Lifting oil cylinder control device and lifting system

Abstract

A lifting oil cylinder control device and a lifting system comprise a first oil cylinder connecting oil port and a second oil cylinder connecting oil port, the first oil cylinder connecting oil port is connected with a first lifting valve connecting oil port through a first oil way, the second oil cylinder connecting oil port is connected with a second lifting valve connecting oil port through a second oil way, and a control valve set is arranged on the first oil way. The second oil way is connected with a cover plate valve through a first branch and connected with the control valve set through a second branch, the cover plate valve is connected with a second oil tank connecting oil port through a third oil way, the first branch is further connected with a top end control port of the cover plate valve through a third branch, and the third branch is connected with a first oil tank connecting port through a fourth branch. The third oil way is connected with a first oil cylinder connecting oil port through the fourth oil way, a second one-way valve is installed on the fourth oil way, the floating function and the lifting valve are separated and independently arranged, the structure of the lifting valve is effectively simplified, the use cost is reduced, and the customization period is shortened.

Description

Technical Field

[0001] The utility model relates to the technical field of dump trucks, in particular to a lifting cylinder control device and a lifting system. Background Art

[0002] The dump truck lifting system is mainly responsible for lifting or tipping the car body to unload materials. The lifting valve is a key component in the dump truck lifting system. The lifting valve is a device used to control the flow direction and flow of hydraulic oil, which is directly related to the lifting and lowering actions of the car body.

[0003] The existing lifting system of mining dump trucks needs to realize the following actions: "lifting", "neutral", "descending" and "floating". When a mining dump truck is driving on the road, the truck bed will vibrate up and down due to bumpy road conditions. In order to prevent the lifting cylinder connected to the truck bed from being subjected to vibration force, the rod chamber and rodless chamber of the lifting cylinder are connected to the oil tank respectively through the "floating" function. At this time, the lifting cylinder is in a "floating" state. When subjected to the force of the truck bed load, the piston rod can be freely extended or retracted. At this time, the lifting cylinder is not affected by the load force, thereby ensuring the service life of the lifting cylinder.

[0004] In the existing lifting system of mining dump trucks, the "floating" function is controlled by the lifting valve, that is, the "lifting", "neutral", "descending" and "floating" control functions are all integrated on the lifting valve, which leads to a complex structure of the lifting valve and an increased flow rate. The multifunctional and large-flow lifting valve needs to be specially customized, with high cost, long customization cycle and poor adaptability. In addition, during the unloading process of the lifting system, as the lifting angle increases, the center of gravity of the bucket and the ore changes, which will produce a pulling force on the bucket lifting cylinder, causing a "cylinder pulling" phenomenon, which may even cause cylinder damage in severe cases. Utility Model Content

[0005] In order to solve the technical problem in the above-mentioned background technology that the "floating" function in the existing dump truck lifting system is controlled by the lifting valve, resulting in a complex lifting valve structure and high use cost, the utility model provides a lifting cylinder control device and a lifting system.

[0006] The technical solution of this utility model is as follows:

[0007] The utility model provides a lifting cylinder control device, comprising: a first oil cylinder connecting oil port and a second oil cylinder connecting oil port, the first oil cylinder connecting oil port is connected to a first lifting valve connecting oil port through a first oil circuit, the second oil cylinder connecting oil port is connected to a second lifting valve connecting oil port through a second oil circuit, a control valve group is arranged on the first oil circuit, the second oil circuit is connected to a cover valve through a first branch circuit, the second oil circuit is connected to the control valve group through a second branch circuit, the cover valve is connected to a second oil tank connecting oil port through a third oil circuit, the first branch circuit is also connected to a top control port of the cover valve through a third branch circuit, the third branch circuit is connected to the first oil tank connecting port through a fourth branch circuit, a solenoid valve is arranged on the fourth branch circuit, and the third oil circuit is connected to the first oil cylinder through the fourth oil circuit The oil port is connected, and a second one-way valve is installed on the fourth oil circuit. With the cooperation of the solenoid valve and the cover valve, the rodless chamber of the cylinder can be directly connected to the hydraulic oil tank, so that the cylinder can be freely extended or retracted under the action of load, thereby realizing the "floating" function. The rodless chamber of the cylinder is not subject to the load force, which increases the service life of the lifting cylinder. The "floating" function is separated from the lifting valve and set independently, which effectively simplifies the structure of the lifting valve, reduces the use cost and customization cycle, and adopts a large-flow adjustable cover plate plug-in cover valve to realize the floating function, which reduces the return oil pressure loss. At the same time, the maximum opening of the valve core is changed by the adjusting device, so the maximum descent speed of the truck bed can be adjusted to meet the descent flow requirements of the truck bed of various tonnage dump trucks.

