JPH0747714Y2 - Torque measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a torque measuring device, and more specifically, to a first embodiment.
The diameter of the pitch circle, which is a virtual circle indicating the arrangement position of the mounting hole in which the wheel mounting bolt is planted as an element of
Is inserted between the wheel mounting portion and the wheel, the type of which is determined by the number of the mounting holes that are substantially evenly arranged on this pitch circle as an element of, and converts the torque acting on the wheel into an electric quantity. The present invention relates to a torque measuring device that measures with

(B) Prior Art As a torque measuring device for measuring torque acting on a wheel of a vehicle such as an automobile, for example, by forming a large number of holes on a virtual circumference of a predetermined radius of a strain plate having a disk shape, Form a spoke-shaped strain-flexing piece extending in the radial direction of the hole, attach a strain gauge to this strain-flexing piece, and further mount the strain-flexing plate fixed so as to be orthogonal to the axis of the drive shaft, Some torque measuring devices that have been fixed to a disk and have the strain gauges configured to convert the torque acting on the wheels into an electric quantity and measure the torque have already been put into practical use.

One example is a torque measuring device (hereinafter referred to as "conventional device") proposed in Japanese Patent Publication No. 60-13453.

However, this conventional device has the following problems.

First, the strain-flexing plate of the conventional device is integrally formed with a mounted portion for mounting the strain-flexing plate on a wheel mounting portion of a drive shaft and the strain-flexing piece for detecting torque, while the wheel is mounted on the wheel. There are more than a dozen types of mounting portions depending on the combination of the first element and the second element, that is, the combination of the pitch circle diameter and the number of mounting holes. Even if the number of mounting holes is limited to four, there are three types of pitch circle diameters (hereinafter abbreviated as “PCD”) of 100 mm, 110 mm, and 114.3 mm, and the wheel mounting portions are different. However, it is necessary to replace the entire torque measuring device, and even if the number of mounting holes is limited, it is necessary to prepare three torque measuring devices corresponding to the type of the wheel mounting part. However, there is the problem of being uneconomical.

Secondly, in the case of the above-mentioned conventional device, the strain gauge for converting the torque into the electric quantity is arranged outside the center of the strain-flexing piece, but this arrangement position is optimum for torque detection. It cannot be said that the desired position can be obtained depending on the width dimension of the strain-flexing piece.

Thirdly, in the above conventional device, when the torque measurement device is mounted on the wheel, the offset of the regular wheel is not secured, and therefore, when the torque measurement is performed under the condition that the offset change causes an error in the measurement. It becomes a fatal defect.

Fourthly, in the above-mentioned conventional device, when the strain-flexing piece of the strain-flexing plate receives an unexpected force such as overload and is completely destroyed, the axle and the disc of the wheel are separated and rotated. The force is not transmitted, and conversely, the braking force is not obtained even when the brake is applied, which is a very dangerous state.

(C) Purpose The present invention has been made in view of the above-mentioned circumstances, and the first object is to provide a wheel mounting bolt regardless of the type of the wheel and the structure of the wheel mounting portion of the drive shaft. Even if the pitch circles of the mounting holes to be planted are different, a common member can be used so that the device as a whole can be manufactured at low cost. Secondly, it is substantially affected by acting forces other than torque such as axial load. The torque acting on the wheel can be faithfully converted to an electric quantity without using the torque. Thirdly, the regular offset can be held, and therefore, the torque measurement under the condition that the offset change causes an error in the measurement. It is to provide a torque measuring device capable of accurately performing.

