Hair dryer

Abstract

To provide a hair dryer capable of efficiently cooling a control board.SOLUTION: The hair dryer includes a cylindrical main body housing having a blow-out port on a front surface side and a suction port on a rear surface side, a blower disposed in the main body housing, an inner cylinder disposed inside the main body housing, a heater disposed inside a blowing passage defined between the main body housing and the inner cylinder, a cylindrical housing disposed on an upstream side coaxially with the inner cylinder and holding the blower inside, and a control board disposed to face a cooling space defined between the main body housing and the cylindrical housing and controlling the blower. The cylindrical housing is set to be larger in diameter than the inner cylindrical body, and the blower passage and the cylindrical housing are connected by a conical trapezoidal inclined wall part whose inner diameter increases from the upstream side to the downstream side, and an air guide hole for communicating the blower passage with the cooling space is provided in the inclined wall part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a hair dryer. [Background technology]

[0002] Conventionally, there has been known a hair dryer in which airflow blown by a blower is heated by a heater and then discharged from an outlet in a main body housing (see, for example, Patent Document 1). The blower is composed of a blowing fan and a motor that drives the fan.

[0003] In the hair dryer described in Patent Document 1, a fan, a motor, and a motor housing that holds the motor are provided inside the main body housing, and a control board that controls the motor is also provided. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6854109 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the hair dryer described in Patent Document 1 has a problem in that the control board is fixed to the outer peripheral surface of the motor housing, and the control board is prone to heat up. The control board is equipped with semiconductors and other components for controlling the motor, and if high temperatures affect the operation of the semiconductors, it may interfere with the rotation of the motor 5. Furthermore, in the hair dryer described in Patent Document 1, the airflow generated by the blower is not guided to the control board, making it impossible to cool it.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hair dryer that can efficiently cool a control board. [Means for solving the problem]

[0007] In order to achieve the above object, one aspect of the present invention is a hair dryer having a cylindrical main housing having an air outlet on the front side and an air intake on the rear side, and an air blower disposed within the main housing, the hair dryer comprising: an inner cylinder disposed within the main housing; a heater disposed within an air flow passage defined between the main housing and the inner cylinder and for heating the airflow generated by the air blower; a cylindrical housing disposed upstream of the airflow on the same axis as the inner cylinder and for holding the air blower therein; and a control board disposed facing a cooling space defined between the main housing and the cylindrical housing and for controlling the air blower, the cylindrical housing having a larger diameter than the inner cylinder, the air flow passage and the cylindrical housing being connected by a truncated conical inclined wall portion whose inner diameter increases from the upstream side to the downstream side of the airflow, and the inclined wall portion having an air guide hole communicating between the air flow passage and the cooling space. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a hair dryer that can efficiently cool a control board. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a hair dryer according to an embodiment of the present invention, as viewed from the front. [Figure 2] FIG. 2 is a perspective view of the hair dryer as viewed from the rear. [Figure 3] FIG. 2 is a cross-sectional view of the hair dryer. [Figure 4] FIG. 2 is an exploded perspective view of the hair dryer. [Figure 5] FIG. 2 is a perspective view of a front cover, an outer cylinder, an inner cylinder, a heater, a motor housing, and a motor. [Figure 6] FIG. 6 is a cross-sectional view of the essential parts of the hair dryer taken along line VI-VI in FIG. 3. [Figure 7]FIG. 7 is a cross-sectional view of the essential parts of the hair dryer taken along line VII-VII in FIG. 3. [Figure 8] FIG. 4 is a perspective view of a motor housing and a second circuit board. [Figure 9] FIG. 10 is a cross-sectional view of a main part of a hair dryer according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] FIG. 1 is a perspective view of a hair dryer 1 according to an embodiment, seen from the front; FIG. 2 is a perspective view of the hair dryer 1, seen from the rear; FIG. 3 is a cross-sectional view of the hair dryer 1; and FIG. 4 is an exploded perspective view of the hair dryer 1.

