CN210558952U - Engineering vehicle hydraulic control device and engineering vehicle - Google Patents

Abstract

The utility model relates to an engineering vehicle technical field, in particular to engineering vehicle liquid accuse device and engineering vehicle. The utility model provides an engineering vehicle liquid accuse device includes: the hydraulic control valve comprises a valve body, wherein an oil inlet, a first working port and an oil return port are formed in the valve body, the oil inlet is connected with the first working port, and the first working port is used for being communicated with a bridge-disengaging hydraulic control device for controlling the engineering vehicle to switch between a four-wheel drive mode and a two-wheel drive mode; and at least one of the energy accumulator and the back pressure valve, wherein the energy accumulator is communicated with an oil way between the oil inlet and the first working port, and the back pressure valve is arranged on the oil way between the oil inlet and the oil return port. The utility model discloses can effectively promote engineering vehicle's performance.

Description

Engineering vehicle hydraulic control device and engineering vehicle

Technical Field

The utility model relates to an engineering vehicle technical field, in particular to engineering vehicle liquid accuse device and engineering vehicle.

Background

The bridge-off hydraulic control device and the suspension hydraulic control device are important components of engineering vehicles such as off-road tyre cranes and the like, wherein the bridge-off hydraulic control device is mainly used for controlling the engineering vehicles to switch between a two-wheel drive mode and a four-wheel drive mode according to the change of the driving working condition, and the suspension hydraulic control device mainly plays a role in damping and buffering.

However, in the existing engineering vehicle, the response speed of the off-axle hydraulic control device and the suspension hydraulic control device is slow, the emergency driving mode switching function cannot be realized, and the damping and buffering effects are poor under severe working conditions, so that the performance of the whole vehicle still needs to be improved.

Disclosure of Invention

The utility model discloses a technical problem that will solve is: the performance of the engineering vehicle is improved.

In order to solve the technical problem, the utility model discloses the first aspect provides an engineering vehicle liquid accuse device, and it includes:

the hydraulic control valve comprises a valve body, wherein an oil inlet, a first working port and an oil return port are formed in the valve body, the oil inlet is connected with the first working port, and the first working port is used for being communicated with a bridge-disengaging hydraulic control device for controlling the engineering vehicle to switch between a four-wheel drive mode and a two-wheel drive mode; and

the energy accumulator is communicated with an oil way between the oil inlet and the first working port, and the back pressure valve is arranged on the oil way between the oil inlet and the oil return port.

In some embodiments, the hydraulic control device for the engineering vehicle further comprises an off-bridge control valve, the off-bridge control valve is arranged on an oil path between the oil inlet and the first working port, and the energy accumulator is communicated with the oil path between the off-bridge control valve and the oil inlet.

In some embodiments, the bridge-disengaging control valve includes a first oil port, a second oil port and a third oil port and has a first working state and a second working state, the first oil port is connected with the oil inlet, the second oil port is communicated with the oil return port, the third oil port is communicated with the first working port, the second oil port is communicated with the third oil port and the first oil port is cut off in the first working state, the first oil port is communicated with the third oil port and the second oil port is cut off in the second working state, and the energy accumulator is communicated with an oil path between the first oil port and the oil inlet.

In some embodiments, the hydraulic control device for the engineering vehicle further comprises a check valve, the check valve is arranged in the bridge release control valve, and the first oil port is blocked by the check valve when the check valve is in the first working state.

In some embodiments, the hydraulic control device of the engineering vehicle further comprises a check valve, the check valve is arranged on an oil path through which hydraulic oil flows to the energy accumulator, and an outlet of the check valve is communicated with the energy accumulator.

In some embodiments, a check valve is disposed on the oil path between the accumulator and the oil inlet, and an inlet of the check valve is in communication with the oil inlet.

In some embodiments, the back pressure valve is a check valve, an inlet of the check valve is communicated with the oil inlet, and an outlet of the check valve is communicated with the oil return port.

In some embodiments, the hydraulic control device of the engineering vehicle comprises a bridge-off hydraulic control device, the bridge-off hydraulic control device comprises a bridge-off oil cylinder, and a rodless cavity of the bridge-off oil cylinder is communicated with the first working port.

