Hydraulic control method and system for overturning of vehicle-mounted tail ladder

Abstract

The invention relates to the technical field of hydraulic machinery, in particular to a hydraulic control method and system for turning of a vehicle-mounted tail ladder, and the method realizes speed reduction of a mechanism at a stroke end point through hydraulic buffering, so that the movement process of the mechanism from fast to slow and then stopping is realized, the impact and noise at the stroke end point of the mechanism are eliminated, and when an oil cylinder is pushed out from a starting position, the oil cylinder is pushed out. Oil entering from an oil port of a rodless cavity can burst through the buffer disc, extension of a piston of the oil cylinder is not affected by buffering, and for one-way buffering of retraction, one-way buffering is designed in the oil cylinder, and an unloading oil way is designed on an external valve group, so that the effects of ground contact automatic unloading when the tail ladder is opened and automatic speed reduction when the tail ladder is closed can be achieved on the oil way; the stop impact of a mechanism stroke end point is eliminated, and the technical problems that when an existing tail ladder is opened, acting force from the ground can be borne, the leveling effect of a vehicle is affected, and when the tail ladder is closed, the tail ladder collides with a compartment, and the structural safety can be affected are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic machinery, and in particular to a hydraulic control method and system for flipping a vehicle-mounted tail ladder. Background Art

[0002] With the continuous development of science and technology, various types of vehicles are widely used in people's production and life. A tail ladder is usually installed on the rear compartment of a wheeled transport vehicle to facilitate people to get on and off the compartment. In order to reduce the space occupied by the tail ladder, most of them need to flip the tail ladder for use.

[0003] At present, the vehicle-mounted hydraulic tail ladder on the market is hingedly connected to the bottom of the car body. The tail ladder rotates around the hinge to achieve the flipping of the tail ladder. The cylinder extends to push the tail ladder down and stops when it touches the ground; the cylinder retracts to raise the tail ladder, and the cylinder stops moving when the tail ladder is closed.

[0004] However, the above-mentioned vehicle-mounted hydraulic tail ladder has the following problems when it is connected to the bottom of the car body by a hinge: 1. When the tail ladder is opened, it must touch the ground before it can stop, but it is difficult to control the oil cylinder to stop in time at the moment of touching the ground by manual operation. Therefore, the thrust of the oil cylinder will act on the ground and reach the maximum value at the moment the tail ladder touches the ground, causing the mechanism and the oil cylinder to be subjected to a large reaction force from the ground, and even affecting the leveling effect of the vehicle; 2. When the tail ladder is retracted, the shutdown impact of closing in place is large, and the tail ladder collides with the car body, which will affect the structural safety. Summary of the invention

[0005] The purpose of the present invention is to provide a hydraulic control method and system for flipping a vehicle-mounted tail ladder, which solves the technical problems that when the existing vehicle-mounted hydraulic tail ladder is connected to the bottom of the car body by a hinge, the thrust of the oil cylinder will act on the ground and reach a maximum value at the moment when the tail ladder touches the ground, so that the mechanism and the oil cylinder are subjected to a large reaction force from the ground, and even the leveling effect of the vehicle is affected; and when the tail ladder is retracted, the shutdown impact when it is closed in place is large, and the tail ladder collides with the car body, which affects the structural safety.

[0006] To achieve the above object, the present invention provides a hydraulic control method for flipping a vehicle-mounted tail ladder, comprising the following steps:

[0007] Open the tail ladder. When the tail ladder is opened to a certain angle, unload the pump under low pressure. At this time, the tail ladder will fall under its own weight until it touches the ground steadily.

[0008] When the tail ladder touches the ground stably, the tail ladder only has its own weight when in contact with the ground, and the oil cylinder does not output thrust, so as to avoid the tail ladder from pressing against the ground when touching the ground;

[0009] A buffer device is designed inside the oil cylinder. When the tail ladder is closed, the oil cylinder will automatically slow down in advance to avoid a severe collision with the carriage.

