JP5955611B2 - Power steering apparatus and method for manufacturing power steering apparatus - Google Patents

Description

  The present invention relates to a power steering device and a method for manufacturing the power steering device.

  For example, an electric power steering device that is a power steering device includes a pinion shaft connected to an input shaft, and a rack shaft that includes a rack that meshes with the pinion of the pinion shaft. Output torque is applied as assist force. At this time, the steering force from the steering wheel is detected by a torque sensor, and a current based on the torque signal from the torque sensor and the vehicle speed signal from the vehicle is supplied to the electric motor.

  As a conventional technique described in the publication, when a torsion torque is input between the first shaft and the second shaft and the elastic member is twisted, the relative position between the hard magnetic body and the soft magnetic body changes. The magnetic flux density generated in the magnetic circuit of the soft magnetic material changes. By detecting the change in the magnetic flux density with a magnetic sensor, the torsional torque applied between the first axis and the second axis is changed. There is what is required (for example, see Patent Document 1). And in this prior art document, the technique which attaches a magnetic sensor to the connector part of the wire harness which connects a torque sensor and a control circuit, and connects with a control circuit by inserting a connector part into a torque sensor from the outside of a housing is disclosed. (For example, see FIG. 19 of Patent Document 1).

JP 2003-149062 A

  Here, for example, a case is considered in which a housing (cover) that rotatably supports an input shaft and an output shaft is divided into a plurality of housings, and these are fixed using housing fixing bolts. Then, there is a mode in which a sensor structure is inserted from the outside into a housing after a plurality of housings are fixed by a fixing member such as a housing fixing bolt, and the sensor structure is held by a fixing member such as a sensor fixing bolt. .

  At this time, in an assembling operation in which no special relevance exists in the work process, these fixing members are generally assembled and fixed at positions having no relevance. Therefore, in the conventional structure, it is possible to divide the housing by removing the housing fixing bolt while the sensor structure is assembled with the sensor fixing bolt. However, if the housing is divided while the sensor structure is held, for example, the detection body attached to the input shaft or the output shaft and the sensor structure come into contact with each other, and there is a concern about breakage of these.

  The present invention has been made to solve such a technical problem. In a power steering device in which a sensor structure is assembled to a housing, the housing is divided while the sensor structure is held. The purpose is to suppress.

The present invention that achieves the above-mentioned object supports the input shaft and the output shaft rotatably, and is divided into a first housing and a second housing, and the first housing and the second housing are divided. Is connected to the housing using a fixing member, a detection body is connected to the input shaft and the output shaft, a sensor structure is held to the housing using a holding member, and the input shaft and the output shaft A measuring device for measuring a relative rotation angle between the first housing and the second housing in a state where the sensor structure of the measuring device is held by the housing. the unlocking of the fixing member while constrained by the holding member, the said first housing and the second housing, a plurality of housing fixing bolts The holding member that holds the sensor structure in the housing is a sensor fixing bolt, and at least one of the plurality of housing fixing bolts in a state where the sensor structure is held in the housing. Limiting the removal of the housing fixing bolt in a state where the sensor structure is held by the housing by being positioned so that the head of the sensor fixing bolt overlaps the space on the extension line in the bolt tightening direction of the fixing bolt This is a power steering device. It should be noted that there is no denying the existence of a plurality of housings as a third housing, a fourth housing, and so on.

According to the present invention, the input shaft and the output shaft are rotatably supported and divided into a first housing and a second housing, and the divided first housing and the second housing each have a fixing member. A detection body is connected to the housing fixed by using the input shaft and the output shaft, a sensor structure is held to the housing using a holding member, and relative rotation between the input shaft and the output shaft is performed. A measuring device for measuring an angle; and a breakage prevention member attached together with the sensor structure, and the first housing and the second housing in a state where the sensor structure of the measuring device is held by the housing. as well as limited by the damage preventing member unlocking of the fixing member fixing the, wherein the first housing second housings A holding member that is tightened by a plurality of housing fixing bolts and that holds the sensor structure in the housing is a sensor fixing bolt, and in a state where the sensor structure is held in the housing, The sensor structure is held in the housing by being positioned so that the breakage prevention member overlaps the space on the extension line in the bolt tightening direction of at least one of the housing fixing bolts. A power steering device that restricts removal of a housing fixing bolt .

  Still further, in the power steering device, the first housing and the second housing are fastened by the plurality of housing fixing bolts from an axial direction of the input shaft, and the sensor structure is Of the plurality of housing fixing bolts, inserted into the housing from a direction intersecting the axis, held by the sensor fixing bolt from a direction intersecting the axial direction, and the sensor structure being held by the housing. When viewed from the axial direction of at least one housing fixing bolt, the head of the sensor fixing bolt or the breakage preventing member is positioned so as to overlap.

