A hydraulic system for a loader and a loader

Abstract

This invention discloses a hydraulic system and a loader suitable for use in loaders. The hydraulic system includes a hydraulic tank, a first hydraulic pump, a second hydraulic pump, a multi-way valve, a priority valve, and a single-connector valve. The first hydraulic pump is connected to the hydraulic tank; the second hydraulic pump is also connected to the hydraulic tank; the inlet of the multi-way valve is connected to the outlet of the first hydraulic pump, and its working port is used to connect to a working device; the inlet of the priority valve is connected to the outlet of the second hydraulic pump, and its CF port is used to connect to the inlet of the steering gear; the inlet of the single-connector valve is connected to the EF port of the priority valve, its return port is connected to the hydraulic tank or the inlet of the multi-way valve, and its working port is used to connect to a third-connector implement. This invention connects the EF outlet of the priority valve to the single-connector valve, and the return port of the single-connector valve merges with the inlet of the multi-way valve, thus meeting the low-flow requirements of the third-connector implement without adding an additional pump and avoiding excessive energy loss.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a hydraulic system suitable for loaders and a loader. Background Technology

[0002] The hydraulic system of a loader generally consists of a working hydraulic system and a steering hydraulic system. The working hydraulic system typically comprises a working pump, a multi-way valve, a working hydraulic cylinder, and their piping; the steering hydraulic system typically comprises a steering pump, a priority valve, a steering gear, and their piping. In practical applications, due to the need for auxiliary implements, a third or even a third or fourth hydraulic circuit is often required.

[0003] In existing technology, there are generally two main types of fixed-displacement hydraulic systems for loaders:

[0004] Option 1: Dual-pump non-combined system, i.e., the working pump supplies the working hydraulic cylinder in the working device separately, and the steering pump supplies the steering cylinder separately;

[0005] Option 2: Dual-pump confluence system, where the steering pump supplies the steering cylinder separately, and the excess flow is combined with the working pump to supply the working hydraulic cylinder in the working device;

[0006] Adding a third or fourth hydraulic circuit typically increases the number of connections in a multi-way valve, expanding a two-way valve into a three-way or four-way valve. In some highly restrictive operating conditions, the third connection often requires a smaller flow rate.

[0007] Although Option 1 has a simple structure, the working pump has a large displacement, and the use of a triple valve cannot meet the working condition where the third valve requires a small flow rate.

[0008] Option 2, the dual-pump confluence system, also has a large inlet flow rate to the multi-way valve, which cannot meet the low flow rate requirement of the third unit.

[0009] Adding a separate pump to supply the flow to the third unit would result in significant energy loss at high speeds. Summary of the Invention

[0010] To address the aforementioned issues, this invention proposes a hydraulic system and loader suitable for loaders. The EF outlet of the priority valve is connected to a single valve, and the return port of the single valve is merged with the inlet of the multi-way valve. This satisfies the low-flow requirement of the third-stage implement without the need for an additional pump, thus avoiding excessive energy loss.

[0011] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0012] In a first aspect, the present invention provides a hydraulic system suitable for a loader, comprising:

[0013] Hydraulic oil tank;

[0014] The first hydraulic pump is connected to the hydraulic oil tank;

[0015] The second hydraulic pump is connected to the hydraulic oil tank;

[0016] A multi-way valve, the oil inlet of which is connected to the oil outlet of the first hydraulic pump, and the working oil port of which is used to connect to the working device.

[0017] The priority valve has its inlet connected to the outlet of the second hydraulic pump, and its CF port is used to connect to the inlet of the steering gear.

[0018] A single-port valve has its inlet connected to the EF port of the priority valve, its return port connected to the inlet of the hydraulic oil tank or the multi-way valve, and its working port used to connect to the third-stage tool.

[0019] In conjunction with the first aspect, optionally, when the return port of the single valve is connected to the inlet port of the multi-way valve, and the valve core of the single valve is in the neutral position, the inlet port and return port of the single valve are connected, and the oil at the outlet of the second hydraulic pump is preferentially supplied to the steering gear through the CF port of the priority valve, and the excess oil is merged into the working device through the EF port of the priority valve.

