Handheld machine tool hydraulic system and excavator

Abstract

The utility model relates to the technical field of engineering machinery, in particular to a handheld machine tool hydraulic system and an excavator. Comprising a handheld machine tool and further comprises an oil tank used for providing hydraulic oil; the oil inlet path is connected with an oil inlet of the handheld machine tool; the oil return path is connected with an oil return opening of the handheld machine tool; the electric proportional pressure reducing valve is arranged on the oil inlet path; the main reversing valve is a hydraulically-controlled two-position two-way valve, an oil inlet of the main reversing valve is communicated with an oil inlet path on the upstream of the pressure reducing valve, and an oil outlet of the main reversing valve is communicated with an oil tank; the main reversing valve is provided with a left position and a right position, the main pump unit comprises a main pump and a pilot pump, oil inlets of the main pump and the pilot pump are connected with an oil tank, an oil outlet of the main pump is connected with the oil inlet path, and an oil outlet of the pilot pump is connected with the right end of the main reversing valve. The electric proportional pressure reducing valve can achieve accurate control over the pressure of a working oil port of the handheld machine tool, and therefore stable hydraulic oil is provided for working of the handheld machine tool.

Description

Technical Field

[0001] The utility model relates to the technical field of construction machinery, in particular to a hydraulic system for a hand-held tool and an excavator. Background Art

[0002] With the rapid increase in the global market share of China's construction machinery industry, especially in the excavator industry, on the basis of the reliability, safety, and stability of the whole machine, how to further expand the application range of excavators. For example, under certain conditions of limited space, the whole excavator cannot operate normally and requires the assistance of hand-held tools. On some large hydraulic equipment, spare oil ports are usually reserved on the main control valve for installing working attachments such as hydraulic hammers and hydraulic shears.

[0003] However, such oil ports usually cannot provide power for various small hand-held hydraulic tools, and even if they can be applied, it is difficult to achieve fine control. Currently, on some large hydraulic equipment, spare oil ports are usually reserved on the main control valve for installing working attachments such as hydraulic hammers and hydraulic shears. However, such oil ports usually cannot provide power for various small hand-held hydraulic tools, and even if they can be applied, it is difficult to achieve fine control.

[0004] Moreover, the operation of the actuator of the hydraulic system is controlled by the operator in the cab, far from the operation site, which is not convenient for operation and poses safety hazards. On the other hand, the pressure and flow rate of the hydraulic system are greatly affected by other operation actions, and it is impossible to achieve fine operation of a multi-functional small hand-held hydraulic tool with independent control. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a hydraulic system for a hand-held tool to solve the problem that the spare oil port on large hydraulic equipment is difficult to be applied to small hand-held hydraulic tools with fine control. To solve the above problems, the utility model adopts the following technical solutions:

[0006] In a first aspect, the utility model provides a hydraulic system for a hand-held tool, including a hand-held tool; a fuel tank for providing hydraulic oil; an oil inlet passage connected to the oil inlet of the hand-held tool; an oil return passage connected to the oil return port of the hand-held tool; and it further includes:

[0007] An electro-hydraulic proportional relief valve provided on the oil inlet passage,

[0008] A main directional control valve, the oil inlet of which is communicated with the oil inlet passage upstream of the relief valve, and the oil outlet is communicated with the fuel tank; the main directional control valve is used to control the on-off of the oil inlet passage upstream of the electro-hydraulic proportional relief valve;

[0009] The main pump unit includes a main pump and a pilot pump. The inlet ports of the main pump and the pilot pump are both connected to the fuel tank. The outlet port of the main pump is connected to the inlet oil passage, and the outlet port of the pilot pump is connected to the control end of the main reversing valve. The pilot pump is used to drive the main reversing valve to change its direction.

[0010] The pilot solenoid valve is arranged on the first oil passage between the pilot pump and the control end of the main reversing valve. The pilot solenoid valve is used to control the on / off of the first oil passage.

[0011] The electromagnetic reversing valve is arranged on the inlet oil passage downstream of the pressure reducing valve. The electromagnetic reversing valve is used to control the on / off of the inlet oil passage downstream of the electro-hydraulic proportional pressure reducing valve.