  The method of manufacturing a power steering apparatus to which the present invention is applied includes a plurality of housings divided into a first housing and a second housing, which rotatably support an input shaft and an output shaft to which a detection body is connected. And a housing fixing step of fixing the first housing and the second housing with respect to the housing after the first housing and the second housing are fixed toward at least one of the plurality of fixing members of the housing. A sensor structure in which a sensor structure for measuring the torque between the input shaft and the output shaft using the detection body is inserted into the housing with a breakage prevention member extending therebetween, and held in the housing by a holding member A structure holding step, wherein the sensor structure holding step includes at least one of the plurality of fixing members used for fixing the housing. The space on the extension of the fixed direction of the fixing member, is characterized by fixing the sensor structure with a portion of the damage preventing member overlap.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a housing is divided | segmented with the power steering apparatus with which a sensor structure is integrated in a housing being hold | maintained.

1 is an overall configuration diagram of an electric power steering apparatus to which the present embodiment is applied. It is a lineblock diagram explaining the handle side gear housing of the electric power steering device to which this embodiment is applied. It is a lineblock diagram explaining the assist side gear housing of the electric power steering device to which this embodiment is applied. It is a block diagram which shows the state by which the sensor structure to which this embodiment is applied was attached to the housing. It is explanatory drawing which shows the 1st example of the sensor breakage prevention structure to which this embodiment is applied. It is explanatory drawing which shows the 2nd example of the sensor breakage prevention structure to which this embodiment is applied. It is explanatory drawing which shows the 3rd example of the sensor breakage prevention structure to which this embodiment is applied. It is explanatory drawing which shows the 4th example of the sensor breakage prevention structure to which this embodiment is applied.

[Overall configuration of power steering system]
First, an electric power steering apparatus 1 that is a power steering apparatus to which the present embodiment is applied will be described with reference to FIGS.
FIG. 1 is an overall configuration diagram of an electric power steering apparatus 1 to which the present embodiment is applied. FIG. 2 is a configuration diagram illustrating the handle-side gear housing 10A of the electric power steering apparatus 1 to which the present embodiment is applied, and is a II-II cross section shown in FIG. FIG. 3 is a configuration diagram illustrating the assist-side gear housing 10B of the electric power steering apparatus 1 to which the present embodiment is applied, and is a cross-sectional view taken along the line III-III shown in FIG. The electric power steering apparatus 1 to which the present embodiment is applied is a so-called double pinion type power steering apparatus, a manual pinion that transmits a steering force from a steering member (steering wheel) to the rack shaft 24, and an electric motor 30. And an assist pinion that transmits the steering assist force from the rack shaft 24 to the rack shaft 24.

  As shown in FIG. 1, the gear housing 10 fixed to a vehicle body frame (not shown) or the like has a handle side gear housing 10A and an assist side gear housing 10B, which are connected around a rack shaft 24. A gear housing 10 is configured. The handle side gear housing 10A supports an input shaft 21 and a handle side pinion shaft (output shaft) 23 (see FIG. 2) in a rotatable manner. The input shaft 21 is connected to an upper shaft (not shown) connected to a steering wheel (not shown).

  On the other hand, the assist side gear housing 10 </ b> B couples the output torque of the electric motor 30 surrounded by the motor case 31 to the rack shaft 24. Left and right tie rods 48 </ b> A and 48 </ b> B are connected to both ends of the rack shaft 24. The tie rods 48A and 48B are connected to a tire (not shown) as a steered portion via a knuckle arm (not shown). The rack shaft 24 is supported by bearings (not shown) provided in the first housing 11 (see FIG. 2) of the handle side gear housing 10A and the first housing 17 (see FIG. 3) of the assist side gear housing 10B. It is supported in a state in which the slidability is kept good in the left-right direction in FIG.

[Configuration of handle side gear housing]
As shown in FIG. 2, the handle side gear housing 10A to which the present embodiment is applied is divided into a first housing 11 and a second housing 12, and these are assembled to form a housing. And it has the housing fixing bolt 13 as a fixing member which fixes the 1st housing 11 and the 2nd housing 12 to be assembled. As will be described later, the housing fixing bolt 13 is provided, for example, at two points in a direction orthogonal to the axial direction (the S direction from top to bottom in FIG. 2) with a straight line or at a certain angle. The first housing 11 and the second housing 12 are tightened toward the end. FIG. 2 shows one of the two housing fixing bolts 13.

