Disclosure of utility model
The present utility model aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the present utility model is to propose an active suspension system that can reduce the consumption of energy of the whole vehicle by the bi-directional electro-hydraulic pump.
Another object of the utility model is to propose a vehicle.
The active suspension system comprises a shock absorber, a damping branch, an active branch, a bidirectional electric liquid pump, a first check valve and a second check valve, wherein the shock absorber comprises a cylinder barrel and a piston, the piston is movably arranged in the cylinder barrel and divides the space in the cylinder barrel into a recovery cavity and a compression cavity, two ends of the damping branch are respectively communicated with the recovery cavity and the compression cavity, the active branch is arranged in parallel with the damping branch, the active branch is provided with the bidirectional electric liquid pump, the first check valve and the second check valve, the bidirectional electric liquid pump is provided with a first inlet and a second inlet, the first inlet is communicated with the recovery cavity, the first check valve is arranged between the first inlet and the first outlet so as to allow oil flowing out of the first inlet to flow into the recovery cavity, the second inlet is communicated with the compression cavity, the second check valve is arranged between the second inlet and the second outlet so as to allow oil flowing out of the second inlet to flow into the compression cavity, and the connecting branch is selectively communicated with the first inlet and the second outlet, and the second check valve is selectively communicated between the first inlet and the second inlet.
Therefore, through the arrangement of the first one-way valve, the second one-way valve and the connecting branch, the framework of the active suspension system can be optimized, the energy consumption of the two-way electric liquid pump 31 to the active suspension system is reduced on the premise of ensuring the active control function of the active suspension system, and the energy conservation of the vehicle is improved.
In some examples of the present utility model, a third check valve is disposed on the connecting branch, one end of the third check valve is communicated with the first inlet and outlet and the first check valve, and the other end of the third check valve is communicated with the damping branch so as to allow oil flowing out of the damping branch to flow to the first inlet and outlet.
In some examples of the present utility model, a fourth check valve is disposed on the connecting branch, one end of the fourth check valve is in communication with the second inlet and outlet and the second check valve, and the other end of the fourth check valve is in communication with the damping branch to allow oil flowing out of the damping branch to flow to the second inlet and outlet.
In some examples of the present utility model, the connecting branch includes a first sub-branch, a second sub-branch, and a third sub-branch, the first end of the first sub-branch is in communication with the damping branch, the first end of the second sub-branch is in communication with the first port and the first check valve, the second end of the second sub-branch is in communication with the second end of the first sub-branch, the first end of the third sub-branch is in communication with the second port and the second check valve, the second end of the third sub-branch is in communication with the second end of the first sub-branch, the third check valve is disposed on the second sub-branch, and the fourth check valve is disposed on the third sub-branch.
In some examples of the utility model, the damping branch is provided with a first damping valve assembly and a second damping valve assembly, the first damping valve assembly and the second damping valve assembly are connected to selectively control the flow direction and damping of oil in the damping branch, and a first end of the connecting branch is connected between the first damping valve assembly and the second damping valve assembly.
In some examples of the utility model, the active suspension system further includes an accumulator in communication between the first and second damper valve assemblies.
In some examples of the utility model, the first damping valve assembly includes a first damping valve and a fifth one-way valve disposed in parallel, the second damping valve assembly includes a second damping valve and a sixth one-way valve disposed in parallel, the first damping valve and the sixth one-way valve allow oil of the recovery chamber to flow to the compression chamber, and the second damping valve and the fifth one-way valve allow oil of the compression chamber to flow to the recovery chamber.
In some examples of the utility model, the first damping valve and the second damping valve are each solenoid valves.
In some examples of the utility model, the active suspension system further comprises a motor electrically connected to the bi-directional electro-liquid pump.
A vehicle according to an embodiment of the utility model includes an active suspension system as described above.
Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.
Detailed Description
Embodiments of the present utility model will be described in detail below, by way of example with reference to the accompanying drawings.
An active suspension system 100 according to an embodiment of the present utility model is described below with reference to fig. 1-4, and the active suspension system 100 may be applied to a vehicle.
