Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art described above.
To this end, a first object of the invention is to propose a braking vacuum assistance system. The system can meet the requirement of conventional brake boosting, and can also ensure that the vacuum degree is quickly established under the condition of continuous braking, so that the braking performance of the braking system is improved, and the driving safety is ensured.
A second object of the present invention is to provide a control method for a brake vacuum assist system.
A third object of the invention is to propose a vehicle.
In order to achieve the above object, an embodiment of a first aspect of the present invention discloses a brake vacuum assist system, including: a vacuum booster; the brake vacuum pump is connected with the vacuum booster through a vacuum pipeline; the vacuum degree detection device is used for detecting the vacuum degree of the brake vacuum boosting system; the vacuum tank can be selectively connected to the vacuum pipeline or disconnected from the vacuum pipeline according to the vacuum degree of the brake vacuum boosting system.
According to the brake vacuum boosting system provided by the embodiment of the invention, the vacuum tank and the brake vacuum pump are connected in parallel, and the control valve controls the opening and closing of the vacuum tank, so that the conventional brake boosting requirement can be met, the vacuum degree can be ensured to be quickly established under the condition of continuous braking, the braking performance of the brake system is further improved, the driving safety is ensured, and meanwhile, the vacuum degree can be quickly established, so that the long-time working condition of the brake vacuum pump is reduced, and the service life of the brake vacuum pump is prolonged.
In some examples, the vacuum tank is connected in parallel with the brake vacuum pump, a control valve is provided between the vacuum tank and the brake vacuum pump, and the brake vacuum assist system further includes: and the controller is respectively connected with the vacuum degree detection device and the control valve and is used for controlling the opening and closing of the control valve according to the vacuum degree of the brake vacuum boosting system so as to enable the vacuum tank to be connected to the vacuum pipeline or disconnected from the vacuum pipeline.
In some examples, the control valve is a normally open control valve.
In some examples, the controller is connected to the brake vacuum pump, and the controller is further configured to control start and stop of the brake vacuum pump according to a vacuum degree of the brake vacuum boosting system.
In some examples, the vacuum detection device is a vacuum sensor.
An embodiment of a second aspect of the invention discloses a control method of a brake vacuum boosting system, which comprises the following steps: judging whether the vacuum degree of the brake vacuum boosting system is lower than a first threshold value or not during the operation of the brake vacuum pump; if yes, further judging whether the duration time exceeds a first preset time; and if so, controlling the control valve to be closed to disconnect the vacuum tank from the vacuum pipeline.
According to the control method of the brake vacuum boosting system, the vacuum tank and the brake vacuum pump are connected in parallel, and the control valve controls the opening and closing of the vacuum tank, so that the conventional brake boosting requirement can be met, the vacuum degree can be quickly established under the condition of continuous braking, the braking performance of the brake system is further improved, the driving safety is ensured, and meanwhile, the vacuum degree can be quickly established, so that the brake vacuum pump is reduced from being in a working state for a long time, and the service life of the brake vacuum pump is prolonged.
In some examples, further comprising: and when the vacuum degree is recovered to a second threshold value and the duration time exceeds a second preset time, controlling the control valve to be opened so as to enable the vacuum tank to be connected to the vacuum pipeline.
In some examples, the first and second thresholds, the first and second predetermined times are precalibrated.
In some examples, further comprising: and controlling the brake vacuum pump to stop running when the vacuum degree of the brake vacuum boosting system is recovered to a vacuum degree closing threshold value during the running of the brake vacuum pump.
In some examples, further comprising: and when the vacuum degree of the brake vacuum boosting system is smaller than a vacuum degree opening threshold value, controlling the brake vacuum pump to operate.
An embodiment of a third aspect of the invention discloses a vehicle, comprising: the brake vacuum assist system according to an embodiment of the first aspect described above. This vehicle connects vacuum tank and brake vacuum pump in parallel to by opening and closing of control valve control vacuum tank, both can satisfy conventional braking helping hand demand, also can guarantee to establish vacuum rapidly under the continuous braking condition, and then improve braking system's braking nature, guarantee driving safety, owing to can establish vacuum rapidly simultaneously, consequently reduced the brake vacuum pump and be in operating condition for a long time, promoted brake vacuum pump's life.
Additional aspects and advantages of the invention 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 invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
The following describes a brake vacuum boosting system, a control method and a vehicle according to an embodiment of the invention with reference to the accompanying drawings.
FIG. 1 is a schematic illustration of a brake vacuum assist system according to one embodiment of the present invention.
As shown in fig. 1, a brake vacuum assist system according to an embodiment of the present invention includes: a vacuum booster 110, a brake vacuum pump 120, a vacuum tank 130, and a vacuum level detection device 160. The vacuum degree detection device 160 is, for example, a vacuum degree sensor.
