JPS6112468A - Steering damper - Google Patents

Abstract

PURPOSE:To make it possible to compensate variations in hydraulic pressure and variations in amount of oil to obtain always a predetermined damping action, by communicating a plurality of oil chambers which are defined by partioning a gear housing by means of pistons, which a hydraulic pressure compensating chamber through valve units having restrictor valves, respectively. CONSTITUTION:In a steering damper in which a rack shaft 3 disposed in a gear housing 1 is slid in its axial direction by driving a pinion gear section 2, there are formed, in the gear housing 1, main chambers 6, 7 defined by pinions 4, 5 secured to the rack shaft 3 and a sub-oil chamber 8. Further, a hydraulic compensating chamber 9 formed in the rack shaft 3, is formed therein with a high-pressure gas chamber 11 by a free piston 10 inserted into the chamber 9. Further, this hydraulic compensating chamber 9 is communicated with the main oil chambers 4, 5 through the sub-oil chamber and valve sections composed of throttle valves 4a, 5a and check valves 5a, 5b, which are formed in the pistons 4, 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a steering damper, and particularly to a rack-and-binion type steering damper.

[Conventional technology]

As a rack-and-binion type steering damper that has been conventionally provided, for example, there is one shown in Fig. 7.

That is, the steering damper has a piston P fixed to a rack shaft AK housed in a gear housing H, and also has a plurality of oil chambers Rt and R2 in the gear housing H, which are partitioned by the piston P. are doing. The piston P has both oil chambers R/, R
An orifice O that allows communication between the two holes is formed.

Therefore, when the rack shaft A slides inside the housing H due to vibrations from the road surface and reaction force from the wheels, for example,
When rack shaft A slides in the direction indicated by arrow X in the figure,
The oil in one oil chamber R1 defined by the piston P passes through orifice 0 and flows into the other oil chamber R, 2, and when passing through this orifice O, a damping effect is exerted, reducing road vibration and The wheel reaction force is not directly transmitted to the steering wheel, and therefore, the steering stability of the vehicle can be achieved.

[Problem that the invention seeks to solve]

However, if the structure is as described above, that is, if the combined volume of the oil chambers Rt, R, 2 remains unchanged, the oil pressure will change due to expansion and contraction of oil due to changes in oil temperature. There is a problem in that the damping force becomes unstable due to the inability to respond to changes in the amount of oil, as well as changes in the amount of oil due to decreases in oil due to evaporation or leakage, resulting in air being mixed in.

In addition, as a measure to solve the above problem, for example, as shown in Figure 7, even if it is decided to form a hydraulic pressure compensation chamber R3 that communicates with the inside of the oil chamber R2, the rack shaft If an attempt is made to generate approximately the same damping force during sliding in both the direction indicated by the arrow At the same time, high sealing performance is required in each part, and there is a risk that improved sealing performance will cause an increase in friction and, as a result, the steering feel will be impaired. be.

In view of the above-mentioned circumstances, the present invention is capable of dealing with changes in oil pressure caused by expansion and contraction of oil due to changes in oil temperature and changes in oil amount due to decrease in oil due to evaporation and leakage, and also prevents impairing the steering feel. It is an object of the present invention to provide a steering damper with a new configuration that can perform a desired damping action without any problems.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has a structure that includes a plurality of oil chambers that are fixed to a rack shaft housed in a gear housing and that are partitioned by pistons and formed in the gear housing. The steering damper is characterized in that each of the plurality of oil chambers is communicated with a hydraulic pressure compensation chamber via a valve unit portion each having a throttle valve.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 shows a steering damper according to an embodiment of the present invention. It has a rack shaft 3 which has a rack gear part (not shown) that meshes with the pinion gear part 2 and is housed so as to be slidable in the left and right directions in the figure.

Note that side rods (not shown) are connected to both ends of the rack shaft 3, which are connected to wheels (not shown). Further, the gear housing 1 is fixed to a vehicle body (not shown).

The gear housing 1 has main oil chambers 6, 7 and a sub oil chamber 8 defined therein by a piston 4.5 fixed to the rack shaft 3. That is, in the gear housing 1, there are formed main oil chambers 6, 7, which are a plurality of oil chambers partitioned by a piston 4.5 VC fixed to the rack shaft 3.

The main oil chambers 6 and 7 are formed separately and independently so that they are not directly communicated with each other, and are located between the two main oil chambers 6 and 7, that is, between the two pistons 4.
, 5, a sub-oil chamber 8 is formed between them.

In the embodiment shown in FIG. 1, the main oil chambers 6 and 7, which are a plurality of oil chambers, are formed separately by two pistons 4.5, but instead of this, as will be described later. Of course, it may be defined by one piston 12 as in other embodiments (see Figure 5).

A hydraulic compensation chamber 9 is formed within the rack 3. A gas chamber 11 is located behind the free piston 10 that defines the hydraulic pressure compensation chamber 9, and the gas chamber 11 is filled with high-pressure dregs. Therefore, an accumulator, so to speak, is formed within the hook shaft 3.

