阅读说明：本技术 一种推土机转向制动控制方法及推土机转向制动控制系统 (Bulldozer steering brake control method and bulldozer steering brake control system ) 是由 陈莉 于 2021-08-24 设计创作，主要内容包括：本发明属于推土机技术领域,公开了一种推土机转向制动控制方法及推土机转向制动控制系统。该推土机转向制动控制方法包括以下步骤：获取手柄的动作方向；如果手柄的动作方向为从中位状态切换到转向状态的去程方向,当制动离合器在结合过程时,获取手柄的实际开度变化速率,如果手柄的实际开度变化速率大于等于第一预设开度变化速率,减小手柄对制动离合器的控制电流输出变化率,使制动离合器的实际结合时间大于等于预设时间。该推土机转向制动控制方法,保证制动离合器的最小泄油时间,从而实现制动离合器从开始结合状态到完全结合状态之间具有充足的时间,避免制动离合器因结合迅速带来的冲击,提高驾驶员驾驶的舒适感。(The invention belongs to the technical field of bulldozers, and discloses a bulldozer steering brake control method and a bulldozer steering brake control system. The bulldozer steering brake control method comprises the following steps: acquiring the action direction of the handle; if the action direction of the handle is a going direction for switching from a neutral position state to a steering state, acquiring the actual opening change rate of the handle when the brake clutch is in a combining process, and if the actual opening change rate of the handle is larger than or equal to a first preset opening change rate, reducing the control current output change rate of the handle to the brake clutch, so that the actual combining time of the brake clutch is larger than or equal to the preset time. The bulldozer steering brake control method ensures the minimum oil drainage time of the brake clutch, so that sufficient time is provided between the starting combination state and the complete combination state of the brake clutch, the impact caused by rapid combination of the brake clutch is avoided, and the driving comfort of a driver is improved.)

1. A bulldozer steering brake control method is characterized by comprising the following steps:

acquiring the action direction of the handle;

if the action direction of the handle is a going direction for switching from a neutral position state to a steering state, acquiring the actual opening change rate of the handle when the brake clutch is in a combining process, and if the actual opening change rate of the handle is larger than or equal to a first preset opening change rate, reducing the control current output change rate of the handle to the brake clutch, so that the actual combining time of the brake clutch is larger than or equal to the preset time.

2. The bulldozer steering brake control method according to claim 1, characterised in that it comprises, before obtaining the actual rate of change of opening of the handle, the steps of:

and judging whether the working state of the brake clutch reaches the starting combination point of the sliding film area of the brake clutch, and if so, acquiring the actual opening change rate of the handle.

3. The steering brake control method for a bulldozer according to claim 1, in which if the direction of operation of the lever is the return direction in which the steering state is switched to the neutral state, the actual rate of change of the opening degree of the lever is obtained while the brake clutch is in the disengagement process, and if the actual rate of change of the opening degree of the lever is equal to or greater than a second predetermined rate of change of the opening degree, the rate of change of the control current output from the lever to the brake clutch is increased so that the actual disengagement time of the brake clutch is less than the predetermined time.

4. A bulldozer steering brake control method according to claim 3, characterised in that it comprises, after said rate of change of control current output of the handle to the brake clutch has been increased, the steps of:

acquiring actual control current of a brake clutch;

and judging whether the actual control current of the brake clutch is larger than or equal to the maximum control current, if so, executing a combination action by the steering clutch, and if not, keeping the steering clutch in a disengagement state all the time.

5. The bulldozer steering brake control method according to claim 1, wherein the rate of change of control current output from the handle to the brake clutch is unchanged if the direction of motion of the handle is unchanged.

6. The bulldozer steering brake control method according to any one of claims 1 to 5, wherein said capturing the direction of actuation of the handle comprises the steps of:

detecting an opening input value of the handle in real time;

comparing the current opening input value with the last opening input value of the handle;

when the current opening input value of the handle is larger than the last opening input value, the action direction of the handle is a going direction for switching from a neutral state to a steering state;

when the current opening input value of the handle is smaller than the last opening input value, the action direction of the handle is a return direction for switching from the steering state to the middle state;

when the current opening input value of the handle is equal to the last opening input value, the action direction of the handle is unchanged.

7. The steering brake control method for a bulldozer according to claim 6, in which after the current opening degree input value of the hand lever is greater than the previous opening degree input value, a first cumulative number of cycles N1 is counted and obtained, and if the first cumulative number of cycles N1 is greater than or equal to a first preset number N0, the direction of movement of the hand lever is the direction of forward movement for switching from the neutral state to the steering state.

