Signal switch of electric tool

Abstract

The utility model discloses an electric tool signal switch, comprising a housing, a housing cover, a push rod, a button, a signal electric brush, a PCB, a commutation core, a commutation electric brush, a commutation cover and the like, the housing cover covers the housing in a sealing manner, so that the signal electric brush, the PCB, the commutation core and the commutation electric brush are all sealed in the housing. The push rod is driven by the key to drive the signal electric brush to make contact with the PCB to form ON-OFF signal output and potentiometer signal output, and the reversing cover is arranged outside the shell cover and drives the reversing core to drive the reversing electric brush at the bottom to make synchronous rotation to make contact with the PCB to form three working state output of a forward rotation signal, a reverse rotation signal or a non-reversing signal. Meanwhile, the reversing core and the reversing cover are fixed through a plurality of ultrasonic welding lines, the sealing ring between the reversing core and the shell cover is specially designed, and the push block and the push rod are of a split structure, so that the electric tool signal switch has the advantages of being small in size, compact in structure, reliable in use and the like due to the structural design. And the waterproof and dustproof function level is improved and promoted.

Description

Technical Field

[0001] The utility model relates to a signal switch, in particular to an electric tool signal switch. Background Art

[0002] The electric tool signal switch involves the start and stop control technology of the electric tool switch motor. Its structure is mainly composed of a shell, a shell cover, a push rod, a button, a signal brush, a PCB board, a reversing core, a reversing brush and a reversing cover. As the size of portable tools on the market becomes more and more exquisite and compact, the requirements for the external dimensions of electric tool signal switches are also becoming more and more compact. However, the structural design of the commonly used electric tool signal switches is currently difficult to meet the market's usage needs due to its large size. At the same time, due to the limitations of size and appearance, it is also found in actual use that there are still many structural defects in the commonly used electric tool signal switches: First, the reversing structure design of the existing electric tool signal switch is mainly a press-in card structure, which specifically refers to the reversing core passing through the top of the shell cover through the connecting column and then directly press-fitting it into the connecting hole of the reversing cover to achieve connection. This connection structure easily causes the reversing cover to loosen from the reversing core during the rotation and force process. Although there is also a fixing structure that connects the reversing core and the reversing cover by adding screws, it will increase the procurement of parts and related The assembly cost increases the product cost and also affects the compactness of the overall structure; second, since the commutation core passes through the connecting hole of the commutation cover at the top of the shell cover through the connecting column, and the commutation core and the commutation cover need to form a rotational commutation relative to the shell cover, a sealing ring is usually required between the commutation core and the shell cover for dynamic sealing, but traditional sealing rings are O-rings, which cannot achieve good dynamic sealing performance in actual use, thereby affecting the waterproof and dustproof level of the electric tool signal switch; third, a connected push block will be designed at one end of the push rod extending into the shell to facilitate the installation of the signal brush. Due to the large volume of the push block, the shell must be designed into an upper and lower structure, and semicircular grooves are designed between the upper and lower structures respectively. When the push block and the push rod are installed in place in the lower structure, the upper structure is buckled on the lower structure to close the push block, and at the same time, the two semicircular grooves are buckled to form a circular hole for the axial reciprocating movement of the push rod. At this time, it is often difficult to achieve good sealing performance between the upper and lower structures at the circular hole forming point, which also greatly affects the normal use of the signal switch. 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 an electric tool signal switch which is small in size, compact in structure, reliable in use, and can effectively improve and enhance the waterproof and dustproof function level.

[0004] The technical problem of the utility model is achieved through the following technical solutions:

[0005] An electric tool signal switch includes a housing, a housing cover, a push rod, a key, a signal brush, a PCB board, a commutation core, a commutation brush and a commutation cover. The housing cover is hermetically closed on the housing, and seals the signal brush, the PCB board, the commutation core and the commutation brush inside. The push rod is driven by the key and drives the signal brush to contact the PCB board to form an ON - OFF signal output and a potentiometer signal output. The commutation core is installed above the PCB board, the commutation brush is installed at the bottom of the commutation core and contacts the PCB board. The commutation cover is arranged outside the housing cover. The commutation core is driven by the commutation cover to rotate, and then drives the commutation brush to rotate synchronously to contact the PCB board to form three working state outputs: forward rotation signal, reverse rotation signal or no commutation signal.

