JPH03186414A - Damping force control device - Google Patents

Abstract

PURPOSE:To attempt improvement of a processing time and operation responsiveness with simplification or the like of constitution attempted and also with control and correction routines integrated into a single item by performing normal and correction controls of damping force not through calculation but by indexing a stored data map. CONSTITUTION:Damping force of a damper (a) is changed by a changing means (b) while a fluid temperature of the damper (a) is detected by a temperature sensor (c). A condition of a vehicle is detected by an input means (d), while the changing means (b) is controlled by a control means (e) being based on an input signal of this means (d). In the control means (e), a data map (f) of optimum damping force, corresponding to the input signal, is stored in a memory part (g). In a control part (h), the optimum damping force is indexed being based on the input signal by the stored data map (f) further with a select signal output. Further, when a detected temperature of the temperature sensor (c) is higher than a preset value, the temperature is corrected by a correcting part (i) in such a manner as changing the optimum damping force in the data map (f) to a high damping side.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a damping force control device for controlling the damping force characteristics of a shock absorber provided between sprung and unsprung parts of a vehicle.
Regarding things that perform temperature correction.

(Prior Art) Conventionally, as a damping force control device, for example,
The one described in the y7z2s-q publication is known.

This damping force control device controls a valve as a damping force changing means provided in a hydraulic shock absorber.In this case, the calculation result based on the piston speed is added to the correction calculation result based on the temperature signal from the temperature sensor. It is configured to add or subtract and output the result to the drive circuit.

That is, changes in the damping force characteristics due to changes in the fluid temperature of the shock absorber are corrected, and constant damping characteristics are always obtained.

(Problem to be Solved by the Invention) However, in such a conventional damping force control device, it is necessary to always calculate and output a correction signal in an arithmetic circuit, and a control routine and a correction routine are provided separately. At the same time, there is a problem that the configuration is complicated and expensive, and the number of calculation routines increases.
There is also the problem that there is a large time delay until the control signal is output, and control responsiveness is poor.

The present invention was made by focusing on such problems,
It is an object of the present invention to provide a damping force control device that can simplify the configuration and improve control responsiveness at the same time.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the damping force control device of the present invention employs the means described below.
This will be explained using the complaint correspondence diagram shown in the figure.

The damping force changing means capable of switching the damping force range of the shock absorber a into a plurality of stages includes a temperature sensor C for detecting the fluid temperature of the shock absorber a, an input means d for detecting the vehicle state, and the input means control means e for outputting a switching signal to the damping force changing means based on an input signal from d; and a storage section 9 provided in the control means e and storing a data map f indicating an optimum damping force range corresponding to the input signal. , a control unit h that indexes the optimum damping force range based on the actual input signal using the data map f of the storage unit 9 and outputs a switching signal based on the index result, and a control unit h that outputs a switching signal based on the index result, and a control unit h that determines that the temperature detected by the temperature sensor C is set to a predetermined value. When the temperature is higher than the temperature, the data map f
A temperature correction unit j is provided to change the optimum damping force range to the high damping side.

Furthermore, in the damping force control device according to claim 2, when the temperature detected by the temperature correction section j or the temperature sensor C is lower than a predetermined temperature, the optimum damping force range of the data map f is set to the low damping force side. The contents have been changed to .

(Function) The function of the present invention will be explained. In addition, the symbols in the explanation are
This corresponds to Figure 1.

When the fluid temperature in the buffer a is a predetermined temperature, the fluid has a predetermined flow resistance.

In this case, the control means e refers to a predetermined data map f in the storage section 9 based on the input signal obtained from the input means d. The control section then indexes the optimum damping force range corresponding to the input signal based on this data map f, and outputs a switching signal based on the index result. Based on this switching signal, the damping force changing means switches to the optimum damping force range.

Next, when the fluid temperature of the buffer a becomes high due to repeated strokes of the buffer a for a long time, the temperature correction section J of the control means e adjusts the control section based on the detected temperature obtained from the temperature sensor C. The content of the data map f indexed by is changed to the high damping force characteristic side.

Therefore, compared to the normal case, the index result in the control section shows that the optimal damping force range for the input signal is a high damping force, and the decrease in fluid flow resistance due to high temperature is compensated for, and in buffer a, the fluid Optimum damping force characteristics similar to those under normal conditions can be obtained without being affected by a decrease in flow resistance.

In addition to the above-mentioned effect, in the damping force control device according to the second aspect, when the fluid temperature of the shock absorber becomes low due to a cold environment, etc., the temperature correction section j of the control means e adjusts the detected temperature obtained from the temperature sensor C. Based on this, the content of the data map f indexed by the control unit is changed to the low damping force characteristic side.

