阅读说明：本技术 平衡阀结构及工程机械 (Balance valve structure and engineering machinery ) 是由 张昆 马宁 李胜虎 于 2021-08-30 设计创作，主要内容包括：本发明提供了一种平衡阀结构及工程机械,其中,平衡阀结构包括阀体以及设置在阀体内的第一流道、第二流道、第一连通通道、第二连通通道、第三连通通道、阀芯、第一单向流通结构、第二单向流通结构、第三单向流通结构以及第四单向流通结构。本发明的平衡阀结构在轮式挖掘机处于平地行驶过程中正常进行进油和回油,在轮式挖掘机处于下坡状态时使回油进入进油油路作为补油,从而使得平衡阀结构具有补油效果,防止出现损坏液压马达,以及出现超速的情况。因此本发明的技术方案解决了现有技术中的轮式挖掘机在下坡时因液压马达供油不足,导致容易损坏液压马达,并引起超速现象,造成安全事故的缺陷。(The invention provides a balance valve structure and engineering machinery, wherein the balance valve structure comprises a valve body, a first flow passage, a second flow passage, a first communicating passage, a second communicating passage, a third communicating passage, a valve core, a first one-way circulation structure, a second one-way circulation structure, a third one-way circulation structure and a fourth one-way circulation structure, wherein the first flow passage, the second flow passage, the first communicating passage, the second communicating passage, the third communicating passage, the valve core, the first one-way circulation structure, the second one-way circulation structure, the third one-way circulation structure and the fourth one-way circulation structure are arranged in the valve body. The balance valve structure of the invention normally carries out oil inlet and oil return when the wheel type excavator is in a flat ground running process, and the oil return enters the oil inlet oil way to be used as oil supplement when the wheel type excavator is in a downhill state, so that the balance valve structure has an oil supplement effect, and the hydraulic motor is prevented from being damaged and the condition of overspeed is prevented. Therefore, the technical scheme of the invention solves the defects that the wheel type excavator in the prior art is easy to damage the hydraulic motor and causes overspeed phenomenon and safety accidents due to insufficient oil supply of the hydraulic motor when going downhill.)

1. A balanced valve structure, characterized by comprising

The hydraulic control valve comprises a valve body (10), wherein a first oil port (11), a second oil port (12), a third oil port (13) and a fourth oil port (14) are formed in the valve body (10), the first oil port (11) and the second oil port (12) are suitable for being communicated with an external oil source, and the third oil port (13) and the fourth oil port (14) are suitable for being communicated with a hydraulic motor;

the valve body (10) is provided with a first flow passage (20), the first flow passage (20) comprises a first section (21), a second section (22) and a communication section (23) connected between the first section (21) and the second section (22), the first oil port (11) and the fourth oil port (14) are both communicated with the first section (21), the connection positions of the first oil port (11) and the fourth oil port (14) and the first section (21) are arranged along the axial direction of the first flow passage (20) in a staggered manner, the second oil port (12) and the third oil port (13) are both communicated with the second section (22), and the connection positions of the second oil port (12) and the third oil port (13) and the second section (22) are arranged along the axial direction of the first flow passage (20) in a staggered manner;

a second flow passage (30) provided in the valve body (10) and spaced apart from the first flow passage (20);

a first communication channel (40), a second communication channel (50) and a third communication channel (60) which are all arranged in the valve body (10), wherein a first end of the first communication channel (40) is communicated with the first section (21) and corresponds to the position of the fourth oil port (14), a first end of the second communication channel (50) is communicated with the second section (22) and corresponds to the position of the third oil port (13), a first end of the third communication channel (60) is communicated with the communication section (23), and a second end of the first communication channel (40), a second end of the second communication channel (50) and a second end of the third communication channel (60) are all communicated with the second flow passage (30);

a valve spool (70) movably disposed in the second flow passage (30), the valve spool (70) having a first speed position in which the first communication passage (40), the second communication passage (50), and the third communication passage (60) are all blocked, and a second speed position in which the second communication passage (50) is selectively communicated with the first communication passage (40) or the third communication passage (60);

a first one-way flow structure (100) and a second one-way flow structure (200) both arranged in the first section (21), the first one-way flow structure (100) being adapted to enable one-way flow of hydraulic oil from the communication section (23) to the first oil port (11), the second one-way flow structure (200) being adapted to enable one-way flow of hydraulic oil from the first oil port (11) to the fourth oil port (14) and the first communication channel (40);

third one-way circulation structure (300) and fourth one-way circulation structure (400), all set up in second section (22), third one-way circulation structure (300) are suitable for make hydraulic oil by intercommunication section (23) extremely the one-way circulation of second hydraulic fluid port (12), fourth one-way circulation structure (400) are suitable for the messenger hydraulic oil by second hydraulic fluid port (12) extremely third hydraulic fluid port (13) with second intercommunication passageway (50) one-way circulation.

