JP7795186B2 - Vibration Generator - Google Patents

Description

The present invention relates to a vibration generating device.

Conventionally, electrodynamic vibration generators are known that vibrate a test object placed on a drive unit using electromagnetic force generated when an excitation coil and a drive coil are excited.

For example, the vibration generator described in Patent Document 1 controls the rotation speed of the blower that cools the excitation coil and drive coil so that the excitation coil and drive coil operate at temperatures close to their limiting temperatures.

JP 2010-276425 A

However, the vibration generator disclosed in Patent Document 1 operates the excitation coil and drive coil at temperatures close to their critical temperatures, which results in a complex control configuration and shortens the lifespan of the coils.

The present invention was made in consideration of the above, and aims to provide a vibration generator that improves the durability of the magnetic path forming member and drive coil by maintaining the temperature of the magnetic path forming member and drive coil that make up the vibration generator as low as possible using a simple control configuration.

In order to solve the above-mentioned problems and achieve the object, a vibration generating device according to the present invention includes a magnetic path forming member that generates a static magnetic field, a mounting section on which a subject is placed, a drive coil that is installed on the mounting section and placed in the static magnetic field with its moving direction restricted, an excitation control section that generates an electromagnetic force in the drive coil that moves the drive coil and the mounting section back and forth along the moving direction, a temperature measuring section that measures the temperatures of the magnetic path forming member and the drive coil, a cooling control section that drives a blower that cools the magnetic path forming member and the drive coil, and a temperature control section that controls the temperature of the magnetic path forming member to be set according to the magnetic path forming member. and a second rotation speed setting unit that sets the rotation speed of the blower to the rotation speed that is preset according to the temperature range based on which of the plurality of temperature ranges that are set according to the driving coil the temperature of the driving coil belongs to, and the cooling control unit is characterized in that it rotates the blower at the higher rotation speed of the blower set by the first rotation speed setting unit or the second rotation speed setting unit.

The vibration generator of the present invention has the advantage of being able to improve the durability of the magnetic path forming member and drive coil by maintaining the temperature of the magnetic path forming member and drive coil that make up the vibration generator as low as possible using a simple control configuration.

FIG. 1 is a schematic diagram of an overall configuration of a vibration generator according to a first embodiment. FIG. 2 is a diagram illustrating an example of a method for setting the blower frequency characteristics according to the temperatures of the excitation coil and the drive coil. FIG. 3 is a flowchart showing an example of the flow of processing performed by the vibration generator in the first embodiment. FIG. 4 is a schematic diagram of an overall configuration of a vibration generator according to the second embodiment. FIG. 5 is a schematic diagram of an overall configuration of a vibration generator according to the third embodiment. FIG. 6 is a schematic diagram of an overall configuration of a vibration generator according to a fourth embodiment. FIG. 7 is a diagram illustrating an example of a method for setting the blower frequency characteristics in accordance with the temperatures of the excitation coil and the drive coil and the operating time of the vibration generator. FIG. 8 is an example of a map showing the relationship between the operating time of the vibration generator and the shift amount of the temperature region. FIG. 9 is a flowchart showing an example of the flow of processing performed by the vibration generator in the fourth embodiment. FIG. 10 is a flowchart showing an example of the flow of the blower frequency characteristic setting process shown in FIG. FIG. 11 is a schematic diagram of an overall configuration of a vibration generator according to a fifth embodiment. FIG. 12 is an example of a map showing the relationship between the operating time of the vibration generator, the color of the excitation coil and the drive coil, and the shift amount of the temperature region. FIG. 13 is a flowchart showing an example of the flow of processing performed by the vibration generator in the fifth embodiment. FIG. 14 is a flowchart showing an example of the flow of the blower frequency characteristic setting process shown in FIG.

Embodiments of a vibration generator according to the present disclosure are described in detail below with reference to the drawings. Note that the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are interchangeable and easily conceivable by those skilled in the art, or those that are substantially identical.

(First embodiment)
[Explanation of the general configuration of the vibration generating device]
First, the overall configuration of an electrodynamic vibration generator 10a according to a first embodiment will be described with reference to Fig. 1. Fig. 1 is an overall schematic diagram of the vibration generator according to the first embodiment.

As shown in Figure 1, the vibration generator 10a of this embodiment includes a fixed unit 21 and a drive unit 12 on which a test object (not shown) is mounted. Note that Figure 1 shows an XZ cross-sectional view of the fixed unit 21 and the drive unit 12.

The fixed portion 21 includes a circular ring-shaped fixed portion 21 made of a magnetically permeable material such as iron, and a circular ring-shaped excitation coil 15 (magnetic flux generating means) that generates magnetic flux flowing through the fixed portion 21. The excitation coil 15 is installed inside the fixed portion 21, and generates a constant magnetic flux in the fixed portion 21 when a DC voltage is applied from a constant voltage source (not shown). More specifically, the excitation coil 15 is positioned so as to generate a magnetic field (static magnetic field) in a direction perpendicular to the drive coil 16 inserted into the gap 23 of the fixed portion 21. The excitation coil 15 is an example of a magnetic path forming member in this disclosure.

The drive unit 12 includes a test table 13 on which the test object is placed, and an elastic part 14 that connects the drive unit 12 to the fixed part 21 and holds the drive unit 12 in a movable state. A drive coil 16 is installed at the bottom of the drive unit 12 and is inserted into the gap 23 in the fixed part 21.

The drive coil 16 is connected to the vibration control unit 28a via a power amplifier 27. The vibration control unit 28a generates the vibration signals required to impart a predetermined pattern of vibration to the test object and applies them to the drive coil 16 via the power amplifier 27. The vibration control unit 28a is an example of an excitation control unit in this disclosure.

The vibration control unit 28a also applies a DC voltage to the excitation coil 15 from a constant voltage source (not shown in Figure 1) to generate a static magnetic field.

In addition, the vibration control unit 28a receives an operation instruction from the operator and sets the control mode of the vibration generator 10a to either normal mode or eco mode. Normal mode and eco mode will be described in more detail below.

The drive unit 12 has a shaft 24 that is inserted into a bearing 25 provided in the fixed unit 21. A bearing 26 is provided in the bearing 25, and this bearing 26 restrains the shaft 24 of the drive coil 16.

The driving unit 12 has its range of motion limited to a predetermined range (in the vertical direction (Z-axis direction) in the example of Figure 2) by a restraint mechanism including a shaft 24, bearings 25 and 26, and the aforementioned elastic unit 14.

In addition, a damper (not shown) can be provided between the fixed part 21 and the drive part 12 as a restraint mechanism. By providing a damper in this way, it is possible to prevent the drive part 12 from being subjected to an excessive vibration force, thereby preventing damage to the drive part 12.

The cooling blower 30 cools the excitation coil 15 and drive coil 16 by drawing in outside air through a through-hole 35, which is an extension of the gap 23, the space through which the drive coil 16 moves. The cooling blower 30 is, for example, a fan equipped with multiple rotating blades. As the cooling blower 30 rotates, outside air around the vibration generator 10a is drawn in from above the gap 23 and sucked out through the through-hole 35 at the bottom of the fixed part 21 into the blower hose 32. In other words, the air that cools the excitation coil 15 and drive coil 16 flows along arrow A shown in FIG. 1. This air flow cools the excitation coil 15 and drive coil 16. The cooling blower 30 is an example of a blower in this disclosure.

The temperature T1 of the excitation coil 15 is measured by the temperature sensor 18. The temperature sensor 18 is, for example, a radiation thermometer. The temperature sensor 18 is installed outside an opening 22a in the fixed portion 21 that faces the excitation coil 15, and measures the temperature T1 of the excitation coil 15 in a non-contact manner. The temperature sensor 18 is an example of a temperature measurement portion in this disclosure.

The temperature T2 of the drive coil 16 is measured by the temperature sensor 19. The temperature sensor 19 is, for example, a radiation thermometer. The temperature sensor 19 is installed outside an opening 22b in the fixed portion 21 that faces the drive coil 16, and measures the temperature T2 of the drive coil 16 in a non-contact manner. The temperature sensor 19 is an example of a temperature measurement portion in this disclosure.

The temperature sensor 18 is installed so as to measure the temperature as far below the excitation coil 15 as possible. This is because when the cooling blower 30 is operating, i.e., when there is air flow along arrow A, the temperature below the excitation coil 15 on the downwind side is often higher than the temperature above the excitation coil 15 on the upwind side, and therefore measuring the temperature of the hottest part is desirable in determining the degree of cooling.

