JPH11141584A - Brake torque measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake torque measuring device to measure the brake torque at the time of braking, in which destruction of a sensor with a high load is precluded while a high measuring accuracy with a low load is well maintained. SOLUTION: On the rotor turnout side of a back metal 204 of a friction pad 202, a slit 214 is furnished in the direction Y intersecting the direction X in which a brake torque is applied, and thereby a moment arm 201 is formed. When the displacement of the acting point F of this moment arm 201 exceeds a certain amount S2, the reaction force from the side with mounting 206 is transmitted to the back metal 204 directly (bypassed) via a stopper pin 222 without passing through the fulcrum P of the moment arm 201.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake torque of a brake mechanism provided on a fixed member side and pressing a friction pad integrated with a backing metal against a rotor connected to a rotating member and rotating together with the rotating member. It relates to a measuring device.

[0002]

2. Description of the Related Art Disc brakes are wheels (rotating members).
By pressing a friction pad provided on the vehicle body (fixing member) side against a rotor connected to the vehicle side and rotating with the wheels, the rotation of the rotor is braked while converting the kinetic energy of the vehicle into heat energy. ing. The friction pad is integrated with a metal backing. When the friction pad is pressed against the rotor, the friction pad receives a force (brake torque) in the tangential direction of the rotor from the rotor side. The back metal is received by a mounting which is a member on the vehicle body side, so that a reaction force is received from the vehicle body side. It has become.

[0003] Such a brake device is used in combination with an ABS (anti-lock brake system) for preventing wheels from being locked even in rainy weather or on a slippery road surface in order to brake the vehicle stably. . It is also used in combination with a vehicle stability control (VSC) device that automatically performs engine output and wheel brake control even in the case of a sudden steering operation such as during emergency avoidance and stabilizes the vehicle. Sometimes.

[0004] In order to more effectively exert the function of such a device, there is a demand for accurately measuring the brake torque currently acting on the brake device at the present time.

Therefore, a device for measuring a brake torque generated between a rotor and a friction pad by providing a sensor in a brake device is disclosed in, for example, Japanese Patent Publication No. 50-185.
No. 47, JP-A-62-38334, Japanese Patent Publication No. 5-798
No. 52, No. 5-85854, or No. 7-
Various proposals have been made in, for example, No. 67907.

FIG. 7 shows a brake torque measuring device disclosed in Japanese Patent Publication No. 50-18547.

[0007] A friction pad 2 is arranged at the center of a caliper (not shown). On the friction pad 2, a back metal 4 having the same planar shape as that of the friction pad 2 is integrally laminated (from above the paper surface). Mountings 6 (on the vehicle body side) are arranged at both ends of the back metal 4 with a slight gap. Reference numeral 8 in the figure denotes a rotor that is connected to a wheel (not shown) and that rotates with the wheel in the direction of arrow A during forward running.

The back metal 4 of the friction pad 2 is pressed by a piston cylinder (not shown) in a direction shown by a dotted line in a direction perpendicular to the plane of the drawing in response to the depression of a brake pedal (not shown). The rotor 8 is strongly contacted. At this time, the back metal 4 of the friction pad 2 is
Side receives its tangential force (= brake torque). Normally, the braking torque is directly received by the mounting 6. However, in this device, in order to measure the braking torque generated between the friction pad 2 and the rotor 8, a sensor 12 disposed in the ball 10 and the mounting 6 is used. The brake torque is received through the control unit.

The sensor 12 belongs to a so-called resistance strain gauge, and is a sensor utilizing the fact that it is deformed according to the load applied and the electric resistance is changed according to the amount of deformation.

[0010]

However, various brake torque measuring devices proposed in the prior art, including the brake measuring device described in Japanese Patent Publication No. 50-18547, measure the brake torque applied to a friction pad. Although various arrangements have been made for the structure of receiving the brake torque in such a manner, the brake torque is directly received by a sensor (resistance wire strain gauge).

