HST electric control mechanism and control method thereof

Abstract

The invention discloses an HST electric control mechanism and a control method thereof. One end of a transmission shaft is sleeved on a control torsion bar of an HST, the other end of the transmission shaft is sleeved with a notch sliding block, a driving motor and the notch sliding block are in matched transmission, a shifting fork shifts the notch sliding block to slide along the transmission shaft, a spring is arranged between the notch sliding block and the transmission shaft, and a proximity switch is arranged on the transmission shaft. In the relaxed state, the spring abuts against the notch sliding block to be connected with the motor, and torsion of the motor is transmitted to a control torsion bar of the HST through the transmission shaft. When the shifting fork is shifted, the notch sliding block is separated from the driving motor, and meanwhile, the notch sliding block triggers the proximity switch; an angle sensor is arranged at the position of an HST control torsion bar; the lower portion of the transmission shaft makes contact with the springback damping device, the springback damping device can be compressed when the transmission shaft rotates in the radial direction, and aligning torque is provided for the transmission shaft. According to the invention, the electric control of the mechanical variable HST is completed, and the capability of quickly returning the control torsion bar of the HST to the neutral position in an emergency state is also realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of hilly and mountainous crawler chassis wire control, and specifically relates to an HST electric control mechanism and a control method thereof. Background Art

[0002] The hydrostatic transmission (HST) system is a closed transmission loop system composed of hydraulic components and control components. It can convert the mechanical energy of the prime mover into hydraulic energy, and then convert the hydraulic energy into mechanical energy for power output. Through the variable control of the control component, the device can achieve stepless speed regulation. It is a transmission component widely used in the field of agricultural machinery. The HST installed in the hilly and mountainous crawler chassis is an important transmission component. By controlling the forward and reverse rotation of the HST output shaft, the crawler chassis can be driven forward and backward.

[0003] The transmission ratio and transmission direction of HST are completely controlled by the swash plate angle of its internal variable pump; and the variable pump displacement of the most widely used mechanically controlled variable HST transmission is directly controlled by the control torsion bar on the component. When the torsion bar is in the middle position, the HST output shaft does not rotate (the variable pump displacement is "0"), and the drive axle it controls does not rotate either. When the torsion bar twists from the middle to the left and right, the HST output shaft rotates from slow to fast in the forward (or reverse) direction, and the forward (or backward) speed of the controlled drive axle changes from slow to fast; its essence is that the control lever changes the displacement (speed regulation) and oil discharge direction (reversing) of the internal variable pump.

[0004] There are two main existing HST control methods. One is to manually operate the control torsion bar of the HST through a series of mechanical structures. Although this method is simple and reliable, it requires the operator to have a certain level of control, and is subject to the control form of pure mechanical variables and cannot meet the needs of intelligent agricultural machinery electronic control. When parking, the vehicle driven by the HST system needs to rotate the control torsion bar to the middle position (i.e., "0" position). In an emergency, there is an extremely high requirement for control accuracy. Once the reverse operation of the control torsion bar exceeds the middle position, the HST output shaft will quickly reverse, and the crawler chassis will quickly move in the opposite direction, causing safety hazards. There is a wire control transformation scheme for the HST that directly drives the control torsion bar of the HST through a motor. When an emergency occurs, the motor can be controlled to rotate the control torsion bar of the HST to the middle position. Although emergency parking can be achieved, the system is completely dependent on the control of the motor; from the operator sending an emergency stop signal to the HST executing the parking action, it is also affected by the motor response time and response speed, and there is a certain time delay. Summary of the invention

[0005] In order to solve the above-mentioned problems existing in the existing HST electric control, the present invention provides an HST electric control mechanism and a control method thereof. The device has a simple structure, and while completing the electric control of the mechanical variable HST, it has the ability to quickly return the control torsion bar of the HST to the neutral position and stop the HST transmission shaft in an emergency state; it not only completes the electric control of the HST system, but also ensures the safety of the entire machine operation.

