CN114454856A - 电动液压制动系统 - Google Patents
电动液压制动系统 Download PDFInfo
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Abstract
根据本发明的实施例提供了一种电动液压制动系统,包括能够执行2‑通道加压/减压控制和1‑通道减压控制的辅助制动系统,从而可以降低制造成本并且使组装过程更容易地进行。
Description
技术领域
本公开涉及一种电动液压制动系统。
背景技术
本部分中描述的主题仅提供有关本公开的背景信息,并不构成现有技术。
当在主制动系统中发生功能异常时,自动驾驶车辆通过设置在主制动系统和多个车轮制动装置之间的辅助制动系统来确保故障保护功能。
同时,常规的辅助制动系统执行2-通道加压/减压控制和2-通道减压控制。例如,常规的辅助制动系统对前轮执行加压/减压功能,并对后轮执行减压功能。为此,应该将包括四个输入管道和四个输出管道的总共八个管道连接到辅助制动系统。结果,存在制动系统的成本和重量增加以及制造过程中的组装复杂的缺点。
发明内容
本公开的主要目的是提供一种电动液压制动系统,其包括能够执行2-通道加压和减压控制以及1-通道减压控制的辅助制动系统。
本发明要解决的技术问题不限于上述问题,本领域技术人员从以下描述中可以清楚地理解其他未提及的问题。
根据本公开的一个实施例,可以提供一种电动液压制动系统,所述电动液压制动系统包括:油箱,用于储存制动油;多个车轮制动装置,其被配置为通过提供液压来向多个车轮提供制动力;主制动系统,其设置在所述油箱和多个所述车轮制动装置之间,并且被配置为将从所述油箱排出的制动油输送到所述车轮制动装置;和辅助制动系统,其设置在所述主制动系统和多个所述车轮制动装置之间,其中,所述辅助制动系统包括:第一进口管线、第二进口管线和第三进口管线,其被配置为在所述主制动系统和所述车轮制动装置之间输送液压;致动单元,其连接到所述第一进口管线上的一点和所述第二进口管线上的一点,被配置为增加所述第一进口管线的内部液压和所述第二进口管线的内部液压,并且包括第一泵和第二泵;第一出口管线,其从所述第一进口管线分支,并且将所述第一进口管线的分支点连接至所述第一泵的入口;第二出口管线,其从所述第二进口管线分支,并且将所述第二进口管线的分支点连接到所述第二泵的入口;以及第三出口管线,其适于由出口阀打开和关闭,并且被配置为使得所述第三进口管线上的一点连接至所述第一出口管线和所述第二出口管线中的至少一者。
如上所述,根据该实施例,电动液压制动系统包括能够执行2-通道加压/减压控制和1-通道减压控制的辅助制动系统,从而可以降低制造成本并且使组装过程更容易地进行。
附图说明
图1示出了根据本公开的实施例的电动液压制动系统的液压回路。
具体实施方式
下面将参考示例性附图详细描述本公开的一些实施例。应当注意,对每个附图中的组件添加附图标记时,相同的组件尽可能具有相同的附图标记,即使它们在不同的附图中示出。另外,在描述本公开时,可以省略对已知相关配置或功能的详细描述,如果这样的描述被认为使本公开的要点不清楚。
在描述根据本公开的实施例的组件时,可以使用诸如第一、第二、i)、ii)、a)、b)等的术语和字符。这样的术语和字符仅用于将组件与其他组件区分开,并且组件的性质、序列、顺序等不受术语和字符的限制。当说某物“包括”或“具有”说明书中的某个组件时,这意味着可以进一步包括而不是排除其他组件,除非有相反的明确说明。
在本公开中,关于管线的相对位置,所谓的“前方”是指随着制动油流动而与油箱10相距更近的部分。所谓的“后方”是指随着制动油流动而与油箱10相距更远的部分。但是,这不仅意味着管线是向前或向后直接连续的,还意味着位置位于相对较远的部分,即使间隔开。
图1是根据本公开的实施例的电动液压制动系统的液压回路图。同时,图1中所示的液压回路图仅仅是为了便于解释而概念性地示出每个部件,应当注意的是,实际液压块的实际位置和液压块内部形成的管线可以变化。此外,在图1中,进口管线表示为粗线,出口管线表示为中等粗细的线,而循环管线表示为细线。
