York cover

Abstract

To provide a yoke cover capable of preventing the peripheral edge of the end face on the opposite side to a pair of yoke arm parts in the axial direction, out of a yoke base part as part of a yoke, from contacting an arm or leg of a human.SOLUTION: A yoke cover 1 includes a first cover plate part 29, and a pair of second cover plate parts 30a, 30b having base ends oscillatably connected to the ends on both cross sides of the first cover plate part 29 for enabling the movement of the front ends away from and close to each other on the basis of oscillation. The front ends of the pair of second cover plate parts 30a, 30b are moved close to each other for engaging each other to actualize a closed state that the first cover plate part 29 and the pair of second cover plate parts 30a, 30b take a cylindrically connected body form and an arrangement space is formed radially inside, and the front ends of the pair of second cover plate parts 30a, 30b are moved away from each other to actualize an opened state that the arrangement space is opened. In the closed state, an other axial side portion of a yoke base part 14 is arranged in the arrangement space.SELECTED DRAWING: Figure 6

Description

Technical Field

[0005]

[0001] The present invention relates to a yoke cover that covers a yoke constituting a universal joint incorporated in a steering device for an automobile.

Background Art

[0002] In a steering device for an automobile, respective end portions of a steering shaft and an intermediate shaft that are not arranged on the same straight line are connected by a universal joint. Among the yokes constituting the universal joint, as a rear yoke coupled to the front end portion of the steering shaft, for example, a pinch bolt type yoke made of a metal material and manufactured by performing forging and cutting processes is used.

[0003] The yoke includes a yoke base portion and a pair of yoke arm portions. The yoke base portion has an inner peripheral surface that fits with the outer peripheral surface of the tip portion of the shaft and is configured in a cylindrical shape. The pair of yoke arm portions extend from two locations on the opposite side in the radial direction of the end portion on one axial side of the yoke base portion to one axial side of the yoke base portion. Further, the yoke base portion has a slit that opens on both sides in the radial direction and on the other axial side at one location in the circumferential direction, a pair of yoke flange portions facing each other with the slit interposed therebetween, and a pair of bolt holes penetrating the pair of yoke flange portions.

[0004] When coupling the front end portion of the steering shaft to such a yoke, the front end portion of the steering shaft is inserted into the inside of the yoke base portion from the other axial side of the yoke base portion. Then, by tightening bolts inserted or screwed into the pair of bolt holes, the inner peripheral surface of the yoke base portion is reduced in diameter, and the inner peripheral surface is pressed against the outer peripheral surface of the front end portion of the steering shaft.

[0005] Conventionally, various structures of yoke covers have been proposed for assembling the tip portion of the shaft to the yoke in a normal positional relationship (see, for example, Japanese Patent Application Laid-Open No. 2008-202742, Japanese Patent Application Laid-Open No. 2009-108875, and Japanese Patent No. 5223914). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2008-202742 [Patent Document 2] Japanese Patent Publication No. 2009-108875 [Patent Document 3] Patent No. 5223914 [Overview of the project] [Problems that the invention aims to solve]

[0007] In passenger car steering systems, the universal joint connecting the steering shaft and the intermediate shaft is usually located inside the steering column's under cover and is not exposed to the passenger compartment. Therefore, this universal joint does not come into contact with, for example, the driver's feet or with people's hands during cleaning of the passenger compartment.

[0008] In contrast, in steering systems for commercial vehicles, the universal joint connecting the steering shaft and the intermediate shaft is sometimes positioned exposed on the passenger side. In recent years, in such cases, it has been proposed to adequately prevent the driver's foot or other body parts from coming into contact with the corners on the periphery of the other end face of the yoke base of the rear yoke, which is coupled to the front end of the steering shaft.

[0009] One possible preventative measure is to use a yoke cover that is assembled to the yoke. However, conventional yoke covers have a structure specifically designed to prevent incorrect assembly of the shaft end to the yoke, and do not have a structure that can adequately prevent the driver's foot or other body parts from coming into contact with the corners on the periphery of the other end face on the axial side of the yoke base. In other words, when a conventional yoke cover is assembled to the yoke, at least a portion of the corners on the periphery of the other end face on the axial side of the yoke base is exposed to the outside of the yoke cover.

[0010] The present invention aims to provide a yoke cover that can prevent the peripheral edge of the end face opposite to the pair of yoke arms in the axial direction from coming into contact with a person's hands, feet, or other body parts. [Means for solving the problem]

[0011] A yoke for a universal joint to which a yoke cover according to one aspect of the present invention is assembled comprises a cylindrical yoke base having an inner circumferential surface that fits with the outer circumferential surface of the tip of a shaft, and a pair of yoke arms extending from two locations on the radially opposite side of one axial end of the yoke base to the axial side of the yoke base, wherein the yoke base has a slit that opens on both radial sides and the other axial side at one location in the circumferential direction, a pair of yoke flanges facing each other on either side of the slit in the other axial portion, and a pair of bolt holes passing through the pair of yoke flanges, wherein the shafts of bolts are inserted through or screwed into the pair of bolt holes, and the heads of the bolts abut against the widthwise outer surface of one of the yoke flanges constituting the pair of yoke flanges, which is part of the outer circumferential surface of the other axial portion of the yoke base.