2. The balanced valve arrangement according to claim 1, characterized in that the first unidirectional flow-through arrangement (100) comprises:

a first one-way valve body (101) disposed within the first segment (21);

a first check valve spool (102), wherein one end of the first check valve spool (102) is movably arranged in the first check valve body (101), and the other end of the first check valve spool (102) is abutted with the joint of the first section (21) and the communication section (23);

and a first elastic structure (103) that is provided between the first check valve body (101) and the first check valve spool (102) and that applies an elastic force to the first check valve spool (102) toward the communication section (23).

3. The balanced valve arrangement according to claim 2, characterized in that the second unidirectional flow-through arrangement (200) comprises:

the second check valve body (201) is fixedly arranged in the first section (21), a first communicating notch (2011) is formed in the side wall of the second check valve body (201), and the first communicating notch (2011) is arranged corresponding to the fourth oil port (14) and the first end of the first communicating channel (40) so that the fourth oil port (14) and the first end of the first communicating channel (40) can be communicated through the first communicating notch (2011);

the second check valve core (202) is movably arranged in the second check valve body (201), a second elastic structure (203) is arranged between the first end of the second check valve core (202) and the bottom wall of the second check valve body (201), and the second end of the second check valve core (202) is suitable for being abutted against the edge, facing the communication section (23), of the first communication notch (2011).

4. The balanced valve structure of claim 3, characterized in that a first accommodation recess (2021) is provided on an end surface of the second check valve spool (202) facing the communication section (23), the first check valve body (101) being disposed within the first accommodation recess (2021).

5. The balanced valve arrangement according to claim 1, characterized in that the third one-way flow arrangement (300) comprises:

a third one-way valve body (301) disposed within the second section (22);

a third check valve spool (302), wherein one end of the third check valve spool (302) is movably arranged in the third check valve body (301), and the other end of the third check valve spool (302) is abutted with the joint of the second section (22) and the communication section (23);

and a third elastic structure (303) that is provided between the third check valve body (301) and the third check valve spool (302), and that applies an elastic force to the third check valve spool (302) toward the communication section (23).

6. The balanced valve arrangement according to claim 5, characterized in that the fourth one-way flow arrangement (400) comprises:

the fourth check valve body (401) is fixedly arranged in the second section (22), a second communication notch (4011) is formed in the side wall of the fourth check valve body (401), and the second communication notch (4011) is arranged corresponding to the third oil port (13) and the first end of the second communication channel (50), so that the third oil port (13) and the first end of the second communication channel (50) can be communicated through the second communication notch (4011);

the fourth check valve core (402) is movably arranged in the fourth check valve body (401), a fourth elastic structure (403) is arranged between the first end of the fourth check valve core (402) and the bottom wall of the fourth check valve body (401), and the second end of the fourth check valve core (402) is suitable for being abutted to the edge, facing the communication section (23), of the second communication notch (4011).

7. The balanced valve structure according to claim 6, characterized in that a second accommodation recess (4021) is provided on an end surface of the fourth check valve spool (402) facing the communication section (23), and the third check valve body (301) is disposed in the second accommodation recess (4021).

8. The balanced valve structure according to claim 1, characterized in that an oil groove (71) is provided in the spool (70), the oil groove (71) is misaligned with both the first communicating passage (40) and the second communicating passage (50) when the spool (70) is in the first gear, the oil groove (71) is communicated with the first communicating passage (40) and the third communicating passage (60) or the oil groove (71) is communicated with the second communicating passage (50) and the third communicating passage (60) when the spool (70) is in the second gear.

9. The balance valve structure according to claim 1, wherein an oil replenishment hole (15) is provided in the valve body (10), the oil replenishment hole (15) communicating with the third communication passage (60).

10. A working machine, characterized by comprising a balanced valve arrangement according to any of claims 1-9.

Technical Field

The invention relates to the technical field of hydraulic elements, in particular to a balance valve structure and engineering machinery.

Background

At present, excavators can be classified into crawler excavators and wheel excavators according to the difference of the traveling modes. The wheel type excavator has the characteristics of high walking speed, no damage to the road surface, capability of realizing long-distance self-transition and quick replacement of various operation devices. Although wheel excavators do not work as efficiently as a grade of track excavator, frequent turnaround makes wheel excavation more economically advantageous than the expensive transfer costs of track excavators. The wheel type excavator has the advantages of flexibility, high efficiency and bright characteristics, and is widely applied to material excavating and moving scenes such as municipal maintenance engineering, road traffic construction, rapid first-aid repair and the like.

The walking speed and the safety and the comfort are improved, the multipurpose is realized to be an important development direction of the wheel type excavator, and along with the development of technologies such as hydraulic pressure high-pressure technology, hydraulic elements and the like, the walking speed of the wheel type excavator is increased by a new height so as to improve the mobility of the wheel excavator. However, when the wheel excavator travels at a high speed and descends, the traveling motor is in a working state that the motor is changed into the pump due to the self weight and inertia of the wheel excavator, and the motor is sucked to be empty, so that the motor valve plate is corroded by air, and the motor is easily damaged. In addition, the wheel excavator is not mechanically braked and is mainly hydraulically braked by a hydraulic motor, so that the motor is overspeed (namely stalled) due to insufficient oil supply in the above state, and the wheel excavator is easy to cause accidents due to the out-of-control danger once the speed is too high.

