Electric brake device

Abstract

An electric brake device (1) which converts rotational motion of a rotating part (6) into linear motion of a linear motion part (7) is provided with a sleeve (9) and a biasing part (12) which biases a load sensor (14) toward a caliper (2) which fixes the sleeve (9). The sleeve (9) is provided with a rotation stopping part (10) and a supporting part (11), wherein the rotation stopping part (10) is used for guiding the linear motion of the linear motion part (7) while stopping the rotation of the linear motion part (7) along with the rotation of the rotating part (6), and the supporting part (11) is used for supporting the force applying part (12).

Description

Technical Field

[0001] The present invention relates to an electric braking device. Background Art

[0002] Patent Document 1 discloses a linear actuator having a shaft body that rotates forward and backward by a motor, a nut screwed onto the shaft body, and a piston tube fixed to the nut and advancing and retreating as the shaft body rotates. The piston tube and the nut are connected by a nut adapter, and the nut adapter prevents the piston tube from rotating.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-029190

[0004] In the linear actuator disclosed in Patent Document 1, the nut adapter has a function of preventing the piston tube from rotating, but there is room for improvement in suppressing the manufacturing cost of the linear actuator. Summary of the Invention

[0005] An object of one aspect of the present invention is to manufacture an electric braking device at low cost.

[0006] To solve the above problems, in an electric braking device according to one aspect of the present invention, the rotational motion of an electric motor is transmitted to a rotating portion of a linear motion conversion mechanism through a transmission mechanism. In the linear motion conversion mechanism, the rotational motion of the rotating portion is converted into a linear motion of a linear motion portion of the linear motion conversion mechanism. By pressing a friction member linked to the linear motion of the linear motion portion against a rotating body that rotates with a wheel, a braking force is generated for the wheel. The electric braking device includes: a sleeve disposed between the transmission mechanism and the friction member in the rotational axis direction of the rotating portion and covering the linear motion portion; a housing that houses the linear motion conversion mechanism and the sleeve and fixes the sleeve; a load sensor disposed between the linear motion portion and the housing in the rotational axis direction and detecting a reaction force of a pressing load of the friction member via the rotating portion; and a biasing portion having elasticity and biasing the load sensor toward the housing. The sleeve is configured to have: an anti-rotation portion that prevents the rotation of the linear motion portion accompanying the rotation of the rotating portion while guiding the linear motion of the linear motion portion; and a support portion that supports the biasing portion.

[0007] According to one aspect of the present invention, an electric braking device can be manufactured at low cost. Brief Description of the Drawings

[0008] Figure 1 It is a schematic cross-sectional view showing an outline of an electric braking device according to Embodiment 1 of the present invention.

[0009] Figure 2 It showsFigure 1 Exploded view of the exploded states of components such as the direct-acting conversion mechanism, sleeve, and load sensor included in the electric braking device shown.

[0010] Figure 3 It shows Figure 1 Exploded view of the exploded states of components such as the direct-acting conversion mechanism, sleeve, and load sensor included in the electric braking device shown.

[0011] Figure 4 Schematic cross-sectional view showing the outline of the electric braking device according to Embodiment 2 of the present invention.

[0012] Figure 5 It shows Figure 4 Exploded view of the exploded states of components such as the direct-acting conversion mechanism, sleeve, piston, and load sensor included in the electric braking device shown.

[0013] Figure 6 It shows Figure 4 Exploded view of the exploded states of components such as the direct-acting conversion mechanism, sleeve, piston, and load sensor included in the electric braking device shown. Detailed implementation mode

[0014] (Embodiment 1)

[0015] Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to Figures 1 to 3 . In addition, the direction from the transmission mechanism 4 toward the rotating body 16 is defined as the X-axis direction, the direction from the electric motor 3 toward the rotating portion 6 is defined as the Y-axis direction, and the direction orthogonal to both the X-axis direction and the Y-axis direction is defined as the Z-axis direction. Figure 1

[0016]

[0017] Figures 1 to 3 Figure 1 With reference to Figure 2 , the outline of the electric braking device 1 will be described. Figure 3 Schematic cross-sectional view showing the outline of the electric braking device 1 according to Embodiment 1 of the present invention. Figure 1 And Figure 2 It shows Figure 3 Exploded view of the exploded states of components such as the direct-acting conversion mechanism 5, sleeve 9, and load sensor 14 included in the electric braking device 1 shown. In addition, in And

[0018] , the flange portion 62 is omitted.

