Skid steer loader engine power control system and skid steer loader

Abstract

This application relates to the field of loader technology, and discloses a skid steer loader engine power control system and a skid steer loader, including an engine, a fuel pump, a pilot control device, an electric regulating valve, a travel drive pump, and a controller. The engine is equipped with a speed detection module; the fuel pump's inlet is connected to the fuel tank; the pilot control device has a connected pilot port and a control port, the pilot port being connected to the fuel pump's outlet via an oil pipe, and an electric regulating valve is installed on the oil pipe; the travel drive pump is used to drive the travel components on both sides of the skid steer loader, and the travel drive pump is equipped with a flow regulating section, which is connected to the control port; the electric regulating valve can regulate the hydraulic oil output flow of the travel drive pump; the controller is electrically connected to the speed detection module and the electric regulating valve respectively. The skid steer loader engine power control system and skid steer loader disclosed in this application aim to solve or improve the problem of engine stalling when the total power of the travel system and the working system exceeds the engine power.

Description

Technical Field

[0001] This application relates to the field of loader technology, specifically to a skid steer loader engine power control system and a skid steer loader. Background Technology

[0002] A skid steer loader, also known as a skid steer steering loader, is a specialized chassis-mounted machine that achieves 360-degree turning on the spot by utilizing the difference in linear speed between its two wheels (or tracks). Its working components are designed with a quick-change mechanism, allowing for rapid replacement or attachment of various components on-site to adapt to different working environments and tasks. It is widely used in landscaping, road and bridge construction, building construction, and agricultural construction. Many of these working components require high power output, consuming significant engine power. Additionally, the skid steer loader's running system is a closed hydrostatic system, which also consumes engine power during movement.

[0003] The engine provides power to both the working system and the travel system. When the total power of the travel system and the working system is greater than the engine power, the engine will reduce its speed and increase its torque to provide the working system with the power required for its operation. If the power of the travel system cannot be adjusted in time, it will cause the engine speed to be too low, resulting in the engine stalling. Utility Model Content

[0004] In view of this, this application provides an engine power control system for a skid steer loader and a skid steer loader to solve or improve the problem of engine stalling when the total power of the travel system and the working system exceeds the engine power.

[0005] In a first aspect, this application provides a skid steer loader engine power control system, comprising: The engine is equipped with a speed detection module; A fuel replenishment pump is connected to the engine drive, and the fuel inlet of the fuel replenishment pump is connected to the fuel tank; A pilot control device is provided with a pilot port and a control port that are connected together. The pilot port is connected to the oil outlet of the oil replenishment pump through an oil pipe, and an electric regulating valve is provided on the oil pipe. A travel drive pump is used to drive the travel components on both sides of the skid steer loader. The travel drive pump is connected to the engine. The travel drive pump is equipped with a flow regulating section, which is connected to the control port. The electric regulating valve can control the pilot oil flow rate delivered from the control port to the flow regulating section to adjust the opening of the flow regulating section, thereby adjusting the hydraulic oil output flow rate of the travel drive pump. The controller is electrically connected to both the speed detection module and the electric regulating valve.

[0006] In this embodiment, when the skid steer loader is working normally, the engine rotates at its rated speed to provide kinetic energy to the working system and the travel system. The engine's output power is constant. When the load on the working system is too large, the engine needs to provide more power. At the same time, the operator moves the loader without reducing the skid steer loader's moving speed, that is, without reducing the power of the skid steer loader's travel system. Therefore, the engine will reduce its own speed to obtain greater torque and provide more power to the working system. However, the engine is prone to stalling when its speed is reduced. Therefore, the speed detection module on the engine monitors the engine speed in real time. When the engine speed drops to a preset value, the controller controls the electric regulating valve to reduce the opening of the electric regulating valve, thereby reducing the pilot oil flow rate delivered by the oil replenishment pump to the pilot port, and thus reducing the pilot oil flow rate delivered from the control port to the flow regulating unit. Reducing the opening of the flow regulating unit further reduces the hydraulic oil output flow rate of the travel drive pump, reducing the engine power consumed by the travel components, so that the engine returns to its rated speed and prevents the engine from stalling.

