Protective devices and power take-off systems

Abstract

The present invention provides a protection device and a power take-off system, the protection device includes: a working circuit; an actuator; a first electronic control device, the first electronic control device includes a first control unit and a first actuator; the protection device also includes an external control circuit, wherein the first control unit is connected to the external control circuit, or the first control unit is connected to the working circuit; when the first control unit is connected to the external control circuit, when the gearbox of the vehicle is in a neutral state, the working circuit is connected; when the first control unit is connected to the external control circuit, the working circuit is disconnected. In the technical solution of the present invention, when the gearbox of the vehicle is in a non-neutral state, the first control unit makes the working circuit always in a disconnected state, thus preventing the fork from breaking due to the operation of the power take-off switch, or the occurrence of gear wear, thereby avoiding the problem of the transfer case malfunctioning due to the on-site operator's misoperation of the power take-off switch.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle transfer cases, and in particular to a protection device and a power take-off system. Background Art

[0002] At present, the transfer case power take-off operation in the related technology is to take power through the power take-off rocker switch, that is, first turn on the transfer case neutral switch, and then press the transfer case power take-off switch, the transfer case starts to respond to the power take-off command, the piston rod in the transfer case pushes the shift fork, and the shift fork drives the combined gear to engage with the power take-off gear. If the engagement is successful, other actuators start to take power to the transfer case. If the engagement fails, the shift fork and the combined gear are continuously pressed against the end face of the high-speed rotating power take-off gear. In this way, the shift fork and the combined gear are subjected to continuous impact, which can easily cause the shift fork to deform or even break, or the tooth surface of the combined gear to wear abnormally, thereby causing the transfer case to malfunction and fail to work normally. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] Therefore, an object of the present invention is to provide a protection device.

[0005] Another object of the present invention is to provide a power take-off system.

[0006] In order to achieve the above-mentioned purpose, an embodiment of the present invention provides a protection device for power take-off protection of a transfer case of a vehicle, the protection device comprising: a working circuit having a first end, the first end being connected to an external power supply line; an actuator being arranged on the working circuit; a power take-off switch being arranged on the working circuit, the power take-off switch being closer to the first end than the actuator; a first electronic control device being arranged on the working circuit, the first electronic control device being located between the actuator and the power take-off switch, the first electronic control device comprising a first control unit and a first actuator, the first actuator being arranged on the working circuit, the first control unit being able to control the action of the first actuator to control the on-off of the working circuit; the protection device further comprising an external control circuit, wherein the first control unit is connected to the external control circuit, or the first control unit is connected to the working circuit; when the first control unit is connected to the external control circuit, the external control circuit is connected or disconnected according to the gear position of the vehicle's transmission, so that the first control unit controls the action of the first actuator, thereby controlling the on-off of the working circuit.

[0007] In this technical solution, when the vehicle's gearbox is in a non-neutral state, the first control unit keeps the working circuit in a disconnected state. At this time, the power take-off switch fails, that is, the power take-off switch cannot control the on and off of the working circuit. This prevents the fork from breaking when the power take-off switch is operated to take power from the transfer case when the gearbox is in a non-neutral state, or the occurrence of abnormal wear on the tooth surface of the gear. This effectively avoids the problem of transfer case failure caused by on-site operators mistakenly operating the power take-off switch when the gearbox is in a non-neutral state due to their operating habits, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case.

[0008] In addition, the protection device in the above embodiment provided by the present invention may also have the following additional technical features:

[0009] In the above technical solution, when the first control unit is connected to the working circuit, the protection device also includes: a control circuit, having an input end and an output end, both of which are connected to the working circuit, the input end is located between the power take-off switch and the first actuator, and the output end is connected to the output port of the actuator; a second electronic control device, the second electronic control device includes a second control unit and a second actuator, the second control unit can control the action of the second actuator to control the on and off of the control circuit, and the second actuator is arranged on the control circuit; wherein the first control unit is arranged on the control circuit, the first control unit is connected to the working circuit through the control circuit, the first control unit is closer to the output end of the control circuit than the second actuator, and the second control unit is connected to the external control circuit; when the vehicle's gearbox is in a neutral state, the external control circuit is turned on, and the second control unit controls the second actuator to act so that the control circuit is connected; when the vehicle's gearbox is in a non-neutral state, the external control circuit is disconnected, and the second control unit controls the second actuator to act so that the control circuit is disconnected.

