A large-current power tool switch

Abstract

The present invention discloses a high-current electric tool switch, whose structure includes a housing, a bracket terminal, a static contact terminal, a positive terminal, a commutation component, a trigger component, a conductive bridge, a commutation rod, etc. Mainly, the conductive bridge is rotationally assembled on a conductive rod through arc-shaped contact, thereby reducing the heat generated in the contact area of the conductive bridge and lowering the temperature rise. At the same time, quick-break and quick-make protrusions are additionally provided on the outer surface of the middle part of the conductive bridge, and elastic seats are provided on both sides for structural cooperation to achieve quick break and make, anti-backlash, and anti-arc between the conductive bridge and the static contact terminal. In addition, double positioning is carried out on the reciprocating rotation of the commutation rod driving the commutation turntable in the commutation bottom shell, which can not only reduce the looseness of the motor terminal caused by impact and vibration during actual use, but also avoid situations such as arc ignition, temperature rise, melting and deformation failure during the use of the commutation component, thereby better ensuring the use reliability of the high-current electric tool switch and extending its service life.

Description

Technical Field

[0001] The present invention relates to an electric tool switch, specifically a high-current electric tool switch. Background Art

[0002] With the increasing power demand of the tool units in the market, the current-carrying requirements for electric tool switches are also getting higher. Currently, the commonly used electric tool switches have limited current applications due to reasons such as the design of the current-carrying structure and local heat generation and temperature rise. First, the main switch structure design forms of existing electric tool switches are mainly the pull-spring structure and the bullet-head structure. The contact parts between the corresponding bracket terminals and the conductive bridging are all formed by stamping process, resulting in local concentrated heat generation in the contact area between the bracket terminals and the conductive bridging during the process of switch closing or opening, and the switch temperature rise is too high. Second, it is difficult for the bullet-head structure of the existing speed control switch to solve problems such as the fast on-off of the switch and the anti-backlash and anti-arcing between the moving and static contacts, resulting in the contacts being more likely to be ablated, adhered, and generate high temperature under the same power conditions, reducing the working reliability and shortening the service life. Third, for the commutation component of the existing electric tool switch, when applying high current and using the commutation component as a current switch, the commutation component cannot effectively and quickly rotate and position, resulting in easy arcing between the commutation connection piece and the motor terminal when the commutation component is used as a switch, and then causing the commutation component to heat up, melt, deform, and fail. Fourth, in the commutation component of the existing electric tool switch, the motor terminal is easily loosened under the influence of impact and vibration during use, which will also cause arcing and heating, melting, and deformation failure of the commutation component during use. At the same time, in addition to the above four main use defects, the existing structural forms also have disadvantages such as complex assembly process, difficulty in realizing automated production, and relatively high cost. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a high-current electric tool switch that can effectively reduce local heat generation and temperature rise in the contact area between the conductive bridging and the bracket terminals, realize the fast on-off, anti-backlash, and anti-arcing between the moving contact on the conductive bridging and the static contact on the static contact piece terminal, and prevent arcing and heating, melting, and deformation failure when the commutation component is used as a switch, thereby better ensuring the use reliability and extending the service life.

[0004] The technical problem of the present invention is realized through the following technical solutions:

[0005] A high-current electric tool switch comprises a housing, a bracket terminal, a static contact terminal, a positive terminal and a reversing assembly installed in the housing, and a trigger assembly and a reversing rod installed outside the housing; the bracket terminal is provided with a conductive bridge that is rotatably installed in a seesaw-like manner, and the conductive bridge has a rear end adjacent to the static contact terminal and a front end away from the static contact terminal; the trigger assembly is provided with a bullet elastically pushed on the outer surface of the conductive bridge, and the bullet is driven by the trigger assembly to slide back and forth along the outer surface of the conductive bridge, and drives the front and rear ends of the conductive bridge to respectively form a seesaw-like rise or fall, and a conductive rod and an elastic seat are provided on the top of the bracket terminal; the inner surface of the middle part of the conductive bridge is fitted on the conductive rod through arc contact rotation, and the outer surface of the middle part of the conductive bridge is provided with a quick-on and off protrusion; the elastic seat has There are elastic side walls extending to both sides of the conductive bridge respectively, and limiting convex bumps are respectively provided on the opposite surfaces of the elastic side walls on both sides; the trigger assembly is pressed inward and moved, and drives the bullet to slide backward over the quick-on and off protrusions, and the bullet pushes the rear end of the conductive bridge to quickly drop and contact the static contact terminal, thereby forming a quick connection and conduction between the static contact terminal and the bracket terminal, and the rear end of the conductive bridge is quickly dropped while it is also pressed down and limited by the limiting convex bumps on the elastic side walls on both sides; the trigger assembly moves outward and resets, and drives the bullet to slide forward over the quick-on and off protrusions, and the bullet pushes the front end of the conductive bridge to quickly drop while the rear end quickly rises to separate from the static contact terminal, thereby forming a quick disconnection and conduction between the static contact terminal and the bracket terminal, and the rear end of the conductive bridge is quickly raised while it is also pushed up and limited by the limiting convex bumps on the elastic side walls on both sides.