[0007] In one optional embodiment, the travel drive pump includes a first travel drive pump and a second travel drive pump, the first travel drive pump and the second travel drive pump being respectively used for transmission connection with the travel components on both sides of the skid steer loader.

[0008] In one optional implementation, the control port includes a first control port and a second control port, and the pilot port is connected to the first control port and the second control port respectively. The first travel drive pump is equipped with a first flow regulating valve, which has a first end and a second end. The first end and the second end are respectively connected to the first control port and the second control port. By regulating the pilot oil flow rate delivered from the first control port to the second control port, the valve core tilt angle of the first flow regulating valve can be controlled to regulate the hydraulic oil output flow rate of the first travel drive pump.

[0009] In one optional implementation, the control port further includes a third control port and a fourth control port, and the pilot port is connected to the third control port and the fourth control port respectively; The second travel drive pump is equipped with a second flow regulating valve, which has a third end and a fourth end. The third end and the fourth end are respectively connected to the third control port and the fourth control port. The flow rate of the pilot oil delivered from the third control port to the fourth control port is regulated, and the valve core tilt angle of the second flow regulating valve can be controlled to regulate the hydraulic oil output flow rate of the second travel drive pump. The first flow regulating valve and the second flow regulating valve are the flow regulating parts.

[0010] In one optional embodiment, a first overflow valve is further included, wherein the input port of the first walking drive pump is connected to the oil inlet of the first overflow valve, and the overflow port of the first overflow valve is connected to the oil tank. And / or, it also includes a second overflow valve, wherein the output port of the first travel drive pump is connected to the oil inlet of the second overflow valve, and the overflow port of the second overflow valve is connected to the oil tank.

[0011] In one optional embodiment, a third overflow valve is also included, wherein the input port of the second travel drive pump is connected to the oil inlet of the third overflow valve, and the overflow port of the third overflow valve is connected to the oil tank. And / or, it also includes a fourth overflow valve, wherein the output port of the second travel drive pump is connected to the oil inlet of the fourth overflow valve, and the overflow port of the fourth overflow valve is connected to the oil tank.

[0012] In one optional embodiment, the pilot control device includes a control handle for controlling the pilot oil flow rate from the first control port to the second control port, and controlling the pilot oil flow rate from the third control port to the fourth control port.

[0013] In one optional embodiment, the pilot control device further includes four control valves, and the control handle is used to control the four control valves to control the pilot oil flow rate from the first control port to the second control port, and to control the pilot oil flow rate from the third control port to the fourth control port.

[0014] In an alternative embodiment, a pressure sensor is also included, which is adapted to be disposed in the oil circuit of the working system and is electrically connected to the controller.

[0015] Secondly, this application also provides a skid steer loader, comprising: Skid steer loader engine power control system; The body, with the walking components provided on both sides of the body; The walking component includes: At least two wheels are mounted on one side of the machine body; At least two hydraulic motors, each of which is connected to the walking wheels on both sides of the machine body via a transmission. The walking drive pump is connected to the two hydraulic motors. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a skid steer loader engine power control system according to an embodiment of this application; Figure 2 for Figure 1 A magnified view of part A in the diagram; Figure 3 for Figure 1 A magnified view of part B in the diagram.

[0018] Explanation of reference numerals in the attached figures: 1. Engine; 2. Speed ​​detection module; 3. Fuel pump; 4. Fuel tank; 5. Pilot control device; 6. Flow regulating unit; 601. First flow regulating valve; 6011. First end; 6012. Second end; 602. Second flow regulating valve; 6021. Third end; 6022. Fourth end; 7. Control port; 701. First control port; 702. Second control port; 703. Third control port; 704. Fourth control port; 8. Electrical regulating valve; 9. Travel drive pump; 901. First travel drive pump; 902. Second travel drive pump; 10. Pilot port; 11. Controller; 12. First relief valve; 13. Second relief valve; 14. Third relief valve; 15. Fourth relief valve; 16. Control handle; 17. Control valve; 18. Pressure sensor; 19. Oil pipe. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] A skid steer loader, also known as a skid steer steering loader, is a specialized chassis-mounted machine that achieves 360-degree turning on the spot by utilizing the difference in linear speed between its two wheels (or tracks). Its working components are designed with a quick-change mechanism, allowing for rapid replacement or attachment of various components on-site to adapt to different working environments and tasks. It is widely used in landscaping, road and bridge construction, building construction, and agricultural construction. Many of these working components require high power output, consuming significant engine power. Additionally, the skid steer loader's running system is a closed hydrostatic system, which also consumes engine power during movement.