  As shown in FIG. 2, the handle side gear housing 10A has an input shaft 21 connected to a steering wheel (not shown). A handle-side pinion shaft (output shaft) 23 connected to the input shaft 21 via a torsion bar 22 is coaxial with the input shaft 21. Further, the handle-side pinion shaft 23 has a pinion 23A, and the pinion 23A is engaged with the handle-side rack 24A of the rack shaft 24. As a result, the rack shaft 24 can move linearly according to the steering torque applied to the steering wheel, and moves in the left-right direction of the gear housing 10 shown in FIG. The input shaft 21 is held by a bearing 21J provided in the second housing 12 of the handle side gear housing 10A, and the handle side pinion shaft 23 is held by bearings 23J and 23K provided in the first housing 11 of the handle side gear housing 10A. Is done.

  Further, in the first housing 11 of the handle side gear housing 10A, a rack guide that presses the handle side rack 24A of the rack shaft 24 against the pinion 23A of the handle side pinion shaft 23 and slidably supports the rack shaft 24. 25 is attached. The rack guide 25 is inserted into the cylinder portion 14 of the first housing 11. The cylinder portion 14 is provided at a portion facing the handle-side pinion shaft 23 across the rack shaft 24. The rack guide 25 includes a cap 25A that is fixed to the cylinder portion 14 by an embedded screw type, and includes a spring 25B that presses the rack shaft 24 from the opposite side of the handle side rack 24A. When the cap 25A is tightened to the cylinder portion 14 of the first housing 11, the spring 25B presses the rack shaft 24, and the handle side rack 24A maintains a good mesh with the pinion 23A.

  Further, the handle-side gear housing 10A of the electric power steering apparatus 1 detects the relative rotation angle between the input shaft 21 and the handle-side pinion shaft (output shaft) 23, and generates a steering torque based on the detected relative rotation angle. A torque detection device 40 for detection is attached.

[Configuration of assist side gear housing]
As shown in FIG. 3, the assist side gear housing 10B to which the present embodiment is applied is a structure in which a first housing 17 and a second housing 18 are assembled, and a cap 19 is further assembled. In the electric power steering device 1 (see FIG. 1), the assist-side pinion shaft 33 to which the output of the electric motor 30 (see FIG. 1) is transmitted in the vertical direction, as described later, while being mounted on the vehicle. Crossed with respect to each other. In the present embodiment, the assist side pinion shaft 33 is placed horizontally in the horizontal direction so as to be along the longitudinal direction of the vehicle.

  In the electric power steering apparatus 1, the motor case 31 of the electric motor 30 shown in FIG. 1 is attached to the second housing 18 of the assist side gear housing 10B shown in FIG. The assist side gear housing 10B is provided with a worm wheel 34 that meshes with a worm gear (not shown) connected to the output shaft of the electric motor 30. Moreover, it has the assist side pinion shaft 33 which rotates in response to the transmission force from the worm wheel 34. For example, the assist side pinion shaft 33 is made of metal, and the worm wheel 34 is formed of a resin molded body integrally formed with the hub 33A of the metal assist side pinion shaft 33, and is fixed to the assist side pinion shaft 33. ing.

  The first housing 17 is provided with a bearing 37 that holds one end side of the assist side pinion shaft 33, and the second housing 18 is provided with a bearing 35 that holds the other end side of the assist side pinion shaft 33. Further, a lock nut 36 for fixing the inner ring of the bearing 35 to the assist side pinion shaft 33 is provided. The lock nut 36 is fixed to the assist side pinion shaft 33 by an embedded screw type, and the inner ring of the bearing 35 is fixed to the assist side pinion shaft 33 by screwing the lock nut 36 into the assist side pinion shaft 33. The The outer ring of the bearing 35 is held by the second housing 18. One end of the assist side pinion shaft 33 is fitted in the inner ring of the bearing 37 with a gap.

  Further, in the first housing 17 of the assist side gear housing 10B, a rack guide that presses the assist side rack 24B of the rack shaft 24 against the pinion 33B of the assist side pinion shaft 33 and slidably supports the rack shaft 24. 38 is attached. The rack guide 38 is inserted into the cylinder portion 17A of the first housing 17. The cylinder portion 17A is provided at a portion facing the assist side pinion shaft 33 across the rack shaft 24. The rack guide 38 includes a cap 38A that is fixed to the cylinder portion 17A by an embedded screw type, and includes a spring 38B that presses the rack shaft 24 from the opposite side of the assist side rack 24B. When the cap 38A is tightened to the cylinder portion 17A of the first housing 17, the spring 38B presses the rack shaft 24, and the assist side rack 24B maintains good engagement with the pinion 33B. It should be noted that both or at least one of the pinion 33B of the assist side pinion shaft 33 and the assist side rack 24B of the rack shaft 24 is a helical gear whose teeth are obliquely crossed with their central axes.

