Electromagnetic locking mechanism for electric motors

Abstract

To provide a lock mechanism of an electric motor which can secure safety when supply of electric power is stopped and release the lock in a no power supply state at the electric motor which is applied to an in-wheel motor etc.SOLUTION: A lock mechanism 40 of an electric motor 10, having a main shaft 12, a rotor 22, and a stator 32, includes: a lock plate 26 disposed on the rotor 22 and including an engagement hole 26a; a solenoid 44 disposed at the stator 32 and having a lock piece 46 which is interposed into the engagement hole 26a; biasing means 48 which causes the lock piece 46 to be interposed into the engagement hole 26a when power supply to the solenoid 44 is not in a proper state; and a lock releasing slide pin 52 which pulls out the lock piece 46 from the engagement hole 26a.SELECTED DRAWING: Figure 3

Description

Technical Field

[0004] , , , , ,

[0003]

[0001] The present invention relates to an electric motor, and particularly to an electromagnetic locking mechanism in an electric motor suitable for application to wheels of a vehicle such as an in-wheel motor.

Background Art

[0002] A so-called in-wheel motor having a wheel on its outer periphery is often applied as a compact driving means to moving means such as bicycles and wheelchairs for which relatively light weight is desired. Patent Document 1 discloses an in-wheel motor as an assist device that can be retrofitted to a wheelchair. Specifically, a drive wheel equipped with an in-wheel motor is arranged between existing wheels constituting the wheelchair. A reduction gear and a brake are provided inside the in-wheel motor disclosed in Patent Document 1. Then, rotation and stop are performed based on an operation signal from an operation unit. Further, in an in-wheel motor having such a configuration, a safety device is provided so that even when an operator (such as an assistant) releases their hand from the operation unit or the handle unit of the wheelchair, a runaway of the in-wheel motor can be avoided. When the safety device is activated, the power supply to the in-wheel motor is cut off, and an emergency stop means is configured to operate.

[0003] Certainly, according to such an in-wheel motor with such safety measures, even when the operator releases their hand from the wheelchair on a slope or the like, the wheelchair will not run away and can be stopped. However, the safety measures disclosed in Patent Document 1 are premised on the battery power supply state being good. Therefore, when the battery is depleted and the operating power cannot be supplied, there is a risk that the safety device will not operate.

[0004] Furthermore, as a safety device for in-wheel motors, a park lock device, such as the one disclosed in Patent Document 2, is also known. Since the park lock is a rotation control mechanism that operates by the mechanical rotation of the park cam, it can be operated regardless of the battery's depletion state. However, in the in-wheel motor disclosed in Patent Document 2, both the speed change gear and the park lock are located outside the casing that makes up the motor, making it difficult to miniaturize the overall device. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-150077 [Patent Document 2] Japanese Patent Publication No. 2019-151163 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to provide a locking mechanism for an electric motor, such as an in-wheel motor, that can ensure safety when the power supply is interrupted and can be released in a state of no power supply. [Means for solving the problem]

[0007] The locking mechanism for an electric motor according to the present invention for achieving the above objective is an electric motor locking mechanism having a rotor that is rotatable about the main shaft and disposed inside a casing through which the main shaft protrudes, and a stator that applies rotational force to the rotor, wherein the locking mechanism comprises a lock plate disposed on the rotor and having at least one hole or recess, a locking member disposed on the stator and capable of sliding in a direction along the direction of intervention into the hole or recess, and a solenoid that enables the locking member to be pulled out of the hole or recess by power supply, a first biasing means that causes the locking member to intervene into the hole or recess when the power supply to the solenoid is not in a proper state, and an unlocking slide pin that moves the solenoid along the sliding direction of the locking member and enables the locking member to be pulled out of the hole or recess, wherein a part of the unlocking slide pin is exposed to the outside of the casing.