Therefore, when a high-sensitivity sensor is used, the sensor is destroyed under a high load (when the brake torque is large). When a low-sensitivity sensor that can withstand a high load is used, a measurement error at a low load is reduced. In fact, the actual situation is that much useful information cannot be obtained (generally, in the case of automatic braking control, there are many controls at a low load).

Further, in the conventional measuring apparatus, since the sensors 12 are mounted on the mounting 6 (or a portion which can be deformed or moved by the force applied to the mounting 6), both sides (the inner side and the outer side) of the rotor 8 are provided. : Friction pads 2 on the upper and lower sides of the paper in the illustrated example)
In the brake device provided with the above, the total brake torque by the friction pads 2 installed on both sides is measured, and there is also a problem that the brake torque generated in each friction pad 2 cannot be measured individually. there were.

The present invention has been made in view of such a problem, and when measuring a brake torque, particularly when a high load is applied while maintaining a highly sensitive measurement accuracy particularly at a low load. It is an object of the present invention to provide a brake torque measuring device that can prevent the sensor from being destroyed and can independently measure the brake torque generated for each friction pad.

[0014]

According to a first aspect of the present invention, there is provided a structure in which a friction pad provided on a fixed member side and integrated with a back metal is pressed against a rotor connected to a rotating member and rotating with the rotating member. In the brake torque measuring device of the brake mechanism, by providing a slit in a direction intersecting the direction in which the brake torque is applied, on the rotor outlet side of the back metal of the friction pad, the fulcrum near the end point of the slit, the vicinity of the starting point, As an action point receiving a reaction force from the fixed member side, a deformable moment arm is provided near the fulcrum of the moment arm, and a brake torque is detected based on a deformation stress applied near the fulcrum. A torque sensor, and the moment arm is displaced by a predetermined amount or more in the vicinity of the point of application of the moment arm to fix the moment arm. The reaction force from the wood side, by which and a bypass means for enabling transmission to the back metal side without passing through the fulcrum of the moment arm is obtained by solving the above problems.

The most basic principle and operation of the present invention will be described with reference to FIG.

In the present invention, the moment arm 101 that is deformed by the brake torque is formed on the back metal 104 itself, unlike the related art. That is, the moment arm 101 is provided with a slit 114 having a width S0 in the direction Y intersecting with the direction X in which the brake torque is applied, on the rotor outlet side E of the back metal 104, so that the slit 114
Are formed so as to be deformable, with the vicinity of the end point as a supporting point P and the vicinity of the starting point as an action point F receiving a reaction force from the mounting (fixing member) 106 side.

A torque sensor 112 is provided near the fulcrum P of the moment arm 101, and detects a brake torque based on a deformation stress (of the back metal 104) applied near the fulcrum P. The moment arm 101 is
When the displacement S in the vicinity of the action point F reaches a predetermined amount S0, the bypass means BP that enables the reaction force from the mounting 106 to be transmitted to the back metal 104 side without passing through the fulcrum P of the moment arm 101 functions. .

As a result, a high-sensitivity torque sensor 112 is used. In particular, when a high load, that is, a large brake torque is applied, a high-precision torque measurement can be performed under a low load, the mounting 106 side is used. Is directly transmitted to the back metal 104 without passing through the vicinity of the fulcrum P where the torque sensor 112 is disposed. Therefore, the destruction of the torque sensor 112 can be reliably prevented.

However, in the structure based on the above basic principle, the interval (width) S0 of the slit 114 is actually set to several tens to ten tens.
The slit 114 having such a small width S0 must be set in units of 0 microns.
In practice, it is very difficult to form a high precision.