[0010] Among them, after the tail ladder is opened to a certain angle, the pump is unloaded under low pressure. At this time, the tail ladder will fall under the action of its own weight until the tail ladder touches the ground stably. The specific method is:

[0011] Extend the oil cylinder to drive the tail ladder to open to a certain angle, and then control the solenoid valves YV2 and YV3 to be energized and YV1 to be de-energized through the program;

[0012] At this time, the pump is unloaded at low pressure, and the pump is allowed to replenish oil to the rodless chamber of the oil cylinder;

[0013] After the oil is replenished, the oil in the rod chamber of the oil cylinder returns from the damping hole Φ3 through the YV2. At this time, the tail ladder lands smoothly under the action of its own weight.

[0014] Among them, when the tail ladder touches the ground stably, the tail ladder only has its own gravity when in contact with the ground, and the oil cylinder does not output thrust, so the specific method to avoid the tail ladder from pressing against the ground when touching the ground is:

[0015] When the tail ladder touches the ground steadily, the tail ladder only has its own weight when in contact with the ground, and the oil cylinder does not output thrust at this time;

[0016] Since the oil cylinder does not output thrust, the tail ladder will not support the ground when it touches the ground. At this time, the tail ladder will not be subjected to a large reaction force from the ground, and will not affect the leveling of the vehicle.

[0017] Among them, the buffer device is designed inside the oil cylinder. When the tail ladder is closed, the oil cylinder will automatically slow down in advance to avoid a severe collision with the carriage. The specific method is:

[0018] The oil cylinder is retracted to drive the tail ladder to close. When the buffer rod inside the oil cylinder begins to enter the buffer hole, a throttling hole is formed, the oil flow area of ​​which gradually decreases as the oil cylinder retracts.

[0019] At this time, the return oil of the rodless chamber of the oil cylinder can only be returned through the triangular throttling groove on the buffer rod. Due to the throttling effect, a return oil back pressure is formed in the rodless chamber which gradually increases as the oil cylinder retracts.

[0020] Since the return oil back pressure will form resistance to the retraction of the oil cylinder, the tail ladder is decelerated and closed until the tail ladder stops.

[0021] The throttle hole, whose oil flow area gradually decreases as the oil cylinder retracts, is formed by a buffer rod, a buffer hole, a buffer spring, a buffer disk and a throttle groove.

[0022] The present invention also provides a hydraulic control system for flipping a vehicle-mounted tail ladder, comprising an oil cylinder and a tail ladder, wherein the oil cylinder is arranged outside the vehicle body, the tail ladder is connected to the output end of the oil cylinder and is located at the bottom of the vehicle body, a buffer hole is arranged in the oil cylinder, a buffer rod is movably arranged in the buffer hole, a throttling groove is arranged on the buffer rod, the buffer hole is connected to a rodless chamber of the oil cylinder, and a buffer disk, a buffer spring, a piston and a piston rod are arranged in the rodless chamber of the oil cylinder from left to right in sequence.

[0023] The top of the buffer hole is connected with a rodless chamber oil port. When the oil cylinder is pushed out from the starting position, the oil entering from the rodless chamber oil port will flush open the buffer plate.

[0024] The invention discloses a hydraulic control method and system for flipping a vehicle-mounted tail ladder. The hydraulic control method relies on hydraulic buffering to achieve deceleration of the mechanism at the end of the stroke, thereby achieving a movement process of the mechanism from fast to slow and then to stop, eliminating the impact and noise at the end of the mechanism stroke. When the oil cylinder is pushed out from the starting position, the oil entering from the oil port of the rodless chamber can flush open the buffer plate, so that the extension of the piston of the oil cylinder is not affected by the buffering. This buffering structure does not affect the starting pressure of the oil cylinder. It is a retracted one-way buffer. By designing a one-way buffer inside the oil cylinder, an external valve The unloading oil circuit is designed in the group, so that the oil circuit can realize the effect of automatic unloading when the tail ladder touches the ground when opening and automatic deceleration when closing, eliminating the shutdown impact at the end point of the mechanism stroke, and solving the technical problems that when the existing vehicle-mounted hydraulic tail ladder is connected to the bottom of the car body by a hinge, the thrust of the oil cylinder will act on the ground and reach the maximum value at the moment when the tail ladder touches the ground, so that the mechanism and the oil cylinder are subjected to a large reaction force from the ground, and even the leveling effect of the vehicle is affected, and when the tail ladder is retracted, the shutdown impact when it is closed is large, and the tail ladder collides with the car body, which affects the structural safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0026] Figure 1 It is a flowchart of a hydraulic control method for flipping a vehicle-mounted tail ladder according to a first embodiment of the present invention.