[0008] Furthermore, in an electric motor locking mechanism having the above-described features, it is preferable to include a reaction force receiver supported by the stator, a second biasing means disposed between the reaction force receiver and the unlocking slide pin, and an operating lever that changes the amount of pressure applied to the unlocking slide pin to extend or retract the second biasing means and move the unlocking slide pin. With these features, the locked state by the locking member can be released simply by operating the operating lever.

[0009] Furthermore, in an electric motor locking mechanism having the above-described features, it is preferable to include a third biasing means that presses the plate surface of the locking plate against the rotor, and the locking plate is supported by the third biasing means relative to the rotor. With these features, even if the locking mechanism is activated when the rotor is rotating at high speed, the frictional force between the locking plate and the rotor will mitigate the impact at the time of locking, thereby preventing damage to internal elements.

[0010] Furthermore, in an electric motor locking mechanism having the above-described features, it is desirable that the locking plate has a hole, the rotor has a recess on the surface facing the locking plate, and that the recess on the rotor has ribs arranged along the radial direction of the rotor, and that the ribs have inclined surfaces facing the recess on the rotor. With these features, even if a locking member interlocked in the locking plate becomes stuck, it is possible to forcibly eject the locking member interlocked in the hole in the locking plate by rotating the rotor with a force greater than the frictional force generated between the rotor and the locking plate. [Effects of the Invention]

[0011] The locking mechanism of the electric motor, having the features described above, ensures safety even if the power supply to the electric motor is interrupted. Furthermore, the lock can be manually released even when there is no power supply. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view showing an electric motor to which the locking mechanism according to the embodiment is applied, fixed to the frame of a mobile body. [Figure 2] This is a perspective view showing the external appearance of an electric motor to which the locking mechanism according to the embodiment is applied. [Figure 3] This is a cross-sectional view of an electric motor to which a locking mechanism according to an embodiment is applied. [Figure 4] This diagram shows a partial cross-section of an electric motor, illustrating the state in which the rotor rotation is locked when the release slide pin, which constitutes the locking mechanism, is pressed in. [Figure 5] This diagram shows a partial cross-section of an electric motor, illustrating the state where the lock release slide pin, which constitutes the locking mechanism, is pulled up, and the rotor is released. [Figure 6]It is a perspective view showing the form of a rotor and a lock plate attached to this rotor. [Figure 7] It is a perspective view showing the configuration of the lock mechanism according to the embodiment. [Figure 8] It is a cross-sectional view for explaining the state in which the rotation of the rotor is locked by the action of the lock mechanism. [Figure 9] It is a cross-sectional view for explaining the state in which the locked state is manually released by the action of the lock mechanism. [Figure 10] It is a cross-sectional view showing the state where the lock piece deeply intervenes in the locking hole of the lock plate and reaches the recess of the rotor mold part. [Figure 11] It is a perspective view for explaining that ribs are provided on the inner circumference of the rotor mold part and the ribs are provided with inclined surfaces. [Figure 12] It is a view for explaining the state of pushing out the lock piece from the engagement hole by the action of the rib.

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the electromagnetic lock mechanism of the electric motor of the present invention will be described in detail with reference to the drawings. Note that the embodiments shown below are an example of a preferred form for implementing the present invention, and as long as the effects are achieved, even if a part of the configuration is changed, it can be regarded as a part of the present invention.

[0014] [Configuration] The electric motor 10 to which the locking mechanism of the electric motor according to this embodiment (hereinafter simply referred to as the locking mechanism 40) is applied is a so-called in-wheel motor used by fixing the main shaft 12 to the frame 70 of a mobile body such as a wheelchair, as shown in Figure 1. The electric motor 10 according to this embodiment is basically composed of a main shaft 12, a casing 14 that makes the main shaft 12 protrude, a rotor 22, and a stator 32, as shown in Figures 2 and 3, and is equipped with the locking mechanism 40. The main shaft 12 is the element that forms the rotation center of the rotor 22, and in this embodiment, it protrudes towards the inner cover 16 side of the casing 14, which will be described in detail later, and is configured to be fixed to the frame.