[0012] [Overall configuration of Hair Dryer 1] As shown in Figures 1 to 3, the hair dryer 1 according to this embodiment mainly comprises a cylindrical main body housing 2, a handle portion 3 connected to the main body housing 2, a blower fan 4 arranged within the main body housing 2, and a motor 5 that drives the fan 4.

[0013] The main body housing 2 has, at both opposing ends, an air intake 21 and an air outlet 22. The air intake 21 is provided on the rear end side of the main body housing 2, and air is drawn into the main body housing 2 through the air intake 21.

[0014] The fan 4 and motor 5 constitute the blower 7, which outputs air drawn in through the air intake 21 as an airflow toward the air outlet 22. The motor 5 is a small motor such as a DC motor. The blower 7 is disposed on the central axis O (see FIG. 3) of the main body housing 2, with the fan 4 facing the air intake 21. Hereinafter, the upstream side of the airflow generated by the blower 7 (the side where the air intake 21 is located relative to the blower 7) will be referred to simply as the "upstream side," and the downstream side of the airflow (the side where the air outlet 22 is located relative to the blower 7) will be referred to simply as the "downstream side." A heater 8 is disposed inside the main body housing 2 to heat the airflow generated by the blower 7 to generate warm air.

[0015] The handle 3 is provided with a push switch 9 for turning the power on and off, a slide switch 10 for adjusting the airflow rate, and a push switch 11 for switching between hot and cold air modes. The handle 3 also houses a first circuit board 12 for a control circuit that controls the entire hair dryer 1, and electronic components such as switches and sensors are also mounted on this first circuit board 12. A power cord 13 is connected to the first circuit board 12, and this power cord 13 is led out from the bottom end of the handle 3.

[0016] The inside of the air intake 21 is covered with a mesh filter 23 and a grill cover 24 (rear cover). The mesh filter 23 makes it difficult for foreign matter such as dust and hair to get into the main housing 2. The grill cover 24 has a plurality of ribs 24a (see FIG. 2) arranged in parallel and at equal intervals. The grill cover 24 allows air to pass through the ventilation holes defined by the ribs 24a. The grill cover 24 is located upstream of the mesh filter 23.

[0017] An inner cylindrical body 31, a motor housing 32 (cylindrical housing), a connection portion 33 (inclined wall portion), a high-voltage generator 27, and a pair of ion generating electrodes (not shown) are provided inside the main body housing 2. The inner cylindrical body 31 is disposed along the direction of the central axis O of the main body housing 2.

[0018] The main housing 2 has an outer cylinder 35 that defines an air passage 34 together with the inner cylinder 31, a front cover 36 that covers the downstream side of the air passage 34, an outer cover 37, and a fixing ring 38.

[0019] The outer cover 37 is disposed on the outer peripheral surface of the main housing 2. The outer cylinder 35 is a cylindrical member fixed to the inner peripheral surface of the outer cover 37. However, this is not limiting, and the outer cylinder 35 and the outer cover 37 may be formed integrally. The air passage 34 is an annular space defined by the inner cylinder 31 and the outer cylinder 35. The downstream end face of the outer cylinder 35 is connected to the front cover 36. In addition, the outer cylinder 35 has a narrowed portion 35a at its downstream end, the radial dimension of which narrows toward the front cover 36.

[0020] The front cover 36 is a disk-shaped member that fits onto the inner circumferential surface of the outer cover 37. The front cover 36 is formed integrally with the outer cylindrical body 35. The front cover 36 has a second partition wall 39 that closes the downstream side of the inner cylindrical body 31, and a plurality of air outlets 22 formed around the second partition wall 39. The second partition wall 39 is formed in a concave shape that is concave from the downstream side to the upstream side.