[0006] The purpose of the present invention is achieved through the following technical solutions, in conjunction with the accompanying drawings:

[0007] As a first aspect of the present invention, there is provided an HST electric control mechanism, including a mechanical part and an electric control system, wherein the mechanical part includes a transmission shaft 3, a rebound damping device 5, a spring 7, a shift fork 8, a notched slider 9 and a frame 12; the electric control system includes an angle sensor 2, a proximity switch 6, a drive motor 10 and a controller, and the controller is electrically connected to the angle sensor 2, the proximity switch 6 and the drive motor 10 respectively; the HST1 is fixed on the frame 12; the angle sensor 2 is installed at the end of the control torsion bar of the HST1; one end of the transmission shaft 3 is sleeved on the control torsion bar of the HST1, and the other end is axially slidably connected to the notched slider 9, and the end of the notched slider 9 is non-fixedly connected to the drive motor to realize driving. The driving motor 12 and the transmission shaft 3 are connected, and the driving motor 10 is installed on the frame 12; a spring 7 is arranged between the notched slider 9 and the transmission shaft 3, and a proximity switch 6 is arranged on the transmission shaft 3. In the relaxed state, the spring 7 is connected to the notched slider 9 and the driving motor 10, and the torque of the driving motor 10 is transmitted to the control torsion bar of the HST through the transmission shaft 3; the shift fork 8 is clamped on the notched slider 9 to push the notched slider 9 to slide axially along the transmission shaft 3, and the notched slider 9 is disengaged from the driving motor through the shift fork 8 and the proximity switch is triggered; the rebound damping device 5 is installed on the frame 12 and is located directly below the transmission shaft 3, and is used to drive the transmission shaft 3 back to the middle position when the transmission shaft 3 is disconnected from the driving motor 10.

[0008] Furthermore, the transmission shaft 3 includes a shaft body, a mounting sleeve 31 is provided at one end of the shaft body, a guide groove 35 is provided at the other end of the shaft body, spring support plates 34 are respectively provided on the shaft body, and a return and drag reduction pulley 33 is installed in the middle of the shaft body; one end of the transmission shaft 3 is assembled with the square head sleeve of the control torsion bar of HST1 through the mounting sleeve 31, and the other end is matched with the guide key 95 of the notched slider 9 through the guide groove 35, so that the notched slider 9 makes axial linear motion relative to the transmission shaft 3; the spring 7 is sleeved on the shaft body of the transmission shaft 3, one end of the spring 7 is against the spring support plate 34, and the other end of the spring 7 is against the notched slider 9; the proximity switch 6 is installed on the spring support plate 34; the bottom of the return and drag reduction pulley 33 is in contact with the rebound damping device 5, and when the transmission shaft 3 rotates axially, the return and drag reduction pulley 33 compresses the rebound damping device 5 to provide a return torque to the transmission shaft 3.

[0009] Furthermore, a circumferential fixing groove 32 is provided on the shaft body of the transmission shaft 3 , and the transmission shaft 3 is connected to the transmission bracket 4 through the fixing groove 32 , and the transmission bracket 4 is fixed on the frame 12 .

[0010] Furthermore, a metal bracket is welded in the middle of the shaft body of the transmission shaft 3 , and two return and drag reduction pulleys 33 are symmetrically mounted on the metal bracket, and the bottom of the return and drag reduction pulleys 33 is in contact with the top surface of the rebound damping device 5 .

[0011] Furthermore, the notched slider 9 is slidably connected to the guide groove 35 of the transmission shaft 3 through the guide key 95 in the shaft hole; a matching notch 91 is provided at the end of the notched slider 9, and is connected to the raised metal head of the motor shaft of the drive motor 10 through the matching notch 91; a support rod 93 is provided at the top of the notched slider 9 for triggering the proximity switch 6; a fork groove 92 is provided on the outer periphery of the notched slider 9 for clamping the fork 8.

[0012] Furthermore, the rebound damping device 5 is composed of an upper plane plate 51, a guide column 52, a damping spring 53, a fixed column 54, a fixing nut 55, and a lower fixing frame 56; the four damping springs 53 are respectively mounted on the four fixing columns 54, the four fixing columns 54 are welded to the bottom of the upper plane plate 51, and the four fixing columns 54 are connected to the lower fixing frame 56 with fixing nuts 55. The upper plane plate 51 is in contact with the return and drag reduction pulley 33 on the transmission shaft 3.

[0013] Furthermore, the control system also includes an operating handle, a display, and a motor driver; the operating handle is installed in the cab to transmit the driver's operating intention to the controller; the angle sensor 2 collects the rotation angle position of the HST control torsion bar in real time and sends an electrical signal to the controller; the controller is installed in the vehicle body to control the received sensor signal and send a control signal to the motor driver; the display is installed in the cab to display the angle of the control torsion bar of HST1, so that the driver knows the working status of HST1; the proximity switch 6 is used to send an electrical signal to the controller when the notch slider 9 is disconnected from the drive motor 10; the motor driver is installed in the vehicle body to receive the control signal of the controller, control the rotation of the drive motor 10, and adjust the control torsion bar angle of HST1.