[0023] The engine provides power to both the working system and the traveling system. When the total power of the traveling system and the working system exceeds the engine power, the engine will reduce its speed and increase torque to provide the working system with the power required for its operation. If the power of the traveling system cannot be adjusted in time, it will cause the engine speed to be too low, leading to engine stalling. Therefore, this application provides an engine power control system for a skid steer loader and a skid steer loader to solve or improve the problem of engine stalling when the total power of the traveling system and the working system exceeds the engine power.

[0024] The following is combined Figures 1 to 3 This describes an embodiment of the present application.

[0025] According to an embodiment of this application, in one aspect, a skid steer loader engine power control system is provided, including an engine 1, a fuel replenishment pump 3, a pilot control device 5, an electric regulating valve 8, a travel drive pump 9, and a controller 11.

[0026] Specifically, such as Figure 1 As shown, engine 1 is equipped with a speed detection module 2; oil replenishment pump 3 is connected to engine 1, and the oil inlet of oil replenishment pump 3 is connected to oil tank 4; pilot control device 5 is equipped with a pilot port 10 and a control port 7 connected together, pilot port 10 is connected to oil outlet of oil replenishment pump 3 through oil pipe 19, and an electric regulating valve 8 is installed on oil pipe 19; travel drive pump 9 is used to drive the travel components on both sides of skid steer loader, travel drive pump 9 is connected to engine 1, travel drive pump 9 is equipped with a flow regulating section 6, flow regulating section 6 is connected to control port 7, and electric regulating valve 8 can control the pilot oil flow rate delivered from control port 7 to flow regulating section 6 to adjust the opening of flow regulating section 6, thereby adjusting the hydraulic oil output flow rate of travel drive pump 9; controller 11 is electrically connected to speed detection module 2 and electric regulating valve 8 respectively.

[0027] In this embodiment, such as Figure 1 As shown, when the skid steer loader is working normally, engine 1 rotates at its rated speed to provide kinetic energy to the working system and the travel system. The output power of engine 1 is constant. When the load in the working system is too large, engine 1 needs to provide more power. At the same time, the operator operates the loader to move it without reducing the moving speed of the skid steer loader, that is, without reducing the power of the skid steer loader's travel system. Therefore, engine 1 will reduce its own speed to obtain greater torque and provide more power to the working system. However, engine 1 is prone to stalling when its speed is reduced. Therefore, the speed detection module 2 on engine 1 monitors the speed of engine 1 in real time. When the speed of engine 1 drops to the preset value, the controller 11 controls the electric regulating valve 8 to reduce the opening of the electric regulating valve 8, thereby reducing the pilot oil flow rate delivered by the oil replenishment pump 3 to the pilot port 10, and thus reducing the pilot oil flow rate delivered from the control port 7 to the flow regulating unit 6. Reducing the opening of the flow regulating unit 6 further reduces the hydraulic oil output flow rate of the travel drive pump 9, reducing the power of engine 1 consumed by the travel components, so that engine 1 returns to its rated speed and prevents engine 1 from stalling.

[0028] It should be noted that the working system refers to the hydraulic system that operates the bucket for operation, taking the bucket as an example. The working system is existing technology and will not be described in detail here.

[0029] It should be noted that the walking system refers to the structure that drives the transfer machine to move, such as wheels or tracks, hydraulic motors, hydraulic pumps, and oil circuit systems. The walking system is existing technology and will not be described in detail here.

[0030] In one embodiment, such as Figure 1 and Figure 3As shown, the travel drive pump 9 includes a first travel drive pump 901 and a second travel drive pump 902, which are respectively used for transmission connection with the travel components on both sides of the skid steer loader.

[0031] In this embodiment, the first travel drive pump 901 and the second travel drive pump 902 drive the travel components on both sides of the skid steer loader respectively, which can control the skid steer loader to move forward, backward and turn, making it more flexible.

