WO2015094142A1

WO2015094142A1 - A valve system which holds load and which equalizes pressure in hydraulic fixtures

Info

Publication number: WO2015094142A1
Application number: PCT/TR2014/000517
Authority: WO
Inventors: Turgay KOLCUOĞLU
Original assignee: Hema Endüstri̇ Anoni̇m Şi̇rketi̇
Priority date: 2013-12-17
Filing date: 2014-12-16
Publication date: 2015-06-25

Abstract

The present invention comprises a poppet (11) which functions as a load check valve, and a pressure balancing slide (9) wherein the poppet (11) functions inside the body at the same time and a spring which separates them from each other. The present invention relates to a valve system (1) having load checking and pressure balancing functions in hydraulic fixtures which balances pressure when the flow passage is from the orifice to the client, and which functions as a load check valve when the flow passage is from the client to the orifice, in other words from the client to the pump. By means of the present invention, less number of pieces is used, simpler casting methods are applied and process duration is shorter and the functions of load check valve and pressure balancing can be realized.

Description

SPECIFICATION

A VALVE SYSTEM WHICH HOLDS LOAD AND WHICH EQUALIZES PRESSURE IN

HYDRAULIC FIXTURES

TECHNICAL FIELD

The present invention comprises a poppet which functions as a load check valve, and a pressure balancing slide wherein the poppet functions and which functions inside the body at the same time, and a spring which separates them from each other. The present invention relates to a valve system having load checking and pressure balancing functions in hydraulic fixtures which balances pressure when the flow passage is from the orifice to the client, and which functions as a load check valve when the flow passage is from the client to the orifice, in other words from the client to the pump.

By means of the present invention, less number of pieces is used; and simpler casting methods are applied and process duration is shorter and the functions of load check valve and pressure balancing can be realized. PRIOR ART

Hydraulic systems comprise the basic principles of electromechanical carriers. The control systems, used in electromechanical carriers, are realized according to hydraulic and pneumatic principle. In hydraulic systems, in the adjustment of the speed of elements converting hydraulic energy to mechanical energy, in other words, in the adjustment of the flow transferred to the elements, the orifices and the pressure differences formed on these orifices are utilized.

The increase of the orifice area or the increase of the pressure difference between the orifice inlet and orifice outlet lead to increase of the flow rate, and the decrease of the orifice area or pressure difference leads to decrease of the flow rate and thus leads to decrease of the speed. By means of a similar rationale in the direction control valves, the variable orifices on the slides are utilized and flow rate adjustment is realized.

In systems having pressure balancing valve, thanks to a pressure balancing valve placed between the orifice and work port, the pressure difference on the orifice is kept fixed. The signal which is required for operation of the variable displacement pumps shall be guided to the signal inlet port of the pump through the valve. By means of this, a fixed pressure difference is formed which is adjusted by means of the control valves provided on the pump.

The pump pressure effects on one end of the flow rate control orifice, and the pump signal pressure effects on the other end of the flow rate control orifice. The reason for this is that the pressure after the slide is determined by the balancing valve. The function of the pressure balancing valve is to balance the pressure at the two ends thereof. By means of this, a fixed pressure difference is provided at every position with respect to the valve adjustment on the pump, and this pressure difference is preserved under every operation condition on both sides of the flow rate adjustment orifice. By means of this, the flow rate control is completely left to the opening amount at the orifice, and thus it is left to the control of the operator. A flow rate will be the correspondence of each opening, and each time said opening is provided, said flow rate will be provided in an independent manner from the load. At the same time, the sections of said pressure balancing valves which send signal to the pump are connected to each other, and the maximum pressure is sent to the pump, and when the maximum flow rate which will be produced by the pump is exceeded, the deceleration which will result from the pressure difference decrease on the pump is shared in all clients in a mutual manner.

However, besides pressure balancing valves used in these systems, additional load check valves are used for a sealing system which will prevent damaging of the pump by the inverse pressure which will occur in cases where load is returned from elements which convert hydraulic energy into mechanical energy.

