Electronic parking actuator with wear alarm function and screw stroke alarm function

Abstract

The utility model discloses an electronic parking actuator with wear alarm and screw stroke alarm functions, which belongs to the field of automobile accessories and is used for the electronic parking actuator. A screw outer shell A and a screw outer shell B form a cavity for accommodating an actuating motor and a screw, the screw input end of the screw extends out of the screw outer shell A, and the screw output end of the screw extends out of the screw outer shell B; the execution motor drives the screw rod to rotate; the end, away from the screw input end, of the screw is connected with a screw sliding block, a PCB is arranged at the position close to the screw sliding block, the PCB is provided with a PCB connecting end electrically connected with a terminal, the PCB is provided with a sensor for detecting the approaching distance of the screw sliding block, the terminal is located in a plug-in end, and the plug-in end is connected with the screw outer shell B. According to the application, the wear thickness of the friction material in the brake shoe in the drum brake can be detected, the stroke of the screw in the electronic parking actuator can be detected, and the damage to the shell due to the fact that the screw exceeds the stroke is avoided.

Description

Technical Field

[0001] This application belongs to the field of automotive parts. Specifically, it particularly relates to an electronic parking actuator that combines wear alarm and screw stroke alarm functions. Background Art

[0002] In commercial vehicle brakes, according to the provisions of Article 7.9.5 of GB7258-2017 "Motor Vehicle Operating Safety Technical Conditions", for passenger cars, trucks, and special operation vehicles with a total mass greater than 3500 Kg equipped with automatic brake clearance adjustment devices, when the service brake linings need to be replaced, an optical or acoustic alarm device should be used to alarm the driver sitting in the driver's seat.

[0003] Therefore, in commercial vehicle brakes, especially drum brakes, it is necessary to set alarm sensors for detecting the wear degree of the friction material on the brake shoes. At the same time, electronic parking brakes have been gradually popularized in existing vehicles. For example, a kind of turbine and worm type electronic parking power assembly for drum brakes disclosed in Chinese Patent Publication No. CN217730418U discloses the following technical solution: A housing and an upper cover are connected to form a cavity inside for installing a motor, a turbine and worm transmission mechanism, and a screw transmission mechanism; in the turbine and worm transmission mechanism, the output shaft of the motor is coaxially fixed to the worm, and the worm meshes with the worm gear to form a worm and worm gear pair; in the screw transmission mechanism, a connecting thread sleeve and the worm gear are coaxially fixedly sleeved, the output shaft of the motor is arranged perpendicular to the screw, the middle of the screw is sleeved in the threaded through hole of the connecting thread sleeve through threads, one end of the screw is non-rotatably limited and installed in the upper cover, and the other end passes through the connecting thread sleeve and the housing and is connected to the brake pull arm.

[0004] In the above-mentioned electronic parking power assembly, the stroke of the screw is not protected. When the friction material in the brake shoes wears to a large extent (that is, beyond the allowable wear degree), the movement distance of the screw inside the electronic parking power assembly will exceed the designed distance, which may cause the housing to be damaged by the screw that exceeds the movement stroke. At the same time, in the above-mentioned prior art CN217730418U patent document, it is also impossible to detect the wear degree of the friction material of the brake shoes through the electronic parking power assembly, and it is still necessary to independently install corresponding wear alarm sensors. Summary of the Invention

[0005] This application provides an electronic parking actuator that combines wear alarm and screw stroke alarm functions, which can detect the wear thickness of the friction material in the brake shoes of the drum brake, and can also detect the screw stroke in the electronic parking actuator, avoiding damage to the housing caused by the screw exceeding the stroke.

[0006] To achieve the above technical objectives, this application is realized through the following technical solutions:

[0007] An electronic parking actuator with both wear alarm and screw stroke alarm functions described in this application includes a screw housing A and a screw housing B. The screw housing A and the screw housing B form a chamber for accommodating the actuator motor and the screw. The screw input end of the screw extends from the screw housing A, and the actuator motor drives the screw to rotate. A screw slider is connected to one end of the screw far from the screw input end, and a PCB board is arranged at a position close to the screw slider. The PCB board has a PCB board connection end electrically connected to the terminal. A sensor for detecting the approaching distance of the screw slider is provided on the PCB board. The terminal is located inside the plug-in end, and the plug-in end is connected to the screw housing B.

[0008] As one of the preferred technical solutions, in this application, a magnetic element is arranged at the end of the screw slider facing the PCB board, and a Hall sensor is arranged on the PCB board.

[0009] As one of the preferred technical solutions, in this application, the PCB board is located inside the plug-in end or the screw housing B.

