JP6956682B2 - Electric drive device and electric power steering device - Google Patents

Description

The present invention relates to an electric drive device and an electric power steering device, and more particularly to an electric drive device and an electric power steering device having a built-in electronic control device.

In the general industrial machinery field, a mechanical control element is driven by an electric motor, but recently, an electronic control unit composed of a semiconductor element or the like that controls the rotation speed and rotation torque of the electric motor is electrically operated. So-called mechanical and electrical integrated electric drive devices that are integrated into motors are beginning to be adopted.

As an example of an electric drive device integrated with electromechanics, for example, in an electric power steering device of an automobile, the rotation direction and rotation torque of the steering shaft that is rotated by the driver operating the steering wheel are detected, and the rotation torque is detected. The electric motor is driven so as to rotate in the same direction as the rotation direction of the steering shaft based on the detected value, and the steering assist torque is generated. In order to control this electric motor, an electronic control unit (ECU: Electronic Control Unit) is provided in the power steering device.

As a conventional electric power steering device, for example, the one described in Japanese Patent Application Laid-Open No. 2017-189033 (Patent Document 1) is known. Patent Document 1 describes an electric power steering device including an electric motor unit and an electronic control unit. The electric motor of the electric motor unit is housed in a storage space formed in a motor housing having a tubular portion made of an aluminum alloy or the like, and the substrate on which the electronic components of the electronic control unit are mounted is the shaft of the motor housing. It is housed in a storage space formed by a synthetic resin cover on the end face wall opposite to the output shaft in the direction.

The substrate of the electronic control unit attached to the end face wall of the motor housing controls the power supply circuit unit, the MOSFET that drives and controls the electric motor, the power conversion circuit unit having a power switching element such as an IGBT, and the power switching element. A control circuit unit is provided, and the output terminal of the power switching element and the input terminal of the electric motor are electrically connected via a bus bar.

Then, electric power is supplied to the electronic control unit from a power source via a connector formed on a cover made of synthetic resin, and detection signals such as an operating state are supplied from detection sensors. The connector and cover function as a lid, and are fixed to the outer peripheral surface of the end face wall with an adhesive so as to seal and close the electronic control unit.

In addition to this, as an electric drive device integrated with an electronic control device, an electric brake, an electric hydraulic controller for various flood control, etc. are known, but in the following description, the electric power steering device is represented as a representative. explain.

Japanese Unexamined Patent Publication No. 2015-134598

Here, in the electric power steering device having the configuration as described in Patent Document 1, the shape of the fixed portion in which the end face wall of the motor housing and the opening surface of the cover are abutted is formed in an annular shape, and further, the fixed portions of both are formed. Is configured to be bonded with an adhesive. This adhesive has a fixing function for fixing the end face wall of the motor housing and the opening surface of the cover, and a waterproof function for preventing moisture such as salt water from entering the storage space formed inside the cover. Also serves as.

Therefore, since the shape of the fixed part where the end face wall and the opening surface of the cover are butted is annular, it is difficult to install the cover in the correct position due to the rotation of the cover when assembling the cover to the end face wall, and the installation work takes time. There is a problem such as such a problem and a problem that there is a risk of erroneous assembly because there is no positioning.

Further, in automobiles, it is often the case that the vehicle travels on a road sprayed with a snow melting agent or the like, or travels on a road close to the coastline. For this reason, it is common to experience salt water infiltrating under the floor of an automobile when driving on a road with melted snow or a road near a rainy coastline. For this reason, if the adhesive is peeled off, salt water will enter the peeled part, and in the worst case, it will cause poor liquidtightness and the salt water will infiltrate the inside of the cover, and the electricity of the electronic control unit will be increased. There is a risk of impairing the reliability of the product.

For this reason, it is advantageous to use an O-ring in order to obtain a reliable waterproof function, but in this case, there is a risk that the O-ring will be shipped in a state where the assembly of the O-ring has been forgotten. Measures are needed. Therefore, there is a demand for an electric drive device and an electric power steering device that meet these problems.

A main object of the present invention is to provide a novel electric drive device and electric power steering device capable of assembling a cover to an end face wall of a motor housing at an accurate position and visually confirming the assembling of an O-ring. To do.