[0012] A yoke cover according to one aspect of the present invention comprises a first cover plate portion and a pair of second cover plate portions, the base ends of which are pivotably connected to the ends on both sides in the width direction of the first cover plate portion, and the tip portions of which can be moved toward and toward each other based on the pivoting. The yoke cover can be in a closed state in which the first cover plate portion and the pair of second cover plate portions are connected in a cylindrical shape by bringing the tip portions of the pair of second cover plate portions closer together and engaging them, thereby creating a space for arrangement radially inward, and an open state in which the tip portions of the pair of second cover plate portions are moved apart from each other to open the space for arrangement. In the closed state, the axial other side portion of the yoke base portion is arranged within the space for arrangement.

[0013] In one embodiment of the present invention, in the closed state, the first cover plate covers the circumferential portion of the outer circumferential surface of the other axial side portion of the yoke base located between the openings of the pair of bolt holes. The pair of second cover plate covers the remaining circumferential portion of the outer circumferential surface.

[0014] In one embodiment of the present invention, in the closed state, the first cover plate covers the radially outer surface of the pair of yoke flanges on the outer circumferential surface of the other axial side portion of the yoke base. The pair of second cover plate covers the remaining circumferential portion of the outer circumferential surface, i.e., the widthwise outer surface of the pair of yoke flanges and the portion that is circumferentially offset from the pair of yoke flanges.

[0015] In one embodiment of the present invention, in the closed state, the first cover plate covers the portion of the outer circumferential surface of the axially opposite portion of the yoke base that is circumferentially separated from the pair of yoke flange portions. The pair of second cover plate covers the remaining circumferential portion of the outer circumferential surface, i.e., the widthwise outer surface of the pair of yoke flange portions and the radially outer surface of the pair of yoke flange portions.

[0016] In one embodiment of the present invention, a yoke cover is provided with a stopper portion connected to at least one of the axial ends of the first cover plate portion. In the closed state, the stopper portion engages axially with a pair of overhangs of the pair of yoke flange portions that protrude radially outward from one axial side portion of the yoke base portion.

[0017] A yoke cover according to one aspect of the present invention includes a slit entry portion connected to the first cover plate portion and entering the slit in the closed state. The slit entry portion opens radially inward from the yoke base portion and has a notched bolt engagement portion that engages with the shaft portion.

[0018] In one embodiment of the present invention, in a yoke cover, of the pair of second cover plate portions, the second cover plate portion that is positioned on the head side with respect to the axial direction of the bolt has a head insertion portion into which the head is inserted.

[0019] In one embodiment of the present invention, the inner side in the width direction of the head insertion portion in the closed state has a concave shape into which the head is inserted, and the outer side in the width direction of the head insertion portion in the closed state has a convex shape.

[0020] In one embodiment of the present invention, the yoke cover of the pair of second cover plate portions, the second cover plate portion located on the opposite side of the bolt head with respect to the axial direction of the bolt, has a protrusion insertion portion into which a protrusion is inserted. This protrusion is formed by a boss portion and / or the tip of the shaft portion protruding from the bolt hole on the outer widthwise surface of the other yoke flange portion of the pair of yoke flange portions, which is part of the outer peripheral surface of the other axial side portion of the yoke base, or by the tip of the shaft portion and a nut that is screwed onto the tip and contacts the outer widthwise surface of the other yoke flange portion.

[0021] In the yoke cover according to one aspect of the present invention, the inner side in the width direction in the closed state of the convex portion insertion portion has a concave shape into which the convex portion is inserted, and the outer side in the width direction in the closed state of the convex portion insertion portion has a convex shape.

[0022] In the yoke cover according to one aspect of the present invention, each of the first cover plate portion and the pair of second cover plate portions has a shape along the circumferential direction with respect to the outer peripheral surface of the other axial side portion of the yoke base portion in the closed state.

[0023] The present invention can be implemented by appropriately combining the configurations of the yoke covers of each of the above-described aspects within a range where no contradiction occurs.

Effects of the Invention

[0024] According to the yoke cover of one aspect of the present invention, it is possible to prevent the peripheral edge portion of the end surface on the opposite side of the pair of yoke arm portions in the axial direction among the yoke base portions constituting the yoke from being touched by a person's hand or foot.

Brief Description of the Drawings

[0025] [Figure 1] FIG. 1 is a diagram schematically showing a steering device to which a yoke cover according to a first example of an embodiment of the present invention is assembled. [Figure 2] FIG. 2 is a perspective view of a yoke with a first example of a yoke cover and bolts assembled thereto as viewed from one axial side. [Figure 3] FIG. 3 is a perspective view of a yoke with a first example of a yoke cover and bolts assembled thereto as viewed from the opposite side of FIG. 2. [Figure 4] FIG. 4(a) is a side view of a yoke with a first example of a yoke cover and bolts assembled thereto, and FIG. 4(b) is a side view of the yoke as viewed from the opposite side of FIG. 4(a). [Figure 5] FIG. 5(a) is a view as viewed from above FIG. 4(a), and FIG. 5(b) is a view as viewed from below FIG. 4(a). [Figure 6]Figure 6(a) is a cross-sectional view of AA in Figure 4(a), and Figure 6(b) is a view of Figure 4(a) from the right side (the other side in the axial direction). [Figure 7] Figure 7 is a perspective view of the first example of the yoke cover, viewed from one side in the axial direction. [Figure 8] Figure 8 is a perspective view showing the yoke cover of the first example unfolded. [Figure 9] Figure 9(a) is a plan view showing the yoke cover of the first example unfolded, and Figure 9(b) is a view of the yoke cover from below Figure 9(a). [Figure 10] Figure 10 is a diagram relating to a second embodiment of the present invention, corresponding to the left half of Figure 3. [Figure 11] Figure 11 is a diagram relating to a third embodiment of the present invention, corresponding to the left half of Figure 3. [Modes for carrying out the invention]

[0026] [Example 1] A first example of an embodiment of the present invention will be described with reference to Figures 1 to 9(b).