In some embodiments, the valve body is further provided with a second working port, and the second working port is used for communicating with the suspension hydraulic control device.

In some embodiments, the hydraulic control device of the engineering vehicle comprises a suspension hydraulic control device, the suspension hydraulic control device comprises a suspension oil cylinder and a switching valve, a rod cavity of the suspension oil cylinder is communicated with the second working port, a rodless cavity of the suspension oil cylinder is connected with the second working port through the switching valve, and the switching valve controls whether the rodless cavity of the suspension oil cylinder is communicated with the second working port or not.

The utility model discloses the second aspect still provides an engineering vehicle, and it includes the utility model discloses an engineering vehicle liquid accuse device.

In some embodiments, the work vehicle is an off-road tire crane.

Based on the energy storage ware that adds, engineering vehicle can realize emergent mode switching function of traveling, and based on the back pressure valve that sets up, engineering vehicle liquid accuse device's response speed is faster, is particularly favorable to realizing better damping buffering effect under abominable operating mode, consequently, the utility model discloses can effectively promote engineering vehicle's performance.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 shows a hydraulic schematic diagram of a hydraulic control device for a construction vehicle according to an embodiment of the present invention.

In the figure:

1. a one-way valve; 2. an overflow valve; 3. a check valve; 4. a bridge release control valve; 41. a check valve; 5. an accumulator; 6. a bridge-off oil cylinder; 7. suspending the oil cylinder; 8. a switching valve; 9. a valve body;

p, an oil inlet; t, an oil return port; A. a first working port; B. and a second working port.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments in the present invention, all other embodiments obtained by the ordinary skilled person in the art without developing the creative work belong to the protection scope of the present invention.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the orientation words such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, and in the case of not making a contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be interpreted as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

In the description of the present invention, it should be understood that the terms "first", "second", etc. are used to define the components, and are only used for the convenience of distinguishing the corresponding components, and if not stated otherwise, the terms have no special meaning, and therefore, should not be interpreted as limiting the scope of the present invention.

Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

Fig. 1 shows a hydraulic schematic diagram of an embodiment of the hydraulic control device of the engineering vehicle.

Although the present invention is applicable to various construction vehicles, for the sake of simplifying the description, the following description will be given only by taking the case where the construction vehicle is an off-road type tire crane as an example.

The cross-country tyre crane is a tyre crane with expanded functions, belongs to special hoisting equipment, integrates the advantages of motor flexibility of an automobile crane, hoisting and running of a crawler crane and the like, adopts a two-axle cross-country chassis for the whole vehicle, comprises a power output system, a power transmission system, a steering system, a suspension system and the like, and has four steering modes and two driving modes.

The two driving modes comprise a two-wheel driving mode only driven by a front axle and a four-wheel driving mode driven by the front axle and the rear axle together so as to meet different driving power requirements of a normal road and a cross-country road. Generally, the work vehicle adopts a two-drive running mode when running on a normal road, and adopts a four-drive running mode when running on an off-road or climbing a slope.

The off-axle hydraulic control device is used for controlling the engineering vehicle to switch between a two-wheel drive running mode and a four-wheel drive running mode, and can control the switching of the running modes by controlling whether a transfer case is in power connection with a rear axle transmission shaft or not. Transfer cases are components of the powertrain system that transfer torque from the transmission to the front and rear axle drive shafts, converting two-drive to four-drive, or four-drive high to four-drive low. Therefore, the axle-disengaging hydraulic control device can control the engineering vehicle to switch between the two-wheel drive running mode and the four-wheel drive running mode by controlling the power connection or power disconnection between the transfer case and the rear axle transmission shaft.

