JP2014516806A - Electric tool and its fan - Google Patents

Abstract

  A fan for a power tool, comprising a fan body formed of a plastic material, and a metal disk attached to a front end portion of the fan body, the metal disk having an annular disk body in the form of a flat plate, For a braking tool, characterized by having teeth configured for speed detection and extending outwardly around the circumference of the annular disc body and a braking surface formed by the front surface of the annular disc body Fans are provided. An electric tool comprising a fan is also provided.

Description

TECHNICAL FIELD The present invention relates to a fan for a power tool and a power tool having such a fan.

BACKGROUND ART Power tools with cooling fan structures, such as circular saws, angle grinders, marble cutters, and other power tools are known in the art. It is desirable for the user to obtain some parameters of the power tool, such as the rotational speed of the rotor of the power tool. In addition, in some applications it is desirable for the user to stop the rotation of the power tool more efficiently.

  EP 2138279 discloses a portable angle grinder provided with a mechanical braking system. The mechanical braking system has a metal disk, which is fixed to the rotor shaft in front of the fan and thus rotates together with the rotor, which metal disk can stop the rotor. When required, it can act as a brake, for example by pressing the brake block against the metal disk by mechanical, electromagnetic or other types of force, which significantly shortens the rotation of the tool Stop in time.

  In the case of some other power tools with a fan structure, such as the Hitachi circular saw C6UVY, an additional metal disk is provided in front of the fan, which is used for speed detection. Is configured for.

  Another example of a power tool provided with a fan structure is a Makita circular saw 5732C. In this case, a sheet metal is embedded in a plastic fan for speed detection.

  All of the power tools described above have some drawbacks. Adding an additional metal disk in front of the fan increases the size of the tool and thereby increases the assembly time. In the case of the Makita circular saw 5732C, the metal disc is embedded in the fan, and the metal disc has only one speed detection function, so the metal disc is for other functions, for example a braking function. Can not be used.

  Therefore, it would be desirable to provide a fan that overcomes the aforementioned drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fan for a power tool and a power tool having such a fan to overcome the above-mentioned drawbacks.

  The disadvantages are overcome by providing special structural features on the surface of the metal disk so that the fan and metal disk are molded as an integral part, which allows the fan to detect speed and mechanically brake. It is possible to have the functions of

  In one aspect of the invention, a fan for a power tool is provided, the fan having a fan body formed from a plastic material and a metal disk attached to the front end of the fan body, the metal disk comprising: Formed by an annular disc body in the form of a flat plate, teeth configured for speed detection extending outward around the circumference of the annular disc body, and the front surface of the annular disc body And a braking surface.

  In a preferred embodiment of the invention, the teeth of the metal disk include a plurality of teeth evenly arranged along the circumferential direction of the metal disk.

  In a preferred embodiment of the invention, the teeth of the metal disk are coplanar with the disk body.

  In a preferred embodiment of the invention, the fan body has a protrusion embedded in a notch between the teeth of the metal disk.

  In a preferred embodiment of the invention, the notch between the teeth is shaped and dimensioned to fit into the protrusion of the fan body.

  In a preferred embodiment of the invention, each tooth of the metal disc is curved with respect to the disc body and has a tip embedded in the material of the fan body.

  In a preferred embodiment of the invention, the total number of teeth is 12 or 24. Of course, any suitable number of teeth can be used as desired.

  In another aspect of the invention, a power tool having the above-described fan is provided.

  In a preferred embodiment of the invention, the power tool further comprises a speed detector facing towards the teeth of the metal disk of the fan.

  In a preferred embodiment of the invention, the power tool further comprises a braking block facing towards the braking surface of the metal disk of the fan.

BRIEF DESCRIPTION OF THE DRAWINGS The above features and advantages as well as other features and advantages will now be described with reference to the embodiments of the invention in connection with the drawings.

1 is an exploded view of a fan according to one embodiment of the present invention. FIG. It is a figure which shows the speed detection use of the fan by this invention. FIG. 3 shows a mechanical braking application of a fan according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Now, some preferred embodiments according to the present invention will be described with reference to the drawings.