The feature of the present invention is the motor housing side composed of an annular groove formed on the end face wall of the motor housing on the side opposite to the output portion of the rotation shaft of the electric motor and retracting along the axis of the motor housing from the end face wall. An annular tip on the cover side and a circle on the motor housing side, which are housed in the annular groove of the annular groove on the motor housing side, which are formed at the opening end of the cover covering the annular groove and the electronic control unit that controls the electric motor. An O-ring arranged between the annular groove portion and the annular tip portion on the cover side is provided, and a positioning groove portion extending outward in the radial direction is formed in a part of the circumferential direction of the annular groove portion on the motor housing side to cover the cover. A part of the lateral annular tip in the circumferential direction extends outward in the radial direction to form a positioning tip to be stored in the positioning groove, and the positioning tip is housed in the positioning groove. In this state, a gap having a predetermined width is formed between the positioning tip portions in the positioning groove portion so that the O-ring can be visually recognized.

According to the present invention, the cover and the motor housing can be reliably positioned by accommodating the positioning tip of the cover-side annular tip in the positioning groove of the motor housing-side annular groove provided on the end face wall of the motor housing. Moreover, since a gap having a predetermined width is formed between the positioning groove portion and the positioning tip portion, the O-ring can be visually confirmed.

It is an overall perspective view of the steering apparatus as an example to which this invention is applied. It is an exploded perspective view of the electric power steering apparatus which becomes an embodiment of this invention. It is a top view of the electric power steering apparatus shown in FIG. 2 as seen from the cover side. It is sectional drawing which shows the AA cross section of the electric power steering apparatus shown in FIG. It is sectional drawing which shows the BB cross section of the electric power steering apparatus shown in FIG. It is a front view which shows the structure of the O-ring used in the electric power steering apparatus. It is an enlarged view of the P part of the electric power steering apparatus shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments, and various modifications and applications are included in the technical concept of the present invention. Is also included in that range.

Before explaining the embodiment of the present invention, the configuration of the steering device as an example to which the present invention is applied will be briefly described with reference to FIG.

First, a steering device for steering the front wheels of an automobile will be described. The steering device 1 is configured as shown in FIG. A pinion (not shown) is provided at the lower end of the steering shaft 2 connected to a steering wheel (not shown), and this pinion meshes with a rack (not shown) long in the left-right direction of the vehicle body. Tie rods 3 for steering the front wheels in the left-right direction are connected to both ends of the rack, and the rack is covered with a rack housing 4. A rubber boot 5 is provided between the rack housing 4 and the tie rod 3.

An electric power steering device 6 is provided to assist the torque when the steering wheel is rotated. That is, the electric motor unit 8 is provided with a torque sensor 7 that detects the rotation direction and the rotation torque of the steering shaft 2, and applies a steering assist force to the rack via the gear 10 based on the detection value of the torque sensor 7. And an electronic control unit (ECU) 9 for controlling the electric motor arranged in the electric motor unit 8. In the electric motor unit 8 of the electric power steering device 6, three locations on the outer peripheral portion on the output shaft side are connected to the gear 10 via screws (not shown), and the electronic control unit is on the side opposite to the output shaft of the electric motor 8 unit. 9 is provided.

In the electric power steering device 6, when the steering shaft 2 is rotated in any direction by operating the steering wheel, the torque sensor 7 determines the rotation direction and rotation torque of the steering shaft 2. After detection, the electronic control unit 9 calculates the drive operation amount of the electric motor based on the detected value. The electric motor is driven by the power switching element of the electronic control unit 9 based on the calculated drive operation amount, and the output shaft of the electric motor is rotated so as to drive the steering shaft 2 in the same direction as the operation direction. The rotation of the output shaft of the electric motor is transmitted from a pinion (not shown) to a rack (not shown) via a gear 10, and the automobile is steered. Since these configurations and actions are already well known, further description thereof will be omitted.

To reiterate, in the electric power steering device having the configuration as described in Patent Document 1, since the shape of the fixed portion where the end face wall of the motor housing and the opening surface of the cover are abutted is an annular shape, the cover is attached to the end face wall. Occasionally, the cover rotates, which makes it difficult to install it in an accurate position and takes time for installation work, and there is a problem that there is a risk of incorrect assembly because there is no positioning. Further, it is advantageous to use an O-ring in order to obtain a reliable waterproof function between the end face wall of the motor housing and the opening surface of the cover. In this case, the O-ring is assembled by assembling the O-ring. There is a risk of forgetting to assemble and shipping, so this measure is necessary.

