Control valve group and motor device

Abstract

The invention relates to the technical field of hydraulic pressure, in particular to a control valve group and a motor device. A control valve set is used for a hydraulic motor and comprises a balance valve, the balance valve is provided with two motor side oil ports and an oil source side oil port, the two motor side oil ports are communicated with the two oil ports of the hydraulic motor, when the balance valve is located at the middle position, the motor side oil ports are not communicated with the oil source side oil port, and when the balance valve is located at the working position, the oil source side oil port is not communicated with the oil source side oil port. The oil inlet selectively receives return oil from the hydraulic motor and allows the return oil to flow through; the control valve is used for controlling connection and disconnection of the two motor side oil ports, the control valve is provided with a middle position and at least two working positions, and when the control valve is located at the middle position, the two motor side oil ports are not communicated; when the control valve is located at different working positions, the communicating opening areas between the two motor side oil ports are different. The technical problem that in the prior art, the remaining opening area is unique, and different speed gears cannot be adapted is solved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic technology, and in particular to a control valve assembly and motor device. Background Technology

[0002] Wheeled excavators and other hydraulically driven equipment often have multiple speed levels (most of which are achieved through different reduction ratios or different motor displacements). On mobile mobile devices, in order to improve motor start-stop, provide braking protection, and reduce the risk of hydraulic motor overspeed and cavitation in open systems, balance valves (BVD valves) are often installed on the hydraulic motors.

[0003] For example, application number CN202123457234.3 discloses a balance valve with a residual opening, including a valve body, a balance valve core assembly on the valve body, an oil inlet and an oil return port on the valve body; the valve body has an oil inlet chamber, an oil return chamber and a balance chamber, the oil inlet and the oil return port are respectively located on both sides of the balance chamber; two sets of one-way valve assemblies are symmetrically arranged in the valve body, the two sets of one-way valve assemblies are respectively located on both sides of the balance chamber; the one-way valve assembly includes a first valve cover, the first valve cover is threaded to the valve body, the first valve cover has a radial hole X; a first valve core is provided in the first valve cover, the first valve core is installed in the first valve cover by a first spring, the first valve core has a throttling hole Y, the throttling hole Y communicates with the radial hole X; the balance valve core assembly includes a main valve core, the main valve core has a throttling hole W, the throttling hole W communicates with the oil inlet chamber and the oil return chamber.

[0004] The aforementioned document employs a balance valve with a residual opening to prevent shocks during motor start-up and shutdown, and uses the residual opening to eliminate excessive pressure differences between the high and low pressure chambers of the motor when the balance valve is in the neutral position. However, the response speed of the balance valve (BVD valve) (from neutral to operating position or from operating to neutral) determines whether the motor starts and stops smoothly without any shock, and this response speed is related to the load pressure. Often, during commissioning, the balance valve (BVD valve) is controlled to achieve the most desired and comfortable effect with a suitable response speed. The residual opening is an adjustment point for the travel balance valve (BVD valve); however, the load pressure often differs at different speed settings. At a certain speed setting, the balance valve (BVD valve) response may be suitable for the system, but at other speed settings, it may not be as adaptable, potentially leading to problems such as large braking shocks or no braking feel. Summary of the Invention

[0005] To address the technical problem in existing technologies where the remaining opening area is unique and cannot adapt to different speed levels, this invention provides a control valve assembly and motor device that solves the aforementioned technical problem.

[0006] To solve the above-mentioned technical problems, the present invention provides a control valve assembly for a hydraulic motor, comprising: The balance valve has two motor-side oil ports and an oil source-side oil port. The two motor-side oil ports are connected to two oil ports of the hydraulic motor. When the balance valve is in the neutral position, the motor-side oil ports and the oil source-side oil ports are not connected. When the balance valve is in the working position, it selectively receives return oil from the hydraulic motor and allows return oil to flow through. A control valve is used to control the opening and closing of two motor-side oil ports. The control valve has a neutral position and at least two working positions. When the control valve is in the neutral position, the two motor-side oil ports are not connected. When the control valve is in different working positions, the opening area connecting the two motor-side oil ports is different. When the hydraulic motor is not in braking condition, the balance valve is in the working position and the control valve is in the neutral position; when the hydraulic motor is in braking condition, the balance valve is in the neutral position and the control valve is in the working position.

