JPH0422111Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to an intermediate shaft installed in a steering system of an automobile or the like, and particularly to an intermediate shaft that can absorb not only the shock of a vehicle collision but also the vibration and noise during normal driving.

[Prior art]

In the steering system of an automobile, a crosshair is used as a steering device that blocks vibrations and sounds from the steering gear side from being transmitted to the steering wheel side, and also absorbs the impact force transmitted to the steering wheel side in the event of a collision. A cylindrical member with a spline inner diameter is press-fitted into the inner hole of the annular yoke connected to the shaft via a rubber bushing, and the steering shaft is spline-fitted into the inner diameter of this cylindrical member, and is then pressed by applying a predetermined axial external force. A transmission joint device is known which has a structure in which both are fixed to each other so that they can be broken, and which is movable by pushing in the axial direction (for example, Japanese Patent Laid-Open No. 53-91236). In this device, vibrations, sounds, etc. are absorbed by the rubber bushing, and when a strong impact force such as a collision occurs, the fixing member between the cylindrical member and the shaft is destroyed, and the two slide relative to each other, resulting in a reduction in displacement. Absorption is taking place.

[Problem that the invention attempts to solve]

In the above-mentioned conventional transmission joint device capable of absorbing vibration, sound, and impact displacement, the steering shaft fits and slides on the cylindrical member fitted inside the rubber bushing. In addition to this, the joint length must be equal to the length of the stroke during shock absorption, so for vehicles where the distance between the upper and lower joints of the steering system cannot be long, there is a sufficient destructive sliding stroke. There is a problem that the displacement cannot be effectively absorbed. In addition, as a transmission coupling device capable of absorbing large displacements, there is also known a structure in which the shaft is divided into two parts and these parts are connected by a coupling ring that can be bent and deformed (for example, JP-A-61
41669 and Japanese Patent Application Laid-Open No. 61-58168), these have the problem that vibrations and sounds during normal running are not absorbed because the split shaft is integrally fixed to the coupling ring.

[Means to solve the problem]

The intermediate shaft structure according to the present invention includes one shaft having a stopper projecting in the radial direction, the other shaft having the same axis as the axis of the one shaft and spaced apart in the axial direction, and one end portion. The other shaft is connected to the other shaft, the one shaft is inserted into the other end without contact, and the outer peripheral part is provided with a stopper contact hole that surrounds the stopper of the one shaft through a predetermined space. a connecting member made of a material, and an elastic member interposed between an inner diameter portion of the connecting member and an outer peripheral portion of the one shaft and connecting the connecting member and the one shaft so as to be elastically displaceable. , the connecting member has a bending deformation portion between the connecting portion of the one shaft and the connecting portion of the other shaft, and the opposing ends of the one shaft and the other shaft are It is configured to have an abutment surface that bends and deforms the bending deformation portion in a direction perpendicular to the axis of the shaft when the two shafts collide with each other in the axial direction.