  For purposes of clarity and simplicity, the same reference numbers in different drawings represent the same or similar functional or structural components.

  Hereinafter, the term representing the direction “back” or “rear” represents the direction from the metal disk toward the rotor of the electric tool, and the term representing the direction “front” or “front” represents the opposite direction.

  Referring to FIG. 1, which shows an exploded view of a fan structure according to one embodiment of the present invention, the illustrated fan may be used for circular saws, angle grinders, marble cutters or other power tools. it can.

  According to this embodiment, the fan 3 may include the metal disk 1 and the fan body 2. The left part of FIG. 1 shows the structure of the metal disk 1, the central part of FIG. 1 shows the detailed structure of the fan body 2, and the right part of FIG. 1 shows the (metal attached to the fan body 2). A fan 3 (with disk 1) is shown.

  The metal disk 1 shown in the left part can be made of a magnetic metal and has high wear resistance and high thermal conductivity. For example, the metal disk 1 can be formed from a sheet metal.

  In FIG. 1, the metal disk 1 is formed in a substantially circular shape, and has an inner through hole 11 that penetrates a thin metal plate at the center. The outer peripheral surface of the substantially circular metal disk 1 is configured to be fitted to the inner surface of the outer peripheral edge portion of the front end portion of the fan body 2. The inner surface of the inner through hole 11 is configured to fit with the outer surface of the hub portion 22 of the fan body 2. According to some embodiments, the metal disk 1 can have other shapes and dimensions suitable for fitting with the inner surface of the outer peripheral edge of the front end of the fan body 2. In some embodiments, the inner through-hole 11 can have other shapes and dimensions suitable for fitting with the outer surface of the hub portion 22 of the fan body 2.

  For example, in the embodiment illustrated in FIG. 1, the metal disk is formed with teeth, such as protrusions, around the circumference of the metal disk that extend radially outward. In other words, the metal disk 1 has a plurality of teeth 12 evenly arranged around the circumference thereof, and a recess or notch 13 formed between adjacent teeth.

  In this embodiment, the recess or notch 13 between each pair of adjacent teeth is generally arcuate and extends radially inward from the outer peripheral surface of the metal disk 1. Each tooth 12 is sized to taper from the root of the tooth 12 toward the tip of the tooth 12. The notch 13 is shaped and dimensioned to fit the surface protrusion 24 of the fan body 2. According to some embodiments, the notch 13 can have other shapes and dimensions suitable for fitting with the surface protrusion 24 of the fan body 2.

  Generally, the total number of teeth 12 is 12 or 24. In this embodiment, twelve teeth are provided, but instead, other numbers of teeth can be provided on the metal disk 1 as desired.

  A fan body 2 according to this embodiment is shown in the central portion of FIG. The fan body 2 can be, for example, a fan body commonly used for circular saws, angle grinders, marble cutters or other power tools. For example, the fan body 2 can be formed from nylon (including fiber reinforced nylon), plastic (including fiber reinforced plastic), or other materials through which magnetic flux can pass. The metal disk 1 can be embedded as an insert in the fan body 2.

  In the illustrated embodiment, the metal disk 1 is fixed to the fan body 2 by the engagement of the surface protrusion 24 of the fan body 2 with the notch 13 of the metal disk 1. However, any other suitable method can be used to secure the metal disk 1 to the fan body 2, for example by other mating structures or by using fasteners or the like.

  For example, in the illustrated embodiment, the metal disk 1 is a substantially flat plate, that is, the metal disk 1 has a disk body in the form of a substantially flat plate, and the teeth 12 are defined by the metal disk 1. It is arranged on a defined plane. However, each tooth 12 extends from a plane defined by the metal disk 1 and has a curved tip with respect to the flat plate-like body of the metal disk 1 so as to be embedded in the material of the fan body 1. Can have. In this case, the surface protrusion 24 can be omitted.

  It can be seen from FIG. 1 that the fan body 2 has an outer peripheral edge portion 21 and a front end hub portion 22.

