Method for manufacturing universal joint
10399188 ยท 2019-09-03
Assignee
Inventors
Cpc classification
F16C35/067
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16C43/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D3/41
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16C19/466
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16C21/005
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B23P11/00
PERFORMING OPERATIONS; TRANSPORTING
F16D2300/12
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16C2229/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B23P11/02
PERFORMING OPERATIONS; TRANSPORTING
F16D2250/0084
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D3/382
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D3/405
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16C21/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16C19/46
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B23P11/00
PERFORMING OPERATIONS; TRANSPORTING
F16D3/38
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B23P11/02
PERFORMING OPERATIONS; TRANSPORTING
F16D3/41
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A universal joint includes a bearing including a bearing cup fitted in a bearing hole of a yoke and rolling elements arranged between the bearing cup and a shaft portion of a cross shaft. A method for manufacturing the universal joint includes: simulating a shrunken state in which a sample bearing cup selected from bearing cups in a same lot is fitted in the bearing hole such that only an outside diameter is restrained, by press-fitting the sample bearing cup into a reference hole of a reference jig; measuring a diameter of an inscribed circle inscribed to the rolling elements in the shrunken state; setting an outside diameter of the shaft portion to a required outside diameter according to the diameter of the inscribed circle; and inserting the bearing cup with the rolling elements between the shaft portion having the required outside diameter and the bearing hole.
Claims
1. A method for manufacturing a universal joint where a bearing is interposed between each shaft portion of a cross shaft and a corresponding bearing hole of a yoke, and the bearing comprises a cylindrical bearing cup fitted in the bearing hole by press-fitting and a plurality of rolling elements annularly arranged between an inner peripheral surface of the bearing cup and an outer peripheral surface of the shaft portion, the method comprising: simulating a shrunken state in which a sample bearing cup selected from among a plurality of bearing cups manufactured in a same lot is fitted in the bearing hole of the yoke such that only an outside diameter is restrained, by press-fitting the sample bearing cup into a reference hole of a reference jig; measuring a diameter of an inscribed circle inscribed to the plurality of rolling elements annularly held along the inner peripheral surface of the sample bearing cup in the simulated shrunken state; setting an outside diameter of the shaft portion of the cross shaft to a required outside diameter that enables a required radial clearance to be achieved according to the measured diameter of the inscribed circle; and inserting the sample bearing cup having undergone measurement of the diameter of the inscribed circle or a non-measured bearing cup not having undergone the measurement of the diameter of the inscribed circle among the bearing cups manufactured in the lot, together with the plurality of rolling elements, between the shaft portion of the cross shaft set to the required outside diameter and the bearing hole.
2. The method for manufacturing the universal joint according to claim 1, wherein when the diameter of the inscribed circle is measured, a single-piece first reference jig having a stiffness equal to that of the yoke is used as the reference jig.
3. The method for manufacturing the universal joint according to claim 1, wherein when the diameter of the inscribed circle is measured, a second reference jig comprising a plurality of split members which define the reference hole, are split in a circumferential direction of the reference hole and are capable of enlarging and shrinking the reference hole is used as the reference jig, and wherein when the diameter of the inscribed circle is measured, after the sample bearing cup is accommodated in the reference hole in an enlarged state of the reference hole of the second reference jig, a load that shrinks the reference hole such that the simulated shrunken state is achieved is applied to the split member.
4. The method for manufacturing the universal joint according to claim 1, wherein when the outside diameter of the shaft portion is set, the cross shaft of a predetermined group is selected from among cross shafts sorted into a plurality of groups by the outside diameter of the shaft portion, and the outside diameter of the shaft portion of the cross shaft to be combined with the sample bearing cup or the non-measured bearing cup is set to the required outside diameter.
5. The method for manufacturing the universal joint according to claim 1, wherein when the outside diameter of the shaft portion is set, the outside diameter of the shaft portion of the cross shaft to be combined with the sample bearing cup or the non-measured bearing cup is finished by finish process and set to the required outside diameter.
6. The method for manufacturing the universal joint according to claim 5, wherein when the diameter of the inscribed circle is measured, the diameters of the inscribed circles at all the bearing cups manufactured in the lot are measured.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
MODE FOR CARRYING OUT THE INVENTION
(11) In the following, embodiments of the present invention will be described in detail with reference to the attached drawings.
(12) <First Embodiment>
(13)
(14) One end 3a of the steering shaft 3 is coupled to a steering member 2 such as a steering wheel. The other end 3b of the steering shaft 3 is coupled to one end 5a of the intermediate shaft 5 through the universal joint 4. The other end 5b of the intermediate shaft 5 is coupled to the pinion shaft 7 through the universal joint 6. A pinion 7a provided in the neighborhood of the end portion of the pinion shaft 7 meshes with rack teeth 8a provided on the rack shaft 8 extending in the direction of the vehicle width (horizontal direction).
