Background
The technology of the shock absorber directly relates to comfort and safety in the running process of the vehicle, vehicles with different purposes have different requirements on the shock absorber, damping control of the shock absorber is a function which is focused in the design and use process of the shock absorber, and whether the function of the shock absorber reaches the requirement depends on the damping control capability completely.
Application number: 201821209280.7, patent name "a supporting vibration damping device and vehicle employing the same", and application number: 201829111. X, two patent documents of a liquid-gas supported vibration damping device and a vehicle adopting the liquid-gas supported vibration damping device disclose several methods for controlling the damping of a vibration damper according to the real-time supporting force value of the supporting vibration damper so as to control the supporting force value of the vibration damper, and the method enables the supporting force value of the vibration damper to be close to the target force value or close to the gravity of a supported object of the vibration damper, so that the purpose of vibration damping is achieved. Several schemes for damping control of a liquid-gas supported shock absorber are also disclosed. In the known technical scheme, the damping control of the liquid-gas supported shock absorber is two-way control, namely, one section of the path through which the liquid flow of the shock absorber flows back and forth is not shared, two groups of damping valves and two groups of auxiliary components are needed, namely, the oil inlet and outlet paths are respectively controlled by adopting different damping valves or respectively controlled by adopting different oil paths, the structure is relatively complex, and a single damping valve can only select one of the tension damping control and the compression damping control to achieve optimal control, namely, the single damping valve can only achieve damping in single optimal control during tension or damping in single optimal control during compression.
Technical problem to be solved by the invention
First, a single fluid flow path or a single damping valve cannot better regulate and control damping of hydraulic cylinders during stretching and compression. That is, the use of a single fluid flow path or a single damping valve does not allow optimal damping control of both the fluid flow into and out of the cylinder.
Secondly, the existing scheme can not detect the direction of liquid flow, and a liquid flow path is required to be divided into a liquid inlet oil way and a liquid outlet oil way, so that the oil way of a hydraulic system is complex, and the cost is high.
Third, the existing damping control method is complex in structure, more in parts and high in cost.
The technical proposal of the invention
The hydraulic cylinder is used as an elastic energy storage element, the hydraulic cylinder is used as a kinetic energy and potential energy conversion executive element, the electric control valve is connected between the hydraulic cylinder and the hydraulic cylinder, the pressure in the hydraulic cylinder, namely the supporting force value of the hydraulic cylinder, is controlled by damping values of the hydraulic cylinder and the electric control valve, a detection device for detecting the flow direction of liquid flow is arranged between the hydraulic cylinder and the hydraulic cylinder, the detection device is used for detecting whether the real-time liquid flow direction flows from the hydraulic cylinder to the hydraulic cylinder or from the hydraulic cylinder to the hydraulic cylinder, the real-time supporting force value of the supporting shock absorber is measured by the force measuring element, the control component compares the real-time supporting force value of the supporting shock absorber measured by the force measuring element with the optimal supporting force value (target supporting force value) required by the supporting shock absorber, and the damping of the electric control valve is controlled in a bidirectional mode by combining the flow direction signals detected by the detection device for detecting the flow direction, so that the supporting force value of the supporting shock absorber is controlled to be close to the target force value to the maximum extent.
Detailed description of the preferred embodiments
Scheme 1, an automatically controlled liquid gas support shock absorber of area liquid flow direction detection device includes: the device comprises a liquid-gas energy accumulator, a liquid flow direction detection device, a hydraulic cylinder, a force measuring element, an electric control valve and a control assembly; the method is characterized in that: the electric control valve is connected in series between the liquid-gas energy accumulator and the hydraulic cylinder, the force measuring element measures the real-time supporting force value of the liquid-gas supporting shock absorber on the supported object, and the liquid flow direction detection device detects the liquid flow direction. The control component compares the supporting force value measured by the force measuring element with the target force value, combines the liquid flow direction signal measured by the liquid flow direction detection device, outputs a control signal to bidirectionally control the damping of the electric control valve, namely, the liquid flow flows from the hydraulic cylinder to the liquid-gas energy storage or from the liquid-gas energy storage to the hydraulic cylinder, and can bidirectionally control the liquid flow damping in real time through the electric control valve, so that the supporting force of the supporting shock absorber is controlled, and the supporting force value of the hydraulic cylinder supporting the shock absorber can reach the optimal supporting force value during compression or extension, namely, is close to or reaches the target supporting force value.
