JP2010190312A - Abrasion amount detection device for brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily detect an abrasion amount in a short time without influencing design of a brake. <P>SOLUTION: The abrasion amount detection device includes a brake disk attached to an axle shaft, a parking brake piston 36 pressed to the brake disk through a brake ring to brake, a parking release oil chamber 44 for driving the parking brake piston 36 to the release side, a parking brake coil spring 42 for driving the parking brake piston 36 to the brake side, and a parking brake valve 55 for supplying and delivering pressure oil to and from the parking release oil chamber 44. An oil amount measurement means 80 is provided for measuring an amount of oil delivered from the parking release oil chamber 44 by the parking brake coil spring 42 when the parking brake is released by the parking brake valve 55, and the abrasion amount of the brake disk and the brake ring can be calculated from strokes of the parking brake piston 36 calculated from the amount of the oil measured by the oil amount measurement means 80. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a brake wear amount detection apparatus suitable for a vehicle, particularly a work vehicle.

  Measuring the amount of brake wear on a vehicle is an extremely important matter in vehicle maintenance. In measuring the amount of wear of a conventional brake, Patent Document 1 detects that the stroke of the brake piston is detected through the shaft by inserting a shaft whose tip is in contact with the brake piston into a detection hole formed in the brake housing. A stroke sensor is provided to detect the amount of wear of the brake.

  In Patent Document 2, an air chamber for injecting air onto the friction surface of the brake disc through the nozzle is provided in the brake pad, and the distance between the brake disc and the nozzle is obtained by measuring the air pressure in the air chamber. Brake pad wear is detected.

Further, Patent Document 3 is provided with an optical sensor for measuring a distance from a friction surface of a brake disk on a back plate of a brake pad.
Further, in the conventional example shown in FIG. 13, an inspection hole 3 facing the brake disc 2 is formed in the brake housing 1, pressure oil is supplied to the brake oil chamber 4, and the brake piston 8 and the brake rings 5, 6 are used. In a state where the brake disk 2 is clamped, a wear gauge 7 is inserted from the inspection hole 3 and the tip portion is inserted between the brake rings 5 and 6. Whether or not the wear gauge 7 is fitted between the brake rings 5 and 6 is confirmed by the scale 7 a of the wear gauge 7. When the wear gauge 7 is fitted between the brake rings 5 and 6, the wear amount of the brake disk 2 has not reached the use limit, and the use can be continued. When the wear gauge 7 is not fitted between the brake rings 5 and 6, it is determined that the wear amount of the brake disk 2 has exceeded the use limit, and the brake piston 8 and the brake rings 5 and 6 are replaced.

Japanese Patent Laid-Open No. 9-257067 (FIG. 2) Japanese Utility Model Publication No. 62-146905 (FIG. 2) Japanese Utility Model Publication No. 6-67935 (FIG. 1)

  However, in Patent Document 1, it is necessary to form a wear measurement hole at a predetermined position of the brake housing and to provide a measurement stroke sensor outside the brake housing, and the design freedom is low due to design limitations. . In Patent Documents 2 and 3, it is necessary to provide a measurement air chamber and sensor in the brake, which complicates the structure of the brake and increases manufacturing and maintenance costs. Further, in the conventional example of FIG. 13, it is necessary to form the inspection hole 3 at a predetermined position of the brake housing 1 corresponding to the brake disk 2 at a position that can be opened and closed from the outside, which hinders the degree of freedom of design and measurement. There was a problem that it took time.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and provide a brake wear detection device that can easily detect a brake in a short time without lowering the degree of freedom in designing the brake.

  The invention according to claim 1 is a braking member attached to a driving member that drives a wheel, a brake piston that presses and brakes the braking member via a friction member, and the brake piston is set to one of a braking side and a releasing side. A first actuating part for driving, a second actuating part for driving the brake piston to the other of the braking side and the releasing side, and a brake operating part for operating the brake, the first actuating part and the second actuating part A brake wear detecting device in which one drive source is a coil spring and the other drive source is pressure oil supplied to the oil chamber, and the coil spring is released when the brake is released by the braking operation section. Provided with an oil amount measuring means for measuring the amount of oil discharged from the oil chamber, from the stroke of the brake piston determined by the oil amount measured by the oil amount measuring means, And requests the wear amount of rotary members and said friction member.

  According to a second aspect of the present invention, in the configuration of the first aspect, the oil amount measuring means includes a measurement oil extraction pipe branched from a pressure oil supply / discharge pipe connected between the brake valve and the oil chamber; A first on-off valve interposed in the pressure oil supply / discharge pipe on the brake valve side from the branch portion, a second on-off valve provided in the measurement oil discharge pipe, and the measurement oil discharge pipe A visual measuring tool capable of measuring the amount of oil.

