JP6603086B2 - Universal Mount Bicycle Power Meter Module - Google Patents

Description

  The present invention relates to a bicycle wattmeter used to indicate the amount of power a bicycle driver consumes during cycling. In particular, the present invention relates to a universal mount bicycle power meter module that can be adapted to any bicycle capable of generating an electrical signal capable of determining power.

  Bicycle power meters are increasingly being used by both professional and amateur bicycle drivers as an aid in developing training. Several different types of bicycle power meters are available, some of which have strain gauges to measure the force applied to the crank, bottom bracket, or rear wheel hub by the bicycle driver. use. While known bicycle power meters using strain gauges are effective in providing an electrical signal indicative of the applied force, they are relatively expensive and somewhat difficult to install.

  US Pat. No. 8,370,087 issued on Feb. 5, 2013 to the same applicant as “Bicycle Power Meter With Frame Mounted Sensor” is a bicycle power meter with a frame-mounted sensor. A bicycle power meter is disclosed that is relatively inexpensive and that can be easily installed by any end user at the time of manufacture, sale at a retail store, or the like. The bicycle power meter has a strain gauge sensor assembly mounted on a relatively compressible web portion located at the end of the rear fork of the bicycle frame. This relatively highly compressible web portion is located in the vicinity of the rear wheel hub and receives a force imparted to the crank by the bicycle driver and transmitted to the hub via the chain and sprocket parts. The sensor assembly includes two stretchable sensors interconnected according to Ohm's law, each of which includes a variable resistance element whose resistance changes as the highly compressible web portion moves. A first layer having a first layer, and a second layer supporting the first layer. The sensor section is connected to the other two resistors in the bridge circuit, and generates a signal indicating the force applied by the bicycle driver. These signals are processed along with the velocity signal to generate a power signal, which is input to the display device. Although this bicycle power meter overcomes the problems existing in the conventional bicycle power meters, its application is limited to bicycles having a relatively compressible web portion on the bicycle frame. . Not all bicycle frames take this configuration.

US Patent No. 8,370,087

  The present invention has a universal mount bicycle wattmeter module that can be mounted on any rear bicycle axle having a male threaded shaft end and rear bicycle frame. This universal mount bicycle power meter module is relatively inexpensive, but provides an electrical signal indicating the force applied by the bicycle driver and combines it with a speed signal to enable real-time power measurements. It is effective.

  In a first aspect, the present invention provides a first end having an opening, a second end configured to be secured to a bicycle frame adjacent to a rear bicycle axle, and a compressible central portion. A first layer having a first layer mounted on the compressible central portion, each having a variable resistance element mounted thereon, and a second layer supporting the first layer. And the second stretch sensor, and the variable resistance elements of the first and second stretch sensors are interconnected according to Ohm's law to display a total resistance value indicative of a bicycle driver's force A strain gauge sensor assembly; firmly fixed to the first end of the board member and screwed into a corresponding male threaded bicycle shaft end to attach the board member to the first end of the bicycle shaft; The first end of the substrate member so that it can be fixed to A mounting nut having a centrally located internal thread through hole aligned with the opening; and mounted on the substrate member and electrically connected to the strain gauge sensor assembly, the total resistance value A bicycle power meter module including: a signal processing unit that converts a power signal into a bicycle driver's power signal.

  The compressible central portion of the substrate member preferably has a width that is narrower than the width of the first and second end portions of the substrate member, and receives the applied force, Promote compression.

  The second end portion of the elongated substrate member is preferably fixed to the bicycle frame portion using an attachment fixture fixed to the second end portion of the elongated substrate member, and the attachment fixture Has a mounting band configured to firmly capture the bicycle frame portion.

  The first and second stretch sensors may be arranged in a positional relationship in which the first layers are opposed to each other, or may be arranged in a positional relationship in which the second layers are opposed to each other.

