Hydraulic pump source switching system, jumbolter and heading machine

Abstract

The hydraulic pump source switching system comprises a plurality of pump source units, and each pump source unit comprises an oil tank, a hydraulic pump, an executing mechanism and an oil tank which are sequentially and circularly connected through a hydraulic pipeline. A bypass oil inlet pipeline is connected between the oil inlet ends of the executing mechanisms in all the pump source units, and a bypass oil return pipeline is connected between the oil return ends of the executing mechanisms. An electromagnetic valve A or a one-way valve is arranged between the hydraulic pump in each pump source unit and the oil inlet end of the executing mechanism, and an electromagnetic valve B is arranged between the bypass oil inlet pipeline and the oil inlet end of each executing mechanism. Compared with the prior art, by adopting the technical scheme, the automation degree is high, the problem of time consumption of manual pipeline replacement in the prior art is solved, and hydraulic oil loss in the hydraulic pipeline replacement process is reduced. According to the technical scheme provided by the utility model, under the condition of reducing the pipeline replacement cost, the switching efficiency of the pump sources can be improved, and seamless switching among various complex pump sources can be realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to hydraulic system technical field, especially point to a kind of hydraulic pump source switching system and anchor rod drilling machine and heading machine. BACKGROUND

[0002] Tunnel support is the key step in tunnel construction, and currently, the number of anchor rod drilling machines on shield equipment is large, and the corresponding pump sources are also large. Tunnel construction environment is poor, especially coal mine tunnel construction stratum is broken, and support amount is large. If any pump source fails, the entire operation surface will be paralyzed.

[0003] In recent years, multi-pump source switching appears in many equipment hydraulic pump stations, but the degree of automation is low, the application scene is relatively simple, and the pump source switching between two or more independent pump stations cannot be solved. For example, the utility model patent disclosed in the authorized announcement No. CN203500184U, a shield machine hydraulic multi-pump source switching system, includes a control pump system composed of a control pump, a segment machine pump system composed of a segment pump and an auxiliary pump system composed of an auxiliary pump. The control pump system is connected to the auxiliary pump system through a pipeline provided with a first ball valve and a pressure reducing valve. The control pump system is connected to the segment machine pump system through a pipeline provided with a first ball valve, a pressure reducing valve and a second ball valve. The technical scheme of the utility model only solves the pump source switching between multiple hydraulic pumps in a single oil tank. For the pump source switching problem of multiple independent oil tank pump stations of anchor rod drilling machines, there is no mature application solution at present.

[0004] In summary, how to realize pump source switching between multiple independent oil tanks is a technical problem to be solved.

[0005] It should be particularly noted that the above technical information is only intended to deepen the understanding of the overall background technology of the utility model, and should not be regarded as acknowledging or implying in any form that the above technical information constitutes prior art known to those skilled in the art. UTILITY MODEL CONTENT

[0006] In view of the deficiencies in the above background technology, the utility model provides a hydraulic pump source switching system, anchor rod drilling machine and heading machine, and the technical problem to be solved is how to realize convenient pump source switching between multiple independent oil tanks.

[0007] The technical scheme of the utility model is:

[0008] The hydraulic pump source switching system comprises a plurality of pump source units, each of which comprises an oil tank, a hydraulic pump, an actuator and an oil tank connected in sequence through a hydraulic pipeline, a bypass oil inlet pipeline connected between the oil inlet ends of the actuators in each pump source unit, a bypass oil return pipeline connected between the oil return ends of the actuators, an electromagnetic valve A or a one-way valve arranged between the hydraulic pump and the oil inlet end of the actuator in each pump source unit, and an electromagnetic valve B arranged between the bypass oil inlet pipeline and the oil inlet end of each actuator. The bypass oil inlet pipeline can interconnect the hydraulic oil between adjacent pump source units, and the electromagnetic valve B can control the opening and closing of the corresponding bypass oil inlet pipeline. When the hydraulic pump of one of the pump source units fails, the oil inlet end of the failed pump source unit can be supplied with oil through the corresponding bypass oil inlet pipeline and the electromagnetic valve B by the other pump source units, so that the actuator in the failed pump source unit can work normally. The electromagnetic valve B can control the opening and closing of the oil path between the hydraulic pump and the actuator in the corresponding pump source unit. When the hydraulic pump of the pump source unit fails, the electromagnetic valve B in the pump source unit is closed to prevent the hydraulic oil pumped out by the other pump source units through the bypass oil inlet pipeline and the electromagnetic valve B from entering the failed hydraulic pump, thereby preventing the hydraulic pump from being damaged by reverse oil inlet. Similarly, the one-way valve can also prevent the failed hydraulic pump from being damaged.