  The invention according to claim 3 is the configuration according to claim 1, wherein the oil amount measuring means includes a measurement oil bypass pipe connected to a pressure oil supply / discharge pipe extending from a brake valve constituting the braking operation section to the oil chamber; A first on-off valve interposed in the pressure oil supply / discharge pipe on the brake valve side from the connecting portion of the measurement oil bypass pipe, a second on-off valve interposed on the oil chamber side of the measurement oil bypass pipe, An oil discharge measuring device that is interposed on the brake valve side of the measurement oil bypass pipe and can measure the amount of oil introduced into the measurement oil bypass pipe; and when the brake is released by the braking operation section, the first on-off valve is Closed, opens the second on-off valve, leads pressure oil to the measurement oil bypass pipe, and determines a brake wear amount from the oil amount measured by the discharged oil measuring device, and the wear amount measurement unit Knowing the required amount of wear to the driver It is obtained by and a notice means that.

  According to a fourth aspect of the present invention, in the configuration of the first to third aspects, the brake is a parking brake, a service brake, a parking service, or a combined service brake.

  According to the first aspect of the present invention, the amount of pressurized oil discharged from the oil chamber is measured by the oil amount measuring means, the stroke of the brake piston is obtained from this oil amount, and the amount of wear of the brake is detected. It is only necessary to take out the pressure oil discharged from the engine, and the structure can be simplified, and the degree of freedom in designing the brake is not reduced, and detection can be performed in a short time.

  According to the second aspect of the present invention, the measurement oil extraction pipe for taking out the pressure oil discharged from the oil chamber and the first and second on-off valves are provided, and the pressure oil is supplied from the oil chamber through the measurement oil extraction pipe. The amount of wear of the brake can be easily detected in a short time.

  According to the third aspect of the present invention, the wear amount measuring unit can automatically detect the wear amount of the brake and notify the driver by the notification means. Ideal for heavy working vehicles.

  According to invention of Claim 4, even if it is a parking brake or a service brake or a parking and a service combined use brake, it can install similarly and can show | play the same effect.

It is a piping diagram which shows the specific example 1 in Example 1 of the abrasion loss detection apparatus of the service brake which concerns on this invention. It is a longitudinal cross-sectional view of the axle part which incorporated the service brake. It is a partial expanded longitudinal cross-sectional view of a service brake. (A)-(c) is operation | movement explanatory drawing of a service brake, (a) is at the time of service brake braking, (b) is at the time of brake release, (c) shows at the time of braking of a parking brake. FIG. 6 is a piping diagram showing a specific example 2; FIG. 6 is a piping diagram showing a specific example 3; It is a piping diagram which shows the specific example 4. It is a piping diagram which shows Example 2 of the abrasion amount detection apparatus of the brake which concerns on this invention. It is a longitudinal cross-sectional view which shows the transmission which incorporated the parking brake. It is an enlarged vertical sectional view of a parking brake. It is a longitudinal cross-sectional view of the axle part incorporating the service brake. It is an enlarged vertical sectional view of a service brake. It is a fragmentary longitudinal cross-section explaining the wear amount detection apparatus by the conventional wear gauge.

Embodiments of the present invention will be described below with reference to the drawings.
[Example 1]
A service brake wear amount detection device that serves both as a parking brake and a service brake will be described with reference to FIGS.

  As shown in FIG. 2, parking and regular service brakes 10F and 10R are respectively provided on the axle shaft 13 of the wheel 11 provided in a pair of left and right on the vehicle body 26 of a large wheel loader, for example. The axle shaft 13 is independently driven by the electric drive motor 12.

(Brake structure)
As shown in FIG. 3, each axle housing 16 includes a service brake 10F or 10R, and planetary gear type first reduction gears 14 and second reduction gears 15, respectively.

  In the first speed reducer 14, an axle shaft 13 connected to the drive motor 12 is rotatably supported by a axle housing 16 via a bearing, and a first sun gear 17 is attached to the axle shaft 13. A plurality of first planet gears 19 are meshed between the first ring gear 18 fixed in the axle housing 16 and the first sun gear 17, and these first planet gears 19 are rotatable on the axle shaft 13. The first planet carrier 20 that is supported is rotatably supported.

  In the second speed reducer 15, a second sun gear 22 is attached to a gear shaft connected to the first planet carrier 19 on the same axis O as the axle shaft 13. A plurality of second planet gears 24 are meshed between the second ring gear 23 mounted in the axle housing 16 and the second sun gear 22, and these second planet gears 24 are bearing to the first planet carrier 19. The second planet carrier 25 is rotatably supported on the axis O via the shaft. A wheel 11 is attached to the outer periphery of the axle housing 16.

