Reversing structure of electric tool switch
By using a combination of Z-type bridge structure and push rod commutation rod in the power tool switch, reliable circuit on and off under high vibration conditions is achieved, and the problems of small contact pressure and mechanical wear are solved. It is suitable for large currents. Improves the safety and service life of the structure.
Patent Information
- Application Number
- CN202420257329.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-02
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-02-02
AI Technical Summary
The commutation structure of existing power tool switches is prone to contact plate rebound under high amplitude and high frequency vibration conditions, causing circuit disconnection, and after long-term use, it leads to mechanical wear and resistance increase, limiting its application range and safety. Especially not suitable for excessive currents.
Using a Z-type bridge structure composed of upper cross rod, vertical rod and lower cross rod, combined with the reciprocating movement of the push rod and the reciprocating rod, the rocker type on-off of the contact end is achieved, providing sufficient contact pressure, and assisted by elastic elements. Contact to avoid mechanical wear and short circuit.
It realizes structural reliability and safety under high vibration conditions, is suitable for excessive current, avoids circuit disconnection problems caused by low contact pressure, and extends service life, avoids the risks of mechanical wear and short circuit.
Smart Images
Figure CN222355022U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a switch reversing structure, in particular to a reversing structure of an electric tool switch with positive and negative reversing, direct current or alternating current. Background Art
[0002] At present, the switching structure of electric tool switches sold and used in the market mainly adopts an elastic contact piece structure, that is, a spring-type structure. The characteristic of this structure is that the contact pressure is small, generally around 30GF~60GF. However, as the power of the whole machine on the market becomes higher and higher, the vibration becomes larger and larger. In the application of high-amplitude and high-frequency vibration working conditions, such as railway wrenches, impact drills and other harsh working conditions, due to the severe vibration of the switch, the contact pressure is small, which will cause the contact piece to rebound instantly, and then the circuit will be accidentally disconnected, which makes the forward and reverse steering of the electric tool disordered, bringing certain safety hazards to the normal use of the electric tool; at the same time, such structures on the existing market either use springs to The circuit is switched on and off by sliding the flexible contact piece on the copper foil of the electronic board, or by sliding two U-shaped springs between the two steering terminals. However, after a long service life, it often causes serious mechanical or electrical wear to the electronic board or the steering terminals, resulting in increased resistance or even short circuits. In addition, in order to ensure that the contact piece has a certain restoring elastic force, its thickness needs to be limited. It is usually made of beryllium copper or stainless steel with a thickness of about 0.12mm. However, contact pieces of this thickness can only be used for over-signal currents, generally a maximum of 0.5A, but cannot be used for excessive currents, resulting in a relatively single application and a limited scope of use. Utility Model Content
[0003] The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a switching structure of an electric tool switch which is reliable in structure, safe in use and applicable to excessive current.
[0004] The technical problem of the utility model is achieved through the following technical solutions:
[0005] A reversing structure for an electric tool switch comprises a shell, an electronic board installed in the shell, and a first steering terminal, a second steering terminal and a third steering terminal on the electronic board; one side of the shell is provided with a push rod that moves axially back and forth and a reversing rod that swings horizontally back and forth, the end of the reversing rod is provided with a reversing assembly, and the reversing assembly is subjected to the horizontal reciprocating swing of the reversing rod to realize the circuit connection and disconnection between the second steering terminal and the third steering terminal, one side of the first steering terminal is provided with a connecting bridge, the middle part of the connecting bridge is rotatably installed on the second steering terminal to form a seesaw structure, one end of the connecting bridge is a contact end that contacts the push rod, and the other end of the connecting bridge forms a free end; the connecting bridge is subjected to the axial reciprocating movement of the push rod to push the contact end and drive the free end to rise or fall, thereby realizing the circuit connection and disconnection between the first steering terminal and the second steering terminal.
[0006] The connecting bridge is a Z-shaped rod composed of an upper crossbar, a vertical rod bent relative to the upper crossbar through a first bending point, and a lower crossbar bent relative to the vertical rod through a second bending point.
[0007] The end of the upper cross bar is a free end, and the second bending point is a contact end that contacts the push rod.