[0009] On the basis of the above technical scheme, as a preferred technical scheme of the hydraulic pump source switching system, a bypass oil return pipeline is connected between the oil return ends of the actuators in each pump source unit, and an electromagnetic valve C is arranged on the bypass oil return pipeline to control the opening and closing of the oil return ends between adjacent pump source units. An electromagnetic valve D is arranged between the oil return end of the actuator and the oil tank in each pump source unit. The technical scheme is a further upgrade of the above technical scheme. The bypass oil return pipeline and the corresponding electromagnetic valve C are arranged, and the electromagnetic valve C can control the opening and closing of the corresponding bypass oil return pipeline. When the hydraulic pump of one of the pump source units fails, the oil inlet end of the failed pump source unit can be supplied with oil through the corresponding bypass oil inlet pipeline and the electromagnetic valve B by the other pump source units, so that the actuator in the failed pump source unit can work normally. Moreover, under the action of the electromagnetic valve D, the hydraulic oil flowing out of the actuator in the failed pump source unit will not flow back to the failed oil tank, but will flow back to the oil tank from which the hydraulic oil is pumped out through the bypass oil return pipeline and the electromagnetic valve C, thereby ensuring that the oil inlet and the oil return use one oil tank.

[0010] On the basis of the above technical solutions, as the preferred technical solutions of the hydraulic pump source switching system, the hydraulic pump and the electromagnetic valve A, the electromagnetic valve B, the electromagnetic valve C and the electromagnetic valve D in each pump source unit are connected with the control unit, and the pumped hydraulic oil in the same oil tank is returned to the same oil tank. This technical solution is a further upgrade of the above technical solution. The electromagnetic valve and the hydraulic pump in each pump oil unit are interconnected and interlocked through the control unit. When the hydraulic pump of one pump oil unit is disabled due to failure, the corresponding electromagnetic valve is automatically closed or opened, so that one hydraulic pump can automatically supply two or more actuators to work. At the same time, the hydraulic oil pumped from the specific oil tank by the hydraulic pump is returned to the specific oil tank after passing through the corresponding actuator.

[0011] On the basis of the above technical solutions, as the preferred technical solutions of the hydraulic pump source switching system, the electromagnetic valve A, the electromagnetic valve B, the electromagnetic valve C and the electromagnetic valve D are all two-position two-way electromagnetic valves. This technical solution provides a preferred type of electromagnetic valve. The two-position two-way electromagnetic valve is selected, which not only has a simple structure and control logic, but also has low cost, easy installation and maintenance.

[0012] On the basis of the above technical solutions, as the preferred technical solutions of the hydraulic pump source switching system, the two-position two-way electromagnetic valve is converted to a pass position when powered on and a closed position when powered off. This technical solution selects the two-position two-way electromagnetic valve as powered on and powered off, which not only has a prominent energy-saving effect, but also has a quick response.

[0013] On the basis of the above technical solutions, as the preferred technical solutions of the hydraulic pump source switching system, a filter is arranged between the hydraulic pump in each pump source unit and the oil inlet end of the actuator, which can filter impurities in the hydraulic oil and ensure stable and reliable oil.

[0014] On the basis of the above technical solutions, as the preferred technical solutions of the hydraulic pump source switching system, the pump source unit is provided with three, and any one of the hydraulic pumps can be used as an emergency pump source for the other two hydraulic pumps. In actual application, the priority of the emergency pump source is set, for example, the left pump source unit is a first-level emergency pump source for the middle pump source, and the right pump source unit is a second-level emergency pump source for the middle pump source. When the middle pump source is disabled due to failure, the first-level emergency pump source supplies oil to the actuators in the middle pump source first, while the actuators of the first-level emergency pump source remain in the original working state, and the second-level emergency pump source remains in the original working state. When the first-level emergency pump source is also disabled due to failure, the second-level emergency pump source supplies oil to the actuators in the middle pump source while keeping the original working state of the actuators, and also considers the original working state of the first-level emergency pump source to keep the actuators in the first-level emergency pump source in the original working state.

