Valve cone and load holding valve with valve cone

Abstract

A valve cone (4) having a valve cone longitudinal axis (L), an axially extending cavity (7), a first fluid connection (8), a second fluid connection (9), a seat surface (10) in the cavity (7), and a check valve (6) which is arranged in the cavity (7) at least partially between the first fluid connection (8) and the second fluid connection (9) and comprises a valve element (11), a prestressing element (12), at least one first mounting element (13), and a mounting pin (15), wherein the valve element (11) forms a tight valve seat with the seat surface (10), and wherein the second fluid connection (9) has a diameter (D2) which corresponds at least to the diameter (D1) of the valve element (11), so that the valve element (11) can be introduced into the cavity (7) of the valve cone (4) through the second fluid connection (9) for mounting the check valve (6), characterized in thatthat the first fluid connection (8) is further designed as a first mounting opening (M1), so that the at least one first mounting element (13) and the prestressing element (12) can be introduced into the cavity (7), the second fluid connection (9) is further designed as a second mounting opening (M2), so that the valve element (11) can be introduced into the cavity (7), and the valve cone (4) comprises a third mounting opening (M3) for introducing the mounting pin (15) into the cavity (7).

Description

[0001] The present invention relates to a valve cone for a load-holding valve. Furthermore, the present invention relates to a load-holding valve, in particular a load-holding valve cartridge, with a valve cone.

[0002] Valve cones used in load-holding valves are known from the prior art. Load-holding valves or load-holding valve cartridges are used in hydraulic systems, both to prevent uncontrolled lowering and to raise loads, for example in forklifts or lifting platforms. To prevent uncontrolled lowering, such a load-holding valve has a seat and a valve cone that rests against the seat without leakage and is preloaded with a pressure that exceeds the maximum permissible load pressure. Lowering occurs by opening the valve cone of the load-holding valve, for example by applying hydraulic control pressure to a control port. If the total load pressure and the control pressure exceed the preload pressure, the load-holding valve opens and a controlled lowering occurs.To lift the load, such valves usually have a check valve, which can be located, for example, within the valve cone. By applying pump pressure to the check valve, it can be moved to an open position, and a load can be lifted by the inflow of hydraulic fluid.

[0003] Check valves arranged within a valve cone of such a load-holding valve are known from the prior art, for example from DE 10 2005 055 360 A1. In such check valves within valve cones, an assembly opening is usually provided axially opposite a valve seat in a cavity of the check valve for mounting the check valve, through which the individual elements of the check valve are introduced into the cavity of the valve cone. This axial assembly opening is subsequently sealed and closed by a closure element, whereby the check valve is fully assembled in the valve cone. The terms "axial" and "radial" in this disclosure refer, unless otherwise defined, to a longitudinal axis of a valve cone, i.e., to the axis extending in the direction of movement of the valve cone and the check valve.

[0004] One problem with such check valves is that the axial arrangement of the mounting opening inevitably places the closure element under constant axial pressure from both the check valve spring and the hydraulic pressure. This can lead to the closure element slipping out if improperly installed or if faulty components are used. Therefore, special care must be taken during installation to prevent failure of the closure element and, subsequently, the check valve. Furthermore, the manufacturing accuracy requirements for the components involved are correspondingly high.

[0005] Against this background, the object of the present invention is to provide a valve cone in which a check valve is provided, which is easy to install and, moreover, meets high safety requirements.

[0006] This object is achieved with a valve cone according to claim 1. Advantageous further developments are described in the subclaims.

[0007] According to the invention, a valve cone is provided with a valve cone longitudinal axis, an axially extending cavity, a first fluid connection, a second fluid connection, a seating surface in the cavity, and a check valve. The check valve is arranged in the cavity at least partially between the first fluid connection and the second fluid connection and comprises a valve element, a biasing element, at least one first mounting element, and a mounting pin. The valve element forms a tight valve seat with the seating surface. Furthermore, the second fluid connection has a diameter that corresponds at least to the diameter of the valve element, so that the valve element can be introduced into the cavity of the valve cone through the second fluid connection for mounting the check valve.

