A Hydraulic Braking Release Control System for a Wheel-End Electric Drive Reducer

Abstract

The present invention discloses a hydraulic braking release control system for a wheel-side electric drive speed reducer, which relates to a braking system. It includes a one-way oil supply device for providing high-pressure hydraulic oil; an accumulator for storing the high-pressure hydraulic oil; a zero-leakage reversing valve, which is used to open the pipeline between the accumulator and the spring parking brake when receiving a braking release instruction, so that the high-pressure hydraulic oil is delivered to the spring parking brake; and when receiving a braking instruction, cut off the pipeline between the accumulator and the spring parking brake; a control valve is installed between the connecting pipeline of the spring parking brake and the one-way oil supply device. The present invention saves space, reduces costs, has a compact structure, avoids the power loss caused by the need for the oil pump to always operate at the rated power in the traditional braking release system, and plays a role in saving energy.

Description

Technical Field

[0001] The present invention relates to a braking system, and more specifically, to a hydraulic braking release control system for a wheel-side electric drive speed reducer. Background Art

[0002] Currently, the engines of traditional skid steer loaders are used as power sources, and the travel is driven by a hydraulic motor. When traveling, the system has high-pressure hydraulic oil to drive the travel motor, so high-pressure hydraulic oil can be provided for the braking system in real time to release the parking brake of the brake disc by the spring parking device.

[0003] However, after the skid steer loader is converted to electric drive, there are generally two braking methods. First, when braking is required, braking can be achieved through a travel reducer connected to the electric motor. Second, high-pressure hydraulic oil is used to drive the spring parking device to brake or release the brake of the brake disc. Due to the high reliability of the oil pressure parking system, the current mainstream braking system still uses oil pressure braking.

[0004] Therefore, the parking braking system of the skid steer loader after the electric conversion still requires an oil tank and an oil pump. And to ensure the timeliness of the spring brake action, when the whole vehicle is working, the oil pump needs to be always in the rated power working state to provide high-pressure hydraulic oil at any time. When the parking brake needs to be released, the oil pump delivers high-pressure hydraulic oil to the spring parking device to release the brake on the brake disc; when braking is required, only the injection of hydraulic oil needs to be stopped and the hydraulic oil in the spring parking device is discharged.

[0005] However, because the oil pump is always in the rated working state when the whole machine is working. This is very wasteful of electric energy on a pure electric skid steer loader and is not conducive to the endurance of the pure electric skid steer loader. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a hydraulic braking release control system for a wheel-side electric drive speed reducer in view of the deficiencies of the prior art, which avoids the electric energy loss caused by the need for the oil pump to always be in the rated power working state in the traditional braking release system and plays a role in saving energy.

[0007] A hydraulic braking release control system for a wheel-side electric drive speed reducer according to the present invention includes:

[0008] A one-way oil supply device for providing high-pressure hydraulic oil;

[0009] An accumulator for storing the high-pressure hydraulic oil;

[0010] A zero-leakage reversing valve is used to open the pipeline between the accumulator and the spring parking brake when receiving a brake release command, so that the high-pressure hydraulic oil is delivered to the spring parking brake; and cut off the pipeline between the accumulator and the spring parking brake when receiving a brake command.

[0011] A control valve is installed between the connecting pipeline of the spring parking brake and the one-way oil supply device.

[0012] The one-way oil supply device includes an oil tank, an oil pump and a first one-way valve; the input end of the oil pump is communicated with the oil tank, the output end of the oil pump is connected with the input end of the first one-way valve through an oil pipe, and the output end of the first one-way valve is connected with the accumulator.

[0013] The one-way oil supply device further includes a pressure reducing valve, and the pressure reducing valve is installed on the oil pipe connecting the oil pump and the first one-way valve.

[0014] The output end of the oil pump is connected with the hydraulic cylinder of the skid steer loader through a reversing valve.

[0015] A pressure switch is installed on the pipeline connecting the zero-leakage reversing valve and the spring parking brake, and the pressure switch is electrically connected with the traveling motor through an ECU.

[0016] The zero-leakage reversing valve is composed of an electromagnetic reversing valve and a valve core self-locking structure for locking and positioning the valve core of the electromagnetic reversing valve.