According to a second aspect of the present invention, there is provided the bypass unit, wherein a column-shaped hole is formed along the slit in parallel with the surface of the back metal to which the friction pad is attached, and the position of the moment arm is reduced. The structure based on the above principle is manufactured at low cost and with high precision by adopting a configuration in which a cylindrical stopper pin having a diameter smaller than the inner diameter of the hole is accommodated in the hole by an amount corresponding to the fixed amount. And displacement of the back metal in the thickness direction (torsion)
Is to be prevented.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

This embodiment, as shown in FIG.
The rotor 208 is connected to a wheel (not shown) that is a rotating member, and is mounted on a mounting (fixed member on the vehicle body side) 206 on a rotor 208 that rotates with the wheel. The rotor 208 presses a friction pad 202 integrated with a back metal 204. The present invention is applied to a known brake mechanism. The friction pad 202 is affixed to the rotor 208 side of the back metal 204, and its planar shape is substantially the same as that of the back metal 204.
Also, the original structure and operation of the brake mechanism are basically the same as those of the related art.

In such a brake mechanism, the brake torque measuring device according to the present embodiment has the following configuration.

That is, as shown in FIG. 1, a moment arm 201 which is deformable by receiving a brake torque is formed on the rotor outlet side E of the back metal 204 of the friction pad 202. More specifically, the moment arm 201 is provided with a slit 214 having a width S1 in a direction Y intersecting the direction X in which the brake torque is applied, so that the vicinity of the end point of the slit 214 is a fulcrum P,
The vicinity of the starting point is formed to be an action point F that receives a reaction force from the mounting 206 side. The sensitivity of the moment arm 201 (the amount of deformation S near the application point F with respect to the brake torque) can be adjusted by adjusting the diameter d1 of the through hole 216 formed at the end point of the slit 214 to obtain a thickness near the fulcrum P of the moment arm 201. By setting the length t appropriately, it is possible to set the optimum value.

The point of action F of the moment arm 201
Is provided with a convex torque receiving portion 201a in order to easily receive the reaction force T1 from the mounting 206.

In the vicinity of the fulcrum P of the moment arm 201, a torque sensor 2 for detecting a brake torque based on the deformation stress (of the back metal 204) applied near the fulcrum P
12 is affixed. The torque sensor 212 is a well-known resistance strain gauge that takes out a deformation state near the fulcrum P of the moment arm 201 as a change in electric resistance. As shown in FIG. ing. This is because the back metal 204 of the friction pad 202 expands due to the frictional heat between the friction pad 202 and the rotor 208, and the error caused by the thermal expansion is obtained by using the detection value of the torque sensor 212A in the thickness direction W where no brake torque is applied. This is because the correction calculation can be performed so as to eliminate.

On the other hand, in this brake torque measuring device,
A bypass means BP for the reaction force T1 from the mounting 206 side is provided. This bypass means BP is configured such that the displacement S in the vicinity of the action point F of the moment arm 201 is a predetermined amount S
2, the reaction force from the mounting 206 can be transmitted to the back metal 204 without passing through the fulcrum P of the moment arm 201.

Specifically, the bypass means BP has the following configuration.

That is, first, the cylindrical hole 220 is
Is formed along the slit 214 in parallel with the attaching surface of the friction pad 202 (the surface parallel to the paper surface in FIGS. 1A and 1B). The inner diameter of the hole 220 is m. Next, a cylindrical stopper pin 222 is housed in the hole 220. The stopper pin 222 has an inner diameter m of the hole 220.
The diameter is smaller by a predetermined amount S2. That is, m
= N + S2. The stopper pin 222 is prevented from falling out of the hole 220 by an appropriate method. For example, after the stopper pin 222 is housed, the hole 220 may be closed with an appropriate material or member such as silicon.

Reference numeral 230 in FIG. 2 is a known pad grip 230 provided between the mounting 206 and the back metal 204 for preventing rust and supporting the back metal.

Next, the operation of this embodiment will be described.