[0010] In this technical solution, when the vehicle's gearbox is in a non-neutral state, the second control unit makes the control circuit always in a disconnected state, so that the first control unit cannot be energized to connect the first actuator to the working circuit, and the working circuit is always in a disconnected state. At this time, the power take-off switch fails, that is, the power take-off switch cannot control the on-and-off of the working circuit. This prevents the transfer case from being broken due to the power take-off switch being operated to take power from the transfer case when the gearbox is in a non-neutral state, or the occurrence of abnormal wear on the tooth surface of the gear, thereby effectively avoiding the problem of transfer case failure caused by the on-site operator's mistaken operation of the power take-off switch when the gearbox is in a non-neutral state due to operating habits.

[0011] In any of the above technical solutions, the protection device also includes a holding circuit, one end of the holding circuit is connected to the control circuit, one end of the holding circuit is connected between the second execution unit and the first control unit, the other end of the holding circuit is connected to the working circuit, and the other end of the holding circuit is connected between the first execution unit and the execution device.

[0012] In this technical solution, during the power taking process, the transmission gear changes and moves from the neutral position to the non-neutral position. The external control circuit is disconnected, the second coil is powered off and stops working, the second armature cannot conduct the control circuit, and the current in the working circuit cannot be introduced into the first coil through the control circuit. However, the holding circuit can introduce the current in the working circuit into the first coil, so that the first coil continues to work, thereby ensuring that the first armature continues to conduct the working circuit, and then ensuring that the power taking work continues.

[0013] In any of the above technical solutions, the first electronically controlled device includes a first relay, and / or the second electronically controlled device includes a second relay.

[0014] In this technical solution, the first relay and / or the second relay is an electromagnetic relay, which is an automatic switching element with an isolation function and is widely used in the field of electromechanical control. It is a universal control element, which facilitates the purchase and subsequent replacement of the second electronic control device.

[0015] In any of the above technical solutions, the first control unit includes a first iron core of a first relay and a first coil arranged on the first iron core, the first coil is connected to an external control circuit, or the first coil is connected to a working circuit; when the first coil is energized, the first control unit generates an electromagnetic force; the first actuator includes a first armature, a first normally open contact and a first normally closed contact of the first relay, one end of the first armature is connected to the working circuit, the first normally open contact and the first normally closed contact are both connected to the working circuit, and the other end of the first armature moves from a first normally closed position in contact with the first normally closed contact to a first normally open position in contact with the first normally open contact under the action of the electromagnetic force.

[0016] In this technical solution, when the vehicle's gearbox is in neutral, the first coil is energized and the first control unit generates electromagnetic force. Under the action of the electromagnetic force, the other end of the first armature contacts the first normally open contact, so that the first armature connects the working circuit, thereby ensuring that the transfer case can work normally, and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case.

[0017] In any of the above technical solutions, the second control unit includes a second iron core of a second relay and a second coil arranged on the second iron core, the second coil is connected to an external control circuit, and when the second coil is energized, the second control unit generates an electromagnetic force; the second actuator includes a second armature, a second normally open contact and a second normally closed contact of the second relay, one end of the second armature is connected to the control circuit, and the second normally open contact and the second normally closed contact are both connected to the control circuit, and under the action of the electromagnetic force, the other end of the second armature moves from a second normally closed position in contact with the second normally closed contact to a second normally open position in contact with the second normally open contact.

[0018] In this technical solution, when the gearbox of the vehicle is in a neutral state, the second coil is energized, and the second control unit generates an electromagnetic force. Under the action of the electromagnetic force, the other end of the second armature contacts the second normally open contact, so that the second armature connects the control circuit. When the power take-off switch is closed, the control circuit is turned on, thereby ensuring that the first coil can be energized to operate, so that the first armature conducts the working circuit, thereby ensuring that the power take-off work can be carried out normally. When the gearbox of the vehicle is in a non-neutral state, under the action of the tension of the return spring of the second control unit, the other end of the second armature contacts the second normally closed contact, so that the second armature disconnects the control circuit. Even if the power take-off switch is closed, the control circuit is still disconnected, so that the first armature cannot conduct the working circuit, thereby making the power take-off switch invalid, thereby effectively avoiding the problem of the transfer case malfunctioning due to the on-site operator's operating habits when the gearbox is in a non-neutral state and misoperating the power take-off switch, thereby ensuring that the transfer case can work normally.

[0019] In any of the above technical solutions, the actuator includes a solenoid valve.

[0020] In this technical solution, when the working circuit is connected, the solenoid valve is powered on and can connect the air circuit in the transfer case, so that the piston rod in the transfer case can push the fork and the combined gear to move to engage with the power take-off gear, thereby completing the power take-off operation of the transfer case. In addition, the solenoid valve is a universal electronic control component, which is easy to purchase and convenient for the later maintenance and replacement of the actuator.

[0021] In any of the above technical solutions, the protection device also includes a driving device connected to the actuator. When the working circuit is connected, the actuator is actuated to control the movement of the piston rod of the driving device.