[0020] In conjunction with the first aspect, optionally, when the return port of the single valve is connected to the inlet port of the multi-way valve, and the valve core of the single valve is in the left or right position, the inlet port and return port of the single valve are not connected. The oil at the outlet of the second hydraulic pump is preferentially supplied to the steering gear through the CF port of the priority valve, and the excess oil is supplied to the third tool through the EF port of the priority valve.

[0021] In conjunction with the first aspect, optionally, if the steering gear is not activated, the entire flow of the second hydraulic pump is supplied to the third actuator through the EF port of the priority valve.

[0022] In conjunction with the first aspect, optionally, when the return port of the single valve is connected to the hydraulic oil tank, the first hydraulic pump and the second hydraulic pump are used to independently control the working device and the third tool, so as to realize the combined action of the working device and the third tool.

[0023] In conjunction with the first aspect, optionally, the working device includes a boom cylinder and a bucket cylinder, the large and small chambers of which are respectively connected to the corresponding working ports on the multi-way valve.

[0024] In conjunction with the first aspect, optionally, the hydraulic system further includes a radiator, which is located on the oil line between the return port of the multi-way valve and the hydraulic oil tank.

[0025] In conjunction with the first aspect, optionally, the hydraulic system further includes a return oil filter, which is located on the oil line between the return port of the multi-way valve and the hydraulic oil tank.

[0026] In conjunction with the first aspect, optionally, the multi-way valve is configured as a three-way valve, which is used to connect to the working device and the fourth-way tool respectively, and to realize the small flow control of the third-way tool and the fourth-way tool.

[0027] In a second aspect, the present invention provides a loader, including a hydraulic system suitable for a loader as described in any one of the first aspects.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] This invention proposes a hydraulic system and loader suitable for loaders, in which the outlet of the priority valve EF is connected to a single valve, and the return port of the single valve is merged with the inlet of the multi-way valve. This satisfies the low flow rate required by the third-stage implement without the need for an additional pump, thus avoiding excessive energy loss.

[0030] Furthermore, when the return port of the single valve is connected to the hydraulic oil tank, the first hydraulic pump and the second hydraulic pump are used to control the working device and the third tool separately, and can also realize the combined action of the working device and the third tool to meet the combined action requirements of the working device and the third tool. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0032] Figure 1 This is a schematic diagram of the hydraulic system provided in the embodiment of the present invention. Figure 1 ;

[0033] Figure 2 This is a schematic diagram of the hydraulic system provided in the embodiment of the present invention. Figure 2 ;

[0034] Figure 3 This is a schematic diagram of the hydraulic system provided in the embodiment of the present invention. Figure 3 ;

[0035] 1-Hydraulic oil tank, 2-First hydraulic pump, 3-Second hydraulic pump, 4-Multi-way valve, 5-Priority valve, 6-Steering gear, 7-Single valve, 8-Steering cylinder, 9-Boom cylinder, 10-Bucket cylinder, 11-Radiator, 12-Return oil filter. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0039] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] The application principle of the present invention will be described in detail below with reference to the accompanying drawings. Example 1

[0041] This invention provides a hydraulic system suitable for loaders, such as... Figure 1 As shown, it includes: hydraulic oil tank 1, first hydraulic pump 2, second hydraulic pump 3, multi-way valve 4, priority valve 5, and single valve 7;

[0042] The first hydraulic pump 2 is connected to the hydraulic oil tank 1 and obtains oil from the hydraulic oil tank 1;

[0043] The second hydraulic pump 3 is connected to the hydraulic oil tank 1 and obtains oil from the hydraulic oil tank 1;

[0044] The inlet P of the multi-way valve 4 is connected to the outlet of the first hydraulic pump 2, and its working port is used to connect to the working device.

