CN103531377A - Switch with power-off protection - Google Patents

Abstract

The invention discloses a switch with power-off protection, which comprises a casing; a button assembly; and at least one set of coil static contacts and coil moving contacts for connecting coil assemblies, and at least one set of coil moving contacts for connecting loads. The main static contact and active contact of the circuit; the coil moving contact and active contact are fixedly arranged on the moving contact frame, and the coil moving contact is an elastic element; the distance between the coil moving contact and the coil static contact is less than The distance between the active contact and the main static contact; the armature is also fixed on the moving contact frame, and the end of the armature away from the contact of the contact assembly is hinged on the coil assembly, and the other end is driven by the button assembly. The armature is provided with an armature reset device for driving the armature to reset, and a locking device for locking the button assembly in the middle position is provided on the outside of the housing. When the power fails, the active contact is separated from the main static contact. Even if the button assembly is pressed, the power tool will not work by itself when the power comes on again, thereby improving the operating safety.

Description

A switch with power-off protection

technical field

The invention relates to the field of electric switches, in particular to a switch with power-off protection.

Background technique

In order to facilitate the control and operation of electric tools such as electric drills, electric hammers, and electric grinders, their control switches are generally arranged at the position of the index finger at the handle. The traditional push switch mainly drives the contact frame to move downward by pressing the button, so that the movable contact arranged on the movable contact holder and the static contact arranged on the base contact and conduct current, and then the electric tool works. Due to the severe vibration of most electric tools during use, the finger controlling the switch cannot always be pressed against the button of the switch due to the vibration, resulting in unstable contact between the moving contact and the static contact. In order to improve the stability of the contact between the moving and static contacts in the switch, a lock button is usually provided on the housing of the power tool to ensure that the switch is always in the ON state. However, once a sudden power failure occurs during use, the operator often forgets to unlock the lock button on the moving and static contacts. When the power comes on again, the electric tool will suddenly work without the on-site staff being prepared, which often causes equipment damage. Or personal injury accident takes place, just need to develop a kind of switch with power failure protection function for this reason. the

For example, Chinese patent document CN101882523A discloses a trigger switch with power failure restart protection function, which is mainly composed of a base body, a shell, a trigger, a lock button, a yoke, a coil, a magnetic core, and an armature; wherein, the base body, The shell, trigger, lock button and related structural components form the mechanical structural part of the switch, and the yoke, coil, magnetic core, armature and related electromagnetic components form the electromagnetic structural part of the switch. When the switch is powered off, the electromagnetic coil loses power, and the armature pushes the locking hook to no longer be attached to the lock button, so that the trigger is removed from the lock, and the circuit of the electric tool is disconnected under the action of the return spring, which plays the role of power-off protection . However, if the switch is held in the hand during a power outage, or it touches other objects when it is placed, so that the button is always under pressure and cannot abdicate to the off position, then the inside of the switch is always in the on state at this time, and when the power comes on again, The electric tool will work immediately, so this kind of trigger switch with power failure restart protection function still has a relatively large safety hazard in the actual use process.

At present, the main solution that can disconnect the dynamic and static contacts in the switch even if the button is pressed during a power failure is to add a circuit board module between the tool side circuit and the switch, and solve it electronically, but the electronic form No matter in terms of connection and breaking capacity, reliability of components, cost, etc., it is not very ideal, and there is an urgent need for another way to solve it. the

Contents of the invention

For this reason, the technical problem to be solved by the present invention is to prevent the electric tool from starting automatically after a power failure, thereby causing a serious safety hazard. Even if the button is pressed during power-on, it can still disconnect the input circuit of the electric tool, which plays the role of power-off protection.

