Engineering vehicle chassis hydraulic control system, engineering vehicle chassis and engineering vehicle

Abstract

The utility model provides an engineering vehicle chassis hydraulic control system, an engineering vehicle chassis and an engineering vehicle, and belongs to the technical field of vehicles. The engineering vehicle chassis hydraulic control system comprises an oil pump and an energy accumulator, an electromagnetic unloading valve is arranged on the energy accumulator or on an oil way between the energy accumulator and the oil pump, and the engineering vehicle chassis hydraulic control system further comprises an electric control module which is connected with the electromagnetic unloading valve and used for outputting a starting instruction to an engine starting device. The electric control module can control the electromagnetic unloading valve to be powered on / off to switch the electromagnetic unloading valve to an unloading position while outputting a starting instruction, and controls the electromagnetic unloading valve to be powered off / on to switch the electromagnetic unloading valve to a cut-off position after an unloading set time. When the engine is started, the electromagnetic unloading valve is switched to the unloading position, pressure in a hydraulic system can be released, on-load starting of the engine is avoided, flameout of the engine is prevented, and the experience feeling of a user, the service life of the engine and the running reliability of the whole machine are guaranteed.

Description

Technical Field

[0001] The utility model relates to an engineering vehicle chassis hydraulic control system, an engineering vehicle chassis and an engineering vehicle, belonging to the technical field of vehicles. Background Art

[0002] The chassis of engineering vehicles often adopts hydraulic control, and the hydraulic control objects include one or more of the service brake, parking brake and steering. For example, the Chinese utility model patent with the authorization announcement number CN217804205U discloses a dual-purpose chassis hydraulic system, a hydraulic chassis and a dual-purpose vehicle for road and rail. The chassis hydraulic system includes a running hydraulic unit, a steering brake unit and a guide hydraulic unit, wherein the steering brake unit includes a filling valve, a steering gear, a steering cylinder, a clutch and a brake, and the filling valve is used to supply oil to hydraulic facilities such as accumulators, brakes and clutches. The brakes include front axle service brakes, rear axle service brakes and parking brakes. An accumulator is provided on the oil circuits connected between the filling valve and the front axle service brakes and the rear axle service brakes, and the accumulator provides an oil source for the front axle service brakes and the rear axle service brakes. A brake valve is also provided on the oil circuit between the front axle service brake, the rear axle service brake and the accumulator. When braking is required during driving, the operator steps on the brake valve (i.e., the foot brake), and the accumulator provides an oil source for the service brake to realize the braking operation.

[0003] In addition, the running hydraulic unit includes a two-gear series pump, which includes a front pump and a rear pump. Both the front pump and the rear pump are quantitative pumps. The front pump is connected to the oil inlet of the steering gear, and the rear pump is connected to the oil inlet of the filling valve. At present, the start of the pump in the chassis hydraulic system is generally powered by the engine, that is, when the engine is started, the quantitative pump will be driven to load the chassis hydraulic system. However, due to the presence of high-pressure oil in the accumulator and the function of the filling valve itself to prevent oil backflow, the chassis hydraulic system itself is in a high-pressure state before the engine is started, which will cause the engine to start under load and easily stall the engine. This problem is particularly prominent in machines working in plateau areas (where oxygen is thin), which not only affects the user experience, but also reduces the service life of the engine, and also affects the driving reliability of the entire machine.

[0004] Therefore, in the prior art, in order to start the engine smoothly, the user can only release the chassis hydraulic system pressure in advance by stepping on the foot brake before starting the engine, that is, by stepping on the foot brake, the accumulator provides high-pressure oil for the service brake, and then releases the foot brake, and the oil in the service brake flows back to the oil tank. In this way, by stepping on the foot brake intermittently, the chassis hydraulic system pressure can be released, and when the engine is started later, the load start can be avoided. However, this method requires different users to be aware of the above operation process, and the users need to have sufficient consciousness, but in fact not all users understand this unconventional engine starting method, and even if they know it, due to operating habits, they will directly ignite and start the engine and miss the above operation process, resulting in the situation that the engine is still started under load. Utility Model Content

