Vibration device and vibration system

Abstract

A vibration device (100) has a leaf spring member (180) that is made of a single piece of elastic material and biases a moving core (160) in a direction that separates the moving core from a stator core (150). The leaf spring member (180) is a component corresponding to a diaphragm of a horn. The natural frequency of the vibration device (100) caused by vibration of the leaf spring member (180) and the moving core (160) is in a range 10-200 Hz. The natural frequency is a desirable frequency for vibrating a vibrated member as the vibration device (100). The vibration device (100) achieves the natural frequency that is favorable for the vibration device (100) by employing technology of the horn.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to vibration devices and vibration systems. A vibration system using a vibration device of the present disclosure is useful, e.g., in a haptic device for alerting occupants of a vehicle.BACKGROUND

[0002] For example, Patent Literature 1 discloses a vibration device that uses a leaf spring and a coil to vibrate a moving core. A horn for vehicles is also known in Patent Literature 2 and the like. Furthermore, Patent Literature 2 discloses a vibration device using a solenoid.PRIOR ART LITERATUREPATENT LITERATURE

[0003] Patent Literature 1 JP2009-33864A Patent Literature 2 JP2011-248183A Patent Literature 3 WO2023-188870A SUMMARY

[0004] The vibration device disclosed in Patent Literature 1 has a greater number of components and has a smaller vibration intensity than the horn disclosed in Patent Literature 2. It is an object of the present disclosure to make it possible to apply horn technology to designing phase and manufacturing phase of the vibration devices for use in haptic devices and the like. It is an object to provide a vibration device in which a housing for the horn and a housing for the vibration device are commonly used, or a common manufacturing line may manufacture both the horn and the vibration device.

[0005] However, the horn is not the vibration device but an alarm, and its purpose is to emit an alarm sound. On the other hand, in the case of the vibration device used in the haptic device or the like, it is not necessary for the device to generate sound, and rather, in many cases, it is required that the device not generate sound. Furthermore, in the case of a horn, it is necessary to vibrate at a frequency required for the alarm sound, and the vibration frequency of the horn does not coincide with the vibration frequency required for the vibration device used in the haptic device or the like. The vibration device shown in Patent Literature 3 uses a structure similar to that of the horn but is not designed to vibrate at a natural frequency suitable for the vibration device.

[0006] In view of the above, the present disclosure makes it possible to apply horn technology to vibration devices within a possible range, while taking into consideration differences and similarities between the horns and the vibration devices. In particular, it makes it possible to vibrate the vibration device at a natural frequency desired for the vibration device at a stage applying the horn technology to the vibration device.

[0007] A vibration device disclosed herein comprises: a housing made of a magnetic material having a bottom portion in a circular plate shape and a side portion in a cylindrical shape integrally continuing from the bottom portion, an end of the side portion being open; a coil in a ring shape disposed on the bottom portion of the housing and excited in response to energization; a stator core made of a magnetic material arranged on the bottom portion of the housing and in an inner circumference of the coil; and a moving core made of a magnetic material and arranged inside the housing to face the stator core. The stator core and the moving core form a magnetic circuit between them in response to energization of the coil. The above structure is also used in horns. The vibration device of the present disclosure has a structure that may share a component with horns.

[0008] The vibration device disclosed herein further comprises: a leaf spring member having an outer circumferential portion fixed to an open end of the side portion of the housing, an inner circumferential portion fixed to the moving core, and a connecting portion connecting the inner circumferential portion and the outer circumferential portion, the leaf spring member being formed from a single plate of elastic material and biasing the moving core in a direction to separate from the stator core. The leaf spring member is a component corresponding to a diaphragm of horns.

[0009] The leaf spring member of the present disclosure enables the moving core to vibrate in response to energization of the coil. In addition, the vibration device of the present disclosure has the natural frequency of 10 Hz or more to 200 Hz or less, which is caused by vibration of the leaf spring member and the moving core. The natural frequency of 10 Hz or more to 200 Hz or less is a desirable frequency for the vibrating device to vibrate a vibrated member. The device achieves the natural frequency that is favorable for the vibration device by employing a technology of the horns.

[0010] The leaf spring member of the vibration device in another aspect of the present disclosure has a plurality of connecting portions, and gap portions are formed between the connecting portions. This reduces the rigidity of the plate itself, and reduces the natural frequency compared to a flat plate formed with no gap portion. This is a desirable structure for setting the natural frequency of the vibration device to be 10 Hz or more to 200 Hz or less.

[0011] In another disclosure of the present disclosure, the plurality of connecting portions of the leaf spring member of the vibration device are bent between an outer periphery and an inner periphery, thereby improving the rigidity of the connecting portions themselves compared to connecting portions formed with no bent portions. This makes the natural frequency different from that of a flat plate formed with no bent portions. This structure is also desirable for setting the natural frequency of the vibration device to be 10 Hz or more to 200 Hz or less.

[0012] In another aspect of the present disclosure, an outer periphery of the leaf spring member of the vibration device is formed by bending into an annular wall portion extending toward a side opposite to the housing. This structure also makes the natural frequency different from that of a leaf spring member formed with no annular wall portion. This is a desirable structure for setting the natural frequency of the vibration device to be 10 Hz or more to 200 Hz or less.