[0015] The casing 14 is an element that houses a part of the main shaft 12, as well as the rotor 22 and stator 32, which will be described in detail later, and a part of the locking mechanism 40. In this embodiment, it also plays the role of a wheel that constitutes the wheels of the moving body. The specific configuration of the casing 14 is not limited, but since it is an element that rotates, it is preferable to make it cylindrical. In this embodiment, it is basically composed of an inner cover 16, an outer cover 18, and a side wall 20. Here, the inner cover 16, outer cover 18, and side wall 20 can be an integrated or separate unit, but it is preferable to have at least an opening for housing the main shaft 12, rotor 22, stator 32, and locking mechanism 40. In the configuration shown in Figure 1, the inner cover 16 is composed of three members, and the outer cover 18 and side wall 20 are composed as an integrated unit. Specifically, the inner cover 16 is composed of a fixing member 16a, a transmission member 16b, and a sealing member 16c. Here, a bearing 16d is provided between the fixed member 16a and the transmission member 16b, and power is transmitted from the variable gear 30 (details to be described later) to the transmission member 16b, causing the sealing member 16c, the side wall 20 fixed to the sealing member 16c, and the outer cover 18 to rotate. A bearing 18b is also provided between the outer cover 18 and the main shaft 12 via a support member 18a.

[0016] Here, when the casing 14 is used as a wheel, a tire can be provided directly or indirectly via spokes and an outer ring or the like on the outer peripheral side of the cylindrical side wall 20.

[0017] The rotor 22 is an element that is housed inside the casing 14 and rotates about the main shaft 12. The rotor 22 of the present embodiment includes a rotor base 22a supported by the main shaft 12 via a bearing 22c, a rotor molded part 22b supported by the rotor base 22a, and a rotor yoke part 24 (24a, 24b) erected in the thickness direction of the rotor molded part 22b at the outer edge of the rotor molded part 22b. The rotor yoke part 24 is provided with an inner yoke 24a disposed inside the coil 32b that constitutes the stator 32, the details of which will be described later, and an outer yoke 24b disposed outside the coil 32b. Further, in the rotor yoke part 24 according to the embodiment, a plurality of permanent magnets 24c are arranged along the inner peripheral surface formed in a cylindrical shape with respect to the outer yoke 24b. When the permanent magnets 24c receive magnetic force, a rotational force is generated in the rotor 22. In the rotor 22 according to the embodiment, a gear is provided on the outer periphery of the rotor base 22a, and power is transmitted to the transmission gear 30 via this gear.

[0018] Furthermore, the rotor mold portion 22b has an uneven surface formed at least on the plate surface facing the inner cover 16, and a lock plate 26 is positioned between the rotor mold portion 22b and the rotor base portion 22a. The lock plate 26 has a locking hole 26a formed in a position that overlaps with the recess formed in the rotor mold portion 22b (see Figure 6). At least one locking hole 26a is sufficient, and if multiple locking holes 26a are provided as shown in Figure 6, they are formed to be located on the circumference of the same circle. With this configuration, when the lock piece 46 provided at the tip of the iron core 44b of the solenoid 44, which will be described in detail later, intervenes in the locking hole 26a, the rotation of the rotor 22 is forcibly stopped. At this time, the recess formed in the rotor mold portion 22b becomes a relief portion for the tip of the lock piece 46, making it possible to reliably intervene in the locking hole 26a (see Figure 10). The lock plate 26 is positioned between the rotor base 22a and the lock plate 26 via a biasing means 28 (third biasing means) such as a wave washer, and is fixed in place by the frictional force pressing its plate surface against the rotor mold portion 22b. Therefore, if the lock piece 46 intervenes in the locking hole 26a while the rotor 22 is rotating at high speed, the rotor mold portion 22b and the lock plate 26 will shift relative to each other, mitigating the impact due to inertial force and preventing damage to the internal components. A friction plate may also be provided between the lock plate 26 and the rotor mold portion 22b to adjust the frictional force. In this embodiment, the part of the lock plate 26 into which the lock piece 46 intervenes is described as a "hole" called the locking hole 26a, but it may also be a recess as long as the lock piece 46 can intervene.