[0027] Figure 1 is a schematic diagram showing the steering device 2 for an automobile to which the yoke cover 1 (see Figures 2 to 6(b)) of this example is assembled.

[0028] In the following explanation in this example, the front-rear direction refers to the front-rear direction of the vehicle, the up-down direction refers to the up-down direction of the vehicle, and the left-right direction refers to the width direction of the vehicle.

[0029] The steering device 2 in this example comprises a steering wheel 3, a steering shaft 4, a steering column 5, a pair of universal joints 6a and 6b, an intermediate shaft 7, and a steering gear unit 8.

[0030] The steering wheel 3, which is rotated by the driver, is attached to the rear end of the steering shaft 4. The steering shaft 4 is rotatably supported inside the steering column 5, which is supported by the vehicle body. The front end of the steering shaft 4 is connected to the pinion shaft 9 of the steering gear unit 8 via a universal joint 6a, an intermediate shaft 7, and another universal joint 6b. The pinion shaft 9 meshes with the rack 10 of the steering gear unit 8. Therefore, when the driver rotates the steering wheel 3, the rotation of the steering wheel 3 is transmitted to the pinion shaft 9. The rotation of the pinion shaft 9 is then converted into linear motion of the rack 10. As a result, a pair of tie rods 11 connected to both ends of the rack 10 are pushed and pulled, and a steering angle corresponding to the amount of rotation of the steering wheel 3 is applied to the left and right steering wheels 12.

[0031] Although not shown in the diagram, the steering device 2 can provide assist driving force from an electric or hydraulic assist device to any of the steering force transmission members, such as the steering shaft 4, pinion shaft 9, or rack 10, in order to reduce the force required to rotate the steering wheel 3.

[0032] In this example, the yoke cover 1 is assembled to one of the yokes 13 that constitute the universal joint 6a, specifically the yoke 13 connected to the front end of the steering shaft 4. The universal joint 6a is constructed by connecting one yoke 13 and the other yoke (not shown) connected to the rear end of the intermediate shaft 7 via a cross shaft (not shown).

[0033] In the following description of the yoke 13 and yoke cover 1, one axial side is the left side in Figures 4(a), 5(a), and 5(b), and the other axial side is the right side in these figures.

[0034] As shown in Figures 2 to 6(b), the yoke 13 in this example is manufactured by forging and machining a metal material and comprises a cylindrical yoke base 14 and a pair of yoke arms 15. The pair of yoke arms 15 extend from two locations on the radially opposite side of one axial end of the yoke base 14, toward one axial side of the yoke base 14. Each of the yoke arms 15 has a circular hole 16 at its tip that is arranged coaxially with respect to the other. The ends of the cross shaft are rotatably supported inside these circular holes 16 via needle bearings.

[0035] The yoke base 14 has an inner circumferential surface 18 that fits with the outer circumferential surface 17 of the front end, which is the tip of the steering shaft 4 (see Figures 4(a) and 4(b)). In this example, male serrations are formed on the outer circumferential surface 17 of the front end of the steering shaft 4, and female serrations that can engage with the male serrations are formed on the inner circumferential surface 18 of the yoke base 14.

[0036] The yoke base 14 has a slit 19 at one circumferential location on the other half of the axial side, which opens on both the radial side and the other axial side.

[0037] The yoke base 14 has a pair of yoke flange portions 20a and 20b facing each other across the slit 19. The pair of yoke flange portions 20a and 20b have a pair of overhangs 21a and 21b on their radially outer portions that extend radially outward from one axial half of the yoke base 14.

[0038] The yoke base 14 has a pair of bolt holes 22a, 22b that pass through a pair of yoke flange portions 20a, 20b. One bolt hole 22a that passes through one yoke flange portion 20a (lower side in Figure 5(b), left side in Figure 6(a), and right side in Figure 6(b)), and the other bolt hole 22b that passes through the other yoke flange portion 20b (upper side in Figure 5(b), right side in Figure 6(a), and left side in Figure 6(b)) are arranged coaxially with each other. At least a portion of the pair of bolt holes 22a, 22b is formed in a pair of protruding portions 21a, 21b, and is located radially outward from one axial half of the yoke base 14. In this example, one bolt hole 22a is configured as a through hole for inserting the shaft portion 24 of the bolt 23. The other bolt hole 22b is configured as a female threaded hole for screwing the shaft portion 24 of the bolt 23.

[0039] Of the outer surface of one yoke flange portion 20a, which is a part of the outer surface of the other axial portion of the yoke base portion 14, the portion around the opening of one bolt hole 22a is used as a seating surface for the inner surface of the head 25 of the bolt 23 to abut against. The other yoke flange portion 20b has a cylindrical boss portion 26 on its outer surface in the width direction, which protrudes more in the axial direction of the bolt hole 22b than the other portion.

[0040] As the yoke to which the yoke cover of the present invention is attached, a yoke can be used in which each of the bolt holes constituting a pair of bolt holes is configured as a through hole. In this case, a boss portion is not provided on the outer surface of the other yoke flange in the width direction, around the opening of the other bolt hole, and a nut is screwed onto the tip of the bolt shaft portion protruding from the other bolt hole. The outer surface of the other yoke flange in the width direction, around the opening of the other bolt hole, is used as a seating surface for which the inner surface of the nut abuts. As the yoke to which the yoke cover of the present invention is attached, a yoke can also be used in which the phase of the arrangement of the pair of yoke arms of the yoke base in the circumferential direction is shifted by an arbitrary angle (for example, about 90°) with respect to the yoke 13 of this example.

