METHOD FOR CALCULATING PRESSURE LOSS OF PARALLEL R-TYPE AUTOMOBILE VIBRATION DAMPER

Abstract

The present invention discloses a method for calculating a pressure loss of a parallel R-type automobile vibration damper. The automobile vibration damper includes a frame, a spring, an axle, a hydraulic cylinder, an upper oil tank, a piston, a lower oil tank, and a resistance adjustment section. The resistance adjustment section is composed of 4 capillaries connected in parallel and solenoid valves. The four capillaries are all coiled into an M shape. The 4 capillaries are R8, R4, R2, and R1 and are connected in series with solenoid valves V.sub.R8, V.sub.R4, V.sub.R2, V.sub.R1, respectively. Due to the viscous effect of oily liquid in the cylinder, when the oily liquid flows through the resistance adjustment section, damping can be adjusted by adjusting the configurations SR, of the solenoid valves V.sub.R8, V.sub.R4, V.sub.R2, and V.sub.R1. The present invention provides a method for calculating a pressure loss of an R-type automobile vibration damper, and achieves the purpose of reducing uncertainties of a control model, which provides a theoretical basis for improving the control quality of the vibration damper.

Claims

1. A method for calculating a pressure loss of a parallel R-type automobile vibration damper, the automobile vibration damper comprising a frame (11), an axle (17) and a hydraulic cylinder (13), wherein a spring (12) is disposed between the frame (11) and the axle (17); an upper end of the hydraulic cylinder (13) is connected to the frame (11) through a piston rod of the hydraulic cylinder (13), and a lower end of the hydraulic cylinder (13) is connected to the axle (17); and a piston (15) in the hydraulic cylinder (13) separates the hydraulic cylinder (13) into an upper oil tank (14) and a lower oil tank (16); and a pipeline between oil delivery ports of the upper oil tank (14) and the lower oil tank (16) is connected with a resistance adjustment section; that is, an oil delivery port D of the resistance adjustment section is connected to an oil delivery port A of the upper oil tank (14), and an oil delivery port C of the resistance adjustment section is connected to an oil delivery port B of the lower oil tank (16); characterized in that the method comprises the following steps: (1) determining a value range of i; (2) calculating flow resistances R.sub.fRi of all capillaries in operation of the resistance adjustment section: $R_{f.Math.R.Math.i}=\frac{128.Math..Math.{\mathrm{.Math.l}}_{R.Math.i}}{\pi .Math..Math.d_{R.Math.i}^4};$ (3) calculating a total flow resistance R.sub.fRt of the resistance adjustment section operating in parallel: $R_{f.Math.R.Math.t}=\frac{1}{\underset{i}{.Math.}.Math.\frac{1}{R_{f.Math.R.Math.i}}};$ and (4) calculating a total pressure loss of the automobile vibration damper:
ΣΔp=R.sub.fRt.Math.q.sub.t.

2. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 1, wherein the resistance adjustment section comprises four capillaries connected in parallel.

3. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 2, wherein the capillaries of the resistance adjustment section are connected in series with solenoid valves.

4. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 3, wherein the four capillaries of the resistance adjustment section have the same cross-sectional area.

5. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 3, wherein a ratio of lengths of the four capillaries of the resistance adjustment section is 8:4:2:1; that is, their lengths are arranged in accordance with an 8421 binary coding rule.

6. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 3, wherein the four capillaries of the resistance adjustment section have the same length.

7. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 3, wherein a ratio of cross-sectional areas of the four capillaries of the resistance adjustment section is 8:4:2:1; that is, their cross-sectional areas are arranged in accordance with an 8421 binary coding rule.

8. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 3, wherein the spring (12) is a helical spring, a leaf spring or a gas spring.

9. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 1, wherein the capillaries in the resistance adjustment section are all coiled into an “M” shape, an “S” shape or a helical shape.

10. The method for calculating a pressure loss of a parallel R-type automobile vibration damper according to claim 9, wherein the solenoid valves of the resistance adjustment section are also connected with a capillary control system; and the capillary control system is configured to control ON and OFF of the solenoid valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] FIG. 1 is a schematic structural diagram of an existing parallel R-type automobile vibration damper.

[0070] FIG. 2 is a schematic diagram of calculating a pressure loss Δp of a single capillary in a method for calculating a pressure loss of a parallel R-type automobile vibration damper according to the present invention.

DETAILED DESCRIPTION

[0071] The present invention will be further described in detail below in conjunction with specific embodiments.

[0072] Embodiment

[0073] As shown in FIG. 1;

[0074] A parallel resistance adjustment section includes four capillaries R8, R4, R2, and R1. The four capillaries are respectively connected in series with solenoid valves V.sub.R8, V.sub.R4, V.sub.R2, and V.sub.R1 which control the operation thereof. A ratio of lengths of the capillaries R8, R4, R2, and R1 is 8:4:2:1. The length of the capillary R1 is L.sub.R1. The diameters of the four capillaries are all d.sub.R.

[0075] A dynamic viscosity μ of oily liquid of a vibration damper and a total flow rate q.sub.t of a resistance adjustment section of the vibration damper are known.

