CN118641073B - Automobile EPB tension sensor and processing method - Google Patents

Abstract

The invention belongs to the technical field of sensors, and particularly relates to an automobile EPB tension sensor and a processing method thereof, wherein one end of the elastic stress body in the axial direction is an induction end, a silicon-based strain gauge is attached to the induction end, the other end of the elastic stress body is a stress end, an inner ring groove penetrating through the end surface of the stress end in the axial direction is formed in the stress end, the inner ring groove divides the stress end into a rod part positioned at the central part and a supporting part positioned at the periphery, the supporting gasket is used for supporting the elastic stress body, and the elastic stress body is fixed with the supporting part and provided with a through groove for the rod part to extend out; the shaft lever is fixed with the shaft lever part, a bearing is sleeved on the shaft lever, and a sleeved part for the EPB tension mechanism to be sleeved is formed between the bearing and the support gasket; the invention replaces the traditional displacement sensor, realizes the detection of the tensile force by utilizing the micro deformation of the elastic stress body, has higher output precision, solves the problem of large output error of the traditional displacement, has smaller volume and leaves larger space allowance for the arrangement of the automobile EPB.

Description

Automobile EPB tension sensor and processing method

Technical Field

The invention belongs to the technical field of sensors, and in particular relates to an automobile EPB tension sensor and a processing method thereof.

Background Art

EPB is electronic parking brake, which refers to the technology of achieving parking brake by electronic control. Most of the EPB tension sensors on the market are electromagnetic induction tension sensors, which use the method of sensing magnet displacement and use springs as induction sources; one end of the spring uses a metal part with a magnet, which pulls the spring, and the spring deforms and senses the displacement of the magnet at the same time, and the tension is converted by the deformation force and displacement.

This EPB tension sensor has the following disadvantages: 1. Due to durability issues, the spring will become over-fatigued after long-term use, resulting in inconsistency between deformation force and displacement measurement and large output error; 2. Because the initial position deviation of the tension mechanism is large before pulling the sensor, the sensor cannot accurately judge the tension through displacement and the zero-point output deviation is large; 3. Because the tension reaches about 3KN, a thick spring is required, which makes the sensor large in size and difficult to install and disassemble.

Summary of the invention

The technical problem to be solved by the present invention is: in order to solve the problem that the electromagnetic induction type tension sensor in the prior art uses a spring as an induction source, which will be excessively fatigued after long-term use, resulting in inconsistency between deformation force and displacement measurement, too large output error, and the spring structure causes the sensor to be large in size, making installation and disassembly difficult. An automotive EPB tension sensor and a processing method are now provided.

In order to solve the above technical problems, the present invention adopts the following technical solution: an automobile EPB tension sensor, which is used in conjunction with an EPB tension mechanism to detect the tension applied to it by the EPB tension mechanism, and the tension sensor comprises:

An elastic force-bearing body, one end of which along the axial direction is a sensing end, and the end surface of the sensing end is attached with a silicon-based strain gauge, and the other end is a force-bearing end, and the force-bearing end is provided with an inner ring groove that penetrates the end surface along the axial direction, and the inner ring groove divides the force-bearing end into a rod portion located in the center and a supporting portion located at the periphery;

A support gasket, used to support the elastic force-bearing body, which is fixed to the support portion and has a through slot for the rod portion to extend;

and a shaft rod, which is fixed to the rod portion and sleeved with a bearing, and a sleeve portion for sleeved with the EPB tension mechanism is formed between the bearing and the support gasket.

Furthermore, the rod portion is threadedly connected to the shaft rod and fixed by welding.

Furthermore, the inner annular groove includes a constant diameter section close to the sensing end and a variable diameter section connected to the constant diameter section, and the cross-sectional area of the variable diameter section gradually increases from the sensing end to the force-bearing end.

Furthermore, one end of the equal-diameter section close to the sensing end is an arc section protruding toward the sensing end.

Furthermore, the silicon-based strain gauge is sintered and fixed to the elastic force-bearing body.

