Manufacturing method of a steering device

Abstract

A manufacturing method of a steering device includes: a characteristic data measurement process of measuring steering device characteristic data, which is an output value of the steering device with respect to the torsional amount of an inspection input shaft (48), i.e., the steering torque, such as the torsional torque of a sector gear shaft (5), or the steering torque of the inspection input shaft (48) with respect to the torsional torque of the sector gear shaft (5), or a graph showing the relationship between the steering torque of the inspection input shaft (48) and the torsional torque of the sector gear shaft (5); and a characteristic data recording process of recording the steering device characteristic data on a bar code (45).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a steering device. Background Art

[0002] As a steering device, for example, a steering device described in Patent Document 1 below is known.

[0003] The steering device of Patent Document 1 includes: an input-side steering device portion having an input shaft for a driver to input a steering torque; and an output-side steering device portion that outputs the steering torque from the input shaft to the power cylinder side. The input-side steering device portion is mounted and fixed to the output-side steering device portion via a plurality of bolts.

[0004] For example, when assembling the input-side steering device portion and the output-side steering device portion shipped from different factories or manufacturers together, the input-side steering device portion and the output-side steering device portion have individual differences including manufacturing errors, and it is difficult to perform control for correcting such individual differences, and there may be a deviation in the steering force due to the above individual differences.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-9682 Summary of the Invention

[0008] The present invention has been made in view of the conventional situation, and an object thereof is to provide a steering device that can suppress a deviation in the steering force due to individual differences in the input-side steering device portion or the output-side steering device portion.

[0009] Solution to the Problem

[0010] In the present invention, as one aspect, a method for manufacturing a steering device includes: a characteristic data measurement step of measuring steering device characteristic data that represents an output value of the steering device with respect to a torsional amount of a first shaft, or a torsional amount of the first shaft with respect to the output value of the steering device, or a relationship between the torsional amount of the first shaft and the output value of the steering device; and a characteristic data recording step of recording the steering device characteristic data on a recording medium.

[0011] According to the present invention, a deviation in the steering force due to individual differences in the input-side steering device portion or the output-side steering device portion can be suppressed. Brief Description of the Drawings

[0012] Figure 1 is a longitudinal sectional view of the steering device according to the first embodiment.

[0013] Figure 2 is Figure 1 a partial enlarged cross-sectional view of the steering device.

[0014] Figure 3 is a graph showing the torsional torque of the sector gear shaft with respect to the steering torque of the inspection input shaft.

[0015] Figure 4 is a graph showing the hydraulic pressure of the working fluid supplied to the power cylinder with respect to the steering torque of the inspection input shaft.

[0016] Figure 5 is a graph showing the discharge flow rate with respect to the pump speed of the inspection pump device.

[0017] Figure 6 is a flowchart showing the first embodiment of the manufacturing method of the steering device.

[0018] Figure 7 is a schematic diagram of the inspection device used in the manufacturing method of the steering device according to the first embodiment.

[0019] Figure 8 is a perspective view of the steering device according to the second embodiment.

[0020] Figure 9 is a partial longitudinal cross-sectional view of the steering device according to the second embodiment.

[0021] Figure 10 is a schematic diagram showing the schematic configuration of the steering device according to the third embodiment.

[0022] Figure 11 is a flowchart showing the fourth embodiment of the manufacturing method of the steering device.

[0023] Figure 12 is a schematic diagram of the inspection device used in the manufacturing method of the steering device according to the fourth embodiment. Detailed Embodiments

[0024] Hereinafter, embodiments of the steering device applied in the manufacturing method of the present invention will be described based on the drawings.

[0025] [First Embodiment]

[0026] (Configuration of Steering Device)

[0027] Figure 1 is a longitudinal cross-sectional view of the steering device according to the first embodiment, Figure 2 is a partial enlarged cross-sectional view of a part including Figure 1 the electric motor 2 of the steering device. In Figure 1In this case, for the sake of convenience in explanation, the side associated with the steering wheel (the upper side in the figure) in the Z direction of the rotation axis of the steering shaft 7, which is not shown, is taken as the "one end", and the side associated with the piston 15 (the lower side in the figure) is taken as the "other end" for explanation. In addition, Figure 3 is a graph showing the torsional torque of the sector gear shaft 5 with respect to the steering torque of the inspection input shaft 48. Figure 4 is a graph showing the hydraulic pressure of the working fluid supplied to the power cylinder 6 with respect to the steering torque of the inspection input shaft 48. Figure 5 is a graph showing the discharge flow rate with respect to the pump speed of the inspection pump device 52.

[0028] The steering device is an integral steering device used in large vehicles and the like, and mainly consists of a steering device main body 1, an electric motor 2, and an EPS controller (ECU) 3.

[0029] The steering device main body 1 includes a rotating mechanism 4, a sector gear shaft 5, and a power cylinder 6.

[0030] The rotating mechanism 4 is for inputting the rotational force from a steering wheel (not shown), and has a steering shaft 7. A part of the steering shaft 7 is accommodated in a housing 8, and the steering shaft 7 includes an input shaft 9, an intermediate shaft 10, and an output shaft 11. One end side of the input shaft 9 is associated with the steering wheel and is used for the driver to input the steering torque. The other end portion of the input shaft 9 is inserted into an opening recess 10a formed at one end side of the intermediate shaft 10. One end side of the intermediate shaft 10 is connected to the input shaft 9 via a first torsion bar 12 so as to be rotatable relative to each other, and is used for inputting the driving torque of the electric motor 2 connected to the outer periphery. The intermediate shaft 10 is inserted into an opening recess 11a formed in a diameter-expanded portion at one end side of the output shaft 11. One end side of the output shaft 11 is connected to the intermediate shaft 10 via a second torsion bar 13 so as to be rotatable relative to each other, and outputs the steering torque input by the intermediate shaft 10 to the piston 15 via a ball screw mechanism 14 as a conversion mechanism.

[0031] The ball screw mechanism 14 is composed of the following parts: the output shaft 11 as a screw having a spiral groove, i.e., a ball groove 14a, formed on the outer peripheral portion at the other end side; the piston 15 as a nut provided on the outer peripheral side of the output shaft 11 and having a spiral groove, i.e., a ball groove 14b, formed on the inner peripheral portion corresponding to the ball groove 14a; and a plurality of balls 14c provided between the piston 15 and the output shaft 11.

[0032] Between the intermediate shaft 10 and the output shaft 11, a well-known rotary valve 16 is formed as a control valve. The rotary valve 16 selectively supplies the working fluid supplied by a pump device 17 mounted on the vehicle to the following first and second fluid chambers (pressure chambers) P1 and P2 corresponding to the amount and direction of torsion of the second torsion bar 13 derived from the relative rotation angle of the intermediate shaft 10 and the output shaft 11.

[0033] The sector gear shaft 5 has a sector gear 5a, which meshes with a rack 15a of a piston 15 provided on the outer periphery of the other end side of the steering shaft 7, and rotates as the piston 15 axially moves. The sector gear shaft 5 is associated with the steering wheel via a link rocker arm (not shown) and is used for steering.

[0034] In this way, the ball screw mechanism 14, the sector gear shaft 5, and the link rocker arm constitute a transmission mechanism that converts the rotational force (steering force) input to the steering shaft 7 into the steering force of the steering wheel. In addition, when a steering device is configured without using the ball screw mechanism 14 or the like, as the above-mentioned transmission mechanism, for example, a rack bar, a pinion shaft, etc. constituting a rack & pinion mechanism can be used.

[0035] The power cylinder 6 is constituted by defining a pair of fluid chambers, namely, the first and second fluid chambers P1 and P2, by a cylindrical piston 15 that is slidably housed in a housing 8, and is a hydraulic actuator that generates an auxiliary torque for assisting the steering torque.

