JPS5950242A - Shock absorber device - Google Patents

Abstract

PURPOSE:To avoid the device from becoming large in size even when the amplitude is large by providing the first means to generate damping force and the second means to generate the damping force which generates damping force based on the signal from the speed detecting means which produces its output in response to the fluid force detected in the first damping force generating means. CONSTITUTION:A fluid pressure detector 27 is provided to detect the fluid pressure inside an upper fluid chamber 19. When vibration is transmitted to a piston 18 through a rod 17, the pressure of oil 23 on downstream side rises and flows through an orifice 24 to cause the damping force which is proportionate to the relative speed of the piston 18. Generally, the relative speed of the piston 18 and the fluid pressure are proportionate. When the piston 18 moves in the direction of arrow D, the fluid pressure becomes positive, and when it moves in the opposite direction, the negative pressure will be generated. Such fluid pressure inside the upper fluid chamber 19 is detected by the fluid pressure detector 27, and is outputted as a fluid pressure signal proportionate to the fluid pressure to to be transmitted to the electro-magnetic coil 26. The magnetic powder in the oil 23 is magnetized to generate the damping force.

Description

[Detailed description of the invention] This invention relates to a shock absorber device.

As a conventional shock absorber device, the one described in, for example, Japanese Patent Laid-Open No. 10844/1984 is known. The structure of this shock absorber device will be explained based on FIG. Ru! It consists of a suspension spring mechanism 1.2, a sensor mechanism 3 that detects the relative speed between the object and the foundation, a cylinder 5 connected to either the object or the foundation, and a piston 6 connected to the other. A cylinder that holds a magnetic fluid 7 between an outer wall surface and an inner wall surface of the cylinder, a piston mechanism, an excitation coil 8 that generates a magnetic flux that magnetizes the magnetic fluid 7, and a control according to the detected value of the sensor mechanism 3. fall voltage to the excitation coil 8
It is configured to control the damping force between the cylinder 5 and the piston 6 by magnetizing the magnetic fluid. The sensor mechanism 3 is composed of a magnetic pickup having a coil 10 supported at one end of the cylinder 5 via a yoke member 9, and a 15-shaped magnet 12 attached to a connecting rod 11.
The annular magnet 12 can pass through the inside. However, in the above-mentioned shock absorber device, since the sensor mechanism 3 is composed of a magnetic pickup disposed at one end of the cylinder 5, when the relative displacement between the object and the base 6jδ is large, the cylinder 5 axis of the magnetic pickup There was a problem in that the length in the direction had to be increased, resulting in an increase in the size of the shock absorber device.

The present invention was made by focusing on such conventional problems, and includes a cylindrical member connected to one of two members that approach and isolate each other due to vibration, and a cylindrical member filled with a material having electrical or electrical characteristics. a magnetically modifiable fluid; and
It is connected to the other of the two members and is slidably inserted into the cylindrical member, and generates a fluid resistance between it and the fluid corresponding to the relative speed of the two members by vibration, and generates a damping force based on the fluid resistance. a first damping force generating means, a speed detecting means for detecting the fluid force caused by the first damping force generating means and outputting a signal corresponding to the relative speed of the two members, a driving means capable of outputting a current signal that changes based on the current signal; and a second damping device that changes the characteristics of the fluid based on the current signal and generates a damping force that can be changed in response to the change in the characteristics of the fluid through the fluid. The above problem can be solved by providing a shock absorber device that can generate force. )1.

Hereinafter, this invention will be explained based on the drawings.