  The signal processing unit preferably includes a bridge circuit having the first and second stretch sensors connected in the first branch and a pair of fixed resistors connected in the second branch; and connected to the bridge circuit An amplifier that amplifies the signal indicating the total resistance value; an analog / digital converter that is connected to the amplifier and converts a signal output from the amplifier into a digital signal; and the analog / digital converter. And a microcomputer for receiving the digital signal and the bicycle speed signal from a corresponding bicycle speedometer and converting the received signal into the power signal. In a preferred wireless embodiment, the signal processing unit is connected to the microcomputer and receives the power signal and generates an equivalent wireless signal; and is connected to the transmitter and the equivalent And an antenna for transmitting the radio signal to a corresponding receiver.

  In a second aspect, the invention provides a bicycle having a frame having a rear portion and a rear axle having a male threaded shaft end adjacent to the rear portion of the frame; and a first end portion having an opening; An elongated substrate member having a second end fixed to the rear portion of the frame and a compressible central portion; mounted on the compressible central portion, each having a variable resistance element mounted thereon; A first layer and a second stretch sensor having a second layer supporting the first layer, and the variable resistance element of the first and second stretch sensors is in accordance with Ohm's law. A strain gauge sensor assembly, which is interconnected to display a total resistance value indicative of a bicycle driver's force; firmly fixed to the first end of the substrate member and aligned with the opening Centered bitch A mounting nut having a through hole and screwed to the male threaded shaft end so that the substrate member is fixed to the shaft end of the first end of the substrate member; And a signal processing unit that is electrically connected to the strain gauge sensor assembly and converts the total resistance value into a bicycle driver's power signal.

  The compressible central portion of the elongated substrate member preferably has a width that is narrower than the width of the first and second ends of the elongated substrate member, and receives the force applied to the center. Promotes compression of the part.

  The second end portion of the elongated substrate member is preferably fixed to the bicycle frame using an attachment fixture fixed to the second end portion of the elongated substrate member, and the attachment fixture is And a mounting band configured to firmly capture the bicycle frame portion.

  The first and second stretch sensors may be arranged in a positional relationship in which the first layers are opposed to each other, or may be arranged in a positional relationship in which the second layers are opposed to each other.

  The signal processing unit preferably includes a bridge circuit having the first and second stretch sensors connected in the first branch and a pair of fixed resistors connected in the second branch; and connected to the bridge circuit An amplifier that amplifies the signal indicating the total resistance value; an analog / digital converter that is connected to the amplifier and converts a signal output from the amplifier into a digital signal; and the analog / digital converter. And a microcomputer for receiving the digital signal and the bicycle speed signal from a corresponding bicycle speedometer and converting the received signal into the power signal. In a preferred wireless embodiment, the signal processing unit is connected to the microcomputer and receives a power signal to generate an equivalent wireless signal; and is connected to the transmitter and the equivalent And an antenna for transmitting the radio signal to a corresponding receiver.

  The present invention considerably facilitates the installation of a bicycle wattmeter for any bicycle having a rear axle with a male threaded shaft end and a rear frame. The bicycle power meter module can be easily fixed to a bicycle part when the bicycle is manufactured. Similarly, the bicycle power meter module can be easily fixed to the bicycle as an additional option at any point in the distribution network, such as a retail store. Bicycle drivers can also add the bicycle power meter module to a bicycle after purchasing the bicycle at a relatively low cost and with little effort.

  For a full understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken together with the accompanying figures.

1 is a plan view of a preferred embodiment of a bicycle power meter module incorporating the present invention. FIG. It is a partial top view at the time of seeing the bicycle which illustrates the power meter module for bicycles of Drawing 1 mounted in a predetermined position from the rear sprocket side. FIG. 3 is an enlarged cross-sectional view taken along line 3-3 of FIG. 2 illustrating the mounting nut, frame, and module base assembly. FIG. 4 is an enlarged cross-sectional view taken along line 4-4 of FIG. 2 illustrating the mounting fixture assembled to the bicycle frame. FIG. 3 is a block diagram of a bicycle power meter module using a single strain gauge sensor assembly configured as a wired device. FIG. 2 is a block diagram of a bicycle power meter module using a single strain gauge sensor assembly configured as a wireless device. FIG. 2 is a schematic diagram of a single strain gauge sensor illustrating the sensor at three different positions. 1 is a schematic diagram illustrating a first embodiment of a dual element strain gauge sensor assembly. FIG. It is the schematic which shows 2nd Embodiment of a double element strain gauge sensor assembly component. It is the schematic which illustrates the bicycle driver | operator's electric power change according to the angular position of a crank.