[0005] The purpose of the utility model is to provide a hydraulic control system for a chassis of an engineering vehicle, so as to solve the problem that the existing chassis hydraulic control system is in a high-pressure state before the engine is started, which causes the engine to start under load and easily stalls the engine, thereby affecting the user experience, the engine service life and the driving reliability of the whole machine. The prior art simply relies on the user's own cognition and consciousness to pre-release the chassis hydraulic system pressure by stepping on the foot brake before the engine starts, but there is a problem that the user's cognition is not in place and negligence still causes the engine to start under load; the purpose of the utility model is also to provide an engineering vehicle chassis and an engineering vehicle, so as to solve the above problems.

[0006] In order to achieve the above purpose, the hydraulic control system of the engineering vehicle chassis in the utility model adopts the following technical solutions:

[0007] The hydraulic control system of the chassis of an engineering vehicle includes an oil pump for being connected to the engine transmission and an accumulator for providing an oil source for the brake. An electromagnetic unloading valve is arranged on the accumulator or on the oil circuit between the accumulator and the oil pump. The electromagnetic unloading valve has an unloading position for supplying the oil in the accumulator or the oil circuit back to the oil tank and a cut-off position for preventing the oil from flowing back to the oil tank. The hydraulic control system of the chassis of the engineering vehicle also includes an electronic control module connected to the electromagnetic unloading valve and used to output a start command to the engine starting device. The electronic control module can control the electromagnetic unloading valve to be on / off while outputting the start command so that it switches to the unloading position, and control the electromagnetic unloading valve to be off / on after the unloading set time so that it switches to the cut-off position.

[0008] The beneficial effect of the above technical solution is that the utility model provides an improved hydraulic control system for the chassis of engineering vehicles, the improvement is that an electromagnetic unloading valve is arranged on the accumulator or on the oil circuit between the accumulator and the oil pump, and the hydraulic control system also includes an electronic control module connected to the electromagnetic unloading valve and used to output a start command to the engine starting device, the electronic control module can control the engine start by outputting the start command, and can also control the electromagnetic unloading valve to turn on / off to switch it to the unloading position while outputting the start command. When the accumulator or the oil circuit is in the unloading position, the oil in the oil circuit flows back to the oil tank, releasing the pressure in the hydraulic system, so that the engine can be prevented from starting with load, thereby preventing the engine from stalling, and thus ensuring the user experience, the service life of the engine and the driving reliability of the whole machine. At the same time, the electronic control module can also control the electromagnetic unloading valve to turn off / on after the unloading setting time to switch it to the cut-off position, preventing the oil from flowing back to the oil tank, realizing the function of normal filling of the accumulator, and ensuring the normal operation of the hydraulic control system.

[0009] By means of the electromagnetic unloading valve and the electronic control module in the utility model, the pressure in the hydraulic system can be released at the same time as the engine is started, thus preventing the engine from starting under load. There is no need to rely on the user's personal cognition and consciousness to step on the foot brake in vain before starting the engine, and the situation of missing unloading and causing the engine to start under load will no longer occur, thereby achieving higher reliability.

[0010] Furthermore, the engineering vehicle chassis hydraulic control system also includes a filling valve for filling the accumulator, and the electromagnetic unloading valve is connected to the oil circuit between the filling valve and the oil pump.

[0011] Furthermore, a one-way valve structure is arranged in the electromagnetic unloading valve, and the one-way valve structure forms the cut-off position.

[0012] Furthermore, the electromagnetic unloading valve is provided with a handle for manually controlling the switching between the unloading position and the cut-off position.

[0013] Furthermore, the engineering vehicle chassis hydraulic control system also includes a relief valve arranged in parallel with the electromagnetic unloading valve.

[0014] Furthermore, the unloading setting time is 3 to 7 seconds.

