JPS6395839A - Electric motor - Google Patents
Electric motorInfo
- Publication number
- JPS6395839A JPS6395839A JP61238027A JP23802786A JPS6395839A JP S6395839 A JPS6395839 A JP S6395839A JP 61238027 A JP61238027 A JP 61238027A JP 23802786 A JP23802786 A JP 23802786A JP S6395839 A JPS6395839 A JP S6395839A
- Authority
- JP
- Japan
- Prior art keywords
- shape memory
- memory alloy
- contact
- electric motor
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910001285 shape-memory alloy Inorganic materials 0.000 claims abstract description 26
- 238000004804 winding Methods 0.000 abstract description 7
- 230000009466 transformation Effects 0.000 abstract description 5
- 230000002265 prevention Effects 0.000 abstract description 2
- 238000009423 ventilation Methods 0.000 description 7
- 238000001816 cooling Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 229910001120 nichrome Inorganic materials 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H37/00—Thermally-actuated switches
- H01H37/02—Details
- H01H37/32—Thermally-sensitive members
- H01H37/323—Thermally-sensitive members making use of shape memory materials
Landscapes
- Motor Or Generator Current Collectors (AREA)
- Dc Machiner (AREA)
- Thermally Actuated Switches (AREA)
Abstract
Description
【発明の詳細な説明】
「産業上の利用分野」
本発明は、電動工具などに採用される電動機の過負荷の
防止に関するものである。DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to prevention of overload of electric motors employed in power tools and the like.
「従来の技術」
電動工具などの工具が負荷に備えられる電動機は、負荷
の増大に伴い過大電流が流れることになる。"Prior Art" In an electric motor whose load is a tool such as a power tool, an excessive current flows as the load increases.
また、整流子電動機などが採用されるが、直巻の場合、
過負荷になると回転数が急激に低下するため、工具が使
用不能となり過負荷による焼損などの事故の発生は少な
いものでおる。In addition, commutator motors are used, but in the case of series winding,
When an overload occurs, the rotational speed drops rapidly, making the tool unusable, and accidents such as burnout due to overload are rare.
しかしながら、特開昭５５−７４３９７号公報に示され
る電動工具に採用されている分巻の電動機の場合、負荷
が大きくなっても回転数が低下しなく、過大電流が流れ
て電動機の焼損が発生することがある。However, in the case of the shunt-wound electric motor used in the power tool disclosed in JP-A-55-74397, the rotational speed does not decrease even when the load increases, and excessive current flows, resulting in burnout of the motor. There are things to do.
この様な過負荷による過大電流は、一般にヒユーズを電
流回路に介在させることにより過負荷時に電源を遮断し
て、焼損に至らないように構成されるものである。In general, a fuse is interposed in the current circuit to prevent excessive current caused by such an overload, thereby cutting off the power supply at the time of overload and preventing burnout.
そして、この様なヒユーズは、各種おり、一般に電流動
作型および温度動作型がある。There are various types of fuses, generally current-operated types and temperature-operated types.
一般には、バイメタルの原理を利用して構成される各種
遮断装置が用いられ、電流動作型では、過電流によりバ
イメタルを加熱させるように構成し、温度動作型では、
巻線の温度を検出してバイメタルを動作させるように構
成されている。In general, various types of interrupting devices are used that are constructed using the principle of bimetal.The current-operated type is configured to heat the bimetal with an overcurrent, and the temperature-operated type is configured to heat the bimetal by overcurrent.
It is configured to operate the bimetal by detecting the temperature of the winding.
この様な過負荷時に電源を遮断するヒユーズは、繰り返
し使用可能な型式が好ましく、電動工具の場合、小形で
軽量であることが望まれるものである。The fuse that cuts off the power in the event of such an overload is preferably of a type that can be used repeatedly, and in the case of power tools, it is desirable that it be small and lightweight.