[0013] Yet another aspect of the present disclosure is a vibration system that uses a vibration device. This vibration system includes a control device that switches between energization and de-energization of the coil. The vibration device may more appropriately control vibrations by using with the control device. This is useful as a system for controlling vibrations in the haptic device or the like.BRIEF DESCRIPTION OF DRAWINGS

[0014] FIG. 1 is a cross-sectional view of an embodiment of a vibration device of the present disclosure. FIG. 2 is a plan view of the vibration device shown in FIG. 1. FIG. 3 is a plan view showing a housing and a coil of the vibration device shown in FIG. 1. FIG. 4 is a diagram showing an example of an arrangement of vibration devices. FIG. 5 is a diagram showing another example of an arrangement of vibration devices. FIG. 6 is a circuit diagram showing a potential circuit of the vibration device shown in FIG. 1. FIG. 7 is a diagram explaining on / off state of a switch of the vibration device shown in FIG. 1. FIG. 8 is a diagram explaining an assembly process of the vibration device shown in FIG. 1. FIG. 9 is a cross-sectional view showing a horn as a comparative example. FIG. 10 is a cross-sectional view of another embodiment of a vibration device of the present disclosure. FIG. 11 is a diagram explaining a vibration state (strong) of the vibration device shown in FIG. 10. FIG. 12 is a diagram explaining a vibration state (soft) of the vibration device shown in FIG. 10. FIG. 13 is a plan view of a vibration device showing another embodiment of a flat spring member. FIG. 14 is a plan view of a vibration device showing yet another embodiment of a flat spring member. FIG. 15 is a plan view of a vibration device showing still another embodiment of a flat spring member. FIG. 16 is a plan view of a vibration device showing yet still another embodiment of a flat spring member. FIG. 17 is a cross-sectional view showing another horn as a comparative example. FIG. 18 is a diagram explaining a transfer function of a resonator member. FIG. 19 is a diagram showing measurement results of desirable natural frequencies. DETAILED DESCRIPTION

[0015] A vibration device 100 of the present disclosure is described with reference to FIG. 1 to FIG. 3. The vibration device 100 is used in the haptic device, and as shown in FIG. 4, a plurality of devices are arranged on, e.g., a seat surface 201 or a back surface 202 of a seat 200 of an automobile. As shown in FIG. 5, the vibration device 100 is also disposed in a seat 203 of a so-called saddle-ride vehicle such as a motorcycle, a snowmobile, or a buggy. In the case of a saddle-ride vehicle seat, a single vibration device 100 may be located in the seat 203.

[0016] The vibration device 100 may be used to transmit information, e.g., failure to fasten a seat belt or warning of predicted danger to a passenger by vibration. A vibration information from the vibration device 100 is information that the passenger can feel directly. Furthermore, since this information is different from normal signal information such as visual or auditory information, it is a particularly useful means of transmitting information as predicted danger information. For example, if a sensor (not shown) detects a possibility of a collision, the vibration device 100 may be vibrated. In an example in which a plurality of vibration devices 100 are arranged in, such as a seat 200 of an automobile, a specific vibration device 100 is selected to vibrate, so that the passenger can be notified of a dangerous direction.

[0017] Regarding an attaching method of the vibration device 100 to the seat 200 of an automobile or the seat 203 of a saddle-ride vehicle, the vibration device 100 may be supported to a portion which is not a rigid body such as a frame in the seat 200 or 203. A storage cavity 205 is formed in a flexible portion such as the seat surface 201 of the seat 200 or 203. That is, the vibration device 100 is supported by fitting it into a storage cavity 205. In this manner, the vibration device 100 is merely positioned and not fixed. According to this, the vibration of the vibration device 100 is transmitted to a flexible vibrated member, and a function of the haptic device is effectively demonstrated.

[0018] However, a combination of the vibration plate and the vibrated member is not limited to being supported in the storage cavity 205. For example, it is possible to support it to the seat 200 or 203 to the frame by means of screws or the like. However, even in the case of screw fastening, a supporting is such that vibration of the vibration device 100 is enabled. In this disclosure, a fixing method that inhibits vibration of the vibration device 100 is referred to as a rigidly coupled manner, but a supporting method for the vibration device 100 is not referred to as the rigidly coupled manner. That is, if the vibration device 100 is attached to a frame of a vehicle body by a screw, the vibration device 100 is positioned in a non-rigidly coupled manner and is pressed by the seat 200 or 203.

[0019] A symbol 120 denotes a housing that is a bottomed multistage cylindrical shape having a small cylindrical portion 121 and a large cylindrical portion 125. A diameter of the large cylindrical portion 125 is about 70 millimeters. A reference symbol 122 denotes a small diameter bottom portion, and a reference symbol 126 denotes a large diameter bottom portion. A reference symbol 130 denotes a bobbin made of an insulating resin material, which is disposed in the small cylindrical portion 121 of the housing 120. The bobbin 130 is wound with a coil 140 by winding an enamel-coated copper wire in many times. FIG. 3 is a plan view after removing a leaf spring member 180 from FIG. 2. As shown in FIG. 3, a flange portion 131 in a circular plate shape is integrally formed with the bobbin 130. Furthermore, a first arm 132 and a second arm 133 extend outward from the flange portion 131. The flange portion 131 is fixed to the large diameter bottom portion 126 of the housing 120 by the first arm 132 and the second arm 133.

[0020] The first arm 132 and the second arm 133 are provided with a first energization terminal 1321 and a second energization terminal 1331, respectively, one of which is electrically connected to a positive terminal 141 and the other of which is electrically connected to the housing 120. The positive terminal 141 is shown in FIG. 2. The positive terminal 141 is electrically connected to the copper wire that constitutes the coil 140 via a second conductive terminal 1331. The negative terminal of a copper wire that constitutes the coil 140 is electrically connected to the housing 120 via a first conductive terminal 1321 and provides an earth connection to the vehicle via the housing 120. However, the negative terminal of the coil 140 may be electrically connected to the negative terminal of the vehicle battery 210 via an electric wire, instead of being connected to an earth. The vehicle battery 210 is shown in FIG. 6.

[0021] A stator core 150 made of iron material is arranged on an inner periphery of the bobbin 130. The stator core 150 is exposed from a hole 123 formed in the small diameter bottom portion 122 of the housing 120. More specifically, the stator core 150 is fixed to the inner periphery of the hole 123. As a fixing method, the stator core 150 may be fitted into the hole 123 and fixed by deforming a portion (crimping or seaming), or the stator core 150 may be screwed into the hole 123. A threaded portion 151 is formed on an outer periphery of the stator core 150, and a nut 152 is screwed thereon.