[0008] A spring seat is provided in the shell, and an elastic element that elastically pushes each other is provided between the spring seat and the upper cross bar; the push rod moves axially outward and pushes the contact end to drive the free end to descend and compress the elastic element; the push rod moves axially inward and pushes the contact end, and cooperates with the elastic reset of the elastic element to drive the free end to tilt upward.
[0009] The upper cross bar and the spring seat are respectively provided with an upper positioning protrusion and a lower positioning protrusion for positioning and installing the two ends of the elastic element.
[0010] A push rod spring is arranged between the end of the push rod and the housing, and the push rod is elastically pushed by the push rod spring to move axially outward.
[0011] The free end tilts upward to contact the first steering terminal to form a circuit conduction, or the free end drops down to separate from the first steering terminal to form a circuit interruption.
[0012] The reversing assembly includes a connecting piece arranged on the reversing rod and elastically pushed to contact the second steering terminal; the reversing rod swings horizontally back and forth, and drives the connecting piece to contact the third steering terminal to form a circuit conduction, or drives the connecting piece to separate from the third steering terminal to form a circuit interruption.
[0013] The end of the reversing rod is provided with a positioning bead that pushes outward elastically, and a plurality of positioning grooves are provided on the inner wall of the shell opposite to the positioning bead. The reversing rod swings horizontally and drives the positioning bead that pushes outward elastically to selectively position in the plurality of positioning grooves.
[0014] The plurality of positioning grooves include a forward rotation positioning groove, a safety positioning groove and a reverse rotation positioning groove. The positioning beads are positioned in the safety positioning grooves. The axis lines of the reversing rod and the push rod are parallel, and the end of the reversing rod abuts against the push rod to limit the axial inward movement of the push rod.
[0015] Compared with the prior art, the utility model mainly provides a connecting bridge on one side of the first steering terminal on the electronic board, and the middle part of the connecting bridge is rotatably installed on the second steering terminal on the electronic board to form a seesaw structure, and one end of the connecting bridge of the seesaw structure is a contact end in contact with the push rod, and the other end of the connecting bridge forms a free end; in this way, when the connecting bridge is subjected to the axial reciprocating movement of the push rod on one side of the shell, it will push the contact end and drive the free end to rise or fall, thereby realizing the circuit connection and disconnection between the first steering terminal and the second steering terminal; obviously, this structure of realizing circuit connection and disconnection through the seesaw movement of the connecting bridge is different from the existing spring-type sliding contact structure, or through two U-shaped springs on the two steering terminals. The sliding structure between the two terminals will no longer cause mechanical wear of the copper foil or the steering terminal on the electronic board caused by sliding after a long life, thus avoiding adverse phenomena such as increased resistance and even short circuit. At the same time, through the seesaw-type contact on and off of the bridge, the steering terminal can also adopt a larger 0.8mm thickness and riveted silver contact structure, so it can be suitable for excessive current, such as a maximum current of 30A. In addition, an elastic element can be added to the free end of the seesaw-type bridge to assist the contact and conduction between the free end and the first steering terminal, thereby providing a sufficiently large contact pressure, such as 1N~2N, to solve the problem of low contact pressure and ensure the reliability of the structure and the safety of use. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic cross-sectional view of the structure of the utility model (a schematic diagram of the structure in which the push rod drives the connecting bridge to separate from the first steering terminal to form a circuit interruption).
[0017] Figure 2 It is a schematic cross-sectional view of the structure of the utility model (a schematic diagram of the structure in which the push rod drives the connecting bridge to contact the first steering terminal to form a circuit conduction).
[0018] Figure 3 It is a schematic diagram of the structure in which the reversing rod is against the push rod in a safe state.
[0019] Figure 4 The schematic diagram of the structure is that the reversing rod drives the connecting piece to contact the third steering terminal to form a circuit conduction.
[0020] Figure 5 The schematic diagram shows the structure in which the reversing rod drives the connecting piece to separate from the third steering terminal to form a circuit interruption.
[0021] Figure 6A schematic diagram of the bridge structure. DETAILED DESCRIPTION
[0022] The embodiments of the present invention will be described in detail below according to the above-mentioned drawings.