[0036] The electric motor (hollow motor) 2 is configured as a three-phase AC brushless motor that imparts a rotational torque to the input shaft 9. The electric motor 2 includes a motor element 18 constituted by a motor rotor 18a and a motor stator 18b, and a motor housing 19 that houses the motor element 18.

[0037] The motor rotor 18a is integrally rotatably mounted on the outer peripheral portion of the input shaft 9 via a cylindrical coupling member 20. The motor stator 18b is disposed on the outer peripheral side of the motor rotor 18a with a predetermined gap therebetween, and is electrically connected to an EPS controller 3 provided outside the housing 8.

[0038] The coupling member 20 is fixed to the intermediate shaft 10 by a well-known key connection in which a key 21 protruding from the outer peripheral portion of the intermediate shaft 10 is inserted into a groove portion 20a formed on the inner peripheral surface of the coupling member 20. Through the above key connection, the coupling member 20 rotates integrally with the intermediate shaft 10 and is supported by a first bearing B1 and a second bearing B2.

[0039] The motor housing 19 is formed of a metallic material such as aluminum alloy. The motor housing 19 includes: a bottomed cylindrical housing main body 24 that houses the motor element 18 or the first and second resolvers 22 and 23 described later; a first closing portion 25 that closes the opening of the housing main body 24 from the side of the electric motor 2; and a second closing portion 26 that closes the opening of the expansion portion 24a from the side opposite to the electric motor 2.

[0040] The housing main body 24 has: a substantially disk-shaped bottom portion 24b formed so as to be able to insert the input shaft 9 or the coupling member 20; a cylindrical tube portion 24c erected from the outer peripheral edge portion of the bottom portion 24b toward the other end side of the steering shaft 7; and a cylindrical expansion portion 24a erected from the outer peripheral edge portion of the bottom portion 24b toward the one end side of the steering shaft 7.

[0041] The opening of the tube portion 24c is closed by a substantially disk-shaped first closing portion 25 formed so as to be able to insert the input shaft 9 or the coupling member 20. The first closing portion 25 is attached and fixed to the opening end face 24d of the tube portion 24c via a fixing member such as a bolt 27. The space surrounded by the first closing portion 25, the bottom portion 24b, the tube portion 24c, and the coupling member 20 becomes a motor housing portion 28 that houses the motor element 18. In addition, the first closing portion 25 is attached and fixed to the adapter member 30 via a fixing member such as a bolt 29. That is, via the adapter member 30, the first closing portion 25 is fixed to the housing 8.

[0042] Furthermore, the opening of the expansion portion 24a is closed by a substantially disk-shaped second closing portion 26 formed so as to be able to insert the input shaft 9 or the coupling member 20. The second closing portion 26 is attached and fixed to the opening end face 24e of the expansion portion 24a via a fixing member such as a bolt 31. The space surrounded by the second closing portion 26, the bottom portion 24b, the expansion portion 24a, and the input shaft 9 becomes a torque sensor housing portion 33 that houses a torque sensor 32 for calculating the steering torque generated by the first torsion bar 12. The space between the second closing portion 26 and the input shaft 9 is hermetically sealed by an annular sealing member 34.

[0043] The torque sensor 32 is composed of a first resolver 22 provided on the outer peripheral side of the coupling member 20 in the torque sensor housing portion 33 and a second resolver 23 provided on the outer peripheral side of the input shaft 9 in the torque sensor housing portion 33.

[0044] The first resolver 22 includes: a first resolver rotor 22a fixed to the outer periphery of one end side of the coupling member 20; and a first resolver stator 22b provided on the outer peripheral side of the first resolver rotor 22a and fixed to the bottom 24b by a fixing member such as a screw member 35. The first resolver stator 22b is fixed to the bottom 24b by the screw member 35 in a state where it abuts against the inner peripheral surface 24g of the thick wall portion 24f of the bottom 24b that overlaps the sector gear shaft 5 in the rotation axis Z direction of the steering shaft 7. The first resolver stator 22b is electrically connected to the EPS controller 3 via an output wiring (not shown). The intermediate shaft rotation angle θa of the intermediate shaft 10 detected by the first resolver 22 is input to the EPS controller 3.

[0045] The second resolver 23 includes: a second resolver rotor 23a fixed to the outer periphery of the input shaft 9 at a position closer to one end side than the first resolver stator 22b; and a second resolver stator 23b provided on the outer peripheral side of the second resolver rotor 23a and fixed to the thick wall portion 24f by a fixing member such as a screw member 36 via a gasket 37. The second resolver stator 23b is electrically connected to the EPS controller 3 via an output wiring (not shown) in the same manner as the first resolver stator 22b. The input shaft rotation angle θh of the input shaft 9 detected by the second resolver 23 is input to the EPS controller 3.

[0046] The torque sensor 32 constituted by the first and second resolvers 22 and 23 calculates the steering torque by multiplying the difference between the input shaft rotation angle θh of the input shaft 9 detected by the second resolver 23 and the intermediate shaft rotation angle θa of the intermediate shaft 10 detected by the first resolver 22 by the torsional spring constant g1 of the first torsion bar 12.

[0047] In addition, in the first and second resolvers 22 and 23, the first and second resolver stators 22b and 23b output sine wave signals and cosine wave signals that satisfy "the number of amplitudes Ax per revolution of the first resolver rotor 22a < 360° / (specified angle θx × 2)", and the rotation angles of the input shaft 9, the electric motor 2, etc. are calculated in the EPS controller 3 based on the respective output signals.

[0048] The first bearing B1 is provided on the inner peripheral surface of an annular first bearing holding portion 24h that protrudes from the vicinity of the inner peripheral edge portion of the bottom 24b toward the other end side of the steering shaft 7, and rotatably supports one end side of the coupling member 20.

[0049] Similarly, the second bearing B2 is provided on the inner peripheral surface of an annular second bearing holding portion 24i that protrudes from the vicinity of the inner peripheral edge portion of the first closing portion 25 so as to face the first bearing holding portion 24h, and rotatably supports the other end side of the coupling member 20.

[0050] Here, for the convenience of the following description, the upper part of the steering device main body 1 in the rotational axis Z direction including the input shaft 9 and the motor housing 19 is defined as the "input side steering device portion 1a", and the lower part of the rotational axis Z direction including the intermediate shaft 10, the output shaft 11, and the housing 8 is defined as the "output side steering device portion 1b". The input side steering device portion 1a and the output side steering device portion 1b are respectively manufactured by different factories or manufacturers and shipped by a common shipper. After obtaining the steering device characteristic data described later at the inspection point, they are assembled at the work point.

[0051] The EPS controller 3 is constituted by including an electronic component such as a memory device 3a or a microcomputer (not shown). In the memory device 3a, the steering device characteristic data recorded on the barcode 45 as a recording medium is recorded via a barcode reader, a computer (PC), and a communication device described later. The barcode 45 is provided, for example, on the outer peripheral surface of the first housing 39 of the housing 8 of the output side steering device portion 1b at a position where it can be externally connected. In addition, instead of using the barcode 45, the steering device characteristic data may be recorded in a computer or a server, and a reference information recording medium such as a two-dimensional code that can refer to the steering device characteristic data may be used to refer to the steering device characteristic data on the computer or the server. In addition, instead of the barcode 45 or the two-dimensional code, an IC chip may be used as a storage medium.

[0052] The steering device characteristic data is data measured in a state where a later-described inspection steering wheel 47, an inspection input shaft 48, a first torque meter 49, a second torque meter 50, an inspection reservoir 51, and an inspection pump device 52 (refer to Figure 7 ) are connected to the output side steering device portion 1b in the inspection room before the final assembly of the steering device, and is data shown by the relationship between the steering torque of the inspection input shaft 48 and the torsional torque of the sector gear shaft 5. In the present embodiment, the steering device characteristic data is the torsional torque of the sector gear shaft 5 with respect to the steering torque of the inspection input shaft 48.