Because the drive coil 16 moves up and down along the Z axis in Figure 1, the temperature sensor 19 is installed in a position where it can always measure the temperature of the drive coil 16 regardless of the position of the drive coil 16. For example, the temperature sensor 19 is installed so that it measures the temperature at a position downwind of the drive coil 16 when the drive coil 16 is located at the windward end of the air flow generated by the cooling blower 30.

In this embodiment, non-contact temperature sensors 18 and 19 are used, but the temperature sensors 18 and 19 may also be contact-type. In that case, sensors such as thermocouples or thermistors are used.

The cooling control unit 28b determines the blower frequency f, which is the rotation speed of the cooling blower 30, based on the temperature T1 of the excitation coil 15 measured by the temperature sensor 18 and the temperature T2 of the drive coil 16 measured by the temperature sensor 19. The cooling control unit 28b then drives the cooling blower 30 at the determined blower frequency f. The cooling control unit 28b is an example of the first rotation speed setting unit and second rotation speed setting unit of the present disclosure.

[Description of how to control blower frequency based on coil temperature]
Next, a method for determining an appropriate blower frequency f according to the temperatures of the excitation coil 15 and the drive coil 16 will be described with reference to Fig. 2. Fig. 2 is a diagram for explaining an example of a method for setting the blower frequency characteristics according to the temperatures of the excitation coil and the drive coil.

The cooling control unit 28b sets the blower frequency f of the cooling blower 30 according to the temperature T1 of the excitation coil 15. The cooling control unit 28b also sets the blower frequency f of the cooling blower 30 according to the temperature T2 of the drive coil 16.

The cooling control unit 28b then drives the cooling blower 30 at the higher of the blower frequency f of the excitation coil 15 and the blower frequency f of the drive coil 16. In other words, the cooling control unit 28b drives the cooling blower 30 at a drive frequency that corresponds to the coil that requires more cooling, either the excitation coil 15 or the drive coil 16.

The vibration generator 10a has a normal mode and an eco mode. In normal mode, the drive unit 12 is driven at an excitation power level of 100%. The blower frequency characteristic N shown in Figure 2 represents the temperature characteristic of the blower frequency f in normal mode. In eco mode, the drive unit 12 is driven by suppressing the excitation power level to, for example, 70%. The blower frequency characteristic E shown in Figure 2 represents the temperature characteristic of the blower frequency f in eco mode.

First, we will explain normal mode. Note that the excitation coil 15 and drive coil 16 are assumed to have the same temperature characteristics.

The cooling control unit 28b determines the temperature range of each coil based on the temperature of each coil measured by the temperature sensors 18 and 19. Specifically, if the coil temperature falls within the safe temperature range Ta (e.g., up to 60°C), the cooling control unit 28b sets the blower frequency f to a constant value (blower frequency fa1), for example, 42 Hz. Note that the blower frequency fa1 is an example of the first predetermined rotation speed in this disclosure.

Furthermore, when the coil temperature falls within the control temperature range Tb (e.g., 60 to 100°C), the cooling control unit 28b sets the blower frequency f, which corresponds to the coil temperature change from 60°C to 100°C, to a blower frequency fa2, which increases proportionally as the coil temperature increases, for example, between 42 Hz and 60 Hz. Note that the blower frequency fa2 is an example of the second predetermined rotation speed in this disclosure. The blower frequency fa2 is higher than the blower frequency fa1.

When the coil temperature falls within the restricted temperature range Tc (e.g., 100-120°C), the cooling control unit 28b sets the blower frequency f to a constant value (blower frequency fa3), for example, 60 Hz. Note that the blower frequency fa3 is an example of the third predetermined rotation speed in this disclosure. The blower frequency fa3 is higher than the blower frequency fa2.

In this embodiment, the temperature characteristics of the excitation coil 15 and the drive coil 16 are the same, so the cooling control unit 28b selects the higher blower frequency f between the blower frequency f set based on the temperature T1 of the excitation coil 15 and the blower frequency f set based on the temperature T2 of the drive coil 16. The cooling control unit 28b then drives the cooling blower 30 at the selected blower frequency f.

Next, we will explain the coil temperature control operation when eco mode is selected. When the coil temperature falls within the safe temperature range Ta (e.g., up to 60°C), the cooling control unit 28b sets the blower frequency f to a constant value (blower frequency fb1), e.g., 0 Hz. In other words, the cooling blower 30 is stopped. Note that the blower frequency fb1 is an example of the first predetermined rotation speed in this disclosure.

Furthermore, when the coil temperature falls within the control temperature range Tb (e.g., 60 to 100°C), the cooling control unit 28b sets the blower frequency f, which corresponds to the coil temperature change from 60°C to 100°C, to a blower frequency fb2, which increases proportionally as the coil temperature increases, for example, between 30 Hz and 54 Hz. Note that the blower frequency fb2 is an example of the second predetermined rotation speed in this disclosure. The blower frequency fb2 is higher than the blower frequency fb1.

When the coil temperature falls within the restricted temperature range Tc (e.g., 100-120°C), the cooling control unit 28b sets the blower frequency f to a constant value (blower frequency fb3), for example, 54 Hz. Note that the blower frequency fb3 is an example of the third predetermined rotation speed in this disclosure. The blower frequency fb3 is higher than the blower frequency fb2.

As explained in the normal mode operation, the cooling control unit 28b selects the higher blower frequency f between the blower frequency f set based on the temperature T1 of the excitation coil 15 and the blower frequency f set based on the temperature T2 of the drive coil 16. The cooling control unit 28b then drives the cooling blower 30 at the selected blower frequency f.

As a result, by selecting eco mode when the excitation force is small, the current supplied from the excitation power supply to the excitation coil is reduced. Furthermore, regardless of which mode is selected, the cooling capacity of the cooling blower 30 can be reduced according to the measured temperature of the excitation coil 15 or drive coil 16, ensuring the durability of the coil while also reducing the overall power consumption of the vibration generator 10a, enabling energy savings.

[Explanation of coil temperature range]
Next, the temperature ranges of the exciting coil 15 and the driving coil 16 will be described in more detail with reference to FIG.

The coil's safe temperature range is the temperature range in which, by not providing cooling to the vibration generator 10a or providing only minimal cooling, the temperature will not reach the limit temperature of the coil's coating or the adhesive that secures the coil's wire even if a sudden temperature change occurs. The coil's safe temperature range Ta is a temperature range in which the coil temperature is, for example, 60°C or below. Note that the safe temperature range Ta is an example of the first temperature range in this disclosure.

By causing the vibration generator 10a to perform a cooling action according to the coil temperature, the temperature range in which the limit temperature of the coil coating material or the adhesive that secures the coil wire is not reached even if a sudden temperature change occurs in the coil is defined as the coil's control temperature range Tb. The coil's control temperature range Tb is a temperature range in which the coil temperature is, for example, between 60 and 100°C. Note that the control temperature range Tb is an example of the second temperature range in this disclosure.

The temperature range in which the coil coating material or the adhesive that secures the coil wire may reach its limit temperature if no cooling action is applied to the vibration generator 10a is defined as the coil's limit temperature range Tc. The coil's limit temperature range Tc is, for example, a temperature range in which the coil temperature falls between 100 and 120°C. The limit temperature range Tc is an example of the third temperature range in this disclosure.

The temperature range at which the function of the vibration generator 10a is impaired, specifically the temperature range at which the insulating material covering the coil or the adhesive securing the coil wire is thermally damaged, potentially impairing the function of the vibration generator 10a, is defined as the coil's critical temperature range Td. The coil's critical temperature range Td is the temperature range at which the coil temperature is, for example, 120 to 180°C or higher.

Note that the specific temperature ranges corresponding to the coil's safe temperature region Ta, coil's control temperature region Tb, coil's restricted temperature region Tc, and coil's critical temperature region Td are merely examples and are set according to the excitation coil 15 and drive coil 16 actually used.

[Explanation of the processing flow performed by the vibration generator]
Next, the flow of processing performed by the vibration generator 10a will be described with reference to Fig. 3. Fig. 3 is a flowchart showing an example of the flow of processing performed by the vibration generator in the first embodiment.

The vibration control unit 28a and the cooling control unit 28b perform various initialization processes (step S11). Examples of initialization processes include reading the vibration waveform to be generated and reading the blower frequency characteristics N and E for normal mode and eco mode shown in Figure 2.

The vibration control unit 28a determines whether operation of the vibration generator 10a has started (step S12). If it is determined that operation of the vibration generator 10a has started (step S12: Yes), the process proceeds to step S13. On the other hand, if it is not determined that operation of the vibration generator 10a has started (step S12: No), step S12 is repeated.

