JP2005329825A - Brake hydraulic device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake hydraulic device for a working vehicle, capable of reducing designing man-hour and manufacturing man-hour. <P>SOLUTION: The brake hydraulic device for the working vehicle comprises main brake devices 3, 4 and a parking brake device 5 actuated by supplying/discharging oil; a hydraulic pump 1 that is a supplying source of the oil; a brake valve 6 controlling an oil flow to the main brake devices 3, 4; a solenoid selector valve 8a controlling an oil flow to the parking brake device 5; first and second accumulators 10, 11 accumulating the oil discharged from the hydraulic pump 1, and supplying the accumulated oil to the main brake devices 3, 4; a third accumulator 12 accumulating the oil discharged from the hydraulic pump 1, and supplying the accumulated oil to the parking brake device 5; a charging means 39 for controlling the accumulating states of these first to third accumulators 10 to 12; and first to third check valves 13 to 15 preventing a back flow of the oil to the charging means 39. And the brake hydraulic device for the working vehicle is equipped with one valve block 20 including the solenoid selector valve 8a, the charging means 39, and the first to third check valves 13 to 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a brake hydraulic device for a work vehicle that uses hydraulic pressure as a power source for operating the brake device.

  An example of this type of brake hydraulic device is disclosed in Patent Document 1. The technology described in Patent Document 1 includes an accumulator that stores oil for operating a brake device in a wheel loader or a hydraulic excavator, and supplies the oil stored in the accumulator to the brake device, thereby braking the brake device. Or in a brake-released state.

  Although not shown in the above-mentioned Patent Document 1, there is a brake device of this type provided with charging means for controlling the pressure accumulation state of the accumulator. The prior art provided with this charging means will be described with reference to FIG.

  The prior art shown in FIG. 2 includes a hydraulic pump 1 serving as an oil supply source, a tank 2 to which oil is returned, main brake devices 3 and 4 to which oil discharged from the hydraulic pump 1 is supplied, and a parking brake. And a device 5. The main brake devices 3 and 4 are brake devices that brake an axle (not shown), for example, and the parking brake device 5 is a brake device that brakes a part of a transmission mechanism that transmits a rotational force to the axle, for example.

  Also, a brake valve 6 that controls the flow of oil supplied to the main brake devices 3, 4, a brake pedal 7 that operates the brake valve 6, and an electromagnetic that controls the flow of oil supplied to the parking brake device 5. And a switching valve 8.

  Also, the first accumulator 10 that stores, for example, oil supplied to the main brake device 3 via the first pipeline 16a and the brake valve 6, and the main brake via the second pipeline 16b and the brake valve 6, for example. The oil is supplied to the parking brake device 5 via the second accumulator 11 in which the oil supplied to the device 4 is stored, the third conduit 17, the fourth conduit 18, the fifth conduit 19, and the electromagnetic switching valve 8. And a third accumulator 12 in which oil is stored.

  Furthermore, the charging means 9 which is provided in the 4th pipe line 18 connected to the hydraulic pump 1, and controls the pressure accumulation state of the 1st-3rd accumulator 10-12, from the 1st-3rd accumulator 10-12 side A first check valve 13, a second check valve 14, and a third check valve 15 that prevent backflow of oil to the charging means 9 are provided. The first check valve 13 is disposed in the first conduit 16a that guides oil to the first accumulator 10, and the second check valve 14 is disposed in the second conduit 16b that guides oil to the second accumulator 11, and the third check valve Reference numeral 15 denotes a fourth pipeline 18 connected to a third pipeline 17 that guides oil to the third accumulator 12.

  In the prior art shown in FIG. 2, when the brake valve 6 is held neutral as shown in FIG. 2, the A2 position and the A4 position are maintained, and the oil in the main brake devices 3 and 4 is returned to the tank 2. . As a result, the main brake devices 3 and 4 are brought into a brake release state. When the electromagnetic switching valve 8 is neutrally held as shown in FIG. 2, it is maintained at the B2 position, and the oil in the parking brake device 5 is returned to the tank 2. As a result, the parking brake device 5 enters a braking state.

  In such a state, the oil discharged from the hydraulic pump 1 passes through the charging means 9, the third check valve 15, the first check valve 13, and the second check valve 14, and the third accumulator 12 and the first accumulator 10. Are supplied to the second accumulator 11 and stored in these first to third accumulators 10-12. The pressure of the oil stored in this way is controlled by the charging means 9.

