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Brake actuation mechanism employing center valve piston

A technology for actuators and valve pistons, applied in brakes, brake transmissions, transportation and packaging, etc., can solve the problem of increasing the hardware cost of brake actuators and ECUs, reducing pressure estimation accuracy and control quality, and large vibration shocks of motor materials And other problems, to achieve the effect of shortening the braking distance of the car, continuous controllable braking hydraulic pressure, and low cost

Inactive Publication Date: 2011-11-02
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

EMB is a distributed brake-by-wire system that uses motors as power sources. The current disadvantages of the EMB system are: because the motor is close to the wheel, its working environment is very harsh, and the temperature of the motor can change up to 200°C during the work process. Using a permanent magnet motor will result in a 20% to 25% change in the motor torque constant, and the motor material must also be able to withstand large vibration shocks
But this technical route also has some disadvantages: 1. In order to obtain higher pressure estimation accuracy and pressure control quality, more pressure sensors and linear proportional valves need to be used in an EHB system, such as Toyota's first-generation EHB The system (named ECB) uses 6 pressure sensors and 6 linear proportional valves, which will significantly increase the cost of the system
2. If the number of pressure sensors and linear proportional valves is reduced in order to control costs, for example, Toyota's second-generation EHB reduces the number of pressure sensors and linear proportional valves to two, which will lead to pressure estimation accuracy under extreme conditions and control quality degradation
3. There are certain potential safety hazards in this technical route, such as the problems that may be caused by the nitrogen leakage failure of the accumulator described in SAE Paper 2003-01-0324 by Delphi Company, etc.
But the use of solenoid valves will increase the cost of brake actuators and ECU hardware

Method used

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  • Brake actuation mechanism employing center valve piston
  • Brake actuation mechanism employing center valve piston
  • Brake actuation mechanism employing center valve piston

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] The overall structure of this embodiment, such as figure 1 As shown, it includes a housing 11, a central valve piston with a control pin hole, a piston driver, a DC motor 116, and an oil pot 123 with a sealing ring 124; the housing 11 includes a right end face with a central hole, The stepped hole and oil storage chamber 125 formed in the housing 11 are composed of left, middle and right round holes; the central valve piston is placed in the left round hole and the middle round hole of the housing, and the piston driving device is placed in the middle and right In the round hole; the left end of the center valve piston and the left round hole form a brake oil chamber 13, and the right end of the center valve piston is connected with the piston driving device, and the piston driving device is connected with the DC motor 116 installed on the right end surface of the housing 11 , the oil pot 123 with sealing ring 124 is installed in the mounting hole processed on the outsi...

Embodiment 2

[0035] The structure of this embodiment, such as Figure 4 , Figure 5 As shown, the difference between this embodiment and the specific implementation of embodiment 1 is that the constraining structure used to prevent the rotation of the nut is different, so the housing 21 and nut 211 used are also slightly different from the housing 11 and nut 111 in embodiment 1. There are different. Specifically, this embodiment cancels the anti-rotation constraining structure of the anti-rotation screw 112 and nut anti-rotation groove 1112 in Embodiment 1, but processes two symmetrical planes on the outer surface of the nut 211. On the inner wall of the housing 21 where the two symmetrical planes are located, two corresponding planes are also processed (for example, milled out or cast out), and the planes on the inner wall of the housing 21 match the planes of the nut 211 to form the housing 21 inner wall and the contact plane 212 of the nut 211, thereby preventing the rotation of the n...

Embodiment 3

[0037] The structure of this embodiment, such as Figure 6 As shown, the difference between this embodiment and Embodiment 1 is that the snap ring, the piston snap ring groove and the nut snap ring groove are canceled, and the piston body 38 and the nut 311 are no longer connected by the snap ring in Embodiment 1, but The connection between the two is realized through the interference fit between the piston body 38 and the nut 311 . The interference fit between the piston body 38 and the nut 311 is realized by a cold packing process: the piston body 38 is dropped into a coolant (such as liquid nitrogen) for a certain period of time to shrink the radial dimension of the piston body 38, and then the piston body 38 is The body 38 is inserted into the nut 311, and when the piston body 38 returns to its original radial dimension as the temperature rises, the piston body 38 and the nut 311 achieve an interference fit, and the two are connected. Of course, other suitable methods such ...

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PUM

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Abstract

The invention relates to a brake actuation mechanism employing a center valve piston and belongs to the technical field of manufacturing of automobiles. The mechanism comprises a shell, the center valve piston in which a control pin hole is formed, a driving device, a direct current motor and an oil pot, wherein the shell comprises a right end face, a stepped hole consisting of a left round hole, a middle round hole and a right round hole, and an oil storage chamber; the center valve piston and the driving device are arranged in the stepped hole; the center valve piston and the left round hole form a brake oil chamber; the center valve piston is connected with the driving device; the driving device is connected with the direct current motor; the oil pot is arranged on the outer side of the shell; the oil storage chamber is communicated with the oil pot; a vertical through hole which is communicated with the control pin hole of the center valve piston is formed on the lower part of the oil storage chamber downwards; and an oil outlet is formed on the left side of the brake oil chamber. The brake actuation mechanism has a simple and compact structure, has the advantage of low cost, makes brake hydraulic pressure rapidly established, contributes to reduction in brake distances and improves driving safety.

Description

technical field [0001] The invention relates to a brake actuator using a central valve piston, and belongs to the technical field of automobile manufacturing. Background technique [0002] The structure of a traditional automotive hydraulic braking system, including a brake pedal, a vacuum booster, a master cylinder, a hydraulic control unit and an electronic control unit, brakes for each wheel, brake lines connecting the master cylinder and the hydraulic control unit, and connecting hydraulic pressure Control unit and brake lines for the individual wheel brakes. There is usually a time delay of 0.3s to 1.0s from the time when the driver produces a braking intention to when the driver's foot steps on the brake pedal. This period is called the driver's reaction time. After the driver steps on the brake pedal, as the brake pedal moves forward, the vacuum booster assists the driver's physical strength and pushes the piston of the master cylinder to move forward. Brake hydraul...

Claims

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Application Information

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IPC IPC(8): B60T13/68B60T13/74
Inventor 王治中王语风宋健李亮于良耀马良旭王伟玮陈友飞孟爱红吴凯辉
Owner TSINGHUA UNIV
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