Steering input device

Abstract

To enable adjustment of play occurring during assembly, the play being caused by variations in shapes of parts of a steering input device.SOLUTION: A steering input device comprises: a shaft 4 to which an operating force is applied; a nut 16 of a linear motion conversion mechanism 12 configured to convert rotation of the shaft 4 into axial displacement of the shaft 4; a restricting member 13 restricting rotation of the nut 16; a biasing member 24 that imparts a biasing force by abutting the restricting member 13; and a seating portion 41 supporting a surface of the biasing member 24 opposite to the surface abutting the restricting member 13. The seating portion 41 has a first seating surface 41a located on one axial side of the shaft 4. The first seating surface 41a is formed on a guide member 27 that retains the biasing member 24 in a housing 15 and permits adjustment of a retaining position of the biasing member 24 relative to the housing 15.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a steering input device. [Background technology]

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

[0003] The steering input device described in Patent Document 1 has a reaction force generating device that can apply a reaction force to a shaft connected to a steering wheel. The reaction force generating device has a shaft, a ball screw mechanism provided around the shaft, first and second cylindrical members provided around the shaft, and a biasing member provided around the first and second cylindrical members and biasing a ball nut of the ball screw mechanism. These shafts and other components are housed in a cylindrical housing, and a long, narrow hole is formed in the housing in the axial direction of the shaft. A stopper bolt that guides the ball nut in the axial direction is inserted into the long hole. The ball nut abuts against both axial ends of the long hole, restricting rotation of the steering wheel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-130426 Summary of the Invention [Problem to be solved by the invention]

[0005] Although Patent Document 1 discloses a structure for restricting rotation of a steering wheel using a ball nut abutting against both axial ends of an elongated hole, it does not take into consideration a structure for adjusting rattling that occurs when assembling a shaft, a ball screw mechanism, etc. due to variations in the shape of the shaft, the ball screw mechanism, etc. caused by manufacturing errors, for example.

[0006] The present invention was devised in consideration of the current situation, and one of its objects is to provide a steering input device that is capable of adjusting rattling that occurs during assembly due to variations in the shapes of each component of the steering input device. [Means for solving the problem]

[0007] In the present invention, the steering input device has a seat portion that receives a surface of the biasing member opposite to a side that abuts against the regulating member when the biasing member applies a biasing force, and this seat portion has a first seat surface on one side in the axial direction of the shaft. The first seat surface is provided on a guide member that holds the biasing member in a housing and is capable of adjusting the holding position of the biasing member relative to the housing. [Effects of the Invention]

[0008] According to the present invention, it is possible to adjust the rattle that occurs during assembly due to variations in the shapes of the components of the steering input device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a steer-by-wire type steering device to which the steering input device of the present invention is applied. [Figure 2] 1 is a perspective view of a steering input device according to an embodiment; [Figure 3] 3 is a longitudinal cross-sectional view of the steering input device taken along line AA in FIG. 2. [Figure 4] 3 is a longitudinal cross-sectional view of the steering input device taken along line BB in FIG. 2. [Figure 5] FIG. 4 is a perspective view of a first restricting member. [Figure 6] FIG. 10 is a perspective view of a second restricting member. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] 10 is a graph showing the operation force relative to the operation angle. [Figure 10]3A and 3B are longitudinal cross-sectional views of the steering input device based on a cross section along line AA in FIG. 2 when the shaft is rotated to the right, where (a) shows the steering input device in the neutral position, (b) shows the steering input device when the shaft is rotated 60 degrees to the right from the neutral position, and (c) shows the steering input device when the shaft is rotated 120 degrees to the right from the neutral position. [Figure 11] 3A and 3B are longitudinal cross-sectional views of the steering input device based on a cross section along line BB in FIG. 2 when the shaft is rotated to the right, where (a) shows the steering input device in the neutral position, (b) shows the steering input device when the shaft is rotated 60 degrees to the right from the neutral position, and (c) shows the steering input device when the shaft is rotated 120 degrees to the right from the neutral position. [Figure 12] 3A and 3B are longitudinal cross-sectional views of the steering input device based on a cross section along line AA in FIG. 2 when the shaft is rotated to the left, where (a) shows the steering input device in the neutral position, (b) shows the steering input device when the shaft is rotated 60 degrees to the left from the neutral position, and (c) shows the steering input device when the shaft is rotated 120 degrees to the left from the neutral position. [Figure 13] 3A and 3B are longitudinal cross-sectional views of the steering input device based on a cross section along line BB in FIG. 2 when the shaft is rotated to the left, where (a) shows the steering input device in the neutral position, (b) shows the steering input device when the shaft is rotated 60 degrees to the left from the neutral position, and (c) shows the steering input device when the shaft is rotated 120 degrees to the left from the neutral position. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a steering input device of the present invention will be described below with reference to the drawings. The following embodiment will be described as an example in which the steering input device is applied to a steer-by-wire steering device mounted on a vehicle.

[0011] FIG. 1 is a schematic diagram of a steer-by-wire steering device to which the steering input device of the present invention is applied.

[0012] The steer-by-wire steering device is configured so that a steering input device (to be described later), in which the driver's steering operation is input via a dial 1, which is a steering input member attached to the vehicle, and a steering mechanism 3 that steers a pair of steerable wheels 2, 2, are mechanically separated.

[0013] Dial 1 is fixed to one end of shaft 4, which is a column shaft provided in the steering input device. Note that instead of dial 1, another steering operation input member, for example a steering wheel, may be fixed to one end of shaft 4. An operation angle sensor 5 is provided on the outer periphery of shaft 4 to detect the operation angle (steering angle) of shaft 4 associated with the driver's steering operation. An operation angle signal detected by operation angle sensor 5 is transmitted to control device 6. In addition, various detection signals other than the operation angle signal are transmitted to control device 6 by external sensor 7. Control device 6 controls electric motor 8 provided in steering mechanism 3 based on the operation angle signal, a steering amount signal (described later), and various detection signals.

