JP2009222148A - Joint - Google Patents

Abstract

An object of the present invention is to provide a joint that can easily make the tightening torques of two bolts the same, does not increase the number of parts, and has high coupling rigidity with a shaft.
A distance L2 from a center 821 of a second bolt 82 to a cut-up position 432A from a coupling cylinder portion 41 of a second slit 432 is determined from a center 811 of the first bolt 81. It is formed larger than the distance L1 from the connecting cylinder portion 41 of 431 to the round-up position 431A. By simply tightening until the tightening torque of the second bolt 82 reaches the same tightening torque T as the tightening torque T of the first bolt 81, the tightening torque of the first bolt 81 and the second bolt 82 can be made the same. Therefore, the tightening operation can be performed in a short time.
[Selection] Figure 4

Description

  The present invention relates to a joint, and more particularly, to a joint that connects shafts that transmit rotation of a steering shaft of a steering device.

  In a steering device that steers the front wheels of a vehicle, the movement of a steering shaft that is rotated by the operation of a steering wheel is transmitted to an input shaft of a steering gear through a universal joint.

  The movement of the steering wheel is transmitted to the steering gear via a steering shaft and an intermediate shaft that are rotatably provided in the steering column, and the direction of the wheel is steered by the steering gear. Normally, the steering shaft and the input shaft of the steering gear cannot be provided on the same straight line.

  For this reason, conventionally, as shown in Patent Document 1, an intermediate shaft is provided between the steering shaft and the input shaft to the steering gear, the end of the intermediate shaft and the steering shaft, and the end of the intermediate shaft and the steering shaft. By connecting the end portion of the input shaft of the gear via a universal joint, power can be transmitted between the steering shaft and the input shaft that do not exist on the same straight line.

  In recent years, there has been an increasing number of column assist type electric power steering devices in which an assist device for applying a steering assist force to a steering shaft is provided between an intermediate shaft and a steering wheel.

  In such column assist type electric power steering, since the rotational torque applied to the intermediate shaft is increased, it is necessary to increase the coupling rigidity of the coupling portion between the intermediate shaft and the universal joint.

  In the universal joint shown in Patent Document 2, the coupling rigidity between the coupling cylinder portion of the yoke and the shaft is increased by fastening the coupling cylinder portion of the yoke and the shaft with two bolts. In the universal joint shown in Patent Document 2, the coupling rigidity between the coupling cylinder portion of the yoke and the shaft is increased, but in order to ensure a predetermined coupling rigidity, the tightening torques of the two bolts are almost the same. Although necessary, it is difficult to tighten the two bolts with the same tightening torque.

  That is, if the two bolts are gradually tightened alternately, the tightening torques of the two bolts can be made the same, but the tightening operation takes time.

  In addition, the universal joint shown in Patent Document 2 is such that the coupling cylinder part of the yoke and the shaft are tightened with bolts via a thin plate-like strap formed as a separate part from the coupling cylinder part. The production cost may increase due to the increase.

JP-A-4-125314 British Patent Application No. 1233828

  An object of the present invention is to provide a joint that can easily tighten two bolts with the same tightening torque, does not increase the number of parts, and has high coupling rigidity with a shaft.

  The above problem is solved by the following means. That is, the first invention is formed in the coupling cylinder part provided with the hole part for fitting the shaft to the proximal end portion so as to be able to transmit the rotational torque, and is formed in the coupling cylinder part and penetrates the hole part. A first slit, which is formed in the coupling cylinder portion so as to face the first slit with the hole interposed therebetween, and a second cylinder which penetrates the hole, and the coupling cylinder which sandwiches the first slit. A first flange portion that is formed integrally with the left and right flange portions, and a first flange portion that is formed integrally with the coupling cylinder portion and sandwiches the second slit, and is configured by a pair of left and right flange portions. 2 flange portions, a first bolt for fastening the pair of left and right flange portions of the first flange portion, and a second bolt for fastening the pair of left and right flange portions of the second flange portion. When the first flange is tightened with a bolt The clamping rigidity of the first flange portion, a joint which is characterized in that it has greater than tightening the rigidity of the second flange portion when the tightening of the second flange portion by the second bolt.