Therefore, the index result in the control section is that the optimal damping force range for the input signal is a low damping force compared to the normal case, and the increase in fluid flow resistance due to low temperature is compensated for, and in buffer a, the fluid Optimum damping force characteristics similar to those under normal conditions can be obtained without being affected by an increase in flow resistance.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the configuration of the embodiment will be explained. In this embodiment, a shock absorber whose damping force characteristics can be switched in eight stages will be explained.

FIG. 2 is an overall diagram showing a damping force control device according to an embodiment of the present invention, in which 1 is a variable damping force type shock absorber, 2 is a pulse motor, 3 is a vertical acceleration sensor, 4 is a load sensor, 5 is an oil temperature sensor, and 6 is a controller.

In the shock absorber 1, a damping force changing means 7 such as an adjuster provided in the piston rod rotates, and the damping force changing means 7 is set on the expansion side.

It is formed so that the damping force range of the pressure (ijll) can be changed simultaneously in multiple stages from a low range to a high range. I am using what I have (
The damping force described in this publication can be changed steplessly). For detailed structure 1, please refer to the specification and drawings of the above-mentioned application.

The pulse motor 2 operates the damping force changing means 7 of the shock absorber 1, and this pulse motor 2 changes the stage in 16 steps. It changes in 16 steps from high range to high range. In this way, the damping force changing means Y can change the damping force range in 16 steps, but in actual control, control is performed in which the damping force range is changed in 8 steps by controlling one step at a time. . The details will be described later.

The acceleration sensor 3 outputs an electric signal according to the vertical acceleration on the sprung body, and is attached to the sprung vehicle body.

The load sensor 4 is provided as a relative speed measuring means for measuring the relative speed between sprung and unsprung parts, and is, for example, provided on the vehicle body mount portion of the shock absorber 1 to receive input from the shock absorber 1 to the vehicle body. Detects the load and outputs an electrical signal according to the load.

The oil temperature sensor 5 is provided in the shock absorber 1 and
Detects the temperature of the oil as a fluid inside the device and outputs an electrical signal according to the temperature.

The controller 6 includes an acceleration sensor 3. Load sensor 4
Based on the input signals from the oil temperature sensor 5 and the oil temperature sensor 5, the buffer 1
A switching signal is output to the pulse motor 2 in order to obtain the optimum damping force characteristic.

That is, this controller 6 includes an interface circuit 61 that inputs signals from each sensor 3°4.5, and an A/D conversion circuit 6 that converts input analog signals into digital signals.
2. A CPU 64 as a control unit that performs control such as index 1 determination based on the data map DM (FIG. 3) stored in the memory circuit 63 as a storage unit; this CPLJ 64;
A drive circuit (control unit) 65 is provided that outputs a switching signal to the pulse motor 2 based on the control result.

Here, the data map DM stored in the memory circuit 63 will be explained.

As shown in FIG. 3, this data map DM stores eight normal data maps DM2 and eight correction data maps in order to switch and control the damping force range of the damping force changing means 1 into eight stages. DMH is also stored.

As an example, FIG. 4(a) shows a normal data map DM5N for the fifth stage of damping force range, and FIG. 4(b) shows a correction data map D for the fifth stage of high damping force.
The figure (e) showing M5□ is the fifth stage low damping force side (4
data map D for correction (equal to the high damping force side of the step)
It shows M4□.

As shown in these figures, the data map DM shows the stages of the damping force range of the damping force changing means 7 at the upper left corner, which is the intersection of the upper column and the left column (the figure shows the 5th stage). , the upper column shows the vertical acceleration data C which is input from the vertical acceleration sensor 3 (corresponding to the spring progress (m/s)), and the left column shows the load data which is input from the load sensor 4 [spring Corresponding to the upper-unsprung relative velocity] D value is shown, and within each square is shown the optimal damping force range corresponding to the vertical velocity data A' obtained from the vertical acceleration data A and the load data D. .

Note that the numbers in each square indicate the stages of the damping force range. That is, FIG. 5 shows the damping force characteristics with respect to the piston speed. As shown in this figure, the damping force changing means 7 can change the damping force characteristics in 16 steps.
The damping force range can be switched in eight steps according to the characteristics shown in ■ to ■. And, between the characteristics of ■ and ■ and on the higher attenuation side than ■, there is a correction range (1, ~ 81.l) with higher damping force characteristics than the damping force characteristics of ■ to ■. The numbers in each square of FIG. 4 (a), (b), and (c) indicate this.

