Pedal simulator valve for hydraulic brake assist systems

Abstract

This invention relates to a pedal simulator valve for a hydraulic brake assist system. The simulator valve includes a housing having a pedal simulator channel and a master cylinder channel extending therethrough. The master cylinder channel is located longitudinally between a first housing surface and the pedal simulator channel. An armature is at least partially located within the housing to selectively reciprocate longitudinally relative to the housing between a first armature position and a second armature position. A lift valve is located within the housing to selectively reciprocate longitudinally relative to the armature between a first lift valve position and a second lift valve position. The lift valve defines a first valve and a second valve, and includes a lift valve orifice extending longitudinally through it and selectively blocked by the first valve. A damped flow fluid path selectively allows fluid communication from the master cylinder channel to the pedal simulator channel. A free-flow fluid path selectively allows fluid communication from the pedal simulator channel to the master cylinder channel.

Description

Technical Field

[0001] This disclosure relates to an apparatus and method using a simulator valve, and more specifically to a method and apparatus for controlling and / or regulating brake pedal descent during the transition between manual braking and assisted braking. Background Technology

[0002] This invention generally relates to vehicle braking systems. Vehicles typically utilize hydraulic braking systems for deceleration and stopping. These systems vary in complexity, but a basic braking system generally includes a brake pedal, a master cylinder, fluid conduits arranged in two similar but separate braking circuits, and wheel brakes in each circuit. The vehicle's driver operates the brake pedal, which is connected to the master cylinder. When the brake pedal is depressed, the master cylinder generates hydraulic pressure in both braking circuits by pressurizing brake fluid. The pressurized fluid travels through the fluid conduits in both circuits to actuate the brake cylinders at the wheels, thereby decelerating the vehicle.

[0003] Basic braking systems typically use brake boosters, which provide force to the master cylinder to assist the pedal force generated by the driver. Boosters can be operated by vacuum or hydraulic means. A typical hydraulic booster senses the movement of the brake pedal and generates pressurized fluid that is introduced into the master cylinder. The fluid from the booster assists the pedal force acting on pistons in the master cylinder, which generate pressurized fluid in channels fluidly connected to the wheel brakes. Therefore, the pressure generated by the master cylinder increases. Hydraulic boosters are usually located near the master cylinder pistons and use booster valves to control the pressurized fluid applied to the booster.

[0004] During the initial movement of the brake pedal unit in assisted mode, the driver pushes the brake pedal, causing the initial movement of the input piston in the master cylinder. Further movement of the input piston pressurizes the input chamber of the master cylinder, causing fluid to flow into the pedal simulator. As fluid transfers into the pedal simulator, the simulated pressure chamber within the pedal simulator expands, resulting in piston movement within the pedal simulator. This piston movement compresses and biases the spring assembly housed within the pedal simulator, providing a feedback force to the driver via the brake pedal. This feedback force simulates the force felt by the driver at the brake pedal, for example, in a conventional vacuum-assisted hydraulic braking system, and is therefore the desired and comfortable "brake feel" for the driver.

[0005] When the vehicle is first started, the brake fluid is under very low pressure or no pressure. In some situations, the driver manually applies the brakes in a "push-through" mode, where the master cylinder applies pressure directly to at least two, and typically four, wheel brakes. As the braking system engages and pressure increases, the system switches to "assist" mode, where an booster supplements or replaces the pressurized fluid sent to the wheel brakes from the driver's push-through force on the brake pedal. However, this transition is not always smooth, and when the pedal simulator is pressurized, it can result in a "pedaldrop" state, which may be uncomfortable for the driver.

[0006] Prior art braking systems are described in U.S. Patent No. 10,730,501, entitled “Vehicle Brake System with Auxiliary Pressure Source,” granted to Blaise Ganzel on August 4, 2020, and in U.S. Patent Application Publication No. 2020 / 0307538, entitled “Brake System with Multiple Pressure Sources,” published by Blaise Ganzel on October 1, 2020. The entire contents of these two patents are incorporated herein by reference for the purposes of this document. Summary of the Invention

[0007] In one aspect, a simulator valve is described. A housing has a central bore extending longitudinally from a first housing surface. The housing includes a pedal simulator channel extending through the housing to at least partially communicate the central bore with the pedal simulator. The housing includes a master cylinder channel extending through the housing to at least partially communicate the central bore with the master cylinder. The master cylinder channel is located longitudinally between the first housing surface and the pedal simulator channel. An armature is located at least partially within the housing to selectively reciprocate longitudinally relative to the housing between a first armature position and a second armature position. A lift valve is located within the housing and at least partially within an armature bore of the armature to selectively reciprocate longitudinally relative to the armature between a first lift valve position and a second lift valve position. The lift valve cooperates with a first valve seat, at least a portion of the armature bore, to define a first valve. The lift valve at least partially defines a second valve, which is longitudinally spaced from and faces the first valve seat. The second valve includes a second valve seat located within the central bore and at least partially spaced from the bore wall of the central bore. The lift valve includes a lift valve orifice extending longitudinally through it and selectively blocked by a first valve. The armature, lift valve, and center orifice cooperate to define a damped flow path between them. This damped flow path selectively allows fluid communication from the master cylinder channel to the pedal simulator channel. When the armature is in the second armature position and the lift valve is in the first lift valve position, the damped flow path allows fluid communication. The armature, lift valve, and center orifice cooperate to define a free flow path between them. This free flow path selectively allows fluid communication from the pedal simulator channel to the master cylinder channel. When the armature is in the second armature position and the lift valve is in the second lift valve position, the free flow path allows fluid communication. Attached Figure Description

[0008] For a better understanding, please refer to the attached diagram, in which:

[0009] Figure 1 This is a schematic cross-sectional side view of a simulator valve in a first state according to one aspect of the invention;

[0010] Figure 2 It is in the second state. Figure 1 A schematic cross-sectional side view of the simulator valve;

[0011] Figure 3 It is in the third state. Figure 1 A schematic cross-sectional side view of the simulator valve;

[0012] Figure 4 In the first phase of the operation, including Figure 1 A schematic hydraulic diagram of the simulator valve;

[0013] Figure 5 It includes the second phase of the operation. Figure 1 A schematic hydraulic diagram of the simulator valve; and

[0014] Figure 6 It is included in the third stage of the operation. Figure 1 A schematic hydraulic diagram of a simulator valve. Detailed Implementation

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0016] The present invention includes, consists of, or is substantially composed of any combination of the following features.