[0006] The bottom surface of the housing cover is provided with a circular installation groove, a circular top hole penetrates upward at the center of the installation groove, and a convex ring is provided on the top surface of the housing cover concentrically designed around the top hole.

[0007] The commutation core is composed of a cylindrical core body and a frustum of a cone coaxially arranged at the top of the core body. The core body is rotationally fitted in the installation groove, and the frustum of the cone is rotationally fitted in the top hole. Positioning beads and positioning grooves for forming the rotational positioning of the core body are respectively arranged between the outer side surface of the core body and the inner side surface of the installation groove.

[0008] The commutation cover is a round cover. A driving block is provided on the top surface of the commutation cover, and a concentrically designed circular groove is provided on the bottom surface of the commutation cover. The commutation cover is positioned and rotated by covering the convex ring on the top surface of the housing cover through the circular groove on the bottom surface.

[0009] Several ultrasonic welding lines are provided at the bottom of the circular groove, and ultrasonic welding fixation is formed by contacting the top surface of the frustum of the cone through the several ultrasonic welding lines.

[0010] A connecting column and a connecting hole that are connected to each other, and a convex block and a groove that are fitted to each other are respectively arranged between the frustum of the cone and the commutation cover.

[0011] A sealing ring sleeved outside the frustum of the cone is provided on the top surface of the core body. The frustum of the cone is rotationally fitted in the top hole, and the sealing ring contacts the inner top surface of the installation groove to form a dynamic seal.

[0012] Sealing grooves are respectively provided on the top surface and the bottom surface of the sealing ring. The sealing grooves are annular trapezoidal grooves concentrically arranged with the sealing ring.

[0013] A side hole is provided on the side surface of the housing. One end of the push rod extends into the housing through the side hole and is provided with a fixedly installed push block. The other end of the push rod is located outside the housing and is provided with a fixedly installed key. An elastic sheath is sleeved outside the push rod, and both ends of the elastic sheath elastically push against the housing and the key respectively. The signal brush is installed on the top surface of the push block.

[0014] The PCB board is provided with a slot, and the shell cover is provided with a jack exposing the slot, and a gasket is arranged between the slot and the jack.

[0015] Compared with the prior art, the utility model mainly seals and covers the shell cover on the shell, so that the signal brush, the PCB board, the commutation core and the commutation brush can all be sealed and enclosed inside; at the same time, the push rod is driven by the key to move axially back and forth, and drives the signal brush to contact the PCB board to form an ON-OFF signal output and a potentiometer signal output; the commutation core is installed above the PCB board, the commutation brush is fixed at the bottom of the commutation core and contacts the PCB board, and the commutation cover is arranged outside the shell cover, then the commutation core is driven by the commutation cover to rotate, and can drive the commutation brush to rotate synchronously to contact the PCB board to form three working state outputs of forward rotation signal, reverse rotation signal or no commutation signal; therefore, the signal switch structure of the electric tool adopting this structure has the advantages of small volume and compact structure; in addition, the commutation core and the commutation cover are fixed by a plurality of ultrasonic welding wires, and the sealing ring between the commutation core and the shell cover is specially designed, that is, sealing grooves are respectively arranged on the top surface and the bottom surface of the sealing ring, and the sealing grooves are annular trapezoidal grooves concentric with the sealing ring, so as to ensure better dynamic sealing performance, and the push block and the push rod are designed as a split structure, then the push block is first placed in the shell, and the push rod can directly extend into the side hole on the side surface of the shell. Therefore, through these structural designs, not only the use reliability of the signal switch of the electric tool is ensured, but also the waterproof and dustproof function level is effectively improved and enhanced. Description of the Drawings

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 It is Figure 1 a three-dimensional exploded view of.

[0018] Figure 3 It is a sectional view of the push rod structure (removing the elastic sheath and the key)

[0019] Figure 4 It is Figure 3 a top view of.

[0020] Figure 5 It is an enlarged sectional view of the commutation structure.

[0021] Figure 6 It is Figure 5 a top view of.

[0022] Figure 7 It is Figure 5 a bottom view of.

[0023] Figure 8 It is a sectional view of the shell cover.

[0024] Figure 9 It is a schematic top view structure of the commutation cover.

[0025] Figure 10 It is a schematic bottom view structure of the commutation cover.

[0026] Figure 11 It is a cross-sectional view of the sealing ring. Specific embodiments

[0027] The embodiments of the present invention will be further described in detail below with reference to the above-mentioned drawings.

