A fifth leg priority retraction leg control system and truck crane

Abstract

This invention discloses a fifth outrigger priority retraction control system and a truck crane. The control system includes a telescopic selection valve, a fifth outrigger vertical reversing valve, and at least one outrigger vertical-to-horizontal switching valve connected in parallel with the fifth outrigger vertical reversing valve. An additional one-way bypass hydraulic branch is added between the sixth working port of the telescopic selection valve and the third working port of the fifth outrigger vertical reversing valve. When the fifth outrigger vertical reversing valve is in the neutral position, the oil flowing from the rod chamber of the fifth outrigger cylinder enters the sixth working port of the telescopic selection valve through the one-way bypass hydraulic branch, and returns to the oil tank after exiting from the third working port of the telescopic selection valve. This invention enables the fifth outrigger to retract automatically or preferentially during user outrigger retraction operations, avoiding problems such as lateral bending of the fifth outrigger or even accidents caused by improper operation or missed operation.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery, specifically relating to a fifth outrigger retraction priority control system and a truck crane. Background Technology

[0002] With the development of domestic construction machinery manufacturing technology, the market demand for truck cranes is no longer limited to basic performance requirements, but also includes higher requirements for reliability, operability, and safety. Currently, most of the company's 8-90t cranes are equipped with a fifth outrigger at the bottom of the cab to improve safety during lifting operations. With the addition of the fifth outrigger, the crane must be retracted in the correct order when retracting the crane, followed by the other vertical outriggers. However, when the crane is finished working and is being retracted, users often forget to retract the fifth outrigger and retract the other vertical outriggers directly. This can cause the unretracted fifth outrigger to bend sideways during crane travel, potentially leading to accidents and posing a safety hazard.

[0003] Existing control systems for outrigger movement, such as Figure 1 (In existing publicly available technology), the reversing handle of the fifth outrigger vertical switching valve 2 is moved to the vertical position, and then the reversing handle of the telescopic selection valve 1 is moved to the outrigger retraction position to retract the fifth outrigger cylinder 4. After the fifth outrigger cylinder is retracted, the vertical cylinders of the front, rear, left, and right outriggers are retracted. However, due to user negligence, during the outrigger retraction process, only the vertical cylinders 5-1, 5-2, 5-3, and 5-4 of the front, rear, left, and right outriggers were retracted, while the fifth outrigger cylinder 4 was not retracted. This caused a lateral bending failure during the crane's relocation process, and even led to an accident.

[0004] Chinese patent CN101839260A discloses a multi-way directional control valve for outriggers with a two-position two-way hydraulic control valve. This patent, by adding a two-position two-way hydraulic control valve, enables sequential control of the retraction and extension of the fifth outrigger. This ensures that the fifth outrigger is retracted immediately under any circumstances, preventing damage to the fifth outrigger cylinder due to asynchronous operation. When retracting, the directional control handle of the selector valve is moved to the retracted position. Pressurized oil entering from port P passes through the retracted position of the selector valve, through the hydraulic control check valve 3 to port H, and then through the connecting pipeline into the small chamber of the fifth outrigger cylinder. Simultaneously, pressurized oil entering from port P passes through the retracted position of the selector valve into the control chamber of the hydraulic control directional control valve, controlling the valve's reversal. This connects the oil passages between the large chamber of the fifth outrigger cylinder, the connecting pipeline, and ports B and T inside the multi-way directional control valve. Therefore, even when the fifth outrigger operating handle is not switched and the fifth outrigger vertical switching valve is still in the neutral position, the fifth outrigger can still retract. However, in this prior art, because the hydraulic directional valve is a two-position two-way spool valve, the probability of the directional valve core getting stuck is higher. When the directional valve core is stuck in the off position, the retraction of the fifth leg cylinder cannot be controlled sequentially, which may lead to the fifth leg bending or even an accident due to missed operation; when the directional valve core is stuck in the on position, the fifth leg cylinder cannot extend normally. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a fifth outrigger priority retraction control system and a truck crane, so that when the user performs the outrigger retraction operation, the fifth outrigger can be retracted either by operating the fifth outrigger vertical reversing valve or automatically prioritized for retraction without operating the fifth outrigger vertical reversing valve, thereby avoiding the fifth outrigger bending or even accidents caused by improper operation or omission of operation.