To achieve the above object, the present invention adopts the following technical solutions:

A switch with power-off protection, comprising a housing; a button assembly, the button assembly is slidably installed inside the housing; a contact assembly, the contact assembly includes at least one set of coils for connecting the coil assembly Static contacts, coil moving contacts, and at least one set of main static contacts and active contacts for connecting the load circuit; the coil static contacts and the main static contacts are fixedly arranged inside the housing , the coil moving contact and the active contact are fixedly arranged on the moving contact frame, the coil moving contact is an elastic element; the distance between the coil moving contact and the coil static contact is less than the The distance between the active contact and the main static contact; the moving contact frame is also fixed with an armature, and the end of the armature away from the contact point of the contact assembly is hinged on the coil assembly, The other end moves up and down under the drive of the button assembly, and the armature is provided with an armature reset device for driving the armature to reset; the outer side of the housing is provided with a locking device for locking the button assembly in the middle position ; when the button assembly is in the middle position, the distance between the button assembly and the armature can reset the armature to its initial position; when the circuit is turned on, the button assembly drives the armature to move downward, so After the coil moving contact first contacts with the coil static contact, the coil assembly generates a magnetic field to attract the armature to move downward, drive and keep the active contact in contact with the main static contact, and turn on the load Circuit; after being connected, the button assembly moves to the middle position and is locked by the locking device. At this time, after the power is cut off, the coil assembly loses power, and the armature resets under the action of the armature reset device, and drives The active contact is kept separated from the main static contact; when the circuit is disconnected, the locking device unlocks the button assembly, and the button assembly moves upward to the initial position, and drives the coil to move The contacts are separated from the coil static contacts.

The button assembly has a push part extending toward the side close to the armature, and the push part is located on the upper side of the armature. When the button assembly is driven to move downward, the push part cooperates with the armature to realize that the armature rotates around the armature. The above hinge moves down. the

The button assembly has a boss extending toward the side close to the coil moving contact, the boss is located below the coil moving contact, when the button assembly is driven to move upward, the boss and the coil The movable contact cooperates to realize the upward movement of the coil movable contact.

A side of the end of the coil movable contact close to the boss is provided with an extension part matched with the boss.

The active contact and the coil moving contact are respectively riveted to opposite sides of the moving contact frame, and the middle position of the moving contact frame is riveted to the armature.

The coil assembly includes a coil and a support frame supporting the coil, and the armature is hinged on a side plate of the support frame away from the contact point.

The end of the armature away from the coil assembly is provided with a groove, and the side plate of the coil assembly away from the button assembly is provided with an upwardly extending protrusion, and the groove is inserted into the protrusion The hinged connection between the armature and the coil assembly is realized.

The armature reset device is a tension spring, one end of the tension spring is hooked to the end of the armature away from the button assembly, and the groove is located between the tension spring and the button assembly, The other end of the tension spring is connected to the lower end of the coil assembly of the coil component.

The locking device includes a connecting rod slidingly arranged between the casing and the button assembly along the moving direction of the button assembly, the upper end of the connecting rod is connected with the upper end of the button assembly, and the connecting rod A lock button is hinged at the lower end of the lock button, and a lock block is provided on the lock button, and a lock slot is provided on the outside of the housing, and the lock block rotates around the hinge shaft and snaps into the lock slot to limit the movement of the button assembly .

A button reset device is provided below the button assembly to drive it to move upwards, the button reset device is a return spring, one end of the return spring is against the lower end of the button assembly, and the other end is against the inside of the housing bottom of the cavity.

The side of the button assembly close to the active contact is also provided with a boss, and the boss extends to the bottom of the main contact; the boss on the side of the active contact is lower than the The boss on one side of the moving contact of the coil.

Beneficial effects of the present invention:

1. In the switch with power-off protection of the present invention, the coil movable contact and the active contact are all elastic elements, and the button assembly has an initial position, an intermediate position and a bottom position; The locking device in the middle position, the distance between the coil moving contact and the coil static contact is smaller than the distance between the active contact and the main static contact; when the button assembly drives the armature downward, the coil moving contact and the coil static contact The head contact, and then the magnetic field generated by the coil assembly attracts the armature to move downward, and then makes the active contact contact with the main static contact, and conducts current for the electric switch. After conducting the current, the button assembly resets upward to the middle position and is locked at the same time The device is locked; under the action of the magnetic field generated by the electromagnetic coil, the coil moving contact and the coil static contact, the active contact and the main static contact are always in contact. When the power fails, the magnetic field generated by the coil assembly disappears, and the coil moving contact and the active contact are separated from the coil static contact and the main static contact respectively under the action of the reset device. In addition, the button of the power-off protection switch of the present invention does not need the button to abdicate outwards, even if the button assembly is pressed by external force, the function of power-off protection can still be realized inside, so the switch with power-off protection of the present invention has more Good safety performance. the

2. The connection between the main static contact and the active contact of the present invention is driven by an electromagnetic coil, and the response is quick, ensuring that the switch can pass the slow test.

