JPH019735Y2 - - Google Patents

Description

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

The present invention relates to an improvement of a breather device for a rack-and-pinion type steering gear rack boot of a vehicle such as an automobile.

[Conventional technology]

Recently, rack-and-pinion type steering gears have been increasingly used as a steering gear system. This rack-and-pinion steering gear has a rack bar that moves in the axial direction when the steering wheel is rotated.
A bellows-shaped rack boot is attached between the rack bar and the end of the rack tube which is slidably fitted and held to prevent muddy water, dust, etc. from entering the rack tube. Then, air circulation holes and air circulation grooves are formed in the rack tube or the rack button to communicate the left and right rack boot chambers, thereby preventing large volume changes in the rack boot chambers due to the sliding of the rack bar (for example, 57-163476 and Utility Model Application Publication No. 57-142679). However, the location where this easy boot is provided is generally in the engine room, and is located in a position that is easily affected by heat, such as the exhaust manifold of the engine. Therefore, if the temperature inside the easy boot increases and the air inside the easy boot expands, and the bellows section is reduced and deformed, the easy boot may become abnormally deformed. Conversely, once the expanded air is cooled,
The interior of the rack boot becomes a negative pressure state, and this negative pressure causes the bellows shape of the rack boot to deform, and the rack bar may not deform smoothly when moving in the axial direction. Therefore, by providing a breather hole in the easy boots or a breather tube via a breather plug in the easy boots, when the air inside the easy boots expands, the expanded air is released outside the easy boots, and the inside of the easy boots becomes a negative pressure state. Sometimes, air is introduced into the easy boots to keep the air pressure inside the easy boots almost constant with the outside pressure.
A breather device for a rack-and-pinion type steering gear rack boot has been proposed in which the bellows of the rack boot can normally contract, expand, and deform (for example, Japanese Utility Model Application No. 57-94573 and No. 58-139371). (see official bulletin).

[Problem that the idea aims to solve]

However, in the case of the breather device for the rack-and-pinion type steering gear rack boot having the above-described structure, muddy water, dust, etc. are likely to enter the rack boot through the breather hole or breather tube provided in the rack boot. Therefore, there is a problem in that it is impossible to avoid the problem that muddy water, dust, etc. that have entered the rack boot have an adverse effect on the sliding parts in the rack tube and the like. Therefore, the present invention was devised to reduce this problem as much as possible, and its purpose is to:
To prevent muddy water, dust, etc. from entering into the rack boots as much as possible by making the opening to the atmosphere of a breather hole provided in the rack boots, etc., in a place where there is little muddy water, dust, etc.

[Means to solve the problem]

Therefore, the present invention employs the following configuration as a means for solving the above-mentioned problems. That is, the present invention provides a breather device for a rack-and-pinion type steering gear rack boot as described above, in which one end of the breather tube is communicated with the rack boot chamber formed by the rack boot or the rack boot chamber, and the rack bar is surrounded by the rack tube and the rack boot. A closed cross-sectional shape that is connected to at least one of the chambers that communicate with the formed rack boot chamber, and that the other end of the breather tube is located close to the region where the one end of the breather tube is connected. It is characterized by an opening into the empty space of the suspension member. Specifically, using FIG. 1 as an example,
In the breather device for a rack-and-pinion type steering gear rack boot according to the present invention, a bellows-shaped rack boot 6 is attached to the axially moving portion 3 of the rack-and-pinion type steering gear. One end of the breather tube 10 is a rack boot chamber A formed by the rack boot 6.
Alternatively, it is provided coupled to a chamber communicating with the rack boot chamber. Furthermore, the other end of this breather tube 10 is opened into a cavity a of a suspension member 11 having a closed cross section and located close to the rack boot 6.