[0053] Here, by referring to Figure 3 , the torsional torque of the sector gear shaft 5 with respect to the steering torque of the inspection input shaft 48 will be described. In Figure 3 , Figure 3 the right curve C1 represents the torsional torque of the sector gear shaft 5 with respect to the torsional amount of the inspection input shaft 48, that is, the steering torque, when the inspection input shaft 48 is torsionally rotated clockwise. On the other hand,Figure 3 The curve C2 on the left side represents the torsional torque of the sector gear shaft 5 with respect to the torsional amount of the inspection input shaft 48, that is, the steering torque, when the inspection input shaft 48 is twisted counterclockwise.

[0054] As Figure 3 shown, the torsional torque of the sector gear shaft 5 with respect to the first clockwise specified steering torque IR1 when the inspection input shaft 48 is twisted clockwise by the first specified amount becomes the first clockwise specified torsional torque OR1. Also, as Figure 3 shown, the torsional torque of the sector gear shaft 5 with respect to the second clockwise specified steering torque IR2 when the inspection input shaft 48 is twisted clockwise by a second specified amount larger than the first specified amount becomes the second clockwise specified torsional torque OR2, which is higher than the first clockwise specified torsional torque OR1. The first clockwise specified torsional torque OR1 and the second clockwise specified torsional torque OR2 are set to relatively small values suitable for lane keeping during automatic steering control of the vehicle.

[0055] Furthermore, as Figure 3 shown, the torsional torque of the sector gear shaft 5 with respect to the first counterclockwise specified steering torque IL1 when the inspection input shaft 48 is twisted counterclockwise by the first specified amount becomes the first counterclockwise specified torsional torque OL1. Also, the torsional torque of the sector gear shaft 5 with respect to the second counterclockwise specified steering torque IL2 when the inspection input shaft 48 is twisted counterclockwise by a second specified amount larger than the first specified amount becomes the second counterclockwise specified torsional torque OL2, which is higher than the first counterclockwise specified torsional torque OL1. The first counterclockwise specified torsional torque OL1 and the second counterclockwise specified torsional torque OL2 are set to relatively small values suitable for lane keeping during automatic steering control of the vehicle.

[0056] In addition, in Figure 3 an example is described in which two specified output values are obtained for the clockwise and counterclockwise directions of the inspection input shaft 48. However, it is also possible to obtain one specified output value or three or more specified output values for the clockwise and counterclockwise directions of the inspection input shaft 48.

[0057] In addition, in Figure 3In this case, since the first and second clockwise specified torsional torques OR1 and OR2 or the first and second counterclockwise specified torsional torques OL1 and OL2 can also be regarded as being uniquely determined with respect to the first and second clockwise specified steering torques IR1 and IR2 or the first and second counterclockwise specified steering torques IL1 and IL2, the steering device characteristic data can also be the steering torque of the input shaft 48 for inspection with respect to the torsional torque of the sector gear shaft 5. That is, the steering device characteristic data can also be the first and second clockwise specified steering torques IR1 and IR2 or the first and second counterclockwise specified steering torques IL1 and IL2 with respect to the first and second clockwise specified torsional torques OR1 and OR2 or the first and second counterclockwise specified torsional torques OL1 and OL2.

[0058] In addition, the steering device characteristic data further includes data representing the relationship between the steering torque of the input shaft 48 for inspection and the hydraulic pressure of the working fluid supplied to the power cylinder 6 (or the hydraulic pressure inside the power cylinder 6).

[0059] Here, by referring to Figure 4 , the relationship between the steering torque of the input shaft 48 for inspection and the hydraulic pressure of the working fluid supplied to the power cylinder 6 will be described. In Figure 4 , Figure 4 the curve C3 on the right side of Figure 4 represents the hydraulic pressure of the working fluid with respect to the steering torque of the input shaft 48 for inspection when the input shaft 48 for inspection is twisted clockwise. On the other hand,

[0060] as Figure 4 shows, the hydraulic pressure of the working fluid with respect to the first clockwise specified steering torque IR1 when the input shaft 48 for inspection is twisted clockwise by the first specified amount becomes the first clockwise hydraulic pressure PR1. In addition, as Figure 4 shows, the hydraulic pressure of the working fluid with respect to the second clockwise specified steering torque IR2 when the input shaft 48 for inspection is twisted clockwise by the second specified amount larger than the first specified amount becomes the second clockwise hydraulic pressure PR2.

[0061] Furthermore, as Figure 4 shows, the hydraulic pressure of the working fluid with respect to the first counterclockwise specified steering torque IL1 when the input shaft 48 for inspection is twisted counterclockwise by the first specified amount becomes the first counterclockwise hydraulic pressure PL1. In addition, the hydraulic pressure of the working fluid with respect to the second counterclockwise specified steering torque IL2 when the input shaft 48 for inspection is twisted counterclockwise by the second specified amount larger than the first specified amount becomes the second counterclockwise hydraulic pressure PL2.

[0062] In addition, the steering device characteristic data also includes the characteristic data of the inspection pump device 52 described later. At the inspection point, generally, an inspection pump device 52 is provided for each inspection line. Therefore, the characteristic data obtained based on the individual differences of the inspection pump device 52 is acquired in advance.

[0063] Here, by referring to Figure 5 , the characteristic data of one inspection pump device 52 will be described. As Figure 5 shown, the discharge amount of the working fluid increases at the first increase rate before the pump speed reaches Revα, and after Revα, it gradually increases at the second increase rate which is smaller than the first increase rate. The characteristic data of the inspection pump device 52 includes: the discharge flow rate Q1 per unit time of the inspection pump device 52 when the inspection pump device 52 is driven at the first specified speed Rev1, that is, the first discharge characteristic data; and the discharge flow rate Q2 per unit time of the inspection pump device 52 when the inspection pump device 52 is driven at the second specified speed Rev2, that is, the second discharge characteristic data. In the present embodiment, the first specified speed Rev1 is smaller than the pump speed Revα, and on the other hand, the second specified speed Rev2 is larger than the pump speed Revα.

[0064] In addition, the characteristic data of the inspection pump device 52 may only include the discharge flow rate Q1 per unit time of the inspection pump device 52 when the inspection pump device 52 is driven at the first specified speed Rev1, that is, the first discharge characteristic data. In addition, the characteristic data of the inspection pump device 52 may not be the characteristic data obtained based on the individual differences of the inspection pump device 52, but the characteristic data obtained based on the form differences of the inspection pump device 52.

[0065] In addition, the steering device characteristic data may also include information on the deviation amount between the neutral position of the inspection input shaft 48 and the neutral position of the transmission mechanism.

[0066] In addition, the EPS controller 3 is electrically connected to the ADAS controller 38 for controlling the automatic driving (automatic steering) of the vehicle such as parking or lane keeping when the driver turns on the automatic driving switch.

[0067] The ADAS controller 38 grasps the surrounding conditions of the vehicle based on the detection signals from radars outside the figure (such as millimeter waves or infrared lasers) or the images from cameras outside the figure, and grasps the vehicle position based on the vehicle position information from GPS, etc. And, when performing automatic steering, for example, when keeping the vehicle in the lane, the ADAS controller 38 calculates the steering angle command θrc for maintaining the vehicle in the specified lane based on the above surrounding conditions and the vehicle position. In addition, when the driver turns on the automatic driving switch, the ADAS controller 38 generates an automatic driving request signal X and sends information to the EPS controller 3 through CAN communication.

[0068] The housing 8 is composed of: a first housing 39 which is in a cylindrical shape with one end open and the other end closed, defining first and second liquid chambers P1 and P2; and a second housing 40 which is provided so as to close the one end opening of the first housing 39 and houses the rotary valve 16 therein. The first and second housings 39 and 40 are fastened to each other by a plurality of fixing mechanisms (such as bolts), not shown, appropriately provided on their outer circumferential portions.

