JP3453654B2 - Torque converter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque amount converter for measuring torque, and particularly when measuring the torque of a wheel rotating at high speed, maintaining a high torsional rigidity necessary for the measurement. At the same time, it relates to a torque amount converter capable of measuring torque with high sensitivity and high accuracy.

[0002]

2. Description of the Related Art A general measuring instrument for measuring torque generated in a wheel or the like of an automobile rotating at high speed is connected to a driving force transmission system between a driving roller rotated by the wheel and a dynamometer or a braking device. A structure is used in which a cylindrical strain generating body is connected between the driving side coupling portion and the driven side coupling portion. Then, a strain gauge is attached to the outer peripheral surface or the inner peripheral surface of the cylindrical strain generating body so that the strain generating force is proportional to the torque generated when the rotational force is transmitted from the driving side coupling portion to the driven side coupling portion. The amount of shear strain of the body is measured electrically. In order to accurately measure the amount of strain with this strain generating element, it was necessary to reduce the outer diameter of the strain generating element or reduce the thickness of the strain generating element to generate a large strain. However, contrary to these necessary conditions, when measuring the amount of torque generated in the wheels of an automobile, a sudden torque change occurs in the power transmission system when the automobile suddenly starts or suddenly stops. To measure a sudden torque change,
The flexure element must have high responsiveness, which requires a high torsional rigidity, which violates the conditions for achieving high sensitivity and high accuracy, and either increases the outer diameter of the flexure element or It was necessary to make the body thicker. In this way, the condition to measure the strain amount with high sensitivity and high accuracy by the flexure element,
The conditions for increasing the responsiveness are contrary to each other, and it has not been easy to realize a measuring instrument satisfying all the conditions.

To solve such a problem,
JP-A-6-229853 and JP-A-7-229
Japanese Patent No. 802 describes a structure of a torque converter as shown below. A thin-walled cylindrical portion is provided in a predetermined narrow region in the rotating direction of the cylindrical strain generating body. By increasing the outer diameter of the thin-walled cylindrical portion as much as possible, it is possible to cope with the occurrence of a sudden torque change at the time of sudden start or sudden stop when measuring the amount of torque generated in the wheels of the automobile,
This makes it possible to provide a transducer with high torsional rigidity.
Then, a predetermined area on the outer peripheral surface of the thin-walled cylindrical portion is subjected to a planar slitting process to provide a thicker wall portion that is thinner than other thin-walled cylindrical portions, and a large strain is generated in the planar strain portion. By doing so, highly accurate measurement is possible. That is,
In a strain-generating body in which a flat strain-generating portion having a thickness thinner than the thickness of the other portion of the thin-walled cylindrical portion is provided in the thin-walled cylindrical portion,
By arbitrarily setting the width, outer diameter, wall thickness of the thin-walled cylindrical portion, and the width, wall thickness, etc. of the processed plane flexure portion,
It is possible to perform high-sensitivity and high-accuracy measurement while ensuring high torsional rigidity.

[0004]

In the torque converter described in the above-mentioned publication, the flat strain portion formed at a predetermined position of the thin-walled cylindrical portion has a constant width as a flat thin-walled portion. And is formed parallel to the central axis. However, this structure is apt to cause twisting and bending bending of the shaft, and is a disadvantageous structure for measuring the torque amount with high accuracy. In this case, a method of preventing the influence of stress concentration by forming roundness on both ends of the flat thin portion is considered, but this is not a sufficient countermeasure method, and the thickness of the flat portion is increased for this countermeasure. There is a problem that the outer shape of the flexure element needs to be increased. Further, the cylindrical strain generating element arranged between the driving side coupling portion and the driven side coupling portion is configured separately, and when these are coupled to assemble the torque converter, the Axis alignment is difficult,
There is a drawback that it takes time to assemble.

The present invention has been made in order to solve the above problems, and has a high torsional rigidity to realize a high responsiveness and to measure a torque amount with high sensitivity and accuracy. The purpose is to provide a torque amount converter.

[0006]

In order to solve the above-mentioned problems, the invention of claim 1 has a drive-side flange, a driven-side flange, and a substantially cylindrical strain generating portion formed between them. It is integrally formed and has an opening at the center thereof, and a groove having an arcuate section in cross section toward the central axis is formed in the entire circumferential direction of the outer peripheral surface of the strain-flexing portion. Strain gauges are attached to the inner peripheral surface of the strain-flexing portion forming the portion at equal intervals around the thinnest portion of the strain-flexing portion. By making the shape of the thin-walled part formed in the strain-flexing part into an arcuate groove shape, the twisting angle generated in the thin-walled part and the bending due to the bending of the shaft can be reduced, and high torsion to maintain high responsiveness The rigidity can be obtained.

In order to solve the above-mentioned problems, the invention of claim 2 is the invention of claim 1, wherein the opening is formed from the driving side flange side toward the driven side flange side. The bottom portion is formed in the driven side flange, and a circuit board for mounting an electronic circuit is mounted in the opening portion.