[0007] According to one embodiment of the present invention, the control valve includes a control valve body and a control valve core. The control valve body is provided with a first oil port and a second oil port. The first oil port and the second oil port are respectively connected to two motor-side oil ports. At least one of the first oil port and the second oil port is connected to the outer periphery of the control valve core through at least two oil passages with different flow areas.

[0008] According to one embodiment of the present invention, the first oil port is connected to the outer periphery of the control valve core via at least two first oil passages, and the first oil passages are equipped with throttling plugs, the throttling orifices of the throttling plugs in different first oil passages being of different sizes; the second oil port is connected to the outer periphery of the control valve core via a second oil passage, and the control valve core controls the opening and closing between the first oil passages and the second oil passages.

[0009] According to one embodiment of the present invention, there are two first oil passages. When the control valve is in the neutral position, neither of the two first oil passages is connected to the second oil passage. When the control valve is in one of the two working positions, it controls the two first oil passages to be connected to the second oil passage respectively.

[0010] According to one embodiment of the present invention, the control valve further includes an electromagnetic component, which drives the control valve core to switch positions.

[0011] According to one embodiment of the present invention, a throttling structure is provided between the first oil port and / or the second oil port and the corresponding motor-side oil port.

[0012] The present invention also provides a motor device, comprising: The oil source has an oil port A and an oil port B, one of which is a high-pressure oil port and the other is a low-pressure oil port; The hydraulic motor has oil port AA and oil port BB. Oil port A is connected to oil port AA in one direction through the first main oil circuit, and oil port B is connected to oil port BB in one direction through the second main oil circuit. High-pressure oil supplied by the oil source is supplied to the hydraulic motor through the first main oil circuit or the second main oil circuit. The control valve assembly has two motor-side oil ports of the balance valve connected to oil port AA and oil port BB respectively, and the oil source-side oil port of the balance valve connected to the oil source.

[0013] According to one embodiment of the present invention, the balance valve has two oil source side ports, which are respectively connected to oil port A and oil port B. The return oil from the hydraulic motor reaches the return oil chamber under the control of the balance valve core, and the return oil chamber is unidirectionally connected to oil port A and oil port B.

[0014] According to one embodiment of the present invention, the balance valve is located between the hydraulic motor and the control valve, the valve body of the balance valve is fixedly connected to the oil port end of the hydraulic motor, and the control valve body is fixed on the valve body of the balance valve.

[0015] According to one embodiment of the present invention, when the hydraulic motor is in braking condition, the control valve switches the operating position according to the speed range of the hydraulic motor.