[0008] Due to the design of the valve cone according to the invention, the valve element, which forms the closing element of the check valve, can be inserted into the valve cone through the second fluid connection during assembly of the check valve. This eliminates the need for an additional axial mounting opening for the valve element and reduces the susceptibility to errors during assembly of the check valve. Thus, a valve cone with an easy-to-install check valve that meets high safety requirements is presented.

[0009] The valve element can be designed as a ball.

[0010] In particular, the first fluid connection is designed as an axially aligned pressure channel and the second fluid connection as a radially aligned control channel. In this case, the first fluid connection in particular has a diameter that is smaller than the diameter of the ball or the valve element and the seating surface in the hollow space is arranged at an axial end of the first fluid connection. The check valve separates the two fluid connections from one another as standard, thus preventing hydraulic fluid from flowing from the second fluid connection to the first fluid connection. Hydraulic fluid only flows from the first to the second hydraulic connection when a pressure is applied at the first fluid connection that overcomes the pressure acting on the ball or the valve element of the check valve, whereby a load can be lifted, for example, in the higher-level hydraulic system. The pressure acting on the ball orThe pressure acting on the valve element is made up of the prestressing force of the prestressing element, which is in particular designed as a spring, and the hydraulic pressure prevailing at the second fluid connection. The seat surface in the valve cone is therefore arranged in particular between the first fluid connection and the second fluid connection in such a way that, when the check valve is in the assembled state, the ball or the valve element is pressed against the seat surface in the axial direction by the prestressing element, thus forming the fluid-tight valve seat. The mounting pin in particular has at least one spindle-shaped end section with a mounting edge, so that during assembly the mounting pin can engage the at least one first mounting element, which in particular has a plate-like region, from below on the plate-like region and press it axially in the cavity towards the seat surface, in order to thus prestress the check valve.

[0011] According to the invention, the first fluid connection is further designed as a first mounting opening so that the at least one first mounting element and the prestressing element can be introduced into the cavity. According to the invention, the second fluid connection is further designed as a second mounting opening so that the ball or the valve element can be introduced into the cavity, and the valve cone comprises a third mounting opening for inserting the mounting pin into the cavity. By inserting the mounting pin into the third mounting opening, the stroke of the valve element or the ball is shortened to such an extent that it can no longer exit from the second mounting opening. The term mounting opening does not merely mean the absence of a closed surface, but encompasses the entire connection area between the outer surface and the cavity of the valve cone.By using both the first and second fluid connections as assembly openings, efficient use of the existing access to the cavity in the valve cone is ensured for easy assembly of the check valve.

[0012] The first mounting opening is expediently aligned along the valve cone's longitudinal axis. Furthermore, the second and third mounting openings are aligned transversely to the valve cone's longitudinal axis. This allows for simple assembly without exerting axial pressure on any closure element. The at least one mounting element and the preloading element are inserted through the first mounting opening, whereupon the ball or valve element is inserted through the second mounting opening, and finally, the mounting pin inserted through the third mounting opening preloads and secures the check valve.

[0013] Furthermore, it is advantageous if the first mounting element has a first cover section and a first jacket section which extends axially therefrom and at least partially surrounds the first mounting element and which, together with the first cover section, forms a first receiving space for the first mounting element. The check valve also comprises a second mounting element which has a second cover section and a second jacket section which extends axially therefrom and at least partially surrounds the first mounting element and which, together with the second cover section, forms a second receiving space for the second mounting element. In particular, the first mounting element and the second mounting element are cup-shaped. In particular, the first and second cover and jacket sections have the same outer diameter, which is adapted in particular to the inner diameter of the cavity of the valve cone in such a way that axial mobility of the first and second mounting elements in the cavity is ensured.This enables simple and stable installation of the check valve in the cavity of the valve cone.

[0014] In this case, it is expedient if the ball or the valve element is arranged adjacent to the second cover section of the second mounting element and the second cover section of the second mounting element comprises a receptacle for centering the ball or the valve element, wherein the receptacle is arranged on a side of the second cover section axially opposite the second receiving space of the second mounting element. The receptacle for centering the ball or the valve element is designed in particular as a recess in the middle of a surface of the second cover section of the second mounting element. Thus, in the assembled state of the check valve and in particular when hydraulic pressure is applied in an open state of the check valve, the ball or the valve element is held by the receptacle centered on the longitudinal axis of the valve cone in the cavity.