Against this background, the present invention proposes an electric power steering device having the following configuration.

In the present invention, a motor housing side circle formed on an end face wall of the motor housing on the side opposite to the output portion of the rotation shaft of the electric motor, and formed by an annular groove formed on the end face wall and retracting along the axis of the motor housing from the end face wall. The annular groove portion, the cover-side annular tip portion housed in the annular groove of the motor housing-side annular groove portion formed at the opening end of the cover covering the electronic control unit that controls the electric motor, and the motor housing-side annular groove portion. It is provided with an O-ring arranged between the groove and the annular tip on the cover side, and a positioning groove extending outward in the radial direction is formed in a part of the circumferential groove on the motor housing side, and the cover side. A part of the annular tip in the circumferential direction extends outward in the radial direction to form a positioning tip to be housed in the positioning groove, and the positioning tip is housed in the positioning groove. In this state, a gap having a predetermined width is formed between the positioning groove portion and the positioning tip portion so that the O-ring can be visually recognized.

According to the present invention, the cover and the motor housing can be reliably positioned by accommodating the positioning tip of the cover-side annular tip in the positioning groove of the motor housing-side annular groove provided on the end face wall of the motor housing. Moreover, since a gap having a predetermined width is formed between the positioning groove portion and the positioning tip portion, the O-ring can be visually confirmed.

Next, a specific configuration of the electric power steering device according to the embodiment of the present invention will be described in detail with reference to FIGS. 2 to 7.

FIG. 2 shows the electric power steering device according to the present embodiment disassembled and viewed from an angle, FIG. 3 shows the electric power steering device viewed from the cover side, and FIG. 4 shows the electric power shown in FIG. The AA cross section of the steering device is shown, FIG. 5 shows the BB cross section of the electric power steering device shown in FIG. 3, and FIG. 6 shows the shape of the O ring. Is an enlargement of the P portion of the electric power steering device shown in FIG.

As shown in FIG. 2, the electric motor portion 8 constituting the electric power steering device includes a motor housing 11 having a tubular portion made of aluminum or an aluminum-based metal such as an aluminum alloy, and an electric motor unit (not shown) housed therein. It consists of a motor. As is well known, the electric motor is provided with a rotating shaft, and a pinion is fixed to the output portion of the rotating shaft to transmit the rotational motion to the rack. The axis of the rotating shaft and the axis of the motor housing are substantially the same, and the electric motor can rotate in the motor housing 11.

Further, the electronic control unit 9 is arranged on the side opposite to the axial output unit of the motor housing 11, and is covered so as to be housed by a cover 12 made of synthetic resin, whereby the electronic control unit 9 is accommodated. Reference numeral 9 has a liquidtight structure.

The motor housing 11 and the cover 12 are integrally fixed by a fixing clip (not shown) on the facing end faces thereof. As shown in FIG. 3, three fixed clip engaging portions 15 formed at equal intervals are formed on the outer peripheral surface of the end face wall 14 of the motor housing 11, and is also an open end of the cover 12. Three fixed clip engaging portions 17 formed at equal intervals are also formed on the outer peripheral surface of the tip region portion 16.

Therefore, the end face wall 14 of the motor housing 11 and the tip region portion 16 of the cover 12 are abutted against each other, and the details will be described later. With the annular tip portion 20 housed, the motor housing 11 and the cover 12 are firmly joined by engaging the fixed cribs having a "C" -shaped cross section with the fixed clip engaging portions 15 and 17, respectively. Can be fixed. The connectors 13A to 13C are formed on the end surface portion of the cover 12 on the side opposite to the end surface wall 14.

Further, a positioning groove portion 23 is formed on the outer peripheral surface of the end face wall 14 of the motor housing 11, and a positioning tip portion 24 is formed on the tip region portion 16 of the cover 12. The details of the annular groove portion 19 on the motor housing side and the annular tip portion 20 on the cover side, and the positioning groove portion 23 and the positioning tip portion 24 will be described with reference to FIGS. 3 to 7.