As shown in connection with fig. 1-4, an active suspension system 100 according to the present utility model may generally include a shock absorber 10, a damping branch 20, an active branch 30, and a connecting branch 40.
The shock absorber 10 may mainly include a cylinder 11 and a piston 12, where the piston 12 is movably disposed in the cylinder 11 and separates the space in the cylinder 11 into a recovery cavity 111 and a compression cavity 112, two ends of the damping branch 20 are respectively connected with the recovery cavity 111 and the compression cavity 112, the driving branch 30 is parallel to the damping branch 20, two ends of the driving branch 30 are respectively connected with the recovery cavity 111 and the compression cavity 112, the driving branch 30 is provided with a bidirectional electric liquid pump 31, the bidirectional electric liquid pump 31 is provided with a first inlet and outlet 311 and a second inlet and outlet 312, the first inlet and outlet 311 is connected with the recovery cavity 111, and the second inlet and outlet 312 is connected with the compression cavity 112.
Specifically, by providing the damping branch 20 and the active branch 30, both ends of the damping branch 20 are respectively communicated with the restoring cavity 111 and the compressing cavity 112, and both ends of the active branch 30 are respectively communicated with the restoring cavity 111 and the compressing cavity 112, and the active branch 30 is arranged in parallel with the damping branch 20, so that oil can selectively flow from one of the restoring cavity 111 and the compressing cavity 112 to the other through at least one of the damping branch 20 and the active branch 30, thereby adapting to different running states and running environments of the vehicle.
Specifically, when the vehicle is traveling normally, there is no need to provide additional primary power to shock absorber 10, shock absorber 10 and damping branch 20 operate, and oil fluid communication in one of rebound chamber 111 and compression chamber 112 can be carried into the other by damping branch 20, damping branch 20 providing a damping force.
When it is desired to provide the vibration damper 10 of the active suspension system 100 with a primary power in a compression direction or a rebound direction to restrain upward or downward movement of the vehicle body, for example, when the vehicle turns, the vehicle passes through a raised road surface such as a deceleration strip, etc., not only can the oil in one of the rebound chamber 111 and the compression chamber 112 be carried into the other through the operation of the damping branch 20 by the operation of the vibration damper 10 and the damping branch 20, but also the oil in one of the rebound chamber 111 and the compression chamber 112 can be carried into the other through the operation of the bi-directional electric liquid pump 31 by the operation of the active branch 30, thereby achieving active control of the active suspension system 100.
In this manner, the active suspension system 100 can adjust its stiffness and damping by controlling the flow path of the oil to accommodate different road conditions and driving requirements, and can significantly improve the handling and riding comfort of the vehicle.
However, when the whole vehicle does not need the main power, since the main branch 30 and the damping branch 20 are connected in parallel, the pressure of the main branch 30 is very small, so as to avoid the possibility of forming a passage through the bidirectional electric liquid pump 31 during the movement of the shock absorber 10, ensure the establishment of the damping force, and power the bidirectional electric liquid pump 31 to lock, and prevent the oil from flowing through the main branch 30, thus the bidirectional electric liquid pump 31 generates electricity consumption.
As shown in fig. 1-4, the active branch 30 is further provided with a first check valve 32 and a second check valve 33, the first check valve 32 is disposed between the first inlet and outlet 311 and the recovery chamber 111 to allow the oil flowing from the first inlet and outlet 311 to flow to the recovery chamber 111, and the second check valve 33 is disposed between the second inlet and outlet 312 and the compression chamber 112 to allow the oil flowing from the second inlet and outlet 312 to flow to the compression chamber 112. And, a first end of the connection branch 40 is connected to the damping branch 20, and a second end of the connection branch 40 is selectively communicated between the first inlet 311 and the first check valve 32, or between the second inlet 312 and the second check valve 33.
Specifically, by disposing the first check valve 32 between the first inlet/outlet 311 and the recovery chamber 111, the first check valve 32 allows the oil flowing out of the first inlet/outlet 311 to flow to the recovery chamber 111, but does not allow the oil flowing out of the recovery chamber 111 to flow to the first inlet/outlet 311, so that when the vehicle does not require main power, the shock absorber 10 is in a compressed state, the oil flowing out of the recovery chamber 111 can only flow to the compression chamber 112 through the damping branch 20, and the oil does not flow to the bi-directional electric liquid pump 31 to form a passage.
