CN1212954C - Pedal force detector for electric auxiliary bicycle - Google Patents

Abstract

To provide a pedaling force detecting device capable of detecting torque in an excellent state while reducing the number of parts and having an easy and small-sized structure. One end of a crankshaft 23 is rotatably journaled by a bearing 51. A cylindrical torsion bar 53 is penetrated and inserted into the outer periphery of the crankshaft 23, the one end is spline-coupled with the outer peripheral surface of the crankshaft 23 in the vicinity of the bearing 51, and the other end is rotatably journaled by a bearing 52. A pedal sprocket 25 is meshed with the outer peripheral surface on the other end side of the torsion bar 53. A pair of magnet rings 55 are mounted along a circumferential direction on external surfaces in the vicinity of the one end side and in the vicinity of the other end side of the torsion bar 53. A pair of MR sensors 501 are arranged at positions facing the magnet rings 55.

Description

The force testing device of electrically assisted bicycle

Technical field

The present invention relates to the force testing device of electrically assisted bicycle, particularly, relate to the force testing device that can detect the electrically assisted bicycle of legpower with the structure of simple and inexpensive well.

Background technology

At the electrically assisted bicycle that is set up in parallel foot power driven system and electrical motor driven system, be in the so-called morpet, utilize pedaling force sensor to detect to be added in the legpower on the pedal, according to the driving torque of this testing result control electro-motor.

Figure 16 is the section-drawing of the S. A. that is equipped with legpower testing agency that is used for the morpet of prior art, is disclosed in No. 2967391 grade of special permission communique.

This S. A. 102, mainly by in axial direction being divided into two input shaft 102a and the output shaft 102b that partly are configured to coaxial shape, be inserted into the inside of each input and output shaft 102a, 102b, at the torsion bar 102c of the both ends of each 102a, 102b spline combination, aforementioned each input and output shaft 102a, 102b are constituted to the spring 111 that axial direction loads mutually.

By the spline combination, the sliding part 921 that has the cam part 921a of convex on the end face is allowed to be attached to slidably on the large-diameter portion of input shaft 102a to axial direction.With utilizing the central portion roughly of the displacement sensor rod 152 that pin 153 can free swaying ground supporting one end, be coupled on the ball cap 924 of input shaft 102b, the stroke detection axle 151 of stroke sensor 150 is connected on the other end of displacement sensor rod 152.

Owing to always utilize coil spring 199 that aforementioned ball cap 924 is pressed to output shaft 102b side, so always one side absorbs its rotation, one side is pressed to output shaft 102a side with aforementioned sliding part 921.On the end face of aforementioned output shaft 102b, form two concavity cam paths 922 that cooperate with the convex cam part 921a of aforementioned sliding part 921 along circumferential direction.

On the gear 113 that is formed at the minor diameter on the aforementioned input shaft 102a colourity minor diameter, the input legpower.On the gear 102e of output shaft 102b, import not shown power-assisted from CD-ROM drive motor.Be combined in the gear 102d on the minor diameter of output shaft 102b, with not shown discharging chain wheel shaft engagement.

In this structure, when torsion bar 102c reverses according to legpower, between input shaft 102a and output shaft 102b, produce phase difference, between output shaft 102b and sliding part 921, also produce phase difference.When ball cap 921 during according to the displacement in axial direction of this phase difference, displacement sensor rod 152 serves as the axle swing with pin 153, and it is passed to stroke sensor 150, detects.

The torque detection means of above-mentioned prior art is because part count is many, so complex structure causes the complicated of the maximization of device and manufacturing process easily.And sliding position and contact site are many, so have to use the material of abrasion test and excellent in te pins of durability.

Summary of the invention

The objective of the invention is, in order to solve the problem of prior art, provide a kind of have part count few, simple and small-sized, the few structure of sliding position and contact site, and carry out the force testing device that torque well detects.