[0015] Furthermore, the electronic control module includes a command unit and an electrical control unit. The command unit is used to output a start command to the engine starting device and to output a command signal to the electrical control unit. The electrical control unit is used to receive the command signal and output a control signal to the electromagnetic unloading valve after logically processing the command signal to control the on / off power of the electromagnetic unloading valve.

[0016] Furthermore, the engineering vehicle chassis hydraulic control system also includes a filling valve for filling the accumulator and a steering gear for realizing chassis steering, and the filling valve has a filling port connected to the oil inlet of the steering gear.

[0017] In order to achieve the above-mentioned purpose, the engineering vehicle chassis in the utility model adopts the following technical solutions:

[0018] The chassis of an engineering vehicle includes a chassis hydraulic control system, which includes an oil pump for being connected to an engine transmission and an accumulator for providing an oil source for a brake. An electromagnetic unloading valve is provided on the accumulator or on an oil circuit between the accumulator and the oil pump. The electromagnetic unloading valve has an unloading position for supplying oil in the accumulator or the oil circuit back to a fuel tank and a cut-off position for preventing the oil from flowing back to the fuel tank. The chassis hydraulic control system also includes an electronic control module connected to the electromagnetic unloading valve and used for outputting a start command to an engine starter. The electronic control module can control the electromagnetic unloading valve to be on / off while outputting the start command so that it switches to the unloading position, and control the electromagnetic unloading valve to be off / on after a set unloading time so that it switches to the cut-off position.

[0019] The beneficial effect of the above technical solution is that: the utility model provides an improved engineering vehicle chassis, the improvement is that an electromagnetic unloading valve is arranged on the accumulator of the chassis hydraulic control system or on the oil circuit between the accumulator and the oil pump, and the hydraulic control system also includes an electronic control module connected to the electromagnetic unloading valve and used to output a start command to the engine starting device, the electronic control module can control the engine start by outputting the start command, and can also control the electromagnetic unloading valve to turn on / off to switch it to the unloading position while outputting the start command. When the accumulator or the oil circuit is in the unloading position, the oil in the oil circuit flows back to the oil tank, releasing the pressure in the hydraulic system, so that the engine can be prevented from starting with load, thereby preventing the engine from stalling, and thus ensuring the user experience, the service life of the engine and the driving reliability of the whole machine. At the same time, the electronic control module can also control the electromagnetic unloading valve to turn off / on after the unloading setting time to switch it to the cut-off position, preventing the oil from flowing back to the oil tank, realizing the function of normal filling of the accumulator, and ensuring the normal operation of the hydraulic control system.

[0020] By means of the electromagnetic unloading valve and the electronic control module in the utility model, the pressure in the hydraulic system can be released at the same time as the engine is started, thus preventing the engine from starting under load. There is no need to rely on the user's personal cognition and consciousness to step on the foot brake in vain before starting the engine, and the situation of missing unloading and causing the engine to start under load will no longer occur, thereby achieving higher reliability.

[0021] Furthermore, the chassis hydraulic control system also includes a charging valve for charging the accumulator, and the electromagnetic unloading valve is connected to the oil circuit between the charging valve and the oil pump.

[0022] Furthermore, a one-way valve structure is arranged in the electromagnetic unloading valve, and the one-way valve structure forms the cut-off position.

[0023] Furthermore, the electromagnetic unloading valve is provided with a handle for manually controlling the switching between the unloading position and the cut-off position.

[0024] Furthermore, the chassis hydraulic control system also includes a relief valve arranged in parallel with the electromagnetic unloading valve.

[0025] Furthermore, the unloading setting time is 3 to 7 seconds.

[0026] Furthermore, the electronic control module includes a command unit and an electrical control unit. The command unit is used to output a start command to the engine starting device and to output a command signal to the electrical control unit. The electrical control unit is used to receive the command signal and output a control signal to the electromagnetic unloading valve after logically processing the command signal to control the on / off power of the electromagnetic unloading valve.

[0027] Furthermore, the chassis hydraulic control system also includes a filling valve for filling the accumulator and a steering gear for realizing chassis steering, and the filling valve has a filling port connected to the oil inlet of the steering gear.