By disposing the second check valve 33 between the second inlet and outlet 312 and the compression chamber 112, the second check valve 33 allows the oil flowing out of the second inlet and outlet 312 to flow to the compression chamber 112, but does not allow the oil flowing out of the compression chamber 112 to flow to the second inlet and outlet 312, so that when the vehicle does not need main power, the shock absorber 10 is in a compressed state, the oil flowing out of the compression chamber 112 can only flow to the recovery chamber 111 through the damping branch 20, and the oil cannot flow to the bi-directional electric liquid pump 31 to form a passage.
In this way, by setting the first check valve 32 and the second check valve 33, when the whole vehicle does not need the main power, the main branch 30 is closed, so that the consumption of the electro-hydraulic pump to the whole vehicle energy can be reduced, and the energy saving performance of the active suspension system 100 can be improved.
It will be appreciated that the arrangement of the first check valve 32 and the second check valve 33 still closes the active branch 30 when the vehicle requires active power, resulting in the bi-directional electro-liquid pump 31 not being able to handle the fluid and providing active power to the shock absorber 10. By providing the connecting branch 40 such that the first end of the connecting branch 40 is connected to the damping branch 20, the second end of the connecting branch 40 is selectively connected between the first inlet/outlet 311 and the first check valve 32 or between the second inlet/outlet 312 and the second check valve 33, so that when the vehicle requires active power, the bi-directional electro-hydraulic pump 31 can also pump the oil in the damping branch 20 and convey it to the recovery chamber 111 or the compression chamber 112, thereby providing active power to the shock absorber 10 and guaranteeing active control of the active suspension system 100.
Therefore, by arranging the first check valve 32, the second check valve 33 and the connecting branch 40, the framework of the active suspension system 100 can be optimized, and the energy consumption of the bidirectional electric liquid pump 31 to the active suspension system 100 is reduced on the premise of ensuring the active control function of the active suspension system 100, so that the energy conservation of the vehicle is improved.
As shown in fig. 1 and 2, the connecting branch 40 is provided with a third check valve 421, one end of the third check valve 421 is communicated with the first inlet/outlet 311 and the first check valve 32, and the other end of the third check valve 421 is communicated with the damping branch 20 to allow the oil flowing out of the damping branch 20 to flow to the first inlet/outlet 311.
Specifically, by communicating one end of the third check valve 421 with the first inlet/outlet 311 and the first check valve 32, and communicating the other end of the third check valve 421 with the damping branch 20, the third check valve 421 may allow the oil flowing out of the damping branch 20 to flow toward the first inlet/outlet 311, the third check valve 421 may block the oil flowing out of the first inlet/outlet 311 from flowing toward the damping branch 20, so that when the active suspension system 100 applies the active compression force, the third check valve 421 may block the oil from returning to the damping branch 20 when the oil flows out of the first inlet/outlet 311 under the action of the bidirectional electric liquid pump 31, and the first check valve 32 may allow the oil to flow to the restoring cavity 111, thereby ensuring the normal application of the active compression force and ensuring the normal operation of the active suspension system 100.
As shown in fig. 1 and 3, the connecting branch 40 is provided with a fourth check valve 431, one end of the fourth check valve 431 is communicated with the second inlet and outlet 312 and the second check valve 33, and the other end of the fourth check valve 431 is communicated with the damping branch 20 to allow the oil flowing out of the damping branch 20 to flow to the second inlet and outlet 312.
Specifically, by communicating one end of the fourth check valve 431 with the second inlet and outlet 312 and the second check valve 33, and communicating the other end of the fourth check valve 431 with the damping branch 20, the fourth check valve 431 may allow the oil flowing out of the damping branch 20 to flow toward the second inlet and outlet 312, the fourth check valve 431 may block the oil flowing out of the second inlet and outlet 312 from flowing toward the damping branch 20, so that when the active suspension system 100 applies the active force in the restoring direction, the oil flows out of the second inlet and outlet 312 under the action of the bidirectional electric liquid pump 31, the fourth check valve 431 may block the oil from returning to the damping branch 20, the second check valve 33 may allow the oil to flow toward the compression chamber 112, thereby ensuring the normal application of the active force in the restoring direction, and ensuring the normal operation of the active suspension system 100.