FIG. 2 shows a first embodiment of the present invention, and the configuration will be explained first. Reference numeral 14 denotes a cylinder body connected to either a vibrating body or a vibrated body (not shown), and both ends of the cylinder body 14 are closed with lids 15 and 16.
A space is defined inside. 17 is a rod made of a non-magnetic material connected to either the vibrating body or the vibrated body, and the rod 17 is slidably passed through the lid 15 and inserted into the cylinder body 14 so as to be relatively displaceable. ing. One end of the rod 17 is slidably received within the cylinder body 14 . ], and the piston 18 defines an expandable and contractible upper liquid chamber 19 and a lower chamber in the space inside the cylinder body 14. The royal chamber is divided into a lower liquid chamber 21 and a gas chamber 22 by a free piston 20 slidably housed in the cylinder body 14, and the gas chamber 22 is filled with gas at a predetermined pressure.
7. The volume of the upper liquid chamber 19, which is increased or decreased by
2 by reducing or expanding the volume of t1'6. The two-part liquid chamber 19 and the lower liquid chamber 21 are filled with oil 23 mixed with magnetic material, and the screw 1-18 communicates the upper liquid chamber 19 and the lower liquid chamber 21. An orifice 24 is formed through which oil 23 can pass. The diameter of this orifice 24 is the diameter of the cylinder body 14 of the piston 18.
The piston 18 (not shown) is designed so that a predetermined damping force F is generated in response to the relative speed to the two-part liquid chamber 19 and the lower liquid chamber 2.
A relief valve communicating with 1 is also provided. The aforementioned rod I7, the piston 18 provided with the orifice 24, and the relief valve constitute the first damping force generating means. Note that such a first damping force generating means adopts a structure similar to the damping force generating mechanism of a general shock absorber.
η, so detailed explanation will be omitted. A core 25 is fixed to one end of the rod 17, and the core 25 is formed into a substantially cross shape as shown in detail in FIG. An electromagnetic coil 2G is wound around the core 25 as shown in Fig. 4, and when the electromagnetic coil 2G is energized, an N pole and an S pole are generated as shown in the figure. . Generally, magnetic flux is concentrated at the opposing portion of the north pole and the south pole, and the magnetic flux density at this opposing portion is high, so as shown in FIG. By winding 21A, it is possible to form a large number of opposing parts of N and S poles, and in order to obtain the same iJ magnetic flux, a pair of N and S poles can be formed by enlarging 21A and increasing the number of turns of the coil. The current efficiency is reduced by 1 compared to when using the S pole.
rli can be set. The core 25 and the electromagnetic coil 2, together with the cylinder body I4, constitute a second damping force generating means. The cylinder body 14 detects the pressure of the oil 23 as a fluid force in the upper liquid chamber 19,
A hydraulic pressure detector 27 is attached which outputs a hydraulic pressure signal proportional to the pressure, and the hydraulic pressure signal is amplified by a predetermined amplification factor G in an amplifier circuit serving as a driving means 28 and output as a current signal. Ru. The driving means 28 is connected to the electromagnetic coil 26 via a lead wire 29, and the lead supply Ji!
The rod 29 enters the hollow part 30 from αj1.1 in addition to the rod 17 and reaches one end of the rod 17.

Next, the effect will be explained. The vibration of the vibrating body causes rod 17
When the vibration is transmitted to the piston 18 through the vibration, the piston 18 reciprocates within the cylinder body 14 connected to the object to be vibrated at a relative speed 2 that does not correspond to the amplitude and frequency of the vibration. As a result, the oil 23 on the downstream side in the direction of movement of the piston 18
The oil 23 flows through the LJ orifice 24.

Due to such a flow of the oil valve 23, a damping force F proportional to the relative speed V of the piston 18 is generated.

Generally, there is a proportional relationship between the relative speed (2) of the piston 18 and the oil pressure P in the liquid chamber 19, as shown by the straight line Δ in FIG.

It can be shown as +3.

1) , (V In addition, when the vibrating body and the vibrated body in Fig. 5 are statically fixed, the oil pressure 1) when the relative speed between the Zunawaji piston 18 and the cylinder body 14 is O value is assumed to be 0 value. In the figure, when the relative speed is C value, the change in the direction of 1 and B toward a straight line indicates the opening of the relief valve. Therefore, when the piston 18 moves in the direction of the arrow in FIG. 2, the oil pressure P takes a positive value, and when it moves in the opposite direction to the arrow, the oil pressure P takes a negative value. The liquid pressure P in the upper liquid chamber +9 is detected by the liquid pressure detector 27 and output as a liquid pressure signal proportional to the liquid pressure P. The hydraulic pressure signal is amplified by a predetermined amplification factor G in an amplifier circuit and transmitted to the electromagnetic coil 26 as a current signal. Therefore, the current value {circle around (2)} of the current signal is in a proportional relationship as indicated by the straight line 2, B2 in FIG. 6, as shown below.