[0006] Technical solution: The present invention includes a telescopic selection valve, a fifth leg vertical reversing valve, and at least one leg vertical-to-horizontal switching valve connected in parallel with the fifth leg vertical reversing valve; an additional one-way bypass hydraulic branch is added between the sixth working port of the telescopic selection valve and the third working port of the fifth leg vertical reversing valve; when the fifth leg vertical reversing valve is not switched to the vertical working position, the oil flowing out of the rod chamber of the fifth leg cylinder enters the sixth working port of the telescopic selection valve through the one-way bypass hydraulic branch, and returns to the oil tank after exiting from the third working port of the telescopic selection valve.

[0007] A one-way bypass hydraulic branch is equipped with a check valve and a hydraulically controlled one-way valve. The oil inlet of the check valve is connected to the third working oil port of the fifth leg vertical reversing valve, and the oil outlet of the check valve is connected to the oil outlet of the hydraulically controlled one-way valve. The oil inlet of the hydraulically controlled one-way valve is connected to the sixth working oil port of the telescopic selector valve. The control oil port of the hydraulically controlled one-way valve is connected to the fifth working oil port of the telescopic selector valve.

[0008] Both the one-way valve and the hydraulically controlled one-way valve have a cone valve structure, which greatly reduces the risk of jamming and improves the safe operation performance of the crane.

[0009] The first and second working ports of the telescopic selector valve are both connected to the P port of the oil tank, the third working port of the telescopic selector valve is connected to the T port of the oil tank, and the fifth working port of the telescopic selector valve is used to connect to the rod chamber of the fifth outrigger cylinder and each outrigger vertical cylinder.

[0010] The sixth working port of the telescopic selector valve is connected to the first working port of the fifth leg vertical reversing valve and the leg vertical-horizontal switching valve.

[0011] The second working port of the fifth leg vertical reversing valve and the second working port of the leg vertical-horizontal switching valve are both connected to the T port of the oil tank.

[0012] The third working port of the fifth leg vertical reversing valve is used to connect to the rodless chamber of the fifth leg cylinder. The third and fourth working ports of each leg vertical-horizontal switching valve are used to connect to the rodless chamber of the corresponding leg cylinder.

[0013] The number of vertical / horizontal switching valves for the outriggers is the same as the number of vertical hydraulic cylinders for the outriggers.

[0014] A hydraulic branch is provided between the P port and T port of the oil tank, and an overflow valve is provided on the hydraulic branch.

[0015] The invention also includes a truck crane comprising a fifth outrigger retraction priority control system.

[0016] Beneficial Effects: Compared with the prior art, the technical solution of the present invention has the following beneficial effects: By designing a one-way bypass hydraulic branch, when the user retracts the outrigger, the fifth outrigger can be retracted either by operating the reversing valve or by automatically prioritizing retraction without operating the fifth outrigger vertical switching valve, thus avoiding problems such as the fifth outrigger bending or even accidents caused by improper operation or missed operation; in addition, the hydraulic control check valve and check valve with cone valve structure greatly reduce the risk of jamming and improve the safe operation performance of the crane. Attached Figure Description

[0017] Figure 1 This is a hydraulic schematic diagram of existing technology;

[0018] Figure 2 This is a hydraulic schematic diagram of the present invention. Detailed Implementation

[0019] The technical solution of the present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0020] like Figure 1 As shown, the outrigger control system of the present invention includes a telescopic selection valve 1, a fifth outrigger vertical reversing valve 2, an outrigger vertical-horizontal switching valve, a hydraulic check valve 4, and a check valve 5. The outrigger vertical-horizontal switching valve includes a front outrigger vertical-horizontal switching valve 31, a rear outrigger vertical-horizontal switching valve 32, a left outrigger vertical-horizontal switching valve 33, and a right outrigger vertical-horizontal switching valve 34. The fifth outrigger vertical reversing valve 2, the front outrigger vertical-horizontal switching valve 31, the rear outrigger vertical-horizontal switching valve 32, the left outrigger vertical-horizontal switching valve 33, and the right outrigger vertical-horizontal switching valve 34 are connected in parallel.

