JP2008082893A - Strain detection device for unsprung member of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a strain detection device for an unsprung member of a vehicle, which is improved in durability without enlarging the detection device. <P>SOLUTION: The strain detection device for the unsprung member of the vehicle for detecting a strain of the unsprung member positioned on an unsprung part of a vehicle suspension is equipped with: a sensor plate fixed to the unsprung member; and a strain detection means mounted on the face on the unsprung member side of the sensor plate. The unsprung member is characterized by having a notch on a part corresponding to the strain detection means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a strain detection device for an unsprung member of a vehicle, such as a brake force detection device that detects a braking force (braking force) by a disc brake and a strain detection device that detects strain of a suspension part such as a suspension arm or a knuckle.

  When performing braking control of a vehicle, braking force is one of important information. For example, if the braking force actually applied can be detected when the brake is applied, the state of the road surface can be easily estimated. If the road surface condition is known, ABS control (anti-skid brake system control) can be performed more accurately, and the vehicle can be safely stopped at a short distance.

  In addition, if the braking force applied to each wheel can be detected when the vehicle is turned or when braking is performed on a road surface having a low friction coefficient (μ), the braking force of each wheel can be individually controlled. Can be done more safely.

  Conventionally, a disc brake that detects a braking force by providing a load cell or attaching a strain gauge to a support engagement portion of a fixed support of a friction pad of a disc brake has been developed.

Japanese Patent Laid-Open No. 6-123665 proposes a braking force measuring device in which a measuring support member is provided between a brake caliper and a knuckle arm. The braking force measuring device disclosed in this publication includes a support member having a pair of substantially vertical beams interposed between a brake caliper and a knuckle arm, and detection means for detecting displacement of the beams. Is done.
JP-A-6-123665

  According to the braking force measuring device described in Patent Document 1 described above, since the cross section of the braking force measuring device is H-shaped, the distance in the axial direction of the brake disc between the caliper bracket and the knuckle increases, and the measuring device increases in size. There is a problem that it ends up. It is also difficult to place a displacement detection device between the two beams.

  Therefore, an object of the present invention is to provide a strain detection device for an unsprung member of a vehicle that has an improved durability without increasing the size of the detection device.

  According to the first aspect of the present invention, there is provided a strain detection device for an unsprung member of a vehicle for detecting a strain of an unsprung member positioned under the unsprung portion of a vehicle suspension, wherein the sensor plate is fixed to the unsprung member. And a strain detecting means attached to a surface of the sensor plate on the unsprung member side, wherein the unsprung member has a notch in a portion corresponding to the strain detecting means. A distortion detection device for an unsprung member of a vehicle is provided.

  According to a second aspect of the invention, in the first aspect of the invention, the notch is closed by the sensor member fixed to the unsprung member to form a sealed structure, and the sensor plate is There is provided a strain detection device for an unsprung member of a vehicle, which has a hole communicating the inside of the notch with the outside.

  According to a third aspect of the present invention, there is provided a strain detection device for an unsprung member of a vehicle for detecting a strain of an unsprung member positioned under the spring of a suspension of the vehicle, wherein the sensor plate is fixed to the unsprung member. And a strain detecting means attached to the surface of the sensor plate on the unsprung member side, and the sensor plate is fixed to the unsprung member by a bolt with a pair of boss portions spaced apart from each other, and the strain The detection means includes a plurality of strain elements attached to a surface of the sensor plate on the unsprung member side with one boss portion interposed therebetween, and the plurality of strain elements are located on the unsprung member side of the sensor plate. A strain detection device for an unsprung member of a vehicle is provided, which is connected to a surface by a wiring pattern printed so as to pass through both sides of the one boss portion.

  According to the first aspect of the present invention, since the strain detecting means is attached to the back surface of the sensor plate, that is, the surface on the unsprung member side, it is possible to prevent damage to the strain detecting means due to rock jumping during vehicle operation, The durability of the strain detection device for an unsprung member of the vehicle is improved.

  According to the second aspect of the present invention, the sensor plate is fixed so that the cutout portion has a sealed structure, and the drainage hole that communicates the inside and the outside of the cutout portion is provided. This can be further improved.