Referring to fig. 1, in some embodiments, the axle-disengaging hydraulic control device includes an axle-disengaging oil cylinder 6, and the axle-disengaging oil cylinder 6 is disposed between the transfer case and the rear axle transmission shaft, and controls the on-off of the torque output from the transfer case to the rear axle transmission shaft through the self-expansion. Specifically, as can be seen from fig. 1, a spring is arranged in a rod cavity of the axle-disengaging oil cylinder 6, when hydraulic oil enters a rodless cavity, a cylinder rod overcomes the spring force and the like to extend outwards under the action of the hydraulic oil, so that the transfer case is in power connection with the rear axle transmission shaft, the torque of the transfer case is transmitted to the rear axle transmission shaft, a four-wheel drive running mode is realized, and when the hydraulic oil is cut off, namely no hydraulic oil enters the rodless cavity, the cylinder rod retracts under the action of the rodless cavity spring, so that the transfer case is separated from the rear axle transmission shaft, and a torque transmission path from the transfer case to the rear axle transmission shaft is cut off, so that a two-wheel drive running mode is realized.

In addition, the suspension system is also an important component of the off-road type tire crane, is arranged between the axle and the frame and is used for supporting the frame, relieving the impact load transmitted to the frame by the uneven road and attenuating the vibration of the bearing system caused by the impact load.

The suspension hydraulic control device is used for controlling and realizing the vibration reduction and buffering functions of the suspension system. Referring to fig. 1, in some embodiments, the suspension hydraulic control device comprises a suspension cylinder 7, and the suspension cylinder 7 is connected with an axle and a frame and used for buffering and reducing boarding vibration through self expansion. Specifically, as can be seen from fig. 1, the rod cavity (small cavity) of the suspension cylinder 7 is communicated with the oil supply path of the suspension cylinder 7, the rodless cavity (large cavity) of the suspension cylinder 7 is connected with the oil supply path of the suspension cylinder 7 through the switching valve 8, and the switching valve 8 controls whether the rodless cavity of the suspension cylinder 7 is communicated with the oil supply path of the suspension cylinder 7. The switching valve 8 comprises a first valve port and a second valve port and has a first state and a second state, the first valve port is communicated with the oil supply path of the suspension cylinder 7, the second valve port is communicated with the large cavity of the suspension cylinder 7, and in the first state, the first valve port and the second valve port are disconnected with each other, the switching valve 8 controls the large cavity of the suspension cylinder 7 to be disconnected with the oil supply path of the suspension cylinder 7, in the second state, the first valve port and the second valve port are communicated with each other, and the switching valve 8 controls the large cavity of the suspension cylinder 7 to be communicated with the oil supply path of the suspension cylinder 7. Specifically, the switching valve 8 is a two-position two-way solenoid valve in fig. 1, and the first state corresponds to the lower position in fig. 1, and the second state corresponds to the upper position in fig. 1.

Based on the arrangement, under the action of the suspension hydraulic control device, the suspension system can realize two suspension modes of rigidity and elasticity, wherein, in the elastic suspension mode, the large cavity and the small cavity of the suspension oil cylinder 7 are communicated, and the pressure difference between the large cavity and the small cavity and the gravity of the upper vehicle are in a balanced state, so that the suspension oil cylinder 7 is in a floating state, under the condition, if the vehicle running road surface has large fluctuation and the chassis has large change of external load, the suspension oil cylinder 7 in the floating state can relax the impact load transmitted to the vehicle body from the uneven road surface and reduce the dynamic load of the vehicle, and in the rigid suspension mode, the large cavity of the suspension oil cylinder 7 is locked, hydraulic oil does not enter and exit the large cavity of the suspension oil cylinder 7, and the high requirement on the rigidity of the vehicle body when the vehicle runs in a suspended manner of lifting on.

Moreover, as shown in fig. 1, the suspension hydraulic control device includes two suspension cylinders 7 and two switching valves 8, the two suspension cylinders 7 respectively correspond to the two wheels on the left and right sides of the rear axle, the two switching valves 8 correspond to the two suspension cylinders 7 one by one, and each suspension cylinder 7 and the corresponding switching valve 8 are combined to form a suspension hydraulic control unit, so that under the action of the two suspension hydraulic control units corresponding to the left and right sides of the rear axle, the suspension system can perform vibration damping support on the frames on the left and right sides of the rear axle, which is beneficial to ensuring that each tire bears the same load.

Therefore, based on the suspension hydraulic control device, the suspension system can become a hydraulic suspension system, the expansion amount of the suspension oil cylinder 7 can be automatically adjusted according to the condition of the road surface, and a good buffering and vibration damping effect is achieved.