[0006] The reversing assembly includes a reversing base shell, a motor terminal installed outside the reversing base shell, a reversing turntable rotatably mounted in the reversing base shell, and a reversing contact installed on the reversing turntable. An eccentric shaft is provided on the reversing turntable, and the eccentric shaft passes through the arc hole on the reversing base shell and is mounted in the straight circular hole at the front of the reversing rod. The middle part of the reversing rod is rotatably mounted in the shell. The reversing rod rotates around the middle part, and drives the eccentric shaft to slide reciprocatingly along the arc hole through the straight circular hole. The eccentric shaft drives the reversing turntable to reciprocate in the reversing base shell, thereby driving the reversing contact to connect the conduction between the motor terminal and the positive terminal or disconnect the conduction between the motor terminal and the positive terminal.

[0007] The front end of the reversing rod is provided with an external positioning bead that elastically pushes forward, and a corresponding wave-shaped shift protrusion is provided on the outer surface of the reversing bottom shell, and the reversing rod rotates around the middle part and drives the external positioning bead to selectively position in the shift protrusion; the reversing turntable is rotatably mounted in the rotating groove of the reversing bottom shell, and the outer circumferential surface of the reversing turntable is provided with an internal positioning bead that elastically pushes outward, and a corresponding number of positioning grooves are provided on the inner groove wall of the rotating groove, and the reversing turntable rotates back and forth in the rotating groove, and drives the internal positioning bead to selectively position in the several positioning grooves.

[0008] An arc-shaped groove extending in the width direction of the conductive connection bridge is provided on the inner surface of the middle part of the conductive connection bridge. The conductive rod is cylindrical. The inner surface of the middle part of the conductive connection bridge is fitted on the cylindrical conductive rod through the arc-shaped groove to form an arc-shaped contact rotation.

[0009] Chamfered inclined surfaces are respectively provided on both sides of the rear end of the conductive connection bridge, and limiting grooves are respectively provided at both ends of the arc-shaped groove; the quick on-off protrusion is a slope provided on the outer surface of the middle part of the conductive connection bridge. The bottom of the slope is close to the front end of the conductive connection bridge as the first passing point, and the top of the slope is close to the rear end of the conductive connection bridge as the second passing point.

[0010] A positioning tongue piece bent backward is provided at the top of the bracket terminal. Connecting notches and connecting holes for the conductive rod to pass through and form a conductive installation are respectively provided on both sides of the positioning tongue piece. A connecting pin for forming a welded conduction with one end of the conductive rod is provided on one side of the connecting notch.

[0011] The elastic seat is a U-shaped seat jointly formed by a bottom plate and elastic side walls bent in the same direction at both ends of the bottom plate. Positioning holes and positioning posts for forming positioning and fitting fixation are respectively provided between the bottom plate and the positioning tongue piece. Positioning feet and positioning notches for forming positioning and fitting fixation are respectively provided between the rear side of the bottom plate and the rear end of the positioning tongue piece.

[0012] An arc-shaped buckle ear is provided on one side of each elastic side wall.

[0013] An installation groove and an anti-loosening convex package are provided on the bracket terminal.

[0014] A static contact point is provided at the top of the static contact terminal. A moving contact point for cooperating with the static contact point is correspondingly provided at the rear end of the conductive connection bridge. The bottoms of the static contact terminal and the bracket terminal both extend out of the housing and are exposed, and a connector assembly for conductive connection is provided between the bottoms of the static contact terminal and the bracket terminal.

