Patent Publication Number: US-2023145896-A1

Title: Non-hydraulic pedal simulator

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from and the benefit of Korean Patent Application No. 10-2021-0152988, filed on Nov. 9, 2021, which is hereby incorporated by reference for all purposes as if set forth herein. 
     BACKGROUND 
     Field 
     Exemplary embodiments of the present disclosure relate to a non-hydraulic pedal simulator, and more particularly, to a non-hydraulic pedal simulator which can implement a pedal force without using hydraulic pressure. 
     Discussion of the Background 
     In general, a braking apparatus refers to a brake system in which an ECU (Electronic Control Unit) senses that a driver steps on a brake pedal, and operates a hydraulic pressure generation unit to supply hydraulic pressure to a master cylinder, such that brake hydraulic pressure is transferred to a wheel cylinder of each wheel to generate a brake force. 
     In such a brake system, when the driver steps on the brake pedal during normal braking, a pedal displacement sensor senses a displacement of the brake pedal. The ECU operates the hydraulic pressure generation unit to supply operating oil, stored in an operating oil storage place, to a boost chamber of the master cylinder, thereby forming pressure in the master cylinder. The pressure in the master cylinder, formed in such a manner, generates brake hydraulic pressure by pressing a piston of the master cylinder. This brake hydraulic pressure is transferred to the wheel cylinder to generate a brake force. 
     At this time, when the pressure of the master cylinder is changed during regenerative braking, a force is transferred to the brake pedal as it is, which causes a bad influence on pedal feeling. When the pedal feeling is degraded, there occurs a gap between the pedal feeling of the driver during braking and how much the brake disk is actually pressed by the brake pad in the wheel cylinder. In this case, braking may be excessively or minimally performed to cause the frequent replacement of consumable parts such as the brake pad, and a safety accident of a vehicle may occur with sudden braking or non-braking. Thus, there is a demand for a device capable of solving such a problem. 
     The related art of the present disclosure is disclosed in Korean Patent Application Publication No. 2014-0030227 published on Mar. 11, 2014 and entitled “Pedal Travel Simulator, Actuating Unit for Hydraulic Brake System and Brake System.” 
     SUMMARY 
     Various embodiments are directed to a non-hydraulic pedal simulator which can implement a pedal force without using hydraulic pressure. 
     In an embodiment, a non-hydraulic pedal simulator may include: a housing part; a piston part inserted into the housing part, and moveable in connection with a pedal rod part; a mounting reaction part mounted on the piston part; a support reaction part inserted into the housing part, disposed on a moving path of the mounting reaction part, and configured to support the mounting reaction part; and a moving reaction part disposed between the piston part and the support reaction part, configured to elastically support the piston part, and supported by the support reaction part while being moved by the piston part. 
     The piston part may include: a piston body part inserted into the housing part; a piston induction part extending from one side of the piston body part such that the pedal rod part is inserted into the piston induction part; a piston mounting part extending from another side of the piston body part, such that the mounting reaction part is inserted into the piston mounting part; a piston sealing part mounted on a circumference of the piston body part, and brought into close contact with the housing part; and a piston stopper part mounted on the housing part, and configured to prevent separation of the piston body part. 
     The mounting reaction part may be press-fitted into the piston part and exposed to an outside of the piston part, and made of an elastic material. 
     The support reaction part may include: a support base part embedded in the housing part; a support rod part coupled to the support base part, and extending toward the mounting reaction part; and a support plate part coupled to an end of the support rod part, and configured to support the mounting reaction part. 
     The support rod part may be insert-molded in the support base part. 
     The support reaction part may further include a support elastic part penetrated by the support rod part, press-fitted into the support base part, made of an elastic material, and configured to provide a reaction force. 
     The moving reaction part may include: a moving support part moveable by the pressing of the piston part; and a moving spring part disposed between the moving support part and the support reaction part, and configured to support the moving support part by using a spring force. 
     The non-hydraulic pedal simulator may further include: a magnetic force generator disposed in any one or more of the pedal rod part, the piston part, or the moving reaction part, and configured to generate a magnetic force; and a position detector mounted in the housing part, and configured to detect a position of the magnetic force generator. 
     The non-hydraulic pedal simulator may be characterized in that the moving reaction part is pressed to generate a primary pedal force as the piston part is moved, the support reaction part presses the mounting reaction part to generate a secondary pedal force as the piston part is additionally moved, and the moving reaction part presses the support reaction part to generate a tertiary pedal force as the piston part is still further moved. 