As shown in fig. 1-3, the connection branch 40 may mainly include a first sub-branch 41, a second sub-branch 42, and a third sub-branch 43, where a first end of the first sub-branch 41 is communicated with the damping branch 20, a first end of the second sub-branch 42 is communicated with the first inlet/outlet 311 and the first check valve 32, a second end of the second sub-branch 42 is selectively communicated with a second end of the first sub-branch 41, a first end of the third sub-branch 43 is communicated with the second inlet/outlet 312 and the second check valve 33, a second end of the third sub-branch 43 is selectively communicated with a second end of the first sub-branch 41, a third check valve 421 is disposed on the second sub-branch 42, and a fourth check valve 431 is disposed on the third sub-branch 43.
In this way, the first sub-branch 41, the second sub-branch 42, the third sub-branch 43, the third check valve 421 and the fourth check valve 431 may form a basic structure of the connection branch 40, and the damping branch 20 may be selectively communicated with the second inlet and outlet 312 of the bi-directional electric liquid pump 31 through the first sub-branch 41, the third sub-branch 43 and the fourth check valve 431, and may be selectively communicated with the first inlet and outlet 311 of the bi-directional electric liquid pump 31 through the first sub-branch 41, the second sub-branch 42 and the third check valve 421.
In the above, by disposing the first check valve 32 and the second check valve 33 on the active branch 30, the first check valve 32 and the second check valve 33 are respectively connected to two ends of the bi-directional electric liquid pump 31, and disposing the third check valve 421 and the fourth check valve 431 on the second sub-branch 42 and the third sub-branch 43, respectively, the flow path of the oil can be defined, and the reliability and stability of the active suspension system 100 can be improved.
As shown in fig. 1-4, the damping branch 20 is provided with a first damping valve assembly 21 and a second damping valve assembly 22, and the first damping valve assembly 21 and the second damping valve assembly 22 are connected to selectively control the flow direction and damping of the oil in the damping branch 20, and a first end of the connecting branch 40 is connected between the first damping valve assembly 21 and the second damping valve assembly 22.
Specifically, by providing the first damping valve assembly 21 and the second damping valve assembly 22 on the damping branch 20, the first damping valve assembly 21 and the second damping valve assembly 22 are connected, so that the flow direction of the oil in the damping branch 20 can be selectively controlled by controlling the first damping valve assembly 21 and the second damping valve assembly 22, and the damping of the oil in the damping branch 20 is controlled, the hardness of the shock absorber 10 is adjusted, and the reliability of the active suspension system 100 is improved.
Further, the first end of the connecting branch 40 is connected between the first damping valve assembly 21 and the second damping valve assembly 22, so that the connection position of the first end of the connecting branch 40 can be optimized, the oil flowing out of the restoring chamber 111 needs to flow through the first damping valve assembly 21 and then flow to the connecting branch 40, and the oil flowing out of the compressing chamber 112 needs to flow through the second damping valve assembly 22 and then flow to the connecting branch 40. In this way, the oil pressure of the oil flowing out of the restoring chamber 111 after passing through the first damping valve assembly 21 and the oil pressure of the oil flowing out of the compressing chamber 112 after passing through the second damping valve assembly 22 also decrease, so that when the active suspension system 100 does not apply the main power, the oil flowing to the connecting branch 40 cannot open the third check valve 421 and the fourth check valve 431, and the oil cannot flow to the bi-directional electric liquid pump 31 of the active branch 30, thereby reducing the consumption of the energy of the bi-directional electric liquid pump 31 for the whole vehicle.