[0015] Advantageously, the preload element is arranged axially between the first mounting element and the second mounting element. A first end portion of the preload element is arranged in the receiving space of the first mounting element, and a second end portion of the preload element is arranged in the receiving space of the second mounting element. This ensures easy installation of the preload element.

[0016] It is expedient if the first mounting element rests on the mounting pin in the cavity and a first, constant throttle is formed between the first mounting element and an inner wall of the cavity. Furthermore, the second mounting element is in positive overlap with the inner wall of the cavity, so that a second, variable throttle is formed between the second mounting element and the inner wall. A fluid-conducting damping chamber is formed between the first mounting element and the second mounting element, wherein an opening and / or closing movement of the check valve is dampened by the damping chamber. By dampening the check valve during its opening and / or closing movement, wear and noise of the check valve are reduced. In addition, jerky movements when lifting a load in the higher-level hydraulic system are prevented.

[0017] Furthermore, it is advantageous if, in the assembled state and with the check valve fully open, the distance between an edge of the second mounting opening and the second mounting element is smaller than the diameter of the ball or valve element. This ensures that the ball or valve element cannot fall out of the valve cone when assembled.

[0018] In a further development, the first mounting element limits the axial mobility of the second mounting element in that the second casing section of the second mounting element strikes the first casing section of the first mounting element when the check valve is fully opened.

[0019] This allows a maximum open position of the check valve to be defined so that the ball or valve element cannot fall out of the valve cone when the check valve is mounted.

[0020] The object is further achieved with a load-holding valve according to claim 10. The load-holding valve according to the invention has a valve cone as described above.

[0021] The invention is explained in more detail below using an exemplary embodiment shown in the figures. The figures schematically show: Fig. 1 an exploded view of a load-holding valve according to the invention designed as a load-holding valve cartridge with a valve cone according to the invention; Fig. 2 a sectional view through the load holding valve cartridge from Fig. 1; Fig. 3 a perspective view of a valve cone according to the invention; Fig. 4 a first side view of the valve cone from Fig. 3; Fig. 5 a second side view of the valve cone from Fig. 3; Fig. 6 a sectional view of the valve cone along the Fig. 4 shown line VI-VI with closed check valve; Fig. 7 a sectional view of the valve cone along the Fig. 5 shown line VII-VII with closed check valve; Fig. 8 a sectional view of the valve cone along the Fig. 4 shown line VI-VI with open check valve; and Fig. 9 a sectional view of the valve cone along the Fig. 5 shown line VII-VII with open check valve.

[0022] In the Fig. 1 and Fig. Figure 2 shows a load-holding valve 1 according to the invention, designed as a load-holding valve cartridge. Such a load-holding valve cartridge 1 is used, for example, to control a hydraulic cylinder or other hydraulic consumer of a higher-level hydraulic system against a load and, when not actuated, to keep the load leak-free. On the one hand, a controlled lowering of a load is achieved, and on the other, a controlled lifting of the load.

[0023] For this purpose, the load-holding valve cartridge 1 has a seat sleeve 2, a spring dome 3, and a valve cone 4. The valve cone 4 is received in the seat sleeve 2 for axial displacement and is formed integrally with a control piston 5. The seat sleeve 2 has a valve seat which interacts with a sealing surface of the valve cone 4 such that, when the sealing surface bears against the valve seat, a first flow path from a channel A to a channel S is closed without leakage. The channel A is connected, for example, to a chamber of a hydraulic cylinder (not shown), which can be extended and retracted against the load. The channel S is connected, for example, to a pressure source, a slide valve, or a shuttle valve.To open the load-holding valve cartridge 1, a pressure is applied to the control piston 5, which moves the control piston 5 and the valve cone 4 connected thereto axially against the preload force generated by a spring system of the spring dome 3 and thus releases the flow path from channel A to channel S.

[0024] To connect channel S with channel A and, for example, extend the hydraulic cylinder (not shown) under load, the valve cone 4 is partially hollow inside, and a check valve 6 is provided in a cavity therein. As shown, the check valve 6 is a ball valve. The check valve 6 bypasses the valve seat of the load-holding valve 1 and, when open, opens a second flow path from channel S to channel A with low throttling resistance.