Furthermore, a limiting gasket is fixed to one end of the shaft rod away from the rod portion, and the shaft rod protrudes radially to form a limiting portion, and the bearing is installed between the limiting gasket and the limiting portion.

Furthermore, the pressure sensor also includes:

The housing has one end portion fixed to the elastic force-bearing body, and a mounting cavity is formed between the two;

A PCB assembly is located in the mounting cavity and has a connecting wire between the PCB assembly and the silicon-based strain gauge;

A connector is provided with a cable between one end and the PCB assembly, and the other end extends out of the installation cavity.

Furthermore, the outer peripheral wall of the elastic force-bearing body is provided with a first step surface for fixing to the support gasket and a second step surface for fixing to the shell.

Furthermore, the elastic force-bearing body is provided with an outer annular groove between the second step surface and the sensing end for isolating the coupling stress generated by the supporting gasket and the shell on the sensing end.

A processing method based on the above-mentioned automotive EPB tension sensor comprises the following steps:

(1) First, glass glue is pasted on the sensing end of the elastic force-bearing body by silk-screen printing;

(2) Paste the silicon-based strain gauge on the melted glass glue, and then sinter the glass glue in a high-temperature tunnel furnace to sinter the silicon-based strain gauge and the elastic force-bearing body into one;

(3) Fixing the support gasket and the first step surface on the elastic force-bearing body by laser welding;

(4) Install the bearing sleeve on the shaft and fix the limit washer to the shaft by press fitting or welding;

(5) Tighten and fix the shaft rod and the rod portion of the elastic force-bearing body, and laser weld them firmly at the connection to form an assembly;

(6) The above assemblies and PCB components are installed and fixed, and the PCB components and the silicon-based strain gauges are electrically connected through connecting wires;

(7) Solder one end of the cable to the PCB assembly and crimp the other end to the connector;

(8) Finally, one end of the shell is fixed to the second step surface on the elastic force-bearing body by laser welding.

The beneficial effects of the present invention are as follows: the present invention replaces the traditional displacement sensor, utilizes the tiny deformation of the elastic force-bearing body to realize the detection of tension, has high output accuracy, solves the problem of large error in the traditional displacement output, and the tension sensor is small in size, leaving more space margin for the layout of the automobile EPB.

Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described below in conjunction with the accompanying drawings and embodiments.

FIG1 is a three-dimensional schematic diagram of an elastic force-bearing body;

Fig. 2 is a cross-sectional view of an elastic force-bearing body;

FIG3 is a three-dimensional schematic diagram of the cooperation between the elastic force-bearing body and the shaft rod;

FIG4 is a three-dimensional schematic diagram of the elastic force-bearing body, the shaft and the connector;

Fig. 5 is a front view of the present invention;

Fig. 6 is a cross-sectional view taken along the A-A direction in Fig. 5;

FIG7 is a schematic diagram of the cooperation between the present invention and the EPB tension mechanism;

In the figure:

1. Elastic force-bearing body; 101. Sensing end; 102. Force-bearing end; 103. Inner ring groove; 1031. Equal diameter section; 1032. Reduced diameter section; 1033. Arc section; 104. Rod; 105. Supporting part; 106. First step surface; 107. Second step surface; 108. Outer ring groove;

2. Silicon-based strain gauge;

3. Support gasket; 301. Groove;

4. shaft; 401. limiting part;

5. Bearings;

6. EPB tension mechanism;

7. Limiting gasket;

8. housing; 801. mounting cavity;

9. PCB assembly; 901. circuit board; 9011. through slot; 902. conditioning chip; 903. small pad; 904. large pad;

10. Connecting wire;

11. Cables;

12. Connector.

DETAILED DESCRIPTION

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner only, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

As shown in FIG. 7 , the present invention is an automotive EPB tension sensor, which is used in conjunction with an EPB tension mechanism 6 to detect the tension applied by the EPB tension mechanism 6. The tension sensor includes an elastic force-bearing body 1, a support pad 3 and a shaft 4;