  In the electric power steering device 1 having such a configuration, the output torque of the electric motor 30 driven according to the detection result of the torque detection device 40 (see FIG. 2) is transmitted through the worm wheel 34 (not shown). And transmitted to the rack shaft 24 via the assist-side pinion shaft 33. In this way, the output torque of the electric motor 30 is applied as an assist force for the movement of the rack shaft 24 by the steering wheel. That is, the rack shaft 24 rotates with the steering torque generated by the rotation of the steering wheel and the auxiliary torque applied from the electric motor 30.

[Configuration of torque detection device]
Next, the torque detection device 40 will be described in detail.
FIG. 4 is a configuration diagram showing a state in which the sensor structure to which the present embodiment is applied is attached to the housing, and is an enlarged view of a portion IV in FIG.
The torque detector 40 includes a relative angle detector 60 that detects a relative rotation angle between the input shaft 21 and the handle-side pinion shaft (output shaft) 23, and a steering torque based on the relative rotation angle detected by the relative angle detector 60. And a torque detection unit 50 for detecting.

First, the relative angle detection unit 60 will be described.
As shown in FIG. 4, the relative angle detection unit 60 includes a magnet 61 as an example of a hard magnetic body attached to the input shaft 21, a soft magnetic yoke 62 disposed in a magnetic field formed by the magnet 61, and And a magnetic flux collecting member 63 that collects magnetic flux from the yoke 62. The relative angle detection unit 60 includes a magnetic sensor 64 that detects a magnetic flux density in a magnetic circuit formed by the magnet 61, the yoke 62, and the magnetism collecting member 63. The relative angle detection unit 60 includes an input side bracket 65 interposed between the magnet 61 and the input shaft 21, and an output side bracket 66 interposed between the yoke 62 and the handle side pinion shaft 23. Yes.

  The magnet 61 has a cylindrical shape, and N poles and S poles are alternately arranged in the circumferential direction of the input shaft 21 and magnetized in the circumferential direction. The magnet 61 is fixed to the input side bracket 65, and the magnet 61 is attached to the input shaft 21 by fixing the input side bracket 65 to the input shaft 21. The magnet 61 rotates with the input shaft 21. Examples of a method for fixing the magnet 61 to the input side bracket 65 include an adhesive and press-fitting. Further, examples of the method for fixing the input side bracket 65 to the input shaft 21 include press fitting, welding, caulking, or screwing.

  The yoke 62 includes a first yoke (not shown) and a second yoke (not shown). The first yoke and the second yoke include a disc-shaped annular portion (not shown) in which a hole having a diameter larger than the outer diameter of the magnet 61 is formed inside, and the input shaft 21 is connected to the annular portion from the annular portion. And a plurality of protrusions (not shown) formed to extend in the axial direction. The plurality of protrusions are curved along the outer circumferential surface of the magnet 61 in the circumferential direction of the magnet 61. The protrusions of the first yoke and the protrusions of the second yoke are formed in the same number as the N pole and S pole of the magnet 61. And these protrusion parts are arrange | positioned a little outside this outer peripheral surface so that the outer peripheral surface of the magnet 61 may be opposed in the rotation radius direction of the input shaft 21.

  The output side bracket 66 is a cylindrical metal member extending in the axial direction of the handle side pinion shaft 23. The yoke 62 is injection-molded together with the output side bracket 66 and is integrally molded. As a result, the first yoke, the second yoke, and the output side bracket 66 are fixed to the handle side pinion shaft 23 in a state where they are a single component. As a method for fixing this, it is possible to exemplify fixing the output side bracket 66 to the handle side pinion shaft 23 by press-fitting, caulking or screwing the output side bracket 66 to the handle side pinion shaft 23.

The magnetic flux collecting member 63 includes a first magnetic flux collecting member 631 and a second magnetic flux collecting member 632.
The first magnetic flux collecting member 631 is disposed above the upper end surface of the annular portion (not shown) of the first yoke (not shown), and the first magnetic flux collecting member 631 extends over a predetermined angle in the circumferential direction. A flat plate-like part (not shown) is formed along the upper end surface. The first magnetic flux collecting member 631 has a first protruding portion 631A that extends downward in the axial direction from the outermost portion of the flat plate-shaped portion and protrudes outward from the lowermost end portion in a direction orthogonal to the axial direction. Yes.

  The second magnetism collecting member 632 is disposed below the lower end surface of the annular portion (not shown) of the second yoke (not shown), and the second magnetic flux collecting member 632 extends over a predetermined angle in the circumferential direction. It has a flat plate-like part (not shown) formed along the lower end surface. The second magnetism collecting member 632 includes a second projecting portion 632A that extends upward in the axial direction from the outermost portion of the flat plate-shaped portion and projects outward from the uppermost end portion in a direction orthogonal to the axial direction. Yes.