(D) Configuration In order to achieve the above-mentioned object, the present invention provides a diameter of a pitch circle of a mounting hole in which a plurality of wheel mounting bolts are planted and the number of the mounting holes substantially equally arranged on the pitch circle. In a torque measuring device which is inserted between a wheel mounting portion whose type is determined by the wheel and converts the torque acting on the wheel into an electric quantity to be measured, the torque measuring device is provided at an end of a drive shaft and has the mounting hole. , A plurality of axle adapters that are selectively detachably mounted with the wheel mounting bolts on each of the plurality of wheel mounting portions having different pitch circles, and a wheel with a large circular hole formed in the center of the disk A disc spacer firmly fitted to the wheel in a state of being fitted in the circular hole of the wheel and holding the same offset as the regular wheel, and the overall shape is a substantially disc shape, Any of the axle adapters is concentrically superposed on the center portion and the disc spacer is concentrically superposed on the peripheral portion, and at least 4 is provided on the circumference of a predetermined radius passing between the center portion and the peripheral portion. A plurality of spoke-shaped strain-flexing pieces extending in the radial direction are formed between the holes adjacent to each other by uniformly forming a number of holes that are divisible by, and the axial thickness of the strain-flexing pieces is in the radial direction. An oval through hole that is formed larger than the minimum width, has a major axis in the radial direction, a minor axis that allows the wheel mounting bolts to pass through, and a major axis that covers the minimum diameter to the maximum diameter of the pitch circle. Is formed, and is selectively selected from among the number of mounting holes provided, and the first portion is provided near the inside of the strain-flexing piece.
The flexure plate that is firmly fixed to the axle adapter with a bolt and has a substantially disc shape, and has a through hole that communicates substantially in the same size as the oval through hole. Also sandwiches a cover, which is superposed on the strain-flexing plate at the outer portion and is firmly fixed to the disc spacer together with the strain-flexing plate with a second bolt, and a predetermined strain-flexing piece of the strain-flexing plate. A pair of the above-mentioned holes is provided with a strain cage attached to one of the first planned attachment surface and the other side of the other intended second attachment surface, and is attached to one of the paired first attachment surface. The strain gauges are connected to the two opposing first and second bridge sides, respectively, and the strain cages attached to the second planned attachment surface of the other of the pair are attached to the first and second bridge sides. Adjacent to each third
And a circuit is connected to each of the fourth bridge sides to form a Wheatstone bridge for torque detection.

The Wheatstone bridge has two strain cage cages attached to one of the pair of first scheduled attachment surfaces and attached to a half circumference portion of the strain generating plate for each half circumference. The first and second bridge sides, each of which is connected to the side by a circuit, are attached to the second planned attachment surface of the other of the pair and attached to the semi-circular portion of the strain-flexing plate by the semi-circle. The third and fourth bridge sides adjacent to each other are respectively circuit-connected to each other.

Hereinafter, an embodiment of the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a side view showing the external appearance of the torque measuring device according to the present invention in a partially broken view, and FIG. 2 is a front view of the embodiment shown in FIG. 1 (however, wheels are omitted), Figure 3 shows the first
The rear view of the axle adapter, which is a component of the embodiment shown in the figure, as viewed from the rear side of FIG. 2, and FIG. 4 show FIG. 1 in more detail, and in particular, the configuration of the wheel slip prevention mechanism part is partially broken. FIG. Note that the broken portion in FIG. 1 is AA ′ in FIG.
According to the arrow.

1 to 3, 1 is a drive shaft as a rotating shaft for driving wheels, 1a is a wheel mounting portion for mounting the wheel of the drive shaft 1, and 1b is a mounting hole formed in the wheel mounting portion 1a. A mounting screw as a wheel mounting bolt that is planted and has a male screw screwed with a hub nut to be described later. The wheel mounting portion 1a shown in this figure has four mounting screws 1b as the second element. , The pitch circle diameter (hereinafter abbreviated as “PCD”) as the first element in which the mounting screws 1b are substantially evenly distributed is 110.
mm.

Reference numeral 2 is a caliper composed of a brake drum, 3 is the wheel (however, the tire portion is omitted), 3a is a rim of the wheel 3, 4 is a disc of the wheel 3 integrated with the rim 3a by welding, in FIG. 4a indicated by a chain double-dashed line will be described in detail later, but in this example, the disc 4 has already been cut out into a large circular shape and does not exist, 5 is a disc spacer having a substantially annular shape, and 5a is the disc spacer 5 A mounting screw hole having a female screw provided on the disk spacer 6
And a welded portion formed by firmly fixing the disc 4 to the disc 4, an axle adapter 7 mounted on the wheel mounting portion 1a, 7a and
7b is a counterbore hole and an insertion hole for a hub bolt as a wheel mounting bolt to which the axle adapter 7 is detachably mounted,
Reference numerals 8 and 8a denote counterbored holes and insertion holes formed in the axle adapter 7 for coupling with a flexure plate, which will be described later, and 9 is a through hole that also penetrates the central portion of the axle adapter 7. In the illustrated embodiment, the hub bolt counterboring holes 7a and the insertion holes 7b are four in number and PCD = 110 mm in correspondence with the wheel mounting portion 1a. In other words, PCD is 100mm other than 110mm above
Or an axle adapter 7 that can handle both 114.3mm
Shall be prepared. In addition, in FIG. 1 and FIG. 2, PCD1, PCD2, and PCD3 are 114.3 mm, 110 mm, and 10 mm, respectively.
PCD of 0 mm is shown.