[0008] Preferably, the control valve group includes a balancing valve and a first one-way valve arranged in parallel, and the second oil circuit is connected to the control port of the balancing valve through a second branch. The balancing valve and the first one-way valve are used in coordination to achieve anti-pullout protection for the lifting cylinder, integrating anti-pullout and floating functions, thereby increasing the service life of the lifting cylinder.

[0009] Preferably, an overflow valve is provided on the fourth oil circuit, and the overflow valve is arranged in parallel with the second one-way valve. When the truck bed is subjected to abnormal load, the valve core of the overflow valve opens, and the rod chamber pressure oil flows back to the oil tank through the fourth oil circuit, the third oil circuit, and the second oil tank connecting oil port to protect the rod chamber from abnormal high-pressure impact.

[0010] Preferably, throttling holes are provided at the second branch and the third branch to facilitate the establishment and regulation of pressure and the control of flow.

[0011] The utility model provides a lifting system, including: a lifting valve, which is connected to a hydraulic oil tank via a filter and a hydraulic pump in sequence, and is connected to a rod chamber and a rodless chamber of a lifting oil cylinder via a control device, so that a "floating" function is separated from the lifting valve and is independently arranged, thereby effectively simplifying the structure of the lifting valve and reducing the use cost and customization cycle of the lifting valve.

[0012] Preferably, the first lifting valve connecting oil port and the second lifting valve connecting oil port are respectively connected to the lifting valve, the first oil cylinder connecting oil port is connected to the rod cavity of the lifting cylinder, and the second oil cylinder connecting oil port is connected to the rodless cavity of the lifting cylinder.

[0013] Preferably, the first oil tank connecting oil port and the second oil tank connecting oil port are both connected to the hydraulic oil tank, so as to facilitate direct connection of the rodless chamber of the lifting cylinder with the hydraulic oil tank to realize control of the floating function.

[0014] It can be seen from the above technical solutions that the advantages of the utility model are:

[0015] 1. The "floating" function is separated from the lifting valve and set independently, so that the lifting valve only needs to satisfy the three action controls of "lifting", "neutral" and "lowering", which can be realized by an ordinary three-position multi-way valve, which effectively simplifies the structure of the lifting valve, reduces the use cost and customization cycle, and adopts a large-flow adjustable cover plate plug-in cover plate valve to realize the floating function, which reduces the return oil pressure loss. At the same time, the maximum opening of the valve core of the cover plate valve can be changed, and the maximum lowering speed of the truck bed can be adjusted to meet the lowering flow requirements of the truck bed of various tonnage dump trucks.

[0016] 2. The second oil circuit is connected to the control port of the balance valve through the second branch. Through the coordinated use of the balance valve and the first one-way valve, the lifting speed of the cylinder can be controlled, the stability is improved, and the "cylinder pulling" phenomenon is avoided. It integrates anti-pulling and floating functions, and increases the service life of the lifting cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the utility model, the drawings required for use in the description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the hydraulic principle of a lifting cylinder control device according to one or more embodiments of the present utility model;

[0019] Figure 2 A schematic diagram of the hydraulic principle of a lifting system according to one or more embodiments of the present invention;

[0020] The components represented by the reference numerals in the figure are:

[0021] 1. Balancing valve; 2. Cover valve; 3. Solenoid valve; 4. Overflow valve; 5. First non-return valve; 6. Second non-return valve; 7. First lifting valve connecting oil port; 8. Second lifting valve connecting oil port; 9. First oil cylinder connecting oil port; 10. Second oil cylinder connecting oil port; 11. First oil tank connecting oil port; 12. Second oil tank connecting oil port; 13. Hydraulic oil tank; 14. Hydraulic pump; 15. Filter; 16. Lifting valve; 17. Control device; 18. Lifting cylinder. DETAILED DESCRIPTION

[0022] In order to make the purpose, features and advantages of the utility model more obvious and easy to understand, the technical scheme of the utility model will be clearly and completely described below in combination with the drawings in the specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the utility model, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0023] Example 1