  According to the invention described in claim 3, since the plurality of strain elements are connected by the wiring pattern printed on the back surface of the sensor plate so as to pass through both sides of one boss, Damage can be prevented and wiring for connecting the strain elements can be easily formed by printing, improving reliability.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view of a disc brake equipped with a brake force detection device according to an embodiment of the present invention. FIG. 2 is a left side view of FIG.

  As shown in FIGS. 1 and 2, the brake disc (disc rotor) 2 is fixed to a wheel (not shown) and rotates together with the wheel. Reference numeral 4 denotes a knuckle (wheel support), which rotatably supports the wheel and is connected to the vehicle body via a suspension (not shown).

  A caliper bracket 8 is attached to the knuckle 4 with bolts 10 and 12. The caliper bracket 8 supports a pair of friction pads 18 and 20 disposed on both sides in the axial direction of the brake disk 2 on both the turn-in side and the turn-out side of the brake disk 2.

  The caliper bracket 8 is slidably fitted with two slide pins 15 and 17 fixed to the brake caliper 6 by two bolts 14 and 16, and the brake caliper 6 is shown in FIG. Thus, a piston (pushing member) 24 is built in that moves forward and backward in a direction parallel to the axis of the brake disc 2 and presses the friction pads 18 and 20 toward the brake disc 2.

  The brake caliper 6 integrally has a wheel cylinder 22, and a piston 24 is fitted in the wheel cylinder 22. The hydraulic pressure from the brake master cylinder is supplied to the piston chamber 26 via the hydraulic pressure supply port 28.

  The brake disc 2 is connected to the hub 3. When hydraulic pressure is supplied from the brake master cylinder into the piston chamber 26 via the hydraulic pressure supply port 28, the piston 24 is pushed leftward in FIG. 3 and the pad 18 is pressed against the brake disc 2.

  The brake caliper 6 moves to the right by the reaction force of the piston 24 pressing the pad 18 against the brake disc 2, and the opposite pad 20 is also pressed against the brake disc 2, thereby braking the rotation of the brake disc 2.

  As is well known, the knuckle 4, the brake caliper 6, the caliper bracket 8 and the like constitute an unsprung member of the suspension.

  Referring to FIG. 4, there is shown a front view of relevant parts of the braking force detection device according to the first embodiment of the present invention. The brake disc 2, the friction pads 18, 20 and the brake caliper 6 are omitted. 5 is a right side view of FIG. 4, and FIG. 6 is a plan view of FIG.

  The caliper bracket 8 has a substantially U shape when viewed from the front, and a pair of brake load receiving portions (brake torque receiving portions) 8a and 8b and inner connecting portions (inner bridge portions) for connecting the brake load receiving portions 8a and 8b, respectively. 8c and an outer connecting portion (outer bridge portion) 8d.

  As best shown in FIG. 4, the caliper bracket 8 has screw holes 32 and 34 into which the bolts 10 and 12 are screwed, and fitting holes 36 and 38 into which the slide pins 15 and 17 are fitted. Yes. The caliper bracket 8 has a substantially line-symmetric shape with respect to a line connecting the rotation center of the brake disk 2 and the center of the piston (pushing member) 24.

  Referring to FIG. 5, the brake load receiving portion 8b includes an inner arm portion 40a connected to the inner connecting portion 8c, an outer arm portion 40b connected to the outer connecting portion 8d, an inner arm portion 40a, and an outer arm portion 40b. It is comprised from the connection part 40c which connects.

  A sensor plate 42 extending in the longitudinal direction of the inner arm portion 40a is fixed to the inner arm portion 40a of the brake load receiving portion 8b by a pair of bolts 44 and 46 spaced apart from each other. A notch 52 is formed on the back surface of the sensor plate 42.

  As best shown in FIG. 4, a strain element 48 is affixed to the inside of the sensor plate 42. A notch 52 is formed in the inner arm 40a corresponding to the sensor plate 42 to which the strain element 48 is attached.

  As described above, in the present embodiment, since the strain element 48 is attached to the back surface side of the sensor plate 42, that is, the caliper bracket 8 side, the sensor element 48 can be prevented from being damaged due to hopping when the vehicle is traveling. The durability of the brake force detection device can be improved.