[0027] Figure 2 This is a specific method diagram of opening the tail ladder of the first embodiment of the present invention. When the tail ladder is opened to a certain angle, the pump is unloaded under low pressure. At this time, the tail ladder will fall under the action of its own weight until the tail ladder touches the ground stably.

[0028] Figure 3This is a specific diagram of the first embodiment of the present invention, when the tail ladder stably touches the ground, the tail ladder only has its own weight when contacting the ground, and the cylinder does not output thrust, so as to avoid the tail ladder from pressing against the ground when touching the ground.

[0029] Figure 4 This is a specific method diagram of designing a buffer device inside the oil cylinder in the first embodiment of the present invention. When the tail ladder is closed, the oil cylinder will automatically decelerate in advance to avoid a severe collision with the car body.

[0030] Figure 5 This is a position diagram of the hydraulic control system for flipping the vehicle-mounted tail ladder according to the second embodiment of the present invention, in which the tail ladder starts to decelerate when closing.

[0031] Figure 6 This is a position diagram of the hydraulic control system for flipping the vehicle-mounted tail ladder according to the second embodiment of the present invention, in which the tail ladder starts to unload when it is opened.

[0032] Figure 7 It is a schematic diagram of the internal buffer structure of the tail ladder cylinder of the hydraulic control system for flipping the vehicle-mounted tail ladder according to the second embodiment of the present invention.

[0033] Figure 8 It is a hydraulic unloading control principle diagram of a hydraulic control system for flipping a vehicle-mounted tail ladder according to a second embodiment of the present invention.

[0034] In the figure: 1-oil cylinder, 2-tail ladder, 3-buffer rod, 4-buffer hole, 5-buffer spring, 6-buffer plate, 7-piston, 8-piston rod, 9-throttle groove, 10-cylinder rodless chamber, 11-rodless chamber oil port. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0036] First embodiment:

[0037] See also Figures 1 to 4 The present invention provides a hydraulic control method for flipping a vehicle-mounted tail ladder 2, comprising the following steps:

[0038] S1. Open the tail ladder 2. When the tail ladder 2 is opened to a certain angle, the pump is unloaded under low pressure. At this time, the tail ladder 2 falls under its own weight until the tail ladder 2 touches the ground stably.

[0039] Specifically, after the tail ladder 2 is opened to a certain angle, the pump is unloaded under low pressure. At this time, the tail ladder 2 falls under its own weight until the tail ladder 2 touches the ground stably. The specific method is:

[0040] S11, extend the oil cylinder 1, drive the tail ladder 2 to open to a certain angle, and then control the solenoid valves YV2 and YV3 to be energized and YV1 to be de-energized through the program;

[0041] S12, at this time, the pump is unloaded under low pressure, and the pump is allowed to replenish oil to the rodless chamber of the oil cylinder 1;

[0042] S13, after the oil is replenished, the oil in the rod chamber of the oil cylinder 1 returns from the damping hole Φ3 through the YV2. At this time, the tail ladder 2 falls smoothly to the ground under the action of its own weight.

[0043] Specifically, the oil cylinder 1 has a certain oil return back pressure, which drives the tail ladder 2 to land smoothly under the certain oil return back pressure by its own weight.

[0044] S2. When the tail ladder 2 touches the ground steadily, the tail ladder 2 only has its own weight when in contact with the ground, and the oil cylinder 1 does not output thrust to prevent the tail ladder 2 from pressing against the ground when touching the ground.