For achieving the above object, the present invention, comprise: by be inserted on the crank shaft from the outside, an end is attached on this crank shaft, the other end is attached to the torque rod on the pedal sprocket, the legpower that wherein will be input on the aforementioned crank shaft detects as aforementioned torsion torsion of bar amount, it is characterized by, it adopts following mechanism.

(1) described force testing device, it is characterized by, it is equipped with: be configured in torsion bar one distolateral and another distolaterally go up, along the circumferential direction with the magnetized a pair of magnet ring of small spacing, respond to the Magnetic Sensor of aforementioned magnet ring, make the supporting device of aforementioned Magnetic Sensor with respect to the magnet ring Elastic Contact.

(2) described force testing device, it is characterized by, it is equipped with: be configured in torsion bar one distolateral and another distolaterally go up, along the circumferential direction with the magnetized a pair of magnet ring of small spacing, respond to the Magnetic Sensor of aforementioned magnetic substance, and, have with respect to the contact part of stipulating that is touched the body elasticity contact, make the supporting device of aforementioned Magnetic Sensor with respect to the magnet ring Elastic Contact.

(3) described force testing device, it is characterized by, it is equipped with: be configured in torsion bar one distolateral and another distolaterally go up, along the circumferential direction with the magnetized a pair of magnet ring of small spacing, the magnetic sensor unit that comprises Magnetic Sensor, and, make the fixed mechanism of the fixing aforementioned magnetic sensor unit of mode of this Magnetic Sensor and aforementioned magnet ring subtend to keep predetermined gap.

According to above-mentioned feature (1), because Magnetic Sensor is flexibly contacted with respect to magnet ring, so, even crank shaft off-centre, also can be always that the relative position relation maintenance of Magnetic Sensor and magnet ring is constant.

According to above-mentioned feature (2), if the contact part that makes supporting device is with magnet ring or be touched body with the same accentric of described magnet ring and contact, because when crank shaft is eccentric, the also same correspondingly displacement of Magnetic Sensor, so, even crank shaft off-centre also can be always constant with the relative position relation maintenance of Magnetic Sensor and magnet ring.

According to above-mentioned feature (3), owing to Magnetic Sensor firmly fixes with respect to vehicle body frame, so can always keep the position relation of Magnetic Sensor and magnet ring constant.

Description of drawings

Fig. 1 is equipped with the lateral plan of the electrically assisted bicycle of legpower detecting sensor of the present invention.

Fig. 2 schematically represents the diagram of the Poewr transmission mechanism of electrically assisted bicycle.

The section-drawing of Fig. 3 CD-ROM drive motor.

The lateral plan of Fig. 4 crank unit.

Fig. 5 is along the section-drawing of the crank shaft of crank unit.

Fig. 6 represents the diagram of an example (one) of the mounting structure of MR sensor.

Fig. 7 represents the diagram of an example (its two) of the mounting structure of MR sensor.

Fig. 8 represents the diagram of an example (its three) of the mounting structure of MR sensor.

Fig. 9 represents the diagram of an example (its four) of the mounting structure of MR sensor.

Figure 10 legpower detects the block diagram (one) of the main portion in loop.

Figure 11 legpower detects the block diagram (its two) of the main portion in loop.

The signal waveforms of the main portion of Figure 12 Figure 10 (no legpower).

The signal waveforms of the main portion of Figure 13 Figure 10 (legpower is arranged).

Figure 14 represents the diagram of phase difference and legpower relation among Figure 10.

Figure 15 represents to ask the diagram of the method for phase difference.

Figure 16 is used for the section-drawing of main portion of legpower testing agency of the morpet of prior art.

Nomenclature

16... motor, 23... crank shaft, 24... pedal, 25... pedal sprocket, 27... chain, 26... driven sprocket, 50... crank unit, 53... torsion bar, 55... magnet ring, 501...MR sensor, 502... sensor base plate, 503... wire harness, 506,507,511... leaf spring, 58,512... retainer, the 510... coil spring, 511a is spring portion in a zigzag.

The specific embodiment

Below, the preferred implementing form that present invention will be described in detail with reference to the accompanying.