[0032] In one embodiment, such as Figure 1 and Figure 2 As shown, the control port 7 includes a first control port 701 and a second control port 702, and the pilot port 10 is connected to the first control port 701 and the second control port 702 respectively. The first travel drive pump 901 is equipped with a first flow regulating valve 601. The first flow regulating valve 601 is provided with a first end 6011 and a second end 6012. The first end 6011 and the second end 6012 are respectively connected to the first control port 701 and the second control port 702. The flow rate of the pilot oil delivered from the first control port 701 to the second control port 702 is regulated, and the valve core tilt angle of the first flow regulating valve 601 can be controlled to regulate the hydraulic oil output flow rate of the first travel drive pump 901.

[0033] In one embodiment, such as Figure 1 and Figure 2 As shown, control port 7 also includes a third control port 703 and a fourth control port 704, and pilot port 10 is connected to the third control port 703 and the fourth control port 704 respectively. The second travel drive pump 902 is equipped with a second flow regulating valve 602. The second flow regulating valve 602 is equipped with a third end 6021 and a fourth end 6022. The third end 6021 and the fourth end 6022 are respectively connected to the third control port 703 and the fourth control port 704. By regulating the pilot oil flow from the third control port 703 to the fourth control port 704, the valve core tilt angle of the second flow regulating valve 602 can be controlled to regulate the hydraulic oil output flow of the second travel drive pump 902. Among them, the first flow regulating valve 601 and the second flow regulating valve 602 constitute the flow regulating part 6.

[0034] In this embodiment, the speed detection module 2 on the engine 1 monitors the speed of the engine 1 in real time. When the speed of the engine 1 drops to a preset value, the controller 11 controls the electric regulating valve 8 to reduce the opening of the electric regulating valve 8, thereby reducing the pilot oil flow rate delivered by the oil replenishment pump 3 to the pilot port 10, and thus reducing the pilot oil flow rate delivered from the first control port 701 to the second control port 702. Reducing the opening of the first flow regulating valve 601 can reduce the hydraulic oil flow rate output by the first travel drive pump 901, thereby reducing the hydraulic oil flow rate delivered to the travel assembly. This can reduce the travel speed of the travel assembly, reduce the power distributed by the engine 1 to the travel assembly, and restore the speed of the engine 1 to the rated speed, preventing the engine 1 from stalling.

[0035] At the same time, it can also reduce the flow rate of pilot oil delivered from the third control port 703 to the fourth control port 704, reduce the opening of the second flow regulating valve 602, reduce the hydraulic oil flow rate output by the second travel drive pump 902, and thus reduce the hydraulic oil flow rate delivered to the travel assembly. This can reduce the travel speed of the travel assembly, reduce the power distributed by the engine 1 to the travel assembly, and restore the speed of the engine 1 to the rated speed, preventing the engine 1 from stalling.

[0036] In some embodiments, the first flow regulating valve and the second flow regulating valve have the same structure. The first flow regulating valve is provided with a valve core that can rotate. By adjusting its rotation angle, the valve core can adjust its opening degree. The flow rate output from the first end 6011 of the first flow regulating valve to the second end 6012 can control the rotation angle of the valve core.

[0037] In one embodiment, such as Figure 1 and Figure 3 As shown, it also includes a first overflow valve 12, the input port of the first travel drive pump 901 is connected to the oil inlet of the first overflow valve 12, and the overflow port of the first overflow valve 12 is connected to the oil tank 4. And / or, it also includes a second overflow valve 13, the output port of the first travel drive pump 901 is connected to the oil inlet of the second overflow valve 13, and the overflow port of the second overflow valve 13 is connected to the oil tank 4.

[0038] In one embodiment, such as Figure 1 and Figure 3 As shown, it also includes a third overflow valve 14. The input port of the second travel drive pump 902 is connected to the oil inlet of the third overflow valve 14, and the overflow port of the third overflow valve 14 is connected to the oil tank 4. And / or, it also includes a fourth overflow valve 15, the output port of the second travel drive pump 902 is connected to the oil inlet of the fourth overflow valve 15, and the overflow port of the fourth overflow valve 15 is connected to the oil tank 4.