[0045] Specifically, when the tail ladder 2 touches the ground stably, the tail ladder 2 contacts the ground only by its own gravity, and the oil cylinder 1 does not output thrust, so as to avoid the tail ladder 2 from pressing against the ground when touching the ground. The specific method is as follows:

[0046] S21, when the tail ladder 2 touches the ground steadily, the tail ladder 2 has only its own weight when in contact with the ground, and the oil cylinder 1 does not output thrust at this time;

[0047] S22. Since the oil cylinder 1 does not output thrust, the tail ladder 2 will not support the ground when it touches the ground. At this time, the tail ladder 2 will not be subjected to a large reaction force from the ground, and will not affect the leveling of the vehicle.

[0048] S3. A buffer device is designed inside the oil cylinder 1. When the tail ladder 2 is closed, the oil cylinder 1 will automatically decelerate in advance to avoid a severe collision with the carriage.

[0049] Specifically, a buffer device is designed inside the oil cylinder 1. When the tail ladder 2 is closed, the oil cylinder 1 will automatically decelerate in advance to avoid a severe collision with the carriage. The specific method is as follows:

[0050] S31, retract the oil cylinder 1 to drive the tail ladder 2 to close, and when the buffer rod 3 inside the oil cylinder 1 begins to enter the buffer hole 4, a throttle hole is formed, the oil passing area of ​​which gradually decreases as the oil cylinder 1 retracts;

[0051] S32, at this time, the return oil of the rodless chamber of the oil cylinder 1 can only return oil through the triangular throttling groove 9 on the buffer rod 3, and the throttling effect forms a return oil back pressure in the rodless chamber that gradually increases as the oil cylinder 1 retracts;

[0052] S33. Since the return oil back pressure will form resistance to the retraction of the oil cylinder 1, the tail ladder 2 is decelerated and closed until the tail ladder 2 stops.

[0053] Specifically, the throttle hole whose oil passing area gradually decreases as the oil cylinder 1 retracts is formed by a buffer rod 3 , a buffer hole 4 , a buffer spring 5 , a buffer disk 6 and a throttle groove 9 .

[0054] When a hydraulic control method for flipping a vehicle-mounted tail ladder 2 of the present embodiment is used, the hydraulic control method relies on hydraulic buffering to achieve deceleration of the mechanism at the end of the stroke, thereby realizing the movement process of the mechanism from fast to slow and then to stop, eliminating the impact and noise at the end of the mechanism stroke, and when the oil cylinder 1 is pushed out from the starting position, the oil entering from the rodless chamber oil port 11 can flush the buffer plate 6, so that the piston 7 of the oil cylinder 1 is extended without being affected by the buffering. This buffering structure does not affect the starting pressure of the oil cylinder 1, and is a retracted one-way buffer. By designing a one-way buffer inside the oil cylinder 1, The valve group is designed with an unloading oil circuit, so that the oil circuit can realize the effects of automatic unloading when the tail ladder 2 touches the ground when opened and automatic deceleration when closed, eliminating the shutdown impact at the end point of the mechanism stroke, and solving the problems that when the existing vehicle-mounted hydraulic tail ladder 2 is connected to the bottom of the car body by a hinge, the thrust of the cylinder 1 will act on the ground and reach the maximum value at the moment when the tail ladder 2 touches the ground, so that the mechanism and the cylinder 1 are subjected to a large reaction force from the ground, and even the leveling effect of the vehicle is affected, and when the tail ladder 2 is retracted, the shutdown impact when it is closed is large, and the tail ladder 2 collides with the car body, which affects the technical problems of structural safety.

[0055] Second embodiment:

[0056] Based on the first embodiment, please refer to Figures 5 to 8 The present invention also provides a hydraulic control system for flipping a vehicle-mounted tail ladder 2 , comprising an oil cylinder 1 and a tail ladder 2 .

[0057] In this embodiment, hydraulic buffering is used to decelerate the mechanism at the end of the stroke, thereby realizing the movement process of the mechanism from fast to slow and then to stop, eliminating the impact and noise at the end of the mechanism's stroke.