[0021] The first and second working ports of the telescopic selector valve 1 are both connected to the P port of the oil tank. The third working port of the telescopic selector valve 1 is connected to the T port of the oil tank. The fourth working port of the telescopic selector valve 1 is connected to the V port. The fifth working port of the telescopic selector valve 1 is used to connect to the rod chambers of the fifth outrigger cylinder 6 and the vertical cylinders 71-74 of the front, rear, left, and right outriggers. The sixth working port of the telescopic selector valve 1 is connected to the first working port of the fifth outrigger vertical reversing valve 2, the front outrigger vertical-horizontal switching valve 31, the rear outrigger vertical-horizontal switching valve 32, the left outrigger vertical-horizontal switching valve 33, and the right outrigger vertical-horizontal switching valve 34. The second working ports of the fifth outrigger vertical reversing valve 2, the front outrigger vertical-horizontal switching valve 31, the rear outrigger vertical-horizontal switching valve 32, the left outrigger vertical-horizontal switching valve 33, and the right outrigger vertical-horizontal switching valve 34 are all connected to the T port of the oil tank. The third working port of the fifth outrigger vertical reversing valve 2 is used to connect to the rodless chamber of the fifth outrigger cylinder 6. The third working ports of the front outrigger vertical-horizontal switching valve 31, rear outrigger vertical-horizontal switching valve 32, left outrigger vertical-horizontal switching valve 33, and right outrigger vertical-horizontal switching valve 34 are used to connect to the rodless chambers of the front, rear, left, and right outrigger vertical cylinders 71-74. The fourth working ports of the front outrigger vertical-horizontal switching valve 31, rear outrigger vertical-horizontal switching valve 32, left outrigger vertical-horizontal switching valve 33, and right outrigger vertical-horizontal switching valve 34 are used to connect to the rodless chambers of the front, rear, left, and right outrigger horizontal cylinders. It can be seen that the front outrigger vertical-horizontal switching valve 31, rear outrigger vertical-horizontal switching valve 32, left outrigger vertical-horizontal switching valve 33, and right outrigger vertical-horizontal switching valve 34 individually control the cylinders in the four directions (front, rear, left, and right). The number of outrigger vertical-horizontal switching valves is the same as the number of outrigger vertical cylinders.

[0022] A hydraulic branch is installed between the P port and T port of the oil tank, and an overflow valve is installed on this hydraulic branch.

[0023] An additional one-way bypass hydraulic branch is added between the sixth working port of the telescopic selector valve 1 and the fourth working port of the fifth leg vertical directional valve 2. The function of this one-way bypass hydraulic branch is that when the fifth leg vertical directional valve 2 is working in a non-vertical position, the oil flowing out of the rod chamber of the fifth leg cylinder 6 enters the sixth working port of the telescopic selector valve 1 through the one-way bypass hydraulic branch, and returns to the oil tank after exiting the third working port of the telescopic selector valve 1. A one-way valve group is installed on this branch.

[0024] A one-way bypass hydraulic branch is equipped with a one-way valve 5 and a hydraulically controlled one-way valve 4. The oil inlet of the one-way valve 5 is connected to the third working oil port of the fifth leg vertical reversing valve 2, the oil outlet of the one-way valve 5 is connected to the oil outlet of the hydraulically controlled one-way valve 4, and the oil inlet of the hydraulically controlled one-way valve 4 is connected to the sixth working oil port of the telescopic selector valve 1.

[0025] When the fifth outrigger vertical switching valve 2 is switched, the retraction process of the fifth outrigger cylinder 6 is as follows: When the lower outrigger vertical cylinder retracts, the fifth outrigger cylinder 6 retracts manually first, and the front, rear, left, and right outrigger vertical cylinders 71-74 retract subsequently. The specific process is as follows:

[0026] First, the fifth outrigger vertical switching valve 2 is switched to the vertical position, and the telescopic selection valve 1 is switched to the retracted position. The pump oil source enters the second working port of the telescopic selection valve 1 from the P port, and after exiting from the fifth working port of the telescopic selection valve 1, it directly enters the rod chamber of the fifth outrigger cylinder 6. The oil exiting from the rodless chamber of the fifth outrigger cylinder 6 enters the third working port of the fifth outrigger vertical switching valve 2, and after exiting from the first working port of the fifth outrigger vertical switching valve 2, it enters the sixth working port of the telescopic selection valve 1. After exiting from the third working port of the telescopic selection valve 1, the oil returns to the oil tank from the T port, forming a loop and realizing the retraction of the fifth outrigger cylinder 6.