[0014] The steering mechanism 3 includes a steering shaft 9, a pair of tie rods 10, 10 connected to both ends of the steering shaft 9 and steering the pair of steerable wheels 2, 2, an electric motor 8 that controls the steering operation of the steering shaft 9, and a steering amount sensor 11 that detects a steering amount signal of the steering shaft 9. The steering amount signal detected by the steering amount sensor 11 is sent to the control device 6.

[0015] FIG. 2 is a perspective view of a steering input device according to one embodiment. FIG. 3 is a longitudinal cross-sectional view of the steering input device taken along line AA in FIG. 2. FIG. 4 is a longitudinal cross-sectional view of the steering input device taken along line BB in FIG. 2. FIGS. 3 and 4 show longitudinal cross-sectional views of the steering input device in a neutral position. Here, the "neutral position" refers to a neutral position in which the dial 1 is not rotated to either the right (right turning) or the left (left turning) relative to the traveling direction of the vehicle, and therefore the first coil spring 25 is not compressed or expanded. FIG. 5 is a perspective view of the first restricting member 19. FIG. 6 is a perspective view of the second restricting member 20. FIG. 7 is a perspective view of the biasing member cover 23. FIG. 8 is a perspective view of the guide member 27.

[0016] The steering input device mainly includes a shaft 4, a linear motion conversion mechanism 12, a restricting member 13, a reaction force generating mechanism 14, and a housing 15.

[0017] First, for convenience of the following explanation, the axial end of the shaft 4 to which the dial 1 is connected is defined as "one end 4a," and the axial end opposite to one end 4a is defined as "the other end 4b." Furthermore, the direction along the longitudinal direction of the shaft 4 is defined as the "axial direction," the direction perpendicular to this axial direction is defined as the "radial direction," and further, the direction along the circumference of the shaft 4 is defined as the "circumferential direction."

[0018] The shaft 4 rotates around a rotation axis O when an operating force is input from the dial 1. As shown in FIG. 3, a D-cut portion 4c for engagement with the dial 1 is formed on the outer periphery of one end 4a of the shaft 4.

[0019] The linear motion conversion mechanism 12 is configured as a ball screw mechanism having a shaft-side ball screw groove 4d, which is a spiral groove formed on the outer peripheral surface of the shaft 4, a nut-side ball screw groove 16a, which is a spiral groove formed on the inner peripheral surface of a nut 16, which is a linear motion member, and a plurality of balls 17 (some of which are shown by dashed lines) arranged between the ball screw grooves 4d and 16a. The balls 17 support the nut 16 so that it can rotate relative to the shaft 4. As a result, the nut 16 converts the rotation of the shaft 4 into axial movement of the shaft 4 via the balls 17.

[0020] Furthermore, instead of the linear motion conversion mechanism 12, which is the ball screw mechanism described above, a linear motion conversion mechanism using thread engagement may be applied to the steering input device of this embodiment. In this case, this linear motion conversion mechanism has a first helical uneven portion (male thread portion) formed on the outer circumferential surface of the shaft 4 and a second helical uneven portion (female thread portion) that engages with the first uneven portion, and has a nut that is a movable member that can move in the axial direction of the shaft 4 in response to the rotation of the dial 1.

[0021] The nut 16 has one axial end face 16b located on the one end 4a side of the shaft 4 (one axial side of the shaft 4) and another axial end face 16c located on the other end 4b side of the shaft 4 (the side opposite the one axial side of the shaft 4). As shown in FIGS. 3 and 4, a circular first recess 16d is formed in the center of the one axial end face 16b of the nut 16. Also, as shown in FIG. 4, first bolt holes 16e are formed along the axial direction of the shaft 4 at positions on both sides of the one axial end face 16b, sandwiching the first recess 16d. A first bolt 18, which is a fixing member used to fix the first restricting member 19 to the nut 16, is screwed into the first bolt hole 16e. Also, a circular second recess 16f having a shape similar to the first recess 16d is formed in the center of the other axial end face 16c of the nut 16. An annular flange portion 16g protruding radially outward from the outer peripheral surface of the nut 16 is formed at a position on the outer peripheral surface of the nut 16 adjacent to the other axial end face 16c.

[0022] The restricting member 13 has a first restricting member 19 fastened to one axial end face 16b of the nut 16, and a second restricting member 20 engaged with the other axial end face 16c of the nut 16.

[0023] 5, the first restricting member 19 has a generally rectangular plate shape and restricts the rotation of the nut 16 that accompanies the rotation of the shaft 4. The first restricting member 19 has a generally circular first central portion 19a, a pair of rectangular first expanding portions 19b that expand in opposite directions from the outer periphery of the first central portion 19a, and a pair of rectangular first narrow portions 19c that protrude outward from the pair of first expanding portions 19b.

[0024] The first central portion 19a has a circular first through hole 19d formed in its center, and the shaft 4 is inserted into the first through hole 19d, as shown in FIGS. 3 and 4 . Furthermore, as shown in FIG. 5 , the first central portion 19a has a pair of first hole portions 19e formed on both sides of the first through hole 19d in the direction X, which is perpendicular to both the longitudinal direction and the thickness direction of the first restricting member 19. As shown in FIG. 4 , each of the first hole portions 19e is a through hole whose diameter decreases stepwise from one end 4a to the other end 4b of the shaft 4, and accommodates the head of the first bolt 18 and a portion adjacent to the head. As shown in FIG. 5 , the width W1 of the first narrow portion 19c along the direction X is narrower than the width W2 of the first expanded portion 19b along the direction X.

[0025] Furthermore, the first narrow portion 19c is slidably supported in a guide groove 31s formed on the inner circumferential surface of the first housing 31, thereby allowing the first restricting member 19 to move smoothly when the nut 16 moves along the axial direction of the shaft 4. Furthermore, the guide groove 31s functions as a rotation stopper that restricts the rotation of the first restricting member 19 attached to the nut 16 when the shaft 4 rotates.