Detailed Description of the Invention

  Referring now to the drawings, FIG. 1 is a plan view of a first embodiment of a bicycle power meter module incorporating the present invention. As shown in this figure, a bicycle power meter module assembly, generally indicated by reference numeral 10, comprises a first end 12, a second opposite end 13, and preferably ends 12,13. Also has an elongated substrate member 11 having a narrow central portion 14. In order to make the length of the elongated substrate member 11 expandable / contractable according to the force applied to the end portion 12, for example, stainless steel having a thickness of 1.0 mm, a relatively high compressible and thin material. Manufactured from.

  Although details will be described later with reference to FIGS. 7 to 9, the strain gauge sensor assembly 15 is fixed to the upper surface of the central portion 14. The strain gauge sensor assembly 15 has a set of resistance conductors electrically connected to the input terminals of the signal processing unit. The signal processing unit will be described later in detail with reference to FIG. 5 (wired type) and FIG. 6 (wireless type). Has been. This signal processor is powered by a small battery 18 that is removably secured to the circuit board 17 (as shown) or directly to the top surface of the end 13 of the board member 11. The power supplied from the battery 18 to the signal processing unit is controlled by an on / off switch 19 that can be manually operated.

  A female screw nut 20 used to fix the bicycle power meter module 10 to one end of the rear axle of the bicycle is fixed to the upper surface of the first end 12 of the board member 11. The nut 20 can be fixed using various techniques, such as welding, brazing, or highly adhesive bonding. What is important in this fixing step is that the nut 20 must be firmly fixed to the substrate member 11 so that relative movement between the nut 20 and the substrate member 11 is prevented. In other words, when the end of the bicycle axle to which the nut 20 is screwed is displaced due to the force applied by the bicycle chain, the strain gauge sensor assembly 15 can sense the amount of this displacement. Similarly, this deviation must be transmitted to the substrate member 11 via the nut 20.

  A pair of attachment openings 22 and 23 are provided at the second opposite end 13 of the substrate member 11. The mounting fixture generally indicated by reference numeral 25 is preferably a conventional automotive hose clamp, so that the end 13 can be fixed to the mounting fixture 25 in the manner shown in FIGS. A mating pair of mounting openings 26, 27 are provided.

  FIG. 2 is a partial plan view of a bicycle illustrating the bicycle power meter module 10 of FIG. 1 mounted at a predetermined position when viewed from the rear sprocket side. As shown in FIGS. 3, 4, and 4, the mounting fixture 25 is first attached to the opposite end 13 of the substrate member 11 using a screw fixture 28 that penetrates the openings 22, 23, 26, and 27. Fixed. Next, in the manner shown in FIG. 2, the module 10 is mounted on the shaft 28 until the board member 11 is firmly secured in place by the opposite end 13 aligned with the bicycle frame component 29. Directed toward the end, it is attached to the sprocket end of the screw shaft 28 by a threaded nut 20. Next, until the opposite end 13 is firmly fixed to the frame component 29, the attachment band 31 of the attachment fixture 25 is passed around the frame component 29, and the band 31 is attached to the peripheral portion of the frame component 29. By tightening, the opposite end 13 of the board member is fixed to the component 29 of the bicycle frame. Thereby, the mechanical attachment of the bicycle power meter module 10 is completed.

  When the bicycle driver applies a force to the pedal attached to the crank during use, the drive chain 35 (FIG. 2) receives the force transmitted to the shaft 28 via the sprocket 36, causing the shaft 28 to move horizontally. To deflect. The deflection of the shaft 28 is transmitted to the strain gauge sensor assembly 15 via the substrate member 11 and changes the signal output from the strain gauge sensor assembly 15. This output signal is processed in a manner described below to generate a signal indicating the amount of power that can be displayed to the bicycle driver.