Target support force value: the supporting force value to be achieved by the supporting vibration absorber can be a force value set according to the actual requirement of supporting vibration absorber, or an approximate gravity value of a supported object supporting the vibration absorber, wherein the approximate gravity value of the supported object can be measured through a force measuring element, for example, an average supporting force value of the supporting vibration absorber in a certain unit period is used as a target supporting force value or an approximate gravity value of the supported object supporting the vibration absorber.
A liquid-gas accumulator: also known as an accumulator or energy storage, is an energy storage element that uses a gas as an elastic medium.
Liquid flow direction detection device: for detecting the flow direction of a fluid, herein a fluid flow direction detection device is used for detecting or determining whether a fluid flow is from the hydraulic cylinder to the fluid-gas accumulator or from the fluid-gas accumulator to the hydraulic cylinder. The mechanical-electrical induction type flow direction detector, differential pressure sensor, pressure sensor and other devices capable of judging the direction of the liquid flow can be used as the liquid flow direction detection device. The method for detecting the flow direction of the liquid flow by the pressure sensors is that the two pressure sensors are connected to two ends of the electric control valve, and when the liquid flow flows through the electric control valve with damping, pressure difference is formed at the two ends of the electric control valve, so that the signals of the two pressure sensors are different in size, and the control component judges the flow direction by comparing the signals of the two pressure sensors, wherein the flow direction of the liquid flow is necessarily from high pressure to low pressure.
Force measuring element: refers to components that can directly or indirectly measure pressure or force values, such as pressure sensors, force sensors, and the like. The pressure sensor is required to be combined with parameters such as the piston area of the hydraulic cylinder to calculate when measuring the supporting force value of the supporting shock absorber.
An electric control valve: means a component which is controlled by current or voltage and has damping action or turn-off action on liquid flow or gas flow, and comprises a magneto-rheological damper, an electro-rheological damper, an electromagnetic valve, a proportional electromagnet type electric control valve and the like. The electric control valve is mainly used for damping liquid flow in the supporting vibration damper so as to adjust the supporting force value of the supporting vibration damper. The liquid flow medium corresponding to the electric control valve of the magneto-rheological damper or the electrorheological damper is magneto-rheological fluid or electrorheological fluid.
And a control assembly: also referred to herein as a controller, the function of the control assembly is to receive signals from the process sensors and to receive signals from other processes that require setting or processing, and to output damping control signals to control the damping value of the electrically controlled valve. The control assembly has the functions of receiving a real-time force value or a real-time pressure value measured by the force measuring element, receiving a flow direction signal value measured by the liquid flow direction detection device and the like, calculating and determining a gravity value and a target force value or a target pressure value of a supported object supporting the shock absorber, comparing the real-time measured value with the target value, and outputting a control signal according to control requirements by combining the liquid flow direction signal according to a comparison result to control the damping of the electric control valve.
The damping control method of the supporting shock absorber with the liquid flow direction detection device comprises the following steps:
When the real-time supporting force value is smaller than the target force value and the flow direction is detected to be that the liquid-gas energy accumulator flows to the hydraulic cylinder, the hydraulic pressure in the liquid-gas energy accumulator is larger than the hydraulic pressure in the hydraulic cylinder, at the moment, the control component outputs a control signal to reduce the damping value of the electric control valve, so that the real-time supporting force value is increased, and the hydraulic cylinder is in a stretching motion state.
When the real-time supporting force value is smaller than the target force value and the flow direction is detected as that the hydraulic cylinder flows to the hydraulic-pneumatic energy accumulator, the hydraulic pressure in the hydraulic-pneumatic energy accumulator is smaller than the hydraulic pressure in the hydraulic cylinder, and at the moment, the control component outputs a control signal to increase the damping value of the electric control valve, so that the real-time supporting force value is increased, and the hydraulic cylinder is in a contracted motion state.
When the real-time supporting force value is larger than the target force value and the flow direction is detected as that the hydraulic cylinder flows to the liquid-gas energy accumulator, the control component outputs a control signal to reduce the damping value of the electric control valve, so that the liquid-gas energy accumulator absorbs energy as much as possible, and the hydraulic cylinder is in a contracted motion state.
