Electric power steering device and electric driving device

Abstract

To provide an electric driving device such as an electric power steering device that can suppress increases in the number of components and costs.SOLUTION: An electric power steering device includes a conductive resin clip disposed in an intermediate part of a harness. The conductive resin clip holds the harness in contact with a shield member of the harness and is directly fixed to a housing.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electric power steering device and an electric drive device. [Background technology]

[0002] Patent Document 1 discloses a wire harness 10 having an electric wire 11 having a core wire and an insulating coating covering the core wire, a braided member 12 covering at least the core wire to provide electromagnetic shielding, a path control member 13 formed in a long shape and having a higher bending rigidity than the electric wire 11, and an exterior member 15 covering the electric wire 11, the braided member 12, and the path control member 13. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-103221 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the wire harness described in Patent Document 1 is applied to an electric drive device such as an electric power steering device, the wire harness acts as an electromagnetic antenna, and noise is easily injected into the wire harness, and conversely, the wire harness is likely to radiate its own noise. For this reason, when applying the wire harness, it is possible to process the end of the braided member 12 as a shielding member and ground this end to a housing by a member other than the holding member of the wire harness itself to allow noise to escape. This requires processing of the wire harness, which poses a problem of increasing the number of parts. An object of the present invention is to provide an electric drive device, such as an electric power steering device, that can suppress an increase in the number of parts. [Means for solving the problem]

[0005] In one embodiment of the electric power steering device, a conductive resin clip is arranged in the middle of the harness, and the conductive resin clip holds the harness in contact with the shielding member of the harness and is fixed directly to the housing. Effect of the Invention

[0006] Therefore, the number of parts can be reduced. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic diagram of an electric power steering device according to a first embodiment, as viewed from the front side of a vehicle. [Diagram 2] 1 is a schematic diagram of a main part of an electric power steering device according to a first embodiment, viewed from the rear side of a vehicle. [Diagram 3] FIG. 1 is a schematic diagram of a harness according to a first embodiment. [Figure 4] FIG. 1 is a perspective view of a snap-fit ​​clip according to a first embodiment. [Diagram 5] FIG. 11 is a schematic diagram of a main part of an electric power steering device according to a second embodiment, as viewed from the rear side of the vehicle. [Figure 6] FIG. 11 is a perspective view of a clip according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Embodiment 1] FIG. 1 is a schematic diagram of an electric power steering device according to a first embodiment, as viewed from the front side of a vehicle. The electric power steering device (electric drive device) 1 is a rack-and-pinion type steering device equipped with an electric motor 3 that applies a steering force to a rack shaft 2. The rack shaft 2 extends in the left-right direction of the vehicle, and tie rods 4 are connected to both ends via joints 5. The rack shaft 2 is accommodated in a rack housing 6 made of an aluminum alloy. An end of the rack housing 6 is covered by a boot 7. An end of the rack shaft 2 protrudes from the boot 7. Movement of the rack shaft 2 moves the tie rod 4, and the steered wheels 8 are steered via the tie rod 4.

[0009] A steering gear housing 9 is provided at one end side (left side in FIG. 1) of the rack housing 6. An input shaft 11 connected to a steering wheel 10 is rotatably supported within the steering gear housing 9. The input shaft 11 is connected to a pinion shaft (not shown) via a torsion bar (not shown) so as to be capable of relative rotation. A torque steering angle sensor (sensor) 12 is provided on the upper part of the steering gear housing 9. The torque steering angle sensor 12 outputs a steering angle sensor output signal according to the amount of relative rotation between the input shaft 11 and the pinion shaft. The pinion shaft meshes with the rack shaft 2 and transmits the steering torque input to the steering wheel 10 to the rack shaft 2.

[0010] An actuator housing 13 is provided on the other end side (right side in FIG. 1) of the rack housing 6. The electric motor 3 is fixed to the actuator housing 13, and an assist mechanism that transmits the output of the electric motor 3 to the rack shaft 2 is also housed therein. The assist mechanism transmits the driving force of the electric motor 3 to a nut via an input pulley, a belt, and an output pulley, and converts it into axial thrust of the rack shaft 2 by a ball screw mechanism. Note that a chain may be used instead of the belt. The electric motor 3 is a so-called EPS power pack integrated with a motor ECU (controller) 14. The motor ECU 14 receives information from other ECUs (e.g., engine ECU) and sensors (e.g., wheel speed sensors) via CAN communication, in addition to a steering angle sensor detection signal from the torque steering angle sensor 12. The motor ECU 14 drives and controls the electric motor 3 based on the various information. In the following description, the electric motor 3 and the motor ECU 14 are collectively referred to as EPP 15.