[0023] like Figure 1 to Figure 6 As shown, 1. housing, 11. spring seat, 2. electronic board, 21. first steering terminal, 22. second steering terminal, 23. third steering terminal, 3. push rod, 31. push rod spring, 32. outer shoulder, 4. connecting bridge, 41. upper cross bar, 42. first bending point, 43. vertical bar, 44. second bending point, 45. lower cross bar, 46. contact point, 5. reversing rod, 6. reversing assembly, 61. connecting piece, 62. push spring, 7. positioning bead, 71. positioning spring, 8. positioning groove, 81. forward rotation positioning groove, 82. safety positioning groove, 83. reverse rotation positioning groove, 9. elastic element, 91. upper positioning protrusion, 92. lower positioning protrusion.
[0024] A reversing structure of an electric tool switch, specifically a reversing structure of an electric tool switch with forward and reverse reversing, direct current or alternating current, mainly comprising a housing 1 and an electronic board 2 fixedly installed in the housing, the electronic board is also called a circuit board or a PCB board, on which a first steering terminal 21, a second steering terminal 22 and a third steering terminal 23 are soldered, and a push rod 3 that moves axially back and forth and a reversing rod 5 that swings horizontally back and forth are provided on one side of the housing 1, and the push rod 3 and the reversing rod 5 are usually designed on the same side of the housing 1, such as Figure 1 As shown, the push rod 3 and the reversing rod 5 are arranged on the right side of the housing 1 at the same time.
[0025] A push rod spring 31 is provided between the end of the push rod 3 and the housing 1, so that under normal conditions, the push rod spring can elastically push the push rod 3 to move axially outward, that is, Figure 1 As shown, the push rod 3 moves axially to the right, and a stop structure is provided between the housing 1 and the push rod 3 to limit the axial movement of the push rod to the right. When the push rod 3 is pressed by the finger and the elastic push of the push rod spring 31 is overcome, the push rod can be driven to move axially inward, that is, Figure 2 As shown, the push rod 3 moves axially to the left, so once the finger pressing force on the push rod 3 is released, the potential energy of the push rod spring 31 is released and the push rod 3 can be automatically pushed to move axially outward and reset.
[0026] The first turning terminal 21 side, i.e. Figure 1 The right side is provided with a bridge 4, which is formed by Figure 6 The upper crossbar 41 shown, the vertical bar 43 bent relative to the upper crossbar through the first bending point 42, and the lower crossbar 45 bent relative to the vertical bar through the second bending point 44 together constitute a Z-shaped bar, and the upper crossbar 41 near the first bending point 42 is rotatably installed on the second steering terminal 22 as the middle part of the bridge 4, that is, Figure 1 As shown, the middle part of the bridge 4 is rotatably mounted on the lower end of the second steering terminal 22 in the shape of "┓" to form a seesaw structure, and one end of the bridge 4, that is, Figure 1 The second bending point 44 at the right end of the bridge is used as the contact end on the push rod 3, and the other end of the bridge 4, that is, Figure 1 The end of the upper crossbar 41 at the left end of the bridge is shown as a free end.
[0027] A spring seat 11 is further provided in the housing 1, and an elastic element 9 is provided between the spring seat and the upper cross bar 41 to elastically push each other. The elastic element of this embodiment uses a cylindrical spring, and an upper positioning protrusion 91 and a lower positioning protrusion 92 are respectively provided on the upper cross bar 41 and the spring seat 11 for positioning and installing the two ends of the elastic element 9.
[0028] In this way, when the bridge 4 is subjected to the axial reciprocating movement of the push rod 3, it will push the contact end and drive the free end to form an upward or downward tilt, so that the circuit between the first steering terminal 21 and the second steering terminal 22 can be switched. Specifically, the push rod 3 is pushed axially outward by the elasticity of the push rod spring 31 under normal conditions to reset, so that the contact end can be pushed to drive the free end to descend and compress the elastic element 9. At this time, the descent of the free end is like Figure 1 As shown, the first steering terminal 21 is separated from the first steering terminal 21 to form a circuit interruption, that is, the power switch of the power tool is powered off and the relevant operations of the power tool cannot be performed; when the push rod 3 is pressed inward by the finger and moves axially inward, it can push the contact end, and cooperate with the elastic reset of the elastic element 9 to drive the free end to bend upward. At this time, the upward bending of the free end is like Figure 2 As shown, the first steering terminal 21 is contacted to form a circuit conduction, that is, the power tool switch is powered on to perform relevant operations of the power tool. In addition, a contact point 46 is also provided on the upper crossbar 41 of the bridge 4 to ensure that the contact with the first steering terminal 21 is more reliable.