[0018] As an example of a device to which the electric braking device 1 is applied, an electromechanical brake called EMB (ElectroMechanical Brake) provided in a vehicle or the like is cited. As Figure 1 shown, the electric braking device 1 includes a caliper 2 (equivalent to a housing), a sleeve 9, a biasing portion 12, and a load sensor 14. In addition, the electric braking device 1 further includes an electric motor 3, a transmission mechanism 4, a linear motion conversion mechanism 5, a piston 8, a thrust bearing 13, a friction member 15, and an ECU (Electronic Control Unit: electronic control unit) not shown.

[0019] <Structure of Electric Motor 3>

[0020] The electric motor 3 is a power source of the electric braking device 1. The electric motor 3 is electrically connected to the ECU and is driven based on the control of the ECU. The electric motor 3 is disposed outside the caliper 2 adjacent to the caliper 2. The electric motor 3 has a rotating shaft 31 provided with a gear 41 meshing with a gear 42. When the electric motor 3 is driven, the rotating shaft 31 rotates, and the rotational motion is transmitted from the gear 41 provided on the rotating shaft 31 to the gear 42.

[0021] <Structure of Transmission Mechanism 4>

[0022] The transmission mechanism 4 is a mechanism that transmits the rotational motion of the electric motor 3 to the rotating portion 6 of the linear motion conversion mechanism 5. The transmission mechanism 4 is disposed outside the caliper 2. The transmission mechanism 4 has gears 41 and 42 that transmit the rotational motion from the electric motor 3. The transmission mechanism 4 transmits the rotational motion of the electric motor 3 to the rotating portion 6 of the linear motion conversion mechanism 5 through the gears 41 and 42. The transmission mechanism 4 has two gears 41 and 42, but may have three or more gears. In addition, the transmission mechanism 4 may be a reduction mechanism that reduces the rotational motion transmitted from the electric motor 3.

[0023] <Structure of Linear Motion Conversion Mechanism 5>

[0024] The linear motion conversion mechanism 5 is a mechanism that converts the rotational motion of the electric motor 3 transmitted from the transmission mechanism 4 into a linear motion. The linear motion conversion mechanism 5 has: a rotating portion 6 to which the rotational motion of the electric motor 3 is transmitted by means of the transmission mechanism 4; and a linear motion portion 7 that converts the rotational motion of the rotating portion 6 into a linear motion and performs linear motion.

[0025] The rotating portion 6 has a rotating shaft portion 61, a flange portion 62, and a threaded portion 63. The rotating shaft portion 61 has the X-axis direction as the rotation axis. In other words, the X-axis direction is the rotation axis direction of the rotating portion 6. The flange portion 62 is provided between an end portion 611 on the friction member 15 side and an end portion 612 on the transmission mechanism 4 side in the rotating shaft portion 61.

[0026] The flange portion 62 extends from the rotating shaft portion 61 toward the outside of the rotating shaft portion 61 in the radial direction of the rotating shaft portion 61. The gear 42 is provided at the end 612 of the rotating shaft portion 61 and meshes with the gear 41. The threaded portion 63 is provided at the end 611 of the rotating shaft portion 61. The threaded portion 63 is formed with an external thread.

[0027] The linear motion portion 7 is formed with a through hole 71 into which the threaded portion 63 of the rotating portion 6 is inserted. Figure 2 as well as Figure 3 As shown, the shape of the direct-acting portion 7 is a substantially cylindrical shape. In the present embodiment, the substantially cylindrical shape includes, for example, a shape in which a portion of the outer circumference or the inner circumference forms a plane, and a shape consisting of two cylindrical portions arranged in the X-axis direction and connected to each other. In the case of the direct-acting portion 7, the shape of the direct-acting portion 7 is a shape in which a portion of the outer circumference forms a plane. The details will be described later.