  The magnetic sensor 64 is attached to the second housing 12 via a detection substrate 54 of the torque detector 50 described later, and in the axial direction, the first protrusion 631A of the first magnetic flux collecting member 631 and the second magnetic flux collector. The member 632 is disposed between the second protrusion 632A. The magnetic sensor 64 is a sensor that detects a magnetic flux density between the first magnetic flux collecting member 631 and the second magnetic flux collecting member 632, converts the detected magnetic flux density into an electric signal (for example, a voltage signal), and outputs the electric signal. A magnetoresistive element, Hall IC, Hall element, etc. can be illustrated.

Next, the torque detector 50 will be described.
The torque detection unit 50 includes a reference value that is an output value of the magnetic sensor 64 in a neutral state in which steering torque is not applied to the steering wheel and the torsion bar 22 is not twisted, and an output value of the magnetic sensor 64. An electric signal corresponding to the steering torque is output based on the above.
The torque detection unit 50 is configured by a detection board 54 on which an arithmetic logic circuit is mounted as shown in FIG. The torque detection unit 50 outputs a torque signal via a terminal 55 connected to the detection board 54. The detection substrate 54 is supplied with a power supply voltage and a GND voltage via a terminal 55. A magnetic sensor 64 is connected to the detection substrate 54.

In the torque detection device 40 configured as described above, the magnetism collecting member 63 and the magnetic sensor 64 of the relative angle detection unit 60 and the detection substrate 54 constituting the torque detection unit 50 are a single structure. The body 51 is assembled in advance, and then attached to the second housing 12.
The sensor structure 51 includes a sensor housing 52 that holds the magnetic flux collecting member 63, a detection board 54 that is attached to the sensor housing 52, a magnetic sensor 64 that is connected to the detection board 54, and a terminal 55. Consists of. The sensor housing 52 is formed by injection molding in which synthetic resin is injected around the magnetic flux collecting member 63 inserted into the mold, and is integrated with the magnetic flux collecting member 63. Further, an O-ring 56 is attached to the sensor housing 52, and when the sensor structure 51 is attached to the second housing 12, an internal sealing property is secured. The sensor structure 51 is fixed to the second housing 12 by a sensor fixing bolt 57 (see FIGS. 5 to 8) that is a holding member.

[Structure to prevent damage to sensor structure]
The sensor structure 51 is attached to the second housing 12 after the second housing 12 is fixed to the first housing 11 by the housing fixing bolt 13 shown in FIG.
Here, as described above, the first protrusion 631A of the first magnetism collecting member 631 and the second protrusion 632A of the second magnetism collecting member 632 shown in FIG. 4 are the yokes fixed to the handle side pinion shaft 23. 62 is located above the first yoke (input side) and below the second yoke (output side). The handle side pinion shaft 23 is held by the first housing 11. Therefore, when the sensor structure 51 is attached to the second housing 12 and the first housing 11 and the second housing 12 are unfixed and disassembled, the first protrusion 631A and the second The protrusion 632A interferes with the first yoke and the second yoke, and the magnetic flux collecting member 63 and the magnetic sensor 64 are damaged or deformed. Further, deformation or breakage of the yoke 62, which is a detection body on the handle side pinion shaft 23 side, may occur.
Therefore, in the present embodiment, in a state where the sensor structure 51 is attached, the operation of touching the housing fixing bolt 13 that fixes the first housing 11 and the second housing 12 is restricted to thereby limit the sensor structure 51. The removal of the second housing 12 and the division of the housing in a state where the is attached are limited.

[First example of sensor damage prevention structure]
FIG. 5 is an explanatory view showing a first example of a sensor breakage prevention structure to which the present embodiment is applied, and shows a first fixed state in which the sensor structure 51 is fixed to the second housing 12. FIG. 5A is a view of the handle-side gear housing 10A viewed from above (input side) in the axial direction of FIG. 2, and FIG. 5B is a view of FIG. 5A viewed from the VV direction. It is. The second housing 12 is integrated with the first housing 11 by two housing fixing bolts 13.