[0014] In the second aspect, the present invention also provides a control method for an HST electric control mechanism, including three modes: HST conventional electric control, HST emergency return to center control, and HST emergency release and reset control. The specific control process is as follows:

[0015] The HST conventional electric control:

[0016] The notched slider 9 of the mechanical part is engaged with the drive motor 10 under the thrust of the spring 9, so that the torque of the drive motor 10 is directly transmitted to the transmission shaft 3, thereby driving the control torsion bar of HST1 to rotate left and right, and at the same time, the angle sensor 2 transmits the rotation angle of the control torsion bar of HST1 to the controller in real time; the operator inputs the operation intention into the controller, and the controller controls the drive motor to rotate, driving the notched slider 9, and the notched slider 9 drives the transmission shaft 3 to overcome the resistance of the rebound damping device 5 and transmit the twisting action to the control torsion bar of HST1, waiting for the operator to complete the twisting operation of the control torsion bar of HST1;

[0017] The HST emergency return control:

[0018] When the control torsion bar of HST1 is not in the middle position and needs to be quickly returned to the middle position, the operator shifts the shift fork 8, driving the notched slider 9 to compress the spring, and the notched slider 9 moves away from the drive motor 10 axially and disconnects from the drive motor 10. At the same time, the notched slider 9 triggers the proximity switch 6 to send a signal to the controller; the drive motor 10 loses control of the transmission shaft 3, and then loses control of the control torsion bar of HST1; the transmission shaft 3 compresses the rebound damping device 5 during the left and right rotation process, and is subjected to a restoring torque opposite to its own movement. When the connection between the drive motor 10 and the transmission shaft 3 is released, the transmission shaft 3 will drive the control torsion bar of HST1 back to the middle position under the action of the restoring torque, completing the return to the middle operation under the condition of only one.

[0019] The HST emergency release reset control:

[0020] When the HST emergency return control occurs, the notch slider 9 touches the proximity switch 6 so that the proximity switch 6 sends a signal to the controller to inform the controller that the notch slider 9 has been separated from the drive motor 10, and the controller controls the drive motor 10 to quickly return to a specific position to wait for the notch slider to reset and cooperate with it; when the emergency situation is relieved, the force acting on the fork 8 is eliminated, and the spring 7 pushes the notch slider 9 to move along the axial direction close to the drive motor 10 until the notch slider 9 is connected and cooperated with the drive motor 10 again, and the drive motor 10 takes over the control torsion bar of the HST1 again.

[0021] The present invention has the following advantages:

[0022] The present invention provides an HST electric control mechanism and a control method thereof. A driving motor and a notch slider cooperate with each other for transmission. One end of a transmission shaft is sleeved on a control torsion bar of the HST, and the other end is sleeved on the notch slider. A shift fork cooperates with an annular notch outside the notch slider. When the shift fork shifts the notch slider, the notch slider slides along the transmission shaft. A spring is arranged between the notch slider and the transmission shaft, and a proximity switch is arranged on the transmission shaft. In a relaxed state, the spring pushes against the notch slider and is connected to the motor, and the torsion of the motor is transmitted to the control torsion bar of the HST through the transmission shaft. When the shift fork shifts, the notch slider is disengaged from the driving motor, and the support rod on the notch slider triggers the proximity switch to send a signal. An angle sensor is installed at the position of the HST control torsion bar for real-time determination of the rotation angle of the HST control torsion bar. The pulley contacts the rebound damping device below the transmission shaft, and the rebound damping device is compressed when the transmission shaft rotates radially, providing a return torque to the transmission shaft.

[0023] The operator's control signal is transmitted to the controller. The controller controls the drive motor to rotate the HST control torsion bar through the motor driver. The angle sensor transmits the position of the HST control torsion bar to the controller. The display screen is connected to the controller to let the operator know the real-time position of the HST control torsion bar. When an emergency occurs, the operator can quickly disconnect the notch slider from the drive motor through the fork. At the same time, the rebound damping device gives the drive shaft a return force to drive the HST control torsion bar to quickly return to the neutral position. When the notch slider is disengaged, it will trigger the proximity switch, which will transmit the signal to the controller. At this time, the control control drive motor rotates back to the initial position. After the fork control force is eliminated, the notch slider is reset and combined with the motor.