As the vehicle advances in the forward direction, the rotor 208 rotates in the direction of arrow A with the rotation of the wheels as shown in FIG. At this time, when a brake pedal (not shown) is depressed, a piston cylinder (not shown) presses the friction pad 202 integrated with the back metal 204 against the rotor 208 by a known mechanism, and pushes the friction pad 202 to the rotor 208.
Pressure contact. As a result, the rotor 208 and the friction pad 2
02, the friction pad 202 and the back metal 2
04 is dragged in the tangential direction X of the rotor 208. This dragged torque corresponds to the brake torque. This brake torque is mounted via a fulcrum P and an action point F of a moment arm 201 formed on the rotor outlet side E of the back metal 204 (fixing member on the vehicle body side).
At the point of action F, a reaction force is received from the mounting 206 side. As a result, the moment arm 201 is deformed in the direction of the arrow Z about the fulcrum P.
When the deformation amount S reaches a predetermined amount S2, a part 220A of the hole 220 is inserted into the stopper pin 22 accommodated in the hole 220.
2, and further deformation is prevented, and at the same time, no matter what high load is applied to the back metal 204, the reaction force from the mounting 206 side is reduced to the moment arm 2.
01, without passing through the fulcrum P of the stopper pin 22.
2 is directly transmitted (bypassed) to the back metal 204 side.

As a result, the range (D) shown in FIG.
) Can be accurately measured.

On the other hand, the hole 220 and the stopper pin 222 of the bypass means BP transmit the reaction force through the vicinity of the fulcrum P of the moment arm 201 when a braking load of a predetermined or higher load is applied to the back metal. In addition to the function of bypassing the moment arm 201, the moment arm 201 also has an effect of preventing the movement of the moment arm 201 in the thickness direction W. That is, since the moment arm 201 is basically formed by cutting the slit 214 on the rotor outlet side of the back metal 204, the moment arm 201 can be deformed in the arrow Z direction by the brake torque, Can also be deformed.
However, the movement of the moment arm 201 in the plate thickness direction W does not contribute to the measurement of the brake torque at all, but also sometimes changes the contact pressure between the friction pad 202 and the rotor 208, and adversely affects the original effect of the brake. Could have an effect. According to this embodiment, the movement of the moment arm 201 in the thickness direction W can be effectively prevented by the contact of the same cylindrical stopper pin 222 accommodated in the cylindrical hole 220. .

As is well known, it is sufficiently possible to form the cylindrical hole 220 with high accuracy in the above-described embodiment and to manufacture the cylindrical stopper pin 222 with high accuracy by the current processing technology. As a result, the management of the predetermined amount S2 can be accurately maintained on the order of microns. As a result, even when the high-sensitivity torque sensor 212 is employed, it is possible to easily set the measurement so that only the appropriate measurement point D can be measured with respect to the break point of the torque sensor 212.

As a result, the brake torque on the low load side can be measured with high sensitivity and with a small error, and the torque sensor can be surely prevented from being broken.

Further, a stopper pin 22 having a slightly different outer diameter is used.
2 is provided, the moment arm 20 is provided.
The predetermined amount S2 (corresponding to the range in which the torque sensor 212 can be measured) S2 can be easily changed.

In the above-described embodiment, the slit 214 is formed in the direction Y substantially perpendicular to the direction X in which the brake torque is applied.
Due to the shape of the slit 214 or the mounting 206, the slit 214 does not necessarily need to be formed in a direction Y perpendicular to the direction X in which the braking torque is applied. The function as 201 can be achieved.

In the above embodiment, the slits 214 are cut from the center of the back metal 204 toward the outer periphery, but may be cut from the outer periphery of the rotor toward the center. In this case, the moment arm naturally serves as a fulcrum near the end point of the slit (the inner circumferential side of the rotor) and the action point near the starting point of the slit (the outer circumferential side of the rotor).

Further, as shown as another embodiment in FIGS. 4 and 5, the slit 314 may be formed substantially at the center of the back metal 304 (the range of reference numeral 314S).