Fig. 1 is the lateral plan that the electrically assisted bicycle of force testing device of the present invention is installed.

Electrically assisted bicycle 1 is a folded form, and vehicle body frame 4 can be roughly folding at the central portion of vehicle body, and it is made of front vehicle frame 2 and back vehicle frame 3, and each vehicle frame 2,3 is connected by connecting portion 10.On the leading section of front vehicle frame 2, head pipe 5 is set, the front fork 6 that front-wheel 7 and handle 8 are installed is bearing on this pipe 5 capable of free rotationly.

The vehicle seat bearing support 11 of oblique upper extension backward is attached on the front end of back vehicle frame 3, but the seat post 13 that easy on and off moves is installed on the seat post installation portion 11a on the rearward end that is arranged at this vehicle seat bearing support 11, and then saddle 14 is installed on the seat post 13.At seat post installation portion 11a seat post height adjustment bar 12 is set.15 of trailing wheels be bearing in the back vehicle frame 3 rearward end on, below the crank unit 50 that will describe the back is installed.

Handle 8a and brake rod 8b are arranged on the aforementioned handle 8, at body forward structure front brake 17 are set, and rear brake 18 is set at the rear portion.On the wheel hub of trailing wheel 15, be provided as the motor 16 of auxiliary power source coaxially.Motor 16 is high torque (HT) and the low three-phase motor that rubs preferably.

The crank 21 that is attached on the pedal 24 is incorporated on the crank shaft 23.The pedaling force sensor that pedal sprocket 25 will be described in detail via the back is attached on the crank shaft 23, and the legpower that is added on the pedal 24 passes to pedal sprocket 25 via pedaling force sensor.Pedal sprocket 25 has on the driven sprocket (not shown) that chain 27 is attached to trailing wheel.Battery 9 as the power supply of motor 16 grades is contained in vehicle body central authorities.

Fig. 2 is a diagram of schematically representing the Poewr transmission mechanism of aforementioned electrically assisted bicycle, and the label identical with the front represented equal part.

Via crank shaft 23, pedal sprocket 25 and chain 27 are input to the driven sprocket 26 of trailing wheel 15 from the legpower of pedal 24 input, and be synthetic with the auxiliary power that motor 16 produces after being slowed down by the gear mechanism of change-speed box 30, drives trailing wheel 15.

Fig. 3 is the section-drawing of motor 16, and the cylinder body 30 of epicyclic gear is by axle 31 supportings.Wheel nave 32 is coupled on the periphery of cylinder body 30.Wheel nave 32 is the annular solids with inner core and urceolus, and the inner core inner peripheral surface contacts with the periphery of cylinder body 30.Utilize bolt 34 to be fixed on the side of wheel nave 32 from the connecting panel 33 that cylinder body 30 stretches out.On the interior week of the urceolus of wheel nave 32, constitute the neodium magnet 35 of the rotor-side magnetic pole of motor 16 with the arranged spaced of regulation.That is, urceolus constitutes the rotor core of holding magnet 35.

Bearing 36 is coupled on the periphery of inner core of wheel nave 32, and stator back plate 37 is coupled on the periphery of this bearing 36.Stator 38 is disposed at the periphery of stator back plate 37, is installed by bolt 40.Stator 38 and rotor core, be the thin gap that the urceolus of wheel nave 32 has regulation, on this stator 38, be wound with three phase windings 39.

On the side of stator back plate 37, the magnetic pole sensor 41 that is made of hall device is set.Magnetic pole sensor 41 perceive from the aforementioned wheel nave 32 outstanding magnet 42 that are provided with by the time flux change that takes place, output is as the position signal of the wheel nave 32 of rotor.Magnetic pole sensor 41 is arranged on three positions mutually corresponding to each of motor 16.

On the side of stator back plate 37, utilization is set carries out on this control basal plate 43, control elements such as CPU and FET being installed to the switch on control basal plate 43 of control usefulness of aforementioned three-phase winding 39 from the position signal of magnetic pole sensor 41.In addition, control basal plate 43 can be integrated with the installation base plate of aforementioned magnetic pole sensor 41 usefulness.