  For example, when the electromagnetic switching valve 8 is switched to the B1 position in an attempt to run the stopped vehicle, the oil in the third accumulator 12 is supplied to the parking brake device 5 via the electromagnetic switching valve 8, and this parking brake The device 5 is in a brake release state.

  In this way, when the brake of the parking brake device 5 is released and the vehicle is in a traveling state, when the brake pedal 7 is depressed, the brake valve 6 is switched to the A1 and A3 positions. As a result, the oil in the first accumulator 10 is supplied to the main brake device 3 via the first conduit 16 a and the brake valve 6, and the oil in the second accumulator 11 is supplied via the second conduit 16 b and the brake valve 6. And supplied to the main brake device 4. Therefore, the main brake devices 3 and 4 are in a braking state.

As described above, the main brake devices 3 and 4 and the parking brake device 5 are braked or released by the pressure oil discharged from the hydraulic pump 1.
JP 2001-158342 A

  In the prior art provided with the charging means 9 as shown in FIG. 2 described above, the electromagnetic switching valve 8 and the first to third check valves 13-15 including the charging means 9 are respectively independent components. Therefore, it is difficult to place the parts, and the design man-hour is increased. Moreover, since the 1st-5th pipe line 16a-19 is formed with a long rubber hose, since an installation operation takes time, a manufacturing man-hour increases. For these reasons, in the prior art shown in FIG. 2, the manufacturing cost tends to be high, and the apparatus cannot be made compact.

  The present invention has been made from the actual situation in the above-described prior art, and an object thereof is to provide a brake hydraulic device for a work vehicle that can reduce the design man-hours and the production man-hours.

  In order to achieve the above object, the present invention provides a main brake device and a parking brake device that are operated by supplying and discharging oil, a hydraulic pump that is a supply source of the oil, and a flow of oil to the main brake device. Brake valve for controlling, switching valve for controlling the flow of oil to the parking brake device, accumulator for accumulating the oil discharged from the hydraulic pump and supplying the accumulated oil to the main brake device and the parking brake device And a brake hydraulic device for a work vehicle, comprising: a charging means for controlling a pressure accumulation state of the accumulator; and a check valve for preventing a reverse flow of oil from the accumulator side to the charging means. One valve block including the charging unit and the check valve is provided.

  According to the present invention configured as described above, the switching valve for controlling the parking brake device, the charging means for controlling the pressure accumulation state of the accumulator, and the check valve for preventing the backflow of oil to the charging means are provided as one valve. Since it is built in the block, it is easy to place parts and reduce design man-hours. Further, since the number of rubber hoses can be reduced, the work for attaching the rubber hoses is reduced. This can reduce the number of manufacturing steps.

  Further, the present invention is characterized in that, in the above invention, the accumulator is directly attached to the valve block without interposing a tubular body.

  In the present invention configured as described above, the pipe connected to the accumulator can also be formed in the valve block. Therefore, the rubber hose is not necessary, and the design man-hours and production man-hours can be reduced.

  Further, in the present invention according to the above-mentioned invention, the accumulator includes three accumulators: a pair of accumulators arranged in relation to the main brake device and a single accumulator arranged in association with the parking brake device. In addition, each of these accumulators is attached to different surfaces among the plurality of surfaces forming the valve block.

  In the present invention, since the switching valve, the charging means, and the check valve are incorporated in one valve block, the arrangement of parts is simplified, the design man-hour can be reduced as compared with the conventional one, and the installation work of the rubber hose can be reduced. Since the number can be reduced, the number of manufacturing steps can be reduced as compared with the conventional method. As a result, the manufacturing cost can be reduced and the apparatus can be made compact.

  The best mode for carrying out a brake hydraulic device for a work vehicle according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a hydraulic circuit diagram showing an embodiment of a brake hydraulic device for a work vehicle according to the present invention. This embodiment is provided in a work vehicle such as a wheel loader or a hydraulic excavator, and the same components as those shown in FIG. 2 described above are denoted by the same reference numerals.

  That is, this embodiment also includes a hydraulic pump 1 that is an oil supply source, a tank 2, main brake devices 3 and 4, and a parking brake device 5, as in the prior art shown in FIG. 2 described above. Yes. A brake valve 6 for controlling the flow of oil supplied to the main brake devices 3 and 4 and a brake pedal 7 for operating the brake valve 6 are provided. Furthermore, the 1st accumulator 10 in which the oil supplied to the main brake device 3 is stored, the 2nd accumulator 11 in which the oil supplied to the main brake device 4 is stored, and the oil supplied to the parking brake device 5 are stored. And a third accumulator 12.