[0015] Compared with the prior art, the present invention mainly adds a conductive rod and an elastic seat on the top of the bracket terminal, and rotatably fits the inner surface of the middle part of the conductive bridge on the conductive rod through arc-shaped contact. There is also a quick on-off protrusion on the outer surface of the middle part of the conductive bridge, and the elastic seat has elastic side walls respectively extending to both sides of the conductive bridge, and limiting convex hulls are respectively arranged on the opposite surfaces of the two elastic side walls. In this way, when the trigger assembly is pressed inward and moves, it can drive the bullet to slide backward over the quick on-off protrusion, and the bullet can push the rear end of the conductive bridge to quickly descend and contact the static contact terminal, thereby forming a quick connection and conduction between the static contact terminal and the bracket terminal. At the same time, when the rear end of the conductive bridge quickly descends, it is also pressed and limited by the limiting convex hulls on the two elastic side walls. When the trigger assembly moves outward and resets, it can drive the bullet to slide forward over the quick on-off protrusion, and the bullet can push the front end of the conductive bridge to quickly descend and the rear end to quickly rise and separate from the static contact terminal, thereby forming a quick disconnection and conduction between the static contact terminal and the bracket terminal. At the same time, when the rear end of the conductive bridge quickly rises, it is also pushed and limited by the limiting convex hulls on the two elastic side walls. Obviously, through the above structural improvements, it can not only effectively reduce local heating and temperature rise in the contact area between the conductive bridge and the bracket terminal, but also achieve quick on-off, anti-backlash, and anti-arcing between the moving contact on the conductive bridge and the static contact on the static contact terminal. At the same time, it also double-positions the reciprocating rotation of the reversing lever driving the reversing turntable in the reversing bottom case, which can not only reduce the looseness of the motor terminal caused by impact and vibration during actual use, but also avoid the occurrence of arcing and sparking between the reversing contact piece and the motor terminal when the reversing assembly is used as a switch, which may lead to the situation of the reversing assembly heating up, melting, deforming, and failing. Therefore, the above structural improvements can better ensure the use reliability of the large-current power tool switch and greatly extend its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic cross-sectional structure diagram of the power tool switch in the open state.

[0017] Figure 2 is Figure 1 a position relationship diagram of the conductive bridge, the bracket terminal, and the static contact terminal in the open state in

[0018] Figure 3 It is a schematic cross-sectional structure diagram of the power tool switch in the closed state.

[0019] Figure 4 is Figure 3 a position relationship diagram of the conductive bridge, the bracket terminal, and the static contact terminal in the closed state in

[0020] Figure 5 It is a three-dimensional exploded view of the various components constituting the present invention disassembled.

[0021] Figure 6 is Figure 5 a three-dimensional exploded view in which all the component parts are completely disassembled.

[0022] Figure 7 is a schematic structural diagram of the conductive bridging installed on the bracket and having an upwardly curved rear end and a downwardly sloping front end.

[0023] Figure 8 is Figure 7 the left view of

[0024] Figure 9 is Figure 7 the right view of

[0025] Figure 10 is Figure 7 the enlarged view at A of

[0026] Figure 11 is Figure 7 the three-dimensional view of

[0027] Figure 12 is Figure 11 the three-dimensional exploded view of

[0028] Figure 13 is a perspective three-dimensional view of one of the bracket terminals.

[0029] Figure 14 is a perspective three-dimensional view of another of the bracket terminals.

[0030] Figure 15 is the three-dimensional view of the elastic seat.

[0031] Figure 16 is the schematic structural diagram of the conductive bridging.

[0032] Figure 17 is Figure 16 the enlarged view at B of

[0033] Figure 18 is Figure 16 the top view of

[0034] Figure 19 is Figure 16 the three-dimensional view of

[0035] Figure 20 is the schematic structural diagram of the trigger assembly.

[0036] Figure 21 is Figure 20 the three-dimensional exploded view of

[0037] Figure 22 is the schematic structural diagram of the reversing lever cooperating with the reversing assembly in one position.

[0038] Figure 23 Rear view of Figure 22 .

[0039] Figure 24 Schematic structural diagram of the reversing rod cooperating with the reversing assembly in another position.

[0040] Figure 25 Rear view of Figure 24 .

[0041] Figure 26 Stereogram of the reversing assembly.

[0042] Figure 27 Stereogram of the side opposite to Figure 26 .

[0043] Figure 28 Exploded stereogram of Figure 27 . Detailed implementation mode

[0044] The embodiments of the present invention will be further described in detail with reference to the above drawings.

[0045] As shown in Figures 1 to 28 , 1. Housing, 10. Connector assembly, 11. Bottom shell, 111. Buckle groove, 12. Shell cover, 13. Spring, 14. Conductive rod, 2. Bracket terminal, 21. Positioning tongue, 211. Positioning post, 212. Positioning notch, 22. Connection notch, 23. Connection hole, 24. Connection pin, 25. Installation groove, 26. Anti-loosening boss, 3. Stationary contact terminal, 30. Stationary contact, 4. Positive terminal, 5. Trigger assembly, 51. Bullet head, 52. Push rod, 521. End hole, 522. Side hole, 53. Dust-proof ring, 54. Trigger block, 55. Positioning pin, 56. Push rod spring, 57. Bullet head spring, 6. Conductive bridge, 60. Moving contact, 61. Arc groove, 62. Quick on-off protrusion, 621. First overshift point, 622. Second overshift point, 63. Limit groove, 64. Chamfered slope, 7. Elastic seat, 71. Bottom plate, 711. Positioning hole, 712. Positioning foot, 72. Elastic side wall, 721. Limit boss, 722. Arc-shaped buckle ear, 8. Reversing rod, 81. Rotating shaft, 82. Straight round hole, 83. Outer positioning bead, 9. Reversing assembly, 91. Reversing bottom shell, 911. Rotating groove, 912. Overshift protrusion, 913. Positioning groove, 914. Arc-shaped hole, 92. Reversing turntable, 921. Eccentric shaft, 93. Inner positioning bead, 94. Reversing connecting piece, 95. Motor terminal.