On the periphery of wheel nave 32, be fixed with not shown trailing wheel wheel rim bonded assembly spoke 44.And then, on a side opposition side of aforementioned control basal plate 43 grades of the installation of stator back plate 37, utilize bolt 45 to be fixed with carriage 46, carriage 46 utilizes not shown bolt to be attached on the plate 29 of aforementioned vehicle body frame 4.

Fig. 4 is mounted in the side cutaway view of the crank unit 50 on the aforementioned vehicle frame bottom, and force testing device 500 is installed on this crank portion.Fig. 5 is the section-drawing along crank shaft.

As shown in Figure 4, crank unit 50 is screwed the bottom at aforementioned vehicle frame at three positions.As shown in Figure 5, in crank unit 50, an end of crank shaft 23 can rotate freely ground axle suspension by bearing 51.Barrel-contoured torsion bar 53 connects the periphery of passing crank shaft 23, and one end spline is attached near the outer peripheral face of the crank shaft 23 the aforementioned bearings 51, and the other end utilizes bearing 52 can rotate freely ground axle suspension with respect to crank unit 50.Aforementioned pedal sprocket 25 is engaged on the other one distolateral outer peripheral face of aforementioned torsion bar 53.

Near the end of aforementioned torsion bar 53 and the other end near lateral surface on, along the circumferential direction be equipped with a pair of magnet ring 55 (55a, 55b).Magnet ring 55 is by along the circumferential direction constituting with small spacing magnetization.With the position of aforementioned magnet ring 55 subtends on, configuration pair of MR sensors 501 (501a, 501b)

Fig. 6 is the section-drawing of an example of the mounting structure of the aforementioned MR sensor 501 of expression, and MR sensor 501 is loaded on the interarea of sensor base plate 502.The detection signal of MR sensor 501 is drawn out to the outside via wire harness 503.

Sensor as aforementioned substrate 502 is fixed on the end that is roughly L shaped plate spring 506.The other end of aforementioned L shaped plate spring 506, the elastic force of utilizing leaf spring 506 with aforementioned MR sensor 501 with respect to the mode of magnet ring 55 Elastic Contact utilize screw 505 be fixed on crank unit 50 below.

According to the device sensor construction, owing to can make MR sensor 501 with respect to magnet ring 55 Elastic Contact, so, even crank shaft 23 off-centre also always can keep MR sensor 501 constant with the relative position relation of magnet ring 55.Thereby,, can correctly detect the legpower of representing in order to the torsional capacity of torsion bar 53 with simple structure no matter whether crank shaft 23 is eccentric.

Fig. 7 is the diagram of another one example of the mounting structure of the aforementioned MR sensor 501 of expression, and sensor as aforementioned substrate 502 is fixed on the end that is roughly L shaped leaf spring 507.One of in the pair of holders 508 that the other end of aforementioned L shaped leaf spring 507 utilizes screw 509 to be fixed to cooperatively interact on (508a).

Aforementioned pair of holders 508 loads ground via coil spring 510 mutual elasticity and cooperates.Another one (508b) in the aforementioned pair of holders 508 so that one of them (508a) with respect to the mode of the assigned position Elastic Contact of magnet ring 55, utilize screw 505 be fixed on crank unit 50 below.

Aforementioned MR sensor 501 and retainer 508 under the assigned position state of contact of a retainer 508a and magnet ring 55, in the mode of MR sensor 501 with the other assigned position Elastic Contact of magnet ring 55, relatively position in advance.

According to this structure, when crank shaft 23 off-centre, retainer 508 displacements, because also correspondingly displacement therewith of MR sensor 501, so, even crank shaft 23 off-centre also always can correctly be located MR sensor 501 with respect to magnet ring 55.