The reference numeral 10 shows a substantially disk-shaped overall shape, and the above-mentioned axle adapter 7
And a strain-flexing plate (which will be described in detail later) that is superposed on the left end face near the center and around the outer periphery in a state where the disc spacer 5 and the disc spacer 5 are not in contact with each other.
a is provided in the strain-flexing plate 10 so as to communicate with the counterbore hole 7a, has a major axis in the radial direction, and has a minor axis diameter of the counterbore hole.
An elliptical hole approximately equal to the diameter of 7a, 11 is a flexure piece, 12 is a mounting screw hole in which a female screw is screwed into a through hole formed in a portion communicating with the insertion hole 8a of the axle adapter 7, and 13 is It is a circular concave portion that is circularly recessed at a predetermined depth so that the axle adapter 7 can be fitted therein. The circular concave portion 13 has a constant diameter regardless of the PCD of the axle adapter 7. On the other hand, the diameter of the outer circumference of the axle adapter 7 has a predetermined diameter that allows it to be fitted into the circular concave portion 13, and is configured so that any axle adapter 7 can be fitted therein. 14 is a penetrating mounting hole formed at a position communicating with the mounting screw hole 5a,
Reference numeral 15 is an annular groove formed by cutting the right end face in the vicinity of the strain-flexing piece 11 so as to have a concave cross section over the entire circumference. Reference numeral 16 is a first bolt that is inserted into the insertion hole 8a in the inside of the strain-flexing piece 11 and is screwed into the mounting screw hole 12 to firmly fix the axle adapter 7 and the strain-flexing plate 10 together. It is a bolt.

Reference numeral 17 denotes a substantially disk-shaped cover which is superposed on the right end surface side of the strain-flexing plate 10, and 18 has a cover 1 having substantially the same shape as the oval hole 10a.
A cover through hole is provided as a through hole which is formed in 7 and communicates with each other, and 19 is a predetermined depth except for the outer peripheral edge portion thereof so that the cover 17 does not contact the strain plate 10 (in particular, the strain piece 11). At the left end face side is a circular recessed part with a circular recess, 19a is the mounting bolt 1
The projecting portion 16a of 6 toward the cover 17 side is an escape hole provided so as not to contact the cover 17, and 20 and 20a are counterbored holes and insertion holes provided at positions communicating with the mounting hole 14. The reference numeral 21 is inserted into the counterbore hole 20, the insertion hole 20a, and the mounting hole 14 on the outer side of the strain-flexing piece 11 and is screwed into the mounting screw hole 5a to integrally integrate the disc spacer 5, the strain-flexing plate 10, and the cover 17. It is a cover mounting bolt as a second bolt for firmly fixing the cover.

Reference numeral 22 is a derailment prevention mechanism section which will be described in detail later, 23 is a gear for speed detection, 23a is a gear mounting screw for mounting the gear 23, 24 is a rotating device of the present embodiment and a non-illustrated immovable portion, for example, the drive described above. A slip ring device for exchanging signals between the vehicle body of the automobile having the shaft 1 and 25, a magnetic sensor 25 for detecting the rotation of the gear 23, 25a a support arm for supporting the magnetic sensor, and 26 a tire center. The position. 27 is a regular offset position of the wheel 3.

The gear 23, the magnetic sensor 25, and the support arm 25a constitute a speed detecting device, and further the strain-flexing plate 10 and the cover.
Hereinafter, the wheel slip prevention mechanism 22, the slip ring device 24, and the speed detection device will be referred to as a torque detector 28.

In the following drawings, the same members as those shown in FIGS. 1 to 3 are designated by the same reference numerals, and the duplicated description will be omitted.

In FIG. 4, 29 is a hub nut for mounting the axle adapter 7 on the axle mounting portion 1a, and 30 to 37 are schematic paths through which the rotational force from the drive shaft 1 is transmitted to the wheel 3, that is, the disc 4. (However, since the cross sections of the upper half and the lower half of the figure are different, the above arrows 30 to 37 are apparently not continuous), and 38 is an arrow indicating the direction of the force applied in the direction of derailing.

39 is an oblique wiring hole communicating with the annular groove 15 and the circular concave portion 19, 40 is a connecting portion formed in the central portion of the flexure plate 10, and 41.
Is a pipe-shaped communication hole that is coaxially provided, and 42 is a columnar portion in which the connecting portion 40 projects in a substantially cylindrical shape to the right of the connecting portion 40.

