PINCH VALVE, DISTRIBUTOR DEVICE FOR A SLURROW SPREADING VEHICLE HAVING A PINCH VALVE AND USE OF A PINCH VALVE

Description

[0001] The invention relates to a pneumatic pinch valve for a liquid manure distribution device, comprising a cylindrical housing and a tubular shut-off element arranged in a cylindrical housing with a connection piece for a compressed air supply. The invention also relates to a distribution device for a liquid manure spreading vehicle, comprising at least one pinch valve.

[0002] Pneumatic pinch valves are well-known in the art for shutting off, regulating, or dosing abrasive, corrosive, and fibrous products such as granules, powders, pellets, dust, and solid-containing liquids, such as liquid manure. When the valve housing, which usually has a connection for a compressed air supply, is pressurized with compressed air or another neutral gas, an elastic shut-off element deforms into a lip shape, thus shutting off the product flow. When the valve housing is released by venting, the shut-off element reopens to full flow due to the pressure of the product flow and / or a restoring force inherent in the shut-off element.

[0003] Such valves are known, for example, from the publications DE 202 17 464 U1 and Ross ET AL: "Pinch valves", November 30, 2019 (2019-11-30), XP093008633.

[0004] DE 10 2013 214 639 A1 discloses a pinch valve used particularly for turbid liquids such as liquid manure or wastewater. The pinch valve's pinch hose is wrapped around the line hose. Applying pressure to the pinch hose, for example, with air pressure or hydraulic oil, squeezes the line hose, thus reducing the diameter of the line hose. The disadvantages of this pinch valve are its high design complexity and its susceptibility to clogging.

[0005] DE 298 22 642 U1 discloses a pinch valve with a tubular housing in which a tubular pinch valve sleeve is arranged, which is secured in the housing by end pieces located on the end faces of the housing. Disadvantages of this type of pinch valve are the complex assembly and the deterioration of its tightness during continuous operation.

[0006] The object of the present invention is to provide a pneumatic pinch valve which is structurally simple and thus inexpensive to manufacture, requires little maintenance and can be operated reliably and is easy to replace, and in particular ensures reliable shut-off without dripping.

[0007] To achieve the object, the invention proposes a pinch valve according to the preamble of patent claim 1, which is characterized in that a shut-off element is formed from an elastic hose having a fabric at least in sections and having a Shore hardness of 40 to 60, and that a housing is formed from an elastic plastic with a Shore hardness of 75 to 95 and that two diametrically arranged, bulbous extensions are formed in the housing for receiving the pinched shut-off element.

[0008] Shore hardness is a parameter primarily used for elastomers and rubber-elastic polymers. It is directly related to the penetration depth and is therefore a measure of the material's hardness. A spring-loaded pin made of hardened steel is used as the indenter. In these methods, the indenter is pressed into the test specimen by a spring force, and the penetration depth thus represents a measure of the Shore hardness.

[0009] The Shore hardness values for the hose and housing according to the invention were determined using a Type A durometer according to DIN ISO 48-4. A test weight of 1 kg is pressed onto the material for 15 s. The intender has a flat tip with a diameter of 0.79 mm and an opening angle of 35° (cf. DIN ISO 48-4:2021-02).

[0010] Surprisingly, it was found that a shut-off element consisting of an elastic hose with a Shore hardness of 40 to 60, preferably 40 to 50, which at least partially has a fabric, has an ideal restoring force. In conjunction with the preferred use or preferred application of the pinch valve as a slurry shut-off valve, the shut-off element reliably opens to full flow due to the pressure of the slurry flow and the above-mentioned restoring force.

[0011] The hose is made of natural rubber, silicone, or a suitable plastic, such as ethylene-propylene-diene rubber, fluororubber, chloroprene rubber, or other plastics, such as chlorosulfonated polyethylene. In a preferred embodiment, the elastic hose is a fabric hose. The fabric is preferably molded into the hose.