[0028] In order to achieve the above-mentioned purpose, the engineering vehicle in the utility model adopts the following technical solutions:

[0029] An engineering vehicle comprises an engine and a chassis, wherein the chassis comprises a chassis hydraulic control system, wherein the chassis hydraulic control system comprises an oil pump connected to the engine transmission and an accumulator for providing an oil source for the brake, an electromagnetic unloading valve is arranged on the accumulator or on the oil circuit between the accumulator and the oil pump, and the electromagnetic unloading valve has an unloading position for supplying oil in the accumulator or the oil circuit back to the oil tank and a cut-off position for preventing the oil from flowing back to the oil tank, and the chassis hydraulic control system also comprises an electronic control module connected to the electromagnetic unloading valve and used for outputting a start command to the engine start device, and the electronic control module can control the electromagnetic unloading valve to be on / off while outputting the start command so as to switch it to the unloading position, and control the electromagnetic unloading valve to be off / on after the unloading set time so as to switch it to the cut-off position.

[0030] The beneficial effect of the above technical solution is that: the utility model provides an improved engineering vehicle, the improvement is that an electromagnetic unloading valve is arranged on the accumulator of the chassis hydraulic control system or on the oil circuit between the accumulator and the oil pump, and the hydraulic control system also includes an electronic control module connected to the electromagnetic unloading valve and used to output a start command to the engine starting device, the electronic control module can control the engine start by outputting the start command, and can also control the electromagnetic unloading valve to turn on / off to switch it to the unloading position while outputting the start command. When the accumulator or the oil circuit is in the unloading position, the oil in the oil circuit flows back to the oil tank, releasing the pressure in the hydraulic system, so that the engine can be prevented from starting with load, thereby preventing the engine from stalling, and thus ensuring the user experience, the service life of the engine and the driving reliability of the whole machine. At the same time, the electronic control module can also control the electromagnetic unloading valve to turn off / on after the unloading setting time to switch it to the cut-off position, preventing the oil from flowing back to the oil tank, realizing the function of normal filling of the accumulator, and ensuring the normal operation of the hydraulic control system.

[0031] By means of the electromagnetic unloading valve and the electronic control module in the utility model, the pressure in the hydraulic system can be released at the same time as the engine is started, thus preventing the engine from starting under load. There is no need to rely on the user's personal cognition and consciousness to step on the foot brake in vain before starting the engine, and the situation of missing unloading and causing the engine to start under load will no longer occur, thereby achieving higher reliability.

[0032] Furthermore, the chassis hydraulic control system also includes a charging valve for charging the accumulator, and the electromagnetic unloading valve is connected to the oil circuit between the charging valve and the oil pump.

[0033] Furthermore, a one-way valve structure is arranged in the electromagnetic unloading valve, and the one-way valve structure forms the cut-off position.

[0034] Furthermore, the electromagnetic unloading valve is provided with a handle for manually controlling the switching between the unloading position and the cut-off position.

[0035] Furthermore, the chassis hydraulic control system also includes a relief valve arranged in parallel with the electromagnetic unloading valve.

[0036] Furthermore, the unloading setting time is 3 to 7 seconds.

[0037] Furthermore, the electronic control module includes a command unit and an electrical control unit. The command unit is used to output a start command to the engine starting device and to output a command signal to the electrical control unit. The electrical control unit is used to receive the command signal and output a control signal to the electromagnetic unloading valve after logically processing the command signal to control the on / off power of the electromagnetic unloading valve.

[0038] Furthermore, the chassis hydraulic control system also includes a filling valve for filling the accumulator and a steering gear for realizing chassis steering, and the filling valve has a filling port connected to the oil inlet of the steering gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a block diagram of the composition of Embodiment 1 of the hydraulic control system for an engineering vehicle chassis of the utility model;

[0040] Figure 2 It is a hydraulic principle diagram of embodiment 1 of the hydraulic control system for the chassis of an engineering vehicle of the utility model;

[0041] Figure 3 This is a partial hydraulic principle diagram of Example 2 of the engineering vehicle chassis hydraulic control system of the utility model.

