JP2016211633A - Yoke for universal joint and manufacturing method of yoke for universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yoke for a universal joint which can improve the rigidity of a female screw part while suppressing an increase of weight, and a manufacturing method of the yoke for a universal joint.SOLUTION: A first yoke 21 is fixed to the other end 3a of a steering shaft 3. The first yoke 21 comprises a first fastening plate 60 and a second fastening plate 70 which are extended in an axial orthogonal direction R from both-side portions 50a of a slit 51 which extends in an axial direction X of the steering shaft 3, oppose each other with the slit 51 sandwiched therebetween, and fasten the steering shaft 3 via a cylindrical part 50. A first hole 61 which penetrates the first fastening plate in a plate thickness direction is formed at the first fastening plate 60, and a second hole 71 which penetrates the second fastening plate 70 in a plate thickness direction D, and has a female screw part 72 at an internal peripheral face is formed at the second fastening plate 70. The second fastening plate 70 includes a heavy thickness part 74 at least at a peripheral edge 73 of the second hole 71, and a plate thickness T2 of the second fastening plate 70 is thicker than a plate thickness T1 of the first fastening part 60.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a universal joint yoke and a method for manufacturing the universal joint yoke.

  The universal joint yoke described in Patent Document 1 below includes a base end portion to which a shaft is coupled, and a pair of holding plate portions that are spaced apart from each other at the base end portion. A screw hole is provided at the opening side end of one holding plate. A through hole having a diameter larger than that of the screw hole is provided substantially concentrically with the screw hole at the opening side end of the other holding plate. Inserting the holding bolt through the hole, screwing the male threaded part formed at the tip of the holding bolt into the screw hole and tightening, the distance between the inner surfaces of the pair of holding plate parts is narrowed, and the tip of the shaft is the base end Fixed to the part.

  By the way, the universal joint yoke can be formed by press-molding a processed plate material such as a metal plate, as described in Patent Document 2 or 3 below.

JP 2006-29343 A JP 2011-220500 A JP 2002-66677 A

  In the universal joint yoke described in Patent Document 1, when the strength of the female thread portion of the screw hole of one retaining plate portion that is screwed with the male thread portion of the retaining bolt is insufficient, the tip portion of the shaft is connected to the universal joint yoke. It cannot be bonded and fixed with appropriate strength to the base end portion of the. In order to improve the strength of the female threaded portion, it is necessary to increase the number of threads of the female threaded portion to be screwed with the male threaded portion to reduce the shear stress that can be received per thread of the female threaded portion.

When forming a yoke by pressing a metal plate as in Patent Document 2 or 3, it is necessary to use a metal plate with a large plate thickness in order to increase the number of threads of the female screw portion, but this is free There is a possibility that the weight of the entire joint yoke increases.
An object of the present invention is to provide a universal joint yoke capable of improving the strength of the internal thread portion while suppressing an increase in weight and a method for manufacturing the universal joint yoke.

  The invention according to claim 1 is a universal joint yoke (21, 22) fixed to the end (3a, 4a, 4b, 5a) of the shaft (3, 4, 5), wherein the axial direction of the shaft A cylindrical portion (50) for fixing the shaft, which is formed with a slit (51) extending in (X), and a portion (50a) on both sides of the slit in the cylindrical portion, is extended in the direction perpendicular to the axis (R). And a first fastening plate (60) and a second fastening plate (70) that are opposed to each other with the slit interposed therebetween and fasten the shaft via the cylindrical portion, and the first fastening plate includes A first hole (61) is formed through the first clamping plate in the thickness direction (D), and the second clamping plate penetrates the second clamping plate in the thickness direction. A second hole (71) provided with an internal thread portion (72) on the inner periphery is formed, and the second fastening plate is at least in front The peripheral portion (73) of the second hole includes a thick portion (74; 74P; 74Q), and the plate thickness (T2; T2P; T2Q) of the second fastening plate is the thickness of the first fastening plate. This is a universal joint yoke thicker than (T1).

The invention according to claim 2 is the universal joint yoke according to claim 1, which is formed by press-molding the metal plate (80).
A third aspect of the present invention is the universal joint yoke according to the first or second aspect, wherein the thick portion includes a cylindrical protrusion (88; 88P; 88Q).
A fourth aspect of the present invention is the universal joint yoke according to the third aspect, wherein the cylindrical protrusion includes an inclined portion (75) inclined with respect to the plate thickness direction of the second fastening plate.