[0012] According to the invention, the cylindrical housing made of an elastic plastic has two diametrically arranged, bulbous extensions, which advantageously accommodate the shut-off element, which deforms into a lip-shaped shape after the housing is pressurized. This enables reliable shut-off of the product flow, in particular liquid manure, without dripping. The connection piece for the compressed air is preferably arranged above a bulbous extension. This advantageously simplifies installation in and connection to a compressed air line in a liquid manure distribution device.

[0013] In addition, a Shore hardness of 75 to 95, preferably 75 to 85, has proven advantageous for the cylindrical housing, as this allows a dimensionally stable pipe section inserted at the upper and lower ends of the shut-off element to be secured using simple fixing devices, such as hose clamps, placed over the housing. These pipe sections naturally provide the inlet and outlet of the pinch valve, or a connection to an inlet and outlet line. Such pipe sections are found, for example, in a distribution device for liquid manure. In a preferred embodiment, the housing is made of polyurethane, as this material is durable and highly resilient.

[0014] The combination of the two preferably rigid pipe sections inserted into the shut-off element, the elastic housing with the specified Shore hardness, and the fixing elements applied to the upper and lower edges creates an air-tight housing interior in a reliable and structurally simple manner. In a preferred embodiment, the housing has undercuts at the upper and lower edges to accommodate the fixing elements.

[0015] The inventive success of the pinch valve for a manure distribution device compared to the prior art, namely reliable closing without dripping and reliable opening due to the typical manure pressure in the distribution device, as well as the high tightness and easy replaceability, can only be achieved by a combination of the claimed Shore hardnesses for the shut-off element and the housing.

[0016] The pinch valve according to the invention is advantageously used in a distribution device, such as a nozzle, trailing hose or soil injection distribution device for a slurry spreading vehicle.

[0017] A slurry spreading vehicle generally comprises a tank for slurry, at least one conveying device for conveying the slurry and a plurality of slurry outlets, such as trailing shoe or trailing hose outlets for spreading the slurry onto an agricultural area.

[0018] The conveying equipment conveys the slurry from the tank via a pipe, pressurizes it, and then conveys it to a distributor head for lateral distribution, such as a distributor head with perforated discs (Exc-Cut distributor head) or a screw (screw distributor bar). From this distributor head, the slurry is then conveyed to the slurry outlets via a number of additional pipes attached to a distribution device.

[0019] The conveying devices are typically pumps driven by a power take-off shaft of the vehicle or tractor via a mechanical transmission. The slurry is then distributed over the agricultural area via the outlets.

[0020] The lines to the slurry outlets are usually mounted on one or more distribution devices, which are attached as side booms on both sides of the slurry spreading vehicle. This allows working widths of over 20 m to be achieved. The outlets are usually spaced approximately 25 cm apart, so that, for example, with a working width of 15 m, 60 lines with slurry outlets are mounted on the distribution device.

[0021] According to the invention, a pinch valve is provided in each individual line mounted on a distribution device leading to a slurry outlet. This allows the slurry flow to be switched on or off, i.e., shut off, across the entire working width, in sections and / or at specific points.

[0022] Advantageously, this allows the agricultural area to be fertilized in sections and / or at specific locations, for example, depending on plant growth data obtained via GPS technology or sensor units arranged on the distribution device. Furthermore, partial shutoff of the slurry flow is possible, for example, at the edge of the area. Finally, the distribution device according to the invention can, depending on the crop to be fertilized, for example, only switch on every second, third, etc. slurry outlet, i.e., supply it with a slurry flow.

[0023] The individual pinch valves are preferably pressurized using compressed air supplied by the tractor. The control, i.e., the pressurization of the individual pinch valves, is carried out primarily by a central processing unit designed as an on-board computer.