8. The steering brake control method for a bulldozer according to claim 6, in which a second cumulative number of cycles N2 is counted and obtained after the current opening input value of the lever is smaller than the previous opening input value, and if the second cumulative number of cycles N2 is greater than or equal to a second preset number N0', the direction of movement of the lever is the return direction for switching from the steering state to the neutral state.

9. The bulldozer steering brake control method according to claim 6, wherein the detection time interval of the opening degree input values of the handles in adjacent pairs is 20 ms.

10. A bulldozer steering brake control system, characterized in that control is performed by the bulldozer steering brake control method according to any one of claims 1 to 9, said bulldozer steering brake control system comprising a handle, a steering clutch and a brake clutch, said handle being electrically connected to said steering clutch and said brake clutch, respectively.

Technical Field

The invention relates to the technical field of bulldozers, in particular to a bulldozer steering brake control method and a bulldozer steering brake control system.

Background

The existing bulldozer realizes the steering and braking processes of the whole bulldozer by controlling a steering clutch and a braking clutch. When the bulldozer walks linearly, the braking clutches on the left side and the right side are in a disengaged state, and the steering clutches on the left side and the right side are in a closed state, so that power transmission is realized, and the bulldozer walks linearly; when the bulldozer steers, the brake clutch and the steering clutch on one side are kept unchanged, and for the steered side, the steering clutch on the side is in a disengaged state, and the brake clutch on the side is in an engaged and gradually pressed state, so that the whole process of steering braking is realized.

When the handle is used for steering, the stroke curve of the handle opening degree and the output current curve of the controller are in one-to-one correspondence, the output current controlled by the controller is executed according to a preset steering clutch current control curve and a preset braking clutch current control curve, and the steering clutch and the braking clutch act under the mutual matching of the control currents. The existing bulldozer can have the following problems when the bulldozer is controlled according to the current curves:

firstly, when the handle is switched from the neutral position state to the steering state and the handle is operated too fast, if the current stroke curve of the handle opening degree is still in one-to-one correspondence with the output current curve of the controller, the brake current of the brake clutch can quickly reach the lowest in the process that the handle reaches the maximum opening degree of the travel, so that the oil drainage time of the brake clutch is insufficient, the brake clutch is combined too fast, the impact of the brake clutch is large, and the discomfort of a driver is increased.

Secondly, when the steering state of the handle is switched to a neutral state and the handle is operated too fast, if the pressure rising curve of the brake clutch returns along the curve set by the existing brake clutch along with the speed of the handle, the pressure of the brake clutch is not completely restored when the handle is quickly returned due to the fact that the pressure building and restoring process of the brake pressure of the brake clutch is slow, and the brake clutch inevitably has a hysteresis phenomenon, namely the brake clutch is not completely disengaged, oil leakage of the steering clutch is started, and large impact is generated in the process of returning the handle, so that the frustration is strong, and the driving experience is poor.

Disclosure of Invention

The invention aims to provide a bulldozer steering brake control method and a bulldozer steering brake control system, which realize accurate control during steering brake and reduce impact caused during steering.

In order to achieve the purpose, the invention adopts the following technical scheme:

bulldozer steering brake control method，The method comprises the following steps:

acquiring the action direction of the handle;

if the action direction of the handle is a going direction for switching from a neutral position state to a steering state, acquiring the actual opening change rate of the handle when the brake clutch is in a combining process, and if the actual opening change rate of the handle is larger than or equal to a first preset opening change rate, reducing the control current output change rate of the handle to the brake clutch, so that the actual combining time of the brake clutch is larger than or equal to the preset time.

Preferably, the method comprises the following steps before acquiring the actual opening degree change rate of the handle:

and judging whether the working state of the brake clutch reaches the starting combination point of the sliding film area of the brake clutch, and if so, acquiring the actual opening change rate of the handle.

Preferably, if the action direction of the handle is a return direction for switching from the steering state to the neutral state, when the brake clutch is in the disengagement process, the actual opening change rate of the handle is acquired, and if the actual opening change rate of the handle is greater than or equal to a second preset opening change rate, the control current output change rate of the handle to the brake clutch is increased, so that the actual disengagement time of the brake clutch is less than the preset time.

