Electronic mechanical brake pressure detection module

Abstract

The invention relates to the technical field of electronic mechanical brakes in the field of brake-by-wire systems, in particular to an electronic mechanical brake pressure detection module which comprises a caliper body, the caliper body comprises a caliper body bridge part, a driving device mounting seat and a pair of clamping jaws, the pair of clamping jaws are oppositely arranged in the direction x, the driving device mounting seat is connected to the end of the caliper body bridge part, and the driving device mounting seat is connected to the end of the caliper body bridge part; the clamping jaw comprises a movable clamping jaw arranged on the driving device mounting seat; the axial driving device is used for driving the movable clamping jaw to move in the direction x; the pressure detection device comprises a strain gauge; the connecting position of the clamp body bridge portion and the driving device installation base is arranged at the axial pressure stress position between the driving device installation base and the axial driving device in the radial direction in an offset mode in the z direction, the symmetric center of the pair of strain gauges right faces the straight line where the z direction is located in the x direction, and the interval direction of the pair of strain gauges is perpendicular to the z direction. And secondary calibration is not needed after installation, so that the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of electronic mechanical brakes in the field of wire-controlled brake systems, and in particular to an electronic mechanical brake pressure detection module. Background Art

[0002] In order to achieve precise control of the clamping force, the electronic mechanical brake (EMB) mostly uses pressure sensors to measure the clamping force as closed-loop control feedback. The measurement accuracy of the clamping force has a great impact on the performance of the EMB. The clamping force detection device of the existing EMB control system can refer to the braking force sensor for the EMB control system disclosed in application number 2022114924601. However, there is often a large deviation between the actual measured value and the theoretical value obtained according to the prior art. This results in the need to adjust the conversion coefficient calibrated by the pressure sensor at the factory. In order to ensure the measurement accuracy of the clamping force, the pressure sensor often needs to be calibrated again after the EMB assembly is assembled, which affects production efficiency. Summary of the invention

[0003] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides an electronic mechanical brake pressure detection module, which does not require secondary calibration after installation, thereby improving production efficiency.

[0004] In order to achieve the above object, the present invention is implemented through the following technical solutions: An electronic mechanical brake pressure detection module, comprising: The caliper body comprises a caliper body bridge, a drive device mounting seat and a pair of claws, wherein the pair of claws are arranged opposite to each other in a direction x and are located at two ends of the caliper body bridge, the drive device mounting seat is connected to the end of the caliper body bridge, and the claws comprise movable claws arranged on the drive device mounting seat; An axial drive device, the axial drive device is mounted on the drive device mounting seat, and the axial drive device is used to drive the movable claw to move in the direction x; A pressure detection device, which is arranged between the axial drive device and the drive device mounting seat in the direction x and is used to detect the axial pressure, and the pressure detection device includes a strain gauge; The connection position between the caliper body bridge and the drive device mounting seat is radially offset along direction z to the axial pressure force position between the drive device mounting seat and the axial drive device. The strain gauge is symmetrically arranged on a plane perpendicular to direction x, and the symmetry center of the strain gauge is opposite to the straight line in direction z in direction x, and the spacing direction of the symmetrically arranged strain gauges is perpendicular to direction z.

[0005] Furthermore, in an electronic mechanical brake pressure detection module in the present application, the symmetry center of a pair of strain gauges corresponds to the radial center of the axial drive device. As a preferred solution of the present application, the influence of the bending deformation of the caliper body on the pressure detection can be further reduced.

[0006] Furthermore, in an electronic mechanical brake pressure detection module in the present application, a varistor is provided on the strain gauge, and all the varistor forms a Wheatstone circuit. As a preferred solution of the present application, the strain gauge is a half-bridge strain gauge, and two half-bridge strain gauges form a Wheatstone full bridge to improve the detection accuracy.

[0007] Furthermore, in an electronic mechanical brake pressure detection module in the present application, the pressure detection device includes a base, a strain gauge is arranged on a first end face of the base, and a second end face is provided at an end of the base away from the first end face for receiving the axial pressure of the axial driving device. The pressure detection device also includes a pressure ring arranged between the base and the driving device mounting seat, and the pressure ring is used to transmit the pressure applied by the base to the driving device mounting seat.

[0008] Furthermore, in an electronic mechanical brake pressure detection module in the present application, an annular mounting groove is provided in the drive device mounting seat, a pressure ring is embedded in the annular mounting groove and abuts against the axial end face of the annular mounting groove, and the pressure ring is sleeved on the base for radially limiting the base.