[0024] In a typical implementation of the present invention, Figure 1 As shown, a lifting cylinder control device is proposed, including: a first lifting valve connecting oil port 7, a second lifting valve connecting oil port 8, a first cylinder connecting oil port 9 and a second cylinder connecting oil port 10, wherein the first lifting valve connecting oil port 7 is connected to the first cylinder connecting oil port 9 through a first oil circuit, the second lifting valve connecting oil port 8 is connected to the second cylinder connecting oil port 10 through a second oil circuit, the first lifting valve connecting oil port 7 and the second lifting valve connecting oil port 8 are used to connect to the lifting valve 16 of the hydraulic system, the first cylinder connecting oil port 9 is used to connect to the rod chamber of the lifting cylinder 18, and the second cylinder connecting port 10 is used to connect to the rodless chamber of the lifting cylinder 18.

[0025] The lifting cylinder control device also includes a balancing valve 1, a cover valve 2 and a solenoid valve 3. The balancing valve 1 is arranged in series on the first oil circuit between the first lifting valve connecting oil port 7 and the first cylinder connecting oil port 9. The first one-way valve 5 is also connected to the first oil circuit between the first lifting valve connecting oil port 7 and the first cylinder connecting oil port 9. The first one-way valve 5 is arranged in parallel with the balancing valve 1.

[0026] The cover valve 2 is located at one side of the second oil circuit between the second lift valve connecting oil port 8 and the second oil cylinder connecting oil port 10. The cover valve 2 has a top control port. The second oil circuit between the second lift valve connecting oil port 8 and the second oil cylinder connecting oil port 10 is connected to the cover valve 2 through a first branch, and the second oil circuit is connected to the control port of the balance valve 1 through a second branch.

[0027] The lifting cylinder control device also includes a first oil tank connecting oil port 11 and a second oil tank connecting oil port 12 for direct connection with a hydraulic oil tank 13. The first branch is also connected to the top control port of the cover valve 2 through a third branch, and the third branch is also connected to the first oil tank connecting oil port 11 through a fourth branch, and a solenoid valve 3 is connected in series on the fourth branch to control the on-off of the fourth branch. The cover valve 2 is connected to the second oil tank connecting oil port 12 through the third oil circuit, so that the second oil circuit can be connected to the second oil tank connecting oil port 12 through the first branch, the cover valve 2, and the third oil circuit.

[0028] Both the second branch and the third branch are provided with throttling holes. The third oil circuit is also connected to the first oil circuit through the fourth oil circuit, and the connection point between the fourth oil circuit and the first oil circuit is located between the first cylinder connecting oil port 9 and the balance valve 1 and the first one-way valve 5. It can also be understood that the third oil circuit is connected to the first cylinder connecting oil port 9 through the fourth oil circuit, and the second one-way valve 6 is installed on the fourth oil circuit.

[0029] The working principle is:

[0030] When the bucket is lifted, the pressure oil from the lifting valve 16 enters the second lifting valve connecting oil port 8, and then passes through the second cylinder connecting port 10 to the rodless chamber of the lifting cylinder 18. At the same time, the pressure oil from the second lifting valve connecting oil port 8 enters the top control port of the cover valve 2, so that the valve core and the valve seat of the cover valve 2 are pressed tightly in a closed state, and the solenoid valve 3 is in a power-off cut-off state. At this time, the pressure begins to rise; at the same time, the pressure oil from the second lifting valve connecting oil port 8 reaches the control port of the balance valve 1. When the pressure rises and exceeds the opening pressure of the balance valve 1, the valve core of the balance valve 1 opens. At this time, the first lifting valve connecting oil port 7 is connected with the first cylinder connecting oil port 9. When the pressure in the cylinder rodless chamber rises and exceeds the bucket load capacity, the cylinder extends to lift the bucket. At this time, the return oil from the cylinder rod chamber reaches the first cylinder connecting oil port 9, and then passes through the first lifting valve connecting oil port 7 to the lifting valve 16 and returns to the oil tank;

[0031] When the bucket is lifted to a certain height, the ore is accumulated at the bottom of the bucket, which generates a pulling force on the lifting cylinder 18, and the pressure in the rodless chamber of the cylinder drops. When the pressure is lower than the opening pressure of the balance valve 1, the balance valve 1 gradually closes the connecting oil path between the first lifting valve connecting oil port 7 and the first cylinder connecting oil port 9. At this time, the oil return from the rod chamber is cut off, and the pressure begins to rise, preventing the cylinder from continuing to extend, avoiding the "cylinder pulling" failure, and improving the stability and service life of the lifting cylinder.