[0016] Based on the above technical solution, the technical effects that the present invention can achieve are as follows: 1. The control valve assembly of the present invention comprises a control valve disposed between the two motor-side oil ports of a balance valve. The control valve controls the opening and closing of the two motor-side oil ports. The control valve has a neutral position and at least two working positions. When the hydraulic motor is in a non-braking condition, the control valve is in the neutral position, the two motor-side oil ports are not connected, and the hydraulic motor can operate normally. When the hydraulic motor is in a braking condition, the balance valve switches to the neutral position, the control valve is in the working position, and the two motor-side oil ports of the balance valve can be connected by the control valve to prevent shock during the start and stop of the hydraulic motor. Furthermore, the control valve has at least two working positions, and the opening area corresponding to different working positions is different, which facilitates matching different speed levels so that different speed levels match different opening areas, enabling the hydraulic motor to achieve smooth and shock-free braking at any speed level. 2. The control valve assembly of the present invention, by setting at least one of the first oil port and the second oil port to be connected to the outer periphery of the control valve core through at least two oil passages with different flow areas, when the control valve core controls the connection of the first oil port and the second oil port, different opening areas can appear to match braking at different speed levels; in order to facilitate the processing of the oil passages in the control valve body and avoid interference, the first oil port is set to connect to at least two first oil passages, and different throttling plugs with different throttling ports are built into different first oil passages to make their flow areas different, and the second oil port is connected to the second oil passage, so that when the control valve core controls the connection of different first oil passages and second oil passages, different opening areas can be achieved between the first oil port and the second oil port. 3. The control valve assembly of the present invention uses an electromagnetic component to drive the control valve core to switch positions. It can control the current of the electromagnetic component according to the speed range of the hydraulic motor, thereby driving the control valve core to switch to different working positions, which facilitates the control of the control valve. 4. In the control valve assembly of the present invention, a throttling structure is provided between the first oil port and / or the second oil port and the corresponding motor-side oil port. The throttling structure and the control valve can achieve series throttling, which can achieve more precise flow regulation. Multiple throttling points can disperse pressure loss and make pressure changes smoother. It can also improve system reliability, and the failure of a single throttling point will not lead to the failure of the overall throttling. 5. In the motor device of the present invention, the control valve is set between the oil source and the hydraulic motor, which can realize precise control of the braking of the hydraulic motor. For example, when the hydraulic motor is in the high speed position, the control valve can be in the working position with a larger opening area that connects the two motor side oil ports, so that the hydraulic motor stops slowly and prevents the impact speed from being too large; when the hydraulic motor is in the low speed position, the control valve can be in the working position with a smaller opening area that connects the two motor side oil ports, so that the hydraulic motor stops quickly and prevents the braking distance from being too long. 6. In the motor device of the present invention, the hydraulic motor, the balance valve and the control valve are stacked together to form a whole, which facilitates assembly and use. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the motor device of the present invention; Figure 2 This is a hydraulic schematic diagram of the motor unit; Figure 3 This is the front view of the control valve; Figure 4 This is a side view of the control valve; Figure 5 This is a rear view of the control valve; Figure 6 This is a bottom view of the control valve; Figure 7 for Figure 3 XX sectional view; Figure 8 for Figure 4 YY sectional view; Figure 9 for Figure 5 ZZ sectional view; In the diagram: 1-Balance valve; 2-Control valve; 21-Control valve body; 211-First oil port; 212-Second oil port; 213-First oil passage; 2131-Throttle plug; 214-Second oil passage; 215-Connecting oil passage; 22-Control valve core; 23-Solenoid assembly; 3-Hydraulic motor; 41-First main oil circuit; 411-First check valve; 42-Second main oil circuit; 421-Second check valve; 51-First throttling structure; 52-Second throttling structure; 61-Third check valve; 62-Fourth check valve. Detailed Implementation

[0018] 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.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] 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 have 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.

[0021] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0022] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0023] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0024] like Figure 1-9 This embodiment provides a control valve assembly for a hydraulic motor 3. The hydraulic motor 3 operates under the drive of an oil source. The control valve assembly includes a balance valve 1 and a control valve 2. The balance valve 1 has two oil ports: one for connecting to the hydraulic motor 3 and the other for connecting to an oil source. The control valve 2 controls the connection between the two oil ports on the motor side of the balance valve 1. The control valve 2 has a neutral position and a working position. When the control valve 2 is in the neutral position, the two oil ports on the motor side are not connected. The control valve 2 has at least two working positions. When the control valve 2 is in the working position, the two oil ports on the motor side are connected. When the control valve 2 is in different working positions, the opening area connecting the two oil ports on the motor side is different.

[0025] The balance valve 1 includes a balance valve body and a balance valve core. The balance valve body is provided with a motor-side oil port and an oil source-side oil port, such as... Figure 2 As shown, there are two oil ports on the motor side: motor side port A1 and motor side port B1. Motor side port A1 and motor side port B1 are connected to two oil ports of the hydraulic motor 3, respectively. There are also two oil source side ports: oil source side port A2 and oil source side port B2. Oil source side port A2 and oil source side port B2 are connected to two oil source ports, respectively. The motor side ports and oil source side ports are connected to the cavity containing the balance valve core via corresponding oil passages. The balance valve core slides within the balance valve body to control the opening and closing of the oil ports.

[0026] Specifically, such as Figure 2 As shown, oil port A1 on the motor side is connected to oil port a via an oil passage, and oil port B1 on the motor side is connected to oil port b via an oil passage. The balance valve body is also provided with a return oil chamber, which is unidirectionally connected to oil source side oil port A2 and oil source side oil port B2. The return oil chamber forms an oil port c. Oil ports a, b, and c are all connected to the cavity where the balance valve core is located. The balance valve core slides to control the opening and closing of oil ports a, b, and c.

[0027] As a preferred technical solution of this embodiment, a third check valve 61 is provided on the oil line from the return oil chamber to the oil source side port A2 to allow the oil in the return oil chamber to flow unidirectionally to the oil source side port A2; a fourth check valve 62 is provided on the oil line from the return oil chamber to the oil source side port B2 to allow the oil in the return oil chamber to flow unidirectionally to the oil source side port B2.