[0022] A moving core 160 is disposed to face the stator core 150 with a magnetic gap therebetween. A size of the magnetic gap varies depending on a magnitude of vibration required for the vibration device 100. This is also true for horns, so there are cases where the magnetic gap of the vibration device 100 is larger than the magnetic gap of the horn, but the reverse is also true. The moving core 160 is also made of iron material. The moving core 160 has a cylindrical shape and has a flange portion 162.

[0023] A leaf spring member 180 in a circular plate shape is disposed on a surface of the moving core 160 on a side opposite to the stator core 150. The leaf spring member 180 is made of stainless steel, which is a magnetic material, and an outer peripheral portion 181 is fixed to an open end 127 of the large cylindrical portion 125 of the housing 120 by curl seaming. The outer peripheral portion 181 is formed into a cup shape by draw pressing. Therefore, an annular wall portion 1812 is formed to bent material toward a side opposite to the housing 120 from the tightening portion 1811. An inner peripheral portion 182 of the leaf spring member 180 is coupled by deformation to an assembly protrusion 163 formed on an end of the moving core 160. The leaf spring member 180 biases the moving core 160 in a direction that pulls the moving core 160 away from the stator core 150.

[0024] As shown in FIG. 2, the leaf spring member 180 has four connecting portions 183 that connect the inner peripheral portion 182 and the outer peripheral portion 181 and are formed radially from the center point. More specifically, the connecting portion 183 connects between the wall portion 1812 of the outer peripheral portion 181 and the inner peripheral portion 182. Four gap portions 184 are formed between the four connecting portions 183. In other words, the connecting portions 183 are also divided into four portions by forming the gap portions 184 at four locations. In this example, the plurality of connecting portions 183 of the leaf spring member 180 are shaped in a point symmetry with respect to a center point. In other word, the leaf spring member 180 has a plurality of connecting portions 183 arranged in a point symmetry with respect to a center point. The center point is on the central axis. The leaf spring member 180 has a shape that is a point symmetry about the central axis. As a result, even if the connecting portions 183 are elastically deformed, the deformation does not produce a component in a direction that rotates the leaf spring member 180. The leaf spring member 180 has a role of guiding the moving core 160 as it reciprocates within the housing 120, but since no rotational movement component occurs in the leaf spring member 180, the moving core 160 can always reciprocate along its axis. That is, the moving core 160 is effectively prevented from tilting or rolling. Since the reciprocating motion of the moving core 160 is the vibration source of the vibration device 100, this stabilizes the behavior of the vibration device 100.

[0025] A rigidity of the leaf spring member 180 made of a single plate member may be reduced by providing at least one gap portion 184. As described below, the horn 10 also has a diaphragm 18 made of a single plate member, but the natural frequency of the diaphragm 18 of the horn 10 is set to in a range of 350-500 Hz. The natural frequency may be reduced even if the same material as the diaphragm 18 of the horn 10 is used by providing the gap portion 184.

[0026] On the other hand, the connecting portion 183 is bent in the up-down direction in FIG. 1 between the outer peripheral portion 181 and the inner peripheral portion 182 to form a bent portion 1831. The rigidity of the leaf spring component 180 is increased by forming the connecting portion 183 in a shape forming a bent portion 1831 comparing with a flat plate. A reduction in the rigidity due to the above-mentioned gap portion 184 is compensated for by the bent portion 1831. The bent portion 1831 is formed by draw pressing, similarly to the formation of the wall portion 1812 described above. Furthermore, due to the formation of the wall portion 1812 described above, the natural frequency of the leaf spring component 180 is different from that of a flat plate that does not have the wall portion 1812.

[0027] Next, operation of a vibration system 300 including the vibration device 100 having the above-described structure is described. In the vibration system 300, the coil 140 of the vibration device 100 is supplied with power from the vehicle battery 210. This power supply is controlled by the control device 220 shown in FIG. 6. That is, the vibration system 300 is a system that controls the energization of the vibration device 100 to vibrate it. In the vibration system 300, it is only necessary to be able to control the energization to the vibration device 100, and instead of the vehicle battery 210, a transformer such as an inverter may be used. Furthermore, if a generator such as an alternator that charges the vehicle battery 210 is used, the vehicle receives power from the generator if the generator is generating electricity.

[0028] The control device 220 does not necessarily have to be a device dedicated to the vibration device 100. For example, a part of the functions of the engine ECU may be implemented by the control device 220. If the engine ECU is used, the control device 220 is disposed in an engine compartment of an automobile or below the seat 203 of a saddle-ride vehicle. In the example of FIG. 6, the control device 220 itself controls the power supply from the vehicle battery 210, but in many examples, the power supply from the vehicle battery 210 to the vibration device 100 is switched by a switching element such as a relay or a semiconductor switch. In that case, the control device 220 sends a control signal to that switch element.

[0029] The control device 220 supplies a square wave of, e.g., about 50-100 Hz with the duty ratio controlled. For example, as shown in FIG. 7, if one turn is 20 milliseconds, the control device 220 performs an energization for 6 milliseconds and a de-energization for 14 milliseconds, resulting in a 30% energization. This vibration mode 221 with 30% current is continued for 100 milliseconds. Thereafter, a non-vibration mode 222 in which the coil 140 is not energized continues for 100 milliseconds.

[0030] In the example of FIG. 7, the vibration mode 221 and the non-vibration mode 222 are alternately performed. If the vibration device 100 is used as the haptic device, the vibration mode 221 and the non-vibration mode 222 are alternately switched during a period when it is necessary to alert the occupant based on a signal from a sensor or the like.

[0031] The example of FIG. 7 is an example of vibration generated by the vibration device 100. The control device 220 may set a vibration magnitude and a vibration varying pattern of the vibration device 100 with a large degree of freedom. In FIG. 7, the duty ratio is set to 30 percent, but 30 percent is just an example. The duty ratio may be smaller or larger. Furthermore, a length of one turn is not limited to 20 milliseconds for performing a duty ratio control. A time period for one turn may be less than 20 milliseconds.