  Invention of Claim 5 is a manufacturing method of the yoke for universal joints of Claim 3 or 4, Comprising: The process of forming the said cylindrical projection part in the 2nd clamping board (81) of a manufacture stage, A drilling step for forming a through hole (85; 85P; 85Q) penetrating the cylindrical protrusion in the plate thickness direction, and an inner diameter portion (86; 86P; 86Q) of the through hole formed in the drilling step And a threading step of forming the second hole by processing the female thread portion.

  In addition, in the above, the numbers in parentheses represent reference numerals of corresponding components in the embodiments described later, but the scope of the claims is not limited by these reference numerals.

According to the first aspect of the present invention, the thickness of the second fastening plate is made thicker than the thickness of the first fastening plate by the thick portion of the peripheral portion of the second hole provided with the female screw portion. ing. For this reason, the number of threads of the female screw portion can be increased, so that the strength of the female screw portion can be ensured. Therefore, the strength of the female screw portion can be improved while suppressing an increase in weight.
According to invention of Claim 2, a thick part can be easily formed by press-molding a metal plate.

According to the third aspect of the invention, the thickness of the second fastening plate can be sufficiently secured by the cylindrical protrusion.
According to invention of Claim 4, since the inclination part of a cylindrical protrusion part inclines with respect to a plate | board thickness direction, it can lengthen the length of a 2nd hole. Therefore, the number of threads of the female thread portion can be increased.

  According to invention of Claim 5, a thick part can be easily provided in the peripheral part of a 2nd hole using a cylindrical projection part.

1 is a schematic front view of a steering apparatus in which a universal joint according to a first embodiment of the present invention is a first universal joint. It is an enlarged view of the periphery of a 1st universal joint. It is the schematic of the cross section of the structure where a 1st yoke fixes a steering shaft, and is equivalent to the cross section which follows the III-III line of FIG. FIG. 4 is an exploded perspective view around a first yoke. (A)-(g) is a schematic sectional drawing which shows the manufacturing process of a 1st yoke in order. (A)-(f) is a schematic sectional drawing which shows a manufacturing process in order in the manufacturing method of 2nd Embodiment of a 1st yoke. (A)-(e) is a schematic sectional drawing which shows a manufacturing process in order in the manufacturing method of 3rd Embodiment of a 1st yoke.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<First Embodiment>
FIG. 1 is a schematic front view of a steering apparatus 1 in which the universal joint according to the first embodiment of the present invention is a first universal joint 7. Referring to FIG. 1, a steering device 1 includes a steering shaft 3 (shaft) in which a steering member 2 such as a steering wheel is coupled to one end, an intermediate shaft 4 (shaft), a pinion shaft 5 (shaft), And a rack bar 6.

The other end 3 a of the steering shaft 3 is connected to one end 4 a of the intermediate shaft 4 via the first universal joint 7. The other end 4 b of the intermediate shaft 4 is connected to one end 5 a of the pinion shaft 5 via the second universal joint 8.
A pinion 5 b is provided on the outer peripheral surface of the other end of the pinion shaft 5. A rack 6 a that meshes with the pinion 5 b is formed at one place on the outer peripheral surface of the rack bar 6. The pinion 5b and the rack 6a constitute a rack-and-pinion type steering mechanism 10 by meshing with each other.

The rack bar 6 is accommodated in a substantially cylindrical housing 11 fixed to the vehicle body. Both end portions of the rack bar 6 protrude to both sides of the housing 11, and tie rods 13 are coupled to the respective end portions via joints 12. Each tie rod 13 is connected to a corresponding steered wheel 14 via a corresponding knuckle arm (not shown).
When the steering member 2 is operated and the steering shaft 3 is rotated, this rotation is transmitted to the pinion shaft 5 via the intermediate shaft 4, and the rack bar 6 along the width direction of the vehicle body is transmitted by the pinion 5b and the rack 6a. Is converted into a linear motion. Thereby, the turning of the steered wheel 14 is achieved.

FIG. 2 is an enlarged view of the periphery of the first universal joint 7.
Referring to FIG. 2, the first universal joint 7 is welded to a first yoke 21 (universal joint yoke) fixed to the other end 3 a (end part) of the steering shaft 3 and one end 4 a of the intermediate shaft 4. And a second yoke 22 fixed by, for example. The first universal joint 7 includes a cross shaft 30 that connects the first yoke 21 and the second yoke 22, a fastening bolt 40 for fixing the first yoke 21 to the other end 3a of the steering shaft 3, Is provided.