In the Canada Patent Document with number CA2147477 existing in the known state of the art, a system is disclosed comprising a tank, a valve group connected to the tank through a line by means of a pump, at least one loading valve and a system having a control portion having a pilot overflow valve for hydraulic liquid control together with the loading valve in the direction of the demand. In such a system, it is desired that there is an auxiliary valve arrangement in the tank direction. For this reason, in order to control hydraulic flow pressure besides the auxiliary valve arrangement, the pilot overflow valve realizes discharging process provided that it stays connected to a corresponding fixed point. In the patent document with number EP2337980B1 existing in the known state of the art, a control valve comprising particularly a housing element - in particular a valve sleeve - is described, and it has a valve bore and a minimum pressured substance connection designed as an axial bore, and moreover, it has a pressured substance connection designed as a radial bore. Moreover, the invention has a main piston transferred in a movable manner inside the valve bore, and a transverse cross section of an opening is controlled between said pressured substance connections. The main piston comprises a first front surface facing the axial bore, and a second front surface dedicated to the opposite side, and a balancing channel connecting both front surfaces as fluid. The feature of the invention when compared with the traditional control valves is that the balancing channel is formed such that the pressure is measured which effects on the first front surface and on the radially out-of-center regions of the first front surface, and particularly on the radially outside regions of the first front surface.

When all these applications are taken into consideration, except the subject matter valve system having load checking and pressure balancing functions in hydraulic fixtures, there is no multi-functional valve having load checking and pressure balancing functions in hydraulic fixtures which balances pressure when the flow passage is from the orifice to the client, and which functions as a load check valve when the flow passage is from the client to the orifice, in other words from the client to the pump.

BRIEF DESCRIPTION OF THE INVENTION

The object of the present invention is to realize load check valve and pressure balancing valve functions by using less number of pieces, by using simpler casting methods and by consuming less processing time thanks to the subject matter multi-functional valve which balances pressure when the flow passage is from the orifice to the client, and which functions as a load check valve when the flow passage is from the client to the orifice, in other words from the client to the pump.

THE DETAILED DESCRIPTION OF THE INVENTION In the subject matter hydraulic systems, the valve which balances pressure and which functions as a load check valve is illustrated in the annexed figures:

In Figure 1 , the integral view of the valve complex comprising pluralities of valves and ^' providing movement of the element converting hydraulic energy into mechanical energy is given. In Figure 2, the view of the system at the moment when the pressure control slide and check valve poppet are closed and when they function as a single slide is given.

In Figure 3, the perspective view of the input-output segments provided on the valve is given.

The pieces illustrated in the figures are numbered one by one, and the correspondence of these numbers is given below.

1. Valve system having load checking and pressure balancing functions in hydraulic fixtures

2. Valve segment complex

3. Cylinder rod

4. Cylinder body

5. Work port

6. Anti-shock valve

7. Valve segment

8. Variable displacement pump

9. Pressure control slide,

10. Valve

11. Valve poppet

12. Pressure control spring

3. Element complex converting hydraulic energy into mechanical energy

14. Direction control slide

15. Pressured fluid waiting region

16. Region whose pressure is balanced

17. Pressure transmission belt

18. Transmission port flow path

19. Hydraulic warning group

20. Flow rate adjustment orifices

21. Input segment

22. Output segment

The subject matter valve system (1), having load checking and pressure balancing functions in hydraulic fixtures, comprises:

- valve segment complex (2) where all members of the valve (10) are positioned and wherein said members function and which is preferably made of cast or steel material,

- a cylinder rod (3) converting hydraulic energy into mechanical energy, a cylinder body (4) comprising cylinder rod (3) and all of the auxiliary members, pluralities of work ports (5) having connection points with the cylinder rod (3) after the pressured fluid is guided by the valve segment (7),

anti-shock valve (6) delimiting the unexpected instant pressures which may occur on the cylinder rod (3) and preventing damaging of the valve segment (8),

valve segment (7) comprising all members of the valve (10) thereon, and which is preferably made of cast material,

variable displacement pump (8) which can produce flow as required with the help of the valves (10) thereon in the direction of the load signal received from the pump and having generally axial .pistons,

a pressure control slide (9) which fixes the pressure between the pressured fluid waiting region (15) and the line, which sends pressure generation signal to the variable displacement pump (8), with the help of the valve poppet (11),

a multi-functional valve (10) having load checking and pressure balancing functions, valve poppet (11) which prevents damaging of the variable displacement pump (8) as a result of return of the fluid in an inverse direction with respect to the flow direction from the cylinder rod (3) to the work port (5) lines due to any reason, and which provides pressure control by joining with the pressure control slide (9),

pressure control spring (12) providing the poppet (11) to be seated to the processed surface in the valve segment (7) by separating the valve poppet (11) from the pressure control slide (9) in cases where there is no flow,

element complex (13) converting hydraulic energy into mechanical energy and comprising cylinder rod (3) and cylinder body (4),

direction control slide (14) which determines the movement direction and speed of the element complex converting hydraulic energy into mechanical energy and which axially moves inside the special housing processed inside the valve segment (7), pressured fluid waiting region (15) where the pressured fluid, produced by the pump (8), waits before said pressured fluid is transferred to the element (13) converting hydraulic energy into mechanical energy,

region (16) whose pressure is balanced and where the fluid waits which is balanced by means of the load signal transferred to the pump (8) by means of the pressure control slide (9),

pluralities of pressure transmission belts (17) which provide the flow, produced by the pump (8), to be transferred to the element complex (13) which converts hydraulic energy into mechanical energy after said flow is guided by the direction control slide (14), - transmission port flow path (18) through which the flow, produced by the pump (8), arrives at the element complex (13) which converts hydraulic energy into mechanical energy after said flow is guided by the direction control slide (14),