When the real-time supporting force value is larger than the target force value and the flow direction is detected to be that the liquid-gas energy accumulator flows to the hydraulic cylinder, the hydraulic pressure in the liquid-gas energy accumulator is larger than the hydraulic pressure in the hydraulic cylinder, at the moment, the control component outputs a control signal to increase the damping value of the electric control valve, so that the real-time supporting force value is reduced, and the hydraulic cylinder is in a stretching motion state.
Solution 2, the electrically controlled liquid-gas supporting damper according to solution 1: the method is characterized in that: the electrically controlled valve is a proportional electromagnet type electrically controlled valve, and the electrically controlled valve comprises: the valve comprises an electric control valve body, a valve core, a proportional electromagnetic coil and a spring.
The working principle is as follows:
When the current of the electromagnet is smaller or no current, the electromagnetic valve core is close to the right due to the action of the spring force, the damping is the maximum value, when the current of the electromagnet is gradually increased, the electromagnetic valve core moves leftwards due to the action of the electromagnetic force, the larger the current is, the larger the leftwards movement amount of the electromagnetic valve core is, the effective drift diameter of the valve is overlarge, and the smaller the damping is, namely the damping of the valve gradually decreases along with the increase of the current, so that the damping value of the electric control valve is controlled.
Scheme 3, the automatically controlled liquid gas supports shock absorber of scheme 1: the method is characterized in that: the electric control valve is a magneto-rheological damper.
The electric control liquid-gas supporting shock absorber according to the scheme 4 and the scheme 1 is characterized in that: the liquid flow direction detection device of the shock absorber mainly comprises a permanent magnet slide valve and a flow direction detection valve body, wherein a reed pipe or a Hall element is arranged on the flow direction detection valve body, and when the permanent magnet slide valve moves upwards or downwards, a control component detects the liquid flow direction through signals of the reed pipe or the Hall element.
The electric control liquid-gas supporting shock absorber according to the scheme 5 and the scheme 1 is characterized in that: the load cell is mainly composed of a force sensor for measuring the supporting force of the shock absorber.
The electric control liquid-gas supporting shock absorber according to the scheme 6 and the scheme 1 is characterized in that: the load cell is mainly constituted by a pressure sensor for measuring the pressure of the fluid flow.
The electric control liquid-gas supporting shock absorber according to the scheme 7 and the scheme 1 is characterized in that: the liquid flow direction detection device of the shock absorber mainly comprises a pressure sensor connected between the electric control valve and the hydraulic cylinder and a pressure sensor connected between the electric control valve and the liquid-gas energy accumulator, and the control component judges the liquid flow direction according to the measured value of the pressure sensor and controls the damping of the electric control valve.
The method for detecting the flow direction of the liquid flow by using a flow direction detection device formed by a pressure sensor comprises the following steps: the pressure sensors are respectively connected to two ends of the electric control valve, namely one sensor is connected between the liquid-gas energy accumulator and the electric control valve, and the other sensor is connected between the hydraulic cylinder and the electric control valve. The control component receives pressure sensor signals, the control component calculates pressure difference at two ends of the electric control valve through comparing the two pressure sensor signals to judge the flow direction of liquid flow, in order to avoid the situation that the flow direction is judged inaccurately due to inaccurate pressure difference measurement caused by measurement errors of the pressure sensor, when the pressure difference signals detected by the control component are smaller than a certain set value (such as 0.02 MPa), and when the damping value of the electric control valve is lower than a certain value (such as the damping value is lower than 2% of the maximum damping) by the control signal output by the control component, the damping value of the shock absorber is increased to a certain set value (such as the damping value is set to 2% of the maximum damping) by the control component, so that the accuracy of pressure difference judgment is maintained, and the accuracy of flow direction detection and damping control is guaranteed.
The electric control liquid-gas supporting vibration damper according to claim 8 or claim 1 or 2, wherein: the liquid flow direction detection device of the shock absorber mainly comprises differential pressure sensors connected to two ends of an electric control valve, the differential pressure sensors measure differential pressure values of the two ends of the electric control valve and transmit differential pressure signals to a controller through differential pressure signal lines, and the controller judges the liquid flow direction according to the differential pressure signals.