Preferably, the method comprises the following steps after increasing the rate of change of the control current output of the handle to the brake clutch:

acquiring actual control current of a brake clutch;

and judging whether the actual control current of the brake clutch is larger than or equal to the maximum control current, if so, executing a combination action by the steering clutch, and if not, keeping the steering clutch in a disengagement state all the time.

Preferably, the rate of change of the control current output from the handle to the brake clutch is constant if the direction of motion of the handle is unchanged.

Preferably, the action direction of the acquisition handle comprises the following steps:

detecting an opening input value of the handle in real time;

comparing the current opening input value with the last opening input value of the handle;

when the current opening input value of the handle is larger than the last opening input value, the action direction of the handle is a going direction for switching from a neutral state to a steering state;

when the current opening input value of the handle is smaller than the last opening input value, the action direction of the handle is a return direction for switching from the steering state to the middle state;

when the current opening input value of the handle is equal to the last opening input value, the action direction of the handle is unchanged.

Preferably, after the current opening degree input value of the handle is greater than the last opening degree input value, the first accumulated number of cycles N1 is counted and acquired, and if the first accumulated number of cycles N1 is greater than or equal to the first preset number of cycles N0, the motion direction of the handle is the going direction for switching from the neutral state to the turning state.

Preferably, after the current opening degree input value of the handle is smaller than the last opening degree input value, the second accumulated number of cycles N2 is counted and acquired, and if the second accumulated number of cycles N2 is greater than or equal to the second preset number of cycles N0', the actuating direction of the handle is the return direction for switching from the steering state to the neutral state.

Preferably, the time interval between the detection of the opening degree input value of the handles in two adjacent times is 20 ms.

In order to achieve the purpose, the invention also provides a bulldozer steering brake control system which is controlled by adopting the bulldozer steering brake control method and comprises a handle, a steering clutch and a brake clutch, wherein the handle is respectively and electrically connected with the steering clutch and the brake clutch.

The invention has the beneficial effects that:

the steering brake control method of the bulldozer, provided by the invention, can obtain the action direction of the handle, and a driver can operate the handle to achieve the purposes of walking and steering. When the action direction of the handle is the going direction, and for the side to be steered, the steering clutch of the side is required to be in a disengaged state, and the braking clutch of the side is in an engaged and gradually pressed state. When the brake clutch is in a combining process, if the actual opening change rate of the handle is greater than or equal to the first preset opening change rate, which means that the actual opening change rate of the handle is larger, the change of the handle is too fast, and the basic oil drainage time of the brake clutch cannot be ensured, the inhibition control of the handle opening value change rate needs to be started, the actual combining time of the brake clutch is greater than or equal to the preset time by reducing the control current output change rate of the handle to the brake clutch, and the minimum oil drainage time of the brake clutch is ensured, so that sufficient time is provided between the starting combining state and the complete combining state of the brake clutch, the impact caused by rapid combination of the brake clutch is avoided, and the driving comfort of a driver is improved.

According to the bulldozer steering brake control system, the handle is respectively and electrically connected with the steering clutch and the brake clutch and is used for controlling the on-off of the steering clutch and the on-off of the brake clutch, so that the bulldozer can walk and steer linearly.

Drawings

FIG. 1 is a schematic structural view of a bulldozer steering brake control system according to an embodiment of the present invention;

FIG. 2 is a schematic view showing the relationship between the opening degree of a handle and a control current in a bulldozer steering brake control system according to an embodiment of the present invention;

FIG. 3 is a flowchart of a bulldozer steering brake control method according to a second embodiment of the present invention;

FIG. 4 is a flowchart of a bulldozer steering brake control method according to a third embodiment of the present invention;

FIG. 5 is a flowchart of a bulldozer steering brake control method according to a fourth embodiment of the present invention;

FIG. 6 is a flowchart of a bulldozer steering brake control method according to a fifth embodiment of the present invention;

FIG. 7 is a flowchart of a bulldozer steering brake control method according to a sixth embodiment of the present invention;

FIG. 8 is a flowchart showing a control method of a bulldozer steering brake according to a seventh embodiment of the present invention.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Example one

The embodiment provides a bulldozer steering brake control system, which comprises a handle, a steering clutch and a brake clutch, wherein the handle is respectively and electrically connected with the steering clutch and the brake clutch and is used for controlling the on-off of the steering clutch and the on-off of the brake clutch, so that the bulldozer can walk and steer linearly. The steering clutch is used for left steering and the braking clutch is used for right steering, the braking clutch is used for left wheel braking and the braking clutch is used for right wheel braking.