In some embodiments, the connection relationship between the bridge-off hydraulic control device and the suspension hydraulic control device and the corresponding oil passages of other working modules is controlled by the same hydraulic valve, and the hydraulic valve can be called as a bridge-off suspension valve. Referring to fig. 1, the off-bridge suspension valve may include a valve body 9, and an oil inlet P, an oil return port T, a first working port a and a second working port B may be disposed on the valve body 9, where the first working port a and the second working port B are respectively communicated with an off-bridge hydraulic control device (specifically, a rodless cavity of the off-bridge oil cylinder 6) and a suspension hydraulic control device (specifically, a rodless cavity of the suspension oil cylinder 7), the oil inlet P is connected with both the first working port a and the second working port B and is communicated with an off-bridge suspension oil supply oil path for providing hydraulic oil for the off-bridge hydraulic control device and the suspension hydraulic control device through the first working port a and the second working port B, and the oil return port T is connected with an oil tank for achieving oil return of the off-bridge hydraulic control device and the suspension hydraulic control device.

The off-bridge suspension oil supply oil path is an oil path corresponding to other working modules of the whole vehicle. Because the oil pressure required by the bridge-disengaging hydraulic control device and the suspension hydraulic control device is usually lower, in order to meet the lower pressure requirements of the bridge-disengaging hydraulic control device and the suspension hydraulic control device, the bridge-disengaging suspension oil supply oil way is generally a finished automobile oil return oil way, namely, a bridge-disengaging suspension valve generally takes oil from the finished automobile oil return oil way, namely, an oil inlet P is generally communicated with the finished automobile oil return oil way, and meanwhile, the pressure of the supplied hydraulic oil is further adjusted, so that the hydraulic oil of the oil return oil way with the pressure higher than the pressure required by the bridge-disengaging hydraulic control device and the suspension hydraulic control device is changed into the hydraulic oil meeting the pressure requirements of the bridge-disengaging hydraulic control device and the suspension hydraulic control.

In the prior art, hydraulic oil for driving the off-axle hydraulic control device to act completely comes from the off-axle suspension oil supply oil way, so that once other working modules of the engineering vehicle are in failure, the off-axle suspension oil supply oil way cannot supply oil to the off-axle hydraulic control device, the off-axle hydraulic control device cannot control to realize the switching of the running mode, and therefore the engineering vehicle cannot switch the running mode under emergency conditions such as failure of other working modules, and potential safety hazards exist. Therefore, the conventional engineering vehicle cannot realize emergency driving mode switching, is difficult to meet the driving mode switching requirement under emergency conditions, and has poor safety performance.

Moreover, the whole vehicle has more actions, and the pressure change on the whole vehicle oil return oil way is larger, so that the problem of poor stability of the pressure of the bridge-disengaging hydraulic control device is caused, the action stability of the bridge-disengaging hydraulic control device is influenced, and the safety risk is increased.

In addition, in the prior art, a pressure reducing valve is generally adopted for reducing pressure, so that the oil pressure is adjusted to meet the requirements of a bridge-disengaging hydraulic control device and a suspension hydraulic control device, however, the pressure reducing valve has the problem of relatively delayed response, which directly influences the response speed of the bridge-disengaging hydraulic control device and the suspension hydraulic control device, especially for the suspension hydraulic control device, when the road surface has large fluctuation and the axle shakes violently, the volume change of oil in the suspension oil cylinder 7 is relatively large, and relatively large instantaneous flow needs to be compensated, however, due to the response delay of the pressure reducing valve, relatively large instantaneous flow cannot be timely compensated for the suspension oil cylinder 7, so that the suspension oil cylinder 7 is difficult to respond rapidly, that is, the response of the suspension flow compensation function is delayed, which influences the vibration reduction and buffering effect of the suspension system, and weakens.

To the above problem, the utility model discloses improve engineering vehicle liquid accuse device to the special operating mode demand on special type lifting device chassis is satisfied better to the performance that promotes the vehicle.