[0021] The fixed ring 38 is located at the downstream end of the main housing 2 and is an annular member that fits onto the inner circumferential surface of the outer cover 37. The fixed ring 38 has a plurality of first locking holes 38a (see FIG. 4). The first locking holes 38a are through-holes that penetrate the fixed ring 38 in the radial direction. The inner circumferential surface of the outer cover 37 is formed with first locking claws 37a (see FIG. 4) that protrude radially inward. The first locking holes 38a are locked by the first locking claws 37a. This fixes the fixed ring 38 to the outer cover 37. The fixed ring 38 abuts against the front cover 36. This prevents the outer cylindrical body 35 and the front cover 36 from coming apart in the axial direction.

[0022] Next, the configuration of the inner cylindrical body 31, heater 8, motor housing 32, connecting portion 33, etc. will be described with reference to FIGS.

[0023] FIG. 4 is an exploded perspective view of the hair dryer 1, FIG. 5 is a perspective view of the front cover 36, the outer cylinder 35, the inner cylinder 31, the heater 8, the motor housing 32, and the motor 5, and FIG. 6 is a cross-sectional view of the main parts along the line VI-VI in FIG. 3.

[0024] [Configuration of inner cylinder 31] 3 to 5, the inner cylinder 31 is located inside the outer cylinder 35 and has a first partition wall 41 that closes the upstream side. An insertion hole 41a is formed in the first partition wall 41. The insertion hole 41a penetrates the first partition wall 41 parallel to the central axis O.

[0025] The inner cylinder 31 has a first tapered outer peripheral surface 42, a constant diameter outer peripheral surface 43, and a second tapered outer peripheral surface 44. The first tapered outer peripheral surface 42 is formed on the outer peripheral surface of the first partition wall 41 and is a tapered outer peripheral surface whose outer diameter increases from the upstream side to the downstream side. The constant diameter outer peripheral surface 43 is an outer peripheral surface that extends with a constant diameter from the first tapered outer peripheral surface 42 along the direction of the central axis O. The second tapered outer peripheral surface 44 is a tapered outer peripheral surface whose outer diameter increases from the constant diameter outer peripheral surface 43 toward the second partition wall 39 of the front cover 36.

[0026] [Heater 8 Configuration] The heater 8 is disposed inside the air passage 34. Specifically, the heater 8 is supported by a heater support plate 45 disposed inside the air passage 34. The heater support plates 45 are erected on the uniform outer peripheral surface 43 of the inner cylindrical body 31 at intervals in the circumferential direction of the inner cylindrical body 31. In the example shown in FIG. 5 , six heater support plates 45 are provided on the uniform outer peripheral surface 43 and are disposed at equal angular intervals of 60°. The heater 8 is, for example, a bent electric heating wire that is spirally wound around the outer edge of the heater support plate 45. Power is supplied to the heater 8 under the control of a control circuit, and the temperature thereof increases. As a result, the airflow blown from the blower 7 is heated inside the air passage 34, and the heated air is discharged from the air outlet 22.

[0027] [Configuration of rectifying fin 46] A plurality of rectifying fins 46 are provided upright on the first tapered outer peripheral surface 42. The plurality of rectifying fins 46 are arranged at intervals in the circumferential direction of the inner cylindrical body 31. More specifically, the plurality of rectifying fins 46 are integrally formed inside the connecting portion 33, and the inner cylindrical body 31 and the connecting portion 33 are connected and integrated together, whereby the rectifying fins 46 are arranged to surround the first tapered outer peripheral surface 42.

[0028] 6, the rectifying fins 46 are arranged at positions different from the heater support plates 45 in the circumferential direction of the inner cylinder 31. Specifically, the rectifying fins 46 are arranged such that their positions in the circumferential direction of the inner cylinder 31 are aligned between adjacent heater support plates 45. This makes it easier for the airflow dispersed by the rectifying fins 46 to hit the heaters 8 supported by the heater support plates 45. Furthermore, the rectifying fins 46 and the heater support plates 45 increase the straightness of the airflow blown from the blower 7, and the airflow is sent to the air outlet 22 without losing wind pressure.

