JPS6114932Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rack-and-pinion type steering device, and particularly to its pinion shaft support structure.

In recent years, there has been a strong demand for automobiles to be lighter and more compact as part of efforts to save energy, and at the same time, it is desired that they be able to provide a large living space. In order to meet these demands, the layout of the various parts arranged in the engine room became an issue, and at the same time, it was necessary to simplify the configuration of each part.
It is required to minimize wasted space and arrange them in high density.

By the way, a rack-and-pinion type steering device is known as one of the steering devices, which is an important component for automobiles along with the engine and brakes.This rack-and-pinion type is lightweight and relatively small. It has advantages such as simple construction, excellent steering performance, and advantageous installation space.As it can meet the above-mentioned requirements, it has been widely adopted in recent automobiles. ing.

However, even with the rack-and-pinion type steering device, which has such advantages, there is still room for improvement in terms of making automobiles lighter and more compact. One of them is the amount of protrusion in the axial direction of the support housing of the pinion shaft, which has a pinion on the tip side that engages with the rack, that is, toward the driver's seat. That is, if the amount of protrusion is large, the operation space of the driver's seat will be narrowed, which is contrary to the expansion of the living space. In particular, in recent years, this kind of rack-and-pinion type steering device has been required to be compatible with power steering, and since its control valve is installed on the support part of the pinion shaft, its axial length has increased. It is desirable to make it as short as possible.

For this reason, the inventors reviewed this type of rack-and-pinion steering device in general, and found a clue to the solution in the support position of the bearing that rotatably supports the pinion shaft. Ta. In other words, in conventional devices of this type, the bearing that supports the pinion shaft is located close to the pinion, but on the outer periphery of the pinion, avoiding the imperfectly threaded part, and the snap spring is located in the annular groove formed on the pinion shaft. The axial position of the bearing was determined by fitting it into the bearing.

However, although the incompletely threaded portion of the pinion described above is necessary for cutting, it does not play any role in the engagement with the easy tooth portion, and even if a bearing is fixed to this portion, there will be no problem with steering operation. do not have. Therefore, by shifting the support position of the bearing to the incompletely threaded portion of the pinion, it is possible to shorten the length of the pinion shaft in the longitudinal direction of the support portion as much as possible.

It is conceivable to simply use a snap spring as a conventional positioning means on the pinion side of such a bearing, but if the snap spring is fixed to the incompletely threaded part in this way,
This poses a problem in terms of strength against the force applied to the pinion shaft in the thrust direction, and cannot necessarily be said to be a preferable positioning means. In other words, a slight force is applied to the pinion shaft in the thrust direction due to the meshing of the rack and pinion, so it is required to have enough strength to absorb this force. It lacks strength.

The present invention was developed in view of these circumstances, and involves fitting a split ring into an annular groove provided in the incompletely threaded portion of the pinion, and using this split ring to control the movement of the bearing toward the pinion. With this simple structure, the bearing can be securely supported and fixed with sufficient strength at the incompletely threaded part of the pinion, thereby minimizing the axial length of the pinion shaft support part. The present invention provides a pinion shaft support structure in a steering device that can be shortened to meet the demand for lighter and more compact automobiles.

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 shows an embodiment in which the pinion shaft support structure according to the present invention is applied to a rack-and-pinion type steering device used for manual steering.
is a pinion shaft having a pinion 2 on its tip side,
The end of the pinion shaft 1 opposite to the pinion 2 is connected to a steering handle (not shown), and is rotated appropriately in the steering direction. Reference numeral 3 designates a housing for accommodating the distal end side of the pinion shaft 1 and for holding a rack 4 that meshes with the pinion 2 so as to be slidable in a direction substantially perpendicular to the pinion shaft 1; It is supported by a guide member 5 made of an elastic body fitted from a lower opening, and biased by a presser member 6 so as to mesh with the pinion 2. As this rack 4 slides in the direction of rotation of the pinion shaft 1, steering wheels (not shown) connected to both ends thereof are steered.