另外,本领域的技术人员可以容易地实现本公开中的油箱10、制动踏板11和主制动系统20的特定部件,因此省略了与之相关的具体图示和描述。
此外,尽管本公开将车轮制动装置(其液压通过辅助制动系统100进行调节)示出为右前轮制动装置FR(front right wheel brake apparatus)、左前轮制动装置FL(frontleft wheel brake apparatus)和左后轮制动装置RL(rear left wheel brakeapparatus),这仅仅是示例。车轮制动装置可以是右前轮、左前轮、右后轮和左后轮中的任意三者。
参考图1,电动液压制动系统1可包括油箱10、制动踏板11、主制动系统20和辅助制动系统100的全部或部分。
油箱10被配置为在其中储存制动油。
制动踏板11引导设置在主制动系统20的主缸(未示出)内的活塞(未示出)的平移运动作为对使用者的踩踏的响应。
多个车轮制动装置FR、FL和RL通过利用从油箱10排出的制动油的液压来对多个车轮(未示出)施加制动力。当驾驶员踩踏制动踏板11时,电控制单元(未示出)通过踏板行程传感器(pedal travel sensor,PTS,未示出)检测驾驶员的制动请求。检测驾驶员的制动请求的电控制单元产生制动信号。在此,制动信号是电信号,该电信号被传递,以便根据驾驶员对制动踏板11的踩踏程度使制动系统20、100各自产生相应的制动力。
主制动系统20设置在油箱10与多个车轮制动装置FR、FL和RL之间,并被配置为将从油箱10排出的制动油输送到多个车轮制动装置FR、FL和RL以及控制制动油的液压。当在主制动系统20的至少一些组件中发生故障时,电控制单元对辅助制动系统100传送辅助制动信号。一旦辅助制动信号被电控制单元传送到辅助制动系统100,辅助制动系统100的全部或部分部件被启动。因此,根据本公开的电动液压制动系统1可以执行故障保护功能。
辅助制动系统100设置在主制动系统20与多个车轮制动装置FR、FL和RL之间。在车辆的自动驾驶期间主制动系统20发生异常的情况下,或者在驾驶员干预直接制动时主制动系统20发生异常的情况下,辅助制动系统100被启动。
辅助制动系统100包括液压输入单元101、102和103、液压输出单元104、105和106、进口管线111、112和113、致动单元、牵引控制阀TCV1和TCV2、进口阀FRIV和FLIV、出口管线121、122和123、出口阀FROV、FLOV和RLOV,蓄能器A1和A2、油腔131和132、循环管线141和142以及高压开关阀HSV1和HSV2中的全部或部分。
液压输入单元101、102和103中的至少一者设置在从主制动系统20排出的制动油通过其流到辅助制动系统100的管线上。液压输入单元101、102和103允许进口管线111、112和113与主制动系统20流体连通。为此,液压输入单元101、102和103设置在辅助制动系统100的边界处。根据本公开的辅助制动系统100包括第一进口管线111、第二进口管线112和第三进口管线113,相应地,辅助制动系统100包括第一液压输入单元101、第二液压输入单元102和第三液压输入单元103。
液压输出单元104、105和106中的至少一者设置在从辅助制动系统100排出的制动油通过其流到多个车轮制动装置FR、FL和RL的管线上。液压输出单元104、105和106允许进口管线111、112和113与多个车轮制动装置FR、FL和RL流体连通。根据本公开的辅助制动系统100包括第一液压输出单元104、第二液压输出单元105和第三液压输出单元106。
进口管线111、112和113形成在液压输入单元101、102和103与液压输出单元104、105和106之间,并且将从主制动系统20排出的制动油输送至多个车轮制动装置FR、FL和RL。进口管线111、112和113包括第一进口管线111,第二进口管线112和第三进口管线113。
第一进口管线111被配置为将从主制动系统20排出的全部或部分制动油输送至第一车轮制动装置FR。此外,第二进口管线112被配置为将从主制动系统20排出的全部或部分制动油输送至第二车轮制动装置FL。