  Referring to FIG. 7, there is shown a front view of relevant parts of a braking force detection device according to a second embodiment of the present invention. As in the first embodiment, the brake disc 2, the friction pads 18 and 20, the brake caliper 6 and the like are omitted.

  8 is a right side view of FIG. 7, and FIG. 9 is a sectional view taken along line 9-9 of FIG. In the description of the present embodiment, substantially the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted to avoid duplication.

  In the present embodiment, the sensor plate 42 is fastened to the inner arm portion 40a of the brake load receiving portion 8b with bolts 44 and 46, thereby closing the notch 52a and making the notch 52a a substantially sealed structure.

  Further, the sensor plate 42 adjacent to the lowermost portion of the notch 52a is formed with a drain hole 54 that communicates the inside and the outside of the sealed notch 52a.

  As described above, in this embodiment, the notch 52a for accommodating the strain element 48 has a substantially sealed structure, and the drain hole 54 for draining water that has entered the notch 52a is formed in the sensor plate 42. The element 42 can be protected from the external environment, and its durability can be improved.

  FIG. 10 is similar to FIG. 8 and shows a side view of the main part of the third embodiment of the present invention. 11 is a cross-sectional view taken along line 11-11 of FIG. This embodiment differs from the second embodiment described above in the shape of the notch formed in the inner arm portion 40a of the brake load receiving portion 8b.

  That is, in the second embodiment shown in FIG. 8, one large notch 52a is formed, but in the third embodiment shown in FIG. 10, two notches 52b and 52c are formed. The sensor plate 42 adjacent to the lowermost ends of the notches 52b and 52c is formed with a drain hole 54 that communicates the inside and the outside of the notches 52b and 52c.

  In the present embodiment as well, as in the second embodiment described above, the strain element 48 is accommodated in the substantially sealed notch 52b, and the water that has entered the notches 52b and 52c can be drained through the drain hole 54. Therefore, it is possible to protect the strain element 48 from the external environment and improve its durability.

  Referring to FIG. 12, there is shown a front view of relevant parts of a braking force detection device according to a fourth embodiment of the present invention. As in the above-described embodiments, the brake disk 2, the friction pads 18, 20 and the brake caliper 6 are omitted. 13 is a right side view of FIG. 12, and FIG. 14 is a rear view of the sensor plate.

  In the description of the present embodiment, substantially the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted to avoid duplication. In the present embodiment, two boss portions 56 and 58 are provided in the inner arm portion 40a of the brake load receiving portion 8b, screw holes are formed in these boss portions, and the sensor plate 42 is attached to the two bolts 44 and 46. Then, the bosses 56 and 58 are fastened.

  Thus, in this embodiment, since the sensor plate 42 is attached to the boss portions 56 and 58, the space 60 is formed between the sensor plate 42 and the inner arm portion 40a. Therefore, the four strain elements 48a, 48b, 48c, and 48d shown in FIG.

  Referring to FIG. 14, the sensor plate 42 has two round holes 43 and 45 for inserting bolts 44 and 46. 62 and 64 are portions where the caliper bracket 8 and the sensor plate 42 come into contact when the sensor plate 42 is fixed to the boss portions 56 and 58.

  Four strain elements 48a, 48b, 48c, and 48d are attached to the back surface of the sensor plate 42 with one boss portion 58 interposed therebetween. The hatched portion 68 is a printed wiring pattern forming portion, and is printed so that the wiring pattern connecting the strain elements 48a, 48b, 48c, 48d passes through both sides of the lower boss portion 58 shown in FIG. This printed wiring pattern is printed so as to form, for example, a bridge circuit that connects the strain elements 48a, 48b, 48c, and 48d.

  In this embodiment, since the wiring pattern for connecting each of the strain elements 48a to 48d is formed on the back surface of the sensor plate 42 by printing, wiring is easy and the strain elements and the print pattern can be protected from hopping. And reliability and durability can be improved.

  When the brake is applied when the vehicle moves forward, the brake disc rotates while the pads 18 and 20 press the brake disc 2, so that the pads 18 and 20 are dragged by the brake disc 2 and move in the rotation direction of the brake disc. Then, it is pressed against the brake load receiving portion 8 b of the caliper bracket 8.