[0027] Then, the front outrigger vertical / horizontal switching valve 31, rear outrigger vertical / horizontal switching valve 32, left outrigger vertical / horizontal switching valve 33, and right outrigger vertical / horizontal switching valve 34 are switched to the vertical position. The telescopic selection valve 1 is switched to the retracted position. The pump oil source enters the second working oil port of the telescopic selection valve 1 from the P oil port, and exits from the fifth working oil port of the telescopic selection valve 1 before directly entering the rod chamber of the front outrigger vertical cylinder 71, rear outrigger vertical cylinder 72, left outrigger vertical cylinder 73, and right outrigger vertical cylinder 74. The oil coming out of the rodless chamber of the front outrigger vertical cylinder 71, rear outrigger vertical cylinder 72, left outrigger vertical cylinder 73, and right outrigger vertical cylinder 74 enters... The oil enters the third working port of the front outrigger vertical / horizontal switching valve 31, the rear outrigger vertical / horizontal switching valve 32, the left outrigger vertical / horizontal switching valve 33, and the right outrigger vertical / horizontal switching valve 34, and exits from the first working port of the front outrigger vertical / horizontal switching valve 31, the rear outrigger vertical / horizontal switching valve 32, the left outrigger vertical / horizontal switching valve 33, and the right outrigger vertical / horizontal switching valve 34 before entering the sixth working port of the telescopic selection valve 1. The oil exits from the third working port of the telescopic selection valve 1 and returns to the oil tank from the T port, forming a circuit to realize the retraction of the front outrigger vertical cylinder 71, the rear outrigger vertical cylinder 72, the left outrigger vertical cylinder 73, and the right outrigger vertical cylinder 74.

[0028] Without switching the fifth outrigger vertical switching valve 2, the retraction process of the fifth outrigger cylinder 6 is as follows: When the lower outrigger vertical cylinder retracts, the fifth outrigger vertical switching valve 2 is not switched and is in the neutral position. Only the front outrigger vertical-horizontal switching valve 31, the rear outrigger vertical-horizontal switching valve 32, the left outrigger vertical-horizontal switching valve 33, and the right outrigger vertical-horizontal switching valve 34 are switched to the vertical position, and the telescopic selection valve 1 is switched to the retraction position. At this time, the pump oil source enters the first telescopic selection valve 1 from the P oil port. The second working port, after exiting from the fifth working port of the telescopic selector valve 1, directly enters the rod chamber of the fifth outrigger cylinder 6, the front outrigger vertical cylinder 71, the rear outrigger vertical cylinder 72, the left outrigger vertical cylinder 73, and the right outrigger vertical cylinder 74; the oil exiting from the rodless chamber of the fifth outrigger cylinder 6 enters the sixth working port of the telescopic selector valve 1 through the check valve 5 and the hydraulic control check valve 4; the oil exiting from the third working port of the telescopic selector valve 1 returns to the oil tank through the T port, forming a loop to realize the retraction of the fifth outrigger cylinder 6.

[0029] The oil exiting from the rodless chambers of the front outrigger vertical cylinder 71, rear outrigger vertical cylinder 72, left outrigger vertical cylinder 73, and right outrigger vertical cylinder 74 enters the third working port of the front outrigger vertical / horizontal switching valve 31, rear outrigger vertical / horizontal switching valve 32, left outrigger vertical / horizontal switching valve 33, and right outrigger vertical / horizontal switching valve 34. After exiting from the first working port of the front outrigger vertical / horizontal switching valve 31, rear outrigger vertical / horizontal switching valve 32, left outrigger vertical / horizontal switching valve 33, and right outrigger vertical / horizontal switching valve 34, it enters the sixth working port of the telescopic selection valve 1. After exiting from the third working port of the telescopic selection valve 1, the oil returns to the oil tank through the T port, forming a loop and realizing the retraction of the front outrigger vertical cylinder 71, rear outrigger vertical cylinder 72, left outrigger vertical cylinder 73, and right outrigger vertical cylinder 74. Therefore, while the vertical cylinders 71-74 of the front, rear, left, and right outriggers retract, the fifth outrigger cylinder 6 can also retract, avoiding the problem of the outrigger bending under force due to forgetting to operate the fifth outrigger.

