electromagnetic brake device

Abstract

The electromagnetic brake device comprises: an armature supported so as to be rotatable around an axis of rotation; a yoke having a groove, an inner cylinder portion and an outer cylinder portion, wherein the groove is formed in an annular shape with the axis of rotation as the center, the inner cylinder portion is substantially cylindrical and formed radially inward of the groove, and the outer cylinder portion is substantially cylindrical and formed radially outward of the groove; and a coil disposed in the groove and generating a magnetic force when energized to cause the yoke to attract the armature, wherein a first opposing surface of the armature opposing the yoke comprises a sliding surface that slides with the outer cylinder portion of the yoke; and a recessed portion disposed radially inward of the sliding surface and recessed in a direction away from the yoke, an inner peripheral edge portion of a second opposing surface of the outer cylinder portion opposing the armature and a third opposing surface of the inner cylinder portion opposing the armature are disposed opposite the recessed portion and are in a non-contacting state with the first opposing surface.

Description

Technical Field

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

[0002] In the past, for example, in vehicles such as automobiles, a shifter that can perform the gearshift of a transmission by performing a rotation operation based on a knob has been used. In addition, in the past, in such a shifter, a technology that brakes the rotation of the knob by an electromagnetic brake has been utilized.

[0003] For example, Patent Document 1 below discloses a technique in which the lower surface of an armature that rotates integrally with an operating handle and a rotating shaft is attracted to the end surface of an outer yoke portion of a yoke core by magnetic force generated by a coil, thereby braking the rotation of the operating handle and the rotating shaft.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-160356 Summary of the Invention

[0007] Technical problem to be solved by the invention

[0008] However, the technology of Patent Document 1 poses a risk of burrs forming on the inner peripheral edge of the outer yoke's end surface during cutting. In this case, these burrs come into contact with the armature's lower surface during armature rotation, potentially reducing braking torque and damaging the coating formed on the armature's lower surface, increasing the sliding load during non-energized operation and shortening the endurance life.

[0009] Means for solving technical problems

[0010] An electromagnetic brake device according to one embodiment includes: an armature supported so as to be rotatable about an axis of rotation; a yoke having a groove, an inner cylindrical portion, and an outer cylindrical portion, the groove being formed in an annular shape centered on the rotation axis, the inner cylindrical portion being substantially cylindrical and formed radially inward of the groove, and the outer cylindrical portion being substantially cylindrical and formed radially outward of the groove; and a coil disposed in the groove for generating a magnetic force when energized to attract the armature to the yoke, wherein a first opposing surface of the armature opposing the yoke includes a sliding surface that slides against the outer cylindrical portion of the yoke, and a recessed portion disposed radially inward of the sliding surface and recessed in a direction away from the yoke, an inner peripheral edge portion of a second opposing surface of the outer cylindrical portion of the yoke opposing the armature and a third opposing surface of the inner cylindrical portion of the yoke opposing the armature are disposed opposite the recessed portion of the armature and are in a non-contacting state with the first opposing surface of the armature.

[0011] Effects of the Invention

[0012] According to one embodiment, it is possible to suppress a decrease in braking torque due to burrs on the inner peripheral edge portion and damage to a coating film formed on the lower surface of the armature. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a cross-sectional view showing a cross section parallel to the XZ plane of the electromagnetic brake device according to one embodiment.

[0014] Figure 2 It is enlarged to show Figure 1 FIG. 1 is a partially enlarged cross-sectional view of portion A of the electromagnetic brake device shown. DETAILED DESCRIPTION

[0015] Hereinafter, an embodiment will be described with reference to the accompanying drawings. For convenience, the Z-axis direction (the axial direction of the rotation axis AX) in the drawings is defined as the vertical direction, and the X-axis direction and the Y-axis direction (the direction orthogonal to the axial direction of the rotation axis AX) in the drawings are defined as the horizontal direction.

[0016] (Overview of Electromagnetic Braking Device 100)

[0017] Figure 1 It is a cross-sectional view showing a cross section parallel to the XZ plane of the electromagnetic brake device 100 according to one embodiment. Figure 1 The electromagnetic brake device 100 shown is a device that is provided coaxially with the rotation axis AX of the rotating shaft member 10 and brakes the rotation of the rotating shaft member 10. Figure 1 As shown, the electromagnetic brake device 100 includes a rotating shaft member 10 , an armature 110 , a yoke 120 , and a coil 130 .