[0042] In the figure: 1. Fuel tank; 2. Gear pump; 3. Engine; 4. Control valve; 4-1. Solenoid unloading valve; 4-1', Solenoid unloading valve; 4-2, Overflow valve; 5. Electrical control unit; 6. Command unit; 7. Working device; 8. Filling valve; 9. Parking brake valve; 10. Relay valve; 11. Parking brake; 12. Steering axle service brake; 13. Drive axle service brake; 14. Drive axle service brake accumulator; 15. Steering axle service brake accumulator; 16. Service brake valve; 17. Steering cylinder; 18. Steering gear. DETAILED DESCRIPTION

[0043] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0044] In view of the technical problems existing in the prior art, the basic technical concept of the utility model is to set an electromagnetic unloading valve on the accumulator or on the oil circuit between the accumulator and the oil pump, and set an electronic control module. The electronic control module can control the engine start by outputting a start command, and can also control the electromagnetic unloading valve to turn on / off to switch it to the unloading position. When the accumulator or the oil circuit is in the unloading position, the oil in the oil tank flows back to the hydraulic system, thus preventing the engine from starting with load, thereby preventing the engine from stalling. The electronic control module can also control the electromagnetic unloading valve to turn off / on after the unloading set time to switch it to the cut-off position, preventing the oil from flowing back to the oil tank, and realizing the function of normal filling of the accumulator.

[0045] Embodiment 1 of the hydraulic control system for the chassis of an engineering vehicle in the utility model:

[0046] As an implementation method, the engineering vehicle chassis hydraulic control system is a chassis hydraulic control system of a tunnel arch installation trolley, specifically as follows Figure 1 As shown, it includes a fuel tank 1, a gear pump 2, an engine 3, a control valve 4, an electrical control unit 5, a command unit 6, and a working device 7.

[0047] like Figure 2As shown, the working device 7 includes hydraulic parts: a charging valve 8, a parking brake valve 9, a relay valve 10, a parking brake 11, a steering axle service brake 12, a driving axle service brake 13, a driving axle service brake accumulator 14, a steering axle service brake accumulator 15, a service brake valve 16, a steering cylinder 17, and a steering gear 18. Among them, the driving axle service brake accumulator 14 provides an oil source for the driving axle service brake 13, and the steering axle service brake accumulator 15 provides an oil source for the steering axle service brake 12. The charging valve 8 is used to flush the driving axle service brake accumulator 14 and the steering axle service brake accumulator 15, and at the same time provide an oil source for the parking brake 11.

[0048] The gear pump 2 is an oil pump, and its oil suction port is connected to the oil tank 1. At the same time, the shaft end of the gear pump 2 is connected to the engine 3. When the engine 3 starts, it drives the gear pump 2 to work synchronously. The oil outlet of the gear pump 2 is connected to the P port of the control valve 4 and the P port of the filling valve 8 respectively. The T port of the control valve 4 is connected to the oil tank 1, that is, the control valve 4 is connected to the oil path between the filling valve 8 and the gear pump 2.

[0049] The O port of the filling valve 8 is connected to the oil inlet of the steering gear 18, that is, the filling valve 8 has a filling port connected to the oil inlet of the steering gear 18, so that the oil source can be provided to the filling valve 8 and the steering gear 18 at the same time through a gear pump 2, thereby simplifying the structure of the hydraulic system. The oil return port of the steering gear 18 is connected to the oil tank 1, and the L and R ports of the steering gear 18 are respectively connected to the two chambers of the steering cylinder 17, and the steering cylinder 17 is connected to the mechanical steering structure on the chassis to realize the chassis steering function.