[0024] The device has a simple structure. While completing the electric control of the mechanical variable HST, it also has the ability to quickly return the HST control torsion bar to the neutral position and stop the HST drive shaft in an emergency. It not only completes the electronic control of the HST system, but also ensures the safety of the entire machine operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a front view of the structure of an HST electric control mechanism described in Example 1 of the present invention;

[0026] Figure 2 It is a schematic diagram of the partial structure of an HST electric control mechanism described in Example 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the transmission shaft structure described in Example 1 of the present invention;

[0028] Figure 4 This is a schematic structural diagram of the rebound damping device described in Example 1 of the present invention;

[0029] Figure 5This is a schematic diagram of the notched sleeve structure in Example 1 of the present invention;

[0030] Figure 6 This is a structural diagram of an electric control system of an HST electric control mechanism described in Example 2 of the present invention;

[0031] Figure 7 A control flow chart of an HST electric control mechanism according to Embodiment 2 of the present invention;

[0032] In the figure:

[0033] 1-HST; 2-angle sensor; 3-transmission shaft; 4-transmission shaft bracket; 5-rebound damping device; 6-proximity switch; 7-spring; 8-shift fork; 9-notch slider; 10-drive motor; 11-motor bracket;

[0034] 31-installation sleeve; 32-fixing groove; 33-returning drag reduction pulley; 34-spring support plate; 35-guide groove;

[0035] 51-upper plane plate; 52-guide column; 53-damping spring; 54-fixing column; 55-fixing nut; 56-lower fixing frame;

[0036] 91-matching notch; 92-fork notch; 93-support rod; 94-spring push surface; 95-guide key. DETAILED DESCRIPTION

[0037] In order to further illustrate the technical invention of the present invention, in conjunction with the accompanying drawings, the specific implementation of the present invention is as follows:

[0038] Example 1

[0039] like Figure 1As shown, the present invention provides an HST electric control mechanism, including a mechanical part and an electric control system, the mechanical part includes HST1, a transmission shaft 3, a transmission shaft bracket 4, a rebound damping device 5, a spring 7, a fork 8, a notched slider 9, a motor bracket 11 and a frame 12; the electric control system includes an angle sensor 2, a proximity switch 6, a drive motor 10 and a controller, and the controller is electrically connected to the angle sensor 2, the proximity switch 6, and the drive motor 10 respectively; the HST1, the transmission shaft bracket 4, the rebound damping device 5, and the motor bracket 11 are all installed on the frame 12; the angle sensor 2 is installed at the end of the control torsion bar of HST1; the transmission shaft 3 is installed on the transmission shaft bracket 4, and one end of the transmission shaft 3 is sleeved on the control torsion bar of HST1 The notch slider 9 is on the rod, and the other end is axially slidably connected with the notch slider 9. The end of the notch slider 9 is non-fixedly connected to the drive motor, and the drive motor 10 is installed on the motor bracket 11; a spring support plate 34 is provided on the transmission shaft 3, and the spring 7 is sleeved on the transmission shaft 3 and the two ends of the spring respectively abut against the spring support plate 34 and the notch slider 9; the proximity switch 6 is installed on the spring support plate 34, and the proximity switch 6 is triggered by the notch slider 9; the fork 8 is clamped on the notch slider 9 to push the notch slider 9 to slide axially along the transmission shaft 3, and the notch slider 9 is disengaged from the drive motor through the fork 8 and the proximity switch is triggered; the rebound damping device 5 is installed directly below the transmission shaft 3, and is used to drive the transmission shaft 3 back to the middle position when the transmission shaft 3 is disconnected from the drive motor 10.

[0040] Furthermore, if Figure 3 As shown, the transmission shaft 3 includes a shaft body, a mounting sleeve 31 is provided at one end of the shaft body, a guide groove 35 is provided at the other end of the shaft body, a circumferential fixing groove 32 and a spring support plate 34 are respectively provided on the shaft body, and a return drag reduction pulley 33 is installed in the middle of the shaft body; the transmission shaft 3 is connected to the transmission bracket 4 through the fixing groove 32, and it is ensured to be coaxial with the control torsion bar of HST1; one end of the transmission shaft 3 is assembled with the square head sleeve of the control torsion bar of HST1 through the mounting sleeve 31, and the other end is assembled with the notched slider 9 through the guide groove 35 The guide key 95 cooperates with the notched slider 9 so that the notched slider 9 can only make axial linear motion relative to the transmission shaft 3; the spring 7 is sleeved on the shaft body of the transmission shaft 3, one end of the spring 7 is pressed against the spring support plate 34, and the other end of the spring 7 is pressed against the spring push surface 94 of the notched slider 9; the proximity switch 6 is installed on the spring support plate 34; the lower part of the return drag reduction pulley 33 is in contact with the upper plane plate 51 of the rebound damping device 5, and when the transmission shaft 3 rotates axially, the rebound damping device 5 will be compressed to provide a return torque to the transmission shaft 3.