1-cG X l) The current signal excites electromagnetic coil 26, and electromagnetic coil 2 (;
The magnetic powder mixed in the oil 23 between the core 25 and the cylinder body 14 is magnetized, and a force that tends to restrain the core 25 and the cylinder body 14 is generated. As a result, a damping force F2 is generated. In this way, the damping force F2 is proportional to the magnetic force, and the magnetic force is proportional to the current value I of the current signal flowing through the electromagnetic coil 26, so the damping force F2 is
is proportional to the current value I of the current signal, and can be shown as follows.

F2 core 1 Based on the above-mentioned relationship between the relative speed V of the piston I8, the oil pressure P, the current value ■, and the damping force F2, the relative speed V of the piston 18 is determined.
The relationship between F and damping force F2 can be expressed as follows.

2ocV Therefore, the damping force F of the shock absorber device is the sum of the above damping forces F, , F2, and the straight line 1111 in FIG.
．． The relative velocity V of the piston 18 as shown in 1□
(The two-dot chain line in FIG. 111 indicates the damping force F1, hereinafter). Note that the amplification factor G of the amplifier circuit may be made variable or the output of the current signal may be turned ON-OFF. If this is done, the damping force F of the shock absorber device can be made variable. For example, as shown in straight lines A3 and B in FIG. 8, the amplification factor G is made non-linear so that when the relative speed V of the piston 18 exceeds a predetermined value, the current value ■ of the current signal becomes approximately constant. Then, the damping force F of the 7-quad absorber device is the straight line H2 in Fig. 9,
The relative velocity V of the piston 18 as indicated by J2'
When it exceeds a predetermined value, the rate of increase decreases. therefore,
When such a shock absorber device is used in a vehicle suspension, the damping force F does not become very large even if the vehicle runs over a protrusion while driving at high speed. As a result, no shock is transmitted to the vehicle body, and the effect of allocating relatively gentle vibrations of the vehicle body can be maintained. Also, the amplification factor of the amplifier circuit is set to
As shown by straight lines A-+ and B-4 in FIG.

may be made larger than the amplification factor G2 of the hydraulic pressure signal when the piston 18 moves in the direction opposite to the direction of the arrow. The damping force F of the shock absorber device can be varied by 2 depending on the moving direction of the piston 18. Therefore, when the rod 17 is connected to the vehicle body side and the cylinder body 14 is connected to the wheel side,
Even if the wheels are pushed up due to unevenness on the road surface while the vehicle is running, the transmission of the pushing up force to the vehicle body can be reduced and the riding comfort can be improved. As described above, in the first embodiment of the present invention, the relative velocity V of the piston 18 and the hydraulic pressure velocity (2) are detected as the oil pressure I) by the hydraulic pressure detector 27, so that the relative velocity V of the piston 18 is detected as the hydraulic pressure I) by the hydraulic pressure detector 27. Even if the shock absorber device is interposed between the vibrating bodies, the axial length of the shock absorber device does not increase, and the shock absorber device can be made smaller.

FIG. 12 is a diagram showing a second embodiment of the present invention, and the first
Components that are the same as those in the embodiment are given the same reference numerals, and explanations thereof will be omitted. 31 is a driving means connected to the hydraulic pressure detector 27, and this driving means 31 includes a frequency detection circuit that detects when the hydraulic pressure signal is above a certain frequency value, and a frequency detection circuit that detects this when the hydraulic pressure signal is above a certain frequency value. has an amplifier circuit that outputs a current signal with a constant amplification factor G, and when the frequency exceeds a certain value, decreases the amplification factor G in inverse proportion to the increase in frequency and outputs a current signal.