  Since the sensor plate 42 is fixed to the outside of the inner arm portion 40a with bolts 44 and 46, when the brake load receiving portion 8b receives a brake load (brake torque), a tensile strain is generated on the back surface of the sensor plate 42. .

  This tensile strain is detected by the strain element 48, and the braking force is detected based on the strain amount of the sensor plate 42 by amplifying the output of the strain element 48 with an amplifier (not shown) connected to the strain element 48.

  Since the distortion of the sensor plate 42 is generated only when the brake torque is transmitted through the brake load receiving portion 8b of the caliper bracket 8, it is not easily affected by the vertical force or the lateral force, and the brake force is accurately detected. Is possible.

  Further, in each of the above-described embodiments, a notch is formed in the brake load receiving portion 8b on the back surface of the bolted sensor plate 42. Therefore, when the sensor plate 42 is not notched when receiving a brake load. In comparison, it becomes easier to deform. As a result, a large distortion is generated by the sensor plate 42, so that the detection accuracy of the braking force can be improved.

  Since the sensor plate 42 is attached in a direction orthogonal to the direction of the brake input applied to the brake load receiving portion 8b of the caliper bracket 8, it is possible to stably detect the strain when the brake is applied.

  It should be noted that other strain detection means may be attached to the sensor plate 42 instead of the strain element 48 of the above-described embodiment.

  In each of the above-described embodiments, the example in which the sensor plate 42 is fixed to the brake load receiving portion 8b of the caliper bracket 8 has been described. However, the present invention is not limited to this, and the sensor plate is attached to another unsprung portion of the suspension. You may make it attach to a member.

1 is an external perspective view of a disc brake equipped with a brake force detection device according to an embodiment of the present invention. It is a left view of the disc brake of FIG. It is a schematic sectional drawing of a disc brake. It is a principal part front view of the braking force detection apparatus of 1st Embodiment of this invention. FIG. 5 is a right side view of FIG. 4. FIG. 5 is a plan view of FIG. 4. It is a principal part front view of the braking force detection apparatus of 2nd Embodiment of this invention. FIG. 8 is a right side view of FIG. 7. FIG. 9 is a sectional view taken along line 9-9 in FIG. 8. It is similar to FIG. 8 and is a principal part side view of the braking force detection apparatus of 3rd Embodiment of this invention. It is the 11-11 line sectional view of FIG. It is a principal part front view of the braking force detection apparatus of 4th Embodiment of this invention. It is a right view of FIG. It is a back view of a sensor plate.

Explanation of symbols

2 Brake disc (disc rotor)
4 Knuckle 6 Brake caliper 8 Caliper bracket 8a, 8b Brake load receiving part (brake torque receiving part)
8c Inner connecting part (inner bridge part)
8d Outer connection part (outer bridge part)
10, 12, 14, 16, 44, 46 Bolt 18, 20 Friction pad 42 Sensor plate 48 Strain element 52, 52a-52c Notch 54 Drain hole 56, 58 Boss portion 68 Printed wiring pattern forming portion

Claims (3)

A strain detection device for an unsprung member of a vehicle that detects strain of an unsprung member located under the unsprung portion of the suspension of the vehicle,
A sensor plate fixed to the unsprung member;
Strain detecting means attached to the unsprung member side surface of the sensor plate;
Comprising
The unsprung member has a notch in a portion corresponding to the strain detecting means, and the unsprung member strain detecting device for a vehicle. The notch is closed by the sensor member fixed to the unsprung member to form a sealed structure,
The strain detection device for an unsprung member of a vehicle according to claim 1, wherein the sensor plate has a hole communicating the inside of the notch with the outside. A strain detection device for an unsprung member of a vehicle that detects strain of an unsprung member located under the unsprung portion of the suspension of the vehicle,
A sensor plate fixed to the unsprung member;
Strain detecting means attached to the unsprung member side surface of the sensor plate;
Comprising
The sensor plate is fixed to the unsprung member with a pair of boss portions separated from each other by bolts,
The strain detecting means includes a plurality of strain elements attached to a surface of the sensor plate on the unsprung member side with one boss portion interposed therebetween,
The plurality of strain elements are connected to a surface of the sensor plate on the unsprung member side by a wiring pattern printed so as to pass through both sides of the one boss portion. Strain detector.