[0058] Among them, the oil cylinder 1 is arranged outside the car, the tail ladder 2 is connected to the output end of the oil cylinder 1 and is located at the bottom of the car, a buffer hole 4 is arranged in the oil cylinder 1, a buffer rod 3 is movably arranged in the buffer hole 4, a throttling groove 9 is arranged on the buffer rod 3, the buffer hole 4 is connected to the oil cylinder rodless cavity 10, and the oil cylinder rodless cavity 10 is sequentially arranged with a buffer disk 6, a buffer spring 5, a piston 7 and a piston 7 rod from left to right.

[0059] Secondly, the throttling groove 9 is a triangular throttling groove 9 with a gradually decreasing longitudinal cross-section.

[0060] At the same time, the buffer hole 4 is connected to a rodless chamber oil port 11 above. When the cylinder 1 is pushed out from the starting position, the oil entering from the rodless chamber oil port 11 will flush open the buffer plate 6, so that the piston 7 of the cylinder 1 can extend without being affected by the buffer. This buffer structure does not affect the starting pressure of the cylinder 1 and is a retracted one-way buffer.

[0061] When the hydraulic control system for turning over the vehicle-mounted tail ladder 2 of this embodiment is used, the opening process of the tail ladder 2 is as follows: when the oil cylinder 1 is extended, the tail ladder 2 is opened to the Figure 2 When the position is Figure 4 As shown), the solenoid valves YV2 and YV3 are energized and YV1 is de-energized through program control. At this time, the pump unloads under low pressure and replenishes oil for the rodless chamber 10 of the oil cylinder, so that the oil in the rod chamber of the oil cylinder 1 returns from the damping hole Φ3 through YV2 (the damping hole forms a return oil back pressure). The tail ladder 2 can fall smoothly to the ground under a certain return oil back pressure by its own weight. When it contacts the ground, it only has its own gravity, and the oil cylinder 1 does not output thrust. In this way, the tail ladder 2 will not be subjected to a large reaction force from the ground when it touches the ground, and will not affect the leveling of the vehicle.

[0062] The closing process of the tail ladder 2 is as follows: when the oil cylinder 1 is retracted, the tail ladder 2 is closed to Figure 1 position, the buffer rod 3 inside the cylinder 1 begins to enter the buffer hole 4, and the buffer rod 3 is processed with the throttling groove 9 with a gradually decreasing longitudinal cross-section. At this time, the buffer rod 3, the buffer hole 4, the buffer spring 5, the buffer plate 6 and the throttling groove 9 form a throttling hole whose oil passing area gradually decreases as the cylinder 1 retracts. At this time, the return oil of the rodless chamber 10 of the cylinder can only return oil through the throttling groove 9 on the buffer rod 3. The throttling effect forms a return oil back pressure in the rodless chamber that gradually increases as the cylinder 1 retracts. The back pressure forms resistance to the retraction of the cylinder 1, causing the tail ladder 2 to slow down and close until it stops. In this way, the method of relying on hydraulic buffering to decelerate the mechanism at the end of the stroke realizes the movement process of the mechanism from fast to slow and then stop, and eliminates the impact and noise at the end of the mechanism stroke.

[0063] When the oil cylinder 1 is pushed out from the starting position, the oil entering from the rodless chamber oil port 11 can flush the buffer plate 6, so that the piston 7 of the oil cylinder 1 can extend without being affected by the buffer. This buffer structure does not affect the starting pressure of the oil cylinder 1. It is a retracted one-way buffer. By designing a one-way buffer inside the oil cylinder 1 and designing a unloading oil circuit on the external valve group, the tail ladder 2 can achieve the effect of automatic unloading when it touches the ground when it is opened and automatic deceleration when it is closed, thereby eliminating the shutdown impact at the end of the mechanism stroke.