[0011] FIG. 2 is a schematic diagram of a main part of the electric power steering device of the first embodiment as viewed from the rear side of the vehicle. The torque steering angle sensor 12 is provided with a sensor side connector 16. A first harness 17 and a second harness 18 are respectively connected to the sensor side connector 16. The length of the first harness 17 is set to be shorter than that of the second harness 18. A first motor-side connector 20 connectable to a first terminal 19 of the EPP 15 is provided at the end of the first harness 17 opposite to the sensor-side connector 16 . Further, a motor-side second connector 22 connectable to a second terminal 21 of the EPP 15 is provided at an end of the second harness 18 opposite to the sensor-side connector 16. The first terminal 19 is provided at a position closer to the steering gear housing 9 (pinion shaft) than the second terminal 21. The first harness 17 and the second harness 18 supply detection signals (control signals) for controlling the drive of the electric motor 3 to the motor ECU 14.

[0012] An adjust screw 6a is attached to the rack housing 6. The adjust screw 6a adjusts the set load of a coil spring that biases the rack shaft 2 toward the pinion shaft via a rack retainer (not shown). Further, a snap-fit ​​clip (conductive clip) K1 made of conductive resin for fixing the first harness 17 and the second harness 18 to the rack housing 6 is attached to the rack housing 6. The snap-fit ​​clip K1 holds the shielding members 24 (see FIG. 3) of the first harness 17 and the second harness 18, and a snap-fit ​​fixing portion K1a is inserted and fixed in a snap-fit ​​clip fixing hole 6b of the rack housing 6 (see FIG. 4).

[0013] FIG. 3 is a schematic diagram of the harness of the first embodiment. The first harness 17 includes an electric wire 23 having a core wire that transmits a detection signal from the torque steering angle sensor 12 to the motor ECU 14 and an insulating coating that covers the core wire, a shielding member 24 that is formed into a tube shape by braiding thin wires of a conductive metal that covers the electric wire 23 and contains it inside, and that blocks noise injected into the first harness 17 from the outside or noise radiated by the core wire of the first harness 17, a path regulating member 25 to which the electric wire 23 is fixed, a fixing member 26 that fixes the shielding member 24 and the path regulating member 25, and an exterior member 27 that covers the electric wire 23, the shielding member 24 and the path regulating member 25. The second harness 18 has a similar structure.

[0014] FIG. 4 is a perspective view of the snap-fit ​​clip of the first embodiment.

[0015] The snap-fit ​​clip K1 formed of conductive resin has a snap-fit ​​fixing portion K1a that is inserted and fixed into the snap-fit ​​clip fixing hole 6b of the rack housing 6 shown in Figure 2, and a band portion K1b that holds the shielding member 24 of the first harness 17 and the second harness 18. That is, the snap-fit ​​clip K1 formed of conductive resin holds the first harness 17 and the second harness 18 in contact with the shielding members 24 of the first harness 17 and the second harness 18, and is fixed directly to the rack housing 6.

[0016] Next, the effects of the first embodiment will be described. (1) The snap-fit ​​clip K1 made of conductive resin holds the shielding members 24 of the first harness 17 and the second harness 18, and the snap-fit ​​fixing portion K1a is inserted and fixed into the snap-fit ​​clip fixing hole 6b of the rack housing 6. Therefore, the shielding member 24 that blocks noise injected from the outside into the first harness 17 and the second harness 18 or noise radiated from the core wires of the first harness 17 and the second harness 18 can be directly connected to the rack housing 6. Furthermore, the radiated noise can be dissipated by being grounded to the rack housing 6, so that no additional member is required. Furthermore, processing of the end portion of the shield member 24 is no longer necessary, and the separate member can be eliminated.

[0017] (2) The shield member 24 is made of conductive metal and is formed into a tube by braiding thin wires. The core wire that transmits the detection signal of the torque steering angle sensor 12 to the motor ECU 14 is placed inside the tube. Therefore, the core wires of the first harness 17 and the second harness 18 are electrically protected from the injection of noise from the outside, and noise emitted from the core wires of the first harness 17 and the second harness 18 can also be prevented from being radiated outside the rack housing 6.