  As schematically shown in FIG. 4, the service brakes 10F and 10R are braked by pressing and holding the same braking member by the parking brake piston 36 and the service brake piston 35, respectively. That is, as shown in FIG. 3, a plurality of brake disks (braking members, inner disks) 32 are attached to the disk hub 21 of the first planet carrier (driving member) 20, and the brake disks 32 are engaged with each other. A plurality of arranged brake rings (friction members, outer disks) 33 are attached to the axle housing 16 via the brake housing 31. In the axle housing 16, a pressure receiving ring (friction member) 34 is disposed on the distal end side of the disk group, and a ring-shaped service brake piston 35 is axially disposed on the proximal end side via a brake pad (not shown). It is arranged so that it can be moved in and out in the O direction. In addition, a ring-shaped parking brake piston 36 is disposed on the inner peripheral side of the service brake piston 35 so as to be freely retractable in the direction of the axis O. Further, a service brake oil chamber (first operation unit, second operation unit, oil chamber) 38 is formed between the service brake piston 35 and the axle housing 16, and a service brake is provided at a predetermined position on the outer periphery of the service brake oil chamber 38. A regular release coil spring (first operating part, second operating part) 39 for improving the response characteristics of the piston 35 is provided.

  Further, the parking brake piston 36 is provided with a claw portion 41 that can bias the service brake piston 35 only to the braking side. Between the parking brake piston 36 and the axle housing 16, a parking brake coil spring (first operating part, second operating part) 42 that biases the parking release piston 36 toward the braking side is interposed. 43 is an adjustment rod which can adjust the stroke of the parking brake piston 36. Further, the movement limit of the parking brake piston 36 is formed in the axle housing 16 at the inner peripheral portion of the parking brake piston 36, and a parking release oil chamber (first operating portion, second operating portion, oil chamber) 44 is formed. An oil chamber forming ring 45 is attached.

(Brake piping system)
FIG. 1 is a piping diagram of the service brakes 10F and 10R.
A pair of service accumulators 65 and a single parking accumulator 67 for accumulating the hydraulic pressure supplied from the variable displacement main hydraulic pump 51, and supply the pressure oil of these service accumulators 65 and parking accumulators 67 to the service brakes 10F and 10R, respectively; A service brake valve (braking operation unit) 54 and a parking brake valve (braking operation unit) 55 for discharging are provided. The service brake valve 54 and the parking brake valve 55 are respectively operated by a service brake pedal (braking operation unit) 56 and a parking brake lever (braking operation unit) 57 provided in the driver's seat.

  In the service brakes 10F and 10L, the first check valve 63 and the second check valve 64 are interposed in the hydraulic oil supply pipe 62 connected between the discharge port of the main hydraulic pump 51 and the pair of regular accumulators 65. Has been. A branch pipe 66 is connected from the hydraulic oil supply pipe 62 between the second check valve 64 and the regular accumulator 65 to the parking accumulator 67. Further, the normal pressure oil supply pipes 68F and 68R are connected to the normal brake valve 54 from the two hydraulic oil supply pipes 62 between the normal accumulator 65 and the second check valve 64, respectively, and the service brake 10F, Common pressure oil supply / discharge pipes (pressure oil supply / discharge pipes) 69F and 69R are connected to the 10 L service brake oil chamber 38 via branch portions 69a to 69d, respectively. Further, a service pressure oil discharge pipe 70 is connected from the service brake valve 54 to the oil tank 61.

  Therefore, when the service brake is operated, the service brake pedal 56 is depressed to operate the service brake valve 54 to the braking position, and the service oil supply pipe 62 and the service pressure oil supply / discharge pipes 69F and 69R are connected. 65 pressure oil is supplied to the service brake oil chamber 38 via the service brake valve 54. As a result, as shown in FIG. 4A, the service brake piston 35 is driven in the braking direction to pressurize the brake disk 32 and the brake ring 33, and the service brake is braked. When releasing the service brake, the user releases the service brake pedal 56 and operates the service brake valve 54 to the release position to connect the service pressure oil supply / discharge pipes 69F and 69R and the service pressure oil discharge pipe 70. Accordingly, the service brake piston 35 is returned to the release direction by the action of the service release coil spring 39, and the pressure oil in the service brake oil chamber 38 is supplied from the service pressure oil supply / discharge pipes 69F and 69R to the service brake valve 54 and the service pressure oil discharge pipe. As shown in FIG. 4 (b), the service brake is released.

  In the parking brake piping device, a parking pressure oil supply pipe 71 is connected from the branch pipe 66 to the parking brake valve 55, and the parking pressure oil supply from the parking brake valve 55 to the parking release oil chambers 44 of the service brakes 10F and 10L, respectively. An exhaust pipe (pressure oil supply / exhaust pipe) 72 is connected via the branch portions 72a to 72d. A parking pressure oil discharge pipe 73 is connected between the parking brake valve 55 and the oil tank 61.