  According to a second invention, in the joint of the first invention, the distance from the center of the second bolt to the position where the second slit is raised from the coupling cylinder portion is the first bolt. The joint is characterized in that it is formed to be larger than the distance from the center to the cut-up position from the coupling cylinder portion of the first cut.

  According to a third invention, in the joint according to any one of the first to second inventions, a female serration that engages with the male serration of the shaft and transmits rotational torque is formed in the hole. It is the coupling characterized by having.

  A fourth invention is a joint according to any one of the first to second inventions, wherein the shaft is formed with a groove engaging with the bolt.

  According to a fifth invention, in the joint according to any one of the first to second inventions, a bearing hole for pivotally supporting the cross shaft on the coupling cylinder portion on the side opposite to the hole portion. A joint having a pair of arms formed integrally.

  A sixth invention is a joint according to any one of the first to second inventions, wherein the joint is a universal joint that connects the intermediate shaft and the steering shaft, or the intermediate shaft and the steering gear, An assist device for applying a steering assist force to the steering shaft is provided between the intermediate shaft and the steering wheel.

  The joint according to the present invention includes a coupling cylinder portion provided with a hole portion for fitting a shaft so that rotational torque can be transmitted to a proximal end portion, and a first slit formed in the coupling cylinder portion and penetrating through the hole portion. And is formed in the coupling cylinder part so as to be opposed to the first slit across the hole, and is provided integrally with the coupling cylinder part across the first slit and the first cylinder. A first flange portion composed of a pair of flange portions; a second flange portion composed of a pair of left and right flange portions provided integrally with the coupling cylinder portion across the second slit; The first bolt that tightens the pair of left and right flange portions of the flange portion and the second bolt that tightens the pair of left and right flange portions of the second flange portion, and the first flange portion is tightened by the first bolt. The tightening rigidity of the first flange portion at the time is It is made larger than the clamping rigidity of the second flange portion when tightening the flange portion.

  Therefore, after the tightening of the first bolt is completed, the tightening torque of the second bolt is simply tightened until the tightening torque of the second bolt reaches the same tightening torque as that of the first bolt. Since the tightening torque can be the same, the tightening operation can be performed in a short time.

  In addition, the first flange portion and the second flange portion formed integrally with the coupling cylinder portion are tightened using the first bolt and the second bolt, respectively, so that the coupling between the shaft and the coupling cylinder portion is performed. The rigidity is large, the number of parts does not increase, and the increase in manufacturing cost is small.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a part of a steering apparatus including a joint according to the present invention, and shows an embodiment applied to an electric power steering apparatus having a steering assisting portion.

  As shown in FIG. 1, the steering device of the present invention includes a steering shaft 12 on which a steering wheel 11 can be mounted on the rear side of the vehicle body (right side of FIG. 1), a steering column 13 inserted through the steering shaft 12, and the steering wheel. An assist device (steering assisting portion) 20 for applying assist torque to the shaft 12 and a steering gear connected to the front side of the vehicle body of the steering shaft 12 (left side in FIG. 1) via a rack / pinion mechanism (not shown). 30.

  The steering shaft 12 is spline-fitted between a female steering shaft 12A and a male steering shaft 12B so as to be able to transmit rotational torque and to be relatively movable in the axial direction. Therefore, when the female steering shaft 12A and the male steering shaft 12B collide, the spline fitting portion moves relative to each other so that the total length can be shortened.

  Further, the cylindrical steering column 13 inserted through the steering shaft 12 combines the outer column 13A and the inner column 13B so that they can be telescopically moved. It has a so-called collapsible structure in which the entire length is shortened while absorbing water.

  The vehicle body front side end portion of the inner column 13B is press-fitted and fixed to the vehicle body rear side end portion of the gear housing 21. Further, the front end portion of the male steering shaft 12B on the vehicle body is passed through the inside of the gear housing 21 and connected to the rear end portion of the assist device 20 on the rear side of the input shaft (not shown).

  The steering column 13 is supported by a support bracket 14 at a middle portion thereof on a part of the vehicle body 18 such as a lower surface of the dashboard. Further, a locking portion (not shown) is provided between the support bracket 14 and the vehicle body 18, and when an impact in a direction toward the front side of the vehicle body is applied to the support bracket 14, the support bracket 14 is locked to the locking bracket 14. It moves away from the vehicle and moves to the front side of the vehicle.