[0015] An anchor rod drilling machine comprises a frame and an actuating mechanism arranged on the frame, and further comprises the hydraulic pump source switching system according to any one of the technical solutions.

[0016] A heading machine comprises a trolley and an actuating mechanism arranged on the trolley, and further comprises the hydraulic pump source switching system according to any one of the technical solutions.

[0017] The hydraulic pump source switching system and the anchor rod drilling machine have high automation degree compared with the existing pump source switching mode, solve the problem of time consumption of manual replacement of pipelines, and reduce the loss of hydraulic oil during replacement of hydraulic pipelines. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present utility model, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present utility model, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 It is a principle block diagram of the hydraulic pump source switching system.

[0020] BRIEF DESCRIPTION OF DRAWINGS

[0021] 1. The first two-position two-way electromagnetic valve reversing valve;

[0022] 2. The second two-position two-way electromagnetic valve reversing valve;

[0023] 3. The third two-position two-way electromagnetic valve reversing valve;

[0024] 4. The fourth two-position two-way electromagnetic valve reversing valve;

[0025] 5. The fifth two-position two-way electromagnetic valve reversing valve;

[0026] 6. The sixth two-position two-way electromagnetic valve reversing valve;

[0027] 7. The filter;

[0028] 8. The hydraulic pump;

[0029] 9. The actuating mechanism;

[0030] 10. The tenth two-position two-way electromagnetic valve reversing valve;

[0031] 11. The eleventh two-position two-way electromagnetic valve reversing valve;

[0032] 12. a twelfth two-position two-way solenoid valve;

[0033] 13. a thirteenth two-position two-way solenoid valve;

[0034] 14. a fourteenth two-position two-way solenoid valve;

[0035] 15. an oil tank. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the core idea of the present application and the following embodiments, all the other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0037] The present application provides these embodiments is to make the present application and complete, and to the person skilled in the art fully express the scope of the present application. It should be noted that: unless otherwise specified, the relative arrangement of components and steps, the composition of materials, numerical expressions and values described in these embodiments should be interpreted as merely exemplary, and not as a limitation.

[0038] It should be noted that, in the description of the present application, unless otherwise specified, the meaning of "several" is greater than or equal to two; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "axial", "radial" and the like is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0039] In addition, "first", "second" and similar words used in the present application do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error. "Include" or "contain" and similar words mean that the elements before the word cover the elements listed after the word, and do not exclude the possibility of also covering other elements.

[0040] It should be noted that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. When it is described that a specific device is located between the first device and the second device, there can be or can not be an intermediate device between the specific device and the first device or the second device.

[0041] All the terms used in the present application have the same meaning as understood by those skilled in the art to which the present application belongs, unless otherwise specifically defined. It should also be understood that the terms defined in general dictionaries should be interpreted to have meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or excessively formalized sense, unless specifically defined here.

[0042] The techniques, methods and devices known to those skilled in the relevant art can not be discussed in detail, but in appropriate cases, the techniques, methods and devices should be considered as part of the specification.

[0043] One purpose of the utility model lies in providing a kind of multi-pump source switching system with simple operation, high efficiency, use multiple pump station scene. To adapt to the harsh working conditions in construction process, reduce the construction downtime, realize side repair side operation, improve construction efficiency, avoid the economic loss of enterprise caused by pump station failure influence construction period.

[0044] To achieve the above purpose, the multi-pump source switching device of the present application has: a plurality of electromagnetic reversing valves, which realize the opening and closing of the oil circuit.

[0045] Further, the filter ensures the cleanliness of the oil source, the hydraulic pump provides power source for the whole system, and the oil tank provides hydraulic oil for the system.

[0046] In the tunnel boring machine of the utility model, as described above, by installing corresponding number of electromagnetic valves at the oil inlet and oil return port of the actuator, one pump source can supply multiple actuators.