  Therefore, when the parking brake is operated, the parking brake valve 55 is operated to the II position by the parking brake lever 57, and the parking brake is supplied when the parking pressure oil supply / discharge pipe 72 and the parking pressure oil discharge pipe 73 are connected. The parking brake piston 36 is driven in the pressing direction by the action of the coil spring 42, and the pressure oil in the parking release oil chamber 44 is discharged to the oil tank 61 through the parking brake valve 55 as shown in FIG. Further, the parking brake is acted by pressurizing the brake disc 32 and the brake ring 33 by the action of the parking brake coil spring 42. When the parking brake is released, the parking brake valve 55 is operated to the I position by the parking brake lever 57 and the parking pressure oil supply pipe 71 and the parking pressure oil supply / discharge pipe 72 are connected. The pressure oil of the accumulator 67 is supplied to the parking release oil chamber 44 through the parking brake valve 55, the parking brake piston 36 is driven in the releasing direction against the parking brake coil spring 42, and the brake disc 32 and the brake ring 33 are moved. The decompression is released and the parking brake is released as shown in FIG.

(Specific example 1 of the wear amount detection device)
A specific example 1 of the wear amount detecting device according to the present invention will be described with reference to FIG. In this specific example 1, the brake disc 32 and the brake ring 33 are pressurized and braked by the parking brake coil spring 42 through the parking brake piston 36 with a constant pressure and then discharged from the parking release oil chamber 44 when released. By measuring the amount of pressure oil by the oil amount measuring means 80, the amount of wear of the brake disc 32 and the brake ring 33 is detected from the stroke of the parking brake piston 36.

  That is, the oil amount measuring means 80 is provided in the branch portions 72a to 72d of the parking pressure oil supply / discharge pipe 72 connected to the parking release oil chambers 44 of the service brakes 10F and 10R, and the branch portions 72a to 72d. A measurement oil extraction pipe 81 connected to each of 72d, a manual first on-off valve 82 interposed in a branching portion 72a to 72d on the parking brake valve 55 side from a connection portion of the measurement oil extraction pipe 81, and measurement Consists of a manually operated second on-off valve 83 interposed in the oil drain pipe 81 and a visually-visible visual measuring tool 84 such as a graduated cylinder for measuring the amount of oil discharged from the outlet of the measurement oil drain pipe 81. Has been. The visual measuring tool 84 is worn in the parking release oil chamber 44 of the service brakes 10F and 10R, the reference capacity corresponding to the stroke of the parking brake piston 36 in a state where the brake is not worn, the brake disc 32 and the brake ring 33. A scale indicating the capacity corresponding to the stroke of the parking brake piston 36 in a state where the limit is reached is formed.

  Therefore, from the braking state of the parking brake, the first on-off valve 82 is closed, the second on-off valve 83 is opened, the visual measuring tool 84 is disposed at the outlet of the measurement oil drain pipe 81, and the parking brake lever 57 is braked. Then, the parking brake valve 55 is operated to the operating position II, and the pressure oil in the parking release oil chamber 44 is discharged from the branch portions 72a to 72d to the visual measurement tool 84 through the measurement oil extraction pipe 81, respectively. Then, from the amount of oil discharged to the visual measuring tool 84, it is possible to detect whether or not the wear amount of each service brake 10F, 10R has reached the use limit and how much wear has occurred, based on the scale. .

  According to the first specific example, when the parking brake is braked, the first on-off valve 82 and the second on-off valve 83 are operated, and the parking brake oil spring 44 operates the parking pressure oil supply / discharge from the parking release oil chamber 44. The pressure oil discharged to the pipe 72 is led out to the measurement oil extraction pipe 81, and the pressure oil discharged from the measurement oil extraction pipe 81 is received by the visual measuring tool 84 and the amount of the oil is measured. The wear amounts of the service brakes 10F and 10R corresponding to the stroke of the piston 36 can be detected. Therefore, the structure can be simplified, and the amount of wear of the service brakes 10F and 10R can be detected in a shorter time without affecting the design of the service brakes 10F and 10R.

  In the first specific example, the oil amount measuring means 80 is provided in each of the branch portions 72a to 72d. However, as indicated by the phantom line, the oil amount measuring means is provided on the parking brake valve 55 side of the parking pressure oil supply / discharge pipe 72. 80A may be provided, or the oil pressure measuring means 80B may be provided in the parking pressure oil discharge pipe 73. In these cases, the total amount of pressure oil discharged from the four parking release oil chambers 44 is received by the visual measurement tool 84, and the total wear amount of all the service brakes 10F, 10R is detected.