[0019] The variable speed gear 30 is located inside the rotor 22 and is an element that converts the rotational speed and torque of the power generated by the rotor 22 and transmits them to the casing 14. In the electric motor 10 according to this embodiment, it is positioned on the stator 32 (stator base 32a) fixed to the main shaft 12 via a bearing 32c and is configured to mesh with both a gear provided on the outer circumference of the rotor base 22a and a gear provided on the inner circumference of the transmission member 16b that constitutes the inner cover 16. With this configuration, when the rotor 22 rotates, its rotational speed and torque are converted according to the gear ratio of the variable speed gear 30 and transmitted to the casing 14, causing the casing 14 to rotate. It is preferable to arrange multiple variable speed gears (for example, three) at equal intervals inside the rotor 22, so that the rotor base 22a functions as a sun gear and the transmission member 16b as an internal gear, thus functioning as a planetary gear. In this configuration, the stator 32 takes on the role of a planetary carrier.

[0020] The stator 32 is fixed relative to the rotor 22 and is an element that generates rotational force on the rotor 22. In this embodiment, it is basically composed of a stator base 32a fixed to the main shaft 12 and a cylindrical coil 32b arranged on the outer edge side of the stator base 32a. In the case of the electric motor 10 according to this embodiment, the stator base 32a is provided with a through hole for inserting the speed change gear 30 and the unlocking slide pin 52 which constitutes the lock mechanism 40 described in detail later. The cylindrical coil 32b is positioned to intervene between the inner yoke 24a and the outer yoke 24b that constitute the rotor 22, and the magnetic force generated by supplying power to the coil 32b makes it possible to rotate the rotor 22.

[0021] In the electric motor 10 according to this embodiment, which has the basic configuration described above, the fixing member 16a constituting the inner cover 16 is provided with a through hole to expose a part of the unlocking slide pin 52 constituting the locking mechanism 40 to the outside of the casing 14.

[0022] The locking mechanism 40 is an element for forcibly stopping the rotation of the rotor 22. In this embodiment, as shown in detail in Figures 7 to 9, it is basically composed of a locking actuation unit 42 and a lock release unit 50. The locking actuation unit 42 is basically composed of a solenoid 44, a locking piece 46, and a biasing means 48 (first biasing means). The solenoid 44 consists of a solenoid body 44a and an iron core 44b that slides along a recess (cylinder) provided in the solenoid body 44a. In a solenoid 44 with this configuration, when power is supplied to the solenoid 44, the iron core 44b is pulled into the solenoid body 44a.

[0023] The lock piece 46 is fixed to the tip of the iron core 44b and is an element that intervenes in the locking hole 26a formed in the lock plate 26 when the iron core 44b is pulled out from the solenoid body 44a. The biasing means 48 is positioned between the solenoid body 44a and the lock piece 46 and generates a force in the direction that pulls the iron core 44b out from the solenoid body 44a. With this configuration, when power is supplied to the solenoid 44, the magnetic force generated in the solenoid body 44a pulls in the iron core 44b, maintaining the state in which the lock piece 46 is lifted out of the engagement hole 26a, i.e., the lock is released. On the other hand, if the power supply to the solenoid 44 is interrupted, or if insufficient power is supplied to operate the solenoid 44, or if the power supply is not in a proper state, the biasing force of the biasing means 48 becomes stronger than the force of the solenoid body 44a pulling in the iron core 44b, causing the iron core 44b to be pulled out from the solenoid body 44a. As a result, the lock piece 46 intervenes in the locking hole 26a, and the rotation of the rotor 22 is forcibly stopped.