Next, the control contents of this controller 6 will be explained based on the flowcharts shown in FIGS. 6 and 7.

In step 101, first, initial settings are performed.

That is, the timer flag is set to O, the damping force range of the damping force changing means 7 is set to the lowest range, and the signs of the load and acceleration A are set to 10.

Next, in step 102, the load signal, which is an analog electrical signal input from the load sensor 4, is converted into a digital signal.

Then, in step 103, the load data D is read into the CPU 65.

Further, in step 104, the acceleration signal, which is an analog electrical signal inputted from the vertical acceleration sensor 3, is converted into a digital signal.

Then, in step 105, the acceleration data A is sent to the CPU 6.
5 and proceeds to the timer 200 shown in FIG.

In the timer routine 200, in step 201,
It is determined whether the timer flag (initial setting is O) is 1. If NO, the process proceeds to step 202; if YES, the process proceeds to step 207.

In step 202, the analog electrical signal from the oil temperature sensor 5 is converted into digital.

In the following step 203, the oil temperature data T is read into the CPU 64.

In the following step 204, a shift value is read from an oil temperature data map (not shown).

Note that this oil temperature data map shows the shift value with respect to the oil temperature, that is, in normal times, the
With the characteristics of ~ ■, the damping force range has been changed to 8 stages,
In this case, the shift value is rOJ. On the other hand, 1.
When switching the damping force range to 8 stages with characteristics 4 to 88, the shift value will be "+1" (in this case, for example, as the same 5th stage damping force range, the data map shown in Figure 4 (b) using DM5H). Also, when shifting to the low damping force side by setting the shift value to "-1", the data map shown in Fig. 4 (C
) data map DMA will be used. Furthermore, if the characteristic indicated by ■ in FIG. 4 is set as the lowest damping force range, and then the characteristics are changed to ■, ■, .

Also, as mentioned above, this shift value is proportional to the oil temperature,
For example, the temperature is changed every predetermined temperature range from 30°C to 40°C.

In step 205 following step 204 as described above, the contents of the data map DM to be indexed in step 106 described later are shifted.

Next, in step 206, the timer flag is set to 1, and the fifth
Proceed to step 106 in the figure.

On the other hand, in step 207, timer counting continues.

In the following step 208, it is determined whether or not the timer counting has ended. If YES, the time flag is set to O in step 209, and if NO, the time flag is set to O in step 106 in FIG.
Proceed to. In other words, since the oil temperature does not change rapidly, it is not necessary to shift the data map DM in step 206 frequently in a short period of time. For this reason, a timer routine such as steps 202 to 205 is performed at predetermined intervals (for example, 40 minutes to 1 hour) by timer counting.

After completing the above-mentioned timer routine, the process proceeds to step 106, where the pulse motor 2 is switched to a switching stage (=
index the optimum damping force range).

In the following step 107, a switching signal is output from the drive circuit 65 to the pulse motor 2 according to the index result of step 106.

In the subsequent step 108, the data map DM corresponding to the stop position of the pulse motor 2 and the number of switching stages of the damping force changing means 7 is read, and one operation flow is thus completed.

The controller 6 repeats the above process.

Next, the operation of the embodiment will be explained.

(a) When the temperature is within the predetermined temperature range: When the oil temperature in the buffer 1 is within the predetermined temperature range, the oil has the desired viscosity.

In this case, the controller 6 uses the normal data map D.
The switching stage (optimal damping force range) of the pulse motor 2 is indexed by the MN in accordance with the load data D and the acceleration data A, and a switching signal is output from the drive circuit 65 to the pulse motor 2 based on this index result. Based on this switching signal, the damping force changing means 7 operates to switch to the optimum damping force range.

(b) When the oil temperature rises Next, when the fluid temperature of the shock absorber 1 becomes high due to repeated strokes of the shock absorber 1 for a long time, the viscosity of the oil in the shock absorber 1 decreases, and the damping force changing means 7 The damping force actually generated for the switching position becomes lower.

In this case, the controller 6 changes the contents of the data map DM to the high damping force characteristic side based on the detected temperature obtained from the oil temperature sensor 5 if this detected temperature is equal to or higher than a predetermined temperature (steps 203 to 205). Incidentally, when the damping force variable means 7 is switched to the fifth stage, if the shift value is "+1", the contents of the data map DM of the fifth stage are changed to the contents of 5H shown in Fig. 4(b). change,
If the shift value is "+2", the normal data map D
M Change the contents to the 6th column of N.