(Specific example 2 of the wear amount detection device)
A specific example 2 of the wear amount detection device according to the present invention will be described with reference to FIG. In this specific example 2, the brake disk 32 and the brake ring 33 are pressurized and braked with a constant pressure by the service brake piston 35 and then released from the service brake oil chamber 38 by the action of the parking brake coil spring 42 when released. The amount of pressure oil discharged through 69a to 69d is measured by the same oil amount measuring means 80 as in the first specific example, so that the wear amount of the service brakes 10F and 10R is detected from the stroke of the service brake piston 35. Is.

  Therefore, in the state where the service brake pedal 56 is depressed to the pedal pressure limit and the service brake is braked, the visual measuring tool 84 is disposed at the outlet of the measurement oil discharge pipe 81, the first on-off valve 82 is closed, and the second on-off valve 83 is provided. Open. Then, the service brake pedal 56 is released and the service brake valve 54 is operated to the release position, and the pressure oil in the parking release oil chamber 44 is introduced into the measurement oil extraction pipe 81 from the branch portions 69a to 69d and is applied to the visual measurement tool 84. Let it drain. Then, from the amount of oil discharged to the visual measuring tool 84, it is possible to detect whether or not the wear amount of each service brake 10F, 10R has reached the use limit and how much wear has occurred, based on the scale. .

  According to the second specific example, the first on-off valve 82 and the second on-off valve 83 are operated to release the normal pressure oil supply / discharge from the normal brake oil chamber 38 before releasing the normal brake pedal 56 that has been depressed to the step pressure limit. The pressure oil discharged to the branch portions 69a to 69d of the pipes 69F and 69R is led out to the measurement oil extraction pipe 81, received by the visual measuring tool 84, and the oil quantity is measured. , 10R can be detected. Therefore, the structure can be simplified, and the amount of wear of the service brakes 10F and 10R can be detected in a shorter time without affecting the design of the service brakes 10F and 10R.

  In the second specific example, the oil amount measuring means 80 is provided in each of the branch portions 69a to 69d. However, as shown by the phantom line, the oil pressure measuring means 80C having the same structure is provided in the normal pressure oil discharge pipe 70. The total amount of pressure oil discharged from the four parking release oil chambers 44 is received by the visual measurement tool 84, and the total wear amount of all the service brakes 10F, 10R is detected.

  Moreover, in the specific examples 1 and 2, the visual measurement tool 84 such as a graduated cylinder is adopted as the oil amount measurement tool 84 and the measurement is manually performed every six months or one year in the normal use state of the vehicle. This is because it is only necessary to measure the amount of wear of the brake at each periodic maintenance, and it is only necessary to carry the visual measuring tool 84 as a maintenance inspection tool.

(Specific example 3 of the wear amount detecting device)
A specific example 3 of the wear amount detection apparatus according to the present invention will be described with reference to FIG. This specific example 3 is an automated version of the specific example 1, and is suitable for a working vehicle in which the brake is heavily worn. Note that the same members as those in the first specific example are denoted by the same reference numerals and description thereof is omitted.

  That is, the oil amount measuring means 90 is provided in each of the branch portions 72a to 72d of the parking pressure oil supply / discharge pipe 72 connected to the parking release oil chamber 44 (oil chamber) of each service brake 10F, 10R. The measurement oil bypass pipe 91 connected between the entrances and exits of the branch parts 72a to 72d (or between the branch parts 72a to 72d and the parking pressure oil supply / discharge pipe 72), and the connection of the measurement oil bypass pipe 91 at the branch parts 72a to 72d The electromagnetic first on-off valve 92 interposed between the parts, the electromagnetic second on-off valve 93 interposed on the parking oil chamber 44 side of the measurement oil bypass pipe 91, and the parking brake of the measurement oil bypass pipe 91 Whenever the time set in the discharged oil measuring device 94 and the timer 95a elapses, the amount of oil introduced to the measuring oil bypass pipe 91 provided on the valve 55 side can be measured automatically. When the key valve 55 is released, the first on-off valve 92 is closed, the second on-off valve 93 is opened, and the amount of oil discharged from the parking release oil chamber 44 to the measurement oil bypass pipe 91 is discharged. The measurement device 94 measures the wear amount measuring unit 95 that detects the wear amount of the service brakes 10F and 10R from the stroke of the parking brake piston 36 by the oil amount, and the wear amount obtained by the wear amount measuring unit 95 is operated. The wear amount display unit (notification means) 96 that informs the person and when the wear amount exceeds the limit amount, the warning buzzer is activated by the signal of the wear amount measurement unit 95 to emit a warning sound, and the warning lamp is turned on. It comprises a wear warning device 97 that informs the driver.

