阅读说明：本技术 一种全液压推土机 (Full hydraulic bulldozer ) 是由 朱耿寅 赵晓云 秦贞佩 关祥龙 姜友山 于 2019-09-17 设计创作，主要内容包括：本发明提出一种全液压推土机,包括控制单元和执行单元,控制单元包括操作机构,执行单元包括至少一个数字变量泵、至少一个数字变量马达、补油泵和控制器,数字变量泵与发动机刚性连接,数字变量泵和数字变量马达构成闭合回路,数字变量泵的输出轴上设有扭矩传感器,数字变量马达的输出轴上设有转速传感器,补油泵与数字变量泵以及数字变量马达相连接,控制器与数字变量泵、数字变量马达、扭矩传感器以及转速传感器电连接,控制器配置为根据扭矩传感器的反馈信号生成数字变量泵的控制量,根据转速传感器的反馈信号生成数字变量马达的控制量,操作机构与控制器电连接。(The invention provides an all-hydraulic bulldozer, which comprises a control unit and an execution unit, wherein the control unit comprises an operating mechanism, the execution unit comprises at least one digital variable pump, at least one digital variable motor, an oil supplementing pump and a controller, the digital variable pump is rigidly connected with an engine, the digital variable pump and the digital variable motor form a closed loop, a torque sensor is arranged on an output shaft of the digital variable pump, a rotating speed sensor is arranged on an output shaft of the digital variable motor, the oil supplementing pump is connected with the digital variable pump and the digital variable motor, the controller is electrically connected with the digital variable pump, the digital variable motor, the torque sensor and the rotating speed sensor, the controller is configured to generate the control quantity of the digital variable pump according to a feedback signal of the torque sensor, the control quantity of the digital variable motor is generated according to the feedback signal of the rotating speed sensor, and the operating mechanism is electrically connected with the controller.)

1. The full hydraulic bulldozer is characterized by comprising a control unit and an execution unit, wherein the control unit comprises an operating mechanism, the execution unit comprises at least one digital variable pump, at least one digital variable motor, an oil supplementing pump and a controller,

The digital variable pump is rigidly connected with the engine, the digital variable pump and the digital variable motor form a closed loop, a torque sensor is arranged on an output shaft of the digital variable pump, a rotating speed sensor is arranged on an output shaft of the digital variable motor,

The oil supplementing pump is connected with the digital variable pump and the digital variable motor,

The controller is electrically connected with the digital variable pump, the digital variable motor, the torque sensor and the rotating speed sensor, the controller is configured to generate a control quantity of the digital variable pump according to a feedback signal of the torque sensor and generate a control quantity of the digital variable motor according to a feedback signal of the rotating speed sensor,

the operating mechanism is electrically connected with the controller.

2. The bulldozer according to claim 1, wherein said execution unit further comprises a filter, an oil distribution block, and a brake directional control valve, said oil supply pump being connected to said oil distribution block through said filter, said oil supply pump supplying hydraulic oil to said digital variable pump, said digital variable motor, and said brake directional control valve through said oil distribution block, respectively.

3. The bulldozer of claim 1, wherein said execution unit further comprises a latch, said latch being electrically connected to said controller.

4. the bulldozer according to claim 1, wherein said control unit further comprises a sample holder and an a/D converter, said sample holder being electrically connected to said a/D converter, and said operating mechanism being electrically connected to said controller via said sample holder and said a/D converter.

5. a dozer as claimed in claim 4, wherein the operating mechanism is a control handle.

6. The motor grader as in claim 1 wherein said operating mechanism further comprises a bumper, said operating mechanism being electrically connected to said controller through said bumper.

7. The bulldozer of claim 1, further comprising an interaction unit, said interaction unit including a keyboard and a display, said keyboard and said display being electrically connected to said controller.

8. The bulldozer according to claim 1, further comprising an external communication unit electrically connected to said controller via a timer counter.

