JPH0222387Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a steering damper, in particular,
Regarding a rack-and-pinion type steering damper.

[Conventional technology]

Examples of conventional rack-and-pinion steering dampers include:
There is one shown in Figure 6.

That is, the steering damper has a piston P fixed to a rack shaft L housed in a gear housing H, and a plurality of oil chambers R ₁ and R ₂ partitioned by the piston P are connected to the gear. It is included in the housing H. The piston P is formed with an orifice P' that allows communication between the oil chambers R ₁ and R ₂ .

Therefore, when the rack shaft L slides in the gear housing H due to vibrations from the road surface and reaction force from the wheels, for example, when the rack shaft L slides in the direction shown by the arrow X in the figure. , the oil in one oil chamber _R1 defined by the piston P is an orifice.
The oil flows through the orifice P' into the other oil chamber _R2 , and when it passes through the orifice P', a damping effect is exerted, and road vibrations and wheel reaction forces are not directly transmitted to the steering wheel. This provides vehicle handling stability.

[Problem that the invention attempts to solve]

However, if the structure is as described above, that is, if the combined volume of the oil chambers R ₁ and R ₂ remains unchanged, the oil pressure will change due to expansion and contraction of oil due to changes in oil temperature. It is not possible to respond to changes in oil volume due to decrease in oil due to evaporation or leakage, which leads to air mixing and a drop in oil pressure.
There is a problem that the damping force becomes unstable.

Furthermore, as a measure to solve the above problem, even if an accumulator Q is installed which communicates with the inside of the oil chamber _R2 , as shown in FIG. If we try to generate approximately equal damping force during sliding in both the direction indicated by arrow _X and the opposite direction, there will be a Extremely high-pressure gas must be filled in, and this high-pressure gas filling requires high sealing performance in each part, and this high sealing property causes an increase in friction, resulting in poor steering operation. There is a risk that this will lead to a loss of sensibilities.

In view of the above-mentioned circumstances, the present invention is capable of responding to changes in oil pressure caused by expansion and contraction of oil due to changes in oil temperature, as well as changes in oil volume due to decrease in oil due to evaporation and leakage, without using a high-pressure accumulator. It is an object of the present invention to provide a steering damper having a new configuration that can perform the damping action and does not impair the operational feeling of the steering wheel.

[Means for solving problems]

In order to solve the above-mentioned problems, the structure of the present invention is such that the inside of the gear housing is divided into two oil chambers by a piston fixed to a double rod type rack shaft housed in the gear housing. In the steering damper, the respective oil chambers are communicated with each other via a valve unit consisting of a throttle valve and a check valve, and an accumulator. The valve unit is formed between the cylinder and the casing, and the valve unit is provided in the casing.

〔Example〕

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

FIG. 1 is a circuit diagram showing the principle of the present invention, and the steering damper according to the present invention has a plurality of oil chambers R ₁ , which are defined by a piston P disposed in a gear housing H, It has _R2 .
The respective oil chambers R ₁ and R ₂ are the throttle valves.
They are connected _to each other through valve unit parts V ₁ and V ² having check valves c ₁ and c ₂ and check valves c 1 and c ₂ .

Therefore, the piston P moves, for example, to the left in the figure, and one oil chamber _R1 side becomes high pressure, and the check valve _o1 in one valve unit section _V1 and the check valve o1 in the other valve unit section _V2 are activated. valve c ₂
If the amount of oil flowing in is insufficient, it will be replenished from inside the accumulator Q, and if the amount of oil flowing in is excessive, it will flow into the other oil chamber R ₂ on the low pressure side. The oil flows into the accumulator Q, and a desired damping effect is exerted when the oil passes through the throttle valve _o1 , and the accumulator Q can cope with expansion and contraction of the oil due to changes in oil temperature, etc.

Since the accumulator Q is always positioned on the low pressure side, there is no need to make the gas pressure particularly high, for example, gas contained in the accumulator Q.