[0028] As a preferred technical solution in this embodiment, the balance valve core reverses under the oil pressure of the two main oil circuits, selectively receiving return oil from the hydraulic motor 3 and allowing return oil to flow through. Specifically, the oil source has two ports, namely port A and port B, one of which is a high-pressure port and the other is a low-pressure port; the hydraulic motor 3 has two ports, namely port AA and port BB, port A and port AA are connected through the first main oil circuit 41, and port B and port BB are connected through the second main oil circuit 42. When port A of the oil source is a high-pressure port and port B is a low-pressure port, oil enters through port AA of the hydraulic motor 3 and exits through port BB; conversely, when port B of the oil source is a high-pressure port and port A is a low-pressure port, oil enters through port BB of the hydraulic motor 3 and exits through port AA. The balance valve core has symmetrically arranged spring elements at both ends. The oil pressure at both ends of the balance valve core is taken from the first main oil circuit 41 and the second main oil circuit 42, respectively. Under the action of the oil pressure at both ends, the oil is reversed, so that the high-pressure oil port of the oil source supplies oil to the hydraulic motor 3 through the main oil circuit, and the oil outlet of the hydraulic motor 3 flows out through the balance valve 1 and returns to the low-pressure oil port of the oil source. Specifically, the balance valve 1 can be set as a three-position three-way valve. When the oil source does not supply oil to the hydraulic motor 3, the balance valve core is in the middle position under the action of the spring elements at both ends, and there is no connection between oil port a, oil port b, and oil port c. When oil port A of the oil source is a high-pressure oil port, oil port A supplies oil to oil port AA of the hydraulic motor 3 through the first main oil circuit 41. The oil pressure of the first main oil circuit 41 is higher than the oil pressure of the second main oil circuit 42, pushing the balance valve core to slide to the first working position. At this time, oil port b and oil port c are connected, and oil BB of the hydraulic motor 3 flows out to oil port b, and then through the balance valve core to The oil flows from port c to port B2 on the oil source side via the second check valve 62, and finally to port B of the oil source. When port B of the oil source is a high-pressure port, port B supplies oil to port BB of the hydraulic motor 3 via the second main oil circuit 42. The oil pressure of the second main oil circuit 42 is higher than that of the first main oil circuit 41, which pushes the valve core of the balance valve to slide to the second working position. At this time, port a and port c are connected, and the oil AA of the hydraulic motor 3 outputs oil to port a, which flows through the valve core of the balance valve to port c, and then through the first check valve 61 to port A2 on the oil source side, and finally to port A of the oil source.

[0029] like Figure 3-9As shown, control valve 2 is used to control the on / off connection between the two motor-side oil ports of balance valve 1, that is, control valve 2 is used to control the on / off connection between motor-side oil port A1 and motor-side oil port B1 of balance valve 1. Control valve 2 includes control valve body 21 and control valve core 22. Control valve body 21 is provided with a first oil port 211 and a second oil port 212. The first oil port 211 and the second oil port 212 are respectively connected to the two motor-side oil ports. The first oil port 211 and the second oil port 212 extend to the outer periphery of control valve core 22 through oil passages inside control valve body 21. Control valve core 22 slides to control the on / off connection between the first oil port 211 and the second oil port 212, thereby controlling the on / off connection between motor-side oil port A1 and motor-side oil port B1.

[0030] In order to achieve different opening areas between the motor side oil port A1 and the motor side oil port B1 when the control valve 2 is in different working positions, at least one of the first oil port 211 and the second oil port 212 can be connected to the outer periphery of the control valve core 22 through at least two oil passages with different flow areas, and the control valve core 22 slides to control the opening and closing of the oil passages.