[0039] In this embodiment, a first overflow valve 12, a second overflow valve 13, a third overflow valve 14, and a fourth overflow valve 15 are provided to relieve pressure when the output pressure of the first travel drive pump 901 and the second travel drive pump 902 is too high, thereby ensuring the stability of the oil circuit.

[0040] In one embodiment, such as Figure 1 and Figure 2 As shown, the pilot control device 5 includes a control handle 16, which is used to control the pilot oil flow rate from the first control port 701 to the second control port 702, and to control the pilot oil flow rate from the third control port 703 to the fourth control port 704.

[0041] In this embodiment, by moving the control handle 16, the operator can manually control the pilot oil flow from the first control port 701 to the second control port 702, and the pilot oil flow from the third control port 703 to the fourth control port 704. In the event of a malfunction of the electric regulating valve 8 or other electronic components, the operator can manually control them.

[0042] In one embodiment, such as Figure 1 and Figure 2 As shown, the pilot control device 5 also includes four control valves 17. The control handle 16 is used to control the four control valves 17 to control the pilot oil flow rate from the first control port 701 to the second control port 702, and to control the pilot oil flow rate from the third control port 703 to the fourth control port 704.

[0043] In one embodiment, such as Figure 1 As shown, it also includes a pressure sensor 18, which is adapted to be installed in the oil circuit of the working system and is electrically connected to the controller 11.

[0044] In this embodiment, the external characteristic curve of the engine 1 is pre-input into the controller 11, and the functional relationship between the torque power of the engine 1 and the speed of the engine 1 is input into the controller 11; then the functional relationship between the speed of the engine 1 (i.e., the spindle speed) and the power of the travel drive pump 9 is transmitted into the controller 11, and the functional relationship between the opening degree of the electric regulating valve 8, the signal of the speed detection module 2, and the pressure signal of the pressure sensor 18 is input into the controller 11.

[0045] The controller 11 receives signals from the speed detection module 2 and the pressure signal from the pressure sensor 18. By reading the signals from the speed detection module 2 and the pressure signal from the pressure sensor 18, the controller 11 processes the signals through a program algorithm to control the opening of the electric regulating valve 8, thereby controlling the pilot oil flow into the pilot port 10, and thus controlling the opening of the first flow regulating valve 601 and the second flow regulating valve 602, thereby controlling the power of the traveling component, realizing intelligent anti-stalling and ensuring that the power of the working system remains unchanged.

[0046] It should be noted that the operator can adjust the moving speed of the traveling component by operating the control handle 16. However, during operation, the operator cannot pay attention to the power of the engine 1 in real time. Therefore, it is easy for the skid steer loader to continue moving at high speed when the output power of the engine 1 is insufficient, which may cause the engine 1 to stall. Intelligent anti-stalling can be achieved through the electric regulating valve 8.

[0047] According to an embodiment of this application, another aspect provides a skid steer loader, including: a skid steer loader engine power control system, a body, a running gear, at least two running wheels, and at least two hydraulic motors.

[0048] Specifically, walking components are installed on both sides of the machine body; The walking assembly includes: at least two walking wheels and at least two hydraulic motors, with the two walking wheels mounted on one side of the machine body; the two hydraulic motors are respectively connected to the walking wheels on both sides of the machine body; and the walking drive pump 9 is connected to the two hydraulic motors.

[0049] It should be noted that the skid steer loader device includes the skid steer loader engine power control system provided in the embodiments of this application, and therefore includes all the above-mentioned advantages of the skid steer loader engine power control system, so it will not be repeated here.

[0050] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended application.

Claims

1. A skid steer loader engine power control system characterized by, include: Engine (1), wherein the engine (1) is provided with a speed detection module (2); The oil replenishment pump (3) is connected to the engine (1) via a transmission, and the oil inlet of the oil replenishment pump (3) is connected to the oil tank (4); Pilot control device (5), the pilot control device (5) is provided with a pilot port (10) and a control port (7) connected together, the pilot port (10) is connected to the oil outlet of the oil replenishment pump (3) through an oil pipe (19), and an electric regulating valve (8) is provided on the oil pipe (19). The travel drive pump (9) is used to drive the travel components on both sides of the skid steer loader. The travel drive pump (9) is connected to the engine (1) in a transmission. The travel drive pump (9) is provided with a flow regulating section (6). The flow regulating section (6) is connected to the control port (7). The electric regulating valve (8) can control the pilot oil flow rate delivered from the control port (7) to the flow regulating section (6) to adjust the opening of the flow regulating section (6) and thus adjust the hydraulic oil output flow rate of the travel drive pump (9). The controller (11) is electrically connected to the speed detection module (2) and the electric regulating valve (8).