In order to solve the above problems, the invention of claim 3 is characterized in that, in the invention of claim 1 or 2, a lid is attached to the opening. Is.

In order to solve the above-mentioned problems, the invention of claim 4 is the invention according to any one of claims 1 to 3, wherein a transformer is attached to an outer side portion of the diameter of the driven side flange. It is characterized by that.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a torque amount converter according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view showing one form of a strain generating element of a torque amount converter according to the present invention, and FIG. 2 is a side view of FIG. 1 and a partial sectional view taken along the line EE. As shown in the figure, the flexure element 1 has a substantially cylindrical shape formed between the driving side flange portion 2, the driven side flange portion 3, and the driving side flange portion 2 and the driven side flange portion 3. It is roughly composed of a distortion section 5.

On the outer (left side in the figure) end face of the driving side flange portion 2, for example, in the middle of the power transmission system between the measuring roller of the chassis dynamo rotated by the wheels of the automobile and the load such as the dynamometer and the brake mechanism. The driving side connecting member (not shown) connected to the above is connected using the screw hole 6. A plurality of screw holes 6 penetrate the drive side flange portion 2 and are provided in a substantially concentric circle at equal intervals. Further, in the driven side flange portion 3, a plurality of load holes (not shown) for a driving force transmission system are provided through the driven side flange portion 3 in a substantially concentric circle at equal intervals.
Are combined using. Further, since the driving side flange portion 2, the driven side flange portion 3, and the strain-flexing portion 5 formed between them rotate when measuring the torque amount, they are necessary for the circuit for measuring the torque amount of the strain-generating portion. Various methods have been adopted for transmitting and receiving various power transmissions and signal transmissions corresponding to the measured torque amount from the outside, that is, from the fixed side that does not rotate during measurement. FIG. 3 is a diagram showing an example in which electric power and signals are transmitted between the driven side flange portion 3 on the rotating side and the fixed side 20 arranged on the outer peripheral portion thereof by using a transformer. In this example, the driven-side flange portion 3 is provided with a secondary-side magnetic core portion 14 of an annular transformer that receives electric power from the fixed side 20 and transmits a signal corresponding to the amount of torque to the fixed side 20. On the fixed side 20, a primary side magnetic core portion 24 of a transformer coupled to the fixed side 20 is installed in a rotary transformer form. That is, the fixed side 20 is the driven side flange portion 3
The secondary side magnetic core portion 14 of the transformer provided on the outer peripheral portion of the transformer has a primary side magnetic core portion 24 of the transformer which is coupled via a minute gap g. It is covered and fixed to the fixed base 21 with screws 23.

The strain-flexing portion 5 is a portion formed between the driving-side flange portion 2 and the driven-side flange portion 3 in the direction of the central axis L of the strain-flexing body 1 by means such as cutting or grinding. Is. The tip of the processed portion formed by this cutting, grinding or the like, that is, the outer peripheral surface 8 of the strain generating portion 5 is formed so as to have an arc shape (R groove shape) toward the central axis L, and the R groove It is formed such that the thickness of the strain-flexing portion 5 is thinnest in the central portion. By forming the R groove shape in this way,
Since the thicknesses between the driving side flange portion 2 and the thinnest portion formed by the R groove and between the driven side flange portion 3 and the thinnest portion formed by the R groove gradually change, both flange portions 2, 3 It is possible to prevent the stress from concentrating on the boundary region between the strained portion 5 and the strained portion 5, and to increase the stress concentrated on the thinnest portion of the R groove, which is different from the conventional case having a flat portion. In comparison, when detecting the same amount of strain, the thinnest portion of the R groove serving as the strain sensing portion can be thickened. Therefore, it is possible to reduce the angle of twist generated by reducing the wall thickness and the bending due to bending of the shaft, and it is possible to measure the torque amount with high accuracy and to prevent a sudden change in the torque amount. It is possible to obtain high torsional rigidity for having high responsiveness.

By adopting the R-groove shape, the wall thickness of the strain sensing portion becomes thicker as it goes away from the thinnest portion which is the center of the R groove, and the strain detection sensitivity is lowered. Since it is possible to increase the stress concentrated on the thinnest portion, it is possible to design the thickness of the strain sensing portion in consideration of the decrease in strain detection sensitivity. The drive-side flange portion 2 and the driven-side flange portion 3 are integrally formed with the strain-flexing portion 5 to form the strain-flexing body 1. The driving-side flange portion 2 and the driven-side flange portion 3 are formed to have a larger outer diameter and a larger wall thickness than the strain-flexing portion 5 that is machined toward the central axis L. As a result, it is possible to obtain a high torsional rigidity having a high responsiveness to the measurement of a sudden torque change.