[0026] 6, the second restricting member 20 has a generally rectangular plate shape and restricts the rotation of the nut 16 that accompanies the rotation of the shaft 4. The second restricting member 20 has a generally circular second central portion 20a, a pair of rectangular second expanding portions 20b that expand in opposite directions from the outer periphery of the second central portion 20a, and a pair of rectangular second narrow portions 20c that protrude outward from the pair of second expanding portions 20b.

[0027] As shown in FIG. 3 , the second restricting member 20 is disposed within the first housing 31 such that the pair of second narrow portions 20c of the second restricting member 20 faces the pair of first narrow portions 19c of the first restricting member 19 in the axial direction of the shaft 4. The second central portion 20a has a circular second through hole 20d formed in its center. The inner diameter of the second through hole 20d is larger than the inner diameter of the first through hole 19d in the first central portion 19a of the first restricting member 19. As shown in FIGS. 3 and 4 , the nut 16 with the shaft 4 inserted therethrough is inserted into the second through hole 20d. Also, as shown in FIGS. 3 and 4 , when the steering input device is in the neutral position, an edge portion 20e on the other end 4b side of the second through hole 20d abuts against an abutment surface 16h located on the one end 4a side of the flange portion 16g of the nut 16. As shown in Fig. 6, the width W3 of the second narrow width portion 20c along direction X (the same direction as direction X shown in Fig. 5) perpendicular to both the longitudinal direction and the thickness direction of the second restricting member 20 is narrower than the width W4 of the second expanded portion 20b along direction X. Also, as shown in Fig. 6, each second narrow width portion 20c has a second hole portion 20f formed in its center. As shown in Fig. 3, the second hole portion 20f is a through-hole formed in a stepped shape with a reduced diameter from the other end 4b side to the one end 4a side of the shaft 4, and accommodates the head of the second bolt 21 and a portion adjacent to the head.

[0028] Furthermore, the second narrow portion 20c is slidably supported in a guide groove 31s formed on the inner circumferential surface of the first housing 31, thereby allowing the second restricting member 20 to move smoothly when the nut 16 moves along the axial direction of the shaft 4. Furthermore, the guide groove 31s functions as a rotation stopper that restricts the rotation of the second restricting member 20 attached to the nut 16 when the shaft 4 rotates.

[0029] The reaction force generating mechanism 14 includes a biasing member guide 22, a biasing member cover 23, and a biasing member 24 including a first coil spring 25 (first biasing member) and a second coil spring 26 (second biasing member).

[0030] The biasing member guide 22 has a cylindrical shape with a bottom that opens toward the other end 4b of the shaft 4. The biasing member guide 22 guides the first coil spring 25 and the second coil spring 26 when they are compressed or expanded. Furthermore, the biasing member guide 22 prevents the second coil spring 26 from coming off. As shown in FIGS. 3 and 4 , the biasing member guide 22 has a circular plate-shaped ceiling wall 22a, a cylindrical peripheral wall 22b that extends from the outer edge of the ceiling wall 22a toward the other end 4b of the shaft 4, and an annular flange wall 22c that protrudes radially outward from the outer circumferential surface of the peripheral wall 22b. The ceiling wall 22a has a circular insertion hole 22d formed in its center. As shown in FIGS. 3 and 4 , the nut 16, with the shaft 4 inserted therein, is inserted into the insertion hole 22d. The inner diameter of the insertion hole 22d is the same as the outer diameter of the nut 16. Therefore, the inner peripheral surface of the insertion hole 22d is slidable relative to the outer peripheral surface of the nut 16.

[0031] The urging member cover 23 supports the urging member guide 22 and covers the second coil spring 26 in cooperation with the urging member guide 22. As shown in Figures 3 and 7, the urging member cover 23 has an annular base portion 23a and a pair of protrusions 23c that protrude from a surface 23b of the annular base portion 23a on the other end portion 4b side toward the other end portion 4b.

[0032] The annular base portion 23a has a circular spring insertion hole 23d formed in its center, and a portion including a first lower spring end surface 25b of the first coil spring 25 is disposed in this spring insertion hole 23d, as shown in Figures 3 and 4. Furthermore, as shown in Figures 3 and 4, when the steering input device is in the neutral position, the surface 23b on the other end 4b side of the annular base portion 23a adjacent to the spring insertion hole 23d abuts against the upper surface 22e of the flange wall 22c of the biasing member guide 22.

[0033] 3 and 7, the pair of protrusions 23c are disposed at positions facing each other in the radial direction of the annular base portion 23a. As shown in FIG. 7, each protrusion 23c is continuous over a range of approximately 30 degrees in the circumferential direction of the annular base portion 23a. As shown in FIG. 3, a second bolt hole 23f is formed in the axial end surface 23e of each protrusion 23c on the other end 4b side, along the axial direction of the shaft 4. A second bolt 21 used to attach the second restricting member 20 to the biasing member cover 23 is screwed into the second bolt hole 23f.

[0034] The first coil spring 25 is a coil-shaped linear spring that is provided coaxially with the shaft 4 when no preload is applied, i.e., when it is at its free length. As shown in FIGS. 3 and 4 , the first coil spring 25 is disposed around a portion of the nut 16 on the one end 4a side and around the peripheral wall 22b of the biasing member guide 22. The inner diameter of the first coil spring 25 is larger than the length of the first central portion 19a of the first restricting member 19 along the radial direction of the shaft 4, i.e., the length of the first central portion 19a along the direction X shown in FIG. 5 . As shown in FIG. 3 , the first coil spring 25 has a first upper spring end surface 25a that abuts against the lower surface 19f of the first restricting member 19 when the steering input device is in the neutral position, and a first lower spring end surface 25b that abuts against the upper surface 22e of the flange wall 22c of the biasing member guide 22 when the steering input device is in the neutral position. As nut 16, which is a linear moving member, moves in the axial direction, first coil spring 25 comes into contact with first restricting member 19, thereby contributing to the application of a biasing force (reaction force) to shaft 4. Note that, for convenience of illustration, Fig. 4 shows first upper spring end surface 25a of first coil spring 25 and first seat surface 41a of guide member 27 as coming into contact, but in reality, they do not come into contact until shaft 4 is rotated to the right by an operating angle of 60 degrees.