[0041] With the front end of the steering shaft 4 (see Figures 4(a) and 4(b)) connected to the yoke 13, the front end of the steering shaft 4 is inserted into the inside of the yoke base 14 from the other axial side of the yoke base 14. A notched bolt engagement portion 27 is provided at one location in the circumferential direction on the outer surface of the front end of the steering shaft 4 and is positioned to align with a pair of bolt holes 22a and 22b. The shaft portion 24 of a bolt 23 is inserted through or screwed into the pair of bolt holes 22a and 22b. Specifically, the shaft portion 24 of a bolt 23 inserted through one bolt hole 22a is screwed into the other bolt hole 22b. The middle portion of the shaft portion 24 engages with the bolt engagement portion 27. This prevents the front end of the steering shaft 4 from coming out axially from the inside of the yoke base 14. The bolt 23 is tightened with the inner surface of the head 25 of the bolt 23 in contact with the widthwise outer surface of one of the yoke flange portions 20a. As a result, the inner circumferential surface 18 of the yoke base 14 is reduced in diameter, and this inner circumferential surface 18 is pressed against the outer circumferential surface 17 of the front end of the steering shaft 4. Specifically, the female serrations on the inner circumferential surface 18 are strongly engaged with the male serrations on the outer circumferential surface 17. This connects the front end of the steering shaft 4 to the yoke 13 in a way that allows for torque transmission.

[0042] Furthermore, in this state, as shown in Figures 5(a), 5(b), 6(a), and 6(b), the tip of the shaft portion 24 of the bolt 23 protrudes slightly outside the boss portion 26. In this example, the boss portion 26 and the tip of the shaft portion 24 constitute the convex portion 28. When implementing the present invention, the boss portion 26 can be omitted, and the convex portion can be formed by the tip of the shaft portion 24 protruding from the other bolt hole 22b. Furthermore, when implementing the present invention, as described above, if a configuration in which a nut is screwed onto the tip of the bolt shaft portion is adopted, the tips of these shaft portions and the nut constitute the convex portion.

[0043] The yoke cover 1 in this example is attached to the yoke 13, as shown in Figures 2 to 6(b). Figures 7 to 9(b) show the yoke cover 1 in this example in its standalone state.

[0044] The yoke cover 1 in this example is entirely made of synthetic resin or synthetic rubber. The yoke cover 1 comprises a first cover plate portion 29 and a pair of second cover plate portions 30a and 30b, the base ends of which are pivotably connected to the ends on both sides of the first cover plate portion 29 in the width direction (left and right direction in Figures 9(a) and 9(b)), and whose respective tip portions can be moved toward and away from each other based on this pivoting. The yoke cover 1 can be configured in two states: a closed state (see Figure 7) in which the first cover plate portion 29 and the pair of second cover plate portions 30a and 30b are connected in a cylindrical shape, forming an inward space S radially, by bringing the ends of the pair of second cover plate portions 30a and 30b closer together and engaging them, and an open state (see Figures 8 to 9(b)) in which the ends of the pair of second cover plate portions 30a and 30b are moved further apart, opening the space S. The yoke cover 1 is attached to the yoke 13 in the closed state, as shown in Figures 2 to 6(b). In this state, the axial other side portion of the yoke base portion 14 (including the axial other side end face 31) is positioned within the space S.

[0045] In this example, the first cover plate portion 29 has a rectangular flat plate shape, as shown in Figures 8 to 9(b).

[0046] One of the second cover plate portions 30a has a flat, straight portion 32a on the base end half, which is closer to the first cover plate portion 29. The base end of the straight portion 32a is pivotably connected to one end of the first cover plate portion 29 in the width direction (the left side in Figures 9(a) and 9(b)) by any structure. In this example, by bending the connection between the base end of the straight portion 32a and one end of the first cover plate portion 29 in the width direction, in other words, by making the connection function as a hinge, it is possible to pivot one of the second cover plate portions 30a relative to the first cover plate portion 29. In this example, the thickness of the connection is the same as the thickness of the first cover plate portion 29 and one of the second cover plate portions 30a. When implementing the present invention, the thickness of the connection can be made smaller than the thickness of the first cover plate portion and one of the second cover plate portions to make the connection easier to bend.

[0047] One of the second cover plate portions 30a has a partially cylindrical curved portion 33a in the tip half, which is the side furthest from the first cover plate portion 29, such that the inner surface (upper surface in Figures 8 and 9(b)) which is positioned radially inward in the closed state (see Figure 7) is concave.

[0048] One of the second cover plate portions 30a has flange portions 34a that are bent at a right angle toward the inner surface at both axial ends of the straight portion 32a and curved portion 33a which are continuous with each other. The one of the second cover plate portions 30a is reinforced by these flange portions 34a.

[0049] One of the second cover plate portions 30a has a head insertion portion 35 located approximately in the center of the straight portion 32a into which the head 25 of the bolt 23 is inserted. When the head insertion portion 35 is closed, the inner side in the width direction, i.e., the inner surface side, has a concave shape into which the head 25 is inserted, and when the head insertion portion 35 is closed, the outer side in the width direction, i.e., the outer surface side, has a convex shape. In this example, such a head insertion portion 35 is configured as a bottomed cylindrical shape (a bottomed cone shape in the illustrated example).