Disclosure of Invention

Therefore, the technical problem to be solved by the present invention is to overcome the defects that the hydraulic motor is not supplied with oil enough when the wheel excavator in the prior art is going downhill, the hydraulic motor is easily damaged, and an overspeed phenomenon is caused, which causes a safety accident, thereby providing a balance valve structure and an engineering machine.

In order to solve the above problems, the present invention provides a balanced valve structure, which includes a valve body, wherein the valve body is provided with a first oil port, a second oil port, a third oil port and a fourth oil port, the first oil port and the second oil port are suitable for being communicated with an external oil source, and the third oil port and the fourth oil port are suitable for being communicated with a hydraulic motor; the first flow passage is arranged in the valve body and comprises a first section, a second section and a communication section connected between the first section and the second section, the first oil port and the fourth oil port are communicated with the first section, the connection positions of the first oil port and the fourth oil port with the first section are arranged in a staggered mode along the axial direction of the first flow passage, the second oil port and the third oil port are communicated with the second section, and the connection positions of the second oil port and the third oil port with the second section are arranged in a staggered mode along the axial direction of the first flow passage; the second flow passage is arranged in the valve body and is arranged at an interval with the first flow passage; the first communicating channel, the second communicating channel and the third communicating channel are all arranged in the valve body, the first end of the first communicating channel is communicated with the first section and corresponds to the position of the fourth oil port, the first end of the second communicating channel is communicated with the second section and corresponds to the position of the third oil port, the first end of the third communicating channel is communicated with the communicating section, and the second end of the first communicating channel, the second end of the second communicating channel and the second end of the third communicating channel are all communicated with the second flow channel; a spool movably disposed in the second flow passage, the spool having a first gear position that disconnects the first, second, and third communication passages, and a second gear position that selectively communicates the second communication passage with the first or third communication passage; the first one-way circulation structure and the second one-way circulation structure are arranged in the first section, the first one-way circulation structure is suitable for enabling hydraulic oil to flow in a one-way mode from the communication section to the first oil port, and the second one-way circulation structure is suitable for enabling hydraulic oil to flow in a one-way mode from the first oil port to the fourth oil port and the first communication channel; the third one-way circulation structure and the fourth one-way circulation structure are arranged in the second section, the third one-way circulation structure is suitable for enabling hydraulic oil to flow in a one-way mode from the communication section to the second oil port, and the fourth one-way circulation structure is suitable for enabling hydraulic oil to flow in a one-way mode from the second oil port to the third oil port and the second communication channel.

Optionally, the first unidirectional flow structure comprises: a first check valve body disposed within the first section; one end of the first check valve core is movably arranged in the first check valve body, and the other end of the first check valve core is abutted with the joint of the first section and the communication section; and a first elastic structure disposed between the first check valve body and the first check valve spool and applying an elastic force toward the communication section to the first check valve spool.

Optionally, the second unidirectional flow structure comprises: the second one-way valve body is fixedly arranged in the first section, a first communicating notch is formed in the side wall of the second one-way valve body, and the first communicating notch, the fourth oil port and the first end of the first communicating channel are correspondingly arranged so that the fourth oil port and the first end of the first communicating channel can be communicated through the first communicating notch; the second check valve core is movably arranged in the second check valve body, a second elastic structure is arranged between the first end of the second check valve core and the bottom wall of the second check valve body, and the second end of the second check valve core is suitable for being abutted against the edge of the orientation communication section of the first communication gap.

Optionally, a first accommodating recess is provided on an end surface of the second check valve spool facing the communication section, and the first check valve body is disposed in the first accommodating recess.

Optionally, the third one-way flow structure comprises: the third one-way valve body is arranged in the second section; one end of the third check valve core is movably arranged in the third check valve body, and the other end of the third check valve core is abutted with the joint of the second section and the communication section; and a third elastic structure disposed between the third check valve body and the third check valve spool and applying an elastic force toward the communication section to the third check valve spool.

Optionally, the fourth one-way flow structure comprises: the fourth one-way valve body is fixedly arranged in the second section, a second communication notch is formed in the side wall of the fourth one-way valve body, and the second communication notch is arranged corresponding to the third oil port and the first end of the second communication channel so that the third oil port and the first end of the second communication channel can be communicated through the second communication notch; and the fourth check valve core is movably arranged in the fourth check valve body, a fourth elastic structure is arranged between the first end of the fourth check valve core and the bottom wall of the fourth check valve body, and the second end of the fourth check valve core is suitable for abutting against the edge of the orientation communication section of the second communication gap.

Optionally, a second accommodating recess is provided on an end surface of the fourth check valve spool facing the communication section, and the third check valve body is disposed in the second accommodating recess.

Optionally, an oil groove is formed in the valve element, when the valve element is in the first gear, the oil groove is staggered with the first communicating channel and the second communicating channel, and when the valve element is in the second gear, the oil groove is communicated with the first communicating channel and the third communicating channel, or the oil groove is communicated with the second communicating channel and the third communicating channel.

The invention also provides a hydraulic motor which comprises the balance valve structure.

