JPH0125745Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power steering device, and particularly to an improved connection structure between a valve sleeve and a pinion shaft.

FIG. 1 shows an example of a conventional power steering device. The pinion shaft 1 is supported by a pinion bearing 2, and the control valve 4 is supported by a pin 3.
The valve sleeve 5 is connected to the torsion bar 7 via a pin 6. The other end of the torsion bar 7 is connected to the valve shaft 9 by a pin 8, so that the pinion shaft 1 and the valve shaft 9 are connected to the torsion bar 7.
connected via. 10 is a valve housing, a valve sleeve 5 is fitted into the inner periphery of the housing 10, and a valve shaft 9 is fitted into the inner periphery of the valve sleeve 5. The valve shaft 9 can rotate by a predetermined angle with respect to the valve sleeve 5 according to the torsion of the torsion bar 7.

FIG. 2 shows the end of the pinion shaft 1 on the control valve 4 side, and a hole 11 into which the torsion bar 7 is loosely fitted is provided in the end.
Further, in the outer wall 12, openings 13A and 13B are cut out at a predetermined opening angle. Outer wall 1
2 is further provided with a pin hole 14, and the pin 3 is press-fitted into this pin hole 14 in advance. Then, the valve sleeve 5 is inserted into the pinion shaft 1 while being shifted to the right in FIG. 1, and the head of the pin 3 is inserted into the pin hole 5A, thereby connecting the pinion shaft 1 and the valve sleeve 5. Ru.

FIG. 3 shows the end of the valve shaft 9 on the pinion shaft side, at which a boss 15 is loosely fitted into openings 13A and 13B provided in the pinion shaft 1, as shown in FIG. It is installed protrudingly. The boss 15 has openings 13A and 13B.
It has a width across flats corresponding to The width across flats of this boss 15 and the openings 13A and 1 of the pinion shaft 1
Each surface of the outer wall 12 facing 3B constitutes a manual stop portion. That is, in FIG. 4, when the valve shaft 9 is rotated to the right, the S surface of the valve shaft 9 contacts the S surface of the outer wall 12, the T surface of the valve shaft 9 contacts the T surface of the outer wall 12, and the pinion shaft is rotated. 1 is rotated. Further, when the valve shaft 9 is rotated to the left, the U surface of the valve shaft 9 is aligned with the U surface of the outer wall 12, and the valve shaft 9 is rotated to the left.
The V surface of the pinion shaft 1 contacts the V surface of the outer wall 12, and the pinion shaft 1 is rotated.

However, in the conventional power steering device configured in this manner, the valve sleeve 5 is supported on the pinion shaft 1 using the pin 3, and therefore has the following drawbacks. That is, () It is difficult to obtain a shape tolerance (deviation degree, perpendicularity) of the pin hole 14 with respect to the stopper portion of the pinion shaft 1, and it is difficult to match the neutral position of the control valve 4 with the neutral position of the manual stopper portion.

() When removing the pinion bearing 2, it is necessary to remove the pin 3, but since the pin 3 is press-fitted and the valve shaft 9 is inside the pin 3, the pin 3 must be pulled out. Therefore, the pin 3 is damaged and cannot be reused. It is also possible to remove the valve shaft 9 and drive in the pin 3, but in this case, it takes time to remove the valve shaft 9, which poses a problem in serviceability.

() A pin hole 14 is bored in the outer wall 12 of the pinion shaft 1, and the cross-sectional area of the outer wall 12 functioning as a manual stop portion is reduced by the amount of the pin hole 14. Further, when the pin 3 is press-fitted into the pin hole 14, internal stress is generated in the outer wall 12.
Therefore, due to these two factors, the strength of the outer wall 12 as a stopper portion is insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power steering device configured to connect a pinion shaft and a valve sleeve by means of a snap spring fitted to the outer wall of the pinion shaft, in order to eliminate such conventional drawbacks. .

The present invention will be explained below based on the drawings.