The electronic control unit 9 housed inside the cover 12 is a power conversion circuit having a power supply circuit unit that generates a necessary power supply and a power switching element including a MOSFET or an IGBT that drives and controls the electric motor of the electric motor unit 8. It is composed of a control circuit unit that controls the power switching element, and the output terminal of the power switching element and the coil input terminal of the electric motor are electrically connected via a bus bar.

As shown in FIG. 3, the connectors 13A to 13C formed on the cover 12 are integrally formed on the end surface portion of the cover 12 on the side opposite to the motor housing 11. Specifically, it includes a pair of power supply connectors 13A, a detection sensor connector 13B, and a control state transmission connector 13C that transmits a control state to an external device.

Then, the electronic control unit 9 housed in the cover 12 is supplied with power from the power supply via the power supply connector 13A, and the detection signals such as the operating state are transmitted from the detection sensors via the detection sensor connector 13B. The control state signal of the current electric power steering device that has been supplied is transmitted via the control state transmission connector 13C.

Returning to FIG. 2, an annular iron side yoke (not shown) is fitted inside the motor housing 11, and an electric motor (not shown) is housed in the side yoke. The output unit (not shown) of the electric motor applies steering assist force to the rack via a pinion. Since the specific structure of the electric motor is well known, the description thereof will be omitted here.

The motor housing 11 is made of an aluminum alloy, and functions as a heat sink member that releases heat generated by an electric motor and heat generated by a power supply circuit unit and a power conversion circuit unit to the outside atmosphere. The electric motor unit 8 is composed of the electric motor and the motor housing 11.

An electronic control unit 9 is attached to an end face wall 14 of the motor housing 11 on the opposite side of the output unit of the electric motor unit 8. The electronic control unit 9 is composed of a power conversion circuit unit, a power supply circuit unit, and a control circuit unit. The end face wall 14 of the motor housing 11 is integrally formed with the motor housing 11, but in addition to this, only the end face wall 14 may be formed separately and integrated with the motor housing 11 by screws or welding. Is.

Here, the power conversion circuit unit, the power conversion circuit unit, and the control circuit unit form a redundant system, and form a dual system of a main electronic control unit and a sub electronic control unit. Normally, the electric motor is controlled and driven by the main electronic control unit, but when an abnormality or failure occurs in the main electronic control unit, the motor is switched to the sub-electronic control unit to control and drive the electric motor.

Therefore, normally, heat from the main electronic control unit is transferred to the motor housing 11, and when an abnormality or failure occurs in the main electronic control unit, the main electronic control unit stops and the sub-electronic control unit operates, and the motor housing 11 operates. The heat from the sub-electronic control unit is transferred to.

Also, unlike this redundant system, the main electronic control unit and the sub electronic control unit are combined to function as a regular electronic control unit, and if an abnormality or failure occurs in one electronic control unit, the other electronic control unit is halved. It is also possible to control and drive the electric motor by the ability of. In this case, the capacity of the electric motor is halved, but the electric power steering function is secured. Therefore, in a normal case, the heat of the main electronic control unit and the sub electronic control unit is transferred to the motor housing 11.

Further, the electronic control unit 9 is composed of a control circuit unit, a power supply circuit unit, and a power conversion circuit unit, and the power conversion circuit unit, the power supply circuit unit, and the control circuit unit are in this order in a direction away from the end face wall 14 side. It is arranged in. The control circuit unit generates a control signal for driving the switching element of the power conversion circuit unit, and is composed of a microcomputer, peripheral circuits, and the like. The power supply circuit unit generates a power supply for driving the control circuit unit and a power supply for the power conversion circuit unit, and is composed of a capacitor, a coil, a switching element, and the like. The power conversion circuit unit adjusts the power flowing through the coil of the electric motor, and is composed of switching elements and the like that form a three-phase upper and lower arm.

Next, a more detailed configuration in the vicinity of the fixed region of the annular groove portion 19 on the motor housing side and the annular tip portion 20 on the cover side, which is the embodiment of the present invention, will be described with reference to FIGS. 3 to 7.