この様な観点からは、バイメタルは、電流容量が大きく
なると外形が大きくなり、また、電流動作型と温度動作
型とでは構造的に相違し、両者の組み合せで両者に適合
する条件を満たすことは困難でおった。From this point of view, bimetals have larger external dimensions as their current capacity increases, and the current-operated type and temperature-operated type are structurally different, and it is difficult to satisfy the conditions for compatibility with both by combining the two. It was difficult.
すなわち、巻線などの温度上昇と過大電流との２つの条
件で動作させることが実質的に困難であった。That is, it is substantially difficult to operate the device under two conditions: temperature rise in the windings, etc., and excessive current.
「発明が解決しようとする問題点」
本発明は、この様な事情に鑑みてなされたものであり、
電動工具などに採用される電動機において、過大電流で
動作する外、温度上昇の条件でも動作するように構成す
ることができる過負荷の防止を行う電動機を提供するこ
とが目的である。"Problems to be Solved by the Invention" The present invention has been made in view of these circumstances,
It is an object of the present invention to provide an electric motor used in electric tools, etc., which can be configured to operate not only with excessive current but also under conditions of increased temperature, and which prevents overload.
「問題点を解決するための手段」
本発明は、電流回路に接点を介在し、この接点に一端が
接触する形状記憶合金を備え、この形状記憶合金の他端
を固定して電流回路に介在させたことによって問題点を
解決している。"Means for Solving the Problems" The present invention provides a shape memory alloy with a contact interposed in the current circuit, one end of which contacts the contact, and the other end of the shape memory alloy is fixed and the shape memory alloy is interposed in the current circuit. By doing so, the problem was resolved.
「作用」
電動機に過大電流が流れると、巻線などが発熱すると共
に形状記憶合金が発熱して変形し、接点が開成されて電
源を遮断することになる。``Operation'' When excessive current flows through the motor, the windings and other parts generate heat and the shape memory alloy is heated and deformed, opening the contacts and cutting off the power supply.
そして、電源が遮断されることにより、電動機の運転が
停止されて、時間の経過に伴い温度が下降し、再び接点
が開成されて運転が開始できる。Then, by cutting off the power supply, the operation of the electric motor is stopped, and as time passes, the temperature decreases, and the contacts are opened again to start operation.
「実施例」
この様な本発明を図面に示された一実施例に基づいて説
明すると、第１図は、本発明の電動機を示す要部の縦断
面図でおり、第２図は、その要部の拡大縦断面図である
。``Example'' The present invention will be described based on an example shown in the drawings. FIG. 1 is a vertical cross-sectional view of the main part of the electric motor of the present invention, and FIG. FIG. 3 is an enlarged longitudinal sectional view of the main part.
第１図おいて、電動機は、固定子１と回転子２とをフレ
ーム３に収容し、電動機を構成している。In FIG. 1, the electric motor includes a stator 1 and a rotor 2 housed in a frame 3.
そして、回転子２には、整流子４が備えられており、ブ
ラシ５．６が対向する位置で接触するように構成されて
いる。The rotor 2 is equipped with a commutator 4, and the brushes 5.6 are configured to come into contact with each other at opposing positions.
ざらに、ブラシ６には、接点７が備えられており、この
接点７にＬ字状に形成された形状記憶合金８の一端が接
触するように備えられており、形状記憶合金８の他端は
固定されている。Roughly speaking, the brush 6 is equipped with a contact 7, one end of which is in contact with the L-shaped shape memory alloy 8, and the other end of the shape memory alloy 8 is brought into contact with the contact 7. is fixed.
また、固定子１の外径側とフレーム３との間には、空間
が形成されており、この空間によって冷却用の通風路９
を形成している。Further, a space is formed between the outer diameter side of the stator 1 and the frame 3, and this space provides a cooling ventilation passage 9.
is formed.
通風路９の一方には、回転子２に固定されたファン１０
が備えられており、ブラシ６が備えられた他方へ強制的
に通風するように構成されている。A fan 10 fixed to the rotor 2 is installed on one side of the ventilation passage 9.
is provided, and is configured to forcibly ventilate to the other provided with the brush 6.