[0050] The A1 port of the charging valve 8 is connected to the steering axle service brake accumulator 15, and then connected to the oil inlet of the relay valve 10, and connected to the P1 port of the service brake valve 16. The A1 port of the service brake valve 16 is connected to the PP port of the relay valve 10, and the A port of the relay valve 10 is connected to the steering axle service brake 12, and the oil return port is connected to the oil tank 1. The A2 port of the charging valve 8 is connected to the driving axle service brake accumulator 14, and is also connected to the P2 port of the service brake valve 16. The A2 port of the service brake valve 16 is connected to the driving axle service brake 13, and the T1 and T2 ports of the service brake valve 16 are connected to the oil tank 1. The SW port of the charging valve 8 is connected to the P port of the parking brake valve 9, and the B port of the parking brake valve 9 is connected to the parking brake 11. At the same time, the T port is connected to the oil tank 1, and the T port of the two-way charging valve 8 is connected to the oil tank 1.

[0051] The control valve 4 includes an electromagnetic unloading valve 4-1 and a relief valve 4-2 arranged in parallel with the electromagnetic unloading valve 4-1. The relief valve 4-2 is used to release the pressure when the oil outlet pressure of the gear pump 2 is too high. The electromagnetic unloading valve 4-1 has an unloading position (i.e. Figure 2left position in the middle) and the shut-off position that prevents backflow to the tank (i.e. Figure 2 In the right position), specifically in the present embodiment, a one-way valve structure is arranged inside the electromagnetic unloading valve 4-1, and the one-way valve structure forms the cut-off position, so that the electromagnetic unloading valve 4-1 has a better oil leakage prevention effect when it is in the cut-off position.

[0052] like Figure 1 As shown, the electrical control unit 5 and the command unit 6 form an electronic control module, wherein the command unit 6 is used to output a start command to the engine starter and output a command signal to the electrical control unit 5. The command unit 6 outputs a start command to the engine starter to control the engine 3 to start. The electrical control unit 5 is connected to the electromagnetic unloading valve 4-1 in the control valve 4. The electrical control unit 5 is used to receive the command signal and output a control signal to the electromagnetic unloading valve 4-1 after logically processing the command signal, and control the electromagnetic unloading valve 4-1 to be energized so that it switches to the unloading position. When the unloading position is reached, the oil in the oil circuit between the filling valve 8 and the gear pump 2 flows back to the oil tank 1, releasing the pressure in the hydraulic system, so that the engine 3 can be prevented from starting with load, thereby preventing the engine 3 from stalling, thereby ensuring the user's experience, the service life of the engine 3, and the driving reliability of the whole machine. At the same time, the electrical control unit 5 can also control the electromagnetic unloading valve 4-1 to be de-energized after the unloading setting time to switch it to the cut-off position, preventing the oil from flowing back to the oil tank 1, realizing the function of normal filling of the accumulator, and ensuring the normal operation of the hydraulic control system. Among them, the unloading setting time is 3 to 7 seconds, preferably 5 seconds.

[0053] In addition, the electromagnetic unloading valve 4-1 is provided with a handle for manually controlling the switching between the unloading position and the cut-off position, so that manual unloading can be achieved in a power-off state.

[0054] The working process of the hydraulic control system of the engineering vehicle chassis in the utility model is as follows:

[0055] When the hydraulic control system is started, at the moment when the engine 3 is ignited, the electromagnetic unloading valve 4-1 is energized to unload, and after 5s, the power is cut off to load. When the pressure of the driving axle service brake accumulator 14 and the steering axle service brake accumulator 15 is lower than the lower limit pressure of the filling valve 8, the gear pump 2 outputs high-pressure oil through the filling valve 8 to fill the driving axle service brake accumulator 14 and the steering axle service brake accumulator 15 until the upper limit pressure of the filling valve 8 is reached, and the filling is stopped. The remaining oil enters the steering gear 18 through the O port. When steering is required, the steering wheel is turned to drive the steering gear 18 to rotate, and the L or R port of the steering gear 18 outputs high-pressure oil to the steering cylinder 17, thereby making the chassis steer.