     The non-hydraulic pedal simulator in accordance with the embodiment of the present disclosure may sequentially increase the reaction forces through the mounting reaction part, the support reaction part, and the moving reaction part while the piston part is moved as a driver presses the pedal. Thus, the non-hydraulic pedal simulator may provide the driver with brake feeling similar to that generated by an existing hydraulic booster, even though an electronic booster is used. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram schematically illustrating a non-hydraulic pedal simulator in accordance with an embodiment of the present disclosure. 
         FIG.  2    is a diagram schematically illustrating a piston part in accordance with the embodiment of the present disclosure. 
         FIG.  3    is a diagram schematically illustrating a support reaction part in accordance with the embodiment of the present disclosure. 
         FIG.  4    is a diagram schematically illustrating a moving reaction part in accordance with the embodiment of the present disclosure. 
         FIG.  5    is a diagram schematically illustrating that a magnetic force generator in accordance with a first embodiment of the present disclosure is disposed. 
         FIG.  6    is a diagram schematically illustrating that a magnetic force generator in accordance with a second embodiment of the present disclosure is disposed. 
         FIG.  7    is a diagram schematically illustrating that a magnetic force generator in accordance with a third embodiment of the present disclosure is disposed. 
         FIG.  8    is a graph schematically illustrating a pedal force for each period in the non-hydraulic pedal simulator in accordance with the embodiment of the present disclosure. 
         FIG.  9    is a diagram schematically illustrating the state of an invalid period in  FIG.  8   . 
         FIG.  10    is a diagram schematically illustrating the state of a first period in  FIG.  8   . 
         FIG.  11    is a diagram schematically illustrating the state of a second period in  FIG.  8   . 
         FIG.  12    is a diagram schematically illustrating the state of a third period in  FIG.  8   . 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     Hereinafter, a non-hydraulic pedal simulator will be described below with reference to the accompanying drawings through various exemplary embodiments. It should be noted that the drawings are not to precise scale and may be exaggerated in thickness of lines or sizes of components for descriptive convenience and clarity only. Furthermore, the terms as used herein are defined by taking functions of the invention into account and can be changed according to the custom or intention of users or operators. Therefore, definition of the terms should be made according to the overall disclosures set forth herein. 
       FIG.  1    is a diagram schematically illustrating a non-hydraulic pedal simulator in accordance with an embodiment of the present disclosure. Referring to  FIG.  1   , a non-hydraulic pedal simulator  1  in accordance with an embodiment of the present disclosure includes a housing part  10 , a piston part  20 , a mounting reaction part  30 , a support reaction part  40 , and a moving reaction part  50 . 
     The housing part  10  is mounted on a vehicle body. For example, the housing part  10  may include a housing body part  11  mounted on the vehicle body and a housing insertion part  12  formed in the housing body part  11  and having a space formed in the longitudinal direction of the housing body part  11  such that the piston part  20 , the mounting reaction part  30 , the support reaction part  40 , and the moving reaction part  50  are embedded in the space. A pedal rod part  90  may be inserted into an end of the housing insertion part  12 , and a corrugated cover part  80  that covers the housing insertion part  12  and the pedal rod part  90  may block the introduction of foreign matters. 
     The piston part  20  is inserted into the housing part  10 , and moved in connection with the pedal rod part  90 . For example, the piston part  20  may be coupled to the pedal rod part  90 . When a driver steps on a pedal, the pedal rod part  90  may be moved to move the piston part  20 . 
     The mounting reaction part  30  is mounted in the piston part  20 . For example, the mounting reaction part  30  may be made of an elastic material to provide a reaction force while supported by the support reaction part  40 . 
     The support reaction part  40  is inserted into the housing part  10 , and disposed on a movement path of the mounting reaction part  30  so as to support the mounting reaction part  30 . For example, the support reaction part  40  may be embedded in the housing part  10 , and maintain a fixed state thereof. The support reaction part  40  may provide an additional reaction force by the pressurization of the moving reaction part  50 . 
     The moving reaction part  50  is disposed between the piston part  20  and the support reaction part  40 , elastically supports the piston part  20 , and is supported by the support reaction part  40  while moved by the piston part  20 . For example, the moving reaction part  50  may provide a reaction force by a spring force while pressed by the piston part  20 . Furthermore, the moving reaction part  50  may press the support reaction part  40  while moved. 
       FIG.  2    is a diagram schematically illustrating the piston part in accordance with the embodiment of the present disclosure. Referring to  FIG.  2   , the piston part  20  in accordance with the embodiment of the present disclosure includes a piston body part  21 , a piston induction part  22 , a piston mounting part  23 , a piston sealing part  24 , and a piston stopper part  25 . 
     The piston body part  21  is inserted into the housing part  10 . For example, the piston body part  21  is disposed in the center of the piston part  20 , and inserted into the housing insertion part  12 . 