[0069] Inside the first housing 39, a power cylinder main body portion 39a is provided along the rotation axis Z direction of the steering shaft 7, and a shaft housing portion 39b is formed so as to be orthogonal to the power cylinder main body portion 39a and with a part facing the power cylinder main body portion 39a. Inside the power cylinder main body portion 39a, a piston 15 associated with the output shaft 11 is housed, whereby the first liquid chamber P1 on one end side and the second liquid chamber P2 on the other end side are defined by the piston 15. Further, inside the shaft housing portion 39b, a sector gear shaft 5 is housed, the axial one end side of which is associated with the piston 15 and the other end side is associated with the steering wheel via a link rocker arm (not shown).

[0070] On the outer circumferential portions of the piston 15 and the sector gear shaft 5, racks 15a and sector gears 5a that can mesh with each other are provided. By the meshing of the racks 15a and the sector gears 5a, along with the axial movement of the piston 15, the sector gear shaft 5 rotates, whereby the link rocker arm is pulled in the vehicle width direction, thus changing the orientation of the steering wheel. Further, at this time, the working fluid in the first liquid chamber P1 is guided to the shaft housing portion 39b, thereby lubricating between the rack 15a and the sector gear 5a.

[0071] On the inner circumferential side of the second housing 40, an axis insertion hole 40a for inserting the intermediate shaft 10 and the output shaft 11 that overlap each other is formed so as to penetrate in a shape of reducing diameter with a height difference along the rotation axis Z direction from one end side to the other end side. And at the large diameter portion on the one end side, a bearing Bn that rotatably supports the output shaft 11 is provided. On the other hand, at the small diameter portion on the other end side, an inlet 41 communicating with the pump device 17, a supply / discharge port 42 for supplying and discharging the hydraulic pressure introduced from the inlet 41 to the respective liquid chambers P1 and P2, and a discharge port 44 for discharging the working fluid discharged from the respective liquid chambers P1 and P2 via the supply / discharge port 42 to the reservoir tank 43 are provided. Further, the supply / discharge port 42 communicates with the first liquid chamber P1 via a first supply / discharge passage L1 provided at the one end side enlarged diameter portion of the output shaft 11, and communicates with the second liquid chamber P2 via a second supply / discharge passage L2 provided inside the first housing 39, etc.

[0072] According to this configuration, in the steering device, when the driver turns the steering wheel, the working fluid pumped by the pump device 17 is supplied to the fluid chambers P1 and P2 on the side corresponding to the steering direction via the rotary valve 16, and the working fluid (remaining amount) corresponding to the supply amount is discharged from the fluid chambers P1 and P2 on the other side to the reservoir tank 43. And, the piston 15 is driven by this hydraulic pressure, and as a result, the auxiliary torque generated based on the hydraulic pressure acting on the piston 15 is imparted to the sector gear shaft 5.

[0073] Figure 6 It is a flowchart showing a first embodiment of a manufacturing method of a steering device. Figure 7 It is a schematic diagram of an inspection device used in the manufacturing method of the steering device of the first embodiment.

[0074] Hereinafter, with reference to Figure 6 the flowchart, the manufacturing method (inspection method) of the steering device will be described.

[0075] First, as Figure 7 shown, in the inspection chamber, the assembled output side steering device portion 1b is set in a posture with the opening 46 of the output side steering device portion 1b facing upward. And, the inspection input shaft 48 connected to the inspection steering wheel 47 is attached to the output side steering device portion 1b, and a first torque meter 49 for detecting the steering torque of the inspection input shaft 48 is attached to the inspection input shaft 48. In addition, a second torque meter 50 for detecting the torsional torque of the sector gear shaft 5 is attached to the sector gear shaft 5. Further, in the output side steering device portion 1b, an inspection reservoir 51 and an inspection pump device 52 for discharging the working fluid in the inspection reservoir 51 to the output side steering device portion 1b are connected. Furthermore, between the inspection pump device 52 and the output side steering device portion 1b, a pressure gauge 53 for detecting the discharge pressure of the inspection pump device 52 and a flow meter 54 for detecting the discharge flow rate from the inspection pump device 52 are provided.

[0076] And, in the working fluid supply process of step S1, the working fluid is supplied from the inspection pump device 52 to the rotary valve 16 in the output side steering device portion 1b. The supply amount of the working fluid is the rated flow rate of the pump device mounted on the vehicle, for example, 18 (L / min). In addition, when the working fluid is supplied, the discharge pressure of the working fluid of the inspection pump device 52 is measured by the pressure gauge 53. The measured discharge pressure of the working fluid is input to a computer (not shown).

[0077] Meanwhile, while continuing the working fluid supply process, the inspection steering wheel 47 is rotated in the input shaft operation process of step S2 to twist the inspection input shaft 48. More specifically, the inspection input shaft 48 is twisted clockwise by a first specified amount, and further, the inspection input shaft 48 is twisted clockwise by a second specified amount that is larger than the first specified amount. Next, the inspection input shaft 48 is twisted counterclockwise by the first specified amount, and further, the inspection input shaft 48 is twisted counterclockwise by a second specified amount that is larger than the first specified amount. Thereby, the specified steering torques IR1, IR2, IL1, IL2 (refer to Figure 3 ) are measured by the first torque meter 49. The measured specified steering torques IR1, IR2, IL1, IL2 are output to a computer (not shown).

[0078] Next, while continuing the working fluid supply process and the input shaft operation process, the torsional torque of the sector gear shaft 5 is measured by the second torque meter 50 in the output value measurement process of step S3. That is, the specified torsional torques OR1, OR2, OL1, OL2 (refer to Figure 3 ) of the sector gear shaft 5 during the working fluid supply process and the input shaft operation process are measured by the second torque meter 50. The measured specified torsional torques OR1, OR2, OL1, OL2 are output to a computer (not shown).

[0079] Then, in the characteristic data recording process of step S4, the specified torsional torques OR1, OR2, OL1, OL2 with respect to the specified steering torques IR1, IR2, IL1, IL2 stored in the computer are recorded on the bar code 45. That is, using a printer (not shown), a bar code 45 including the specified torsional torques OR1, OR2, OL1, OL2 with respect to the specified steering torques IR1, IR2, IL1, IL2 is produced.

[0080] Next, in the recording medium mounting process of step S5, the bar code 45 is mounted on the outer peripheral surface of the output side steering device portion 1b.

[0081] After that, at the work point, the input side steering device portion 1a is mounted on the output side steering device portion 1b, and these steering device portions 1a, 1b and the EPS controller 3 are mounted on the vehicle together.

[0082] Then, in the steering device characteristic data reading process of step S6, the specified torsional torques OR1, OR2, OL1, OL2 with respect to the specified steering torques IR1, IR2, IL1, IL2 are read using a bar code reader (not shown).

[0083] Further, in the process of reflecting the steering device characteristic data in step S7, the specified torsional torques OR1, OR2, OL1, and OL2 with respect to the specified steering torques IR1, IR2, IL1, and IL2 read are reflected in the memory device 3a of the EPS controller 3 via a computer and a communication device (not shown).

