JP5379103B2 - Disc brake drag torque measuring instrument and pad equipped with the measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque detector which does not interfere with a piston or a caliper body by storing a dragging torque detecting portion in a pressure plate. <P>SOLUTION: A dragging torque measuring apparatus has a holding portion for holding a friction material, and the holding portion has a structure in which a first pressure plate and a second pressure plate are laminated. The first pressure plate and the second pressure plate are laminated so as to relatively move in a rotation tangential direction of a disc rotor. An elastic body attached with a distortion gauge through a fitting hole formed on the first pressure plate is fixed to the second pressure plate while holding the first pressure plate. Dragging torque generated between the friction material and the disc rotor is measured on the basis of a measurement value detected by the distortion gauge. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a drag torque measuring device for a disc brake and a pad provided with the measuring device.

  Disc brakes used as braking devices for automobiles, railway vehicles, etc., brake pads provided on calipers press the disc rotor that rotates together with the wheels, and the rotation of the wheels is reduced or reduced by friction between the disc rotor and the brake pads. It has a mechanism to stop. The brake pad is actuated by a brake operation by the driver, but in order to improve the response of the brake, it is desirable that the brake pad is slightly in contact with the disc rotor even when the brake operation is not performed. However, depending on the degree of drag by which the disc rotor drags the brake pad due to this contact, drag torque due to frictional force generated between the disc rotor and the brake pad acts as an unnecessary braking force, which contributes to deterioration of fuel consumption and the like. In addition, vibrations generated by drag are transmitted to the vehicle body, which causes discomfort to the passengers. Therefore, in the development of disc brakes, the drag torque is quantitatively measured in order to realize a smaller drag torque.

As a conventional disc brake drag torque measuring instrument, one disclosed in Patent Document 1 below is known.
This drag torque measuring device is provided with a guide path that allows displacement of the friction material in the rotational tangential direction of the disk rotor in a holding portion that holds the friction material that generates braking friction with the disk rotor, and An elastic member that deforms due to the displacement of the friction material is interposed between the friction material and the holding portion, and a load detection means that detects the friction force between the disk rotor and the friction material from the amount of deformation of the elastic member due to the displacement of the friction material. It is characterized by providing.

  The friction material of this measuring instrument is allowed to displace in the rotational tangent direction of the disk rotor by the guide path, so even if the frictional force between the friction material and the disk rotor fluctuates in the actual running state, Following this, the elastic member is deformed in accordance with the frictional force. The load detecting means detects the friction force from the deformation amount of the elastic member. Thus, in the actual running state, the drag torque generated between the friction material and the disk rotor can be measured in real time from the friction force.

  However, in the conventional torque measuring device, since the portion that detects the drag torque is provided in the portion that protrudes from the pressure plate of the pad, the layout is very easy to interfere with the caliper body or the piston. It becomes difficult. Further, since the shim cannot be attached, there is a disadvantage that the attachment state of the pad at the time of measurement is different from the normal use state.

JP 10-16761 A

  The present invention is an improvement of the above-described problem. Since the drag torque detecting portion is disposed inside the pressure plate, a shim can be attached and there is no interference with the piston and the caliper body. Accordingly, the drag torque can be measured in a normal use state. Also, with this device, the drag torque of the inner pad and outer pad can be measured separately.

Therefore, the problem solving means adopted by the present invention is:
A drag torque measuring device for a disc brake that presses a friction material against a disc rotor and brakes a wheel by friction between the disc rotor and the friction material, and the drag torque measuring device has a holding portion that holds the friction material. The holding portion has a configuration in which a first pressure plate and a second pressure plate are laminated, and the first pressure plate and the second pressure plate are laminated so as to be relatively movable in the rotational tangent direction of the disk rotor, and the first pressure plate An elastic body having a strain gauge attached thereto through a fitting hole formed in the first pressure plate is fixed to the second pressure plate while holding the first pressure plate, and friction is based on the measured value detected by the strain gauge. The drag torque generated between the material and the disk rotor is measured. A drag torque measuring device of the disc brake according to. The disc brake drag torque measuring device is characterized in that a sliding member capable of relative movement between the first pressure plate and the second pressure plate is disposed between the first pressure plate and the second pressure plate.
The disc brake drag torque measuring device is characterized in that displacement of the disc rotor in the rotational tangential direction is allowed by a guide path formed on one of the first pressure plate and the second pressure plate.
The disc brake drag torque measuring device is characterized in that a step for restricting the movement of the second pressure plate is provided in the first pressure plate.
The measured value detected from the strain gauge is configured to be temperature-corrected, and is a disc brake drag torque measuring device.
The disc brake drag torque measurement is characterized in that the elastic body is configured as a height that does not protrude from the surface of the first pressure plate in a state in which the first pressure plate and the second pressure plate are assembled. It is a vessel.
Further, the pad is characterized in that the drag torque measuring device described above is provided in at least one of the inner pad and the outer pad.
Moreover, it is a pad characterized by including the drag torque measuring device described above in a pressure plate laminate.