As shown in connection with fig. 1-4, the active suspension system 100 may further include an accumulator 50, the accumulator 50 being in communication with the first damping valve assembly 21 and the second damping valve assembly 22. Specifically, by providing the accumulator 50 in the active suspension system 100 and having the accumulator 50 in communication with the first and second damping valve assemblies 21, 22, and since the first end of the connecting branch 40 is also connected between the first and second damping valve assemblies 21, 22, the second end of the connecting branch 40 is in turn connected to the active branch 30, the active branch 30 may also be in communication with the accumulator 50 through the connecting branch 40, i.e. the accumulator 50 may be in communication with both the damping branch 20 and the active branch 30.
In this manner, the accumulator 50 may function to store and release oil.
Specifically, when the active suspension system 100 requires the damper 10 to output active power, the bi-directional electro-hydraulic pump 31 may draw oil from the accumulator 50 through the connecting branch 40, supplementing the rebound or compression chambers 111, 112, respectively. The accumulator 50 may also selectively release or store oil based on system pressure when the active suspension system 100 does not require the damper 10 to output active power, thereby ensuring proper operation of the active suspension system 100.
It should be noted that, the accumulator 50 is communicated with the first damping valve assembly 21 and the second damping valve assembly 22, so that the oil in the recovery cavity 111 needs to be depressurized by the first damping valve 211 and then flows through the accumulator 50, and the oil in the compression cavity 112 needs to be depressurized by the second damping valve 221 and then flows through the accumulator 50, so that the oil pressure balance of the active suspension system 100 can be ensured, and the normal operation of the active suspension system 100 can be ensured.
As shown in connection with fig. 1 to 4, the first damping valve assembly 21 may include a first damping valve 211 and a fifth check valve 212, the first damping valve 211 and the fifth check valve 212 being disposed in parallel, the second damping valve assembly 22 may include a second damping valve 221 and a sixth check valve 222, the second damping valve 221 and the sixth check valve 222 being disposed in parallel, the first damping valve 211 and the sixth check valve 222 allowing oil of the restoring chamber 111 to flow toward the compressing chamber 112, and the second damping valve 221 and the fifth check valve 212 allowing oil of the compressing chamber 112 to flow toward the restoring chamber 111.
Specifically, the first damping valve assembly 21 may be made to include a first damping valve 211 and a fifth check valve 212, the first damping valve 211 and the fifth check valve 212 being disposed in parallel. The first damping valve 211 can be selectively opened and closed to provide damping force for the oil in the branch circuit and adjust the oil pressure in the branch circuit. The fifth check valve 212 allows oil flowing from the second damping valve assembly 22 to flow to the recovery chamber 111, and the fifth check valve 212 does not allow oil flowing from the recovery chamber 111 to flow to the second damping valve assembly 22.
And, the second damping valve assembly 22 may be made to include a second damping valve 221 and a sixth check valve 222, the second damping valve 221 and the sixth check valve 222 being disposed in parallel. The second damping valve 221 may be selectively opened and closed to provide damping force to the oil in the branch and regulate the oil pressure in the branch. The sixth check valve 222 allows oil flowing from the first damping valve assembly 21 to flow to the compression chamber 112, and the sixth check valve 222 does not allow oil flowing from the compression chamber 112 to flow to the first damping valve assembly 21.
It will be appreciated that, because the first damper valve assembly 21 and the second damper valve assembly 22 are connected, the first damper valve 211 and the sixth check valve 222 may form one oil flow path that allows oil from the recovery chamber 111 to flow to the compression chamber 112, and the second damper valve 221 and the fifth check valve 212 may form another oil flow path that allows oil from the compression chamber 112 to flow to the recovery chamber 111, such that when oil flows between the recovery chamber 111 and the compression chamber 112 through the damper branch 20, the flow paths may be different when the flow directions are different, thereby improving the reliability of the active suspension system 100.
Further, the first damping valve 211 and the second damping valve 221 are both solenoid valves. Specifically, the first damping valve 211 and the second damping valve 221 may be both set as electromagnetic valves, so that the first damping valve 211 and the second damping valve 221 may be quickly responded by an electronic control system (such as an electronic control unit ECU) according to information (such as a vehicle speed, a road surface condition, a vehicle body posture, etc.) provided by the sensor, and it may be convenient to adjust and control the flow and the damping of the oil conducted by the branch where the first damping valve 211 and the second damping valve 221 are located, so that the hardness or softness of the shock absorber 10 may be adjusted in real time, so that the adjustment and control may be more timely and accurate, and the working performance of the active suspension system 100 may be improved.