[Effect]

According to the above-mentioned means, when the air in the rack boot chamber A expands or contracts due to the influence of the heat source of the engine, etc., the expansion or contraction occurs in the breather tube 1.
0, the bellows shape of the rack boot 6 is always maintained normally, and the expansion and contraction deformation operations are performed normally. Further, as the rack boot 6 contracts, the breather tube 10 communicates with the rack boot chamber A or the rack boot chamber A, and at least one of the chambers B communicates with the rack boot chamber formed by surrounding the rack bar 1 with the rack tube 7 and the rack boot 15. When outside air is introduced into the room, the other end of the breather tube 10 opens into the empty chamber a of the suspension member 11, which has a closed cross-section, so only a small amount of muddy water, dust, etc. enters from the breather tube 10. It is.

【Example】

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. 1 and 2 show a first embodiment of the present invention, with FIG. 1 being a plan view and FIG. 2 being a sectional view taken along the line -- in FIG. This first embodiment has a breather tube 10 in a rack boot chamber A formed by a rack boot 6.
An example is shown in which the following are combined. This embodiment will be explained with reference to FIGS. 1 and 2. In order to transmit steering force to a rack-and-pinion type steering gear, a rack bar 1 is connected to a joint shaft 3 via a ball joint 2.
is connected to. The rack boot 6 prevents muddy water from flowing into the rack tube 7 that slidably supports the ball joint 2 and the rack bar 1 in this transmission system.
Provided to prevent the infiltration of dust, etc.
It is arranged so as to surround the connecting portion of the ball joint 2 between the rack bar 1 and the joint shaft 3. One end of the rack boot 6 is attached to the joint shaft 3 with a clamp 8, and the other end is attached to the rack tube 7 with a clamp 9. This forms a rack boot chamber A. The rack boot 6 is formed into a bellows shape so as to be able to follow the movement of the joint shaft 3 due to the easy stroke, and is made of rubber or resin. Then, the illustration of the easy boots 6 (first
Figure) A breather hole 4 is provided on the right side.
A breather plug 5 is fitted and attached to this breather hole 4. Furthermore, by attaching one end of a breather tube 10 made of an elastic material such as rubber or resin to this breather plug 5,
Breather tube 10 is connected to rack boot chamber A within rack boot 6. The other end of the breather tube 10 is inserted into a cavity a of a suspension member 11 having a closed cross section and located close to the rack boot 6, as shown in FIG.
The other end of 0 is open. To insert the breather tube 10 into the empty chamber a of the suspension member 11, an insertion hole 12 is bored in one side of the suspension member 11, and the breather tube 10 is inserted through this insertion hole 12. . The insertion hole 12 is large enough for the breather tube 10 to be inserted therein, and preferably has a diameter as small as possible. This is because it is possible to prevent muddy water, dust, etc. from entering from the insertion hole 12 into the empty space a of the suspension member 11 as much as possible. Note that 13 shown in FIG. 1 is a well-known air circulation hole provided in the rack tube 7, and the air in the rack boot chamber A can be moved to the rack boot chamber on the opposite side through this air circulation hole 13. ing. Further, 15 is a rack bush for slidably supporting the rack bar 1. moreover,
As can be seen from FIG. 1, the rack tube 7 is connected to the suspension member 11 via the bracket 14.
is supported by 3 and 4 show a second embodiment of the present invention, with FIG. 3 being a plan view and FIG. 4 being a sectional view taken along the line -- in FIG. Note that in FIGS. 3 and 4, parts corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals, and detailed explanation thereof will be omitted. This second embodiment shows an embodiment in which a breather tube 10 is connected to a chamber B which communicates with a rack boot chamber A and which is formed by surrounding a rack bar 1 with a rack tube 7 and a rack bush 15. In this embodiment, a breather hole 4 is provided in the latch tube 7.
A breather plug 5 is inserted into the housing, one end of a breather tube 10 is attached to the breather plug 5, and the breather tube 10 is connected to the chamber B of the rack tube 7. The other end of the breather tube 10 is inserted into the cavity a of the suspension member 11 and opened, as in the first embodiment. The chamber B formed by surrounding the rack bar 1 with the rack tube 7 and the rack bush 15 is communicated with the rack boot chamber A through an air circulation hole 13 provided at the left end of the rack tube 7, as shown in FIG. ing. In each of the first and second embodiments described above, the rack boot chamber A or the rack bar 1 communicating with the rack boot chamber A is connected to the rack tube 7 and the rack boot 1.
One end of the breather tube 10 is connected to at least one of the chambers B surrounded by the chamber B, and the other end of the breather tube 10 opens into the empty chamber a of the suspension member 11. Due to the influence of the heat source, etc., the air in the easy boot chamber A and the room B that communicates with the easy boot chamber expands.
If it contracts, the expansion or contraction is corrected through the breather tube 10. Therefore, the bellows shape of the rack boot 6 is always maintained normally, and the rack boot 6 is normally expanded and contracted as the rack bar 1 slides. In addition, in the above-mentioned operation, the air flow from the breather tube 10 to the rack boot chamber A occurs due to the expansion and contraction operations.
When outside air is introduced into the room B which is in communication with the rack boot room, muddy water, dust, etc. may enter at the same time. However, Breathatube 10
Since the cavity a of the suspension member 11, which is open at the other end, has a closed cross-sectional shape, muddy water hardly ever enters the cavity a, and only a small amount of dust enters the cavity a. . Therefore, the amount of muddy water and dust that enters from the breather tube 10 is very small. In particular, by making the size of the insertion hole 12 of the suspension member 11 into which the other end of the breather tube 10 is inserted as small as possible as described above, muddy water and dust existing in the empty chamber a of the suspension member 11 can be removed. Since it is small,
The effect becomes even more pronounced. Note that by making the breather tube 10 made of an elastic material, the insertion hole 12 can be made smaller. That is, even if the breather tube 10 comes into contact with the end surface of the insertion hole 12 of the suspension member 11 as the rack bar 1 slides, the breather tube 10 is elastically deformed, so the insertion hole 12 can be made smaller by that amount, and muddy water, dust, etc. Infiltration can be further reduced. Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-mentioned embodiments, but includes various embodiments within the scope of the claims for utility model registration. Yes, for example, the breather tube may be integrally molded into the boot.

