Hydraulic cooling system of crushing excavator and excavator

Abstract

The invention discloses a crushing excavator hydraulic cooling system and an excavator, and belongs to the technical field of engineering machinery, the crushing excavator hydraulic cooling system comprises a crushing device and an excavating device, the excavating device is connected with a main valve through an excavating oil return passage, and the main valve is connected with a hydraulic oil tank through a main oil return passage and a bypass oil return passage; the crushing device is connected with a crushing oil return passage; the crushing oil return passage is connected with the main oil return passage; the second crushing oil return passage is connected with the crushing oil return passage and the bypass oil return passage; and the second crushing oil return passage is provided with a third back pressure valve. The crushing oil return passage is not connected with the main valve any more, hydraulic oil cannot directly return to the hydraulic oil tank from the second back pressure valve, but enters the radiator, and the heat dissipating capacity can be increased; a second crushing oil return passage and a third back pressure valve are arranged, the opening pressure of the second crushing oil return passage is increased, hydraulic oil in the crushing oil return passage flows through the radiator without back pressure to be radiated and returns to the hydraulic oil tank, and the situation that the radiator is damaged due to the fact that the pressure of the crushing oil return passage is too high under extreme conditions is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering machinery, and in particular relates to a hydraulic heat dissipation system of a crushing excavator and the excavator. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Excavators are usually equipped with a bucket and a crushing device, making them dual-purpose machines. Figure 1 As shown, the conventional heat dissipation of hydraulic oil in crushing working condition is consistent with the heat dissipation of hydraulic oil in bucket working condition, that is, the high temperature oil first returns to the main valve 5 for convergence, and then passes through the main return oil passage 501 of the main valve 5 and then returns to the hydraulic oil tank 7 through the radiator 6, or directly returns to the hydraulic oil tank 7 through the bypass return oil passage 502.

[0004] When the hydraulic oil return volume is small, the return oil pressure is low, and the hydraulic oil passes through the first back pressure valve 8 on the main return oil passage, enters the radiator 6 for heat dissipation, and then returns to the hydraulic oil tank. When the hydraulic oil return volume is large, the return oil pressure is high, and the second back pressure valve opening condition is reached. Part of the hydraulic oil will pass through the second back pressure valve and directly return to the hydraulic oil tank to prevent the return oil pressure from being too high.

[0005] However, the crushing operation has high power and large oil return flow, which results in high oil return pressure, causing excessive high-temperature hydraulic oil to return directly to the hydraulic oil tank through the bypass oil return passage 502 instead of the radiator 6. In this way, when the ambient temperature is high in summer, the crushing operation often causes the hydraulic system to heat up due to insufficient heat dissipation of the hydraulic oil, resulting in low efficiency of the hydraulic system and even causing the excavator to shut down. Summary of the invention

[0006] In view of the above problems, the present invention provides a hydraulic heat dissipation system and an excavator for a crushing excavator, wherein a crushing return oil passage is connected between a first back pressure valve and a radiator, and the hydraulic oil in the crushing return oil passage no longer enters the main valve, and can no longer directly return to the hydraulic oil tank from the second back pressure valve, but directly enters the radiator, thereby increasing its heat dissipation; by setting a second crushing return oil passage and a third back pressure valve, the third back pressure valve and the second back pressure valve are connected in series, and the opening pressure of the second crushing return oil passage is increased, so that the hydraulic oil in the crushing return oil passage can flow through the radiator without back pressure to dissipate heat and return to the hydraulic oil tank, and can also avoid the situation in extreme cases where the pressure of the crushing return oil passage is too high, causing damage to the radiator.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] In a first aspect, a hydraulic heat dissipation system for a crushing excavator is provided, comprising a crushing device and an excavating device, wherein an oil outlet of the excavating device is connected to an excavating oil return passage connected to a main valve, and the main valve is connected to a hydraulic oil tank via a main oil return passage and a bypass oil return passage;

[0009] The oil outlet of the crushing device is connected to the crushing oil return passage; the crushing oil return passage is connected to the main oil return passage; it also includes a second crushing oil return passage; the second crushing oil return passage is connected between the crushing oil return passage and the bypass oil return passage; a third back pressure valve is arranged on the second crushing oil return passage.