Specifically, the handle is electrically connected with the controller, and the controller controls the steering clutch and the brake clutch by controlling the steering electromagnetic valve and the brake electromagnetic valve, so that the steering and the braking of the whole machine are controlled. Wherein, the steering clutch and the braking clutch are both normally closed clutches.

FIG. 2 is a schematic diagram showing the relationship between the opening degree of the handle and the control current in the steering brake control system for a bulldozer, the opening degree of the handle being shown on the abscissa, the control current being shown on the ordinate, the control curve for the brake clutch being shown on the solid line, and the control curve for the steering clutch being shown on the dotted line.

As shown in fig. 2, during steering, as the angle of deviation of the handle from the neutral state to the left or right gradually increases, that is, the opening degree of the handle is gradually increased, the steering solenoid valve on the side to be steered is first gradually energized, the steering clutch pressure is gradually increased to a set value as the control current of the steering solenoid valve is gradually increased, the friction plate of the steering clutch is disengaged, and the brake solenoid valve in the disengaged state is gradually powered off, the control current of the brake solenoid valve is gradually reduced, point A represents the starting combination point of the brake clutch, point B represents the combination completion point of the brake clutch, a sliding film area of the brake clutch is formed between the point A and the point B, namely, the friction plates of the brake clutch are gradually combined, the pressure of the brake clutch is gradually reduced to zero, and the braking process is realized after the friction plates of the brake clutch are completely combined.

As shown in fig. 2, during the steering return stroke, as the deviation angle of the handle is gradually reduced to the left or the right, that is, the opening degree of the handle is gradually reduced, the brake solenoid valve is gradually energized, as the control current of the brake solenoid valve is gradually increased, the brake clutch friction plate is in a separated state at the point a, after the brake clutch pressure is gradually increased to a set value, the steering solenoid valve is gradually de-energized, as the control current of the steering solenoid valve is gradually reduced, the steering clutch pressure is gradually reduced to zero, and after the steering clutch friction plate is completely combined, the power combination is realized.

Example two

When the existing handle is in a range of gradually increasing opening degree, because the steering clutch needs to be quickly disengaged and the braking clutch needs to be pressed, if the handle is quickly operated, the control current of the braking clutch can be quickly reduced, the pressure of the braking clutch can be quickly reduced, so that the oil leakage of the braking clutch is too fast, the braking clutch is violently combined, the steering impact is very large, and a driver has extreme discomfort.

In order to solve this problem, the present embodiment provides a bulldozer steering brake control method, which includes the steps of:

firstly, acquiring the action direction of a handle;

the driver can walk and turn by operating the handle. The action direction of the handle comprises a going direction for switching from a neutral state to a steering state, a return direction for switching from the steering state to the neutral state and no change of the action direction.

And secondly, if the action direction of the handle is a going direction for switching from a neutral state to a steering state, acquiring the actual opening change rate of the handle when the brake clutch is in a combining process, and if the actual opening change rate of the handle is greater than or equal to a first preset opening change rate, reducing the control current output change rate of the handle to the brake clutch so that the actual combining time of the brake clutch is greater than or equal to a preset time.

When the action direction of the handle is the going direction, and for the side to be steered, the steering clutch of the side is required to be in a disengaged state, and the braking clutch of the side is in an engaged and gradually pressed state. When the brake clutch is in a combining process, if the actual opening change rate of the handle is greater than or equal to the first preset opening change rate, which means that the actual opening change rate of the handle is larger, the change of the handle is too fast, and the basic oil drainage time of the brake clutch cannot be ensured, the inhibition control of the handle opening value change rate needs to be started, the actual combining time of the brake clutch is greater than or equal to the preset time by reducing the control current output change rate of the handle to the brake clutch, and the minimum oil drainage time of the brake clutch is ensured, so that sufficient time is provided between the starting combining state and the complete combining state of the brake clutch, the impact caused by rapid combination of the brake clutch is avoided, and the driving comfort of a driver is improved.

It can be understood that if the actual opening degree change rate of the handle is smaller than the first preset opening degree change rate, the actual opening degree change rate of the handle is smaller, the change of the handle is within a normal range, the control current output change rate of the handle to the brake clutch is not changed, and the minimum oil drainage time of the brake clutch can be ensured without weakening the control current output change rate of the handle to the brake clutch.