The elastic force-bearing body 1 is a rotating body, as shown in FIG1 and FIG2 , one end of which along the axial direction is a sensing end 101, and the end surface of the sensing end 101 is attached with a silicon-based strain gauge 2, and the other end is a force-bearing end 102, and the force-bearing end 102 is provided with an inner ring groove 103 that penetrates through its end surface along the axial direction, and the position of the inner ring groove 103 corresponds to the attachment position of the silicon-based strain gauge 2, and the arrangement interval suitable for the silicon-based strain gauge 2 can be designed and constructed by the groove diameter size;

The inner annular groove 103 divides the force-bearing end 102 into a rod portion 104 located in the center and a supporting portion 105 located on the periphery. The depth of the inner annular groove 103 corresponds to the tensile force required to be tested by the elastic force-bearing body 1. The greater the tensile force, the smaller the depth of the inner annular groove 103. The smaller the tensile force, the greater the depth of the inner annular groove 103, so that the sensing end 101 has a deformation amount.

The support pad 3 is used to support the elastic force-bearing body 1. As shown in FIG. 3 and FIG. 4 , it is fixed to the support portion 105 and has a through slot 301 for the rod portion 104 to extend out.

The shaft rod 4 is shown in Figures 5 and 6. It is fixed to the rod portion 104 and is sleeved with a bearing 5. A sleeve portion for sleeve mounting of an EPB tension mechanism 6 is formed between the bearing 5 and the support gasket 3. The EPB tension mechanism 6 includes a tension rod and a tension ring fixed to the tension rod. The tension ring is sleeved on the sleeve portion, and is rotated at high speed through the bearing 5 and applies tension to the shaft rod 4 along the axial direction.

When the EPB tension mechanism 6 applies tension to the shaft 4, the tension is transmitted to the rod 104 through the shaft 4, the sensing end 101 produces micrometer-level deformation, and the silicon-based strain gauge 2 attached to the sensing end 101 undergoes resistance changes to generate a voltage signal, which is transmitted to the EPB ECU controller to output the tension value; the tension sensor replaces the traditional displacement sensor, and realizes the detection of tension through the slight deformation of the elastic force-bearing body 1. The output accuracy can reach ±0.5%, which solves the problem of large error in traditional displacement output, and the tension sensor is small in size, leaving more space for the layout of the automobile EPB.

In some examples, the rod 104 is threadedly connected to the shaft 4 and welded to fix, and the end of the rod 104 close to the shaft 4 protrudes toward the direction of the shaft 4 to form a threaded section, and the end of the shaft 4 close to the rod 104 is provided with a threaded groove, and the threaded section of the rod 104 is screwed into the threaded groove of the shaft 4 to achieve a threaded connection between the two, and the end faces of the rod 104 and the shaft 4 close to each other are laser welded; because the EPB tension mechanism 6 applies axial tension to the tension sensor while also rotating at high speed, and realizes high-frequency steering during the rotation process, if the elastic force-bearing body 1 and the shaft 4 are only threadedly connected, the EPB tension mechanism 6 may drive the shaft 4 to rotate when rotating, causing the shaft 4 and the elastic force-bearing body 1 to loosen, so welding and fixing are also required to improve the connection strength between the shaft 4 and the elastic force-bearing body 1.

In some examples, as shown in FIG. 2 , the inner annular groove 103 includes a constant diameter section 1031 close to the sensing end 101 and a variable diameter section 1032 connected to the constant diameter section 1031 , and a cross-sectional area of the variable diameter section 1032 gradually increases from the sensing end 101 toward the force-bearing end 102 , thereby effectively reducing the force-bearing area of the supporting surface of the support portion 105 , helping to form a greater stress strain at the sensing end 101 and thereby improving the accuracy of the tension sensor, and also facilitating the processing of the inner annular groove 103 .

In some examples, one end of the equal-diameter section 1031 close to the sensing end 101 is an arc section 1033 protruding toward the sensing end 101 , which is beneficial to the uniform transition of deformation and force when the elastic force-bearing body 1 is pulled.