[0018] For example, the electromagnetic brake device 100 is used in a shifting device that can shift the gears of a transmission by performing a rotation operation based on an operating handle (not shown). In this case, for example, the electromagnetic brake device 100 is installed on a rotating shaft component 10 that rotates in conjunction with the rotation of the operating handle, and the armature 110 is connected to the rotating shaft component 10 in a manner that can move in the up and down directions (Z-axis direction) and is fixed in the rotation direction. Moreover, the electromagnetic brake device 100 brakes the rotation of the operating handle and the rotating shaft component 10 by using the magnetic force generated by the coil 130 to cause the yoke 120 to attract the armature 110. However, this is not limited to this, and the electromagnetic brake device 100 can be used in any device as long as it has at least a rotating shaft component 10.

[0019] The armature 110 is a disc-shaped component. The armature 110 has a through hole 111 that passes through the armature 110 in the vertical direction (Z-axis direction) with the rotation axis AX as the center. The inner diameter of the through hole 111 is approximately the same size as the outer diameter of the rotation axis component 10. In addition, although not shown in the figure, it has a D-shaped cutout shape extending in the direction of the rotation axis to prevent rotation. Therefore, the armature 110 can move in the vertical direction relative to the rotation axis component 10 and can rotate integrally with the rotation direction. In a state where the rotation axis component 10 is inserted, the armature 110 is supported by the rotation axis component 10 (or other components that rotate integrally with the rotation axis component 10) so as to be rotatable around the axis of rotation AX. As a result, the armature 110 rotates integrally with the rotation axis component 10 with the rotation axis AX as the rotation center.

[0020] The armature 110 has a first facing surface 112 that is circular in plan view and faces the yoke 120. An annular sliding surface 112A is provided on the radially outer portion of the first facing surface 112. The sliding surface 112A faces and contacts a second facing surface 123A of the outer cylindrical portion 123 of the yoke 120. As a result, the sliding surface 112A slides on the second facing surface 123A when the armature 110 rotates.

[0021] A circular recess 112B, recessed in a plan view and directed away from the yoke 120 (in the positive Z-axis direction), is formed on the first opposing surface 112 of the armature 110, radially inward of the sliding surface 112A. This ensures that the portion of the first opposing surface 112 of the armature 110 radially inward of the sliding surface 112A is slightly spaced from the third opposing surface 124A of the inner cylindrical portion 124 of the yoke 120 and does not contact the third opposing surface 124A.

[0022] For example, the armature 110 is formed using a magnetic material (eg, iron) so as to be attracted to the yoke 120 by the magnetic force generated by the coil 130 .

[0023] The yoke 120 is a cylindrical component made of a magnetic material (e.g., iron) and is located below the armature 110. The yoke 120 forms a magnetic circuit extending from the inner and outer cylinders 124 and 123 through the armature 110, attracting the armature 110 using the magnetic force generated by the coil 130. This allows the yoke 120 to brake the rotation of the armature 110.

[0024] The yoke 120 has a circular through-hole 121 centered on the rotation axis AX. The through-hole 121 extends through the yoke 120 in the vertical direction (Z-axis direction). The inner diameter of the through-hole 121 is approximately the same as the outer diameter of the rotating shaft component 10. The rotating shaft component 10, which rotates integrally with the armature 110, is inserted through the through-hole 121. However, the yoke 120 is not fixed to the rotating shaft component 10 and therefore does not rotate integrally with the rotating shaft component 10.

[0025] The yoke 120 also has a groove 122 formed by cutting out a circular, concave notch centered on the rotation axis AX from its upper surface downward (in the negative Z-axis direction). Thus, the yoke 120 has a generally cylindrical outer cylinder portion 123 formed radially outward of the groove 122, and a generally cylindrical inner cylinder portion 124 formed radially inward of the groove 122.

[0026] The yoke 120 is formed by powder metallurgy of sintered metal powder. In the case of powder metallurgy, even bulk metals that are difficult to machine or insoluble materials can be formed into complex shapes with high precision. The height of the Z-direction of the opposing surface of the yoke 120 that faces the armature 110 is formed to be flat (same height). However, the opposing surface of the yoke 120 that faces the armature 110 is divided by the groove 122 into a second opposing surface 123A of the outer cylinder 123 that faces the armature 110 and a third opposing surface 124A of the inner cylinder 124 that faces the armature 110.

[0027] Coil 130 is formed into a cylindrical shape by winding multiple layers of electric wire within groove 122 of yoke 120. When energized, coil 130 generates a magnetic force, which attracts armature 110 to yoke 120. This magnetic force allows electromagnetic brake device 100 to brake the rotation of rotating shaft member 10, which rotates integrally with armature 110. Specifically, electromagnetic brake device 100 can brake the rotation of the operating handle, which rotates in conjunction with the rotation of rotating shaft member 10.