[0022] In this technical solution, when the working circuit is connected, the actuator is powered on and can connect the air circuit of the drive device in the transfer case, so that the pneumatic operating mechanism in the drive device can push the shift fork and the combined gear to move to engage with the power take-off gear, thereby completing the power take-off operation of the transfer case.

[0023] In any of the above technical solutions, the protection device also includes a shift fork connected to the piston rod and a coupling gear connected to the shift fork, and the piston rod can move with the shift fork and the coupling gear.

[0024] In this technical solution, the piston rod drives the shift fork and the combined gear to move together to engage with the power take-off gear, thereby completing the power take-off operation of the transfer case.

[0025] The technical solution of the second aspect of the present invention provides a power take-off system, which includes a protection device as described in any one of the technical solutions of the first aspect and a power take-off gear connected to the protection device.

[0026] The power take-off system provided by the technical solution of the second aspect of the present invention includes the protection device of any one of the technical solutions of the first aspect, and thus has all the beneficial effects of any of the above technical solutions, which will not be repeated here.

[0027] In the above scheme, the protection device in the power take-off system can prevent the fork from breaking or abnormal wear of the gear tooth surface caused by operating the power take-off switch to take power from the transfer case when the gearbox is not in neutral state, thereby effectively avoiding the problem of transfer case failure caused by on-site operators mistakenly operating the power take-off switch when the gearbox is not in neutral state due to operating habits, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case.

[0028] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 A schematic structural diagram of a protection device according to Embodiment 1 of the present invention is shown (a driving device, a shift fork and a coupling gear are not shown);

[0031] Figure 2 A schematic structural diagram of a protection device according to a second embodiment of the present invention is shown (a driving device, a shift fork and a coupling gear are not shown);

[0032] Figure 3 A schematic structural diagram of a protection device according to Embodiment 3 of the present invention is shown (a driving device, a shift fork and a coupling gear are not shown).

[0033] in, Figures 1 to 3 The corresponding relationship between the reference numerals and the component names is as follows:

[0034] 10: working circuit; 12: first end; 14: second end; 20: first electronic control device; 22: first control unit; 24: first execution unit; 30: execution device; 32: output port; 40: control circuit; 42: input end; 44: output end; 50: second electronic control device; 52: second control unit; 54: second execution unit; 60: holding circuit; 70: power take-off switch; 90: external control circuit. DETAILED DESCRIPTION

[0035] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein may be combined with each other.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0038] It should be noted that the transfer case power take-off operation in the related art is to take power by operating the power take-off switch 70. When the power take-off switch 70 is pressed, the power take-off switch 70 issues a power take-off command, and the transfer case starts to respond to the power take-off command.

[0039] It should be noted that the working circuit 10 of the protection device in the present application has a first end 12 and a second end 14. The first end 12 is connected to an external power supply line, and the second end 14 is connected to a ground line.

[0040] The present invention and the embodiments of the present invention provide a protection device, which can judge the gear state of the vehicle gearbox, that is, judge whether the gear is in neutral or non-neutral, and respond to different states. If the gear of the gearbox is in a non-neutral state, the working circuit 10 in the protection device is always in a disconnected state, and the above-mentioned power take-off instruction is invalid, thereby effectively avoiding the problem that the on-site operator misoperates the power take-off switch 70 when the gearbox is in a non-neutral state due to operating habits, causing the transfer case to malfunction. If the gear of the gearbox is in a neutral state, the working circuit 10 in the protection device is in a connected state, and the above-mentioned power take-off instruction is executed normally, thereby ensuring that the transfer case power take-off operation can be carried out smoothly.

[0041] The protection device of the present invention and the embodiment of the present invention can protect the transfer case of the vehicle, and can avoid the misoperation of the on-site operator, thereby reducing the failure rate of the transfer case. In addition, the protection device of the present invention and the embodiment of the present invention has a low manufacturing cost (i.e., the manufacturing cost of the protection device is about 30 yuan), and has a strong protection ability for the transfer case with expensive manufacturing cost (i.e., the manufacturing cost of the transfer case is about 36,000 yuan), so the protection device has a high cost performance.

[0042] Refer to the following Figures 1 to 3 Protection devices according to some embodiments of the present invention are described.