9. The bulldozer according to claim 1, in which said execution unit includes a first digital variable pump, a second digital variable pump, a first digital variable motor, a second digital variable motor,

The first digital variable pump and the second digital variable pump are rigidly connected with the engine, the first digital variable pump and the first digital variable motor form a closed loop, the second digital variable pump and the second digital variable motor form a closed loop, output shafts of the first digital variable pump and the second digital variable pump are respectively provided with a first torque sensor and a second torque sensor, and output shafts of the first digital variable motor and the second digital variable motor are respectively provided with a first rotating speed sensor and a second rotating speed sensor.

10. The bulldozer of claim 9, wherein said first digital variable displacement pump and said second digital variable displacement pump are rigidly coupled to said engine by couplings.

Technical Field

the embodiment of the invention relates to the engineering machinery technology, in particular to a full-hydraulic bulldozer.

Background

The bulldozer is suitable for pushing, excavating, backfilling earthwork and other bulk cargo operations on the ground of roads, railways, mines, airports and the like, and is indispensable mechanical equipment for construction of national defense engineering, mine construction, urban and rural roads and the like and water conservancy construction and the like.

The traditional full hydraulic bulldozer mainly drives a walking pump by an engine, then drives a walking motor by a hydraulic system, and then drives a track by final drive to realize walking. Because the traditional full-hydraulic bulldozers drive the caterpillar tracks to finally walk by means of final transmission, the bulldozers with different horsepower all need to design a unique final transmission (speed reducer), but the final transmission is easy to wear and heat internal parts in work, so that the maintenance is very inconvenient. The problems of the conventional full hydraulic bulldozer also include: under the shoveling working condition, the resistance of bulldozing is very large, and the engine always works near the maximum torque, so that the power loss of the engine is caused. The earth moving and unloading conditions are slightly less in earth moving resistance, but can also cause loss of engine power. In a reverse working condition, the bulldozer has small resistance to bulldozing, and the bulldozer is often required to have high speed and low oil consumption, and although the power loss of the engine is small, the oil consumption is high.

Disclosure of Invention

The invention provides an all-hydraulic bulldozer, wherein an engine of the all-hydraulic bulldozer can work in an optimal working area, so that the aims of reducing the fuel consumption of the engine and saving energy are fulfilled.

The embodiment of the invention provides an all-hydraulic bulldozer, which comprises a control unit and an execution unit, wherein the control unit comprises an operating mechanism, and the execution unit comprises at least one digital variable pump, at least one digital variable motor, an oil supplementing pump and a controller. The digital variable pump is rigidly connected with the engine, the digital variable pump and the digital variable motor form a closed loop, a torque sensor is arranged on an output shaft of the digital variable pump, and a rotating speed sensor is arranged on an output shaft of the digital variable motor. The oil supplementing pump is connected with the digital variable pump and the digital variable motor. The controller is electrically connected with the digital variable pump, the digital variable motor, the torque sensor and the rotating speed sensor, and the controller is configured to generate a control quantity of the digital variable pump according to a feedback signal of the torque sensor and generate a control quantity of the digital variable motor according to a feedback signal of the rotating speed sensor. The operating mechanism is electrically connected with the controller.

furthermore, the execution unit further comprises a filter, an oil distribution block and a brake reversing valve, the oil supplementing pump is connected with the oil distribution block through the filter, and the oil supplementing pump respectively provides hydraulic oil for the digital variable pump, the digital variable motor and the brake reversing valve through the oil distribution block.

Further, the execution unit further comprises a latch, and the latch is electrically connected with the controller.

Further, the control unit further comprises a sample holder and an A/D converter, the sample holder is electrically connected with the A/D converter, and the operating mechanism is electrically connected with the controller through the sample holder and the A/D converter.

Further, the operating mechanism is a control handle.

further, the operating mechanism further comprises a buffer, and the operating mechanism is electrically connected with the controller through the buffer.