When it is determined in step S12 that operation of the vibration generator 10a has begun, the vibration control unit 28a generates a vibration signal and applies it to the drive coil 16 via the power amplifier 27. The vibration control unit 28a also applies a DC voltage from a constant voltage source (not shown in FIG. 1) to the excitation coil 15 to generate a static magnetic field (step S13).

The temperature sensor 18 measures the temperature of the excitation coil 15, and the temperature sensor 19 measures the temperature of the drive coil 16 (step S14). Next, proceed to steps S15 and S19.

Following step S14, the cooling control unit 28b determines which temperature region the temperature of the drive coil 16 belongs to (step S15). If it is determined that the temperature region is the safe temperature region Ta, the process proceeds to step S16. If it is determined that the temperature region is the controlled temperature region Tb, the process proceeds to step S17. If it is determined that the temperature region is the restricted temperature region Tc, the process proceeds to step S18.

If it is determined in step S15 that the temperature range is within the safe temperature range Ta, the cooling control unit 28b sets the blower frequency f to f1 (step S16). Then, the process proceeds to step S23.

If it is determined in step S15 that the temperature region is in the control temperature region Tb, the cooling control unit 28b sets the blower frequency f to f2 (step S17). Then, the process proceeds to step S23.

If it is determined in step S15 that the temperature range is within the restricted temperature range Tc, the cooling control unit 28b sets the blower frequency f to f3 (step S18). Then, the process proceeds to step S23.

Following step S14, the cooling control unit 28b determines which temperature region the temperature of the excitation coil 15 belongs to (step S19). If it is determined that the temperature region is the safe temperature region Ta, the process proceeds to step S20. If it is determined that the temperature region is the controlled temperature region Tb, the process proceeds to step S21. If it is determined that the temperature region is the restricted temperature region Tc, the process proceeds to step S22.

If it is determined in step S19 that the temperature range is within the safe temperature range Ta, the cooling control unit 28b sets the blower frequency f to f4 (step S20). Then, the process proceeds to step S23.

If it is determined in step S19 that the temperature region is in the control temperature region Tb, the cooling control unit 28b sets the blower frequency f to f5 (step S21). Then, the process proceeds to step S23.

If it is determined in step S19 that the temperature range is within the restricted temperature range Tc, the cooling control unit 28b sets the blower frequency f to f6 (step S22). Then, the process proceeds to step S23.

Following steps S16, S17, or S18, or steps S20, S21, or S22, the cooling control unit 28b drives the cooling blower 30 at the higher blower frequency of either the set blower frequencies f1, f2, or f3, or the set blower frequencies f4, f5, or f6 (step S23).

The vibration control unit 28a determines whether a stop command for the vibration generator 10a has been input (step S24). If it is determined that a stop command has been input (step S24: Yes), the vibration generator 10a ends the processing in FIG. 3. On the other hand, if it is determined that a stop command has not been input (step S24: No), the processing returns to step S14, and the vibration generator 10a repeats the above-described processing.

The above processing flow applies when the vibration generator 10a is operating in normal mode. When operating in eco mode, the blower frequency f is set based on the blower frequency characteristic E shown in Figure 2.

The processing flow shown in Figure 3 is for the case where the excitation coil 15 and drive coil 16 have the same temperature characteristics. However, in general, the excitation coil 15 and drive coil 16 have different temperature characteristics due to differences in the wire material used, the insulating material, the adhesive used to secure the wire material, etc. The vibration generator 10a of this embodiment can drive the cooling blower 30 at an appropriate blower frequency f even in such cases.

If the temperature characteristics of the excitation coil 15 and drive coil 16 are different, the temperature ranges (safe temperature range Ta, control temperature range Tb, and limit temperature range Tc) of each coil will be different.

In such a case, the blower frequency characteristics N and E shown in Figure 2 are set for the excitation coil 15 and the drive coil 16, respectively. The cooling control unit 28b sets a blower frequency f corresponding to the temperature T1 of the excitation coil 15 and a blower frequency f corresponding to the temperature T2 of the drive coil 16. The cooling control unit 28b then compares the blower frequency f corresponding to the temperature T1 of the excitation coil 15 with the blower frequency f corresponding to the temperature T2 of the drive coil 16, and drives the cooling blower 30 at the higher blower frequency f.

As described above, the vibration generator 10a of this embodiment reciprocates the drive coil 16, whose direction of movement is restricted, by the electromagnetic force generated by the vibration control unit 28a (excitation control unit) in a static magnetic field generated by the excitation coil 15 (magnetic path forming member). The temperature of the excitation coil 15 is measured by the temperature sensor 18 (temperature measurement unit), and the temperature of the drive coil 16 is measured by the temperature sensor 19 (temperature measurement unit). The cooling control unit 28b (first rotation speed setting unit) sets the rotation speed of the cooling blower 30 (blower) based on which of multiple temperature ranges set for the excitation coil 15 the temperature belongs to. Furthermore, the cooling control unit 28b (second rotation speed setting unit) sets the rotation speed of the cooling blower 30 (blower) based on which of multiple temperature ranges set for the drive coil 16 the temperature belongs to. The cooling control unit 28b then rotates the cooling blower 30 at the higher of the rotation speeds of the cooling blower 30 set according to the temperature of the excitation coil 15 and the rotation speed of the cooling blower 30 set according to the temperature of the drive coil 16. Therefore, with a simple configuration, the temperatures of the excitation coil 15 (magnetic path forming member) and drive coil 16 that make up the vibration generator 10a can be maintained as low as possible, thereby improving the durability of the excitation coil 15 and drive coil 16.

Furthermore, in the vibration generator 10a of this embodiment, the temperature range of the excitation coil 15 and drive coil 16 includes a safe temperature range Ta (first temperature range) that prevents the excitation coil 15 and drive coil 16 from reaching a critical temperature that would impair their operation, even if a temperature change occurs in the excitation coil 15 and drive coil 16, by setting the rotation speed of the cooling blower 30 to a first predetermined rotation speed. Therefore, it is possible to prevent a decrease in the durability of the excitation coil 15 and drive coil 16 due to heat.

In addition, in the vibration generator 10a of this embodiment, the cooling control unit 28b stops the cooling blower 30 when the higher of the rotation speed of the cooling blower 30 (blower) set by the cooling control unit 28b (first rotation speed setting unit) and the rotation speed of the cooling blower 30 set by the cooling control unit 28b (second rotation speed setting unit) is equal to or lower than a predetermined rotation speed. Therefore, by stopping the cooling blower 30, the overall power consumption of the vibration generator 10a can be reduced.

In addition, in the vibration generator 10a of this embodiment, the temperature range of the excitation coil 15 and drive coil 16 includes a control temperature range Tb (second temperature range) in which, by setting the rotation speed of the cooling blower 30 to a second predetermined rotation speed that is higher than the first predetermined rotation speed, the excitation coil 15 and drive coil 16 are prevented from reaching a limit temperature that would impair their operation, even if a temperature change occurs in the excitation coil 15 and drive coil 16. Therefore, because the rotation speed of the cooling blower 30 is controlled based on a preset temperature range, the coil temperature can be controlled with a simple configuration.

Furthermore, in the vibration generator 10a of this embodiment, when the higher of the temperatures of the excitation coil 15 and the drive coil 16 falls within the control temperature region Tb (second temperature region), the cooling control unit 28b sets the first rotation speed setting unit and the second rotation speed setting unit to rotation speeds that gradually increase in response to an increase in the temperature. Therefore, by increasing the rotation speed of the cooling blower 30 in response to an increase in temperature, cooling performance that corresponds to the coil temperature can be achieved.

Furthermore, in the vibration generator 10a of this embodiment, the temperature range of the excitation coil 15 and drive coil 16 includes a limited temperature range Tc (third temperature range) in which the excitation coil 15 and drive coil 16 do not reach a limit temperature that would impair their operation, even if a temperature change occurs in the excitation coil 15 and drive coil 16, by setting the rotation speed of the cooling blower 30 to a third predetermined rotation speed that is higher than the second predetermined rotation speed. Therefore, because the rotation speed of the cooling blower 30 is controlled based on a preset temperature range, the coil temperature can be controlled with a simple configuration.

In addition, in the vibration generator 10a of this embodiment, the temperature sensor 18 (temperature measurement unit) is installed to measure the temperature of the excitation coil 15 (magnetic path forming member) at a position on the downwind side of the air flow generated by the cooling blower 30 (blower). Therefore, cooling control can be performed based on the temperature of the downwind area of the excitation coil 15, where the temperature is generally higher, further improving cooling performance.