[0046] A high-current electric tool switch, as shown in Figures 1 to 6 , is mainly used as an electric tool switch with high current-carrying requirements. In this embodiment, Figure 1The left side of the shown view is the rear end of the power tool switch, and the right side of the view is the front end of the power tool switch. Its structure includes a housing 1, a bracket terminal 2, a static contact terminal 3, a positive terminal 4, and a commutation component 9 installed in the housing, as well as a trigger assembly 5 and a commutation rod 8 installed outside the housing, etc.

[0047] Among them, the housing 1 is formed by snap - fitting and fixing a bottom shell 11 and a shell cover 12. Both the bottom shell 11 and the shell cover 12 are made of non - conductive plastic materials, and other components are enclosed by the snap - fitting of the bottom shell 11 and the shell cover 12.

[0048] The static contact terminal 3, the bracket terminal 2, and the positive terminal 4 are arranged side by side at intervals in the order from left to right as Figure 1 、 Figure 3 shown. The bottoms of the static contact terminal 3, the bracket terminal 2, and the positive terminal 4 all extend out of the bottom of the housing 1 and are exposed. A connector assembly 10 for conductive connection is provided between the bottom of the static contact terminal 3 and the bottom of the bracket terminal 2.

[0049] After the top of the static contact terminal 3 is vertically bent, a fixed static contact point 30 is provided; on the top of the bracket terminal 2, there are a conductive rod 14, an elastic seat 7, and a conductive bridge 6 rotatably mounted on the conductive rod 14 in a rocker - like manner. The specific structure is as follows: the top of the bracket terminal 2 is provided with a positioning tongue 21 that is stamped and bent 90 degrees and extends backward, that is, vertically bent toward the static contact terminal 3 as Figure 13 、 Figure 14 shown. The positioning tongue is provided with a positioning post 211 formed by stamping into a cylindrical shape, and a rectangular positioning notch 212 is provided at the rear end of the positioning tongue; on both sides of the positioning tongue 21, there are respectively a connection notch 22 and a connection hole 23. The connection notch 22 refers to a notch groove with an upward opening on one side of the positioning tongue 21, and the notch groove is bent 90 degrees backward. The connection hole 23 refers to a rectangular through - hole on the other side of the positioning tongue 21, and the through - hole is bent 90 degrees backward.

[0050] The conductive rod 14 is cylindrical. Both ends of the cylindrical conductive rod 14 are respectively inserted into the connection notch 22 and the connection hole 23 to form a conductive installation. A connection pin 24 is provided on one side of the connection notch 22, and the conductive rod 14 bent at one end of the connection notch is welded and conducted with the connection pin 24 through a welding process or a soldering process.

[0051] An installation groove 25 is provided on one side of the connection hole 23, and an anti - loosening boss 26 is provided in the middle of the bracket terminal 2. The bracket terminal 2 is fitted and installed in the housing 1 through the mating of the installation groove 25 and the anti - loosening boss 26, thus forming a relatively stable installation structure. The design purpose is that during the use of the power tool switch, even if it is affected by impacts, vibrations, etc., the bracket terminal 2 will not become loose in installation, ensuring the reliability of the use of the bracket terminal 2.

[0052] The described conductive bridging 6 is a long strip-shaped component. An arc-shaped groove 61 extending in the width direction of the conductive bridging is provided on the inner surface of the middle part of the conductive bridging 6. And the conductive bridging 6 is exactly assembled on the cylindrical conductive rod 14 through the arc-shaped groove 61 on the inner surface of the middle part to form smooth rotation of arc-shaped contact, that is, seesaw-type rotation, so that the conductive bridging 6 has the rear end adjacent to the static contact terminal 3 and the front end far from the static contact terminal 3. A moving contact 60 is also provided at the rear end of the conductive bridging 6, which can form a mating contact conduction with the static contact 30 at the top of the static contact terminal 3; Limiting grooves 63 are respectively provided at both ends of the arc-shaped groove 61, which can be clamped on the top of the support terminal 2.

