuator housing 5, the motor connection portion The wiring distance between the motor 28 and the electric motor 7 can be shortened, and the wiring resistance and noise can be reduced.

  The present invention is not limited to the configuration of the above-described embodiment. For example, the specific shape of the ECU housing 11 and the specific electronic components mounted on the circuit board 20 do not depart from the spirit of the present invention. It can be freely changed in accordance with the specifications of the motor control device 10 and the like.

2 ... Electric actuator unit (electric actuator)
5 ... Actuator housing 11 ... ECU housing 20 ... Circuit board 21 ... Microcomputer (arithmetic processing element)
22: Switching element (semiconductor drive element)

Claims (5)

An ECU housing having a bottom wall integrated with an actuator housing that houses the electric actuator;
An arithmetic processing element for calculating a drive operation amount of the electric actuator;
A semiconductor drive element for generating a drive signal for the electric actuator;
A flat circuit board housed in the ECU housing and mounted on the front or back surface with the semiconductor drive element;
With
An electronic control device, wherein the semiconductor drive element or the side surface opposite to the mounting area of the semiconductor drive element on the circuit board is arranged to be able to transfer heat to the ECU housing. In the circuit board, a drive control circuit that drives and controls the electric actuator is configured by a plurality of conductor patterns arranged in a laminated manner, and through a metal fastening member that is inserted through a plurality of fastening holes that penetrate in the thickness direction. Fixed to the ECU housing,
2. The electronic control device according to claim 1, wherein the conductor pattern is disposed in proximity to a hole edge of the fastening hole, and heat generated in the conductor pattern is configured to be able to transfer heat to the ECU housing. .   3. The conductor pattern is formed in a substantially annular shape so as to surround a hole edge of the fastening hole, and is provided with a heat transfer portion for heat transfer to the ECU housing. Electronic control unit. A drive control device for an electric actuator used for drive control of a brake device of a vehicle,
The electric actuator is
Hydraulic pressure generating means for generating brake hydraulic pressure based on axial movement of a piston member slidably provided inside the actuator housing;
An electric motor for applying a moving force to the piston member;
Power transmission means for converting and transmitting the rotational force of the electric motor to the linear movement force of the piston member;
Consisting of
The drive control apparatus for an electric actuator according to claim 1, wherein the semiconductor drive element is arranged to be biased toward the hydraulic pressure generating means. The ECU housing is composed of a housing main body that is open at the side of the actuator housing, and a cover member that closes the opening of the housing main body.
On the side surface facing the cover member, a connector for connecting to an external electronic device protrudes from the circuit board, and on the side surface facing the housing body, a motor used for connection to the electric motor The drive control device for an electric actuator according to claim 4, wherein the connection portion is protruded.

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