3. The circuit breaking of the present invention relies on the boss on the button assembly to push the coil moving contact and the coil static contact to separate, so that the magnetic field disappears quickly after the coil assembly is powered off, and under the action of the tension spring, the main static contact and the active contact The contacts are disconnected quickly, thereby improving the rapid breaking capacity of the switch.

4. The button assembly of the present invention is also provided with a boss on the side close to the active contact, and extends to the vertical lower side of the main contact, where the boss is mainly to prevent the active contact from contacting the main static contact. When it cannot be broken due to long-term work or other reasons, the boss at this place can push the active contact upward to realize forced breaking, thereby further improving the breaking capacity of the entire switch.

Description of drawings

In order to make the content of the invention more easily understood, the present invention will be described in further detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

Fig. 1 is an exploded view of the overall structure of the band power-off protection switch of the present invention;

Fig. 2 is the electrical schematic diagram of the band power-off protection switch of the present invention;

Fig. 3 is the top view of the belt power-off protection switch of the present invention;

Fig. 4 is the A-A sectional view when the belt power-off protection switch of the present invention is in the initial position;

Fig. 5 is a B-B partial sectional view when the belt power-off protection switch of the present invention is in the initial position;

Fig. 6 is an A-A sectional view when the switch with power-off protection of the present invention is pressed down until the dynamic and static contacts of the coil just come into contact;

Fig. 7 is a B-B partial cross-sectional view when the switch with power-off protection of the present invention is pressed down until the dynamic and static contacts of the coil are just in contact;

Fig. 8 is an A-A sectional view when the coil with the power-off protection switch of the present invention attracts the armature;

Fig. 9 is an A-A sectional view of the present invention when the switch with power-off protection is at the bottom position;

Fig. 10 is an A-A sectional view of the present invention with a power-off protection switch in the middle position;

Fig. 11 is an A-A sectional view when the switch with power-off protection of the present invention is in the middle position and suddenly loses power;

Fig. 12 is a B-B cross-sectional view when the switch with power-off protection of the present invention is in the middle position and suddenly loses power;

Fig. 13 is a schematic diagram of the structure when the boss on the button assembly of the present invention cooperates with the extension on the coil moving contact;

Fig. 14 is a structural schematic diagram of another embodiment of the button assembly;

Fig. 15 is a schematic structural view of the locking device of the present invention when the button assembly is not locked;

Fig. 16 is a schematic structural view of the locking device of the present invention when locking the button assembly;

Fig. 17 is a sectional view along line C-C of Fig. 15 .

The reference signs in the figure represent:

1-shell; 2-button assembly; 3-contact assembly; 31-coil static contact; 32-coil moving contact; 33-main static contact; 34-active contact; 35-moving contact frame; 36 -armature; 360-groove; 37-propelling part; 38-boss; 39-extension; 4-coil assembly; 41-side plate; 410-protrusion; Connecting rod; 72-lock button; 73-lock block; 74-lock groove; 75-spring.