  According to the present invention, it is possible to detect a drag torque in the same use state as that of a normal caliper, and to achieve specific operational effects such as being able to separately measure the drag torque of the inner pad and the outer pad. it can.

It is a see-through | perspective perspective view of the pressure plate part which comprises the drag torque measuring device of the disc brake of this invention. It is an assembly drawing of the torque measuring device. FIG. 3 is an assembly diagram of the torque measuring device viewed from the side opposite to FIG. 2. (A) is a plan view of the same torque measurement, (B) is a BB cross-sectional view in (B), and (C) is a cross-sectional view along AA in (B). It is a top view of a pad. It is a perspective external view of an elastic body (plate spring). It is the top view and detection circuit diagram of a torque measuring device in the state where two strain gauges were attached. It is the top view and detection circuit diagram of a torque detector of the state which attached four strain gauges. It is the figure which measured the relationship between temperature and a strain gauge output beforehand. It is the figure which measured the relationship between the output of a strain gauge and drag torque at normal temperature. It is explanatory drawing which subtracts the part for the temperature drift which measured the relationship between temperature and a strain gauge output previously from the output of a strain gauge at the time of a measurement, and calculates | requires drag torque.

In the present invention, drag torque can be measured in a normal use state, and the feature of the configuration is that it has a holding portion that holds a friction material, and the holding portion includes a first pressure plate and a second pressure plate. The first pressure plate and the second pressure plate are stacked so as to be relatively movable in the rotational tangent direction of the disk rotor, and through a fitting hole formed in the first pressure plate. An elastic body to which a strain gauge is attached is fixed to the second pressure plate while holding the first pressure plate, and drag torque generated between the friction material and the disk rotor is generated based on a measurement value detected by the strain gauge. It can be measured.
According to the present invention, since the drag torque detecting unit does not jump out of the pressure plate by the above configuration, it is possible to attach a shim and to achieve effects such as no interference with the piston and the caliper body. . Also, with this apparatus, it is possible to measure the drag torque of the inner pad and the outer pad separately.

Embodiments of a disc brake drag torque measuring device according to the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of a pressure plate portion constituting a drag torque measuring device for a disc brake according to the present invention, FIG. 2 is an assembly view of the torque measuring device, and FIG. 3 is a torque measurement as viewed from the opposite side to FIG. 4A is a plan view of the torque measuring device, FIG. 4B is a cross-sectional view taken along the line BB in FIG. 4B, and FIG. 4C is a cross-sectional view taken along the line A-A in FIG. 5 is a plan view of the pad, FIG. 6 is a perspective external view of an elastic body (leaf spring), FIG. 7 is a plan view and a detection circuit diagram of a torque measuring device with two strain gauges attached, and FIG. 8 is a strain diagram. FIG. 9 is a relationship diagram between strain gauge output and temperature, FIG. 10 is a relationship diagram between strain gauge output and drag torque, and FIG. 11 is a drag diagram. It is a torque correction figure.

  In FIG. 2, a brake pad P according to the present invention that constitutes a disc brake is composed of a friction material M and a pressure plate PP that holds the friction material M. The pressure plate PP is clearly shown in each of the aforementioned drawings. As shown, the first pressure plate 1 and the second pressure plate 2 are stacked.