【Example】

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 8 is a schematic side view of an automobile steering system to which the present invention is applied. Car body part 2
The upper end of the main steering shaft 2 is inserted into and rotatably supported by the steering column 3, which has its upper part supported by an upper bracket 26 fixed to the body part 8 and its lower end supported by a lower bracket 27 fixed to the vehicle body part 28. A steering wheel 1 is fixed to one part, and an intermediate shaft 5 is connected to the other lower end via an upper joint 4. Furthermore, the lower end of the intermediate shaft 5 is connected to a steering gear 7 via a lower joint 6. A steering system section is configured by being connected to the input shaft 29. In this embodiment, the intermediate shaft 5 is divided into two parts, and has an upper shaft 11 and a lower shaft 12 separated from each other in the axial direction, and the opposing ends thereof have a bendable shape that can be bent to be deformed as described later. The entire structure having a deformed portion in the middle is connected by a tube 10, which is a connecting member made of a single piece of material. FIG. 1 is a partially cutaway side view of the intermediate shaft of the first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line - - of FIG. 1, and FIG. FIG. Upper shaft 1 on the main steering shaft side
1 (one shaft) and the lower shaft 12 (the other shaft) on the steering gear side are spaced apart in the axial direction and face each other on the same axis, and their opposing ends are both formed into a conical shape. A U-shaped yoke 8, which forms part of the upper joint, is fixed to one end (upper end) of the upper shaft 11. The yokes 8 are formed with opposing holes 30 into which cross-shaft bearings are fitted. Both shafts 11,1
2 is inserted into a tube 10 having a bending deformation portion in which a plurality of diamond-shaped cut holes 14 penetrating in the radial direction are provided in a mesh shape around the periphery. The lower shaft 12 is inserted into an inner hole of a tube end plate 15 fixed to the end (lower end) of the tube 10 by welding, and is fixedly connected by welding. The upper shaft 11 is connected to the tube 10
It is coupled to the opposite end portion (upper end) via an elastic ring which is an elastic member so as to be elastically displaceable. The elastic ring body consists of an annular rubber bush 18 disposed between an outer ring 16 and an inner ring 17, which are fixed to each other to form an integral structure. A ring 17 is fitted onto the outer diameter portion of the upper shaft 11 by means of press fitting or the like. As shown in FIGS. 1 and 2, a pin 19, which is a cylindrical stopper extending in the diametrical direction, is implanted and fixed at the tip of the upper shaft 11 so as to protrude in the radial direction. Circular stopper hole 2 provided in tube 10
A stopper hole 20 is formed with a stopper contact surface that is loosely inserted into the pin 19 and faces the pin 19 with a predetermined space therebetween. The inner diameter D of the stopper hole 20 is slightly smaller than the outer diameter d of the stopper pin 19.
It is formed to have a slightly larger diameter so as to have a gap S.
Therefore, the pin 19 and the stopper hole 20 face each other with a predetermined space not only in the axial direction of the tube 10 but also in the radial direction of the tube, and as will be described later, in the event of a vehicle collision, the pin 19 in the radial direction of the tube The stopper hole 20 can be brought into contact with the stopper hole 20. With this configuration, the torque applied to the upper shaft during normal operation is small, so there is little torsional deformation of the rubber bush 18, and the stopper pin 1
9 and the stopper hole 20 do not contact each other, and the tube 1
0 and the upper shaft 11 are connected only through the rubber bush 18, so vibrations and sounds brought from the steering gear side are transmitted from the lower shaft 12 on the gear side to the tube 10; and upper shaft 1
It is absorbed by the rubber bush 18 interposed between 1 and 1. Therefore, the vibrations and sounds are caused by the main steering shaft 2 connected to the upper shaft 11.
Almost no signal is transmitted to the steering wheel. When the steering wheel is left stationary or suddenly turned while driving, the torsional deformation of the rubber bushing 18 becomes large, but in this case, the stopper pin 19
comes into contact with the stopper hole 20 of the tube 10, resulting in metal-to-metal engagement and maintaining rotational connection. With such a structure, even if the rubber bushing 18, which is an elastic body, becomes fatigued or slips at its press-fitted portion, a safe connection is ensured by the engagement between the stopper pin 19 and the tube 10. As mentioned above, since there is normally a gap S between the stopper pin 19 and the stopper hole 20, vibrations and sounds are not transmitted from this part to the upper shaft 11 via the pin 19. When a car crashes, a large impact force is applied to the lower shaft 12, causing the lower shaft 12 to be pushed upward. At this time, the tube 10 is crushed,
The opposing shaft ends of the upper shaft 11 and the lower shaft 12 are in contact with each other, but since the shaft ends are formed as conical protrusions, if the tips of the shafts come into contact with each other in the axial direction, the shafts will be misaligned and the tube 10 will not move. 11,
12 in a direction perpendicular to the axis, absorbing large displacements and preventing the main steering shaft from being pushed up. FIGS. 4 and 5 are a partially cutaway side view and a cross-sectional view showing a second embodiment of the present invention. The difference from the first embodiment described above is that a serration portion 21 is formed on the inner peripheral surface of the inner ring 17 of the elastic ring body and the outer peripheral surface of the upper shaft 11, and by this serration fitting, the upper shaft 11 and the inner ring 17 Therefore, the connection between the elastic ring and the upper shaft 11 is made more secure, and a serration is also formed at the shaft end of the lower shaft 12.
Other than this, the second embodiment is the same as the first embodiment, so the same parts as in the first embodiment are denoted by the same reference numerals, and explanations that overlap with those in the first embodiment will be omitted. Figures 6 and 7 are the third and third versions of the present invention, respectively.
This shows a fourth example. 3 in Figure 6
In this embodiment, the tube 10 as a connecting member is a one-piece metal tube with no holes on the circumferential surface, and instead, the middle portion of the tube is formed to have a larger diameter than both ends, and this large diameter portion and the small diameter portions at both ends are connected by a wave-shaped step portion 22, and are designed to be crushed or bent at this step portion. In the fourth embodiment, the intermediate portion of the integral tube 10 serving as the connecting member is formed into a bellows shape, and the bellows portion 25 can be deformed and crushed by impact. In both the third and fourth embodiments,
Divided upper shaft 11 and lower shaft 12
The tips of the upper shaft 11 and the lower shaft 12 are formed as surfaces 23 and 24 that are inclined with respect to a plane perpendicular to the shaft axis, thereby allowing the tips of the upper shaft 11 and the lower shaft 12 to bend and fall when they come into contact with each other. ing. In addition, in both the third and fourth embodiments, the serration fitting between the elastic ring body and the upper shaft 11 is performed in the second embodiment.
This is the same as in the embodiment. In the embodiment of this invention, an example is shown in which the elastic ring body is provided on the upper shaft side, but the upper shaft and lower shaft may be used upside down. In the third and fourth embodiments, since the circumferential surface of the bending deformation portion of the connection member is not cut away and is formed as a continuous surface, the torsional rigidity is improved compared to the first embodiment. Note that the elastic ring rubber bush does not necessarily have to be annular, and may be, for example, an elastic body divided into a plurality of pieces in the circumferential direction. The outer ring or inner ring of the elastic ring may be omitted and the rubber bushing may be directly fixed to the inner circumference of the tube or the outer circumference of the shaft. Furthermore, a rubber bushing may be provided not only at one end of the tube but also at both ends.