[0028] The inner peripheral surface of the through hole 71 is formed with an internal thread into which the external thread of the threaded portion 63 is threadedly engaged. The external thread of the threaded portion 63 is threadedly engaged with the internal thread of the linear motion portion 7, so that the rotational motion of the rotating portion 6 is converted into the linear motion of the linear motion portion 7. The threaded portion 63 and the linear motion portion 7 may constitute a ball screw, for example.

[0029] In more detail, if the rotational motion of the electric motor 3 in the first rotational direction is transmitted to the rotating portion 6, the direct-acting portion 7 is directly moved in the positive direction of the X-axis, and if the rotational motion of the electric motor 3 in the second rotational direction opposite to the first rotational direction is transmitted to the rotating portion 6, the direct-acting portion 7 is directly moved in the negative direction of the X-axis. The front end 711 of the friction member 15 side in the direct-acting portion 7 is fixed to the piston 8. The direct-acting portion 7 is, for example, a nut member. In addition, the direct-acting portion 7 and the piston 8 may be integrated with each other.

[0030] <Structure of piston 8>

[0031] The piston 8 is disposed between the linear motion part 7 and the friction member 15 in the X-axis direction, and covers the outer peripheral surface of the first cylindrical part 101. The shape of the piston 8 is cylindrical. The outer diameter of the piston 8 is greater than the inner diameter of the second cylindrical part 102, and the inner diameter of the piston 8 is less than the outer diameter of the second cylindrical part 102.

[0032] The piston 8 is linearly moved in the positive direction of the X-axis by the linear motion part 7, and the piston 8 is linearly moved in the positive direction of the X-axis, and the piston 8 is pressed toward the friction member 15 by the linear motion part 7. In addition, the piston 8 is linearly moved in the negative direction of the X-axis by the linear motion part 7. In this way, the piston 8 is linked to the linear motion of the linear motion part 7. An opening hole 81 is formed in the piston 8, and the threaded part 63, the linear motion part 7, and the first cylindrical part 101 of the sleeve 9 are inserted into the opening hole 81.

[0033] <Structure of Friction Member 15>

[0034] The friction member 15 is a member that presses against a rotating body 16 that rotates together with a wheel H provided in a vehicle to generate a braking force on the wheel H. As the friction member 15, there are a first friction member 151 located on the linear motion conversion mechanism 5 side with respect to the rotating body 16, and a second friction member 152 located on the side opposite to the first friction member 151 with the rotating body 16 interposed therebetween.

[0035] The first friction member 151 is mounted on the piston 8 via a mounting plate A1. The second friction member 152 is mounted on the caliper 2 via a mounting plate A2. The first friction member 151 is linked to the linear motion of the piston 8. In other words, the first friction member 151 is a member that presses against the rotating body 16 by being linked to the linear motion of the linear motion portion 7, thereby generating a braking force on the wheel H.

[0036] If the first friction member 151 moves linearly in the direction toward the rotating body 16, that is, the positive X-axis direction, the rotating body 16 is clamped and pressed by the first friction member 151 and the second friction member 152. If the rotating body 16 is pressed by the first friction member 151 and the second friction member 152, a frictional force is generated between each of the friction members in the first friction member 151 and the second friction member 152 and the rotating body 16. This frictional force acts on the wheel H as a force in the direction opposite to the rotation direction of the rotating body 16. Thereby, a braking force on the wheel H is generated.

[0037] If the pressing load of the friction member 15 is strong, the frictional force on the rotating body 16 becomes strong, and the braking force on the wheel H becomes strong. If the pressing load of the friction member 15 is weak, the frictional force on the rotating body 16 becomes weak, and the braking force on the wheel H becomes weak. On the other hand, if the first friction member 151 moves in the direction away from the rotating body 16, that is, the negative X-axis direction, the pressing of the rotating body 16 by the first friction member 151 and the second friction member 152 is released. Since no frictional force is generated on the rotating body 16, the braking force on the wheel H disappears.

[0038] <Structure of Caliper 2>

[0039] The caliper 2 is provided to straddle the peripheral portion of the rotating body 16 from both sides of the rotating body 16. The caliper 2 houses the linear motion conversion mechanism 5, the piston 8, the sleeve 9, the biasing portion 12, the thrust bearing 13, the load sensor 14, and the friction member 15. The caliper 2 has a cylinder portion 21 that opens on the positive X-axis side.