[0010] As one of the preferred technical solutions, in this application, the output end of the actuator motor drives the screw to move along its own central axis direction through a turbine assembly. The turbine assembly at least includes a driving gear located at the output end of the actuator motor and a transmission gear meshing with the driving gear. The transmission gear is threadedly connected to the screw.

[0011] As one of the preferred technical solutions, in this application, the screw housing A has a connection end, and the connection end has a connection hole with a screw slider.

[0012] Compared with the prior art, this application has the following beneficial effects:

[0013] By improving the structure of the electronic parking actuator itself, this application places the detection device inside the electronic parking actuator without making major changes to the appearance of the original electronic parking actuator, ensuring the integrity and reliability of the product, and expanding the functions of the product itself. It can simultaneously detect the wear degree of the friction material of the braking system and also detect its own working stroke to avoid self-damage. Description of the Drawings

[0014] Figure 1 is the three-dimensional view of this application Figure 1 .

[0015] Figure 2 is the three-dimensional view of this application Figure 2 .

[0016] Figure 3 is the exploded view of this applicationFigure 1 。

[0017] Figure 4 is the explosion view of the present application Figure 2 。

[0018] In the figure: 1. Screw housing A; 2. Screw housing B; 3. Plug-in end; 4. Connecting end of the actuating motor; 5. Screw input end; 6. Screw; 7. Transmission gear; 8. Driving gear; 9. Actuating motor; 10. Screw slider; 11. Magnetic element; 12. PCB board; 13. PCB board connecting end; 14. Terminal; 15. Connecting end; 16. Bushing. Specific embodiments

[0019] The technical solutions described in the present application will be discussed in detail below with reference to the accompanying drawings and embodiments.

[0020] Embodiment 1

[0021] As Figures 1 to 4 shown, an electronic parking actuator with both wear alarm and screw stroke alarm functions includes a screw housing A1 and a screw housing B2. The screw housing A1 and the screw housing B2 form a chamber for accommodating the actuating motor 9 and the screw 6. The screw input end 5 of the screw 6 extends from the screw housing A1, and the actuating motor 9 drives the screw 6 to rotate. It is characterized in that: a screw slider 10 is connected to one end of the screw 6 far from the screw input end 5, a PCB board 12 is arranged near the screw slider 10, the PCB board 12 has a PCB board connecting end 13 electrically connected to the terminal 14, the PCB board 12 is provided with a sensor for detecting the approaching distance of the screw slider 10, the terminal 14 is located in the plug-in end 3, and the plug-in end 3 is connected to the screw housing B2.

[0022] Embodiment 2

[0023] Continue to refer to Figures 1 to 4 , an electronic parking actuator with both wear alarm and screw stroke alarm functions, a magnetic element 11 is arranged at the end of the screw slider 10 facing the PCB board 12, and a Hall sensor is arranged on the PCB board 12. The PCB board 12 is located in the plug-in end 3 or the screw housing B2. The output end of the actuating motor 9 drives the screw 6 to move along its own central axis direction through a turbine assembly. The turbine assembly at least includes a driving gear 8 located at the output end of the actuating motor 9 and a transmission gear 7 meshing with the driving gear 8. The transmission gear 7 is threadedly connected to the screw 6. The screw housing A1 has a connecting end 15, and the connecting end 1� has a connecting hole with the screw slider 10.

[0024] The structures and connection relationships of the remaining parts are the same as those described in Embodiment 1. To avoid redundancy in the text, they will not be elaborated here. Those skilled in the art can understand the technical solutions described in Embodiment 2 based on Embodiment 1.

[0025] Based on the above embodiments, the present application uses the following space to elaborate in detail on the technical features involved, the functions or roles played by these technical features, and the working process of the present application, so as to help those skilled in the art fully understand the technical solutions described in the present application and be able to reproduce them.

[0026] In the present application, the screw housing A1 and the screw housing B2 form a space for accommodating the execution motor 9, the turbine assembly, the screw 6, and the screw slider 10. Moreover, a connection hole for the screw slider 10 is provided on the screw housing A1.

[0027] An execution motor connection end 4 for realizing the electrical signal input of the execution motor 9 is further provided on the screw housing A1. A housing extending away from the direction where the screw housing A1 is located and for accommodating the screw 6 is further provided on the screw housing B2. A screw slider 10 is provided in this part of the housing. The screw slider 10 is located at one end of the screw 6, and the screw input end 5 at the other end of the screw 6 extends out of the screw housing A1.

[0028] In the present application, the execution motor 9 drives the screw 6 to move along its own central axis through the turbine assembly. The turbine assembly in the present application at least includes a driving gear 8 located at the output end of the execution motor 9 and a transmission gear 7 for driving the screw 6 to move along its own central axis. The transmission gear 7 meshes with the driving gear 8 for transmission. For the remaining structure of the turbine assembly, refer to the worm and gear transmission mechanism disclosed in the patent document CN217730418U.

