JPS6069338A - rod guide - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front guide for slidably holding a piston front of a shock absorber.

A shock absorber applied to a vehicle generally consists of a cylindrical body and a piston rond to which a piston is slidably mounted within the cylindrical body. - Attached to the mouth, the shock absorber absorbs the downward movement of the wheels in response to uneven road surfaces through the expansion and contraction movement of the shock absorber, and generates damping force during this expansion and contraction to improve riding comfort. .

In this way, the shock absorber performs its function through relative movement in the axial direction between the cylinder body and the piston rod to which the piston is attached, so the piston rod is held slidably relative to the cylinder body via the front guide. are doing. Although it is common to use low-friction oil metal etc. as the front guide, the force acting on the shock absorber does not coincide with the axial direction of the piston Ron, and side forces act laterally on the shock absorber. There is also. This side force acts on the shock absorber as a bending moment, which causes friction between the piston rod and the rod guide, making it impossible to obtain a stable damping force, resulting in poor riding comfort.

Utility Model Application Publication No. 52-4616 has been proposed to solve this problem. The content of this prior example is that a ball bearing is provided in a straight line in the guide of the piston rond, and although it is effective to some extent in reducing friction due to side force, it cannot be said to be sufficient.

An object of the present invention is to provide a front guide that can exhibit a remarkable effect in reducing friction than the above-mentioned prior art. The inner ring holds a plurality of bearing groups consisting of a large number of ball bearings arranged in a ring shape, radially centered around the piston rod, and roller bearings, etc. are arranged between the inner ring and the outer ring. The gist is that a bearing has been inserted.

Embodiments of the present invention will be described below based on the accompanying drawings.

Fig. 1 is a side sectional view showing the internal structure of a hydraulic shock absorber to which the front guide according to the present invention is applied, Fig. 2 is a plan sectional view of the same shock absorber, and Fig. 3 is a side view showing the structure of the rod guide. 4 are exploded perspective views of the rod guide.

1 in the figure is an outer tube, an inner tube 2 is disposed inside the outer tube 1, a piston rod 3 is inserted into the inner tube 2, and the lower end of the piston rod 3 is connected to the inner surface of the inner tube 2. A piston 4 that slides into contact with is fixedly attached. An oil chamber A is formed by the Aracle tube 1 and the inner tube 2, and an oil chamber B is formed inside the inner tube 2.

1. The top of the inner tube 2 is supported by the side plate 5, and a front guide 7, which is the gist of the present invention, is provided between the side plate 5 and the 41υ plate 60 above this, and the piston rod 3 is supported slidably. do.

Here, a sole ring 8 is fitted onto the inner peripheral surface of the side plate 6 to prevent oil leakage from the oil chamber B and to obtain a stable damping force. Furthermore, an oil seal 10 is held above the side plate 6 by an oil seal case 9.

Next, details of the front guide 7 will be explained based on FIGS. 2 to 4.

The rod guide 7 has an inner ring 11 and an outer ring 12.
further includes a first inner ring 11a and a second inner ring 11b disposed outside of the first inner ring 11a. The first inner ring 11a is made up of blocks 13 having a prismatic shape and blocks 14 having an oval cross section, which are alternately and integrally continuous. The protrusion 15 that contacts the outer surface of the block 13 of the first inner ring 11a and the first inner ring 11
Four portions 16 facing the block 14 of a are formed alternately and continuously, and step portions 17° 1 are provided at the upper and lower portions of the recessed portion 16.
A locking piece 20 of the upper holder 19 having an arcuate inner surface 19a is fitted to the stepped portion 17, and a locking piece 20 of the lower holder 21 which also has an arcuate inner surface 21a is fitted to the step 18. 22 is fitted.

Then, the second inner ring 11b is fitted onto the first inner ring 11a, and the upper and lower holding bodies 19.21 are fitted onto the stepped portion 17 of the second inner ring 11b.
, 18, a ring-shaped ball bearing holding space S1 is formed. A ring-shaped bearing fir 25 is formed by housing a large number of ball bearings 24 in this space S1. Next, the ball bearing 24 is inserted from inside the first inner ring 11a.
. . , a part of the bearing group 25 is exposed and the piston rod 3 is exposed as shown in the plan cross-sectional view of FIG. They are arranged and held radially around the center.

In fact, in the space S2 between the second inner ring 11b and the outer ring 12, a roller bearing 28 is held by upper and lower retaining plates 29 and 29, and is disposed therein. A protrusion 30 for regulating the vertical position of the roller bearing 28 and a piece 31 for regulating the horizontal position of the roller bearing 28 are formed on the holding plate 29. Thrust play on the upper and lower surfaces of the rod guide 7 assembled in this way)
32. It is mounted in the outer tube 1 while being held by the side plates 5 and 6 via 32.

1. As shown in FIGS. 1 and 2, a vertical groove 33 is formed on the outer circumferential surface of the side plate 5.6 and the outer circumferential surface of the outer ring 12. The scraped hydraulic oil is returned to the oil chamber A.

In the illustrated example, the roller bearing 28 is provided between the second inner ring 11b and the outer ring 12, but a ball bearing or the like may be provided.

In the following, the piston rod 3 is slid in the axial direction via the ball bearing 24 with extremely low friction, and the twisted piston rod 3 is rotated around the axis smoothly via the roller bearing 28. .

FIG. 5 is a graph showing the relationship between the side force and friction of a shock absorber using the front guide according to the present invention and a conventional shock absorber, where the solid line 11 is for the present invention and the dashed line 42 is for the conventional shock absorber. show. As is clear from this graph, the shock absorber using the rod guide according to the present invention has a characteristic line 7. is almost the same, indicating that even if a large side force is applied, there is only a slight increase in friction.

As explained above, according to the present invention, the guide of the piston rod of the shock absorber is composed of an inner ring and an outer ring, and the inner ring has a plurality of bearing groups in which a large number of ball bearings are arranged in a ring shape. This allows the piston rod to slide in the axial direction with extremely small friction, and since a bearing is also interposed between the inner ring and the outer ring, rotation around the axis of the piston rod is prevented. This can be done smoothly without any significant friction.

Therefore, even if a large side force is applied to the shock absorber, the generation of friction can be suppressed to an extremely small amount, and many effects such as greatly improving riding comfort can be achieved.

[Brief explanation of drawings]

FIG. 1 is a side sectional view, not showing the internal structure, of a hydraulic shock absorber using a front guide according to the present invention, FIG. Figure 4 is an exploded perspective view of the front guide, and Figure 5 is a graph showing the relationship between side force and friction. In addition, in the drawing, 1 is the outer tube, 2 is the inner tube,
3, the piston rod 11 is an inner ring, 11a is a first inner ring, 11b is a second inner ring, 1
2 is an outer ring, 19.21 is a holding body, 24 is a ball bearing, 25 is a bearing group, 27 is a holding plate, and 28 is a roller bearing. Patent Applicant Showa Seisakusho Co., Ltd. Agent Bu ``Riju 2 1) Yong-Immediate Question Patent Attorney Kuni Ohashi Production Volume Patent Attorney Yu Koyama Figure 1 Figure 2 Figure 3 Figure 5 → Sasumi Force (kg )

Claims (1)

[Claims] In a front guide that slidably holds a piston rond of a buffer W, the front guide has an inner ring and an outer ring, and the inner ring has a plurality of bearing groups in which a large number of ball bearings are arranged in a ring shape around the piston rond. A rod guide that is held radially and is characterized in that a bearing is also interposed between the inner ring and the outer ring.