[0035] The second coil spring 26 is a coiled linear spring that is provided coaxially with the shaft 4 in a preloaded state. The second coil spring 26 applies a biasing force after the first coil spring 25 applies a biasing force. The second coil spring 26 has a smaller outer diameter than the first coil spring 25. The spring constant of the second coil spring 26 is set to be the same as the spring constant of the first coil spring 25. The second coil spring 26 is disposed around the nut 16 between the top wall 22a of the biasing member guide 22 and the second restricting member 20. As shown in FIG. 3 , the second coil spring 26 has a second upper spring end surface 26a that abuts against a surface 22f on the other end 4b side of the top wall 22a of the biasing member guide 22, and a second lower spring end surface 26b that abuts against an upper surface 20g, which is a surface on the one end 4a side of the second restricting member 20, when the steering input device is in the neutral position. As the nut 16, which is a linear moving member, moves in the axial direction, the second coil spring 26 comes into contact with the second restricting member 20, thereby contributing to the application of a biasing force to the shaft 4. Note that, for convenience of illustration, in FIG. 4, the second lower spring end surface 26b of the second coil spring 26 and the second seat surface 41b of the first housing 31 are shown to be in contact with each other, but in reality, they do not come into contact with each other until the shaft 4 is rotated to the left by an operating angle of 60 degrees.

[0036] 3, a guide member 27 is disposed closer to the one end 4a than the first restricting member 19, and the guide member 27 holds the first coil spring 25 within the first housing 31 and adjusts the holding position of the first coil spring 25 with respect to the first housing 31. As shown in Fig. 8, the guide member 27 is formed in a generally cylindrical shape. As shown in Fig. 8, the guide member 27 has a cylindrical tubular portion 27a and a pair of cubic radial protrusions 27c that protrude radially outward in opposite directions from positions adjacent to an upper surface 27b of the tubular portion 27a on the outer circumferential surface of the tubular portion 27a.

[0037] The inner diameter of the cylindrical portion 27a is larger than the outer diameter of the first central portion 19a of the first restricting member 19, i.e., the outer diameter of the first central portion 19a along the direction X. As shown in FIGS. 3 and 8, a third bolt hole 27e is formed in the center of a tip end surface 27d located on the tip side of each radial protrusion 27c, and a third bolt 28 used to attach the guide member 27 to the first housing 31 is screwed into this third bolt hole 27e. As shown in FIG. 3, when the guide member 27 is attached to the first housing 31, an upper surface 27b of the cylindrical portion 27a and an upper surface 27f of each radial protrusion 27c of the guide member 27 are spaced from a lower surface 32h, which is the surface on the other end 4b side of the second housing 32.

[0038] 8, a pair of rectangular cutouts 27g recessed from the first seating surface 41a toward the upper surface 27b are formed in positions corresponding to the pair of radial protrusions 27c on a first seating surface 41a (described later) that is the underside of the cylindrical portion 27a. The cutouts 27g are large enough to accommodate the first extension portions 19b of the first restricting member 19. With the guide member 27 configured in this manner, when the first restricting member 19 moves toward the one end 4a as the nut 16 moves toward the one end 4a during clockwise rotation of the dial 1, the first central portion 19a and the pair of first extension portions 19b of the first restricting member 19 can move toward the one end 4a through the interior of the cylindrical portion 27a of the guide member 27 and the pair of cutouts 27g.

[0039] As shown in FIGS. 3 and 4 , a stopper member 29 is provided in the space inside the cylindrical portion 27a of the guide member 27. The stopper member 29 determines the stroke end of the first restricting member 19, which moves with the nut 16 when the nut 16 moves toward the one end 4a. As shown in FIG. 4 , the stopper member 29 has an annular ring portion 29a and a protrusion 29b that protrudes radially outward from the outer circumferential surface of the ring portion 29a. As shown in FIGS. 3 and 4 , the shaft 4 is inserted into a central hole 29c provided in the center of the ring portion 29a. When the shaft 4 is inserted into the central hole 29c, a predetermined gap separates the outer circumferential surface of the shaft 4 from the inner surface of the central hole 29c so that the ring portion 29a does not interfere with the rotation of the shaft 4. As shown in FIG. 4 , a pin insertion hole 29d is formed through the protrusion 29b along the axial direction of the shaft 4. A pin 30 is inserted into the pin insertion hole 29d, and a tip portion 30a of the pin 30 is fitted into a fitting hole 32i formed in a lower surface 32h of the second housing 32. As shown in Fig. 4, when the tip portion 30a of the pin 30 is fitted into the fitting hole 32i, the guide member 27 is fixed to the second housing 32 in a cantilevered manner via the pin 30.

[0040] The housing 15 includes a first housing 31 and a second housing 32 attached to the first housing 31 .

[0041] The first housing 31 is made of a metal material or a synthetic resin material and has a cylindrical shape with a bottom. The first housing 31 accommodates a part of the shaft 4, the linear motion conversion mechanism 12, the restricting member 13, the reaction force generating mechanism 14, the guide member 27, and the stopper member 29. As shown in Figures 3 and 4, the first housing 31 has a cylindrical peripheral wall 31a and a bottom wall 31d provided at a position near the other end 31c, which is the end on the side to which the second housing 32 is not attached, of both ends 31b, 31c of the peripheral wall 31a.

[0042] A bolt insertion hole 33 for accommodating the head 28a and adjacent base portion 28b of the third bolt 28 is formed radially through the peripheral wall 31a at a position facing the pair of radial protrusions 27c of the guide member 27. As shown in Fig. 3, the bolt insertion hole 33 has a stepped shape that reduces in diameter from the outer peripheral surface 31e to the inner peripheral surface 31f of the first housing 31. The bolt insertion hole 33 is located on the outer peripheral surface 31e side and has a head portion accommodating portion 33a that accommodates the head 28a of the third bolt 28, and a base portion accommodating portion 33b that communicates with the head portion accommodating portion 33a and accommodates the base portion 28b of the third bolt 28.