  In the example shown in FIGS. 5A and 5B, as the shape of the second housing 12, there are approximately 90 angles at two points in the direction perpendicular to the axial direction, where the bolts and nuts are fixed. It is configured to be arranged. These two fixing points are located on the insertion direction side of the sensor structure 51, and each part is fastened by the housing fixing bolt 13. The bolt fastening direction of the housing fixing bolt 13 is the S direction in the figure (see FIGS. 5B and 2). The S direction is a direction from the input side in the axial direction of the input shaft 21 and the handle side pinion shaft (output shaft) 23 toward the output side (from the upper direction to the lower direction in FIG. 2). For example, a hexagon socket is inserted into the head of the housing fixing bolt 13, and the housing fixing bolt 13 is tightened in the S direction by an assembly tool such as a wrench with a ratchet. After the first housing 11 and the second housing 12 are integrated by the housing fixing bolt 13, the direction T intersects with the T direction (the axis direction of the input shaft 21 and the handle side pinion shaft (output shaft) 23) in FIG. The sensor structure 51 is inserted into the second housing 12. The sensor structure 51 is fixed to the second housing 12 by two sensor fixing bolts 57 that are similarly tightened from the T direction (direction intersecting the axial direction).

  In the first fixed state shown in FIGS. 5A and 5B, the sensor structure 51 and the sensor fixing bolt 57 exist in the space on the extension line in the S direction that is the bolt fastening direction of the housing fixing bolt 13. ing. That is, there is an overlap by a dimension L shown in FIG. As a result, it is difficult to fit the hexagon socket into the head of the housing fixing bolt 13 in a state where the sensor structure 51 is attached to the second housing 12 by the sensor fixing bolt 57. For example, if a thin hexagon wrench or the like is inserted from the side, the housing fixing bolt 13 can be loosened somehow, but this is not a tool employed in normal assembly. Access (tool pressing operation) from the S direction (axial direction), which is the bolt tightening direction, is required by a tool employed in normal assembly. According to the present embodiment, a part of the sensor structure 51 and a part of the sensor fixing bolt 57 are in the way, and a tool for loosening the housing fixing bolt 13 cannot be used. As described above, by restricting the operation of touching the housing fixing bolt 13, the division of the housing in a state where the sensor structure 51 is attached can be restricted.

[Second example of sensor damage prevention structure]
FIG. 6 is an explanatory diagram showing a second example of a sensor breakage prevention structure to which the present embodiment is applied. In the first example shown in FIGS. 5A and 5B, the two fixing points of the second housing 12 are obstructed by the main body of the sensor structure 51 and / or the sensor fixing bolt 57, and the sensor structure 51 is In the attached state, the housing fixing bolt 13 was configured not to be loosened. In the second example shown in FIG. 6, the housing in the state where the one fixing portion of the second housing 12 is obstructed by the main body of the sensor structure 51 and / or the sensor fixing bolt 57 and the sensor structure 51 is attached. One of the fixing bolts 13 is configured not to be loosened.

  In the second housing 12 of the second example shown in FIG. 6, two fixing points exist at two points in the direction orthogonal to the axial direction, that is, two points on the diametrical extension line in the direction intersecting the axial direction. doing. The housing fixing bolt 13 interferes with the main body of the sensor structure 51 and / or the sensor fixing bolt 57 in a space at one of the fixing points. Therefore, a part of the sensor structure 51 and a part of the sensor fixing bolt 57 are in the way, and a tool for loosening the bolt cannot be used for one of the housing fixing bolts 13. Although it is not two places like the 1st example, division of a housing in the state where sensor structure 51 was attached can be restricted similarly. In addition, in this 2nd example, the fixing location of the 1st housing 11 and the 2nd housing 12 exists in two points on the extension line | wire of the diameter direction of the direction which cross | intersects an axial direction. In such a case, the tightening of the first housing 11 and the second housing 12 using the housing fixing bolt 13 can be stabilized as compared with the first example.

[Third example of sensor damage prevention structure]
FIG. 7 is an explanatory diagram showing a third example of a sensor breakage prevention structure to which the present embodiment is applied. In the third example shown in FIG. 7, the housing structure of the sensor structure 51 is devised. When the sensor structure 51 is attached to the second housing 12, the housing structure of the sensor structure 51 interferes. Thus, access to the housing fixing bolt 13 from the tightening direction using the tool (axial direction, S direction in FIG. 2) is restricted.

In the third example shown in FIG. 7, a projecting portion 51 </ b> A shown in FIG. 7 is formed in a sensor housing 52 (see FIG. 4) that is a housing of the sensor structure 51. When the sensor structure 51 is assembled to the second housing 12, the overhanging portion 51A allows part or all of the housing fixing bolts 13 used for tightening the second housing 12 to be disposed on the output side in the axial direction. It overhangs so as to cover it with space. The overhanging portion 51A can be integrally formed by injection molding with resin when the sensor housing 52 is formed.
According to the third example shown in FIG. 7, as in the first and second examples described above, the housing is divided with the sensor structure 51 attached (the first housing 11 and the second housing 12). Can be limited. Moreover, when determining the assembly position of the first housing 11 and the second housing 12, the necessity of designing in consideration of the mounting position of the sensor structure 51 is reduced, and the degree of freedom in housing design can be increased.

