nozzle body

Abstract

Nozzle body of an agricultural field sprayer with a valve element which is displaceable by an electric motor drive element and with which an outlet channel leading to at least one spray nozzle can be shut off from the inlet channel connected to it, characterized in that the valve element (10) is designed as a valve tappet (9), that the drive element is designed as an electric motor (14), that by a rotary movement generated by the electric motor (14), the linearly displaceable valve tappet (9) can be displaced, on the one hand, into a position which releases the flow from the inlet channel (4) to the outlet channel (7) and, on the other hand, into a position which blocks the flow from the inlet channel (4) to the outlet channel (7), that the valve tappet (9) is assigned a spring element (18) which loads the valve tappet (9) in the direction of its shut-off position, that the valve tappet (9) passes through the motor drive element (14),that the spring element (18) is arranged or acts on the end region of the valve tappet (9) facing away from the shut-off region of the valve tappet (9).

Description

[0001] The invention relates to a nozzle body according to the preamble of claim 1.

[0002] Such a nozzle body is known, for example, from DE 697 19 530 T2. In this nozzle body, the electromechanical drive element, which actuates the movable plunger to close the inlet channel, is designed as an electromagnet comprising a coil and an armature. This design is disadvantageous because, at least in the opening or closing position of the valve element, the electromechanical drive element must be constantly supplied with electrical energy. This necessitates a relatively robust electrical system, which is relatively expensive and complex.

[0003] Furthermore, there is the following problem: the electromagnets must be relatively large because they have to counteract the pressure prevailing in the discharge line or inlet channel during the closing process.

[0004] German patent DE 10 2004 0 11 737 A1 discloses another nozzle body with a valve plunger that is pressed towards a closed position by a compression spring. Here, the plunger is moved into the closed position solely by the force of the spring. If the plunger of this nozzle body is to be moved into its open position against the force of the spring, compressed air is applied to the compressed air connection, causing the plunger to be moved into its open position against the force of the compression spring. This necessitates a relatively robust pneumatic or, alternatively, electrical system, which is also relatively expensive and complex.

[0005] Another nozzle body is known from DE 10 2004 056 867 A1. This nozzle body also has a valve tappet. This valve tappet is not designed as a continuous shaft, but is rotated by a sleeve turned by the drive shaft of the electric motor. A spring load on the valve tappet is not provided here.

[0006] The invention is based on the objective of being able to move the nozzle bodies, which are arranged at a distance from each other on a distributor linkage, into the respective switching position by means of an electromechanical drive element and a valve element that can be moved with a small amount of electrical energy required.

[0007] This problem is solved by the subject matter of claim 1.

[0008] As a result of these measures, by designing the drive element as an electric motor, it is achieved that the electromotive drive element only needs to be supplied with electrical energy during the positioning process.

[0009] By assigning a spring element to the valve element designed as a valve tappet, which loads the valve tappet in the direction of its closing position, the electric motor is given force support during the closing process to shut off the intake channel via the valve tappet.

[0010] This power assistance supports the electric motor. This power assistance counteracts the injection pressure. This auxiliary force can be easily applied using a spring element. The spring allows some of the high force required to close the valve to be transferred to the opening state. The spring helps the electric motor to close the valve but hinders its opening. This disadvantage is acceptable because only frictional force needs to be overcome. By installing the spring, the required force of the electric motor can be significantly reduced. This has the advantage of achieving a larger safety margin, thus ensuring reliable operation over the long term. Furthermore, an electric motor designed as a stepper motor can be operated at a higher stepping frequency. This makes it possible to significantly shorten the switching time of the valve.

[0011] A simple conversion of the rotary motion of the electric motor into a linear motion for adjusting the valve tappet is achieved by the valve tappet having a screw-like threaded area that interacts with a nut-like threaded area of ​​a rotatably driven motor element of the electric motor to move the valve tappet.

[0012] The arrangement of the spring element supporting the shut-off process according to the invention is achieved by the valve tappet passing through the motor drive element, and by the spring element being arranged or acting on the end region of the valve tappet facing away from the shut-off region of the valve tappet.

[0013] To ensure that the spring element not only guarantees the simple closing of the intake port by moving the valve tappet, but also that the electric motor has sufficient force to push the valve tappet into the opening position, the spring element is designed such that the spring force that can be applied by the spring element corresponds to at least one third of the maximum counterforce that can be applied by the pressurized fluid to be discharged in the intake port.

[0014] Further details of the invention can be found in the description of the example and the drawings. These show Fig. 1. The nozzle body in a front view, Fig. 2 the nozzle body in cross-section, with the plunger in the shut-off position and Fig. 3 the nozzle body in cross-section according to Fig. 2, wherein the valve tappet is in the flow-releasing position.