  The fan body 2 has an end surface 23, and a recess extends along the axial direction on the end surface 23, and the metal disk 1 is fitted in the recess. As shown in the central part of FIG. 1, the recess has a thickness equal to or greater than the thickness of the metal disk 1, so that the metal disk 1 is attached to the fan body 2 when the fan body 2 is attached. It does not extend beyond. As shown in FIG. 1, the surface protrusion 24 extends from the inner peripheral surface of the front end outer peripheral edge 21 toward the center of the fan body 2 so as to be in close contact with the inner surface of the recess. The surface protrusions 24 are shaped and dimensioned to be embedded in corresponding notches 13 between the teeth of the metal disk 1, and each surface protrusion 24 is smaller than the thickness of the recess, but the metal disk 1. Therefore, the metal disk can function better when attached to the fan body 2.

  In general, the total number of surface protrusions 24 is 12 or 24, corresponding to the number of cooperating teeth of the metal disk 1. In this embodiment, the number of surface protrusions 24 and the number of teeth are shown as twelve. In addition and alternatively, other numbers of surface protrusions 24 can be used to cooperate with a corresponding number of teeth of the metal disk.

  The front end hub portion 22 of the fan body 2 fits with the inner through hole 11 of the metal disk 1 in order to fit with the inner through hole 11 of the metal disk 1 when the metal disk 1 is attached to the fan body 2. Have suitable dimensions and shape. A part of the outer peripheral edge 21 of the front end that extends outward along the axial direction with respect to the recess in the end surface 23 is to be fitted with the outer peripheral surface of the metal disk 1 when the metal disk 1 is attached to the fan body 2. And an inner surface dimensioned to fit with the outer peripheral surface of the metal disk.

  As shown in the right part of FIG. 1, the metal disk 1 can be securely fixed to the fan body 2 when the metal disk 1 is attached to the fan body 2. The inner surface of the inner through hole 11 of the metal disk 1 fits with the outer surface of the front end hub portion 22 of the fan body 2, and the outer peripheral surface of the metal disk 1 extends outward from the recess in the end surface 23 along the axial direction. The notch 13 in the outer peripheral surface of the metal disk 1 is fitted with the surface protrusion 24 in the recess of the fan body 2 in the end surface 23.

  Thus, by fitting the metal disk 1 with the fan body 2, the metal disk 1 can be reliably fitted to the fan body 2, that is, the rotor 5 of the electric tool. Thereby, the metal disk 1 rotates together with the fan body 2 and the rotor 5, and the metal disk 1 has the same rotational speed as the fan body 2, so that the rotor 5 is stopped by stopping the metal disk 1. Can do.

  In addition, it can be seen from FIG. 1 that most of the front surface of the metal disk 1 is exposed to the outside of the fan body 2 when the metal disk 1 is attached to the fan body 2. This allows a sufficient area to be used, for example, to cooperate with a brake disk configured for braking.

  In a first application according to the invention, the fan 3 can be used for rotor speed detection, as shown in FIG. The application of the fan 3 for speed detection according to this embodiment will now be described with reference to FIG.

  Referring to FIG. 2, the fan 3 and the rotor 5 described above are shown. For the sake of clarity only, the small block in FIG. 2 shows a speed detector, and reference numeral 6 in FIG. 2 is used to identify the speed detector for speed detection.

  The speed detector 6 may be a conventional speed detector widely used in the art. The speed detector 6 is connected to an information display system such as a display or an information processing system such as a computer.

  In FIG. 2, the fan 3 is shown assembled to the rotor 5 so as to rotate together with the rotor 5, and therefore the rotational speed of the fan 3 is equal to the rotational speed of the rotor 5. Since the metal disk 1 is securely fitted to the fan body 2, the fan 3 has the same rotational speed as the rotor 5. In FIG. 2, the attached speed detector 6 is shown adjacent to the outer periphery of the fan 3. The rotational speed of the metal disk 1 and thus the rotor 5 can be determined by the speed detector 6 by detecting the number of teeth passing through the speed detector 6 per unit time.

  The speed detector 6 can feed back information about the rotational speed of the rotor 5 to any system that communicates with the speed detector 6 after the information has been detected by the speed detector 6.