[0032] Also, a vibration pattern may be changed by changing lengths of the vibration mode 221 and the non-vibration mode 222, or only the vibration mode 221 may be continued. The vibration mode is not limited to the example shown in FIG. 7, and a plurality of vibration varying patterns may be provided, and these may be repeated. Furthermore, a plurality of types of vibration varying patterns may be generated randomly.

[0033] If the coil 140 is energized, the coil 140 is excited and a magnetic circuit is created around the coil 140. In this example, the housing 120, the stator core 150, the moving core 160 and the leaf spring member 180 form a magnetic circuit. In this magnetic circuit, since a magnetic gap is formed between the moving core 160 and the stator core 150, that moving core 160 is attracted to the stator core 150.

[0034] The leaf spring member 180 works as means for restricting the movement of the moving core 160 during this period. If the moving core 160 moves towards the stator core 150, the leaf spring member 180 is elastically deformed, and an elastic force generated by the elastic deformation urges the moving core 160 in a direction of pulling it back from the stator core 150. In this example, even if the moving core 160 is displaced toward the stator core 150, the moving core 160 and the stator core 150 are prevented from colliding with each other. Specifically, the magnetic force of the coil 140 is adjusted to control the attraction force of the moving core 160. More specifically, a time for which an attraction force is applied is controlled by adjusting a time for which a current is applied to the coil 140 through duty ratio control.

[0035] If the vibration device 100 is used as the haptic device, a vibration with the natural frequency in a range of about 10 Hz or more to 200 Hz or less is easily detectable by an occupant. In this specification, a range of 10 Hz or more to 200 Hz may be referred to as "a range of 10-200 Hz". In addition, since a square wave in a range of about 10-200 Hz is a frequency corresponding to low-pitched sounds, for example, if the vibration device 100 is attached to the seat 200 of an automobile and is vibrated in conjunction with a speaker, it is also possible to generate vibrations in the seat 200 that correspond to low-pitched sounds. However, using it simultaneously with a speaker is just one example of its use, and the haptic device is mainly used as attracting attention of the occupant.

[0036] However, the frequency in the range of 10-200 Hz is not controlled by the control device 220. That is, the natural frequency of the vibration device 100 is different from a frequency of the control signal from the control device. First, the natural frequency of the vibration device 100 is described. The natural frequency of the vibration device 100 may depend on many factors including an attraction force generated in the magnetic gap between the moving core 160 and the stator core 150 by energizing the coil 140, and a spring force of the leaf spring member 180 that resists the attraction force. Since the outer peripheral portion 181 of the leaf spring member 180 is fixed to the housing 120 by curl seaming, a rigidity determined by the material, plate thickness, shape, etc. of the housing 120 also relates to the natural frequency. Furthermore, since the housing 120 is supported by the vibrated member such as the seat 200 or 203 in a non-rigidly coupled manner, the supporting manner may also affect the natural frequency. Finally, the vibration of the vibration device 100 in a state in which the vibration device 100 is supported on the vibrated member creates the natural frequency, and the natural frequency is transmitted as a vibration to the occupant. Vibrations transmitted to an occupant are most easily sensed by the occupant, if the natural frequency is in the range of 10-200 Hz. In a sensitivity of an occupant, the occupant may be more likely to sense a vibration in a range of 50-150 Hz that is narrower than the range of 10-200 Hz as a notification signal. The most desirable frequency for the notification signal is in a range of 80-100 Hz.

[0037] FIG. 19 shows measurement results showing a relationship between evaluation levels of a sensed degree by the occupant and the natural frequency. The result depends on a sensitivity evaluation by the human, the level "A" indicates very clearly sensed vibration to the back or thighs of the occupant. The level "B" is lower than the level "A", but the level "B" indicates a level in which a vibration is sufficiently sensed as a signal. The level "C" indicates a level in which the occupant can still sense a vibration as a signal. The level "D" indicates a level in which the occupant cannot sense a signal.

[0038] Next, in this example, the control signal in the control device 220 is a square wave in a range of 50-100 Hz that may suit for a duty ratio control. As described above, if the duty ratio is 30% in the case of 50 Hz, the control device energizes for 6 milliseconds and deenergizes for 14 milliseconds. This does not vibrate the moving core 160 for 6 milliseconds and 14 milliseconds, but rather controls an amount of current flowing to the coil 140. In the above example, the vibration mode 221 lasts for 100 milliseconds and the non-vibration mode 222 lasts for 100 milliseconds.

[0039] After entering the vibration mode 221, the vibration device 100 starts vibrating, and the vibration has the above-mentioned natural frequency, which is in a range of 10-200 Hz in this example. The vibration at the natural frequency of the vibration device 100 continues during the vibration mode 221 and continues until the vibration of the vibration device 100 is attenuated and disappears even after entering into the non-vibration mode 222.

[0040] As a more specific example, it has the vibration mode 221 with a duty ratio of 100% at 100 Hz square wave continues for 10 milliseconds, and the non-vibration mode 222 with a duty ratio of 0% continues for 990 milliseconds. In this case, the coil 140 is excited once per second, and causes the vibration device 100 to vibrate. The vibration of the vibration device 100 at this time is the natural frequency. The vibration of the vibration device 100 starts with a large vibration and gradually attenuates. The vibration of the vibration device 100, whether it is a large vibration at the start of vibration or a small vibration after damping, is the natural frequency.

[0041] In this example, the moving core 160 is attracted to a side of the stator core 150 only once per second, and thereafter vibrates at the natural frequency of the leaf spring member 180. As described above, since the leaf spring member 180 is formed with the gap portion 184, a shape of the gap portion 184 is adjusted to regulate an elastic coefficient of the leaf spring member 180 to vibrate the vibration device 100 at a range of 10-200 Hz. Furthermore, the natural frequency of the vibration device 100 may be adjusted by providing a bent portion 1831 on the connecting portion 183 or by providing a wall portion 1812 on the outer peripheral portion 181.