The invention also provides engineering machinery comprising the hydraulic motor or the balance valve structure.

The invention has the following advantages:

the oil inlet of the first oil port and the oil return of the second oil port are taken as examples:

when the wheel excavator normally travels, the hydraulic oil of outside oil source enters into first section through first hydraulic fluid port, because first one-way circulation structure makes hydraulic oil from the one-way circulation of intercommunication section to first hydraulic fluid port, consequently hydraulic oil makes first one-way circulation structure close, because the one-way circulation structure of second makes hydraulic oil from first hydraulic fluid port to fourth hydraulic fluid port and the one-way circulation of first intercommunication passageway, consequently the one-way circulation structure of second is opened, hydraulic oil partly enters into to hydraulic motor from the fourth hydraulic fluid port, another part flows into in the first intercommunication passageway. The hydraulic oil pushes the valve core in the first communicating channel, the valve core moves from the first gear to the second gear, the balance valve is opened at the moment, and the opening degree of the balance valve controls the walking speed of the wheel type excavator. The return oil of the hydraulic motor enters the second section from the third oil port, and the fourth one-way circulation structure enables the hydraulic oil to flow in a one-way mode from the second oil port to the third oil port, and the valve core is located at the second gear, so that the return oil enters the communication section through the second communication channel and the third communication channel. Because the third one-way circulation structure enables the hydraulic oil to flow from the communication section to the second oil port in a one-way mode, the oil return pressure enables the third one-way circulation structure to be opened, and oil return is discharged from the second oil port into an oil tank of an external oil source.

When the wheel type excavator runs on a downhill in the driving process, due to the gravity and inertia effect of the wheel type excavator, the hydraulic motor generates a state that the motor is changed into a pump, and the oil return pressure in the hydraulic system is larger than the oil inlet pressure. The pressure at the second oil port is higher due to the above condition, so that the third one-way circulation structure is closed, the pressure in the communication section is larger than the pressure in the first section, and the first one-way circulation structure is opened. At the moment, the return oil of the hydraulic motor enters from the fourth oil port, passes through the second communicating channel, the third communicating channel and the communicating section and then enters the first section, and therefore oil supplement is conducted on the oil inlet.

When the wheel type excavator changes from a downhill state to a flat ground running state, the oil return pressure is reduced and is smaller than the oil inlet pressure, the first one-way circulation structure is closed at the moment, and the third one-way circulation structure is opened, so that the oil return can be discharged into an oil tank of an external oil source through the second oil port.

According to the process, the oil inlet and the oil return are normally carried out in the process that the wheel type excavator runs on the flat ground, and the oil return enters the oil inlet oil way to be used as oil supplement when the wheel type excavator is in a downhill state, so that the balance valve structure has an oil supplement effect, and the hydraulic motor is prevented from being damaged and the condition of overspeed is prevented. Therefore, the technical scheme of the invention solves the defects that the wheel type excavator in the prior art is easy to damage the hydraulic motor and causes overspeed phenomenon and safety accidents due to insufficient oil supply of the hydraulic motor when going downhill.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a diametrically opposed view of a cross-section of a valve body of the balanced valve structure of the present invention;

FIG. 2 is a schematic diagram of another opposite view of a cross-section of the valve body of the balanced valve structure of the present invention;

FIG. 3 shows a side schematic view of the balanced valve structure of the present invention;

FIG. 4 shows a schematic cross-sectional view of the balanced valve structure of the present invention;

FIG. 5 shows an enlarged schematic view at A in FIG. 4;

FIG. 6 shows an enlarged schematic view at B in FIG. 4;

fig. 7 shows a schematic front view of a valve body of the balanced valve structure of the present invention.

Description of reference numerals:

10. a valve body; 11. a first oil port; 12. a second oil port; 13. a third oil port; 14. a fourth oil port; 15. an oil supplementing port; 20. a first flow passage; 21. a first stage; 22. a second stage; 23. a communicating section; 30. a second flow passage; 40. a first communicating passage; 50. a second communicating passage; 60. a third communicating passage; 70. a valve core; 71. an oil sump; 100. a first one-way flow structure; 101. a first check valve body; 102. a first check valve spool; 103. a first elastic structure; 200. a second one-way flow structure; 201. a second check valve body; 2011. a first communication gap; 202. a second check valve spool; 2021. a first accommodation recess; 203. a second elastic structure; 300. a third one-way flow structure; 301. a third check valve body; 302. a third check valve spool; 303. a third elastic structure; 400. a fourth one-way flow structure; 401. a fourth check valve body; 4011. a second communication gap; 402. a fourth check valve spool; 4021. a second accommodation recess; 403. and a fourth elastic structure.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 1 and 2 and fig. 4, the balance valve structure of the present embodiment includes a valve body 10, a first flow passage 20, a second flow passage 30, a first communication passage 40, a second communication passage 50, a third communication passage 60, a valve spool 70, a first one-way flow structure 100, a second one-way flow structure 200, a third one-way flow structure 300, and a fourth one-way flow structure 400. The above-described structure will first be described in detail below.

