JP2008082890A - 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 easily-mountable on the unsprung member, and prevents the detection device from being deformed or damaged at the mounting/dismounting time of a signal wire. <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 with at least two bolts; a strain detection means mounted on the sensor plate; and a strain detection means mounted on the sensor plate on a position outside a range between the two bolts, connected electrically to the strain detection means, and detachable from the signal wire for transmitting a signal to a sprung part of the vehicle. The device has a characteristic wherein the unsprung member of a part on which a connector is mounted has a flat support part for supporting the sensor plate. <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 detect a strain for an unsprung member of a vehicle without increasing the size of the detecting device, being easy to attach to the unsprung member, and further, the detecting device being not deformed or damaged when the signal line is attached or detached. Is to provide a device.

  According to the first aspect of the present invention, there is provided a strain detection device for an unsprung member of a vehicle that detects a strain of an unsprung member positioned under the spring of the suspension of the vehicle, and the unsprung member includes at least two bolts. A fixed sensor plate, strain detection means attached to the sensor plate, and attached to the sensor plate at a position outside the range between the two bolts, and electrically connected to the strain detection means And a signal line for transmitting a signal on a spring of the vehicle and a detachable connector, and the unsprung member of the portion to which the connector is attached has a planar support portion for supporting the sensor plate. There is provided a strain detection device for an unsprung member of a vehicle.

  According to the first aspect of the present invention, since the unsprung member of the portion where the connector is mounted has the flat support portion that supports the sensor plate, the connector can be attached and detached without the sensor plate being deformed. it can.

  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, a front view of the main part of the braking force detection device according to the embodiment of the present invention is shown. 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.

  A strain gauge 48 is attached to the outside of the sensor plate 42. The sensor plate 42 is electrically connected to a strain gauge 48, and a signal line (not shown) for transmitting a signal and a detachable connector 54 are fixed on a spring of the vehicle. That is, a wiring pattern for connecting the strain gauge 48 and the attached connector 54 is provided on the sensor plate 42.

  The arm portion 40a of the brake load receiving portion 8b of the sensor plate 42 outside the range between the pair of bolts 44 and 46 to which the connector 54 is attached has a planar support portion 50 that supports the back surface of the sensor plate 42. ing. Thereby, the connector 54 can be attached to and detached from the sensor plate 42 without the sensor plate 42 being deformed.

  When the brake is applied when the vehicle moves forward, the brake disc rotates while the pads 18 and 20 press against 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), the sensor plate 42 is compressed and strained.

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

  Furthermore, in this embodiment, since the notch 52 is formed in the brake load receiving portion 8b on the back surface of the bolted sensor plate 42, the sensor plate 42 is compared with the case where there is no notch when receiving the brake load. Therefore, 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 gauge 48 of the above-described embodiment.

  In the above-described embodiment, 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 used as another unsprung member of the suspension. You may make it attach to. In this case, it is a feature of the present invention that the unsprung member has a planar support portion that supports the sensor plate at a portion where the connector is mounted.

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 brake force detection apparatus of embodiment of this invention. FIG. 5 is a right side view of FIG. 4. FIG. 5 is a plan view of FIG. 4.

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 gauge 50 Planar support portion 52 Notch 54 Connector

Claims (1)

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 with at least two bolts;
Strain detecting means attached to the sensor plate;
A signal line that is attached to the sensor plate at a position outside the range between the two bolts and is electrically connected to the strain detecting means, and transmits a signal onto a spring of the vehicle, and a detachable connector. Equipped,
The unsprung member for a vehicle unsprung member according to claim 1, wherein the unsprung member of the portion to which the connector is attached has a planar support portion for supporting the sensor plate.