可以通过致动单元来增加在第一进口管线111和第二进口管线112内流动的流体的液压。致动单元包括电动机以及泵SP1和SP2,电动机被配置为致动第一泵SP1和第二泵SP2。第一泵SP1的出口部分连接到第一进口管线111上的一点。第二泵SP2的出口部分连接到第二进口管线112上的一点。当第一泵SP1和第二泵SP2中的至少一者被致动时,连接到泵SP1和SP2各自的进口管线111和112中的至少一者的内部液压可增加。
第一牵引控制阀TCV1设置在第一进口管线111上的一点处,并且第一进口管线111的打开和关闭由第一牵引控制阀TCV1调节。在此,第一牵引控制阀TCV1设置在第一进口管线与第一泵SP1的出口部分连接的点的前方。第一牵引控制阀TCV1形成为常开型。因此,在不施加辅助制动信号的非动力模式下,第一牵引控制阀TCV1打开。当第一牵引控制阀TCV1关闭时,由第一泵SP1加压的部分制动油不会反流至主制动系统20。
第一进口阀FRIV设置在第一进口管线111上的另一点处,并且第一进口管线111的打开和关闭由第一进口阀FRIV调节。同时,第一进口阀FRIV设置在第一进口管线111与第一泵SP1的出口部分连接的点的后方。第一进口阀FRIV形成为常开型。因此,在不施加辅助制动信号的非动力模式下,第一进口阀FRIV打开。当第一进口阀FRIV关闭时,由第一泵SP1加压的部分制动油不被输送到车轮制动装置FR。结果,能够进行制动油的压力控制。
对于第二进口管线112、第二牵引控制阀TCV2和第二进口阀FLIV的描述分别由对于第一进口管线111、第一牵引控制阀TCV1和第一进口阀FRIV的描述代替。
第三进口管线113被配置为将从主制动系统20排出的全部或部分制动油输送到第三车轮制动装置RL。当电控制单元施加辅助制动信号时,连接到第三液压输入单元103的管线(未示出)可以在主制动系统20内部处于短路结构中。当电控制单元传送辅助制动信号时,第三进口管线113可以直接连接到油箱10。结果,当驾驶员干预制动时,通过制动踏板11的踩踏而增加的液压可以直接传递到第三车轮制动装置RL。
同时,第三进口管线113未被致动单元加压,仅第一进口管线111和第二进口管线112被致动单元加压。因此,根据本公开的辅助制动系统100能够执行2-通道加压控制。
出口管线121、122和123连接到进口管线111、112和113上的一点,使得进口管线111、112和113中的至少一些制动油分流。
出口管线121、122和123包括第一出口管线121、第二出口管线122和第三出口管线123。
第一出口管线121的一端连接到第一进口管线111上的分支点,该分支点形成在第一进口阀FRIV的后方,并且另一端连接到第一泵SP1的入口部分。
第一出口阀FROV设置在第一出口管线121上的一点处,并且第一出口管线121的打开和关闭由第一出口阀FROV调节。第一出口阀FROV形成为常闭型。因此,在不施加辅助制动信号的非动力模式下,第一出口阀FROV关闭。当第一出口阀FROV打开时,至少一些流经第一进口管线111的加压的制动油被排放到第一出口管线121。因此,可以减小输送到第一车轮制动装置FR的液压。
第一蓄能器A1可以进一步设置在第一出口阀FROV的后方形成的第一出口管线121上的另一点。第一蓄能器A1被配置为临时接收从第一出口管线121输送的全部或部分制动油。因此,可以将由于制动油的波动而在第一出口管线中发生的损伤最小化。在此,所谓的在第一出口管线121中发生的损伤包括,例如,当管线长时间暴露于连续波动时,在至少部分管线中发生的疲劳、变形、磨损等。
用于第二出口管线122、第二出口阀FLOV和第二蓄能器A2的描述分别被用于第一出口管线121、第一出口阀FROV和第一蓄能器A1的描述代替。
同时,根据本公开的辅助制动系统100的电控制单元(未示出)依据所需的制动来确定是否使用蓄能器A1和A2。例如,在缓慢制动的情况下,仅各出口阀FROV、FLOV和RLOV中的部分出口阀打开,使得制动油仅流经打开的出口管线121、122和123并且从进口管线111、112和113分流。这里,由于被分流的制动油的量与突然制动的情况相比相对较小,所以制动油未被蓄能器A1和A2接收。然而,在突然制动的情况下,所有出口阀FROV、FLOV和RLOV都打开,从而制动油流过整个出口管线121、122和123,并且从进口管线111、112和113分流。这里,由于被分流的制动油的量比缓慢制动的情况相比相对较大,因此制动油被蓄能器A1和A2接收。