[0043] Embodiment 1

[0044] like Figure 1 As shown, the present invention and the embodiments of the present invention provide a protection device, which includes a working circuit 10, an actuator 30, a power take-off switch 70 and a first electric control device 20. The working circuit 10 has a first end 12, which is connected to an external power supply line, and the actuator 30 is arranged on the working circuit 10. The power take-off switch 70 is arranged on the working circuit 10, and the power take-off switch 70 is closer to the first end 12 than the actuator 30. The first electric control device 20 is arranged on the working circuit 10, and the first electric control device 20 is located between the actuator 30 and the power take-off switch 70. The first electric control device 20 includes a first control unit 22 and a first actuator 24, and the first actuator 24 is arranged on the working circuit 10. The first control unit 22 can control the action of the first actuator 24 to control the on and off of the working circuit 10. The protection device also includes an external control circuit 90, wherein the first control unit 22 is connected to the external control circuit 90, or the first control unit 22 is connected to the working circuit 10. When the first control unit 22 is connected to the external control circuit 90, the external control circuit 90 is connected or disconnected according to the gear position of the vehicle's transmission (non-neutral state or neutral state), so that the first control unit 22 controls the first execution unit 24 to operate, thereby controlling the on and off of the working circuit 10.

[0045] In the above arrangement, when the vehicle's gearbox is in a non-neutral state, the first control unit 22 keeps the working circuit 10 in a disconnected state at all times, and the power take-off switch 70 fails at this time, that is, the power take-off switch 70 cannot control the on-off of the working circuit 10, thereby preventing the fork from breaking due to the operation of the power take-off switch 70 to take power from the transfer case when the gearbox is in a non-neutral state, or the occurrence of abnormal wear on the tooth surface of the gear, thereby effectively avoiding the problem of the transfer case malfunctioning due to the on-site operator's operating habits and misoperating the power take-off switch 70 when the gearbox is in a non-neutral state, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case.

[0046] It should be noted that the external control circuit 90 can receive the gear information of the transmission and automatically switch on and off according to the gear state of the transmission, that is, if the vehicle's transmission is in a non-neutral state, the external control circuit 90 is disconnected, and if the vehicle's transmission is in a neutral state, the external control circuit 90 is connected. The above method enables the first electronic control device 20 to have a gear judgment function, that is, when the vehicle's transmission is in a neutral state, the external control circuit 90 is connected, and the first control unit 22 controls the first execution unit 24 to operate so that the working circuit 10 is connected; when the vehicle's transmission is in a non-neutral state, the external control circuit 90 is disconnected, and the first control unit 22 controls the first execution unit 24 to operate so that the working circuit 10 is disconnected.

[0047] Specifically, Figure 1 As shown, in the first embodiment of the present invention, the first electronic control device 20 includes a first relay. The first relay is an electromagnetic relay, which is an automatic switching element with an isolation function, widely used in the field of electromechanical control, and is a universal control element, which facilitates the purchase and subsequent replacement of the first electronic control device 20.

[0048] Specifically, in the first embodiment of the present invention, the first control unit 22 includes a first iron core and a first coil disposed on the first iron core, the first coil is connected to the external control circuit 90, and when the first coil is energized, the first control unit 22 generates an electromagnetic force. The first execution unit 24 includes a first armature, a first normally open contact, and a first normally closed contact, one end of the first armature is connected to the working circuit 10, the first normally open contact and the first normally closed contact are both connected to the working circuit 10, and the other end of the first armature moves from a first normally closed position in contact with the first normally closed contact to a first normally open position in contact with the first normally open contact under the action of the electromagnetic force.

[0049] In the above arrangement, when the vehicle's gearbox is in neutral, the first coil is energized, and the first control unit 22 generates electromagnetic force. Under the action of the electromagnetic force, the other end of the first armature contacts the first normally open contact, so that the first armature connects the working circuit 10, thereby ensuring that the transfer case can work normally, and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case.

[0050] It should be noted that the first control unit 22 also includes a reset spring. When the vehicle's gearbox is in a non-neutral state, the first coil is de-energized, and the electromagnetic force generated by the first control unit 22 disappears. Under the pulling force of the reset spring, the other end of the first armature contacts the first normally closed contact, so that the first armature disconnects the working circuit 10, thereby effectively avoiding the problem of transfer case malfunction caused by on-site operators mistakenly operating the power take-off switch 70 due to operating habits when the gearbox is in a non-neutral state, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case.

[0051] Specifically, in the first embodiment of the present invention, the actuator 30 includes a solenoid valve. In the above configuration, when the working circuit 10 is turned on, the solenoid valve is powered on and can connect the air path in the transfer case, so that the piston rod in the transfer case can push the fork and the combined gear to move to engage with the power take-off gear, thereby completing the power take-off operation of the transfer case. In addition, the solenoid valve is a universal electronic control component, which is easy to purchase and is convenient for the later maintenance and replacement of the actuator 30.

[0052] Specifically, in the first embodiment of the present invention, the protection device further includes a driving device connected to the actuator 30. When the working circuit 10 is connected, the actuator 30 is actuated to control the movement of the piston rod of the driving device.