[0017] Figure 1 A simulator valve 100 is shown, which includes a housing 102 having a central bore 104 extending longitudinally downward from a first housing surface 106. Although in Figures 1 to 3 Valve 100 is shown in cross-sectional view, but those skilled in the art will readily be able to conceive of the ways in which the components of valve 100 interact with each other in three dimensions (e.g., in a sealing and / or fluid communication manner) according to the teachings of the present invention. Housing 102 includes a pedal simulator channel 108 extending therethrough to at least partially align a central bore 104 in fluid communication with the pedal simulator (schematically shown at 110). Housing 102 includes a master cylinder channel 112 extending therethrough to at least partially align the central bore 104 in fluid communication with the master cylinder (schematically shown at 114). The master cylinder channel 112 is longitudinally disposed between the first housing surface 106 and the pedal simulator channel 108.

[0018] Any suitable number, configuration, and type of additional structures can be provided for valve 100 to facilitate its assembly and / or use, such as, but not limited to, the stepped inner bore IB shown in the figures.

[0019] Armature 116 is at least partially located within housing 102 for selective longitudinal reciprocating motion relative to housing 102. Armature 116 moves between a first armature position and a second armature position in any desired manner, such as by reference below. Figures 1 to 3 Describes movement controlled and applied by electric and / or magnetic means.

[0020] The lift valve 118 is located within the housing 102 and at least partially within the armature port 120 of the armature 116. The lift valve 118 is configured to selectively reciprocate longitudinally relative to the armature between a first lift valve position and a second lift valve position in any desired manner, such as by referring to the following... Figures 1 to 3 The movement is described as being controlled and applied by an electric and / or magnetic means. The lift valve 118 at least partially defines a first valve (schematically shown in the area indicated by 122) that cooperates with at least a portion of a first valve seat 124 of an armature port 120.

[0021] As shown, the first valve 122 may include a valve ball 126 held in a longitudinal position relative to a first valve seat 124 of an armature bore 120. When present, the valve ball 126 may be press-fitted into a portion of the armature bore 120 and may be provided for self-sealing, wear compensation, and / or any other purpose. As shown here, the valve ball 126 interacts sealably with the shoulder of a lift valve 118 to collectively form the first valve 122.

[0022] The lift valve 118 also at least partially defines a second valve at a longitudinally spaced and oppositely facing position from the first valve seat 124 (schematically shown in the area indicated by 128). The second valve 128 includes a second valve seat 130 located within a central bore 104 and at least partially spaced from the bore wall 132 of the central bore 104. The lift valve 118 includes a lift valve orifice 134 extending longitudinally therethrough. The lift valve orifice 134 is selectively blocked by the first valve 122 (e.g., and as will be assumed below, by the valve ball 126 of the first valve 122).

[0023] Figure 1 The illustration shows a scenario where the simulator valve 100 is de-energized or closed. This occurs, for example, when the vehicle and / or the braking system, including the simulator valve 100, is in a deactivated state. Figure 1 As shown, a magnetic gap 136 exists between the armature 116 and the core 138, and the core spring 140 is in Figure 1 The armature 116 is pushed downward in the orientation so as to simultaneously close the first valve seat 124 and the second valve seat 130 by pushing the armature 116 downward to the lift valve 118.

[0024] The core 138 is configured to selectively and magnetically attract the first end 142 of the armature 116 longitudinally. The armature 116 itself is positioned longitudinally between the core 138 and the lift valve 118. As shown, the armature attraction surface 144 of the core 138 can be substantially planar. This contrasts with the stepped armature attraction surface of known prior art two-stage simulator valves and can facilitate attracting the first end 142 of the armature with a more efficient and forceful motion than those known valves. For example, compared to known devices, the armature 116 does not need to travel as far to close the magnetic gap 136 using the substantially planar armature attraction surface 144 shown.

[0025] As described above, the core spring 140 can be positioned longitudinally between the armature 116 and the core 138, typically longitudinally away from the core 138 to bias the armature 116. Therefore, the magnetic force from the core 138 must overcome the spring force of the core spring 140 to displace the armature 116. Figure 1 The first position shown is moved to Figure 2 The second position shown.

[0026] As also shown in these figures, the core sleeve 146 may be at least partially received in the central bore 104 of the housing 102 to maintain the core 138 in a predetermined spaced-out relationship with the housing 102. The armature 116 is at least partially enclosed within the core sleeve 146 and is thereby guided to selectively reciprocate longitudinally relative to the core 138 between a first armature position and a second armature position.

[0027] It is conceivable that the core sleeve 146 can completely longitudinally enclose the armature 116 therein. A core 138 may be located at the first end 148 of the core sleeve 146. The core sleeve 146 defines a second valve seat 130 at or near its second end 150, which is longitudinally spaced from the first end 148. As shown in these figures, the second valve seat 130 may be provided by a shoulder of the core sleeve 146.

[0028] As mentioned above, Figure 1 The armature 116 is shown in the first (lowest) armature position. When the armature 116 is in this first armature position, the core spring 140 pushes the armature 116 downward, thereby preventing both the armature 116 and the lift valve 118 from moving. Figure 1 The valve moves upward in the orientation, and the lift valve 118 is held in the first (lowest) lift valve position by the armature 116.