[0050] One of the second cover plate portions 30a is provided with a one-sided engaging portion 36 at the axial center of the tip of the curved portion 33a. The one-sided engaging portion 36 is positioned to protrude radially outward from the curved portion 33a. The one-sided engaging portion 36 has a snap-fit ​​piece 37 that protrudes more than the tip surface of the curved portion 33a in the direction normal to the tip surface.

[0051] The other second cover plate portion 30b has a flat, straight portion 32b on the base end half, which is closer to the first cover plate portion 29. Similar to the first second cover plate portion 30a, the base end of the straight portion 32b is pivotably connected to the end of the first cover plate portion 29 on the other side in the width direction (the right side in Figures 9(a) and 9(b)).

[0052] The other second cover plate portion 30b has a partially cylindrical curved portion 33b in the tip half, which is the side furthest from the first cover plate portion 29, such that the inner surface (upper surface in Figures 8 and 9(b)) which is radially inward in the closed state (see Figure 7) is concave.

[0053] The other second cover plate portion 30b has flange portions 34b that are bent at a right angle toward the inner surface at both axial ends of the mutually continuous straight portion 32b and curved portion 33b. The other second cover plate portion 30b is reinforced by these flange portions 34b.

[0054] The other second cover plate portion 30b has a protrusion insertion portion 38 located approximately in the center of the straight portion 32b into which the protrusion 28 is inserted. When the protrusion insertion portion 38 is closed, the inner side in the width direction, i.e., the inner surface side, has a concave shape into which the protrusion 28 is inserted, and when the protrusion insertion portion 38 is closed, the outer side in the width direction, i.e., the outer surface side, has a convex shape. In this example, such a protrusion insertion portion 38 is configured as a bottomed cylindrical shape (a bottomed cone shape in the illustrated example).

[0055] The other second cover plate portion 30b is provided with a other-side engaging portion 39 at the axial center of the tip of the curved portion 33b. The other-side engaging portion 39 is positioned to protrude radially outward from the curved portion 33b. The other-side engaging portion 39 has a through hole 40 through which a snap-fit ​​piece 37 can be inserted.

[0056] One-sided engaging portion 36 and the other-sided engaging portion 39 are mutually reciprocal. To engage the one-sided engaging portion 36 and the other-sided engaging portion 39, the snap-fit ​​piece 37 of the one-sided engaging portion 36 is inserted through the through-hole 40 of the other-sided engaging portion 39, and the claws provided at the tip of the snap-fit ​​piece 37 protruding from the through-hole 40 are engaged with the opening periphery of the through-hole 40. To disengage the one-sided engaging portion 36 and the other-sided engaging portion 39, the claws of the snap-fit ​​piece 37 are disengaged from the opening periphery of the through-hole 40, and the snap-fit ​​piece 37 is removed from the through-hole 40.

[0057] The yoke cover 1 in this example further comprises a pair of stopper portions 41. The pair of stopper portions 41 are connected to the ends of the first cover plate portion 29 at both axial ends. More specifically, the pair of stopper portions 41 are flat plates that are bent at a right angle from both axial ends of the first cover plate portion 29 toward the inner surface (upper surface in Figures 8 and 9(b)) of the first cover plate portion 29, which is located radially inward in the closed state (see Figure 7). When implementing the present invention, any shape can be adopted for each of the stopper portions constituting the pair of stopper portions. When implementing the present invention, at least one of the pair of stopper portions can be omitted.

[0058] The yoke cover 1 in this example further includes a slit entry portion 42. The slit entry portion 42 is connected to the first cover plate portion 29. More specifically, the slit entry portion 42 is connected to the center of the inner surface of the first cover plate portion 29 in the width direction. The slit entry portion 42 is configured as a flat plate extending in the axial direction and in the direction normal to the inner surface. The ends on both sides of the slit entry portion 42 in the axial direction are connected to the center of a pair of stopper portions 41 in the width direction. The slit entry portion 42 has a notched bolt engagement portion 43 in the axial middle portion that opens towards the tip side, which is radially inward in the closed state (see Figure 7). When implementing the present invention, the slit entry portion may be omitted.

[0059] In the yoke cover 1 of this example, by swinging a pair of second cover plate portions 30a and 30b relative to the first cover plate portion 29, it is possible to move the tip of one second cover plate portion 30a and the tip of the other second cover plate portion 30b toward and away from each other.

[0060] As shown in Figures 8 to 7, the yoke cover 1 can be closed by swinging a pair of second cover plate portions 30a and 30b toward each other, so that the tips of the pair of second cover plate portions 30a and 30b abut each other, and by engaging one side engaging portion 36 with the other side engaging portion 39, the first cover plate portion 29, one second cover plate portion 30a, and the other second cover plate portion 30b are connected in a cylindrical shape, and an arrangement space S is formed radially inward.

[0061] As shown in Figures 7 to 8, the yoke cover 1 can be opened to open the arrangement space S by disengaging the engagement between one side engagement portion 36 and the other side engagement portion 39, thereby causing the pair of second cover plate portions 30a and 30b to swing in a direction in which their respective ends move away from each other.

[0062] When implementing the present invention, any structure can be adopted as the structure for removably engaging the tip portions of a pair of second cover plates.

[0063] In this example, when closed, the axial end of the yoke cover 1 does not have a sharp corner around its entire circumference when viewed from the axial side.

