CN2487504Y

CN2487504Y - Portable electric wrench

Info

Publication number: CN2487504Y
Application number: CN 01246752
Authority: CN
Inventors: 陈晓翎
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-07-26
Filing date: 2001-07-26
Publication date: 2002-04-24
Anticipated expiration: 2011-07-26

Abstract

The utility model discloses a portable electric wrench which comprises an outer casing, a power source, an elastic connecting part and a clutch, wherein the elastic connecting part is arranged on the output end of the power source and the other end of which is fixedly arranged on a flywheel of the clutch; after a bolt or a nut is locked, the flywheel rotating in high speed together with an impact block collides with an eccentric block fixedly arranged on a main shaft, then the flywheel is bound to stop rotation; and due to the existence of the elastic connecting part, an electric motor can still rotate and transfer moment and moment of inertia into deformation and distortion of the elastic connecting part; after the impact block breaks away from the eccentric block and is then released, the electric motor is prevented from stall, thereby the service life of the electric motor is prolonged, and the operation of the prior electric wrench is more reliable and more stable.

Description

Portable electric wrench

Technical field

The utility model relates to electric tool.

Background technology

Electric wrench is widely used in the dismounting of bolt, nut and fastening, in product assembling and repairing trades, is widely used.The patent No. 00216188.5 has been introduced a kind of portable electric wrench, owing to introduced a kind of novel clutch configuration, make power only 100 watts low-voltage DC function reach the locking torque of 300 Newton meters, the overwhelming majority of dismounting easily doughnuts.Simultaneously, adopt the structure of planetary reducer, solved general gear reduction unit because of influenced by the side direction power of tearing open to cause the disadvantage of electric machine main shaft bending.But because the electric machine main shaft of electric wrench is between the flywheel all being integrated structure more closely, in case flywheel moment stops, all will cause the stall of motor, flywheel is before moment stops, motor is the maximum speed state just, the rotary inertia that the motor internal rotor is had, output torque is a maximum when adding motor rotation blockage, these energy all focus on the junction of rotor, silicon steel sheet, commutator and motor shaft, under this forward and reverse impact many times, can cause to produce between motor shaft and silicon steel sheet, the commutator and become flexible, cause motor to damage; Moreover motor rotation blockage will produce very big electric current, and will be bigger more than ten times than running current, and the automobile cigarette lighter fuse generally uses the 15A specification, if select motor with these parameters, this motor operate as normal power output will be very little, can not satisfy the needs in the actual use.

Summary of the invention

Problem to be solved in the utility model is that the connector with cushioning effect is set between power source output shaft and coupling flywheel, prolongs the service life of motor with the protection motor.

Embodiment of the present utility model is: portable electric wrench, comprise the hand-held shell, shell is provided with switch, in be provided with by interior and form support, bearing, the axle sleeve of relative position every the location, power source is fastened on the support, bearing and shaft room are provided with clutch, anterior with the joining main shaft of clutch is the square cylinder that matches with standard cartridges, it is characterized in that being provided with resilient coupling between described power source and the clutch, this resilient coupling one end connects with the power source output shaft, and the other end is connected with the flywheel of clutch.

Described power source is motor or the motor that has decelerator, and this decelerator is located in the case of fixing with support.

Compared with prior art; the utility model has utilized resilient coupling to make the drive mechanism of torque; make the resilient connection that is combined between power output and the coupling flywheel with cushioning effect; in the moment that flywheel stops operating; motor still can rotate; this moment, the rotary inertia deformation potential that is converted into resilient coupling of motor internal rotor was stored; thereby protected motor; prolonged the service life of motor; simultaneously as long as motor is still rotating; extension spring in the clutch impact block can be returned to main shaft on eccentric block break away from; then just there has not been stall in motor; this just can produce the electric wrench of bigger locking torque in the power supply allowed band, this electric wrench work is more reliable; stable.

Description of drawings

Fig. 1 has provided the utility model structural representation.

The specific embodiment

1 embodiment that is provided is described in detail the utility model again with reference to the accompanying drawings.

As shown in Figure 1, portable electric wrench has a hand-held plastic casing (11), and switch (10) is located at upper surface of outer cover, and support (9), bearing (16), axle sleeve (2) are to decide their relative position every location and installation in the disjunctor in the shell.

Power source is fastened on the support, and described power source can be the motor (12) of motor or band decelerator, and the motor with decelerator must not obtain big moment with the big motor of power, but cost is higher, and existing is that embodiment is illustrated with the latter.Decelerator is located in the case of fixing with support (9) (13), and decelerator is a planetary reducer, comprises planetary gear set (8) and centre wheel (14), and motor output shaft connects with the centre wheel close-fitting.The superiority of using planetary reducer is to reduce the motor side force, makes motor shaft indeformable.