An opening 10 is formed in the central portion of the flexure element 1 with the central axis L as the center. The opening 10 is formed from the drive-side flange 2 side to penetrate the strain-flexing part 5 toward the driven-side flange 3 side, and the bottom 12 thereof reaches inside the driven-side flange 3. Further, the opening 1 has a lid 1
1 is provided, and the lid 11 is normally used (when measuring the torque amount).
It is in a cold state covered with. Inside the opening 10, a plurality of strain gauges (described later) attached to the side surface, an electronic circuit that processes the output of the Wheatstone bridge circuit configured by the strain gauges, and electric power transmitted from the outside are supplied to the electronic circuit power supply. A circuit board 13 on which a circuit for conversion is mounted is provided. By providing the lid 11 and closing the opening 10, it is possible to prevent problems such as peeling of the attached strain gauge and disconnection of circuit wiring due to wind force, centrifugal force, and the like generated by high-speed rotation during measurement.

FIG. 4 shows a plan view of the strain-flexing part 5. Eight strain gauges (A1 to A4, B1 to B4) are attached at predetermined intervals on the inner peripheral surface of the opening 10 formed through the strain-flexing portion 5. A dotted line 15 shown in the drawing indicates the thinnest wall portion of the R groove formed on the outer peripheral surface of the strain-flexing portion 5, and the strain gauges (A1 to A4, B1 to B4) attached to the opening 10 are:
It is affixed to the inner peripheral surface corresponding to the thinnest part of the R groove. Each strain gauge is coated with butyl rubber, moisture-proofed, and potted with silicon.

Further, strain gauges (A1 to A4, B1 to B4)
Are connected as shown in FIG. 5 to form a Wheatstone bridge circuit 16. The attached strain gauge is distinguished into a strain gauge that becomes a compressive strain and a strain gauge that becomes a tensile strain by a shearing force proportional to the amount of torque generated in the flexure element 1, and the resistance change of both strain gauges is output. Are formed so as to be added in an electronic circuit (circuit board 13) to which is connected.

[0018]

As described above, according to the torque amount converter of the present invention, the strain-generating portion is cut into the R-groove shape so that the stress is concentrated on the thinnest portion of the strain-generating portion. Therefore, as compared with the conventional flat strain element, the thickness of the thinnest portion required for detecting the same amount of strain, that is, the strain sensing portion can be thickened. It is possible to obtain high torsional rigidity that has high responsiveness to a sudden change in the amount of torque. Further, since the angle of twist and the bending due to the bending of the shaft can be reduced, it is possible to measure the torque amount with high accuracy.

Further, since the driving side flange portion, the driven side flange portion, and the strain generating portion are integrally formed, the outer diameter and the wall thickness of the driving side flange portion and the driven side flange portion can be increased, High torsional rigidity can be obtained, and ideal deformation of the strain sensing portion can be realized at the time of measuring the torque amount, and highly sensitive and highly accurate torque measurement can be performed.

Further, since the lid is provided at the opening, it is possible to prevent the attached strain gauge from being broken or broken due to wind force, centrifugal force, etc. due to high speed rotation at the time of measurement.
It is possible to prevent the deterioration of the circuit board or the like provided in the opening due to the influence of moisture or dust from the outside.

[Brief description of drawings]

FIG. 1 is a plan view showing one form of a flexure element of a torque amount converter according to the present invention.

FIG. 2 is a side view of FIG. 1 and a partial cross-sectional view taken along line EE.

FIG. 3 (a) is a plan view showing an embodiment of a torque amount converter according to the present invention. (B) It is a side view of Drawing (a), and a partial sectional view in line FF.

FIG. 4 is a plan view showing one form of a strain-flexing portion according to the present invention.

FIG. 5 is a diagram showing a Wheatstone bridge circuit configured by a strain gauge.

[Explanation of symbols]

1 strain body 2 Drive side flange 3 Driven side flange 5 strain section 6, 7 screw holes 8 outer peripheral surface 10 openings 11 lid 12 bottom 13 Circuit board 14 Secondary side magnetic core 24 Primary magnetic core

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Claims (4)

(57) [Claims] 1. A driving side flange, a driven side flange,
A substantially cylindrical strain generating portion formed between them is integrally configured, and an opening portion is provided at the center thereof, and the entire outer circumferential surface of the strain generating portion is circumferentially cross-section toward the central axis. Is an inner circumferential surface of the strain-flexing portion forming an arc-shaped groove and forming a part of the side surface of the opening, and strain gauges are arranged at equal intervals at positions around the thinnest portion of the strain-flexing portion. A torque amount converter characterized by being attached. 2. The opening portion is formed from the driving side flange side toward the driven side flange side, the bottom portion is formed in the driven side flange, and an electronic circuit mounting is formed in the opening portion. The torque amount converter according to claim 1, further comprising a circuit board for use therein. 3. The torque amount converter according to claim 1, wherein a lid is attached to the opening. 4. The torque amount converter according to claim 1, wherein a transformer is attached to an outer side portion of the diameter of the driven side flange.