[0009] Furthermore, in an electronic mechanical brake pressure detection module in the present application, the pressure detection device also includes a circuit board and a cover body, the cover body is arranged on the first end face, the strain gauge and the circuit board are arranged in the cover body, and the strain gauge is electrically connected to the circuit board.

[0010] Furthermore, in an electronic mechanical brake pressure detection module in the present application, the axial drive device includes a driving shaft, a driving screw and a transmission nut that cooperates with the driving screw, the driving screw is mounted on the driving shaft, the transmission nut is slidably arranged in the driving device mounting seat along the direction x, the driving device mounting seat is provided with a sliding cavity for accommodating the sliding of the transmission nut, and the transmission nut is connected to the movable claw. As a preferred solution of the present application, the driving screw is driven to rotate by the driving shaft to drive the transmission nut to move in the sliding cavity, thereby driving the movable claw to move.

[0011] Furthermore, in the electronic mechanical brake pressure detection module of the present application, the base is sleeved on the driving shaft, the midpoint of the line connecting the symmetrically arranged strain gauges corresponds to the rotation center of the driving shaft, a limiting step is provided on the driving shaft, and the axial drive device also includes a thrust bearing axially abutting between the limiting step and the second end face. As a preferred solution of the present application, the thrust bearing is used to transmit the axial thrust of the limiting step to the second end face, and avoid surface wear caused by direct contact between the limiting step and the second end face.

[0012] It can be seen from the above technical solution that the present invention has the following beneficial effects: The present invention provides an electronic mechanical brake pressure detection module. After analysis, it is found that the reason for the measurement error of the pressure sensor is that there is a radial offset in the connection position between the caliper body bridge and the drive device mounting seat. When the EMB assembly is clamped, the axial force of the axial drive device acts on the claw on the opposite side of the movable claw on one side, and the reaction force on the other side acts on the drive device mounting seat. Since the connection position between the caliper body bridge and the drive device mounting seat is not coaxial with the axial pressure, an additional bending moment will be generated, causing the caliper body to bend and deform. This additional bending moment will cause the pressure on the drive device mounting seat to be unevenly distributed in the offset direction. In this regard, based on the above structure, the principle of an electronic mechanical brake pressure detection module is: a pair of strain gauges are distributed on both sides of the offset direction of the caliper body bridge, so that the spacing direction of the strain gauges is perpendicular to the offset direction, so that the pair of strain gauges receive uniform bending deformation, so as to reduce the influence of the bending deformation of the caliper body on pressure detection. Therefore, an electronic mechanical brake pressure detection module based on the present application does not need to be calibrated again after installation, which improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A planar cross-sectional view of an electronic mechanical brake pressure detection module in an embodiment of the present application (the cross-sectional view is along the axis of the driving shaft); Figure 2 is a cross-sectional view of an electronic mechanical brake pressure detection module in an embodiment of the present application at the position of a strain gauge (the cross section is perpendicular to the direction x); Figure 3 An exploded view of components of a pressure detection device in an embodiment of the present application; Figure 4 is a schematic diagram of the bending deformation of the caliper body; In the figure: 1-caliper body; 11-caliper body bridge; 12-movable claw; 13-drive device mounting seat; 131-annular mounting groove; 132-sliding cavity; 2-axial drive device; 21-driving shaft; 211-limiting step; 22-driving screw; 23-driving nut; 24-thrust bearing; 3-pressure detection device; 31-strain gauge; 32-base; 321-first end surface; 322-second end surface; 33-pressure ring; 34-circuit board; 35-cover body. DETAILED DESCRIPTION

[0014] Combination Figures 1 to 3 An electronic mechanical brake pressure detection module is shown, comprising: The caliper body 1 comprises a caliper body bridge portion 11, a drive device mounting seat 13 and a pair of claws, wherein the pair of claws are arranged opposite to each other in a direction x and are located at two ends of the caliper body bridge portion 11, the drive device mounting seat 13 is connected to the end of the caliper body bridge portion 11, and the claws comprise a movable claw 12 arranged on the drive device mounting seat 13; An axial driving device 2, the axial driving device 2 is mounted on a driving device mounting seat 13, and the axial driving device 2 is used to drive the movable claw 12 to move in a direction x; A pressure detection device 3, which is disposed between the axial drive device 2 and the drive device mounting seat 13 in the direction x and is used to detect axial pressure. The pressure detection device 3 includes a strain gauge 31; The connection position of the caliper bridge 11 and the drive device mounting seat 13 is offset in the radial direction along the direction z to the axial pressure force position between the drive device mounting seat 13 and the axial drive device 2, and the strain gauge 31 is symmetrically arranged on a plane perpendicular to the direction x, and the symmetry center of the strain gauge 31 is directly opposite to the straight line in the direction z in the direction x, and the spacing direction of the symmetrically arranged strain gauges 31 is perpendicular to the direction z. In this embodiment, the number of strain gauges 31 is 2.