Even in this case, although the overall shapes of the friction pad 302 and the mounting 306 integrated with the back metal 304 are slightly different from those of the above-described embodiment, the brake torque measuring device itself is basically a moment arm formed by the slit 314. 301 is mounting 3
A reaction force is received by the torque sensor 312 and detected by the torque sensor 312, and the same operation as in the above-described embodiment can be obtained.

Reference numeral 330 denotes the mounting 30
6 is a known pad clip 330 provided between the back metal 6 and the back metal 304 for preventing rust and supporting the back metal.

As described above, this embodiment differs from the above-described embodiment only in the method of forming the slits and the shapes of the backing metal, the friction pad, and the mounting. Only the same reference numerals are given in the drawings, and the detailed description will be omitted because they are duplicated.

The brake torque measuring device is as follows.
In the brake mechanism in which the back metal and the friction pad are provided as a pair on the inner side and the outer side with the rotor interposed,
Naturally, it is applicable, in which case the braking torque on each side can be measured independently. As a result, for example, when one side of the friction pad is more worn, and imbalance occurs between the inner side and the outer side of the brake squeal characteristic, the friction is precisely controlled by hydraulic control. Independent control over the pads is also possible.

[0045]

As described above, according to the present invention,
An excellent effect is obtained that the sensor can be prevented from being destroyed under a high load while maintaining high measurement accuracy under a low load by using a highly sensitive torque sensor. Further, for example, in a brake mechanism having a plurality of friction pads on the outer side and the inner side, an effect is obtained that the brake torque acting on each friction pad can be detected independently. Can be

[Brief description of the drawings]

FIG. 1 is a partial enlarged front view of a portion indicated by an arrow I in FIG. 2 partially showing a partial side view and a partial bottom view showing an embodiment of a brake torque measuring device to which the present invention is applied.

FIG. 2 is an overall schematic front view of the brake torque measuring device according to the embodiment;

FIG. 3 is a graph showing a range of brake torque that can be measured by the brake torque measuring device of the present embodiment.

FIG. 4 is an overall schematic front view corresponding to FIG. 2, showing another embodiment of the present invention.

FIG. 5 is a partially enlarged front view of a portion V in FIG. 4;

FIG. 6 is a partial schematic front view of a back metal provided with a moment arm on a rotor outlet side for explaining the principle of the present invention.

FIG. 7 is a front view of a conventional brake torque measuring device, partially including a wiring diagram.

[Explanation of symbols]

 201, 301: Moment arm 202, 302 ... Friction pad 204, 304 ... Backing metal 206, 306: Mounting 208, 308 ... Rotor 212, 312 ... Torque sensor 214, 314 ... Slit 220, 320 ... Hole 222, 322 ... Stopping pin P ... Supporting point F: point of application BP: bypass means S2: predetermined amount

Claims (2)

[Claims] 1. A brake torque measuring device for a brake mechanism, wherein a friction pad provided on a fixed member side and integrated with a backing metal is pressed against a rotor connected to a rotating member and rotating together with the rotating member. By providing a slit in a direction intersecting the direction in which the brake torque is applied, on the rotor outlet side of the back metal of the pad, the vicinity of the end point of the slit as a fulcrum, and the vicinity of the starting point as an action point receiving a reaction force from the fixed member side. ,
A moment arm formed so as to be deformable; and a torque sensor provided near the fulcrum of the moment arm and detecting a brake torque based on a deformation stress applied to the vicinity of the fulcrum. And a bypass means for transmitting a reaction force from the fixed member side to the back metal side without passing through a fulcrum of the moment arm by a displacement of a predetermined amount or more near the action point. Torque measuring device. 2. The apparatus according to claim 1, wherein said bypass means forms a columnar hole along said slit in parallel with a friction pad attaching surface of said back metal, and an amount corresponding to said predetermined amount of said moment arm. A brake torque measuring device, wherein a cylindrical stopper pin having a diameter smaller than the inner diameter of the hole is accommodated in the hole.