Detailed ways

Referring to Figures 1-2, a switch with power-off protection includes a housing 1; a button assembly 2, which is slidably installed inside the housing 1; a contact assembly 3, the contact assembly 3 Including at least one set of coil static contacts 31 and coil moving contacts 32 for connecting the coil assembly 4, and at least one set of main static contacts 33 and active contacts 34 for connecting the load circuit; in this implementation One set of the coil static contact 31, the coil moving contact 32, the main static contact 33, and the active contact 34 are set respectively, of course, multiple sets can also be set according to specific needs. The coil static contact 31 and the main static contact 33 are fixedly arranged inside the housing 1, and the coil moving contact 32 and the active contact 34 are fixedly arranged on the moving contact frame 35. The coil moving contact 32 and the active contact 34 are both elastic elements; the distance between the coil moving contact 32 and the coil static contact 31 is smaller than the distance between the active contact 34 and the main static contact The distance between 33; the moving contact frame 35 is also fixed with an armature 36, and one end of the armature 36 away from the contact point of the contact assembly 3 is hinged on the coil assembly 4, and the other end of the armature 36 is on the The button assembly 2 is driven to move up and down; the armature 36 is provided with an armature reset device that drives the armature 36 to reset. As a specific structure of this embodiment, the armature reset device is a tension spring 5, and the pull spring 5 One end of the spring 5 is hooked to the end of the armature 36 away from the button assembly 2, and the groove 360 is located between the extension spring 5 and the button assembly 2, and the extension spring 5 The other end is connected to the lower end of the coil component coil assembly 4 . The outer side of the housing 1 is provided with a locking device for locking the button assembly 2 in the middle position; when the button assembly 2 is in the middle position, the distance between the button assembly 2 and the armature 36 can make The armature 36 is reset to the initial position. At this time, the coil movable contact 32 and the coil static contact 31, as well as the active contact 34 and the main static contact 33 are respectively in the disconnected state, and the entire switch In power-off protection state.

Referring to Fig. 3-10, when the circuit is turned on, the button assembly 2 drives the armature 36 to move downward, the coil moving contact 32 first contacts the coil static contact 31, and the coil assembly 4 generates a magnetic field Attract the armature 36 to move downward, drive and keep the active contact 34 in contact with the main static contact 33, and connect the load circuit; A certain amount of elastic deformation occurs during the movement, so that the active contact 34 can contact the main static contact 33 . After the circuit in the electric tool is connected, the button assembly 2 moves from the bottom position to the middle position and is locked by the locking device; at this time, if the power is suddenly cut off, the magnetic field generated by the coil assembly 4 disappears , the armature 36 resets under the action of the tension spring 5, and drives the active contact 34 to keep separated from the main static contact 33. In this embodiment, the armature 36 only needs to rotate a small angle around the hinge axis to realize the contact or disconnection between the main static contact 33 and the active contact 34 .

Referring to Figures 11-13, if the circuit of the working electric tool is disconnected, the button assembly 2 must first be unlocked, and then the button assembly 2 should be reset upwards to the initial position to drive the coil moving contact The head 32 is separated from the fixed coil contact 31 .

As a specific structure of the switch with power-off protection of the present invention, in order to make the above-mentioned switch break quickly, that is, the button assembly 2 can more easily drive the moving contact 32 to move upward. One side of the coil moving contact 32 extends with a boss 38, the boss 38 is located below the coil moving contact 32, and the side of the coil moving contact 32 end close to the boss 38 An extension part 39 is provided to cooperate with the boss 38 , and the boss 38 cooperates with the coil movable contact 32 to realize the upward movement of the coil movable contact 32 with the button assembly 2 .

In order to ensure reliable contact between the button assembly 2 and the armature, in this embodiment, the push button assembly 2 has a push portion 37 extending toward the side close to the armature 36, the push portion 37 is located on the upper side of the armature 36, and drives When the button assembly 2 moves downward, the pushing part 37 cooperates with the armature 36 to realize the armature 36 moves downward around the hinge. the

In this embodiment, the active contact 34 and the coil movable contact 32 are respectively riveted on opposite sides of the movable contact frame 35, and the middle position of the movable contact frame 35 is riveted with the armature 36, and the The active contact 34 , the coil movable contact 32 , and the armature 36 are basically arranged in parallel, and the contacts of the coil movable contact 32 and the active contact 34 are close to the button assembly 2 .

The coil assembly 4 includes a coil and a support frame supporting the coil, and the armature 36 is hinged on a side plate 41 of the support frame on a side away from the contact. The above-mentioned hinge structure adopts the following specific structure, the end of the armature 36 away from the coil assembly 4 is provided with a groove 360, and the side plate 41 of the coil assembly 4 away from the button assembly 2 is provided with an upwardly extending protrusion The groove 360 is plugged into the protrusion 410 to realize the hinge connection between the armature 36 and the coil assembly 4 .