[0024] The iron core 44b and the lock piece 46 are fixed together via an engagement pin 46a. The engagement pin 46a is intercepted by an elongated hole 60a provided in the unlock slider 60, which will be described in detail later, and its range of movement is restricted. Therefore, the sliding width of the iron core 44b (the transition width from the protruding state to the retracted state) is restricted by the length of the elongated hole 60a.

[0025] The unlocking section 50 is an element for manually releasing a locked state that occurs when the power supply to the solenoid 44 is interrupted or when insufficient power is supplied for operation. In this embodiment, it is basically composed of an unlocking slide pin 52, a reaction force receiver 54, a biasing means 56 (second biasing means), an operating lever 58, an unlocking slider 60, and a connecting pin 62. The unlocking slide pin 52 is an element for pulling up the unlocking slider 60, and a part of it is exposed to the outside of the casing 14 via a fixing member 16a, and it is configured so that the unlocking slide pin 52 can be slid in the thickness direction of the casing 14 (rotor 22) by operation from outside the casing 14.

[0026] The reaction force receiver 54 is the basic element that receives the biasing force when the unlocking slide pin 52 is actuated via the biasing means 48. The specific configuration of the reaction force receiver 54 is not limited, but it is fixed to a part of the stator 32 or to the main shaft 12. In this embodiment, as shown in detail in Figure 2, a cylinder 54a is provided to intervene a part of the unlocking slide pin 52. This is because the operation can be stabilized by sliding the unlocking slide pin 52 using the cylinder 54a as a guide (Note that the cylinder is omitted in Figures 8 and 9 for simplification).

[0027] The biasing means 56 is an element that pushes back the unlocking slide pin 52 (increasing the portion that protrudes from the casing 14) with respect to the reaction force receiver 54. In this embodiment, it is positioned between the reaction force receiver 54 and the stepped portion of the unlocking slide pin 52, and deforms in the compression direction when the unlocking slide pin 52 is pushed in, and extends to push back the unlocking slide pin 52 when the pressure on the unlocking slide pin 52 is released.

[0028] The operating lever 58 is an element for controlling the sliding position of the unlocking slide pin 52. The operating lever 58, shown in detail in Figures 8 and 9, consists of a cam portion 58a that contacts the rear end of the unlocking slide pin 52 and a lever portion 58b. The cam portion 58a can be rotated around the rotation axis 58c by operating the lever portion 58b. The cam portion 58a has two pressing portions at different distances from the rotation axis. In the example shown in Figures 8 and 9, when the lever portion 58b is in a position parallel to the main shaft 12 (the position shown in Figures 5 and 9), the unlocking slide pin 52 is pushed back, and when the lever portion 58b is in a position perpendicular to the main shaft 12 (the position shown in Figures 4 and 8), the unlocking slide pin 52 is pushed in.

[0029] The unlock slider 60 is connected to the unlock slide pin 52 via a connecting pin 62 and is an element for pulling back (lifting up) the iron core 44b, which has become protruding from the solenoid body 44a (pulled out by the biasing means 48) due to the operation of the unlock slide pin 52, towards the solenoid body 44a. The iron core 44b is engaged with the unlock slider 60 via an engagement pin 46a whose range of movement is restricted by an elongated hole 60a. When the iron core 44b is in the protruding state, the engagement pin 46a is located at the lower end of the elongated hole 60a.

[0030] Therefore, the biasing means 56 operates in such a way that the unlocking slide pin 52 is pulled up, causing the unlocking slider 60 to pull up the iron core 44b. Thus, the biasing force of the biasing means 56 that pulls up the unlocking slide pin 52 is configured to be stronger than the biasing force of the biasing means 48 that causes the iron core 44b to protrude.

