Motor and hydraulic cylinder connecting structure for electric control booster

Abstract

The invention relates to a motor and hydraulic cylinder connecting structure for an electric control booster, and belongs to the field of automobile braking systems. The motor, the ball screw, the piston and the hydraulic cylinder take the valve body as a carrier, the axis of the motor, the ball screw, the piston and the hydraulic cylinder are coaxially fixed on the valve body through screws or fastening glue, a nut of the ball screw is in threaded connection with the piston, a rotor bottom hole in the motor is in radial interference fit with the tail end of a lead screw of the ball screw, the axial end face is limited, and a gap H is reserved between the bottom end face of the nut and the bottom end face of the rotor. A gap exists between the bottom end face of the nut and the bottom end face of the rotor, so that tightening torque generated by contact friction between the nut and the rotor is avoided; and when the piston needs to move again to build pressure, the locked-rotor phenomenon cannot occur. The product is high in compatibility, small in size and low in cost, and electric control, manufacturing and assembling processes are easy to achieve. The electric control booster can be applied to electric control booster products needing an electric control strategy of voltage building back and forth.

Description

Technical Field

[0001] The present invention belongs to the field of automotive braking systems, and particularly relates to a connection structure between a motor and a hydraulic cylinder for an electronically controlled booster. Background Art

[0002] With the increasing development of new energy vehicles, the field of traditional automotive parts is facing a major revolution. The traditional fuel engine is gradually replaced by a battery, and due to the development needs of electrification and intelligence, the traditional vacuum booster is gradually withdrawing from the market, and is gradually replaced by electronically controlled booster products.

[0003] The electronically controlled booster product is such that while the controller receives the travel signal of the vehicle's brake pedal sensed by the displacement sensor, the force is transmitted to the hydraulic cylinder by controlling the output torque of the motor, and the brake fluid in the hydraulic cylinder transmits the hydraulic pressure to the brake wheel cylinder through the brake pipeline to achieve the purpose of vehicle braking.

[0004] In current industry products, the motor transmits the torque to the hydraulic cylinder based on structures such as a rack and pinion, a worm and worm gear, and a ball screw. Among them, the transmission structure with a ball screw as the main component is relatively simple and has a high transmission efficiency. Through the transmission ratio of the planetary gear train (reduction mechanism) in the reduction mechanism, it realizes providing a large input force for the hydraulic cylinder with a small output torque of the motor; achieving the purpose that the electronically controlled booster can use a motor with a small power and volume to achieve a large output hydraulic pressure, and the product has stronger compatibility.

[0005] Although the transmission structure with a ball screw as the main component has many advantages, it is found in use that when the nut on the ball screw returns, the rear end face of the nut contacts and rubs against the bottom face of the motor rotor to generate a tightening torque; resulting in the problem that a large torque is required for the nut and the motor rotor to disengage during the forward stroke, or they cannot disengage under a certain motor torque, that is, the phenomenon of jamming occurs, thereby causing the product to fail and seriously affecting driving safety. Summary of the Invention

[0006] The present invention provides a connection structure between a motor and a hydraulic cylinder for an electronically controlled booster to solve the problem that when the nut on the current ball screw returns, the rear end face of the nut contacts and rubs against the bottom face of the motor rotor to generate a tightening torque, resulting in the phenomenon of jamming.

[0007] The technical solution adopted by the present invention is that it includes a motor, a ball screw, a piston, a valve body, a hydraulic cylinder, and a controller. Among them, the motor, the ball screw, the piston, and the hydraulic cylinder are carried by the valve body, and are coaxially fixed on the valve body through screws or fastening glue. The nut of the ball screw is threadedly connected to the piston. The bottom hole of the rotor inside the motor has an interference fit with the tail end of the screw rod of the ball screw in the radial direction and is axially limited. In the assembled state of the nut of the ball screw, there is a gap H between the bottom end face of the nut and the bottom end face of the rotor.

[0008] The rotor and the end of the lead screw are fastened together by screws to ensure synchronous rotation of the motor rotor and the lead screw.

[0009] The motor is a coreless motor.