A fitting hole 23 a is formed in each of the pair of arm portions 23 of the first yoke 21. In addition, illustration of the fitting hole 23a of one arm part 23 is abbreviate | omitted here. A fitting hole 24 a is formed in each of the pair of arm portions 24 of the second yoke 22.
The cross shaft 30 has four cylindrical shaft portions 33. Each shaft portion 33 is inserted into a corresponding fitting hole 23 a of the first yoke 21 and a corresponding fitting hole 24 a of the second yoke 22.

A male serration 31 is formed on the outer periphery of the other end 3 a of the steering shaft 3. A circumferential groove 32 that crosses the male serration 31 is formed on the outer periphery of the other end 3 a of the steering shaft 3.
The first yoke 21 may be fixed to one end 4 a (end portion) of the intermediate shaft 4, and the second yoke 22 may be fixed to the other end 3 a of the steering shaft 3. In this case, the male serration 31 and the circumferential groove 32 are formed at one end 4 a of the intermediate shaft 4.

Referring to FIG. 1, the second universal joint 8 has the same configuration as the first universal joint 7. In the second universal joint 8, the first yoke 21 (see FIG. 2) is fixed to one of the one end 5a (end portion) of the pinion shaft 5 and the other end 4b (end portion) of the intermediate shaft 4. The second yoke 22 (see FIG. 2) is fixed to the other side.
FIG. 3 is a schematic view of a cross section of the structure in which the first yoke 21 fixes the steering shaft 3, and corresponds to a cross section taken along line III-III in FIG. FIG. 4 is an exploded perspective view around the first yoke 21.

Referring to FIG. 3, the first yoke 21 is formed, for example, by press molding a single metal plate. The first yoke 21 includes a tubular portion 50 for fixing the steering shaft 3, and a first fastening plate 60 and a second fastening plate for fastening the other end 3 a of the steering shaft 3 via the tubular portion 50. 70 with a single member.
Referring to FIG. 4, cylindrical portion 50 has an end-cylinder shape having end portions 50 a on the upstream side and the downstream side in the tightening direction of bolt 40 (corresponding to a central axis direction J described later). It is. The cylindrical portion 50 extends in the same direction as the axial direction X of the steering shaft 3. The cylindrical portion 50 forms a slit 51 extending in the axial direction X between the pair of end portions 50a. The pair of end portions 50 a constitutes portions on both sides of the slit 51 in the tubular portion 50. On the inner periphery of the cylindrical portion 50, a female serration 52 that is serrated and fitted with the male serration 31 of the other end 3a of the steering shaft 3 is formed.

Referring to FIG. 3, the first clamping plate 60 and the second clamping plate 70 are arranged in a direction perpendicular to the axis R (the axial direction of the cylindrical portion 50 corresponding to the axial direction X of the steering shaft 3) from the pair of end portions 50 a. Extending in a direction perpendicular to each other) and facing each other with the slit 51 interposed therebetween.
The fastening bolt 40 includes a shaft portion 43 having a center axis C extending in the center axis direction J. A head 41 is provided at one end of the shaft portion 43. A male screw part 42 is provided at the other end of the shaft part 43. The first tightening plate 60 is formed with a first hole 61 that penetrates the first tightening plate 60 in the plate thickness direction D. The fastening bolt 40 is inserted into the first hole 61. The second tightening plate 70 is formed with a second hole 71 that penetrates the second tightening plate 70 in the plate thickness direction D. The second hole 71 is provided with an internal thread portion 72 that engages with the external thread portion 42 of the tightening bolt 40 on the inner periphery. The second fastening plate 70 is screwed with the fastening bolt 40. The first fastening plate 60 and the second fastening plate 70 are configured to fasten the other end 3 a of the steering shaft 3 via the tubular portion 50 with the fastening bolt 40.

  The second fastening plate 70 includes at least a peripheral portion 73 of the second hole 71, a thick portion 74 that is thicker than the plate thickness T <b> 1 of the first fastening plate 60, and a thin wall portion other than the thick portion 74. Part 76. The plate thickness T2 (corresponding to the plate thickness of the thick portion 74) of the second fastening plate 70 is larger than the plate thickness T1 of the first fastening plate 60 (T2> T1). The thickness TT of the thin portion 76 is equal to the thickness T1 of the first fastening plate 60 (TT = T1).