In addition, in the vibration generator 10a of this embodiment, the temperature sensor 19 (temperature measurement unit) is installed to measure the temperature at a position on the downwind side of the drive coil 16 when the drive coil 16 is positioned at the windward end of the air flow generated by the cooling blower 30 (blower). Therefore, cooling control can be performed based on the temperature of the downwind region of the drive coil 16, where the temperature is generally higher, further improving cooling performance.

Furthermore, in the vibration generator 10a of this embodiment, the magnetic path forming member is the excitation coil 15. Therefore, by controlling the amount of magnetic flux generated in the excitation coil 15, the operating state of the vibration generator 10a can be switched, for example, between normal mode and eco mode.

Second Embodiment
[Explanation of the general configuration of the vibration generating device]
Next, a vibration generator 10b according to a second embodiment will be described with reference to Fig. 4. Fig. 4 is a schematic diagram of the entire vibration generator according to the second embodiment.

In Figure 4, the fixed unit 21 and drive unit 12 are shown in an XZ cross section. The vibration generator 10b has almost the same configuration as the vibration generator 10a. What makes it different from the vibration generator 10a is that the excitation coil 15 is divided into an upper excitation coil 15a and a lower excitation coil 15b. The temperature sensor 18, which measures the temperature of the excitation coil 15, is installed so as to measure the temperature of the lower excitation coil 15b, which is located downwind of the cooling air generated by the cooling blower 30.

When the cooling blower 30 is operating, a temperature gradient generally occurs in the temperature of the excitation coil 15, causing the temperature of the lower excitation coil 15b on the downwind side to rise. Therefore, the cooling control unit 28b drives the cooling blower 30 at a blower frequency f determined according to the method described in the first embodiment, based on the temperature of the lower excitation coil 15b and the temperature of the drive coil 16.

On the other hand, when the cooling blower 30 is stopped, the temperature of the upper excitation coil 15a tends to be higher than the temperature of the lower excitation coil 15b. The temperature of the upper excitation coil 15a can be estimated from the temperature of the lower excitation coil 15b using previously acquired temperature data of the upper excitation coil 15a and lower excitation coil 15b when the cooling blower 30 is stopped. The cooling control unit 28b then drives the cooling blower 30 at the blower frequency f determined according to the method described in the first embodiment, based on the estimated temperature of the upper excitation coil 15a and the temperature of the drive coil 16.

[Explanation of the processing flow performed by the vibration generator]
The flow of the process performed by the vibration generator 10b is substantially the same as the flow of the process performed by the vibration generator 10a described in the first embodiment (see FIG. 3), and therefore a flowchart thereof will be omitted.

The difference from the processing in Figure 3 is that when the vibration generator 10b is in eco mode and the cooling blower 30 is stopped, the cooling control unit 28b (first rotation speed setting unit) estimates the temperature of the upper excitation coil 15a based on the temperature of the lower excitation coil 15b.

If the estimated temperature of the upper excitation coil 15a does not fall within the safe temperature region Ta (first temperature region), the cooling control unit 28b determines the temperature of the upper excitation coil 15a as the temperature of the excitation coil 15 and again performs the temperature determination of the excitation coil 15 (step S15 in Figure 3).

On the other hand, if the estimated temperature of the upper excitation coil 15a falls within the safe temperature range Ta, the cooling control unit 28b continues to stop the cooling blower 30.

In other words, the cooling control unit 28b sets the blower frequency f of the cooling blower 30 based on the higher of the temperatures of the upper excitation coil 15a and the lower excitation coil 15b.

In the above explanation, the temperature of the upper excitation coil 15a is estimated from the measured temperature of the lower excitation coil 15b while the cooling blower 30 is stopped. However, a temperature sensor may also be installed in the upper excitation coil 15a to measure the temperatures of both the upper excitation coil 15a and the lower excitation coil 15b.

As described above, the vibration generator 10b of this embodiment includes an upper excitation coil 15a installed on the upwind side of the cooling air from the cooling blower 30, and a lower excitation coil 15b installed on the downwind side. The temperature sensor 18 (temperature measurement unit) measures the temperature of the lower excitation coil 15b. The cooling control unit 28b also estimates the temperature of the upper excitation coil 15a from the temperature of the lower excitation coil 15b, and sets the higher of the temperature of the lower excitation coil 15b and the temperature of the upper excitation coil 15a as the temperature of the excitation coil 15. Therefore, when multiple divided excitation coils are installed, there is no need to measure the temperatures of all of the excitation coils, which simplifies the equipment configuration.

(Third embodiment)
[Explanation of the general configuration of the vibration generating device]
Next, a vibration generator 10c according to a third embodiment will be described with reference to Fig. 5. Fig. 5 is a schematic diagram of the entire vibration generator according to the third embodiment.

In Figure 5, the fixed unit 21 and the drive unit 12 are shown in an XZ cross section. The vibration generator 10c has almost the same configuration as the vibration generator 10a. It differs from the vibration generator 10a in that it has a permanent magnet 17 instead of the excitation coil 15.

The permanent magnet 17 has a circular ring shape and generates a magnetic flux inside the fixed part 21 in the same direction as the magnetic flux generated by the excitation coil 15 of the vibration generator 10a. Therefore, the vibration generator 10c does not require the constant voltage source provided in the vibration generator 10a that applies a DC voltage to the excitation coil 15 to generate a static magnetic field.

The temperature sensor 20, which measures the temperature of the permanent magnet 17, is installed outside the opening 22c facing the permanent magnet 17. The opening 22c is located downwind of the cooling air generated by the cooling blower 30. A copper ring 36 is installed on the inner circumferential surface of the permanent magnet 17 so that it is in contact with the inner circumferential surface, and the temperature sensor 20 measures the surface temperature of the copper ring 36. The copper ring 36 has high thermal conductivity, so it immediately reflects the temperature of the permanent magnet 17. Therefore, the temperature of the copper ring 36 measured by the temperature sensor 20 is approximately equal to the temperature of the permanent magnet 17.

The cooling control unit 28b of the vibration generator 10c determines the blower frequency f for cooling the permanent magnet 17 based on the temperature T3 of the permanent magnet 17 measured by the temperature sensor 20. The cooling control unit 28b also determines the blower frequency f for cooling the drive coil 16 based on the temperature T2 of the drive coil 16 measured by the temperature sensor 19. The temperature sensor 19 is installed outside the opening 22b facing the permanent magnet 17. The temperature sensor 19 measures the temperature of the drive coil 16 through the opening 22b, which penetrates the permanent magnet 17 and the copper ring 36.

The cooling control unit 28b compares the blower frequency f for cooling the permanent magnet 17 with the blower frequency f for cooling the drive coil 16, and drives the cooling blower 30 at the higher blower frequency f.

In the vibration generator 10c, a static magnetic field is formed using a permanent magnet 17, so there is no need to pass an excitation current. This reduces the power consumption of the vibration generator 10c.

In addition, the use of permanent magnets 17 prevents the heat generated when an excitation current is passed through the excitation coil 15, further reducing the rotation speed of the cooling blower 30. This further reduces the power consumption of the vibration generator 10c.

In this way, vibration generator 10c is able to reduce power consumption, and therefore does not have the operating state switching function (normal mode and eco mode) that vibration generator 10b has.

[Explanation of temperature range of permanent magnets]
The permanent magnet 17 has temperature characteristics similar to those of the excitation coil 15 and the drive coil 16. That is, there is a risk that the magnetic force will decrease at high temperatures. As with the excitation coil 15 and the drive coil 16, a temperature range can also be set for the permanent magnet 17.

The safe temperature range of the permanent magnet 17 is the temperature range in which the limit temperature of the permanent magnet 17 will not be reached even if a sudden temperature change occurs in the permanent magnet 17, by performing no cooling action or only a minimum cooling action on the vibration generator 10c. The safe temperature range Ta of the permanent magnet 17 is the temperature range in which the temperature of the permanent magnet 17 is, for example, 60°C or less.

By causing the vibration generator 10c to perform a cooling action according to the temperature of the permanent magnet 17, the temperature range in which the limit temperature of the permanent magnet 17 is not reached even if a sudden temperature change occurs in the permanent magnet 17 is defined as the control temperature range Tb of the permanent magnet 17. The control temperature range Tb of the permanent magnet 17 is a temperature range in which the temperature of the permanent magnet 17 is, for example, 60 to 80°C.

