Balance valve

Abstract

A balance valve relates to the technical field of hydraulic valves. Comprising a valve body; the valve seat is fixedly arranged in the valve body, and an inner cavity is formed in the middle of the valve seat; the valve body is provided with a first oil port and a second oil port which are communicated with the inner cavity; a plurality of valve seat holes are formed in the valve seat; the main valve element is arranged in the valve seat in a sliding mode, and a containing cavity is formed between the tail of the main valve element and the valve seat end cover; a main valve element upper side hole, an axial small hole, a main valve element lug hole, a pilot valve cavity, a first spring containing cavity and a second spring containing cavity which are sequentially communicated are formed in the main valve element. A plurality of main valve core radial holes are formed in the main valve core; according to the utility model, the steel ball is not easy to fall off from the ear hole and enter the large hole to cause the risk of incapability of maintaining pressure, and meanwhile, the through-flow capability can be ensured, and the energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic valves, in particular to an improvement on the structure of a balancing valve. Background Art

[0002] A common balancing valve product structure currently on the market, such as Figure 1 As shown, it mainly includes: a control piston, a valve body, a main valve core, a pilot valve core, a valve seat, a first spring, and a second spring. The mating surfaces of the existing balancing valve include: the two mating surfaces of the pilot valve core and the main valve core, and the oil-sealing cone surface between the pilot valve core and the main valve core. Because the gap between the two mating surfaces of the pilot valve core and the main valve core is very small, in order to avoid the difficulty of installing the pilot valve core and the occurrence of sticking during movement, high-precision requirements are imposed on the coaxiality of the inner hole of the main valve core and the coaxiality of the two mating surfaces of the pilot valve core and the oil-sealing cone surface. This leads to problems such as excessive difficulty in part processing, difficulty in ensuring precision, and high processing costs.

[0003] It is clear that the existing balancing valve still has inconveniences and defects in its structure and use, and further improvement is urgently needed. The most important requirement for a balancing valve is safety (seal reliability), so the improved structure must prioritize safety and secondly meet the performance requirements of the original balancing valve under various operating conditions. Utility Model Content

[0004] In view of the above problems, the utility model provides a balancing valve which reduces the concentricity requirement of the main valve core and the pilot valve core, and reduces the processing cost and processing cycle.

[0005] The technical solution of this utility model is:

[0006] A balancing valve, comprising:

[0007] Valve body;

[0008] The valve seat is fixedly arranged in the valve body and has an inner cavity in the middle; the valve body is provided with a first oil port and a second oil port communicating with the inner cavity; the valve seat is provided with a plurality of valve seat holes;

[0009] The main valve core is slidably arranged in the valve seat, and a cavity is formed between the tail and the valve seat end cover; the main valve core is provided with a main valve core upper side hole, an axial small hole, a main valve core ear hole, a pilot valve cavity, a first spring accommodating cavity and a second spring accommodating cavity that are connected in sequence; the main valve core is provided with a plurality of main valve core radial holes;

[0010] The pilot valve core is slidably arranged in the pilot valve cavity and is provided with a pilot inner hole with a tail opening; a front end of the pilot valve core is provided with a plurality of pilot valve core inclined holes in communication with the pilot inner hole, and an outer cylindrical surface is provided with a plurality of pilot valve core radial holes in communication with the pilot inner hole; the front end of the pilot valve core is provided with a boss extending into the ear hole of the main valve core to form a ball cavity matched with the steel ball with the ear hole of the main valve core;

[0011] The first spring has one end located in the first spring accommodating cavity and connected with the pilot valve core and the other end connected with the valve seat end cover;

[0012] The second spring has one end located in the second spring accommodating cavity and the other end connected with the valve seat end cover;

[0013] The control piston is slidably arranged in the valve seat, the front end of the control piston is matched with the axial small hole, and the steel ball is moved towards the pilot valve core by sliding the control piston forward.

[0014] Specifically, the valve body is provided with a pilot control port for pushing the control piston to slide forward.

[0015] Specifically, the valve seat and the end cover are detachably and sealingly fixedly connected through threads.

[0016] Specifically, the hole diameter of the first spring accommodating cavity is smaller than the hole diameter of the second spring accommodating cavity.

[0017] Specifically, the first spring is sleeved on the pilot valve core.

[0018] The tail portion of the pilot valve core is provided with an outer cylindrical step for limiting the first spring.

[0019] Specifically, the excess step surface between the first spring accommodating cavity and the second spring accommodating cavity is connected with the end portion of the second spring.