  The thick portion 74 includes a cylindrical protrusion 88 that protrudes from the peripheral portion 73 in the plate thickness direction D. The cylindrical protrusion 88 includes an inclined portion 75 that is inclined with respect to the central axis direction of the second hole 71 (corresponding to the plate thickness direction D). The steering shaft 3 is inserted into the cylindrical portion 50 of the first yoke 21 with the male serration 31 of the steering shaft 3 aligned with the irregularities of the female serration 52 of the cylindrical portion 50 of the first yoke 21, and the tightening bolt 40 is rotated. Then, when it is moved in the central axis direction J, the first fastening plate 60 is pushed toward the second fastening plate 70 by the head 41 of the fastening bolt 40, and the second fastening that is screwed with the fastening bolt 40 is performed. The attached plate 70 is pulled toward the first fastening plate 60 side. Thereby, the 1st clamping board 60 and the 2nd clamping board 70 mutually approach so that the slit 51 may be narrowed. Therefore, the other end 3 a of the steering shaft 3 has a cylindrical portion 50 provided integrally with the first tightening plate 60 and the second tightening plate 70 by the first tightening plate 60 and the second tightening plate 70. Tightened through. Therefore, the male serration 31 of the other end 3 a of the steering shaft 3 and the female serration 52 of the cylindrical portion 50 of the first yoke 21 are firmly serrated and the first yoke 21 is fixed to the steering shaft 3.

Next, a method for manufacturing the first yoke 21 will be described.
FIG. 5A to FIG. 5G are schematic cross-sectional views sequentially showing manufacturing steps of the first yoke 21.
The manufacturing method of the first yoke 21 includes a drawing process (see FIGS. 5A to 5C) for forming the second fastening plate 70 of the first yoke 21, and a drilling process [FIG. ) And FIG. 5 (e)] and a threading step [see FIG. 5 (f) and FIG. 5 (g)].

  First, in the drawing step, as shown in FIG. 5A, a portion to be processed (worked portion 81) in the metal plate 80 prepared for forming the first yoke 21 (see FIG. 3) is formed as a mold. 90. The mold 90 includes a receiving die 91 formed with a truncated cone-shaped recess 91a and a pressing die 92 formed with a truncated cone-shaped protruding portion 92a inserted into the recessed portion 91a and movable toward the receiving die 91. Including.

In the drawing process, as shown in FIG. 5 (b), the processed portion 81 is press-molded by the mold 90, so that the processed portion 81 has a cup-shaped cylindrical shape as shown in FIG. 5 (c). A protrusion 82 is formed. The workpiece 81 is the second fastening plate 70 at the manufacturing stage.
The cylindrical projection 82 is formed by integrating a tapered peripheral side wall 83 and a bottom 84 that are inclined with respect to the plate thickness direction of the workpiece 81 (corresponding to the plate thickness direction D of the second fastening plate 70). Including.

In the drilling step, as shown in FIG. 5D, a part of the peripheral side wall 83 and the bottom 84 of the cylindrical protrusion 82 are removed using a drill 93. As a result, as shown in FIG. 5 (e), a through-hole 85 that penetrates the peripheral side wall 83 formed in the drawing step in the plate thickness direction D is formed in the workpiece 81.
In the screw machining step, as shown in FIG. 5 (f), the female screw portion 72 is machined using the tap 94 in the inner diameter portion 86 of the through hole 85 formed in the drilling step. As a result, as shown in FIG. 5G, the second hole 71 having the female screw portion 72 provided on the inner periphery is formed, and the second fastening plate 70 is formed. A part 83a of the peripheral side wall 83 remaining in the drilling step is a cylindrical protrusion that is a part of the thick part 74 of the peripheral edge 73 of the second hole 71 after the second fastening plate 70 is formed. 88 inclined portions 75 are formed.

Note that portions other than the second fastening plate 70 in the first yoke 21 are formed by press molding using a mold 90 or another mold (not shown).
Through the above steps, the first yoke 21 on which the second fastening plate 70 is formed is completed.
According to the first embodiment, since the thick portion 74 is provided in the peripheral portion 73 of the second hole 71, the plate thickness T2 of the second fastening plate 70 (corresponding to the plate thickness of the thick portion 74) is The plate thickness T1 of the first fastening plate 60 (corresponding to the plate thickness TT of the thin portion 76) is made thicker. Therefore, it is not necessary to use a metal plate 80 having a thickness equivalent to the thickness of the thick portion 74 in order to ensure the strength of the female screw portion 72 provided in the second hole 71. That is, even with the first yoke 21 made of a metal plate, the thick portion 74 can be easily formed by the above manufacturing process. Therefore, the number of threads of the female screw portion 72 can be increased, so that the strength of the female screw portion 72 can be ensured. Therefore, the strength of the female screw portion 72 can be improved while suppressing an increase in weight.