[0029] Now go to Figure 2 The simulator valve 100 is shown in a second "transition" configuration. (The transition configuration is also the assisted configuration when the brake pedal is applied.) For example, the second configuration may occur when the vehicle is first started and the vehicle's braking system transitions between a manual application mode and an assisted mode for braking. The armature 116, the lift valve 118, and the center orifice 104 collectively and cooperatively define a damped flow path between themselves during this initial or "transition" period of operation of the simulator valve 100; this damped flow path... Figure 2The arrow "D" indicates this. The damped flow fluid path D selectively allows fluid communication through it from the master cylinder passage 112 to the pedal simulator passage 108. The damped flow fluid path D allows fluid communication through it when the armature 116 is in the second raised armature position (due to being magnetically attracted to the core 138) and the lift valve 118 is still in the first lowest lift valve position. Therefore, when the braking system transitions from manual application to assisted application, fluid can be transferred from the master cylinder 114 (powered at least partially by the pressure of the driver's foot on the brake pedal) to the pedal simulator 110 via the damped flow fluid path D.

[0030] During the transition phase, when simulator valve 100 is in Figure 2 In the configuration shown, the double-acting plunger of the braking system pushes fluid into the pedal simulator 110. The driver's active pedal feel control is based on feedback from the pedal travel sensor and the pressure sensor.

[0031] When the ball 126 is present, the longitudinal movement of the lift valve 118 away from the armature 116 opens the first valve 122, allowing fluid flow (i.e., damped flow path D) through the ball 126 and into the lift valve orifice 134. This fluid flow path is created at least in part by the ball 126 being engaged with the armature 116 (e.g., via frictional engagement with the armature orifice 120), which in turn... Figure 1 configuration transition to Figure 2 During configuration, the brake fluid moves away from the lift valve 118. As a result of generating a damped flow fluid path D, the brake fluid can travel from the double-acting plunger and / or master cylinder 114 to the pedal simulator 110.

[0032] Now for reference Figure 3 The back pressure generated by the fluid accumulation within the pedal simulator 110 has already pushed the lift valve 118 in... Figure 3 The first valve 122 is pushed upwards to the second lift valve position. This is the "assist" configuration when the driver releases the brake pedal. Here, the first valve 122 closes again, and the valve ball 126 re-engages with the lift valve 118. Therefore, the fluid path through the lift valve orifice 134 is no longer available. Thus, the armature 116, the lift valve 118, and the center orifice 104 cooperate to define a free fluid path between them; this relatively undamped flow path... Figure 3 The free-flowing fluid path F is indicated by the arrow "F". It selectively allows fluid communication from the pedal simulator channel 108 to the master cylinder channel 112.

[0033] When armature 116 is in the second armature position and lift valve 118 is in the second lift valve position, a free-flow fluid path F allows fluid communication through it. Once the free-flow fluid path F is established, pedal simulator 110 can be used to selectively feed pressure back to master cylinder 114 to help achieve the appropriate pedal feel for the driver, or for any other desired reason. Based on the driver's request, the double-acting plunger will continue to build up the higher assist pressure transmitted via the brake pedal during this mode.

[0034] Figure 2 and Figure 3 The simulator valve 100 is shown in both "assistance application and release" modes, which are actually used for the entire braking system and continue until the vehicle is turned off or some other event occurs that causes the assist application to stop. The simulator valve 100 is "open" at all times when assist is applied. Which of the first valve seat 124 and the second valve seat 130 is open depends on whether the driver applies or releases the brake pedal. If the driver does not apply or release the brake pedal, both the first valve seat 124 and the second valve seat 130 may be partially open.

[0035] In the event of intentional or unintentional loss of power to the solenoid controlling the core 138, the core spring 140 will overcome the force previously provided by the currently de-energized solenoid and magnetically applied via the core 130 to push the armature 116 down back to the first armature position and thus re-establish the magnetic gap 136 and return the simulator valve 100 to the "manual application" mode.

[0036] Refer again Figure 1 It can be envisioned that when armature 116 is in the first armature position and lift valve 118 is in the first lift valve position, fluid can be allowed to flow along the free-flowing fluid path F, such as... Figure 1 As shown. This flow is permitted when the pressure in the pedal simulator 110 is greater than the pressure in the master cylinder 114 by an amount sufficient to overcome the spring (and other) forces acting on the area of ​​the second valve seat 130. That is, even when the simulator valve 100 is in a manually applied, "closed," or de-energized position, a predetermined amount of fluid flow is permitted through the second valve 128 between the second valve seat 130 and the lift valve 118. This permitted flow can contribute to achieving desired efficiency in the system, as well as the driver's brake pedal feel and response characteristics, and will occur, for example, when the fluid pressure in the pedal simulator 110 is higher than the fluid pressure in the master cylinder 114. However, to emphasize... Figure 1 In the case where armature 116 is in the first armature position and lift valve 118 is in the first lift valve position (i.e., in...), Figures 1 to 3When both are at their lowest position in the orientation, the free-flowing fluid path F and the damped-flowing fluid path D are essentially blocked from flowing.

[0037] It is also conceivable that at least one of the free-flowing fluid path F and the damped-flowing fluid path D may include at least one filter 152 (in Figures 1 to 3 Two filters (illustrated by way of example) are used to filter fluid flowing through them. When present, the filter 152 can be of any desired type and can be located at any desired location within the simulator valve 100. For example, the lower filter 152 shown is located below the lift valve 118 in the central orifice 104. It is conceivable that the cylindrical upper filter 152 can also, or alternatively, be located in the area substantially surrounding the lift valve 118; that is, immediately between the master cylinder passage 112 and the core sleeve 146. Those skilled in the art will be able to readily provide one or more suitable filters 152 according to the specific usage requirements of the invention.