[0053] In the above arrangement, when the working circuit 10 is connected, the actuator 30 is powered on and can connect the air circuit of the drive device in the transfer case, so that the pneumatic operating mechanism in the drive device can push the shift fork and the combined gear to move to engage with the power take-off gear, thereby completing the power take-off operation of the transfer case.

[0054] Preferably, in the first embodiment of the present invention, the driving device is a pneumatic cylinder. When the working circuit 10 is connected, the solenoid valve of the actuator 30 is energized and operates, thereby opening the air circuit of the pneumatic cylinder. In this way, high-pressure air is introduced into the cylinder body of the pneumatic cylinder, and the high-pressure air drives the piston rod to move, thereby ensuring that the power take-off operation of the transfer case can be carried out normally.

[0055] Specifically, in the first embodiment of the present invention, the protection device further comprises a shift fork connected to the piston rod and a coupling gear connected to the shift fork, and the piston rod can move with the shift fork and the coupling gear. In the above arrangement, the piston rod drives the shift fork and the coupling gear to move together to mesh with the power take-off gear, thereby completing the power take-off operation of the transfer case.

[0056] Combine the following Figure 1 The working principle of the protection device in the first embodiment of the present invention is described in detail below:

[0057] When the gear position of the transmission is in neutral, the external control circuit 90 is energized, the first coil is energized, and electromagnetic force is generated. Under the action of the electromagnetic force, the other end (free end) of the first armature contacts the first normally open contact, and the first armature connects the working circuit 10. When the power take-off switch 70 is closed, the entire working circuit 10 is turned on. At this time, the solenoid valve is energized and the air path of the pneumatic cylinder is turned on, so that high-pressure air is introduced into the cylinder body of the pneumatic cylinder. The high-pressure air drives the piston rod to move, and the piston rod drives the shift fork and the combined gear to move together to engage with the power take-off gear, thereby completing the power take-off operation of the transfer case.

[0058] When the gear position of the transmission is in a non-neutral state, the external control circuit 90 is powered off, the first coil is not energized, and under the pulling force of the return spring, the other end (free end) of the first armature contacts the first normally closed contact, and the first armature disconnects the working circuit 10. At this time, even when the power take-off switch 70 is closed, the entire working circuit 10 is still in a disconnected state. At this time, the solenoid valve stops working, and the air path of the pneumatic cylinder is not connected, so that the piston rod cannot move, and the combined gear cannot engage with the power take-off gear, thereby failing to complete the power take-off operation of the transfer case.

[0059] As can be seen from the above, the protection device in the first embodiment of the present invention has the following functions:

[0060] 1. When the gearbox is not in neutral, the power take-off operation of the transfer case is invalid;

[0061] 2. When the transmission is in neutral, the transfer case can perform power take-off operations.

[0062] Embodiment 2

[0063] The second embodiment differs from the first embodiment in the following ways:

[0064] like Figure 2As shown, in the second embodiment of the present invention, when the first control unit 22 is connected to the working circuit 10, the protection device further includes a control circuit 40 and a second electric control device 50. The control circuit 40 has an input end 42 and an output end 44, both of which are connected to the working circuit 10, the input end 42 is located between the power take-off switch 70 and the first actuator 24, and the output end 44 is connected to the output port 32 of the actuator 30. The second electric control device 50 includes a second control unit 52 and a second actuator 54, the second control unit 52 can control the action of the second actuator 54 to control the on and off of the control circuit 40, and the second actuator 54 is arranged on the control circuit 40. The first control unit 22 is arranged on the control circuit 40, the first control unit 22 is connected to the working circuit 10 through the control circuit 40, the first control unit 22 is closer to the output end 44 of the control circuit 40 than the second actuator 54, and the second control unit 52 is connected to the external control circuit 90. When the vehicle's transmission is in a neutral state, the external control circuit 90 is turned on, and the second control unit 52 controls the second execution unit 54 to operate so that the control line 40 is connected. When the vehicle's transmission is not in a neutral state, the external control circuit 90 is turned off, and the second control unit 52 controls the second execution unit 54 to operate so that the control line 40 is disconnected.

[0065] In the above arrangement, when the vehicle's gearbox is in a non-neutral state, the second control unit 52 makes the control circuit 40 always in a disconnected state, so that the first control unit 22 cannot be powered on to connect the first actuator 24 to the working circuit 10. The working circuit 10 is always in a disconnected state. At this time, the power take-off switch 70 fails, that is, the power take-off switch 70 cannot control the on-off of the working circuit 10. This prevents the fork from breaking due to the operation of the power take-off switch 70 to take power from the transfer case when the gearbox is in a non-neutral state, or the occurrence of abnormal wear on the tooth surface of the gear, thereby effectively avoiding the problem of the transfer case malfunctioning due to the on-site operator's operating habits and misoperating the power take-off switch 70 when the gearbox is in a non-neutral state, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case.