[0012] The controller is connected to the control ends of the electro-hydraulic proportional pressure reducing valve, the pilot solenoid valve, and the electromagnetic reversing valve. The controller is used to control the valve core opening of the electro-hydraulic proportional pressure reducing valve. The controller is also used to control the pilot solenoid valve to change its direction so that the first oil passage can be switched between the connected state and the disconnected state. The controller is also used to control the electromagnetic reversing valve to change its direction so that the inlet oil passage downstream of the electro-hydraulic proportional pressure reducing valve can be switched between the connected state and the disconnected state.

[0013] Optionally, the main reversing valve is a hydraulically controlled two-position two-way valve. The right end of the main reversing valve is the control end, and the outlet port of the pilot pump is connected to the right end of the main reversing valve. The main reversing valve has a left position and a right position, and a spring is connected to the left end of the main reversing valve. When the main reversing valve is in the left position, the inlet port and the outlet port are connected, and the inlet oil passage upstream of the electro-hydraulic proportional pressure reducing valve is disconnected. When the main reversing valve is in the right position, the inlet port and the outlet port are not connected, and the inlet oil passage upstream of the electro-hydraulic proportional pressure reducing valve is connected.

[0014] Optionally, the electromagnetic reversing valve is an electrically controlled two-position two-way valve. The left end of the electromagnetic reversing valve is the control end. A spring is connected to the right end of the electromagnetic reversing valve. The electromagnetic reversing valve has a left position and a right position. When the electromagnetic reversing valve is in the left position, the inlet port is connected to the outlet port, and the inlet oil passage downstream of the electro-hydraulic proportional pressure reducing valve is connected. When the electromagnetic reversing valve is in the right position, the inlet port is not connected to the outlet port, and the inlet oil passage downstream of the electro-hydraulic proportional pressure reducing valve is disconnected.

[0015] Optionally, the control end of the pilot solenoid valve is the right end. The pilot solenoid valve has a left position and a right position. When the pilot solenoid valve is in the left position, the inlet port is connected to the pilot pump, and the outlet port is connected to the control end of the main reversing valve. When the pilot solenoid valve is in the right position, the inlet port and the outlet port are not connected.

[0016] Optionally, it further includes:

[0017] A stop valve is arranged on the inlet oil passage downstream of the electro-hydraulic proportional pressure reducing valve.

[0018] Optionally, it further includes:

[0019] A one-way valve is provided on the oil return path.

[0020] Optionally, the main pump is an adjustable pump, and the main pump includes a variable mechanism; the variable mechanism is hydraulically controlled; a spring is connected to the left end of the variable mechanism; the hydraulic system further includes:

[0021] A proportional solenoid valve is provided between the pilot pump and the variable mechanism, with the oil inlet connected to the pilot pump and the oil outlet connected to the right end of the variable mechanism.

[0022] Optionally, the control end of the proportional solenoid valve is connected to the controller, and the controller is used to control the on-off of the oil inlet and outlet of the proportional solenoid valve and control the valve core opening of the proportional solenoid valve by the magnitude of the current.

[0023] In a second aspect, the present invention further provides an excavator, which includes the above-mentioned handheld tool hydraulic system.

[0024] Compared with the prior art, the present utility model has the following beneficial effects:

[0025] 1. When the hydraulic system in the present invention is in use, it can first reduce the pressure of the hydraulic oil through the pressure reducing valve group so that the pressure of the hydraulic oil can meet the usage requirements of the handheld tool.

[0026] 2. The present invention can also control the output flow rate of the main pump through the proportional solenoid valve to cooperate with the electro-hydraulic proportional pressure reducing valve and the stop valve to achieve precise control of flow rate and pressure, thereby providing stable hydraulic oil for the working oil port of the handheld tool and meeting the working conditions of the handheld tool.

[0027] 3. The present invention uses the pressure oil output by the pilot pump to drive the main directional control valve to change direction through the pilot solenoid valve, and can more stably control the on-off of the first oil circuit through the main control valve. That is, the pilot pump in this embodiment can not only start prior to the main pump to establish an initial pressure, but also pre-control the main directional control valve to change to the right position to connect the first oil circuit. Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of a handheld tool hydraulic system in Embodiment 1.