[0031] As a preferred embodiment, a first oil port 211 is connected to the outer periphery of the control valve core 22 via at least two first oil passages 213, and a second oil port 212 is connected to the outer periphery of the control valve core 22 via a second oil passage 214. Each first oil passage 213 contains a throttling plug 2131, and the throttling orifice size of the throttling plug 2131 in different first oil passages 213 is different. When the control valve 2 is in different operating positions, the control valve core 22 can control the connection between different first oil passages 213 and second oil passages 214. In this embodiment, there are two first oil passages 213, and each of the two first oil passages 213 contains a throttling plug 2131, with the two throttling plugs 2131 having different throttling orifice sizes. One end of each of the two first oil passages 213 extends to the outer periphery of the control valve core 22, forming oil port d and oil port e that communicate with the cavity containing the control valve core 22; the other end of each of the two first oil passages 213 is connected to the connecting oil passage 215, which extends to the connecting first oil port 211. One end of the second oil passage 214 is connected to the second oil port 212, and the other end extends to the outer periphery of the control valve core 22, forming oil port f that communicates with the cavity containing the control valve core 22. The control valve core 22 can then slide to control the opening and closing of oil ports d, e, and f. The control valve 2 is a three-position three-way valve. When the control valve 2 is in the neutral position, oil ports d, e, and f are not connected; when the control valve 2 is in either of the two working positions, oil ports d and e are connected to oil port f.

[0032] As a preferred embodiment, the control valve 2 further includes an electromagnetic component 23. The electromagnetic component 23 is disposed at one end of the control valve core 22, and an elastic element is disposed at the other end of the control valve core 22. The electromagnetic component 23 acts on the control valve core 22 to control the position of the control valve core 22 within the control valve body 21. Specifically, the electromagnetic component 23 includes an electromagnetic coil, which can be supplied with different magnitudes of current to vary the force exerted on the control valve core 22. In this embodiment, the electromagnetic coil can be supplied with a first current and a second current, where the first current is less than the second current. When the electromagnetic coil is supplied with the first current, the force exerted by the electromagnetic component 23 on the control valve core 22 and the force exerted by the elastic element on the control valve core 22 are equal in magnitude and opposite in direction, and the control valve core 22 is in the neutral position, with no connection between oil ports d, e, and f. When no current is supplied to the electromagnetic component 23, the control valve core 22 is in the first working position under the action of the elastic element, and oil ports f and e are connected. When the electromagnetic component 23 is supplied with the second current, the force exerted by the electromagnetic component 23 on the control valve core 22 is greater than the force exerted by the elastic element on the control valve core 22, and the control valve core 22 is in the second working position, with oil ports f and d connected.

[0033] As a preferred technical solution in this embodiment, such as Figure 6 As shown, the first oil port 211 and the second oil port 212 are located on the same surface of the control valve body 21, which facilitates installation and connection.

[0034] As a preferred embodiment, the first oil port 211 is connected to the motor-side oil port A1, and the second oil port 212 is connected to the motor-side oil port B1. Alternatively, the first oil port 211 can be connected to the motor-side oil port B1, and the second oil port 212 can be connected to the motor-side oil port A1.

[0035] As a preferred embodiment, a throttling structure is provided between the first oil port 211 and / or the second oil port 212 and the corresponding connected motor-side oil port to form a series throttling structure. In this embodiment, a first throttling structure 51 is also provided between the motor-side oil port A1 and the first oil port 211, and a second throttling structure 52 is also provided between the motor-side oil port B1 and the second oil port 212. When the control valve 2 is in the working position, a series throttling structure can be realized, consisting of the first throttling structure 51, the throttling plug in the first oil passage 213, and the second throttling structure 52 connected in series. The first throttling structure 51 and the second throttling structure 52 can be, but are not limited to, throttling plugs.

[0036] like Figure 1-2As shown, this embodiment also provides a motor device, including an oil source, a hydraulic motor 3, and the aforementioned control valve group. The oil source has an oil port A and an oil port B, one of which is a high-pressure oil port and the other is a low-pressure oil port. The hydraulic motor 3 has an oil port AA and an oil port BB. Oil port A is connected to oil port AA in one direction via a first main oil circuit 41, and oil port B is connected to oil port BB in one direction via a second main oil circuit 42. High-pressure oil supplied by the oil source is supplied to the hydraulic motor 3 via the first main oil circuit 41 or the second main oil circuit 42. The two motor-side oil ports of the balance valve 1 are connected to oil ports AA and BB, respectively, and the oil source-side oil port of the balance valve 1 is connected to the oil source. Specifically, the motor-side oil port A1 of the balance valve 1 is connected to the oil port AA of the hydraulic motor 3, and the motor-side oil port B1 of the balance valve 1 is connected to the oil port BB of the hydraulic motor 3; the oil source-side oil port A2 of the balance valve 1 is connected to the oil port A of the oil source, and the oil source-side oil port B2 of the balance valve 1 is connected to the oil port B of the oil source.