第三出口管线123一端连接到第三进口管线113上的一点,另一端连接到第一出口管线121。在这种情况下,第三出口管线123和第一出口管线121相连接处的点形成在第一出口阀FROV的后方。结果,通过第三出口管线123输送的制动油可以与在第一出口管线121中流动的制动油汇合。
第三出口管线123连接到第一出口管线121和第二出口管线122中的至少一者。如本公开的图1所示,例如,第一出口管线121和第二出口管线122可以被连接并且流体连通。在这种情况下,通过第三出口管线123输送的制动油可以被第一蓄能器A1和第二蓄能器A2中的至少一者接收。然而,本公开不限于此,并且第一出口管线121和第二出口管线122可以不连接。在这种情况下,通过第三出口管线123输送的制动油仅汇入第一出口管线121,并且仅被第一蓄能器A1接收。
第三出口阀RLOV设置在第三出口管线123上的一点处,并且第三出口管线123的打开和关闭由第三出口阀RLOV调节。第三出口阀RLOV形成为常闭型。因此,在非动力模式下,第三出口阀RLOV关闭。当第三出口阀RLOV打开时,至少一些流经第三进口管线113的加压的制动油分流到第三出口管线123。结果,可以减小输送到第三车轮制动装置RL的液压。
在根据本公开的辅助制动系统100中,随着出口阀FROV、FLOV和RLOV的打开,提供至车轮制动装置FR、FL和RL中的液压减小。即,辅助制动系统100可以执行3-通道减压控制。
综上所述,根据本公开的实施例的辅助制动系统100不参与右后轮的车轮制动装置中的加压/减压控制。即,辅助制动系统100能够执行2-通道加压/减压控制和1-通道减压控制。因此,包括辅助制动系统100的根据本公开的的电动液压制动系统1可以包括连接到三个液压输入单元101、102和103的三条管线以及连接到三个液压输出单元104、105和106的三条管线。在传统的辅助制动系统中,应将超过八条管线连接到辅助制动系统以进行4-通道加压/减压,但是根据本发明的辅助制动系统100即使总共六条管线连接至此也能够进行辅助制动功能。因此,根据本公开的电动液压制动系统1具有降低成本的效果。此外,在车辆制造期间,有利地简化了辅助制动系统100的配管工作,并且简化了车辆的组装。
也可以在第一进口管线111上设置第一油腔131。在这种情况下,第一油腔131设置在第一牵引控制阀TCV1的前方。第一油腔131可以临时接收从主制动系统20中排出的制动油中的至少部分制动油。
循环管线141和142中的每一者的一端连接到油腔131和132,另一端连接到邻近泵SP1和SP2的入口部分的出口管线121和122。在此,循环管线141或142的另一端连接至出口管线121或122的位置优选形成在蓄能器A1或A2的后方。结果,从蓄能器A1和A2以及油腔131和132排出的制动油被供应到致动单元,从而可以为要被致动的致动单元提供所需的足够量的制动油。
第一高压开关阀HSV1设置在第一循环管线141上的一点处,并且第一循环管线141的打开和关闭由第一高压开关阀HSV1调节。第一高压开关阀HSV1形成为常闭型。因此,在非动力模式下,第一高压开关阀HSV1关闭。当第一高压开关阀HSV1打开时,第一油腔131中所容纳的制动油中的至少一些制动油被提供给致动单元。
用于第二高压开关阀HSV2和第二循环管线142的描述被用于第一高压开关阀HSV1和第一循环管线141的描述代替。
当在施加辅助液压信号时从油箱10供应的液压不足时,油腔131和132中所容纳的制动油中的至少部分制动油可以供应到致动单元。因此,在制动油从油箱10供应并且压力升高的情况下,根据本公开的辅助制动系统100可以具有快速响应性。
上述描述仅是对本发明的技术构思的说明,在不脱离本发明的本质特征的情况下,各种修改和变型对于本领域技术人员将是显而易见的。因此,本实施例并非旨在限制本发明的技术构思,而是通过示例的方式进行描述,并且本发明的技术构思的范围不受这些实施例的限制。本发明的保护范围应由技术方案来解释,并且在其等效范围内的所有技术构思应被解释为包括在范围内。