[0066] like Figure 2 As shown, in the second embodiment of the present invention, the second electric control device 50 includes a second relay. The second relay is an electromagnetic relay, which is an automatic switch element with an isolation function, widely used in the field of electromechanical control, and is a universal control element, which facilitates the purchase and subsequent replacement of the second electric control device 50.

[0067] Specifically, in the second embodiment of the present invention, the second control unit 52 includes a second iron core of a second relay and a second coil disposed on the second iron core, the second coil is connected to the external control circuit 90, and when the second coil is energized, the second control unit 52 generates an electromagnetic force. The second execution unit 54 includes a second armature, a second normally open contact, and a second normally closed contact of a second relay, one end of the second armature is connected to the control circuit 40, the second normally open contact and the second normally closed contact are both connected to the control circuit 40, and the other end of the second armature moves from a second normally closed position in contact with the second normally closed contact to a second normally open position in contact with the second normally open contact under the action of the electromagnetic force.

[0068] In the above arrangement, when the gearbox of the vehicle is in a neutral state, the second coil is energized, and the second control unit 52 generates an electromagnetic force. Under the action of the electromagnetic force, the other end of the second armature contacts the second normally open contact, so that the second armature connects the control circuit 40. When the power take-off switch 70 is closed, the control circuit 40 is turned on, thereby ensuring that the first coil can be energized to operate, so that the first armature conducts the working circuit 10, thereby ensuring that the power take-off work can be carried out normally. When the gearbox of the vehicle is in a non-neutral state, under the action of the tension of the return spring of the second control unit 52, the other end of the second armature contacts the second normally closed contact, so that the second armature disconnects the control circuit 40. Even if the power take-off switch 70 is closed, the control circuit 40 is still disconnected, so that the first armature cannot conduct the working circuit 10, thereby making the power take-off switch 70 invalid, thereby effectively avoiding the problem of the transfer case malfunctioning due to the on-site operator's operating habits when the gearbox is in a non-neutral state and misoperating the power take-off switch 70, thereby ensuring that the transfer case can work normally.

[0069] The other structures of the second embodiment are the same as those of the first embodiment and will not be described again here.

[0070] Lower combination Figure 2 The working principle of the protection device in the second embodiment of the present invention is described in detail below:

[0071] When the vehicle's gearbox is in neutral, the second coil is energized, and the second control unit 52 generates electromagnetic force. Under the action of the electromagnetic force, the other end of the second armature contacts the two normally open contacts, so that the second armature connects the control circuit 40. When the power take-off switch 70 is closed, the control circuit 40 is turned on, and the first coil is energized to make the first armature turn on the working circuit 10. At this time, the solenoid valve is energized to turn on the air path of the pneumatic cylinder, so that high-pressure air is introduced into the cylinder body of the pneumatic cylinder, and the high-pressure air drives the piston rod to move, and the piston rod drives the shift fork and the combined gear to move together to engage with the power take-off gear, thereby completing the power take-off operation of the transfer case.

[0072] When the vehicle's gearbox is in a non-neutral state, the second coil is de-energized, and under the action of the tension of the return spring of the second control unit 52, the other end of the second armature contacts the second normally closed contact, so that the second armature disconnects the control circuit 40. Even if the power take-off switch 70 is closed, the control circuit 40 is still disconnected, and the first coil is de-energized and stops working. At this time, the first armature cannot conduct the working circuit 10, the solenoid valve cannot be powered on, high-pressure air cannot be passed into the cylinder body of the pneumatic cylinder, and the piston rod cannot drive the shift fork and the combined gear to move together to engage with the power take-off gear, thereby failing to complete the power take-off operation of the transfer case.

[0073] As can be seen from the above, the protection device in the second embodiment of the present invention has the following functions:

[0074] 1. When the gearbox is not in neutral, the power take-off operation of the transfer case is invalid;

[0075] 2. When the transmission is in neutral, the transfer case can perform power take-off operations.

[0076] Embodiment 3

[0077] The third embodiment differs from the second embodiment in the following ways:

[0078] like Figure 3 As shown, in the third embodiment of the present invention, the protection device also includes a holding circuit 60, one end of the holding circuit 60 is connected to the control circuit 40, one end of the holding circuit 60 is connected between the second execution unit 54 and the first control unit 22, the other end of the holding circuit 60 is connected to the working circuit 10, and the other end of the holding circuit 60 is connected between the first execution unit 24 and the execution device 30.