[0056] When braking is required during driving, the service brake valve 16 is stepped on, and the two accumulators release oil into the P1 and P2 ports of the service brake valve 16. After decompression, the oil is output from the A1 port to the PP port of the relay valve 10. Correspondingly, the A port of the relay valve 10 outputs proportional pressure oil to the steering axle service brake 12. Secondly, the A2 port of the service brake valve 16 outputs oil to the drive axle service brake 13, thereby realizing the service braking function of the steering axle and the drive axle.

[0057] When parking brake is required, parking brake valve 9 is powered off, and the oil of parking brake 11 returns to the oil tank through T port of parking brake valve 9. The brake pad of parking brake 11 is clamped with the brake disc by its own spring force to realize the parking brake function. When parking brake needs to be released, parking brake valve 9 is powered on, and the high-pressure oil of accumulator enters P port of parking brake valve 9 through charging valve 8. After decompression, pressure oil is output to parking brake 11 through B port. The high-pressure oil overcomes the spring force of parking brake 11 to separate the brake pad from the brake disc, thereby releasing parking brake.

[0058] In terms of electricity, when the engine 3 is ignited, the command unit 6 outputs the engine start command to the engine start device to start the engine 3, and outputs the command signal to the electrical control unit 5. After the electrical control unit 5 performs logic processing, it immediately outputs the control signal to control the electromagnetic unloading valve 4-1 to be energized, so that the control valve 4 is not loaded, and the function of no-load starting of the engine 3 is realized. At the same time, the electrical control unit 5 starts timing after receiving the command signal. After the time reaches 5 seconds, it outputs the control signal again to control the electromagnetic unloading valve 4-1 to be de-energized, and realizes the automatic loading function of the gear pump 2 supplying oil to the filling valve 8.

[0059] In other implementations of the chassis hydraulic control system of an engineering vehicle: the engineering vehicle may also be a rock drilling trolley or a wet spraying trolley or a road-rail vehicle, and the corresponding chassis hydraulic control system is the chassis hydraulic control system of these vehicles.

[0060] In other implementations of the hydraulic control system for the engineering vehicle chassis: the gear pump may also be replaced by other forms of oil pumps such as a plunger pump.

[0061] In other implementations of the hydraulic control system for the engineering vehicle chassis: the steering gear may be equipped with a separate oil pump, that is, the steering gear no longer shares an oil pump with the filling valve.

[0062] In other implementations of the hydraulic control system for the engineering vehicle chassis: by changing the setting position of the electromagnet, the electromagnetic unloading valve can be switched to the unloading position when the power is off, and switched to the cut-off position when the power is on.

[0063] In other embodiments of the engineering vehicle chassis hydraulic control system: the electronic control module may no longer distinguish between the command unit and the electrical control unit, but is an independent complete module, which is connected to the electromagnetic unloading valve and is used to output a start command to the engine starting device, and the module can control the electromagnetic unloading valve to be on / off while outputting the start command to switch it to the unloading position, and control the electromagnetic unloading valve to be off / on after the unloading set time to switch it to the cut-off position.

[0064] In other implementations of the engineering vehicle chassis hydraulic control system: the unloading setting time may also be 3 seconds, 4 seconds, 6 seconds or 7 seconds, and of course may not be within the range of 3 to 7 seconds, such as 2 seconds or 8 seconds.

[0065] In other implementations of the engineering vehicle chassis hydraulic control system: the engineering vehicle chassis hydraulic control system may not include a relief valve arranged in parallel with the electromagnetic unloading valve, and in this case the control valve is only composed of the electromagnetic unloading valve.

[0066] In other implementations of the hydraulic control system for the engineering vehicle chassis: the electromagnetic unloading valve may not include a handle and may only be electrically controlled.

[0067] In other implementations of the hydraulic control system for the engineering vehicle chassis: the electromagnetic unloading valve can also be connected to the oil circuit between the charging valve and the accumulator to release the oil in the accumulator for unloading. Of course, it can also be directly set on the accumulator. By releasing the pressure in the hydraulic system, it can prevent the engine from starting under load.