[0041] Preferably, the shaft body of the transmission shaft 3 is a cylindrical metal rod, a mounting sleeve 31 is welded to the left end face of the cylindrical metal rod, and two annular discs are welded to the right side of the mounting sleeve 31; the two annular discs and the empty space in the middle together constitute a fixing groove 32; a metal bracket is welded in the middle of the shaft body, and two return and drag reduction pulleys 33 are symmetrically installed on the metal bracket; a spring support plate 34 is welded to the right side of the return and drag reduction pulley, and the spring support plate 34 is a metal disc; two guide grooves 35 are symmetrically milled on the right end of the cylindrical metal rod parallel to both sides of the axis.

[0042] The spring support plate 34 is drilled with a mounting hole for mounting the proximity switch 6; when the shift fork 8 shifts the notched slider 9 to disengage from the output shaft of the drive motor 10, the support rod 93 of the notched slider 9 triggers the proximity switch 6 and sends a signal to the controller.

[0043] Furthermore, if Figure 5 As shown, the notched slider 9 is sleeved on the transmission shaft 3, and is slidably connected to the guide groove 35 of the transmission shaft 3 through the guide key 95 in the shaft hole, so that the notched slider 9 can slide smoothly along the transmission shaft 3; a matching notch 91 is provided at the end of the notched slider 9, and is connected to the raised metal head of the drive motor 10 through the matching notch 91; a support rod 93 is provided at the top of the notched slider 9 for triggering the proximity switch 6; a fork groove 92 is provided on the outer periphery of the notched slider 9 for clamping the fork 8.

[0044] Furthermore, the driving motor 10 is a DC motor, and a rectangular metal block is welded on the top end of the motor shaft, and the metal block can be fully engaged with the matching notch 91 of the notch slider 9.

[0045] Preferably, if Figure 5 As shown, the main body of the notched slider 9 is a cylindrical structure, and a rectangular matching notch 91 is opened on the right end face; a circular metal sheet is welded on the side of the outer circumference of the cylindrical structure away from the matching notch 91, and the metal sheet and the front end shoulder of the cylinder together form a fork notch 92, and the forked part of the fork 8 is inserted into the fork notch 92. Since the fork notch 92 is circular, the fork 8 can only move the notched slider 9 along the axial direction without affecting the rotational movement of the notched slider 9; a metal strip, i.e., a support rod 93, is welded on the upper end of the spring push surface 94 for triggering the proximity switch 6; there are two guide keys 95 in the cylinder for sliding connection with the guide groove 35 of the transmission shaft 3. The outer end surface of the front end shoulder of the notched slider 9 is a spring push surface 94, which is mainly used to fit the spring 7. In the natural state, the spring 7 presses against the notched slider 9 and cooperates with the output shaft of the drive motor 10 to transmit the torque of the motor to the control torsion bar of HST1 through the transmission shaft 3; when the operator drives the notched slider 9 to make axial movement through the fork 8, the spring 7 is compressed and the notched slider 9 is disengaged from the drive motor 10, and the proximity switch 6 is triggered to send a signal to the controller.

[0046] Furthermore, if Figure 4 As shown, the rebound damping device 5 is composed of an upper plane plate 51, a guide column 52, a damping spring 53, a fixing column 54, a fixing nut 55, and a lower fixing frame 56; four damping springs 53 are respectively mounted on four fixing columns 54, and the four fixing columns 54 are symmetrically welded at the four corners of the bottom of the upper plane plate 51, and the four fixing columns 54 are connected to the lower fixing frame 56 by fixing nuts 55.

[0047] Furthermore, the transmission shaft bracket 4 is an A-shaped metal frame with two mounting holes at the bottom for fixing the frame itself, and a cylindrical metal sleeve welded on the top for interconnecting with the transmission shaft 3; the transmission shaft 3 is coaxially installed with the mounting holes on the transmission shaft bracket 4.