[0017] The valve core self-locking structure includes a valve core clamping solenoid valve, a valve rod, a spring and a positioning groove opened on the valve core of the electromagnetic reversing valve; the valve core clamping solenoid valve is fixedly installed at one end of the electromagnetic reversing valve, the valve rod is fixedly installed at one end of the valve core of the valve core clamping solenoid valve, and the valve rod sequentially passes through the housings of the valve core clamping solenoid valve and the electromagnetic reversing valve movably and contacts the valve core of the electromagnetic reversing valve; a limiting piece is fixedly arranged on the side wall of one end of the valve rod located inside the electromagnetic reversing valve, and the spring is sleeved on the valve rod above the limiting piece.

[0018] A second one-way valve is installed on the pipeline connecting the spring parking brake and the zero-leakage reversing valve.

[0019] Beneficial effects

[0020] The advantages of the present invention are as follows:

[0021] 1. Through the settings of the accumulator and the zero-leakage reversing valve, only high-pressure hydraulic oil needs to be reserved in the accumulator in advance, so that when it is necessary to release the brake of the brake disc, there is no need to start the oil pump again, and only the hydraulic oil in the accumulator needs to be sent to the spring brake. It avoids the power consumption caused by the need for the oil pump of the traditional brake release system to always work at the rated power, and plays a role in saving energy.

[0022] 2. The valve between the accumulator and the spring brake adopts a zero-leakage directional valve, which has a small leakage volume. After the spool of the valve acts, it is not necessary for the zero-leakage directional valve to work continuously, further reducing energy consumption.

[0023] 3. The hydraulic cylinder and the accumulator share one oil pump, which plays the role of saving space, reducing costs and having a compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the hydraulic brake release control system of the present invention;

[0025] Figure 2 It is a schematic structural diagram of the zero-leakage directional valve of the present invention when the self-locking is released;

[0026] Figure 3 It is a schematic structural diagram of the zero-leakage directional valve of the present invention when it is in the self-locking state;

[0027] Figure 4 is Figure 2 The enlarged structural diagram at position A in

[0028] Wherein: 1 - oil tank, 2 - oil pump, 3 - directional valve, 4 - hydraulic cylinder, 5 - pressure reducing valve, 6 - first one-way valve, 7 - accumulator, 8 - pressure switch, 9 - zero-leakage directional valve, 10 - spring parking brake, 11 - traveling motor, 91 - electromagnetic directional valve, 92 - spool, 93 - spool clamping solenoid valve, 94 - valve stem, 95 - spring, 96 - limit piece, 97 - positioning groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following is a further description of the present invention in conjunction with embodiments, but it does not constitute any limitation to the present invention. Any limited modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0030] Refer to Figures 1 - 4 , a wheel-side electric drive reducer hydraulic brake release control system of the present invention includes a one-way oil supply device, an accumulator 7, a zero-leakage directional valve 9 and a control valve.

[0031] Among them, the one-way oil supply device is used to provide high-pressure hydraulic oil. The one-way oil supply device includes an oil tank 1, an oil pump 2, a pressure reducing valve 5 and a first one-way valve 6.

[0032] The input end of the oil pump 2 is connected to the fuel tank 1, and the output end of the oil pump 2 is connected to the input end of the first one-way valve 6 through an oil pipe. The pressure reducing valve 5 is installed on the oil pipe connecting the oil pump 2 and the first one-way valve 6. The setting of the pressure reducing valve 5 can prevent the oil pressure input into the accumulator 7 from being too high, resulting in the problem that the oil pressure in the accumulator 7 exceeds the set pressure value. The output end of the first one-way valve 6 is connected to the accumulator 7. The first one-way valve 6 is used to prevent the hydraulic oil in the accumulator 7 from flowing back to the fuel tank 1.

[0033] The accumulator 7 is used to store high-pressure hydraulic oil and deliver the high-pressure hydraulic oil outward.

[0034] In addition, the input end of the hydraulic cylinder 4 is connected to the output end of the oil pump 2 through the reversing valve 3. Among them, the hydraulic cylinder 4 is a hydraulic cylinder on the skid steer loader for lifting the bucket. That is, the hydraulic cylinder 4 and the accumulator 7 in this embodiment share an oil pump 2. When the skid steer loader starts, the oil pump 2 rotates. When the hydraulic cylinder 4 does not act, the reversing valve 3 is in the neutral position, and the oil of the oil pump 2 directly flows back to the fuel tank. The output port pressure of the oil pump 2 is very low and cannot supply oil to the accumulator 7. When the reversing valve 3 is reversed, the oil return path of the oil pump 2 to the fuel tank is cut off, and the output port pressure of the oil pump 2 increases, and then hydraulic oil is filled into the accumulator 7 or the hydraulic cylinder 4. Through such a setting, the function of using a single pump for two purposes is realized, which not only saves space, reduces costs, but also improves the overall compactness of the system.