[0029] In the figure: 1. Main pump unit; 101. Main pump; 102. Pilot pump; 103. Variable mechanism; 104. Proportional solenoid valve; 2. Pilot solenoid valve; 3. Main reversing valve; 4. Controller; 5. Display; 6. Handheld tool; 7. Pressure reducing valve group; 701. Electro-hydraulic proportional pressure reducing valve; 702. Electromagnetic reversing valve; 703. Check valve; 8. Stop valve; 9. Inlet oil circuit; 10. Return oil circuit. Detailed implementation mode

[0030] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0031] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention. Embodiment 1

[0032] Combined with Figure 1 , this embodiment provides a hydraulic system for a handheld tool, a fuel tank for providing hydraulic oil; an inlet oil circuit connected to the inlet of the handheld tool 6; a return oil circuit 10 connected to the return port of the handheld tool 6; the hydraulic system further includes:

[0033] An electro-hydraulic proportional pressure reducing valve 701 is arranged on the inlet oil circuit 9;

[0034] The main reversing valve 3 is a two-position two-way valve controlled hydraulically. Its oil inlet is connected to the oil inlet passage 9 upstream of the electro-hydraulic proportional pressure reducing valve 701, and its oil outlet is connected to the oil tank. The main reversing valve 3 has a left position and a right position, and a spring is connected to the left end of the main reversing valve 3. When the main reversing valve 3 is in the left position, the oil inlet and the oil outlet are connected. When the main reversing valve 3 is in the right position, the oil inlet and the oil outlet are not connected.

[0035] The main pump unit 1 includes a main pump 101 and a pilot pump 102. The oil inlets of the main pump 101 and the pilot pump 102 are both connected to the oil tank. The oil outlet of the main pump 101 is connected to the oil inlet passage 9, and the oil outlet of the pilot pump 102 is connected to the right end of the main reversing valve 3.

[0036] Specifically, when the hydraulic system in this embodiment is in use, firstly, the electro-hydraulic proportional pressure reducing valve 701 can reduce the pressure of the hydraulic oil so that the pressure of the hydraulic oil can meet the usage requirements of the handheld tool 6. In addition, in this embodiment, the pressure oil output by the pilot pump 102 is used to drive the main reversing valve 3 to reverse, and the on-off of the first oil passage can be controlled more stably through the main reversing valve 3. When the main reversing valve 3 is in the left position, the oil inlet and the oil outlet of the main reversing valve 3 are connected, and the hydraulic oil on the oil inlet passage 9 directly flows back to the oil tank through the main reversing valve 3. When the main reversing valve 3 is in the right position, the oil inlet and the oil outlet of the main reversing valve 3 are not connected, and the hydraulic oil flows to the electro-hydraulic proportional pressure reducing valve 701. That is to say, the pilot pump 102 in this embodiment can not only start prior to the main pump 101 to establish an initial pressure, but also pre-control the main reversing valve 3 to reverse to the right position so that the hydraulic oil can flow to the electro-hydraulic proportional pressure reducing valve 701.

[0037] In this embodiment, the hydraulic system further includes:

[0038] A controller 4, communicatively connected to the electro-hydraulic proportional pressure reducing valve 701. The controller 4 is configured to output a first control signal to the electro-hydraulic proportional pressure reducing valve 701 and control the spool opening position of the electro-hydraulic proportional pressure reducing valve 701 to control the pressure reducing ratio of the electro-hydraulic proportional pressure reducing valve 701.

[0039] Specifically, the electro-hydraulic proportional pressure reducing valve 701 in this embodiment can be controlled by the first control signal output by the controller 4 to maintain different pressure reducing ratios according to the actual flow demand.

[0040] The hydraulic system in this embodiment further includes an electromagnetic directional control valve 702. The electromagnetic directional control valve 702 is an electrically controlled two-position two-way valve, which is arranged on the oil inlet line 9 downstream of the electro-hydraulic proportional pressure reducing valve 701. The oil inlet of the electromagnetic directional control valve 702 is connected to the oil outlet of the electro-hydraulic proportional pressure reducing valve 701, and the oil outlet is connected to the oil inlet of the handheld tool 6. The electromagnetic directional control valve 702 has a left position and a right position. When the electromagnetic directional control valve 702 is in the left position, the oil inlet is communicated with the oil outlet. When the electromagnetic directional control valve 702 is in the right position, the oil inlet is not communicated with the oil outlet.

[0041] The electromagnetic directional control valve 702 is communicatively connected to the controller 4. The controller 4 is configured to output a second control signal to the electromagnetic directional control valve 702 to make the electromagnetic directional control valve 702 work in the left position. When the electromagnetic directional control valve is an electro-hydraulic proportional directional control valve, the controller also controls the spool opening position of the electromagnetic directional control valve 702.