Therefore, in the second embodiment shown in FIG. 12, when the vibration of the vibrating body has a low frequency below a certain value, the amplification factor G is kept constant and damped as shown in FIG. The force F is shown by the dashed dotted lines K and 1- in FIG. 14, and changes like a tin.

However, when the vibration of the vibrating body has a high frequency higher than a certain value, the amplification factor G in the amplifier circuit decreases as the frequency increases. As a result, the damping force F of the shock absorber device decreases compared to when the frequency is low, as shown by broken lines M and N in FIG. Therefore, when such an absorber device is used in a vehicle's suspension, it can prevent the high-frequency microvibrations generated in the tires while the vehicle is running from being transmitted to the vehicle body, improving the ride comfort of the vehicle. can be done.

Further, since the relative velocity V of the piston 18 is detected as the hydraulic pressure P by the hydraulic pressure detector 27, the shock absorber device can be made into a small size similar to the first embodiment.

FIG. 15 is a diagram showing the third embodiment of the present invention, and the first
Components that are the same as those in the embodiment are denoted by the same reference numerals, and their explanation will be omitted. Reference numeral 32 denotes a hollow inner case connected to the vibrating body, and one end of the inner case 32 slidably passes through the other end of a non-magnetic outer case 33 connected to the vibrated body. is inserted into. A guide 34 is fixed to one end of the inner case 32, and a groove 35 is formed in the guide 34, as shown in FIG. The space defined by the outer case 33 and the inner case 32 is filled with oil 23 mixed with magnetic powder, and the upper part of the oil 23 is filled with gas to adjust the volume of the space.

Furthermore, a shock absorber 36 as a first damping force generating means is housed in a space defined by the outer case 33 and the inner case 3Z, and the cylinder body 14 of the shock absorber 36 is attached to one end of the outer case 33. Fixed. On the other hand, the rod 17 of the shock absorber 36 is connected to the inner case 3.
A load cell 37 is interposed between the rotor l'17 and the inner case 32. 38
is a seal that prevents gas from leaking outside. The shock absorber 3G described above converts the relative velocity J of the inner case 32 relative to the outer case 33 into a damping force F as a fluid force, and this damping force F1 is converted by the load cell 37 into a signal corresponding to the relative velocity ■. be done. The signal output from the row 1 cell 37 is amplified in the amplifier circuit of the drive means 39 and sent as a current signal to the electromagnetic coil 40 supported by the outer case 33 via the core 33a and capable of exciting the magnetic 5) in the oil. . Therefore, in addition to the damping force F caused by the shock absorber 36, the magnetic powder in the oil is magnetized by the current signal output from the drive means 39, and the core 33a and the inner case 32 are restrained, thereby increasing the damping force F2. occurs. Here, the amplifier circuit of the drive means 39 is provided with a dead zone R as shown in FIG. It is pickled in such a way that it corresponds to the relative velocity V of . That is, in the shock absorber 36, friction is generated between the cylinder body 14 and the piston 18 and between the cylinder body 14 and the u-rad 17 due to the movement of the piston 18.
The load cell 37 also detects the friction force caused by these frictions. Therefore, the signal output from the load cell 37 represents the sum of the damping force F of the shock absorber 36 and the frictional force. Therefore, if the dead zone R is not provided and the signal from the load cell 37 is directly amplified, a current signal as shown by the broken line S and '1' in FIG. The relationship with the coupled speed is also as shown by broken lines u and w in FIG. 18, so the restraining force between the core and the inner case 32 increases in the region where the relative speed V of the inner case 32 is small, supporting the operation of the shock absorber device. Produces P. Therefore, as mentioned above, the insensitive 3iF R is installed to remove the portion of the signal from the load cell 37 that corresponds to the force generated by the friction of the shock absorber 36, and to convert the current signal into a current signal as indicated by the straight lines A3 and B5 in FIG. Do as shown.