Wherein one end of the vacuum booster 110 is connected to the brake pedal 140. The brake vacuum pump 120 is connected to the vacuum booster 110 via a vacuum line. The vacuum level detection device 160 is used to detect the vacuum level of the brake vacuum assist system. The vacuum tank 130 may be selectively connected to or disconnected from the vacuum line according to the degree of vacuum of the brake vacuum assist system.
As a specific example, as shown in connection with fig. 1, the vacuum tank 130 is connected in parallel with the brake vacuum pump 120, and a control valve 150 is provided between the vacuum tank 130 and the brake vacuum pump 120. One end of the control valve 150 is connected to the vacuum tank 130, wherein the control valve 150 is normally open, i.e.: the control valve 150 is a normally open control valve, for example, a normally open solenoid valve. The brake vacuum assist system further includes a controller (not shown in fig. 1) respectively connected to the vacuum level detection device 160 and the control valve 150, for controlling the control valve 150 to open and close according to the vacuum level of the brake vacuum assist system, so as to connect or disconnect the vacuum tank 130 to or from the vacuum line. For example: one end of the vacuum booster 110 is connected to the brake pedal 150 and the other end is connected to the other end of the control valve 150 and the brake vacuum pump 120, respectively, through a vacuum degree sensor 160. During operation of the brake vacuum pump 120, when the vacuum level of the brake vacuum assist system is lower than a first threshold value and the duration exceeds a first predetermined time, the control valve 150 is closed to disconnect the vacuum tank 130 from the vacuum line until the vacuum level is restored to a second threshold value and the duration exceeds a second predetermined time, the control valve 150 is opened to allow the vacuum tank 130 to be connected into the vacuum line.
It should be noted that the first threshold and the second threshold, and the first predetermined time and the second predetermined time are obtained by calibration in advance.
In one embodiment of the present invention, the controller is connected to the brake vacuum pump 120, and the controller is further configured to control the start and stop of the brake vacuum pump 120 according to the vacuum level of the brake vacuum boosting system. For example: during operation of the brake vacuum pump 120, the brake vacuum pump 120 stops operating when the vacuum level of the brake vacuum assist system returns to the vacuum shut-off threshold.
Specifically, when the vacuum level of the brake vacuum assist system is detected to be lower than the on threshold Vac on (i.e., the vacuum level on threshold), the brake vacuum pump 120 starts to operate, and when the vacuum level of the brake vacuum assist system reaches the off threshold Vac off (i.e., the vacuum level off threshold), the brake vacuum pump stops operating.
Further, the controller controls the brake vacuum pump 120 to operate when the vacuum level of the brake vacuum boosting system is less than the vacuum opening threshold.
The control valve 150 (i.e., the normally open solenoid valve) works as follows, and in a normal state, the control valve 150 is in an open state, and the vacuum tank 130 is connected in parallel to the brake vacuum boosting system. When the vacuum degree of the brake vacuum boosting system is lower than the vacuum degree opening threshold value, the brake vacuum pump 120 works, the control valve 150 is in an open state, and the vacuum tank 130 is connected to the brake vacuum boosting system in parallel. During operation of the brake vacuum pump 120, the vacuum level is below a certain threshold A MPa (i.e., the first threshold) and maintained for X seconds (i.e., the first predetermined time), the control valve 150 is closed, and the vacuum reservoir 130 is isolated from the brake vacuum assist system. When the vacuum degree is restored to B MPa (namely, a second threshold value) and Y seconds can be maintained (namely, a second preset time), the control valve 150 is opened, and the vacuum tank 130 is connected in parallel to the brake vacuum boosting system. It should be noted that, when the vacuum degree is restored to B MPa (i.e. the second threshold) and Y seconds can be maintained (i.e. the second predetermined time), the conditions for opening the control valve 150 further include: the brake pedal state is a state in which the brake pedal is not depressed.
In the above description, the values Vac on, Vac off, A, B, X, Y may be calibrated in advance through multiple tests to determine reasonable values. According to the environmental pressure value and the working capacity of the existing vacuum pump, Vac on-50 Mpa, Vac off-80 Mpa and A, B are selected from-50 Mpa to-80 Mpa, and the optimal control calibration is carried out according to a control strategy at X, Y.
That is, the brake vacuum boosting system starts self-checking after being powered on, starts to detect the vacuum degree Vac after the self-checking is completed, starts to work when Vac is less than or equal to Vac on, and starts to work when Vac is less than or equal to a Mpa and lasts for X seconds, which indicates that the vacuum degree can not be established in a short time, the driver still has a brake demand, but the brake vacuum boosting system can not provide enough brake boosting to influence the maneuverability and safety of vehicle driving, at this time, the control valve 150 is closed, and the vacuum tank 130 is separated from the brake vacuum boosting system. When the vacuum degree Vac is greater than or equal to BMPa and lasts for Y seconds, which indicates that the vacuum degree is enough to meet the braking assistance requirement, the control valve 150 is opened, the vacuum tank 130 is connected in parallel to the braking vacuum assistance system, and when the vacuum degree Vac of the system is greater than or equal to Vac off, the braking vacuum pump 120 stops working.