[0043] The head accommodating portion 33a is an oval-shaped slot that is longer in the axial direction of the shaft 4 when viewed from outside the first housing 31 in the radial direction of the shaft 4. The head accommodating portion 33a may be formed in a rectangular shape instead of an oval shape. Similarly, the root accommodating portion 33b is an oval-shaped slot that is longer in the axial direction of the shaft 4 when viewed from outside the first housing 31 in the radial direction of the shaft 4 and is smaller in length than the head accommodating portion 33a. The root accommodating portion 33b may be formed in a rectangular shape instead of an oval shape. The head 28a and the root 28b of the third bolt 28 are movable in the axial direction of the shaft 4 via the head accommodating portion 33a and the root accommodating portion 33b, which are elongated holes.

[0044] 3, when the third bolt 28 is threaded into the third bolt hole 27e of the radial protrusion 27c of the guide member 27, a continuous annular gap 34 remains between the tip end surface 27d of the radial protrusion 27c and the back surface 28c of the head 28a of the third bolt 28. This gap 34 has a width sufficient to allow the portion 33c of the peripheral wall 31a constituting the root portion accommodating portion 33b to be inserted when the head 28a and the root portion 28b of the third bolt 28 move in the axial direction of the shaft 4 through the elongated head portion accommodating portion 33a and the root portion accommodating portion 33b.

[0045] Furthermore, an annular protruding portion 31g that protrudes radially outward from the shaft 4 is formed on the outer peripheral surface 31e of the first housing 31 at a position closer to the other end 4b than the bolt insertion holes 33. As shown in FIG. 4, fourth bolt holes 31h are formed in the annular protruding portion 31g along the axial direction of the shaft 4. Three fourth bolt holes 31h are formed at equally spaced positions in the circumferential direction of the shaft 4. Fourth bolts 35 used to attach the second housing 32 to the first housing 31 are screwed into the fourth bolt holes 31h.

[0046] The bottom wall 31d has a thick portion 31dx (FIG. 4) and a thin portion 31dy (FIG. 3) that are continuous over a range of 180 degrees in the circumferential direction of the shaft 4. As shown in FIG. 4, a circular recess 31i is formed in the center of the thick portion 31dx, recessing from a second bearing surface 41b (described later) that is the upper surface of the thick portion 31dx toward the other end 4b. The width of the recess 31i along the radial direction of the shaft 4 is larger than the outer diameter of the flange portion 16g of the nut 16. As shown in FIG. 4, when the steering input device is in the neutral position, a portion including the flange portion 16g of the nut 16 is disposed within the recess 31i. An insertion hole 31k, through which the shaft 4 is inserted, is formed in the center of a bottom 31j of the recess 31i and extends along the axial direction of the shaft 4.

[0047] 3 and 4, the thick-walled portion 31dx and the thin-walled portion 31dy share a common lower surface 31m located on the other end 4b side. A small cylindrical portion 31n is formed in the center of the lower surface 31m, continuing from the lower surface 31m toward the other end 4b side. As shown in FIGS. 3 and 4, the inner periphery 31o of the small cylindrical portion 31n extends along the axial direction of the shaft 4 from the open end 31p of the small cylindrical portion 31n to a position closer to the one end 4a than the lower surface 31m. The inner diameter of the small cylindrical portion 31n is larger than the inner diameter of the insertion hole 31k formed in the center of the bottom 31j. Therefore, the hole edge 31q of the insertion hole 31k on the other end 4b side is located adjacent to the inner periphery 31o of the small cylindrical portion 31n. A first ball bearing 36, which is a bearing for rotatably supporting the shaft 4, is provided at a position adjacent to the hole edge portion 31q on the inner periphery 31o of the small cylindrical portion 31n.

[0048] A cup-shaped closing member 37 is provided closer to the other end 4b than the first ball bearing 36. A male thread 37a is formed on the outer periphery of the closing member 37, and this male thread 37a is threadedly engaged with a female thread 31r formed on the inner periphery 31o of the small cylindrical portion 31n. This threaded engagement presses the outer race 36a of the first ball bearing 36 against the hole edge 31q of the insertion hole 31k, thereby fixing the outer race 36a to the first housing 31. As shown in FIGS. 3 and 4 , an annular nut member 38 is provided on the outer periphery of the shaft 4 closer to the other end 4b than the first ball bearing 36. The nut member 38 has a female thread 38a formed on the inner periphery, and this female thread 38a is threadedly engaged with a male thread 4e formed on the outer periphery of the shaft 4.

[0049] The second housing 32 is made of a metal or synthetic resin material and has a cylindrical shape with a bottom, and is a lid member that closes the opening on the one end 4a side of the first housing 31. The second housing 32 has a disk-shaped base wall portion 32a and a cylindrical wall portion 32b that continues from the outer edge of the base wall portion 32a to the annular protruding portion 31g of the first housing 31.

[0050] A cylindrical protrusion 32d is formed in the center of an upper surface 32c, which is the surface of the base wall 32a on the one end 4a side, and rises from the upper surface 32c toward the one end 4a side along the axial direction of the shaft 4. The inner periphery of the cylindrical protrusion 32d has a diameter that decreases in two stages from the one end 4a side to the other end 4b side, thereby forming a large diameter portion 32e, a medium diameter portion 32f, and a small diameter portion 32g.

[0051] An oil seal 39, which is a sealing member that seals between the inner periphery of the cylindrical protrusion 32d and the outer periphery of the shaft 4, is provided in the large diameter portion 32e. The oil seal 39 generates a viscous sensation due to friction with the shaft 4 when the dial 1 begins to be turned, and this viscous sensation gives the driver the feeling that they are operating the dial 1. Note that the sealing member does not have to be the oil seal 39 as long as it seals between the inner periphery of the cylindrical protrusion 32d and the outer periphery of the shaft 4; for example, an O-ring or a dust seal may be provided. Furthermore, an O-ring or a dust seal may be provided in combination with the oil seal 39. A second ball bearing 40, which is a bearing that rotatably supports the shaft 4, is provided in the medium diameter portion 32f.