[0025] In the following, the valve cone 4 according to the invention is described with reference to the Fig. 3 to 9. The valve cone 4 comprises a valve cone longitudinal axis L, an axially extending cavity 7, a first fluid connection 8, a second fluid connection 9, a seating surface 10 in the cavity 7, and the check valve 6. The check valve 6 is arranged in the cavity 7 partially between the first fluid connection 8 and the second fluid connection 9. Furthermore, the check valve 6 comprises a valve element 11 designed as a ball, a biasing element 12 designed as a spring 12, a first mounting element 13, a second mounting element 14, and a mounting pin 15. The second fluid connection 9 has a diameter D2 that corresponds at least to the diameter D1 of the valve element 11 designed as a ball, so that the valve element 11 designed as a ball can be introduced into the cavity 7 of the valve cone 4 through the second fluid connection 9 for mounting the check valve 6.

[0026] The first fluid connection 8 is in particular an axially aligned pressure channel, as in Fig. 6, which is connected to channel S from Fig. 2 is in fluid communication. Furthermore, the first fluid connection 8 is designed as a first mounting opening M1. During assembly of the check valve 6 in the valve cone 4, first the first mounting element 13, then the spring 12, and then the second mounting element 14 are inserted through the first mounting opening M1 into the cavity 7.

[0027] The second fluid connection 9 is in particular a radially aligned control channel which is connected to the channel A according to Fig. 2 is in fluid communication. Furthermore, the second fluid connection 9 is designed as a second mounting opening M2. During assembly of the check valve 6, after the first mounting element 13, spring 12 and second mounting element 14 have been inserted through the first mounting opening M1, the valve element 11 designed as a ball is inserted through the second mounting opening M2. Therefore, the diameter D2 of the second fluid connection 9 is just so much larger than the diameter D1 of the valve element 11 designed as a ball that the latter can be inserted into the cavity 7 through the second fluid connection 9.

[0028] Furthermore, the valve cone 4 comprises a third assembly opening M3 for the introduction of the assembly pin 15 into the cavity 7. As shown for example in Fig. 6, the second mounting opening M2 and the third mounting opening M3 are aligned transversely to the valve cone's longitudinal axis L, i.e., radially. The first mounting opening M1, on the other hand, is aligned along the valve cone's longitudinal axis L, i.e., axially, and has a diameter D3 that is smaller than the diameter D1 of the spherical valve element 11. Adjacent to the axially lower end of the mounting opening M1 is the seat surface 10, with which the spherical valve element 11 forms the tight valve seat.

[0029] The first mounting element 13 is pot-shaped and comprises a first cover section 13a and a first casing section 13b extending axially therefrom and completely circumferential in this embodiment, which, together with the first cover section 13a, forms a first receiving space 13c of the first mounting element 13.

[0030] The second mounting element 14 is also pot-shaped and comprises a second cover section 14a and a second casing section 14b extending axially therefrom, which in this embodiment completely encircles the casing section 14b, which, together with the second cover section 14a, forms a second receiving space 14c of the second mounting element 14. As shown, the axial extent of the first casing section 14b is smaller than the axial extent of the second casing section 14b.

[0031] Furthermore, the second mounting element 14 comprises a receptacle 14d for centering the valve element 11 designed as a ball, which in the mounted state is arranged adjacent to the cover section 14a of the second mounting element 14, as for example in Fig. 7. The receptacle 14d is arranged on a side of the cover section 14a axially opposite the receiving space 14c.

[0032] For example, in Fig. As can be seen in Figure 7, the spring 12 is arranged axially between the first mounting element 13 and the second mounting element 14. A first end portion of the spring 12 is arranged in the first receiving space 13c of the first mounting element 13, and a second end portion of the spring 12 is arranged in the second receiving space 14c of the second mounting element 14.