[0020] The utility model adopts a steel ball to replace the valve core to seal oil. The steel ball is a national standard part, which can be directly purchased, and has good sealing effect. In addition, the new structure of the balance valve reduces the cooperation surface of the main valve core and the pilot valve core, reduces the coaxiality requirement of the main valve core inner hole and the pilot valve core, thereby reducing the machining difficulty and production cost of the parts. In addition, the design of the ear hole of the main valve core and the boss of the pilot valve core can prevent the steel ball from falling off from the ear hole into the large hole and causing the danger of unable to maintain pressure, and can also ensure the flow capacity and reduce energy consumption. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only are the embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on the provided drawings without any creative effort.

[0022] Figure 1 is a sectional view of a balance valve in the background art;

[0023] Figure 2 is a structural schematic view of the balance valve in a load holding condition;

[0024] Figure 3 is a structural schematic view of the balance valve in a load lifting condition;

[0025] Figure 4 is a structural schematic view of the balance valve in a load lowering initial opening condition;

[0026] Figure 5 is a structural schematic view of the balance valve in a load lowering full opening condition;

[0027] Figure 6 is a structural schematic view of an ear hole of the main valve core;

[0028] Figure 7 is a structural schematic view of a pilot valve core and a boss thereof;

[0029] In the figure, 1 is a control piston, 2 is a valve body, 201 is a first oil port, 202 is a second oil port, 3 is a main valve core, 4 is a pilot valve core, 5 is a valve seat, 6 is a first spring, 7 is a steel ball, 8 is a second spring, 9 is a valve seat hole, 10 is a main valve core radial hole, 11 is a pilot valve core radial hole, 12 is a pilot valve core inclined hole, 13 is a main valve core ear hole, 14 is an axial small hole, 15 is a main valve core upper side hole, 16 is a cavity, 17 is a pilot control port, and 18 is a boss. DETAILED DESCRIPTION

[0030] The purpose of the present application is to provide a new structure of a balance valve, to reduce the concentricity requirement of the main valve core 3 and the pilot valve core 4, to reduce the production precision requirement, to reduce the processing cost and processing period.

[0031] A balance valve comprises:

[0032] a valve body 2;

[0033] a valve seat 5 fixedly arranged in the valve body 2, and provided with an inner cavity in the middle part; the valve body 2 is provided with a first oil port 201 and a second oil port 202 in communication with the inner cavity; the valve seat 5 is provided with a plurality of valve seat holes 9;

[0034] The main valve core 3 is slidably arranged in the valve seat 5, and a cavity 16 is formed between the tail and the end cover of the valve seat 5. The main valve core 3 is provided with a main valve core upper side hole 15, an axial small hole 14, a main valve core ear hole 13, a pilot valve cavity, a first spring accommodating cavity and a second spring accommodating cavity which are sequentially communicated. The main valve core 3 is provided with a plurality of main valve core radial holes 10.

[0035] The pilot valve core 4 is slidably arranged in the pilot valve cavity and is provided with a pilot inner hole with a tail opening. In this case, the end towards the steel ball 7 is usually referred to as the front end, and vice versa as the tail or end. The front end of the pilot valve core 4 is provided with a plurality of pilot valve core inclined holes 12 which are in communication with the pilot inner hole, and the outer cylindrical surface is provided with a plurality of pilot valve core radial holes 11 which are in communication with the pilot inner hole. The front end of the pilot valve core 4 is provided with a boss 18 which extends into the main valve core ear hole 13 and forms a ball cavity which is adapted to the steel ball 7 with the main valve core ear hole 13, so as to ensure that the steel ball does not fall off inside the main valve core ear hole. The steel ball is located in the main valve core ear hole 13 and is abutted by the main valve core axial small hole 14 and the boss of the pilot valve core 4 on both sides;

[0036] The first spring 6 is located at one end of the first spring accommodating cavity and is connected with the pilot valve core 4, and the other end is connected with the end cover of the valve seat 5.

[0037] The second spring 8 is located at one end of the second spring accommodating cavity and is connected with the end cover of the valve seat 5.

[0038] The control piston 1 is slidably arranged in the valve seat 5, and the front end is adapted to the axial small hole 14. By sliding the control piston 1 forward, the steel ball is pushed to move towards the pilot valve core 4.

[0039] The valve body 2 is provided with a pilot control port 17 for pushing the control piston 1 to slide forward.

[0040] The valve seat 5 and the end cover are detachably and sealingly fixedly connected through threads.

[0041] The hole diameter of the first spring accommodating cavity is smaller than the hole diameter of the second spring accommodating cavity.

[0042] The first spring 6 is sleeved on the pilot valve core 4.

[0043] The tail of the pilot valve core 4 is provided with an outer cylindrical step for limiting the first spring (6).

[0044] The excess step surface between the first spring accommodating cavity and the second spring accommodating cavity is connected with the end of the second spring 8.