[0037] As a preferred technical solution in this embodiment, in order to ensure that oil is supplied unidirectionally to oil port AA when oil port A is a high-pressure oil port, a first check valve 411 is provided on the first main oil circuit 41; in order to ensure that oil is supplied unidirectionally to oil port BB when oil port B is a high-pressure oil port, a second check valve 421 is provided on the second main oil circuit 42.

[0038] As a preferred technical solution in this embodiment, the balance valve 1 can be disposed between the hydraulic motor 3 and the control valve 2. The valve body of the balance valve is fixedly connected to the oil port end of the hydraulic motor 3. The control valve body 21 is fixed on the valve body of the balance valve. The hydraulic motor 3, the balance valve 1 and the control valve 2 can form an integral structure. The oil ports of the three can be connected through the oil passage in the valve body or the external pipeline.

[0039] As a preferred embodiment, when the hydraulic motor 3 is in a non-braking condition, the balance valve 1 switches to the working position under the oil pressure of the two main oil circuits to facilitate the return of oil from the hydraulic motor 3, while the control valve 2 is in the neutral position; when the hydraulic motor 3 is in a braking condition, the balance valve 1 switches to the neutral position, and the control valve 2 switches to the working position. The control valve 2 can switch the working position according to the speed range of the hydraulic motor 3.

[0040] Based on the above technical solution, the motor device in this embodiment can be used for the walking drive of a wheeled excavator, and its working principle is as follows: Taking oil port A as the high-pressure port and oil port B as the low-pressure port as an example.

[0041] When the hydraulic motor 3 is working normally, oil is supplied from port A to port AA of the hydraulic motor 3 via the first main oil circuit 41, and oil is discharged from port BB of the hydraulic motor 3. Since the oil pressure of the first main oil circuit 41 is higher than that of the second main oil circuit 42, the balance valve core switches to the first working position under the action of the oil pressure of the first main oil circuit 41, and port b and port c are connected. The oil discharged from port BB reaches port b, then flows through the balance valve core to port c, and then flows unidirectionally to port B2, reaching port B. During this process, the solenoid coil of the control valve 2 can be supplied with the first current. The electromagnetic component 23 and the elastic element work together to keep the control valve core 22 in the neutral position. At this time, ports d, e and f of the control valve 2 are not connected, so the two motor-side ports A1 and B1 of the balance valve 1 are not connected.

[0042] When the hydraulic motor 3 is in the first speed gear, which is a low speed gear, and the oil supply stops, the balance valve core of the balance valve 1 switches to the neutral position under the action of the springs at both ends. Ports a, b, and c are not connected, and a pressure difference exists between ports AA and BB of the hydraulic motor 3. At this time, since the hydraulic motor 3 is in the low speed gear, no current flows through the solenoid coil of the control valve 2. The control valve core 22 moves to the first working position under the action of the elastic element, connecting ports f and e. The oil at port B1 on the motor side of the balance valve 1 can then connect to port A1 on the motor side via the control valve 2, buffering the oil at ports AA and BB of the hydraulic motor 3. In this case, the opening area is the first opening area. The smaller first opening area allows for rapid stopping at low speeds, preventing excessive braking distance and ensuring smooth operation of the main unit.

[0043] When the hydraulic motor 3 is in the second speed gear, which is the high-speed gear, and the oil supply stops, the balance valve core of the balance valve 1, under the action of the springs at both ends, switches to the neutral position. Ports a, b, and c are not connected, and a pressure difference exists between ports AA and BB of the hydraulic motor 3. At this time, since the hydraulic motor 3 is in the high-speed gear, a second current is supplied to the solenoid coil of the control valve 2. This second current is greater than the first current, and the force exerted by the solenoid component 23 on the control valve core 22 is greater than the force exerted by the elastic element. The control valve core 22 moves to the second working position, connecting ports f and d. The oil at port B1 of the balance valve 1 can then connect to port A1 via the control valve 2, buffering the oil at the two ports of the hydraulic motor 3. In this case, the opening area is the second opening area, which is larger than the first opening area. The throttling effect of the second opening area is less than that of the first opening area, allowing for a slow stop at high speeds to prevent excessive impact speeds that could affect the stability of the main unit's operation.