[0033] As in the Fig. 6 to 9, in the assembled state, the first mounting element 13 rests in the cavity 7 on the mounting pin 15. Between the first mounting element 13 and an inner wall 16 of the cavity 7, a first, constant throttle 17 is formed. As also shown in the Fig. 6 to 9, the second mounting element 14, namely the second jacket section 14b, is in positive overlap with the inner wall 16 of the cavity 7, so that a second, variable throttle 18 is formed between the second mounting element 14 and the inner wall 16. The variability of the second throttle 18 results from the axial mobility of the second mounting element 14 during the opening and closing movements of the check valve 6. For example, the positive overlap, i.e. the gap between the outer circumferential surface of the second mounting element 14 or the second jacket section 14b and the inner wall 16, is in the open position of the check valve 6 (cf. Fig. 8) significantly longer than in the closed position (cf. Fig. 6). A fluid-conducting damping chamber 19 is thus formed between the first mounting element 13 and the second mounting element 14. This dampens the opening and closing movements of the check valve 6.

[0034] As in Fig. 8, in the assembled state when the check valve 6 is fully open, a distance D4 between an edge 20 of the second mounting opening M2 and the second mounting element 14 is smaller than the diameter D1 of the valve element 11 designed as a ball. This ensures that the valve element 11 designed as a ball cannot fall out of the valve cone 4 even when the check valve 6 is fully open.

[0035] As in the Fig. 8 and Fig. 9, the first mounting element 13 limits the axial mobility of the second mounting element 14 in that the second jacket section 14b of the second mounting element 14 strikes the first jacket section 13b of the first mounting element 13 when the check valve 6 is fully opened.

[0036] The following describes the method already indicated above for assembling the check valve 6 in the cavity 7 of the valve cone 4. The individual components of the check valve 6 are initially all located outside the valve cone 4 and the cavity 7 is completely empty. The assembly method comprises the following steps in sequence: First, the first assembly element 13 is introduced through the first assembly opening M1 into the cavity 7 of the valve cone 4. Then, the prestressing element 12 is introduced through the first assembly opening M1 into the cavity 7. In particular, the first end section of the prestressing element 7 is arranged in the receiving space 13c of the first assembly element 13. Then, the second assembly element 14 is introduced through the first assembly opening M1 into the cavity 7.In particular, the receiving space 14c of the second mounting element 14 is pushed over the second end portion of the pretensioning element 12, so that an end portion of the pretensioning element 12 is arranged in the receiving space 14c of the second mounting element 14.

[0037] At this point, the mounting pin 15 is not yet located in the cavity 7, so that the ball-shaped valve element 11 can be inserted into the cavity through the second mounting opening M2. In particular, the ball-shaped valve element 11 is pushed through the second mounting opening such that it rests in the receptacle 14d of the second mounting element 14 and is thus already centered on the valve cone's longitudinal axis L.

[0038] In the final step, the mounting pin 15 is inserted into the third mounting hole M3. For this purpose, the mounting pin 15 has two spindle-shaped end sections 15a with mounting edges 15b, see, for example. Fig. 6 and Fig.7. The mounting pin 15 is inserted into the third mounting opening M3 until it abuts the first mounting element 13. The mounting pin 15 is then rotated, causing the mounting edge 15b to engage a lower edge of the plate-shaped cover section 13a and lift the first mounting element 13. By screwing it in, the mounting pin 15 is inserted into the third mounting opening M3 and the check valve 6 is preloaded.

[0039] Optionally, the mounting pin 15 is designed so that it has a slightly larger diameter than the third mounting opening M3, so that in a final step the mounting pin 15 is pressed into the third mounting opening M3 and the check valve is thus fully assembled. List of reference symbols 1 load holding valve / load holding valve cartridge 2 seat sleeve 3 spring dome 4 valve cones 5 control pistons 6 Check valve 7 Cavity 8 first fluid connection (pressure channel) 9 second fluid connection (control channel) 10 Seat (in the valve cone) 11 Valve element 12 springs 13 first assembly element 13a first lid section 13b first mantle section 13c first recording room 14 second mounting element 14a second lid section 14b second mantle section 14c second recording room 14d recording 15 Mounting pin 15a spindle-shaped end section 15b Mounting edge 16 Interior wall 17 first, constant throttle 18 second, variable throttle 19 Damping chamber 20 edge A, S channel D1, D2, D3 diameter D4 distance L Valve cone longitudinal axis M1 first mounting opening M2 second mounting opening M3 third mounting hole