[0048] Furthermore, when the shift fork 8 is not subjected to force, the spring 7 provides an outward thrust to the notched slider 9, so as to support the notched slider 9 and prevent it from disengaging from the driving motor 10.

[0049] Furthermore, if Figure 2 As shown, the shift fork 8 is an integrated structure, the upper part of which is a handle perpendicular to the plane of the frame 12, and the lower part is a door-shaped metal sheet, and the longer metal strips on both sides of the door-shaped metal sheet can be inserted into the notch slider 9 of the notch slider 9. When a force is applied to the shift fork axially away from the drive motor 10, the shift fork 8 can drive the notch slider 9 to disconnect it from the drive motor 10.

[0050] The control torsion bar, spring 7, notched slider 9 and output shaft of the driving motor 10 of the HST 1 are coaxially connected to the transmission shaft 3 and can rotate axially around the transmission shaft 3 .

[0051] Furthermore, the control system includes an operating handle, an angle sensor 2, a controller, a display, a proximity switch 6, a drive motor 10, and a motor driver; the operating handle is installed in the cab to transmit the driver's operating intention to the controller; the angle sensor 2 is installed at the end of the HST control torsion bar, its outer ring is fixed to the HST housing, and the inner ring is fixed to the HST1 control torsion bar, real-time acquisition of the HST control torsion bar rotation angle position, and sends an electrical signal to the controller; the controller is installed in the vehicle body to control the reception of sensor signals and send control signals to the motor driver; the display is installed in the cab to display the angle of the HST1 control torsion bar so that the driver knows the working status of HST1; the proximity switch 6 is installed on the round hole on the spring support plate 34 of the transmission shaft 3 to send an electrical signal when the notch slider 9 is disconnected from the drive motor 10; the drive motor 10 is installed on the motor bracket 11 to rotate the HST1 control torsion bar; the motor driver is installed on the vehicle body to receive the control signal of the controller and control the drive motor 10. The signal output ends of the angle sensor 2 and the proximity switch 6 are both connected to the controller. The operator's control intention is transmitted to the controller through the electrical signal sent by the operating handle. After receiving the signal, the controller sends a signal to the motor driver according to the set control logic to control the rotation of the drive motor 10 and adjust the control torsion bar angle of HST1.

[0052] Furthermore, the operating handle should be a self-resetting handle, and when there is no external force, the handle is located in the middle position; in principle, the placement position of the operating handle should be designed to be mutually exclusive with the placement position of the handle 8.

[0053] Example 2

[0054] The present invention also provides a method for controlling an HST electric machine. The control scheme includes three modes: conventional HST electric control, emergency return to center control, and emergency release and reset control of HST. The specific control process is as follows:

[0055] HST conventional electric control:

[0056] In this case, the notch slider 9 of the mechanical part is pushed by the spring 9 so that the notch 91 cooperates with the protruding metal head of the driving motor 10, so that the torque of the motor can be directly transmitted to the transmission shaft 3 and then drive the control torsion bar of HST1 to rotate left and right. At the same time, the angle sensor 2 installed at the end of the control torsion bar of HST1 can transmit the position of the control torsion bar of HST1 to the controller in real time. The operator knows the rotation position of the control torsion bar of HST1 at this time through the display connected to the controller, and inputs the operation intention into the controller through the handle. The controller uses the input signal of the angle sensor 2 and the input signal of the handle as the control basis, controls the motor driver to drive the motor to rotate and drive the notch slider 9, and the notch slider 9 drives the transmission shaft 3 to overcome the resistance of the compression rebound damping device 5 when it rotates left and right and transmits the twisting action to the control torsion bar of HST1, waiting for the operator to complete the twisting operation of the control torsion bar of HST1.

[0057] HST emergency return control:

[0058] In case of emergency, i.e. the control torsion bar of HST1 is not in the middle position and needs to return to the middle position quickly, the operator moves the shift fork 8 to drive the notch slider 9 to compress the spring. At this time, the notch slider 9 moves away from the drive motor 10 axially, driving the matching notch 91 of the notch slider 9 to disconnect from the protruding metal head of the drive motor 10. At the same time, the support rod 93 on the notch slider 9 touches the proximity switch 6 so that the proximity switch 6 sends a signal to the controller, informing the controller that the notch slider 9 has been separated from the drive motor 10, and the drive motor 10 loses control of the transmission shaft 3, and then loses control of the control torsion bar of HST1. Since the drive shaft 3 will compress the rebound damping device 5 during the left and right rotation, and is subjected to a return force opposite to its own movement, when the connection between the drive motor 10 and the transmission shaft 3 is released, the transmission shaft 3 will drive the control torsion bar of HST1 back to the middle position under the action of the return force, thereby completing the return operation in the case of only one.