  In the present embodiment, in particular, the electromagnetic switching valve 8a that controls the flow of oil supplied to the parking brake device 5, the charging means 39 that controls the pressure accumulation state of the first to third accumulators 10-12, One valve block 20 including a first check valve 13, a second check valve 14, and a third check valve 15 that prevent backflow of oil from the third accumulator 10-12 side to the charging means 39 is provided. .

  Further, the first to third accumulators 10-12 are directly attached to the valve block 20 without interposing a tubular body such as a rubber hose. For example, each of the first to third accumulators 10-12 is attached to a different surface among a plurality of surfaces forming the valve block 20.

  Various passages are formed in the valve block 20 described above. That is, a first passage 40 that guides oil to the first accumulator 10 and is provided with the first check valve 13; a second passage 41 that guides oil to the second accumulator 11 and is provided with the second check valve 14; The fourth passage for guiding the pressure oil discharged from the hydraulic pump 1, the third passage 42 connected to the first passage 40 and the second passage 41, the fourth passage 43 for guiding the oil to the third accumulator 12, and the fourth passage. 43 and the 5th channel | path 44 which connects the electromagnetic switching valve 8a.

  In addition, a third passage 42 that guides the discharge pressure of the hydraulic pump 1 is provided in one control unit of a pressure control valve 21 that selectively guides oil to the first accumulator 10, the second accumulator 11, and the third accumulator 12. A sixth passage 45 having one end connected and the other end connected to the third passage 42; the other of the relief valve 22 and the pressure control valve 21 for controlling the pressure of the oil stored in the first accumulator 10 and the second accumulator 11 A seventh passage 46 that connects to the control section of the first passage 46, an eighth passage 47 that connects the seventh passage 46 and the third passage 42 portion on the downstream side of the pressure control valve 21, a relief valve 42, and the tank 2 And a ninth passage 48 to be connected.

  A throttle 26 is provided in a sixth passage 45 that connects one control portion of the pressure control valve 21 and the third passage 42 that guides the discharge pressure of the hydraulic pump 1. One end is connected to the seventh passage 46 that connects the other control part of the pressure control valve 21 and the relief valve 22, and the throttle 28 is also arranged in the eighth passage 47 that the other end is connected to the third passage 42. is there. A throttle 29 is also provided in a portion of the third passage 42 located between the connection point between the eighth passage 47 and the third passage 42 and the pressure control valve 21.

  The valve block 20 includes a tenth passage 49 that connects the pressure control valve 21 and the tank 2, an eleventh passage 50 that connects the tenth passage 49 and the electromagnetic switching valve 8a, and a tenth passage 49. The 12th channel | path 51 which connects the 4th channel | path 43 which guides pressure oil to the 3rd accumulator 12 is provided.

  The third check valve 15 described above is provided in the twelfth passage 51. Further, the third accumulator 12 is stored in the portion of the tenth passage 49 located between the connection point of the twelfth passage 51 and the tenth passage 49 and the connection point of the first passage 50 and the tenth passage 49. A relief valve 23 for controlling the oil pressure is provided.

  The valve block 20 includes a pilot passage 52 having one end connected to the control unit of the relief valve 22 and the other end connected to the first passage 40.

  The above-described pressure control valve 21, relief valve 22, throttles 26, 28, 29, etc. constitute a charging means 39.

  As in the prior art shown in FIG. 2 described above, this embodiment configured as described above is also maintained at the A2 position and the A4 position when the brake valve 6 is held neutral as shown in FIG. The oil in the main brake devices 3 and 4 is returned to the tank 2. As a result, the main brake devices 3 and 4 are brought into a brake release state. When the electromagnetic switching valve 8a is neutrally held as shown in FIG. 1, the oil is stored in the C2 position and the oil in the parking brake device 5 is returned to the tank 2. As a result, the parking brake device 5 enters a braking state.

  In such a state, the oil discharged from the hydraulic pump 1 is, for example, the position D1, the throttle 29, the first and second check valves 13, 14 of the pressure control valve 21 included in the third passage 42, the charging means 39. The first and second accumulators 10 and 11 are supplied via the first and second passages 40 and 41, and oil is stored in these first and second accumulators 10 and 11.