Fig. 8 is the diagram of another example of the mounting structure of the aforementioned MR sensor 501 of expression, and sensor as aforementioned substrate 502 is fixed on the end of leaf spring 511.On the other end of aforementioned leaf spring 511, form spring 511a in a zigzag, with utilize its elastic force with a retainer 512a with respect to another retainer 512b to the spring-loading mode of crank direction, (512a is between subtend face 512b) to be contained in the pair of holders 512 that makes up slidably mutually.In the contact part of a retainer 512a mode with respect to the assigned position Elastic Contact of magnet ring 55, utilize screw 505 with another retainer 512b be fixed on crank unit 50 below.

Aforementioned MR sensor 501 and retainer 512, relative positioning in advance is so that make assigned position state of contact at a retainer 512a and magnet ring 55 to the other assigned position Elastic Contact of MR sensor 501 with magnet ring 55.

According to this form of implementation, needn't prepare coil spring in addition, just can obtain the effect identical with the structure of earlier figures 7.In addition, in Fig. 7, structure shown in Figure 8, illustrated that situation about one of making in the retainer with respect to magnet ring 55 contacts is illustrated, still, other the body that is touched of crank shaft 23 and torsion bar 53 grades and magnet ring 55 the same accentrics has been contacted.

Fig. 9 is the diagram of further another one example of the mounting structure of the aforementioned MR sensor 501 of expression, and sensor as aforementioned substrate 502 is fixed on the end that is roughly L shaped retainer 504.The other end of aforementioned L shaped retainer 504 with the gap with MR sensor 501 and magnet ring 55 remain on specified value () mode for example, 50 microns, utilize screw 505 be fixed on crank unit 50 below.

According to this sensor fixing structure, because MR sensor 501 can not contact with magnet ring 55, so, can improve the durability of MR sensor 501 and magnet ring 55.

Figure 10 is the block diagram of the structure of the main portion that legpower detects the loop in this form of implementation of expression, and in each MR sensor 501, two two variable resistance body R1, R2 that change according to the different resistance values of magnetic force are connected in series.

On output signal V1, the V2 of each MR sensor 501a (501b), if on aforementioned torsion bar 53, do not produce when reversing, as shown in figure 12, some initial phase difference θ ref that the deviation when only producing because of the manufacturing assembling causes.Relative therewith, when on torsion bar 53, producing when reversing, as shown in figure 13, on each output signal V1, V2 except that aforementioned initial phase difference θ ref, also further the torsional capacity of generation and torsion bar 53, be the relevant phase difference θ F of legpower.

In this form of implementation, in order to detect the phase difference θ F of the aforementioned legpower of representative quantitatively, the output signal V1 (V2) of each MR sensor 501a (501b), via high-pass filter (HPF) 202a (202b), clipping amplifier 203a (203b) and wave shaping are input among the CPU205 of interior dress with comparator 204a (204b).CPU205, as shown in figure 15, to the delay time n of output signal V2 with respect to output signal V1, and the cycle N of output signal V1 counts, and obtains phase difference θ F according to following formula (1).

Phase difference θ F=n/N360[degree]-θ ref... (1)

Here, because phase difference and legpower demonstrate constant characteristic as shown in figure 14, so, just can obtain legpower by the formula of substitution simple proportional simply if detect phase difference θ F.

Figure 11 is the block diagram of structure of the main portion of the expression legpower other form of implementation that detects the loop, and the form with bridge circuit on each MR sensor 501 connects four the variable resistance body R1～R4s of resistance value along with magnetic force change, and two outputs are antiphases.If utilize this bridge circuit, can reduce noise, so, can obtain legpower more accurately.

According to the present invention, can reach following effect.

(1) according to the 1st, 2 aspect of the present invention, owing to can make Magnetic Sensor with respect to magnet ring Elastic Contact, so, even crank axle off-centre also can always keep Magnetic Sensor and magnet ring Relative position relation is constant.

(2) according to the 3rd～6 aspect of the present invention, when crank axle is eccentric, because therefore corresponding Geomagnetic sensor also is subjected to displacement, so, even crank axle off-centre also can always keep magnetic to pass The relative position relation of sensor and magnet ring is constant.