[0010] Preferably, a first back pressure valve is provided on the main oil return passage, and a radiator is further provided between the first back pressure valve and the hydraulic oil tank.

[0011] Preferably, the crushing oil return passage is connected to the main oil return passage between the first back pressure valve and the radiator.

[0012] Preferably, a second back pressure valve is provided on the bypass oil return passage.

[0013] Preferably, one end of the second crushing oil return passage is connected to the crushing oil return passage, and the other end is connected to the bypass oil return passage between the second back pressure valve and the main valve.

[0014] Preferably, the opening pressure of the third back-pressure valve is greater than the opening pressure of the second back-pressure valve; and the opening pressure of the second back-pressure valve is greater than the opening pressure of the first back-pressure valve.

[0015] Preferably, the oil inlet of the crushing device is connected to the crushing control system through a crushing oil inlet passage.

[0016] Preferably, the oil inlet of the excavation device is connected to the excavation control system via an excavation oil inlet passage.

[0017] In a second aspect, an excavator is provided, which utilizes any one of the above-mentioned hydraulic heat dissipation systems for a crushing excavator.

[0018] Compared with the prior art, the present invention has the following advantages and positive effects:

[0019] The present invention connects the crushing oil return passage between the first back pressure valve and the radiator. The hydraulic oil in the crushing oil return passage no longer enters the main valve, and can no longer directly return to the hydraulic oil tank from the second back pressure valve, but directly enters the radiator, thereby increasing its heat dissipation. By setting the second crushing oil return passage and the third back pressure valve, the third back pressure valve and the second back pressure valve are connected in series, and the opening pressure of the second crushing oil return passage is increased, which can realize that the hydraulic oil in the crushing oil return passage can flow through the radiator without back pressure to dissipate heat and return to the hydraulic oil tank, and can also avoid the situation in extreme cases where the pressure of the crushing oil return passage is too high, causing damage to the radiator.

[0020] The present invention can realize multiple flow distributions and multiple heat dissipation of hydraulic oil by using a set of heat dissipation system; it can meet the requirements of small heat dissipation and low back pressure under bucket working condition, and can meet the requirements of large heat dissipation under crushing working condition, thus avoiding the possibility of high temperature of hydraulic system caused by crushing working condition, greatly saving development cost and improving the reliability of excavator operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 is a schematic diagram of a heat dissipation system of the prior art;

[0023] Figure 2 is a schematic diagram of a heat dissipation system according to Embodiment 1 or 2 of the present invention;

[0024] In the figure:

[0025] 1. Crushing device; 101. Crushing oil inlet passage; 102. Crushing oil return passage; 103. Second crushing oil return passage; 2. Excavating device; 201. Excavating oil inlet passage; 202. Excavating oil return passage; 3. Crushing control system; 4. Excavating control system; 5. Main valve; 501. Main oil return passage; 502. Bypass oil return passage; 6. Radiator; 7. Hydraulic oil tank; 8. First back pressure valve; 9. Second back pressure valve; 10. Third back pressure valve. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0027] The present invention is described in detail below in conjunction with the accompanying drawings.

[0028] Example 1

[0029] This embodiment discloses a hydraulic heat dissipation system for a crushing excavator, such as Figure 2 As shown, the crushing device 1 and the excavating device 2 are included. The oil inlet of the crushing device 1 is connected to the crushing control system 3 through the crushing oil inlet passage 101, and the oil outlet of the crushing device 1 is connected to the crushing oil return passage 102. The crushing control system 3 controls the supply of hydraulic oil to the crushing device 1, thereby realizing the action of the crushing device 1, and the hydraulic oil flows out through the crushing oil return passage 102.

[0030] The oil inlet of the excavation device 2 is connected to the excavation control system 4 through the excavation oil inlet passage 201, and the oil outlet of the excavation device 2 is connected to the excavation oil return passage 202 and the main valve 5, and the main valve 5 is connected to the hydraulic oil tank 7 through the main oil return passage 501 and the bypass oil return passage 502. The excavation control system 4 controls the supply of hydraulic oil to the excavation device 2, so as to realize the action of the excavation device 2, and the hydraulic oil flows to the main valve 5 through the excavation oil return passage 202, and then flows back to the hydraulic oil tank 7 through the main oil return passage 501 or the bypass oil return passage 502.