In order to avoid the situation that the flow direction judgment is inaccurate due to inaccurate measurement of the differential pressure caused by measurement errors of the differential pressure sensor, as in the method adopted in the scheme 7, when the differential pressure signal detected by the control component is smaller than a certain set value (such as 0.02 MPa), and when the damping value of the electric control valve is lower than a certain value (such as the damping value is lower than 2% of the maximum damping) by the control signal output by the control component, the damping value of the shock absorber is increased to a certain set value (such as the damping value is set to be 2% of the maximum damping) by the control component, so that the accuracy of the differential pressure judgment is maintained, and the accuracy of flow direction detection and damping control is ensured.
The beneficial effects of the invention are that
1. The damping control device has the advantages that a single liquid flow path or a single electric control valve can realize optimal adjustment and control effects on damping of the hydraulic cylinder during stretching and compressing according to damping control requirements.
2. Through the detection of the flow direction of the liquid flow, the liquid-gas supporting shock absorber can adjust the damping of the electric control valve in real time according to the flow direction of the liquid flow so as to achieve the optimal damping control requirement.
3. The damping control is simpler and more practical, the variable damping control is easier to realize, and the damping self-adaption function is easier to realize.
4. The liquid-gas supporting shock absorber has simpler structure, fewer parts and lower cost.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
Preferred embodiment 1. Fig. 1 liquid-gas supporting vibration damper with flow direction detecting device
The liquid-gas supported damper includes: the device comprises a liquid-gas energy accumulator (2), a liquid flow direction detection device (15), a pressure sensor (13), a hydraulic cylinder (10), an electric control valve (11) and a controller (6).
The flow direction detection device may be a magnetic induction type liquid flow direction detection device shown in fig. 5 and 6, and the liquid flow direction detection device mainly comprises: the flow direction detection valve comprises a flow direction detection valve body (22), a permanent magnet slide valve (25), a spring (24), a valve joint (23) and a reed pipe or Hall element (26). When the liquid flow is static or flows downwards in the figure, the permanent magnetic slide valve (25) is kept in the middle position by the spring force or is pushed to the lower side in the figure by the action of the liquid flow, and the reed switch or the Hall element (26) has no signal; when the fluid flow is upward, the force of the fluid flow pushes the permanent magnet slide valve (25) to the upper side of the figure, and the reed pipe or the Hall element (26) detects the magnetic signal and transmits the magnetic signal to the controller (6) to determine the direction of the fluid flow.
Working principle:
The liquid flow direction detection device (15) and the electric control valve (11) are connected in series between the liquid-gas energy accumulator (2) and the hydraulic cylinder (10), the electric control valve (11) can adopt a magneto-rheological damper, the proportional electromagnet type electric control valve shown in fig. 4 can also be adopted, the pressure sensor (13) is connected between the hydraulic cylinder (10) and the electric control valve (11), the pressure sensor (13) measures the pressure in the hydraulic cylinder (10) and transmits a pressure signal to the controller (6) through the pressure sensor signal wire (14), and the liquid flow direction detection device (15) transmits a liquid flow direction signal to the controller (6) through the flow direction detection signal wire (16). The controller (6) calculates a real-time supporting force value and an average supporting force value in unit time of the supporting vibration damper according to the pressure signal, compares the calculated average supporting force value in unit time as a target supporting force value of the supporting vibration damper with the real-time supporting force value, and outputs a control signal to control a damping value of the electric control valve (11) by combining a liquid flow direction signal so that the supporting force value of the supporting vibration damper is close to or equal to the target supporting force value.
The damping control method comprises the following steps:
When the real-time supporting force value is smaller than the target force value and the flow direction is detected that the liquid-gas energy accumulator (2) flows to the hydraulic cylinder (10), the hydraulic pressure in the liquid-gas energy accumulator (2) is larger than the hydraulic pressure in the hydraulic cylinder (10), at the moment, a control signal is output by the controller (6) to reduce the damping value of the electric control valve (11), so that the real-time supporting force value is increased, and the hydraulic cylinder (10) is in a stretching motion state.
When the real-time supporting force value is smaller than the target force value and the flow direction is detected that the hydraulic cylinder (10) flows to the hydraulic-pneumatic energy accumulator (2), the hydraulic pressure in the hydraulic-pneumatic energy accumulator (2) is smaller than the hydraulic pressure in the hydraulic cylinder (10), at the moment, a control signal is output by the controller (6) to increase the damping value of the electric control valve (11), so that the real-time supporting force value is increased, and the hydraulic cylinder (10) is in a contracted motion state.