The temperature range in which the permanent magnet 17 may reach its limit temperature if no cooling action is performed on the vibration generator 10c is defined as the limit temperature range Tc of the permanent magnet 17. The limit temperature range Tc of the permanent magnet 17 is a temperature range in which the coil temperature is, for example, between 80 and 100°C.

The critical temperature range Td of the permanent magnet 17 is the temperature range at which the function of the vibration generator 10c is impaired. Specifically, the temperature range at which the permanent magnet 17 is irreversibly demagnetized due to a rise in temperature of the permanent magnet 17, and the permanent magnet 17 may not regain its original magnetic force even if the temperature of the permanent magnet 17 is lowered. The critical temperature range Td of the permanent magnet 17 is the temperature range at which the temperature of the permanent magnet 17 is, for example, 100 to 150°C or higher.

Note that the temperature ranges listed above are merely examples and should be set appropriately depending on the permanent magnet 17 actually used.

[Explanation of the processing flow performed by the vibration generator]
The vibration generator 10c performs the same processing as the vibration generator 10a (see FIG. 3), except that it measures the temperature T3 of the permanent magnet 17 instead of the temperature T1 of the excitation coil 15.

That is, instead of step S15 in FIG. 3, the vibration generator 10c determines the temperature T3 of the permanent magnet 17. Then, instead of steps S16, S17, and S18 in FIG. 3, it sets the blower frequency f according to the temperature range of the permanent magnet 17.

The rest of the processing flow is the same as in the flowchart in Figure 3.

As explained above, in the vibration generator 10c of this embodiment, the magnetic path forming member is a permanent magnet 17. Therefore, the excitation coil 15 is not required, and the power consumption of the vibration generator 10c can be reduced.

(Fourth embodiment)
[Explanation of the general configuration of the vibration generating device]
Next, a vibration generator 10d according to a fourth embodiment will be described with reference to Fig. 6. Fig. 6 is a schematic diagram illustrating the entire vibration generator according to the fourth embodiment.

In addition to the components of the vibration generator 10a described in the first embodiment (see Figure 1), the vibration generator 10d also includes an operating time accumulator 29. Furthermore, the vibration generator 10d includes a cooling control unit 28c instead of the cooling control unit 28b included in the vibration generator 10a.

The operating time accumulator 29 accumulates the operating time of the vibration generator 10d.

The cooling control unit 28c shifts the multiple temperature regions set according to the excitation coil 15 (magnetic path forming member) and the multiple temperature regions set according to the drive coil 16 to lower temperatures by an amount corresponding to the operating time accumulated by the operating time accumulator 29. The cooling control unit 28c also cools the excitation coil 15 and the drive coil 16 by rotating the cooling blower 30 based on the rotation speed of the cooling blower 30, which is set based on the multiple temperature regions shifted to lower temperatures according to the operating time accumulated by the operating time accumulator 29.

The method by which the cooling control unit 28c determines the rotation speed of the cooling blower 30 is as described in the first embodiment. Note that the cooling control unit 28c is an example of the first rotation speed setting unit and second rotation speed setting unit of this disclosure.

[Setting the blower frequency according to the operating time of the vibration generator]
A method for setting the blower frequency f according to the operating time Ot of the vibration generator 10d will be described using Figures 7 and 8. Figure 7 is a diagram illustrating an example of a method for setting the blower frequency characteristics according to the temperatures of the excitation coil and drive coil and the operating time of the vibration generator. Figure 8 is an example of a map showing the relationship between the operating time of the vibration generator and the amount of shift in the temperature range.

The graph in Figure 7, like the graph described in the first embodiment (see Figure 2), shows the blower frequency characteristics N, E, which are the rotation speed of the cooling blower 30 according to the temperature T of the excitation coil 15 and the drive coil 16.

The durability of the excitation coil 15 and drive coil 16 may decrease if they are operated for a long period of time. Therefore, in this embodiment, the temperature ranges shown in Figure 2 are shifted to lower temperatures depending on the operating time Ot of the vibration generator 10d.

For example, Figure 7 shows an example in which the safe temperature range Ta, control temperature range Tb, and limit temperature range Tc shown in Figure 2 have each been shifted to lower temperatures by a temperature shift amount ΔT (ΔT = 5°C in the example of Figure 7). That is, in the example of Figure 7, the safe temperature range Ta is set to up to 55°C, the control temperature range Tb is set to 55 to 95°C, and the limit temperature range Tc is set to 95 to 120°C.

It is desirable to set the temperature shift amount ΔT between the temperature ranges (safe temperature range Ta, controlled temperature range Tb, and restricted temperature range Tc) of the excitation coil 15 and drive coil 16 larger as the operating time Ot of the vibration generator 10d becomes longer. Therefore, the cooling control unit 28c sets the temperature shift amount ΔT based on, for example, the map shown in FIG. 8.

For example, if the operating time Ot of the vibration generator 10d is within 50,000 hours, the cooling control unit 28c sets the temperature shift amount ΔT to 0°C. If the operating time Ot of the vibration generator 10d is between 50,000 and 100,000 hours, the cooling control unit 28c sets the temperature shift amount ΔT to -5°C. If the operating time Ot of the vibration generator 10d exceeds 100,000 hours, the cooling control unit 28c sets the temperature shift amount ΔT to -10°C. Note that the operating time Ot and temperature shift amount ΔT shown in Figure 8 are merely examples, and values are set appropriately depending on the vibration generator 10d.

[Explanation of the processing flow performed by the vibration generator]
Next, the flow of processing performed by the vibration exciter 10d will be described with reference to Fig. 9. Fig. 9 is a flowchart showing an example of the flow of processing performed by the vibration exciter 10d in the fourth embodiment.

The vibration control unit 28a and the cooling control unit 28c perform various initialization processes (step S31). These initialization processes are similar to those described in step S11 of Figure 3.

The vibration control unit 28a determines whether operation of the vibration generator 10d has started (step S32). If it is determined that operation of the vibration generator 10d has started (step S32: Yes), the process proceeds to step S33. On the other hand, if it is not determined that operation of the vibration generator 10d has started (step S32: No), step S32 is repeated.

If it is determined in step S32 that operation of the vibration generator 10d has started, the cooling control unit 28c reads the operating time Ot of the vibration generator 10d from the operating time accumulator 29 (step S33).

Next, the cooling control unit 28c performs a blower frequency characteristic setting process (step S34). The blower frequency characteristic setting process is a process for setting the blower frequency characteristics N, E (Figure 7) according to the operating time Ot of the vibration generator 10d. The specific processing content of the blower frequency characteristic setting process will be described later (see Figure 10).

The vibration control unit 28a generates a vibration signal and applies it to the drive coil 16 via the power amplifier 27. The vibration control unit 28a also applies a DC voltage from a constant voltage source (not shown in FIG. 6) to the excitation coil 15 to generate a static magnetic field (step S35).

The operating time accumulator 29 accumulates the operating time Ot of the vibration generator 10d (step S36). Note that the operating time Ot of the vibration generator 10d is the accumulated value of the elapsed time since the excitation coil 15 and the drive coil 16 were excited in step S35.

The temperature sensor 18 measures the temperature of the excitation coil 15, and the temperature sensor 19 measures the temperature of the drive coil 16 (step S37).

Next, the cooling control unit 28c performs a blower frequency characteristic setting process to set the blower frequency characteristics N and E (Figure 7) (step S38). Note that the blower frequency characteristic setting process is the same as steps S15 to S22 in the flowchart of Figure 3.

The cooling control unit 28c drives the cooling blower 30 at the higher blower frequency of either one of the blower frequencies f1, f2, or f3 set based on the temperature determination process of the excitation coil 15 and the drive coil 16, or one of the set blower frequencies f4, f5, or f6 (step S39).

The vibration control unit 28a determines whether a stop command has been input for the vibration generator 10d (step S40). If it is determined that a stop command has been input (step S40: Yes), the process proceeds to step S41. On the other hand, if it is not determined that a stop command has been input (step S40: No), the process returns to step S36, and the vibration generator 10d repeats the above-described process.

If it is determined in step S40 that a command to stop the vibration generator 10d has been input, the operating time accumulator 29 stores the operating time Ot of the vibration generator 10d at that time (step S41). The vibration generator 10d then ends the processing of FIG. 9.

Next, the flow of the blower frequency characteristic setting process will be explained using Figure 10. Figure 10 is a flowchart showing an example of the flow of the blower frequency characteristic setting process shown in Figure 9.