[0029] [Configuration of air outlet 22] The air passage 34 communicates with a plurality of air outlets 22 formed in the front cover 36. The air outlets 22 are arranged in the circumferential direction around the inner cylinder 31 and the second partition wall 39. More specifically, the air outlets 22 are formed in the shape of arc slits centered on the central axis O. As described above, the inner cylinder 31 has the second tapered outer peripheral surface 44, and the outer cylinder 35 has the narrowed portion 35a, so that the air passage 34 has a shape that tapers toward the air outlets 22.

[0030] [Configuration of motor housing 32] The motor housing 32 holds the blower 7 therein and is formed in a cylindrical shape with an inner diameter smaller than the air passage 34. More specifically, the motor 5 is coaxially fixed to the motor housing 32 along the central axis O. The motor housing 32 is arranged coaxially with the main housing 2 and is arranged upstream of the inner cylindrical body 31. The upstream end of the motor housing 32 is connected to the upstream end of the main housing 2. More specifically, the outer diameter (diameter dimension of the outer peripheral surface) of the motor housing 32 is set to be larger than the outer diameter of the constant diameter outer peripheral surface 43 of the inner cylindrical body 31. The inner diameter (diameter dimension of the inner peripheral surface) of the motor housing 32 is set to be approximately the same as the outer diameter of the constant diameter outer peripheral surface 43 of the inner cylindrical body 31. The shape of the motor housing 32 is not limited to a cylindrical shape, and may be a rectangular cylindrical shape or a polygonal cylindrical shape with pentagons or more sides.

[0031] A high-voltage generator 27 is also disposed on the outer peripheral surface of the motor housing 32. The high-voltage generator 27 supplies positive and negative high-voltage pulse voltages to a positive ion generating electrode and a negative ion generating electrode (not shown), respectively. The positive ion generating electrode and the negative ion generating electrode are disposed symmetrically with respect to the central axis O, and at least a portion of each electrode protrudes into the air passage 34. The positive and negative high voltages supplied from the high-voltage generator 27 cause positive and negative ions to be emitted from the tips of the positive ion generating electrode and the negative ion generating electrode, respectively.

[0032] [Configuration of connection part 33] The connecting portion 33 connects the air passage 34 and the motor housing 32, and is formed in a truncated cone shape with an inner diameter that increases from the upstream side to the downstream side. This allows the airflow generated by the blower 7 to pass through the connecting portion 33 and be sent into the air passage 34.

[0033] The connecting portion 33 is integrally formed with the aforementioned rectifying fin 46 and abutment portion 47. The abutment portion 47 is a disk-shaped member located at the center of the connecting portion 33 and has a female screw hole 47a in its center. The rectifying fin 46 connects the outer circumferential surface of the abutment portion 47 to the inner circumferential surface of the connecting portion 33. In other words, the abutment portion 47 is connected to the connecting portion 33 via the rectifying fin 46. The connecting portion 33 has a plurality of second engaging holes 33a (see FIG. 5). The second engaging holes 33a are through holes that penetrate the connecting portion 33 in the radial direction. Second engaging claws 35b that protrude radially outward are formed on the outer circumferential surface of the outer cylindrical body 35. The second engaging holes 33a are engaged with the second engaging claws 35b. This connects the connecting portion 33 to the outer cylindrical body 35.

[0034] The female screw hole 47a is threadedly engaged with a screw 48 (see FIG. 3) inserted into the insertion hole 41a of the first partition wall 41. This fastens the first partition wall 41 to the abutment portion 47. In other words, fastening the first partition wall 41 to the abutment portion 47 connects the inner cylinder body 31 to the connecting portion 33 and the motor housing 32.