Further, the intelligent terminal also comprises an interaction unit, wherein the interaction unit comprises a keyboard and a display, and the keyboard and the display are electrically connected with the controller.

Further, the controller also comprises an external communication unit which is electrically connected with the controller through a timing counter.

Further, the execution unit comprises a first digital variable pump, a second digital variable pump, a first digital variable motor and a second digital variable motor,

The first digital variable pump and the second digital variable pump are rigidly connected with the engine, the first digital variable pump and the first digital variable motor form a closed loop, the second digital variable pump and the second digital variable motor form a closed loop, output shafts of the first digital variable pump and the second digital variable pump are respectively provided with a first torque sensor and a second torque sensor, and output shafts of the first digital variable motor and the second digital variable motor are respectively provided with a first rotating speed sensor and a second rotating speed sensor.

further, the first digital variable pump and the second digital variable pump are rigidly connected with the engine through a coupling.

Compared with the prior art, the invention has the beneficial effects that: the full-hydraulic bulldozer provided by the invention has a compact structure, can realize power matching between the digital variable pump and the engine, ensures that the engine works in an optimal working area, reduces the fuel consumption of the engine and saves energy. The full hydraulic bulldozing and digital control method can improve the operation comfort and the operation quality.

drawings

FIG. 1 is a schematic structural view of an all-hydraulic bulldozer in the embodiment;

FIG. 2 is a schematic structural view of another all-hydraulic bulldozer in the embodiment;

FIG. 3 is a schematic structural view of another all-hydraulic bulldozer in the embodiment;

FIG. 4 is a diagram illustrating an exemplary embodiment of an execution unit;

FIG. 5 is a block diagram of a control method of the all-hydraulic bulldozer in the embodiment.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic structural diagram of an all-hydraulic bulldozer in the embodiment, and referring to fig. 1, the embodiment proposes an all-hydraulic bulldozer, which includes a control unit 1 and an execution unit 2, the control unit 2 includes an operating mechanism 101, and the execution unit 2 includes at least one digital variable pump 201, at least one digital variable motor 202, an oil make-up pump 203 and a controller 204. The digital variable pump 201 is rigidly connected with the engine 205, the digital variable pump 201 and the digital variable motor 202 form a closed loop, a torque sensor is arranged on an output shaft of the digital variable pump 201, and a rotating speed sensor is arranged on an output shaft of the digital variable motor 202. The charge oil pump 203 is connected to the digital variable pump 201 and the digital variable motor 202. The controller 204 is electrically connected to the digital variable pump 201, the digital variable motor 202, the torque sensor, and the rotation speed sensor, and the controller 204 is configured to generate a control amount of the digital variable pump 201 based on a feedback signal of the torque sensor and generate a control amount of the digital variable motor 202 based on a feedback signal of the rotation speed sensor. The operating mechanism 101 is electrically connected to the controller 204. The operating mechanism 101 is used to input a control instruction to the controller 204.

Optionally, the digital variable pump 201 is a digital variable plunger pump, and the digital variable motor 202 is a digital variable plunger motor. Alternatively, the digital variable displacement pump 201 may be rigidly connected to the engine 205 by a coupling.

The full hydraulic bulldozer provided by the embodiment is a closed system. That is, the digital variable pump 201 and the digital variable motor 202 form a closed pump structure, and the closed pump structure proposed in this embodiment has a small volume and a large power, and can achieve a good energy saving effect. The controller 204 collects a torque signal of the digital variable pump 201 through the torque sensor, a control signal aiming at the digital variable pump 201 is generated according to the torque signal, a closed-loop control link is formed between the controller 204 and the digital variable pump 201, and the control signal aiming at the digital variable pump 201 can be corrected according to the actual working condition of the engine through the closed-loop control link, so that the engine 205 and the digital variable pump 201 can be effectively matched when the throttle is arranged at different positions, and the oil consumption of the full hydraulic bulldozer during operation is further reduced.