In FIGS. 3 and 4, the motor housing side annular groove portion 19 has an annular groove 18 having a rectangular cross section that recedes along the axial direction of the motor housing 11 on the outer peripheral side of the end face wall 14 of the motor housing 11. Is formed. Further, at the open end of the cover 12, a cover-side annular tip portion 20 housed in the annular groove 18 of the motor housing-side annular groove portion 19 is formed.

A locking portion 21 is formed on the outer peripheral surface of the tip region portion 16 of the cover 12, and the locking portion 21 and the end surface of the end face wall 14 of the motor housing 11 are abutted against each other to form an annular tip on the cover side of the cover 12. The storage depth of the portion 20 in the annular groove 18 is controlled. As a result, the compression rate of the O-ring, which will be described later, is managed.

A liquid-tightening O-ring 22 is arranged between the annular groove 18 of the annular groove 19 on the motor housing side and the annular tip 20 on the cover side, and is controlled to a predetermined compressibility. As a result, a predetermined sealing function can be ensured between the annular groove 18 of the annular groove 19 on the motor housing side and the respective wall surfaces of the annular tip 20 on the cover side, and the intrusion of salt water or the like from the outside can be prevented. Can be done. The O-ring 22 may be nitrile-based or silicon-based.

Next, the characteristic configuration of this embodiment will be described with reference to FIGS. 3 and 5 to 7. As shown in FIG. 3, a positioning groove portion 23 extending outward in the radial direction is formed in a part of the annular groove portion 19 on the motor housing side in the circumferential direction. Similarly, a positioning tip portion 24 extending outward in the radial direction is also formed in a part of the cover-side annular tip portion 20 in the circumferential direction and housed in the positioning groove portion 23.

The positioning groove portion 23 and the positioning tip portion 24 are combined in pairs, and in the present embodiment, two positioning groove portions 23 and 17 are provided so as to sandwich the fixing clip engaging portions 15 and 17. When positioning the motor housing 11 and the cover 12, at least one positioning portion is required, but if there are three or more, dimensional control becomes difficult and it is not a good idea. Therefore, in the present embodiment, two fixed clip engaging portions 15 and 17 are provided so as to sandwich the fixed clip engaging portions 15 and 17. If there is no problem in positioning, the number is not necessarily limited to this number.

Since the positioning groove portion 23 and the positioning tip portion 24 are provided in this way, even if the shape of the fixed portion in which the end face wall 14 and the cover 12 of the motor housing 11 are butted is an annular shape, the end face wall 14 covers the end face wall 14. When assembling the cover 12, the cover 12 does not rotate and can be assembled at an accurate position, the assembling work can be performed in a short time, and since there is a positioning mechanism, there is no risk of erroneous assembly. It can act and be effective.

Further, as shown in FIGS. 5 and 7, with the positioning tip portion 24 housed in the positioning groove portion 23, the inner peripheral wall surface 23W of the positioning groove portion 23 in the circumferential direction is viewed in the radial direction. A gap G having a predetermined width is formed between (see FIG. 7) and the outer peripheral wall surface 24W (see FIG. 7) of the positioning tip portion 24 in the circumferential direction so that the protruding portion 22P of the O-ring 22 can be visually recognized. ..

Further, as shown in FIG. 6, the O-ring 22 is formed in an annular shape along the annular groove 18 formed in the annular groove portion 19 on the motor housing side, and the positioning groove portion is partially formed in the circumferential direction thereof. Two protrusions 22P to be housed in 23 are formed.

Therefore, the O-ring 22 is housed and arranged in the annular groove 18 with the protruding portion 22P housed in the positioning groove 23. Here, the radial length L of the protruding portion 22P can be set in the following two ways.

One method is that the radial length L of the protruding portion 22P is the positioning tip portion in a state where the positioning tip portion 24 of the cover 12 is housed in the positioning groove portion 23 and a fixed load is not applied by the fixing clip. This is a case where the length is set to exceed 24 W on the outer peripheral wall surface in the radial direction of 24.