[0031] Here, the arrangement of the locking actuation part 42 and the lock release part 50 in the locking mechanism 40 is such that it satisfies the following three conditions. Firstly, as shown in Figures 4 and 8, when the lock release slide pin 52 is pushed in and the iron core 44b is pulled into the solenoid body 44a, the lock piece 46 does not intervene in the locking hole 26a of the lock plate 26. Secondly, when the lock release slide pin 52 is pushed in and the iron core 44b is pulled out from the solenoid body 44a, the lock piece 46 intervene in the locking hole 26a of the lock plate 26. Thirdly, as shown in Figures 5 and 9, when the lock release slide pin 52 is pushed back, the lock release slider 60 pushes (pulls up) the iron core 44b toward the solenoid body 44a, so that the lock piece 46 does not intervene in the locking hole 26a of the lock plate 26.

[0032] In this embodiment, as shown in Figure 7, a plastic magnet 52a is provided on the unlocking slide pin 52, and a Hall element sensor 54b is placed on the reaction force receiver 54, so that it is possible to detect whether the unlocking slide pin 52 is in the pushed-in position or the pushed-out position.

[0033] [Effects / Effects] In an electric motor 10 with this configuration, the operating lever 58 is usually set to a position perpendicular to the main shaft 12 (hereinafter also referred to as position A), as shown in Figures 4 and 8. In this state, if the power supply from the battery (not shown) is interrupted, or if sufficient power is not supplied for operation, the pressing force from the biasing means 48 becomes stronger than the pulling force from the solenoid body 44a on the iron core 44b, causing the iron core 44b to protrude from the solenoid body 44a. When the iron core 44b is pulled out from the solenoid body 44a, the lock piece 46 provided at its tip intervenes in the locking hole 26a of the lock plate 26, forcibly stopping the rotation of the rotor 22. This makes it possible to avoid situations where a mobile object such as a wheelchair unexpectedly runs out of control (for example, rolling down a slope on its own due to gravity) even if the power supply from the battery is interrupted on a slope.

[0034] Furthermore, if the power supply from the battery is interrupted, causing the iron core 44b to protrude from the solenoid body 44a and forcibly stopping the rotation of the rotor 22, the operating lever 58 is rotated to a position parallel to the main shaft 12 (hereinafter also referred to as position B), as shown in Figures 5 and 9, after confirming the safety of the operation, thereby pulling up the unlocking slide pin 52. When the unlocking slide pin 52 is pulled up, the iron core 44b, which is linked to the unlocking slide pin 52 via the unlocking slider 60, is also pulled up.

[0035] In this way, by pulling up the release slide pin 52, the iron core 44b constituting the solenoid 44 can be raised, thereby releasing the forced stop of the rotor 22 even if the power supply to the solenoid 44 is interrupted. As a result, even if the power supply from the battery is interrupted, it becomes possible to manually release the lock and move the moving object, thus avoiding situations where the object is forced to stand still.

[0036] Therefore, by providing the locking mechanism 40 described above, safety can be ensured when the power supply to the electric motor 10 is stopped, and the locked state can be released even when there is no power supply.

[0037] [Application Forms] Furthermore, in the electric motor 10 equipped with the locking mechanism 40 according to the above embodiment, as shown in Figure 11, a rib 22b1 can be provided in the recess of the rotor mold portion 22b, along the radial direction of the rotor 22. When a rib 22b1 is provided in the rotor mold portion 22b in this manner, it is preferable to make the side surface of the rib 22b1 an inclined surface.

[0038] As described above, when the rotation of the rotor 22 is forcibly stopped by the locking mechanism 40, the manual release of this locked state is achieved by the biasing force of the biasing means 56, which pulls up the release slide pin 52. However, as shown in Figure 10, if the lock piece 46 is deeply engaged in the locking hole 26a and pressed against the opening cross section of the locking hole 26a, the frictional force generated between the opening cross section and the lock piece 46 may exceed the biasing force of the biasing means 56. In such a situation, the locked state will not be released by simply operating the operating lever 58.