(15) The pinion shaft 7 and the rack shaft 8 constitute a rack and pinion mechanism A. The rack shaft 8 is supported in such a manner as to be linearly reciprocatable through a plurality of non-illustrated bearings in a housing 9 fixed to a vehicle body (not shown).
(16) Both end portions of the rack shaft 8 protrude toward both sides of the housing 9, and to each end portion, a tie rod 10 is coupled. The tie rods 10 are coupled to corresponding wheels 11 through corresponding knuckle arms (not shown), respectively.
(17) When the steering member 2 is operated to rotate the steering shaft 3, this rotation is converted into a linear motion of the rack shaft 8 in the horizontal direction of the vehicle by the pinion 7a and the rack teeth 8a. Thereby, turning of the corresponding wheels 11 is achieved.
(18)
(19) Likewise, the universal joint 6 is provided with the yoke 20 provided on the end portion of the pinion shaft 7, the yoke 21 provided on the other end 5b of the intermediate shaft 5 and the cross shaft 22 coupling the yokes 20 and 21.
(20) The yokes 20 and 21 have a U shape, and each have a pair of arm portions 23. In
(21) Since the universal joints 4 and 6 have completely the same structure, in the following, description will be given in conformance with the universal joint 4.
(22) The arm portions 23 each have a bearing hole 25 through which the corresponding shaft portion 24 of the cross shaft 22 is inserted. In
(23) The universal joint 4 is provided with a bearing 26 interposed between an outer peripheral surface 24a of the shaft portion 24 and an inner peripheral surface 25a of the corresponding bearing hole 25. The arm portion 23 rotatably supports the corresponding shaft portion 24 through the bearing 26 fitted in the bearing hole 25 and held.
(24) The bearing 26 includes a cylindrical bearing cup 28 having a bottom and fitted in the bearing hole 25 by press-fitting and a plurality of rolling elements 27 held by the bearing cup 28. The rolling elements 27 are, for example, needle rollers.
(25) The bearing cup 28 is made of a sheet metal plate member, and includes a cylindrical peripheral wall 29, a bottom wall 32 provided on one end of the peripheral wall 29 in the axial direction and an annular flange portion 30 extended inward in the radial direction of the peripheral wall 29 from the other end of the peripheral wall 29 in the axial direction. The bearing cup 28 has an opening 34 at the other end of the peripheral wall 29 in the axial direction.
(26) Part of an outer peripheral surface 29a of the peripheral wall 29 is in pressure contact with the inner peripheral surface 25a of the bearing hole 25 of the arm portion 23. The annular flange portion 30 is in contact with an annular oil seal 31 fitted to the outside of the base end portion of the shaft portion 24, and the gap between the bearing cup 28 and the shaft portion 24 is sealed.
(27) The plurality of rolling elements 27 are annularly arranged between an inner peripheral surface 29b of the peripheral wall 29 of the bearing cup 28 and the outer peripheral surface 24a of the shaft portion 24. The plurality of rolling elements 27 are in rolling contact with both the inner peripheral surface 29b and the outer peripheral surface 24a. The bearing cup 28 rotatably supports the shaft portion 24 through the rolling elements 27.
(28) Referring to
(29) When the inscribed circle diameter D1 is larger than the shaft portion outside diameter D2 (D1>D2), the radial clearance S takes a positive value (S>0). The radial clearance S in this case is referred to as positive clearance.
(30) When the inscribed circle diameter D1 is smaller than the shaft portion outside diameter D2 (D1<D2), the radial clearance S takes a negative value (S<0). The radial clearance S in this case is referred to as negative clearance.
(31) Next, a method for manufacturing the universal joint 4 will be described.
(32)
(33) As shown in
(34)
(35) At the press-fitting step as the simulating step shown in
(36) The first reference jig 35 is, for example, a cylindrical or annular single-piece jig. Since the first reference jig 35 has a stiffness equal to that of the yoke 21 [see
(37) Then, at the inscribed circle diameter measuring step shown in
(38) The press-fitting step and the inscribed circle diameter measuring step are performed on some of the bearing cups 28 selected from among the bearing cups 28 in the same lot. The bearing cups 28 having undergone the inscribed circle diameter measuring step will be referred to as measured bearing cups 60 (sample bearing cups). Of the bearing cups 28 in the same lot as that of the measured bearing cups 60, the bearing cups 28 not having undergone the inscribed circle diameter measuring step will be referred to as non-measured bearing cups 61 [see
(39) Then, at the finishing step as the shaft portion outside diameter setting step shown in
(40) Then, at the shaft portion inserting step shown in
(41) Then, at the bearing cup inserting step shown in
(42) For the bearing cup inserting step, both the measured bearing cup 60 and the non-measured bearing cup 61 may be used.