[0015] The nozzle body 1 is attached to a distributor boom of a field sprayer by means of its fastening elements 2. These nozzle bodies 1 are arranged at regular intervals on the distributor boom of the field sprayer. The nozzle body 1 has a continuous connecting line 3, which connects it to a supply line for the liquid to be applied. This liquid line is connected to an inlet channel 4 of a valve assembly 5. Furthermore, the inlet channel 4 is connected to an annular channel 6, which in turn leads to the outlet channel 7, which in turn leads to a spray nozzle attached to the nozzle body 1 at the outlet end 8 by means of a union nut (not shown).

[0016] In the area of ​​the annular channel 6 connecting the inlet channel 4 with the outlet channel 7, a valve arrangement 5 with a valve element 10 designed as a valve tappet 9 is arranged. This valve element 10 is arranged in a housing 11, which is fastened to the housing 13 of the nozzle body 1 by means of a union nut 12.

[0017] The outlet channel 7 leading to the spray nozzle is to be shut off from the inlet channel 4 via the valve tappet 9.

[0018] If the valve tappet 9 is in the Fig. When the valve tappet 9 is in the left-hand position shown in Figure 2, it blocks the annular channel 6 and the inlet channel 4 from the outlet channel 8. The annular channel 6 is connected to the outlet port 8 via the through-bore 13. When the valve tappet 9 is in the right-hand position, it closes the annular channel 6 and the inlet channel 4 from the outlet port 8. Fig. 3, the valve element 10 of the valve tappet 9 releases the through-bore 13, which connects the inlet channel 4 with the outlet channel 7 via the annular channel 6, so that the liquid from the supply line 3 can flow via the inlet channel 4, the annular channel 6, the through-bore 13 to the outlet channel 7 and thus to the nozzle body not shown, located at the outlet end 8 of the outlet channel 7.

[0019] The valve tappet 9 is moved into its respective position by an electric drive element 14, which is designed as an electric motor. For this purpose, the valve tappet 9 has a screw-like thread 15 at a distance from the valve element 10. This screw-like threaded section 15 interacts with a nut-like threaded section 16 of the rotatably driven motor element of the electric motor 14 to move the valve tappet 9. The electric motor 14 is connected to a power supply by means of the power cable 17 and can be switched on and off accordingly via suitable control and adjustment means in order to move the valve tappet 9 into the respective intended position via the electric motor 14.

[0020] The rotary motion generated by the electric motor 14, due to the screw-like threaded sections 15 and 16 which interact with the rotatably driven motor element of the electric motor 14, allows the valve tappet 9 to be moved in a linear direction. The linearly movable valve tappet 9 thus allows, on the one hand, a position that opens the flow from the inlet port 4 to the outlet port 7 ( Fig. 3) and on the other hand into a position that blocks the flow from the inlet channel 4 to the outlet channel 7 ( Fig. 2) be postponed.

[0021] To move the valve tappet 9 from its open position to its closed position against the pressure prevailing in the system using the lowest possible motor force from the electric motor 14, a spring element 18 is assigned to the valve tappet 9, which exerts a force in the direction of its closed position. To facilitate the positioning of this spring element 18 acting on the valve tappet 9, the valve tappet 9 extends through the motor drive element 14. Thus, the spring element 18 can be positioned on the end region of the valve tappet 9 facing away from the closed position, allowing it to act on the valve tappet 9 from this side. The spring element 18, which is designed as a compression spring, is configured such that the spring force it can exert corresponds to at least one-third of the maximum counterforce that can be exerted by the pressurized fluid to be discharged from the inlet channel 4.

[0022] This spring element 18 thus exerts a supporting force on the valve element 10 in the direction of its closed position. When opening, the motor element 14 must push the valve tappet 9 into its open position against the force of the spring element 18. This is acceptable, however, since only minor frictional forces of the valve tappet 9 and in the threaded transmission 15, 16 have to be overcome when opening.

Claims

[1] Nozzle body of an agricultural field sprayer with a valve element which can be moved by an electric motor drive element and with which an outlet channel leading to at least one spray nozzle can be shut off from the inlet channel connected to it, characterized by, that the valve element (10) is designed as a valve tappet (9), that the drive element is designed as an electric motor (14), that by means of a rotary movement generated by the electric motor (14) the linearly displaceable valve tappet (9) can be displaced on the one hand into a position that allows the flow from the inlet channel (4) to the outlet channel (7) and on the other hand into a position that blocks the flow from the inlet channel (4) to the outlet channel (7), that a spring element (18) is assigned to the valve tappet (9) which loads the valve tappet (9) in the direction of its blocking position, that the valve tappet (9) passes through the motor drive element (14), that the spring element (18) is arranged on or acts on the end region of the valve tappet (9) facing away from the blocking region of the valve tappet (9). [2] Nozzle body according to claim 1, characterized by, that the valve tappet (9) has a screw-like threaded area (15) which interacts with a nut-like threaded area (16) of a rotatably driven motor element of the electric motor (14) to displace the valve tappet (9). [3] Nozzle body according to claim 1, characterized by , that the spring element (18) is designed such that the spring force that can be applied by the spring element (18) corresponds to at least one third of the maximum counterforce that can be applied by the liquid to be discharged under pressure in the inlet channel (4).

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