The columnar portion 43 is attached to the right end surface of the columnar portion 42.
A substantially disk-shaped derailing stopper having a diameter larger than 40, 44 is a stopper mounting bolt for mounting this derailing stopper 43, 45 is a gap for not contacting the cover 17 and the derailing stopper 43, 46
Is a cover flange portion projecting like a flange in the right center portion of the cover 17 and into which the columnar portion 42 of the strain-flexing plate 10 is fitted concentrically and loosely to the extent that it does not affect the torque measurement. Reference numeral 47 is a bearing inserted between the cover flange portion 46 and the columnar portion 42, 47a is a snap ring for fixing the bearing 47, and 47b is a fitting end portion of the columnar portion 42 and the cover flange portion 46. It is a dustproof and dripproof packing that is installed in the. Reference numeral 23 denotes the gear referred to in the explanation of FIG. 1, but a cylindrical portion is formed on the left end face side of the gear 23, and the cylindrical portion concentrically fitted to the outer periphery of the cover flange portion 46 is By fixing with the gear mounting screw 23a, the gear 23 rotates integrally with the cover 17 (that is, the wheel 3), and the magnetic sensor 25 detects this, so that the speed can be measured. Reference numeral 48 denotes a rotating body portion of the slip ring device 24 in which a connecting flange portion 48a is connected to the gear 23 with a mounting screw 48b and is concentrically and rotatably supported by the gear 23. The operation of the speed detecting device is well known and will not be described.

5 and 6 are diagrams showing the structure of the strain-flexing plate 10 in detail. FIG. 5 is a front view, and FIG. 6 is a sectional view taken along the line BB 'in FIG.

In FIGS. 5 and 6, reference numeral 14 has already been described, but 16 insertion holes, 15 which have been bored on the same radius and through which the cover mounting bolt 21 of FIG. 1 is inserted, have also been described. , A circular groove having a concave cross-section formed in the circumferential direction at a radial position slightly inward of the insertion hole 14, and 50 from the circular groove 15 to the wiring oblique hole.
39 is a wiring groove having a concave cross section, which is connected to 39, 51 is a mounting hole into which the stopper mounting bolt 44 is screwed, and 52 is 32 strain strains as a number of holes uniformly arranged inside the annular groove 15. The piece forming hole, 11 has already been described, but a spoke-like forming piece having a minimum width S between the adjacent strain generating piece forming holes 52 and a thickness t in the axial direction. The strain piece is formed so that the thickness t is larger than the minimum width S. 53 is a torque strain piece selected every other one of the strain pieces 11 in the circumferential direction, 54 and 55 are provided on the torque strain piece 53 of the strain plate 10, and a strain gauge described later is provided. It is the strain gauge attachment surface to be attached (hereinafter, simply referred to as “attachment surface”).

Each strain piece 11 has a surface visible in the clockwise direction and a surface visible in the counterclockwise direction. In this example, the former will be referred to as the first attachment scheduled surface and the latter will be referred to as the second attachment scheduled surface. . Therefore, the scheduled attachment surfaces 54 and 55 become the first intended attachment surface 55 and the second intended attachment surface 54, respectively. A1, A2,
A3, ..., A16 are strain gauges for torque detection attached to the first attachment surface of each strain element 53 for torque, B1, B2, B3, ...
, B16 is a strain gauge for torque detection attached to the second scheduled attachment face of each strain element 53 for torque.

FIG. 7 is an enlarged cross-sectional view showing an attached state of a strain gauge for torque detection as a representative of the portion of the second scheduled attachment surface 54 shown in FIG.

In FIG. 7, reference numeral 56 indicates the position of the minimum width S of each of the strain detecting pieces 53 for torque detection, and in this example, it is the center of the strain generating piece 53 which substantially coincides with the center of the strain generating piece forming hole 52. 57 is strain gauge B1
Reference numeral 1 is a base, 58 is a strain receiving portion (so-called gauge grid) for detecting the bending stress, 59 is a gauge tab, and 60 is a gauge lead.

As can be seen from the figure, the strain receiving portion 58 of the strain gauge B11 is
The base 57 is attached to the second planned surface 54 so that the position where maximum bending stress is generated is inward of the center 56 by a distance P. The applicant has experimentally confirmed that the above-mentioned position generates the maximum bending stress.

FIG. 8 is a circuit diagram showing an embodiment of a torque detecting bridge (Wheatstone bridge).

In the figure, 61 to 64 are connection terminals of the bridge, and 65 is a series branch path in which strain gauges A1 to A8 attached to a portion corresponding to a half circumference of the strain plate 10 are connected in series.
The first side 66, which is connected in between, faces the first side 64, and the series branch of the strain gauges A9 to A16 attached to the portion corresponding to the remaining half of the above half circumference is the connection terminal 62. The second side 67, 68 connected between the first and second sides 64, 64 is adjacent to the first side 65 and the second side 66 and faces each other. Of these, 67 is a half circumference of the flexure plate 10. The third side, which is formed by connecting the series branches of the strain gauges B1 to B8 of between the connection terminals 61 and 64, 6
Reference numeral 8 denotes a fourth side formed by connecting in series the branch branches of the strain gauges B9 to B16 attached to the portion corresponding to the remaining half circumference of the strain plate 10 in parallel between the connection terminals 62 and 63. In this example, the connection terminals 61 and 62 are output terminals of the bridge, and the connection terminals 63 and 64 are bridge power supply input terminals.