In other words, if the actual opening degree change rate of the handle is relatively large, the control current output change rate of the brake clutch by the handle needs to be weakened, so that the output value of the handle is smaller than the input value of the handle; if the actual opening change rate of the handle is relatively small, the control current output change rate of the brake clutch does not need to be weakened by the handle, so that the output value of the handle is equal to the input value of the handle, namely, the control current output change rate is directly output without conversion.

As shown in FIG. 3, the bulldozer steering brake control method provided in this embodiment comprises the following specific steps:

s1, acquiring the action direction of the handle;

s2, if the action direction of the handle is the going direction for switching from the neutral state to the steering state;

s3, acquiring the actual opening change rate of the handle;

s4, judging whether the actual opening degree change rate of the handle is larger than or equal to a first preset opening degree change rate, if so, executing S5, and if not, executing S6;

s5, reducing the control current output change rate of the handle to the brake clutch, and enabling the actual combination time of the brake clutch to be larger than or equal to the preset time;

and S6, the control current output change rate of the brake clutch is not required to be processed by the handle.

EXAMPLE III

This embodiment is similar to the second embodiment, except for the identification of the operating state of the brake clutch. The method for controlling the steering brake of the bulldozer comprises the following steps before the actual opening change rate of the handle is obtained:

and judging whether the working state of the brake clutch reaches the starting combination point of the sliding film area of the brake clutch, and if so, acquiring the actual opening change rate of the handle.

In order to ensure that the brake clutch has sufficient pressure relief time, whether the state of the brake clutch reaches the initial pressure end of the brake clutch sliding film area is identified, and whether the working state of the brake clutch reaches the initial combination point (shown as point A in figure 2) of the brake clutch sliding film area is judged, which means that the brake clutch slides from the initial combination point and gradually realizes combination of the friction plates, and the clutch can be ensured to have sufficient combination time only by reducing the control current output change rate of the handle to the brake clutch in the combination process of the brake clutch.

Since the operating state of the brake clutch can be characterized by the control current and the internal pressure of the brake clutch, the following two ways can be used to determine whether the operating state of the brake clutch reaches the initial engagement point of the brake clutch diaphragm region.

The first method comprises the following steps:

acquiring actual control current I of a brake clutch;

and judging whether the actual control current I of the brake clutch is equal to a first preset control current I1, if so, judging that the state of the brake clutch reaches the initial combination point of the sliding film area of the brake clutch.

It can be understood that when the second preset control current I2 < the actual control current I of the brake clutch < the first preset control current I1, the state of the brake clutch is a gradually engaged state, i.e., enters the slip film region T1; when the actual control current I of the brake clutch is equal to the second preset control current I2, the brake clutch reaches the engagement completion point of the brake clutch diaphragm region.

And the second method comprises the following steps:

acquiring actual pressure of a brake clutch;

and judging whether the actual pressure of the brake clutch is greater than or equal to a first preset pressure, if so, judging that the state of the brake clutch reaches the starting combination point of a sliding film area of the brake clutch.

It is understood that a pressure sensor is provided inside the brake clutch, and the actual pressure of the brake clutch is detected by the pressure sensor.

As shown in FIG. 4, the bulldozer steering brake control method provided in this embodiment comprises the following specific steps:

s1, acquiring the action direction of the handle;

s2, the action direction of the handle is the going direction for switching from the neutral state to the steering state;

s21, judging whether the working state of the brake clutch reaches the starting connection point of the sliding film area of the brake clutch, if so, executing S3; if not, executing S6;

s3, acquiring the actual opening change rate of the handle;

s4, judging whether the actual opening degree change rate of the handle is larger than or equal to a first preset opening degree change rate, if so, executing S5, and if not, executing S6;

s5, reducing the control current output change rate of the handle to the brake clutch, enabling the actual combination time of the brake clutch to be larger than or equal to the preset time, and returning to S1;

and S6, the control current output change rate of the brake clutch is not processed by the handle, and the process returns to S1.

Example four

When the existing handle returns in a return stroke with gradually-reduced opening degree, if the handle returns quickly, the control current of the brake clutch returns according to an original curve, because the brake clutch has a hysteresis phenomenon inevitably, the pressure of the brake clutch is recovered too slowly, so that the pressure recovery of the brake clutch is delayed, the brake clutch is not completely disengaged, the steering clutch begins to drain oil, the brake clutch and the steering clutch generate large impact due to mutual interference, and the jerking feeling is strong.