[0040] A direct-acting conversion mechanism 5, a piston 8, a sleeve 9, a biasing portion 12, a thrust bearing 13, and a load sensor 14 are disposed within an opening formed in the cylinder portion 21. A rotary shaft portion 61 is inserted into a through-hole 22 formed in the cylinder portion 21 and a through-hole 43 formed in the outer wall of the transmission mechanism 4.

[0041] <Structure of the sleeve 9 and the biasing portion 12>

[0042] The sleeve 9 is disposed between the transmission mechanism 4 and the friction member 15 in the X-axis direction and covers the direct-acting portion 7. The sleeve 9 has an anti-rotation portion 10 and a support portion 11 and is fixed to the cylinder portion 21 of the caliper 2. The sleeve 9 is formed by arranging a first cylindrical portion 101 having a cylindrical shape and a second cylindrical portion 102 having a cylindrical shape in the X-axis direction. The anti-rotation portion 10 stops the rotation of the direct-acting portion 7 and guides the linear motion of the direct-acting portion 7 when the rotating portion 6 rotates. In other words, the anti-rotation portion 10 stops the rotation of the direct-acting portion 7 accompanying the rotation of the rotating portion 6 and guides the linear motion of the direct-acting portion 7. The following will be described in detail.

[0043] As Figure 2 and Figure 3 shown, the shape of the anti-rotation portion 10 is a substantially cylindrical shape. More specifically, the anti-rotation portion 10 has a first cylindrical portion 101 and a second cylindrical portion 102 that are arranged and connected in the X-axis direction.

[0044] A through-hole 103 for fitting the direct-acting portion 7 is formed in the first cylindrical portion 101. In other words, the direct-acting portion 7 is fitted to the inner peripheral surface of the first cylindrical portion 101. Planes, namely first planes 721 and 722, formed on a part of the outer peripheral surface of the direct-acting portion 7 are in contact with planes, namely second planes 104 and 105, formed on a part of the inner peripheral surface of the through-hole 103 of the first cylindrical portion 101, respectively.

[0045] The first planes 721 and 722 are in contact with the second planes 104 and 105, respectively, and the direct-acting portion 7 moves linearly in the X-axis direction. A through-hole 106 formed in the second cylindrical portion 102 communicates with the through-hole 103. The inner diameter of the second cylindrical portion 102 is larger than the inner diameter of the first cylindrical portion 101, and the outer diameter of the second cylindrical portion 102 is larger than the outer diameter of the first cylindrical portion 101. As Figure 1 shown, a threaded portion 63 is disposed inside the through-hole 103, and the rotary shaft portion 61, the flange portion 62, the thrust bearing 13, and the load sensor 14 are disposed inside the through-hole 106.

[0046] As described above, the linear motion part 7 is fitted into the through hole 103 formed in the rotation prevention part 10 having a substantially cylindrical shape, and the first planes 721 and 722 formed on a part of the outer peripheral surface of the linear motion part 7 are in contact with the second planes 104 and 105 formed on a part of the inner peripheral surface of the rotation prevention part 10. Thus, the rotation of the linear motion part 7 accompanying the rotation of the rotation part 6 can be prevented by the rotation prevention part 10.

[0047] In addition, the processing of forming the first planes 721 and 722 in the linear motion part 7 and the second planes 104 and 105 in the rotation prevention part 10 is simpler than the processing of forming a convex part in the linear motion part 7 and forming a groove for fitting the convex part in the part into which the linear motion part 7 is fitted. Thus, the electric braking device 1 can be manufactured at low cost.

[0048] Moreover, since the rotation of the linear motion part 7 can be prevented by the rotation prevention part 10, there is no need for the processing of forming a convex part in the linear motion part 7 and forming a groove for fitting the convex part in the part into which the linear motion part 7 is fitted. In addition, there is no need for the processing of forming a convex part in the piston 8 and forming a groove for fitting the convex part in the cylinder part 21. On top of that, there is no need for the processing of forming an external thread in the piston 8 and forming an internal thread for screwing the external thread in the cylinder part 21 with a diameter larger than the diameter of the piston 8 in order to fix the load sensor 14. Since these processes are not required, the electric braking device 1 can be manufactured at low cost.