[0035] Next, the configuration of the second circuit board 49 (control board) and the cooling space 52 will be described with reference to Figures 7 and 8. Figure 7 is a cross-sectional view of the main part taken along line VII-VII in Figure 3, and Figure 8 is a perspective view of the motor housing 32 and the second circuit board 49.

[0036] [Configuration of second circuit board 49] 7, the hair dryer 1 includes a substantially rectangular plate-shaped second circuit board 49 (control board) in the space defined between the motor housing 32 and the main housing 2. The second circuit board 49 is connected to the motor 5 and the first circuit board 12 via wiring (not shown). A temperature sensor (not shown) provided inside the air passage 34 is also connected to the second circuit board 49. Various circuit elements such as semiconductors for controlling the motor 5 and the heater 8 are mounted on the second circuit board 49.

[0037] As described above, second circuit board 49 is connected to first circuit board 12, and first circuit board 12 controls the power supplied to each component in response to the user's operation of switches 9 to 11. Second circuit board 49 controls motor 5 and heater 8 in response to control signals from first circuit board 12 and temperature detection signals from the temperature sensor. Specifically, second circuit board 49 controls motor 5 and heater 8 in response to temperature measurement values ​​corresponding to the temperature detection signals and the selection states of switches 9 to 11.

[0038] Furthermore, the second circuit board 49 controls the high-voltage generator 27 in response to a temperature detection signal from the temperature sensor. This allows ions to be emitted from the ion generating electrode in accordance with the temperature conditions of the outside air and the airflow, and the ions to be mixed into the airflow discharged from the air outlet 22. Thus, an appropriate amount of ions can be always emitted in accordance with the usage environment of the hair dryer 1.

[0039] [Configuration of cooling space 52] The motor housing 32 and the connecting portion 33 have a frame-shaped wall portion 51 formed on the outer peripheral surfaces thereof so as to stand radially outward from the motor housing 32. The frame-shaped wall portion 51 is formed in a U-shape extending in the axial direction of the motor housing 32 and the connecting portion 33, and is open radially outward.

[0040] The second circuit board 49 is fastened to the frame-shaped wall portion 51 by, for example, screws (not shown), and closes the open radial outer side of the frame-shaped wall portion 51. As a result, a cooling space 52 is defined inside the main housing 2, surrounded by the outer circumferential surfaces of the motor housing 32 and the connection portion 33, the frame-shaped wall portion 51, and the second circuit board 49. In other words, the cooling space 52 is defined between the main housing 2 and the motor housing 32, and one surface of the second circuit board 49 faces the cooling space 52.

[0041] The connecting portion 33 is provided with a first air introducing hole 53 that connects the air flow passage 34 and the cooling space 52. The first air introducing hole 53 is a through-hole that passes through the connecting portion 33 parallel to the central axis O. As a result, the airflow generated by the blower 7 passes through the first air introducing hole 53 and is sent into the cooling space 52. The first air introducing hole 53 shown in FIG. 6 is an arc-shaped through-hole when viewed from the direction of the central axis O. However, the shape of the first air introducing hole 53 is not limited to this, and it may be a circular or polygonal through-hole.

[0042] 7 and 8, the hair dryer 1 includes two second circuit boards 49, and the motor housing 32 and the connection portion 33 include two cooling spaces 52 and two first air holes 53 corresponding to the second circuit boards 49. The cooling spaces 52 and the first air holes 53 are disposed at positions corresponding to the second circuit boards 49. In other words, they are provided at positions overlapping with the second circuit boards 49 in the circumferential direction of the motor housing 32. More specifically, the second circuit boards 49 are disposed at equal angular intervals of 180° in the circumferential direction (see FIG. 6), and the cooling spaces 52 and the first air holes 53 are provided at the same angular intervals as the second circuit boards 49 and at positions overlapping with the second circuit boards 49 in the circumferential direction of the motor housing 32. The number of second circuit boards 49 is not limited to this, and may be three or more. In this case, it is preferable that the cooling spaces 52 and the first air holes 53 are provided at positions overlapping with multiple control boards in the circumferential direction.