[0079] In the above setting, during the power taking process, the transmission gear changes and moves from the neutral position to the non-neutral position. The external control circuit 90 is disconnected, the second coil is powered off and stops working, the second armature cannot conduct the control circuit 40, and the current in the working circuit 10 cannot be introduced into the first coil through the control circuit 40. However, the holding circuit 60 can introduce the current in the working circuit 10 into the first coil, so that the first coil continues to work, thereby ensuring that the first armature continues to conduct the working circuit 10, and then ensuring that the power taking work continues.

[0080] The other structures of the third embodiment are the same as those of the second embodiment and will not be described here in detail.

[0081] It should be noted that the working principle of the protection device in the third embodiment is basically the same as that of the protection device in the second embodiment, which will not be described here. The protection device in the third embodiment is additionally provided with a holding circuit 60, so that during the power taking process, even if the gear position of the transmission changes, that is, moves from the neutral position to the non-neutral position, the protection device in the third embodiment can still ensure that the power taking work continues. The protection device in the third embodiment of the present invention has the following functions:

[0082] 1. When the gearbox is not in neutral, the power take-off operation of the transfer case is invalid;

[0083] 2. When the gearbox is in neutral, the transfer case can be operated to take off power;

[0084] 3. During the process of the transfer case taking off power, when the gear position of the transmission is switched from neutral to non-neutral, the control circuit 40 is still in an energized state, thereby maintaining uninterrupted power taking operation.

[0085] The present invention provides a power take-off system for a transfer case, the power take-off system comprising a protection device as described in any one of the embodiments of the first aspect and a power take-off gear connected to the protection device.

[0086] In the above arrangement, the protective device in the power take-off system can prevent the fork from breaking due to the operation of the power take-off switch 70 to take power from the transfer case when the gearbox is not in neutral, or the abnormal wear of the tooth surface of the gear, thereby effectively avoiding the problem of the transfer case malfunctioning due to the on-site operator's operating habits and the misoperation of the power take-off switch 70 when the gearbox is not in neutral, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case. The power take-off system provided by the technical solution of the second aspect of the present invention includes any of the protective devices in the first aspect of the embodiments, and thus has all the beneficial effects of any of the above embodiments, which will not be repeated here.

[0087] From the above description, it can be seen that in the first embodiment of the present application, when the vehicle's gearbox is in a non-neutral state, the first control unit 22 keeps the working circuit 10 in a disconnected state at all times. At this time, the power take-off switch 70 fails, that is, the power take-off switch 70 cannot control the on-off of the working circuit 10. This prevents the fork from breaking when the power take-off switch 70 is operated to take power from the transfer case when the gearbox is in a non-neutral state, or the occurrence of abnormal wear on the tooth surface of the gear. This effectively avoids the problem of the transfer case malfunctioning due to the on-site operator's operating habits and misoperating the power take-off switch 70 when the gearbox is in a non-neutral state, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case. In embodiments 2 and 3 of the present application, when the vehicle's gearbox is in a non-neutral state, the second control unit 52 makes the control circuit 40 always in a disconnected state, so that the first control unit 22 cannot be energized to connect the first actuator 24 to the working circuit 10, and the working circuit 10 is always in a disconnected state. At this time, the power take-off switch 70 fails, that is, the power take-off switch 70 cannot control the on-off of the working circuit 10, thereby preventing the fork from breaking or abnormal wear of the tooth surface of the combined gear caused by operating the power take-off switch 70 to take power from the transfer case when the gearbox is in a non-neutral state, thereby effectively avoiding the problem of transfer case failure caused by on-site operators mistakenly operating the power take-off switch 70 when the gearbox is in a non-neutral state due to operating habits, thereby ensuring that the transfer case can work normally and the upper oil pump connected to the transfer case power take-off can smoothly take power from the transfer case. In the third embodiment, during the power taking process, the transmission gear changes and moves from the neutral position to the non-neutral position. The external control circuit 90 is disconnected, the second coil is powered off and stops working, the second armature cannot conduct the control circuit 40, and the current in the working circuit 10 cannot be introduced into the first coil through the control circuit 40. However, the holding circuit 60 can introduce the current in the working circuit 10 into the first coil, so that the first coil continues to work, thereby ensuring that the first armature continues to conduct the working circuit 10, and further ensuring that the power taking work continues.

