CN1481974A

CN1481974A - Electrodynamic wind artillery and starting motor type electric tool

Info

Publication number: CN1481974A
Application number: CNA021143943A
Authority: CN
Inventors: 王向东
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-09-11
Filing date: 2002-09-11
Publication date: 2004-03-17

Abstract

The present invention is one kind electric tool for assembling and disassembling large screw bolt, named electric percussion gun. It consists of starting motor and percussion device and may has reducing mechanism. The application of starting motor makes the large electric assembling tool possess wide application foreground. The starting motor may be used also in other electric tools.

Description

Electric pneumatic gun and starting motor type electric tool

Electric pneumatic gun is to utilize the percussion mechanism of the common wind big gun of start type direct motor drive and a kind of new-type hand-held assembling power tool that forms.

The assembling that present people generally use also rests in the application of miniwatt (1kw is following) electrical motor with motor with hand held electric tool, and as power-operated wrench, electric screw driver etc., these low-power machines generally all are single-phase series excitation type motors.Even also use the fastener of some high-power (more than the 1kw) big specification of electrical equipment dismounting (more than the M20) once in a while, as the motor tire Screw setting and loosening machine, three-phase main-frequency spanner, intermediate frequency spanner etc.But these equipment all show all very heavy in actual applications, perhaps need costliness and complicated additional equipment (frequency conversion unit), and inefficiency, even can not compare the general layout that Here it is has caused nowadays high-power (more than the 1kw) assembling to be ruled all the land by wind big gun (particularly import wind big gun) with hand-held tool market with the air driven tools (wind big gun) of same specification.

Trace it to its cause, very simple in fact, it is exactly high-power electric instrument motor (three-phase cage type motor, the three-phase mid-frequency motor, large-scale single-phase series motors etc.) compare with the air motor in the air driven tools (as the wind big gun), have many shortcomings that are difficult to overcome and inferior position, for example it is than air motor heaviness, starting torque and horsepower output are little, also have fearful electrical safety hidden danger etc. simultaneously.

Purpose of the present invention aims to provide a kind of simple and reliable, output torque is big, safety easy to use, and energy consumption is little, and the power tool that cost is low---electric pneumatic gun replaces and is widely used in big specification fastener now, air driven tools---the wind big gun of particularly big-and-middle-sized motor tire screw assembling.Provide a kind of new power---start type motor for power tool simultaneously.By the motor-driven power tool of start type the starting motor type instrument.

Technical scheme of the present invention is: utilize to have big torque, high rotating speed, the low pressure of soft torque rotary speed characteristic (42V is following) series excitation type actuating motor or DC start type motor are as the propulsion source of power tool (electric pneumatic gun), drive percussion mechanism or ball screw groove beater mechanism in the wind big gun, come the fastener of the big specification of dismounting (bolt) to obtain powerful impulsive torque.

Electric pneumatic gun (abbreviation electric blasting) and other power tool are technological cores of the present invention with selecting for use of motor.

According to air driven tools particularly wind big gun work characteristics and target (bolt) wind big gun requirement and essential light and handy characteristic of hand-held tool and safety performance have been determined that just electric blasting must meet the following conditions with selecting for use of motor:

1, high pulling torque, high rotating speed and soft mechanical specialities;

2, volume is little, and is in light weight, and mechanical strength is big, shock-resistant;

3, power is big, and overload capacity is strong;

4, electrical safety performance and Electro Magnetic Compatibility are good.

According to above-mentioned condition, we have chosen a kind of short time duty motor from vast as the open sea motor ocean, because of it is usually used in the starting of combustion engine, so be commonly called as start type motor or starting motor.But series excitation type motor AC/DC wherein; No matter be with direct current or source of AC, the armature coil of this motor all adopts thick flat bare bar copper coiled one circle, and is coupled to each other by commutator segment and forms armature loop, so this kind motor claims single-turn circular coil armature type motor again, be called for short the single-turn type motor, distinguish other multiturn formula motor with this.