そして、この通風は、フレーム３の一方から他方へ貫通
するように通風窓１１．１２が構成され内部の冷却を行
うように構成されている。The ventilation windows 11 and 12 are configured to pass through the frame 3 from one side to the other, thereby cooling the inside of the frame 3.
第２図において、電動機は、ブラシ６の外側へ延設され
た接点７が備えられており、接点７には、Ｌ字状に形成
された形状記憶合金８が接触している。In FIG. 2, the electric motor is equipped with a contact point 7 extending to the outside of the brush 6, and a shape memory alloy 8 formed in an L-shape is in contact with the contact point 7.
そして、形状記憶合金８は、形状の変る変態点がおよそ
１２０℃となっており、通風路９の冷却風を受けるよう
に位置されている。The shape memory alloy 8 has a transformation point at which its shape changes at about 120° C., and is positioned so as to receive the cooling air from the ventilation passage 9.
また、接点７は、比較的電気抵抗の高い材料、例えば、
鉄やタングステンざらにはバイメタルに採用されるニク
ロムなどの材料で、各種電気抵抗が必る程度高く電流に
よって発熱が１ｑられる材料で形成されている。Further, the contact 7 is made of a material with relatively high electrical resistance, for example,
The iron or tungsten grain is made of a material such as nichrome, which is used in bimetals, and has various electrical resistances that are as high as possible and that generates 1q of heat due to the electric current.
形状記憶合金８は、Ｌ字状に形成されており、１２０’
Ｃ程度の変態点になるとＬ字状に曲げられた角度が大き
くなるように変形して接点７との接触状態が解除されて
接触が開成されるように構成されている。The shape memory alloy 8 is formed in an L shape and has a diameter of 120'.
When it reaches a transformation point of about C, the L-shaped bending angle is deformed to become larger, and the contact state with the contact point 7 is released, and the contact is opened.
そして、形状記憶合金８は、リード線１３が接続されて
おり、リード線１３を介して図示されない電源に接続さ
れ、ブラシ６を介して回転子２に電流を通じるように構
成されている。The shape memory alloy 8 is connected to a lead wire 13, and is connected to a power source (not shown) via the lead wire 13, and is configured to conduct current to the rotor 2 via the brush 6.
この様な構成において、電動機は、回転子２が回転して
図示されない工具を回転させると、電動工具として作業
ができるものでおり、過負荷になると電流が多くなる。In such a configuration, the electric motor can be operated as a power tool when the rotor 2 rotates to rotate a tool (not shown), and when overloaded, the electric current increases.
そして、電流が多くなると接点７が発熱し、その発熱が
形状記憶合金８を加熱して、変態点に達すると接点７と
形状記憶合金８との接触が開成される。When the current increases, the contact 7 generates heat, which heats the shape memory alloy 8, and when the transformation point is reached, the contact between the contact 7 and the shape memory alloy 8 is opened.
従って、接点７を介して流れていた電流が遮断され、回
転子２の回転が停止する。Therefore, the current flowing through the contact 7 is cut off, and the rotation of the rotor 2 is stopped.
この様な形状記憶合金８の変態点での動作は、電動機が
比較的過負荷な状態で運転されている場合、通風口９の
通風が固定子１などの発熱のために温度が上昇して幾分
加熱されることになり、電流の増加によって相当敏感に
動作することになる。The operation of the shape memory alloy 8 at the transformation point is such that when the electric motor is operated under relatively overload, the temperature of the ventilation in the ventilation opening 9 increases due to the heat generated by the stator 1, etc. It will heat up somewhat and will be quite sensitive to increased current.
このため、過電流の状態が一定時間継続すること、すな
わち形状記憶合金８を加熱する時間が長くなり、その間
に巻線の温度が上昇して焼損に至るといった問題点を解
消することができる。Therefore, it is possible to solve the problem that the overcurrent state continues for a certain period of time, that is, the time to heat the shape memory alloy 8 becomes long, and the temperature of the winding increases during that time, leading to burnout.