  The upper end portion of the gear housing 21 is also supported on a part of the vehicle body 18. In this embodiment, the height position of the steering wheel 11 and the longitudinal position of the vehicle body can be freely adjusted by providing a tilt mechanism and a telescopic mechanism. Such a tilt mechanism and a telescopic mechanism are well known in the art and are not characteristic features of the present invention, and thus detailed description thereof is omitted.

  The output shaft 23 protruding from the end face on the front side of the vehicle body of the gear housing 21 is connected to the rear end portion of the intermediate shaft 16 via the universal joint 15. Further, the input shaft 31 of the steering gear 30 is connected to the front end portion of the intermediate shaft 16 via another universal joint 17. The intermediate shaft 16 is fitted on the vehicle body front side of the male intermediate shaft (male shaft) 16A on the vehicle body rear side of the female intermediate shaft (female shaft) 16B, so that rotational torque can be transmitted and relative movement in the axial direction is possible. Is fitted.

  A pinion (not shown) is coupled to the input shaft 31. A rack (not shown) fitted in the steering gear 30 so as to be reciprocally slidable meshes with the pinion, and the rotation of the steering wheel 11 moves the tie rod 32 to steer a wheel (not shown).

  A case 261 of an electric motor 26 is fixed to the gear housing 21 of the assist device 20, and a worm is coupled to a rotating shaft (not shown) of the electric motor 26. A worm wheel (not shown) is attached to the output shaft 23, and the worm of the rotating shaft of the electric motor 26 is engaged with the worm wheel.

  A torque sensor (not shown) is provided around an intermediate portion of the axial length of the output shaft 23. The direction and magnitude of torque applied from the steering wheel 11 to the steering shaft 12 is detected by a torque sensor.

  The electric motor 26 is driven according to the detected value of the torque sensor, and auxiliary torque is generated in a predetermined direction in a predetermined direction on the output shaft 23 via a speed reduction mechanism composed of a worm and a worm wheel.

  FIG. 2 is a front view of the universal joint of the embodiment of the present invention, and shows an example applied to the universal joints 15 and 17 of FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 4 is a cross-sectional view taken along the line BB in FIG. 5A is a cross-sectional view showing a state in which the bolt and the shaft are removed from FIG. 3, FIG. 5B is a front view showing the shaft of FIG. 2, and FIG. 5C is C in FIG. It is -C sectional drawing.

  As shown in FIGS. 2 to 5, the universal joint according to the embodiment of the present invention includes a yoke 4, 4 having bifurcated arm portions 42, 42 and a cross that couples the bifurcated arm portions 42, 42 to each other. The shaft 6 is configured. Although not shown, the arm portions 42 and 42 are formed with a pair of circular holes (bearing holes), and a bearing for fitting with the cross shaft 6 is inserted therein.

  The yoke 4 is provided with a substantially rectangular coupling cylinder portion 41 near the base end, and a shaft (FIG. 1) is provided on the inner peripheral surface of the axis (the center in the left and right and vertical directions in FIG. 3) of the coupling cylinder portion 41. Female serrations (holes) 45 for fitting the male intermediate shaft 16A, female intermediate shaft 16B, output shaft 23, input shaft 31, etc.) 7 are formed.

  As shown in FIGS. 2 to 4, the coupling cylinder portion 41 has a first slit 431 and a second slit extending in the vertical direction of FIGS. 3 and 4 and penetrating the female serration 45 with the female serration 45 interposed therebetween. The cut 432 is formed. The first slit 431 is formed on the upper side of the female serration 45, and the second slit 432 is formed on the lower side of the female serration 45. The gaps δ1 and δ2 (see FIGS. 3 and 5A) of the first cut 431 and the second cut 432 are formed with the same dimensions.

  A first flange portion 46 including a left flange portion 461 and a right flange portion 462 is formed integrally with the coupling cylinder portion 41 with the first slit 431 interposed therebetween. In addition, a second flange portion 47 including a left flange portion 471 and a right flange portion 472 is formed integrally with the coupling cylinder portion 41 with the second slit 432 interposed therebetween.