Claims

[1] Valve cone (4) with a valve cone longitudinal axis (L), an axially extending cavity (7), a first fluid connection (8), a second fluid connection (9), a seat surface (10) in the cavity (7), and a check valve (6) which is arranged in the cavity (7) at least partially between the first fluid connection (8) and the second fluid connection (9) and comprises a valve element (11), a prestressing element (12), at least one first mounting element (13), and a mounting pin (15), wherein the valve element (11) forms a tight valve seat with the seat surface (10), and wherein the second fluid connection (9) has a diameter (D2) which corresponds at least to the diameter (D1) of the valve element (11), so that the valve element (11) can be introduced into the cavity (7) of the valve cone (4) through the second fluid connection (9) for mounting the check valve (6), characterized byin that the first fluid connection (8) is further designed as a first mounting opening (M1) so that the at least one first mounting element (13) and the prestressing element (12) can be introduced into the cavity (7), the second fluid connection (9) is further designed as a second mounting opening (M2) so that the valve element (11) can be introduced into the cavity (7), and the valve cone (4) comprises a third mounting opening (M3) for introducing the mounting pin (15) into the cavity (7). [2] Valve cone (4) according to claim 1, characterized by that the first mounting opening (M1) is aligned along the valve cone longitudinal axis (L) and the second mounting opening (M2) and the third mounting opening (M3) are aligned transversely to the valve cone longitudinal axis (L). [3] Valve cone (4) according to claim 1 or 2, characterized byin that the first mounting element (13) comprises a first cover section (13a) and an at least partially circumferential first jacket section (13b) extending axially therefrom, which forms a first receiving space (13c) of the first mounting element (13) with the first cover section (13a), wherein the check valve (6) comprises a second mounting element (14) which comprises a second cover section (14a) and an at least partially circumferential second jacket section (14b) extending axially therefrom, which forms a second receiving space (14c) of the second mounting element (14) with the second cover section (14a). [4] Valve cone (4) according to claim 3, characterized byin that the valve element (11) is arranged adjacent to the second cover section (14a) of the second mounting element (14) and the second cover section (14a) of the second mounting element (14) comprises a receptacle (14d) for centering the valve element (11), wherein the receptacle (14d) is arranged on a side of the second cover section (14a) axially opposite the second receiving space (14c) of the second mounting element (14). [5] Valve cone (4) according to claim 3 or 4, characterized by that the prestressing element (12) is arranged axially between the first mounting element (13) and the second mounting element (14), wherein a first end portion of the prestressing element (12) is arranged in the first receiving space (13c) of the first mounting element (13) and a second end portion of the prestressing element (12) is arranged in the second receiving space (14c) of the second mounting element (14). [6] Valve cone (4) according to one of claims 3 to 5, characterized byin that the first mounting element (13) rests on the mounting pin (15) in the cavity (7), and a first, constant throttle (17) is formed between the first mounting element (13) and an inner wall (16) of the cavity (7), and the second mounting element (14) is in positive overlap with the inner wall (16) of the cavity (7), so that a second, variable throttle (18) is formed between the second mounting element (14) and the inner wall (16), wherein a fluid-conducting damping chamber (19) is formed between the first mounting element (13) and the second mounting element (14), wherein an opening and / or closing movement of the check valve (6) is damped by the damping chamber (19). [7] Valve cone (4) according to one of the preceding claims 3 to 6, characterized bythat in the assembled state, when the check valve (6) is fully open, a distance (D4) between an edge (20) of the second assembly opening (M2) and the second assembly element (14) is smaller than the diameter (D1) of the valve element (11). [8] Valve cone (4) according to one of claims 3 to 7, characterized by that the first mounting element (13) limits the axial mobility of the second mounting element (14) in that the second casing section (14b) of the second mounting element (14) strikes the first casing section (13b) of the first mounting element (13) when the check valve (6) is fully opened. [9] Valve cone (4) according to one of the preceding claims, characterized by that the valve element (11) is designed as a ball. [10] Load-holding valve with a valve cone (4) according to one of claims 1 to 9.

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