2. The skid steer loader engine power control system according to claim 1, characterized in that, The travel drive pump (9) includes a first travel drive pump (901) and a second travel drive pump (902), which are respectively used to drive the travel components on both sides of the skid steer loader.

3. The skid steer loader engine power control system according to claim 2, characterized in that, The control port (7) includes a first control port (701) and a second control port (702), and the pilot port (10) is connected to the first control port (701) and the second control port (702) respectively; The first travel drive pump (901) is provided with a first flow regulating valve (601). The first flow regulating valve (601) is provided with a first end (6011) and a second end (6012). The first end (6011) and the second end (6012) are respectively connected to the first control port (701) and the second control port (702). The flow rate of the pilot oil delivered from the first control port (701) to the second control port (702) can be regulated, and the valve core tilt angle of the first flow regulating valve (601) can be controlled to regulate the hydraulic oil output flow rate of the first travel drive pump (901).

4. The skid steer loader engine power control system according to claim 3, characterized in that, The control port (7) further includes a third control port (703) and a fourth control port (704), and the pilot port (10) is connected to the third control port (703) and the fourth control port (704) respectively; The second travel drive pump (902) is provided with a second flow regulating valve (602), which is provided with a third end (6021) and a fourth end (6022). The third end (6021) and the fourth end (6022) are respectively connected to the third control port (703) and the fourth control port (704). By regulating the pilot oil flow rate delivered from the third control port (703) to the fourth control port (704), the valve core tilt angle of the second flow regulating valve (602) can be controlled to regulate the hydraulic oil output flow rate of the second travel drive pump (902). The first flow regulating valve (601) and the second flow regulating valve (602) are the flow regulating unit (6).

5. The skid steer loader engine power control system according to claim 4, characterized in that, It also includes a first overflow valve (12), the input port of the first walking drive pump (901) is connected to the oil inlet of the first overflow valve (12), and the overflow port of the first overflow valve (12) is connected to the oil tank (4); And / or, it also includes a second overflow valve (13), the output port of the first walking drive pump (901) is connected to the oil inlet of the second overflow valve (13), and the overflow port of the second overflow valve (13) is connected to the oil tank (4).

6. The skid steer loader engine power control system according to claim 4 or 5, characterized in that, It also includes a third overflow valve (14), the input port of the second walking drive pump (902) is connected to the oil inlet of the third overflow valve (14), and the overflow port of the third overflow valve (14) is connected to the oil tank (4); And / or, it also includes a fourth overflow valve (15), the output port of the second walking drive pump (902) is connected to the oil inlet of the fourth overflow valve (15), and the overflow port of the fourth overflow valve (15) is connected to the oil tank (4).

7. The skid steer loader engine power control system according to claim 4, characterized in that, The pilot control device (5) includes a control handle (16), which is used to control the pilot oil flow rate from the first control port (701) to the second control port (702) and to control the pilot oil flow rate from the third control port (703) to the fourth control port (704).

8. The skid steer loader engine power control system according to claim 7, characterized in that, The pilot control device (5) further includes four control valves (17), and the control handle (16) is used to control the four control valves (17) to control the pilot oil flow rate from the first control port (701) to the second control port (702), and to control the pilot oil flow rate from the third control port (703) to the fourth control port (704).

9. The skid steer loader engine power control system according to claim 1, characterized in that, It also includes a pressure sensor (18), which is adapted to be installed in the oil circuit of the working system and is electrically connected to the controller (11).

10. A skid steer loader, characterized in that, include: The skid steer loader engine power control system according to any one of claims 1 to 9; The body, with the walking components provided on both sides of the body; The walking component includes: At least two wheels are mounted on one side of the machine body; At least two hydraulic motors, each of which is connected to the walking wheels on both sides of the machine body via a transmission. The walking drive pump (9) is connected to the two hydraulic motors.

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