[0049] In addition, it may be that the second plane 104 is formed on the inner peripheral surface of the through hole 103 and the second plane 105 is not formed. In other words, it may be that one second plane 104 is formed on the inner peripheral surface of the through hole 103. In this case, the first plane 721 is formed on the outer peripheral surface of the linear motion part 7 and the first plane 722 is not formed. In addition, the first cylindrical part 101 and the second cylindrical part 102 may be integrated with each other.

[0050] The support part 11 supports the biasing part 12. The biasing part 12 has elasticity and is provided on the support part 11. The biasing part 12 is, for example, a helical spring. In addition, the biasing part 12 is not limited to a helical spring, and may be, for example, a disc spring. When the biasing part 12 is a helical spring, a plurality of biasing parts 12 are provided on the support part 11. When the biasing part 12 is a disc spring, at least one biasing part 12 is provided on the support part 11. The biasing part 12 biases the flange part 62 toward the cylinder part 21 of the caliper 2, and thus biases the load sensor 14 toward the cylinder part 21.

[0051] The support part 11 is the first step formed on the inner peripheral surface of the rotation prevention part 10. More specifically, as Figure 3As shown, the support portion 11 is a first step formed between the inner peripheral surface of the first cylindrical portion 101 and the inner peripheral surface of the second cylindrical portion 102 by making the inner diameter of the second cylindrical portion 102 larger than the inner diameter of the first cylindrical portion 101. In other words, the support portion 11 is the first step formed between the through-hole 103 and the through-hole 106. The support portion 11 is formed on the side of the transmission mechanism 4 as compared with the first cylindrical portion 101.

[0052] With the above structure, the urging portion 12 can be supported by the first step formed on the inner peripheral surface of the rotation prevention portion 10, and the load sensor 14 can be urged toward the caliper 2. In addition, by connecting the first cylindrical portion 101 and the second cylindrical portion 102, the support portion 11 for supporting the urging portion 12 can be easily formed on the inner peripheral surface of the rotation prevention portion 10.

[0053] In addition, as Figure 1 and Figure 2 shown, a second step ST is formed on the outer peripheral surface of the rotation prevention portion 10. The second step ST formed on the outer peripheral surface of the rotation prevention portion 10 restricts the movement of the piston 8 in the direction toward the transmission mechanism 4 in the X-axis direction. More specifically, as the piston 8 moves linearly in the negative X-axis direction, the end portion 82 of the piston 8 on the side of the transmission mechanism 4 comes into contact with the second step ST. Thereby, the movement of the piston 8 in the direction toward the transmission mechanism 4 is restricted by the second step ST.

[0054] With the second step ST formed on the outer peripheral surface of the rotation prevention portion 10, the sleeve 9 can have the function of restricting the movement of the piston 8 in the direction toward the transmission mechanism 4 in the X-axis direction. By making the shape of the sleeve 9 a shape obtained by arranging the first cylindrical portion 101 and the second cylindrical portion 102 with different diameters, the first step formed on the inner peripheral surface of the sleeve 9 and the second step ST formed on the outer peripheral surface of the sleeve 9 can have different functions.

[0055] Therefore, the sleeve 9 can be made to have three functions: the function of guiding the linear movement of the linear movement portion 7, the function of urging the load sensor 14 toward the caliper 2, and the function of restricting the movement of the piston 8 in the direction toward the transmission mechanism 4 without making the shape of the sleeve 9 complicated. Thereby, the number of components of the electric braking device 1 can be reduced, and the electric braking device 1 can be manufactured at low cost.

[0056] In addition, the second step ST formed on the outer peripheral surface of the rotation prevention portion 10 is a step formed between the outer peripheral surface of the first cylindrical portion 101 and the outer peripheral surface of the second cylindrical portion 102 by making the outer diameter of the first cylindrical portion 101 smaller than the outer diameter of the second cylindrical portion 102. By connecting the first cylindrical portion 101 and the second cylindrical portion 102, it is possible to easily form the second step ST on the outer peripheral surface of the rotation prevention portion 10 that restricts the movement of the piston 8 toward the transmission mechanism 4 side. The length of the first cylindrical portion 101 in the X-axis direction is such that the piston 8 does not fall off from the first cylindrical portion 101 even when the friction member 15 wears.