[0042] In FIG. 6, a reference numeral 225 denotes a magnetic sensor which detects excitation of the coil 140. The magnetic sensor 225 is formed of, e.g., a Hall element, and feeds back the excitation of the coil 140 to the control device 220. The control device 220 is also provided with a switch 226, and the vibration device 100 may be stopped by turning off the switch 226, as necessary. However, the magnetic sensor 225 and the switch 226 may be eliminated if necessary.

[0043] The vibration device 100 of the present disclosure may share a common configuration with the horn 10 of an automobile. As a comparative example, the horn 10 is shown in FIGS. 9 and 17, in which a horn housing 12, a horn coil 14 and a horn stator core 15 are the same as the housing 120, the coil 140 and the stator core 150 of the present disclosure. That is, the vibration device 100 of the present disclosure is designed to use common component with the horn 10 in terms of the housing 120, the coil 140, and the stator core 150. FIG. 9 shows a flat horn that has a resonator member 19 having a flat plate shape. FIG. 17 shows a trumpet horn that has a resonator member 20 having a spiral shape. In either type of horns 10, the horn housing 12, the horn coil 14, the horn stator core 15 and the horn moving core 16 are similar.

[0044] Due to a difference in the magnetic gap, the amplitude of the moving core 160 of the vibration device 100 of this embodiment is greater than the amplitude of the horn moving core 16. However, the size of the magnetic gap of the vibration device 100 is not always larger than that of the horn 10. The size of the magnetic gap is set depending on an intended use of the vibration device 100 and the horn 10. In an example in which the magnetic gap of the vibration device 100 is larger than that of the horn 10, the weight of the moving core 160 of the vibration device 100 may be made heavier than the weight of the horn moving core 16. This makes it possible to increase the vibration component required for the vibration device 100.

[0045] On the other hand, there are following differences between the vibration device 100 and the horn 10 of the present disclosure. The vibration device 100 of the present disclosure is stored in a storage cavity 205 of the seat 200 or 203. That is, the vibration device 100 is placed on a flexible member such as a seat 200 and vibrates the vibrated member. In contrast, the horn 10 has a mounting stay 11 fixed to a horn housing 12. The mounting stay 11 is then attached to a rigid portion of the vehicle. For example, it is fixed to the frame of the vehicle at a front of the vehicle in a rigidly coupled manner.

[0046] A major difference between the vibration device 100 and the horn 10 is the leaf spring member 180. In the case of the horn 10, the leaf spring member 180 is not used, but the diaphragm 18 in a circular plate shape is used. The horn 10 uses the diaphragm 18 to generate an audible warning sound. On the other hand, the vibration device 100 is required to be operated quietly, the leaf spring member 180 is designed to hardly generate any noise even when it vibrates. For example, the rigidity of the leaf spring member 180 is adjusted by adjusting a size or a shape of the gap portion 184 so that a vibration does not reach a level like an alarm sound. In this way, the leaf spring member 180 is a member that corresponds to the diaphragm 18, but the sound generating functions are different, since the leaf spring member 180 is a member that suppresses sound generation while the diaphragm 18 is a member that actively generates sound.

[0047] As described above, the horn 10 has the diaphragm 18 made of a single plate member. In contrast, the vibration device 100 is also formed from a single plate material, but the gap portion 184 is formed in the plate spring member 180 to reduce the rigidity. Therefore, the horn 10 has the natural frequency of the diaphragm 18 in a range of 350-500 Hz, but the natural frequency of the leaf spring member 180 in the vibration device 100 is set lower than that. This allows the vibration of the vibration device 100 to be in the range of 10-200 Hz. Shapes corresponding to the wall portion 1812 and the bent portion 1831 of the vibration device 100 are also used in the horn 10 of FIGS. 9 and 17. By devising a shape for this purpose, the natural frequency of the vibration device 100 is set to be in the range of 10-200 Hz. On the other hand, the horn 10 has a similar shape but with a unique vibration frequency of 350 Hz or more.

[0048] In the horn 10, the horn moving core 16 collides with the horn stator core 15 when the horn coil 14 is excited or de-excited, thereby generating an alarm sound. In contrast, the moving core 160 does not collide with the stator core 150 in the vibration device 100. One of the reasons for making the air gap between the moving core 160 and the stator core 150 larger is to prevent this collision.

[0049] In the above example, the moving core 160 is heavier and has a larger amplitude than the horn moving core 16. Furthermore, collision with the stator core 150 is also avoided. The shape of the gap portion 184 is determined so as to achieve this behavior. The shapes of the gap portions 184 are designed as described above, therefore, the leaf spring member 180 has a shape of a point-symmetric arrangement that can avoid tilting of the moving core 160.

[0050] Furthermore, although the horn 10 includes the resonator member 19 having a flat plate shape and the resonator member 20 having a spiral shape that vibrate together with the diaphragm 18, a resonance plate or a resonance member may not be a component of the vibration device 100 of the present disclosure. This is because the vibration device 100 is not required to generate noise, but rather is required to be quiet. In the horn 10, the resonator member 19 causes a multiple harmonic resonance. As shown in FIG. 18, the multiple harmonic resonance refers to a phenomenon in which a resonant component resonates with a vibration component that is an integer multiple of a fundamental frequency f0, thereby increasing the sound pressure level. The multiple harmonic resonance is related to resonance member functions of the resonator member 19 having a flat plate shape and the spiral shape resonance member 20. In contrast, the vibration device 100 does not include the resonator member 19 having a flat plate shape or the spiral shape resonance member 20, and therefore vibrates only at the natural frequency of the leaf spring member 180. That is, the vibration device 100 does not actively utilize the multiple harmonic resonance. Therefore, in this disclosure, no multiple harmonic resonance means that the multiple harmonic resonance is not actively utilized.