[0010] The ball screw includes a lead screw, a nut, and a push rod head. The nut is threadedly connected to the lead screw, and the push rod head is assembled at the front end of the lead screw.

[0011] The front end of the lead screw has an internal hexagonal hole and a round hole for assembling the push rod head.

[0012] The assembly state of the nut is that the ball head of the push rod head is in contact and mating with the ball socket of the piston.

[0013] The push rod head has a cylindrical tail end with a rectangular through groove in the middle, an external hexagonal shape in the middle, and a ball head structure at the head.

[0014] The tail end of the push rod head is radially interference-fitted with the round hole on the lead screw, and the external hexagonal shape has a small radial clearance fit with the internal hexagonal hole on the lead screw.

[0015] The front end face of the inner hole of the piston has a ball socket structure.

[0016] The valve body includes hydraulic channels connected to a liquid storage tank, a solenoid valve, a simulation cylinder, a pedal simulator, and the vehicle's braking pipeline.

[0017] The advantages of the present invention are novel structure. Based on the motor transmitting torque to the hydraulic cylinder through the ball screw and related transmission system parts, design optimization has been carried out. When the piston and the nut move back and the pressure is relieved, and when reaching the initial assembly state, under the contact and limit of the ball head of the push rod head and the ball socket of the piston, the nut reaches the limit dimension during its return stroke. At this time, there is a gap between the bottom end face of the nut and the bottom end face of the rotor, and there will be no contact friction to generate a tightening torque between the two; when the piston needs to move forward again to build pressure, there will be no jamming phenomenon. The product has strong compatibility, small volume, and low cost, and the electronic control, manufacturing, and assembly processes are relatively easy to implement. It can be applied to electronic control booster products that require reciprocating pressure building in electronic control strategies, as well as in conventional braking, wire control braking, active collision avoidance, adaptive cruise control, intelligent driving, and braking energy recovery systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a schematic structural diagram of the ball screw of the present invention; Figure 3 is a schematic structural diagram of the push rod head of the present invention; Figure 4 is Figure 3 the right view of; Figure 5 It is a schematic structural view of the front end face of the inner hole of the piston of the present invention; Figure 6 It is a schematic structural view of a clearance H left between the bottom end face of the nut and the bottom end face of the rotor of the present invention. Detailed implementation mode

[0019] Refer to Figure 1 、 2 、6, and it includes a motor 1, a ball screw 2, a piston 3, a valve body 4, a hydraulic cylinder 5 and a controller 6. Among them, the motor 1, the ball screw 2, the piston 3 and the hydraulic cylinder 5 take the valve body 4 as a carrier, and the axes are coaxially fixed on the valve body 4 through screws or fastening glue. The nut 2.2 of the ball screw 2 is threadedly connected with the piston 3. The bottom hole of the rotor 1.1 inside the motor 1 has an interference fit with the tail end of the screw rod 2.1 of the ball screw 2 in the radial direction and is limited in the axial end face. In the assembled state of the nut 2.2 of the ball screw 2, there is a clearance H between the bottom end face 2.2.1 of the nut and the bottom end face 1.1.1 of the rotor.

[0020] Refer to Figure 1 , to prevent loosening during work, the rotor 1.1 and the tail end of the screw rod 2.1 are fastened together by a screw 1.2 to ensure the synchronous rotation of the motor rotor 1.1 and the screw rod 2.1.

[0021] The motor 1 is a coreless motor.

[0022] Refer to Figure 2 , the ball screw 2 includes a screw rod 2.1, a nut 2.2 and a push rod head 2.3. Among them, the nut 2.2 is threadedly connected with the screw rod 2.1, and the push rod head 2.3 is assembled at the front end of the screw rod 2.1.

[0023] Refer to Figure 2 , the front end of the screw rod 2.1 has an internal hexagonal hole 2.1.1 and a round hole 2.1.2 for assembling the push rod head 2.3.

[0024] Refer to Figure 1 , in the assembled state of the nut 2.2, the ball head 2.3.3 of the push rod head 2.3 is in contact and cooperation with the ball socket 3.1 of the piston 3.