[0029] Obviously, compared with the existing spring-type sliding contact structure, or the sliding structure between two steering terminals through two U-shaped springs, this structure that realizes circuit on-off through the seesaw movement of the bridge 4 will no longer have the problem of mechanical wear of the copper foil or steering terminals on the electronic board caused by sliding after a long life, thus avoiding adverse phenomena such as increased resistance and even short circuit; moreover, through the seesaw contact on-off of the bridge 4, the steering terminal can also adopt a larger 0.8mm thickness and riveted silver contact structure, so it can be suitable for excessive current, such as a maximum current of 30A.
[0030] In particular, an elastic element 9 is added to the free end of the seesaw bridge 4 to assist the contact and conduction between the free end and the first steering terminal 21, thereby providing a sufficiently large contact pressure, such as 1N~2N, to solve the problem of low contact pressure and ensure the reliability of the structure and the safety of use.
[0031] A reversing assembly 6 is disposed at the end of the reversing rod 5 , and the reversing assembly can realize the circuit connection and disconnection between the second steering terminal 22 and the third steering terminal 23 by the horizontal reciprocating swing of the reversing rod 5 .
[0032] The reversing assembly 6 includes a connecting piece 61 disposed on the reversing rod 5 and elastically pushed by a pushing spring 62 to contact the second steering terminal 22. When the reversing rod 5 performs horizontal reciprocating swing, the connecting piece 61 is driven to contact the third steering terminal 23 to form a circuit conduction, or the connecting piece 61 is driven to separate from the third steering terminal 23 to form a circuit interruption. In actual work, the contact and conduction between the second steering terminal 22 and the third steering terminal 23 achieved by the connecting piece 61 can be used as the forward rotation working state of the electric tool. When the connecting piece 61 separates from the third steering terminal 23 and the circuit is interrupted, it is the reverse rotation working state of the electric tool.
[0033] At the same time, a positioning bead 7 is provided at the end of the reversing rod 5 and is elastically pushed outward by a positioning spring 71, and a plurality of positioning grooves 8 are arranged side by side on the inner wall of the shell 1 opposite to the positioning bead 7. When the reversing rod 5 swings back and forth horizontally, the positioning bead 7 that is elastically pushed outward can be driven to selectively position in the plurality of positioning grooves 8.
[0034] In this embodiment, a plurality of positioning grooves 8 are configured as a positive rotation positioning groove 81, a safety positioning groove 82 and a reverse rotation positioning groove 83. Figure 3 As shown, the reversing rod 5 swings horizontally and drives the positioning bead 7 to be positioned in the safety positioning groove 82. At this time, the axis lines of the reversing rod 5 and the push rod 3 are exactly parallel, and the end of the reversing rod 5 needs to abut against the outer shoulder 32 on the push rod 3, thereby limiting the axial inward movement of the push rod 3, that is, ensuring that the push rod 3 cannot be operated to start the power tool switch, thereby playing a safety protection role. In this state, the connecting piece 61 is detached from the third steering terminal 23.
[0035] Figure 4 As shown, the reversing rod 5 swings horizontally and drives the positioning bead 7 to be positioned in the forward rotation positioning groove 81. At this time, the reversing rod 5 will drive the connecting piece 61 to contact the third steering terminal 23 to form a circuit conduction, so that the electric tool is in the forward rotation state. Once the push rod 3 is pressed inward and moves axially inward to conduct the circuit, the entire electric tool can form a forward rotation working state.
[0036] Figure 5 As shown, the reversing rod 5 swings horizontally and drives the positioning bead 7 to be positioned in the reverse rotation positioning groove 83. At this time, the reversing rod 5 will drive the connecting piece 61 to disengage from the third steering terminal 23 to form a circuit interruption, so that the power tool is in a reverse state. Once the push rod 3 is pressed inward and moves axially inward to conduct the circuit, the entire power tool can form a reverse rotation working state.