As shown in fig. 1 and 2, the valve body 10 is provided with a first oil port 11, a second oil port 12, a third oil port 13 and a fourth oil port 14, the first oil port 11 and the second oil port 12 are suitable for being communicated with an external oil source, and the third oil port 13 and the fourth oil port 14 are suitable for being communicated with a hydraulic motor. Specifically, the valve body 10 in the present embodiment is formed by joining two split structures from the left and right. In practice, fig. 1 shows an inside surface elevation of one of the separate structures, and fig. 2 shows an inside surface elevation of the other of the separate structures. As can be seen from fig. 1 and 2, the first and second oil ports 11 and 12 are provided on one of the split structures and are passage structures, and the third and fourth oil ports 13 and 14 are provided on the other split structure and are passage structures. Of course, the valve body 10 may be integrally cast, and not be a separate structure.

The first oil port 11 and the second oil port 12 are adapted to be communicated with an external oil source, that is, one of the first oil port 11 and the second oil port 12 is used as an oil inlet, and the other is used as an oil return port. The third oil port 13 and the fourth oil port 14 are adapted to communicate with a hydraulic motor, that is, one of the third oil port 13 and the fourth oil port 14 allows hydraulic oil to enter the hydraulic motor from the valve body 10, and the other allows oil return of the hydraulic motor to enter the valve body 10.

As shown in fig. 1 and 2, a first flow passage 20 is provided in the valve body 10, the first flow passage 20 including a first section 21, a second section 22, and a communication section 23 connected between the first section 21 and the second section 22. The first oil port 11 and the fourth oil port 14 are both communicated with the first section 21, and the connection positions of the first oil port 11 and the fourth oil port 14 with the first section 21 are arranged along the axial direction of the first flow passage 20 in a staggered manner. The second oil port 12 and the third oil port 13 are both communicated with the second section 22, and the connection position of the second oil port 12, the third oil port 13 and the second section 22 is arranged along the axial direction of the first flow passage 20 in a staggered manner. Specifically, the first flow passage 20 is a straight flow passage, the communicating section 23 is located between the first section 21 and the second section 22, and the diameters of the first section 21 and the second section 22 (since the first section 21 and the second section 22 are stepped channels, the diameters of the first section 21 and the second section 22 refer to the respective diameters of both) are larger than the diameter of the communicating section 23. As can be seen from fig. 1 and 2, the first flow passage 20 is actually an axisymmetric structure along the center line of the valve body 10. As described above, the first port 11, the second port 12, the third port 13, and the fourth port 14 are all channel structures, so that the connection between the first port 11 and the first section 21 and the connection between the fourth port 14 and the first section 21 refer to the connection between the two channels and the first section 21, and the connection between the second port 12 and the third port 13 and the second section 22 refer to the connection between the two channels and the second section 22.

As shown in fig. 1 and 2, when the two split structures are spliced to form the valve body 10, a connection point of the fourth oil port 14 and the first section 21 is located at an outer side of a connection point of the first oil port 11 and the first section 21, and a connection point of the third oil port 13 and the second section 22 is located at an outer side of a connection point of the second oil port 12 and the second section 22. In fact, the four connections are arranged in a manner that is axially symmetrical with respect to the center axis of the valve body 10.

As shown in fig. 1 to 3, the second flow passage 30 is provided in the valve body 10 and spaced apart from the first flow passage 20. Specifically, the second flow channel 30 is disposed in parallel with the first flow channel 20, and the second flow channel 30 is located below the first flow channel 20. The second flow passage 30 is used to mount a valve element 70, and the specific structure of the valve element 70 will be described below.

As shown in fig. 1 and 2, in the solution of the present embodiment, the first communication passage 40, the second communication passage 50, and the third communication passage 60 are all provided in the valve body 10. The first end of the first communication passage 40 communicates with the first section 21 and corresponds in position to the fourth port 14. The first end of the second communication passage 50 communicates with the second section 22 and corresponds in position to the third port 13, and the first end of the third communication passage 60 communicates with the communication section 23. The second end of the first communication passage 40, the second end of the second communication passage 50, and the second end of the third communication passage 60 are all in communication with the second flow passage 30. Specifically, the first, second, and third communication passages 40, 50, and 60 serve to communicate the spaces within the first and second flow passages 20 and 30. As can be seen from fig. 2, the upper end of the first communication passage 40 communicates with the first section 21, and the upper end of the first communication passage 40 is at the same position as the fourth port 14 in the axial direction of the first flow passage 20 (or both have an overlapping portion), and the lower end of the first communication passage 40 communicates with the second flow passage 30. The upper end of the second communication passage 50 communicates with the second segment 22, and the upper end of the second communication passage 50 is at the same position as the third oil port 13 in the axial direction of the first flow passage 20 (or both have an overlapping portion), and the lower end of the second communication passage 50 communicates with the second flow passage 30. The upper end of the third communicating channel 60 communicates with the communicating section 23, and the lower end of the third communicating channel 60 communicates with the second flow passage 30.