Owing to adopt this version, so this motor has following characteristics; Big electric current, small resistor, high rotating speed, big torque, overload capacity extra-heavy, armature winding structure is rigorous, sturdy and durable simultaneously, and the power especially big (can reach 5.5kw) exported in the scope that hand-held formula instrument is allowed of volume and weight.

Above characteristic is just meeting all conditions of electric blasting with motor, also meets the usage condition of most of power tools with motor simultaneously.

The start type motor can be divided into the shunt excitation formula, DC-AC two-use type series excitation formula, and compound-wound and magneto are several.The same with starter for internal combustion engine, AC/DC type series excitation formula wherein and permanent magnetism slowdown type motor are more suitable in electric blasting and other power tool.DC-AC two-use type series excitation formula actuating motor particularly, when load increases, armature and magnetic field increase simultaneously, rotating speed also descends thereupon, and torque becomes square ground to increase with electric current, this soft speed row and big starting torque make motor can successfully drag percussion mechanism and produce big impact torsion and rotary torsion.Generally speaking, the electric blasting that series excitation type actuating motor drives does not need the adapted speed reduction gearing, and this has very important significance for the structure of simplifying electric blasting and other power tool.

The DC starter is produced by permanent magnet owing to magnetic field, so voltage range broad that its is suitable for is simple in structure light and handy, and electrical efficiency height, low cost of manufacture.Be suitable for most of power tools.But as the electric blasting motor, the hard characteristics of its mechanical movement characteristic also are the big shortcomings with respect to the series excitation actuating motor.For remedying this shortcoming, make the DC actuating motor that electric blasting uses and be typically equipped with planetary gear reducing mechanism, to reach the purpose that increases motor output torque and reduce motor volume.Although the structure that the employing of this speed reduction gearing makes electric blasting is complicated,, still has certain meaning for hand-held tool.

Start type motor and the difference structurally of other motor have just determined except that characteristics such as the big torque of electromagnetic power is big, the characteristics that also have many suitable power tools (particularly electric blasting) to require:

1, because armature resistance is very little, when motor ran into strong resistance, when the armature current generation that increases rapidly became the torque of square increase with electric current, the heat of generation was but much smaller than multiturn formula electric motor with armature.Particularly in the use of impact type electric driven instrument, the resistance of workpiece slows down motor even braking all is inevitable at power tool.And be common.Therefore, armature is very disadvantageous being decelerated increase that the electric current that increases rapidly with glancing impact makes the armature temperature to the work of power tool, and these characteristics of single-turn type motor have suppressed this unfavorable factor to a great extent;

2, the armature loop machinery intensity of using thick copper bar to make is big, shock-resistant, so just is more suitable in impact type motor instrument;

3, the low resistance of armature has just determined the operating voltage of start type motor spy low (42V is following).Such Extra Low Voltage actuating motor power tool electrical safety performance brilliance in use belongs to the III type electric tool

4, to also have characteristics are the numbers of turn that reduced the armature loop coil to greatest extent to the start type motor, also improved the ampere-turn ratio of winding to greatest extent, and low-voltage dc power supply being extensive use of in this type electric tool.These are to reducing the armature sparking on commutator, and it is quite favourable improving commutation ability.Simultaneously also make the electromagnetic compatibility of starting motor type electric tool reach splendid degree.

In sum, the start type motor is the electric blasting optimal selection of motor.

Starting motor type electric tool is compared with other instrument, has lot of advantages, wherein comparing the advantage that is shown with other motor type power tool is exactly that foregoing start type motor is compared advantage and the consequent beneficial effect that is shown with other motor, seldom states here.