[0053] A quick on-off protrusion 62 formed by stamping is provided on the outer surface of the middle part of the conductive bridging 6. The quick on-off protrusion is a slope provided on the outer surface of the middle part of the conductive bridging 6, and the bottom of the slope is close to the front end of the conductive bridging as the first passing point 621, and the top of the slope is close to the rear end of the conductive bridging as the second passing point 622.

[0054] The elastic seat 7 is as Figure 15 shown. It is a U-shaped seat jointly composed of a bottom plate 71 and elastic side walls 72 bent in the same direction at both ends of the bottom plate. A circular positioning hole 711 is provided on the bottom plate 71, and a positioning foot 712 bent upward is provided at the rear side of the bottom plate 71; In this way, after the elastic seat 7 is positioned and assembled with the positioning post 211 on the positioning tongue piece 21 through the positioning hole 711 on the bottom plate 71, it is fixed integrally by riveting; It is also fixed by positioning and fitting by the positioning foot 712 at the rear side of the bottom plate 71 being stuck in the positioning notch 212 at the rear end of the positioning tongue piece 21, so that the elastic seat 7 is installed and fixed on the top of the support terminal 2.

[0055] At the same time, the two elastic side walls 72 of the elastic seat 7 respectively extend on both sides of the rear end of the conductive bridging 6. The two elastic side walls 72 form a relatively convex arc shape, and limiting convex bumps 721 are respectively provided on the opposite surfaces of the elastic side walls 72 on both sides of the rear end of the conductive bridging 6, and an arc-shaped buckle ear 722 is provided on one side of each elastic side wall 72; Among them, when the rear end of the conductive bridging 6 descends rapidly, it can be pressed and limited by the limiting convex bumps 721 on the two elastic side walls 72 on both sides, that is, to ensure that the power tool switch maintains a relatively stable open state; When the rear end of the conductive bridging 6 rises rapidly, it can be pushed and limited by the limiting convex bumps 721 on the two elastic side walls 72 on both sides, that is, to ensure that the power tool switch maintains a relatively stable closed state; Chamfered slopes 64 are respectively provided on both sides of the rear end of the conductive bridging 6 to facilitate the downward or upward limiting of the limiting convex bumps 721, and the arc-shaped buckle ears 722 on both sides mainly provide elastic force to press the conductive bridging 6 and make the arc-shaped groove 61 on the inner surface of the middle part of the conductive bridging 6 form a tight and reliable contact with the outer surface of the conductive rod 14 without loosening.

[0056] The described trigger assembly 5 is as Figure 20 , Figure 21 shown, including a push rod 52. The inner end of the push rod, that is, Figure 1 the shown rear end extends into the housing 1 and is provided with an end hole 521. The outer end of the push rod, that is, Figure 1 the shown front end extends out of the housing 1 and installs a trigger block 54. A dust-proof ring 53 is also sleeved on the outer end of the push rod 52 at an interval from the trigger block 54 to play a role in dust prevention when the push rod 52 reciprocates; a positioning pin 55 elastically pushed backward by a push rod spring 56 is arranged in the end hole 521, and the positioning pin is positioned and fixed in the housing 1. Thus, the push rod spring 56 can provide an elastic outward moving reset thrust for the push rod 52. Correspondingly, when the trigger block 54 is pressed inward, it will drive the push rod 52 to move inward synchronously and compress the push rod spring 56; a side hole 522 with a downward opening is arranged on the front bottom side of the push rod 52. A bullet 51 elastically pushed downward by a bullet spring 57 is arranged in the side hole, and the bullet is just elastically pushed on the outer surface of the conductive bridge 6. Therefore, the bullet 51 can slide back and forth on the outer surface of the conductive bridge 6 under the internal and external driving of the trigger assembly 5, and can drive the front and rear ends of the conductive bridge to rotate around the conductive rod 14 respectively to form a seesaw-like rise or fall.

[0057] Moreover, when the bullet 51 slides back and forth on the outer surface of the conductive bridge 6 under the drive of the trigger assembly 5, it will pass through the quick on-off projection 62. Specifically, when the trigger assembly 5 is pressed inward and drives the bullet 51 to slide backward past the first gear point 621 but not past the second gear point 622, the elastic thrust on the bullet 51 acts directly on the conductive rod 14. At this time, the rear end of the conductive bridge 6 is still pushed and limited upward by the limit bumps 721 on the two elastic side walls 72, that is, the power tool switch is still in the off state in this structural state.

[0058] When the trigger assembly 5 continues to be pressed inward and drives the bullet 51 to continue to slide backward past the second gear point 622, the elastic thrust on the bullet 51 acts directly on the rear end of the conductive bridge 6. At this time, the elastic thrust received by the rear end of the conductive bridge will overcome the upward pushing limit of the limit bumps 721 on the two elastic side walls 72, so as to push the rear end of the conductive bridge 6 to quickly descend and contact the static contact terminal 3, thereby quickly connecting the conduction between the static contact terminal 3 and the bracket terminal 2. That is, the power tool switch is in the on state in this structural state, and while the rear end of the conductive bridge 6 quickly descends, it is also pressed and limited downward by the limit bumps 721 on the two elastic side walls 72.