similar to the digital variable pump 201, a closed-loop control system is also formed between the controller 204 and the digital variable motor 202, and the controller 204 directly generates a control signal for the digital variable motor 202, so that stepless speed regulation of the full hydraulic bulldozer can be realized, namely, how much driving speed can be obtained by how much driving speed is required, and thus, a speed reducer is not required in the full hydraulic bulldozer, and meanwhile, the controller 204 directly receives a rotating speed signal of the digital variable motor 202, so that when a plurality of variable motors 202 are used, the controller 204 can accurately stabilize the rotating speed of each digital variable motor 202 at a specified rotating speed, and thus, the single crawler driven by the digital variable motor 202 does not have gradual change or jump of speed, thereby effectively avoiding the phenomenon of 'deviation' and improving the operation quality.

In order to realize accurate control of the digital variable pump 201 and the digital variable motor 202 under complex conditions, the present embodiment adopts a fuzzy control method to generate the control quantities of the digital variable pump 201 and the digital variable motor 202. Specifically, in the present embodiment, a three-dimensional fuzzy control method is adopted, that is, an error of the torque signal or the rotational speed signal, an increment of the error, and an increment of the error are used as inputs, and a fuzzy control rule is established for the control signals of the motors of the digital variable pump 201 and the digital variable motor 202 as outputs. The error of the torque and the rotating speed is calculated by the following formula:

E(U(T))＝K₁×e(U(T_k))＝K₁×[R_T-y(U(T_k))]

E(U(V))＝K₁×e(U(V_k))＝K₁×[R_V-y(U(V_k))]

The increment of the error is calculated by the following formula:

ΔE(U(T))＝K₂×Δe(U(T_k))＝K₂×[e(U(T_k))-e(U(T_k-1))]

ΔE(U(V))＝K₂×Δe(U(V_k))＝K₂×[e(U(V_k))-e(U(V_k-1))]

The increment of the error increment is calculated by the following formula:

ΔE²(U(T))＝K₃×Δe²(U(T_k))＝K₃×[Δe(U(T_k))-Δe(U(T_k-1))]

ΔE²(U(V))＝K₃×Δe²(U(V_k))＝K₃×[Δe(U(V_k))-Δe(U(V_k-1))]

in the above equation, K ₁, K ₂, K ₃ are quantization factors of linguistic variables, R _T, R _V are set initial control signal reference values, U (T _k), U (V _k) are a sequence of torque and rotation speed output by a torque sensor and a rotation speed sensor, y (U (T _k), y (U (V _k) are control signals corresponding to the above sequence, the rotation speed or torque of the engine 205 is regarded as a univariate function of the throttle opening degree, at this time, each throttle opening degree value may correspond to a rotation speed or torque of the engine 205, that is, each throttle opening degree value may correspond to power of the engine 205, based on which, a power balance mode is constructed:

M_en_e＝f(ΔP，S，T)

Based on the above power balance equation, an initial reference torque may be determined by combining an accelerator opening value and an initial displacement of the digital variable pump 201, and then an initial control signal reference value R _T may be set according to the initial reference torque, so that when the all-hydraulic bulldozer is in a certain operating condition, if the torque of the digital variable pump 201 changes, the controller 204 may generate a control signal for the digital variable pump 201, and further change the displacement of the digital variable pump 201, so that power matching between the engine 205 and the digital variable pump 201 may be achieved.

fig. 5 is a block diagram of a control method of the full hydraulic bulldozer in the embodiment, referring to fig. 5, the same as the two-dimensional fuzzy control, and the three-dimensional fuzzy control process is as follows:

Step 1, calculating errors E (U (T)), E (U (V)) of torque and rotating speed, error increments delta E (U (T), delta E (U (V)), error increment delta E ² (U (T)) and delta E ² (U (V));

Step 2, fuzzifying the accurate error, the error increment and the increment of the error increment to obtain fuzzy quantity;

step 3, making a decision according to a fuzzy control rule to obtain a fuzzy control quantity;

and 4, converting the fuzzy control quantity into an accurate control signal.