[0057] <Fixing of the second cylindrical portion 102 to the cylinder portion 21>

[0058] The second cylindrical portion 102 is fixed to the cylinder portion 21 of the caliper 2. More specifically, the second cylindrical portion 102 is fixed to the cylinder portion 21 by fastening a screw that passes through a through hole formed in the bottom portion 211 of the cylinder portion 21 to a threaded hole formed in the end portion 102E on the transmission mechanism 4 side of the second cylindrical portion 102. In addition, the second cylindrical portion 102 can also be fixed to the cylinder portion 21 by fastening a screw that passes through a through hole formed in the end portion 102E to a threaded hole formed in the bottom portion 211.

[0059] As a modification, the second cylindrical portion 102 can also be fixed to the cylinder portion 21 by fastening a screw that passes through a through hole formed in the side portion 212 of the cylinder portion 21 to a threaded hole formed on the outer peripheral surface of the second cylindrical portion 102. In addition, the second cylindrical portion 102 can also be fixed to the cylinder portion 21 by fastening a screw that passes through a through hole formed on the outer peripheral surface of the second cylindrical portion 102 to a threaded hole formed in the side portion 212.

[0060] As another modification, the second cylindrical portion 102 can also be fixed to the cylinder portion 21 by screwing an external thread formed on the outer peripheral surface of the second cylindrical portion 102 with an internal thread formed on the inner peripheral surface of the cylinder portion 21.

[0061] <Structure of the thrust bearing 13 and the load sensor 14>

[0062] The thrust bearing 13 is arranged between the flange portion 62 and the load sensor 14 in the X-axis direction. The load sensor 14 is provided between the linear motion portion 7 and the caliper 2 in the X-axis direction, and detects the reaction force of the pressing load of the friction member 15 via the rotating portion 6. More specifically, the load sensor 14 is provided between the thrust bearing 13 and the cylinder portion 21 in the X-axis direction. As Figure 2 and Figure 3 shown, the load sensor 14 is, for example, an annular load sensor. In addition, the load sensor 14 is not limited to an annular load sensor, and can also be a button-type load sensor.

[0063] <Structure of ECU>

[0064] The ECU is a control unit that controls the electric braking device 1. The ECU includes a processor such as a CPU (Central Processing Unit), and a computer having a memory such as a RAM or a ROM. In addition, the ECU includes a drive circuit for driving the electric motor 3, and an input / output interface for acquiring data of the reaction force of the pressing load detected by the load sensor 14.

[0065] The ECU is disposed outside the caliper 2. The ECU is electrically connected to the electric motor 3 and the load sensor 14. The ECU controls the rotational speed per unit time of the electric motor 3 based on the data of the reaction force of the pressing load detected by the load sensor 14, thereby controlling the braking force applied to the wheel H.

[0066] Based on the above, the sleeve 9 fixed to the caliper 2 has two functions: a function of stopping the rotation of the linear motion portion 7 accompanying the rotation of the rotating portion 6 while guiding the linear motion of the linear motion portion 7, and a function of applying a force to the load sensor 14 toward the caliper 2. Thus, compared with the case where the caliper 2 has the above two functions, the machining of the caliper 2 becomes simple, and the electric braking device 1 can be manufactured at low cost.

[0067] (Embodiment 2)

[0068] Hereinafter, Embodiment 2 of the present invention will be described. In addition, for convenience of explanation, components having the same functions as those described in Embodiment 1 are denoted by the same reference numerals, and their descriptions will not be repeated. Figure 4 is a schematic cross-sectional view showing an outline of the electric braking device 1A according to Embodiment 2 of the present invention. Figure 5 and Figure 6 is a perspective view showing Figure 4 a state in which the components such as the linear motion conversion mechanism 5A, the sleeve 9A, the piston 8A, and the load sensor 14 included in the electric braking device 1A shown are disassembled. In addition, in Figure 5 and Figure 6 the flange portion 62 is omitted.

[0069] As Figure 4 shown, the electric braking device 1A is different from the electric braking device 1 in terms of changing the linear motion conversion mechanism 5 to the linear motion conversion mechanism 5A, changing the piston 8 to the piston 8A, and changing the sleeve 9 to the sleeve 9A.