  FIG. 7 illustrates a single stretch sensor 40 having the property that the ohmic resistance changes by a predictable amount in response to the linear longitudinal displacement of the sensor body. The stretch sensor 40 has a first layer 42 with a thin variable resistance element 43 provided thereon, and a second base layer 44 that holds the first layer 42 and provides the sensor 40 with additional mechanical strength. The resistance value of the sensor 40 depends on the longitudinal displacement of the sensor body. As shown in FIG. 7, when the sensor 40 is displaced in one direction (exemplified as a bend), ie, the first direction, the resistance value increases to (R + r). Here, R corresponds to the residual resistance value of the sensor 40, and r corresponds to the resistance value added by the displacement in the first direction. Similarly, when the sensor 40 is displaced in the opposite direction, the resistance value decreases to (R−r).

  FIG. 8 illustrates a strain gauge sensor assembly 15 of the type incorporated into the power meter configuration shown in FIGS. 1 and 2. As shown in this figure, the sensor assembly 15 has two two-layer stretch sensors 40a, 40b each having a first layer 42a, 42b and a second layer 44a, 44b. The stretch sensors 40a and 40b are arranged so that the first layers 42a and 42b face each other in the relationship of (R + r) and (R−r). As the sensor assembly 15 is displaced by the force applied to the shaft 28 of the right rear fork 12, the total resistance value of each stretch sensor will change in the same direction and in the opposite direction.

  FIG. 9 illustrates another type of strain gauge sensor assembly 50 that may be incorporated into the power meter configuration shown in FIGS. 1 and 2. As shown in this figure, the sensor assembly 50 has two two-layer stretch sensors 40a, 40b each having a first layer 42a, 42b and a second layer 44a, 44b. The stretch sensors 40a and 40b are arranged so that the second layers 44a and 44b face each other in a relationship of (R−r) and (R + r). As the sensor assembly 50 is displaced by the force applied to the shaft 28 of the right rear fork 12, the total resistance value of each stretch sensor will change in the same direction and in the opposite direction.

  FIG. 5 is a block diagram of a bicycle power meter device using a single strain gauge sensor assembly configured as a wired device. As shown in this figure, the stretch sensors 40a and 40b including the strain gauge sensor assembly 15 or 50 are connected to a set of fixed resistors 52 and 54 by a well-known Wheatstone bridge circuit configuration. The uppermost node of the bridge is connected to a potential source Vc supplied by a battery 18. The lowest node of the bridge is connected to circuit ground. The node on the right side is connected to one end of the fixed resistors 52 and 54, and functions as one output terminal of the bridge circuit. The second end of the fixed resistor 52 is connected to one end of the stretch sensor 40a and the supply voltage Vc. The second end of the fixed resistor 54 is connected to one end of the stretch sensor 40b and circuit ground. The other ends of the stretch sensors 40a and 40b are connected together and function as the other output terminal of the bridge circuit.

  The output terminal of the bridge circuit is connected to the input terminal of an amplifier 55 that amplifies the bridge signal. The amplifier 55 is preferably a device of the type MAX4197 available from Maxim. The amplified signal output from the amplifier 55 is input to an analog / digital (A / D) converter 56 that converts the amplified analog signal into an equivalent digital signal. A digital signal output from the A / D converter 56 is input to an input port of the microcomputer 58. The A / D converter 56 and the microcomputer 58 are preferably combined in a device of the type PIC 10F202 available from Microchip. A speed signal from a bicycle speedometer (not shown) is also input to the microcomputer 58. Microcomputer 58 processes the force and velocity signals using well known algorithms and provides a signal indicative of the magnitude of power. The signal indicating the magnitude of the power is input to the multi-function display device 60 that displays the current power value in a form readable by the bicycle driver. In the embodiment shown in FIG. 5, each of the devices is interconnected by a connection according to Ohm's law.