On the other hand, both sides of the pinion 2 are rotatably supported within the pinion shaft 1 and housing 3 by a pair of needle bearings 8 and ball bearings 9, and the outer ring portion of the ball bearings 9 is connected to the side opening of the housing 3. It is fixed to the housing 3 side in a state where movement in the axial direction is restricted by an annular member 10 screwed into the housing 3 . Note that reference numeral 11 in the figure is a sealing member disposed between the pinion shaft 1 and the annular member 10.

According to the present invention, in the device having the above-described structure, the support position of the ball bearing 9 relative to the pinion shaft 1 is moved as close to the pinion 2 side as possible, so that the support position of the ball bearing 9 relative to the pinion shaft 1 is A distinctive feature is that the protrusion is made as short as possible, thereby meeting the demands for more compact automobiles and larger living spaces.

In other words, in the conventional device, a snap spring is used as a member to stop the ball bearing 9 from moving toward the pinion 2, so it is impossible to fix the incompletely threaded portion 2a of the pinion 2 due to its strength. Support and fixation can be performed simply and reliably by using two split rings 12, 12.

To explain this in detail, according to this embodiment, an annular groove 13 is formed in the incompletely threaded portion 2a of the pinion 2, which does not participate in meshing with the rack 4, and a large diameter groove is formed in the incompletely threaded portion 2a of the pinion 2, as shown in FIG. A cross section consisting of a portion 14 and a small diameter portion 15 continuous thereto is approximately L-shaped.
It is configured to fit the split rings 12, 12 into it. In this case, the two split rings 12, 12 are fitted into the annular groove 13 with the large diameter portion 14 side located on the pinion 2 side. These split rings 12, 12 are prevented from coming off in the outer radial direction by having their small diameter portions 15 pivotingly support the inner ring portion of the ball bearing 9, and the annular groove 1
As a result, the pinion 2 side of the ball bearing 9 can be reliably locked by the large diameter portion 14.

In addition, in this embodiment, the two split rings 12, 12
The case is shown in which each part is set so that the outer diameter of the small diameter part 15 is equal to the outer diameter of the pinion shaft 1 that pivotally supports the ball bearing 9 when the small diameter part 15 is fitted into the annular groove 13. The present invention is not limited to this, but it may be possible to prevent the ball bearing 9 from slipping off in the radial direction by pivotally supporting a portion of the ball bearing 9.

The ball bearing 9 is locked on the opposite side from the pinion 2 by a snap spring 17 which is fitted into an annular groove 16 similarly formed on the pinion shaft 1 and caulked. It will be fixed on top. At this time, the supporting position of the ring 17 is a position away from the incompletely threaded portion 2a of the pinion 2, and no problem arises in terms of its strength.

Therefore, according to such a configuration, it is possible to bring the support position of the ball bearing 9 to the pinion shaft 1 as close to the pinion 2 side as possible, and to minimize the axial length of the support portion of the pinion shaft 1. can be shortened. In particular, the split rings 12, 12 are different from conventional snap rings,
Since it is easily and reliably fitted into the annular groove 13 having a large groove depth, it has excellent strength.

Figure 3 shows another embodiment in which the present invention is applied to a rack-and-pinion type steering device used for power steering, and in this figure, the same or corresponding parts as in Figure 1 are designated by the same numbers. The explanation will be omitted.

Here, to briefly describe the differences from the above-described embodiments, in this power steering device, the pinion shaft 1 is divided into two parts, front and rear, and a front pinion shaft 1a having a pinion 2 and a rear pinion shaft 1b. It is composed of. Both shafts 1a and 1b are connected by a torsion bar 20, and a sleeve 21 and a rotor 22, which constitute a rotary valve serving as a control valve as a power steering device, are integrally provided at opposing ends thereof. . Further, the sleeve 21 and the rotor 22 are surrounded by a housing 3a that is formed separately from the housing 3 that houses the pinion 2, and an oil passage formed inside the housing 3a is connected to the sleeve 21 and the rotor 22. By selectively switching by rotation, a power cylinder (not shown) disposed on the rack 4 side is actuated to generate a steering assist force. In addition, in the figure, 23,2
4, 25, and 26 are openings connected to the left and right pressure chambers of the power cylinder, the oil pump, and the tank, respectively, and 27 is a ball bearing that supports the rear pinion shaft 1b.