[0052] A continuous annular groove 32j is formed in a position adjacent to the cylindrical wall portion 32b on a lower surface 32h, which is the surface of the base wall portion 32a on the other end 4b side. As shown in FIGS. 3 and 4, one end 31b of the peripheral wall 31a of the first housing 31 and a portion nearby are fitted into the annular groove 32j. As shown in FIG. 4, a bolt through hole 32k is formed in the cylindrical wall portion 32b and extends along the axial direction of the shaft 4. The second housing 32 is attached and fixed to the first housing 31 by threading a fourth bolt 35 through the bolt through hole 32k and into a fourth bolt hole 31h in the annular protrusion 31g of the first housing 31. The bolt through holes 32k are formed in three locations at equal intervals around the circumference of the shaft 4.

[0053] Next, a description will be given of the seat portion 41 that receives the surface of the biasing member 24 opposite to the side that abuts against the restricting member 13 when the biasing member 24 applies a biasing force to the shaft 4 as the shaft 4 rotates right or left through an operating angle of 60 degrees or more. The seat portion 41 has a first seat portion 41a provided on one side in the axial direction of the shaft 4, i.e., on the side of one end 4a, and a second seat portion 41b provided on the side opposite to the one side in the axial direction of the shaft 4, i.e., on the side of the other end 4b.

[0054] 4 and 8, the first bearing surface 41a is the lower surface of the cylindrical portion 27a of the guide member 27. When the shaft 4 rotates clockwise, for example, through an operating angle of 60 degrees, and the nut 16 moves toward the one end 4a while pushing up the first restricting member 19 toward the one end 4a, the first bearing surface 41a comes into contact with a first upper spring end surface 25a, which is the surface of the first coil spring 25 of the biasing member 24 on the one end 4a side. At this time, the second lower spring end surface 26b of the second coil spring 26 of the biasing member 24 comes into contact with the upper surface 20g of the second restricting member 20. The contact between the first bearing surface 41a and the first upper spring end surface 25a determines the fixed position of the first coil spring 25 relative to the housing 15. Furthermore, as described above, head 28a and base 28b of third bolt 28 are movable in the axial direction of shaft 4 via head accommodating portion 33a and base accommodating portion 33b, which are elongated holes, and therefore guide member 27 into which third bolt 28 is screwed is also movable in the axial direction of shaft 4. Therefore, guide member 27 can adjust the holding position of first coil spring 25 with respect to first housing 31 by moving in the axial direction of shaft 4.

[0055] 4, the second bearing surface 41b is the upper surface of the thick-walled portion 31dx of the bottom wall 31d of the first housing 31. When the shaft 4 rotates leftward, for example, through an operating angle of 60 degrees, and the nut 16 moves toward the other end 4b while pulling the first restricting member 19 downward, the second coil spring 26 is pressed toward the other end 4b via the compressed first coil spring 25 and the biasing member guide 22, causing the second bearing surface 41b to abut against a second lower spring end surface 26b, which is the surface of the second coil spring 26 of the biasing member 24 on the other end 4b side. At this time, the first upper spring end surface 25a of the first coil spring 25 of the biasing member 24 abuts against a lower surface 19f of the first restricting member 19.

[0056] 9 is a graph showing the operating force versus the operating angle. The two-stage spring characteristics using first coil spring 25 and second coil spring 26 will now be described.

[0057] First, the spring constant of the first coil spring 25 is defined as "K1," while the spring constant of the second coil spring 26 is defined as "K2." As shown in FIG. 9 , when the operating angle is from 0 degrees to less than 60 degrees (small steering angle region), the biasing force of only the first coil spring 25 acts on the shaft 4, so the operating force applied to the shaft 4 increases linearly against a reaction force based on the spring constant K1 (operating force gain K1). Then, when the operating angle reaches 60 degrees and the operating force reaches a predetermined load, approximately 0.125 N·m in this embodiment, the biasing force of the second coil spring 26 also acts in addition to the biasing force of the first coil spring 25. Therefore, the composite spring constant K, which is obtained by regarding the first coil spring 25 and the second coil spring 26 as being connected in series, can be obtained from the equation "1 / K = 1 / K1 + 1 / K2." As described above, the spring constant of the first coil spring 25 and the spring constant of the second coil spring 26 in this embodiment are the same, so the equation "1 / K = 2 / K" holds. Rearranging this equation yields "K = K / 2." Therefore, in this embodiment, in the operating angle range of 60 degrees to 180 degrees (large steering angle region), the operating force applied to the shaft 4 increases linearly against a reaction force based on the composite spring constant K / 2 (operating force gain K / 2). That is, as shown in FIG. 9 , the operating force in the large steering angle region increases linearly at half the rate of the operating force in the small steering angle region. Therefore, in the large steering angle region, the dial 1 is operated with half the force required in the small steering angle region. While the spring constant of the first coil spring 25 and the spring constant of the second coil spring 26 in this embodiment are the same, different spring constants may be used depending on the desired reaction force characteristics.

[0058] 10(a) to 10(c) are longitudinal cross-sectional views of the steering input device taken along line AA in FIG. 2 when the shaft 4 is rotated to the right. More specifically, FIG. 10(a) shows the steering input device in the neutral position, FIG. 10(b) shows the steering input device when the shaft 4 is rotated 60 degrees to the right from the neutral position, and FIG. 10(c) shows the steering input device when the shaft 4 is rotated 120 degrees to the right from the neutral position. FIGS. 11(a) to 11(c) are longitudinal cross-sectional views of the steering input device taken along line BB in FIG. 2 when the shaft 4 is rotated to the right. More specifically, FIG. 11(a) shows the steering input device in the neutral position, FIG. 11(b) shows the steering input device when the shaft 4 is rotated 60 degrees to the right from the neutral position, and FIG. 11(c) shows the steering input device when the shaft 4 is rotated 120 degrees to the right from the neutral position. 10(a) to 10(c) and 11(a) to 11(c), the position of the other axial end face 16c of the nut 16 in the neutral position is indicated by a broken line.