  FIG. 6 is a block diagram of a bicycle wattmeter device using a single strain gauge sensor assembly configured as a wireless device. In this figure, elements corresponding to the same elements of the system of FIG. 5 are given the same reference numerals. In the system of FIG. 6, the processed power signal is input to a wireless transmitter 62 disposed on the circuit board 17. Transmitter 62 is preferably a product of the type nRF24AP2 ANT + available from Nordic Semiconductor, Norway. The transmitter 62 transmits these power signals via the antenna 63 (FIG. 1) to a receiver 64 that is disposed near the multifunction display device 60 and supplies power signals to the multifunction display device 60.

  In the bicycle power meter device, the strain gauge assembly parts 15 and 50, the amplifier 55, the A / D converter 56, the microcomputer 58 and the transmitter 62 are all mounted on the circuit board 17 in both the wired type and the wireless type. In contrast, the multi-function display device 60 and receiver 64 are mounted in a convenient location for the bicycle driver to view the display, typically somewhere on the bicycle handle.

  When the bicycle driver applies a force to the bicycle pedal during use, the magnitude of this force is monitored by a bridge circuit and converted into a visible power display signal for observation by the bicycle driver. FIG. 10 is a schematic view illustrating a change in electric power of a bicycle driver according to the angular position of the crank. In the position (a), the pedal is substantially horizontal and the bicycle driver is applying the maximum force with the front pedal. In the position (b), the pedal is substantially vertical and the bicycle driver is applying minimal force. In position (c), the pedal is substantially horizontal, and again, the bicycle rider is applying maximum force with the front pedal; while in position (d), the pedal is substantially vertical. And the bicycle driver gives the least force.

  As will be apparent, the bicycle power meter module produced in accordance with the teachings of the present invention is advantageous in cost and ease of installation over known bicycle power meters using strain gauges. More specifically, the bicycle power meter module 10 is suitable for any bicycle having a threaded rear shaft end portion into which the nut 20 can be screwed and a rear frame portion to which the attachment band 31 of the attachment fixture 25 can be fixed. However, it can be attached relatively easily. This attachment can be performed at a bicycle factory or elsewhere in the distribution process (eg, retail store, bicycle rider as a user, etc.). Furthermore, the bicycle power meter module manufactured in accordance with the teachings of the present invention can be configured in either a wired or wireless manner, and thus has high flexibility in the attachment process.

  While the present invention has been described above with reference to specific embodiments, various modifications, alternative configurations, and equivalents may be employed without departing from the spirit of the present invention. For example, although specific circuit components have been disclosed, other equivalent components may be employed as needed. Accordingly, the above description is not intended to limit the invention, which is defined by the appended claims.

DESCRIPTION OF SYMBOLS 10 Bicycle power meter module assembly part 11 Elongation board | substrate member 12 1st edge part 13 2nd edge part 14 Center part 15 Strain gauge sensor assembly part 17 Circuit board 18 Small battery 19 On-off switch 20 which can be operated manually Female thread type nut 22 , 23, 26, 27 Mounting opening 25 Mounting fixture 28 Screw fixture 29 Frame component 31 Mounting band 35 Drive chain 36 Sprocket 40 Stretch sensor 40a, 40b Double-layer stretch sensor 42 First layer 42a, 42b First layer 43 Variable resistance element 44 Second base layer 44a, 44b Second layer 50 Strain gauge sensor assembly 52, 54 Fixed resistance 55 Amplifier 56 A / D converter 58 Microcomputer 60 Multi-function display device 62 Transmitter 63 Antenna 64 Receiver

Claims (14)