Further, since it is not necessary to use a metal plate 80 having a plate thickness equivalent to the plate thickness (plate thickness T2 of the thick portion 74) where the female screw portion 72 is formed in order to ensure the strength of the female screw portion 72, the first An increase in material cost of one yoke 21 can also be suppressed.
Further, the thick portion 74 can be easily formed on the metal plate 80 by press molding.
In addition, the thick portion 74 can be easily provided on the peripheral edge 73 of the second hole 71 using the cylindrical protrusion 88.
Further, the inclined portion 75 of the cylindrical protrusion 88 is inclined with respect to the central axis direction of the second hole 71. For this reason, the length of the second hole 71 can be increased. Therefore, the number of threads of the female thread portion 72 can be increased.

Second Embodiment
The first yoke 21 of the second embodiment can be manufactured by the following manufacturing method.
FIG. 6A to FIG. 6F are schematic cross-sectional views sequentially showing the manufacturing steps in the manufacturing method of the first embodiment of the first yoke 21. In the manufacturing method of the first yoke 21 of the second embodiment shown in FIG. 6, the same components as those of the manufacturing method of the first yoke 21 of the first embodiment shown in FIG. The same applies to FIG. 7 described later).
The manufacturing method of the second embodiment of the first yoke 21 includes a drilling step [see FIGS. 6A to 6D] and threading for forming the second fastening plate 70 of the first yoke 21. The process [refer FIG.6 (e)-FIG.6 (f)] is included.

In the drilling step in the manufacturing method of the second embodiment, specifically, burring is performed on the workpiece 81.
In the burring process, first, as shown in FIGS. 6A and 6B, a pilot hole 81 a is formed in the workpiece 81 using a drill 95.
Next, as shown in FIG. 6 (c), while the lower hole 81 a is expanded by the cylindrical male jig 97, the peripheral edge 81 b of the lower hole 81 a is inside the cavity 96 a provided in the female jig 96. It gradually rises along the peripheral surface 96b. The inner peripheral surface 96b of the cavity 96a of the female jig 96 is configured by a cylindrical surface or a tapered surface provided with a draft angle. As a result, as shown in FIG. 6D, a through hole 85P that penetrates the workpiece 81 in the plate thickness direction D is formed by expanding the lower hole 81a. Moreover, the cylindrical protrusion part 88P is formed in the peripheral part 87P of the through-hole 85P by raising the peripheral part 81b of the lower hole 81a in rib shape. Thus, the cylindrical protrusion 88P is formed in the peripheral part 87P by burring.

  In the screw machining step, as shown in FIG. 6 (e), the female thread portion 72 is machined using the tap 94 in the inner diameter portion 86 </ b> P of the through hole 85 </ b> P formed in the drilling step. As a result, as shown in FIG. 6 (f), the second hole 71 in which the cylindrical protrusion 88 </ b> P is formed in the peripheral edge 73 is formed. Thus, the 2nd clamping board 70 is formed also by the manufacturing method of 2nd Embodiment. The thick portion 74P of the second fastening plate 70 formed by the manufacturing method of the second embodiment includes a cylindrical protrusion 88P. The plate thickness T2P of the thick portion 74P includes the height T3P of the cylindrical protrusion 88P.

As described above, the cylindrical projection 88P is formed on the workpiece 81 by burring.
According to 2nd Embodiment, there exists the same effect as 1st Embodiment.
When the inner peripheral surface 96 b of the cavity 96 a of the female jig 96 is formed by a tapered surface, the cylindrical protrusion 88 </ b> P includes an inclined portion that is inclined with respect to the central axis direction of the second hole 71. In this case, since the length of the 2nd hole 71 can be lengthened, the number of the screw threads of the internal thread part 72 can be increased.

<Third Embodiment>
The first yoke 21 of the third embodiment can be manufactured by the following manufacturing method.
FIG. 7A to FIG. 7E are schematic cross-sectional views sequentially showing the manufacturing steps in the manufacturing method of the first yoke 21 of the third embodiment.
The manufacturing method of the first yoke 21 according to the third embodiment includes a drilling process for forming the second fastening plate 70 of the first yoke 21 [see FIGS. 7A to 7C] and threading. The process [refer FIG.7 (d) and FIG.7 (e)] is included.