  Therefore, when a predetermined driving time set in the timer 95a has elapsed, the parking brake lever 57 is released from the braking state of the parking brake, and at the same time, each oil amount measuring means is determined by a command signal from the wear amount measuring unit 95. The first open / close valve 92 of 90 is closed and the second open / close valve 93 is opened. Further, the parking brake valve 55 is operated to the operating position I, and the pressure oil in the parking release oil chamber 44 is discharged to the branch portions 72a to 72d by the action of the parking brake coil spring 42, and further introduced into the measurement oil bypass pipe 91. The The amount of oil discharged from the parking release oil chamber 44 is measured by the discharged oil measuring device 94, and the wear amount measuring unit 95 determines the brake disc 32 of the service brakes 10F and 10R from the stroke of the parking brake piston 36 based on the amount of oil. The amount of wear of the brake ring 33 is obtained. Further, the wear amount of the service brakes 10F and 10R calculated by the wear amount measuring unit 95 is displayed on the wear amount display unit 96. When the wear amount of the service brakes 10F and 10R calculated by the wear amount measuring unit 95 exceeds the use limit, the wear warning device 97 notifies the driver by lighting a warning sound or a warning lamp. When the measurement is finished, the second on-off valve 93 is closed and the first on-off valve 92 is opened by a signal from the wear amount measuring unit 95.

  According to the third specific example, the wear amount measuring unit 95 automatically detects the amount of oil introduced from the parking release oil chamber 44 into the measurement oil bypass pipe 91 at each set time, and the service brakes 10F and 10R. The wear amount can be obtained, and the driver can be informed periodically by the wear amount display unit 96 and the wear amount warning unit 97, which is optimal for a working vehicle in which the service brakes 10F and 10R are severely worn by repeated running and stopping. Become.

  In the specific example 1, the oil amount measuring means 90 is provided in each of the branch portions 72a to 72d. However, as indicated by a virtual line, the parking brake oil 55 side of the parking pressure oil supply / discharge pipe 72 or the parking pressure oil is provided. The oil amount measuring means 90A or 90B is provided in the discharge pipe 73 so that the total amount of pressure oil discharged from the four parking release oil chambers 44 is received by the discharge oil measuring device 94, and the brake disks 32 of all the service brakes 10F and 10R and The total amount of wear of the brake ring 33 can also be measured.

(Specific example 4 of the wear amount detection device)
A specific example 4 of the wear amount detecting apparatus according to the present invention will be described with reference to FIG. This specific example 4 is automated by providing the oil amount measuring means 90 (90C) in the specific example 2, and the same members as those in the specific examples 1 to 3 are denoted by the same reference numerals and the description thereof is omitted.

  That is, the oil amount measuring means 90 is provided at the branch portions 69a to 69d of the service pressure oil supply / discharge pipes 69F and 69R connected to the service brake oil chambers 38 of the service brakes 10F and 10R, respectively.

  In the above configuration, when a predetermined operation time set in the timer 95a has elapsed, the service brake pedal 56 that has been depressed to the depression pressure limit is released, and at the same time, each oil amount measuring means 90 is received by a command signal from the wear amount measuring unit 95. The first on-off valve 92 is closed and the second on-off valve 93 is opened, and the service brake valve 56 is operated to the release position, whereby the pressure oil in the service brake oil chamber 38 is operated by the service release coil spring 39. Is discharged to the branch portions 69 a to 69 d and introduced into the measurement oil bypass pipe 91. Then, the amount of oil discharged from the service brake oil chamber 38 is measured by the discharged oil measuring device 94, and the wear amount measuring unit 95 wears the service brakes 10F and 10R from the stroke of the service brake piston 35 due to the oil amount. Find each quantity. Further, the wear amount display unit 96 displays the wear amounts of the service brakes 10F and 10R. When the wear amount exceeds the limit amount, the wear warning device 97 notifies the driver by a warning sound or lighting of a warning lamp. When the measurement is completed, the second on-off valve 93 is closed and the first on-off valve 92 is opened by a command signal from the wear amount measuring unit 95.

  According to the specific example 4, the wear amount of the service brake is automatically detected at the set time by the wear amount measuring unit 95 and periodically detected by the wear amount display unit 96 and the wear amount warning unit 97. It is possible to notify the driver, and it is particularly suitable for a working vehicle such as a wheel loader that repeatedly runs and stops violently on a rough ground.

  In the specific example 4, the oil amount measuring means 90 is provided in each of the branch portions 69a to 69d. However, as indicated by the phantom line, the oil pressure measuring means 90C is provided in the normal pressure oil discharge pipe 70, and the four oil amount measuring means 90C are provided. The total amount of oil discharged from the parking release oil chamber 44 can be measured by the discharged oil measuring device 94 to measure the total wear of all the service brakes 10F, 10R.