In this embodiment, it should be noted that the ball bearing 9 supporting the front pinion shaft 1a is located on the opposite side of the pinion 2 due to the presence of a large diameter sleeve 21 integrally formed with the pinion shaft 1a. This means that it cannot be inserted. For this reason,
According to this embodiment, the housing 3 divided into two parts,
A ball bearing 9 is disposed at the joint portion of the pinion shaft 3a, and the ball bearing 9 is fitted into the pinion shaft 1a from the end on the pinion 2 side.

To explain this in detail, an annular groove 3 is formed on the pinion shaft 1a corresponding to the incompletely threaded portion 2a of the pinion 2.
0, and a locking step portion 31 for locking the rear end portion of the ball bearing 9 is formed at a position separated by an axial length of the ball bearing 9 from the annular groove 30. Then, by fitting into the annular groove 30 two split rings 32, 32 formed by dividing the annular groove into two as shown in FIG. It is configured to lock the pinion 2 side of the bearing 9. Further, a collar 33 is fitted to the outer periphery of these two-split rings 32, 32, thereby restricting separation of the two-split rings 32, 32 in the outer radial direction.

Therefore, according to such a structure, the strength against the axial movement of the ball bearing 9 by the split rings 32, 32 is guaranteed, and the same effects can be obtained as in the above-described embodiment. It will be easily understood.

In addition, in this embodiment, the two-split ring 32,
As a member for preventing the member 32 from coming off in the outer radial direction, there are various other possible members, such as a snap ring, a spring, and even a wire, in addition to the above-mentioned collar 33. In short, an annular groove may be used.

As explained above, according to the pinion shaft support structure in the steering device according to the present invention, two split rings are fitted into the annular groove formed in the incompletely threaded portion of the pinion, and are used to support the pinion shaft. Since the movement of the bearing towards the pinion side is stopped, it is possible to securely support and fix the bearing on the pinion shaft with sufficient strength, despite its simple structure.
As a result, the axial length of the pinion shaft support portion 3 can be shortened as much as possible to meet the demands for lighter and more compact automobiles and larger living spaces.

In addition, although all the embodiments of the input shaft support structure in the steering device according to the present invention are shown using a pinion shaft, it goes without saying that the invention can also be applied to a ball screw type worm shaft in the same steering device.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional side view showing an embodiment in which the pinion shaft support structure according to the present invention is applied to a rack-and-pinion type steering device for manual steering, and Fig. 2 is an exploded view showing an enlarged view of the main parts. FIG. 3 is a cross-sectional side view showing another embodiment in which the present invention is applied to a rack-and-pinion type steering device for power steering; FIG. 4 is an exploded perspective view showing an enlarged view of the main parts thereof. It is. 1, 1a...Pinion shaft, 2...Pinion, 2a...Incomplete threaded part, 4...Rack, 9...Ball bearing, 12,3
2...Split ring, 13, 30...Annular groove, 14...Large diameter part, 15...Small diameter part, 17...Ring, 31...Engagement Stop portion, 33... Collar (annular body).

Claims (1)

[Claims for Utility Model Registration] (1) A two-split ring in which an annular groove is formed in the incompletely threaded portion of the pinion that engages easily, and the pinion side of the input shaft support pairing is locked in this annular groove. An input shaft support structure in a steering device, characterized in that it is fitted with a. (2) The split ring consists of a large-diameter part on the pinion side and a small-diameter part continuous to the large-diameter part, and a part of the bearing is pivotally supported by this small-diameter part, so that separation in the outer radial direction is restricted. An input shaft support structure in a steering device according to claim 1, characterized in that: (3) The input shaft in the steering device as set forth in claim 1 of the utility model registration claim, wherein the split ring is restricted from detaching in the outer radial direction by an annular body fitted on its outer periphery. Support structure.