[0059] HST emergency release reset control:

[0060] This control method is based on the premise of the second HST emergency return control. When the second HST emergency return control scheme occurs, the support rod 93 on the notch slider 9 triggers the proximity switch 6 so that the proximity switch 6 sends a signal to the controller to inform the controller that the notch slider 9 has been separated from the drive motor 10. When the controller receives this signal, it will control the drive motor 10 to quickly return to a specific position to wait for the notch slider to reset and cooperate with it. When the emergency situation is relieved, the force exerted by the operator on the fork 8 is eliminated, and the spring 7 pushes the notch slider 9 to move along the axial direction close to the drive motor 10 until the matching notch 91 of the notch slider 9 is connected and matched with the raised metal head of the drive motor 10 again, and the drive motor 10 takes over the control torsion bar of HST1 again.

Claims

1. An HST electric control mechanism, characterized in that: The invention comprises a mechanical part and an electric control system, wherein the mechanical part comprises a transmission shaft (3), a rebound damping device (5), a spring (7), a shift fork (8), a notched slider (9) and a frame (12); the electric control system comprises an angle sensor (2), a proximity switch (6), a drive motor (10) and a controller, wherein the controller is electrically connected to the angle sensor (2), the proximity switch (6) and the drive motor (10) respectively; The HST (1) is fixed on a frame (12); the angle sensor (2) is installed at the end of the control torsion bar of the HST (1); one end of the transmission shaft (3) is sleeved on the control torsion bar of the HST (1), and the other end is axially slidably connected to a notched slider (9); the end of the notched slider (9) is non-fixedly connected to the drive motor to realize the drive motor (12) and the transmission shaft (3); the drive motor (10) is installed on the frame (12); a spring (7) is arranged between the notched slider (9) and the transmission shaft (3), and a proximity switch (6) is arranged on the transmission shaft (3); in a relaxed state, the spring (7) The notched slider (9) is connected to a driving motor (10) to transmit the torque of the driving motor (10) to a control torsion bar of the HST through a transmission shaft (3); a shift fork (8) is clamped on the notched slider (9) to push the notched slider (9) to slide axially along the transmission shaft (3), and the notched slider (9) is disconnected from the driving motor through the shift fork (8) and a proximity switch is triggered; a rebound damping device (5) is installed on a frame (12) and is located directly below the transmission shaft (3), and is used to drive the transmission shaft (3) back to a middle position when the transmission shaft (3) is disconnected from the driving motor (10).

2. A HST electric control mechanism as claimed in claim 1, characterized in that: The transmission shaft (3) comprises a shaft body, one end of which is provided with a mounting sleeve (31), the other end of which is provided with a guide groove (35), the shaft body is provided with spring support plates (34), and a return and drag reduction pulley (33) is installed in the middle of the shaft body; one end of the transmission shaft (3) is assembled with the square head sleeve of the control torsion bar of the HST (1) through the mounting sleeve (31), and the other end is engaged with the guide key (95) of the notched slider (9) through the guide groove (35), so that the notched slider (9) is axially movable relative to the transmission shaft (3). The spring (7) is sleeved on the shaft body of the transmission shaft (3), one end of the spring (7) is pressed against the spring support plate (34), and the other end of the spring (7) is pressed against the notched slider (9); the proximity switch (6) is installed on the spring support plate (34); the bottom of the return drag reduction pulley (33) is in contact with the rebound damping device (5), and when the transmission shaft (3) rotates axially, the return drag reduction pulley (33) compresses the rebound damping device (5) to provide a return torque to the transmission shaft (3).

3. A HST electric control mechanism as claimed in claim 2, characterized in that: A circumferential fixing groove (32) is provided on the shaft body of the transmission shaft (3), and the transmission shaft (3) is connected to a transmission bracket (4) via the fixing groove (32), and the transmission bracket (4) is fixed on the frame (12).

4. A HST electric control mechanism as claimed in claim 2, characterized in that: A metal bracket is welded in the middle of the shaft body of the transmission shaft (3), and two return and drag reduction pulleys (33) are symmetrically mounted on the metal bracket, and the bottom of the return and drag reduction pulleys (33) is in contact with the top surface of the rebound damping device (5).