[0084] [Effects of the First Embodiment]

[0085] In the first embodiment, as a mode of the steering device, the steering device includes a steering shaft 7, a transmission mechanism, a power cylinder 6, and a rotary valve 16. The steering shaft 7 includes an input shaft 9, an output shaft 11, and first and second torsion bars 12 and 13 provided between the input shaft 9 and the output shaft 11. The transmission mechanism can transmit the rotation of the steering shaft 7 to the steering wheel. The power cylinder 6 includes a power cylinder main body portion 39a, a piston 15, a first liquid chamber P1, and a second liquid chamber P2. The power cylinder 6 can apply a steering force for steering the steering wheel to the transmission mechanism. The rotary valve 16 can selectively supply the working fluid supplied from the pump device 17 to the first liquid chamber P1 and the second liquid chamber P2 in response to the torsion of the first and second torsion bars 12 and 13. The manufacturing method of the steering device includes: a working fluid supply process of supplying the working fluid from the inspection pump device 52 to the rotary valve 16; a first shaft operation process of twisting the inspection input shaft 48; an output value measurement process of measuring the torsional torque of the sector gear shaft 5 when the working fluid supply process and the first shaft operation process are performed; a characteristic data measurement process of measuring the steering device characteristic data, which represents the torsional torque of the sector gear shaft 5 with respect to the steering torque of the inspection input shaft 48, or the steering torque of the inspection input shaft 48 with respect to the torsional torque of the sector gear shaft 5, or the relationship between the steering torque of the inspection input shaft 48 and the torsional torque of the sector gear shaft 5; a characteristic data recording process of recording the steering device characteristic data on the barcode 45; and a recording medium installation process of installing the barcode 45 or a two-dimensional code capable of referring to the steering device characteristic data on the steering device. Further, the manufacturing method of the steering device further includes a steering device characteristic data reading process and a steering device characteristic data reflecting process. The steering device characteristic data reading process is a process of reading the steering device characteristic data from the barcode 45 or a process of obtaining the steering device characteristic data by referring to the steering device characteristic data using a reference information recording medium. The steering device characteristic data reflecting process is a process of storing the steering device characteristic data in the memory device 3a of the EPS controller 3, which is mounted on the vehicle together with the steering device and drives and controls the electric motor 2 that applies a rotational force to the input shaft 9.

[0086] More specifically, for the manufacturing method of the steering device, regarding the output-side steering device portion 1b, steering device characteristic data representing the torsional torque of the sector gear shaft 5 with respect to the steering torque of the inspection input shaft 48 is measured, stored as a bar code 45 or a two-dimensional code, and the stored steering device characteristic data is reflected in the memory device 3a of the EPS controller 3 for controlling the electric motor 2. Further, the memory device 3a of the EPS controller 3 refers to the steering device characteristic data recorded in the memory device 3a when controlling the electric motor 2. Thus, a steering torque suitable for applying a desired torsional torque to the sector gear shaft 5 acts on the input shaft 9. Therefore, the EPS controller 3 applies the steering torque to the input shaft 9 in a manner that corrects individual differences including manufacturing errors of each output-side steering device portion 1b, and can suppress deviations in the steering force caused by individual differences. Thereby, the operation of the steering device can be made stable. The steering device according to the present embodiment is particularly advantageous in the following cases: when the input-side steering device portion 1a including the input shaft 9 and the output-side steering device portion 1b including the output shaft 11 are respectively manufactured at different factories or manufacturers and shipped by a common shipper, and assembled at the operation point of the shipper; when it is necessary to replace the input-side steering device portion 1a due to reasons such as a failure in the already assembled input-side steering device portion 1a and output-side steering device portion 1b.

[0087] Further, in the first embodiment, the working fluid supply process drives the inspection pump device 52 such that the flow rate of the working fluid supplied from the inspection pump device 52 to the rotary valve 16 within a predetermined time becomes a predetermined amount.

[0088] More specifically, since the correlation between the steering torque of the inspection input shaft 48 and the torsional torque of the sector gear shaft 5 is easily affected by the discharge flow rate of the working fluid of the inspection pump device 52, in order to suppress this influence, the inspection pump device 52 is driven such that the flow rate of the working fluid becomes a predetermined amount. Thereby, the torsional torque of the sector gear shaft 5 with respect to the steering torque of the inspection input shaft 48 is stabilized. Thus, accurate data is reflected in the memory device 3a, and deviations in the steering force can be suppressed.

[0089] Furthermore, in the first embodiment, the steering device characteristic data is data related to the steering torque of the inspection input shaft 48 when the torsional torque of the sector gear shaft 5 is a predetermined value.

[0090] Therefore, during the steering control of the vehicle, a simple control logic for uniquely determining the steering torque of the inspection input shaft 48 based on a predetermined torsional torque of the sector gear shaft 5 enables easier control of the steering force compared to the case where such a control logic is not provided. This control is particularly advantageous during the automatic steering control of a vehicle in which the desired torsional torque is known in advance.

[0091] In addition, in the first embodiment, the steering device characteristic data includes: first data related to a first clockwise specified steering torque IR1 of the inspection input shaft 48 when the torsional torque of the sector gear shaft 5 is a first clockwise specified torsional torque OR1; and second data related to the first clockwise specified steering torque IR1 of the inspection input shaft 48 when the torsional torque of the sector gear shaft 5 is a second clockwise specified torsional torque OR2.

[0092] More specifically, the above-mentioned first clockwise specified torsional torque OR1 and second clockwise specified torsional torque OR2 represent two relatively small values suitable for lane keeping during automatic steering control of the vehicle. By using such two values, the changes in the steering state can be flexibly responded to. Specifically, the steering torque can be appropriately determined corresponding to the change in the output value required by the steering device, and the deviation of the steering force can be flexibly suppressed.

[0093] Furthermore, in the first embodiment, the steering device characteristic data is the torsional torque of the sector gear shaft 5 when the inspection input shaft 48 is twisted by a specified amount.

[0094] Therefore, during the steering control of the vehicle, a simple control logic that uniquely determines the specified torsional torque of the sector gear shaft 5 based on the specified steering torque with respect to the inspection input shaft 48 can more easily control the steering force compared to the case without such a control logic.

[0095] In addition, in the first embodiment, the transmission mechanism is a ball screw mechanism 14 provided between the output shaft 11 and the steering wheel, a rack 15a of the piston 15, and a sector gear 5a meshing with the rack 15a, and the steering device characteristic data is the output of the sector gear 5a.

[0096] More specifically, the steering device characteristic data is the torsional torque of the sector gear shaft 5 having the sector gear 5a. In the output of the sector gear shaft 5, the individual differences of the power cylinder 6 or the ball screw mechanism 14 including manufacturing errors or assembly errors are reflected. Therefore, by considering the output of the sector gear shaft 5, the steering device characteristic data becomes more accurate data. Relying on the control of the electric motor 2 based on this accurate data, a more appropriate steering torque is given to the input shaft 9. Thus, the deviation of the steering force can be appropriately suppressed, and the operation of the steering device can be made more stable.

[0097] Furthermore, the first-axis operation process includes a process of clockwise-twisting the input shaft 48 for inspection and a process of counterclockwise-twisting the input shaft 48 for inspection. The steering device characteristic data includes: the first and second clockwise specified twisting torques OR1 and OR2 of the sector gear shaft 5 obtained when the input shaft 48 for inspection is clockwise-twisted; and the first and second counterclockwise specified twisting torques OL1 and OL2 of the sector gear shaft 5 obtained when the input shaft 48 for inspection is counterclockwise-twisted.

[0098] For example, due to main reasons such as the position deviation of the first torsion bar when the first torsion bar provided inside the input shaft 48 for inspection is fixed by a pin, when the input shaft 48 for inspection is clockwise- and counterclockwise-twisted by the same rotation amount respectively, the first and second clockwise specified twisting torques OR1 and OR2 and the first and second counterclockwise specified twisting torques OL1 and OL2 of the sector gear shaft 5 sometimes become different values (different magnitudes). Therefore, by controlling the electric motor 2 in consideration of the difference between the first and second clockwise specified twisting torques OR1 and OR2 and the first and second counterclockwise specified twisting torques OL1 and OL2, the balance of the steering force in the clockwise and counterclockwise directions can be maintained, and the discomfort of steering generated by the driver can be suppressed.

[0099] Furthermore, in the first embodiment, the steering device characteristic data includes information related to the deviation amount between the neutral position of the input shaft 48 for inspection and the neutral position of the steering wheel connected to the transmission mechanism.

[0100] For example, when performing a rotation operation of rotating the input shaft 48 for inspection clockwise from the neutral position of the input shaft 48 for inspection and then returning counterclockwise, sometimes the neutral position of the input shaft 48 for inspection is inconsistent with the neutral position of the transmission mechanism, and sometimes the desired output characteristics cannot be obtained. Therefore, by performing control considering the information related to the deviation amount between the neutral position of the input shaft 48 for inspection and the neutral position of the transmission mechanism, the desired output characteristics of the steering device can be obtained when the input shaft 48 for inspection is rotated clockwise and then returned counterclockwise.