[0064] Specifically, in the closed state, the axial end of the yoke cover 1 on the other side has corners when viewed from the other side in the axial direction, i.e., in Figure 6(b), on both the left and right ends of the lower end. However, these corners are not sharp and have a large radius of curvature (R shape). The radius of curvature of the R shape is preferably 1.0 mm or more, and more preferably 2.5 mm or more.

[0065] At the other axial end of the yoke cover 1 in the closed state, the connection portion between the outer surface of one second cover plate portion 30a and the other axial side of the flange portion 34a, the connection portion between the outer surface of the other second cover plate portion 30b and the other axial side of the flange portion 34b, and the connection portion between the outer surface of the first cover plate portion 29 and the other axial side of the stopper portion 41 are each provided with an R-shaped chamfer. The radius of curvature of the R shape is preferably 1.0 mm or more, and more preferably 2.5 mm or more.

[0066] In this example, the front end of the steering shaft 4 can be connected to the yoke 13 using bolts 23, and then the yoke cover 1 can be assembled to the yoke 13.

[0067] When assembling the yoke cover 1 to the yoke 13, first, with the yoke cover 1 in the open state (see Figures 8 to 9(b)), the slit entry portion 42 is inserted into the slit 19, and the middle portion of the shaft portion 24 of the bolt 23 is engaged with the bolt engagement portion 43 of the slit entry portion 42. At the same time, a pair of stopper portions 41 are positioned to sandwich a pair of protruding portions 21a and 21b, which constitute a pair of yoke flange portions 20a and 20b, from both axial sides. Then, the first cover plate portion 29 covers the radial outer surface (lower surface in Figures 6(a) and 6(b)) of the pair of yoke flange portions 20a and 20b on the outer circumferential surface of the other axial side portion of the yoke base portion 14. The slit entry portion 42 does not protrude radially inward from the inner circumferential surface 18 of the yoke base portion 14.

[0068] In this example, in this state, the yoke cover 1 is positioned axially with respect to the yoke 13 based on the engagement of the bolt engagement portion 43 of the slit entry portion 42 with the shaft portion 24 of the bolt 23, and / or the axial engagement of a pair of stopper portions 41 and a pair of protruding portions 21a and 21b. Furthermore, the first cover plate portion 29 is positioned radially with respect to the yoke 13 based on the contact of the inner surface of the first cover plate portion 29 and / or the tip of one of the pair of stopper portions 41 on the axial side with respect to the radially outer surface of the pair of yoke flange portions 20a and 20b.

[0069] Next, by swinging the pair of second cover plate portions 30a and 30b toward each other, the head 25 of the bolt 23 is inserted into the concave portion of the head insertion portion 35, and the convex portion 28 is inserted into the concave portion of the convex portion insertion portion 38. At the same time, the tips of the pair of second cover plate portions 30a and 30b are brought together, and the engagement portion 36 on one side and the engagement portion 39 on the other side are engaged, thereby closing the yoke cover 1. As a result, as shown in Figures 2 to 6(b), the axial other side portion of the yoke base 14 (including the axial other side end face 31) is positioned within the arrangement space S of the yoke cover 1.

[0070] In this example, in the closed state, the pair of second cover plates 30a and 30b cover the remaining circumferential portion of the outer circumferential surface of the other axial side portion of the yoke base 14 (= the circumferential portion that is away from the radially outer surface of the pair of yoke flange portions 20a and 20b covered by the first cover plate 29), specifically the widthwise outer surface of the pair of yoke flange portions 20a and 20b, and the portion that is circumferentially away from the pair of yoke flange portions 20a and 20b.

[0071] In other words, one second cover plate portion 30a covers the remaining circumferential portion of the outer surface of the other axial portion of the yoke base portion 14, specifically the half on the head 25 side with respect to the axial direction of the bolt 23 (the portion to the left of the dashed line α in Figure 6(a), and the portion to the right of the dashed line α in Figure 6(b)). Specifically, the straight portion 32a of one second cover plate portion 30a covers the flat surface portion of the aforementioned half, which is the outer surface in the width direction of one yoke flange portion 20a. The curved portion 33a of one second cover plate portion 30a covers the cylindrical convex surface portion of the aforementioned half, which is located further from the slit 19 than the flat surface portion with respect to the circumferential direction. The head insertion portion 35 covers the head 25.

[0072] In contrast, the other second cover plate portion 30b covers the remaining circumferential portion of the outer circumferential surface of the axially opposite portion of the yoke base portion 14, specifically the half opposite to the head 25 with respect to the axial direction of the bolt 23 (the portion to the right of the dashed line α in Figure 6(a), and the portion to the left of the dashed line α in Figure 6(b)). Specifically, the straight portion 32b of the other second cover plate portion 30b covers the flat surface portion of the other half, which is the outer surface in the width direction of the other yoke flange portion 20b. The curved portion 33b of the other second cover plate portion 30b covers the cylindrical convex surface portion of the other half, which is located further from the slit 19 than the flat surface portion with respect to the circumferential direction. The convex insertion portion 38 covers the convex portion 28.

[0073] In this example, when the pair of second cover plates 30a and 30b are closed, the tips of the flange portions 34a and 34b located at one axial end of the pair of second cover plates 30a and 30b each abut against the cylindrical convex surface of the outer circumferential surface of the yoke base 14, thereby positioning the pair of second cover plates 30a and 30b radially with respect to the yoke 13.

[0074] In other words, in this example, when closed, the yoke cover 1 is fitted onto the axial side portion of the yoke base 14 without any rattling.