[0028] Figure 2 It is enlarged to show Figure 1 FIG. 1 is a partially enlarged cross-sectional view of a portion A of the electromagnetic brake device 100 .

[0029] like Figure 2As shown, the third opposing surface 124A of the inner cylindrical portion 124 of the yoke 120 faces the recess 112B of the first opposing surface 112 of the armature 110. Consequently, the third opposing surface 124A is separated from the first opposing surface 112 (the inner bottom surface 112Ba of the recess 112B) by a very small predetermined distance (e.g., 0.05 mm), that is, it is in a non-contact state with the first opposing surface 112. Consequently, even if there are variations in the component accuracy (flatness, etc.) of the armature 110, the electromagnetic brake device 100 according to one embodiment does not contact the third opposing surface 124A of the yoke 120 located radially inward. This reduces the rotational load on the armature 110 and prevents a decrease in the attraction force holding the armature 110.

[0030] In addition, if Figure 2 As shown, the sliding surface 112A of the armature 110 faces and contacts the second facing surface 123A of the outer cylindrical portion 123 of the yoke 120. Thus, the sliding surface 112A of the armature 110 slides on the second facing surface 123A as the armature 110 rotates.

[0031] Here, the sliding surface 112A is coated with a polyurethane-based baking varnish. Thus, the electromagnetic brake device 100 of one embodiment can reduce the friction coefficient between the sliding surface 112A and the second opposing surface 123A during non-braking (non-adsorption) and increase the friction coefficient between the sliding surface 112A and the second opposing surface 123A during braking (adsorption).

[0032] In addition, if Figure 2 As shown, the inner peripheral edge portion 123Aa of the second opposing surface 123A of the yoke 120 (the boundary portion of the second opposing surface 123A with the groove 122) is located at a position opposing the recessed portion 112B of the first opposing surface 112 of the armature 110. As a result, the inner peripheral edge portion 123Aa of the second opposing surface 123A is separated from the first opposing surface 112 of the armature 110 (the inner bottom surface 112Ba of the recessed portion 112B), that is, is in a non-contact state with the first opposing surface 112.

[0033] Thus, even if burrs are formed on the inner peripheral edge portion 123Aa of the second opposing surface 123A during machining to achieve a highly flat surface, the first opposing surface 112 will not come into contact with the burrs on the inner peripheral edge portion 123Aa during rotation of the armature 110. Consequently, the electromagnetic brake device 100 of one embodiment can suppress a reduction in braking torque caused by burrs on the inner peripheral edge portion 123Aa and can also suppress damage to the polyurethane paint applied to the sliding surface 112A.

[0034] In addition, if Figure 2As shown, the inner peripheral edge 112Aa of the sliding surface 112A of the armature 110 (the boundary between the sliding surface 112A and the recess 112B) is positioned radially outward of the inner peripheral edge 123Aa of the second opposing surface 123A by a predetermined distance (e.g., 1.0 mm). Consequently, even if machining burrs are formed on the inner peripheral edge 123Aa of the second opposing surface 123A, the electromagnetic brake device 100 according to one embodiment does not contact the burrs on the inner peripheral edge 123Aa during armature 110 rotation. Consequently, the electromagnetic brake device 100 according to one embodiment can suppress the effects of the burrs on the inner peripheral edge 123Aa on the braking torque and can also prevent damage to the polyurethane paint applied to the sliding surface 112A.

[0035] In addition, if Figure 2 As shown, the outer peripheral edge 112Ab of the sliding surface 112A of the armature 110 (the outermost diameter portion of the sliding surface 112A) is located radially inward of the outer peripheral edge 123Ab of the second opposing surface 123A (the outermost diameter portion of the second opposing surface 123A). Consequently, even if machining burrs form on the outer peripheral edge 123Ab of the second opposing surface 123A, the electromagnetic brake device 100 according to one embodiment does not contact the burrs on the outer peripheral edge 123Ab during armature 110 rotation. Consequently, the electromagnetic brake device 100 according to one embodiment can suppress the effects of the burrs on the outer peripheral edge 123Ab on the braking torque and prevent damage to the polyurethane paint applied to the sliding surface 112A.

[0036] In addition, if Figure 2 As shown, the first facing surface 112 of the armature 110 has a step 112C at the boundary between the sliding surface 112A and the inner bottom surface 112Ba of the recess 112B, making the first facing surface 112 of the armature 110 uneven in the height direction. Meanwhile, the second facing surface 123A and the third facing surface 124A of the yoke 120 are formed to be flat in the height direction. Thus, the electromagnetic brake device 100 of one embodiment processes the complex yoke 120 flat, making processing easier than with a step formed in the yoke 120, and enabling the gap between the armature 110 and the yoke 120 to be formed with relatively high precision.