(43) According to the first embodiment, the diameter shrunken state when the bearing cup 28 selected from the same lot is fitted in the bearing hole 25 of the actual yokes 20 and 21 so that only the outside diameter is restrained is simulated by using the first reference jig 35, and the inscribed circle diameter D3 of the rolling elements 27 in the simulated diameter shrunken state of the bearing cup 28 is measured. By setting, according to the measured inscribed circle diameter D3, the shaft portion outside diameter D2 of the cross shaft 22 that enables the required radial clearance S to be achieved, variation of the radial clearance S at the time of the actual assembly can be suppressed in the same lot.
(44) Moreover, the first reference jig 35 which is a single-piece jig having a stiffness equal to that of the yokes 20 and 21 is easy to manufacture.
(45) Moreover, by finishing the shaft portion outside diameter D4 of the cross shaft 22 by finish processing, the variation of the radial clearance S can be further suppressed.
(46) <Second Embodiment>
(47)
(48) The method for manufacturing the universal joint 4 of the second embodiment shown in
(49) That is, the method for manufacturing the universal joint 4 of the second embodiment is provided with a bearing cup accommodating step (step S11), a diameter shrinking step as the simulating step (step S12), an inscribed circle diameter measuring step (step S13) and the finishing step as the shaft portion outside diameter setting step (step S3), the shaft portion inserting step (step S4) and the bearing cup inserting step (step S5) in succession.
(50) Moreover, as in the first embodiment, since the universal joint 6 has completely the same structure as the universal joint 4, description will be given in conformance with the universal joint 4.
(51)
(52) Referring to
(53) The second reference jig 65 includes a plurality of split members 45. The plurality of split members 45 define a reference hole 66 therebetween and are split in the circumferential direction C of the reference hole 66. In the second embodiment, the split members 45 are provided in a pair.
(54) The load detection member 40 is, for example, a load cell, and fixed to one base 43.
(55) The cylinder 41 is attached to the load detection member 40. The cylinder 41 is, for example, a hydraulic cylinder or an electric cylinder. The cylinder 41 includes a cylinder body 46 as a fixing portion and a cylinder rod 47 as a movable portion.
(56) The cylinder body 46 is fixed to the one base 43 through the load detection member 40. The cylinder rod 47 is coupled to one split member 45, and driven by the cylinder body 46 in the axial direction X of the cylinder rod 47. The pair of bases 43 are fixed to each other in a state of facing in the axial direction X.
(57) The support member 42 is fixed to the other base 43, and supports the other split member 45. The support member 42 is disposed on the opposite side of the cylinder 41 with the second reference jig 65 in between. The support member 42 has a V-shaped recess where a pair of support surfaces 42a are formed. The pair of support surfaces 42a each abut on the other split member 45.
(58) The cross-sectional shape of the recess of the support member 42 may be any shape as long as it can support the other split member 45 in such a manner that the centers of support by the split members 45 (corresponding to the curvature centers of the support surfaces of the split members 45) with respect to the bearing cup 28 coincide with each other when the bearing cup 28 is supported in a predetermined diameter shrunken state between the arc-surface-form support surfaces of the pair of split members 45. Therefore, the cross-sectional shape of the recess of the support member 42 is not limited to the V shape but may be a polygonal shape or an arc shape.
(59) The other split member 45 moves in the axial direction X integrally with the cylinder rod 47. For this reason, the size of the reference hole 66 of the second reference jig 65 changes by the cylinder rod 47 moving in the axial direction X.
(60) Specifically, when the cylinder rod 47 moves toward the one base 43, the reference hole 66 is enlarged so as to have a diameter where the bearing cup 28 can be accommodated without pressurized (for example, with the provision of play in the radial direction). When the cylinder rod 47 moves toward the other base 43, the reference hole 66 is shrunken so as to have a diameter where the bearing cup 28 is fitted by press-fitting and a state where it is shrunken to a predetermined diameter is achieved. As described above, in the second reference jig 65, the diameter of the reference hole 66 can be enlarged or shrunken by the movement of the one split member 45 in the axial direction X.
(61)
(62) At the bearing cup accommodating step shown in
(63) Then, at the shrinking step as the simulating step shown in
(64) By the reference load F1 being applied to the bearing cup 28, a stress balance condition equal to the stress balance condition of the bearing cup 28 and the yoke 21 when the bearing cup 28 is press-fitted into the bearing hole 25 of the yoke 21 is simulated. That is, by the shrinking step, simulation of the shrunken state when the selected bearing cup 28 is fitted in the bearing hole 25 of the yoke 21 so that only the outside diameter is restrained is achieved.