As a result, the relationship between the damping force F of the shock absorber device and the relative speed ■ of the inner case 32 is expressed by the straight line 11 in FIG.
4. As shown by J4, the shock absorber device can operate smoothly. Further, in the third embodiment, the relative speed V of the inner case 32 is detected by the load cell 37, so that the shock absorber device can be downsized similarly to the first embodiment.

Figures 19 and 20 show a fourth embodiment of the present invention, in which the same components as in the first embodiment are denoted by the same reference numerals (=1 and the explanation will be omitted. 41 is installed on the rod 17 and one end is This passage 41 opens to the lower liquid chamber 21, and this passage 41 transmits the liquid pressure P of the lower liquid chamber 21 to the liquid pressure detector 27 via the adapter 42.
can be transmitted. In this fourth embodiment, the first
Not only can the shock absorber device be made smaller as in the embodiment, but even when the cylinder body 14 is connected to a vibrating body, the fluid pressure detector 27 does not vibrate because it is fixed to the vehicle body, and the fluid pressure sensor 27 can be detected easily. The durability of the container 27 can be improved.

In each of the above embodiments, the first damping force generating means is the rod 17, the piston 18 in which the orifice 24 is formed,
Although the upper end of the piston 43 and the chamber 44 are communicated with each other as shown in FIG.
Vortex generating holes 45 and 46 extending tangentially to the inner circumference and the chamber 4
4 and an orifice 47 communicating with the lower end of the piston 43;
Alternatively, the piston 43 may be configured with a piston 43 having a shape. Furthermore, in each of the embodiments described in Section 2, the oil 23 mixed with magnetic powder is filled into the cylinder body 14, etc., but it may be filled with a magnetic fluid, a magnetic material, or a magnetic fluid. Alternatively, electrodes may be provided and filled with an electrical fluid having a winding effect.

As explained above, according to the present invention, the shock absorber device is moved closer to each other by vibration, and the cylindrical member connected to the - side of the two parts separated by M11 is filled with electricity. 9, the fluid resistance corresponding to the relative velocity of the two members is created between the fluid that can be changed by magnetism and the fluid that is slidably inserted into the cylindrical member that is connected to the other of the two members α and that vibrates. A first damping force generating means that generates a damping force based on fluid resistance, and a signal that detects the fluid force caused by the first damping force generating means and generates a signal corresponding to the relative speed of the two members. A speed detecting means for outputting, a driving means capable of outputting a current signal that changes based on the signal from the speed detecting means, and an l capable of changing the characteristics of the fluid based on the current signal and corresponding to changes in the characteristics of the fluid. (Since it is equipped with a second damping force generating means that generates a damping force through a fluid, it is possible to prevent the shock absorber from increasing in size even when the amplitude of vibration generated between two parts is large. The effect is that it can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing a conventional shock absorber device, FIG. 2 is a partially sectional front view showing a first embodiment of the present invention, and FIG. 3 is a perspective view showing the electromagnetic coil of FIG. Figure 4 is a plan view of Figure 3,
Figure 5 is a graph showing the relationship between the relative speed of the piston of the shock absorber device and the oil pressure, Figure 6 is a graph showing the relationship between the oil pressure and current signal of the shock absorber device shown in Figure 2, and Figure 7 is a graph showing the relationship between the oil pressure and the current signal of the shock absorber device shown in Figure 2. A graph showing the relationship between the relative speed of the piston and the damping force when the current signal of FIG. 6 is given,
Fig. 8 is a graph showing the relationship between oil pressure and current signal when the amplification factor in the amplification circuit Fllk of the device shown in Fig. 2 is made non-linear, and Fig. 9 is a graph showing the relationship between the oil pressure and the current signal when the current signal shown in Fig. 8 is applied to the piston. Graph showing the relationship between relative speed and damping force, 1st
Figure 0 is a graph showing the relationship between oil pressure and current signal when the amplification factor in the amplifier circuit of the device shown in Figure 2 is varied depending on the direction of movement of the piston, and Figure 11 is a graph showing the relationship between the oil pressure and the current signal when the current signal in Figure 10 is given. FIG. 12 is a partially sectional front view showing the second embodiment of the present invention, and FIG. 13 is a graph showing the relationship between the relative speed of the piston and the damping force when Figure 14 is a graph showing the relationship between the relative speed of the piston and the damping force when a current signal based on the amplification factor 1 in Figure 13 is given, and Figure 15 is a graph showing the relationship between the frequency and the amplification factor. A partially sectional front view showing a third embodiment of the present invention, FIG.
P) View showing the guide in the figure, Figure 17 is a graph showing the relationship between the force applied to the load cell and the current signal in Figure 15, and the first
Figure 8 is a graph showing the relationship between the relative speed of the inner case and the damping force when the current signal in Figure 17 is given;
The figures are a partially sectional front view showing a fourth embodiment of the invention, and a second embodiment.
0 is an RI view of the electromagnetic coil shown in FIG. 19, and FIG. 21 is a partially sectional front view showing another example of the first damping force generating means in the first to fourth embodiments. 14---One cylindrical member (cylinder body), 17.18
．． 24.43-47--first damping force generating means (rod, piston, orifice, piston, chamber, vortex generating hole, orifice), 23--oil mixed with magnetic powder), 25.
2G, 40 - - - Second damping force generating means (core, electromagnetic coil), 2 27.37 - - Speed detecting means (hydraulic pressure detector, load cell). Patent Applicant Nissan Motor Co., Ltd. Patent Attorney Yugagun Part 3 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 1I 229- Figure 16 Figure 17 Figure 1: l-4"-elL's PBJ force old diagram