5. The HST electric control mechanism according to claim 2, characterized in that: The notched slider (9) is slidably connected to the guide groove (35) of the transmission shaft (3) through a guide key (95) in the shaft hole; a matching notch (91) is provided at the end of the notched slider (9), and is connected to a protruding metal head of a motor shaft of a driving motor (10) through the matching notch (91); a support rod (93) is provided at the top of the notched slider (9) for actuating a proximity switch (6); and a shift fork notch (92) is provided on the outer periphery of the notched slider (9) for clamping the shift fork (8).

6. The HST electric control mechanism according to claim 2, characterized in that: The rebound damping device (5) is composed of an upper plane plate (51), a guide column (52), a damping spring (53), a fixing column (54), a fixing nut (55), and a lower fixing frame (56); four damping springs (53) are respectively mounted on four fixing columns (54); the four fixing columns (54) are welded to the bottom of the upper plane plate (51); the four fixing columns (54) are connected to the lower fixing frame (56) by fixing nuts (55); and the upper plane plate (51) is in contact with a return-to-center drag-reducing pulley (33) on the transmission shaft (3).

7. The HST electric control mechanism according to claim 1, characterized in that: The control system further comprises an operating handle, a display, and a motor driver; the operating handle is installed in the cab and is used to transmit the driver's operating intention to the controller; the angle sensor (2) collects the rotation angle position of the HST control torsion bar in real time and sends an electrical signal to the controller; the controller is installed in the vehicle body and is used to control the received sensor signal and send a control signal to the motor driver; the display is installed in the cab and is used to display the angle of the HST (1) control torsion bar so that the driver knows the working state of the HST (1); the proximity switch (6) is used to send an electrical signal to the controller when the notch slider (9) is disconnected from the drive motor (10); the motor driver is installed in the vehicle body and is used to receive the control signal of the controller, control the drive motor (10) to rotate, and adjust the control torsion bar angle of the HST (1).

8. A control method for a HST electric control mechanism according to any one of claims 1 to 7, characterized in that: It includes three modes: HST conventional electric control, HST emergency return to center control and HST emergency release and reset control. The specific control process is as follows: The HST conventional electric control: The notched slider (9) of the mechanical part is engaged with the driving motor (10) under the thrust of the spring (9), so that the torque of the driving motor (10) is directly transmitted to the transmission shaft (3), thereby driving the control torsion bar of the HST (1) to rotate left and right, and at the same time, the angle sensor (2) transmits the rotation angle of the control torsion bar of the HST (1) to the controller in real time; the operator inputs the operation intention into the controller, and the controller controls the driving motor to rotate, driving the notched slider (9), and the notched slider (9) drives the transmission shaft (3) to overcome the resistance of the rebound damping device (5) and transmit the twisting action to the control torsion bar of the HST (1), and the operator completes the twisting operation of the control torsion bar of the HST (1); The HST emergency return control: When the control torsion bar of the HST (1) is not in the middle position and needs to be quickly returned to the middle position, the operator shifts the shift fork (8), driving the notched slider (9) to compress the spring, and the notched slider (9) moves away from the drive motor (10) in the axial direction and is disconnected from the drive motor (10). At the same time, the notched slider (9) triggers the proximity switch (6) to send a signal to the controller; the drive motor (10) loses control of the transmission shaft (3), and then loses control of the control torsion bar of the HST (1); the transmission shaft (3) compresses the rebound damping device (5) during the left and right rotation process, and is subjected to a return torque opposite to its own movement. When the connection between the drive motor (10) and the transmission shaft (3) is released, the transmission shaft (3) will drive the control torsion bar of the HST (1) back to the middle position under the action of the return torque, completing the return operation under the condition of only one. The HST emergency release reset control: When the HST emergency return control occurs, the notch slider (9) touches the proximity switch (6) so that the proximity switch (6) sends a signal to the controller to inform the controller that the notch slider (9) has been separated from the drive motor (10), and the controller controls the drive motor (10) to quickly return to a specific position to wait for the notch slider to reset and cooperate with it; when the emergency situation is relieved, the force acting on the fork (8) is eliminated, and the spring (7) pushes the notch slider (9) to move along the axial direction close to the drive motor (10) until the notch slider (9) and the drive motor (10) are connected and cooperated again, and the drive motor (10) takes over the control torsion bar of the HST (1) again.

Images