[Fourth example of sensor damage prevention structure]
FIG. 8 is an explanatory diagram showing a fourth example of a sensor breakage prevention structure to which the present embodiment is applied. In the fourth example shown in FIG. 8, a fixing release limiting member 58 that covers the housing fixing bolt 13 when the sensor structure 51 is assembled is provided separately from the sensor structure 51 and the housing. As in the other examples, in the state where the sensor structure 51 is attached to the second housing 12, the tightening direction using the tool with respect to the housing fixing bolt 13 (axial direction, S direction in FIG. 2). Access from is restricted.

  8 is clamped and fixed together when the sensor structure 51 is clamped and fixed by the sensor fixing bolt 57, for example. That is, it has two holes with a pitch that matches the mounting position of the sensor structure 51 and has two legs that extend in the direction of the housing fixing bolt 13 in FIG. 8 when mounted on the second housing 12. . These two holes are formed with dimensions that allow the sensor fixing bolt 57 to be inserted without stress. For example, it is formed of a U-shaped sheet metal or a resin molded product. The fourth example shown in FIG. 8 can also limit the division of the housing with the sensor structure 51 attached. That is, when the sensor structure 51 is attached, the fixing release restricting member 58 is located in the space in the axial direction of the housing fixing bolt 13 (the S direction in FIG. 2), and the sensor structure 51 is removed for the first time. The fixing release limiting member 58 can be removed from the space in the axial direction of the housing fixing bolt 13. As a result, the housing fixing bolt 13 is not removed while the sensor structure 51 is attached.

  Each aspect shown in the present embodiment described above is an example, and does not limit selection of other aspects. For example, as a modification of the fourth example shown in FIG. 8, the fastening direction of the sensor structure 51 by the sensor fixing bolt 57 in the state where the fixing release limiting member 58 covers the space in the axial direction of the housing fixing bolt 13. The axial direction (the S direction in FIG. 2) may be the same as the fastening direction of the housing fixing bolt 13.

[First Manufacturing Method of Power Steering Device]
Next, a method for manufacturing a power steering apparatus to which the present embodiment is applied will be described.
First, as a first manufacturing method, a method for manufacturing the sensor breakage prevention structure of the first example, the second example, and the third example described above will be described.
First, as shown in FIG. 4, a detection body that is a part of the torque detection device 40 is connected to the input shaft 21 and the handle-side pinion shaft (output shaft) 23. That is, by attaching the input side bracket 65 to the input shaft 21, the magnet 61 fixed to the input side bracket 65 is connected to the input shaft 21. Further, by attaching the output side bracket 66 to the handle side pinion shaft (output shaft) 23, the yoke 62 integrally formed with the output side bracket 66 is connected to the handle side pinion shaft (output shaft) 23. As shown in FIG. 2, the input shaft 21 and the handle-side pinion shaft (output shaft) 23 to which these detectors (a part of the torque detector 40) are connected are connected to the first housing 11 and the second housing 12. And rotatably supported through a bearing 23J, a bearing 23K, and a bearing 21J. And the 1st housing 11 and the 2nd housing 12 are clamped and fixed from the axial direction (S direction of FIG. 2) with the two housing fixing bolts 13, for example. Thereby, a housing fixing process is performed.

  Next, after the first housing 11 and the second housing 12 are fixed by the housing fixing bolt 13, the sensor structure 51 of the torque detection device 40 is inserted into the second housing 12. This insertion direction is a direction intersecting the axial direction (the S direction in FIG. 2), more specifically, a direction orthogonal to each other. Then, the sensor structure 51 is fixed to the second housing 12 by tightening with two sensor fixing bolts 57 from the same direction as the insertion direction. Accordingly, as in the first example, the second example, and the third example described above, a part of the sensor structure 51 or a part of the sensor fixing bolt 57 that is a holding member is fixed in the fixing direction of the housing fixing bolt 13 ( The sensor structure 51 can be fixed in a state where it overlaps the space on the extension line in the axial direction. In this way, the sensor structure holding step is performed.

[Second Manufacturing Method of Power Steering Device]
Next, as a second manufacturing method, a method for manufacturing the above-described sensor damage prevention structure of the fourth example will be described.
In this second manufacturing method, the housing fixing step is the same as in the first manufacturing method described above. Then, after the first housing 11 and the second housing 12 are fixed by the housing fixing bolt 13, the sensor structure 51 is tightened by the two sensor fixing bolts 57 with the fixing release limiting member 58 interposed therebetween, and the fixing release limit is set. The member 58 and the sensor structure 51 are fixed to the second housing 12. The fixing release limiting member 58 extends toward at least one (two in the present embodiment) of the plurality of housing fixing bolts 13 that fix the housing (the first housing 11 and the second housing 12). That is, the sensor structure 51 can be fixed in a state where a part of the fixing release limiting member 58 overlaps with a space on an extension line in the fixing direction (axial direction) of at least one housing fixing bolt 13. In this way, the sensor structure holding step of the second manufacturing method is performed.