In the drilling step in the manufacturing method of the third embodiment, specifically, flow drilling or the like is performed on the workpiece 81.
In the flow drilling process, as shown in FIG. 7A, the flow drill 98 rotated at a high speed is pressed against the workpiece 81 from the plate thickness direction D. As a result, as shown in FIGS. 7B and 7C, the through hole 85Q that penetrates the processed portion 81 in the plate thickness direction D in the portion of the processed portion 81 against which the flow drill 98 is pressed. It is formed. At this time, a cylindrical projection 88Q is formed on the peripheral edge 87Q of the through hole 85Q by a portion where the flow drill 98 pushes the workpiece 81 into a rib shape.

  In the screw machining step, as shown in FIG. 7D, the female screw portion 72 is machined using the tap 94 in the inner diameter portion 86Q of the through hole 85Q formed in the drilling step. As a result, as shown in FIG. 7E, the second hole 71 in which the cylindrical protrusion 88Q is formed in the peripheral edge 73 is formed. Thus, the 2nd clamping board 70 is formed also by the manufacturing method of 3rd Embodiment. The thick part 74Q of the second fastening plate 70 formed by the manufacturing method of the third embodiment includes a cylindrical protrusion 88Q. The plate thickness T2Q of the thick portion 74Q includes the height T3Q of the cylindrical protrusion 88Q.

As described above, the cylindrical projection 88Q is formed on the workpiece 81 by flow drilling. According to 3rd Embodiment, there exists the same effect as 1st Embodiment.
Although the thick portions 74, 74P, 74Q are shown in an emphasized manner, for example, the plate thickness T1 of the first fastening plate 60 is about 7 mm and the plate thickness of the thick portions 74, 74P, 74Q. If T2, T2P, and T2Q are about 8 mm, the effects of the present invention can be sufficiently obtained.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims.
For example, the second yoke 22 may be a universal joint yoke having the same configuration as the first yoke 21.
The universal joint yoke (first yoke 21) of the present invention can be applied to any universal joint used in the steering device 1. Further, the universal joint yoke (first yoke 21) of the present invention is not limited to the universal joint used in the steering device 1, and can be applied to any universal joint that connects shafts together.

DESCRIPTION OF SYMBOLS 3 ... Steering shaft, 3a ... Other end, 4 ... Intermediate shaft, 4a ... One end, 4b ... Other end, 5 ... Pinion shaft, 5a ... One end, 21 ... 1st yoke, 22 ... 2nd yoke, 50 ... Cylindrical shape Part 50a ... end part 51 ... slit 60 first clamp plate 61 first hole 70 second clamp plate 71 second hole 72 female thread 73 peripheral edge 74 74P; 74Q ... thick part, 75 ... inclined part, 80 ... metal plate, 81 ... processed part, 85; 85P; 85Q ... through hole, 86; 86P; 86Q ... inner diameter part, 88; 88P; 88Q ... cylinder D-shaped projection, D: plate thickness direction, R: axis perpendicular direction, T1: plate thickness, T2; T2P; T2Q: plate thickness, X: axis direction

Claims (5)

A universal joint yoke fixed to the end of the shaft,
A cylindrical portion for fixing the shaft, in which a slit extending in the axial direction of the shaft is formed;
A first fastening plate and a second fastening plate that extend in a direction perpendicular to the axis from both sides of the slit in the cylindrical portion, face each other across the slit, and clamp the shaft via the cylindrical portion. And comprising
The first fastening plate is formed with a first hole penetrating the first fastening plate in the thickness direction,
The second fastening plate is formed with a second hole that penetrates the second fastening plate in the plate thickness direction and has an internal thread portion on the inner periphery thereof.
The second fastening plate includes a thick portion at least at a peripheral portion of the second hole, and the thickness of the second fastening plate is larger than the thickness of the first fastening plate. yoke.   The universal joint yoke according to claim 1, wherein the universal joint yoke is formed by press-molding a metal plate.   The universal joint yoke according to claim 1, wherein the thick portion includes a cylindrical protrusion.   4. The universal joint yoke according to claim 3, wherein the cylindrical protrusion includes an inclined portion inclined with respect to the plate thickness direction of the second fastening plate. A method for manufacturing a universal joint yoke according to claim 3 or 4,
Forming the cylindrical protrusion on the second fastening plate at the manufacturing stage;
A drilling step of forming a through-hole penetrating the cylindrical protrusion in the plate thickness direction;
And a threading step of forming the second hole by processing the female screw portion on the inner diameter portion of the through hole formed in the drilling step.

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