[0059] When the trigger assembly 5 is pressed inward and moved, the push rod spring 56 will always be compressed. Therefore, when the inward pressing force on the trigger assembly 5 is released, the trigger assembly will be pushed outward to reset by the elastic force of the push rod spring 56, and drive the bullet 51 to slide forward past the second overshift point 622. Due to the special ramp design of the quick on-off protrusion 62, the bullet 51 also quickly slides past the first overshift point 621, and the elastic force pushing on the bullet 51 directly acts on the front end of the conductive bridging 6. At this time, the front end of the conductive bridging will quickly drop while the rear end of the conductive bridging quickly rises. The quickly rising rear end of the conductive bridging will overcome the downward limit of the limit protrusions 721 on the elastic side walls 72 on both sides and quickly disengage from the static contact terminal 3, thereby forming a quick disconnection of the conduction between the static contact terminal and the bracket terminal 2, that is, the electric tool switch will be in the off state in this structural state, and at the same time as the rear end of the conductive bridging 6 quickly rises, it is also pushed and limited by the limit protrusions 721 on the elastic side walls 72 on both sides.

[0060] The commutation assembly 9 includes a commutation bottom case 91, a motor terminal 95 installed outside the commutation bottom case, a commutation turntable 92 rotatably assembled in the commutation bottom case 91, and a commutation contact piece 94 elastically installed on the commutation turntable 92 through a spring 13. An eccentric shaft 921 is provided on the commutation turntable 92, and the eccentric shaft passes through an arc-shaped hole 914 on the commutation bottom case 91 and is assembled in a straight circular hole 82 at the front part of the commutation rod 8. The middle part of the commutation rod 8 is rotatably installed in the housing 1 through a rotating shaft 81, specifically installed in a circular shaft hole formed by the semi-circular buckling grooves 111 of the bottom case 11 and the case cover 12. In this way, when the commutation rod 8 rotates around the rotating shaft 81 in the middle, it can drive the eccentric shaft 921 to reciprocate along the arc-shaped hole 914 through the straight circular hole 82. The eccentric shaft 921 can drive the commutation turntable 92 to rotate reciprocally in the commutation bottom case 91, and then drive the commutation contact piece 94 to connect or disconnect the conduction between the motor terminal 95 and the positive terminal 4.

[0061] In addition, an outer positioning bead 83 elastically pushed forward by a spring 13 is provided at the front end of the reversing lever 8. Correspondingly, an undulating shifting projection 912 is provided on the outer surface of the reversing bottom case 91. Therefore, when the reversing lever 8 rotates around the rotating shaft 81, the outer positioning bead 83 can be driven to be positioned within the shifting projection 812. At the same time, the reversing turntable 92 is rotatably assembled in the rotating groove 911 of the reversing bottom case 91. An inner positioning bead 93 elastically pushed outward by a spring 12 is also provided on the outer circumferential surface of the reversing turntable 92. Correspondingly, a plurality of positioning grooves 913 are provided on the inner groove wall of the rotating groove 911. And when the reversing turntable 92 reciprocally rotates in the rotating groove 911, the inner positioning bead 93 can be driven to be positioned within the plurality of positioning grooves 913. Thus, the reciprocating rotation of the reversing lever 8 driving the reversing turntable 92 in the rotating groove 911 of the reversing bottom case 91 forms a double positioning, so that not only can the loosening of the motor terminal 95 caused by impacts and vibrations during actual use be reduced, but also the situation where an electric arc is easily generated between the commutating contact piece 94 and the motor terminal 95 when the commutation assembly 9 is used as a switch due to the inability of the commutation assembly to effectively and quickly perform rotational positioning, and then the commutation assembly 9 is heated, melted, deformed, and fails can be avoided.

[0062] In summary, the present invention mainly has the following structural advantages:

[0063] 1. As a current-carrying component, for the support terminal 2, since the outer circumferential surface of the conductive rod 14 and the arc-shaped groove 61 of the conductive connection bridge 6 adopt an arc surface contact fit, during the on or off operation process, the generation of electric arcs is effectively reduced, and an obvious arc extinguishing effect is achieved. Thus, the possibility of heat generation at the contact part between the two is reduced, and a greater current-carrying capacity is also obtained.

[0064] 2. Structurally, the support terminal 2 adopts the form of a connection notch 22 and a connection hole 23 to install the conductive rod 14, and one end of the conductive rod is welded to the connection pin 24 of the support terminal 2, which can not only ensure the installation stability of the conductive rod 14, but also effectively improve the contact current-carrying capacity. Moreover, the structure and assembly process are simpler, greatly reducing the production cost.