[0044] The high-speed and low-speed gears can be distinguished by setting a speed threshold. When the speed of the hydraulic motor 3 is lower than the speed threshold, it is in low-speed gear; when the speed of the hydraulic motor 3 is higher than the speed threshold, it is in high-speed gear.

[0045] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A control valve assembly for a hydraulic motor (3), characterized in that, include: The balance valve (1) has two motor-side oil ports and two oil source-side oil ports. The two motor-side oil ports are connected to the two oil ports of the hydraulic motor (3). When the balance valve (1) is in the neutral position, the motor-side oil ports and the oil source-side oil ports are not connected. When the balance valve (1) is in the working position, it selectively receives the return oil from the hydraulic motor (3) and allows the return oil to flow through. The control valve (2) is used to control the opening and closing of the two motor side oil ports. The control valve (2) has a neutral position and at least two working positions. When the control valve (2) is in the neutral position, the two motor side oil ports are not connected. When the control valve (2) is in different working positions, the opening area between the two motor side oil ports is different. When the hydraulic motor (3) is not in braking condition, the balance valve (1) is in the working position and the control valve (2) is in the neutral position; when the hydraulic motor (3) is in braking condition, the balance valve (1) is in the neutral position and the control valve (2) is in the working position.

2. A control valve assembly according to claim 1, characterized in that, The control valve (2) includes a control valve body (21) and a control valve core (22). The control valve body (21) is provided with a first oil port (211) and a second oil port (212). The first oil port (211) and the second oil port (212) are respectively connected to two motor-side oil ports. At least one of the first oil port (211) and the second oil port (212) is connected to the outer periphery of the control valve core (22) through at least two oil passages with different flow areas.

3. A control valve assembly according to claim 2, characterized in that, The first oil port (211) is connected to the outer periphery of the control valve core (22) via at least two first oil passages (213). The first oil passage (213) has a built-in throttling plug (2131), and the throttling orifice of the throttling plug (2131) in different first oil passages (213) is different. The second oil port (212) is connected to the outer periphery of the control valve core (22) via a second oil passage (214). The control valve core (22) controls the opening and closing between the first oil passage (213) and the second oil passage (214).

4. A control valve assembly according to claim 3, characterized in that, There are two first oil passages (213). When the control valve (2) is in the neutral position, the two first oil passages (213) are not connected to the second oil passage (214). When the control valve (2) is in two working positions, it controls the two first oil passages (213) to be connected to the second oil passage (214) respectively.

5. A control valve assembly according to claim 3, characterized in that, The control valve (2) also includes an electromagnetic component (23), which drives the control valve core (22) to switch positions.

6. A control valve assembly according to any one of claims 2-5, characterized in that, A throttling structure is provided between the first oil port (211) and / or the second oil port (212) and the corresponding motor-side oil port.

7. A motor device, characterized in that, include: The oil source has an oil port A and an oil port B, one of which is a high-pressure oil port and the other is a low-pressure oil port; The hydraulic motor (3) has an oil port AA and an oil port BB. The oil port A is connected to the oil port AA in one direction through the first main oil circuit (41), and the oil port B is connected to the oil port BB in one direction through the second main oil circuit (42). The high-pressure oil supplied by the oil source is supplied to the hydraulic motor (3) through the first main oil circuit (41) or the second main oil circuit (42). According to any one of claims 1-6, the two motor-side oil ports of the balance valve (1) are respectively connected to oil port AA and oil port BB, and the oil source-side oil port of the balance valve (1) is connected to an oil source.

8. A motor device according to claim 7, characterized in that, The balance valve (1) has two oil source side ports, which are connected to oil port A and oil port B respectively. The return oil from the hydraulic motor (3) reaches the return oil chamber under the control of the valve core of the balance valve (1). The return oil chamber is connected to oil port A and oil port B in one direction.

9. A motor device according to claim 7, characterized in that, The balance valve (1) is located between the hydraulic motor (3) and the control valve (2). The valve body of the balance valve is fixedly connected to the oil port of the hydraulic motor (3). The control valve body (21) is fixed on the valve body of the balance valve.

10. A motor device according to claim 7, characterized in that, When the hydraulic motor (3) is in braking condition, the control valve (2) switches the working position according to the speed range of the hydraulic motor (3).

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