Wherein the blurring method is the same as the two-dimensional blurring control. For example, to simplify the complexity of three-dimensional fuzzy control, the control rules may be described in the form of a paging table, i.e., an error corresponding to an increment of an error increment of different states (word variables) and a state and a corresponding control strategy in which the error increment may occur are established. For example, the error (a), the error increment (B), and the increment of the error increment all have five states NB, NS, ZO, PS, and PB, and when the increment of the error increment belongs to the state NB, the fuzzy control rule is as shown in table 1:

TABLE 1

When the increment of the error increment belongs to other four states, the fuzzy control rule table is similar to table 1, and is not described herein again. Illustratively, the fuzzy control quantity is converted into a precise control signal by a weighted average method, the control signal acts on the stepping motors of the digital variable pump 201 and the digital variable motor 202, and the precise control of the stepping motors causes the precise movement of the pistons of the digital cylinders of the digital variable pump 201 and the digital variable motor 202, so as to rotate the swash plates in the digital variable pump 201 and the digital variable motor 202 to a specified inclination angle. The flow of hydraulic oil in the closed pump structure is controlled by controlling the inclination angle of the swash plate in the digital variable pump 201, so that the power matching between the digital variable pump 201 and the engine 205 is realized. The control of the advancing speed and the advancing direction of the full-hydraulic bulldozer is realized by controlling the inclination angle of the swash plate in the digital variable motor 202, specifically, the advancing and the backing of the full-hydraulic bulldozer are realized by changing the inclination direction of the swash plate, and the advancing speed of the full-hydraulic bulldozer is changed by changing the inclination angle of the swash plate.

The performance of the travel control system of the full hydraulic bulldozer is an important factor influencing the performance of the bulldozer, and determines the level of operation productivity. The execution unit provided by the embodiment is a core component in the driving control system, and the control method of utilizing the execution unit and combining the execution unit can reduce the labor intensity of operators and improve the economy and the dynamic property of the operation of the full hydraulic bulldozer.

Fig. 2 is a schematic structural diagram of another all-hydraulic bulldozer in the embodiment, referring to fig. 2, optionally, the execution unit 2 further includes a filter 206, an oil distribution block 207, and a brake directional valve 208, the oil supply pump 203 is connected to the oil distribution block 207 through the filter 206, and the oil supply pump 203 supplies hydraulic oil to the digital variable pump 201, the digital variable motor 202, and the brake directional valve 208 through the oil distribution block 207, respectively.

The transmission shaft of the oil supply pump 203 is connected in series with the transmission shaft of the digital variable pump 201, the oil supply pump 203 is mainly used for improving the oil absorption performance of a closed pump structure formed by the digital variable pump 201 and the digital variable motor 202, and meanwhile, hydraulic oil is supplied to a rod cavity of the digital variable pump 201 and a rodless cavity of the digital variable motor 202, so that the stepping motors in the digital variable pump 201 and the digital variable motor 202 can drive the swash plate to move. When the oil replenishing pump 203 replenishes the hydraulic oil leaked in the closed pump structure, a certain heat dissipation effect can be achieved. Optionally, in order to improve the heat dissipation effect, a flush valve may be installed on the digital variable displacement pump 201, a certain amount of hot hydraulic oil is led out from the closed pump structure through the flush valve, enters an oil tank of the oil supply pump 203, and then cooled hydraulic oil is supplied to the closed pump structure through the oil supply pump 203, so as to accelerate the heat dissipation.

optionally, the execution unit 2 further includes a latch 209, and the latch 209 is electrically connected to the controller 204. The control signal generated by the controller 204 is stored by the latch, and the jitter of the control signal output by the controller 204 is reduced by the latch 209. The latch 209 may be a functional unit on the controller 204 or a latch unit independent from the controller 204.