[Effect of the idea]

As explained above, the present invention has one shaft having a stopper projecting in the radial direction, the other shaft having the same axis as the axis of the one shaft and spaced apart in the axial direction, and the stopper having the stopper protruding in the radial direction. The other shaft is connected to the other shaft, the one shaft is inserted into the other end without contact, and the outer periphery is provided with a stopper contact hole that surrounds the stopper of the one shaft through a predetermined space. a connecting member; and an elastic member interposed between an inner diameter portion of the connecting member and an outer circumferential portion of the one shaft and connecting the connecting member and the one shaft so as to be elastically displaceable; The connecting member has a bent portion between the connecting portion of the one shaft and the connecting portion of the other shaft, and the opposing ends of the one shaft and the other shaft are axially aligned with each other. Since it has a contact surface that bends and deforms the bending deformation part in a direction perpendicular to the axis of the shaft when it comes into collision contact with the shaft in the direction,
The rubber bushing part of this elastic member can effectively absorb vibrations and sounds from the steering gear side, and the tube of the connecting member bends in the radial direction when the steering gear and lower joint retreat during a vehicle collision, absorbing large displacements. It is possible to obtain an intermediate shaft that is possible. After the tube is crushed to some extent and the tips of the upper and lower shafts of the divided intermediate shaft come into contact with each other, the upper and lower shafts of the divided intermediate shaft may be bent tightly due to misalignment or eccentric load on the inclined surface. It is easy to manufacture as the whole is made of one piece and can be formed using a molding machine, etc. It has a compact, simple and inexpensive structure that prevents the shaft from being pushed up in the event of a vehicle collision, and also reduces vibration and noise during normal driving. It has the effect of being absorbed effectively.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of the first embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line in Fig. 1, and Fig. 4 is a cross-sectional view taken along the - line in Fig. 1. Second idea
FIG. 5 is a cross-sectional view taken along the line -- in FIG. 4, and FIGS. 6 and 7 are partially cut-away side views of the third and fourth embodiments of the present invention, respectively. FIG. 8 is a schematic side view of a steering system to which the present invention is applied. 5... Intermediate shaft, 10...
...Tube, 11... Upper shaft, 12... Lower shaft, 14... Cut hole, 16... Outer ring, 17
...Inner ring, 18...Rubber bush, 19...Stopper pin, 20...Stopper hole, 21...
Serration section, 22... Step section, 23, 24...
...Sloped surface, 25 ... Bellows section, S ... 〓 between.

Claims (1)

[Scope of utility model registration request] one shaft having a stopper projecting in the radial direction, another shaft having the same axis as the axis of the one shaft and spaced apart in the axial direction, and one end of which the other shaft is joined and the other end thereof a connecting member made of an integral material into which the one shaft is inserted without contact and having a stopper abutting hole on the outer periphery that surrounds the stopper of the one shaft via a predetermined space; and an inner diameter of the connecting member. an elastic member interposed between the connecting member and the outer periphery of the one shaft and connecting the connecting member and the one shaft in an elastically displaceable manner; and a connecting portion of the other shaft, and the opposing ends of the one shaft and the other shaft are arranged so that when the opposing ends of the one shaft and the other shaft collide with each other in the axial direction, An intermediate shaft having an abutment surface that bends and deforms the bending deformation portion in a direction perpendicular to the axis of the shaft.