Therefore, the index result in the data map DM indicates that the optimum damping force range is a higher damping force than in the normal case, and the above-mentioned decrease in oil viscosity is corrected.

(c) When the oil temperature drops When the fluid temperature of the buffer 1 drops due to a cold environment, etc.
In the shock absorber 1, the viscosity of the oil increases, and the damping force actually generated with respect to the switching position of the damping force changing means 7 increases.

In this case, the controller 6 changes the contents of the data map DM to the low damping force characteristic side based on the detected temperature obtained from the oil temperature sensor 5 if this detected temperature is below a predetermined temperature (steps 203 to 205). Incidentally, when the damping force variable means 7 is switched to the fifth stage, if the shift value is "-1", the contents of the data map DM of the fifth stage are changed to 4□ shown in Fig. 4(c). Change the content to
If the shift value is "-2", the normal data map D
Change the contents to the 4th row of MN.

Therefore, the index result in the data map DM is that the optimum damping force range is a lower damping force than in the normal case, and the above-mentioned increase in oil viscosity is corrected.

As explained above, in the damping force control device of this embodiment, the memory circuit 6
Since the optimum damping force is set by indexing the data map 63 stored in the controller 3, the configuration of the controller 6 can be simplified, thereby reducing costs. , it has the feature that control responsiveness can be increased because it only performs indexing. Incidentally, in the case of this embodiment, the data map DM corresponding to the stop position of the pulse motor 2 is read based on step 108 in FIG. Arrange the adjacent data map DM (for example, the 6th row if it is currently the 5th row), and then arrange the data map DM next to the low attenuation side (similarly the 4th row).
Next, arrange the data map DMs two adjacent rows (same as the seventh row) on the high attenuation side, and then arrange the two adjacent data maps DMs on the low attenuation side (similarly the third row). In this way, the indexing time can be shortened.

Furthermore, in this embodiment, depending on the oil temperature change in the shock absorber 1,
Since the contents of the data map DM are changed, it is possible to always obtain constant damping force control characteristics by correcting changes in damping force characteristics due to changes in oil viscosity due to changes in oil temperature. It has characteristics.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment. For example, in the embodiments, damping force characteristics may be switched in multiple stages. For example, the configuration is not limited to that shown in this embodiment.

Further, in the embodiment, an example was shown in which the damping force range was switched to eight stages by the damping force changing means, but the number of switching stages may be changed to any number of stages as long as it is plural.

In addition, in the example, one correction characteristic (indicated by 1H to 8H in Fig. 4) was set between the damping force characteristics (indicated by ■ to ■ in Fig. 4) normally used. You may set multiple correction characteristics, or
Conversely, the damping force characteristics may be shifted to adjacent damping force characteristics without having such correction characteristics.

(Effects of the Invention) As explained above, in the damping force control device of the present invention, correction is made in response to temperature changes in the shock absorber, and constant damping force control that is not affected by temperature changes is achieved. However, in the present invention, the normal control and correction control are performed by indexing the data map stored in the storage unit instead of by calculation, so the configuration is simpler than in the case where calculation is performed. At the same time, the correction routine and the control routine can be integrated into one routine instead of being separated, and the time required for the control routine can be shortened. This provides the effect of improving responsiveness.

[Brief explanation of drawings]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is an overall diagram showing an embodiment of the damping force control device of the present invention, Fig. 3 is a conceptual diagram showing a data map, and Fig. 4 (a), (b) ( c) is a diagram showing the 5th stage normal data map, 5th stage correction data map, and 4th stage correction data map, respectively.
The figure is a damping force characteristic diagram of the shock absorber, and FIGS. 6 and 7 are flowcharts showing the operation flow of the controller. a''・Buffer b...Damping force changing means c=・Temperature sensor d...Input means e''・Control means f-...Data map 9...Storage section h...Control section j... Temperature correction section

Claims (1)

[Scope of Claims] 1) damping force changing means capable of switching the damping force range of the shock absorber into a plurality of stages; input means that includes a temperature sensor that detects the fluid temperature of the shock absorber and detects the vehicle state; a control means for outputting a switching signal to the damping force changing means based on an input signal from the input means; a storage section provided in the control means and storing a data map indicating an optimum damping force range corresponding to the input signal; ,
a control unit that indexes the optimum damping force range based on the actual input signal using the data map in the storage unit and outputs a switching signal based on the index result; A damping force control device comprising: a temperature correction section that changes the optimum damping force range of the data map to a high damping side in some cases; 2) The temperature correction unit changes the optimum damping force range of the data map to a lower damping force side when the temperature detected by the temperature sensor is lower than a predetermined temperature. damping force control device.