  The first pressure plate 1 is configured to be detachably held on the caliper support side, and a substantially square hole 1a is formed at the center thereof. This hole 1a is a hole for fitting and locking an elastic body (plate spring) 3 fixed to the second pressure plate 2. In the figure, the left and right ends of the hole 1a are aligned with bent portions 3a of the elastic body 3 to be described later. A stepped portion 4 is formed. Further, as shown in FIG. 3, the first pressure plate 1 is formed with two rows of recesses 6 for accommodating the flat rails 5 with the holes 1a interposed therebetween. The depth of the recess 6 is formed such that the roller 5a of the flat rail 5 slightly protrudes when the flat rail 5 is housed in the recess 6, and the longitudinal direction of the recess 6 is the rotational tangent of the disk rotor. It is formed so as to be parallel to the direction. Further, the second pressure plate 2 is fitted into the first pressure plate 1 and the second pressure plate 2 allows the displacement of the disk rotor in the rotational tangential direction with respect to the first pressure plate 1 (FIG. 4). Further, the movement amount of the second pressure plate 2 is limited at the end portion in the movement direction of the second pressure plate 2 as shown in FIG. A stepped portion 8 is formed.

  On the other hand, as shown clearly in FIG. 2, the second pressure plate 2 has a friction material M attached to one surface side, and a screw hole 10 for fixing the elastic body 3 is formed in the substantially central portion on the other surface side. In addition, a flat rail holding portion 9 that holds the flat rail 5 is provided.

As shown in FIG. 6, the elastic body 3 that locks the first pressure plate 1 is formed in a substantially rectangular shape by a spring material, and both ends of the elastic body 3 are bent upward as locking portions of the first pressure plate 1. The screw hole 3b for fixing the elastic body 3 to the 2nd pressure plate 2 is formed in the center part while being formed as 3a. The height h of the bent portion 3a formed at both ends of the elastic body 3 is such that the elastic body 3 does not protrude from the surface of the first pressure plate 1 when the elastic body 3 is engaged with the first pressure plate 1. It is formed as a height.
Therefore, it can be mounted on a vehicle, a full-size dynamometer or a drag tester with the actual disc brake state.

The assembled state of the first pressure plate 1 and the second pressure plate 2 will be described with reference to FIGS.
2 and 3, the guide rail 7 (FIG. 4 (FIG. 4 (B)) is formed by storing and holding the flat rail 5 in the recess 6 for storing the flat rail of the first pressure plate 1 and then forming the second pressure plate 2 on the first pressure plate. ), (C))) and fit them together. Thereafter, the elastic body 3 is fitted into the hole of the first pressure plate 1, and the elastic body 3 is fixed to the second pressure plate 2 with screws 3c, whereby both are laminated and integrated. In this state, as described above, the bent portion of the elastic body 3 does not protrude from the surface of the first pressure plate 1.

  When both are assembled, the second pressure plate 2 can move in the rotational tangential direction of the disk rotor with respect to the first pressure plate 1 by the action of the flat rail 5. When the first and second pressure plates 1 and 2 are assembled, the stepped portion 8 (see FIG. 4B) formed on the first pressure plate 1 and the end surface of the second pressure plate 2 A clearance 11 is formed between the two. The clearance 11 disappears when the torque more than the target drag torque is generated (that is, the end face of the second pressure plate 2 hits the step portion 8 of the first pressure plate 1), and the first and second The amount of displacement of the pressure plate is limited, and permanent deformation of the elastic body (leaf spring) 3 can be prevented. The disc brake drag torque can be easily measured by attaching the pressure plate PP having the above configuration to the conventional pressure plate and attaching it to the vehicle.

Next, the strain gauge 3d attached to the elastic body 3 for locking the first pressure plate 1 to the second pressure plate 2 will be described.
As shown in FIG. 7, two strain gauges 3d are attached to the left and right of the elastic body 3, and the amount of strain is measured by a known Whiston bridge circuit to measure the drag torque. Further, four strain gauges 3d can be attached to the left and right of the elastic body 3, as shown in FIG. 8, and the amount of strain is measured by a known Whiston bridge circuit to measure the drag torque.

