GEAR ADJUSTING DEVICE FOR ELECTRIC IMPACT DRILL

A gear adjusting device for an electric impact device, comprising a front gearbox housing, a torsional cover rotationally sleeved at the top of the front gearbox housing, a reduction mechanism disposed at the bottom of the front gearbox housing and a tripping structure disposed within the torsional cover. The tripping structure consists of an adjusting screw, a tripping cushion, an adjusting ring and an impact conversion cushion. The adjusting ring can lock the tripping cushion and the impact conversion cushion. The torsional cover and the adjusting ring are provided with corresponding upper bosses and lower bosses, so the torsional cover drives the adjusting ring to rotate during anticlockwise rotation and when the torsional cover rotates clockwise, the adjusting ring does not rotate. Therefore, gear switching can be conducted when the torsional cover is rotated anticlockwise, achieving the effects of short adjustment stroke and quick switching.

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates to the technical field of electrical tools, in particular to a gear adjusting device for an electric impact drill.

Description of Related Art

An electric impact drill is a common electric decorating tool, usually provided with three gear shifts, namely a screw gear, an electric drill gear and an impact gear. The adjustment of the three gear shifts are conducted by regulating and changing the torsional torque and tripping of inner structures in the drills. The most common adjusting method is rotation of a torsional cover. However, during the adjustment process of the existing electric impact drills, the torsional stroke of the torsional cover is too large, so users sometimes fail to obtain accurate adjustment due to insufficient torsional stroke, thereby affecting operation quality and operation speed and bringing potential safety dangers in use.

BRIEF SUMMARY OF THE INVENTION

The objective of the present invention is to provide a gear adjusting device for an electric impact drill to solve the problem of excessive large gear adjusting torsional stroke of the existing electric impact drill.

A gear adjusting device for an electric impact drill consists of a front gearbox housing, a torsional cover rotationally sleeved at the top of the front gearbox housing, a reduction mechanism disposed at the bottom of the front gearbox housing and a tripping structure disposed within the torsional cover. The tripping structure consists of an adjusting screw in threaded connection with the torsional cover, a tripping cushion, an adjusting ring and an impact conversion cushion. The adjusting screw is connected with a plurality of vertical compression springs. The adjusting screw is connected with one end of each of the plurality of vertical compression springs, and the other end of each of the compression springs is connected with the tripping cushion. The tripping cushion, the adjusting ring and the impact conversion cushion are disposed on the front gearbox housing in turn from the bottom up. A lock structure for locking the impact conversion cushion is disposed at the upper end face of the adjusting ring. A lock structure for locking the tripping cushion is disposed at the lower end face of the adjusting ring. An upper boss is disposed at the upper end of the inner surface of the torsional cover; a corresponding lower boss is disposed on the upper end face of the adjusting ring; and the lower boss is positioned on the right side of the upper boss.

In one of the embodiments, the impact conversion cushion includes a round ring and three poke rods which are uniformly distributed on the circumference of the round ring in a radiative way. Lock grooves, corresponding to the poke rods, are formed at the upper end face of the adjusting ring. The tripping cushion is ring-shaped. The tripping cushion is internally provided with a plurality of limiting projections inwards. Lock grooves, corresponding to the limiting projections, are formed at the lower end face of the adjusting ring. Horizontal lock platforms are formed among the lock grooves. When the adjusting ring locks the tripping cushion or the impact conversion cushion, the lock platforms contact the limiting projections or the poke rods.

In one of the embodiments, a plurality of bosses are disposed at the front end of the front gearbox housing, and the adjusting ring is sleeved below the bosses, so the adjusting ring cannot move up and down.

In one of the embodiments, each boss is formed with a limiting chute which extends along the vertical direction, and the poke rods are embedded in the limiting chutes.

In one of the embodiments, a positioning block is equipped above the adjusting screw; the top end of the positioning block is connected with the torsional cover; a chute is formed at the inner side of the adjusting screw along the vertical direction; a sliding portion matched with the chute is disposed at the lower end of the positioning block; and the adjusting screw is in sliding connection with the sliding portion of the positioning block.

In one of the embodiments, an output shaft penetrates the middle of the front gearbox housing; the bottom of the output shaft is connected with the reduction mechanism; the output shaft is sleeved with an impact structure; the round ring of the impact conversion cushion is sleeved on the output shaft; and the impact structure is disposed below the impact conversion cushion.

In one of the embodiments, a reset torsional spring is connected between the tripping cushion and the adjusting ring.