[0070] <Structure of the linear motion conversion mechanism 5A>

[0071] The direct-acting conversion mechanism 5A is different from the direct-acting conversion mechanism 5 in terms of changing the rotating part 6 to the rotating part 6A and changing the direct-acting part 7 to the pressing part 7A. The rotating part 6A is different from the rotating part 6 in that it has a thread part 63A instead of the thread part 63 and further has a connecting part 64. The connecting part 64 is provided at the end 611 of the rotating shaft part 61. The connecting part 64 connects the rotating shaft part 61 and the thread part 63A. An opening hole 65 is formed in the thread part 63A, and an internal thread is formed on the inner peripheral surface of the opening hole 65. The thread part 63A is, for example, a nut component.

[0072] The pressing part 7A presses the bottom surface of the opening hole 81A formed in the piston 8A against the friction member 15. The pressing part 7A has a thread part 71A and a pressing plate 72A. An external thread that engages with the internal thread of the opening hole 65 is formed on the thread part 71A. By engaging the external thread of the thread part 71A with the internal thread of the opening hole 65, the rotational motion of the rotating part 6A is converted into the linear motion of the pressing part 7A.

[0073] The end 711A of the thread part 71A on the friction member 15 side is fixed to the pressing plate 72A. The pressing plate 72A extends along the YZ plane. The shape of the pressing plate 72A is substantially a circular plate shape. By the pressing part 7A moving linearly in the positive X-axis direction, the pressing plate 72A comes into contact with the bottom surface of the opening hole 81A. As a result, the piston 8A moves linearly in the positive X-axis direction, and the piston 8A is pressed against the friction member 15 by the pressing part 7A.

[0074] <Structure of the piston 8A>

[0075] The piston 8A is different from the piston 8 in terms of changing the opening hole 81 to the opening hole 81A. As Figure 5 and Figure 6 shown, the shape of the piston 8A is substantially a cylindrical shape. The fourth planes 82A and 83A, which are planes formed on a part of the inner peripheral surface of the opening hole 81A, respectively contact the fifth planes 73A and 74A, which are planes formed on a part of the outer peripheral surface of the pressing plate 72A. The direct-acting part in this embodiment is the part having the piston 8A and the pressing part 7A.

[0076] <The sleeve 9A>

[0077] The sleeve 9A is different from the sleeve 9 in terms of changing the anti-rotation part 10 to the anti-rotation part 10A. The anti-rotation part 10A is different from the anti-rotation part 10 in that the first cylindrical part 101 is changed to the first cylindrical part 101A. The shape of the anti-rotation part 10A is substantially a cylindrical shape. The anti-rotation part 10A is fitted into the opening hole 81A formed in the piston 8A. More specifically, the first cylindrical part 101A is fitted into the opening hole 81A.

[0078] When the first cylindrical portion 101A is fitted into the opening hole 81A, the third planes 104A and 105A, which are planes formed on a part of the outer peripheral surface of the first cylindrical portion 101A, respectively contact the fourth planes 82A and 83A, which are planes formed on a part of the inner peripheral surface of the piston 8A. The third planes 104A and 105A respectively contact the fourth planes 82A and 83A, and the fifth planes 73A and 74A respectively contact the fourth planes 82A and 83A, and the pressing portion 7A linearly moves in the X-axis direction.

[0079] According to the above structure, the piston 8A does not rotate relative to the sleeve 9A fixed to the caliper 2, and the pressing portion 7A does not rotate relative to the piston 8A. Thus, by the third planes 104A and 105A respectively contacting the fourth planes 82A and 83A, it is possible to stop the rotation of the piston 8A and the pressing portion 7A accompanying the rotation of the rotating portion 6A.

[0080] In addition, the processing of forming the third planes 104A and 105A in the rotation stopping portion 10A and the fourth planes 82A and 83A in the piston 8A is simpler than the processing of forming a groove in the piston 8A and a convex portion that fits into the groove in a member fitted to the piston 8A. Thus, the electric braking device 1A can be manufactured at low cost.

[0081] Moreover, by using a linear motion portion having a piston 8A with a substantially cylindrical shape and a pressing portion 7A that presses the bottom surface of the opening hole 81A formed in the piston 8A against the friction member 15, it is possible to stop the rotation of the linear motion portion accompanying the rotation of the rotating portion 6A by the rotation stopping portion 10A.