  By the way, in the disc brake, frictional heat is generated by friction between the friction material M of the brake pad and the disc rotor, and the temperature becomes high. In actual driving conditions, the temperature varies widely because of braking and non-braking. Therefore, the torque signal output from the drag torque measuring device includes a detection error due to temperature fluctuation during actual traveling, and causes temperature drift. For this reason, it is necessary to subtract this temperature drift from the measured value.

In the present invention, the temperature drift is corrected as follows.
First, in measuring the drag torque, the relationship between temperature and strain gauge output is measured in advance (FIG. 9).
Further, the relationship between the output of the strain gauge and the drag torque is measured at room temperature (FIG. 10). The relationship between the output of the strain gauge and the drag torque measures a proportional relationship.
At high temperatures, the temperature drift is included in the output of the strain gauge. Therefore, as shown in FIG. 11, the temperature drift is based on FIG. 9 in which the relationship between the temperature and the strain gauge output is measured in advance from the output of the strain gauge. Subtracting the minute D, the drag torque is obtained from the relationship of FIG.
By doing so, the temperature drift at the time of measuring the output of the strain gauge can be corrected.

  Next, the usage form of the above-described drag torque measuring device will be described. The drag torque measuring device can be used in at least one of the inner pad and the outer pad, and the drag torque measuring device described above can be used. It can be incorporated into a pressure plate laminate.

  As described above, according to the present invention, drag torque can be detected in the same use state as that of a normal caliper. Moreover, since the drag torque of the inner pad and the outer pad can be measured separately, the factor of which pad is dragging can be analyzed. The drag torque measuring device may be provided only on one side of the inner / outer, or one of them may be rearranged in the middle.

  In this example, two or four strain gauges are used. However, the number of strain gauges may be other than the above as required. Further, instead of the flat rail, it is also possible to interpose a slippery member with low frictional resistance between the first and second pressure plates. In the above example, the flat rail is housed in the recess formed in the first pressure plate, but the flat rail can be housed in the recess formed in the second pressure plate.

  INDUSTRIAL APPLICABILITY The present invention can be used in the field of vehicles equipped with a brake, in particular, an automobile disc brake.

P Brake pad PP Pressure plate M Friction material 1 First pressure plate 1a Hole 2 Second pressure plate 3 Elastic body 3a Bending part 3b Screw hole 3c Screw 3d Strain gauge 4 Step part 5 Flat rail 5a Roller 6 Concave part 7 Guide path 8 stage Part 9 Flat rail holding part 10 Screw hole 11 Clearance

Claims (8)

A drag torque measuring device for a disc brake that presses a friction material against a disc rotor and brakes a wheel by friction between the disc rotor and the friction material, and the drag torque measuring device has a holding portion that holds the friction material. The holding portion has a configuration in which a first pressure plate and a second pressure plate are laminated, and the first pressure plate and the second pressure plate are laminated so as to be relatively movable in the rotational tangent direction of the disk rotor, and the first pressure plate An elastic body having a strain gauge attached thereto through a fitting hole formed in the first pressure plate is fixed to the second pressure plate while holding the first pressure plate, and friction is based on the measured value detected by the strain gauge. The drag torque generated between the material and the disk rotor is measured. Drag torque measuring device of the disc brake according to. The disc brake drag torque measuring device according to claim 1, wherein a sliding member capable of relative movement between the first pressure plate and the second pressure plate is disposed between the first pressure plate and the second pressure plate. 3. The disc brake drag torque measurement according to claim 2, wherein displacement of the disc rotor in a rotational tangential direction is allowed by a guide path formed on one of the first pressure plate and the second pressure plate. vessel. 4. The disc brake drag torque measuring device according to claim 2, wherein the first pressure plate is provided with a step for restricting the movement of the second pressure plate. 5. The disk brake drag torque measuring device according to claim 1, wherein the measured value detected from the strain gauge is configured to be temperature-corrected. The said elastic body is comprised as a height which does not protrude from the surface of a 1st pressure plate in the state which assembled | attached the 1st pressure plate and the 2nd pressure plate. The disc brake drag torque measuring instrument according to any one of the above. A pad comprising the drag torque measuring device according to any one of claims 1 to 6 in at least one of an inner pad and an outer pad. A pad comprising the pressure plate laminate including the drag torque measuring device according to any one of claims 1 to 6.

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