[0101] In addition, in the first embodiment, the steering device characteristic data is data representing the relationship between the specified steering torques IR1, IR2, IL1, IL2 of the input shaft 48 for inspection and the hydraulic pressure inside the power cylinder 6, or data representing the relationship between the specified steering torques IR1, IR2, IL1, IL2 of the input shaft 48 for inspection and the hydraulic pressures PR1, PR2, PL1, PL2 of the working fluid supplied to the power cylinder 6.

[0102] The hydraulic pressure inside the power cylinder 6 or the hydraulic pressure of the working fluid supplied to the power cylinder 6 can be controlled based on the magnitude of the steering torque of the inspection input shaft 48. Therefore, by obtaining the relationships between the specified steering torques IR1, IR2, IL1, IL2 of the inspection input shaft 48 and the hydraulic pressures PR1, PR2, PL1, PL2 inside the power cylinder 6 or of the working fluid supplied to the power cylinder 6 as data, in the case of performing control in which the hydraulic pressure inside the power cylinder 6 or the like changes based on the magnitudes of the specified steering torques IR1, IR2, IL1, IL2 of the inspection input shaft 48, the desired torsional torque of the sector gear shaft 5 can also be obtained. Thus, the deviation of the steering force can be accurately suppressed, and the operation of the steering device can be made more stable.

[0103] Furthermore, in the first embodiment, the steering device characteristic data further includes the characteristic data of the inspection pump device 52.

[0104] The steering device characteristic data is obtained at the inspection point of the shipper, but at this inspection point, an inspection pump device 52 is sometimes provided on each inspection line. In this case, due to the individual differences of the inspection pump devices 52, the discharge flow rate of the working fluid from the inspection pump device 52 may sometimes be different. Therefore, by appropriately controlling the electric motor 2 in consideration of the difference in the discharge flow rate of the working fluid, the deviation of the steering force can be accurately suppressed, and the operation of the steering device can be made more stable.

[0105] In addition, in the first embodiment, the characteristic data of the inspection pump device 52 is the discharge flow rate per unit time of the inspection pump device 52 when the inspection pump device 52 is driven at a specified rotational speed.

[0106] According to the individual differences of the above-mentioned inspection pump devices 52, the discharge flow rate per unit time of each inspection pump device 52 when driven at a specified rotational speed is different. Therefore, by obtaining as data the discharge flow rate considering the individual differences of the inspection pump devices 52 and appropriately controlling the electric motor 2 corresponding to the discharge flow rate per unit time of the working fluid of the pump device 17, the deviation of the steering force can be accurately suppressed, and the operation of the steering device can be made more stable.

[0107] Furthermore, in the first embodiment, the characteristic data of the inspection pump device 52 includes: the discharge flow rate Q1 per unit time of the inspection pump device 52 when the inspection pump device 52 is driven at the first specified rotational speed Rev1, that is, the first discharge characteristic data; and the discharge flow rate Q2 per unit time of the inspection pump device 52 when the inspection pump device 52 is driven at the second specified rotational speed Rev2, that is, the second discharge characteristic data.

[0108] The discharge flow rate of the inspection pump device 52 varies corresponding to the rotational speed of a drive device such as an engine or an electric motor 2. Therefore, by obtaining first and second discharge characteristic data corresponding to the difference in the rotational speed of the inspection pump device 52, the electric motor 2 can be appropriately controlled corresponding to the rotational speed of the pump device 17. Thereby, the deviation of the steering force can be accurately suppressed, and the operation of the steering device can be made more stable.

[0109] In addition, in the first embodiment, the recording medium or the reference information recording medium mounted on the output side steering device section 1b is a bar code 45 or a two-dimensional code.

[0110] Therefore, it is only necessary to attach a bar code 45 or a two-dimensional code having a very small area compared to the large outer peripheral surface of the first housing 39 of the output side steering device section 1b. For example, by using a plurality of bar codes 45 having different information, a large amount of information can be reflected in the memory device 3a of the EPS controller 3.

[0111] Furthermore, in the first embodiment, the recording medium mounted on the output side steering device section 1b may also be an IC chip.

[0112] Thereby, a large amount of information can be recorded with a mounting area smaller than that of the bar code 45 or the two-dimensional code.

[0113] [Second Embodiment]

[0114] Figure 8 It is a perspective view of the steering device of the second embodiment. Figure 9 It is a partial longitudinal sectional view of the steering device of the second embodiment.

[0115] In the second embodiment, the electric motor 2 is not a hollow motor, but is connected to a connecting shaft 56 provided around the input shaft 9 via a speed reducer 55 constituted by a worm gear formed by meshing a worm shaft 59 with a worm wheel 60.

[0116] The electric motor 2 is integrally formed with the EPS controller 3 and is housed in a motor housing 58 integrally formed with an input-side housing 57 that houses the input shaft 9 and the like. The electric motor 2 has a motor shaft (not shown), and one axial end portion of the motor shaft is connected to a worm shaft 59. A thread 59a is integrally formed on the outer periphery of the worm shaft 59, and the thread 59a meshes with a helical tooth portion 60a of a worm gear 60. The worm gear 60 is connected to the outer peripheral portion of a connecting shaft 56 by a well-known key connection via a key (not shown). The connecting shaft 56 has a concave portion 56a on one axial end face, and a part of the other axial end side of the input shaft 9 is embedded in the concave portion 56a. In addition, the other axial end portion of the connecting shaft 56 has a male thread portion 56b, and the male thread portion 56b is screwed into a female thread portion 10b of an opening concave portion 10a provided on one axial end face of an intermediate shaft 10. The connecting shaft 56 is rotatably supported by a third bearing B3 provided on the outer peripheral surface on one axial end side and a fourth bearing B4 provided on the outer peripheral surface on the other axial end side.

[0117] The torque sensor 32A is provided around the connecting shaft 56 fixed to the outer peripheral surface of the input shaft 9 in a state where the first torsion bar 12 passes through the inside of the annular torque sensor 32A. The torque sensor 32A mainly includes a permanent magnet 62, a pair of first and second magnetic yokes 63, 64, a pair of first and second magnetic flux concentrating rings 65, 66, and a magnetic force sensor 67. The permanent magnet 62, the magnetic yokes 63, 64, and the magnetic flux concentrating rings 65, 66 are all arranged on a circle substantially concentric with the rotation line Z of the steering shaft 7.

[0118] The permanent magnet 62 is formed of a magnetic material into a substantially cylindrical shape and is a magnetic member mounted and fixed to the outer periphery of one end portion of the connecting shaft 56. The permanent magnet 62 is configured by alternately arranging (magnetizing) N poles and S poles along the circumferential direction of the permanent magnet 62.

[0119] The pair of magnetic yokes 63, 64 are both formed of a soft magnetic material into a substantially cylindrical shape. One end sides of the magnetic yokes 63, 64 on the side of the intermediate shaft 10 are arranged in a row along the circumferential direction and are arranged to face the permanent magnet 62 in the radial direction. On the other hand, on the other end side, the first magnetic yoke 63 is arranged on the inner peripheral side and the second magnetic yoke 64 is arranged on the outer peripheral side so as to face each other in the radial direction.

[0120] A pair of magnetic flux collecting rings 65 and 66 are substantially circular rings that collect the magnetic flux generated by the permanent magnet 62 leaking to the other end sides of the two magnetic yokes 63 and 64 within a specified range, and are arranged in the radial space between the other end sides of the magnetic yokes 63 and 64. The magnetic flux collecting ring 65 is arranged on the outer peripheral side, and the magnetic flux collecting ring 66 is arranged on the inner peripheral side, and the two face each other in the radial direction. A Hall element 68 is arranged in the radial space between the magnetic flux collecting rings 65 and 66. At a specified position in the circumferential direction of the magnetic flux collecting ring 65, a magnetic flux collecting portion 65a that is pushed inward in the radial direction is provided. On the other hand, at a position in the circumferential direction of the magnetic flux collecting ring 66 that faces the magnetic flux collecting portion 65a, a magnetic flux collecting portion 66a that protrudes outward in the radial direction is provided.