Starting motor type electric tool compare with air driven tools or electric blasting compare the advantage (beneficial effect) that is had with the wind big gun be exactly that power tool is than air tool advantage;

1, energy consumption is little, the additional equipment small investment:

2, stable working, noise is less;

3, replace complicated accurate air motor with actuating motor, reduced manufacturing journey difficulty, grand low manufacturing cost has been simplified the maintenance and repair program, has prolonged service life;

4, easy to use, applied range.Starting motor type electric tool can produce the variation of different power, variety classes and different structure shape, the starting motor type electric tool extended familys of seriation according to the difference of situations such as target environment for use, to satisfy the needs of various different conditions.

In a word, starting motor type electric tool not only has the advantage of power tool but also possess air tool advantage, and the global advantage that it shows is the best of breed of this two classes instrument advantage.

Classification with the start type motor is the same, starting motor type electric tool can be divided into the series excitation formula, the shunt excitation formula, compound-wound and magneto etc. are several, wherein series excitation formula has the horsepower output height, big and the characteristics that can AC/DC of moment of torsion, and magneto actuating motor structure is simple relatively, electrical efficiency is higher, and the rotating break-in is easy.

It must be noted that the dual-purpose characteristics of series excitation formula start type motor AC and DC are very more square, but are used for the DC series type motor that automobile start is used, when using alternating current, can run into a lot of adverse factors.As the high heat because iron loss is big, decrease in efficiency etc.So also must correspondingly be improved when DC-AC two-use series excitation formula start type motor is used for power tool, the structure that forms as the silicon steel plate stacking that magnetic pole of the stator is changed into by mutually insulated is to reduce eddy current etc.

The rotating break-in principle of start type motor is the same with common electric machine principle of the same type, is to realize by the direction of current that changes armature or magnetic field winding such as the break-in of series excitation formula actuating motor.Magneto then only needs the both positive and negative polarity exchange of power supply just can be realized.

Electric blasting is selected for use by following factor decision with motor;

1, the size of percussion mechanism inertial mass, in general, the power of motor just becomes with the size of rotary inertia.

2, the object of electric blasting work, the resistance of target is big more, and selecting for use of motor must be high-power, big torque, vice versa.

3, the working environment of electric blasting has in the place of civil power and can select the AC/DC actuating motor for use, does not have the place of civil power can select the series excitation DC start motor of DC power supply such as storage battery or permanent magnetic DC actuating motor etc. for use.

It needs to be noted: the use of DC start motor type power tool is more flexible, such as, get stuck, has a power failure suddenly or does not have field work of fixed location etc., can both use storage battery that power supply is provided easily.On the portable vehicle such as automobile and tractor, also can use its loaded power, wherein the direct current electric blasting in addition can become automobile and tractor with the indispensable instrument of car, as jack.These all be other any power wind big gun and power tool all can not have make things convenient for attribute.

Because starting motor type electric tool belongs to same class motor---start type motor with motor with the starter for internal combustion engine motor, so belong to the short time duty motor, though in the use of power tool, the average load of motor is little with respect to the load of starter motor for internal combustion engine, but starting motor type electric tool still can only be made periodically intermittent duty power tool, and its load duration factor must remain on 25% or below.Secondly, it is to have certain requirements that the actuating motor type electric tool is used the capacity or the power of power supply (storage battery, startup power supply etc.), and the size of the secondary winding resistance of the internal resistance of storage battery or starting transformer all can produce fundamental influence to the horsepower output and the moment of start type motor.Therefore comprise that all high-power (more than the 1kw) starting motor type electric tools of electric blasting all must reasonably select power supply.Also must select the thickness and the length of connecting wire simultaneously, should make the lead tubbiness reduce resistance as far as possible.The resistance of connecting wire is preferably less than 0.002 Ω.

However, many advantages that the start type motor is shown make it still can satisfy the requirement of most of power tools, the power tool of intermittent duty periodically particularly, with the high-power impact type electric driven instrument as electric blasting, the application of start type motor is just right especially.

Claims

1, the start type motor is in the application of field of power tools;

2, have assembling of wind big gun function and use power tool by the motor-driven hand-held of Extra Low Voltage start type.