FIG. 2 shows a modification of FIG. 1, in which flow paths l ₁ and l ₂ that communicate the oil chambers R ₁ and R 2 in the gear housing H with the valve unit parts V ₁ and V ₂ , respectively, are shown _. A variable throttle valve O is installed in the mutually communicating bypass flow path l.
It has been decided that the following will be installed. In the case shown in FIG. 2, the damping force generated in the valve unit parts V ₁ and V ₂ can be adjusted arbitrarily by operating the variable throttle valve O depending on the vehicle running conditions, road surface conditions, etc. It has the advantage of being able to make changes and adjustments. In the case shown in FIG. 2, the variable throttle valve O may of course be replaced by another fixed type throttle valve.

FIG. 3 is a schematic diagram showing the principle _{of the} steering damper according to the present invention. This figure shows an example in which it is formed inside the housing H.

In the embodiment shown in FIG. 3, a suitable casing 1 is integrally formed within the gear housing H, and a double rod type rack shaft L is slidably inserted into the shaft core of the casing 1. I'm letting you do it.
The casing 1 has oil chambers R ₁ and R ₂ defined by a piston P fixed to a rack shaft L. Further, the casing 1 has valve unit parts V ₁ and V ₂ respectively, and communicates with the outside of the casing 1, that is, into the gear housing H, via the valve unit parts V ₁ and V ₂ . It is something that

An accumulator Q is formed within the gear housing H. That is, the above casing 1
An accumulator Q is formed between the gear housing H and the gear housing H as an outer cylinder positioned outside the casing 1. In the illustrated embodiment, there is no rubber membrane or the like disposed inside the accumulator Q, but this is because the gear housing H and the easy shaft L are usually kept horizontal or approximately horizontal. Taking this into account, if the gas in the gas chamber G in the accumulator Q were to flow into the oil chamber in the casing 1,
If there is a risk of intrusion into R ₁ or R ₂ ,
Of course, it is necessary to provide the above-mentioned rubber film and the like.

As shown in FIG. 4, the valve unit parts V ₁ and V ₂ formed in the casing 1 have throttle valves o ₁ and o ₂ and check valves c ₁ and c ₂ , respectively. Each of the above throttle valves o ₁ and o ₂ is connected to each oil chamber.
The check valves c ₁ and c ₂ allow the flow from R ₁ and R 2 into the oil chamber R ₃ in the accumulator Q, and the check valves c 1 and c ₂ allow the flow from the oil chamber R ₃ in the accumulator Q to the oil chambers R ₁ and R ₂ . This allows for inflow.

Therefore, when the rack shaft L housed in the gear housing H slides, for example, in the direction indicated by the arrow X in FIG.
Due to this sliding movement, the inside of the oil chamber _R1 becomes a high pressure side, and the oil in the oil chamber _R1 flows into the oil chamber _R3 in the accumulator Q through the throttle valve _o1 . At this time, the other oil chamber _R2 is on the low pressure side, so oil from the oil chamber _R3 in the accumulator Q flows into the other oil chamber _R2 via the check valve _c2 . That is,
The oil leaked from one oil chamber _R1 is transferred to the other oil chamber _R2.
This is what will flow into the country.

However, if the amount of oil flowing out from one oil chamber _R1 is expanding and the amount of oil flowing into the other oil chamber _R2 becomes excessive, the oil will flow into the other oil chamber _R2 . Any surplus oil that is not obtained will be stored in the accumulator Q. In addition, if the amount of oil flowing out from one oil chamber R ₁ is contracted and the amount of oil flowing into the other oil chamber R ₂ becomes too small, the amount of oil flowing out from the other oil chamber R ₂ becomes too small.
The oil that is insufficient to flow into the tank will be replenished from the accumulator Q.

Note that the inside of the accumulator Q is always on the low pressure side when oil flows out from the oil chamber R ₁ or R ₂ , so the gas pressure sealed in the gas chamber G inside the accumulator Q is specially controlled. There is no need to use high pressure.

FIG. 5 is a schematic diagram showing the principle of another steering damper according to the present invention, in which the valve unit parts V ₁ and V ₂ and the accumulator Q shown in FIG. 3 are formed outside the gear housing H. This figure shows an example.