Wherein, to the problem that can't realize emergent mode switching function that traveles, the utility model discloses add energy storage ware 5 on the fuel feeding oil circuit of taking off bridge hydraulic control device. As shown in fig. 1, in some embodiments, the accumulator 5 is in communication with the oil passage between the oil inlet P and the first working port a.

Based on the additionally arranged energy accumulator 5, the hydraulic oil of the off-bridge hydraulic control device does not completely depend on the off-bridge suspension oil supply oil way corresponding to other working modules of the off-bridge tire crane for supplying oil to the off-bridge hydraulic control device, but the energy accumulator 5 can be used as an auxiliary pressure source, so that when the off-bridge suspension oil supply oil way has an emergency situation such as failure, the energy accumulator 5 can provide the hydraulic oil for the off-bridge hydraulic control device, the off-bridge hydraulic control device can still act, the cylinder rod of the off-bridge oil cylinder 6 can rapidly respond to the stretching out and control the running mode switching, namely, under the action of the energy accumulator 5, the off-bridge tire crane can realize the emergency running mode switching function, so that the running mode switching requirement of the off-bridge tire crane under the emergency situation can be met, and the safety performance of the off-bridge tire crane is effectively improved.

Meanwhile, the accumulator 5 is additionally arranged, so that a pressure stabilizing effect can be achieved on the bridge-disengaging hydraulic control device, the influence of pressure fluctuation of an oil return line of the whole vehicle on the bridge-disengaging hydraulic control device is reduced, the oil pressure of the bridge-disengaging hydraulic control device can be maintained within a set range, and the safety risk caused by the pressure fluctuation is reduced.

Referring to fig. 1, in some embodiments, the hydraulic control device for the engineering vehicle further includes an off-bridge control valve 4, and the off-bridge control valve 4 is disposed on an oil path between the oil inlet P and the first working port a, and is used for controlling whether the oil inlet P is communicated with the first working port a. Specifically, as can be seen from fig. 1, the bridge-off control valve 4 includes a first oil port, a second oil port and a third oil port, and has a first working state and a second working state, the first oil port is connected to the oil inlet P, the second oil port is communicated to the oil return port T, the third oil port is communicated to the first working port a, and when the first working state is reached, the second oil port is communicated to the third oil port and the first oil port is closed, and when the second working state is reached, the first oil port is communicated to the third oil port and the second oil port is closed. Based on this, through controlling the switching between the first working state and the second working state of the bridge-disengaging control valve 4, the connection or disconnection between the oil inlet P and the first working port A can be controlled, so that whether the oil is supplied to the rodless cavity of the bridge-disengaging oil cylinder 6 or not is controlled, further, whether the cylinder rod of the bridge-disengaging oil cylinder 6 extends or not is controlled, and the running mode switching is controlled.

The bridge release control valve 4 shown in fig. 1 is a two-position three-way electromagnetic valve, and the bridge release control valve 4 can be controlled to switch between a first working state (corresponding to the right position in fig. 1) and a second working state (corresponding to the left position in fig. 1) by controlling whether the bridge release control valve 4 is electrified, so as to control whether the bridge release hydraulic control device controls the running mode switching. However, this is not a limitation of the present invention, and for example, the off-bridge control valve 4 may be a hydraulic valve adopting other control modes, such as a hydraulic control valve, a pneumatic control valve, or a manual control valve.

Under the condition that the bridge-disengaging control valve 4 is arranged, the energy accumulator 5 can be communicated with an oil path between the bridge-disengaging control valve 4 and the oil inlet P, and particularly can be communicated with an oil path between a first oil port of the bridge-disengaging control valve 4 and the oil inlet P, so that the oil can be supplied to the bridge-disengaging hydraulic control device by the energy accumulator 5 more reliably under emergency, meanwhile, the pressure in front of the bridge-disengaging control valve 4 can be stabilized, the pressure fluctuation in front of the bridge-disengaging control valve 4 is reduced, the pressure in front of the bridge-disengaging control valve 4 is always maintained in a set range, and the switching process of running modes is more stable, safe and reliable.