[0076] According to the conditions of this embodiment, size parameters of all capillaries in the resistance adjustment section may be solved first. Then, a total pressure loss ΣΔp of the vibration damper under various operating conditions may be calculated according to the following steps:

[0077] (1) determining a value range of i;

[0078] (2) calculating flow resistances R.sub.fRi of all capillaries in operation of the resistance adjustment section:

[00016]$R_{f.Math.R.Math.i}=\frac{128.Math..Math.{\mathrm{.Math.l}}_{R.Math.i}}{\pi .Math..Math.d_{R.Math.i}^4};$

[0079] (3) calculating a total flow resistance R.sub.fRt of the resistance adjustment section operating in parallel:

[00017]$R_{f.Math.R.Math.t}=\frac{1}{\underset{i}{.Math.}.Math.\frac{1}{R_{f.Math.R.Math.i}}};$

and

[0080] (4) calculating a total pressure loss of the automobile vibration damper:

ΣΔp=R.sub.fRt.Math.q.sub.t.

[0081] In this way, a capillary control system can reduce uncertainties of a control model and improve the control quality of the vibration damper by using the method for calculating a pressure loss of a parallel R-type automobile vibration damper.

[0082] In this embodiment, because an analytical method for calculating a pressure loss is implemented, it is possible to conduct calculation easily according to various operating conditions (various value ranges of i), thereby providing a theoretical basis for reducing uncertainties of the control model.

[0083] This embodiment will be further explained with the following five points.

[0084] 1. Regarding the solenoid valves that control the operation of the capillaries of the resistance adjustment section

[0085] In FIG. 1, in the resistance adjustment section, operation of each capillary is controlled by a solenoid valve. For a capillary that is always in operation, it may be unnecessary to connect it with a solenoid valve. That is, the number of capillaries and the number of solenoid valves are not necessarily exactly equal.

[0086] 2. Regarding the name of “parallel R-type automobile vibration damper”

[0087] In the name of “parallel R-type automobile vibration damper”, “parallel” means that the resistance adjustment section is adjusted by parallel capillaries. “R type” refers to the manner in which the capillaries R8, R4, R2, and R1 and their corresponding solenoid valves adjust the resistance of the vibration damper under the control of the control system. Its characteristic is as follows: outside the cylinder body of the hydraulic cylinder, according to the resistance characteristics of the capillary, a plurality of (which may be four or another number) parallel (or serial) capillaries are arranged based on specific parameters (such as area, length, flow resistance, reciprocal of flow resistance, or flow resistance of hydraulic oil under certain operating condition, etc.) in accordance with certain rules (such as 8421 proportion binary coding rule, or other proportion or non-proportion rules), and the solenoid valve of the corresponding capillary is controlled by the control system to achieve the purpose of adjusting resistance.

[0088] When the vibration damper works in the above-mentioned “R-type” manner, it is also called an R-type vibration damper or R-type automobile vibration damper.

[0089] In the R-type vibration damper, the capillary does not have to be very thin. “Thin” means that a resistance will be produced when hydraulic oil flows through the capillary. That is to say, the capillary is an oil pipe or path that produces a resistance when hydraulic oil passes through.

[0090] The capillary of the R-type vibration damper may be processed into a helical shape, an “S” shape and other shapes in addition to an “M” shape. These shapes are only listed as specific shapes, and many shapes may be listed in practical applications, which can be flexibly determined according to specific requirements. The materials for making these capillary oil paths may be steel, copper, various alloys, non-metallic materials, etc. The method for making capillary oil paths may be a method of forming a tube, a method of machining, a method of 3D printing, and the like.

[0091] 3. Instructions on equations

[0092] When a Newtonian fluid is in a stable flow and laminar flow state, assuming that the capillary is a straight capillary placed horizontally, and ignoring the partial pressure loss of the capillary and the pressure loss of the connecting pipeline, the present invention derives the above calculation equations. If the actual operating conditions are significantly different from the above conditions and assumptions, the equations will have errors. Compared with the previous situation without these equations, even if the equations have errors, for the system identification of the control system, the calculation method according to the present invention can still reduce uncertainties of the control model and provide a theoretical basis for improving the control quality of the vibration damper. Of course, according to the calculation method of the present invention and additional experiments, the calculation method may also be modified, thereby further improving the control quality of the vibration damper.

[0093] 4. Regarding the spring of the automobile vibration damper

[0094] In addition to a helical spring, a gas spring, an oil-gas spring and other springs may also be used as the spring in the vibration damper according to the present invention.

[0095] 5. Regarding a ratio of flow resistance reciprocals of the capillaries of the resistance adjustment section operating in parallel

[0096] In this embodiment, because the ratio of lengths of the capillaries R8, R4, R2, and R1 is 8:4:2:1, and their diameters are all d.sub.R, a ratio of flow resistance reciprocals

[00018]$\frac{1}{R_{\mathrm{fR}.Math..Math.1}},\frac{1}{R_{\mathrm{fR}.Math..Math.2}},\frac{1}{R_{\mathrm{fR}.Math..Math.4}},\mathrm{and}.Math..Math.\frac{1}{R_{\mathrm{fR}.Math..Math.8}}$

of the capillaries R1, R2, R4, and R8 is 8:4:2:1. In the design of the resistance adjustment section, in addition to the 8:4:2:1 arrangement, the ratio may also be 100:90:80:70 or 100:88:75:62 or 100:70:41:16, etc. Of course, the ratio may also be other ratios obtained by methods such as least squares.

[0097] As described above, the present invention can be implemented.

[0098] The implementation of the present invention is not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention should be equivalent replacement methods, and are included in the protection scope of the present invention.