[0031] It can be understood that the excavation control system 4 and the crushing control system 3 are both existing technologies, which are used to control the excavation device and the crushing device to perform operating actions. This embodiment does not involve improvements to the excavation control system 4 and the crushing control system 3, and no further details will be given here.

[0032] like Figure 1 As shown, the main oil return passage 501 is provided with a first back pressure valve 8. In this embodiment, the first back pressure valve 8 is a 2.5 bar back pressure valve. When the pressure is greater than 2.5 bar, the first back pressure valve 8 opens to form a passage. The bypass oil return passage 502 is provided with a second back pressure valve 9. In this embodiment, the second back pressure valve 9 is a 4.5 bar back pressure valve. When the pressure is greater than 4.5 bar, the second back pressure valve 9 opens to form a passage. The main oil return passage 501 is also provided with a radiator 6, which is arranged between the first back pressure valve 8 and the hydraulic oil tank 7, and is used to dissipate heat and cool the hydraulic oil passing through.

[0033] It can be understood that when the flow rate of the hydraulic oil is large, the pressure is high, and the hydraulic oil pressure is greater than 4.5 bar, the second back-pressure valve 9 opens, and a part of the hydraulic oil will directly enter the hydraulic oil tank 7 through the bypass return oil passage 502 to prevent the return oil pressure from being too high; when the flow rate of the hydraulic oil is small, the pressure is relatively low, and the hydraulic oil pressure is lower than 4.5 bar, the hydraulic oil only passes through the main return oil passage 501, dissipates heat and cools down through the radiator 6, and then returns to the hydraulic oil tank 7.

[0034] like Figure 1 As shown, the crushing oil return passage 102 is connected to the main oil return passage 501, specifically, the crushing oil return passage 102 is connected to the main oil return passage 501 between the first back pressure valve 8 and the radiator 6. Since the first back pressure valve 8 is equivalent to a one-way valve, the hydraulic oil in the crushing oil return passage 102 cannot flow back to the main valve 5, and can only flow through the radiator 6 and then enter the hydraulic oil tank 7.

[0035] like Figure 1As shown, the crushing oil return passage 102 is also connected to one end of the second crushing oil return passage 103, and the other end of the second crushing oil return passage 103 is connected to the bypass oil return passage 502. Specifically, the other end of the second crushing oil return passage 103 is connected to the bypass oil return passage 502 between the second back pressure valve 9 and the main valve 5. The second crushing oil return passage 103 is provided with a third back pressure valve 10, and the third back pressure valve 10 is a 6 bar back pressure valve in the embodiment. It should be noted that the specific models of the first back pressure valve, the second back pressure valve, and the third back pressure valve are set according to actual needs, and the relationship is that the opening pressure of the third back pressure valve is greater than the opening pressure of the second back pressure valve, and the opening pressure of the second back pressure valve is greater than the opening pressure of the first back pressure valve.

[0036] It can be understood that, since the third back pressure valve 10 on the second crushing oil return passage 103 is arranged before the radiator 6, and the third back pressure valve 10 is also connected in series with the second back pressure valve 9, the second crushing oil return passage can achieve higher pressure regulation accuracy and a larger regulation range, which can further enhance stability. This makes the opening pressure of the second crushing oil return passage 103 reach 10.5 bar in this embodiment.

[0037] That is to say, when the pressure of the hydraulic oil in the crushing oil return passage 102 is less than 10.5 bar, the second crushing oil return passage 103 will not be opened, and the hydraulic oil in the crushing oil return passage 102 will flow through the radiator 6 for heat dissipation before entering the hydraulic oil tank. In addition, since the hydraulic oil in the crushing oil return passage 102 cannot flow back to the main valve 5, the hydraulic oil in the crushing oil return passage 102 can no longer directly return to the hydraulic oil tank from the second back pressure valve. When the hydraulic oil pressure is greater than 4.5 bar and less than 10.5 bar, the hydraulic oil directly enters the radiator, thereby increasing the heat dissipation of the hydraulic oil in the crushing oil return passage.