[0028] As Figures 1 to 11 shown, 1. Housing, 11. Side hole, 2. Push rod, 21. Push block, 22. Button, 23. Elastic sheath, 24. Pin, 25. Signal brush, 26. Push rod spring, 3. PCB board, 31. GND contact, 32. REV contact, 33. FOR contact, 34. Slot, 4. Commutation brush, 41. Positioning hole, 42. Contact foot, 5. Sealing gasket, 6. Commutation core, 61. Core body, 611. Horizontal hole, 62. Round platform, 621. Connecting column, 622. Protrusion, 63. Spring, 64. Positioning bead, 65. Positioning column, 7. Sealing ring, 72. Sealing groove, 8. Housing cover, 81. Top hole, 82. Convex ring, 83. Jack, 84. Installation groove, 85. Positioning groove, 9. Commutation cover, 91. Driving block, 92. Connecting hole, 93. Round groove, 94. Groove, 95. Ultrasonic welding line.

[0029] An electric tool signal switch, as Figure 1 , Figure 2 shown, relates to the start-stop control technology of the switch motor of an electric tool. Its structure includes a housing 1, a housing cover 8, a push rod 2, a button 22, a signal brush 25, a PCB board 3, a commutation core 6, a commutation brush 4, a commutation cover 9, etc. The housing cover 8 is hermetically covered on the housing 1 and seals the signal brush 25, the PCB board 3, the commutation core 6, and the commutation brush 4 inside.

[0030] The bottom surface of the housing cover 8 is provided with a circular installation groove 84, and a circular top hole 81 runs through upward at the center of the installation groove. The top surface of the housing cover 8 is provided with a convex ring 82 concentrically designed around the top hole.

[0031] The housing 1 is a rectangular box-like structure with an open top. On the side of the housing 1, that is Figure 1A circular side hole 11 is provided on the right side wall shown; the push rod 2 is a cylindrical rod. One end of the push rod extends into the housing 1 through the side hole 11 and is fixedly installed with a push block 21 placed in the housing through a pin 24. The other end of the push rod is located outside the housing and is provided with a fixedly installed button 22. Therefore, the push rod 2 can perform axial reciprocating movement driven by the button, and at the same time, it also drives the push block 21 in the housing to form synchronous axial reciprocating movement; a push rod spring 26 is provided in the housing 1 to elastically push against the push block 21. Therefore, under normal conditions, due to the elastic push of the push rod spring 26, the push rod 2 is always in a trend of moving outwards, mainly playing the role of resetting the push rod 2.

[0032] An elastic sheath 23 is sleeved outside the push rod 2. The two ends of the elastic sheath elastically push against the housing 1 and the button 22 respectively. Its function is to ensure the waterproof and dustproof performance between the push rod and the side hole 11 when the push rod 2 undergoes axial reciprocating movement, and at the same time, it can also assist the push rod spring 26 to ensure the successful reset of the push rod 2.

[0033] In this embodiment, two signal brushes 25 are designed in total. The two signal brushes are arranged side by side on the top surface of the push block 21; in this way, the axial reciprocating movement of the push rod 2 and the push block 21 will drive one of the signal brushes 25 to contact the PCB board 3 to form an ON - OFF signal output, and the other signal brush 25 contacts the PCB board 3 to form a potentiometer signal output.

[0034] The PCB board 3 is fixed in the housing 1. The commutation core 6 is installed above the PCB board 3, and the commutation brush 4 is fixed at the bottom of the commutation core 6 and contacts the PCB board 3.

[0035] The commutation core 6 is composed of a cylindrical core body 61 and a frustum 62 coaxially arranged at the top of the core body. The core body 61 is rotationally fitted in the installation groove 84, and the frustum 62 is rotationally fitted in the top hole 81. At the center of the frustum 62, a connecting column 621 extending upwards coaxially in a cylindrical shape is provided. On both sides of the connecting column, convex blocks 622 with central symmetry design are provided.

[0036] The commutation cover 9 is arranged outside the housing cover 8, specifically on the top of the housing cover. The commutation cover 9 is a circular cover. A driving block 91 is provided on the top surface of the commutation cover, which can be used for an external force to be applied on the driving block to drive the rotation of the commutation cover 9. A concentrically designed circular groove 93 is provided on the bottom surface of the commutation cover 9. The commutation cover 9 is rotationally positioned by covering the convex circular ring 82 on the top surface of the housing cover 8 through the circular groove on the bottom surface. A circular connecting hole 92 penetrates upwards at the center of the circular groove 93. Grooves 94 are provided on both sides of the connecting hole and are symmetrically distributed at the bottom of the circular groove; several ultrasonic welding lines 95 are also provided at the bottom of the circular groove 93.