The oil pressure compensation chamber 9 is communicated with the two main oil chambers 6 and 7 via the sub oil chamber 8, respectively. That is, ]
As shown in FIG. 72, throttle valves 4α and 5α are formed in the pistons 4 and 5, respectively, and the throttle valves 4a and 5α are respectively formed in the pistons 4 and 5.
5a, oil can pass from the main oil chambers 6, 7 side to the sub oil chamber 8 side, and check valves 4h, 5b are formed on the piston 4.5, respectively. The check valves 414 and 5b allow oil to flow from the sub oil chamber 8 side to the main oil chambers 6 and 7 side. Therefore, the hydraulic pressure compensation chamber 9, that is, the accumulator, communicates with the main oil chambers 6 and 7, which are a plurality of oil chambers, through the throttle valves 4α, 5a and the check valves 4b, 5b, that is, the valve unit portion, respectively. This is what we are doing.

The operation will be explained as follows based on Fig. 3 and Fig. 4 which show the principle of the part F below. That is,
The main oil chambers 6° 7, which are a plurality of oil chambers, are each connected to an accumulator QK, which is a hydraulic compensation chamber 9, through a valve unit part (2), and one oil chamber, e.g. When the volume of the main oil chamber 6 is narrowed, the oil in the one main oil chamber 6 is transferred to the other through the throttle valve 4α of one valve unit part (■) and the check valve 5h of the other valve unit part (■). Excess oil that cannot flow into the main oil chamber 7 of the first oil chamber 7 and cannot flow into the other main oil chamber 7 flows into the accumulator Q.

Conversely, if the pistons 4 and 5 slide so that the volume of the other main oil chamber 7 is narrowed, the oil in the other main oil chamber 7 is , through the throttle valve 5α and the check valve 4h of one valve unit section (■), and the excess oil that cannot flow into the one main oil chamber 6 flows into the accumulator Q. There will be an influx. In addition, even if the oil flows on the side 11 above, if the amount of oil flowing into the main oil chambers 6 and 7 is insufficient, of course it will be replenished from the accumulator Q. be.

Therefore, the oil in each main oil chamber 6, 7 flows out through the throttle valves 4a, 5α, so that the throttle valves 4a, 5α,
5α, the desired damping force is generated, and even if there is oil that cannot flow into each main oil chamber 6, 7 due to a rise in oil temperature, the oil will flow into the accumulator Q. This makes it possible to deal with the expansion of oil as the temperature rises. Conversely, even if there is oil pressure or oil volume shortage due to oil contraction, evaporation, or leakage due to a drop in oil temperature, the accumulator Q
As a result, oil is replenished from the engine, and it is also possible to prevent a decrease in damping force or inoperability due to insufficient oil pressure or insufficient amount of oil.

In addition, the throttle valve 4 in the valve unit part ■ in Fig. 3
Check valve 4c in series with a and 5α.

5C is the sub-oil chamber 8 of the throttle valve 4a and 5α in the fang 2 diagram.
Check valve 4c that closes the side opening.

5C, the check valves 4ty and 5c may be omitted as shown in FIG. That is, in Fig. 4, for example, when one of the main oil chambers 6 is contracted to become a high-pressure side, no backflow of oil occurs through the throttle valve 4α communicating with the main oil chamber 6Vc. , a check valve 4 connected in series with the throttle valve 4a.
c (see Figure 3) may be omitted.

Fig. 5 shows a steering damper according to another embodiment of the present invention, and in this embodiment, a main oil chamber 6, which is a plurality of oil chambers formed in the gear housing 1,
An accumulator Q (see Fig. J-3), which constitutes the valve unit part V (see Fig. 3) and the hydraulic compensation chamber 9 (see Fig. A-1) connected to the gear housing 1, is formed outside the gear housing 1. This embodiment differs from the embodiment shown in FIG. 1 in that the embodiment shown in FIG.

This embodiment will be described below, focusing on the differences from the previous embodiments. In addition, the codes used in Figure 5 are as follows:
The same reference numerals used in the figures of the above-mentioned embodiment indicate that the basic configuration is the same, and this also applies to the figure 6 of the teeth described later.

In the steering damper shown in FIG. 5, a plurality of main oil chambers 6 and 7 are formed in the gear housing 1.
is partitioned by one piston 12 fixed to the rack shaft 3. Then, the piston 1
Oil does not pass between the two main oil chambers 6 and 7 via the two parts.

However, the main oil chambers 6 and 7 are connected to a tank T disposed outside the gear housing 1 via passages 13 and 14, and can communicate within the tank T.

As mentioned above, the valve unit section V (see figure g-3) is disposed inside the tank T, and
The valve unit part V has one end fixed to the tank TVC and the other end fixed to the tank T to the accumulator Q (,31-3
It has a base shaft 16 connected to a partition wall 15 fixed to form a section (see figure), and has valve discs 17, 18 disposed on the base shaft 16 at appropriate intervals. The valve disc 17° 18 has an oil chamber 19 communicating with the main oil chamber 6 via a passage 13 in the tank T, an oil chamber 20 communicating with the main oil chamber 7 via a passage 14, and both oil chambers. Sub-oil chambers 8 that allow communication between oil chambers 19 and 20 are respectively defined as sections. Furthermore, a passage 21 is formed inside the base shaft 16, one end of which opens into the sub-oil chamber 8, and the other end of which opens into the hydraulic pressure compensation chamber 9.