  A first screw hole 481 is formed in the left flange portion 461 of the first flange portion 46 in a direction perpendicular to the flange surface (the left-right direction in FIGS. 3 and 5A). Also, the left flange portion 471 of the second flange portion 47 has a first screw hole with a female serration 45 sandwiched in a direction perpendicular to the flange surface (left and right direction in FIGS. 3 and 5A). A second screw hole 482 is formed at a position symmetrical to 481.

  A first through hole 491 is formed in the right flange portion 462 of the first flange portion 46 concentrically with the first screw hole 481. A second through hole 492 is formed in the right flange portion 472 of the second flange portion 47 concentrically with the second screw hole 482. Therefore, if the first bolt 81 is inserted into the first through hole 491, the second bolt 82 is inserted into the second through hole 492, and the first bolt 81 and the second bolt 82 are rotated, respectively. The first bolt 81 and the second bolt 82 are screwed into the first screw hole 481 and the second screw hole 482, respectively.

  As shown in FIGS. 4, 5 </ b> B, and 5 </ b> C, a male serration 71 that engages with the female serration 45 is formed on the outer periphery of the end of the shaft 7. An annular groove 72 is formed on the outer periphery of the end of the shaft 7. The annular groove 72 is parallel to the axis of the shaft 7, and an arbitrary planar shape passing through the axis of the shaft 7 is formed in a convex arc shape toward the axis of the shaft 7.

  Accordingly, when the first bolt 81 and the second bolt 82 are inserted into the first through hole 491 and the second through hole 492, the male serration 71 of the shaft 7 is engaged with the female serration 45 of the coupling cylinder portion 41. In combination, the rotational torque can be transmitted. At the same time, the outer circumferences of the first bolt 81 and the second bolt 82 engage with the annular groove 72 of the shaft 7, so that the shaft 7 does not come out of the female serration 45.

  As shown in FIG. 4, the first cutting 431 and the second cutting 432 are simultaneously formed by milling. That is, the center 51 of the milling cutter (flat milling) 5 having a diameter D is separated from the central axis 451 of the female serration 45 by a distance S downward as viewed in FIG. Cut the milling cutter 5 from the left side. The thickness of the blade of the milling cutter 5 has the same dimensions as the gaps δ1 and δ2 (see FIGS. 3 and 5A) of the first cutting 431 and the second cutting 432.

  When the milling is completed, as shown in FIG. 4, the distance L2 from the center 821 of the second bolt 82 to the round-up position 432A from the coupling cylinder portion 41 of the second slit 432 is equal to that of the first bolt 81. It is formed larger than the distance L1 from the center 811 to the cut-up position 431A from the coupling cylinder portion 41 of the first slit 431.

  As a result, the tightening rigidity of the first flange portion 46 when the first flange portion 46 is tightened with the first bolt 81 is the same as that when the second flange portion 47 is tightened with the second bolt 82. The fastening rigidity of the second flange portion 47 is surely larger.

  That is, when any one of the first bolt 81 or the second bolt 82 is tightened, the gap (δ1 or δ2) of the cut (431 or 432) of the other flange portion is expanded.

  However, since the tightening rigidity of the first flange portion 46 is larger than the tightening rigidity of the second flange portion 47, if the first flange portion 46 is first tightened and then the second flange portion 47 is tightened, When the second flange portion 47 is tightened, the gap δ1 of the first flange portion 46 is small, so that the variation in the tightening torque of the first bolt 81 that tightens the first flange portion 46 is suppressed to a small value. Therefore, it is not necessary to retighten the first bolt 81.

  That is, the procedure for tightening the first bolt 81 and the second bolt 82 is as follows. First, the first bolt 81 is used to tighten the first flange portion 46, and the first bolt 81 has a predetermined tightening torque. Tighten until T is reached. Next, the second flange portion 47 is tightened with the second bolt 82 until the tightening torque of the second bolt 82 reaches the same tightening torque T as the tightening torque T of the first bolt 81.

  The tightening rigidity of the first flange portion 46 is larger than the tightening rigidity of the second flange portion 47. When the second flange portion 47 is tightened with the second bolt 82 after the tightening of the first bolt 81 is completed, the tightening torque of the second bolt 82 is greater than the tightening torque T of the first bolt 81. Gradually increases from a small tightening torque state and approaches the tightening torque T of the first bolt 81.