[Example 2]
A second embodiment of the wear amount detection device when the parking brake and the service brake are installed independently will be described with reference to FIGS.

(Parking brake structure)
As shown in FIG. 9, the parking brake 100 is built in a case 102 of a transmission 101. The transmission 101 has an input shaft 104 to which power is input via a torque converter 103, and power to the wheels. And a plurality of intermediate transmission shafts that are linked and connected via a transmission gear, and a parking brake 100 is provided at the end of the low-speed transmission shaft 106 among these intermediate transmission shafts. ing.

  As shown in FIG. 10, the parking brake 100 includes a plurality of brake discs 108 attached to the low speed transmission shaft 106 via a disc hub 107, and a brake 102 attached to the case 102 via a brake housing 109. A parking brake piston 111 capable of applying pressure to the brake disc 108 and the brake ring 110 between a plurality of arranged brake rings 110 and the pressure receiving member 114 for braking, and parking for biasing the parking brake piston 111 toward the braking side. A brake coil spring 112 and a parking release oil chamber 113 for driving the parking brake piston 111 to the release side against the parking brake coil spring 112 by pressure oil are provided.

(Structure of service brake)
As shown in FIG. 11, the service brake 120 </ b> R (120 </ b> F) is provided in a gear case 122 to which front and rear axle shafts 121 are connected, and is driven by a propeller shaft 123 in the gear case 122. The axle shaft 121 is connected to the differential gear group 124 and the differential output shaft 125 output from the differential gear group 124 via a planetary gear type reduction gear 126.

  As shown in FIG. 12, the service brakes 120 </ b> F and 120 </ b> R are a plurality of brake disks 127 attached to the differential output shaft 125 via a disk hub 134, and brakes attached to the gear case 122 via a brake housing 128. A service brake piston 131 capable of pressurizing and braking the brake disk 127 and the brake ring 129 between a plurality of brake rings 129 disposed between the disks 127 and the pressure receiving member 130 of the gear case 122, and a service brake using pressure oil A service brake oil chamber 132 for driving the piston 131 to the brake side and a service release coil spring 133 for biasing the service brake piston 131 to the release side are provided.

(Brake piping system)
FIG. 8 is a piping diagram of the parking brake 100 and the service brakes 120F and 120R. The same members as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  A parking pressure oil supply / discharge pipe 141 is connected from the parking brake valve 55 to the parking release oil chamber 113 of the parking brake 100, and an oil amount measuring means 90 is provided in the parking pressure oil supply / discharge pipe 141. The service brake valve 54 is connected to the service brake oil chamber 132 of the front wheel service brake 120F via the service pressure oil supply / discharge pipe 142F and its branch portions 142a and 142b, and from the service brake valve 54 to the service brake 120R for the rear wheel. Is connected to the normal brake oil chamber 132 via a normal pressure oil supply / discharge pipe 142R and its branch portions 142c and 142d, and oil amount measuring means 90 is provided in each of the branch portions 142a to 142d.

  In the above configuration, when the predetermined driving time set in the timer 95a has elapsed and the parking brake valve 55 is operated to the braking position I, the first on-off valve 92 is closed by a command signal from the wear amount measuring unit 95, The second on-off valve 93 is opened, and the pressure oil discharged from the parking release oil chamber 113 by the parking brake coil spring 112 is introduced from the parking pressure oil supply pipe 141 into the measurement oil bypass pipe 91. Then, the oil amount is measured by the discharged oil measuring device 94, and the wear amount measuring unit 95 obtains the wear amounts of the brake disc 108 and the brake ring 110 of the parking brake 100 from the stroke of the parking brake piston 111 based on this oil amount. Further, the wear amount display unit 96 displays the wear amount of the parking brake 100. When the wear amount of the parking brake 100 exceeds the limit amount, a warning sound is emitted by the wear warning device 97 or a warning lamp is turned on to notify the driver.

  Further, when a predetermined operation time has elapsed and the service brake pedal 56 is depressed to the depression pressure limit and the release service brake valve 54 is braked and then released, the first signal is sent from the wear amount measuring unit 95 according to a command signal. The on-off valve 92 is closed, the second on-off valve 93 is opened, and the pressure oil discharged from the service brake oil chamber 132 is introduced into the measurement oil bypass pipe 91. Then, the oil amount is measured by the discharged oil measuring device 94, the stroke of the parking brake piston 111 is calculated based on the measured oil amount by the wear amount measuring unit 95, and the brake disc 127 and the brake ring 129 of the service brakes 120F and 120R are worn. Find the amount. Further, the wear amount display unit 96 displays the wear amounts of the service brakes 120F and 120R. When the wear amount of any of the service brakes 120F and 120R exceeds the limit amount, a warning sound is emitted by the wear warning device 97 or a warning lamp is turned on to notify the driver.