[0025] Refer to Figure 3 、 4 , the push rod head 2.3 has a cylindrical tail end 2.3.1 with a rectangular through groove in the middle, an external hexagonal shape 2.3.2 in the middle, and a ball head 2.3.3 structure at the head.

[0026] The tail end 2.3.1 on the push rod head 2.3 has an interference fit with the round hole 2.1.2 on the screw rod 2.1 in the radial direction, and the external hexagonal shape 2.3.2 has a small clearance fit with the internal hexagonal hole 2.1.1 on the screw rod 2.1 in the radial direction.

[0027] Refer toFigure 5 The front end face of the inner hole of the piston 3 is provided with a ball socket 3.1 structure.

[0028] The valve body 4 includes hydraulic channels connected to a liquid storage tank, a solenoid valve, an analog cylinder, a pedal simulator, and the vehicle's braking pipeline.

[0029] Working principle Using the motor 1 as the power source, the rotation of the motor rotor 1.1 causes the fixed lead screw 2.1 to rotate; the rotation of the lead screw 2.1 drives the nut 2.2 to move linearly on the basis of the rotation-limiting structure. The nut 2.2 is threadedly fixed to the piston 3, and finally the purpose of building pressure during the forward stroke and relieving pressure during the return stroke of the piston 3 in the hydraulic cylinder 5 is achieved;

[0030] At the same time, when the piston 3 and the nut 2.2 move back to relieve pressure and reach the initial assembly state, the ball head 2.3.3 of the push rod head 2.3 contacts and limits the ball socket 3.1 of the piston 3, and the nut 2.2 returns to the limit dimension; at this time, there is a gap H between the bottom end face 2.2.1 of the nut and the bottom end face 1.1.1 of the rotor, and there will be no contact friction to generate a tightening torque between the two; when the piston needs to move forward again to build pressure, it will not be unable to rotate forward due to the previously generated frictional tightening torque, that is, there will be no jamming phenomenon.

Claims

1. A motor and hydraulic cylinder connection structure for an electronically controlled booster, characterized in that: It includes a motor, a ball screw, a piston, a valve body, a hydraulic cylinder and a controller, wherein the motor, ball screw, piston and hydraulic cylinder use the valve body as a carrier, and are coaxially fixed to the valve body by screws or fasteners. The nut of the ball screw is threadedly connected to the piston. The bottom hole of the rotor inside the motor is radially interference fit with the tail end of the ball screw, and the axial end face is limited. When the nut of the ball screw is in the assembled state, a gap H is left between the bottom end face of the nut and the bottom end face of the rotor.

2. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 1, characterized in that: The rotor and the tail end of the screw rod are fastened together by screws to ensure that the motor rotor and the screw rod rotate synchronously.

3. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 1, characterized in that: The motor is a coreless motor.

4. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 1, characterized in that: The ball screw comprises a screw rod, a nut and a push rod head, wherein the nut is threadedly connected to the screw rod, and the push rod head is assembled at the front end of the screw rod.

5. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 4, characterized in that: The front end of the screw rod is provided with a hexagonal hole and a round hole for assembling a push rod head.

6. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 4, characterized in that: The assembly state of the nut is that the ball head of the push rod head is in contact with the ball socket of the piston.

7. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 4, characterized in that: The putter head has a cylindrical tail end with a rectangular through slot in the middle, a middle part is an outer hexagonal shape, and a head adopts a ball head structure.

8. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 7, characterized in that: The tail end of the push rod head is radially interference fitted with the circular hole on the screw rod, and the outer hexagonal hole is radially matched with the inner hexagonal hole on the screw rod with a small clearance.

9. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 1, characterized in that: The front end surface of the piston inner hole is provided with a ball and socket structure.

10. The motor and hydraulic cylinder connection structure for an electronically controlled booster according to claim 1, characterized in that: The valve body includes a hydraulic channel connected to a liquid storage tank, a solenoid valve, a simulation cylinder, a pedal simulator and a brake pipeline of the entire vehicle.

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