[0068] Embodiment 2 of the hydraulic control system for the chassis of an engineering vehicle in the utility model:

[0069] like Figure 3 As shown, this embodiment is different from Embodiment 1 in that the cut-off position of the electromagnetic unloading valve 4-1' in this embodiment is not a one-way valve structure. In the cut-off position, the oil inlet and the oil outlet are not connected in any direction, and the two oil ports are completely blocked.

[0070] The embodiment of the engineering vehicle chassis in the utility model is as follows: the engineering vehicle chassis includes a chassis hydraulic control system, and the specific structure of the chassis hydraulic control system is the same as the engineering vehicle chassis hydraulic control system in the above embodiment, which will not be repeated here.

[0071] An embodiment of an engineering vehicle in the utility model is as follows: the engineering vehicle includes an engine and a chassis, the chassis includes a chassis hydraulic control system, and the specific structure of the chassis hydraulic control system is the same as the engineering vehicle chassis hydraulic control system in the above embodiment, which will not be repeated here.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the description and drawings of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydraulic control system for an engineering vehicle chassis, comprising an oil pump for transmission connection with an engine and an accumulator for providing an oil source for a brake, characterized in that: An electromagnetic unloading valve is arranged on the accumulator or on the oil circuit between the accumulator and the oil pump. The electromagnetic unloading valve has an unloading position for allowing the oil in the accumulator or the oil circuit to flow back to the oil tank and a stop position for preventing the oil from flowing back to the oil tank. The engineering vehicle chassis hydraulic control system also includes an electronic control module connected to the electromagnetic unloading valve and used to output a start command to the engine starting device. The electronic control module can control the electromagnetic unloading valve to be on / off while outputting the start command so that it switches to the unloading position, and control the electromagnetic unloading valve to be off / on after the unloading set time so that it switches to the stop position.

2. The engineering vehicle chassis hydraulic control system according to claim 1, characterized in that: The engineering vehicle chassis hydraulic control system also includes a filling valve for filling the accumulator, and the electromagnetic unloading valve is connected to the oil circuit between the filling valve and the oil pump.

3. The engineering vehicle chassis hydraulic control system according to claim 1 or 2, characterized in that: A one-way valve structure is arranged inside the electromagnetic unloading valve, and the one-way valve structure forms the cut-off position.

4. The engineering vehicle chassis hydraulic control system according to claim 1 or 2, characterized in that: The electromagnetic unloading valve is provided with a handle for manually controlling the switching between the unloading position and the cut-off position.

5. The engineering vehicle chassis hydraulic control system according to claim 1 or 2, characterized in that: The engineering vehicle chassis hydraulic control system also includes a relief valve arranged in parallel with the electromagnetic unloading valve.

6. The engineering vehicle chassis hydraulic control system according to claim 1 or 2, characterized in that: The unloading setting time is 3~7 seconds.

7. The engineering vehicle chassis hydraulic control system according to claim 1 or 2, characterized in that: The electronic control module includes a command unit and an electrical control unit. The command unit is used to output a start command to the engine starter and to output a command signal to the electrical control unit. The electrical control unit is used to receive the command signal and output a control signal to the electromagnetic unloading valve after logically processing the command signal to control the on / off power of the electromagnetic unloading valve.

8. The engineering vehicle chassis hydraulic control system according to claim 1 or 2, characterized in that: The engineering vehicle chassis hydraulic control system also includes a filling valve for filling the accumulator and a steering gear for realizing chassis steering. The filling valve has a filling port connected to the oil inlet of the steering gear.

9. An engineering vehicle chassis, including a chassis hydraulic control system, characterized in that: The chassis hydraulic control system is the engineering vehicle chassis hydraulic control system as described in any one of claims 1 to 8.

10. An engineering vehicle comprising an engine and a chassis, the chassis comprising a chassis hydraulic control system, characterized in that: The chassis hydraulic control system is the engineering vehicle chassis hydraulic control system as described in any one of claims 1 to 8.

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