According to this method, the annular tip portion 20 of the cover 12 and the annular tip portion 20 of the cover 12 with the O-ring 22 and the protruding portion 22P housed in the annular groove 18 formed in the end face wall 14 of the motor housing 11 and the positioning groove portion 23. When the positioning tip portion 24 is housed and arranged in the annular groove 18 formed on the end face wall 14 of the motor housing 11 and the positioning groove portion 23, the inner peripheral wall surface 23W of the positioning groove portion 23 in the circumferential direction and the positioning tip portion The presence or absence of the protruding portion 22P of the O-ring 22 can be visually confirmed by the gap G having a predetermined width formed between the outer peripheral wall surfaces 24W in the circumferential direction of the 24. That is, a part of the protruding portion 22P of the O-ring 22 exposed from the gap G can be confirmed.

Therefore, since the existence of the O-ring 22 can be confirmed before the fixing work by the fixing clip, the O-ring 22 can be easily reassembled even if the assembly of the O-ring 22 is forgotten.

In another method, the radial length L of the protruding portion 22P is the positioning tip in a state where the positioning tip portion 24 of the cover 12 is housed in the positioning groove portion 23 and a fixed load is not applied by the fixing clip. This is a case where the length is set so as not to exceed the outer wall surface 24W in the radial direction of the portion 24.

According to this method, the annular tip portion 20 of the cover 12 and the annular tip portion 20 of the cover 12 with the O-ring 22 and the protruding portion 22P housed in the annular groove 18 formed in the end face wall 14 of the motor housing 11 and the positioning groove portion 23. When the positioning tip portion 24 is housed and arranged in the annular groove 18 formed on the end face wall 14 of the motor housing 11 and the positioning groove portion 23, the presence or absence of the O-ring 22 cannot be visually confirmed.

However, when a fixed load is applied by a fixing clip to fix the motor housing 11 and the cover 12, or a fixed load simulating the fixing clip is applied, the positioning tip portion 24 formed on the annular tip portion 20 of the cover 12 is applied. The protruding portion 22P of the O-ring 22 is compressed to form a gap G having a predetermined width formed between the inner peripheral wall surface 23W in the circumferential direction of the positioning groove portion 23 and the outer peripheral wall surface 24W in the circumferential direction of the positioning tip portion 24. A part of the protruding portion 22P is deformed and protrudes to be exposed, whereby the presence of the protruding portion 22P of the O-ring 22 can be visually confirmed.

Therefore, since the existence of the O-ring 22 can be confirmed by the gap G, the O-ring 22 can be reassembled even if the assembly of the O-ring 22 is forgotten. Further, when the fixing clip is attached, the compressed state of the protruding portion 22P of the O-ring 22 by the fixing clip can be confirmed at the same time, so that it can be easily confirmed whether or not the sealing function is surely obtained.

In the above-described embodiment, the gap G in which the protruding portion 22P of the O-ring 22 can be visually recognized between the inner peripheral wall surface 23W in the circumferential direction of the positioning groove portion 23 and the outer peripheral wall surface 24W in the circumferential direction of the positioning tip portion 24. However, it is also possible to form a gap G in which the protruding portion 22P of the O-ring 22 can be visually recognized between the side wall surface in the circumferential direction of the positioning groove portion 23 and the side wall surface in the circumferential direction of the positioning tip portion 24. can. For example, it can be formed in the region portion of the side wall surface 23S shown in FIG.

Here, as shown in FIG. 7, the two opposing side wall surfaces 23S of the positioning groove portion 23 sandwiching the side surface in the circumferential direction of the positioning tip portion 24 are directed toward the bottom surface of the positioning groove portion 23. It is inclined so that the length between the two side wall surfaces 23S is shortened. The positioning groove portion 23 is made of a metal such as an aluminum alloy, the positioning tip portion 24 is made of a synthetic resin, and the shape in the circumferential direction and the cross-sectional shape thereof are made rectangular.

Therefore, when the positioning tip portion 24 is pushed into the positioning groove portion 23, the rectangular positioning tip portion 24 is deformed so as to follow the shape of the two opposing side surface surfaces 23S of the positioning groove portion 23. There is no gap between the two, and accurate positioning is possible.