Further, in the tank T, an accumulator Q is formed as described above, and the accumulator Q is a free piston that partitions and forms a hydraulic compensation chamber 9 inside the partition wall 15. 10 and has a gas chamber 11 behind it. The oil pressure compensation chamber 9 is communicated with the main oil chambers 6 and 7 via the sub oil chamber 8 and the oil chambers 19 and 20, respectively.

Figure 6 shows a more specific embodiment of the tank T, that is, the valve unit section V and the accumulator Q, and this embodiment will be briefly described below.

The tank T includes an appropriate sleeve 22 formed in a cylindrical shape.
One end of the base shaft 16 is fixed to one end of the cover member 23 by tightening a nut 25, and the other end of the cover member 23 is fixed with a nut 25. A plug 26 for gas filling is driven in. A partition wall 15 that partitions the inside of the tank T into a valve unit section V and an accumulator Q is fixed to the other end of the base shaft 16 with a nut 27.

Further, the valve disc 1 disposed on the base shaft 16
7.18, an inner oil passage 28, 29 and outer oil passages 30, 31 are bored, respectively. And the inner oil passage 28
, 29, which corresponds to the throttle valve 4 (see figure UF5) located adjacent to the opening on the side of the sub-oil chamber 8, and an outer oil passage 30°3.
Check valves 4h and 5h are arranged adjacent to the openings on the side of the oil chambers 19 and 20 of 1.

Note that on the outer periphery of the sleeve 22 constituting the tank T, a portion corresponding to the outside of the oil chambers 19 and 20 is
Connectors 34 and 35 are fixed, and the connector 3
4.35, the main oil chambers 6, 7 (see Fig. 5) and the oil chambers 19, 20 are communicated by a passage 13.14.

In addition, in this embodiment, when fixing the valve disk 17.18 to the base shaft 16, a spacer 36.37 that also serves as a stopper and a valve stopper that presses the leaf valve 32.33 against the valve disk 17.18 are used. 38.3
In particular, the spacers 4o are provided with a passage 2 in the base shaft 16.
1 and a sub-oil chamber 8 are formed therein.

In any of the embodiments described above, the valve unit section V is formed within the gear housing 1 or within the tank T, but it may be formed within the rack shaft 3 instead. Further, the valve unit section V and the accumulator Q may be formed separately inside and outside the gear housing 1, respectively.

〔Effect of the invention〕

As described above, according to the present invention, since the amount of oil stored in both main oil chambers, which are multiple oil chambers that house oil for damping, is variable, oil expansion due to changes in oil temperature can be prevented. It is possible to cope with oil pressure changes due to contraction, and it is also possible to cope with changes in oil amount due to oil evaporation or leakage, which has the advantage of providing stable damping force.

In addition, the gas pressure in the gas chamber of the accumulator that constitutes the hydraulic compensation chamber is sufficient to be at the level normally used, so the sealing performance of various parts due to the extremely high pressure gas filling is improved, and the resulting increase in friction, etc. There is also the advantage that there is no risk of deterioration of the operational feeling.

Furthermore, if the valve unit and accumulator are formed outside the gear housing that constitutes the steering damper, it can be used without requiring major design changes to the conventional steering damper, making it economical. It also has the advantage of being superior in terms of gender.

[Brief explanation of drawings]

Figure 1 is a partially cutaway front view of a steering damper according to an embodiment of the present invention, Figure 2 is an enlarged sectional view of the cross section shown in Figure 1, and Figures 2 and 3. is a circuit diagram showing the principle shown in Fig. 1, Fig. 4 is a principle circuit diagram showing a partially modified version of Fig. 3, and Fig. 5 is a steering damper according to another embodiment of the present invention. Figure 6 is a cross-sectional view showing more specifically what the schematic diagram in Figure 5 shows, and Figure 7 is a diagram showing a conventional steering damper in a manner similar to Figure 1, including some schematic diagrams. It is a figure shown almost similarly to a figure. 1... Gear housing, 3... Rack shaft, 4.5.
12...Piston, 4α, 5a...e Throttle valve, 6,7
...Main oil chamber, 9...Hydraulic pressure compensation chamber, Qe...Accumulator, T.1 tank, ■...Valve unit section.

Claims (4)

[Claims] (1) In a steering damper having a plurality of oil chambers formed in the gear housing and partitioned by a piston fixed to a rack shaft housed in the gear housing, the plurality of oil chambers are A steering damper, characterized in that the steering damper is connected to a hydraulic compensation chamber through valve unit sections each having a throttle valve. (2) A steering damper according to claim 1, wherein a valve unit having a throttle valve and a hydraulic compensation chamber are formed in a gear housing. (3) The steering damper according to claim 1, wherein the valve unit having the throttle valve is formed in the piston, and the hydraulic compensation chamber is formed in the rack shaft. (4) The steering damper according to claim 1, wherein the valve unit having the throttle valve and the hydraulic compensation chamber are formed outside the gear housing.