[0075] In this example, the first cover plate portion 29 and the pair of second cover plate portions 30a and 30b each have a shape that, when closed, is aligned circumferentially with respect to the outer peripheral surface of the other axial portion of the yoke base portion 14, as shown in Figures 6(a) and 6(b).

[0076] To remove the yoke cover 1 from the yoke 13, the engagement between one side engagement portion 36 and the other side engagement portion 39 is released, and the pair of second cover plate portions 30a and 30b are swung in a direction away from each other. This opens the yoke cover 1, allowing it to be removed from the yoke 13.

[0077] When implementing the present invention, in the closed state of the yoke cover, it can be arbitrarily determined which portion of the outer circumferential surface of the axially opposite portion of the yoke base is covered by the first cover plate portion and the pair of second cover plate portions. For example, when implementing the present invention, the portion of the outer circumferential surface of the axially opposite portion of the yoke base that is circumferentially separated from the pair of yoke flange portions can be covered by the first cover plate portion, and the remaining circumferential portion of the outer circumferential surface, which is the widthwise outer surface of the pair of yoke flange portions and the radially outer surface of the pair of yoke flange portions, can be covered by the pair of second cover plate portions.

[0078] According to the yoke cover 1 in this example, it is possible to prevent the corner portion 44 (see Figures 4 to 6) located on the periphery of the end face 31 on the other axial side of the yoke base 14 that constitutes the yoke 13 from coming into contact with a person's hands or feet.

[0079] In other words, in the manufacturing of the yoke 13, the end face 31 is finished by machining, so the corners 44 on the periphery of the end face 31 become sharp. Therefore, it is desirable to prevent such corners 44 from coming into contact with people's hands or feet. In this example, with the yoke cover 1 attached to the yoke 13, the axially opposite portion of the yoke base 14 (including the axially opposite end face 31) is positioned within the arrangement space S located radially inside the yoke cover 1. Therefore, the corners 44 on the periphery of the axially opposite end face 31 of the yoke base 14 are not exposed to the outside of the yoke cover 1. Thus, it is possible to prevent the corners 44 from coming into contact with people's hands or feet. Specifically, it is possible to prevent the corners 44 from coming into contact with the driver's feet or with people's hands when cleaning the interior of the vehicle.

[0080] In this example, when the yoke cover 1 is attached to the yoke 13 in the closed position, the axial end of the yoke cover 1 does not have a sharp corner. Therefore, safety can be ensured in case the driver's foot or other body part comes into contact with the axial end of the yoke cover 1.

[0081] The yoke cover 1 in this example is equipped with a head insertion portion 35 that covers the head 25 of the bolt 23. This prevents the driver's foot or other body parts from coming into contact with the head 25.

[0082] In this example, the yoke cover 1 is provided with a protrusion insertion portion 38 that covers the protrusion 28. This prevents the driver's foot or other body parts from coming into contact with the protrusion 28. When implementing the present invention, a cylindrical protrusion insertion portion without a bottom, or a protrusion insertion portion configured as a through hole penetrating the other second cover plate portion, can also be used.

[0083] In this example, with the yoke cover 1 attached to the yoke 13, the yoke cover 1 covers the radially outer opening of the slit 19 of the yoke 13. This prevents the driver's feet or other body parts from touching the radially outer opening edge of the slit 19. In other words, in the manufacturing of the yoke 13, the slit 19 is finished by machining, so the radially outer opening edge of the slit 19 becomes a sharp corner. The yoke cover 1 in this example prevents the driver's feet or other body parts from touching such corners.

[0084] The structure of this example has an engagement portion between the head 25 of the bolt 23 and the head insertion portion 35, an engagement portion between the protrusion 28 and the protrusion insertion portion 38, an engagement portion between a pair of protruding portions 21a and 21b and a pair of stopper portions 41, and an engagement portion between the intermediate portion of the shaft portion 24 of the bolt 23 and the bolt engagement portion 43 of the slit entry portion 42. Based on each of these engagement portions, axial movement of the yoke cover 1 relative to the yoke 13 can be prevented.

[0085] In this example, the first cover plate portion 29 and the pair of second cover plate portions 30a and 30b each have a shape that, when closed, conforms to the circumferential direction with respect to the outer peripheral surface of the other axial side portion of the yoke base portion 14. Therefore, the yoke cover 1 can be made compact when closed.

[0086] [Example 2] A second example of an embodiment of the present invention will be described with reference to Figure 10.

[0087] In this example, the head insertion portion 35a that constitutes the yoke cover 1a is configured in a conical or cylindrical shape. In this example, since the head insertion portion 35a is positioned around the head 25 of the bolt 23, it is possible to effectively prevent the driver's foot or other body parts from hitting the head 25.

[0088] In this example, even after the yoke cover 1a is assembled to the yoke 13, the head 25 of the bolt 23 can be visually inspected from outside the yoke cover 1a through the opening of the head insertion portion 35a. Therefore, when performing pre-shipment inspections of vehicles, it is possible to visually check from outside the yoke cover 1a whether any bolts 23 have been forgotten during assembly. The other configurations and effects are the same as in the first example.

[0089] [Example 3] A third embodiment of the present invention will be described with reference to Figure 11.

[0090] In this example, the head insertion portion 35b that constitutes the yoke cover 1b is made up of a through hole that penetrates one of the second cover plate portions 30a. In this example, with the yoke cover 1b assembled to the yoke 13, the head 25 of the bolt 23 protrudes to the outside of the yoke cover 1b through the head insertion portion 35b. Therefore, when performing pre-shipment inspections of the vehicle, it is possible to visually check from the outside of the yoke cover 1a whether any bolts 23 have been left in place.