And, in order to further improve the pressure stability before the bridge release control valve 4, as shown in fig. 1, in some embodiments, the engineering vehicle hydraulic control device further includes a check valve 41 and a check valve 3, wherein: the check valve 41 is arranged in the bridge release control valve 4, and when the bridge release control valve is in the first working state, the first oil port is blocked by the check valve 41; the check valve 3 is arranged on an oil path of hydraulic oil flowing to the energy accumulator 5, and an outlet of the check valve 3 is communicated with the energy accumulator 5.

The check valve 41 is arranged to plug the first oil port in the first working state, so that the bridge-release control valve 4 becomes a cut-off reversing valve, the first oil port can be cut off more tightly in the first working state, pressure oil in the energy accumulator 5 can be more reliably prevented from entering the bridge-release control valve 4 through the first oil port in the first working state, pressure loss of the energy accumulator 5 caused by the pressure loss is reduced, the energy accumulator 5 can more reliably provide hydraulic oil with required pressure for a bridge-release hydraulic control device when needed, and the pressure stability before the bridge-release control valve 4 is further improved.

The check valve 3 is arranged on the oil supply path of the energy accumulator 5, and the check valve 3 is utilized to control hydraulic oil to flow to the energy accumulator 5 only from the oil inlet P but not to flow reversely, namely, the hydraulic oil cannot flow to the oil inlet P from the energy accumulator 5, so that the pressure loss of the energy accumulator 5 can be reduced, and the pressure stability before the bridge-release control valve 4 is improved.

The check valve 41 and the check valve 3 may be provided in only one of them, and the embodiment shown in fig. 1, in which the check valve 41 and the check valve 3 are provided at the same time, has the advantage that the accumulator 5 can be sealed in both the upstream direction and the downstream direction of the accumulator 5, so that pressure loss of the hydraulic oil stored in the accumulator 5 due to the flow of the hydraulic oil into the bridge-off control valve 4 and pressure loss of the hydraulic oil stored in the accumulator 5 due to the flow of the hydraulic oil back to the vehicle oil return line are both prevented, and thus pressure loss of the accumulator 5 can be more reliably avoided, and the pre-valve pressure of the bridge-off control valve 4 can be more stably maintained within a set range.

The position of the check valve 3 on the oil supply path of the energy accumulator 5 is not limited, for example, as shown in fig. 1, the check valve 3 is disposed on the oil path between the energy accumulator 5 and the oil inlet P, and the check valve 3 is located inside the valve body 9 and belongs to a part of the off-bridge suspension valve, and an inlet of the check valve 3 may be communicated with the oil inlet P, or the check valve 3 may also be disposed outside the valve body 9 and located on the oil return path of the entire vehicle, and an inlet of the check valve 3 may be communicated with the oil tank.

In addition, to the slow problem of response speed because of utilizing relief pressure valve regulated pressure to cause, the utility model discloses replace the relief pressure valve with the back pressure valve, set up the back pressure valve on the oil circuit between oil inlet P and oil return opening T, utilize the back pressure valve to control by the pressure of oil inlet P flow direction to take off the bridge hydraulic control device and hang the hydraulic control device's hydraulic oil for the oil pressure satisfies the demand of taking off the bridge hydraulic control device and hanging the hydraulic control device.

Compared with a pressure reducing valve, the response speed of the back pressure valve is high, so that the response speed of the bridge-off hydraulic control device and the response speed of the suspension hydraulic control device are increased, the bridge-off hydraulic control device can be controlled more quickly to realize the switching of the driving modes, the suspension hydraulic control device can respond to the change of the road condition more quickly, and a more effective buffering and vibration reduction effect is provided.

In particular, the bypass backpressure valve is adopted to replace a pressure reducing valve to adjust oil pressure, and the suspension hydraulic control device is favorable for realizing a faster suspension flow compensation function. Because, under extreme road conditions, rock when the axle distance, when suspension cylinder 7 flow change is great, the back pressure valve can start more rapidly, for suspension cylinder 7 more promptly compensate great instantaneous flow, respond suspension cylinder 7's dynamic flow demand more rapidly, realize better damping buffering effect, effectively promote the cross-country ability of vehicle.