[0038] Figures 4 to 6 The use of schematically illustrates Figures 1 to 3 The simulator valve 100 and the braking system 200. Figures 4 to 6 In the figure, "bold" lines or thick lines indicate components or parts of the braking system 154 that are under fluid pressure. Dashed lines indicate components or parts of the braking system 200 that are affected by fluid pressure and flow in the pattern shown in the figure.

[0039] Simulator valve 100 is not limited to use in Figures 4 to 6In the braking system 200, it can be used in any suitable setup where magnetic actuation control of hydraulic flow is desired. For example, the simulator valve 100 can be used in braking systems shown and described in the following common patent applications: U.S. patent application No. XX / XXX,XXX (Attorney's File No. ZF(BEJ)-029438US PRI) entitled “Hydraulic Brake Boost”, filed concurrently with this application; U.S. patent application No. XX / XXX,XXX (Attorney's File No. ZF(BEJ)-030117US PRI) entitled “Apparatus and Method for Control of a Hydraulic Brake System”, filed concurrently with this application; and / or U.S. patent application No. XX / XXX,XXX (Attorney's File No. ZF(BEJ)-029439US PRI) entitled “Apparatus and Method for Control of a Hydraulic Brake System”, filed concurrently with this application. The entire contents of all these patent applications are incorporated herein by reference in their entirety for purposes of integrity.

[0040] Braking system 200 is a hydraulically assisted braking system, wherein the pressure of the assist fluid is used to apply braking force to braking system 200. Braking system 200 can be suitably used in ground vehicles, such as motor vehicles with four wheels, wherein wheel brakes are associated with each wheel. Furthermore, braking system 200 can be equipped with other braking functions, such as anti-lock braking (ABS) and other slip control features, to effectively brake the vehicle. Components of braking system 200 can be housed in one or more blocks or housings. The blocks or housings can be made of a solid material such as aluminum, which has been drilled, machined, or otherwise formed to accommodate the various components. Fluid conduits can also be formed within the blocks or housings.

[0041] In the illustrated embodiment of braking system 200, there are four wheel brakes 202A, 202B, 202C, and 202D. Wheel brakes 202A, 202B, 202C, and 202D can have any suitable wheel brake configuration that operates by applying pressurized brake fluid. Each of wheel brakes 202A, 202B, 202C, and 202D may include, for example, a brake caliper mounted on a vehicle to engage a friction element (such as a brake disc) that rotates with the wheel, thereby achieving braking of the associated wheel. Wheel brakes 202A, 202B, 202C, and 202D can be associated with any combination of the front and rear wheels of the vehicle on which braking system 200 is installed. For example, braking system 200 can be configured as a diagonally split system as shown, such that the master cylinder secondary pressure circuit is associated with providing fluid to diagonal wheel brakes 202A and 202B, and the master cylinder primary pressure circuit is associated with providing fluid to diagonal wheel brakes 202C and 202D. In this example, wheel brake 202A can be associated with the right rear wheel of the vehicle on which braking system 200 is installed, and wheel brake 202B can be associated with the left front wheel. Wheel brake 202C can be associated with the left rear wheel, and wheel brake 202D can be associated with the right front wheel. Alternatively, although not shown here, braking system 200 can be configured as a vertically split braking system, such that wheel brakes 202A and 202B are associated with wheels on the front or rear axle of the vehicle, and wheel brakes 202C and 202D are associated with wheels on the other axle of the vehicle.

[0042] The braking system 200 generally includes a brake pedal unit generally indicated by 204, a pedal simulator generally indicated by 110, a plunger assembly (also referred to as a double-acting plunger) generally indicated by 208, and a fluid reservoir 210. The reservoir 210 stores and holds hydraulic fluid for the braking system 200. The fluid within the reservoir 210 is preferably maintained at atmospheric pressure or approximately atmospheric pressure, but may be stored at other pressures if necessary. The reservoir 210 is schematically shown to have three tanks or sections to which three fluid lines are connected. These sections may be separated by several inner walls within the reservoir 210 and are configured to prevent complete drainage of the reservoir 210 in the event that one of these sections is depleted due to a leak in one of the three lines connected to the reservoir 210. Alternatively, the reservoir 210 may comprise multiple separate housings. The reservoir 210 may include at least one fluid level sensor 212 that detects the fluid level in one or more sections of the reservoir 210.

[0043] The plunger assembly 208 of the braking system 200 serves as a pressure source to provide the desired pressure level to the wheel brakes 202A, 202B, 202C, and 202D during typical or normal braking application. After braking is applied, fluid from the wheel brakes 202A, 202B, 202C, and 202D can return to the plunger assembly 208 and / or be transferred to the reservoir 210. In the depicted embodiment, the plunger assembly 208 is a double-acting plunger assembly configured to also provide assist pressure to the braking system 200 during both the rearward and forward strokes of the piston in the plunger assembly 208.

[0044] The braking system 200 also includes at least one electronic control unit or ECU 214. ECU 214 may include a microprocessor and other circuitry. ECU 214 receives various signals, processes the signals, and controls the operation of various electrical components of the braking system 200 in response to the received signals. ECU 214 may be connected to various sensors, such as reservoir fluid level sensor 212, pressure sensor, stroke sensor, switch, wheel speed sensor, and steering angle sensor. ECU 214 may also be connected to an external module (not shown) for receiving information related to the vehicle's yaw rate, lateral acceleration, longitudinal acceleration, or other characteristics of vehicle operation for any reason, such as, but not limited to, controlling the braking system 200 during vehicle braking, stability control, or other operating modes. Additionally, ECU 214 may be connected to an instrument cluster for collecting and providing information related to warning indicators such as the ABS warning light, brake fluid level warning light, and traction control / vehicle stability control indicator light.