According to the brake vacuum boosting system provided by the embodiment of the invention, the vacuum tank and the brake vacuum pump are connected in parallel, and the control valve controls the opening and closing of the vacuum tank, so that the conventional brake boosting requirement can be met, the vacuum degree can be ensured to be quickly established under the condition of continuous braking, the braking performance of the brake system is further improved, the driving safety is ensured, and meanwhile, the vacuum degree can be quickly established, so that the long-time working condition of the brake vacuum pump is reduced, and the service life of the brake vacuum pump is prolonged.
FIG. 2 is a flow chart of a method of controlling a brake vacuum assist system according to one embodiment of the present invention. As shown in fig. 2, a control method of a brake vacuum assist system according to an embodiment of the present invention includes the steps of:
s301: during the operation of the brake vacuum pump, whether the vacuum degree of the brake vacuum boosting system is lower than a first threshold value or not is judged
S302: if so, further determining whether the duration exceeds a first predetermined time.
S303: if yes, the control valve is controlled to be closed to disconnect the vacuum tank from the vacuum pipeline.
Further, when the vacuum degree is recovered to a second threshold value and the duration time exceeds a second preset time, the control valve is controlled to be opened so that the vacuum tank is connected to the vacuum pipeline.
In one embodiment of the present invention, the first threshold and the second threshold, and the first predetermined time and the second predetermined time are calibrated in advance.
In one embodiment of the invention, the method further comprises: and controlling the brake vacuum pump to stop running when the vacuum degree of the brake vacuum boosting system is recovered to a vacuum degree closing threshold value during the running of the brake vacuum pump.
In one embodiment of the invention, the method further comprises: and when the vacuum degree of the brake vacuum boosting system is smaller than a vacuum degree opening threshold value, controlling the brake vacuum pump to operate.
Specifically, as shown in FIG. 3, when the vacuum degree of the brake vacuum boosting system is detected to be lower than the opening threshold Vac on (i.e., the vacuum degree opening threshold), the brake vacuum pump 120 is controlled to start to operate, and when the vacuum degree of the brake vacuum boosting system reaches the closing threshold Vac off (i.e., the vacuum degree closing threshold), the controller controls the brake vacuum pump to stop operating.
Further, when the vacuum degree of the brake vacuum boosting system is less than the vacuum degree opening threshold value, the brake vacuum pump 120 is controlled to operate.
The control valve 150 (i.e., the normally open solenoid valve) operates in a normal state, in which the control valve 150 is in an open state and the vacuum tank 130 is connected in parallel to the brake vacuum assist system. When the vacuum degree of the brake vacuum boosting system is lower than the vacuum degree opening threshold value, the brake vacuum pump 120 works, the control valve 150 is in an open state, and the vacuum tank 130 is connected to the brake vacuum boosting system in parallel. During operation of the brake vacuum pump 120, the vacuum level is below a certain threshold A MPa (i.e., the first threshold) and maintained for X seconds (i.e., the first predetermined time), the control valve 150 is closed, and the vacuum reservoir 130 is isolated from the brake vacuum assist system. When the vacuum degree is restored to B MPa (namely, a second threshold value) and Y seconds can be maintained (namely, a second preset time), the control valve 150 is opened, and the vacuum tank 130 is connected in parallel to the brake vacuum boosting system. It should be noted that, when the vacuum degree is restored to B MPa (i.e. the second threshold) and Y seconds can be maintained (i.e. the second predetermined time), the conditions for opening the control valve 150 further include: the brake pedal state is a state in which the brake pedal is not depressed.
According to the control method of the brake vacuum boosting system, the vacuum tank and the brake vacuum pump are connected in parallel, and the control valve controls the opening and closing of the vacuum tank, so that the conventional brake boosting requirement can be met, the vacuum degree can be quickly established under the condition of continuous braking, the braking performance of the brake system is further improved, the driving safety is ensured, and meanwhile, the vacuum degree can be quickly established, so that the brake vacuum pump is reduced from being in a working state for a long time, and the service life of the brake vacuum pump is prolonged.
It should be noted that a specific implementation manner of the control method of the brake vacuum assist system in the embodiment of the present invention is similar to that of the brake vacuum assist system in the embodiment of the present invention, and please refer to the description of the method part specifically, and details are not described here in order to reduce redundancy.
Further, an embodiment of the present invention discloses a vehicle, including: a brake vacuum assist system according to any one of the embodiments described above. This vehicle connects vacuum tank and brake vacuum pump in parallel to by opening and closing of control valve control vacuum tank, both can satisfy conventional braking helping hand demand, also can guarantee to establish rapidly at the vacuum under the continuous braking condition, and then improve braking system's braking nature, guarantee driving safety, reduced the brake vacuum pump simultaneously and be in operating condition for a long time, promoted brake vacuum pump's life.
In addition, other configurations and functions of the vehicle according to the embodiment of the present invention are known to those skilled in the art, and are not described herein in detail to reduce redundancy.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean 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 invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.