Claims (5)

[Claims] (1) Approaching each other due to vibration δI [In a shock absorber device that is interposed between two separated members and damps vibrations, a cylindrical part connected to one of the two parts H, and a cylindrical part connected to one of the two parts H, A fluid that is filled and whose characteristics can be changed electrically or magnetically is connected to the other of the two members, is slidably inserted into the cylindrical portion, and is caused by vibration to change the relative velocity of the two members. a first damping force generation means that generates a corresponding fluid resistance and generates a damping force based on the fluid resistance; and a fluid force caused by the first damping force generation means that is detected and corresponds to the relative velocity of the two members. a speed detection means for outputting a signal; a drive means capable of outputting a current signal that changes based on the signal from the speed detection means; and a drive means capable of outputting a current signal that changes based on the signal from the speed detection means; A shock absorber device comprising: second damping force generating means for generating a possible damping force via fluid. (2) The driving means amplifies the amplification factor when the relative velocity of the two members indicated by the signal output from the speed detection means is small, and the amplification factor when the relative velocity of the two members indicated by the signal output from the speed detection means is large. Claim 1, characterized in that it has an amplifier circuit that outputs a current signal with a current signal larger than the current signal.
Shock absorber device as described in section. (3) The driving means makes the amplification factor of the signal output by the speed detection means when the two members approach each other smaller than the amplification factor of the signal output from the speed detection means when the two members move away from each other, so that the current The shock absorber device according to claim 1, further comprising an amplifier circuit that outputs a signal. (4) a frequency detection circuit in which the drive means detects a signal in a specific frequency range from the signal output from the speed detection means;
an amplifier circuit that amplifies the signal outputted by the speed detection means with different amplification factors depending on whether the signal is within the specific frequency range or the signal outputted from the speed detection means is outside the specific frequency range, and outputs the current signal; A shock absorber device according to claim 1, characterized in that: (5) The speed detecting means has a load cell that receives the force from the first damping force generating means and outputs a speed signal according to the nuclear force, and the driving means detects the speed signal from the first damping force generating means and the first damping force generating means.
Equipped with an amplifier circuit that removes and amplifies the portion corresponding to the force generated by friction with the damping force generating means and outputs a current signal,
Patent d? is characterized in that the amplitude of the vibrations of the two members forms a dead zone near the O value. The shock absorber device according to item 1.