[0045] The braking system 100 also includes a first isolation valve 216 and a second isolation valve 218. Isolation valves 216 and 218 can be, for example, solenoid-actuated three-way valves. Isolation valves 216 and 218 are typically operable to two positions, such as... Figures 4 to 6 As schematically shown, the first isolation valve 216 and the second isolation valve 218 each have a port that is selectively in fluid communication with an output conduit 220, which is normally connected to the output end of the plunger assembly 208. The first isolation valve 216 and the second isolation valve 218 also include ports that are respectively in fluid communication with a first master cylinder conduit 222 and a second master cylinder conduit 224, which are each connected to the brake pedal unit 204 via a master cylinder 114, as shown below. Figure 4As shown. The first isolation valve 216 and the second isolation valve 218 also include ports that are in fluid communication with the first wheel brake conduit 226 and the second wheel brake conduit 228, respectively, which supply fluid to and from the wheel brakes 202A, 202B, 202C and 202D.

[0046] In some applications, the first isolation valve 216 and / or the second isolation valve 218 may be mechanically designed such that, when in their de-energized position, fluid is allowed to flow, respectively, from the output conduit 220 to the first wheel brake conduit 226 and the second wheel brake conduit 228, and to the first master cylinder conduit 222 and the second master cylinder conduit 224, bypassing the normally closed seats of valves 216 and 218. Therefore, although the three-way valves 216 and 218 are not schematically shown to indicate this fluid flow position, it should be noted that the valve design allows for such fluid flow. This may be helpful, for example, in performing a self-diagnostic test of the braking system 100.

[0047] The braking system 200 also includes various solenoid-actuated valves (“slip control valve devices”) to allow controlled braking operations, such as, but not limited to, ABS, traction control, vehicle stability control, dynamic rear-pairing, regenerative braking hybrid, and autonomous braking. A first set of valves includes a first application valve 230 and a first discharge valve 232 in fluid communication with a first wheel brake conduit 226 for cooperatively supplying fluid received from a first isolation valve 216 to the right rear wheel brake 202A and for cooperatively releasing pressurized fluid from the right rear wheel brake 202A to a reservoir conduit 234 in fluid communication with a reservoir 210. A second set of valves includes a second application valve 236 and a second discharge valve 238 in fluid communication with the first wheel brake conduit 226 for cooperatively supplying fluid received from the first isolation valve 216 to the left front wheel brake 202B and for cooperatively releasing pressurized fluid from the left front wheel brake 202B to the reservoir conduit 234. The third set of valves includes a third application valve 240 and a third discharge valve 242, which are in fluid communication with the second wheel brake conduit 228, for cooperatively supplying fluid received from the second isolation valve 218 to the left rear wheel brake 202C, and for cooperatively releasing pressurized fluid from the left rear wheel brake 202C to the reservoir conduit 234. The fourth set of valves includes a fourth application valve 244 and a fourth discharge valve 246, which are in fluid communication with the second wheel brake conduit 228, for cooperatively supplying fluid received from the second isolation valve 218 to the right front wheel brake 202D, and for cooperatively releasing pressurized fluid from the right front wheel brake 202D to the reservoir conduit 234. Note that during normal braking events, fluid flow occurs through the de-energized open application valves 230, 236, 240, and 244. In addition, the discharge valves 232, 238, 242, and 246 are preferably in their de-energized closed position during normal braking to prevent unwanted fluid from flowing into the reservoir 210.

[0048] Brake pedal unit 204 is connected to brake pedal 248 and is actuated by the driver of the vehicle when the driver presses brake pedal 248. Brake sensor or switch 250 may be connected to ECU 214 to provide a signal indicating the depressurization of brake pedal 248. Brake pedal unit 204 can serve as a backup source of pressurized fluid to substantially replace the normal supply of pressurized fluid from plunger assembly 208 in certain fault conditions of braking system 200 and / or during the initial activation of braking system 200. This situation is referred to as a manual push event or “manual application”, and is... Figure 4As shown, the brake pedal unit 204 can supply pressurized fluid to the wheel brakes 202A, 202B, 202C, and 202D as needed to the first master cylinder line 222 and the second master cylinder line 224 (normally closed at the first isolation valve 216 and the second isolation valve 218 during normal braking application). This situation occurs in... Figure 4 The diagram schematically illustrates that master cylinder 114 and wheel brakes 202A, 202B, 202C, and 202D are under pressure (shown in bold), wherein both pressure and fluid flow through at least the first master cylinder conduit 222 and the second master cylinder conduit 224, the first wheel brake conduit 226, and the second wheel brake conduit 228, and from there to wheel brakes 202A, 202B, 202C, and 202D. This flow is primarily propelled from master cylinder 114 by mechanical pressure from the driver's foot on brake pedal 248. Returning to the reference simulator valve 100, Figure 1 The situation shown exists Figure 4 In the circuit, armature 116 and lift valve 118 are both in their first positions.

[0049] like Figures 4 to 6 As schematically shown, the brake pedal unit 204 includes a master cylinder with a housing 252 for slidably accommodating various cylindrical pistons and other components. Note that the housing is not specifically shown schematically in the figures, but rather the walls of the bore are illustrated. The housing 252 may be formed as a single unit or comprise two or more separately formed portions joined together. The input piston 254 is connected to the brake pedal 248 via a connecting rod arm 256. Under certain conditions, leftward movement of the input piston 254 can increase the pressure within the master cylinder 114.

[0050] Master cylinder 114 is in fluid communication with pedal simulator 110 via master cylinder passage 108. Input piston 254 is slidably disposed in a bore in housing 252 of master cylinder 114. When brake pedal unit 204 is in its rest position (driver does not press brake pedal 248), the structure of master cylinder 114 allows fluid communication between the bore in housing 252 and reservoir 210 via reservoir passage 258.