FIG. 9 is an enlarged plan view showing, in an exaggerated manner, the vicinity of the torque straining piece 53 having the second scheduled attachment surface 54 in order to explain the torque detecting operation.

In the figure, 69 and 70 are arrows indicating the direction of action of force and the direction of action of reaction force, 71 is an external force portion of the torque strain piece 53, 72 is an inner portion, and 73 is, for example, the second attachment scheduled surface. FIG. 5 is a diagram showing a distribution of bending stress on 54.

The assembling procedure of the present embodiment configured as above will be briefly described. First, the strain gauge is attached to the position shown in FIG. 5, more specifically, in the state shown in FIG. The connections of these strain gauges are as shown in Fig.8.
Since the strain gauges A1 to A8 are described as representatives, the cage leads are connected in series in series from A1 to A2, A2 to A3, and the connected gauge leads are connected. Place along the annular groove 15. Also,
The gauge leads on the side of the strain gauges A1 and B1 that are connected to the connection terminals 61 are connected along the inside of the nearest wiring groove 50, and with another lead wire from this connection point, the wiring groove 51 is sequentially connected. Preparation is made so that the slip ring portion 24 can be connected through the wiring oblique hole 39 and the communication hole 41.

On the other hand, the primary processing of the wheel 3 is performed. That is, a commercially available general wheel 3 has a disc 4 as shown in FIG.
Is integrally molded up to the cutting portion 4a indicated by the one-dot chain line, so this cutting portion 4a is cut into a large circular shape and removed,
The disk spacer 5 is fitted into the circular hole formed by this, and welded at the welding portion 6 to firmly fix the disk 4 and the disk spacer 5. The regular offset 27 can be held by this primary processing.

The strain-flexing plate 10 thus formed is superposed on the disk spacer 5 integrated with the wheel 3 to form the columnar portion 42 of the strain-flexing plate 10.
And the bearing 47 and packing on the connecting part 40, respectively.
After fitting the 47b, the cover flange portion 46 is fitted into the bearing 47, and the cover 17 is attached to the strain-flexing plate 10.
And strain it by hand to rotate the elliptical hole 10a of the strain plate 10 and cover 1.
The positions of the through holes 18 of the same shape 7 are aligned. Then, the cover mounting bolt 21 is sequentially inserted into the counterbore hole 20 of the cover 17, the insertion hole 20a, and the mounting hole 14 of the flexure plate 10, and is screwed into the mounting screw hole 5a of the disk spacer 5 to be firmly fixed.

Then, next, on the right end face of the columnar portion 42, the release wheel stopper 43 is formed.
With stopper mounting bolt 44.

Then, in advance, after fixing the gear 23 to the flange portion 48a of the rotating body portion 48 of the slip ring device 24 with the mounting screw 48b, the lead wire that has come to the communication hole 41 described above is the rotating body of the slip ring device 24. While being connected to the slip ring side of the portion 48, the cylindrical portion of the gear 23 is fitted into the outer periphery of the cover flange portion 46 and fixed by the gear mounting screw 23a, the cover 17, the strain plate 10 and the rotating body. The parts 48 are concentrically connected.

In the torque detector 28 integrated with the gear 3 as described above, the elliptic hole 10a of the strain plate 10 and the counterbore hole 7 of the axle adapter 7 are provided.
The axle adapter 7 is fitted in the circular concave portion 13 of the flexure plate 10 so as to communicate with a, the axle adapter 7 is superposed on the torque detector 28, and the mounting bolts 16 are sequentially attached. Strain plate that is inserted into the countersunk hole 8 and the insertion hole 8a of
The torque detector 28 is firmly connected to the axle adapter 7 by screwing and tightening in the mounting screw hole 12 of 10.

Next, attach the hub nut 29 from the cover 17 side to the through hole 18
10a, counterbore 7a, insertion hole 7b
Axle adapter 7 is attached to drive shaft 1 by screwing it onto mounting screw 1b of a.
Install. The assembly is completed as described above. Therefore, since the torque detector 28 can be used in common by simply replacing the number of axle adapters 7 corresponding to the type of the wheel mounting portion 1a (particularly PCD), only one torque detector is required, which is economically advantageous. Extremely large.

Next, the operation of this embodiment thus assembled will be described. First, the torque detection operation will be described.