[0091] Furthermore, in the structure of this example, since the head 25 of the bolt 23 protrudes outside the yoke cover 1b through the head insertion portion 35b, the front end of the steering shaft can also be connected to the yoke 13 using the bolt 23 after the yoke cover 1b has been assembled to the yoke 13. The other configurations and effects are the same as in the first example. [Explanation of Symbols]

[0092] 1, 1a, 1b Yoke cover 2. Steering system 3. Steering Wheel 4. Steering shaft 5. Steering column 6a, 6b Universal joint 7 Intermediate shaft 8. Steering Gear Unit 9 Pinion shaft 10 racks 11 Tie Rod 12 Steering wheels 13 York 14 Yoke base 15. Yoke Arm 16 circular hole 17 Outer surface 18 Inner surface 19 slits 20a, 20b Yoke flange section 21a, 21b Overhang 22a, 22b Bolt holes 23 volts 24 Shaft section 25 Head 26 Boss Section 27 Bolt engagement part 28 Convex part 29. First cover plate section 30a, 30b Second cover plate section 31 End face 32a, 32b Straight section 33a, 33b Curved section 34a, 34b Tsuba 35, 35a, 35b Head insertion section 36 One-sided engagement portion 37 snap-fit ​​pieces 38 Convex insertion part 39 Other side engaging part 40 through hole 41 Stopper section 42 Slit entry section 43 Bolt engagement part 44 corners

Claims

1. A yoke cover for a universal joint, comprising a cylindrical yoke base having an inner circumferential surface that fits with the outer circumferential surface of the tip of a shaft, and a pair of yoke arms extending from two locations on the radially opposite side of one axial end of the yoke base toward one axial side of the yoke base, wherein the yoke base has a slit opening at one circumferential location on both radial sides and the other axial side, a pair of yoke flanges facing each other across the slit on the other axial side portion, and a pair of bolt holes passing through the pair of yoke flanges, the shafts of bolts being inserted through or screwed into the pair of bolt holes, and the heads of the bolts abutting against the widthwise outer surface of one of the pair of yoke flanges, which is part of the outer circumferential surface of the other axial side portion of the yoke base, The device comprises a first cover plate portion and a pair of second cover plate portions, the base ends of which are pivotably connected to the ends on both sides in the width direction of the first cover plate portion, and the tip portions of which can be moved toward and away from each other based on the pivoting motion. By bringing the tips of the pair of second cover plate portions closer together and engaging them, the first cover plate portion and the pair of second cover plate portions are connected in a cylindrical shape to form a cylindrical body, creating a closed state in which an arrangement space is formed radially inward, and an open state in which the tips of the pair of second cover plate portions are moved apart from each other to open the arrangement space. In the closed state, the other axial portion of the yoke base is positioned within the arrangement space. Yoke cover.

2. In the closed state, the first cover plate portion covers the circumferential portion of the outer circumferential surface of the other axial side portion of the yoke base portion located between the openings of the pair of bolt holes, and the pair of second cover plate portions covers the remaining circumferential portion of the outer circumferential surface, as described in claim 1.

3. The yoke cover according to claim 2, wherein the circumferential portion of the outer circumferential surface of the other axial portion of the yoke base located between the openings of the pair of bolt holes is the radially outer surface of the pair of yoke flanges.

4. At least one of the ends on both sides of the axial direction of the first cover plate portion is provided with a stopper portion connected to that end, In the closed state, the stopper portion engages axially with a pair of protruding portions of the pair of yoke flange portions that extend radially outward from one axial side portion of the yoke base. The yoke cover according to claim 3.

5. It is connected to the first cover plate portion and includes a slit entry portion that enters the slit in the closed state, The slit entry portion opens radially inward from the yoke base and has a notched bolt engagement portion that engages with the shaft portion. The yoke cover according to claim 3.

6. The yoke cover according to claim 2, wherein of the pair of second cover plate portions, the second cover plate portion positioned on the head side with respect to the axial direction of the bolt has a head insertion portion into which the head is inserted.

7. The yoke cover according to claim 6, wherein the inner side in the width direction of the head insertion portion in the closed state has a concave shape into which the head is inserted, and the outer side in the width direction of the head insertion portion in the closed state has a convex shape.

8. The yoke cover according to claim 2, wherein the second cover plate portion of the pair of second cover plate portions, which is positioned on the opposite side of the bolt head with respect to the axial direction of the bolt, has a boss portion that protrudes from the bolt hole in the outer widthwise surface of the other yoke flange portion of the pair of yoke flange portions, which is a part of the outer circumferential surface of the other yoke flange portion of the pair of yoke flange portions, and / or the tip of the shaft portion that protrudes from the bolt hole, or the tip of the shaft portion and a nut that is screwed onto the tip and contacts the outer widthwise surface of the other yoke flange portion.

9. The yoke cover according to claim 8, wherein the inner side in the width direction of the protrusion insertion portion in the closed state has a concave shape into which the protrusion is inserted, and the outer side in the width direction of the protrusion insertion portion in the closed state has a convex shape.

10. The yoke cover according to any one of claims 1 to 9, wherein each of the first cover plate portion and the pair of second cover plate portions has a shape that conforms to the circumferential direction with respect to the outer peripheral surface of the other axial side portion of the yoke base portion when in the closed state.

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