CN2134706Y - Electronic speed governing switch for single-phase series exciting electric tools - Google Patents

Abstract

The utility model relates to an electronic speed governing switch for single-phase series exciting electric tools. The utility model is characterized in that two seesaw type movable contact bridges form asymmetrical shapes and are orderly and respectively arranged on the support feet of two fixed contact sheets, two hollow sliding columns are orderly arranged on a fixed rack connected with a hand push rod, and springs are arranged in the two hollow sliding columns to respectively press the two movable contact bridges. The switch has low requirement of the processing precision for the movable contact bridges and the fixed contact sheets, convenient assembly, reliable motion, long service life, small appearance and size and firm wire connection.

Description

Electronic speed governing switch for single-phase series exciting electric tools

The utility model relates to a kind of single with series excitation electric tool electronic speed-regulating switch, particularly a kind of seesaw type movable contact bridge, and overall dimension is little, and binding post is the electronic speed-regulating switch of screw compressing tablet structure.

At present, the external many single-phase series excitation electric tool of producing has adopted electronic speed-regulating switch, also begins to adopt it on domestic some single-phase series excitation electric tool.But its conservation of power, the service behaviour of improvement instrument makes machining state optimization and a tractor serves several purposes.In November nineteen ninety, we develop a kind of novel electron and transfer electronic speed-regulating switch at the shortcoming of existing electronic speed-regulating switch, to Chinese patent application utility model patent (application number 90 2 15477 X); On November 6th, 1991, Patent Office of the People's Republic of China grants patent.The movable contact spring of this switch is a slidingtype, therefore moves, and the requirement on machining accuracy height of static contact, good to guarantee dynamic and static contact contact, can influence product qualified rate when producing in batches but requirement on machining accuracy is high.

The purpose of this utility model provides a kind of seesaw type movable contact bridge, processing is easy, the life-span is long, overall dimension is little and wiring is firm single-phase series excitation electric tool electronic speed-regulating switch of adopting.

The technical solution of the utility model is: static contact 8,7,6 is planar alignment successively, be characterised in that seesaw type movable contact bridge 1 and 2 is asymmetric shape, and one in front and one in back place on the leg 21 of static contact 8 respectively and on the leg 22 of static contact 7 (referring to Fig. 1, Fig. 2); Hollow traveller 4 and 5 one in front and one in back is contained in to be pressed on the fixed mount 18 that is connected with handspike 14 shown in Figure 4ly, all establishes spring 19 in the two hollow travellers and makes column cap protrude fixed mount 18, is pressed on respectively on movable contact bridge 1 and 2.Press when moving behind the handspike 14, fixed mount 18 and be contained in frame hollow traveller 4 and 5 with after move, when hollow traveller 4 when the last plane of movable contact bridge 1 slips over the leg 21 of static contact 8, movable contact bridge 1 is lifted up and is engaged with static contact 7, be that static contact 8 and 7 is connected, though and this moment, hollow traveller 5 was slided behind the last plane of movable contact bridge 2, but do not cross leg 22 places of static contact 7, so movable contact bridge 2 is not lifted up, electronic building brick (thyristor T and control circuit) 9 plays speed governing effect (referring to Fig. 3) for prior art; When after pressing handspike 14, moving on to the end, leg 22 places that hollow traveller 5 is just crossed static contact 7 make movable contact bridge 2 lift up and engage with still 6, be that static contact 6 is connected with static contact 7,8, electronic building brick 9 is inoperative, and motor obtains rated voltage and rotation at full speed, because the potential difference between the static contact 6 and 7 is thyristor T voltage drop (referring to Fig. 3), difference is less, the action of movable contact bridge 2 is fast in addition, so it is little to switch on or off instantaneous electric arc, switch life is long; Because no relative slippage between movable contact bridge 1,2 and the static contact 7,6, so their requirement on machining accuracy is low, do not need during assembling the contact-making surface between them is calibrated, be easy to make the product qualified rate height, the position of back-moving spring 12, the structure of binding post and the profile of switch, all identical with prior art patent No. 90215477X, thus realized the purpose of this utility model.

The utility model is compared with similar products at home and abroad, movable contact bridge one static contact novel structure, and requirement on machining accuracy is lower, and is easy to assembly, and the life-span is long; Reliable in action, overall dimension and wiring fixing keep advanced level.

Fig. 1 is the elevational cross-sectional view of this real new structure;

Fig. 2 is the vertical view cutaway drawing of the utility model structure;

Fig. 3 is the novel electrical schematic diagram of this reality;

Fig. 4 is the vertical view and the cutaway view of hollow traveller and fixed mount.