Preferably, the control unit 2 further includes a sample holder 102 and an a/D converter 103, the sample holder 102 is electrically connected to the a/D converter 103, and the operating mechanism 101 is electrically connected to the controller 204 through the sample holder 102 and the a/D converter 103. For ease of operation, the operating mechanism 101 is a control handle. In this embodiment, the control handle body is provided with a stroke switch in the front-back direction and a stroke sensor in the left-right direction, and command signals output by the stroke switch and the stroke sensor are converted into digital signals through the sampling holder 102 and the a/D converter 103, so that high-precision control of the digital variable pump 201 and the digital variable motor 202 is realized.

The optional operating mechanism 101 also includes a damper through which the operating mechanism 101 is electrically connected to the controller 204. The full hydraulic bulldozer may be provided with a plurality of operating mechanisms 101, for example, a control handle and a digital signal input device (for example, PLC device) may be provided at the same time, and at this time, the digital signal input device is electrically connected to the controller 204 through a buffer, and a command signal of the digital signal input device is temporarily stored through the buffer, so that the controller 204 can obtain the command signal, and the digital signal input device and the controller 204 can work in coordination.

fig. 3 is a schematic structural view of another all-hydraulic bulldozer according to the embodiment, and referring to fig. 3, the all-hydraulic bulldozer further includes an interaction unit 4, the interaction unit 4 includes a keyboard 401 and a display 402, and the keyboard 401 and the display 402 are electrically connected to the controller 204. The keyboard 401 is used to input an instruction for adjusting the main control program into the controller 204. The display 402 is mainly used for displaying relevant control parameters of the full hydraulic bulldozer.

The full hydraulic bulldozer in the embodiment may further comprise an external communication unit 5, and the external communication unit 5 is electrically connected to the controller 204 through the timer counter 6. Illustratively, the external communication unit 5 may be a remote control device by which unmanned driving is achieved, wherein the timing counter 6 is used to perform timing sampling of the command signal sent by the external communication unit 5 in order to achieve high-precision control of the all-hydraulic bulldozer.

Fig. 4 is a schematic diagram of an execution unit structure in the embodiment, and referring to fig. 4, as an alternative, the execution unit 2 includes a first digital variable pump 21, a second digital variable pump 22, a first digital variable motor 24, and a second digital variable motor 23. The first digital variable pump 21 and the second digital variable pump 22 are rigidly connected to the engine 205, the first digital variable pump 21 and the first digital variable motor 24 form a closed loop, and the second digital variable pump 22 and the second digital variable motor 23 form a closed loop. The output shafts of the first digital variable pump 21 and the second digital variable pump 22 are respectively provided with a first torque sensor and a second torque sensor. The output shafts of the first digital variable motor 24 and the second digital variable motor 23 are respectively provided with a first rotating speed sensor and a second rotating speed sensor. Wherein, the first digital variable pump 21 and the second digital variable pump 22 form a serial pump structure. Alternatively, the first and second digital variable pumps 21 and 22 may be rigidly connected to the engine 205 through a transfer case.

The control of the left and right driving wheels of the full hydraulic bulldozer can be independently finished by arranging two digital variable pumps and two digital variable motors. The design complexity of the control method is reduced, and meanwhile, the control devices of the left driving wheel and the right driving wheel are separately designed, so that the maintenance difficulty can be reduced.

As an alternative, it is also possible to use one digital variable pump for controlling two digital variable motors, i.e. the execution unit 2 comprises a first digital variable pump 21, a first digital variable motor 24, a second digital variable motor 23. The first digital variable pump 21 is rigidly connected to the engine 205, and the first digital variable pump 21, the first digital variable motor 24, and the second digital variable motor 23 form a closed loop. A first torque sensor is provided on the output shaft of the first digital variable pump 21. The output shafts of the first digital variable motor 24 and the second digital variable motor 23 are respectively provided with a first rotating speed sensor and a second rotating speed sensor. The use of a digital variable pump further simplifies the construction of the actuator unit 2.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. 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.