[0065] 3. The installation groove 25 and the anti-loosening convex bulge 26 designed on the support terminal 2 can position the support terminal 2 in the housing 1 without loosening, avoiding the generation of an electric arc between the conductive connection bridge 6 and the conductive rod 14 caused by vibrations during use, and extending the service life of the electric tool switch.

[0066] 4. The elastic force generated by the arc-shaped buckle ear 722 on the shrapnel seat 7 can ensure that the conductive connection bridge 6 and the conductive rod 14 on the support terminal 2 can effectively maintain good contact even under vibration conditions, preventing the generation of electric arcs and overheating phenomena.

[0067] V. When the trigger assembly 5 drives the bullet 51 to slide backward, that is, when the power tool switch is switched from the off state to the on state, the elastic force generated by the two limiting protrusions 721 on the shrapnel seat 7 cooperates with the quick on-off protrusion 62 on the conductive bridging 6 and the chamfered inclined surfaces 64 on both sides of its rear end, enabling the conductive bridging 6 to be quickly connected to the static contact terminal 3, avoiding the generation of bounce during the closing process, and still being able to maintain effective contact under vibration conditions, avoiding arcing and ablation between the contacts, and prolonging the electrical service life of the power tool switch.

[0068] VI. When the trigger assembly 5 drives the bullet 51 to slide forward, that is, when the power tool switch is switched from the on state to the off state, the elastic force generated by the two limiting protrusions 721 on the shrapnel seat 7 cooperates with the quick on-off protrusion 62 on the conductive bridging 6, enabling the conductive bridging 6 to be quickly disconnected from the static contact terminal 3, avoiding arcing and ablation between the contacts, and prolonging the electrical service life of the power tool switch.

[0069] VII. The outer positioning beads 83 at the front end of the reversing lever 8 and the shifting protrusions 912 on the reversing bottom shell 91, as well as the inner positioning beads 93 on the outer circumferential surface of the reversing turntable 92 and several positioning grooves 913 on the inner groove wall of the rotating groove 911 form a dual positioning and are used in combination, greatly enhancing the quick reversing ability of the reversing assembly 9, effectively preventing the generation of arcs between the reversing connecting piece 91 and the motor terminal 95, and prolonging the electrical service life of the power tool switch.

[0070] The above are only specific embodiments of the present invention. Those skilled in the art should understand that any structural design equivalent to this embodiment should be included within the protection scope of the present invention.

Claims

1. A large-current electric tool switch, comprising a housing (1), a bracket terminal (2), a static contact terminal (3), a positive terminal (4) and a commutation assembly (9) installed in the housing, and a trigger assembly (5) and a commutation rod (8) installed outside the housing (1); a rocker-type rotatably mounted conductive contact bridge (6) is provided on the bracket terminal (2), and the conductive contact bridge has a rear end adjacent to the static contact terminal (3) and a front end away from the static contact terminal (3); a bullet head (51) elastically pushing against the outer surface of the conductive contact bridge (6) is provided on the trigger assembly (5), and the bullet head is driven by the trigger assembly (5) to slide back and forth along the outer surface of the conductive contact bridge (6), and drives the front and rear ends of the conductive contact bridge (6) to respectively form a rocker-type rise or fall, characterized in that The top of the described bracket terminal (2) is provided with a conductive rod (14) and an elastic seat (7); the inner surface of the middle part of the conductive connection bridge (6) is rotationally fitted on the conductive rod (14) through an arc-shaped contact, and a quick on-off protrusion (62) is provided on the outer surface of the middle part of the conductive connection bridge (6); the elastic seat (7) has elastic side walls (72) respectively extending to both sides of the conductive connection bridge (6), and limiting convex bumps (721) are respectively provided on the opposite surfaces of the two elastic side walls; the trigger assembly (5) is pressed and moved inward, and drives the bullet head (51) to slide backward over the quick on-off protrusion (62), and the bullet head (51) pushes the rear end of the conductive connection bridge (6) to quickly descend to contact the static contact terminal (3), thereby forming a quick conductive connection between the static contact terminal and the bracket terminal (2), and when the rear end of the conductive connection bridge (6) quickly descends, it is also pressed and limited by the limiting convex bumps (721) on the two elastic side walls (72); the trigger assembly (5) moves outward to reset, and drives the bullet head (51) to slide forward over the quick on-off protrusion (62), and the bullet head (51) pushes the front end of the conductive connection bridge (6) to quickly descend and the rear end to quickly rise to separate from the static contact terminal (3), thereby forming a quick disconnection of the conductive connection between the static contact terminal and the bracket terminal (2), and when the rear end of the conductive connection bridge (6) quickly rises, it is also pushed and limited by the limiting convex bumps (721) on the two elastic side walls (72).