附图标记
1:制动系统
10:油箱
11:制动踏板
20:主制动系统
100:辅助制动系统
111、112、113:进口管线
121、122、123:出口管线
131、132:油腔
141、142:循环管线
TCV:牵引控制阀
HSV:高压开关阀
IN:进口阀
OV:出口阀
SP:泵
Claims (10)
1.一种电动液压制动系统,包括:
油箱,用于储存制动油;
多个车轮制动装置,其被配置为通过提供液压来向多个车轮提供制动力;
主制动系统,其设置在所述油箱和多个所述车轮制动装置之间,并且被配置为将从所述油箱排出的制动油输送到所述车轮制动装置;和
辅助制动系统,其设置在所述主制动系统和多个所述车轮制动装置之间,
其中,所述辅助制动系统包括:
第一进口管线和第二进口管线,其被配置为在所述主制动系统和多个所述车轮制动装置之间输送液压;
致动单元,其连接到所述第一进口管线上的一点和所述第二进口管线上的一点,被配置为增加所述第一进口管线的内部液压和所述第二进口管线的内部液压,并且包括第一泵和第二泵;
第一出口管线,其从所述第一进口管线分支,并且将所述第一进口管线的分支点连接至所述第一泵的入口;和
第二出口管线,其从所述第二进口管线分支,并且将所述第二进口管线的分支点连接到所述第二泵的入口。
2.根据权利要求1所述的电动液压制动系统,其中,所述辅助制动系统还包括:
第三进口管线,其被配置为在所述主制动系统和多个所述车轮制动装置之间输送液压;和
第三出口管线,其适于由出口阀打开和关闭,并且被配置为使得所述第三进口管线上的一点连接至所述第一出口管线和所述第二出口管线中的至少一者。
3.根据权利要求1所述的电动液压制动系统,其中,所述辅助制动系统还包括:
第一油腔,其设置在所述第一进口管线和所述致动单元的连接点的前方的所述第一进口管线上,并且被配置为在其中接收制动油;和
第二油腔,其设置在所述第二进口管线和所述致动单元的连接点的前方的所述第二进口管线上,并且被配置为在其中接收制动油。
4.根据权利要求3所述的电动液压制动系统,其中,所述辅助制动系统还包括:
第一循环管线,其连接所述第一油腔和所述第一泵的入口;和
第二循环管线,其连接所述第二油腔和所述第二泵的入口。
5.根据权利要求1所述的电动液压制动系统,其中,所述辅助制动系统还包括:
第一牵引控制阀,其设置在所述第一进口管线上,并且被配置为调节所述第一进口管线的打开和关闭;和
第二牵引控制阀,其设置在所述第二进口管线上,并且被配置为调节所述第二进口管线的打开和关闭。
6.根据权利要求5所述的电动液压制动系统,其中,所述辅助制动系统还包括:
第一进口阀,其设置在所述第一牵引控制阀的后方形成的所述第一进口管线上的一点和与所述第一出口管线的分支点之间,并且被配置为调节所述第一进口管线的打开和关闭;和
第二进口阀,其设置在所述第二牵引控制阀的后方形成的所述第二进口管线上的一点和与所述第二出口管线的分支点之间,并且被配置为调节所述第二进口管线的打开和关闭。
7.根据权利要求2所述的电动液压制动系统,其中,所述辅助制动系统还包括:
第一出口阀,其设置在所述第一出口管线中,并且被配置为调节所述第一出口管线的打开和关闭;
第二出口阀,其设置在所述第二出口管线中,并且被配置为调节所述第二出口管线的打开和关闭;和
第三出口阀,其设置在所述第三出口管线中,并且被配置为调节所述第三出口管线的打开和关闭。
8.根据权利要求7所述的电动液压制动系统,其中,所述辅助制动系统还包括:
第一蓄能器,其被配置为接收从所述第一出口管线排出的制动油中的至少一些制动油;和
第二蓄能器,被配置为接收从所述第二出口管线排出的制动油中的至少一些制动油。
9.根据权利要求8所述的电动液压制动系统,其中,所述辅助制动系统的特征在于所述第一蓄能器和所述第二蓄能器中的至少一者被配置为接收从所述第三出口管线排出的制动油中的至少一些制动油。
10.根据权利要求1所述的电动液压制动系统,其中,所述辅助制动系统还包括:
多个液压输入单元,其形成为与所述主制动系统相邻,并且连接至所述进口管线;和
多个液压输出单元,其形成为与多个所述车轮制动装置相邻,并且连接至所述进口管线。