As shown in connection with fig. 1, the active suspension system 100 may further include a motor 60, the motor 60 being electrically connected to the bi-directional electro-liquid pump 31. Specifically, by electrically connecting the motor 60 with the bi-directional electric liquid pump 31, the power of the motor 60 can be transmitted to the bi-directional electric liquid pump 31 to drive the bi-directional electric liquid pump 31 to rotate forward or reverse, so that the control of the bi-directional electric liquid pump 31 can be realized, and the active suspension system 100 is more intelligent and controllable.
As such, the active suspension system 100 may include at least three operating states, a compression direction active force applied state, a rebound direction active force applied state, and a no active force applied state. When the vehicle works, the motor 60, the first damping valve 211, the second damping valve 221 and the shock absorber 10 can be controlled to work according to the actual running condition, so that the active suspension system 100 can be switched between different working states, thereby ensuring the riding comfort and improving the use experience of users.
As shown in fig. 1 and 2, when the active suspension system 100 requires the shock absorber 10 to output a compression direction active force to restrain upward movement of the vehicle body, the restoration chamber 111 needs to be increased with oil as indicated by an arrow, and the shock absorber 10 is rapidly shortened. At this time, on the one hand, the second damping valve 221 is in the softest mode, the first damping valve 211 is in the hardest mode, the oil flows to the accumulator 50 through the second damping valve 221, and flows to the recovery chamber 111 through the second damping valve 221 and the fifth check valve 212, and the second damping valve 221 and the fifth check valve 212 can prevent the oil in the recovery chamber 111 from flowing out, on the other hand, the motor 60 is driven to rotate the bi-directional electric liquid pump 31 in the forward direction, and the oil in the accumulator 50 is transported to the recovery chamber 111 through the first sub-branch 41, the third sub-branch 43 and the first check valve 32 and compressed to the compression chamber 112, thereby generating the compression direction active force.
As shown in connection with fig. 1 and 3, when the active suspension system 100 requires the damper 10 to output a rebound direction active force to restrain the vehicle body from moving downward, the flow path of the oil is shown by the arrow, the compression chamber 112 needs to be increased with the oil, and the damper 10 is rapidly stretched. At this time, on the one hand, the first damping valve 211 is in the softest mode, the second damping valve 221 is in the hardest mode, the oil flows to the accumulator 50 through the second damping valve 221, and flows to the compression chamber 112 through the second damping valve 221 and the sixth check valve 222, the second damping valve 221 and the sixth check valve 222 prevent the outflow of the oil in the compression chamber 112, on the other hand, the motor 60 is driven to reversely rotate the bi-directional electric liquid pump 31, and the oil in the accumulator 50 is carried to the compression chamber 112 through the first sub-branch 41, the second sub-branch 42 and the second check valve 33, so that the main power application in the restoring direction is realized.
Referring to fig. 1 and 4, when the active suspension system 100 does not have the main power applied, the flow path of the oil is shown by the arrow, and the first check valve 32 and the second check valve 33 close the active branch 30, so that the consumption of energy by the bi-directional electric liquid pump 31 can be reduced. In the stretched state of the shock absorber 10, the oil in the recovery chamber 111 returns to the compression chamber 112 through the first damping valve 211 and the sixth check valve 222 in sequence, and the first damping valve 211 generates a damping force, thereby improving the driving stability. And, in the compressed state of the shock absorber 10, the oil of the compression chamber 112 returns to the restoring chamber 111 through the second damping valve 221 and the fifth check valve 212, and the second damping valve 221 generates a damping force, improving the driving stability.
A vehicle according to the present utility model may include the active suspension system 100 described above. Specifically, the active suspension system 100 not only can satisfy the application of the active force to the shock absorber 10 to realize active control, but also can prevent oil from passing through the bidirectional electric liquid pump 31 when the shock absorber 10 does not need the active force, thereby avoiding the consumption of energy by the bidirectional electric liquid pump 31.
In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.
In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.
Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the spirit and scope of the utility model as defined by the appended claims and their equivalents.