     The piston induction part  22  is extended from one side of the piston body part  21 , such that the pedal rod part  90  is inserted into the piston induction part  22 . For example, the piston induction part  22  may have a pipe shape into which the pedal rod part  90  can be inserted. The piston induction part  22  may be coupled to the pedal rod part  90  through a pin. 
     The piston mounting part  23  is extended from the other side of the piston body part  21 , and the mounting reaction part  30  is inserted into the piston mounting part  23 . For example, the piston mounting part  23  may have a pipe shape into which the mounting reaction part  30  can be press-fitted. The mounting reaction part  30  inserted into the piston mounting part  23  may maintain the state in which the surface thereof is exposed to the outside. 
     The piston sealing part  24  is mounted on the circumference of the piston body part  21 , and comes into close contact with the housing part  10 . For example, the piston sealing part  24  may be made of an elastic material such as rubber, and inserted into a groove formed along the circumference of the piston body part  21  so as to come into close contact with the inside of the housing insertion part  12 . 
     The piston stopper part  25  is mounted on the housing part  10 , and prevents the separation of the piston body part  21 . For example, the piston stopper part  25  may be formed in a band shape to surround the piston induction part  22 , and fixed to the housing insertion part  12  so as to prevent an unintended separation of the piston body part  21  from the housing part  10 . 
     The mounting reaction part  30  in accordance with the embodiment of the present disclosure is press-fitted into the piston part  20  so as to be exposed to the outside, and formed of an elastic material. For example, the mounting reaction part  30  may be press-fitted into the piston mounting part  23 . The mounting reaction part  30  may not protrude to the outside, but be exposed to the outside while inserted into the piston mounting part  23 . Between the mounting reaction part  30  and the piston mounting part  23 , a space may be formed so that the mounting reaction part  30  provides a reaction force while expanded in a lateral direction by an external force. 
       FIG.  3    is a diagram schematically illustrating the support reaction part in accordance with the embodiment of the present disclosure. Referring to  FIG.  3   , the support reaction part  40  in accordance with the embodiment of the present disclosure includes a support base part  41 , a support rod part  42 , and a support plate part  43 . 
     The support base part  41  is embedded in the housing part  10 . For example, the support base part  41  may be inserted into the housing insertion part  12  and fixed to the deepest position thereof. 
     The support rod part  42  is coupled to the support base part  41 , and extended toward the mounting reaction part  30 . For example, the support rod part  42  may have one end coupled to the support base part  41 , and have a length in the longitudinal direction of the housing insertion part  12 . The support rod part  42  may penetrate the moving reaction part  50 . The support rod part  42  may be formed in the support base part  41  through insert-molding. For example, the support rod part  42  may be made of a metallic material, and the support base part  41  may be made of resin. The support rod part  42  and the support base part  41  may be formed as one body by insert molding. 
     The support plate part  43  is coupled to an end of the support rod part  42 , and supports the mounting reaction part  30 . For example, when the piston mounting part  23  is moved, the support plate part  43  may be inserted into the piston mounting part  23  and coupled to an end of the support rod part  42  through a bolt or rivet so as to support the mounting reaction part  30  embedded in the piston mounting part  23 . 
     The support reaction part  40  in accordance with the embodiment of the present disclosure may further include a support elastic part  44 . The support elastic part  44  is penetrated by the support rod part  42 , press-fitted into the support base part  41 , and made of an elastic material to provide a reaction force. For example, the support base part  41  may have a support insertion part  49  formed to face the mounting reaction part  30 , and the support elastic part  44  inserted into the support insertion part  49  may provide an additional reaction force. Between the support elastic part  44  and the support insertion part  49 , a space may be formed so that the support elastic part  44  provides a reaction force while expanded in a lateral direction by an external force. 
       FIG.  4    is a diagram schematically illustrating the moving reaction part in accordance with the embodiment of the present disclosure. Referring to  FIG.  4   , the moving reaction part  50  in accordance with the embodiment of the present disclosure includes a moving support part  51  and a moving spring part  52 . 
     The moving support part  51  is moved by the pressing of the piston part  20 . For example, the moving support part  51  may be penetrated by the support rod part  42 , and brought into surface contact with the piston mounting part  23 . When the pedal rod part  90  pushes the piston part  20 , the piston part  20  may be pushed to move the moving support part  51  toward the support elastic part  44 . When the moving support part  51  is moved by an external force so as to reach the support elastic part  44 , the moving support part  51  may press the support elastic part  44  to provide a reaction force. The moving support part  51  may have a protruding end which is inserted into the support insertion part  49  so as to press the support elastic part  44 . 