Clutch is located between bearing and the axle sleeve, and the flywheel (17) of a hollow " Qian " type is arranged, and the bearing pin (6) that is located at flywheel " Qian " type both sides connects impact block (4), and the impact block cross section is Type, last plane is provided with pressing plate (5), the pressing plate two ends are arranged in the rectangular opening of flywheel " Qian " type both sides, two ends are equipped with the extension spring (not shown), be bearing in inner close-fitting one eccentric block (7) of the main shaft (1) in retainer assembly (3) and the bearing (16), and make axial location by shaft block ring (18).

Decelerator and clutch are connected into the soft connection with cushioning effect by resilient coupling, and resilient coupling one end connects with reducer output shaft, and the other end connects with coupling flywheel.Resilient coupling can be spring (15), helical spring or pagoda shape spring, and the cross sectional shape of spring can be circular or square or rectangle.Resilient coupling also can be the rubber sleeve that two ends are inlaid with metalwork, and what the utility model adopted is the rounded helical spring in cross section.

The operation principle of electric wrench that below underdraws is so that further understand the technical solution of the utility model.

The utility model has adopted the low-voltage direct low-power machine, after the planetary gear set speed change, is passed to the flywheel of certain mass by spring.When motor has just started, flywheel is static, spring is undeformed, because flywheel mass is heavier, the electric motor starting electric current will be very big, and spring reduces the electric motor starting electric current, torsional moment passes to flywheel slowly starts it, from the static maximum speed that accelerates to, eccentric block on the main shaft and rotatable impact block are not collided, so flywheel rotates and the main shaft transfixion.After flywheel reaches maximum speed, pressing plate overcomes tension spring tension and outwards flies away from flywheel square hole qualification position under action of centrifugal force, impact block loses platen pressure, collide with eccentric block, flywheel just drives main shaft, sleeve (not shown) on the main shaft, bolt in the sleeve or nut rotation, increasing along with the locking resistance, flywheel slows down rapidly, pressing plate reduces to be subjected to tension spring tension and is returned to the position of pressing mutually with impact block at centrifugal force, owing to the influence of pressing frictional force mutually is difficult for throwing off, in the time of must treating that flywheel decelerates to quite slowly, pressing plate centrifugal force reduces, and extension spring is just strong to break away from impact block and eccentric block, flywheel is decelerated to and stops operating, electric wrench is returned to initial duty again, through repeatedly repeatedly, and bolt, nut just is locked.

After flywheel stops operating, be subjected to the pulling of extension spring to depress impact block because lose the pressing plate of centrifugal force with the speed of bump, make impact block return the origin-location rapidly,, behind planetary reducer, make spring produce the deformation distortion though this moment, the flywheel motor that stops operating still can rotate.Certainly the permission deformation quantity of spring is limited, makes the motor rotation time also very short as only allowing about 1 circle (if only allowing about half-turn with rubber sleeve), as long as but this limited time is arranged, the stall phenomenon of motor just can not occur.

Claims

1. portable electric wrench, comprise hand-held shell (11), shell is provided with switch (10), in be provided with by interior and form support (9), bearing (16), the axle sleeve (2) of relative position every the location, power source is fastened on the support (9), bearing and shaft room are provided with clutch, anterior with the joining main shaft of clutch (1) is the square cylinder that matches with standard cartridges, it is characterized in that being provided with resilient coupling between described power source and the clutch, this resilient coupling one end connects with the power source output shaft, and the other end connects with the flywheel of clutch.

2. portable electric wrench according to claim 1 is characterized in that described power source is motor or the motor (12) that has decelerator, and this decelerator is located in the case of fixing with support (9) (13).

3. portable electric wrench according to claim 1 is characterized in that described resilient coupling is spring (15), helical spring or pagoda shape spring.

4. portable electric wrench according to claim 1 is characterized in that described resilient coupling is the rubber sleeve that two ends are inlaid with metalwork.

5. portable electric wrench according to claim 3 is characterized in that described spring (15) cross sectional shape can be circular or square or rectangle.

6. portable electric wrench according to claim 2 is characterized in that described decelerator is a planetary reducer, in be provided with planetary gear set (8) and centre wheel (14), motor (12) output shaft connects with the centre wheel close-fitting.

7. portable electric wrench according to claim 1 is characterized in that described clutch has the flywheel (17) of a hollow " Qian " type, and the bearing pin (6) that is located at flywheel " Qian " type both sides connects impact block (4), and the impact block cross section is

Type, last plane is provided with pressing plate (5), and the pressing plate two ends are arranged in the rectangular opening of flywheel " Qian " type both sides, and two ends are equipped with extension spring, be bearing in inner close-fitting one eccentric block (7) of the main shaft in retainer assembly (3) and the bearing (16), and make axial location by back-up ring (18).