[0045] The oil inlet P of the priority valve 5 is connected to the oil outlet of the second hydraulic pump 3, its CF port is connected to the oil inlet of the steering gear 6, and its LS port is connected to the LS port of the steering gear 6; the steering gear 6 is also used to connect to the steering device; in specific implementation, the steering device is selected as the steering cylinder 8.

[0046] The oil inlet P of the single valve 7 is connected to the EF port of the priority valve 5, and its return port T is connected to the oil inlet P of the hydraulic oil tank 1 or the multi-way valve 4. Its working port is used to connect to the third-stage machine tool.

[0047] In this embodiment of the invention, the hydraulic system applicable to the loader is to connect the EF outlet of the priority valve 5 to the single valve 7, and the return port of the single valve 7 is merged with the inlet of the multi-way valve 4. This satisfies the low flow rate required by the third-stage implement without adding an additional pump, thus avoiding excessive energy loss. Example 2

[0048] Based on Embodiment 1, in this embodiment of the invention, the return port T of the single valve 7 is connected to the inlet port P of the multi-way valve 4.

[0049] When the valve core of the single valve 7 is in the neutral position, the oil inlet P of the single valve 7 is connected to the oil return port T. The oil at the outlet of the second hydraulic pump 3 is preferentially supplied to the steering gear 6 through the CF port of the priority valve 5, and the excess oil is merged into the working device through the EF port of the priority valve 5.

[0050] When the valve core of the single valve 7 is in the left or right position, the oil inlet and return port of the single valve 7 are not connected. The oil at the outlet of the second hydraulic pump 3 is preferentially supplied to the steering gear 6 through the CF port of the priority valve 5, and the excess oil is supplied to the third tool through the EF port of the priority valve 5.

[0051] In the specific implementation process, the single valve can be a three-position six-way valve with the valve core in the middle position. When the valve core is in the middle position, its oil inlet P is connected to the oil return port T. When the valve core is in the left or right position, its oil inlet P is not connected to the oil return port T, and the oil at its oil inlet P is supplied to the third-position machine tool.

[0052] In one specific embodiment of the present invention, if the steering gear 6 is not activated, the entire flow of the second hydraulic pump 3 is supplied to the third auxiliary machine through the EF port of the priority valve 5.

[0053] In one specific embodiment of the present invention, the working device includes a boom cylinder 9 and a bucket cylinder 10, the large and small chambers of which are respectively connected to the corresponding working ports on the multi-way valve 4. See details below. Figure 1 .

[0054] In one specific embodiment of the present invention, the hydraulic system further includes a radiator 11, which is disposed on the oil line between the return port of the multi-way valve 4 and the hydraulic oil tank 1, and is used to cool the oil at the return port of the multi-way valve 4.

[0055] In one specific embodiment of the present invention, the hydraulic system further includes a return oil filter 12, which is disposed on the oil line between the return port of the multi-way valve 4 and the hydraulic oil tank 1, and is used to filter the oil at the return port of the multi-way valve 4 to ensure that the oil in the hydraulic oil tank 1 is not contaminated.

[0056] The hydraulic system for loaders in this embodiment of the invention mainly has the following working states:

[0057] State 1: When the third-unit machine is not in operation, if the working device and steering device are operated, priority valve 5 will ensure that oil is supplied to the steering device first, and the rest of the oil is supplied to the working device.

[0058] State 2: When operating the third machine tool alone, without activating the steering device, all the flow output from the second hydraulic pump 3 is supplied to the third machine tool.

[0059] State 3: When operating the third-link machine tool and simultaneously operating the working device, the first hydraulic pump 2 supplies oil to the working device, the second hydraulic pump 3 prioritizes supplying oil to the steering device, and the excess oil is supplied to the third-link machine tool. The working device and the third-link machine tool are supplied with oil by different hydraulic pumps, which can realize compound actions and meet the needs of special working conditions.