(65) Then, at the inscribed circle diameter measuring step shown in
(66) At the inscribed circle diameter measuring step of the second embodiment, the inscribed circle diameters D3P related to all the bearing cups 28 in the same lot are measured. For this reason, the bearing cups 28 used at the finishing step (step S3), the shaft portion inserting step (step S4) and the bearing cup inserting step (step S5) of the second embodiment are all the measured bearing cups 60.
(67) According to the second embodiment, the shrunken state when the bearing cup 28 selected from the same lot is fitted in the bearing hole 25 of the actual yokes 20 and 21 so that only the outside diameter is restrained is simulated by using the second reference jig 65, and the inscribed circle diameter D3P of the rolling elements 27 in the simulated shrunken state of the bearing cup 28 is measured. By setting, according to the measured inscribed circle diameter D3P, the shaft portion outside diameter D2 of the cross shaft 22 that enables the required radial clearance S to be achieved, variation of the radial clearance S at the time of the actual assembly in the same lot can be suppressed. Moreover, individual setting of the radial clearance S (see
(68) Moreover, an operation to press-fit the bearing cup 28 in the axial direction of the reference hole 66 is unnecessary. For this reason, the life of the second reference jig 65 can be prolonged.
(69) Moreover, by finishing the shaft portion outside diameter D4 of the cross shaft 22 by finish processing, the variation of the radial clearance S can be further suppressed.
(70) Moreover, the shaft portion outside diameter D2 of the cross shaft 22 can be set to an outside diameter suitable for each individual bearing cup 28. For this reason, the variation of the radial clearance S can be still further suppressed.
(71) This invention is not limited to the above-described embodiments, and various modifications are possible within the scope recited in the claims.
(72) For example, referring to
(73) At the selecting step, a predetermined group of cross shafts 22 are selected from among the cross shafts 22 sorted into a plurality of groups by the outside diameter of the shaft portion 24. Thereby, the shaft portion outside diameter D4 of the cross shaft 22 combined with the measured bearing cups 60 or the non-measured bearing cups 61 is set to a required shaft portion outside diameter D2. When the method for manufacturing the universal joints 4 and 6 includes the selecting step, at the inscribed circle diameter measuring step, the inscribed circle diameter D3 is measured for each lot. For this reason, by selecting the cross shafts 22 of the group suitable for combination, variation of the radial clearance S can be suppressed.
(74) Moreover, although not shown, the method for manufacturing the universal joints 4 and 6 of the second embodiment may include the selecting step instead of the finishing step.
(75) Moreover, at the inscribed circle diameter measuring step of the first embodiment, the inscribed circle diameters D3 related to all the bearing cups 28 in the same lot may be measured.
(76) Moreover, at the inscribed circle diameter measuring step of the second embodiment, the inscribed circle diameters D3P related to some of the bearing cups 28 in the same lot may be measured. That is, the bearing cups 28 used at the finishing step (step S3), the shaft portion inserting step (step S4) and the bearing cup inserting step (step S5) of the second embodiment may be the non-measured bearing cups 61.
(77) Moreover, the method for manufacturing the universal joint of the present invention is not limited to the universal joints 4 and 6 for the intermediate shaft 5 but may also be applied to general universal joints having a cross shaft.
INDUSTRIAL APPLICABILITY
(78) According to the method for manufacturing the universal joint of the present invention, a plurality of universal joints where the radial clearance variation is suppressed can be manufactured.
DESCRIPTION OF REFERENCE SIGNS
(79) 4: Universal Joint
(80) 6: Universal Joint
(81) 20: Yoke
(82) 21: Yoke
(83) 22: Cross Shaft
(84) 24: Shaft portion
(85) 24a: Outer Peripheral Surface
(86) 25: Bearing Hole
(87) 26: Bearing
(88) 27: Rolling Element
(89) 27a: Inscribed Circle
(90) 28: Bearing Cup
(91) 29b: Inner Peripheral Surface
(92) 35: First Reference Jig
(93) 36: Reference Hole
(94) 45: Split Member
(95) 60: Measured Bearing Cup (Sample Bearing Cups)
(96) 61: Non-measured Bearing Cup
(97) 65: Second Reference Jig
(98) 66: Reference Hole
(99) C: Circumferential Direction
(100) D2: Required Shaft Portion Outside Diameter
(101) D3: Inscribed Circle Diameter
(102) D3P: Inscribed Circle Diameter
(103) D4: Shaft Portion Outside Diameter
(104) F1: Reference Load
(105) S: Required Radial Clearance