CN2591605Y

CN2591605Y - Central-shaft pedal torque sensor

Info

Publication number: CN2591605Y
Application number: CN 02291587
Authority: CN
Inventors: 李平
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-12-20
Filing date: 2002-12-20
Publication date: 2003-12-10
Anticipated expiration: 2012-12-20

Abstract

The utility model relates to a central-shaft pedal torque sensor which can be used not only for a motor-driven bicycle. A torsion spring transducer is additionally arranged in a middle joint and is combined with a displacement sensor to provide accurate one to one boosting signal without changing the external dimension of the middle joint; the displacement sensor adopts a magnetic loop and a hall element, so the utility model can carry on linear type measurement, continuous measurement and non-contact type measurement and directly provide output large signal having an interface with a motor controller or a measurement instrument easily. The utility model has the advantages of small volume, fully closed and simple structure, high reliability, long service life, and convenient installation, and can be applied to other measurements at low speed and with large torque.

Description

Middle shaft type scrunches torque sensor

The middle shaft type that the utility model relates to a kind ofly can directly export the linear electric signal of torque, can carry out non-cpntact measurement continuously scrunches torque sensor, especially can not change center tap physical dimension, small size, the totally-enclosed middle shaft type that is easy to again install and use substantially and scrunch torque sensor, belong to assistance type electric bicycle field.

The pedal-type torque sensor is the core component that the assistance type electric bicycle is realized 1: 1 true power-assisted, has occurred polytype at present.Position branch according to installing has middle shaft type, sprocket-type, chain-type, flywheel-type, electric motor built-in etc.All there is in various degree shortcoming in the existing various torque sensor that scrunches, has limited its large-scale popularization on the assistance type electric bicycle and has used.For example: shaft type sensor use torsion bar-foil gauge is made the torque transmitter in some, because distortion is too little, sensor output signal is low excessively, only is the millivolt level, thereby must install the electronic circuit amplification additional; Because sensor need be introduced power supply and output signal, be to keep the low-cost contact measurement mode that then needs to use brush and slip ring usually again, thereby must make the limited external interference that also is subject to of its life-span because of the long-term contact wear under the riding condition.Industrially utilize mode that rotary transformer introduces power supply and output signal too high and volume is difficult to employing more greatly because of cost.

Use the frame mode of torsion bar and bidentate wheel combination, by be output as the little phase signal of pulse with it, this is difficult to simple process usually, and volume is also big, and the result makes metering circuit complicated.

Axis centering type torque sensor is a kind of design preferably, but outside dimension is excessive, owing to significantly changed the physical dimension of center tap thereby caused it to install and use inconvenience.

Some axis or sprocket-type use the magnet steel and the electric pulse of magnetosensitive Hall switch element output to measure, but it is also non-constant in people's pedal is stepped on a week to scrunch torque, if the magnet steel usage quantity very little then can't accurately gather, measure instantaneous torque variation; For overcoming this shortcoming magnet steel quantity is increased greatly, this will increase cost again; In addition, the equally also not easy-to-use ball bearing made using of this pulse signal output is handled.

Photoimpact formula torque sensor equally also has above-mentioned shortcoming, and tighter usually to the seal request of structure, otherwise the intrusion of moist and dust will make working sensor lose efficacy very soon.

The characteristic that some chain-type sensors have utilized chain to move up and down scrunching tensioning under the pulling force, but this move and chain pull between exist strong nonlinear to concern that the big slightly output signal of a torque is promptly saturated, therefore can't really realize large-scale torque measurement and 1: 1 true power-assisted.

The electric bicycle that sales volume is very big is many with speed pickup control power-assisted in the market, the significant deficiency of this car is pedal fast more, power-assisted is big more, not to provide 1: 1 electric power-assisted fully according to the actual required power of the pedaling size of the people place road conditions of riding, consequently the electricity power-assisted is more little on the contrary when climbing and contrary wind etc. is just needing big power-assisted, does not reach the true labor-saving effect of riding.

Abroad, many countries make laws, and for the consideration of riding safety, the total ban electric bicycle is set out on a journey in the pure electronic mode of motor vehicle.Adapt to 1: 1 true power-assisted vehicle that exported country's rules are determined fully for participating in international big market competition, just must providing.Also there is the tendency that adopts this legislation in the domestic existing big city.At present the greatest problem of mass-produced electric bicycle is that car body is overweight or continuation mileages for one time charging is still shorter, adopts 1: 1 true assistance type electric bicycle that car body weight is alleviated greatly or continuation mileages for one time charging is doubled.Therefore, true assistance type electric bicycle had great market prospect and substantial economics in 1: 1, in any case its importance can not be underestimated.