[0037] In this way, the frustum 62 of the commutation core 6 and the commutation cover 9 can be interconnected through the connecting posts 621 and the connecting holes 92, and then the bumps 622 and the grooves 94 are fitted with each other to facilitate the synchronous rotation of the commutation cover 9 driving the commutation core 6. After the commutation cover 9 contacts the top surface of the frustum 62 of the commutation core 6 through a plurality of ultrasonic welding lines 95 and is ultrasonically welded and fixed, it effectively prevents the commutation cover 9 from loosening from the commutation core 6 during the rotation and stress application process.

[0038] A sealing ring 7 sleeved outside the frustum 62 is provided on the top surface of the core body 61. Sealing grooves 71 are provided on the top and bottom surfaces of the sealing ring, and the sealing grooves are annular trapezoidal grooves concentric with the sealing ring. Therefore, with this specially designed sealing ring, when the frustum 62 rotates and is fitted in the top hole 81, the sealing ring 7 can contact the inner top surface of the mounting groove 84, thus achieving better dynamic sealing performance.

[0039] The commutation brush 4 is a circular ring plate. Two centrally symmetrically arranged positioning holes 41 are provided on the circular ring plate, and the two positioning holes are sleeved on the positioning posts 65 at the bottom of the commutation core 6, so that the commutation brush 4 is positioned and fitted at the bottom of the commutation core. Two concave contact feet 42 are also provided on the circular ring plate that is distributed at 90° from the two positioning holes. The two contact feet can have a certain elasticity through the concave design. Therefore, the commutation brush 4 elastically contacts the PCB board 3 through the two contact feet 42. In this way, when the commutation core 6 is driven by the commutation cover 9 to rotate, it can drive the commutation brush 4 to rotate synchronously and contact the PCB board 3 to output three working states: forward rotation signal, reverse rotation signal, or no commutation signal. Specifically, the PCB board 3 is provided with a GND contact 31, a REV contact 32, and a FOR contact 33. Usually, one of the contact feet 42 of the commutation brush 4 is always elastically contacting the GND contact 31 during the rotation of the commutation brush. When the other contact foot elastically contacts the REV contact 32 during the rotation of the commutation brush, that is, when the GND contact 31 and the REV contact 32 are conducted to form a forward rotation signal output, or when the other contact foot elastically contacts the FOR contact 33 during the rotation of the commutation brush, that is, when the GND contact 31 and the FOR contact 33 are conducted to form a reverse rotation signal output, or when the other contact foot does not elastically contact the FOR contact 32 and the FOR contact 33 during the rotation of the commutation brush, a no commutation signal output will be formed.

[0040] In addition, positioning beads 64 and positioning grooves 85 for constituting the rotational positioning of the core body are respectively provided between the outer side surface of the core body 61 and the inner side surface of the mounting groove 84. The specific structure is as follows: a transverse hole 611 that penetrates through the axis line and runs horizontally is provided in the core body 61. Positioning beads 64 are respectively provided at both ends of the transverse hole. A spring 63 is provided in the transverse hole to elastically push the two positioning beads 64 respectively to contact the inner side surface of the mounting groove 84. Three positioning grooves 85 are provided on the inner side surface of the mounting groove 84 and respectively correspond to the positions outputting the three working states of forward rotation signal, reverse rotation signal or no commutation signal. In this way, as the commutation core 6 rotates, the positioning beads 64 will be driven to select and position in the positioning grooves 85 at corresponding positions, thereby ensuring the accuracy of the contact position of the commutation brush 4 on the PCB board 3.

[0041] A slot 34 is provided on the PCB board 3, and a jack 83 exposing the slot is correspondingly provided on the shell cover 8. A gasket 5 is provided between the slot 34 and the jack 83. Its function is to prevent the glue from overflowing and polluting the PCB board 3 through the gasket 5 when the slot 34 and the jack 83 are fixed by injecting glue.