  According to the second embodiment, even a vehicle in which the parking brake 100 and the service brakes 120F and 120R are separately arranged can be installed in the same manner as the service brakes 10F and 10R, and have the same effects. Can do. Further, the oil amount measuring means 90 can be selectively provided.

  Instead of the oil amount measuring means 90 and 90C, the manual type oil amount measuring means 80 and 80C of the specific example 1 or 2 of the first embodiment can be provided in the second embodiment.

10F, 10R Service brake 31 Brake housing 32 Brake disc (braking member)
33 Brake ring (friction member)
34 Pressure receiving ring (friction member)
35 Service brake piston (brake piston)
36 Parking brake piston (brake piston)
38 Common brake oil chamber (first and second working parts)
39 Common release coil spring (first and second actuating parts)
42 Parking brake coil spring (first and second operating parts)
44 Parking release oil chamber (first and second working parts)
54 Service brake valve (braking operation part)
55 Parking brake valve (braking operation part)
69F, 69R Service pressure oil supply / discharge pipe 70 Service pressure oil discharge pipe 72 Parking pressure oil supply / discharge pipe 72a to 72d Branch 73 Parking pressure oil discharge pipe 80, 80A, 80B Oil amount measuring means 81 Measurement oil discharge pipe 82 1 On-off valve 83 Second on-off valve 84 Visual measuring tool 90, 90A, 90B Oil amount measuring means 91 Measuring oil bypass pipe 92 First on-off valve 93 Second on-off valve 94 Drained oil measuring device 95 Abrasion amount measuring unit 96 Abrasion amount display 97 Abrasion warning device 100 Parking brake 106 Low speed transmission shaft 108 Brake disc (braking member)
110 Brake ring (friction member)
111 Parking brake piston (brake piston)
112 Parking brake coil spring (first and second operating parts)
113 Parking release oil chamber (first and second working parts)
120R, 120F Service brake 121 Axle shaft 125 Differential output shaft 127 Brake disc (braking member)
129 Brake ring (friction member)
131 Service brake piston (brake piston)
132 Common brake oil chamber (first and second operating parts)
133 Common release coil spring (first and second actuating parts)
141 parking pressure oil supply / discharge pipes 142F, 142R service pressure oil supply / discharge pipes 142a to 142d branching section

Claims (4)

A braking member attached to a driving member for driving the wheel;
A brake piston that presses and brakes the braking member via a friction member;
A first actuating portion for driving the brake piston to one of a braking side and a releasing side;
A second operating part for driving the brake piston to the other of the braking side and the releasing side;
A braking operation section for operating the brake;
A brake wear detection device in which one drive source of the first operating part and the second operating part is a coil spring and the other drive source is pressure oil supplied to an oil chamber,
An oil amount measuring means for measuring the amount of oil discharged from the oil chamber by the coil spring when the brake is released by the braking operation section;
The brake wear amount detection device characterized in that the wear amount of the brake member and the friction member is obtained from the stroke of the brake piston obtained from the oil amount measured by the oil amount measuring means. The oil amount measuring means is interposed in the measured oil discharge pipe branched from the pressure oil supply / discharge pipe connected between the brake valve and the oil chamber, and in the pressure oil supply / discharge pipe on the brake valve side from the branch portion. A first on-off valve, a second on-off valve provided in the measurement oil extraction pipe, and a visual measurement tool capable of measuring the amount of oil discharged from the measurement oil extraction pipe. The brake wear amount detecting device according to claim 1. Oil quantity measuring means
A measurement oil bypass pipe connected to a pressure oil supply / discharge pipe from the brake valve constituting the braking operation section to the oil chamber;
A first on-off valve interposed in the pressure oil supply / discharge pipe on the brake valve side from the connecting portion of the measurement oil bypass pipe;
A second on-off valve interposed on the oil chamber side of the measurement oil bypass pipe;
An exhaust oil measuring device that can measure the amount of oil introduced into the measurement oil bypass pipe interposed on the brake valve side of the measurement oil bypass pipe,
When the brake is released by the braking operation unit, the first on-off valve is closed, the second on-off valve is opened, pressure oil is led out to the measurement oil bypass pipe, and the brake is performed from the oil amount measured by the discharged oil measuring device. A wear amount measuring unit for obtaining the wear amount of
The brake wear amount detection device according to claim 1, further comprising notification means for notifying the driver of the wear amount obtained by the wear amount measuring section. The brake wear amount detection device according to any one of claims 1 to 3, wherein the brake is a parking brake, a service brake, a parking service, or a service brake.

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