In other words, the accumulator Q is a valve unit part.
A partition wall formed between an appropriate casing 1 having V ₁ and V ₂ and an appropriate outer cylinder 2 disposed outside of the casing 1, and fixed within the casing 1. The oil chambers 4 and 5 defined within the casing 1 by the member 3 are formed to communicate with each other via valve unit portions V ₁ and V ₂ , respectively. The oil chambers 4 and 5 in the casing 1 are connected to pipe lines 6 and 7 that are protruded from the casing 1 and protrude to the outside of the outer cylinder 2, and channels l 1 and ₇ that are connected to the pipe lines 6 and 7, respectively. The oil chambers R ₁ and R ₂ in the gear housing H are communicated with each other via l ₂ .

That is, in this embodiment, the gear housing H
Valve unit parts V ₁ , V ₂ and an accumulator Q are formed inside an outer cylinder 2 formed in a so-called tank shape on the outside of the steering damper. The tube 2 portion can be disposed at a desired separate position, which has the advantage that it is less likely to be subject to restrictions on the layout of the vehicle.

Note that in this embodiment as well, the gear housing H
The oil from the oil chambers R ₁ and R ₂ that are divided inside the casing 1 flows through the oil chambers 4 and 5 inside the casing 1, but also through the valve unit parts V ₁ and V ₂ to the accumulator Q. Of course, the desired damping force is obtained when the oil flows into the throttle valves o ₁ and o _{2 and passes through the throttle valves o 1 and o 2} , respectively. Furthermore, even when there is a change in the amount of oil, it is of course possible to cope with the change in the amount of oil through the intervention of the accumulator Q. Further, in the case of the accumulator Q formed inside the outer cylinder 2, the internal pressure inside the accumulator Q is either the oil chamber R ₁ in the gear housing H,
In _other words, the pressure is always lower than the internal pressure with the oil chambers 4 and 5 in the casing 1, and it goes without saying that the gas pressure sealed in the gas chamber G in the accumulator Q does not need to be particularly high. .

[Effect of idea]

As described above, according to the present invention, oil expands or contracts due to changes in oil temperature in the damper part of the steering damper, and furthermore, oil volume changes or oil pressure changes due to oil evaporation or leakage occur. Even if a damping force is generated, the desired damping force can be generated accordingly, and since it is not necessary to install an accumulator to fill in high-pressure gas, the operation feeling of the steering damper due to the high sealing performance in each part will be impaired. This has the advantage of eliminating concerns.

As a result, according to the present invention, it is possible to improve the steering stability of the vehicle, and the processing and manufacturing of the steering damper is simplified, making it possible to reduce costs. Moreover, the effect of increasing its versatility can be obtained.

Further, according to the present invention, since the rack shaft is of the double rod type extending on both sides of the piston, the pressure receiving area of the piston is equal, and the left and right damping forces can be equalized.

Furthermore, since the valve unit is provided in the casing, the installation space for the valve is large, and manufacturing is easy and the structure is simple.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the principle of a steering damper according to the present invention, Fig. 2 is a circuit diagram showing a modification of Fig. 1, and Fig. 3 is a circuit diagram showing the principle of a steering damper according to an embodiment of the present invention. 4 is a partially enlarged schematic diagram thereof, FIG. 5 is a schematic diagram showing the principle of a steering damper according to another embodiment, and FIG.
The figure is a partially cutaway front view of a conventional steering damper. 1...Casing, 2...Outer cylinder, _c1 , _c2 ...Check valve, H...Gear housing, L...Rack shaft, _o1 , _o2 ...Throttle valve, P...Piston, Q... …
Accumulator, R ₁ , R ₂ ... Oil chamber, V ₁ , V ₂ ...
Valve unit part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a steering damper in which the inside of a gear housing is divided into two oil chambers by pistons fixed to double rod type rack shafts housed in the gear housing, The oil chambers are communicated with each other via a valve unit consisting of a throttle valve and a check valve, and an accumulator, and the accumulator is located between a casing and an outer cylinder arranged to surround the outside of the casing. A steering damper characterized in that the valve unit portion is formed in the casing. (2) The steering system according to claim 1, wherein the casing has a shaft core inserted into the shaft so as to be slidable therethrough, and the outer cylinder is a gear housing having the casing inside. damper. (3) The casing, the outer cylinder, and the accumulator provided between the two are arranged separately from the gear housing, and the casing has two oil chambers partitioned by partition members. Become,
The steering damper according to claim 1, wherein each of the oil chambers is communicated with the oil chamber in the gear housing via a flow path.