5 and 6 show an embodiment of the present invention, and FIG. 6 shows a cross section taken along the line -- in FIG. Components similar to those in FIGS. 1 to 3 are designated by the same reference numerals, and their explanations will be omitted. Here, reference numeral 21 denotes a snap spring, and as shown in FIG. 7, a convex portion 22 is provided protrudingly provided on the outer circumferential surface, and an alignment portion 23 is formed on the inner circumferential surface facing the convex portion 22. The shape of the alignment portion 23 corresponds to the opening angle of the openings 13A and 13B formed in the outer wall 12 of the pinion shaft 1. That is, when fitting the snap ring 21 into the ring groove 24 carved on the outer circumferential surface of the outer wall 12 as shown in FIG. Insert. Therefore, the circumferential position of the snap spring 21 is restricted by the stopper portion, that is, the S surface and the U surface of the outer wall 12, and the axial position of the pinion shaft 1 in the snap spring 21 is restricted by the ring groove 24.
regulated by. Reference numeral 25 denotes a hole drilled in the valve sleeve 5, and this hole 25 has a shape corresponding to the shape of the convex portion 22 of the snap ring 21.

In order to support the valve sleeve 5 with the pinion shaft 1 formed in this way, first insert the snap ring 2 into the ring groove 24 of the pinion shaft 1.
Fit 1. At this time, the snap ring 21 is positioned in the circumferential direction by fitting the positioning portion 23 of the snap ring 21 into the opening 13A. Next, when the valve sleeve 5 is inserted into the end of the pinion shaft 1 by aligning the convex part 22 of the snap spring 21 with the hole 25 of the valve sleeve 5, the convex part 22 is inserted into the hole 25, and thereby the valve sleeve 5 is supported by the pinion shaft 1.

Note that the snap spring 21 has a shape as shown in FIG.
If the shape is such that the rotational angle phase is shifted from that of the valve, the neutral point of the valve can be changed, so that the neutral point can be easily adjusted.

As described above, according to the present invention, the pinion shaft and the valve sleeve are connected and supported using the snap spring whose position in the circumferential direction is regulated by the manual stop portion of the pinion shaft, so that the neutral point of the manual stop portion and the neutral point of the control valve are Positioning with points can be performed with high precision. Furthermore, since there is no need to remove the valve shaft or torsion bar when removing the valve sleeve, serviceability is improved. Furthermore, it was necessary to accurately drill a pin hole for supporting the valve sleeve in the pinion shaft, but with the present invention, there is no need to drill the pin hole, reducing the machining time of the pinion shaft, thereby reducing the cost of the pinion shaft. can be reduced.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a conventional power steering device, Fig. 2 is a perspective view showing the end shape of the pinion shaft, and Fig. 3 is a perspective view showing the end shape of the valve shaft. Figure 4 is a cross-sectional view taken along the - line in Figure 1, Figure 5 is a cross-sectional view showing an embodiment of the present invention, Figure 6 is a cross-sectional view taken along the line -
The figure is a perspective view showing the same snap ring, and FIG. 8 is a plan view showing another example of the snap ring. 1... Pinion shaft, 4... Control valve, 5... Valve sleeve, 7... Torsion bar, 9... Valve shaft, 12... Outer wall,
13A, 13B...opening, 21...snat spring, 22...convex portion, 23...positioning portion, 24...
...Ring groove, 25...hole, S, T, U, V...surface (manual stopper part).

Claims (1)

[Scope of utility model registration request] The valve shaft has a pinion shaft provided with a stopper portion, a valve sleeve connected to the pinion shaft so as to rotate together with the pinion shaft, and a valve shaft connected to the pinion shaft via a torsion bar. When the valve shaft is displaced by a predetermined angle or more with respect to the pinion shaft, the valve shaft comes into contact with the stopper portion and directly transmits the rotation of the valve shaft to the pinion shaft, and when the torsion bar is twisted, the valve shaft In the power steering device in which a rotational displacement is generated between the pinion shaft and the valve sleeve, a snap spring having a protruding portion on the outer circumferential surface is fitted onto the outer circumferential surface of the pinion shaft, and the snap spring is rotated at the stopper portion. the position of the snap spring in the axial direction of the pinion shaft is regulated by a ring groove on the outer circumferential surface; a hole corresponding to the shape of the convex portion is bored in the valve sleeve; A power steering device characterized in that a convex portion is inserted into the hole to connect the pinion shaft and the valve sleeve.