[0051] Although the vibration device 100 does not include the resonator member 19 having a flat plate shape or the spiral shape resonance member 20, it is possible to dispose a cover 190 for protecting the leaf spring member 180. The cover 190 is described in another embodiment shown in FIG. 10. In the embodiment of FIG. 1, the cover 190 is not used, it is because the device is designed so as to be the leaf spring member 180 does not come into direct contact with the vibrated member by taking an arrangement position of the vibration device 100 into consideration.

[0052] As described above, in the vibration device 100, the excitation and de-excitation of the coil 140 is controlled by the control device 220 disposed outside the vibration device 100. It is also possible to use a control device in the horn 10. However, in the comparative example shown in FIG. 9, the fixed contact 22 is attached to the horn housing 12, and the movable contact is attached to the horn moving core 16. If the horn moving core 16 moves due to energization, the movable contact separates from the fixed contact 22. If it is energized in response to separation, the movable contact is pressed against the fixed contact 22 by the spring force. Then, if the movable contact comes into contact with the fixed contact 22, an energization begins again. The horn coil 14 is repeatedly energized and de-energized so that the horn 10 generates sound by repeating such an operation. The first arm 132 described above is utilized to mount the movable contact, when used with the horn 10.

[0053] The vibration device 100 of the present disclosure is designed to share a component with the horn 10, and therefore it is possible to share the same manufacturing line with the horn 10. Next, a method of assembling the vibration device 100 is described with reference to FIG. 8, while also referring to a method of assembling the horn 10. The housing 120, the stator core 150, and the coil 140 are assembled in the housing assembling process S100. The housing assembling process S100 is the same for both the vibration device 100 and the horn 10.

[0054] Next, insulation of the coil 140 is ensured by a sealing process S103. This sealing process S103 may also be performed in common by the vibration device 100 and the horn 10. Next, a moving core assembling process S104 is performed. The moving core 160 is fixed to the inner peripheral portion 182 of the leaf spring member 180. In the case of the horn 10, the horn moving core 16 and the resonator member 19 having a flat plate shape are fixed to the inner periphery of the diaphragm 18. The manufacturing lines may share the moving core assembly process S104.

[0055] Next, an outer periphery assembling process S105 is performed in which the outer peripheral portion 181 of the leaf spring member 180 is fixed to the housing 120. This outer periphery assembling process S105 may also be performed on the manufacturing lines for the horn 10 and the vibration device 100. Next, the nut 152 is screwed onto the threaded portion 151 formed on the outer periphery of the stator core 150. An assembling process S106 is performed in which the stator core 150 is fixed to the small diameter bottom portion 122 of the housing 120 by the screw. In the case of the horn 10, the mounting stay 11 is fixed with a stop screw 15. This process may be also sheared in the manufacturing line for the vibration device 100 and in the manufacturing line for the horn 10.

[0056] Next, a printing process S107 is performed to print some texts on a product. Then an electrical inspecting process S108 is performed to inspect electrical properties such as a disconnection or resistance. Next, a performance inspecting process S109 is performed whether the product actually generates vibration. Since the processes are common, it is possible to share the manufacturing line processes.

[0057] Next, another embodiment of the vibration device 100 is described with reference to FIG. 10. In this example, the housing 120 has a cylindrical shape, with no distinction between a small diameter portion and a large diameter portion. The outer diameter of the housing 120 is illustrated in a reduced manner. In the embodiment of FIG. 10, the stator core 150 is integrally formed with the bottom portion of the housing 120. Moreover, the bobbin 130 and the housing 120 are fixed together by adhesion rather than by using rivets. However, rivets may also be used, and press fitting or secondary molding may also be used.

[0058] In the embodiment of FIG. 10, the cover 190 is also shown. The cover 190 may be made of metal or resin. If it is made of metal, it is fixed together with the leaf spring member 180 to the open end 127 of the housing 120 by curl seaming. Even if it is made of metal, since the cover 190 does not form a magnetic circuit, it does not have to be made of a magnetic material. If it is made of resin, the cover 190 is fixed to the open end 127 of the housing 120 by adhesive. The leaf spring member 180 may be prevented from contacting the seat surface 201 and the like by using the cover 190, even if the vibration device 100 is incorporated into the seat 200 as the haptic device. This ensures the reciprocating movement of the leaf spring member 180 and the moving core 160 and stabilizes the behavior of the vibration device 100.

[0059] It is also possible to change an amplitude of the moving core 160 by changing the voltage applied to the coil 140. In FIG. 11, the amplitude is exaggerated, the amplitude of the moving core 160 is increased by applying a large voltage. Conversely, if the voltage applied to the coil 140 is reduced, it is also possible to reduce the amplitude of the moving core 160 as shown in FIG. 12. Therefore, the voltage applied to the coil 140 can be adjusted not only in the embodiment of FIG. 10 but also in the above-mentioned embodiments. The voltage applied to the coil 140 is controlled by the control device 220.

[0060] In the embodiment shown in FIG. 2, the number of connecting portions 183 is four, but the number of connecting portions 183 may be set appropriately. As shown in FIGS. 13 to 16, the number and shape of the connecting portions 183 may be changed. In the example of FIG. 13, three connecting portions 183 are provided, and the gap portions 184 are fan shape. In the example of FIG. 14 and FIG. 15, there are five connecting portions 183. The gap portion 184 may be formed in an oval-shape as shown in FIG. 14. The gap portion 184 may be formed in a trapezoidal shape as shown in FIG. 15. The number of connecting portions 183 may be ten, and the gap portion 184 is formed in a trapezoidal shape as shown in FIG. 16.

[0061] FIGS. 13 to 16 are all plan views, but the basic cross-sectional shape is the same as that of FIG. 1. That is, the wall portion 1812 is formed on the outer peripheral portion 181 of the leaf spring member 180, and the bent portion 1831 is formed on the connecting portion 183. However, the rigidity of the leaf spring member 180 also changes depending on shapes of the connecting portions 183 and the gap portions 184. Therefore, shapes of the wall portion 1812 and the bent portion 1831 are each finely adjusted so that desired value of the natural frequency of the vibration device 100 is obtained.