As shown in fig. 4, the valve spool 70 is movably disposed in the second flow passage 30, and the valve spool 70 has a first gear position in which the first, second, and third communication passages 40, 50, and 60 are all interrupted, and a second gear position in which the second communication passage 50 is selectively communicated with the first or third communication passage 40 or 60. Specifically, the spool 70 is disposed movably in the second flow passage 30 in the axial direction thereof. The valve core 70 is provided with an oil groove 71, when the valve core 70 is in the first gear (i.e. the middle position in fig. 4), the oil groove 71 corresponds to the third communication channel 60, and the oil groove 71 is dislocated with the first communication channel 40 and the second communication channel 50, at this time, the first communication channel 40, the second communication channel 50 and the third communication channel 60 are separated. Since one of the first and second oil ports 11 and 12 takes oil and the other returns oil, the spool 70 has two second gear positions. Specifically, when the first oil port 11 is filled with oil, the spool 70 is pushed to the right position, at which time the oil groove 71 communicates with and communicates the second communication passage 50 and the third communication passage 60. When the second port 12 is filled with oil, the valve spool 70 is pushed to the left position, and at this time, the oil groove 71 communicates with and communicates the first communication passage 40 and the third communication passage 60.

Further, the two ends of the valve core 70 are limited by plugs, and meanwhile, a spring is arranged between the right end of the valve core 70 and the plugs, and the spring can enable the valve core 70 to reset to the first gear from the second gear.

As shown in fig. 4 and 5, the first one-way flow structure 100 and the second one-way flow structure 200 are both disposed within the first section 21. Further, the first one-way flow structure 100 is adapted to enable one-way flow of the hydraulic oil from the communication section 23 to the first oil port 11, and the second one-way flow structure 200 is adapted to enable one-way flow of the hydraulic oil from the first oil port 11 to the fourth oil port 14 and the first communication passage 40.

As shown in fig. 4 and 6, the third one-way flow structure 300 and the fourth one-way flow structure 400 are disposed in the second section 22, the third one-way flow structure 300 is adapted to enable one-way flow of the hydraulic oil from the communication section 23 to the second oil port 12, and the fourth one-way flow structure 400 is adapted to enable one-way flow of the hydraulic oil from the second oil port 12 to the third oil port 13 and the second communication passage 50.

According to the above structure, the operation of the balanced valve structure of the present embodiment is described below, and the first oil port 11 feeds oil, and the second oil port 12 feeds oil as an example.

When the wheel excavator normally travels, hydraulic oil of an external oil source enters the first section 21 through the first oil port 11, the first one-way circulation structure 100 enables the hydraulic oil to flow in one way from the communication section 23 to the first oil port 11, so the first one-way circulation structure 100 is closed by the hydraulic oil, the second one-way circulation structure 200 enables the hydraulic oil to flow in one way from the first oil port 11 to the fourth oil port 14 and the first communication channel 40, so the second one-way circulation structure 200 is opened, one part of the hydraulic oil enters the hydraulic motor from the fourth oil port 14, and the other part of the hydraulic oil flows into the first communication channel 40. The hydraulic oil pushes the valve core 70 in the first communication passage 40, and moves the valve core 70 from the first gear to the second gear (i.e., the right gear in fig. 4), at which time the balance valve is opened, and the opening degree of the balance valve controls the traveling speed of the wheel excavator. The return oil of the hydraulic motor enters the second section 22 from the third oil port 13, and because the fourth one-way flow structure 400 makes the hydraulic oil flow in one direction from the second oil port 12 to the third oil port 13, and the spool 70 is in the second gear position, the return oil enters the communication section 23 through the second communication passage 50 and the third communication passage 60. Since the third one-way flow structure 300 makes the hydraulic oil flow from the communication section 23 to the second oil port 12 in one way, the oil return pressure makes the third one-way flow structure 300 opened, and the oil return is discharged from the second oil port 12 into the oil tank of the external oil source.

When the wheel type excavator runs on a downhill in the driving process, due to the gravity and inertia effect of the wheel type excavator, the hydraulic motor generates a state that the motor is changed into a pump, and the oil return pressure in the hydraulic system is larger than the oil inlet pressure. This causes the pressure at the second port 12 to become high, so that the third one-way flow structure 300 is closed, and the pressure in the communication section 23 is greater than the pressure in the first section 21, so that the first one-way flow structure 100 is opened. At this time, the return oil of the hydraulic motor enters from the fourth oil port 14, passes through the second communication channel 50, the third communication channel 60 and the communication section, and then enters the first section 21, so that the oil is replenished to the oil inlet.

When the wheel excavator changes from the downhill state to the flat traveling state, the oil return pressure is reduced and is less than the oil inlet pressure, at this time, the first one-way flow structure 100 is closed, and the third one-way flow structure 300 is opened, so that the oil return can be discharged into the oil tank of the external oil source through the second oil port 12.

According to the process, the oil inlet and the oil return are normally carried out when the wheel type excavator runs on a flat ground, and the oil return enters the oil inlet oil way to be used as oil supplement when the wheel type excavator is in a downhill state, so that the balance valve structure has an oil supplement effect, and the hydraulic motor is prevented from being damaged and the condition of overspeed is prevented. Therefore, the technical scheme of the embodiment solves the defects that the hydraulic motor is easy to damage, the overspeed phenomenon is caused and safety accidents are caused due to insufficient oil supply of the hydraulic motor when the wheel type excavator in the prior art goes downhill.