  Further, when the pressure in the sixth passage 45 increases as the pressure in the third passage 42 increases, the pressure control valve 21 is switched to the D2 position, and the oil discharged from the hydraulic pump 1 is supplied to the tenth passage 49, The oil is supplied to the third accumulator 12 through the 12 passage 51, the third check valve 15, and the fourth passage 43, and oil is stored in the third accumulator 12.

  Therefore, for example, when the electromagnetic switching valve 8a is switched to the C1 position in order to drive the vehicle that is stopped, the oil in the third accumulator 12 passes through the fourth passage 43, the fifth passage 44, and the electromagnetic switching valve 8a. Is supplied to the parking brake device 5, and the parking brake device 5 is in a brake-released state.

  Thus, when the brake of the parking brake device 5 is released and the vehicle is in a traveling state, when the brake pedal 7 is depressed, the brake valve 6 is switched to the positions A1 and A3 in FIG. Thus, the oil in the first accumulator 10 is supplied to the main brake device 3 via the first passage 40 and the brake valve 6, and the oil in the second accumulator 11 is supplied to the main brake device 6 via the second passage 41 and the brake valve 6. It is supplied to the brake device 4. Therefore, the main brake devices 3 and 4 are in a braking state.

  According to the present embodiment configured as described above, the electromagnetic switching valve 8a that controls the flow of oil supplied to the parking brake device 5 and the charging that controls the pressure accumulation state of the first to third accumulators 10-12. One valve block 20 includes means 39, first to third check valves 13-15 for preventing backflow of oil to the charging means 39, throttles 26, 28, 29, and passages 40-51. Since it is made to do, component arrangement becomes simple and a design man-hour can be reduced.

  In addition, the first to third accumulators 13-15 are directly attached to the valve block 20 without interposing a tubular body, and are attached to different surfaces of the plurality of surfaces forming the valve block 20, so that the first The pipes connected to the first to third accumulators 13-15 can also be formed in the valve block 20 as the passages 40, 41, 43, etc. as described above. Accordingly, the rubber hose can be omitted, and the rubber hose mounting operation can be eliminated. This can reduce the number of manufacturing steps.

  As a result, the present embodiment can reduce the manufacturing cost and realize a compact apparatus.

1 is a hydraulic circuit diagram showing an embodiment of a brake hydraulic device for a work vehicle according to the present invention. It is a hydraulic circuit diagram which shows the brake hydraulic device of the working vehicle provided with the conventional charging means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Tank 3 Main brake device 4 Main brake device 5 Parking brake device 6 Brake valve 7 Brake pedal 8a Electromagnetic switching valve 10 1st accumulator 11 2nd accumulator 12 3rd accumulator 13 1st check valve 14 2nd check valve 15 Third check valve 20 Valve block 20a surface 20b surface 20c surface 21 Pressure control valve 22 Relief valve 23 Relief valve 26 Restriction 28 Restriction 29 Restriction 39 Charging means 40 First passage 41 Second passage 42 Third passage 43 Fourth passage 44 5th passage 45 6th passage 46 7th passage 47 8th passage 48 9th passage 49 10th passage 50 11th passage 51 12th passage 52 Pilot passage

Claims (3)

A main brake device that operates by supplying and discharging oil, a parking brake device, a hydraulic pump that is a supply source of the oil, a brake valve that controls the flow of oil to the main brake device, and a parking brake device Switching valve for controlling the flow of oil, accumulator for accumulating the oil discharged from the hydraulic pump and supplying the accumulated oil to the main brake device and the parking brake device, and charging for controlling the accumulator pressure accumulation state And a brake hydraulic device for a work vehicle comprising a check valve for preventing backflow of pressure oil from the accumulator to the charging means,
A brake hydraulic device for a work vehicle, comprising a valve block including the switching valve, the charging means, and the check valve. In the invention of claim 1,
A brake hydraulic device for a work vehicle, wherein the accumulator is directly attached to the valve block without interposing a tubular body. In the invention of claim 2,
The accumulator comprises three accumulators, a pair of accumulators arranged in relation to the main brake device and a single accumulator arranged in relation to the parking brake device, and each of these accumulators is A brake hydraulic device for a work vehicle, wherein the brake hydraulic device is attached to different surfaces of the plurality of surfaces forming the valve block.

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