When the real-time supporting force value is larger than the target force value and the flow direction is detected as that the hydraulic cylinder (10) flows to the liquid-gas energy accumulator (2), the controller (6) outputs a control signal to reduce the damping value of the electric control valve (11) at the moment, so that the liquid-gas energy accumulator (2) absorbs energy as much as possible, and the hydraulic cylinder (10) is in a contraction motion state.
When the real-time supporting force value is larger than the target force value and the flow direction is detected that the liquid-gas energy accumulator (2) flows to the hydraulic cylinder (10), the hydraulic pressure in the liquid-gas energy accumulator (2) is larger than the hydraulic pressure in the hydraulic cylinder (10), at the moment, a control signal is output by the controller (6) to increase the damping value of the electric control valve (11) so as to reduce the real-time supporting force value, and the hydraulic cylinder (10) is in a stretching motion state.
A proportional solenoid-operated electrically controlled valve (as shown in fig. 4), the electrically controlled valve comprising: an electric control valve body (19), a valve core (18), a proportional electromagnetic coil (17) and a spring (24). The working principle is as follows: when the current of the proportional electromagnetic coil (17) is smaller or no current, the electromagnetic valve core (18) is close to the right due to the action of a spring force, the damping is the maximum value, when the current of the proportional electromagnetic coil (17) is gradually increased, the electromagnetic valve core (18) moves leftwards due to the action of electromagnetic force, the larger the current is, the larger the left movement amount of the electromagnetic valve core (18) is, the larger the effective path of the valve is, the smaller the damping is, namely the damping of the valve is gradually reduced along with the increase of the current, and therefore the damping value of the electric control valve is controlled.
Preferred scheme 2. Liquid-gas supporting vibration damper with differential pressure type flow direction detecting device
The liquid-gas supported damper includes: the hydraulic and pneumatic energy accumulator (2), a flow direction detection device formed by a differential pressure sensor (12), a force transducer (9), a hydraulic cylinder (10), an electric control valve (11) and a controller (6).
Working principle:
An electric control valve (11) is connected in series between the liquid-gas energy accumulator (2) and the hydraulic cylinder (10), a differential pressure sensor (12) is connected to two sides of the electric control valve (11), the differential pressure sensor (12) measures differential pressure values at two ends of the electric control valve (11) and transmits differential pressure signals to the controller (6) through a differential pressure signal wire (7), and the force sensor (9) transmits real-time measuring force values to the controller (6) through a force sensor signal wire (8). The controller (6) calculates a real-time supporting force value and an average supporting force value in unit time according to the measured value of the force sensor (9), compares the calculated average supporting force value in unit time as a target supporting force value of the supporting shock absorber with the real-time supporting force value, and combines the damping value of the electric control valve (6) controlled by the flow direction signal obtained by judging according to the differential pressure signal to enable the supporting force value of the supporting shock absorber to be close to or equal to the target supporting force value.
The damping control method is the same as that adopted in the preferred embodiment 1.
Preferred embodiment 3. Liquid-gas supporting vibration damper of flow direction detecting device composed of pressure sensor
The liquid-gas supported damper includes: the hydraulic and pneumatic energy accumulator (2), a flow direction detection device formed by a pressure sensor (13), a hydraulic cylinder (10), an electric control valve (11) and a controller (6).
Working principle:
An electric control valve (11) is connected in series between the liquid-gas accumulator (92) and the hydraulic cylinder (10), pressure sensors (13) are respectively connected to two sides of the electric control valve (11), and the pressure sensors (13) measure pressure values of two sides of the electric control valve (11) and transmit pressure signals to the controller (6) through pressure sensor signal lines (14). The controller (6) calculates a real-time supporting force value according to the measured value of the pressure sensor (13), calculates an average supporting force value in unit time, and judges the flow direction of the liquid flow; and comparing the calculated average supporting force value in unit time as a target supporting force value of the supporting shock absorber with a real-time supporting force value, and combining the damping value of the liquid flow direction control electric control valve to enable the supporting force value of the supporting shock absorber to be close to or equal to the target supporting force value.
The damping control method is the same as that adopted in the preferred embodiment 1.