[0029] In the present application, a plug-in end 3 is provided at the open end of the housing where the screw slider 10 is located. The plug-in end 3 has a terminal 14, and the terminal 14 is electrically connected to a PCB board connection end 13. The PCB board connection end 13 is located on a PCB board 12, and a sensor for detecting the approach of the screw slider 10 is also provided on the PCB board 12. Specifically, a Hall sensor may be provided on the PCB board 12, and a magnetic element 11 cooperating with the Hall sensor is provided on the screw slider 10. The magnetic element 11 can be a permanent magnet. In the present application, the sensor (such as a Hall sensor) for measuring the magnetic element 11 is soldered to the PCB board 12 in the form of a patch. When the magnetic element 11 approaches the Hall sensor, it can change the magnetic field intensity around the Hall sensor, and the change in the magnetic field intensity can cause the Hall sensor to generate a corresponding level signal, and this level signal is sent to the vehicle ECU through the PCB board 12, the PCB board connection end 13, and the terminal 14. The vehicle ECU determines whether the screw 6 is in a position where an alarm is required based on this level signal. The action threshold of the Hall sensor can be adjusted by the magnetic flux of the magnetic element 11 to adapt to the output of the level signal under different induction distance requirements.

[0030] In the present application, the stroke of the screw 6 needs to be measured according to the wear degree of different brakes, so as to determine the stroke of the screw slider 10 at the end of the screw 6, and then a stroke distance is set as the limit alarm position.

[0031] In a vehicle equipped with a parking brake, during the braking process of the brake shoe and the brake drum, since the friction material on the brake shoe gradually wears, the pulling distance of the brake pull arm gradually increases, and the moving distance of the screw 6 into the housing where the screw housing B2 is located gradually increases, that is, the moving distance in the direction of the plug-in end 3 gradually increases. When the friction material on the brake shoe wears to the set position (i.e., the set wear limit position), or even exceeds the set position, due to the limitation of the space where the screw 6 is located and the installation space of the screw housing, the movement of the screw 6 along the direction of its own central axis may cause damage to the tail end of the housing where the screw 6 is located. Therefore, in the present application, a screw slider 10 and a magnetic element 11 are provided at the tail end of the screw 6. By calibrating the limit positions of the screw slider 10 and the magnetic element 11, the corresponding PCB board 12 and its sensor can sense the limit positions of the magnetic element 11 and output corresponding level signals. Then, when the screw slider 10 and the magnetic element 11 at the tail end of the screw 6 run to the set positions, an alarm signal can be sent in time to remind the driver to pay attention to replacing the friction material on the brake shoe and to protect the electronic parking power assembly to prevent the screw 6 from exceeding the set stroke.

[0032] Finally, although this specification is described in terms of embodiments, not every embodiment contains only an independent technical solution. This narrative style of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electronic parking actuator with both wear alarm and screw stroke alarm functions, comprising a screw housing A (1) and a screw housing B (2). The screw housing A (1) and the screw housing B (2) form a chamber for accommodating an actuator motor (9) and a screw (6). The screw input end (5) of the screw (6) extends from the screw housing A (1), and the actuator motor (9) drives the screw (6) to rotate. It is characterized in that: One end of the screw rod (6) far from the input end (5) of the screw rod is connected with a screw slider (10), a PCB board (12) is arranged at a position close to the screw slider (10), the PCB board (12) has a PCB board connection end (13) electrically connected to a terminal (14), a sensor for detecting the approaching distance of the screw slider (10) is arranged on the PCB board (12), the terminal (14) is located in the plug-in end (3), and the plug-in end (3) is connected with the screw housing B (2).

2. The electronic parking actuator with both wear alarm and screw stroke alarm functions according to claim 1, characterized in that: A magnetic element (11) is arranged at the end of the screw slider (10) facing the PCB board (12), and a Hall sensor is arranged on the PCB board (12).

3. An electronic parking actuator with both wear alarm and screw stroke alarm functions according to claim 1, characterized in that: The PCB board (12) is located in the plug-in end (3) or the screw housing B (2).

4. An electronic parking actuator with both wear alarm and screw stroke alarm functions according to claim 1, characterized in that: The output end of the actuating motor (9) drives the screw rod (6) to move along its own central axis direction through a turbine assembly. The turbine assembly at least includes a driving gear (8) located at the output end of the actuating motor (9) and a transmission gear (7) meshing with the driving gear (8) for transmission. The transmission gear (7) is threadedly connected to the screw rod (6).

5. An electronic parking actuator having both a wear alarm and a screw stroke alarm function according to claim 1, characterized in that: The screw housing A (1) has a connection end (15), and the connection end (15) has a connection hole with the screw slider (10).

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