[0032] When the truck bed is lowered, the pressure oil from the lift valve 16 enters the first lift valve connecting oil port 7, then passes through the first non-return valve 5, and reaches the rod chamber of the lift cylinder 18 through the first cylinder connecting oil port 9. Then the pressure starts to rise, pushing the cylinder piston rod to retract and realize the lowering of the truck bed. At this time, the oil in the rodless chamber passes through the second cylinder connecting port 10 and the second lift valve connecting oil port 8 to the lift valve 16 and returns to the oil tank.

[0033] After starting the "floating" function, the solenoid valve 3 is energized, and the pressure at the top control port of the cover valve 2 flows back to the hydraulic oil tank 13 through the solenoid valve 3 and the first tank connecting oil port 11. The valve core of the cover valve 2 loses the function of controlling the oil, and the pressure oil at the second lift valve connecting oil port 8 enters the cover valve 2 and pushes open the valve core, so that the cover valve 2 is connected to the second tank connecting oil port 12, and then flows back to the tank; at this time, the second lift valve connecting oil port 8 and the hydraulic oil tank 13 are in a connected state (it can also be understood that the rodless chamber of the cylinder is connected to the hydraulic oil tank), and the cylinder It can move freely under the action of load. When the truck bed is in a high-position lifted state, it will slowly descend to the frame. At this time, the rod chamber is in an empty state, and the pressure oil in the rodless chamber enters the rod chamber through the third oil circuit, the fourth oil circuit, and the second one-way valve 6; when the dump truck is in normal driving, the truck bed is in the initial state of the frame. Due to bumpy road conditions, the truck bed can vibrate slightly freely up and down. At this time, the rodless chamber of the cylinder is connected to the oil tank, and the cylinder can be freely extended or retracted. The rodless chamber of the cylinder is not subject to load force, thereby increasing the service life of the lifting cylinder.

[0034] In this embodiment, a relief valve 4 is also installed on the fourth oil circuit, and the relief valve 4 is arranged in parallel with the second one-way valve 6. When the truck bed is subjected to abnormal load, the pressure in the rod chamber of the cylinder, that is, the pressure at the first cylinder connecting oil port 9 and the second cylinder connecting oil port 10, rises abnormally. When it exceeds the set pressure of the relief valve 4, the valve core of the relief valve 4 opens, and the rod chamber pressure oil flows back to the oil tank through the fourth oil circuit, the third oil circuit, and the second oil tank connecting oil port 12. The function of the relief valve 4 is to set the maximum pressure of the rod chamber to protect the rod chamber from abnormally high pressure shock.

[0035] The "floating" function is independently realized through the valve group, and the floating function is realized by using the cover valve 2 with large flow adjustable cover plate plug-in, which reduces the return oil pressure loss. At the same time, the maximum opening of the valve core is changed by the adjustment device, and the maximum lowering speed of the truck bed can be adjusted to meet the lowering flow requirements of the truck bed of dump trucks of various tonnages.

[0036] Example 2

[0037] In a typical implementation of the present invention, Figure 2As shown, a lifting system is proposed, including: a hydraulic oil tank 13, a hydraulic pump 14, a filter 15, a lifting valve 16, the control device 17 mentioned in Example 1 and a lifting cylinder 18, the lifting valve 16 is connected to the hydraulic oil tank 13 through the filter 15 and the hydraulic pump 14 in sequence, and the lifting valve 16 is connected to the rod chamber and the rodless chamber of the lifting cylinder 18 through the control device 17.

[0038] Specifically, the first lifting valve connecting oil port 7 and the second lifting valve connecting oil port 8 of the control device 17 are respectively connected to the lifting valve 16, the first cylinder connecting oil port 9 is connected to the rod chamber of the lifting cylinder 18, and the second cylinder connecting oil port 10 is connected to the rodless chamber of the lifting cylinder 18.

[0039] The first tank connection port 11 and the second tank connection port 12 of the control device 17 are directly connected to the hydraulic oil tank 13 respectively.