[0035] The zero-leakage reversing valve 9 is used to open the pipeline between the accumulator 7 and the spring parking brake 10 when receiving the brake release instruction, so that high-pressure hydraulic oil is delivered to the spring parking brake 10; and when receiving the brake instruction, the pipeline between the accumulator 7 and the spring parking brake 10 is cut off.

[0036] In this embodiment, the zero-leakage reversing valve 9 is composed of an electromagnetic reversing valve 91 and a valve core self-locking structure for locking and positioning the valve core 92 of the electromagnetic reversing valve 91. The electromagnetic reversing valve 91 adopts the DLEH or DLEHM type.

[0037] Among them, the valve core self-locking structure includes a valve core clamping solenoid valve 93, a valve rod 94, a spring 95, and a positioning groove 97 opened on the valve core 92 of the electromagnetic reversing valve 91. The valve core clamping solenoid valve 93 is fixedly installed at one end of the electromagnetic reversing valve 91. The valve rod 94 is fixedly installed at one end of the valve core of the valve core clamping solenoid valve 93. The valve rod 94 sequentially passes through the valve core clamping solenoid valve 93 and the housing of the electromagnetic reversing valve 91 movably and contacts the valve core 92 of the electromagnetic reversing valve 91. A limiting piece 96 is fixedly arranged on the side wall of the end of the valve rod 94 located inside the electromagnetic reversing valve 91. The spring 95 is sleeved on the valve rod 94 above the limiting piece 96.

[0038] When the electromagnetic reversing valve 91 is energized, the valve core 92 of the electromagnetic reversing valve 91 acts, and the position of the valve core 92 will be from as Figure 2The position shown is moved to as Figure 3 shown, and the internal passage of the electromagnetic directional control valve 91 is conducted. Moreover, at this time, since the positioning groove 97 on the valve core 92 corresponds to the position of the valve rod 94, the valve rod 94 will fall into the positioning groove 97 under the action of the spring 95, realizing the self-locking of the valve core 92, so that when the electromagnetic directional control valve 91 loses power, the valve core 92 will not reset. That is, the hydraulic oil in the accumulator 7 can be supplied to the spring parking brake 10 through the electromagnetic directional control valve 91, so that the spring parking brake 10 is always in the parking release state.

[0039] After the traveling motor 11 stops rotating, the ECU sends an electrical signal to the valve core clamping solenoid valve 93 to make it energized first and then de-energized. When the valve core clamping solenoid valve 93 is energized, the valve core of the valve core clamping solenoid valve 93 moves upward, which will drive the valve rod 94 to move upward and disengage from the positioning groove 97. At this time, the valve core 92 of the electromagnetic directional control valve 91 can be reset under the action of its internal return spring, so that the inner cavity of the electromagnetic directional control valve 91 is in the off state, and further cut off the supply of hydraulic oil to the spring parking brake 10.

[0040] The control valve is installed between the connecting pipeline of the spring parking brake 10 and the fuel tank 1. When it is necessary to release the braking state of the brake disc by the spring parking brake 10, the accumulator 7 supplies oil to the spring parking brake 10, and the control valve is in the closed state, so that the pressure state of the hydraulic oil in the spring parking brake 10 is the same as that of the hydraulic oil in the accumulator 7. When it is necessary for the spring parking brake 10 to be in the braking state of the brake disc, the control valve opens to discharge the hydraulic oil in the spring parking brake 10 into the fuel tank 1, so that the spring parking brake 10 resets and brakes the brake disc of the skid loader.

[0041] To prevent the hydraulic oil in the spring parking brake 10 from flowing back, a second one-way valve is installed on the pipeline connecting the spring parking brake 10 and the zero-leakage directional control valve 9.

[0042] A pressure switch 8 is installed on the pipeline connecting the zero-leakage directional control valve 9 and the spring parking brake 10. The pressure switch 8 is electrically connected to the traveling motor 11 through the ECU. The pressure switch 8 is used to control the action of the traveling motor 11. When there is high-pressure hydraulic oil on the pipeline connecting the zero-leakage directional control valve 9 and the spring parking brake 10, the pressure switch 8 closes. After the ECU receives the electrical signal sent by the pressure switch 8, it issues a control signal to drive the traveling motor 11 to start.