[0051] The braking system 200 may also include an optional solenoid-actuated simulator test valve 260, which can be electronically controlled between an open position and an electrically closed position. The simulator test valve 260 is not required during normal braking application or for manual advance mode. The simulator test valve 260 can be actuated to a closed position during various test modes to determine the proper operation of other components of the braking system 200. For example, the simulator test valve 260 can be actuated to a closed position to prevent flow to the reservoir 210 via the reservoir line 258, so that the pressure built up in the brake pedal unit 204 can be used to monitor fluid flow to determine whether leakage may occur through seals of various components of the braking system 200.

[0052] The braking system 200 also includes a first plunger valve 262 and a second plunger valve 264. The first plunger valve 262 is preferably a normally closed valve actuated by a solenoid. Therefore, in the de-energized state, such as... Figure 4 As shown, the first plunger valve 262 is in the closed position. The second plunger valve 264 is preferably a normally open valve actuated by a solenoid. Therefore, in the de-energized state, the second plunger valve 264 is in the open position, as shown. A check valve may be arranged within the second plunger valve 264 such that when the second plunger valve 264 is in its closed position, fluid can still flow through the second plunger valve 264 in the direction from the first plunger output conduit 266 (from the plunger assembly 208) to the output conduit 220 leading to the first isolation valve 216 and the second isolation valve 218. During the backward stroke of the piston of the plunger assembly 208, pressure can be generated within the plunger assembly 208 to be output to the output conduit 220. The braking system 200 also includes a check valve 268, which, for example, allows fluid to flow in the direction from the conduit 270 (from the reservoir 210) to the conduit 266 and into the plunger assembly 208 during the generation of pressure during the backward stroke of the piston of the plunger assembly 208.

[0053] During the initial manual push operation of the brake pedal unit 204, sufficient leftward movement of the input piston 254 will prevent fluid from flowing from the master cylinder 114 into the reservoir line 258 and thus into the reservoir 210, but will put the system into a flow-through state, in which the driver's foot applies pressure to the master cylinder 114, which then (in response to pressure from the brake pedal 248) allows fluid to flow through the first master cylinder line 222 and the second master cylinder line 224, the first isolation valve 216 and the second isolation valve 218, the first wheel brake line 226 and the second wheel brake line 228, and to the wheel brakes 202A, 202B, 202C, and 202D. Further leftward movement of the input piston 254 will pressurize the master cylinder 114, causing fluid to flow through the pedal simulator channel 108 to the pedal simulator 110, which simultaneously opens during the transition of operation of the simulator valve 100, as... Figure 2 As shown and as described above, when fluid is transferred to the pedal simulator 110, the pedal simulator 110 provides a feedback force to the driver of the vehicle via the brake pedal 248. This feedback force simulates the force felt by the driver at the brake pedal 248, for example, in a conventional vacuum-assisted hydraulic braking system.

[0054] The simulated pressure chamber 272 of the pedal simulator 110 is in fluid communication with the pedal simulator channel 108, and the pedal simulator channel 108 is in fluid communication with the master cylinder 114 of the brake pedal unit 204. For example... Figures 4 to 6 As shown, solenoid-actuated simulator valve 100 (see above for reference) Figures 1 to 3 (Detailed Description) is positioned between pedal simulator channel 108 and master cylinder channel 112 to selectively control fluid flow between master cylinder 114 and pedal simulator 110 for any desired reason. An example of desired operation of simulator valve 100 is during fault and / or initial / start-up states, where brake pedal unit 204 is used to provide a pressurized fluid source to wheel brakes 202A, 202B, 202C, and 202D in a push-type manner, as described herein.

[0055] In summary, a braking system 200 is provided for actuating a pair of front wheel brakes 202B, 202D and a pair of rear wheel brakes 202A, 202C. The rear wheel brakes 202A, front wheel brakes 202B, rear wheel brakes 202C, and front wheel brakes 202D can be actuated individually or in groups as needed, in any order or sequence, in any combination, or according to the requirements of a particular operating environment. While a diagonal braking system is shown herein as an example, it is contemplated that the invention can be used with split braking systems or any other configuration, whether currently known or not. The system includes a reservoir 210 for holding fluid and a master cylinder 114, which can be operated during manual push mode by actuating a brake pedal 248 connected to the master cylinder 114 to generate braking actuation pressure. Braking actuation pressure is applied at a first output terminal and a second output terminal (e.g., a first master cylinder line 222 and a second master cylinder line 224) to actuate the pair of front wheel brakes 202B, 202D and the pair of rear wheel brakes 202A, 202C. A pressurized fluid source (here, plunger assembly 208) is configured to actuate the pair of front wheel brakes 202B, 202D and the pair of rear wheel brakes 202A, 202C during non-faulty normal braking events. An electronic control unit 214 is configured to control the pressurized fluid source. The pedal simulator 110 is selectively in fluid communication with the master cylinder. The braking system 200 also includes a simulator valve 100 shown and described herein, which selectively allows fluid communication between the master cylinder 114 and the pedal simulator 110.

[0056] During use, the braking system 200 moves from the start-up or "manual application" mode to the steady-state "assist" mode via a "transition" mode, as described above. Figures 1 to 3 The manual application mode is typically only entered when assisted startup is not available for a particular startup sequence. Figures 4 to 6 The overall state and operation of the braking system 200 are schematically shown, corresponding to these three modes.