そして、形状記憶合金８は、ブラシ６に組付ける必要は
なく、電動機の冷却だめの通風路など運転の温度の影響
を受ける部分であれば、同様に動作するものであり、必
要に応じて任意の部分に備えることができるものでおる
。The shape memory alloy 8 does not need to be assembled to the brush 6, and can operate in the same way in any part that is affected by the operating temperature, such as the ventilation path of the cooling tank of an electric motor, and can be used as needed. This is something you can prepare for.
また、接点７に加熱の機能を備える外、形状記憶合金８
に接点７と同様の接点材料を備えることで加熱を行って
も良く、別にニクロム電線等を配設して形状記憶合金８
を加熱しても良い。In addition, the contact point 7 has a heating function, and the shape memory alloy 8
Heating may be performed by providing a contact material similar to that of the contact 7, or a shape memory alloy 8 may be heated by separately arranging a nichrome electric wire or the like.
You can also heat it.
「発明の効果」
本発明によれば、形状記憶合金によって任意の温度で電
源を遮断するように構成し、過電流によって動作させる
ように構成しており、小形で確実に設定温度で動作が１
ｑられるものとなり、電動工具などに採用される電動機
に極めて効果が大きく、焼損を確実に防止することがで
きる電動機を得ることができる。"Effects of the Invention" According to the present invention, the shape memory alloy is configured to cut off the power at an arbitrary temperature, and is configured to be activated by overcurrent, and is small and reliably operates at the set temperature.
Therefore, it is possible to obtain a motor that is extremely effective for use in electric tools and the like and can reliably prevent burnout.
第１図は、本発明の電動機を示す要部の縦断面図でおり
、第２図は、その要部の拡大縦断面図である。
１・・・固定子、 ２・・・回転子、 ３・・・フレー
ム、６・・・ブラシ、 ７・・・接点、 ８・・・形状
記憶合金、１０・・・ファン。FIG. 1 is a vertical cross-sectional view of the main parts of the electric motor of the present invention, and FIG. 2 is an enlarged vertical cross-sectional view of the main parts. DESCRIPTION OF SYMBOLS 1... Stator, 2... Rotor, 3... Frame, 6... Brush, 7... Contact, 8... Shape memory alloy, 10... Fan.
Claims (1)
点を介在し、この接点に一端が接触する形状記憶合金を
備え、この形状記憶合金の他端を固定して電流回路に介
在させたことを特徴とする電動機。In an electric motor that carries a load such as a tool, a contact is interposed in the current circuit, a shape memory alloy is provided with one end in contact with the contact, and the other end of the shape memory alloy is fixed and interposed in the current circuit. electric motor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61238027A JPH0630558B2 (en) | 1986-10-08 | 1986-10-08 | Commutator motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61238027A JPH0630558B2 (en) | 1986-10-08 | 1986-10-08 | Commutator motor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6395839A true JPS6395839A (en) | 1988-04-26 |
| JPH0630558B2 JPH0630558B2 (en) | 1994-04-20 |
Family
ID=17024076
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61238027A Expired - Lifetime JPH0630558B2 (en) | 1986-10-08 | 1986-10-08 | Commutator motor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0630558B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000312459A (en) * | 1999-03-12 | 2000-11-07 | Robert Bosch Gmbh | Electric motor with heat safety device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6114488A (en) * | 1984-06-28 | 1986-01-22 | Matsushita Electric Ind Co Ltd | Overload protecting apparatus for compressor |
-
1986
- 1986-10-08 JP JP61238027A patent/JPH0630558B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6114488A (en) * | 1984-06-28 | 1986-01-22 | Matsushita Electric Ind Co Ltd | Overload protecting apparatus for compressor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000312459A (en) * | 1999-03-12 | 2000-11-07 | Robert Bosch Gmbh | Electric motor with heat safety device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0630558B2 (en) | 1994-04-20 |
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