The cooling control unit 28c determines the length of the operating time Ot of the vibration generator 10d read from the operating time integrator 29 in step S33 (step S51). If it is determined that the operating time Ot is within 50,000 hours, the process proceeds to step S52. If it is determined that the operating time Ot is between 50,000 and 100,000 hours, the process proceeds to step S53. If it is determined that the operating time exceeds 100,000 hours, the process proceeds to step S54.

If it is determined in step S51 that the operating time Ot is within 50,000 hours, the cooling control unit 28c sets the temperature shift amount ΔT to 0°C (step S52). Then, the process proceeds to step S55.

If it is determined in step S51 that the operating time Ot is between 50,000 and 100,000 hours, the cooling control unit 28c sets the temperature shift amount ΔT to -5°C (step S53). Then, the process proceeds to step S55.

If it is determined in step S51 that the operating time Ot exceeds 100,000 hours, the cooling control unit 28c sets the temperature shift amount ΔT to -10°C (step S54). Then, the process proceeds to step S55.

Following steps S52, S53, and S54, the cooling control unit 28c determines the relationship between the temperatures of the excitation coil 15 and drive coil 16 and the blower frequency f of the cooling blower 30, i.e., the blower frequency characteristics N and E (step S55). Then, the process returns to the main routine (Figure 9).

As described above, the vibration generator 10d of this embodiment further includes an operating time accumulator 29 that accumulates the operating time Ot of the vibration generator 10d, and the cooling control unit 28c (first rotation speed setting unit and second rotation speed setting unit) shifts the multiple temperature ranges set according to the excitation coil 15 (magnetic path forming member) and the multiple temperature ranges set according to the drive coil 16 to lower temperatures by an amount corresponding to the operating time Ot accumulated by the operating time accumulator 29. Therefore, by maintaining the temperatures of the excitation coil 15 and drive coil 16 that constitute the vibration generator 10d as low as possible according to the operating time Ot of the vibration generator 10d, the durability of the excitation coil 15 and drive coil 16 can be improved.

Furthermore, in the vibration generator 10d of this embodiment, the cooling control unit 28c (first rotation speed setting unit and second rotation speed setting unit) sets multiple temperature ranges based on a pre-set map showing the correspondence between the operating time Ot of the vibration generator 10d and multiple temperature ranges. Therefore, it is possible to easily set the blower frequency characteristics N and E according to the operating time Ot of the vibration generator 10d.

The configuration of this embodiment can also be applied to the vibration generator 10b described in the second embodiment and the vibration generator 10c described in the third embodiment.

Fifth Embodiment
[Explanation of the general configuration of the vibration generating device]
Next, a vibration generator 10e according to a fifth embodiment will be described with reference to Fig. 11. Fig. 11 is a schematic diagram illustrating the entire vibration generator according to the fifth embodiment.

In addition to the components of the vibration generator 10d described in the fourth embodiment (see Figure 6), the vibration generator 10e also includes color sensors 40 and 41 and a coil deterioration determination unit 45. Furthermore, the vibration generator 10e includes a cooling control unit 28d instead of the cooling control unit 28c included in the vibration generator 10d.

The color sensor 40 is installed outside the opening 22d in the fixed portion 21 that faces the excitation coil 15 and measures the color of the surface of the excitation coil 15 in a non-contact manner. The color sensor 40 is, for example, a photodiode equipped with R (Red), G (Green), and B (Blue) color filters. The color sensor 40 may also be a photoelectric conversion element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The color sensor 40 measures the color of the surface of the excitation coil 15 illuminated by the lighting function of an optical fiber 42 installed in the color sensor 40 in a non-contact manner. The measurement range is, for example, a narrow range with a diameter of approximately 4 mm, 8 mm, or 25.4 mm. The color sensor 40 outputs, for example, lightness, hue, and saturation in the L ^* a ^* b ^* color system. The color sensor 40 is an example of a color measurement unit in the present disclosure.

The excitation coil 15 is typically a coil formed from wire, covering material, and adhesive, which is then vacuum-impregnated with insulating varnish. Alternatively, the wire and covering material may be covered with insulating paper and then vacuum-impregnated. Therefore, the color sensor 40 measures the color of the varnish or paper insulating material on the surface of the vacuum-impregnated excitation coil 15.

The color sensor 41 is installed outside the opening 22e in the fixed portion 21 facing the drive coil 16 and measures the color of the surface of the drive coil 16 in a non-contact manner. The color sensor 41 is, for example, a photodiode equipped with R, G, and B color filters. The color sensor 41 may also be a photoelectric conversion element such as a CCD or CMOS. The color sensor 41 measures the color of the surface of the drive coil 16 illuminated by the lighting function of an optical fiber 43 installed in the color sensor 41 in a non-contact manner. The measurement range is, for example, a narrow range of approximately 4 mm, 8 mm, or 25.4 mm in diameter. The color sensor 41 outputs, for example, lightness, hue, and saturation in the L ^* a ^* b ^* color system. The color sensor 41 is an example of a color measurement unit in this disclosure.

The drive coil 16 is formed, for example, by applying adhesive to the surface of the cylindrical core material of the coil, called a bobbin, and then winding wire on top of it. The wires are wound so that the gaps between them are as small as possible, and adhesive is also applied to the gaps between the wires. In other words, the surface of the drive coil 16 has areas where the coating material is exposed and areas where adhesive has been applied between the wires. Therefore, the color sensor 41 measures the color of the exposed coating material areas or the adhesive areas.

The coil deterioration determination unit 45 determines the degree of deterioration of the excitation coil 15 and the drive coil 16 based on the surface color of the excitation coil 15 measured by the color sensor 40 and the surface color of the drive coil 16 measured by the color sensor 41.

The excitation coil 15 and drive coil 16 gradually deteriorate due to the physical load caused by vibrations generated during operation of the vibration generator 10e, the temperature of the excitation coil 15 and drive coil 16, and the operating time of the vibration generator 10e. The degree of deterioration is reflected in discoloration of the excitation coil 15 and drive coil 16. The surfaces of new excitation coils 15 and drive coils 16 exhibit the color of the coil coating material (an insulating material such as polyimide or polyamide), for example, a copper color. As the coil deterioration progresses, the color of the coil surface tends to gradually darken (approach black). The coil deterioration determination unit 45 determines to what extent the surface color of the excitation coil 15 and drive coil 16 has approached black from its new state.

As mentioned above, adhesive is applied between the wires of the excitation coil 15 and the drive coil 16. The adhesive is, for example, a thermosetting polymer resin material (epoxy-based). Such adhesives are colorless and transparent or slightly cloudy, but tend to darken depending on the usage conditions of the vibration generator 10e.

The coil deterioration determination unit 45 stores the surface colors of new excitation coils 15 and drive coils 16 measured by the color sensors 40 and 41 in the vibration generator 10e. Then, using the stored colors as a reference, the coil deterioration determination unit 45 determines the degree of discoloration of the surface colors of each coil currently measured by the color sensors 40 and 41.

The occurrence of discoloration can be determined, for example, based on the color difference in the L ^* a ^* b ^* color system. For example, assume that two colors have lightness L1 ^* and lightness L2 ^* , hue a1 ^* and hue a2 ^* , and saturation b1 ^* and saturation b2 ^* . In this case, the color difference ΔE ^* ab between the two colors is calculated using formula (1).

ΔE ^* ab = [(L1 ^* - L2 ^* ) ² + (a1 ^* - a2 ^* ) ² + (b1 ^* - b2 ^* ) ² ] ^1/2 ... (1)

The coil deterioration determination unit 45 pre-stores a map that corresponds the color difference ΔE ^* ab calculated by equation (1) with the degree of deterioration of the excitation coil 15 and drive coil 16 (e.g., small degree of deterioration, medium degree of deterioration, large degree of deterioration), and outputs the degree of deterioration of the coil determined based on the map.

The change in the color of the coil may be determined based on the color difference in the L ^* a ^* b ^* color system, or may be determined based on the change in RGB values.

The cooling control unit 28d shifts the multiple temperature ranges set according to the excitation coil 15 (magnetic path forming member) and the multiple temperature ranges set according to the drive coil 16 to lower temperatures by an amount corresponding to the colors of the excitation coil 15 and the drive coil 16 measured by the color sensors 40, 41 (color measurement units) and the operating time accumulated by the operating time accumulation unit 29. The cooling control unit 28d also cools the excitation coil 15 and the drive coil 16 by rotating the cooling blower 30 based on the rotation speed of the cooling blower 30, which is set based on the multiple temperature ranges shifted to lower temperatures.