[0030] In this design, the hydraulically controlled check valve 4 is a cone valve structure. The pressure at the external control port of the hydraulically controlled check valve 4 comes from the pressure in the small chamber. That is, the control oil source for the hydraulically controlled check valve 4 comes from the oil inlet of the rod chambers of the fifth outrigger cylinder 6 and the vertical cylinders 71-74 of the front, rear, left, and right outriggers, ensuring full opening while reducing the risk of jamming. Therefore, the valve disc of the hydraulically controlled check valve 4 will only be opened when the vertical cylinders of the lower outriggers retract. During the extension of the vertical cylinders of the lower outriggers, the low-pressure oil will not open the valve disc of the hydraulically controlled check valve 4.

[0031] The one-way valve 5 is a cone valve structure, which ensures that during the extension action of the outrigger, if the fifth outrigger vertical switching valve 2 is not manually operated to switch to the vertical position, the fifth outrigger will not automatically extend when the telescopic selection valve 1 is operated to switch to the extension position. This prevents the fifth outrigger from suddenly extending without recognizing the surrounding environment, which could cause the fifth outrigger cylinder 6 to encounter an obstacle and malfunction, thus making the extension action of the fifth outrigger controllable.

[0032] The present invention also provides a truck crane, which includes a fifth outrigger retraction priority control system.

Claims

1. A fifth outrigger priority retraction control system, comprising a telescopic selection valve (1), a fifth outrigger vertical reversing valve (2), and at least one outrigger vertical-to-horizontal switching valve connected in parallel with the fifth outrigger vertical reversing valve (2); characterized in that: An additional one-way bypass hydraulic branch is added between the sixth working port of the telescopic selector valve (1) and the third working port of the fifth leg vertical reversing valve (2). When the fifth leg vertical reversing valve (2) is not reversed to the vertical working position, the oil flowing out of the rodless chamber of the fifth leg cylinder (6) enters the sixth working port of the telescopic selection valve (1) through the one-way bypass hydraulic branch, and returns to the oil tank after coming out from the third working port of the telescopic selection valve (1). A check valve (5) and a hydraulically controlled check valve (4) are provided on the one-way bypass hydraulic branch. The oil inlet of the check valve (5) is connected to the third working oil port of the fifth leg vertical reversing valve (2), and the oil outlet of the check valve (5) is connected to the oil outlet of the hydraulically controlled check valve (4). The oil inlet of the hydraulically controlled check valve (4) is connected to the sixth working oil port of the telescopic selector valve (1). The control oil port of the hydraulically controlled check valve (4) is connected to the fifth working oil port of the telescopic selector valve (1). Both the one-way valve (5) and the hydraulic one-way valve (4) are cone valve structures, and the pressure at the external control port of the hydraulic one-way valve (4) comes from the pressure in the small cavity.

2. The fifth leg priority retraction leg control system of claim 1, wherein: The first and second working ports of the telescopic selector valve (1) are both connected to the P port of the oil tank. The third working port of the telescopic selector valve (1) is connected to the T port of the oil tank. The fifth working port of the telescopic selector valve (1) is used to connect the fifth outrigger cylinder (6) and the rod chamber of each outrigger vertical cylinder.

3. The outrigger control system for preferential retraction of the fifth outrigger according to claim 1, characterized in that: The sixth working port of the telescopic selection valve (1) is connected to the first working port of the fifth leg vertical reversing valve (2) and the leg vertical-horizontal switching valve.

4. The outrigger control system for preferential retraction of the fifth outrigger according to claim 1, characterized in that: The second working port of the fifth leg vertical reversing valve (2) and the second working port of the leg vertical-horizontal switching valve are both connected to the T port of the oil tank.

5. The outrigger control system for preferential retraction of the fifth outrigger according to claim 1, characterized in that: The third working port of the fifth leg vertical reversing valve (2) is used to connect to the rodless chamber of the fifth leg cylinder (6). The third working port and the fourth working port of each leg vertical-horizontal switching valve are used to connect to the rodless chamber of the corresponding leg cylinder.

6. The outrigger control system for preferential retraction of the fifth outrigger according to claim 5, characterized in that: The number of vertical / horizontal switching valves for the outriggers is the same as the number of vertical hydraulic cylinders for the outriggers.

7. The outrigger control system for priority retraction of the fifth outrigger according to claim 1, characterized in that: A hydraulic branch is provided between the P port and T port of the oil tank, and an overflow valve is provided on the hydraulic branch.

8. A truck crane, characterized in that: The outrigger control system includes the fifth outrigger retraction priority control system as described in any one of claims 1 to 7.

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