The back pressure valve is operated by the elastic force of the built-in spring to maintain the pressure required by the pipeline system, and various valve structures such as an overflow valve, a one-way valve, a sequence valve and the like can be adopted. As shown in fig. 1, in some embodiments, the back pressure valve is a check valve 1, an inlet of the check valve 1 is communicated with the oil inlet P, and an outlet of the check valve 1 is communicated with the oil return port T. The pressure reducing function is realized by adopting the check valve 1 as a back pressure valve, the structure is simpler, the system cooperation can be simplified, the cost is reduced, and the working stability and the reliability of the system can be improved.

The check valve 41, the check valve 3, and the check valve 1 are actually check valves, and may be referred to as a first check valve, a second check valve, and a third check valve, respectively, for convenience of distinction.

Meanwhile, as shown in fig. 1, in some embodiments, the hydraulic control device of the engineering vehicle further comprises a relief valve 2, an inlet of the relief valve 2 is communicated with the oil inlet P, and an outlet of the relief valve 2 is communicated with the oil return port T. The overflow valve 2 can perform unloading and safety protection, particularly can prevent the pressure overshoot caused by the rapid action of the suspension oil cylinder 7 in a place with large road condition fluctuation, and reduces the damage to the system caused by large pressure impact.

When the hydraulic control device shown in fig. 1 works, hydraulic oil of an oil return path of the whole vehicle enters the inside of the off-bridge suspension valve from the oil inlet P, and becomes hydraulic oil meeting the requirements of off-bridge and suspension under the pressure regulating action of the check valve 1, then the hydraulic oil flows out of the off-bridge suspension valve in two paths, one path flows to the off-bridge oil cylinder 6 through the off-bridge control valve 4 and the first working port a and serves as a control oil source of the off-bridge hydraulic control device, and the other path enters the suspension oil cylinder 7 through the second working port B.

In addition, the hydraulic control device of the engineering vehicle can realize the emergency driving mode switching function and the suspension flow compensation function and has higher response speed by additionally arranging the energy accumulator 5 and the check valve 41, changing the off-bridge control valve 4 into a stop reversing valve and changing the off-bridge control valve into the check valve 1 serving as an off-bridge suspension valve bypass backpressure valve to adjust the oil pressure. Now briefly described as follows:

(1) emergency driving mode switching function

The whole vehicle has more actions, and the pressure change on the oil return circuit is larger, so the pressure of the oil inlet P is relatively unstable, the energy accumulator 5 is added in front of the bridge release control valve 4 to stabilize the pressure before the valve, and the check valve 41 and the check valve 3 are added to avoid the pressure loss of the energy accumulator 5, so that the pressure before the bridge release control valve 4 is always maintained in a set range.

Under emergency, the off-bridge control valve 4 can be controlled to be electrified to be switched to the left position, at the moment, the energy accumulator 5 provides energy storage pressure for the off-bridge oil cylinder 6 through the off-bridge control valve 4, the off-bridge oil cylinder 6 rapidly responds and stretches out, the torque of the transfer case is output to the rear axle transmission shaft, the driving mode is switched from two-wheel drive to four-wheel drive, and the emergency driving mode switching function is achieved.

(2) Suspension flow compensation function

When the elastic suspension mode is needed, the switching valve 8 can be controlled to be electrified, the switching valve 8 is switched to be in the first state, the large cavity and the small cavity of the suspension oil cylinder 7 are communicated with the oil inlet P at the same time, and the suspension oil cylinder 7 is in a floating state. When the load on the ground changes in the running process, so that the axle fluctuates and shakes, the stress of the suspension oil cylinder 7 changes, the cylinder rod moves up and down along with the axle, and the vibration of getting on the vehicle is reduced.

When the axle shakes violently, the corresponding suspension oil cylinder 7 stretches out and draws back from top to bottom to a great extent, so that the volume change of oil in the suspension oil cylinder 7 is great, and the dynamic response of the suspension oil cylinder 7 is met by compensating the great instantaneous flow through the oil inlet P. On oil return oil circuit was directly received to oil inlet P, can provide great flow, and adopt the check valve to do the back pressure valve, open rapidly, make hydraulic oil can get into suspension cylinder 7 more in time fully, satisfy flow dynamic change demand, when 7 big chamber volumes of suspension cylinder reduce suddenly, fluid can discharge rapidly, suspension cylinder 7 responds more fast under extreme road conditions, it is faster to make whole car hang dynamic behavior response, effectively strengthen the shock attenuation buffering effect, promote the cross-country ability of hoist.