In FIG. 5, it is assumed that the outer peripheral side of the flexure plate 10 is fixed and the inner peripheral side is given a rotational force in the clockwise direction indicated by the arrow M. The deformation mode of the strain-flexing piece 53 at this time will be described with reference to FIG. 9 as a representative one in which the strain gauges A11 and B11 are attached.

By receiving a force in the direction of arrow 69, the first portion of the inner portion 72 of the strain-flexing piece 53 is
The surface to be attached 55 is compressed, and the opposite surface to be attached is the second surface
54 side extends. Therefore, the resistance value of the strain gauge A11 decreases, and the resistance value of the strain gauge B11 increases. That is,
Strain gauge B1 attached to the second attachment surface 54 of the strain plate 10
The resistance values of the strain gauges A1 to A16 attached to the first attachment surface 55 decrease. That is, the eighth
In the bridge shown in the figure, the first side 65 and the second side 66 have a decreased resistance value, and the third side 67 and the fourth side 68 have a increased resistance value, so that the detection current flows from the connection terminals 61 to 62. . It goes without saying that if the direction of the rotational force M is reversed, the direction of the detected current is reversed.

Next, the removal of interference in this torque detection operation will be described. First, the force in the axial direction of the drive shaft 1, that is, the interference of the side force is first reduced by making the thickness t sufficiently larger than the width S of the strain-flexing piece 11.
In addition, strain gauges A1 to A16 and B1 to B16 for torque detection are attached to the inner side where large bending stress is generated as shown in the diagram 73 of FIG. 9, and as shown in FIG. The sensitive axis of is selected in the orthogonal direction in which the influence of the side force is the least, and thirdly, the slight influence is electrically canceled by the distribution of the strain gauges on each side of the torque detection bridge. Eventually, the side force will have no practical effect.

Next, it is assumed that a vertical force indicated by an arrow V in FIG. 5, that is, a wheel load is received. In order not to complicate the explanation, the pair of strain gauges A15 and B15 that receive the largest wheel load, A
A pair of 7, B7 is explained as a representative. By the force V, the strain gauges A7 and B15 are expanded, and conversely the strain gauges B7 and A15 are compressed. Therefore, in the bridge of FIG. 8, the resistance increases at the first side 65 and the fourth side 68, and the resistance decreases at the third side 67 and the second side 66, and the potential between the connection terminals 61 and 62 does not change. The load is canceled.

Further, when a force (wheel load) in the vertical direction V indicated by an arrow V is received, a strain-flexing piece located above a horizontal line passing through the drive shaft 1
11 is stretched, but a strain-flexing piece located below the horizontal line
11 is compressed, and its expansion amount and compression amount are equal, so
The effect of vertical forces is canceled electrically.

Next, the action when the strain-flexing piece 11 is destroyed for some reason (for example, overload), that is, the action of the wheel slip prevention mechanism 22 will be described.

As shown in FIG. 4, the rotational force of the drive shaft 1 is generated by the wheel mounting portion 1a.
Is transmitted from the hub nut 29 to the axle adapter 7 in the order of arrows 30 and 31, and further via the mounting bolt 16 to the arrow.
32 and 33 are transmitted to the inner portion of the strain-flexing piece 11 in this order, and are transmitted to the outer portion via the strain-flexing piece 11 (at this time, torque is detected), and the arrow 34 is passed through the cover mounting bolt 21. , 35, 36 are transmitted in this order, and finally are transmitted from the disc spacer 5 to the disc 4 as indicated by an arrow 37, and the wheel 3 rotates.

Now, it is assumed that the flexure piece 11 is destroyed. In order to make the description easy to understand, it is assumed that the strain-flexing piece 11 is completely destroyed, and thus the inner side and the outer side of the strain-flexing piece 11 are completely separated. Then, hereinafter, a combined body including the wheel 3, the outer peripheral edge portion of the strain-flexing plate 10 (the portion on the outer side of the strain-flexing piece 11) and the cover 17 will be referred to as a separating body portion.

In such a state, the rotational force is transmitted only to the arrow 33 and the wheel 3 does not rotate. Conversely, if you apply the brakes, you will not get the braking force,
It will be very dangerous. In the example of FIG. 4, in such a case, with respect to the rotation direction, the protruding portion 16a of the mounting bolt 16 is
(See FIG. 1) is regulated by the escape hole 19a of the cover 17,
Only a small gap between the clearance hole 19a and the protruding portion 16a can rotate freely, and in effect, the separating body portion can transmit the rotating force of the axle adapter 7, and the braking is effective. Become.

Further, when the strain-flexing piece 11 is broken as described above, the axial center of the separation body portion is limited to the length of the diameter of the strain-flexing piece forming hole 52,
That is, the shaft center of the wheel 3 and the shaft center of the drive shaft 1 tend to deviate from each other, but the flange portion 46 of the cover 17 is concentrically fitted to the columnar portion 44 of the flexure plate 10 via the bearing 47. Therefore, the axis does not deviate as described above.