2. The large-current electric tool switch according to claim 1, characterized in that The described commutation assembly (9) includes a commutation bottom case (91), a motor terminal (95) installed outside the commutation bottom case, a commutation turntable (92) rotationally fitted inside the commutation bottom case (91), and a commutation connection piece (94) installed on the commutation turntable. An eccentric shaft (921) is provided on the commutation turntable (92), and the eccentric shaft passes through an arc-shaped hole (914) on the commutation bottom case (91) and is fitted inside a straight circular hole (82) at the front part of the commutation rod (8). The middle part of the commutation rod (8) is rotationally installed inside the housing (1); the commutation rod (8) rotates around the middle part and drives the eccentric shaft (921) to reciprocally slide along the arc-shaped hole (914) through the straight circular hole (82). The eccentric shaft (921) drives the commutation turntable (92) to reciprocally rotate inside the commutation bottom case (91), thereby driving the commutation connection piece (94) to connect or disconnect the conductive connection between the motor terminal (95) and the positive terminal (4).

3. The large-current electric tool switch according to claim 2, characterized in that The front end of the reversing lever (8) is provided with an outer positioning bead (83) that elastically pushes forward. Correspondingly, on the outer surface of the reversing bottom shell (91), there is a wave-shaped overshift protrusion (912). The reversing lever (8) rotates around the middle and drives the outer positioning bead (83) to be selectively positioned within the overshift protrusion (912); the reversing turntable (92) is rotatably fitted in the rotating groove (911) of the reversing bottom shell (91). On the outer circumferential surface of the reversing turntable (92), there is an inner positioning bead (93) that elastically pushes outward. Correspondingly, on the inner groove wall of the rotating groove (911), there are several positioning grooves (913). The reversing turntable (92) reciprocally rotates within the rotating groove (911) and drives the inner positioning bead (93) to be selectively positioned within the several positioning grooves (913).

4. The large-current electric tool switch according to claim 1, characterized in that On the inner surface of the middle part of the conductive connecting bridge (6), there is an arc-shaped groove (61) extending along the width direction of the conductive connecting bridge. The conductive rod (14) is cylindrical. The inner surface of the middle part of the conductive connecting bridge (6) is fitted on the cylindrical conductive rod (14) through the arc-shaped groove (61) to form an arc-shaped contact rotation.

5. The large-current electric tool switch according to claim 1, characterized in that On both sides of the rear end of the conductive connecting bridge (6), there are respectively chamfered inclined surfaces (64). At both ends of the arc-shaped groove (61), there are respectively limiting grooves (63); the quick on-off protrusion (62) is a slope provided on the outer surface of the middle part of the conductive connecting bridge (6). The bottom of the slope is close to the front end of the conductive connecting bridge as the first overshift point (621), and the top of the slope is close to the rear end of the conductive connecting bridge as the second overshift point (622).

6. The large-current electric tool switch according to claim 1, characterized in that On the top of the bracket terminal (2), there is a positioning tongue (21) bent backward. On both sides of the positioning tongue, there are respectively a connection notch (22) and a connection hole (23) through which the conductive rod (14) passes to form a conductive installation. On one side of the connection notch, there is a connection pin (24) that forms a welded conduction with one end of the conductive rod (14).

7. The large-current electric tool switch according to claim 6, characterized in that The elastic seat (7) is a U-shaped seat jointly formed by a bottom plate (71) and elastic side walls (72) bent in the same direction at both ends of the bottom plate. Between the bottom plate (71) and the positioning tongue (21), there are respectively a positioning hole (711) and a positioning post (211) that form positioning and fitting fixation. Between the rear side of the bottom plate (71) and the rear end of the positioning tongue (21), there are respectively a positioning foot (712) and a positioning notch (212) that form positioning and fitting fixation.

8. The large-current electric tool switch according to claim 7, wherein On one side of each elastic side wall (72), there is an arc-shaped buckle ear (722).

9. The large-current electric tool switch according to claim 1, characterized in that On the bracket terminal (2), there are an installation groove (25) and an anti-loosening convex bump (26).

10. The large-current electric tool switch according to claim 1, wherein On the top of the static contact terminal (3), there is a static contact point (30). Correspondingly, at the rear end of the conductive connecting bridge (6), there is a moving contact point (60) that cooperates with the static contact point. The bottoms of the static contact terminal (3) and the bracket terminal (2) both extend out of the housing (1) and are exposed. Between the bottoms of the static contact terminal (3) and the bracket terminal (2), there is a connector assembly (10) for conductive connection.

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