[0042] The electromagnetic directional control valve 702 is arranged on the oil inlet line 9 downstream of the electro-hydraulic proportional pressure reducing valve 701. After being reduced in pressure by the electro-hydraulic proportional pressure reducing valve 701, the pressure of the oil line is relatively small. In this embodiment, the on-off of the oil line at this place can be controlled more stably through the commutation of the electromagnetic directional control valve 702.

[0043] In this embodiment, the hydraulic system further includes a stop valve 8, which is arranged on the oil inlet line 9 downstream of the electro-hydraulic proportional pressure reducing valve 701 and is used to control the fluid flow rate at the working oil port of the handheld tool 6. Specifically, in this embodiment, the stop valve 8 can further control the hydraulic oil pressure so that the adjustment of the hydraulic oil pressure is more delicate to achieve the fine operation of the handheld tool 6.

[0044] A check valve 703 is arranged on the oil return line 10.

[0045] In addition, the main pump 101 is an adjustable pump, and the main pump includes a variable mechanism 103. The variable mechanism 103 is hydraulically controlled, and a spring is connected to the left end of the variable mechanism 103.

[0046] The hydraulic system further includes:

[0047] A proportional solenoid valve 104 is arranged between the pilot pump 102 and the variable mechanism 103. The oil inlet is connected to the pilot pump 102, and the oil outlet is connected to the right end of the variable mechanism 103.

[0048] In this embodiment, the proportional solenoid valve 104 is communicatively connected to the controller 4. The controller 4 is configured to output a fourth control signal to the proportional solenoid valve 104 to communicate the oil inlet and the oil outlet of the proportional solenoid valve 104 and control the spool opening of the proportional solenoid valve 104 by the magnitude of the current.

[0049] In this embodiment, the variable mechanism 103 and the proportional solenoid valve 104 can control the output flow rate of the main pump 101 to cooperate with the electro-hydraulic proportional pressure reducing valve 701 and the stop valve 8 to achieve precise control of flow rate and pressure, thereby providing stable hydraulic oil for the working oil port of the handheld tool 6 and meeting the working conditions of the handheld tool 6.

[0050] Combined with Figure 1 , in this embodiment, the controller 4 is controlled by the display 5, and the specific usage process is as follows:

[0051] On the display 5, select the handheld tool 6 mode, input the required pressure and flow rate parameters of the tool, the display 5 transmits a signal to the controller 4, and after the controller 4 processes the signal;

[0052] Output the first control signal to the electro-hydraulic proportional pressure reducing valve 701 of the pressure reducing valve group 7. After the electro-hydraulic proportional pressure reducing valve 701 is energized, the spool works at a fixed opening position to control the pressure;

[0053] Output the second control signal to the electromagnetic directional valve 702 of the pressure reducing valve group 7. After the electromagnetic directional valve 702 is energized, it works at a certain fixed opening position in the left position;

[0054] Output the third control signal to the pilot solenoid valve 2. After the pilot solenoid valve 2 receives the control signal, it works in the left position. The pressure oil output by the pilot pump 102 acts on the right end of the main directional valve 3 after passing through the P (inlet oil) and A (outlet oil) ports of the pilot solenoid valve 2, and the main directional valve 3 works in the right position;

[0055] Output the fourth control signal to act on the proportional solenoid valve 104. The pressure oil output by the pilot pump 102 acts on the right end of the variable mechanism 103 after passing through the inlet oil port and the outlet oil port of the proportional valve 104. By controlling the opening degree of the variable mechanism 103, the displacement of the main pump 101 is controlled, and further the output flow rate of the main pump 101 is controlled.

[0056] The hydraulic oil output by the main pump 101 in the main pump unit 1 acts on the inlet oil port of the handheld tool 6 after passing through the electro-hydraulic proportional pressure reducing valve 701, the electromagnetic directional valve 702, and the stop valve 8 of the pressure reducing valve group 7, and the return oil returns to the fuel tank through the return oil port of the handheld tool 6 and the check valve 703 on the return line 10. Embodiment 2

[0057] This embodiment provides an excavator, which includes a handheld tool hydraulic system as described in Embodiment 1.