  In another application according to the invention, the fan 3 can also be used for mechanical braking, as shown in FIG. The use of the fan 3 for mechanical braking according to this embodiment will be described with reference to FIG.

  Referring to FIG. 3, the fan 3 and the rotor 5 described above are shown. For the sake of clarity only, reference numeral 4 in FIG. 3 denotes a braking block for mechanical braking.

  Similar to the fan shown in FIG. 2, the fan 3 in FIG. 3 is shown assembled to the rotor 5 so as to rotate with the rotor 5, and therefore the rotational speed of the fan 3 is the rotation speed of the rotor 5. Equal to speed. The rotation of the metal disk 1 and thus the rotor 5 of the electric tool can be stopped by the metal disk 1 being securely fitted to the fan body 2.

  When the rotor 5 is stopped, as shown in FIG. 3, the brake block 4 is pressed against the metal disk 1 by, for example, mechanical force, electromagnetic force or other type of force. The front surface of the metal disk 1 in contact with the braking block 4 can be considered as a braking surface. Since the metal disk 1 stops rotating, the fan 3 and the rotor 5 are stopped. Alternatively, in order to stop the rotor 5 more quickly, a braking block with a larger contact area, for example an annular braking block, can be used. The two positions of the braking block are shown in FIG. 3, the two positions shown being on the one hand a non-braking position where the braking block 4 is spaced from the metal disk and on the other hand the braking block 4 is And a braking position pressed against the metal disk.

  In order to enhance the braking effect, a part of the front surface of the metal disk 1 opposite to the brake block 4 can be subjected to a surface treatment in order to increase the durability and braking reliability of the metal disk 1.

  According to the embodiment of the present invention, the metal disk 1 is securely fixed to the fan body 2 by the effect of fitting the outer peripheral surface, the effect of fitting the notch 13, and the effect of fitting the inner through hole 11. The material of the metal disk 1 is a magnetic material, and the material forming the fan body 2 is suitable for being penetrated by the magnetic flux, so that the rotation speed of the rotor 5 is determined by detecting the rotation speed of the metal disk 1. can do.

  According to the embodiment of the present invention, a good braking effect can be obtained by the reliable engagement of the metal disk 1 with the fan body 2, and the rotor 5 can correspondingly stop rotating.

  According to the present invention, the metal disk 1 attached to the fan body 2 can be used simultaneously for speed detection and mechanical braking.

  The fan according to the present invention can be used in any suitable power tool, and all power tools with such a fan are within the scope of the present invention.

  Although several specific embodiments have been described above, the embodiments are merely shown as examples for purposes of illustration and are not intended to limit the scope of the invention. Rather, the structures described herein may be embodied in many other forms, and various substitutions and modifications may be made to the structures and forms described herein without departing from the spirit or scope of the invention. Can be made.

Claims (10)

  A fan for a power tool, comprising a fan body formed of a plastic material and a metal disk attached to a front end of the fan body, the metal disk being an annular disk in the form of a flat plate A body, teeth extending outwardly around the circumference of the annular disc body and configured for speed detection, and a braking surface formed by the front surface of the annular disc body A fan for braking tools.   The fan according to claim 1, wherein the teeth of the metal disk include a plurality of teeth evenly arranged along a circumferential direction of the metal disk.   The fan according to claim 2, wherein the teeth of the metal disk are flush with the disk body.   The fan according to claim 3, wherein the fan body has a protrusion embedded in a notch between teeth of the metal disk.   The fan of claim 4, wherein the notch between the teeth is shaped and dimensioned to fit with the protrusion of the fan body.   3. A fan according to claim 2, wherein each tooth of the metal disk has a tip which is curved with respect to the disk body and embedded in the material of the fan body.   The fan of claim 2, wherein the total number of teeth is 12 or 24.   An electric tool comprising the fan according to any one of claims 1 to 7.   The power tool according to claim 8, further comprising a speed detector facing the teeth of the metal disk of the fan.   The power tool according to claim 9, further comprising a braking block facing a braking surface of the metal disk of the fan.

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