[0037] The above description is only a specific embodiment of the present invention. Those skilled in the art should understand that any structural design equivalent to this embodiment should be included in the protection scope of the present invention.
Claims
1. A reversing structure of an electric tool switch, comprising a housing (1), an electronic board (2) installed in the housing, and a first reversing terminal (21), a second reversing terminal (22) and a third reversing terminal (23) on the electronic board; a push rod (3) that moves axially back and forth and a reversing rod (5) that swings horizontally back and forth are provided on one side of the housing (1); a reversing assembly (6) is provided at the end of the reversing rod, and the reversing assembly is subjected to the horizontal reciprocating swing of the reversing rod (5) to realize the circuit switching between the second reversing terminal (22) and the third reversing terminal (23), characterized in that A connecting bridge (4) is provided on one side of the first steering terminal (21), and the middle part of the connecting bridge is rotatably mounted on the second steering terminal (22) to form a seesaw structure. One end of the connecting bridge (4) is a contact end that contacts the push rod (3), and the other end of the connecting bridge (4) forms a free end. The connecting bridge (4) is subjected to the axial reciprocating movement of the push rod (3) to push the contact end and drive the free end to tilt up or down, thereby realizing the circuit connection and disconnection between the first steering terminal (21) and the second steering terminal (22).
2. The switching structure of the electric tool switch according to claim 1, characterized in that The connecting bridge (4) is a Z-shaped rod composed of an upper crossbar (41), a vertical rod (43) bent relative to the upper crossbar via a first bending point (42), and a lower crossbar (45) bent relative to the vertical rod (43) via a second bending point (44).
3. The switching structure of the electric tool switch according to claim 2, characterized in that The end of the upper cross bar (41) is a free end, and the second bending point (44) is a contact end that contacts the push rod (3).
4. The switching structure of the electric tool switch according to claim 2, characterized in that A spring seat (11) is provided in the housing (1), and an elastic element (9) is provided between the spring seat and the upper cross bar (41) to elastically push each other; the push rod (3) moves axially outward and pushes the contact end to drive the free end downward to compress the elastic element (9); the push rod (3) moves axially inward and pushes the contact end, and cooperates with the elastic reset of the elastic element (9) to drive the free end upward.
5. The switching structure of the electric tool switch according to claim 4, characterized in that The upper cross bar (41) and the spring seat (11) are respectively provided with an upper positioning protrusion (91) and a lower positioning protrusion (92) for positioning and installing the two ends of the elastic element (9).
6. The switching structure of the electric tool switch according to claim 4, characterized in that A push rod spring (31) is provided between the end of the push rod (3) and the housing (1), and the push rod spring elastically pushes the push rod (3) to move axially outward.
7. The switching structure of the electric tool switch according to claim 4, characterized in that The free end tilts upward to contact the first steering terminal (21) to form a circuit conduction, or the free end drops down to separate from the first steering terminal (21) to form a circuit interruption.
8. The switching structure of the electric tool switch according to claim 1, characterized in that The reversing assembly (6) comprises a connecting piece (61) arranged on the reversing rod (5) and elastically pushed to contact the second steering terminal (22); the reversing rod (5) performs horizontal reciprocating swing and drives the connecting piece (61) to contact the third steering terminal (23) to form a circuit conduction, or drives the connecting piece (61) to separate from the third steering terminal (23) to form a circuit interruption.
9. The switching structure of the electric tool switch according to claim 8, characterized in that The end of the reversing rod (5) is provided with a positioning bead (7) that is elastically pushed outward, and a plurality of positioning grooves (8) are provided on the inner wall of the housing (1) opposite to the positioning bead. The reversing rod (5) performs horizontal reciprocating swing and drives the positioning bead (7) that is elastically pushed outward to selectively position itself in the plurality of positioning grooves (8).
10. The switching structure of the electric tool switch according to claim 9, characterized in that The plurality of positioning grooves (8) include a forward rotation positioning groove (81), a safety positioning groove (82) and a reverse rotation positioning groove (83), the positioning bead (7) is positioned in the safety positioning groove (82), the axis lines of the reversing rod (5) and the push rod (3) are parallel, and the end of the reversing rod (5) abuts against the push rod (3) to limit the axial inward movement of the push rod.