Referring to FIGS. 15-17 , in this embodiment, the locking device includes a connecting rod 71 slidably arranged between the housing 1 and the button assembly 2 along the moving direction of the button assembly 2 , and the connecting rod The upper end of 71 extends to one side of the button assembly 2, and is provided with a U-shaped opening, which is clipped to the reduced diameter section provided on the upper end of the button assembly 2; the lower end of the connecting rod 71 is hinged with a lock button 72 , the lock button 72 is provided with a lock block 73, and the outer side of the housing 1 is provided with a lock slot 74, and the lock block 73 rotates around the hinge shaft and snaps into the lock slot 74 to limit the button assembly 2 In addition, the connecting rod is also provided with a spring 75 that forces the button assembly 2 to move upward to the initial position. The upper end of the spring 75 is against the protrusion in the middle of the connecting rod 71, and its lower end is against the switch body; when the button When the assembly 2 moves upwards from the bottom position to the middle position, press the lock button 72 to rotate around the hinge axis, and make the lock block 73 snap into the lock groove 74. At this time, the connecting rod 71 is locked, and the button assembly 2 cannot move up and down.

Referring to Fig. 13, in this embodiment, a button reset device is provided below the button assembly 2 to drive it to move upwards, the button reset device is a return spring 6, and one end of the return spring 6 is against the button assembly 2, and the other end is against the bottom of the inner cavity of the housing 1. A return spring is provided below the button assembly 2, so that the button assembly 2 can automatically move upward from the bottom position to the middle position, or move the button assembly 2 from the middle position to the initial position. Of course, in other embodiments, the button reset device may not be provided, and when the button assembly 2 is reset, the button assembly 2 can be manually pulled up to the initial position directly.

Referring to FIG. 14 , as another embodiment of the present invention, the side of the button assembly 2 close to the active contact 34 is also provided with a boss 38 , and the boss 38 extends to the main contact 34 The breaking distance from the boss 38 on the active contact 34 side to the active contact 34 is slightly larger than the breaking distance from the boss 38 on the coil moving contact 32 side to the coil moving contact 32. The purpose of setting the boss 38 at this place is mainly to prevent the active contact 34 and the main static contact 33 from being stuck together due to long-term contact or other reasons and cannot be broken. When the intermediate position moves to the initial position, the active contact 34 can be actively pushed upward to realize forced breaking, thereby further improving the breaking capacity of the entire switch and ensuring the safety of electricity use; under normal circumstances, once the magnetism of the coil assembly 4 disappears, then The active contact 34 and the main static contact 33 can be quickly separated under the action of the tension spring 5, thereby ensuring that the switch can meet the requirements of the slow breaking test.

The above-mentioned specific implementation is only a detailed explanation of the technical solutions of the present invention, and the present invention is not limited to the above-mentioned embodiments. Those skilled in the art should understand that all improvements and substitutions based on the above-mentioned principles and spirits on the basis of the present invention should be Within the protection scope of the present invention.

Claims (11)

1. with a switch for power-off protection, comprise housing (1); Button assembly (2), described button assembly (2) is slidably mounted on described housing (1) inside; Contact assembly (3), described contact assembly (3) comprises at least one group of coil fixed contact (31) for closing coil assembly (4), coil moving contact (32), and at least one group of main fixed contact (33), active contact (34) that is used for connecting load circuit;

It is characterized in that:

Described coil fixed contact (31), described main fixed contact (33) are fixedly installed on described housing (1) inside, it is upper that described coil moving contact (32), described active contact (34) are fixedly installed on action contact frame (35), and described coil moving contact (32) is flexible member; Distance between described coil moving contact (32) and described coil fixed contact (31) is less than the distance between described active contact (34) and described main fixed contact (33); On described action contact frame (35), be also fixed with armature (36), one end away from described contact assembly (3) contact of described armature (36) is articulated with on described coil block (4), the other end is realized and being moved up and down under the driving of described button assembly (2), and described armature (36) is provided with the armature resetting means that drives described armature (36) to reset;

Described housing (1) outside is provided with for described button assembly (2) being locked in to the locking device in centre position; When described button assembly (2) mediates, the distance between described button assembly (2) and described armature (36) can make described armature (36) be reset to initial position;