In order to overcome the existing deficiency that scrunches torque sensor, the utility model provides a kind of middle shaft type to scrunch torque sensor, and this sensor does not change the physical dimension of center tap substantially, and volume is little, the structure sealing, thereby be easy to install and use.Especially this sensor adopts non-contact measurement, has linear characteristic, can directly export large-signal, therefore is easy to and the metering circuit matching treatment, has also prolonged sensor serviceable life greatly.

The utility model is that the new solution that the existing scheme existing problems of solution are adopted is: using has big torsional angle distortion to make the torque conversion element with the torsion spring or the spiral torsion tube of linear characteristic under given moment of torsion, use and companys, same external diameter, coaxial bull torsion spring or multi-head spiral fluting torsion tube, utilize superposition principle to solve the difficult problem of high pulling torque measurement in small space; Torsion spring or the torsion tube combination of using axle and common spring material to make are not reducing the too high problem of cost that the independent high elastic modulus alloy axle of using is brought that substitutes under the axle strength condition usually; Use permanent magnetic ring and the linear hall element displacement transducer in conjunction with compositions such as cam structures, solving rotary torque is the difficult problem of torque non-cpntact measurement and large-signal output; Employing with torque transfer with small-sized displacement transducer all pack into center tap inner solve existing size sensor greatly, the problem of not sealing.

Below in conjunction with accompanying drawing and example the utility model is further specified.

Fig. 1 is the longitudinal profile structural map that scrunches first embodiment of torque sensor

Fig. 2 is the longitudinal profile structural map that scrunches second embodiment of torque sensor

1. axis, 2. left side axle bowls, 3. locknuts, 4. steel balls, 5. torsion springs, 6. left side lids, 7. left magnet ring 8. linear Hall element 9. cables 10. sensor holders 11. balladeur trains 12. right magnet ring 13. garden post cam tube 14. five-way pipes 15. rollers 16. hinge wheels 17. support columns 18. transmission tubes 19. axle sleeves 20. right axle bowl 21. left gusset plate 22. right gusset plate 23. locknuts 24. key pieces 25. keys 26. pull bars 27. rubber seal rings among the figure

Specific implementation method

In figure one, on the axis (1) in the five-way pipe (14) a side steel ball raceway and axle body disjunctor are only arranged, opposite side steel ball raceway be positioned at can rotate on the axis and only can the unidirectional axle sleeve (19) that outwards moves along axis (1) on, axle sleeve (19) is located by the shoulder backstop on the axis (1); Torsion spring (5) pine is placed in the surface, outer garden at axis (1) middle part, and two ends are inserted axis (1) respectively and gone up in the hole of leaving on the steel ball raceway inner side end or groove with axle sleeve (19); Five-way pipe (14) is stretched out in axle sleeve (19) outer end, has screw thread, locating slot or chain on it, hinge wheel (16) press locating slot or key locking together with its left gusset plate (21), right gusset plate (22) with locknut (23) and fix and its on; Axle sleeve (19) is gone up steel ball raceway inner side end top and is fixed with key piece (24), is fixed with transmission tube (18) on the key piece (24), and roller (15) is fixed on transmission tube (18) surface, interior garden and inserts in the cam path on surface, the outer garden of garden post cam tube (13); Support column (17) is enclosed within the Wai Yuan surface of torsion spring (5), and an end is fixed on the outer garden of steel ball raceway inboard, axis (1) left side, and other end sliding sleeve is gone up on the outer garden of steel ball raceway inboard in axle sleeve (19); Support column (17) middle part is fixed with key (25) on the outer garden, and this key (25) inserts in the keyway of leaving vertically on the garden post cam tube (13), make garden post cam tube (13) can only be vertically on support column (17) parallel being moved to the left and resetting by torsion spring (5); The fixedly connected displacement transducer of left end of garden post cam tube (13), displacement transducer includes balladeur train (11), the two ends of balladeur train (11) are fixed with a pair of permanent magnetic ring: left magnet ring (7), right magnet ring (12), two magnet rings are embedded in relatively at certain intervals in the balladeur train with same polarity respectively and are coaxial staggered relatively with the axis, Hall element (8) inserts between two magnet rings, contact with the surface of a magnet ring wherein when nothing scrunches power or approaching, the sensor holder (10) of installation Hall element is fixed on the outside surface of five-way pipe (14).