[0038] In this way, the hydraulic oil in the crushing oil return passage can flow through the radiator without back pressure to dissipate heat and then return to the hydraulic oil tank; it can also avoid the situation in extreme cases where the pressure in the crushing oil return passage is too high and causes damage to the radiator.

[0039] Working principle:

[0040] When the excavation device is used, the hydraulic oil of the excavation device flows to the main valve 5 through the excavation oil return passage 202; when the pressure of the hydraulic oil is lower than 4.5 bar, the hydraulic oil flows through the main oil return passage 501, flows through the radiator 6 for heat dissipation and cooling, and then returns to the hydraulic oil tank 7; when the pressure of the hydraulic oil is greater than 4.5 bar, the second back pressure valve 9 opens, and part of the hydraulic oil directly enters the hydraulic oil tank 7 through the bypass oil return passage 502 to prevent the return oil pressure from being too high;

[0041] When the crushing device is working, when the hydraulic oil pressure is lower than 10.5 bar, the hydraulic oil passes through the crushing oil return passage 102 and no longer enters the main valve 5, but directly flows through the radiator 6 for heat dissipation, and then enters the hydraulic oil tank 7; when the hydraulic oil is higher than 10.5 bar, the hydraulic oil flows into the hydraulic oil tank 7 through the second crushing oil return passage, which can dissipate the heat of the hydraulic oil in the crushing oil return passage to the greatest extent and meet the demand for large heat dissipation.

[0042] The advantage of the present invention is that a set of heat dissipation system is used to achieve multiple flow distributions of hydraulic oil and multiple heat dissipation amounts; it can meet the needs of small heat dissipation and low back pressure under bucket working conditions, and can also meet the needs of large heat dissipation under crushing working conditions, thus avoiding the possibility of high temperature of the hydraulic system caused by high temperature in summer under crushing working conditions, greatly saving development costs and improving the reliability of excavator operation.

[0043] Example 2

[0044] This embodiment discloses an excavator, which utilizes the hydraulic heat dissipation system of the crushing excavator disclosed in Embodiment 1.

[0045] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A hydraulic heat dissipation system for a crushing excavator, comprising a crushing device and an excavating device, characterized in that: The oil outlet of the excavation device is connected to the excavation oil return passage and connected to the main valve, and the main valve is connected to the hydraulic oil tank through the main oil return passage and the bypass oil return passage; The oil outlet of the crushing device is connected to the crushing oil return passage; the crushing oil return passage is connected to the main oil return passage; it also includes a second crushing oil return passage; the second crushing oil return passage is connected between the crushing oil return passage and the bypass oil return passage; a third back pressure valve is arranged on the second crushing oil return passage.

2. A hydraulic heat dissipation system for a crushing excavator as claimed in claim 1, characterized in that: A first back pressure valve is arranged on the main oil return passage, and a radiator is arranged between the first back pressure valve and the hydraulic oil tank.

3. A hydraulic heat dissipation system for a crushing excavator as claimed in claim 2, characterized in that: The crushing oil return passage is connected to the main oil return passage between the first back pressure valve and the radiator.

4. A hydraulic heat dissipation system for a crushing excavator as claimed in claim 1, characterized in that: A second back pressure valve is arranged on the bypass oil return passage.

5. A hydraulic cooling system for a crushing excavator as claimed in claim 4, characterized in that: One end of the second crushing oil return passage is connected to the crushing oil return passage, and the other end is connected to the bypass oil return passage between the second back pressure valve and the main valve.

6. A hydraulic cooling system for a crushing excavator as claimed in claim 1, characterized in that: The opening pressure of the third back-pressure valve is greater than the opening pressure of the second back-pressure valve; the opening pressure of the second back-pressure valve is greater than the opening pressure of the first back-pressure valve.

7. A hydraulic cooling system for a crushing excavator as claimed in claim 1, characterized in that: The oil inlet of the crushing device is connected to the crushing control system through a crushing oil inlet passage.

8. The hydraulic cooling system for a crushing excavator according to claim 1, characterized in that: The oil inlet of the excavating device is connected to the excavating control system through an excavating oil inlet passage.

9. An excavator, characterized in that: A hydraulic cooling system for a crushing excavator as described in any one of claims 1 to 8 is used.

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