[0064] What is disclosed above is only one or more preferred embodiments of the present application, and cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A hydraulic control method for flipping a vehicle-mounted tail ladder, characterized in that: The following steps are involved: Open the tail ladder. When the tail ladder is opened to a certain angle, unload the pump under low pressure. At this time, the tail ladder will fall under its own weight until it touches the ground steadily. When the tail ladder touches the ground stably, the tail ladder only has its own weight when in contact with the ground, and the oil cylinder does not output thrust, so as to avoid the tail ladder from pressing against the ground when touching the ground; A buffer device is designed inside the oil cylinder. When the tail ladder is closed, the oil cylinder will automatically slow down in advance to avoid a severe collision with the carriage.

2. The hydraulic control method for flipping a vehicle-mounted tail ladder according to claim 1, characterized in that: After the tail ladder is opened to a certain angle, the pump is unloaded under low pressure. At this time, the tail ladder will fall under the action of its own weight until the tail ladder touches the ground stably. The specific method is: Extend the oil cylinder to drive the tail ladder to open to a certain angle, and then control the solenoid valves YV2 and YV3 to be energized and YV1 to be de-energized through the program; At this time, the pump is unloaded at low pressure, and the pump is allowed to replenish oil to the rodless chamber of the oil cylinder; After the oil is replenished, the oil in the rod chamber of the oil cylinder returns from the damping hole Φ3 through the YV2. At this time, the tail ladder lands smoothly under the action of its own weight.

3. The hydraulic control method for flipping a vehicle-mounted tail ladder according to claim 1, characterized in that: When the tail ladder touches the ground stably, the tail ladder only has its own gravity when in contact with the ground, and the oil cylinder does not output thrust, so the specific method to avoid the tail ladder from pressing against the ground when touching the ground is as follows: When the tail ladder touches the ground steadily, the tail ladder only has its own weight when in contact with the ground, and the oil cylinder does not output thrust at this time; Since the oil cylinder does not output thrust, the tail ladder will not support the ground when it touches the ground. At this time, the tail ladder will not be subjected to a large reaction force from the ground, and will not affect the leveling of the vehicle.

4. The hydraulic control method for flipping a vehicle-mounted tail ladder according to claim 1, characterized in that: The buffer device is designed inside the oil cylinder. When the tail ladder is closed, the oil cylinder will automatically slow down in advance to avoid a severe collision with the carriage. The specific method is as follows: The oil cylinder is retracted to drive the tail ladder to close. When the buffer rod inside the oil cylinder begins to enter the buffer hole, a throttling hole is formed, the oil flow area of ​​which gradually decreases as the oil cylinder retracts. At this time, the return oil of the rodless chamber of the oil cylinder can only be returned through the triangular throttling groove on the buffer rod. Due to the throttling effect, a return oil back pressure is formed in the rodless chamber which gradually increases as the oil cylinder retracts. Since the return oil back pressure will form resistance to the retraction of the oil cylinder, the tail ladder is decelerated and closed until the tail ladder stops.

5. The hydraulic control system for turning over the vehicle-mounted tail ladder as claimed in claim 4, characterized in that: The throttle hole, whose oil passing area gradually decreases as the oil cylinder retracts, is formed by a buffer rod, a buffer hole, a buffer spring, a buffer disk and a throttle groove.

6. A hydraulic control system for turning over a vehicle-mounted tail ladder, using the hydraulic control method for turning over a vehicle-mounted tail ladder according to any one of claims 1 to 5, characterized in that: It includes an oil cylinder and a tail ladder, wherein the oil cylinder is arranged outside the carriage, the tail ladder is connected to the output end of the oil cylinder and is located at the bottom of the carriage, a buffer hole is arranged in the oil cylinder, a buffer rod is movably arranged in the buffer hole, a throttling groove is arranged on the buffer rod, the buffer hole is connected to a rodless cavity of the oil cylinder, and a buffer disk, a buffer spring, a piston and a piston rod are arranged in the rodless cavity of the oil cylinder from left to right in sequence.

7. The hydraulic control system for turning over the vehicle-mounted tail ladder as claimed in claim 6, characterized in that: The buffer hole is connected with a rodless chamber oil port above. When the oil cylinder is pushed out from the starting position, the oil entering from the rodless chamber oil port will flush open the buffer plate.

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