[0060] State 4: When the steering device and the third-link tool are operated simultaneously, the priority valve 5 ensures that the oil output from the second hydraulic pump 3 is preferentially supplied to the steering device, and the excess oil output from the second hydraulic pump 3 is supplied to the third-link tool, thus meeting the requirements of priority steering and the operation of the third-link tool. Example 3

[0061] like Figure 2 As shown, in this embodiment of the invention, the EF port of the priority valve 5 is connected to the oil inlet P of the single valve 7, and the oil outlet T of the single valve 7 is connected back to the hydraulic oil tank 1. Therefore, the hydraulic system in this embodiment of the invention is a dual-pump non-combining hydraulic system.

[0062] The first hydraulic pump 2 and the second hydraulic pump 3 are used to control the working device and the third tool separately, so as to realize the combined action of the working device and the third tool.

[0063] The hydraulic system in this embodiment of the invention not only retains the advantage that the working speed of the dual-pump non-combining hydraulic system is not affected by the steering action, but also meets the requirements of the third unit for small flow conditions. Example 4

[0064] like Figure 3 As shown, if the machine operation requires two oil sources, based on embodiment 1, the multi-way valve 4 is set as a three-way valve. The three-way valve is used to connect to the working device and the fourth machine respectively, so as to realize the small flow control of the third and fourth machines.

[0065] The hydraulic system in this embodiment of the invention is a dual-pump confluence system, which can realize small flow control of the third and fourth pumps respectively, greatly improving the adaptability of the machine. Example 5

[0066] This invention provides a loader, including the hydraulic system suitable for a loader as described in any of embodiments 1-4.

[0067] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention.

[0068] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A hydraulic system suitable for loaders, characterized in that, include: Hydraulic oil tank; The first hydraulic pump is connected to the hydraulic oil tank; The second hydraulic pump is connected to the hydraulic oil tank; A multi-way valve, the oil inlet of which is connected to the oil outlet of the first hydraulic pump, and the working oil port of which is used to connect to the working device. The priority valve has its inlet connected to the outlet of the second hydraulic pump, and its CF port is used to connect to the inlet of the steering gear. A single valve, whose inlet is connected to the EF port of the priority valve, whose return port is connected to the inlet of the hydraulic oil tank or the multi-way valve, and whose working port is used to connect to the third-stage tool. When the return port of the single valve is connected to the inlet port of the multi-way valve, and the valve core of the single valve is in the neutral position, the inlet port and the return port of the single valve are connected. The oil at the outlet of the second hydraulic pump is preferentially supplied to the steering gear through the CF port of the priority valve, and the excess oil is merged into the working device through the EF port of the priority valve. When the return port of the single valve is connected to the hydraulic oil tank, the first hydraulic pump and the second hydraulic pump are used to control the working device and the third tool separately, so as to realize the combined action of the working device and the third tool. When the return port of the single valve is connected to the inlet port of the multi-way valve, and the valve core of the single valve is in the left or right position, the inlet port and return port of the single valve are not connected. The oil at the outlet of the second hydraulic pump is preferentially supplied to the steering gear through the CF port of the priority valve, and the excess oil is supplied to the third tool through the EF port of the priority valve.

2. A hydraulic system suitable for a loader according to claim 1, characterized in that: If the steering gear is not activated, the full flow of the second hydraulic pump is supplied to the third control unit through the EF port of the priority valve.

3. A hydraulic system suitable for a loader according to claim 1, characterized in that: The working device includes a boom cylinder and a bucket cylinder, the large and small chambers of which are respectively connected to the corresponding working ports on the multi-way valve.

4. A hydraulic system suitable for a loader according to claim 1, characterized in that: The hydraulic system also includes a radiator, which is located on the oil line between the return port of the multi-way valve and the hydraulic oil tank.

5. A hydraulic system suitable for a loader according to claim 1, characterized in that: The hydraulic system also includes a return oil filter, which is located on the oil line between the return port of the multi-way valve and the hydraulic oil tank.

6. A hydraulic system suitable for a loader according to claim 1, characterized in that: The multi-way valve is configured as a three-way valve, which is used to connect to the working device and the fourth-way tool respectively, and to realize the flow control of the third-way tool and the fourth-way tool.

7. A loader, characterized in that: The hydraulic system for a loader includes any one of claims 1-6.

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