[0059] When the shaft 4 is rotated 60 degrees to the right from the neutral position shown in FIGS. 10(a) and 11(a), the nut 16 moves toward the one end 4a along the axial direction of the shaft 4. Then, as shown in FIGS. 10(b) and 11(b), the first lower spring end surface 25b of the first coil spring 25 is pressed toward the one end 4a via the second restricting member 20, the second coil spring 26, and the biasing member guide 22, compressing the first coil spring 25. As a result, a reaction force corresponding to the biasing force of the first coil spring 25 acts to rotate the shaft 4 to the left. Furthermore, at the position shown in FIGS. 10(b) and 11(b), the first upper spring end surface 25a of the first coil spring 25 abuts against the first seat surface 41a of the guide member 27. Note that the second coil spring 26 is not compressed at operating angles less than 60 degrees. Furthermore, when the nut 16 moves toward the one end 4a, the first restricting member 19 moves toward the one end 4a, with the first central portion 19a and the pair of first expansion portions 19b passing through the inside of the cylindrical portion 27a of the guide member 27 and the inside of the pair of cutout portions 27g.

[0060] 10(b) and 11(b), the nut 16 shown in FIGS. 10(c) and 11(c) moves further toward the one end 4a along the axial direction of the shaft 4. The first coil spring 25 continues to be compressed, and at the same time, the second lower spring end surface 26b of the second coil spring 26 is pressed toward the one end 4a by the second restricting member 20, compressing the second coil spring 26. As a result, a reaction force corresponding to the biasing forces of the first coil spring 25 and the second coil spring 26 acts to rotate the shaft 4 to the left. Furthermore, as shown in FIG. 10(c), the upper surface 19g of the first restricting member 19 abuts against an opposing surface 27h, which is the surface of the pair of radial protrusions 27c of the guide member 27 on the other end 4b side. 10(c) and 11(c), the upper surface 22e of the flange wall 22c of the biasing member guide 22 is spaced apart from the lower surface 23b of the annular base portion 23a of the biasing member cover 23.

[0061] 12(a) to 12(c) are longitudinal cross-sectional views of the steering input device taken along line AA in FIG. 2 when the shaft 4 is rotated to the left. More specifically, FIG. 12(a) shows the steering input device in the neutral position, FIG. 12(b) shows the steering input device when the shaft 4 is rotated 60 degrees to the left from the neutral position, and FIG. 12(c) shows the steering input device when the shaft 4 is rotated 120 degrees to the left from the neutral position. 13(a) to 13(c) are longitudinal cross-sectional views of the steering input device taken along line BB in FIG. 2 when the shaft 4 is rotated to the left. More specifically, FIG. 13(a) shows the steering input device in the neutral position, FIG. 13(b) shows the steering input device when the shaft 4 is rotated 60 degrees to the left from the neutral position, and FIG. 13(c) shows the steering input device when the shaft 4 is rotated 120 degrees to the left from the neutral position. 12(a) to 12(c) and 13(a) to 13(c), the position of one axial end face 16b of the nut 16 in the neutral position is shown by a broken line.

[0062] When the shaft 4 is rotated leftward by 60 degrees from the neutral position shown in FIGS. 12(a) and 13(a), the nut 16 moves axially toward the other end 4b of the shaft 4. Then, as shown in FIGS. 12(b) and 13(b), the first upper spring end surface 25a of the first coil spring 25 is pressed toward the other end 4b by the first restricting member 19, compressing the first coil spring 25. As a result, a reaction force corresponding to the biasing force of the first coil spring 25 acts to rotate the shaft 4 rightward. Then, the second coil spring 26 is pressed toward the other end 4b via the first restricting member 19, the first coil spring 25, and the biasing member guide 22, causing the second lower spring end surface 26b of the second coil spring 26 to abut against a second seating surface 41b formed on the bottom wall 31d of the first housing 31. It should be noted that the second coil spring 26 is not compressed at an operating angle of less than 60 degrees.

[0063] When the shaft 4 is further rotated leftward by 60 degrees from the position shown in FIGS. 12(b) and 13(b), the nut 16 shown in FIGS. 12(c) and 13(c) moves further toward the other end 4b along the axial direction of the shaft 4. The first coil spring 25 continues to be compressed, and at the same time, the second upper spring end surface 26a of the second coil spring 26 is pressed toward the other end 4b via the first restricting member 19, the first coil spring 25, and the biasing member guide 22, thereby compressing the second coil spring 26. As a result, a reaction force corresponding to the biasing forces of the first coil spring 25 and the second coil spring 26 acts to rotate the shaft 4 rightward. Furthermore, as shown in FIGS. 12(c) and 13(c), the upper surface 22e of the flange wall 22c of the biasing member guide 22 is spaced from the lower surface 23b of the annular base portion 23a of the biasing member cover 23. As shown in FIGS. 12(c) and 13(c), the other axial end face 16c of the nut 16 abuts against the bottom 31j of the recessed portion 31i.

[0064] As described above, in this embodiment, the first restricting member 19 is provided on one axial end surface 16b of the nut 16, and further, the guide member 27, which can adjust the fixed position of the first coil spring 25 relative to the housing 15, is provided closer to the one end 4a than the first restricting member 19. The cylindrical portion 27a of the guide member 27 is formed with a first seating surface 41a, and when the nut 16 and the first restricting member 19 move toward the one end 4a during clockwise rotation of the shaft 4, the first upper spring end surface 25a of the first coil spring 25 abuts against this first seating surface 41a, thereby setting the fixed position of the first coil spring 25. Because the guide member 27 can set the fixed position of the first coil spring 25 in this way, by appropriately setting the height position of the guide member 27 when assembling the steering input device, it is possible to adjust rattling that occurs during assembly due to variations in the shapes of the various components. More specifically, various components, such as the first stop member 19, nut 16, second stop member 20, first coil spring 25, second coil spring 26, biasing member guide 22, and biasing member cover 23, are formed with manufacturing errors that deviate from their ideal shapes, resulting in shape variations. Therefore, assembling components with such variations may result in rattle between adjacent components. Therefore, in this embodiment, when the nut 16 moves toward the one end 4a, the first upper spring end surface 25a of the first coil spring 25 abuts against the first seating surface 41a, and the rattle is concentrated toward the one end 4a and absorbed by the guide member 27. Therefore, rattle that occurs during assembly due to shape variations of the components can be adjusted.