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06502602A (ja) * | 1990-11-22 | 1994-03-24 | アルフレッド・テヴェス・ゲーエムベーハー | アンチロック制御を含む液圧ブレーキ装置 |
CN110035937A (zh) * | 2016-12-14 | 2019-07-19 | 罗伯特·博世有限公司 | 车辆制动系统和方法 |
US20200207320A1 (en) * | 2018-12-28 | 2020-07-02 | Zf Active Safety Gmbh | Hydraulic motor vehicle brake system and method for operating same |
CN114435326A (zh) * | 2020-11-03 | 2022-05-06 | 现代摩比斯株式会社 | 用于车辆的电子制动装置的液压块 |
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JP4211071B2 (ja) * | 1997-12-25 | 2009-01-21 | 株式会社アドヴィックス | 車両の制動制御装置 |
KR101415205B1 (ko) * | 2012-03-08 | 2014-07-04 | 주식회사 만도 | 차량용 브레이크 시스템 |
KR102339516B1 (ko) * | 2015-01-13 | 2021-12-16 | 현대모비스 주식회사 | 자동차의 브레이크 시스템 |
KR102416289B1 (ko) * | 2019-04-18 | 2022-07-05 | 현대모비스 주식회사 | 전자식 유압 브레이크 장치 |
KR102484451B1 (ko) * | 2021-01-22 | 2023-01-02 | 현대모비스 주식회사 | 전자식 유압 브레이크 장치 및 제어방법 |
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- 2020-12-09 US US17/116,820 patent/US11780418B2/en active Active
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Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06502602A (ja) * | 1990-11-22 | 1994-03-24 | アルフレッド・テヴェス・ゲーエムベーハー | アンチロック制御を含む液圧ブレーキ装置 |
CN110035937A (zh) * | 2016-12-14 | 2019-07-19 | 罗伯特·博世有限公司 | 车辆制动系统和方法 |
US20200207320A1 (en) * | 2018-12-28 | 2020-07-02 | Zf Active Safety Gmbh | Hydraulic motor vehicle brake system and method for operating same |
CN114435326A (zh) * | 2020-11-03 | 2022-05-06 | 现代摩比斯株式会社 | 用于车辆的电子制动装置的液压块 |
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DE102020134994B4 (de) | 2022-06-02 |
DE102020134994A1 (de) | 2022-05-12 |
KR20220063385A (ko) | 2022-05-17 |
US11780418B2 (en) | 2023-10-10 |
US20220144234A1 (en) | 2022-05-12 |
KR102441937B1 (ko) | 2022-09-07 |
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