[0058] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A handheld tool hydraulic system, comprising a handheld tool (6); an oil tank for providing hydraulic oil; an oil inlet circuit (9) connected to an oil inlet of the handheld tool (6); and an oil return circuit (10) connected to an oil return port of the handheld tool (6); characterized in that: Also includes: The electric proportional pressure reducing valve (701) is arranged on the oil inlet passage (9). A main reversing valve (3), the oil inlet of which is connected to the oil inlet passage (9) located upstream of the electric proportional pressure reducing valve (701), and the oil outlet of which is connected to the oil tank; A main pump unit (1) comprises a main pump (101) and a pilot pump (102); the oil inlets of the main pump (101) and the pilot pump (102) are both connected to an oil tank; the oil outlet of the main pump (101) is connected to the oil inlet path (9); the oil outlet of the pilot pump (102) is connected to a control end of the main reversing valve (3); the pilot pump (102) is used to drive the main reversing valve (3) to switch direction; A pilot solenoid valve (2) is provided on a first oil circuit between the pilot pump (102) and a control end of the main reversing valve (3); An electromagnetic reversing valve (702) is provided on the oil inlet passage (9) downstream of the electric proportional pressure reducing valve (701); A controller (4) is electrically connected to the control ends of the electric proportional pressure reducing valve (701), the pilot solenoid valve (2) and the solenoid reversing valve (702); the controller (4) is used to control the valve core opening of the electric proportional pressure reducing valve (701); the controller (4) is also used to control the reversing of the pilot solenoid valve (2) so that the first oil circuit switches between a connected state and a disconnected state; the controller (4) is also used to control the reversing of the solenoid reversing valve (702) so that the oil inlet circuit (9) downstream of the electric proportional pressure reducing valve (701) switches between a connected state and a disconnected state.

2. A handheld tool hydraulic system according to claim 1, characterized in that: The main reversing valve (3) is a two-position two-way valve controlled by hydraulic power, and the right end of the main reversing valve (3) is a control end; the main reversing valve (3) has a left position and a right position, and the left end of the main reversing valve (3) is connected to a spring; when the main reversing valve (3) is in the left position, the oil inlet and the oil outlet are connected, and the oil inlet path (9) upstream of the electric proportional pressure reducing valve (701) is disconnected; when the main reversing valve (3) is in the right position, the oil inlet and the oil outlet are not connected, and the oil inlet path (9) upstream of the electric proportional pressure reducing valve (701) is connected.

3. A handheld tool hydraulic system according to claim 1, characterized in that: The electromagnetic reversing valve (702) is an electrically controlled two-position two-way valve; the left end of the electromagnetic reversing valve is a control end; the right end of the electromagnetic reversing valve (702) is connected to a spring, and the electromagnetic reversing valve (702) has a left position and a right position. When the electromagnetic reversing valve (702) is in the left position, the oil inlet is connected to the oil outlet, and the oil inlet path (9) downstream of the electric proportional pressure reducing valve (701) is connected; when the electromagnetic reversing valve (702) is in the right position, the oil inlet is not connected to the oil outlet, and the oil inlet path (9) downstream of the electric proportional pressure reducing valve (701) is disconnected.

4. A handheld tool hydraulic system according to claim 1, characterized in that: The control end of the pilot solenoid valve (2) is the right end. The pilot solenoid valve (2) has a left position and a right position. When the pilot solenoid valve (2) is in the left position, the oil inlet is connected to the pilot pump, and the oil outlet is connected to the control end of the main reversing valve; when the pilot solenoid valve (2) is in the right position, the oil inlet and the oil outlet are not connected, and the first oil circuit is disconnected.

5. The handheld implement hydraulic system according to claim 1, characterized in that: Also includes: The stop valve (8) is arranged on the oil inlet passage (9) downstream of the electric proportional pressure reducing valve (701).

6. A handheld tool hydraulic system according to claim 1, characterized in that: Also includes: A one-way valve (703) is provided on the oil return line (10).

7. A handheld tool hydraulic system according to claim 1, characterized in that: The main pump (101) is an adjustable pump, and comprises a variable mechanism (103); the variable mechanism (103) is hydraulically controlled; a spring is connected to the left end of the variable mechanism (103); the hydraulic system further comprises: The proportional solenoid valve (104) is arranged between the pilot pump (102) and the variable mechanism (103), with an oil inlet connected to the pilot pump (102) and an oil outlet connected to the right end of the variable mechanism (103).

8. A handheld implement hydraulic system according to claim 7, characterized in that: The control end of the proportional solenoid valve (104) is electrically connected to the controller (4), and the controller (4) is used to control the on / off of the oil inlet and the oil outlet of the proportional solenoid valve (104), and to control the valve core opening of the proportional solenoid valve (104) by the magnitude of the current.

9. An excavator, characterized in that: A handheld tool hydraulic system comprising the hydraulic system of any one of claims 1-8.

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