In conclusion, by using the above technical scheme, the present invention has at least the following technical characteristics and progresses.

1. The torsional cover and the adjusting screw are connected by screw threads. In use, rotating the torsional cover can drive the adjusting screw to move up and down, thereby changing the elastic force of the compression springs and realizing different torsion outputs. Different torsion outputs can be achieved by direct rotation of the torsional cover.

2. The torsional cover and the adjusting ring are provided with corresponding upper bosses and lower bosses, so the torsional cover drives the adjusting ring to rotate during anticlockwise rotation and when the torsional cover rotates clockwise, the adjusting ring does not rotate. Besides, the adjusting ring can switch the locking function of the tripping cushion and the impact conversion cushion during rotation, thereby realizing the switching of the electric drill gear. Therefore, gear switching can be conducted when the torsional cover is rotated anticlockwise, achieving the effects of short adjustment stroke and quick switching.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is described in further detail in conjunction with the attached drawings and embodiments.

As shown inFIG. 1,FIG. 2andFIG. 3, a gear adjusting device for an electric impact drill consists of a front gearbox housing1, a torsional cover2rotationally sleeved at the top of the front gearbox housing1, a reduction mechanism3disposed at the bottom of the front gearbox housing1and a tripping structure disposed within the torsional cover2. The tripping structure consists of an adjusting screw4in threaded connection with the torsional cover2, a tripping cushion42, an adjusting ring43and an impact conversion cushion44. The adjusting screw41is connected with a plurality of vertical compression springs45. The adjusting screw41is connected with one end of each of the plurality of vertical compression springs45, and the other end of each of the compression springs45is connected with the tripping cushion42. The tripping cushion42, the adjusting ring43and the impact conversion cushion44are disposed on the front gearbox housing1in turn from the bottom up. A lock structure for locking the impact conversion cushion44is disposed at the upper end face of the adjusting ring43. A lock structure for locking the tripping cushion42is disposed at the lower end face of the adjusting ring43. An upper boss21is disposed at the upper end of the inner surface of the torsional cover2; a corresponding lower boss432is disposed at the upper end face of the adjusting ring43; and the lower boss432is positioned on the right side of the upper boss21. The torsional cover2rotates to drive the adjusting screw41to move up and down. The vertical movement of the adjusting screw41changes the compression quantity of the compression springs45in connection with the adjusting screw41. By adjusting the compression quantity of the compression springs45, the torsional cover2outputs different torsions. The lower boss432is positioned on the right side of the upper boss21, so when the torsional cover2rotates anticlockwise, the upper boss21positioned at the inner surface thereof drives the lower boss432to rotate, namely driving the adjusting ring43to rotate. During the rotation process, the adjusting ring43locks the tripping cushion42and the impact conversion cushion44, thereby presenting different states of the impact electric drill. Therefore, when the gear adjusting device is used for carrying out the adjustment, it is only needed to rotate the torsional cover2anticlockwise. In this way, the adjustment stroke is short, mode switching is achieved by one step, and inaccurate adjustment is avoided.

In one of the embodiments, the impact conversion cushion44includes a round ring442and three poke rods441which are uniformly distributed on the circumference of the round ring442in a radiative way. Lock grooves431, corresponding to the poke rods441, are formed at the upper end face of the adjusting ring43. The tripping cushion is ring-shaped. The tripping cushion42is internally provided with a plurality of limiting projections421inwards. Lock grooves431, corresponding to the limiting projections421, are formed at the lower end face of the adjusting ring43. Horizontal lock platforms433are formed among the lock grooves431. When the adjusting ring43locks the tripping cushion42or the impact conversion cushion44, the lock platforms433contact the limiting projections421or the poke rods441. When the lock grooves431contact the limiting projections421or the poke rods441, the adjusting ring is in a non-locked state. The adjustment mechanism is as follows.