(3) according to the 7th aspect of the present invention, because Magnetic Sensor is securely solid with respect to vehicle body frame Fixed, so, can always keep the relative position relation of Magnetic Sensor and magnet ring constant.

Claims (7)

1. the force testing device of an electrically assisted bicycle, comprise: by be inserted on the crank shaft from the outside, an end is attached on this crank shaft, the other end is attached to the torsion bar on the pedal sprocket, wherein, the legpower that is input on the aforementioned crank shaft is detected as aforementioned torsion torsion of bar amount, it is characterized by, be equipped with:

Be configured in torsion bar one distolateral and another distolaterally go up, along the circumferential direction with the magnetized a pair of magnet ring of small spacing,

Respond to the Magnetic Sensor of aforementioned magnet ring,

Make the supporting device of aforementioned Magnetic Sensor with respect to the magnet ring Elastic Contact.

2. the force testing device of electrically assisted bicycle as claimed in claim 1 is characterized by,

Aforementioned supporting device has the one end and is fixed to leaf spring on the Magnetic Sensor,

The other end of aforementioned leaf spring is to fix with the mode that aforementioned magnet ring contacts the elastic force of aforementioned Magnetic Sensor utilization regulation with respect to frame part.

3. the force testing device of an electrically assisted bicycle, comprise: by be inserted on the crank shaft from the outside, an end is attached on this crank shaft, the other end is attached to the torsion bar on the pedal sprocket, wherein, the legpower that is input on the aforementioned crank shaft is detected as aforementioned torsion torsion of bar amount, it is characterized by, be equipped with:

Be configured in torsion bar one distolateral and another distolaterally go up, along the circumferential direction with the magnetized a pair of magnet ring of small spacing,

Respond to the Magnetic Sensor of aforementioned magnet ring,

And, have with respect to the contact part of stipulating that is touched the body elasticity contact, make the supporting device of aforementioned Magnetic Sensor with respect to the magnet ring Elastic Contact.

4. the force testing device of electrically assisted bicycle as claimed in claim 3 is characterized by, and aforementioned supporting member comprises:

Pair of holders,

Make in the aforementioned pair of holders one with wherein another mutual spring-loading coil spring,

Make an aforementioned retainer and the aforementioned fixed mechanism that is touched fixing aforementioned another retainer of mode that body elasticity contacts with the elastic force of utilizing the said spiral spring,

Aforementioned Magnetic Sensor is fixing at one end to be gone up, and the other end is fixed on the plate-shaped springs on the aforementioned retainer.

5. the force testing device of electrically assisted bicycle as claimed in claim 4 is characterized by, and aforementioned supporting member comprises:

Aforementioned Magnetic Sensor is fixing at one end to be gone up, the plate-shaped springs of the word spring portion that on the other end, has,

Utilize the aforementioned mutual spring-loading pair of holders of word spring portion,

Make an aforementioned retainer and the aforementioned fixed mechanism that is touched fixing aforementioned another retainer of mode that body elasticity contacts with the elastic force of utilizing aforementioned word spring portion.

6. as the force testing device of each the described electrically assisted bicycle in the claim 3 to 5, it is characterized by, the aforementioned body that is touched is in aforementioned magnet ring, torsion bar and the crank shaft any.

7. the force testing device of an electrically assisted bicycle, comprise: by be inserted on the crank shaft from the outside, an end is attached on this crank shaft, the other end is attached to the torsion bar on the pedal sprocket, wherein, the legpower that is input on the aforementioned crank shaft is detected as aforementioned torsion torsion of bar amount, it is characterized by, be equipped with:

Be configured in torsion bar one distolateral and another distolaterally go up, along the circumferential direction with the magnetized a pair of magnet ring of small spacing,

The magnetic sensor unit that comprises Magnetic Sensor, and

To keep predetermined gap to make the fixed mechanism of the fixing aforementioned magnetic sensor unit of mode of this Magnetic Sensor and aforementioned magnet ring subtend.

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