Now the utility model is described in detail in conjunction with above-mentioned each figure.

Press Fig. 1, shown in Figure 2, the handspike made from engineering plastics 14 of pressing is positioned at housing 11 fronts, and its rear end is fastened by housing 11 tops, its top is provided with rotating speed and adjusts knob 17, its underpart is spring seat 16, in the seat backstay 15 is arranged, and the front portion of back-moving spring 12 is enclosed within on the backstay 15; Housing 11 is also made with engineering plastics, and housing 11 internal upper parts are established lock-button 3, and seesaw type movable contact bridge 1,2 is established in the bottom, static contact 8,7,6 electronic building bricks 9, binding post 10 and brace; Housing 11 bottoms are connected with a spring casket 13 that stretches out forward, with spring base 16 fits of pressing handspike 14 bottoms, back-moving spring 12 rear portions place in the spring casket 13, static contact 8,7,6 is planar alignment successively, movable contact bridge 1 and 2 is asymmetric shape, and one in front and one in back places on the leg 21 of static contact 8 respectively and on the leg 22 of static contact 7; Hollow traveller 4 and 5 one in front and one in back be contained in press the fixed mount 18 that handspike 14 is connected on, all establish spring 19 in the two hollow travellers and make column cap protrude fixed mount 18, be pressed on respectively on movable contact bridge 1 and 2.By shown in Figure 3, electronic building brick 9 is made up of thyristor T and control circuit, and both open connection; Two lead-out wires of electronic building brick 9 link to each other with 6 with static contact 7 respectively; Binding post 10 has five, even screw compressing tablet structure, there are four binding posts in the front, middle two series connection, be not connected with other inner conductive parts, two binding posts in both sides are connected with 6 with static contact 8 respectively by brace separately, and two inlet wires of single phase poaer supply are connected to two binding posts of front end, and two binding posts in rear end connect two lead-out wires of motor.A binding post of reverse side is equipped with for radio interference suppressor and connects.The operator presses and presses handspike 14, with the fixed mount 18 that links to each other and be contained on the frame hollow traveller 4 and 5 with after move, movable contact bridge 1 makes static contact 8 and 7 connect earlier under hollow traveller 4 presses, thyristor T conducting in the electronic building brick 9, single-phase series motor obtains low-voltage in the electric tool, and the beginning slow-speed is moving; Do not have no progeny and move along with pressing handspike 14, the control road in the electronic building brick 9 makes motor obtain high voltage gradually, the corresponding quickening of rotating speed; When pressing handspike 14 by on earth the time, hollow traveller 5 just presses movable contact bridge 2, make static contact 6 with, 7,8 connect, electronic building brick 9 is inoperative by short circuit, motor obtains rated voltage and rotates at full speed; At this moment, the operator can press lock-button 3 according to the operation needs, makes that to press handspike 14 fixing; Motor connects running; Want the motor stall, just let go after handspike 14 buttons 3 to be locked automatically reset by pressing again, press handspike 14 and under back-moving spring 12 effects, move forward to original position automatically fast, cut off motor power.Turn is pressed the rotating speed on handspike 14 tops and is adjusted knob 17, can adjust the speed adjustable range of electronic building brick.In order to be applicable to the handle of newly-designed electric tool, the upper length 11 of housing 11 is with 25.5 ± 0.1mm, and lower length 12 is with 22.5 ± 1.0mm, and width b is with 16.5 ± 1.0mm the best.

Claims (2)

1, a kind of by pressing the single-phase series excitation electric tool electronic speed-regulating switch that handspike, rotating speed adjustment knob, lock-button, back-moving spring, housing, movable contact bridge, static contact, electronic building brick (thyristor and control circuit), binding post and brace are formed, it is characterized in that the board-like movable contact bridge 1 of a. and 2 is asymmetric shape, and one in front and one in back place on the leg 21 of static contact 8 respectively and on the leg 22 of static contact 7; B. hollow traveller 4 and 5 one in front and one in back is contained in to be pressed on the fixed mount 18 that handspike 14 is connected, and all establishes spring 19 in the two hollow travellers and makes column cap protrude fixed mount 18, is pressed on respectively on movable contact bridge 1 and 2.

2, single-phase series excitation electric tool electronic speed-regulating switch according to claim 1, the upper length 11 that it is characterized in that housing 14 is that 25.5 ± 1.0mm, lower length 12 are 22.5 ± 1.0mm, width b is 16.5 ± 1.0mm.

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