[0088] In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0089] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front” and “back” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0090] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0091] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A protection device for protecting the power take-off of a transfer case of a vehicle, characterized in that: The protection device comprises: A working circuit (10) having a first end (12), wherein the first end (12) is connected to an external power supply line; An actuator (30) is arranged on the working circuit (10); A power take-off switch (70) is arranged on the working line (10), and the power take-off switch (70) is closer to the first end (12) than the actuator (30); A first electric control device (20) is arranged on the working circuit (10); the first electric control device (20) is located between the actuator (30) and the power take-off switch (70); the first electric control device (20) comprises a first control unit (22) and a first actuator (24); the first actuator (24) is arranged on the working circuit (10); the first control unit (22) can control the action of the first actuator (24) to control the on / off of the working circuit (10); The protection device further comprises an external control circuit (90), wherein the first control unit (22) is connected to the external control circuit (90), or the first control unit (22) is connected to the working circuit (10); when the first control unit (22) is connected to the external control circuit (90), the external control circuit (90) is turned on or off according to the gear position of the transmission of the vehicle, so that the first control unit (22) controls the first execution unit (24) to operate, thereby controlling the on and off of the working circuit (10); When the first control unit (22) is connected to the working circuit (10), the protection device further comprises: a control circuit (40) having an input end (42) and an output end (44), wherein the input end (42) and the output end (44) are both connected to the working circuit (10), the input end (42) is located between the power take-off switch (70) and the first actuator (24), and the output end (44) is connected to an output port (32) of the actuator (30); a second electric control device (50), the second electric control device (50) comprising a second control unit (52) and a second execution unit (54), the second control unit (52) being capable of controlling the second execution unit (54) to operate so as to control the on / off of the control circuit (40), and the second execution unit (54) being arranged on the control circuit (40); The first control unit (22) is arranged on the control circuit (40), the first control unit (22) is connected to the working circuit (10) through the control circuit (40), the first control unit (22) is closer to the output end (44) of the control circuit (40) than the second execution unit (54), and the second control unit (52) is connected to the external control circuit (90); when the gearbox of the vehicle is in a neutral state, the external control circuit (90) is connected, and the second control unit (52) controls the second execution unit (54) to operate so that the control circuit (40) is connected; when the gearbox of the vehicle is in a non-neutral state, the external control circuit (90) is disconnected, and the second control unit (52) controls the second execution unit (54) to operate so that the control circuit (40) is disconnected; The protection device further comprises a holding circuit (60), one end of the holding circuit (60) being connected to the control circuit (40), one end of the holding circuit (60) being connected between the second execution unit (54) and the first control unit (22), the other end of the holding circuit (60) being connected to the working circuit (10), and the other end of the holding circuit (60) being connected between the first execution unit (24) and the execution device (30); The first electric control device (20) comprises a first relay; The first control unit (22) comprises a first iron core of the first relay and a first coil arranged on the first iron core, the first coil being connected to the external control circuit (90), or the first coil being connected to the working circuit (10); when the first coil is energized, the first control unit (22) generates an electromagnetic force; the first execution unit (24) comprises a first armature, a first normally open contact and a first normally closed contact of the first relay, one end of the first armature being connected to the working circuit (10), the first normally open contact and the first normally closed contact both being connected to the working circuit (10), and the other end of the first armature being moved from a first normally closed position in contact with the first normally closed contact to a first normally open position in contact with the first normally open contact under the action of the electromagnetic force; The first control part (22) also includes a reset spring; when the first coil is powered off, the electromagnetic force generated by the first control part (22) disappears, and under the pulling force of the reset spring, the other end of the first armature contacts the first normally closed contact.

2. The protection device according to claim 1, characterized in that: The second electric control device (50) includes a second relay.

3. The protection device according to claim 2, characterized in that: The second control unit (52) includes a second iron core of the second relay and a second coil arranged on the second iron core, the second coil is connected to the external control circuit (90), and when the second coil is energized, the second control unit (52) generates an electromagnetic force; the second actuator (54) includes a second armature, a second normally open contact and a second normally closed contact of the second relay, one end of the second armature is connected to the control circuit (40), the second normally open contact and the second normally closed contact are both connected to the control circuit (40), and the other end of the second armature moves from a second normally closed position in contact with the second normally closed contact to a second normally open position in contact with the second normally open contact under the action of the electromagnetic force.

4. The protection device according to claim 1, characterized in that: The actuator (30) comprises a solenoid valve.

5. The protection device according to claim 1, characterized in that: The protection device also includes a driving device connected to the actuator (30). When the working circuit (10) is connected, the actuator (30) is activated to control the movement of the piston rod of the driving device.

6. The protection device according to claim 5, characterized in that: The protection device further comprises a shift fork connected to the piston rod and a coupling gear connected to the shift fork, and the piston rod can move with the shift fork and the coupling gear.

7. A power take-off system for a transfer case, characterized in that: The power take-off system comprises a protection device according to any one of claims 1 to 6 and a power take-off gear connected to the protection device.

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