- hydraulic warning group (19) which functions by means of hydraulic pressure providing axial movement of the slide (14) and which realizes centering with the spring (12),

- flow rate adjustment orifices (20) which are in notch form and which provide transmission of desired amount of flow from the waiting region (15) to the region (16) whose pressure is balanced by means of the axial movement of the slide (14), - input segment (21) where the oil input and tank load signal connecting processes can be realized for the valve segment complex (2),

- output segment (22) whereon the required valves (10) are mounted and providing integrity of the valve complex (2). The subject matter valve system (1), having load checking and pressure balancing functions in hydraulic fixtures, is used in fixtures comprising a variable displacement pump (8) producing flow in order to form a fixed pressure difference, and a valve (10) mounted on the pump (8) and providing adjustment of said fixed pressure, and a direction control valve which guides the flow, coming frorri the pump (8), to the system components (13) converting hydraulic energy into mechanical energy and which has variable orifices (20) thereon for adjustment of the flow rate. Each valve segment (22) guides the flow to a separate client. The load signal lines of all valve segments (22) are joined and the valves (10) are connected to the same side thereof. The subject matter the valve system (1), having load checking and pressure balancing functions in hydraulic fixtures, comprises pluralities of valves (10) and it is a structure providing control of the movement of the element (13) converting hydraulic energy into mechanical energy. The whole valve segment complex (2) comprises an input segment and an output segment. Thanks to the valves (10) provided on the axial piston variable displacement pump (9), the fluid waits at a predetermined waiting pressure in a pressured fluid waiting region (15) without any flow or with a slight flow (only in order to compensate the leakages formed in the system).

The direction control slide (14) is moved at certain amounts axially in order to provide movement of the element complex (13), converting hydraulic energy into mechanical energy, in the desired direction and in the desired speed. By means of this movement, the desired flow rate is adjusted and thus the speed of the element (13) converting hydraulic energy into mechanical energy is adjusted thanks to the flow rate adjustment orifices (20). Here, thanks to the pressure control slide (9), the pressure difference between the pressured fluid waiting point (15) and the region (16) whose pressure is balanced is kept fixed. In order to realize this, the pressure control slide (9) and the check valve poppet (11) are closed, and they function as a single slide (9). Since the areas provided below and above said single slide (9) are equal, the pressures are also equal. Since the pressure provided above this slide (9) is kept fixed thanks to the valve (10) provided on the axial piston variable displacement pump (8), the pressure difference between the pressured fluid waiting point (15) and the region (16) whose pressure is balanced is kept fixed, and the flow rate and thus the speed of the element (13), converting hydraulic energy into mechanical energy, depend only on the opened areas of the flow rate adjustment orifices (20) provided on the direction control slide (14).

Thus, when the user brings the direction control slide (1 ) to the same point, the same speed is provided. When the slide (14) is brought to the intermediate position and when the flow is stopped again, the valve poppet (11) returns to the prior position thereof with the help of the pressure control spring (12).

In order to prevent damaging of the pump (8) as a result of pressure load in inverse direction due to the pressure in return direction formed because of an unexpected reason in the element (13) converting hydraulic energy into mechanical energy, said pressure is prevented from being transferred to the pump (8) by using the check valve poppet (11).

Thanks to the subject matter invention, less number of pieces is used, simpler casting methods are used and less processing duration is consumed, and both the load check valve and the pressure balancing valve can fulfill their functions.

Claims

1. A valve system (1) having load checking and pressure balancing functions in hydraulic fixtures, characterized by comprising a pressure control slide (9) which fixes the pressure between the pressured fluid waiting region (15) and the line, which sends pressure generation signal to the variable displacement pump (8), with the help of the valve poppet (1-1); valve poppet (11) which prevents damaging of the variable displacement pump (8) as a result of return of the fluid in an inverse direction with respect to the flow direction from the cylinder rod (3) to the work port (5) lines due to any reason, and which provides pressure control by joining with the pressure control slide (9); and pressure control spring (12) providing the poppet (11) to be seated to the processed surface in the valve segment (7) by separating the valve poppet (11) from the pressure control slide (9) in cases where there is no flow.