The method by which the cooling control unit 28d determines the rotation speed of the cooling blower 30 is as described in the first embodiment. Note that the cooling control unit 28d is an example of the first rotation speed setting unit and second rotation speed setting unit of the present disclosure.

[Setting the blower frequency according to the coil color and the operating time of the vibration generator]
A method for setting the blower frequency f according to the operating time Ot of the vibration generator 10e will be described with reference to Fig. 12. Fig. 12 is an example of a map showing the relationship between the operating time of the vibration generator, the color of the excitation coil and the drive coil, and the amount of shift in the temperature range.

It is desirable to set the temperature shift amount ΔT of the temperature ranges (safe temperature range Ta, control temperature range Tb, and limit temperature range Tc) of the excitation coil 15 and drive coil 16 larger the greater the degree of deterioration determined based on the color of the excitation coil 15 or drive coil 16. It is also desirable to set the temperature shift amount ΔT larger the longer the operating time Ot of the vibration generator 10e. Therefore, the cooling control unit 28d sets the temperature shift amount ΔT, for example, based on the map shown in FIG. 12.

For example, if the operating time Ot of the vibration generator 10e is within 50,000 hours and the degree of coil deterioration is small or medium, the cooling control unit 28d sets the temperature shift amount ΔT to 0°C. If the degree of coil deterioration is large, the cooling control unit 28d sets the temperature shift amount ΔT to -5°C.

Furthermore, if the operating time Ot of the vibration generator 10d is between 50,000 and 100,000 hours, and the degree of coil deterioration is small or medium, the cooling control unit 28d sets the temperature shift amount ΔT to -5°C. If the degree of coil deterioration is large, the cooling control unit 28d sets the temperature shift amount ΔT to -10°C.

Furthermore, if the operating time Ot of the vibration generator 10d exceeds 100,000 hours and the degree of coil deterioration is small or medium, the cooling control unit 28d sets the temperature shift amount ΔT to -10°C. If the degree of coil deterioration is large, the cooling control unit 28d sets the temperature shift amount ΔT to -15°C.

Note that the operating time Ot, degree of deterioration, and temperature shift amount ΔT shown in Figure 12 are examples, and values are set appropriately depending on the vibration generating device 10e.

The cooling control unit 28d may also set the temperature shift amount ΔT based solely on the degree of deterioration determined based on the color of the excitation coil 15 or drive coil 16.

[Explanation of the processing flow performed by the vibration generator]
Next, the flow of processing performed by the vibration exciter 10e will be described with reference to Fig. 13. Fig. 13 is a flowchart showing an example of the flow of processing performed by the vibration exciter 10e in the fifth embodiment.

The vibration control unit 28a and the cooling control unit 28d perform various initialization processes (step S61). These initialization processes are similar to those described in step S11 of Figure 3.

The vibration control unit 28a determines whether operation of the vibration generator 10e has started (step S62). If it is determined that operation of the vibration generator 10e has started (step S62: Yes), the process proceeds to step S63. On the other hand, if it is not determined that operation of the vibration generator 10e has started (step S62: No), step S62 is repeated.

If it is determined in step S62 that operation of the vibration generator 10e has started, the cooling control unit 28d reads the operating time Ot of the vibration generator 10e from the operating time accumulator 29 (step S63).

The color sensor 40 measures the color of the excitation coil 15. The color sensor 41 also measures the color of the drive coil 16 (step S64).

The coil deterioration determination unit 45 determines the degree of deterioration of the excitation coil 15 and the drive coil 16. The cooling control unit 28d then performs a blower frequency characteristic setting process to set the blower frequency characteristics N, E (Figure 7) based on the operating time Ot of the vibration generator 10e and the degree of deterioration of the excitation coil 15 and the drive coil 16 (step S65). Specific details of the blower frequency characteristic setting process performed in step S65 will be described later (see Figure 14).

The vibration control unit 28a generates a vibration signal and applies it to the drive coil 16 via the power amplifier 27. The vibration control unit 28a also applies a DC voltage from a constant voltage source (not shown in FIG. 11) to the excitation coil 15 to generate a static magnetic field (step S66).

The operating time accumulator 29 accumulates the operating time Ot of the vibration generator 10e (step S67). Note that the operating time Ot of the vibration generator 10e is the accumulated value of the elapsed time since the excitation coil 15 and the drive coil 16 were excited in step S66.

The temperature sensor 18 measures the temperature of the excitation coil 15, and the temperature sensor 19 measures the temperature of the drive coil 16 (step S68).

Next, the cooling control unit 28d performs a temperature determination process for the excitation coil 15 and the drive coil 16 (step S69). Note that the temperature determination process for the excitation coil 15 and the drive coil 16 is the same as steps S15 to S22 in the flowchart of FIG. 3.

The cooling control unit 28d drives the cooling blower 30 at the higher blower frequency of either one of the blower frequencies f1, f2, or f3 set based on the temperature determination process of the excitation coil 15 and the drive coil 16, or one of the set blower frequencies f4, f5, or f6 (step S70).

The vibration control unit 28a determines whether a stop command for the vibration generator 10e has been input (step S71). If it is determined that a stop command has been input (step S71: Yes), the process proceeds to step S72. On the other hand, if it is not determined that a stop command has been input (step S71: No), the process returns to step S67, and the vibration generator 10e repeats the above-described process.

If it is determined in step S71 that an instruction to stop the vibration generator 10e has been input, the operating time integrator 29 stores the operating time Ot of the vibration generator 10e at that time (step S72). The vibration generator 10e then ends the processing of FIG. 13.

Next, the flow of the blower frequency characteristic setting process will be explained using Figure 14. Figure 14 is a flowchart showing an example of the flow of the blower frequency characteristic setting process shown in Figure 13.

The coil deterioration determination unit 45 determines the deterioration state of the excitation coil 15 and the drive coil 16 based on the color of the excitation coil 15 measured by the color sensor 40 and the color of the drive coil 16 measured by the color sensor 41 (step S81). If the deterioration state is determined to be low, the process proceeds to step S82. If the deterioration state is determined to be medium, the process proceeds to step S86. If the deterioration state is determined to be high, the process proceeds to step S90.

If it is determined in step S81 that the deterioration state is low, the cooling control unit 28d determines the length of the operating time Ot of the vibration generator 10e (step S82). If it is determined that the operating time Ot is within 50,000 hours, the process proceeds to step S83. If it is determined that the operating time Ot is between 50,000 and 100,000 hours, the process proceeds to step S84. If it is determined that the operating time exceeds 100,000 hours, the process proceeds to step S85.

If it is determined in step S82 that the operating time Ot is within 50,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to 0°C (step S83). Then, the process proceeds to step S94.

If it is determined in step S82 that the operating time Ot is between 50,000 and 100,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to -5°C (step S84). Then, the process proceeds to step S94.

If it is determined in step S82 that the operating time Ot exceeds 100,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to -10°C (step S85). Then, the process proceeds to step S94.

If the deterioration state is determined to be moderate in step S81, the cooling control unit 28d determines the length of the operating time Ot of the vibration generator 10e (step S86). If the operating time Ot is determined to be within 50,000 hours, the process proceeds to step S87. If the operating time Ot is determined to be between 50,000 and 100,000 hours, the process proceeds to step S88. If the operating time is determined to exceed 100,000 hours, the process proceeds to step S89.

If it is determined in step S86 that the operating time Ot is within 50,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to 0°C (step S87). Then, the process proceeds to step S94.

If it is determined in step S82 that the operating time Ot is between 50,000 and 100,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to -5°C (step S88). Then, the process proceeds to step S94.

If it is determined in step S82 that the operating time Ot exceeds 100,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to -10°C (step S89). Then, the process proceeds to step S94.

If it is determined in step S81 that the deterioration state is severe, the cooling control unit 28d determines the length of the operating time Ot of the vibration generator 10e (step S90). If it is determined that the operating time Ot is within 50,000 hours, the process proceeds to step S91. If it is determined that the operating time Ot is between 50,000 and 100,000 hours, the process proceeds to step S92. If it is determined that the operating time exceeds 100,000 hours, the process proceeds to step S93.

If it is determined in step S90 that the operating time Ot is within 50,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to -5°C (step S91). Then, the process proceeds to step S94.

If it is determined in step S90 that the operating time Ot is between 50,000 and 100,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to -10°C (step S92). Then, the process proceeds to step S94.

If it is determined in step S90 that the operating time Ot exceeds 100,000 hours, the cooling control unit 28d sets the temperature shift amount ΔT to -15°C (step S93). Then, the process proceeds to step S94.