[0043] The working principle of the present invention is as follows: When the skid steer loader starts, the oil pump 2 rotates. When the hydraulic cylinder 4 does not act, the directional control valve 3 is in the neutral position, and the oil from the oil pump 2 directly flows back to the fuel tank. When the directional control valve 3 is switched to make the pipeline between the oil pump 2 and the accumulator 7 conduct, the oil pump 2 transports the hydraulic oil in the fuel tank 1 to the accumulator 7. After the accumulator 7 is filled with high-pressure hydraulic oil, the directional control valve 3 is switched again to make it in the neutral position. Since the oil pumped out by the oil pump 2 flows back to the fuel tank 1 when the directional control valve 3 is in the neutral position, at this time, the oil pump 2 can be in the closed or idle operation state to reduce the power consumption and play a role in saving energy.

[0044] When it is necessary to release the braking of the brake disc by the spring parking brake 10, the spool 92 of the zero-leakage directional control valve 9 acts to make the pipeline between the accumulator 7 and the spring parking brake 10 conduct, and the control valve is in the closed state. The accumulator 7 supplies oil to the spring parking brake 10 to make the spring parking brake 10 release the braking of the brake disc. When it is necessary to brake the brake disc, the spool 92 of the zero-leakage directional control valve 9 resets to cut off the pipeline between the accumulator 7 and the spring parking brake 10, and the control valve is in the open state. The hydraulic oil in the spring parking brake 10 flows back to the fuel tank 1 to make the spring parking brake 10 reset and brake the brake disc.

[0045] The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which will not affect the implementation effect of the present invention and the practicability of the patent.

Claims

1. A hydraulic braking release control system for a wheel-side electric drive speed reducer, characterized in that, Comprising: A one-way oil supply device for providing high-pressure hydraulic oil; An accumulator (7) for storing the high-pressure hydraulic oil; A zero-leakage reversing valve (9) which, upon receiving a brake release command, opens the pipeline between the accumulator (7) and the spring parking brake (10) to enable the high-pressure hydraulic oil to be delivered to the spring parking brake (10); and upon receiving a brake command, cuts off the pipeline between the accumulator (7) and the spring parking brake (10); A control valve installed between the pipeline connecting the spring parking brake (10) and the one-way oil supply device; The one-way oil supply device includes an oil tank (1), an oil pump (2), and a first one-way valve (6); the input end of the oil pump (2) is connected to the oil tank (1), the output end of the oil pump (2) is connected to the input end of the first one-way valve (6) through an oil pipe, and the output end of the first one-way valve (6) is connected to the accumulator (7); The zero-leakage reversing valve (9) consists of an electromagnetic reversing valve (91) and a valve core self-locking structure for locking and positioning the valve core (92) of the electromagnetic reversing valve (91); The valve core self-locking structure includes a valve core clamping solenoid valve (93), a valve rod (94), a spring (95), and a positioning groove (97) formed on the valve core (92) of the electromagnetic reversing valve (91); the valve core clamping solenoid valve (93) is fixedly installed at one end of the electromagnetic reversing valve (91), the valve rod (94) is fixedly installed at one end of the valve core of the valve core clamping solenoid valve (93), and the valve rod (94) sequentially passes through the housings of the valve core clamping solenoid valve (93) and the electromagnetic reversing valve (91) movably and contacts the valve core (92) of the electromagnetic reversing valve (91); a limiting piece (96) is fixedly provided on the side wall of one end of the valve rod (94) located inside the electromagnetic reversing valve (91), and the spring (95) is sleeved on the valve rod (94) above the limiting piece (96).

2. The hydraulic braking release control system of a wheel-side electric drive speed reducer according to claim 1, wherein, The output end of the oil pump (2) is connected to the hydraulic cylinder (4) of the skid steer loader through a reversing valve (3).

3. The hydraulic braking release control system for a wheel hub motor-driven speed reducer according to claim 1, wherein The one-way oil supply device further includes a pressure reducing valve (5), and the pressure reducing valve (5) is installed on the oil pipe connecting the oil pump (2) and the first one-way valve (6).

4. The hydraulic braking release control system for a wheel hub motor-driven speed reducer according to claim 1, wherein, A pressure switch (8) is installed on the pipeline connecting the zero-leakage reversing valve (9) and the spring parking brake (10), and the pressure switch (8) is electrically connected to the travel motor (11) through an ECU.

5. The hydraulic brake release control system for a wheel-side electric drive speed reducer according to claim 1, characterized in that, A second one-way valve is installed on the pipeline connecting the spring parking brake (10) and the zero-leakage reversing valve (9).

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