The above description is only exemplary embodiments of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (12)

1. A hydraulic control device for a working vehicle, comprising:

the hydraulic control system comprises a valve body (9), wherein an oil inlet (P), a first working port (A) and an oil return port (T) are formed in the valve body (9), the oil inlet (P) is connected with the first working port (A), and the first working port (A) is used for being communicated with a bridge-disengaging hydraulic control device for controlling the engineering vehicle to be switched between a four-wheel drive mode and a two-wheel drive mode; and

at least one in accumulator (5) and the back pressure valve, accumulator (5) with oil inlet (P) with oil circuit intercommunication between first working port (A), the back pressure valve set up in oil circuit between oil inlet (P) with oil return port (T).

2. The engineering vehicle hydraulic control device according to claim 1, further comprising an off-bridge control valve (4), wherein the off-bridge control valve (4) is disposed on an oil path between the oil inlet (P) and the first working port (A), and the accumulator (5) is communicated with the oil path between the off-bridge control valve (4) and the oil inlet (P).

3. The engineering vehicle hydraulic control device of claim 2, wherein the bridge-release control valve (4) comprises a first oil port, a second oil port and a third oil port, and has a first working state and a second working state, the first oil port is connected with the oil inlet (P), the second oil port is communicated with the oil return port (T), the third oil port is communicated with the first working port (A), the second oil port is communicated with the third oil port and the first oil port is cut off when the first working state is achieved, the first oil port is communicated with the third oil port and the second oil port is cut off when the second working state is achieved, and the energy accumulator (5) is communicated with an oil path between the first oil port and the oil inlet (P).

4. The working vehicle hydraulic control device according to claim 3, characterized by further comprising a check valve (41), wherein the check valve (41) is disposed in the bridge release control valve (4), and the first oil port is blocked by the check valve (41) in the first operation state.

5. The engineering vehicle hydraulic control device according to claim 1, further comprising a check valve (3), wherein the check valve (3) is arranged on an oil path of hydraulic oil flowing to the energy accumulator (5), and an outlet of the check valve (3) is communicated with the energy accumulator (5).

6. The engineering vehicle hydraulic control device as claimed in claim 5, wherein the check valve (3) is arranged on an oil path between the accumulator (5) and the oil inlet (P), and an inlet of the check valve (3) is communicated with the oil inlet (P).

7. The hydraulic control device of the engineering vehicle as claimed in any one of claims 1 to 6, wherein the back pressure valve is a check valve (1), an inlet of the check valve (1) is communicated with the oil inlet (P), and an outlet of the check valve (1) is communicated with the oil return port (T).

8. The working vehicle hydraulic control device according to claim 1, characterized in that the working vehicle hydraulic control device comprises the off-bridge hydraulic control device, the off-bridge hydraulic control device comprises an off-bridge oil cylinder (6), and a rodless cavity of the off-bridge oil cylinder (6) is communicated with the first working port (a).

9. The hydraulic control device of the engineering vehicle as claimed in claim 1, characterized in that a second working port (B) is further arranged on the valve body (9) and is used for communicating with the suspension hydraulic control device.

10. The working vehicle hydraulic control device according to claim 9, characterized in that the working vehicle hydraulic control device comprises the suspension hydraulic control device, the suspension hydraulic control device comprises a suspension cylinder (7) and a switching valve (8), a rod chamber of the suspension cylinder (7) is communicated with the second working port (B), a rod-free chamber of the suspension cylinder (7) is connected with the second working port (B) through the switching valve (8), and the switching valve (8) controls whether the rod-free chamber of the suspension cylinder (7) is communicated with the second working port (B).

11. A working vehicle comprising a working vehicle hydraulic control apparatus according to any one of claims 1 to 10.

12. The work vehicle according to claim 11, characterized in that the work vehicle is an off-road tire crane.

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