[0047] The specific implementation is as follows:

[0048] A kind of hydraulic pump source switching system, such as Figure 1As shown, each pump source unit comprises an oil tank 15, a hydraulic pump 8, an actuator 9 connected in sequence by hydraulic pipelines, and a bypass oil inlet pipeline and a bypass oil return pipeline are connected between the oil inlet ends of the actuators 9 and between the oil return ends of the actuators 9 respectively, and a solenoid valve A or a check valve is arranged between the hydraulic pump 8 and the oil inlet end of the actuator 9 in each pump source unit, and a solenoid valve B is arranged between the bypass oil inlet pipeline and the oil inlet end of each actuator 9.

[0049] The bypass oil inlet pipeline provided in the embodiment can interconnect the hydraulic oil between adjacent pump source units, and the solenoid valve B can control the opening and closing of the corresponding bypass oil inlet pipeline, so that when the hydraulic pump of one pump source unit is disabled due to a fault, the oil inlet end of the disabled pump source unit can be supplied with oil by the corresponding bypass oil inlet pipeline and solenoid valve B of other pump source units, so that the actuator 9 in the disabled pump source unit can work normally. The solenoid valve B can control the opening and closing of the oil path between the hydraulic pump 8 and the actuator 9 in the corresponding pump source unit, so that when the hydraulic pump of a pump source unit is disabled due to a fault, the solenoid valve B in the pump source unit is closed to prevent the hydraulic oil pumped out by other pump source units through the bypass oil inlet pipeline and the solenoid valve B from entering the disabled hydraulic pump, thereby preventing the hydraulic pump from being damaged by reverse oil inlet. Similarly, the check valve can also prevent the disabled hydraulic pump from being damaged.

[0050] Based on the above embodiment, as a preferred embodiment of the hydraulic pump source switching system, a bypass oil return pipeline is connected between the oil return ends of the actuators 9 in each pump source unit, and a solenoid valve C is arranged on the bypass oil return pipeline to control the opening and closing of the oil return ends between adjacent pump source units; and a solenoid valve D is arranged between the oil return end of the actuator 9 and the oil tank 15 in each pump source unit.

[0051] The embodiment is a further upgrade of the above embodiment, and the bypass oil return pipeline and the corresponding solenoid valve C are provided. The solenoid valve C can control the opening and closing of the corresponding bypass oil return pipeline, so that when the hydraulic pump of one pump source unit is disabled due to a fault, the oil inlet end of the disabled pump source unit can be supplied with oil by the corresponding bypass oil inlet pipeline and solenoid valve B of other pump source units, so that not only the actuator 9 in the disabled pump source unit can work normally, but also the hydraulic oil flowing out of the actuator 9 in the disabled pump source unit will not flow back to the disabled oil tank 15, but will flow back to the oil tank 15 from which the hydraulic oil is pumped out through the bypass oil return pipeline and the solenoid valve C, thereby ensuring that the oil inlet and the oil return use one oil tank 15.

[0052] On the basis of the above-mentioned embodiment, as a preferred embodiment of the hydraulic pump source switching system, the hydraulic pump and the electromagnetic valve A, the electromagnetic valve B, the electromagnetic valve C and the electromagnetic valve D in each pump source unit are connected with the control unit, so that the pumped hydraulic oil in the same oil tank 15 flows back to the same oil tank 15. This embodiment is a further upgrade of the above-mentioned embodiment. The control unit interlocks the electromagnetic valve and the hydraulic pump in each pump oil unit. When the hydraulic pump of one pump oil unit is disabled due to failure, the corresponding electromagnetic valve is automatically closed or opened, so that one hydraulic pump can automatically supply two or more actuators 9 to work. At the same time, the hydraulic oil pumped from a specific oil tank 15 by the hydraulic pump still flows back to the specific oil tank 15 after passing through the corresponding actuator 9.

[0053] On the basis of the above-mentioned embodiment, as a preferred embodiment of the hydraulic pump source switching system, the electromagnetic valve A, the electromagnetic valve B, the electromagnetic valve C and the electromagnetic valve D are all two-position two-way electromagnetic valves. This embodiment provides a preferred type of electromagnetic valve. The two-position two-way electromagnetic valve is selected, which not only has a simple structure and control logic, but also has low cost, easy installation and maintenance.