Following steps S83, S84, S85, S87, S88, S89, S91, S92, and S93, the cooling control unit 28d determines the relationship between the temperatures of the excitation coil 15 and drive coil 16 and the blower frequency f of the cooling blower 30, i.e., the blower frequency characteristics N and E (step S94). Then, the process returns to the main routine (Figure 13).

As described above, the vibration generator 10e of this embodiment further includes color sensors 40, 41 (color measurement units) that measure the colors of the excitation coil 15 (magnetic path forming member) and the drive coil 16, and the cooling control unit 28d (first rotation speed setting unit and second rotation speed setting unit) shifts the multiple temperature ranges set according to the excitation coil 15 and the multiple temperature ranges set according to the drive coil 16 to lower temperatures by amounts corresponding to the colors of the excitation coil 15 and drive coil 16 measured by the color sensors 40, 41. Therefore, by maintaining the vibration generator 10e at the lowest possible temperature according to the colors of the excitation coil 15 and drive coil 16, the durability of the excitation coil 15 and drive coil 16 can be improved.

Furthermore, in the vibration generator 10e of this embodiment, the cooling control unit 28d (first rotation speed setting unit and second rotation speed setting unit) sets multiple temperature ranges based on a pre-set map showing the correspondence between the colors of the excitation coil 15 (magnetic path forming member) and drive coil 16 and multiple temperature ranges. Therefore, it is possible to easily set the blower frequency characteristics N and E according to the degree of deterioration of the excitation coil 15 and drive coil 16.

The configuration of this embodiment can also be applied to the vibration generator 10b described in the second embodiment and the vibration generator 10c described in the third embodiment.

The above describes an embodiment of the present invention, but the above-described embodiment is presented as an example and is not intended to limit the scope of the present invention. This novel embodiment can be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Furthermore, this embodiment is included within the scope and spirit of the invention, as well as the invention and its equivalents as set forth in the claims.

10a, 10b, 10c, 10d, 10e...Vibration generator, 12...Driver, 13...Test stand, 14...Elastic portion, 15...Exciter coil (magnetic path forming member), 15a...Upper excitation coil (magnetic path forming member), 15b...Lower excitation coil (magnetic path forming member), 16...Drive coil, 17...Permanent magnet (magnetic path forming member), 18, 19, 20...Temperature sensor (temperature measuring unit), 21...Fixed portion, 22a, 22b, 22c, 22d, 22e...Opening, 23...Air gap, 24...Shaft, 25...Bearing, 26...Bearing, 27...Power amplifier, 28a...Vibration control unit (excitation control unit), 28b, 28c...Cooling control unit (first rotation speed setting unit, second rotation speed setting unit), 29...Operating time integrator, 30...Cooling Blower (blower), 32...blower hose, 35...through hole, 36...copper ring, 40, 41...color sensor (color measurement unit), 42, 43...optical fiber, 45...coil deterioration determination unit, E, N...blower frequency characteristics, f, f1, f2, f3, f4, f5, f6...blower frequency, fa1, fb1...blower frequency (first predetermined rotation speed), fa2, fb2...blower frequency (second predetermined rotation speed), fa3, fb3...blower frequency (third predetermined rotation speed), Ot...operating time, T, T1, T2, T3...temperature, Ta...safe temperature range (first temperature range), Tb...control temperature range (second temperature range), Tc...limit temperature range (third temperature range), Td...limit temperature range, ΔT...temperature shift amount

Claims (15)

a magnetic path forming member that generates a static magnetic field;
a placement unit on which a subject is placed;
a drive coil that is installed on the mounting section and placed in the static magnetic field with its direction of movement restricted;
an excitation control unit that generates an electromagnetic force in the drive coil that causes the drive coil and the placement unit to reciprocate along the movement direction;
a temperature measuring unit for measuring the temperatures of the magnetic path forming member and the drive coil;
a cooling control unit that drives a blower that cools the magnetic path forming member and the drive coil;
a first rotation speed setting unit that sets the rotation speed of the blower to a rotation speed that is preset in accordance with a plurality of temperature ranges that are set in accordance with the temperature range of the magnetic path forming member, based on which of the plurality of temperature ranges the temperature of the magnetic path forming member belongs to;
a second rotation speed setting unit that sets the rotation speed of the blower to a rotation speed that is preset according to a plurality of temperature ranges that are set according to the temperature range of the drive coil, based on which the temperature of the drive coil belongs to,
the cooling control unit rotates the blower at a higher rotation speed out of the rotation speed of the blower set by the first rotation speed setting unit and the rotation speed of the blower set by the second rotation speed setting unit.
Vibration generator. the temperature range includes a first temperature range in which, by setting the rotation speed of the blower to a first predetermined rotation speed, the magnetic path forming member and the drive coil are prevented from reaching a critical temperature that would impair their operation even if a temperature change occurs in the magnetic path forming member and the drive coil;
The vibration generator according to claim 1 . The cooling control unit
stopping the blower when the higher of the rotation speed of the blower set by the first rotation speed setting unit and the rotation speed of the blower set by the second rotation speed setting unit is equal to or lower than a predetermined rotation speed;
The vibration generating device according to claim 2 . the temperature range includes a second temperature range in which the rotation speed of the blower is set to a second predetermined rotation speed that is higher than the first predetermined rotation speed, so that even if a temperature change occurs in the magnetic path forming member and the drive coil, the magnetic path forming member and the drive coil do not reach a limit temperature that would impair their operation;
The vibration generating device according to claim 2 or 3. The cooling control unit
when a higher temperature of the magnetic path forming member and the drive coil falls within the second temperature range, the first rotation speed setting unit and the second rotation speed setting unit set rotation speeds that gradually increase in accordance with the increase in temperature.
The vibration generating device according to claim 4 . The temperature range includes a third temperature range in which the rotation speed of the blower is set to a third predetermined rotation speed that is higher than the second predetermined rotation speed, so that even if a temperature change occurs in the magnetic path forming member and the drive coil, the magnetic path forming member and the drive coil do not reach a limit temperature that would impair their operation.
The vibration generator according to claim 4 or 5. The vibration generator further includes an operating time accumulator that accumulates an operating time of the vibration generator,
the first rotation speed setting unit and the second rotation speed setting unit shift a plurality of temperature regions set in accordance with the magnetic path forming member and a plurality of temperature regions set in accordance with the drive coil to lower temperatures by an amount corresponding to the operation time accumulated by the operation time accumulating unit,
The vibration generator according to any one of claims 1 to 6. the first rotation speed setting unit and the second rotation speed setting unit set the plurality of temperature regions based on a predetermined map showing a correspondence relationship between an operating time of the vibration generator and the plurality of temperature regions.
The vibration generator according to claim 7 . a color measuring unit that measures the colors of the magnetic path forming member and the drive coil,
the first rotation speed setting unit and the second rotation speed setting unit shift the plurality of temperature regions set according to the magnetic path forming member and the plurality of temperature regions set according to the drive coil toward lower temperatures by an amount corresponding to the operating time of the vibration generator and the degree of deterioration of the magnetic path forming member and the drive coil determined based on the colors of the magnetic path forming member and the drive coil measured by the color measurement unit;
The vibration generator according to any one of claims 1 to 8. the first rotation speed setting unit and the second rotation speed setting unit set the plurality of temperature regions based on a preset map indicating a correspondence relationship between the colors of the magnetic path forming member and the drive coil and the plurality of temperature regions;
The vibration generator according to claim 9. the temperature measuring unit is installed to measure the temperature of the magnetic path forming member at a position on the leeward side of the air flow generated by the blower.
The vibration generator according to any one of claims 1 to 10. the temperature measuring unit is installed so as to measure the temperature at a position on the downwind side of the drive coil when the drive coil is positioned on the windward side of the air flow generated by the blower.
The vibration generator according to any one of claims 1 to 11. The magnetic path forming member is an excitation coil.
The vibration generator according to any one of claims 1 to 12. The excitation coil is provided in two coils, one on the upstream side and the other on the downstream side of the cooling air from the cooling control unit,
The first rotation speed setting unit
The rotation speed of the blower is set based on which of a plurality of temperature ranges set according to the excitation coils the higher temperature of one of the excitation coils measured by the temperature measurement unit and the temperature of the other excitation coil estimated based on the temperature of each excitation coil according to the operating state of the cooling control unit belongs to.
The vibration generator according to claim 13. The magnetic path forming member is a permanent magnet.
The vibration generator according to any one of claims 1 to 8 .