In order to solve this problem, the bulldozer steering brake control method provided in this embodiment further includes the steps of:

if the action direction of the handle is a return direction for switching from the steering state to the neutral state, when the brake clutch is in a disengagement process, acquiring the actual opening change rate of the handle, and if the actual opening change rate of the handle is greater than or equal to a second preset opening change rate, increasing the control current output change rate of the handle to the brake clutch, so that the actual disengagement time of the brake clutch is less than the preset time. The first preset opening degree change rate and the second preset opening degree change rate may be the same or different, and it is preferable that the first preset opening degree change rate and the second preset opening degree change rate are the same in this embodiment.

When the action direction of the handle is the going direction, and for the side which is turned before, after the brake clutch on the side is gradually switched from the engaged state to the disengaged state, the steering clutch on the side is switched from the disengaged state to the engaged state. When the brake clutch is in a disengaging process, the actual opening change rate of the handle is obtained and is used for judging the return stroke change condition of the handle, if the actual opening change rate of the handle is larger than or equal to a second preset opening change rate, the actual opening change rate of the handle is larger, if the handle is changed too fast, the brake clutch returns back according to an original preset curve, the pressure of the brake clutch is possibly recovered too slowly, the following performance of the pressure of the brake clutch and the change of the handle is poor, the speed of the handle output value is accelerated by increasing the control current output change rate of the handle to the brake clutch, the pressure of the brake clutch can be recovered quickly, the pressure of the brake clutch and the following performance of the handle are good, the pause feeling caused by large impact is avoided, and the driving experience of a driver is improved.

As shown in FIG. 5, the bulldozer steering brake control method provided in the present embodiment includes the steps of:

s1, acquiring the action direction of the handle;

s7, if the action direction of the handle is the return direction for switching from the steering state to the neutral state;

s8, acquiring the actual opening change rate of the handle;

s9, judging whether the actual opening degree change rate of the handle is larger than or equal to a second preset opening degree change rate, if so, executing S10, and if not, executing S6;

s10, increasing the control current output change rate of the handle to the brake clutch to ensure that the actual disengagement time of the brake clutch is less than the preset time, and returning to S1;

and S6, the control current output change rate of the brake clutch is not processed by the handle, and the process returns to S1.

EXAMPLE five

In the present embodiment, the steering clutch is further controlled based on the fourth embodiment.

The bulldozer steering brake control method provided by the embodiment comprises the following steps after the control current output change rate of the brake clutch by the handle is increased:

acquiring actual control current of a brake clutch;

and judging whether the actual control current of the brake clutch is larger than or equal to the maximum control current, if so, executing a combination action by the steering clutch, and if not, keeping the steering clutch in a disengagement state all the time.

Because of the relationship of mechanical structure, the steering clutch and the braking clutch can not be interfered with each other, namely the steering clutch and the braking clutch can not drain oil simultaneously, and the steering clutch can drain oil only after the pressure of the braking clutch is completely recovered. When the actual control current of the brake clutch exceeds the first preset control current and reaches the maximum control current, the friction plate of the brake clutch is just in a complete and thorough disengagement state. Therefore, when the actual control current of the brake clutch is larger than or equal to the maximum control current, the steering clutch executes a combination action, namely oil drainage can be performed only after the pressure of the brake clutch is completely recovered, and the steering clutch can ensure that oil drainage has certain time. In other words, in the return stroke, after the pressure of the brake clutch is restored, the steering clutch may start the drain process with a predetermined current curve.

As shown in fig. 6, the bulldozer steering brake control method provided in the present embodiment includes the steps of:

s1, acquiring the action direction of the handle;

s7, if the action direction of the handle is the return direction for switching from the steering state to the neutral state;

s8, acquiring the actual opening change rate of the handle;

s9, judging whether the actual opening degree change rate of the handle is larger than or equal to a second preset opening degree change rate, if so, executing S10, and if not, executing S6;

s10, increasing the control current output change rate of the handle to the brake clutch to ensure that the actual disengagement time of the brake clutch is less than the preset time;

s11, acquiring actual control current of the brake clutch;

s12, judging whether the actual control current of the brake clutch is larger than or equal to the maximum control current, if so, executing S13, and if not, executing S14;

s13, the steering clutch executes the combination action and returns to S1;

s14, the steering clutch is always in a disengaged state, and the operation returns to S1;

and S6, the control current output change rate of the brake clutch is not processed by the handle, and the process returns to S1.