[0043] [Effects of the embodiment] As described above, the hair dryer 1 according to this embodiment can achieve the following effects.

[0044] The second circuit board 49 that controls the motor 5 is disposed facing the cooling space 52 defined between the main body housing 2 and the motor housing 32, and the connecting portion 33 is provided with a first air introducing hole 53 that connects the air flow passage 34 and the cooling space 52. Therefore, airflow W2 (see FIG. 7), which is part of the airflow W1 generated by the air blower 7, is introduced into the cooling space 52 through the first air introducing hole 53. Therefore, the airflow W2 introduced into the cooling space 52 can cool the second circuit board 49. In particular, this prevents a rise in the temperature of semiconductors and other precision electronic components mounted on the second circuit board 49, thereby maintaining normal operation of the motor 5.

[0045] Furthermore, because second circuit board 49 closes the radially outer side of cooling space 52 surrounded by frame-shaped wall portion 51, airflow W2 guided into cooling space 52 does not leak to the outside. In other words, because a certain amount or more of airflow W2 is guided into cooling space 52, second circuit board 49 can always be cooled efficiently. [Other Examples] The configuration of the cooling space 52 is not limited to the above embodiment. As shown in a modified example in FIG. 9 , a straightening rib 54 and a second air guide hole 55 may be provided. The straightening rib 54 is provided inside the frame-shaped wall portion 51 (cooling space 52) and on the outer peripheral surface of the motor housing 32. The straightening rib 54 is a columnar or plate-shaped rib extending in the axial direction of the motor housing 32, i.e., parallel to the central axis O. By providing the straightening rib 54, the airflow W2 can be distributed throughout the entire cooling space 52. The second air guide hole 55 is a through-hole provided in the motor housing 32 and communicating with the cooling space 52. This allows a larger amount of airflow to be guided from the blower 7 through the second air guide hole 55, in addition to the same effects as the above embodiment. In other words, the efficiency of cooling the second circuit board 49 can be further improved.

[0046] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims. [Explanation of symbols]

[0047] 1 hair dryer 2 Main body housing 3 Handle 4 Fans 5 motors 7. Blower 8 Heater 21 Air intake 22 Air outlet 31 Inner cylinder 32 Motor housing 33 Connection 34 Ventilation passage 35 outer cylinder 36 Front cover 37 Outer cover 38 Fixed ring 39 Second bulkhead 41 First Bulkhead 42 First tapered outer surface 43 Equal diameter outer circumferential surface 44 Second tapered outer surface 45 Heater support plate 49 Second circuit board 51 Frame-shaped wall 52 Cooling space 53 First air intake hole 54 Straightening rib 55 Second air hole

Claims

1. A hair dryer having a cylindrical main body housing having an air outlet on a front side and an air intake on a rear side, and a blower device disposed inside the main body housing, an inner cylinder disposed inside the main body housing; a heater disposed inside an air passage defined between the main housing and the inner cylinder, the heater heating the airflow generated by the air blower; a cylindrical housing that is arranged coaxially with the inner cylinder and upstream of the airflow, and that holds the blower device therein; a control board that is disposed facing a cooling space defined between the main housing and the cylindrical housing and that controls the air blower; Equipped with the cylindrical housing has a larger diameter than the inner cylindrical body, The air passage and the cylindrical housing are connected by a truncated cone-shaped inclined wall portion whose inner diameter increases from the upstream side to the downstream side of the air flow, an air hole communicating the air passage with the cooling space is provided in the inclined wall portion; A hair dryer characterized by:

2. The hair dryer according to claim 1, A plurality of the control boards are provided, The hair dryer according to claim 1, wherein the cooling space and the air hole are provided at positions overlapping with a plurality of the control boards in the circumferential direction.

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