As described above in detail, according to the present embodiment, the first housing 11 and the second housing 12 are fixed by the sensor structure 51, the sensor fixing bolt 57, and the fixing release limiting member 58 provided separately. Release can be restricted. That is, the first housing 11 and the second housing 12 cannot be removed while the sensor structure 51 is attached, and the housing can be disassembled only by removing the sensor structure 51 from the housing. Thereby, for example, damage to the torque detection device 40 such as the sensor structure 51 can be reduced.
Moreover, according to this Embodiment, it is also possible to restrict | release the above fixation cancellation with a simple manufacturing process.

DESCRIPTION OF SYMBOLS 1 ... Electric power steering apparatus, 10 ... Gear housing, 10A ... Handle side gear housing, 11 ... 1st housing, 12 ... 2nd housing, 13 ... Housing fixing bolt, 21 ... Input shaft, 23 ... Handle side pinion shaft (output) Axis), 40 ... Torque detector, 50 ... Torque detector, 51 ... Sensor structure, 57 ... Sensor fixing bolt, 60 ... Relative angle detector

Claims (4)

A housing that rotatably supports the input shaft and the output shaft, and is divided into a first housing and a second housing, and the divided first housing and the second housing are fixed using a fixing member. When,
A measuring device in which a detection body is connected to the input shaft and the output shaft, a sensor structure is held in the housing using a holding member, and a relative rotation angle between the input shaft and the output shaft is measured; With
In the state where the sensor structure of the measuring device is held by the housing, the fixing member fixing the first housing and the second housing is restricted from being released by the holding member , and
The first housing and the second housing are fastened by a plurality of housing fixing bolts,
The holding member for holding the sensor structure in the housing is a sensor fixing bolt, and the bolt of at least one housing fixing bolt among the plurality of housing fixing bolts in a state where the sensor structure is held in the housing. The sensor fixing bolt is positioned so that the head of the sensor fixing bolt overlaps the space on the extension line in the tightening direction, thereby restricting removal of the housing fixing bolt in a state where the sensor structure is held by the housing. Power steering device. A housing that rotatably supports the input shaft and the output shaft, and is divided into a first housing and a second housing, and the divided first housing and the second housing are fixed using a fixing member. When,
A measuring device in which a detection body is connected to the input shaft and the output shaft, a sensor structure is held in the housing using a holding member, and a relative rotation angle between the input shaft and the output shaft is measured;
A damage preventing member attached together with the sensor structure,
In the state where the sensor structure of the measuring device is held by the housing, the fixing of the fixing member that fixes the first housing and the second housing is restricted by the breakage preventing member , and
The first housing and the second housing are fastened by a plurality of housing fixing bolts,
The holding member for holding the sensor structure in the housing is a sensor fixing bolt, and the bolt of at least one housing fixing bolt among the plurality of housing fixing bolts in a state where the sensor structure is held in the housing. By locating the breakage prevention member so as to overlap the space on the extension line in the tightening direction, the removal of the housing fixing bolt in a state where the sensor structure is held by the housing is limited. Power steering device. The first housing and the second housing are tightened by the plurality of housing fixing bolts from the axial direction of the input shaft,
The sensor structure is inserted into the housing from a direction that intersects the axial direction, is held by the sensor fixing bolt from a direction that intersects the axial direction, and the sensor structure is held by the housing. The at least one of the plurality of housing fixing bolts is positioned so that at least a part of the head of the sensor fixing bolt or the damage preventing member overlaps when viewed from the axial direction of at least one housing fixing bolt. The power steering apparatus according to claim 1 or 2 . A housing fixing step of rotatably supporting an input shaft and an output shaft to which the detection body is coupled, and fixing the housing divided into the first housing and the second housing using a plurality of fixing members;
The input shaft with the breakage preventing member extending toward at least one of the plurality of fixing members of the housing between the first housing and the second housing after being fixed. And a sensor structure holding step of inserting a sensor structure for measuring torque between the output shaft and the output shaft into the housing and holding the sensor structure in the housing by a holding member,
The sensor structure holding step includes the sensor structure in a state where a part of the breakage prevention member overlaps a space on an extension line in a fixing direction of at least one fixing member of the plurality of fixing members used for fixing the housing. A method for manufacturing a power steering apparatus, comprising fixing a body.

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