Further, with respect to the axial direction, the separator part is
Since it cannot contact the drive shaft 1 (leftward in FIG. 1) because it abuts on the central part of the drive shaft 1, it tries to move in the direction of derailing as indicated by arrow 38. However, in this embodiment, the cover flange portion 46, which is about to move in the direction of the arrow 38, is regulated by the derailing stopper 43, so that the derailing is not performed.

Note that the gap 45 is a slight amount so that the cover flange portion 46 and the derailing stopper 43 do not come into contact with each other and do not affect the torque measurement. So-called backlash does not occur.

Further, simply describing other actions, the packing 47b prevents dust and water from entering the bearing 47 and the like from the through hole 18 via the circular concave portion 19.

Further, the annular groove 15, the circular concave portion 19, the protruding portion of the mounting bolt 16
The cover 17 does not regulate this deformation of the strain-flexing piece 11 that is deformed by receiving the torque to be measured by the gap between the clearance hole 16a and the escape hole 19a, the clearance 45b between the cover flange portion 46 and the derailing stopper 43, and the bearing 47. That is, since the cover 17 is loosely overlapped with the strain-flexing plate 10 with respect to the torque detection operation, it does not affect the torque detection.

Thus, according to the present embodiment, the wheel mounting portion of the drive shaft 1
1a, that is, the number (type) of axle adapters 7 corresponding to the number of mounting screws 1b and PCD are prepared, and
Among the types of 1a, a strain plate 10 of the type corresponding to the number of mounting screws 1b (that is, regardless of PCD) is prepared, and the disc spacer 5 is fixed to the disc 4 of the axle 3 at the welding portion 6. , The flexure plate 10 and the cover 17 are fixed to the flexure plate 10 by overlapping the axle adapter 7 at the central portion of the flexure plate 10 on the opposite side to the cover 17, and the columnar portion 42 of the flexure plate 10 with the derailing stopper 43. Is provided to form a wheel slip prevention mechanism portion 22, and a stop ring device 24 and a speed detection device are connected to the torque detector.
Since the 28 is configured to be fixed to the wheel mounting portion 1a with the axle adapter 7, one torque detector 28
There is an advantage that the torque can be measured regardless of the types of the PCD of the wheel mounting portion 1a and the wheel 3.

In addition, even if the strain-flexing piece 11 should be destroyed, the wheel removal prevention mechanism 22 can prevent wheel removal, and the mounting bolt 16 and the cover 17 can maintain the transmission of the rotational force, so that the driving force and the braking force can be retained. Therefore, the above-mentioned danger can be prevented.

In addition, since the strain gauges A1 to A16 and B1 to B16 are attached to the strain receiving portion 58 on the inner side by P from the position of the minimum width S of the strain-flexing piece 11, the maximum output is obtained and the torque is increased. It has the advantage of high detection sensitivity.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

For example, the length of the mounting bolt 16 is not limited to having the protruding portion 16a as shown in FIG. 1, but as shown in FIG.
It may be set to a length that stays within 0.

(E) Effects As described in detail above, according to the present invention, firstly, an axle adapter which has a simple structure and can be easily manufactured according to the type of the wheel and the structure of the wheel mounting portion of the drive shaft is provided. Since it is possible to install this device in common on all types of wheels by simply preparing a plurality of types of flexure plates corresponding to the number of wheel mounting bolts, it is possible to install this device in common. Each time the type of wheel or the structure of the wheel mounting part is different like this, the effect corresponding to this is compared with a strain plate, or one that has to make many disks and connecting members with detection parts However, it is possible to provide an extremely economical torque measuring device that is easy to manufacture and has a small number of constituent parts.

Secondly, to provide a torque measuring device capable of faithfully converting a torque acting on a wheel into an electric quantity without being substantially affected by an axial load or a force in the axial direction of a drive shaft, that is, a side force. You can

Thirdly, there is provided a torque measuring device capable of holding a regular offset, and therefore capable of accurately measuring torque under the condition that an offset change gives an error to the measurement under conditions that are close to those of an actual vehicle. Can be provided.