[0082] <Deformation Example>

[0083] In Figure 1 In the electric braking device 1 shown, it may also be that when the first cylindrical portion 101 is fitted into the opening hole 81, two third planes formed on a part of the outer peripheral surface of the first cylindrical portion 101 respectively contact two fourth planes formed on a part of the inner peripheral surface of the piston 8. In this case, the two third planes respectively contact the two fourth planes, and the linear motion portion 7 linearly moves in the X-axis direction.

[0084] In addition, in the deformation example, it may also be that the first planes 721 and 722 are not formed on the outer peripheral surface of the linear motion portion 7, and the second planes 104 and 105 are not formed on the inner peripheral surface of the through hole 103 of the first cylindrical portion 101. In this case, the shapes of the linear motion portion 7 and the first cylindrical portion 101 become cylindrical shapes. Based on the above, a plane is formed on at least a part of either the inner peripheral surface or the outer peripheral surface of the first cylindrical portion 101.

[0085] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Claims

1. An electric braking device, wherein the rotational motion of an electric motor is transmitted to a rotating part of a linear motion conversion mechanism through a transmission mechanism, and in the linear motion conversion mechanism, the rotational motion of the rotating part is converted into a linear motion of a linear motion part of the linear motion conversion mechanism. By pressing a friction member linked to the linear motion of the linear motion part against a rotating body that rotates together with a wheel, a braking force is generated for the wheel. Wherein, It includes: A sleeve, which is arranged between the transmission mechanism and the friction member in the rotational axis direction of the rotating part and covers the linear motion part; A housing, which houses the linear motion conversion mechanism and the sleeve and fixes the sleeve; A load sensor, which is arranged between the linear motion part and the housing in the rotational axis direction and detects the reaction force of the pressing load of the friction member via the rotating part; And A biasing part, which has elasticity and biases the load sensor toward the housing; The sleeve is configured to have: an anti-rotation part, which anti-rotates the rotation of the linear motion part accompanying the rotation of the rotating part while guiding the linear motion of the linear motion part; and a supporting part, which supports the biasing part.

2. The electric braking device according to claim 1, Wherein, The shape of the anti-rotation part is a substantially cylindrical shape; The linear motion part is fitted with the inner peripheral surface of the anti-rotation part; The rotation of the linear motion part is anti-rotated by the contact between a first plane and a second plane. The first plane is a plane formed on a part of the outer peripheral surface of the linear motion part, and the second plane is a plane formed on a part of the inner peripheral surface of the anti-rotation part.

3. The electric braking device according to claim 1, Wherein, The shapes of the anti-rotation part and the linear motion part are substantially cylindrical shapes; The anti-rotation part is fitted with an opening hole formed in the linear motion part; The rotation of the linear motion part is anti-rotated by the contact between a third plane and a fourth plane. The third plane is a plane formed on a part of the outer peripheral surface of the anti-rotation part, and the fourth plane is a plane formed on a part of the inner peripheral surface of the linear motion part.

4. The electric braking device according to any one of claims 1 to 3, Wherein, The sleeve is a shape formed by arranging a first cylindrical part with a cylindrical shape and a second cylindrical part with a cylindrical shape in the rotational axis direction. Among them, both the inner diameter and the outer diameter of the second cylindrical part are larger than those of the first cylindrical part; This electric braking device is provided with a cylindrical piston linked to the linear motion part. The piston is arranged between the linear motion part and the friction member in the rotational axis direction and covers the outer peripheral surface of the first cylindrical part. The outer diameter of the piston is equal to or greater than the inner diameter of the second cylindrical part, and the inner diameter of the piston is equal to or less than the outer diameter of the second cylindrical part; The supporting part is a first step formed between the inner peripheral surface of the first cylindrical part and the inner peripheral surface of the second cylindrical part by making the inner diameter of the second cylindrical part larger than the inner diameter of the first cylindrical part. The movement of the piston in the direction toward the transmission mechanism is restricted by a second step, which is formed between the outer peripheral surface of the first cylindrical portion and the outer peripheral surface of the second cylindrical portion by making the outer diameter of the first cylindrical portion smaller than the outer diameter of the second cylindrical portion.

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