[0045] As Figure 2As shown, in this case, a third spring is connected to the left side of valve seat 5, and its left end is connected to the damping piston. The damping piston, pressed by the third spring, is pressed against valve body 2 on its left side, with its inner cavity nested in control piston 1. After the control piston 1 is pushed rightward a certain distance, it abuts and slides against the damping piston. A sleeve is located on the left side of valve seat 5, outside the third spring. After the damping piston moves a certain distance, it passes through the sleeve's left limit.

[0046] It should be noted that the above-mentioned new balancing valve structure has three states, namely load holding condition, load lifting condition and load lowering condition.

[0047] Load holding condition:

[0048] like Figure 2 As shown, no oil is flowing into pilot control port 17, meaning control piston 1 is inactive. Under the action of first spring 6, pilot valve core 4 presses against steel ball 7. Under the dual action of the first spring force and the load pressure from second oil port 202, steel ball 7 presses against the small hole in main valve core 3. Under the triple action of the two spring forces and the load pressure from second oil port 202, main valve core 3 presses against valve seat 5. Consequently, the oil path from second oil port 202 to first oil port 201 is cut off, and the load is maintained in a stable state.

[0049] Load lifting conditions:

[0050] like Figure 3 As shown, when the pilot control port 17 is not flowing with oil, that is, the control piston 1 is not moving, the pressure oil enters the valve body 2 and even the valve seat 5 from the first oil port 201, acting on the left end surface of the main valve core 3 and the steel ball 7, overcoming the load pressure of the second oil port 202 and the spring force of the two springs. Since the spring force is relatively small, the main valve core 3, the steel ball 7 and the pilot valve core 4 can open synchronously to the right, realizing the flow of oil from the first oil port 201 to the second oil port 202. The oil flow direction is as follows: Figure 3 As indicated by the arrow.

[0051] Initial operating condition with load reduction:

[0052] like Figure 4 As shown, the oil in the pilot control port 17 acts on the control piston 1, pushing the control piston 1 to the right. The control piston 1 and the steel ball 7 are pressed against each other, overcoming the spring force of the first spring 6 and the load pressure of the second oil port 202, and the steel ball 7 opens to the right. The high-pressure oil in the second oil port 202 passes through the valve seat hole 9 in sequence (each valve hole refers to Figure 2 As shown), the main valve core radial hole 10, the pilot valve core radial hole 11, the pilot valve core inclined hole 12, the main valve core ear hole 13, the main valve core axial hole 14 and the main valve core upper side hole 15 are arranged along the Figure 4 The arrow indicates that the oil flows into the first oil port 201. At this time, the flow rate is relatively small, so that when the load initially decreases, the flow rate will not increase suddenly and affect the stability of the load.

[0053] Load drop full open condition:

[0054] After the load drop initial opening, the reference Figure 4 and as Figure 5 shown, the pilot control port 17 oil pressure continues to increase, pushing the control piston 1 to continue to move to the right and top the main valve core 3, at this time the pilot valve core 4 is also pushed to the position of sealing the main valve core radial hole 10.

[0055] The cavity 16 oil is sequentially discharged from the tail opening of the pilot inner hole, the pilot valve core inclined hole 12, the main valve core ear hole 13, the main valve core axial small hole 14 and the main valve core upper hole 15, and then along the arrow to the first oil port 201. The subsequent control piston 1 does not need to overcome the load pressure, but only needs to overcome the spring force. After the control piston 1 pushes away the main valve core 3, if the pilot control port 17 oil pressure continues to increase, it can push the control piston 1 against the damping piston. The damping piston and the third spring will hinder the control piston 1 from opening the main valve core 3, and the pilot control port 17 must match a larger oil pressure to continue to push the main valve core 3.

[0056] When the pilot control port 17 oil pressure makes the control piston 1 push the right end of the damping piston against the sleeve, the load drop full open is achieved. As Figure 5 shown, the second oil port 202 oil flows through the valve seat hole 9 to the first oil port 201 along the arrow. The main function of the sleeve is to limit the control piston 1, that is, to limit the opening size of the main valve core 3.

[0057] When the pilot control port 17 stops supplying oil, that is, the control piston 1 retracts, the pilot valve core 4, the steel ball 7 and the main valve core 3 are closed under the action of the two springs, the oil path from the second oil port 202 to the first oil port 201 is cut off, and the load is in a stable holding state.