[0015] After analysis, it was found that the reason for the measurement error of the pressure sensor is that there is a radial offset in the connection position between the caliper bridge 11 and the drive device mounting seat 13. When the EMB assembly is clamped, the axial force of the axial drive device 2 acts on the claw on the opposite side of the movable claw 12 on one side, and the reaction force on the drive device mounting seat 13 on the other side. Since the connection position between the caliper bridge 11 and the drive device mounting seat 13 is not coaxial with the axial pressure, an additional bending moment will be generated, causing the caliper body 1 to occur as follows: Figure 4 The bending deformation shown in the figure, this additional bending moment will cause the pressure on the drive device mounting seat 13 to be unevenly distributed in the offset direction. In this regard, based on the above structure, the principle of an electronic mechanical brake pressure detection module is: a pair of strain gauges 31 are distributed on both sides of the offset direction of the caliper body bridge 11, so that the spacing direction of the strain gauges 31 is perpendicular to the offset direction, so that the pair of strain gauges 31 receive uniform bending deformation to reduce the influence of the bending deformation of the caliper body 1 on pressure detection. Therefore, an electronic mechanical brake pressure detection module based on the present application does not need to be calibrated again after installation, which improves production efficiency.

[0016] In this embodiment, the symmetry center of the pair of strain gauges 31 corresponds to the radial center of the axial drive device 2, which can further reduce the influence of the bending deformation of the caliper body 1 on the pressure detection.

[0017] In this embodiment, a piezoresistor is provided on the strain gauge 31, and all the piezoresistors form a Wheatstone circuit. In this embodiment, the strain gauge 31 is a half-bridge strain gauge, and two half-bridge strain gauges form a Wheatstone full bridge to improve the detection accuracy.

[0018] Combination Figure 3 As shown, in this embodiment, the pressure detection device 3 includes a base 32, a strain gauge 31 is arranged on a first end surface 321 of the base 32, and a second end surface 322 for receiving the axial pressure of the axial drive device 2 is arranged at one end of the base 32 away from the first end surface 321. The pressure detection device 3 also includes a pressure ring 33 arranged between the base 32 and the drive device mounting seat 13, and the pressure ring 33 is used to transmit the pressure applied by the base 32 to the drive device mounting seat 13. In this embodiment, the base 32 is annular.

[0019] In this embodiment, an annular mounting groove 131 is provided in the drive device mounting seat 13, and a pressure ring 33 is embedded in the annular mounting groove 131 and abuts against the axial end surface of the annular mounting groove 131. The pressure ring 33 is sleeved on the base 32 to limit the radial position of the base 32.

[0020] In this embodiment, the pressure detection device 3 further includes a circuit board 34 and a cover body 35 . The cover body 35 is covered on the first end surface 321 . The strain gauge 31 and the circuit board 34 are arranged in the cover body 35 . The strain gauge 31 is electrically connected to the circuit board 34 .

[0021] In this embodiment, the axial drive device 2 includes a drive shaft 21, a drive screw 22 and a drive nut 23 that is in transmission cooperation with the drive screw 22. The drive screw 22 is mounted on the drive shaft 21. The drive nut 23 is slidably arranged in the drive device mounting seat 13 along the direction x. The drive device mounting seat 13 is provided with a sliding cavity 132 for accommodating the sliding of the drive nut 23. The drive nut 23 is connected to the movable claw 12. The drive shaft 21 drives the drive screw 22 to rotate to drive the drive nut 23 to move in the sliding cavity 132, thereby driving the movable claw 12 to move.