[0121] The magnetic force sensor 67 is composed of a Hall element 68 that is accommodated in the radial gap between the magnetic flux collecting portion 65a and the magnetic flux collecting portion 66a and a connection terminal 70 for connecting the Hall element 68 to a control substrate 69 arranged above the torque sensor 32A. The magnetic force sensor 67 detects the magnetic flux passing between the magnetic flux collecting portions 65a and 66a by using the Hall effect of the Hall element 68, and outputs a signal corresponding to the magnetic flux to the control substrate 69. Thereby, the relative rotation angle between the input shaft 9 and the intermediate shaft 10 in the control substrate 69 is calculated, and the steering torque based on the relative rotation angle is calculated.

[0122] [Effects of the Second Embodiment]

[0123] In the second embodiment, the rotational force of the electric motor 2 is transmitted to the connecting shaft 56 through the meshing of the thread 59a and the helical gear portion 60a constituting the speed reducer 55.

[0124] According to the steering device in which the electric motor 2 is connected to the connecting shaft 56 via the speed reducer 55, it is also possible to suppress the deviation of the steering force caused by the individual differences of the output side steering device portion 1b, and to stabilize the operation of the steering device.

[0125] [Third Embodiment]

[0126] Figure 10 It is a schematic diagram showing the schematic configuration of the steering device of the third embodiment.

[0127] In the third embodiment, the electric motor 2 is configured to apply a rotational force not to the input shaft 9 but to the intermediate shaft 10.

[0128] On the outer peripheral portion of the intermediate shaft 10, a worm wheel 60 having a helical gear portion 60a on the outer periphery is fixed. The helical gear portion 60a meshes with the thread 59a of a worm shaft 59 that rotates integrally with a motor shaft (not shown) of the electric motor 2. In addition, the intermediate shaft 10 is connected to the output shaft 11 via a coupling shaft 71.

[0129] The output shaft 11 has a pinion 11b at its end portion, and the pinion 11b engages with a rack 72a integrally formed on the outer periphery of the rack bar 72 to constitute a so-called rack & pinion mechanism. Both ends of the rack bar 72 are connected to the corresponding front wheels 75A and 75B via two tie rods 73A and 73B and two steering arms 74A and 74B, respectively. Further, on the output shaft 11, a control valve 78 is provided to control the supply of working oil from the pump device 17 connected to the reservoir tank 76 to the power cylinder 6 based on the amount and direction of torsion of the second torsion bar 13.

[0130] The power cylinder 6 is provided between one axial end portion of the rack bar 72 and the rack 72a. The power cylinder 6 has a piston 15 integrally provided with the rack bar 72, and a first liquid chamber P1 and a second liquid chamber P2 separated by the piston 15. The first liquid chamber P1 is connected to the control valve 78 via a first flow path 77, while the second liquid chamber P2 is connected to the control valve 78 via a second flow path 79.

[0131] [Effect of the Third Embodiment]

[0132] In the third embodiment, the electric motor 2 is configured to apply a rotational force to the intermediate shaft 10.

[0133] According to the steering device having such an electric motor 2, it is also possible to suppress the deviation of the steering force caused by the individual differences of the output side steering device portion 1b, and to stabilize the operation of the steering device.

[0134] [Fourth Embodiment]

[0135] Figure 11 It is a flowchart showing a fourth embodiment of a manufacturing method of a steering device. Figure 12 It is a schematic diagram of an inspection device used in the manufacturing method of the steering device of the fourth embodiment.

[0136] In the fourth embodiment, for the electric servo unit portion 80 including the electric motor 2 and the EPS controller 3 having the input side steering device portion 1a of the second embodiment, characteristic data of the electric servo unit portion as an output value of the electric motor 2 is measured.

[0137] Hereinafter, with reference to Figure 11 the flowchart, a manufacturing method (inspection method) of the steering device in the present embodiment will be described.

[0138] First, as Figure 12 shown, in the inspection chamber, a third torque meter 81 for measuring the steering torque of the input shaft 9 is mounted on the input shaft 9.

[0139] Then, in the motor command current value transmission process of step S11, the computer 82 calculates a prescribed motor command current value (motor command torque) and transmits the prescribed motor command current value to the EPS controller 3 via CAN communication of the communication device 83.

[0140] Then, in the command current output process of step S12, the EPS controller 3 outputs a prescribed motor command current value to the electric motor 2.

[0141] Moreover, while continuously performing the command current output process, in the electric servo unit part characteristic data measurement process of step S13, the output value of the electric motor 2 during the command current output process, that is, the electric servo unit part characteristic data, namely the steering torque with respect to the prescribed motor command current value, is measured. More specifically, when current is passed through the electric motor 2 based on the prescribed motor command current value, the electric motor 2 causes the input shaft 9 of the electric servo unit part 80 to generate a steering torque via a speed reducer (not shown in the figure), and this steering torque is measured using the third torque meter 81. The measured steering torque is output to the computer 82 and transmitted to the EPS controller 3 via CAN communication of the communication device 83. Additionally, it is also possible to measure the output value of the above-mentioned speed reducer during the command current output process in the electric servo unit part characteristic data measurement process.

[0142] Then, in the electric servo unit part characteristic data recording process of step S14, the steering torque with respect to the prescribed motor command current value is recorded on the bar code 84 for the electric servo unit part. That is, using a printer (not shown), a bar code 84 for the electric servo unit part including the steering torque with respect to the prescribed motor command current value is created.

[0143] Moreover, in the recording medium mounting process for the electric servo unit part of step S15, the bar code 84 for the electric servo unit part is mounted on the EPS controller 3 of the electric servo unit part 80. Additionally, instead of the bar code 84 for the electric servo unit part, a two-dimensional code for the electric servo unit part that can refer to the steering torque with respect to the prescribed motor command current value can be used. Moreover, instead of the bar code 84 for the electric servo unit part or the two-dimensional code for the electric servo unit part, an IC chip can be used.

[0144] Then, in the electric servo unit part characteristic data reflection process of step S16, the steering torque with respect to the prescribed motor command current value is reflected in the overall controller that uniformly controls the vehicle.

[0145] [Effects of the Fourth Embodiment]

[0146] In the fourth embodiment, the manufacturing method of the steering device further includes an instruction current output process, an electric servo unit part characteristic data measurement process, an electric servo unit part characteristic data recording process, and an electric servo unit part recording medium mounting process. The steering device can be connected to the electric servo unit part in a state of being mounted on a vehicle. The electric servo unit part includes an electric motor 2 that applies a rotational force to an input shaft 9 and an EPS controller 3 that drives and controls the electric motor 2. The instruction current output process is a process of outputting a prescribed instruction current value from the EPS controller 3 to the electric motor 2. The electric servo unit part characteristic data measurement process is a process of measuring the output value of the electric motor 2 when the instruction current output process is performed, that is, the electric servo unit part characteristic data. The electric servo unit part characteristic data recording process is a process of recording the electric servo unit part characteristic data on a bar code 84 for the electric servo unit part. The electric servo unit part recording medium mounting process is a process of mounting the bar code 84 for the electric servo unit part or a two-dimensional code for the electric servo unit part that can refer to the electric servo unit part characteristic data on the electric servo unit part 80.

[0147] More specifically, individual differences exist not only in the output-side steering device part 1b but also in the input-side steering device part 1a. That is, in the electric servo unit part 80 of the input-side steering device part 1a, individual differences exist, including differences in the mechanical characteristics of the electric motor 2 and differences in the output characteristics of the electric servo unit part 80 due to deviations of current sensors. Therefore, by reflecting the electric servo unit part characteristic data including such individual differences in the overall controller that uniformly controls the vehicle, it is possible to suppress deviations in the steering force caused by individual differences in the input-side steering device part 1a. As a result, the operation of the steering device can be made stable.