EXAMPLE six

In the method for controlling the steering brake of the bulldozer, when the change direction of the opening degree of the handle is forward travel, if the actual opening degree change rate of the handle is relatively large, the change rate of the control current output of the handle to the brake clutch is reduced to a certain extent, the oil drainage process of the brake clutch is delayed, the actual combination time of the brake clutch is more than or equal to the preset time, so that the brake clutch has sufficient combination time, and the impact is reduced; when the change direction of the opening degree of the handle is a return stroke, the control current output change rate of the handle to the brake clutch can be increased to a certain extent, the pressure recovery of the brake clutch is accelerated, the recovery time is shortened, and the reaction agility of the whole vehicle is improved while good driving experience is ensured.

If the action direction of the handle is not changed, the control current output change rate of the handle to the brake clutch is not changed. The action direction of the handle is not changed, namely the actual opening degree change rate of the handle is zero, and the control current output change rate of the brake clutch does not need to be weakened by the handle, so that the output value of the handle is equal to the input value of the handle, namely the output is directly output without conversion.

As shown in fig. 7, the bulldozer steering brake control method provided in the present embodiment includes the steps of:

s1, acquiring the action direction of the handle;

s2, if the action direction of the handle is the going direction for switching from the neutral state to the steering state;

s21, judging whether the working state of the brake clutch reaches the starting connection point of the sliding film area of the brake clutch, if so, executing S3; if not, executing S6;

s3, acquiring the actual opening change rate of the handle;

s4, judging whether the actual opening degree change rate of the handle is larger than or equal to a first preset opening degree change rate, if so, executing S5, and if not, executing S6;

s5, reducing the control current output change rate of the handle to the brake clutch, and enabling the actual combination time of the brake clutch to be larger than or equal to the preset time;

s6, the control current output change rate of the brake clutch does not need to be processed by the handle;

s7, if the action direction of the handle is the return direction for switching from the steering state to the neutral state;

s8, acquiring the actual opening change rate of the handle;

s9, judging whether the actual opening degree change rate of the handle is larger than or equal to a second preset opening degree change rate, if so, executing S10, and if not, executing S6;

s10, increasing the control current output change rate of the handle to the brake clutch to ensure that the actual disengagement time of the brake clutch is less than the preset time;

s11, acquiring actual control current of the brake clutch;

s12, judging whether the actual control current of the brake clutch is larger than or equal to the maximum control current, if so, executing S13, and if not, executing S14;

s13, executing a combination action by the steering clutch;

s14, the steering clutch is always in a disengaged state;

s15, if the action direction of the handle is not changed, executing S6.

EXAMPLE seven

In this embodiment, the movement direction of the grip is described in detail in addition to the sixth embodiment.

The method for controlling the steering brake of the bulldozer, which is provided by the embodiment, comprises the following steps of:

firstly, detecting an opening input value of a handle in real time;

the opening input value of the handle is detected in real time, so that the opening input value is conveniently recorded every time. The detection time interval of the opening input values of the handles in two adjacent times is 20ms, the opening input values of the handles are collected by the sensor, and the controller controls the sensor to collect the opening of the handles once every 20ms so as to ensure the detection accuracy.

It should be noted that the sensor may actually acquire a parameter that is a handle opening voltage value, and then convert the parameter, and may be characterized by a percentage or a numerical value in an interval of 0 to 255.

Secondly, comparing the current opening input value with the last opening input value of the handle;

for example, after the opening degree input value of the first handle is detected, the opening degree input values of the first and second handles are compared, and after the third handle opening degree value detection is completed, the opening degree input values of the second and third handles are compared, and so on.

Thirdly, when the current opening input value of the handle is larger than the last opening input value, the action direction of the handle is a forward direction for switching from the neutral state to the steering state;

if the present opening degree input value of the handle is greater than the last opening degree input value, it may be determined that the angle by which the handle deviates leftward or rightward from the neutral position state gradually increases, meaning that the opening degree of the handle has a tendency to increase, so that it is possible to define the actuation direction of the handle as a forward direction in which the steering to the left or right is performed, from the neutral position state to the steering state.