[0058] It should be noted that the position of the steel ball is assumed to be not Figure 6 the main valve core ear hole 13 but a simple circular hole, and the diameter of the circular hole should be as small as possible to ensure that the steel ball does not fall out of the circular hole. If the steel ball falls out, it may slide to the outside of the pilot valve core boss, thereby jamming the pilot valve core back, which will cause the balance valve to lose pressure, posing a serious safety problem. However, if the diameter of the circular hole is too small, it will not be able to guarantee the flow capacity of the load drop condition, and at the same time, it will increase the energy consumption of the balance valve. Therefore, the ear hole structure is innovated, which can not only limit the steel ball in a small area, but also not reduce the flow capacity. In addition, the position and size of the ear hole are adjustable, thereby flexibly adjusting the flow capacity and energy consumption of the load drop condition, and of course, the stability of the condition.

[0059] The depth of the ear hole 13 of the main valve core must be sufficient and have a margin to ensure that the steel ball 7 is still limited in the ear hole under the load drop full open working condition. At this time, the setting of the boss 18 of the pilot valve core can ensure that the pilot valve core 4 pushes against the steel ball 7 to limit the free swing of the steel ball 7. In addition, the diameter of the boss 18 is flexible, which will affect the flow capacity of the load drop working condition, and then affect the stability and energy consumption of the balance valve.

[0060] In general, the innovation and advantages of the present application are that a steel ball 7 is first used to replace the valve core oil seal. The steel ball 7 is a national standard part and can be directly purchased, and the oil sealing effect is good. In addition, the new structure of the balance valve of the present application reduces the number of matching surfaces of the main valve core 3 and the pilot valve core 4, reduces the coaxiality requirement of the inner hole of the main valve core 3 and the pilot valve core 4, thereby reducing the machining difficulty of the parts and the production cost; in addition, the design of the ear hole 13 of the main valve core and the boss 18 of the pilot valve core can ensure that the steel ball 7 is not easy to fall off from the ear hole into the large hole and cause the danger of unable to maintain pressure, and at the same time can ensure the flow capacity and reduce the energy consumption. In addition, according to the requirements of the stability and energy consumption of the load drop working condition on the scene, the ear hole and the boss 18 can be adjusted, so that the balance valve is more matched with the performance requirements of the scene.

[0061] The principles and implementation modes of the present application are described in specific examples in this paper, and the above examples are only used to help understand the method and its core idea of the present application. It should be noted that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A balancing valve, characterized in that: include: Valve body (2); The valve seat (5) is fixedly arranged in the valve body (2), and has an inner cavity in the middle; the valve body (2) is provided with a first oil port (201) and a second oil port (202) communicating with the inner cavity; the valve seat (5) is provided with a plurality of valve seat holes (9); The main valve core (3) is slidably arranged in the valve seat (5), and a cavity (16) is formed between the tail and the end cover of the valve seat (5); the main valve core (3) is provided with a main valve core upper side hole (15), an axial small hole (14), a main valve core ear hole (13), a pilot valve cavity, a first spring accommodating cavity and a second spring accommodating cavity, which are connected in sequence; the main valve core (3) is provided with a plurality of main valve core radial holes (10); A pilot valve core (4) is slidably arranged in the pilot valve cavity and is provided with a pilot inner hole with a tail opening; a front end of the pilot valve core (4) is provided with a plurality of pilot valve core inclined holes (12) communicating with the pilot inner hole, and an outer circular surface is provided with a plurality of pilot valve core radial holes (11) communicating with the pilot inner hole; a front end of the pilot valve core (4) is provided with a boss (18) extending into the main valve core ear hole (13), and a ball cavity adapted to the steel ball (7) is formed with the main valve core ear hole (13); A first spring (6), one end of which is located in the first spring accommodating chamber and connected to the pilot valve core (4), and the other end of which is connected to the end cover of the valve seat (5); A second spring (8), one end of which is located in the second spring accommodating cavity and the other end of which is connected to the end cover of the valve seat (5); The control piston (1) is slidably disposed in the valve seat (5), and its front end is adapted to the axial small hole (14). The control piston (1) slides forward, pushing the steel ball to move toward the pilot valve core (4).

2. A balancing valve according to claim 1, characterized in that: The valve body (2) is provided with a pilot control port (17) for pushing the control piston (1) to slide forward.

3. A balancing valve according to claim 1, characterized in that: The valve seat (5) and the end cover are fixedly connected via a threaded, detachable seal.

4. A balancing valve according to claim 1, characterized in that: The aperture of the first spring accommodating cavity is smaller than the aperture of the second spring accommodating cavity.

5. The balancing valve according to claim 1, characterized in that: The first spring (6) is sleeved on the pilot valve core (4); The tail of the pilot valve core (4) is provided with an outer circular step for limiting the first spring (6).

6. A balancing valve according to claim 1, characterized in that: A transition step surface between the first spring accommodating cavity and the second spring accommodating cavity is connected to the end of the second spring (8).

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