In some examples, the silicon-based strain gauge 2 is sintered and fixed to the elastic force-bearing body 1 .

In some examples, as shown in Figure 6, a limiting gasket 7 is fixed to one end of the shaft rod 4 away from the rod portion 104, and the middle portion of the shaft rod 4 protrudes radially to form a limiting portion 401, and the bearing 5 is installed between the limiting gasket 7 and the limiting portion 401, and the outer diameter of the limiting gasket 7 is smaller than the outer diameter of the bearing 5 to ensure that the EPB tension mechanism 6 does not rub against the limiting gasket 7 during high-frequency rotation and reversing, thereby ensuring the durability of the limiting gasket 7, and the bearing 5 has a cover on the outside, which isolates the bearing 5 inside it from the limiting gasket 7 outside, thereby ensuring the durability of the bearing 5 and preventing it from being easily worn.

In some examples, as shown in FIGS. 4-6 , the pressure sensor further includes:

The housing 8 has one end fixed to the elastic force-bearing body 1, and a mounting cavity 801 is formed between the two;

The PCB assembly 9 is located in the installation cavity 801. The PCB assembly 9 includes a circuit board 901. A conditioning chip 902 is fixed at the center of the circuit board 901. Through slots 9011 are provided on both sides of the conditioning chip 902 on the circuit board 901. The positions of the through slots 9011 correspond to the positions of the silicon-based strain gauge 2. A small pad 903 is provided at the notch of the through slot 9011. A connecting wire 10 is provided between the small pad 903 and the silicon-based strain gauge 2.

And a connector 12, a cable 11 is arranged between one end of the connector and the large pad 904 on the PCB assembly 9, and the other end extends out of the mounting cavity 801.

In some examples, the outer peripheral wall of the elastic force-bearing body 1 is provided with a first step surface 106 for fixing to the support gasket 3 and a second step surface 107 for fixing to the shell 8. The support gasket 3 and the first step surface 106 are laser welded, and the shell 8 and the second step surface 107 are also laser welded.

In some examples, the elastic force-bearing body 1 is provided between the second step surface 107 and the sensing end 101 with an outer annular groove 108 for isolating the coupling stress generated by the support gasket 3 and the shell 8 on the sensing end 101, thereby improving the detection accuracy of the tension sensor.

In some examples, a method for processing an automotive EPB tension sensor includes the following steps:

(1) First, glass glue is pasted on the sensing end 101 of the elastic force-bearing body 1 by silk-screen printing;

(2) Paste the silicon-based strain gauge 2 onto the melted glass glue, and then sinter the glass glue in a high-temperature tunnel furnace to sinter the silicon-based strain gauge 2 and the elastic force-bearing body 1 into one body;

(3) Fixing the support gasket 3 and the first step surface 106 on the elastic force-bearing body 1 by laser welding;

(4) Sleeve the bearing 5 on the shaft 4, and fix the limit washer 7 to the shaft 4 by press fitting or welding;

(5) Tighten and fix the shaft rod 4 and the rod portion 104 of the elastic force-bearing body 1, and laser weld the connection to form an assembly;

(6) The above assembly and PCB assembly 9 are installed and fixed, and the PCB assembly 9 and the silicon-based strain gauge 2 are electrically connected through the connecting wire 10;

(7) One end of the cable 11 is welded to the PCB assembly 9, and the other end is crimped to the connector 12;

(8) Finally, one end of the shell 8 is fixed to the second step surface 107 on the elastic force-bearing body 1 by laser welding.

Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims (10)

1. The utility model provides an automobile EPB tension sensor, its cooperation is used with EPB pulling force mechanism (6) for detect the pulling force that EPB pulling force mechanism (6) applyed it, its characterized in that: the tension sensor includes:

The elastic stress body (1) is provided with an induction end (101) at one end along the axial direction, a silicon-based strain gauge (2) is attached to the end surface of the induction end (101), the other end is provided with a stress end (102), the stress end (102) is provided with an inner ring groove (103) penetrating through the end surface along the axial direction, and the inner ring groove (103) divides the stress end (102) into a rod part (104) positioned at the central part and a supporting part (105) positioned at the periphery;

A support pad (3) for supporting the elastic force-receiving body (1), which is fixed to the support portion (105) and has a through groove (301) through which the rod portion (104) extends;

And the shaft lever (4) is fixed with the lever part (104) and is sleeved with a bearing (5), and a sleeved part for the EPB tension mechanism (6) to be sleeved is formed between the bearing (5) and the supporting gasket (3).

2. The automotive EPB tension sensor of claim 1, wherein: the rod part (104) is in threaded connection with the shaft rod (4) and is fixed by welding.

3. The automotive EPB tension sensor of claim 1, wherein: the inner ring groove (103) comprises an equal-diameter section (1031) close to the induction end (101) and a variable-diameter section (1032) communicated with the equal-diameter section (1031), and the sectional area of the variable-diameter section (1032) gradually increases from the induction end (101) to the direction of the stress end (102).

4. A car EPB tension sensor according to claim 3, wherein: one end of the constant diameter section (1031) close to the induction end (101) is an arc section (1033) protruding towards the induction end (101).

5. The automotive EPB tension sensor of claim 1, wherein: the silicon-based strain gauge (2) and the elastic stress body (1) are sintered and fixed.

6. The automotive EPB tension sensor of claim 1, wherein: one end of the shaft lever (4) far away from the shaft portion (104) is fixedly provided with a limiting gasket (7), the shaft lever (4) protrudes radially to form a limiting portion (401), and the bearing (5) is arranged between the limiting gasket (7) and the limiting portion (401).

7. The automotive EPB tension sensor of claim 1, wherein: the tension sensor further includes:

A shell (8) with one end fixed with the elastic stress body (1) and a mounting cavity (801) formed by enclosing the two;

the PCB assembly (9) is positioned in the mounting cavity (801), and a connecting wire (10) is arranged between the PCB assembly and the silicon-based strain gauge (2);

and a connector (12) with a cable (11) arranged between one end and the PCB assembly (9) and the other end extending out of the mounting cavity (801).

8. The automotive EPB tension sensor of claim 7, wherein: the outer peripheral wall of the elastic stress body (1) is provided with a first step surface (106) used for being fixed with the supporting gasket (3) and a second step surface (107) used for being fixed with the shell (8).

9. The automotive EPB tension sensor of claim 8, wherein: an outer ring groove (108) for isolating coupling stress generated by the supporting gasket (3) and the shell (8) on the induction end (101) is arranged between the second step surface (107) and the induction end (101) of the elastic stress body (1).

10. A method for processing an automotive EPB tension sensor according to any one of claims 1-9, characterized in that: the method comprises the following steps:

(1) Firstly, pasting glass cement on an induction end (101) of an elastic stress body (1) through a silk screen printing process;

(2) The silicon-based strain gauge (2) is stuck on the melted glass cement, and then the glass cement is sintered through a high-temperature tunnel furnace, so that the silicon-based strain gauge (2) and the elastic stress body (1) are sintered into a whole;

(3) Fixing the support gasket (3) and the first step surface (106) on the elastic stress body (1) in a laser welding mode;

(4) The bearing (5) is sleeved on the shaft lever (4), and the limiting gasket (7) is fixed with the shaft lever (4) in a press fit or welding mode;

(5) The shaft lever (4) and the lever part (104) of the elastic stress body (1) are screwed and fixed, and meanwhile, the laser welding is firm at the joint to form an assembly;

(6) The assembly and the PCB assembly (9) are installed and fixed, and the PCB assembly (9) and the silicon-based strain gauge (2) are electrically connected through a connecting wire (10);

(7) One end of a cable (11) is welded and fixed with the PCB assembly (9), and the other end is crimped and fixed with the connector (12);

(8) Finally, one end of the shell (8) is welded and fixed with a second step surface (107) on the elastic stress body (1) by laser.