[0040] The hydraulic pump 14 provides a pressure oil source for the system. After sucking oil from the hydraulic oil tank 13, it enters the lifting valve 16 through the filter 15. The lifting valve 16 is mainly composed of a three-position reversing valve and a relief valve to realize the three functions of "lifting", "neutral position" and "lowering". It can adopt electric control or hydraulic pilot control. The A and B ports of the working connection of the lifting valve 16 are respectively connected to the first lifting valve connecting oil port 7 and the second lifting valve connecting oil port 8 of the control device 17, and then connected to the rod chamber and rodless chamber of the lifting cylinder 18 through the first cylinder connecting oil port 9 and the second cylinder connecting oil port 10 respectively.

[0041] It is understandable that one or more lifting cylinders 18 may be provided, and one or more corresponding first cylinder connecting oil ports 9 and second cylinder connecting oil ports 10 may also be provided. The specific number is determined according to actual design requirements.

[0042] The anti-pulling function and floating function required for the work of mining dump trucks are integrated to avoid the "cylinder pulling" failure of the bucket during the unloading process, and to meet the requirement that the bucket lifting cylinder is in the "floating" function during normal driving of the dump truck and will not be affected by the change of the load force of the bucket. The "floating" function is realized by the cover valve 2, which has the advantages of large flow and small pressure loss. At the same time, the maximum opening size of the valve core of the cover valve 2 is adjustable to meet the flow requirements of dump trucks of different tonnages when the bucket is lowered. Since the "floating" function is realized separately in the control device, the function of the lifting valve 16 is reduced and the structure of the lifting valve 16 is simplified. The function of the lifting valve 16 only needs to meet the three actions of "lifting", "neutral" and "lowering", which can be achieved by an ordinary three-position multi-way valve, which reduces the design, development and production threshold of the lifting valve 16 for mining dump trucks, and the overall matching design of the dump truck lifting system is more flexible and diversified.

[0043] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lifting cylinder control device, comprising: The first oil cylinder connecting oil port (9) and the second oil cylinder connecting oil port (10) are characterized in that the first oil cylinder connecting oil port (9) is connected to the first lifting valve connecting oil port (7) through the first oil circuit, the second oil cylinder connecting oil port (10) is connected to the second lifting valve connecting oil port (8) through the second oil circuit, a control valve group is provided on the first oil circuit, the second oil circuit is connected to the cover valve (2) through the first branch, the second oil circuit is connected to the control valve group through the second branch, the cover valve (2) is connected to the second oil tank connecting oil port (12) through the third oil circuit, the first branch is also connected to the top control port of the cover valve (2) through the third branch, the third branch is connected to the first oil tank connecting oil port (11) through the fourth branch, the fourth branch is provided with a solenoid valve (3), the third oil circuit is connected to the first oil cylinder connecting oil port (9) through the fourth oil circuit, and a second check valve (6) is installed on the fourth oil circuit.

2. A lifting cylinder control device according to claim 1, characterized in that: The control valve group comprises a balancing valve (1) and a first one-way valve (5) which are arranged in parallel, and the second oil circuit is connected to the control port of the balancing valve (1) through a second branch circuit.

3. A lifting cylinder control device according to claim 1, characterized in that: The fourth oil circuit is provided with an overflow valve (4), and the overflow valve (4) is arranged in parallel with the second one-way valve (6).

4. A lifting cylinder control device according to claim 1, characterized in that: The second branch and the third branch are both provided with throttling holes.

5. A lifting system, characterized in that: A lifting cylinder control device as claimed in any one of claims 1 to 4 is used, comprising: a lifting valve (16), the lifting valve (16) being connected to the hydraulic oil tank (13) via a filter (15) and a hydraulic pump (14) in sequence, and the lifting valve (16) being connected to the rod chamber and the rodless chamber of the lifting cylinder (18) via a control device (17).

6. A lifting system according to claim 5, characterized in that: The first lifting valve connecting oil port (7) and the second lifting valve connecting oil port (8) are respectively connected to the lifting valve (16), the first oil cylinder connecting oil port (9) is connected to the rod chamber of the lifting oil cylinder (18), and the second oil cylinder connecting oil port (10) is connected to the rodless chamber of the lifting oil cylinder (18).

7. A lifting system according to claim 5, characterized in that: The first oil tank connecting oil port (11) and the second oil tank connecting oil port (12) are both connected to the hydraulic oil tank (13).

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