While connecting circuit, described button assembly (2) drives described armature (36) to move downward, after described coil moving contact (32) first contacts with described coil fixed contact (31), described in described coil block (4) generation magnetic field suction, armature (36) moves downward, drive and keep described active contact (34) to contact with described main fixed contact (33), connecting load circuit; After connection, described button assembly (2) moves to described centre position and is locked by described locking device, now after power-off, described coil block (4) dead electricity, described armature (36) resets under the effect of armature resetting means, and drives described active contact (34) and described main fixed contact (33) to keep released state; During open circuit, described locking device is removed the locking to described button assembly (2), and described button assembly (2) moves up to initial position, and drives described coil moving contact (32) separated with described coil fixed contact (31).

2. a kind of switch with power-off protection according to claim 1; it is characterized in that: described button assembly (2) is to being extended with pushing part (37) near described armature (36) one sides; described pushing part (37) is positioned at described armature (36) upside; while driving described button assembly (2) to move down, described pushing part (37) coordinate with described armature (36) and realize described armature (36) and move down around described hinged place.

3. a kind of switch with power-off protection according to claim 1 and 2; it is characterized in that: described button assembly (2) is extended with boss (38) to the side near described coil moving contact (32); described boss (38) is positioned at described coil moving contact (32) below; while driving described button assembly (2) to move up, described boss (38) coordinates with described coil moving contact (32) to be realized described coil moving contact (32) and moves up.

4. a kind of switch with power-off protection according to claim 3, is characterized in that: a side of the close described boss (38) of described coil moving contact (32) end is provided with the extension (39) coordinating with described boss (38).

5. according to the arbitrary described a kind of switch with power-off protection of claim 1-4; it is characterized in that: described active contact (34) and described coil moving contact (32) are riveted on respectively the relative both sides of described action contact frame (35), and described armature (36) is riveted in the centre position of described action contact frame (35).

6. according to the arbitrary described a kind of switch with power-off protection of claim 1-5; it is characterized in that: described coil block (4) comprises coil and support the bracing frame of described coil, described armature (36) is hinged on the side plate (41) away from described contact one side of support frame as described above.

7. according to the arbitrary described a kind of switch with power-off protection of claim 1-6; it is characterized in that: one end away from described coil block (4) of described armature (36) is provided with groove (360); the side plate away from described button assembly (2) of described coil block (4) (41) is provided with upwardly extending projection (410), and described groove (360) is plugged into be realized described armature (36) and be articulated and connected with described coil block (4) in described projection (410).

8. according to the arbitrary described a kind of switch with power-off protection of claim 1-7; it is characterized in that: described armature resetting means is extension spring (5); one end of described extension spring (5) is articulated to the end away from described button assembly (2) of described armature (36); and described groove (360) is positioned between described extension spring (5) and described button assembly (2), the other end of described extension spring (5) is connected with the lower end of described coil component coil block (4).

9. according to the arbitrary described a kind of switch with power-off protection of claim 1-8, it is characterized in that: described locking device comprises along the direction of motion of described button assembly (2) and is slidably arranged in the connecting rod (71) between described housing (1) and described button assembly (2), the upper end of described connecting rod (71) is connected with the upper end of described button assembly (2), the lower end of described connecting rod (71) is hinged with cage knob (72), described cage knob (72) is provided with lock dog (73), the outside of described housing (1) is provided with locked groove (74), described lock dog (73) rotates and snaps in described locked groove (74) to limit described button assembly (2) motion around jointed shaft.

10. according to the arbitrary described a kind of switch with power-off protection of claim 1-9; it is characterized in that: the below of described button assembly (2) is provided with and drives its push-button reset device moving upward; described push-button reset device is back-moving spring (6); one end of described back-moving spring (6) is against the lower end of described button assembly (2), and its other end is against the bottom of described housing (1) inner chamber.

11. according to the arbitrary described a kind of switch with power-off protection of claim 3-10, it is characterized in that: a side of the close described active contact (34) of described button assembly (2) is also provided with boss (38), and described boss (38) extends to the below of described main contact (34); The described boss (38) of described active contact (34) one sides is lower than the described boss (38) of described coil moving contact (32) one sides.

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