[0022] In this embodiment, the base 32 is sleeved on the driving shaft 21, the midpoint of the line connecting the symmetrically arranged strain gauges 31 corresponds to the rotation center of the driving shaft 21, a limiting step 211 is provided on the driving shaft 21, and the axial driving device 2 also includes a thrust bearing 24 axially abutting between the limiting step 211 and the second end face 322. That is, in this embodiment, the pressure detection device 3 is arranged between the thrust bearing 24 and the axial end face of the annular mounting groove 131 in the direction x. Among them, the thrust bearing 24 is used to transmit the axial thrust of the limiting step 211 to the second end face 322, and avoid the limiting step 211 and the second end face 322 directly fitting and contacting to cause surface wear.

[0023] The technical principles of the present invention are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without creative work, and these methods will fall within the scope of protection of the present invention.

Claims

1. An electronic mechanical brake pressure detection module, comprising: A caliper body (1), the caliper body (1) comprising a caliper body bridge portion (11), a drive device mounting seat (13) and a pair of claws, the pair of claws being arranged opposite to each other in a direction x and located at two ends of the caliper body bridge portion (11), the drive device mounting seat (13) being connected to an end of the caliper body bridge portion (11), and the claws comprising a movable claw (12) arranged on the drive device mounting seat (13); An axial drive device (2), the axial drive device (2) being mounted on a drive device mounting seat (13), the axial drive device (2) being used to drive the movable claw (12) to move in a direction x; A pressure detection device (3), the pressure detection device (3) being arranged between the axial drive device (2) and the drive device mounting seat (13) in the direction x for detecting axial pressure, the pressure detection device (3) comprising a strain gauge (31); Features: The connection position between the caliper body bridge portion (11) and the drive device mounting seat (13) is offset in the radial direction along the direction z to the axial pressure force position between the drive device mounting seat (13) and the axial drive device (2); the strain gauge (31) is symmetrically arranged on a plane perpendicular to the direction x, the symmetry center of the strain gauge (31) is directly opposite to the straight line in the direction z in the direction x, and the spacing direction of the symmetrically arranged strain gauges (31) is perpendicular to the direction z.

2. The electronic mechanical brake pressure detection module according to claim 1, characterized in that: The symmetry center of the strain gauge (31) corresponds to the radial center of the axial drive device (2).

3. The electronic mechanical brake pressure detection module according to claim 1, characterized in that: The strain gauge (31) is provided with a varistor, and all the varistor forms a Wheatstone circuit.

4. The electronic mechanical brake pressure detection module according to claim 1, characterized in that: The pressure detection device (3) comprises a base (32), the strain gauge (31) is arranged on a first end surface (321) of the base (32), and a second end surface (322) is provided at one end of the base (32) away from the first end surface (321) for receiving the axial pressure of the axial drive device (2). The pressure detection device (3) further comprises a pressure ring (33) arranged between the base (32) and the drive device mounting seat (13), and the pressure ring (33) is used to transmit the pressure applied by the base (32) to the drive device mounting seat (13).

5. The electronic mechanical brake pressure detection module according to claim 4, characterized in that: An annular mounting groove (131) is provided in the drive device mounting seat (13), a pressure ring (33) is embedded in the annular mounting groove (131) and abuts against an axial end surface of the annular mounting groove (131), and the pressure ring (33) is sleeved on the base (32) for radially limiting the base (32).

6. The electronic mechanical brake pressure detection module according to claim 4, characterized in that: The pressure detection device (3) further comprises a circuit board (34) and a cover body (35); the cover body (35) is disposed on the first end surface (321); the strain gauge (31) and the circuit board (34) are disposed inside the cover body (35); and the strain gauge (31) is electrically connected to the circuit board (34).

7. An electronic mechanical brake pressure detection module according to claim 4, characterized in that: The axial drive device (2) comprises a drive shaft (21), a drive screw (22) and a drive nut (23) that is in transmission cooperation with the drive screw (22); the drive screw (22) is mounted on the drive shaft (21); the drive nut (23) is slidably arranged in a drive device mounting seat (13) along a direction x; a sliding cavity (132) for accommodating the sliding of the drive nut (23) is provided on the drive device mounting seat (13); and the drive nut (23) is connected to the movable claw (12).

8. The electronic mechanical brake pressure detection module according to claim 7, characterized in that: The base (32) is sleeved on the driving shaft (21), the midpoint of the line connecting the symmetrically arranged strain gauges (31) corresponds to the rotation center of the driving shaft (21), the driving shaft (21) is provided with a limiting step (211), and the axial driving device (2) further comprises a thrust bearing (24) axially abutting between the limiting step (211) and the second end surface (322).

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