Of course, as will be understood by those skilled in the art, when the second oil port 12 is filled with oil and the first oil port 11 is filled with oil, the operation process of the balanced valve structure is repeated in a left-right position. In fact, the first port 11 feeding oil and the second port 12 feeding oil control the forward rotation and the reverse rotation of the hydraulic motor, respectively.

The specific structures of the first, second, third, and fourth one-way flow structures 100, 200, 300, and 400 will be described in detail below.

As shown in fig. 4 and 5, in the solution of the present embodiment, the first one-way flow structure is a 100-position one-way valve. The first one-way flow structure 100 includes a first one-way valve body 101, a first one-way valve spool 102, and a first elastic structure 103. Wherein the first check valve body 101 is disposed within the first segment 21. One end of the first check valve spool 102 is movably disposed in the first check valve body 101, and the other end of the first check valve spool 102 abuts against a connection between the first segment 21 and the communication segment 23. The first elastic structure 103 is disposed between the first check valve body 101 and the first check valve spool 102, and applies an elastic force to the first check valve spool 102 toward the communication section 23. Specifically, a stepped surface is formed between the first section 21 and the communicating section 23, and a plug is provided at an end of the first check valve spool 102 and is plugged on the stepped surface. Therefore, when oil is fed from the first port 11, the pressure of the fed oil pushes the first check valve spool 102 against the step surface and closes the first one-way flow structure 100. When the wheel excavator runs to a downhill, as can be seen from the above, the right side pressure of the end plug of the first check valve core 102 in fig. 5 is greater than the left side pressure, and at this time, the first check valve core 102 is opened, so that the return oil can enter the oil inlet path through the first check valve core 102.

Preferably, the first check valve body 101 is a sleeve structure, the left end of the first check valve core 102 is inserted into the first check valve body 101, the first elastic structure 103 is a spring, the spring is disposed in the first check valve body 101, and one end of the spring abuts against the bottom wall of the first check valve body 101, and the other end abuts against the left end of the first check valve core 102.

As shown in fig. 4 and 5, in the solution of the present embodiment, the second one-way flow structure 200 includes a second one-way valve body 201 and a second one-way valve spool 202. The second check valve body 201 is fixedly arranged in the first section 21, a first communicating notch 2011 is formed in the side wall of the second check valve body 201, and the first communicating notch 2011 is correspondingly arranged with the first ends of the fourth oil port 14 and the first communicating channel 40, so that the first ends of the fourth oil port 14 and the first communicating channel 40 can be communicated through the first communicating notch 2011. The second check valve spool 202 is movably disposed in the second check valve body 201, and a second elastic structure 203 is disposed between a first end of the second check valve spool 202 and a bottom wall of the second check valve body 201. The second end of the second one-way valve spool 202 is adapted to abut with a rim of the first communication notch 2011 facing the communication section 23. Specifically, the second check valve body 201 is also of a sleeve structure, and an end (i.e., a left end in fig. 5) of the second check valve body 201 facing away from the communication section 23 blocks an end opening of the first section 21. A first communicating notch 2011 is formed in the side wall of the second check valve body 201, the first communicating notch 2011 is multiple and is arranged at intervals along the circumferential direction, and the multiple first communicating notches 2011 enable hydraulic oil to flow into the fourth oil port 14 or the first communicating channel 40 after passing through the side wall of the second check valve body 201.

As can be seen from fig. 5, a plug is disposed at the right end of the second check valve element 202, an inclined surface is disposed at the side of the plug, the outer diameter of the inclined surface is greater than the inner diameter of the second check valve body 201, and the inclined surface is clamped at the first communication notch 2011. The above-described structure enables the second check valve spool 202 to move linearly only over the axial length of the first communication notch 2011. The second elastic structure 203 is a spring, and the left end of the spring abuts against the bottom wall of the second check valve body 201, and the right end abuts against the second check valve spool 202. The elastic force of the spring causes the plug of the second check valve spool 202 to abut against the end (i.e., the right end in fig. 5) of the first communication notch 2011 facing the communication section 23.

When the first oil port 11 is filled with oil, the filling pressure pushes the second check valve core 202, and then a part of the hydraulic oil enters the hydraulic motor through the fourth oil port 14 and another part of the hydraulic oil enters the second flow passage 30 through the first communication passage 40 through the first communication notch 2011. When the first oil port 11 is used as an oil return port, hydraulic oil in the hydraulic motor firstly enters the second check valve core 202 through the fourth oil port 14 and the first communication notch 2011, and the oil return pressure closes the second check valve core 202 and tightly pushes the right end of the first communication notch 2011. At this time, the return oil cannot directly flow to the first oil port 11, and referring to fig. 4, the return oil passes downward through the first communication passage 40, the oil groove 71 and the third communication passage 60 and then enters the communication section 23, and the first check valve spool 102 is pushed open at the communication section 23, so that the return oil returns through the first oil port 11.