[0018] (3) The snap-fit ​​clip K1 formed of conductive resin has a snap-fit ​​fixing portion K1a that is inserted into and fixed in the snap-fit ​​clip fixing hole 6b of the rack housing 6, and a band portion K1b that holds the shielding member 24 of the first harness 17 and the second harness 18. Therefore, the snap-fit ​​clip K1 made of conductive resin can be physically fixed and connected to the rack housing 6, and can also be electrically connected, eliminating the need for additional parts such as screws to connect to the rack housing 6.

[0019] (4) The rack housing 6 is made of an aluminum alloy. Therefore, the rack housing 6 itself can dissipate noise.

[0020] [Embodiment 2] FIG. 5 is a schematic diagram of a main part of an electric power steering device of the second embodiment as viewed from the rear side of the vehicle, and FIG. 6 is a perspective view of a clip of the second embodiment.

[0021] The basic configuration of the second embodiment is similar to that of the first embodiment, so only the differences from the first embodiment will be described. In embodiment 1, the shielding members 24 of the first harness 17 and the second harness 18 are held by a snap-fit ​​clip K1 formed of conductive resin, and the snap-fit ​​fixing portion K1a is inserted and fixed into the snap-fit ​​clip fixing hole 6b of the rack housing 6. In embodiment 2, the band portion (fixing portion) K2a of the tie-wrap clip K2 formed of conductive resin fastens the shielding members 24 of the first harness 17 and the second harness 18 together with the outer periphery of the rack housing 6 to hold them in place.

[0022] Next, the effects of the second embodiment will be described. In addition to the effects (1), (2), and (4) of the first embodiment, the following effects are achieved. (1) There is no need to process the snap-fit ​​clip fixing holes 6b in the rack housing 6, which further reduces costs. Since the clip is fastened directly to the rack housing 6, the adhesion is good and the resistance value is stable, making it easier for noise to escape.

[0023] Other Embodiments The above describes an embodiment for carrying out the present invention, but the specific configuration of the present invention is not limited to the configuration of the embodiment, and design changes and the like that do not deviate from the gist of the invention are also included in the present invention. For example, in the embodiment, an electric power steering device has been described as an example of an electric drive device, but the present invention is not limited to this, and the conductive resin clip of the present embodiment can be applied to electric drive devices such as electric brake devices and electric powertrains for automobiles that have a harness that is held in a housing and covered with a shielding member in order to supply a control signal to a control unit. [Explanation of symbols]

[0024] 1...electric power steering device (electric drive device), 6...rack housing (housing), 12...torque steering angle sensor (sensor), 14...motor ECU (control unit), 17...first harness (harness), 18...second harness (harness), 24...shield member, K1...snap-fit ​​clip (conductive resin clip), K1a...snap-fit ​​fixing portion (fixing portion), K2...tie-wrap clip (conductive resin clip), K2a...band portion (fixing portion)

Claims

1. An electric power steering apparatus provided with a control unit that controls a motor and a sensor that detects a steering state, electrically connected to each other, and having a harness covered with a shield member, wherein a conductive resin clip is disposed at an intermediate portion of the harness, the conductive resin clip holds the harness in a state of being in contact with the shield member of the harness and is directly fixed to the housing, the conductive resin clip has a fixing portion that can be fixed to the housing, the fixing portion has a snap-fit shape, characterized in that it is an electric power steering apparatus.

2. The electric power steering apparatus according to claim 1, wherein the shield member is a conductive metal, formed in a tube shape by braiding thin wire strands, and a core wire for transmitting a detection signal of the sensor to the control unit is accommodated in the tube, characterized in that it is an electric power steering apparatus.

3. The electric power steering apparatus according to claim 1, wherein the housing is formed of an aluminum alloy, characterized in that it is an electric power steering apparatus.

4. An electric drive apparatus having a harness held by a housing and covered with a shield member to supply a control signal to a control unit, wherein a conductive resin clip is disposed at an intermediate portion of the harness, the conductive resin clip holds the harness in a state of being in contact with the shield member of the harness and is directly fixed to the housing, the conductive resin clip has a fixing portion that can be fixed to the housing, the fixing portion has a snap-fit shape, characterized in that it is an electric drive apparatus.

5. The harness is composed of a first harness and a second harness, each of the first harness and the second harness is covered with a shield member, the first harness and the second harness are collectively inserted and fixed by a snap-fit type fixing portion, characterized in that it is an electric power steering apparatus.

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