[0037] Thus, in the electromagnetic brake device 100 according to one embodiment, the yoke 120 can be formed into a complex shape, and further, the yoke 120 can be easily subjected to secondary processing.

[0038] As mentioned above, although one embodiment of the present invention has been described in detail, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

[0039] For example, in one embodiment, the recess 112B is set as a continuous circular recess of the same depth, but it can also be divided into an annular recess opposite to the inner peripheral edge portion 123Aa of the second opposing surface 123A and a circular recess opposite to the third opposing surface 124A, and the depths and shapes of each can also be different.

[0040] This international application claims the benefit of priority based on Japanese Patent Application No. 2020-081953, filed on May 7, 2020, the entire contents of which are incorporated herein by reference.

[0041] Description of Reference Numerals

[0042] 10 Rotating axis components

[0043] 100 Electromagnetic brake device

[0044] 110 Armature

[0045] 111 through hole

[0046] 112 first opposing surface

[0047] 112A sliding surface

[0048] 112Aa Inner circumference

[0049] 112Ab peripheral part

[0050] 112B concave part

[0051] 112Ba inner bottom surface

[0052] 112C steps

[0053] 120 yoke

[0054] 121 through hole

[0055] 122 grooves

[0056] 123 outer cylinder part

[0057] 123A Second opposing surface

[0058] 123Aa Inner circumference

[0059] 123Ab peripheral part

[0060] 124 inner cylinder

[0061] 124A Third opposing surface

[0062] 130 Coil

[0063] AX rotary axis

Claims

1. An electromagnetic brake, characterized in that: have: an armature supported so as to be rotatable about a rotation axis; a yoke having a groove, an inner cylindrical portion, and an outer cylindrical portion, wherein the groove is formed in an annular shape centered on the rotation axis, the inner cylindrical portion is substantially cylindrical and formed radially inward of the groove, and the outer cylindrical portion is substantially cylindrical and formed radially outward of the groove; and The coil is disposed in the groove and generates magnetic force when energized, causing the yoke to attract the armature. The first opposing surface of the armature, which is opposed to the yoke, has: a sliding surface that slides with the outer cylindrical portion of the yoke; and a recessed portion that is provided radially inward of the sliding surface and is recessed in a direction away from the yoke. The inner peripheral edge portion of the second facing surface of the outer cylindrical portion of the yoke, which faces the armature, and the third facing surface of the inner cylindrical portion of the yoke, which faces the armature, are arranged facing the recessed portion of the armature and are in a non-contact state with the first facing surface of the armature. An outer peripheral edge portion of the sliding surface in the armature is provided radially inward of an outer peripheral edge portion of the second opposing surface in the yoke.

2. The electromagnetic brake according to claim 1, wherein The first facing surface of the armature has a step at a boundary between the sliding surface and the inner bottom surface of the recessed portion. The second opposing surface and the third opposing surface of the yoke are formed to be flat with respect to each other.

3. The electromagnetic brake according to claim 1 or 2, characterized in that The yoke is formed by powder metallurgy of sintering metal powder.

4. An electromagnetic brake, characterized in that: have: an armature supported so as to be rotatable about a rotation axis; a yoke having a groove, an inner cylindrical portion, and an outer cylindrical portion, wherein the groove is formed in an annular shape centered on the rotation axis, the inner cylindrical portion is substantially cylindrical and formed radially inward of the groove, and the outer cylindrical portion is substantially cylindrical and formed radially outward of the groove; and The coil is disposed in the groove and generates magnetic force when energized, causing the yoke to attract the armature. The first opposing surface of the armature, which is opposed to the yoke, has: a sliding surface that slides with the outer cylindrical portion of the yoke; and a recessed portion that is provided radially inward of the sliding surface and is recessed in a direction away from the yoke. The inner peripheral edge portion of the second facing surface of the outer cylindrical portion of the yoke, which faces the armature, and the third facing surface of the inner cylindrical portion of the yoke, which faces the armature, are arranged facing the recessed portion of the armature and are in a non-contact state with the first facing surface of the armature. At least one of the sliding surface of the armature and the second opposing surface of the yoke is coated with a polyurethane-based baking varnish.

5. The electromagnetic brake according to claim 4, characterized in that The first facing surface of the armature has a step at a boundary between the sliding surface and the inner bottom surface of the recessed portion. The second opposing surface and the third opposing surface of the yoke are formed to be flat with respect to each other.

6. The electromagnetic brake according to claim 4 or 5, characterized in that The yoke is formed by powder metallurgy of sintering metal powder.

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