As shown in fig. 5, in the solution of the present embodiment, a first accommodating recess 2021 is provided on an end surface of the second check valve spool 202 facing the communicating section 23, and the first check valve body 101 is disposed in the first accommodating recess 2021. Specifically, the first check valve body 101 is disposed in the second check valve spool 202, so that the first and second one-way flow structures 100 and 200 are integrated into a two-stage check valve structure, thereby making the two structures simple and convenient to install. Through adjusting the elastic force of first elastic construction 103 and second elastic construction 203, can make two check valves work independently, the one-way circulation effect does not influence each other.

As shown in fig. 4 and 6, the third one-way flow structure 300 and the fourth one-way flow structure 400 are both one-way valves. The third one-way flow structure 300 includes a third one-way valve body 301, a third one-way valve spool 302, and a third resilient structure 303. Wherein the third check valve body 301 is disposed within the second segment 22. One end of the third check valve spool 302 is movably disposed in the third check valve body 301, and the other end of the third check valve spool 302 abuts against a connection between the second segment 22 and the communication segment 23. The third elastic structure 303 is disposed between the third check valve body 301 and the third check valve spool 302, and applies an elastic force to the third check valve spool 302 toward the communication section 23.

The fourth one-way flow structure 400 includes a fourth one-way valve body 401 and a fourth one-way valve spool 402. The fourth check valve body 401 is fixedly arranged in the second section 22, a second communication notch 4011 is formed in the side wall of the fourth check valve body 401, and the second communication notch 4011 is correspondingly arranged with the first ends of the third oil port 13 and the second communication passage 50, so that the first ends of the third oil port 13 and the second communication passage 50 can be communicated through the second communication notch 4011. The fourth check valve core 402 is movably disposed in the fourth check valve body 401, a fourth elastic structure 403 is disposed between a first end of the fourth check valve core 402 and a bottom wall of the fourth check valve body 401, and a second end of the fourth check valve core 402 is adapted to abut against an edge of the second communication notch 4011 facing the communication section 23.

Further, a second accommodation recess 4021 is provided on an end surface of the fourth check valve spool 402 facing the communication section 23, and the third check valve body 301 is disposed in the second accommodation recess 4021.

As will be understood by those skilled in the art with reference to fig. 3 to 5, in fact, the third one-way flow structure 300 and the fourth one-way flow structure 400 are the same as the first one-way flow structure 100 and the second one-way flow structure 200, and the four are arranged along the center line of the valve body 10 in a mirror symmetry manner, so that the detailed description of the first one-way flow structure 100 and the second one-way flow structure 200 is referred to for the specific structures of the third one-way flow structure 300 and the fourth one-way flow structure 400, and will not be further described herein.

As shown in fig. 7, in the solution of the present embodiment, the valve body 10 is further provided with an oil supply port 15, and the oil supply port 15 is communicated with the third communication channel 60. Specifically, as can be seen in fig. 1 and 7, the oil compensating port 15 is a pipe structure, one end of which extends into the second flow passage 30 and communicates with the third communicating passage 60, and the other end of which is adapted to be connected with an external pipeline. The oil supply port 15 communicates with an external oil source, and supplies oil into the third communication passage 60. In combination with the operation process of the above-mentioned balance valve structure (taking the first oil port 11 as an example, and the second oil port 12 as an example), when the wheel excavator travels on flat ground, the hydraulic oil entering from the oil supply port 15 flows back to the oil tank from the second oil port 12 after passing through the third communication channel 60, the communication section 23 and the third one-way flow structure 300. When the wheel excavator is in a downhill driving state, the spool 70 is pushed back to the vicinity of the neutral position (but not completely returned to the neutral position) due to an increase in pressure at the oil return port, so that the communication areas of the second communication passage 50 and the third communication passage 60 are reduced, and the oil return flow rate is reduced. At this time, the oil supply port 15 can supply oil to the third communicating passage 60 from the outside, so that the oil supply amount to the oil inlet is increased, and the oil supply effect is enhanced.

The embodiment also provides a hydraulic motor which comprises the balance valve structure.

The embodiment also provides engineering machinery comprising the hydraulic motor. And preferably the work machine is a wheeled excavator.

Of course, it will be understood by those skilled in the art that the above-described balancing valve structure may be used in other construction machines and other machines provided with balancing valves, and is not limited to the use of the above-described balancing valve structure only in wheeled excavators.

According to the above description, the present patent application has the following advantages:

1. the oil inlet and the oil outlet are provided with the secondary check valve, so that oil can be supplemented more quickly;

2. because the balance valve has the oil supplementing function, oil can be supplemented when the oil supply of the motor is insufficient, the motor is better protected, and the situations of air suction and stalling are prevented;

3. the flow rate of the balance valve capable of supplementing oil is determined by the drift diameter of the balance valve, so that the size of the flow rate can be changed by replacing the specification of the balance valve core according to the actual condition;

4. the whole structure has no pilot control, optimizes various flow passage holes, has simple, compact and reliable structure and very excellent engineering value.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.