[0042] The utility model has the advantages of small volume and compact structure. In particular, the commutation core 6 and the commutation cover 9 are fixed by a plurality of ultrasonic welding lines 95, the sealing ring 7 between the commutation core 6 and the shell cover 8 is specially designed, and the push block 21 and the push rod 2 are designed as a split structure. Then, the push block 21 is first placed in the housing 1, and the push rod 2 can be directly inserted into the housing 1 from the side hole 11 on the side surface of the housing. Therefore, through these structural designs, not only the use reliability of the signal switch of the power tool is ensured, but also the waterproof and dustproof function level is effectively improved and enhanced.

[0043] The above are only specific embodiments of the utility model. Those skilled in the art should understand that any structural design equivalent to this embodiment should be included within the protection scope of the utility model.

Claims

1. A signal switch for an electric tool, comprising a housing (1), a housing cover (8), a push rod (2), a button (22), a signal brush (25), a PCB board (3), a commutation core (6), a commutation brush (4) and a commutation cover (9), characterized in that The shell cover (8) is sealed and covered on the shell (1), and the signal brush (25), the PCB board (3), the commutation core (6) and the commutation brush (4) are all sealed and enclosed therein; the push rod (2) is driven by the key (22) and drives the signal brush (25) to contact the PCB board (3), thereby forming an ON-OFF signal output and a potentiometer signal output; the commutation core (6) is installed above the PCB board (3), the commutation brush (4) is installed at the bottom of the commutation core (6) and contacts the PCB board (3), the commutation cover (9) is arranged outside the shell cover (8), and the commutation core (6) is driven by the commutation cover (9) to rotate, thereby driving the commutation brush (4) to rotate synchronously and contact the PCB board (3) to form three working state outputs: a forward signal, a reverse signal or no commutation signal.

2. The electric tool signal switch according to claim 1, characterized in that The bottom surface of the shell cover (8) is provided with a circular installation groove (84), the center of which penetrates upward to form a circular top hole (81), and the top surface of the shell cover (8) is provided with a convex ring (82) designed concentrically around the top hole (81).

3. The electric tool signal switch according to claim 2, characterized in that The commutation core (6) is composed of a cylindrical core body (61) and a truncated cone (62) coaxially arranged on the top of the core body; the core body (61) is rotatably mounted in the mounting groove (84), and the truncated cone (62) is rotatably mounted in the top hole (81); a positioning bead (64) and a positioning groove (85) for rotatably positioning the core body are respectively arranged between the outer side surface of the core body (61) and the inner side surface of the mounting groove (84).

4. The electric tool signal switch according to claim 3, characterized in that The reversing cover (9) is a round cover, the top surface of which is provided with a driving block (91), the bottom surface of which is provided with a concentric circular groove (93), and the reversing cover (9) fits the circular groove (93) on the bottom surface to cover the convex circular ring (82) on the top surface of the shell cover (8) to form a positioning rotation.

5. The electric tool signal switch according to claim 4, characterized in that A plurality of ultrasonic welding lines (95) are provided at the bottom of the circular groove (93), and the plurality of ultrasonic welding lines contact the top surface of the truncated table (62) to form ultrasonic welding fixation.

6. The electric tool signal switch according to claim 3, characterized in that The truncated table (62) and the reversing cover (9) are respectively provided with connecting columns (621) and connecting holes (92) that are connected to each other, and protrusions (622) and grooves (94) that fit together.

7. The electric tool signal switch according to claim 3, characterized in that The top surface of the core body (61) is provided with a sealing ring (7) sleeved on the outside of the truncated table (62). The truncated table (62) is rotatably mounted in the top hole (81) and the sealing ring (7) contacts the inner top surface of the mounting groove (84) to form a dynamic seal.

8. The electric tool signal switch according to claim 7, characterized in that The top surface and the bottom surface of the sealing ring (7) are respectively provided with sealing grooves (71), and the sealing grooves are annular trapezoidal grooves arranged concentrically with the sealing ring (7).

9. The electric tool signal switch according to claim 1, characterized in that A side hole (11) is provided on the side of the housing (1); one end of the push rod (2) extends into the housing (1) through the side hole (11) and is provided with a fixed push block (21); the other end of the push rod is located outside the housing (1) and is provided with a fixed button (22); an elastic sheath (23) is provided outside the push rod, and the two ends of the elastic sheath are elastically pushed on the housing (1) and the button (22) respectively; the signal brush (25) is installed on the top surface of the push block (21).

10. The electric tool signal switch according to claim 1, characterized in that The PCB board (3) is provided with a slot (34), the shell cover (8) is provided with a plug hole (83) that exposes the slot, and a sealing gasket (5) is provided between the slot (34) and the plug hole (83).

Images