[0057] exist Figure 4 In the "manual application" mode, simulator valve 100 is in Figure 1 The power-off or off position is shown. When the driver initially applies foot pressure to the brake pedal 248, the brake pedal 248 pressurizes the master cylinder 114 (as shown in the bold shaded area of ​​this component) and causes fluid (as shown by the dashed lines of these components) to flow through the first master cylinder conduit 222 and the second master cylinder conduit 224, as well as the first wheel brake conduit 226 and the second wheel brake conduit 228, and from there directly to the wheel brakes 202A, 202B, 202C, and 202D. Similarly, this is the push-pull situation, where the driver's foot pressure on the brake pedal 248 directly pushes the brake fluid towards the wheel brakes 202A, 202B, 202C, and 202D.

[0058] From Figure 1 and Figure 4 configuration conversion to Figure 2 The "assistance" configuration and Figure 5 During the “transition” configuration, at least simulator valve 100, plunger assembly 208, first plunger valve 262, and first isolation valve 216 are electrically actuated, which moves braking system 200 into the “transition” mode. (As a side note, although the second isolation valve 218 is not yet energized at this point, a predetermined amount of flow can be allowed through the second isolation valve 218 to help suppress or soften the transition phase as needed.)

[0059] Now for reference Figure 5 At least the master cylinder 114, the first master cylinder pipe 222 and the second master cylinder pipe 224, the first wheel brake pipe 226 and the second wheel brake pipe 228, the check valve 268, and the hydraulic lines directly leading to the wheel brakes 202A, 202B, 202C, and 202D are maintained at the desired pressure, and the simulator valve 100 has been moved to... Figure 2 The location shown. Therefore, in Figure 2 In the orientation, armature 116 has been magnetically pulled upward by core 138 into the second armature position, thereby pulling valve ball 126 away from lift valve 118 (lift valve remains in the first lift valve position) and opening damped flow path D. As a result, fluid is allowed to flow from master cylinder 114 through damped flow path D to pedal simulator 110.

[0060] The "transition" mode passes quite quickly (on the order of a fraction of a second to a second or two, depending on many other factors), and once the pedal simulator 110 has gained sufficient boost (from... Figure 5 When the downward arrow in the simulated pressure chamber 272 indicates that the system enters the "assist application" mode, as shown in the image, the system enters the "assist application" mode. Figure 6 The entire braking system 200 is schematically shown.

[0061] refer to Figure 6 The second isolation valve 218 has been activated (in addition to the previously activated component). Figure 6The illustrated "assist application" mode includes master cylinder 114, plunger assembly 208, check valve 268, pedal simulator 110, first master cylinder line 222 and second master cylinder line 224, and wheel brakes 202A, 202B, 202C, and 202D (as well as portions of the wheel brake hydraulic system leading to drain valves 232, 238, 242, and 246), which "maintain" fluid pressure or help prevent fluid from flowing back into reservoir 210 while allowing assist pressure to decrease and flow. Fluid is allowed to flow under pressure through output line 220, first wheel brake line 226, and second wheel brake line 228, and through application valves 230, 236, 240, and 244 to wheel brakes 202A, 202B, 202C, and 202D. The plunger assembly 208 continues to build up higher assist pressure based on the driver's request, and the ECU 214 controls the system to execute the braking request from the driver during further operation of the braking system 200, until a system failure occurs or the vehicle is deactivated.

[0062] It is conceivable that during the transition between manual braking and assisted braking, the pedal descent (the driver's "feel" of the brake pedal) using the simulator valve 100 shown and described herein can be actively controlled and adjusted based on customer preference. If the transition pedal feel is preferred, the braking system including the simulator valve 100 according to various aspects of the invention can also allow the user to cancel the pedal descent.

[0063] As used herein, the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including” as used herein may specify the presence of the stated feature, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0064] As used herein, the term “and / or” can include any and all combinations of one or more of the associated listed items.

[0065] It should be understood that when an element is referred to as "on another element," "attached to another element," "connected to another element," "connected to another element," "in contact with another element," "adjacent to another element," etc., the element may be directly on the other element, directly attached to the other element, directly connected to the other element, directly connected to the other element, directly in contact with the other element, or directly adjacent to the other element, or there may be intermediate elements. Conversely, when an element is referred to as, for example, "directly on another element," "directly attached to another element," "directly connected to another element," "directly connected to another element," "directly in contact with another element," or "directly adjacent to another element," there are no intermediate elements. Those skilled in the art will also understand that references to structures or features "directly adjacent to" another feature may have overlapping or subordinate portions, while references to structures or features "adjacent to" another feature may not have overlapping or subordinate portions.

[0066] This document may use spatially relative terms such as “below,” “under,” “lower,” “above,” “upper,” “near,” “farer,” etc., to describe the relationship between one element or feature and another element or feature as shown in the figure. It should be understood that, in addition to the orientations shown in the figure, spatially relative terms may also include different orientations of the equipment in use or operation. For example, if the equipment in the figure is inverted, an element described as “below” or “under” other elements or features would be oriented as “above” other elements or features.

[0067] As used herein, the phrase "at least one of X and Y" can be interpreted as including X, Y, or a combination of X and Y. For example, if an element is described as having at least one of X and Y, then the element may include X, Y, or a combination of X and Y at a given time, and the choice may vary over time. Conversely, the phrase "at least one X" can be interpreted as including one or more Xs.

[0068] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. Therefore, the “first” element discussed below may also be referred to as the “second” element without departing from the teachings of this disclosure. The sequence of operations (or steps) is not limited to the order given in the claims or drawings, unless otherwise specifically indicated.