As described above, according to the present invention, an annular groove formed on the end face wall of the motor housing on the side opposite to the output portion of the rotation shaft of the electric motor and retracting along the axis of the motor housing from the end face wall. An annular groove on the motor housing side, and an annular tip on the cover side housed in the annular groove on the motor housing side, which is formed at the open end of the cover covering the electronic control unit that controls the electric motor. , An O-ring arranged between the annular groove on the motor housing side and the annular tip on the cover side is provided, and a part of the annular groove on the motor housing side in the circumferential direction is a positioning groove extending outward in the radial direction. Is formed, and a positioning tip portion that extends outward in the radial direction and is housed in the positioning groove portion is formed in a part of the circumferential direction of the cover-side annular tip portion, and the positioning groove portion is used for positioning. With the tip portion housed, a gap having a predetermined width is formed between the positioning tip portions in the positioning groove portion so that the O-ring can be visually recognized.

According to this, the cover and the motor housing can be reliably positioned by accommodating the positioning tip of the cover-side annular tip in the positioning groove of the motor housing-side annular groove provided on the end face wall of the motor housing. Moreover, since a gap having a predetermined width is formed between the positioning groove portion and the positioning tip portion, the O-ring can be visually confirmed.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

6 ... Electric power steering device, 8 ... Electric motor unit, 9 ... Electronic control unit, 11 ... Motor housing, 12 ... Cover, 13A to 13C ... Connector, 14 ... End face wall, 15 ... Fixed clip engaging part, 16 ... Cover Tip area (open end), 17 ... Fixed clip engaging part, 18 ... Circular groove, 19 ... Motor housing side annular groove, 20 ... Cover side annular tip, 21 ... Locking part, 22 ... O Ring, 22P ... projecting portion, 23 ... positioning groove portion, 23S ... side wall surface of positioning groove portion, 24 ... positioning tip portion.

Claims (14)