In Fig. 2, have on the boss in outer garden, support column (17) middle part and the hole or the groove of axis (1) parallel axes are used to lay pull bar (26), pull bar (26) can be along the hole or the parallel axes of groove move; The right-hand member of pull bar (26) inserts in the groove of garden post cam tube (13), utilize the back-up ring of pull bar (26) one ends to be connected with garden post cam tube (13) and promoted translation and resetted by torsion spring (5) by garden post cam tube (13), the other end of pull bar (26) is connected with displacement transducer.

According to torque sensor of the present utility model, its torsion spring (5) is the parallel coiling torsion spring (5) of single head or bull, also can use two ends to have the single head or the multi-step thread torsion tube of boss; Balladeur train (11), support column (17), transmission tube (18) are nonmagnetic substance and make; Magnet ring (7), (12) are whole garden ring, also can constitute for two halves garden ring; For guaranteeing sealing, prevent the intrusion of dust and rainwater, can install the rotary seal rubber ring additional with axle sleeve (19) axle journal rotation joint at left side axle bowl (2) and axis (1) axle journal, right side axle bowl (20), with highly reliable, the long-life of assurance sensor.

Claims

1, a kind of middle shaft type scrunches torque sensor, form by torsion spring-displacement transducer and axis-sprocket wheel-crank two large divisions, it is characterized in that torsion spring become give-displacement transducer places in the center tap five-way pipe fully, on the axis in the five-way pipe side steel ball raceway and axle body disjunctor are only arranged, opposite side steel ball raceway then is positioned at and can rotating on the axis and only can be unidirectional on the axle sleeve that the outer axis moves, and axle sleeve is inwardly then located by the step backstop on the axis; The torsion spring pine is placed in surface, outer garden, axis middle part, and insert respectively in the hole of leaving on the steel ball raceway inner side end on axis and the axle sleeve or groove at two ends; The five-way pipe is stretched out in the axle sleeve outer end, has screw thread, locating slot or key on it, and hinge wheel is locked thereon by locating slot or key with nut together with its gusset plate; The top of steel ball raceway inner side end is fixed with the key piece on the axle sleeve, is fixed with transmission tube on the key piece, and roller is fixed on transmission tube surface, interior garden and inserts in the cam path on the outer surface, garden of garden post cam tube; Garden post cam tube directly or by pull bar is fixedlyed connected with balladeur train, and balladeur train is enclosed within the outside of support column; Support column is enclosed within the surface, outer garden of torsion spring, and an end is fixed in the outer garden of axis steel ball raceway inboard, and other end pine is placed in the outer garden of steel ball raceway inboard on the axle sleeve; The support column middle part is fixed with key on the outer garden, and key inserts in the keyway of leaving vertically on the post cam tube of garden; The fixedly connected displacement transducer of left end of garden post cam tube, displacement transducer is made of magnetosensitive linear hall element and a pair of permanent magnetic ring and balladeur train, magnet ring is embedded in relatively at certain intervals in the balladeur train with the same polarity face respectively and is staggered relatively with the axis axis coaxle, Hall element inserts between two magnet rings, contact with the surface of a magnet ring wherein when nothing scrunches power or approaching, the sensor holder of installation Hall element is fixed on the outside surface of five-way pipe.

2, shaft type scrunches torque sensor in according to claim 1, it is characterized in that the hole or the groove that have on the boss in outer garden, support column middle part with the axis parallel axes are used to lay pull bar, pull bar can be along the hole or the parallel axes of groove move; The right-hand member of pull bar inserts in the groove of garden post cam tube, utilizes the back-up ring of pull bar one end to be connected with garden post cam tube and by the promotion translation of garden post cam tube and resetted by torsion spring, the other end of pull bar is connected with displacement transducer.

3, middle shaft type according to claim 1 scrunches torque sensor, it is characterized in that torsion spring is the parallel coiling torsion spring of single head or bull.

4, middle shaft type according to claim 1 scrunches torque sensor, it is characterized in that torsion spring has the single head or the multi-step thread torsion tube of boss for the torsion tube two ends.

5, middle shaft type according to claim 1 scrunches torque sensor, it is characterized in that balladeur train, support column, transmission tube are nonmagnetic substance and make.

6, middle shaft type according to claim 1 scrunches torque sensor, it is characterized in that magnet ring can be a whole garden ring, also can be that two halves garden ring constitutes.

7, middle shaft type according to claim 1 scrunches torque sensor, it is characterized in that left side axle bowl and middle shaft neck, right side axle bowl install the rotary seal rubber ring additional with axle sleeve axle journal rotation joint.

8, middle shaft type according to claim 1 scrunches torque sensor, and its purposes is not limited only to electric bicycle, is applicable to that also the measurement of other low speed, big torque is used.