[Brief description of drawings]

FIG. 1 is a side view showing an external appearance of an embodiment of a torque measuring device according to the present invention with a part broken away (cross section taken along the line AA ′ in FIG. 2), and FIG. 1 is a front view in which the wheels of the embodiment shown in FIG. 1 are omitted, FIG. 3 is a rear view of the axle adapter shown in FIG. 1 seen from the rear side of the front view, and FIG. 4 is the embodiment of FIG. FIG. 5 and FIG. 6 are side views showing a partially broken configuration of the wheel slip prevention mechanism included in FIG. 5, which show the configuration of the strain-flexing plate in detail, and FIG. 5 is a front view and FIG. Is a cross-sectional view taken along the line BB 'in FIG. 5, and FIG. 7 is an enlarged view showing an attached state of a strain gauge for torque detection with one of the second planned attachment surfaces shown in FIG. 5 as a substitute. A sectional view, FIG. 8 is a circuit diagram showing an embodiment of a Wheatstone bridge for torque detection, and FIG. 9 is a second attachment scheduled surface for explaining the torque detection operation. Is an enlarged plan view showing an exaggerated near the torque for the strain generating pieces. 1 …… Drive shaft, 1a …… Wheel mounting part, 1b …… Mounting screw hole,
2 ... Caliper, 3 ... Wheel, 3a ... Rim, 4 ... Disc, 4a ... Cutting part, 5 ... Disc spacer, 5a, 1
2 ... Mounting screw hole, 6 ... Welded part, 7 ... Axle adapter, 7a, 8,20 ... Counterboring hole, 7b, 8a, 20a ... Insertion hole, 9 ...
… Through hole, 10… Strain plate, 10a… Elliptical hole, 11… Strain piece, 13, 19… Circular concave part, 15… Annular groove, 16… Mounting bolt, 16a… Projection Part, 17 ... cover, 18 ... cover through hole, 19a ... escape hole, 21 ... cover mounting bolt, 22
…… Derailment prevention mechanism, 23 …… Gear, 23a …… Gear mounting screw, 24 …… Slip ring device, 25 …… Magnetic sensor, 27
...... Regular offset position, 28 ...... Torque detector.

Claims (2)

[Scope of utility model registration request] 1. A wheel mounting portion and a wheel, the type of which is determined by the diameter of a pitch circle of a mounting hole into which a plurality of wheel mounting bolts are planted and the number of the mounting holes substantially equally arranged on the pitch circle. In a torque measuring device that is interposed between the wheel and the wheel and converts the torque acting on the wheel into an electric quantity for measurement, a plurality of the wheels provided at the end of the drive shaft and having different pitch circles and the number of the mounting holes. A plurality of axle adapters that are alternatively and removably mounted on the respective mounting portions with the wheel mounting bolts, a wheel with a large circular hole formed in the center of the disk, and fitted into the circular hole of this wheel And the disk spacer firmly fixed to the wheel while maintaining the same offset as the regular wheel, and the overall shape is substantially disk-shaped, and any of the above-mentioned axle adapters is near the center. In addition, the disk spacers are concentrically overlapped with each other in the peripheral portion, and a number of holes divisible by at least 4 are uniformly formed on the circumference of a predetermined radius passing between the central portion and the peripheral portion. A plurality of spoke-shaped strain elements extending in the radial direction are formed between the holes adjacent to each other, whereby the axial thickness of the strain elements is formed larger than the minimum width in the radial direction, and An oval through hole is formed with a major axis and a minor axis that allows the wheel mounting bolts to pass through, and a major axis that covers the minimum diameter to the maximum diameter of the pitch circle. A flexure plate which is selectively selected from among the prepared flexure plates and which is firmly fixed to the axle adapter with a first bolt in the vicinity of the inside of the flexure piece, and which has a substantially disc shape and the elliptical shape. About the size of the through hole A cover which has a through hole communicating with each other, is superposed on the strain plate at a position outside the strain piece, and is firmly fixed to the disc spacer together with the strain plate by a second bolt. When,
A pair of the strain-flexing plates sandwiching a predetermined strain-flexing piece, and a strain cage attached to each of the first planned surface for attachment and the second planned surface for attachment on the other side of the hole. The strain gauges attached to the first surface to be attached, which forms one side, are connected to the two opposing first and second bridge sides, respectively, and are attached to the second surface to be attached, which forms the other side of the pair. A torque measuring device characterized in that a strain cage is connected to third and fourth bridge sides respectively adjacent to the first and second bridge sides to form a Wheatstone bridge for torque detection. 2. A Wheatstone bridge has two strain cages attached to a first surface to be attached, which is one of a pair, and a strain cage attached to a semi-circumferential portion of the strain-flexing plate. Of the strain cages, which are respectively circuit-connected to the bridge sides of the pair, are attached to the second surface to be attached forming the other side of the pair, and are attached to the half-circumferential portion of the strain-flexing plate for each half-circle. The torque measuring device according to claim 1, wherein the torque measuring device is configured by respectively connecting circuits to the third and fourth bridge sides adjacent to the bridge side.