JPH03632Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a pulsation absorbing device that absorbs pulsations in pressure fluid supplied from a pump to a power steering device or the like.

<Prior art> Conventionally, when high-pressure fluid is supplied from a pump to a power steering device, a resonance box 3 is connected in the middle of a pipe 1 via a throttle 2 as a pulsation absorbing device for the high-pressure fluid, as shown in FIG. This aperture 2 and resonance box 3
The pulsation is absorbed by the action of

<Problems to be Solved by the Invention> In such a conventional resonance pulsation absorbing device, pulsation at a frequency f as shown in the following equation is absorbed.

In this equation, V is the volume of the resonance box, S is the opening area of the diaphragm, is the path length of the diaphragm, and C is the pressure wave propagation velocity.

As is clear from this equation, in the conventional pulsation absorber, the pulsation frequency that can be absorbed is uniquely determined by the volume of the resonance box 3, the aperture area of the diaphragm, and the path length of the diaphragm. It was not possible to absorb the pulsation of the engine, and it was not optimal as a pulsation absorbing device for a pump for a power steering system whose rotation is constantly fluctuating.

<Means for Solving the Problems> The present invention has been made in order to solve such conventional problems. A diaphragm tapered across the length, a resonance box connected to the diaphragm and having a larger space than the diaphragm, and a tapered valve body that matches the diaphragm. The control valve is provided with a control valve that controls the opening area and length of the passage formed between the valve body and the throttle by moving it forward and backward according to the flow rate.

<Operation> Since the present invention has the above configuration, it operates the control valve based on changes in the pump rotation speed and adjusts the opening area of the throttle and the passage length of the throttle, thereby suppressing pulsation in a wide frequency band. This makes it possible to cope with devices whose rotational speed changes over a wide range, such as pumps for power steering equipment.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 2, 10 is a pump, and 11 is a steering device. These pumps 10 and steering device 1
1 are connected by piping devices 12 and 13, and high pressure fluid from the pump 10 is supplied to the steering device 11 via the piping device 12, and the steering device 1
The discharged fluid from 1 is adapted to be discharged into a tank 14 via a piping arrangement 13.

The pulsation absorbing device 20 of the present invention is connected in the middle of the piping device 12 on the high pressure side. As shown in FIG.
1, and the fluid chamber 22 of this resonance box 21 is connected to the piping 1.
2, and this diaphragm 23.
4 and a control valve 24 that controls the passage length L of the throttle 23. The control valve 24 includes a solenoid 25, a movable spool 26 that is displaced in the axial direction when the solenoid 25 is energized, and a valve shaft 27 that is integrally connected to the movable spool 26.
A tapered valve body 28 is integrally formed with the valve shaft 27 and inserted into a tapered hole constituting the throttle 23.
It becomes more. In a normal state, the movable spool 26 is positioned at a predetermined axial position by springs 29 and 30, and then as the solenoid 25 is energized, the movable spool 26 is displaced in the axial direction, and the tapered valve body 28 Insert into the aperture 23,
The clearance G of the throttle 23 and the passage length L are controlled.

The solenoid 25 includes a solenoid drive circuit 3.
A microprocessor 31 is connected via 2. The microprocessor 31 receives a signal from the rotation sensor 30 and applies a current to the solenoid 25 according to the input signal. The rotation sensor 30 may directly detect the rotation of the power steering device pump 10, or may detect the rotation of the automobile engine that rotationally drives the pump 10.

According to the pulsation absorbing device of the present invention, the pulsating high-pressure fluid flows into the resonance box 22 through the throttle 23, so that the pulsation is absorbed by the action of the resonance box 22, and the high-pressure fluid without pulsation is used as the steering wheel. It is supplied to the collecting device 11.

Also, if the engine speed changes, pump 1
The rotation of 0 also changes, and the frequency band of the pulsation changes accordingly.

However, in the present invention, a change in the rotational speed of the pump 10 (or a change in the engine rotational speed) is detected by the rotational sensor 30, and the signal thereof is input to the microprocessor 31. Based on this signal, the microprocessor 31 applies a predetermined applied current to the solenoid 25 via the solenoid drive circuit 32, whereby the valve body 25 is displaced in the axial direction together with the movable spool 26, and the passage area S of the throttle 23 and the passage The length L is adjusted, and at the same time the aperture 23
The gap G between the valve body 28 and the valve body 28 changes to adjust the opening surface S of the diaphragm 23, and as a result, pulsations in different frequency bands can be absorbed.

<Effects of the invention> As mentioned above, the pulsation absorbing device of the invention consists of a diaphragm connected to a pipe and formed into a tapered shape over a predetermined length, and a resonance box connected to the diaphragm and having a space wider than the diaphragm. and a tapered valve body that matches the throttle, and the opening area and length of the passage formed between the valve body and the throttle by moving the valve body forward and backward according to changes in the pump rotation speed, etc. By changing the opening area and length of the passage, the width of the pulsation frequency that can be absorbed can be increased. Compared to conventional methods, piping can be shortened and piping work can be done more easily, reducing costs. Further, since it is sufficient to move the valve body slightly forward and backward in order to change the opening area and length of the passage, the pulsation absorbing device can be miniaturized.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a pulsation absorbing device showing an embodiment of the present invention, Fig. 2 is an overall view showing a piping device connecting a pump and a steering device, and Fig. 3 is a diagram showing a conventional pulsation absorbing device. It is. 10...Pump, 11...Steering device, 12,1
3... Piping device, 20... Pulsation absorption device, 21...
Resonance box, 23... Throttle, 24... Control valve, 30...
...Rotation sensor, 31...Microprocessor.

Claims (1)

[Scope of utility model registration request] A pulsation absorbing device that is connected to a pipe that connects a pump and a hydraulic device such as a power steering device, and includes a throttle connected to the pipe and formed in a tapered shape over a predetermined length; A resonance box that is connected and has a space larger than the throttle, and a tapered valve body that matches the throttle, and by moving the valve body forward and backward according to changes in the pump rotation speed, etc., there is a gap between the valve body and the throttle. A pulsation absorbing device comprising: a control valve for controlling the opening area and length of a passage formed in the pulsation absorption device.