To drive the motor housing in which the electric motor for driving the mechanical control element is housed and the electric motor arranged on the end face wall side of the motor housing on the side opposite to the output portion of the rotation shaft of the electric motor. An electric drive device including an electronic control unit and a cover that covers the electronic control unit.
A motor housing side annular groove portion formed on the end face wall of the motor housing on the side opposite to the output portion of the rotating shaft and formed of an annular groove that recedes from the end face wall along the axis of the motor housing. ,
A cover-side annular tip portion housed in the annular groove of the motor housing-side annular groove portion formed at the open end of the cover that covers the electronic control unit that controls the electric motor.
An O-ring arranged between the annular groove on the motor housing side and the annular tip on the cover side is provided.
A positioning groove extending outward in the radial direction is formed in a part of the annular groove portion on the motor housing side in the circumferential direction, and a part in the circumferential direction of the annular tip portion on the cover side is directed outward in the radial direction. A positioning tip portion that extends and is housed in the positioning groove portion is formed, and at the same time,
With the positioning tip portion housed in the positioning groove portion, a gap having a predetermined width is formed between the positioning groove portion and the positioning tip portion so that the O-ring can be visually recognized. Electric drive device. In the electric drive device according to claim 1,
An electric drive device characterized in that a protruding portion housed in the positioning groove portion is integrally formed on the O-ring. In the electric drive device according to claim 2,
A plurality of fixing clip engaging portions are formed on the outer peripheral surface of the cover and the outer peripheral surface of the end face wall of the motor housing, and the fixing clips formed on the outer peripheral surface of the cover and the outer peripheral surface of the end face wall. An electric drive device characterized in that the cover is fixed to the motor housing by engaging a fixing clip with the engaging portion. In the electric drive device according to claim 3,
The motor housing side annular groove portion and the cover side annular tip portion are provided with two positioning groove portions and the positioning tip portion on the front motor housing side annular groove portion and the cover side annular tip portion with the fixed clip engaging portion interposed therebetween. Drive device. In the electric drive device according to claim 2,
The radial length L of the protruding portion formed on the O-ring is such that the positioning tip portion is housed in the positioning groove portion and a fixed load is not applied by the fixing clip. The length is set to exceed the outer peripheral wall surface in the circumferential direction of
When the positioning tip is housed in the positioning groove while the protruding part of the O-ring is housed in the positioning groove, a part of the protruding part of the O-ring is exposed in the gap. An electric drive device characterized by this. In the electric drive device according to claim 2,
The radial length L of the protruding portion formed on the O-ring is such that the positioning tip portion is housed in the positioning groove portion and a fixed load is not applied by the fixing clip. The length is set so that it does not exceed the outer peripheral wall surface in the circumferential direction.
The protruding portion of the O-ring is housed in the positioning groove portion, and the tip portion for positioning is housed in the positioning groove portion and a load is applied. An electric drive device characterized in that a part is deformed and exposed. In the electric drive device according to claim 2,
The end face wall of the motor housing is made of metal, and the cover is made of synthetic resin.
The two side wall surfaces facing each other in the circumferential direction of the positioning groove portion are inclined so that the length between the two side wall surfaces becomes shorter toward the bottom surface of the positioning groove portion, and the positioning tip portion An electric drive device characterized in that the shape in the circumferential direction and the cross-sectional shape thereof are formed in a rectangular shape. An electric motor that applies steering assist force to the steering shaft based on the output from a torque sensor that detects the rotation direction and rotation torque of the steering shaft, a motor housing that houses the electric motor, and rotation of the electric motor. Electric power steering provided with an electronic control unit for driving the electric motor and a cover covering the electronic control unit, which are arranged on the end face wall side of the motor housing on the side opposite to the output unit of the shaft. It ’s a device,
A motor housing side annular groove portion formed on the end face wall of the motor housing on the side opposite to the output portion of the rotating shaft and formed of an annular groove that recedes from the end face wall along the axis of the motor housing. ,
A cover-side annular tip that is formed at the open end of the cover that covers the electronic control unit that controls the electric motor and is housed in the annular groove of the motor housing-side annular groove.
An O-ring arranged between the annular groove on the motor housing side and the annular tip on the cover side is provided.
A positioning groove extending outward in the radial direction is formed in a part of the annular groove portion on the motor housing side in the circumferential direction, and a part in the circumferential direction of the annular tip portion on the cover side is directed outward in the radial direction. A positioning tip portion that extends and is housed in the positioning groove portion is formed, and at the same time,
With the positioning tip portion housed in the positioning groove portion, a gap having a predetermined width is formed between the positioning groove portion and the positioning tip portion so that the O-ring can be visually recognized. Electric power steering device. In the electric power steering device according to claim 8.
An electric power steering device characterized in that a protruding portion housed in the positioning groove portion is integrally formed on the O-ring. In the electric power steering device according to claim 9.
A plurality of fixing clip engaging portions are formed on the outer peripheral surface of the cover and the outer peripheral surface of the end face wall of the motor housing, and the fixing clips formed on the outer peripheral surface of the cover and the outer peripheral surface of the end face wall. An electric power steering device characterized in that the cover is fixed to the motor housing by engaging a fixing clip with the engaging portion. In the electric power steering device according to claim 10.
The motor housing side annular groove portion and the cover side annular tip portion are provided with two positioning groove portions and the positioning tip portion on the front motor housing side annular groove portion and the cover side annular tip portion with the fixed clip engaging portion interposed therebetween. Power steering device. In the electric power steering device according to claim 9.
The radial length L of the protruding portion formed on the O-ring is such that the positioning tip portion is housed in the positioning groove portion and a fixed load is not applied by the fixing clip. The length is set to exceed the outer peripheral wall surface in the circumferential direction of
When the positioning tip is housed in the positioning groove while the protruding part of the O-ring is housed in the positioning groove, a part of the protruding part of the O-ring is exposed in the gap. An electric power steering device characterized by this. In the electric power steering device according to claim 9.
The radial length L of the protruding portion formed on the O-ring is such that the positioning tip portion is housed in the positioning groove portion and a fixed load is not applied by the fixing clip. The length is set so that it does not exceed the outer peripheral wall surface in the circumferential direction.
The protruding portion of the O-ring is housed in the positioning groove portion, and the tip portion for positioning is housed in the positioning groove portion and a load is applied. An electric power steering device characterized in that a part is deformed and exposed. In the electric power steering device according to claim 9.
The end face wall of the motor housing is made of metal, and the cover is made of synthetic resin.
The two side wall surfaces facing each other in the circumferential direction of the positioning groove portion are inclined so that the length between the two side wall surfaces becomes shorter toward the bottom surface of the positioning groove portion, and the positioning tip portion An electric power steering device characterized in that the shape in the circumferential direction and the cross-sectional shape thereof are formed in a rectangular shape.

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