[0148] In addition, in the present embodiment, the electric servo unit part 80 further includes a speed reducer provided between the electric motor 2 and the input shaft 9. The electric servo unit part characteristic data measurement process is a process of measuring the output value of the speed reducer when the instruction current output process is performed.

[0149] More specifically, individual differences including differences in mechanical characteristics also exist in the speed reducer. By reflecting the output value including such individual differences in the overall controller, it is possible to suppress deviations in the steering force caused by individual differences in the speed reducer. As a result, the operation of the steering device can be made stable.

Claims

1. A manufacturing method of a steering device, The steering device includes a steering shaft, a transmission mechanism, a power cylinder, and a rotary valve, The above-mentioned steering shaft has a first shaft, a second shaft, and a torsion bar provided between the first shaft and the second shaft, The above-mentioned transmission mechanism can transmit the rotation of the steering shaft to the steering wheel, The above-mentioned power cylinder has a power cylinder main body, a piston, a first liquid chamber, and a second liquid chamber, and can impart a steering force for steering the steering wheel to the above-mentioned transmission mechanism, The above-mentioned rotary valve can selectively supply the working fluid supplied from the pump device to the first liquid chamber and the second liquid chamber according to the torsion of the torsion bar, Among them, The manufacturing method of the above-mentioned steering device has: A working fluid supply process that supplies working fluid from the above-mentioned pump device to the above-mentioned rotary valve; An inspection input shaft operation process that twists the inspection input shaft connected to the above-mentioned first shaft; An output value measurement process that measures the output value of the above-mentioned steering device when performing the above-mentioned working fluid supply process and the above-mentioned inspection input shaft operation process; A characteristic data measurement process that measures steering device characteristic data, which represents the output value of the above-mentioned steering device with respect to the twist amount of the above-mentioned inspection input shaft, or the twist amount of the above-mentioned inspection input shaft with respect to the output value of the above-mentioned steering device, or the relationship between the twist amount of the above-mentioned inspection input shaft and the output value of the above-mentioned steering device; A characteristic data recording process that records the above-mentioned steering device characteristic data on a recording medium; and A recording medium installation process that installs the above-mentioned recording medium or a reference information recording medium capable of referring to the above-mentioned steering device characteristic data on the above-mentioned steering device.

2. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned working fluid supply process drives the above-mentioned pump device so that the flow rate of the working fluid supplied from the above-mentioned pump device to the above-mentioned rotary valve within a specified time becomes a specified amount.

3. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned steering device characteristic data is data related to the twist amount of the above-mentioned inspection input shaft when the output value of the above-mentioned steering device is a specified value.

4. The manufacturing method of the steering device according to claim 3, wherein, The above-mentioned steering device characteristic data includes: first data related to the twist amount of the above-mentioned inspection input shaft when the output value of the above-mentioned steering device is a first specified value; and second data related to the twist amount of the above-mentioned inspection input shaft when the output value of the above-mentioned steering device is a second specified value.

5. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned steering device characteristic data is the output value of the above-mentioned steering device when the above-mentioned inspection input shaft is twisted by a specified amount.

6. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned transmission mechanism is a ball screw mechanism provided between the above-mentioned second shaft and the above-mentioned steering wheel, a rack provided on the above-mentioned piston, and a sector gear meshing with the above-mentioned rack. The above-mentioned steering device characteristic data is the output of the above-mentioned sector gear.

7. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned inspection input shaft operation process includes a process of twisting the above-mentioned inspection input shaft clockwise and a process of twisting the above-mentioned inspection input shaft counterclockwise. The above-mentioned steering device characteristic data includes: a clockwise output value of the steering device obtained when twisting the above-mentioned inspection input shaft clockwise; and a counterclockwise output value of the steering device obtained when twisting the above-mentioned inspection input shaft counterclockwise.

8. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned steering device characteristic data includes information about the deviation amount between the neutral position of the above-mentioned inspection input shaft and the neutral position of the steering wheel connected to the above-mentioned transmission mechanism.

9. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned steering device characteristic data is data representing the relationship between the twist amount of the above-mentioned inspection input shaft and the hydraulic pressure inside the above-mentioned power cylinder, or data representing the relationship between the twist amount of the above-mentioned inspection input shaft and the hydraulic pressure of the working fluid supplied to the above-mentioned power cylinder.

10. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned steering device characteristic data further includes the characteristic data of the above-mentioned pump device.

11. The manufacturing method of the steering device according to claim 10, wherein, The characteristic data of the above-mentioned pump device is the discharge flow rate of the above-mentioned pump device per unit time when the above-mentioned pump device is driven at a specified speed.

12. The manufacturing method of the steering device according to claim 10, wherein, The characteristic data of the above-mentioned pump device include: the discharge flow rate of the above-mentioned pump device per unit time when the above-mentioned pump device is driven at the first specified rotational speed, i.e., the first discharge characteristic data; and the discharge flow rate of the above-mentioned pump device per unit time when the above-mentioned pump device is driven at the second specified rotational speed, i.e., the second discharge characteristic data.

13. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned recording medium or the above-mentioned reference information recording medium installed in the above-mentioned steering device is a barcode or a two-dimensional code.

14. The manufacturing method of the steering device according to claim 1, wherein, The above-mentioned recording medium installed in the above-mentioned steering device is an IC chip.

15. The manufacturing method of the steering device according to claim 1, wherein, The manufacturing method of the above-mentioned steering device further includes a steering device characteristic data reading step and a steering device characteristic data reflecting step. The above-mentioned steering device characteristic data reading step is a step of reading the above-mentioned steering device characteristic data from the above-mentioned recording medium, or a step of obtaining the above-mentioned steering device characteristic data by referring to the above-mentioned steering device characteristic data using the above-mentioned reference information recording medium. The above-mentioned steering device characteristic data reflecting step is a step of storing the above-mentioned steering device characteristic data in the memory device of the controller, and the controller is mounted on the vehicle together with the above-mentioned steering device and drives and controls an electric motor that applies a rotational force to the above-mentioned first shaft.

16. The manufacturing method of the steering device according to claim 1, wherein, The manufacturing method of the above-mentioned steering device further includes a command current output step, an electric servo unit part characteristic data measurement step, an electric servo unit part characteristic data recording step, and an electric servo unit part recording medium installation step. The above-mentioned steering device can be connected to the electric servo unit part in a state of being mounted on a vehicle. The above-mentioned electric servo unit part includes an electric motor that applies a rotational force to the above-mentioned first shaft and a controller that drives and controls the above-mentioned electric motor. The above-mentioned command current output step is a step of outputting a specified command current value from the above-mentioned controller to the above-mentioned electric motor. The above-mentioned electric servo unit part characteristic data measurement step is a step of measuring the output value of the above-mentioned electric motor when the above-mentioned command current output step is performed, i.e., the electric servo unit part characteristic data. The above-mentioned electric servo unit part characteristic data recording step is a step of recording the above-mentioned electric servo unit part characteristic data on the electric servo unit part recording medium. The above-mentioned electric servo unit part recording medium installation step is a step of installing the above-mentioned electric servo unit part recording medium or the electric servo unit part reference information recording medium that can refer to the above-mentioned electric servo unit part characteristic data on the above-mentioned electric servo unit part.

17. The manufacturing method of the steering device according to claim 16, wherein, The above-mentioned electric servo unit part further includes a speed reducer. The above-mentioned speed reducer is provided between the above-mentioned electric motor and the above-mentioned first shaft. The above-mentioned electric servo unit part characteristic data measurement step is a step of measuring the output value of the above-mentioned speed reducer when the above-mentioned command current output step is performed.

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