[0069] While aspects of this disclosure have been specifically shown and described with reference to the examples above, those skilled in the art will understand that various additional aspects can be contemplated. For example, the specific methods of using the device described above are merely illustrative; those skilled in the art can readily identify any number of tools, sequences of steps, or means / options for positioning the device or its components in a position substantially similar to that shown and described herein. For clarity in the accompanying drawings, some of the repeating components shown are not specifically numbered, but those skilled in the art will recognize, based on the numbered components, the element numbers that should be associated with the unnumbered components; the presence or absence of element numbers in the drawings is not intended to or imply a distinction between similar components. Any of the described structures and components may be integrally formed as a single monolithic workpiece or integral workpiece, or may be composed of individual sub-components, any of these constructions including any suitable stock or custom components and / or any suitable materials or combinations of materials. Any of the described structures and components may be disposable or reusable depending on the needs of a particular use environment. Any component may be provided with user-perceptible markings to indicate the material, configuration, at least one dimension, etc., associated with that component. These user-perceptible markings may help a user select a component from an array of similar components for a particular use environment. A “predetermined” state can be determined at any time before the manipulated structure actually reaches that state; “predetermined” occurs no later than immediately before the structure reaches the predetermined state. The term “substantially” is used herein to indicate a mass that is largely (but not necessarily entirely) specified – “substantially” mass acknowledges the possibility of including some relatively few non-mass items. While some components described herein are shown as having specific geometries, all structures of this disclosure may have any suitable shape, size, configuration, relative relationships, cross-sectional area, or any other physical properties desired for a particular application. Any structure or feature described with reference to one aspect or configuration may be provided, alone or in combination with other structures or features, to any other aspect or configuration, as it would be impractical to describe every aspect and configuration discussed herein as having all the options discussed with respect to all other aspects and configurations. Devices or methods combining any of these features should be understood to fall within the scope of this disclosure as defined by the following claims and any equivalents.

[0070] Other aspects, objectives, and advantages can be obtained by studying the accompanying drawings, the disclosure, and the appended claims.

Claims

1. A simulator valve, the simulator valve comprising: A housing having a central hole extending longitudinally from a first housing surface, the housing including a pedal simulator channel extending through the housing to at least partially configure the central hole in fluid communication with a pedal simulator, the housing including a master cylinder channel extending through the housing to at least partially configure the central hole in fluid communication with a master cylinder, the master cylinder channel being located longitudinally between the first housing surface and the pedal simulator channel; An armature, at least partially located within the housing, for selective longitudinal reciprocating motion relative to the housing between a first armature position and a second armature position; A lift valve, located within the housing and at least partially within an armature bore of the armature, is selectively longitudinally reciprocating relative to the armature between a first lift valve position and a second lift valve position. The lift valve cooperates with a first valve seat comprising at least a portion of the armature bore to define a first valve, and the lift valve at least partially defines a second valve longitudinally spaced from and facing the first valve seat. The second valve includes a second valve seat located within the central bore and at least partially spaced from the bore wall of the central bore. The lift valve includes a lift valve bore extending longitudinally through the lift valve and selectively blocked by the first valve. The armature, the lift valve, and the center orifice cooperate to define a damped flow path between them, which selectively allows fluid communication from the master cylinder channel to the pedal simulator channel. This damped flow path allows fluid communication when the armature is in the second armature position and the lift valve is in the first lift valve position. The armature, the lift valve, and the center orifice cooperate to define a free-flowing fluid path between them, which selectively allows fluid communication from the pedal simulator channel to the master cylinder channel. When the armature is in the second armature position and the lift valve is in the second lift valve position, the free-flowing fluid path allows fluid communication.

2. The simulator valve of claim 1, wherein the simulator valve includes a core for selectively magnetically attracting a first end of the armature in the longitudinal direction, the armature being positioned between the core and the lift valve in the longitudinal direction.

3. The simulator valve according to claim 2, wherein, The armature attraction surface of the core is substantially planar.

4. The simulator valve of claim 2, wherein the simulator valve includes a core spring positioned longitudinally between the armature and the core to bias the armature longitudinally away from the core.

5. The simulator valve according to claim 2, wherein, The core sleeve is at least partially housed in the central hole of the housing to maintain the core in a spaced-out relationship with the housing, and the armature is at least partially enclosed within the core sleeve and thereby guided to selectively reciprocate longitudinally relative to the core.

6. The simulator valve according to claim 5, wherein, The core sleeve completely longitudinally encloses the armature within the core sleeve, wherein the core is located at a first end of the core sleeve, and the core sleeve defines the second valve seat at a second end of the core sleeve.

7. The simulator valve according to claim 1, wherein, The first valve includes a valve ball held in a longitudinal position relative to the first valve seat, wherein longitudinal movement of the lift valve away from the armature opens the first valve to allow fluid to flow through the valve ball and into the lift valve orifice.

8. The simulator valve according to claim 1, wherein, When the armature is in the first armature position and the lift valve is in the first lift valve position, both the free-flow fluid path and the damped flow fluid path are substantially blocked from flowing.

9. The simulator valve according to claim 8, wherein, When the armature is in the first armature position and the lift valve is in the first lift valve position, a predetermined amount of fluid is allowed to flow along the free-flowing fluid path.

10. The simulator valve according to claim 1, wherein, At least one of the free-flowing fluid path and the damped flowing fluid path includes a filter for filtering the fluid flow passing through it.

11. The simulator valve according to claim 1, wherein, When the armature is in the first armature position, the lift valve is held in the first lift valve position by the armature.

12. A braking system for actuating a pair of front wheel brakes and a pair of rear wheel brakes, the braking system comprising: Liquid reservoir; The master cylinder, which is operable during manual push mode by actuation of a brake pedal connected to the master cylinder, generates braking actuation pressure at a first output end and a second output end for actuating the pair of front wheel brakes and the pair of rear wheel brakes. A pressurized fluid source for actuating the pair of front wheel brakes and the pair of rear wheel brakes during a non-faulty normal braking event; An electronic control unit is used to control the pressurized fluid source; as well as A pedal simulator, the pedal simulator being used for selective fluid communication with the master cylinder; The braking system further includes a simulator valve according to claim 1, wherein the simulator valve selectively allows fluid communication between the master cylinder and the pedal simulator.

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