[0062] Only the positive terminal 141 is shown on an outside in the example of FIG. 2. A connector 145 is shown on an outside in the examples of FIGS. 13 to 16. A positive power source and a negative power source from the vehicle battery 210 or the like are supplied to the connector 145. The important point is not the number of connecting portions 183 or the shape of gap portions 184, but the fact that connecting portions 183 are arranged radially and point-symmetrically from the center point. This prevents the moving core 160 from tilting if the moving core 160 moves back and forth.

[0063] In the embodiment of FIG. 13, the area of the gap portion 184 is relatively larger, therefore there is a possibility that the magnetic circuit is saturated at the connecting portion 183 when the coil 140 is excited. However, even in this case, the magnetic circuit is formed by passing through the gap portion 184. Therefore, making the leaf spring member 180 by a magnetic material is a desirable design to form a magnetic circuit, but non-magnetic materials such as stainless steel or resin materials may also be used. In that case, a magnetic flux may jump from the housing 120 to the moving core 160, and although the magnetic efficiency may be decreased, it may still be possible to function as the vibration device 100.

[0064] In the above-described embodiment, the moving core 160 is prevented from coming into contact with the stator core 150 by adjusting the air gap between the moving core 160 and the stator core 150, by adjusting the applied voltage and application time of the coil 140, and by adjusting the elastic coefficient of the leaf spring member 180. This is a desirable embodiment for making the vibration device 100 operate quietly. However, it is also possible to design the moving core 160 so as to be tolerant of contact with the stator core 150 to some extent. In this case, it is desirable to form a coating on both or either one of the moving core 160 and the stator core 150 to suppress the collision noise between the moving core 160 and the stator core 150.

[0065] In the above embodiment, the gap portions 184 are formed between the connecting portions 183 of the leaf spring member 180. This is a desirable embodiment in terms of adjusting the rigidity of the leaf spring member 180 and suppressing the generation of sound due to the leaf spring member 180. Furthermore, in order to prevent the generation of a rotational component when the connecting portion 183 is elastically deformed, the shape of the gap portion 184 may be devised, and in that sense, this is also a desirable embodiment. However, the gap portion 184 may be made smaller or eliminated by adjusting the material and thickness of the leaf spring member 180. Even if the vibration device 100 does not have the gap portion184, it is possible to vibrate the vibration device 100 at the natural frequency in a range of 10-200 Hz. Even if a shape does not have the gap portion 184, it is possible to suppress a generation of sound to some extent.

[0066] Furthermore, in the above embodiment, a shape of the leaf spring member 180 is devised so that the moving core 160 reciprocates correctly along the axis if the leaf spring member 180 is elastically deformed. This is a desirable embodiment since it is possible to suppress tilting and rolling of the moving core 160. However, depending on the tolerance of the manufacturing process, etc., some tilt of the moving core 160 is enabled. In the present disclosure, the leaf spring member 180 is designed to generate no rotational component around a center point when the connecting portions 183 are elastically deformed. However, the leaf spring member 180 may generate unavoidable rotation. It should be understood that this no rotational component means the leaf spring member 180 may permit unavoidable rotational component around a center point.

[0067] It should be noted that the above is a preferred example of the present disclosure, and it is desirable for the vibration device 100 of the present disclosure to share a component with the horn 10. However, for example, as in the embodiment shown in FIG. 10, the vibration device 100 may be designed independently from the horn 10. In this case, there are no components shared with the horn 10, but knowledge of the horn 10 may be used in designing the vibration device 100. Therefore, a something that the vibration device 100 of the present disclosure can shear with the horn includes not limited to shearing a shape of a specific component, but also shearing an idea of a designing concept or designing knowledge.

[0068] Furthermore, in the present disclosure, the manufacturing line for the vibration device 100 can be shared with the manufacturing line for the horn 10, which makes it possible to reduce production costs. This is a desirable example of the use of the present disclosure. However, depending on the destination and other factors, it is possible to produce only the vibration device 100. Even in a manufacturing line for the vibration device 100 only, it is possible to utilize knowledge from the manufacturing line for the horn 10. To reiterate just to avoid any doubt, even if a dedicated manufacturing line is uses for the vibration device 100, it is possible to use techniques for assembly, inspection, etc. that can also be used in the manufacturing line for the horn 10. Furthermore, the materials and sizes described in the above examples are merely examples of the present disclosure and may be replaced with other materials, etc. For example, the housing 120, the stator core 150, and the moving core 160 may be made of any magnetic material, it is possible to use material other than iron.

[0069] Moreover, a desirable application of the vibration device 100 of the present disclosure is as the haptic device for alerting the occupant in an automobile or a saddle-ride vehicle. In particular, in vehicles, haptic devices that can alert occupants without appealing to their sense of sight may become increasingly important in the future. However, the use of the vibration device 100 is not necessarily limited to vehicles. It may be used as a device for generating vibrations in various vibrated members.(Disclosure of Technical Idea)

[0070] This description discloses multiple technical ideas described in multiple sections listed below. Some sections may be written in a multiple dependent form, where a subsequent section refers to preceding sections selectively. In addition, some sections may be described in a multiple dependent form referring to another multiple dependent form.

[0071] These sections written in the multiple dependent form define multiple technical ideas.