[0054] On the basis of the above-mentioned embodiment, as a preferred embodiment of the hydraulic pump source switching system, the two-position two-way electromagnetic valve is converted to a pass position when powered on and to a closed position when powered off. In this embodiment, the two-position two-way electromagnetic valve is selected to be powered on to be open and powered off to be closed, which not only has a significant energy-saving effect, but also has a fast response.

[0055] On the basis of the above-mentioned embodiment, as a preferred embodiment of the hydraulic pump source switching system, a filter 7 is arranged between the hydraulic pump 8 and the oil inlet end of the actuator 9 in each pump source unit, which can filter impurities in the hydraulic oil and ensure stable and reliable oil.

[0056] On the basis of the above-mentioned embodiment, as a preferred embodiment of the hydraulic pump source switching system, the pump source unit is provided with three pump sources, any one of which can be used as an emergency pump source for the other two hydraulic pump sources. In actual application, the priority of the emergency pump source is set, for example, the left pump source unit is a first-level emergency pump source for the middle pump source, and the right pump source unit is a second-level emergency pump source for the middle pump source. When the middle pump source is disabled due to failure, the first-level emergency pump source supplies oil to the actuators 9 in the middle pump source, while the actuators 9 of the first-level emergency pump source remain in the original working state, and the second-level emergency pump source remains in the original working state. When the first-level emergency pump source is also disabled due to failure, the second-level emergency pump source supplies oil to the actuators 9 in the middle pump source while keeping the actuators 9 of the second-level emergency pump source in the original working state, and also considers the original working state of the first-level emergency pump source to keep the actuators 9 in the first-level emergency pump source in the original working state.

[0057] Specifically, as Figure 1As shown, when the pump source units include three left, middle and right ones, the electromagnetic valve A in the left pump source unit is a fourth two-position two-way electromagnetic valve 4, the electromagnetic valve A in the middle pump source unit is a fifth two-position two-way electromagnetic valve 5, and the electromagnetic valve A in the right pump source unit is a sixth two-position two-way electromagnetic valve 6; the electromagnetic valve B in the left pump source unit is a first two-position two-way electromagnetic valve 1, the electromagnetic valve B in the middle pump source unit is a second two-position two-way electromagnetic valve 2, and the electromagnetic valve B in the right pump source unit is a third two-position two-way electromagnetic valve 3; the electromagnetic valve D in the left pump source unit is a tenth two-position two-way electromagnetic valve 10, the electromagnetic valve D in the middle pump source unit is an eleventh two-position two-way electromagnetic valve 11, and the electromagnetic valve D in the right pump source unit is a twelfth two-position two-way electromagnetic valve 12; the electromagnetic valve C between the left pump source unit and the middle pump source unit is a thirteenth two-position two-way electromagnetic valve 13, and the electromagnetic valve C between the middle pump source unit and the right pump source unit is a fourteenth two-position two-way electromagnetic valve 14.

[0058] In the initial state, each electromagnetic valve and the hydraulic pump 8 are in the closed state; in the normal working state, the fourth two-position two-way electromagnetic valve 4, the fifth two-position two-way electromagnetic valve 5, the sixth two-position two-way electromagnetic valve 6, the tenth two-position two-way electromagnetic valve 10, the eleventh two-position two-way electromagnetic valve 11 and the twelfth two-position two-way electromagnetic valve 12 are in the power-on conducting state, and each hydraulic pump 8 is in the normal working state, while the first two-position two-way electromagnetic valve 1, the second two-position two-way electromagnetic valve 2, the third two-position two-way electromagnetic valve 3, the thirteenth two-position two-way electromagnetic valve 13 and the fourteenth two-position two-way electromagnetic valve 14 are in the power-off closed state. If the hydraulic pump 8 in the middle pump source unit is disabled due to failure, the fifth two-position two-way electromagnetic valve 5 and the eleventh two-position two-way electromagnetic valve 11 are power-off closed, the first two-position two-way electromagnetic valve 1, the second two-position two-way electromagnetic valve 2 and the thirteenth two-position two-way electromagnetic valve 13 are power-on conducting, and the other electromagnetic valves are in the state in the normal working state; or if the hydraulic pump 8 in the middle pump source unit is disabled due to failure, the fifth two-position two-way electromagnetic valve 5 and the eleventh two-position two-way electromagnetic valve 11 are power-off closed, the second two-position two-way electromagnetic valve 2, the third two-position two-way electromagnetic valve 3 and the fourteenth two-position two-way electromagnetic valve 14 are power-on conducting, and the other electromagnetic valves are in the state in the normal working state.