[Effect of the idea]

As described above, according to the present invention, the breather tube is connected to at least one of the rack boot chamber and the chamber that communicates with the rack boot chamber and is formed by surrounding the rack bar with the breather tube and the rack boot chamber. Since the other end is opened into the empty chamber of the suspension member, which has a closed cross-sectional shape, there is almost no muddy water or dust in the empty chamber of the suspension member, so when the breather tube acts as a breather,
This has the effect of minimizing muddy water and dust entering the rack boot chamber or a chamber communicating with the rack boot chamber. In addition, in this invention, the other end of the breather tube is inserted and opened into the empty space of the suspension member located close to the part where the one end of the breather tube is joined, so the installation length of the breather tube is short. This has the effect of eliminating the need for

[Brief explanation of the drawing]

1 and 2 show a breather device for a rack-and-pinion type steering gear rack boot according to a first embodiment of the present invention.
The figure is a plan view, Figure 2 is a sectional view taken along the - line in Figure 1,
3 and 4 show a breather device for a rack-and-pinion type steering gear rack boot according to a second embodiment of the present invention, and FIG.
The figure is a plan view, and FIG. 4 is a sectional view taken along the line -- in FIG. 3. Explanation of symbols, 1... Rack bar, 3... Joint shaft, 4... Breather hole, 5... Breather plug, 6... Rack boot, 7... Rack tube, 10... Breather tube, 11... Suspension member , 12...insertion hole, A...easy boot chamber, B...chamber communicating with the easy boot chamber, a...vacant room for suspension member.

Claims (1)

[Scope of utility model registration request] A bellows-shaped rack boot is attached to the axially moving part of the rack and pinion type steering gear, one end of the breather tube is communicated with the rack boot chamber formed by the rack boot or the rack boot chamber, and the rack bar is surrounded by the rack tube and the rack boot. The other end of the breather tube is connected to at least one of the chambers communicating with the rack boot chamber formed by the breather tube. A breather device for a rack-and-pinion type steering gear rack boot characterized by an opening in a hollow space of a cross-sectional suspension member.