[0039] As described above, in this embodiment, the rotor mold portion 22b and the lock plate 26 are supported by frictional force. Therefore, by applying a rotational force to the rotor 22 such that a force stronger than the frictional force between them is applied (by rotating the casing 14 and thus the rotor 22 by rotating the wheels of the moving body, etc.), a relative displacement occurs between the lock plate 26 and the rotor mold portion 22b, as shown in Figure 12.

[0040] Specifically, as shown in Figure 12(A), when the rotor mold portion 22b slides relative to the lock plate 26 in the direction indicated by arrow A, the rib 22b1 formed in the recess contacts the lock piece 46 protruding towards the recess through the locking hole 26a (see Figure 12(B)). From this state, if the rotor mold portion 22b is further moved relative to the lock plate 26 in the direction of arrow A, as shown in Figure 12(C), the side surface of the lock piece 46 intercepted in the locking hole 26a contacts the side surface of the rib 22b1, and the iron core 44b is pushed up in the direction of arrow B. This action makes it easier for the lock piece 46 to come out of the locking hole 26a, and it becomes possible to pull it out with the biasing force of the biasing means 56. [Explanation of Symbols]

[0041] 10…Electric motor, 12…Main shaft, 14…Casing, 16…Inner cover, 16a…Fixing member, 16b…Transmission member, 16c…Sealing member, 16d…Bearing, 18…Outer cover, 18a…Support member, 18b…Bearing, 20…Side wall, 22…Rotor, 22a…Rotor base, 22b…Rotor mold part, 22b1…Rib, 22c…Bearing, 24…Rotor yoke part, 24a…Inner yoke, 24b…Outer yoke, 24c…Permanent magnet, 26…Lock plate, 26a…Locking hole, 28…Biasing means, 30…Speed ​​change gear, 32…Stator, 32a ………Stator base, 32b………Coil, 32c………Bearing, 40………Locking mechanism, 42………Locking actuation part, 44………Solenoid, 44a………Solenoid body, 44b………Iron core, 46………Locking piece, 46a………Engaging pin, 48………Biasing means, 50………Release part, 52………Release slide pin, 52a………Plastic magnet, 54………Reaction force receiver, 54a………Cylinder, 54b………Hall element sensor, 56………Biasing means, 58………Operating lever, 58a………Cam part, 58b…Lever part, 58c……Rotating shaft, 60………Release slider, 60a………Slotted hole, 62………Connecting pin, 70………Frame.

Claims

1. A locking mechanism for an electric motor having a rotor positioned inside a casing through which the main spindle protrudes and which is rotatable about the main spindle, and a stator that applies rotational force to the rotor, A locking plate disposed on the rotor and having at least one hole or recess, A solenoid is provided which is arranged on the stator and includes a locking member that is slidable in a direction along the direction of intervention into the hole or recess, and which can be pulled out of the hole or recess by power supply, A first biasing means for intervening the locking member into the hole or recess when the power supply to the solenoid is not in an appropriate state, The system includes a release slide pin that moves the solenoid along the sliding direction of the locking member, allowing the locking member to be pulled out of the hole or recess, A locking mechanism for an electric motor, characterized in that a portion of the aforementioned unlocking slide pin is exposed to the outside of the casing.

2. The reaction force receiver supported by the stator, A second biasing means is disposed between the reaction force receiver and the unlocking slide pin, The locking mechanism for an electric motor according to claim 1, further comprising an operating lever for moving the release slide pin by changing the amount of pressure applied to the release slide pin to extend or retract the second biasing means.

3. The locking mechanism for an electric motor according to claim 1 or 2, further comprising a third biasing means for pressing the plate surface of the lock plate against the rotor, wherein the lock plate is supported by the third biasing means relative to the rotor.

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