     The moving spring part  52  is disposed between the moving support part  51  and the support reaction part  40 , and supports the moving support part  51  by using a spring force. For example, the moving spring part  52  may be formed in a coil spring shape and supported by the support base part  41  while surrounding the support elastic part  44 , and support the edge of the moving support part  51 . The moving support part  51  may be returned to the original position by the moving spring part  52 . 
       FIG.  5    is a diagram schematically illustrating that a magnetic force generator in accordance with a first embodiment of the present disclosure is disposed,  FIG.  6    is a diagram schematically illustrating that a magnetic force generator in accordance with a second embodiment of the present disclosure is disposed, and  FIG.  7    is a diagram schematically illustrating that a magnetic force generator in accordance with a third embodiment of the present disclosure is disposed. Referring to  FIGS.  1  and  5  to  7   , the non-hydraulic pedal simulator  1  in accordance with the embodiment of the present disclosure further includes a magnetic force generator  60  and a position detector  70 . 
     The magnetic force generator  60  is disposed in any one or more of the pedal rod part  90 , the piston part  20 , and the moving reaction part  50 , and serves to generate a magnetic force. The position detector  70  is mounted in the housing part  10 , and serves to detect the position of the magnetic force generator  60 . 
     One or more magnetic force generators  60  may be mounted on the pedal rod part  90  ( FIG.  5   ), mounted on the piston body part  21  ( FIG.  6   ), or mounted on the moving support part  51  ( FIG.  7   ). The position detector  70  may be disposed outside the housing insertion part  12 , measure the position of the magnetic force generator  60  in real time, and detect a stroke according to the position of the magnetic force generator  60 . 
     Through the above-described configuration, the piston part  20  is moved to press the moving reaction part  50 , thereby generating a primary pedal force. With the primary pedal force generated, the piston part  20  is additionally moved so that the support reaction part  40  additionally presses the mounting reaction part  30 , thereby generating a secondary pedal force. With the secondary pedal force generated, the piston part  20  is additionally moved so that the moving reaction part  50  additionally presses the support reaction part  40 , thereby generating a tertiary pedal force. 
       FIG.  8    is a graph schematically illustrating a pedal force for each period in the non-hydraulic pedal simulator in accordance with the embodiment of the present disclosure, and  FIG.  9    is a diagram schematically illustrating the state of an invalid period in  FIG.  8   .  FIG.  10    is a diagram schematically illustrating the state of a first period in  FIG.  8   ,  FIG.  11    is a diagram schematically illustrating the state of a second period in  FIG.  8   , and  FIG.  12    is a diagram schematically illustrating the state of a third period in  FIG.  8   . Referring to  FIGS.  8  to  12   , an operation of the non-hydraulic pedal simulator  1  in accordance with the embodiment of the present disclosure will be described as follows. 
     When a driver steps on the pedal, the piston part  20  is moved by the pedal rod part  90 . At this time, a period before the piston part  20  comes into contact with the moving support part  51  is an invalid period. In the invalid period, no pedal force is generated (see  FIG.  9   ). 
     When a first period arrives as the pedal is continuously pressed, the moving spring part  52  is compressed to generate the primary pedal force while the moving support part  51  is moved by the piston part  20 . The first period starts at the point of time that the moving spring part  52  is compressed, and lasts until the support plate part  43  reaches the mounting reaction part  30  (see  FIG.  10   ). 
     When the second period following the first period arrives as the pedal is continuously pressed, the compression of the moving spring part  52  lasts while the piston part  20  is additionally moved, and the mounting reaction part  30  mounted on the piston part  20  is compressed by the fixed support plate part  43  so as to generate the secondary pedal force. The second period starts at the point of time that the mounting reaction part  30  is compressed, and lasts until the moving support part  51  reaches the support elastic part  44  (see  FIG.  11   ). 
     When the third period following the second period arrives as the pedal is continuously pressed, the compression of the moving spring part  52  lasts while the piston part  20  is additionally moved, the compression of the mounting reaction part  30  lasts, and the support elastic part  44  is compressed by the moving support part  51  so as to generate a tertiary pedal force. The third period starts at the point of time that the support elastic part  44  is compressed (see  FIG.  12   ). 
     The non-hydraulic pedal simulator  1  in accordance with the embodiment of the present disclosure may sequentially increase the reaction forces through the mounting reaction part  30 , the support reaction part  40 , and the moving reaction part  50  while the piston part  29  is moved as a driver presses the pedal. Thus, the non-hydraulic pedal simulator  1  may provide the driver with brake feeling similar to that generated by an existing hydraulic booster, even though an electronic booster is used. 
     Although exemplary embodiments of the disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure as defined in the accompanying claims. Thus, the true technical scope of the disclosure should be defined by the following claims.