[0072] (Technical Idea 1) a housing made of a magnetic material having a bottom portion in a circular plate shape and a side portion in a cylindrical shape integrally continuing from the bottom portion, an end of the side portion being open; a coil in a ring shape disposed on the bottom of the housing and excited in response to energization; a stator core made of a magnetic material arranged on the bottom portion of the housing and in an inner circumference of the coil; a moving core made of a magnetic material and arranged inside the housing to face the stator core; and a leaf spring member having an outer circumferential portion fixed to an open end of the side portion of the housing, an inner circumferential portion fixed to the moving core, and a connecting portion connecting the inner circumferential portion and the outer circumferential portion, the leaf spring member being formed from a single plate of elastic material and biasing the moving core in a direction to separate from the stator core, wherein the stator core and the moving core forms a magnetic circuit between them in response to energization of the coil, and wherein the leaf spring member enables the moving core to vibrate in response to energization of the coil, and wherein a natural frequency of the vibration device caused by vibration of the leaf spring member and the moving core is in a range of 10 Hz or more to 200 Hz or less. (Technical Idea 2)

[0073] The vibration device according to Technical Idea 1, wherein the leaf spring member has a plurality of connecting portions to form gap portions between the connecting portions, thereby reducing a rigidity and reducing a natural frequency compared to a leaf spring member having no gap portion.(Technical Idea 3)

[0074] The vibration device according to Technical Idea 2, wherein each of the plurality of connecting portions of the leaf spring member has a bent portion between the outer circumferential portion and the inner circumferential portion, the bent portion improving a rigidity compared to a connecting portion with no bent portion and providing the natural frequency different from a connecting portion with no bent portion.(Technical Idea 4)

[0075] The vibration device according to Technical Idea 2 or 3, wherein the plurality of connecting portions of the leaf spring member are shaped in a point symmetry with respect to a center point, and wherein the leaf spring member generates no rotational component around a center point when the connecting portions are elastically deformed.(Technical Idea 5)

[0076] The vibration device according to any one of Technical Ideas 1-4, wherein an outer periphery of the leaf spring member is formed by bending into an annular wall portion extending toward a side opposite to the housing to provide the natural frequency which is different from a leaf spring member formed with no annular wall portion.(Technical Idea 6)

[0077] The vibration device according to any one of Technical Ideas 1-5, wherein no resonator member is provided on the leaf spring member at a side opposite to the bottom portion of the housing (120), and wherein only the natural frequency of the leaf spring member is used, and no multiple harmonic resonance exists.(Technical Idea 7)

[0078] The vibration device according to any one of Technical Ideas 1-6, wherein a natural frequency of the vibration device caused by vibration of the leaf spring member and the moving core is in a range of 10 Hz or more to 200 Hz or less,(Technical Idea 8)

[0079] The vibration device according to any one of Technical Ideas 1-7, wherein the housing and the vibrated member are coupled in a non-rigidly coupled manner, and the housing is supported so as to be vibrated relative to the vibrated member.(Technical Idea 9)

[0080] The vibration device according to Technical Idea 8, wherein the vibrated member in which the housing is disposed is a seat of a vehicle, and a storage cavity for supporting the vibration device is provided in the seat, and the housing is stored in the storage cavity of the seat.(Technical Idea 10)

[0081] A vibration system, comprising: a vibration device according to any one of Technical Ideas 1 to 9; and a control device is provided to switch between energization and de-energization of the coil.

Claims

1. A vibration device (100), comprising: a housing (120) made of a magnetic material having a bottom portion in a circular plate shape and a side portion in a cylindrical shape integrally continuing from the bottom portion, an end of the side portion being open; a coil (140) in a ring shape disposed on the bottom portion of the housing and excited in response to energization; a stator core (150) made of a magnetic material arranged on the bottom portion of the housing and in an inner circumference of the coil; a moving core (160) made of a magnetic material and arranged inside the housing to face the stator core; and a leaf spring member (180) having an outer circumferential portion fixed to an open end of the side portion of the housing, an inner circumferential portion fixed to the moving core, and a connecting portion connecting the inner peripheral portion and the outer peripheral portion, the leaf spring member being formed from a single plate of elastic material and biasing the moving core in a direction to separate from the stator core, wherein the stator core (150) and the moving core (160) forms a magnetic circuit between them in response to energization of the coil, and wherein the leaf spring member (180) enables the moving core to vibrate in response to energization of the coil, and wherein a natural frequency of the vibration device (100) caused by vibration of the leaf spring member (180) and the moving core (160) is in a range of 10 Hz or more to 200 Hz or less.

2. The vibration device according to claim 1, wherein the leaf spring member (180) has a plurality of connecting portions (183) to form gap portions (184) between the connecting portions (183), thereby reducing a rigidity and reducing a natural frequency compared to a leaf spring member having no gap portion.

3. The vibration device according to claim 2, wherein the connecting portion (183) of the leaf spring member has a bent portion (1831) between the outer peripheral portion (181) and the inner peripheral portion (182), the bent portion (1831) improving a rigidity compared to a connecting portion with no bent portion and providing the natural frequency different from a connecting portion with no bent portion.

4. The vibration device according to claim 2 or 3, wherein the plurality of connecting portions (183) of the leaf spring member (180) are shaped in a point symmetry with respect to a center point, and wherein the leaf spring member (180) generates no rotational component around the center point when the connecting portions (183) are elastically deformed.

5. The vibration device according to any one of claims 1-4, wherein an outer periphery of the leaf spring member (180) is formed by bending into an annular wall portion (1812) extending toward a side opposite to the housing (120) to provide the natural frequency which is different from a leaf spring member formed with no annular wall portion.

6. The vibration device according to any one of claims 1-5, wherein no resonator member is provided on the leaf spring member (180) at a side opposite to the bottom portion of the housing (120), and wherein only the natural frequency of the leaf spring member (180) is used, and no multiple harmonic resonance exists.

7. The vibration device according to any one of claims 1-6, wherein the natural frequency of the vibration device (100) caused by vibration of the leaf spring member (180) and the moving core (160) are in a range of 50 Hz or more to 150 Hz or less.

8. The vibration device according to any one of claims 1-7, wherein the housing (120) and a vibrated member are coupled in a non-rigidly coupled manner, and the housing (120) is supported so as to be vibrated relative to the vibrated member.

9. The vibration device according to claim 8, wherein the vibrated member in which the housing is disposed is a seat (200, 203) of a vehicle, and a storage cavity (205) for supporting the vibration device is provided in the seat, and the housing (120) is stored in the storage cavity (205) of the seat (200, 203).

10. A vibration system, comprising: the vibration device (100) according to any one of claims 1-9, and a control device (220) which switches between energization and de-energization of the coil (140).

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