An elongated substrate member having a first end having an opening, a second end configured to be secured to a bicycle frame adjacent to the rear bicycle axle, and a compressible central portion;
First and second stretch sensors mounted on the compressible central portion, each having a first layer on which a variable resistance element is mounted, and a second layer supporting the first layer. A strain gauge sensor assembly, wherein the variable resistance elements of the first and second stretch sensors are interconnected according to Ohm's law to output a total resistance value indicative of a bicycle driver's force; ;
Wherein said elongated substrate member is firmly secured to the first end, as the corresponding said elongated substrate member is screwed to the bicycle axis end with external thread can be fixed to the bicycle axis of said first end, A mounting nut having a centrally located internal thread through hole aligned with the opening at the first end of the elongated substrate member;
Signal processing mounted on the elongated substrate member and electrically connected to the strain gauge sensor assembly to convert the total resistance value and a corresponding bicycle speed signal from the bicycle speedometer into a bicycle driver power signal Department:
Bicycle power meter module having. The compressible central portion of the elongated substrate member has a width that is narrower than the widths of the first and second end portions, and receives the applied force to promote compression of the central portion. Item 2. The bicycle power meter module according to Item 1.   The mounting fixture further comprising an attachment fixture secured to the second end of the elongated substrate member, the attachment fixture having an attachment band configured to firmly capture the bicycle frame portion. The bicycle power meter module according to 1.   2. The bicycle power meter module according to claim 1, wherein the first and second stretch sensors are arranged in a positional relationship in which the first layers face each other.   2. The bicycle power meter module according to claim 1, wherein the first and second stretch sensors are arranged in a positional relationship in which the second layers face each other. The signal processing unit
A bridge circuit having the first and second stretch sensors connected in the first branch and a set of fixed resistors connected in the second branch;
An amplifier connected to the bridge circuit for amplifying a signal indicative of the total resistance value;
An analog / digital converter connected to the amplifier and converting a signal output from the amplifier into a digital signal;
And a microcomputer connected to the analog / digital converter for receiving the digital signal and the bicycle speed signal from the corresponding bicycle speedometer and converting the received signal into the power signal. Item 2. The bicycle power meter module according to Item 1. A transmitter connected to the microcomputer for receiving the power signal and generating an equivalent radio signal;
The bicycle power meter module according to claim 6, further comprising an antenna connected to the transmitter and transmitting the equivalent radio signal to a corresponding receiver. A frame having a rear portion, and a rear axle having a male threaded shaft end adjacent to the rear portion of the frame; and
An elongated substrate member having a first end having an opening, a second end secured to the rear of the frame, and a compressible center;
First and second stretch sensors mounted on the compressible central portion, each having a first layer on which a variable resistance element is mounted, and a second layer supporting the first layer. And the variable resistance elements of the first and second stretch sensors are interconnected according to Ohm's law to output a total resistance value indicative of a bicycle driver's force; ;
It is rigidly secured to said first end of said elongated substrate member having a female screw through hole positioned in the center aligned with the said opening, the elongated substrate member of the first of the elongated substrate member A mounting nut screwed onto the male threaded shaft end to be secured to the shaft end of the end;
Signal processing mounted on the elongated substrate member and electrically connected to the strain gauge sensor assembly to convert the total resistance value and a corresponding bicycle speed signal from the bicycle speedometer into a bicycle driver power signal Bicycle wattmeter module with:
With a bicycle.   The compressible central portion of the elongated substrate member has a width that is narrower than the widths of the first and second end portions, and receives the applied force to promote compression of the central portion. Item 10. The bicycle according to item 8. 9. The mounting fixture according to claim 8, further comprising a mounting fixture fixed to the second end of the elongated substrate member, the mounting fixture having a mounting band firmly fixed to a rear portion of the frame. bicycle.   The bicycle according to claim 8, wherein the first and second stretch sensors are arranged in a positional relationship in which the first layers face each other.   The bicycle according to claim 8, wherein the first and second stretch sensors are arranged in a positional relationship in which the second layers face each other. The signal processing unit
A bridge circuit having the first and second stretch sensors connected in the first branch and a set of fixed resistors connected in the second branch;
An amplifier connected to the bridge circuit for amplifying a signal indicative of the total resistance value;
An analog / digital converter connected to the amplifier and converting a signal output from the amplifier into a digital signal;
And a microcomputer connected to the analog / digital converter for receiving the digital signal and the bicycle speed signal from the corresponding bicycle speedometer and converting the received signal into the power signal. Item 10. The bicycle according to item 8. A transmitter connected to the microcomputer for receiving the power signal and generating a radio signal equivalent to the power signal;
Which is connected to the transmitter, the pre-Symbol radio signals of the same or the like, and an antenna for transmitting to the receiver a corresponding, bicycle according to claim 13.

Images