[0065] In this embodiment, the first housing 31 is formed with a bolt insertion hole 33 that penetrates radially through the shaft 4 and in which the head 28a and root 28b of the third bolt are disposed. The third bolt 28 movably attaches the guide member 27 to the first housing 31. The bolt insertion hole 33 has a head accommodating portion 33a and a root accommodating portion 33b that are elongated holes that increase in length along the axial direction of the shaft 4 when viewed radially from outside the first housing 31. Therefore, the head 28a and root 28b of the third bolt can move in the axial direction of the shaft 4 through the head accommodating portion 33a and the root accommodating portion 33b, and therefore, rattles between the various components described above, such as the first stop member 19, due to variations in their shapes can be easily absorbed and adjusted.

[0066] Furthermore, in this embodiment, the cylindrical first housing 31 with a bottom has a bottom wall 31d, and the bottom wall 31d is formed with a second seating surface 41b, which serves as a seating surface on the other end 4b side, against which the second lower spring end surface 26b of the second coil spring 26 can abut. As described above, the seating surface can be switched from the first seating surface 41a abutting against the first coil spring 25 to the second seating surface 41b abutting against the second coil spring 26. Therefore, it is not necessary to provide two coil springs dedicated to each of the rotation directions of the shaft 4, and reaction forces corresponding to the clockwise and counterclockwise rotations of the shaft 4 can be generated by only the pair of the first coil spring 25 and the second coil spring 26.

[0067] The biasing member 24 also includes a first coil spring 25 that is attached without a preload and a second coil spring 26 that is attached with a preload and applies a biasing force after the first coil spring 25 applies a biasing force. This allows the operating force of the dial 1 to be changed in two stages, with an operating angle of 60 degrees in between, as shown in FIG. 9 . The operating force increases at a predetermined rate (gradient of increase) until the steering angle reaches 60 degrees, but after 60 degrees, it increases at half the rate compared to when the steering angle is less than 60 degrees. Therefore, in the large steering angle range above 60 degrees, driver fatigue caused by steering can be reduced, and a decrease in vehicle maneuverability can be suppressed.

[0068] Furthermore, in this embodiment, the linear motion conversion mechanism 12 and the reaction force generation mechanism 14 are provided coaxially, that is, on the shaft 4. Therefore, compared to a steering input device in which the linear motion conversion mechanism is provided on one shaft and the reaction force generation mechanism is provided on another shaft parallel to the one shaft, and the linear motion conversion mechanism and the reaction force generation mechanism are connected via a connecting member, the dimensions of the steering input device, particularly the dimensions of the steering input device along the radial direction of the shaft, can be made smaller.

[0069] Furthermore, in a steering input device connected via the above-mentioned connecting member, a moment is generated in the linear motion conversion mechanism via the connecting member due to the compression and extension of the spring provided in the reaction force generating mechanism, which may cause interference between the nut and shaft of the linear motion conversion mechanism.

[0070] However, in this embodiment, the linear motion conversion mechanism 12 and the reaction force generation mechanism 14 are provided coaxially, so that interference between the nut and the shaft due to the generation of the moment does not occur. [Explanation of symbols]

[0071] 4 shaft, 12 linear motion conversion mechanism, 14 reaction force generating mechanism, 19 first restricting member, 20 second restricting member, 22 biasing member guide, 23 biasing member cover, 25 first coil spring, 26 second coil spring, 27 guide member, 28 third bolt, 29 stopper member, 31 first housing, 32 second housing, 33 bolt insertion hole, 33a head accommodating portion, 33b base accommodating portion, 41 seating surface portion, 41a first seating surface, 41b second seating surface

Claims

1. A steering input device in which a driver's steering operation is input via a steering input member attached to a vehicle, a shaft that receives an operating force from the steering input member and rotates around a rotation axis; a linear motion member that converts rotation of the shaft into axial movement of the shaft; A restricting member including a first restricting member and a second restricting member that restrict rotation of the linearly moving member relative to the shaft and allow axial movement of the linearly moving member, the first restricting member is fastened to one side of the shaft of the linear motion member in the axial direction, the second restricting member engages with the linearly moving member on the side opposite to the one side; a biasing member that is provided coaxially with the shaft and that applies a biasing force by coming into contact with the restricting member as the linear motion member moves; a seat portion that receives a surface of the biasing member opposite to a side that abuts against the restricting member when the biasing member applies a biasing force; a housing that accommodates a portion of the shaft, the linear motion member, the restricting member, the biasing member, and the seat portion; and The seat portion includes a first seat on one side in the axial direction of the shaft and a second seat on the opposite side to the first side, The steering input device, wherein the first seating surface is provided on a guide member that holds the biasing member within the housing and that is capable of adjusting a holding position of the biasing member relative to the housing.

2. The steering input device according to claim 1, The guide member and the housing are fastened together by bolts, a bolt insertion hole that penetrates the housing in a radial direction of the shaft and accommodates a head and a base of the bolt; The steering input device, wherein the bolt insertion hole is an elongated hole having a long length along the axial direction of the shaft.

3. The steering input device according to claim 2, The housing is formed in a cylindrical shape with a bottom, The steering input device, wherein the second seating surface is formed on a bottom wall of the housing.

4. The steering input device according to claim 3, a steering input device, wherein the biasing member includes a first biasing member and a second biasing member that is attached in a preloaded state and applies a biasing force after the first biasing member applies a biasing force.

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