[0059] If the hydraulic pumps 8 in the left pump source unit and the middle pump source unit are disabled due to failure, the fourth two-position two-way electromagnetic valve 4, the fifth two-position two-way electromagnetic valve 5, the tenth two-position two-way electromagnetic valve 10 and the eleventh two-position two-way electromagnetic valve 11 are power-off closed, the first two-position two-way electromagnetic valve 1, the second two-position two-way electromagnetic valve 2, the third two-position two-way electromagnetic valve 3, the thirteenth two-position two-way electromagnetic valve 13 and the fourteenth two-position two-way electromagnetic valve 14 are power-on conducting, and the other electromagnetic valves are in the state in the normal working state.

[0060] An anchor rod drilling machine comprises a frame and an actuator 9 arranged on the frame, and further comprises the hydraulic pump source switching system of any one of the above embodiments.

[0061] A heading machine comprises a trolley and an actuator arranged on the trolley, and further comprises the hydraulic pump source switching system of any one of the above embodiments.

[0062] The details not described in the present application are conventional technical means known to those skilled in the art.

[0063] The above shows and describes the basic principles, main features and beneficial effects of the present application. The above is only a preferred embodiment of the present application and does not limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A hydraulic pump source switching system comprising a plurality of pump source units, each of which comprises an oil tank (15) - a hydraulic pump (8) - an actuator (9) - an oil tank (15) connected in series by hydraulic lines, characterized in that: The bypass oil inlet pipe is connected between the oil inlet ends of the actuators (9) in each pump source unit, the bypass oil return pipe is connected between the oil return ends of the actuators (9), and the hydraulic pump (8) in each pump source unit is provided with a solenoid valve A or a check valve between the oil inlet end of the actuator (9) and the bypass oil inlet pipe is provided with a solenoid valve B between the oil inlet end of each actuator (9).

2. The hydraulic pump source switching system of claim 1, wherein: The bypass oil return pipe is connected between the oil return ends of the actuators (9) in each pump source unit, the bypass oil return pipe is provided with a solenoid valve C for controlling the on-off of the oil return ends between adjacent pump source units, and the oil return end of the actuator (9) in each pump source unit is provided with a solenoid valve D between the oil tank (15).

3. The hydraulic pump source switching system of claim 2, wherein: The hydraulic pump, the solenoid valve A, the solenoid valve B, the solenoid valve C and the solenoid valve D in each pump source unit are connected with the control unit, so that the pumped hydraulic oil in the same oil tank (15) flows back to the same oil tank (15).

4. The hydraulic pump source switching system of any one of claims 1-3, wherein: The solenoid valve A, the solenoid valve B, the solenoid valve C and the solenoid valve D are two-position two-way solenoid valves.

5. The hydraulic pump source switching system of claim 4, wherein: The two-position two-way solenoid valve is converted to a pass-through position when powered and to a closed position when power is lost.

6. The hydraulic pump source switching system of any of claims 1-3, 5, wherein: The hydraulic pump (8) in each pump source unit is provided with a filter (7) between the oil inlet end of the actuator (9).

7. The hydraulic pump source switching system of claim 6, wherein: The pump source unit is provided with three.

8. A roof bolter comprising a frame and an actuator (9) arranged on the frame, characterized in that: Further comprising the hydraulic pump source switching system of any one of claims 1-7.

9. A heading machine comprising a trolley and an actuator (9) arranged on the trolley, characterized in that: Further comprising the hydraulic pump source switching system of any one of claims 1-7.

Images