Fourthly, when the current opening input value of the handle is smaller than the last opening input value, the action direction of the handle is a return direction for switching from the steering state to the neutral state;

if the present opening degree input value of the handle is smaller than the last opening degree input value, it may be determined that the angle by which the handle deviates leftward or rightward from the neutral position state gradually decreases, meaning that the opening degree of the handle has a tendency to decrease, so that it is possible to define the actuating direction of the handle as a return direction for switching from the steering state to the neutral position state, the return direction being a direction for returning to the neutral position after performing the steering direction to the left or right.

And fifthly, when the current opening input value of the handle is equal to the last opening input value, the action direction of the handle is unchanged.

If the current opening degree input value of the handle is equal to the last opening degree input value, it can be determined that the angle of the handle deviating to the left or right with respect to the neutral position state is constant, meaning that the opening degree of the handle remains constant, and thus it can be defined that the motion direction of the handle is not changed.

If the direction of the handle opening is determined only by comparing the opening input value of the handle at this time with the opening input value at the last time, various errors can be inevitably generated in the real-time monitoring process, and the detection effect is influenced.

In order to ensure the accuracy of determining the action direction of the handle, after the current opening input value of the handle is greater than the last opening input value, a first accumulated cycle number N1 is counted and obtained, and if the first accumulated cycle number N1 is greater than or equal to a first preset number N0, the action direction of the handle is a going direction for switching from a neutral state to a steering state.

Specifically, if the current opening degree input value of the handle is greater than the last opening degree input value, the count of the occurrence times Flag1 is started, and as long as the current opening degree input value of the handle is greater than the last opening degree input value, the sequential times of superposition and accumulation are performed, that is, Flag1 is Flag1+1, so as to obtain the first accumulated number of times N1, if the first accumulated number of times N1 is greater than or equal to the first preset number of times N0, the first preset number of times N0 is preferably 3 times, that is, if the current opening degree input value of the handle is greater than the last opening degree input value in three consecutive comparisons, it can be determined more accurately, and the motion direction of the handle is the forward direction for switching from the neutral state to the steering state.

In order to ensure the accuracy of determining the action direction of the handle, after the current opening degree input value of the handle is smaller than the last opening degree input value, a second accumulated cycle number N2 is counted and obtained, and if the second accumulated cycle number N2 is larger than or equal to a second preset number N0', the action direction of the handle is a return direction for switching from a steering state to a neutral state.

Specifically, if the current opening degree input value of the handle is smaller than the last opening degree input value, the count of the occurrence times Flag2 is started, and as long as the current opening degree input value of the handle is smaller than the last opening degree input value, the sequential times of superposition and accumulation are performed, that is, Flag2 is Flag2+1, so as to obtain the second cumulative cycle number N2, if the second cumulative cycle number N2 is greater than or equal to the second preset number N0 ', the second preset number N0' is preferably 3, that is, if the current opening degree input value of the handle is smaller than the last opening degree input value in three consecutive comparisons, it can be determined more accurately, and the action direction of the handle is a return direction in which the steering state is switched to the neutral state.

As shown in FIG. 8, the method for controlling the steering brake of a bulldozer according to the present embodiment comprises the following steps:

s100, detecting an opening input value of a handle in real time;

s200, comparing the current opening input value with the last opening input value of the handle;

s300, if the current opening input value of the handle is larger than the last opening input value;

s301, counting and acquiring a first accumulated cycle number N1;

s302, judging whether the first accumulated cycle time N1 is larger than or equal to a first preset time N0, if so, executing S303, and if not, executing S304;

s303, the action direction of the handle is a forward travel direction for switching from the neutral state to the steering state, and the process returns to S100;

s304, the action direction of the handle is unchanged, and the operation returns to S100;

s400, if the current opening input value of the handle is smaller than the last opening input value;

s401, counting and acquiring a second accumulated cycle number N2;

s402, judging whether the second accumulated cycle time N2 is larger than or equal to a second preset time N0', if so, executing S403, and if not, executing S304;

s403, the action direction of the handle is a return direction for switching from the steering state to the neutral state, and the process returns to S100;

and S500, if the current opening input value of the handle is equal to the last opening input value, executing S304.

In the description herein, it is to be understood that the terms "upper", "lower", "right", and the like are based on the orientations and positional relationships shown in the drawings and are used for convenience in description and simplicity in operation, but do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be constructed in a particular operation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used merely for descriptive purposes and are not intended to have any special meaning.

In the description herein, references to the description of "an embodiment," "an example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example.

In addition, the foregoing is only the preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.