When the torsional cover2is positioned at a screw gear, the lock grooves431at the lower end face of the adjusting ring43contact the limiting projections421of the tripping cushion42, while the lock platforms433at the upper end face of the adjusting ring43contact the poke rods441of the impact conversion cushion44, which means that, at this time, the tripping cushion42is not locked, while the impact conversion cushion44is locked, and the tripping cushion42moves up and down such that the gearbox can trip without impact. When the torsional cover2is rotated anticlockwise, the upper boss21on the torsional cover2drives the lower boss432on the adjusting ring43to rotate, realizing rotation of the adjusting ring43. At this time, the lock platforms433at the lower end face of the adjusting ring43rotate onto the limiting projections421of the tripping cushion42, while the lock platforms433at the upper end face of the adjusting ring43still contact the poke rods441. At this time, both tripping cushion42and impact conversion cushion44are locked, and the torsional cover2is positioned at an electric drill gear. If the torsional cover2is continuously rotated anticlockwise to drive the adjusting ring43to continue to rotate, the lock platforms at the lower end face of the adjusting ring43still contact the limiting projections421of the tripping cushion42, and the lock grooves431at the upper end face of the adjusting screw43contact the poke rods441. At this time, the tripping cushion42is locked, while the impact conversion cover44can move up and down in the lock grooves431, so an impact structure6below the impact conversion cushion44achieves an impact effect, meaning that the torsional cover2is positioned at an impact gear.

In one of the embodiments, a plurality of bosses11are disposed at the front end of the front gearbox housing1, and the adjusting ring43is disposed below the bosses11, so the adjusting ring43cannot move up and down. The adjusting ring43changes positions of the lock grooves431at the upper and lower end faces thereof through rotation, driving the lock platforms433to press the tripping cushion42and/or the impact conversion cushion44to achieve the locking effect. If the adjusting ring43moves up and down, the lock platforms433cannot press the tripping cushion42and/or the impact conversion cushion44, failing to achieve the locking effect and having the gear adjusting function blocked. Therefore, the arrangement of the bosses11can prevent the adjusting ring43from moving up and down.

In one of the embodiments, each boss11is formed with a limiting chute111which extends along the vertical direction, and the poke rods441are embedded in the limiting chutes111. The poke rods441are embedded in the limiting chutes111so that the impact conversion cushion44can move up and down only. When the impact conversion cushion44is locked, the electric impact drill is in the screw or electric drill state; when the impact conversion cushion44is not locked, the impact conversion cushion44can move up and down in the limiting chute111, and at this time, the electric impact drill is in the impacting state. The adjusting screw43is positioned below the bosses11, and the locking state of the impact conversion cushion44is decided by the fixing state of the poke rods441made by the adjusting ring43, so the embodiment of the poke rods441in the limiting chute111is good for control over the poke rods441by the adjusting rods43.

In one of the embodiments, a positioning block46is equipped above the adjusting screw41; the top end of the positioning block46is connected with the torsional cover2; a chute411is formed at the inner side of the adjusting screw41along the vertical direction; a sliding portion461matched with the chute411is disposed at the lower end of the positioning block46; and the adjusting screw41is in sliding connection with the sliding portion461of the positioning block46. The torsional cover2is rotated to drive the adjusting screw41in connection with the torsional cover2, and then the adjusting screw41moves to adjust the compression springs45in connection with the adjusting screw41, so the torsional cover2realizes different torsion outputs according to the compression quantity of the compression springs45. In order to improve the conversion rate of the rotation energy of the torsional cover2, the adjusting screw41can move only in the vertical direction. The positioning block46plays the role of positioning the adjusting screw41in the horizontal direction. Due to the connection between the chute411and the sliding portion461, the adjusting screw41can only move vertically along the direction in which the sliding portion461is disposed. When the torsional cover2is rotated to perform adjustment, the rotational torque thereof is directly converted into the vertical journey of the adjusting screw41, bringing convenience to the adjustment of the torsion, thereby realizing the objective of the quick gear adjustment.

In one of the embodiments, an output shaft5penetrates the middle of the front gearbox housing1; the bottom of the output shaft5is connected with the reduction mechanism3; the output shaft5is sleeved with an impact structure6; the round ring442of the impact conversion cushion44is sleeved on the output shaft5; and the impact structure6is disposed below the impact conversion cushion44. When the impact conversion cushion44is locked by the adjusting ring43, the impact structure6cannot conduct normal contact and is positioned at the screw gear or electric drill gear. When the impact conversion cushion44is not locked by the adjusting ring43, the impact conversion cushion can axially move up and down, the impact structure6can perform normal contact, and at this time, the lower end face of the adjusting ring43locks the tripping cushion42such that the reduction mechanism3cannot trip. Then, the electric impact drill conducts the impacting function.

In one of the embodiments, a reset torsional spring7is connected between the tripping cushion42and the adjusting ring43. The adjusting ring43automatically resets by the action force of the reset torsional spring7to facilitate adjustment to the gear in the next time.

One specific embodiment of the present invention is described in detail above, which does not limit the structural characteristics of the present invention. Changes or modifications made by any skilled in this field on the basis of the present invention shall fall within the patented scope of the present invention.