  Therefore, the tightening torque of the first bolt 81 and the second bolt 82 is made the same only by tightening until the tightening torque of the second bolt 82 reaches the same tightening torque as the tightening torque T of the first bolt 81. Therefore, the tightening operation is easy and can be performed in a short time.

  In the universal joint according to the embodiment of the present invention, the first flange portion 46 and the second flange portion 47 formed integrally with the yoke 4 are used by using the first bolt 81 and the second bolt 82, respectively. tighten. Therefore, the coupling rigidity between the shaft 7 and the coupling cylinder portion 41 of the yoke 4 is large, the number of parts is not increased, and the increase in manufacturing cost is small.

  In the above embodiment, the coupling cylinder portion 41 is formed in a substantially rectangular shape, but various shapes such as a circle and an ellipse are possible. Moreover, although the example which formed the female serration in the connection cylinder part was demonstrated in the said Example, hole parts, such as a female spline, two planes, a polygonal hole, and an elliptical hole, may be sufficient.

BRIEF DESCRIPTION OF THE DRAWINGS It is the side view which showed the whole steering apparatus provided with the coupling of this invention, and was cut in part, Comprising: The Example applied to the electric power steering apparatus which has a steering assistance part is shown. It is a front view of the universal joint of the Example of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. (A) is sectional drawing which shows the state which removed the volt | bolt and the axis | shaft from FIG. 3, (B) is a front view which shows the axis | shaft of FIG. 2, (C) is CC sectional drawing of (B).

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Steering wheel 12 Steering shaft 12A Female steering shaft 12B Male steering shaft 13 Steering column 13A Outer column 13B Inner column 14 Support bracket 15 Universal joint 16 Intermediate shaft 16A Male intermediate shaft 16B Female intermediate shaft 17 Universal joint 18 Car body 20 Assist device 21 Gear Housing 23 Output shaft 26 Electric motor 261 Case 30 Steering gear 31 Input shaft 32 Tie rod 4 Yoke 41 Coupling tube portion 42 Arm portion 431 First cut 431A Cut-up position 432 Second cut-off 432A Cut-up position 45 Female serration 451 Center axis 46 First flange portion 461 Left flange portion 462 Right flange portion 47 Second flange portion 471 Left flange Die portion 472 Right flange portion 481 First screw hole 482 Second screw hole 491 First through hole 492 Second through hole 5 Milling cutter 51 Center 6 Cross shaft 7 Axis 71 Male serration 72 Annular groove 81 First Bolt 811 center 82 Second bolt 821 center

Claims (6)

A coupling cylinder portion having a hole portion for fitting the shaft to the proximal end portion so that rotational torque can be transmitted,
A first slit formed in the coupling cylinder and penetrating through the hole;
A second slit that is formed in the coupling cylinder portion so as to face the first slit across the hole and penetrates the hole;
A first flange portion provided integrally with the coupling cylinder portion with the first slit interposed therebetween, and configured by a pair of left and right flange portions;
A second flange portion, which is provided integrally with the coupling cylinder portion across the second slit, and is composed of a pair of left and right flange portions;
A first bolt for tightening a pair of left and right flange portions of the first flange portion;
A second bolt for tightening the pair of left and right flange portions of the second flange portion;
The tightening rigidity of the first flange portion when the first flange portion is tightened with the first bolt, and the tightening rigidity of the second flange portion when the second flange portion is tightened with the second bolt A joint characterized by its larger size. The joint according to claim 1,
The distance from the center of the second bolt to the position where the second cut is raised from the coupling cylinder part is the distance from the center of the first bolt to the coupling cylinder part of the first cut. A joint characterized by being formed larger than the distance to the position. In the joint according to any one of claims 1 to 2,
A female serration that engages with the male serration of the shaft and transmits rotational torque is formed in the hole. In the joint according to any one of claims 1 to 2,
The joint is characterized in that a groove for engaging with the bolt is formed on the shaft. In the joint according to any one of claims 1 to 2,
The coupling cylinder portion is integrally formed with a pair of arm portions having bearing holes for supporting the cross shaft on the side opposite to the hole portion. In the joint according to any one of claims 1 to 2,
The joint is a universal joint that connects the intermediate shaft and the steering shaft, or the intermediate shaft and the steering gear.
A joint characterized in that an assist device for applying a steering assist force to the steering shaft is provided between the intermediate shaft and the steering wheel.

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