[0024] In a preferred embodiment of the distribution device according to the invention, the pinch valves in the lines extending from the distributor head to the slurry outlets are located in the immediate vicinity of the distributor head. This allows the entire line section extending from the distributor head to the slurry outlet to drain if blocked by the pinch valve. This advantageously prevents clogging by drying slurry in the blocked line section. This embodiment is particularly suitable for viscous slurry containing solids.

[0025] In a further preferred embodiment of the distribution device according to the invention, the pinch valves are arranged in the lines, extending from the distributor head to the slurry outlets, in the immediate vicinity of the outlets. This results in an immediate shutoff of the slurry flow after pressure is applied to the pinch valve. This advantageously virtually eliminates any dripping of slurry still present in the respective shutoff line section. This embodiment is particularly suitable for thin-bodied slurry.

[0026] An exemplary embodiment of the invention is explained in detail below with reference to the drawing. The figure shows a section AA through the pinch valve according to the invention.

[0027] The pneumatic pinch valve (1) comprises a cylindrical housing (2) made of elastic plastic with a Shore hardness of 75 to 95, with two diametrically arranged, bulbous extensions (3, 3'), a connecting piece (4) for a compressed air supply, and undercuts (5, 5') formed on the upper and lower edges for receiving fixing means. An air-pressure-tight housing interior (10) is created via two rigid pipe sections (6, 6') inserted into the shut-off element (9), the elastic housing, the elastic shut-off element (9), and the fixing means (7, 7') applied to the upper and lower edges. In a distribution device for a slurry spreading vehicle, the pinch valve is formed in a line section, a generally flexible line (8, 8') leading from the distributor head to the slurry outlet.

[0028] Located inside the housing is the shut-off element (9), which consists of an elastic hose with a Shore hardness of 40 to 60, at least partially covered with a fabric. The shut-off element (9) rests against the upper and lower edges of the inside of the housing (2). The two rigid pipe sections (6, 6') are inserted into the hose-shaped shut-off element (9).

[0029] The pinch valve according to the invention proves to be cost-effective and low-maintenance, and can also be easily replaced. Accordingly, the pinch valve is used in manure distribution devices. List of reference symbols

[0030] 1 Pinch valve 2 Housing 3 Extensions 4 Connection pieces 5 Undercuts 6 Pipe sections 7 Fixing means 8 Pipe 9 Shut-off element 10 Housing interior

Claims

1. Pneumatic pinch valve (1) for a distributor device for liquid manure, having a cylindrical housing (2) and a hose-shaped shut-off element (9) which is arranged in the cylindrical housing (2) with a connection piece (4) for a compressed air supply, characterized in that the shut-off element (9) is formed from an elastic hose which has a Shore hardness of 40 to 60 and has a fabric at least in sections, and in that the housing (2) is formed from an elastic plastic with a Shore hardness of 75 to 95, at least in sections comprising a fabric and having a Shore hardness of 40 to 60, and in that the housing (2) is formed from an elastic plastic having a Shore hardness of 75 to 95, and in that two diametrically arranged, belly-shaped extensions (3, 3') are formed in the housing (2) for receiving the crimped shut-off element (9).

2. Pinch valve according to claim 1, characterized in that the connection piece (4) for the compressed air is arranged above a bulbous extension (3, 3').

3. Pinch valve according to one of the preceding claims, characterized in that the housing (2) has undercuts (5, 5') at the upper and lower edge for receiving fixing means (7, 7').

4. Pinch valve according to one of the preceding claims, characterized in that the housing (2) is made of polyurethane.

5. Distribution device for a liquid manure spreading vehicle with a plurality of attached pipes (8, 8') extending from a distributor head and leading to liquid manure outlets, characterized in that a pinch valve (1) according to one of claims 1 to 4 is formed in each individual pipe (8, 8') leading to a liquid manure outlet.

6. Distribution device according to claim 5, characterized in that the pinch valves (1) are formed in the pipes (8, 8'), starting from the distributor head to the liquid manure outlets in the immediate vicinity of the distributor head.

7. Distribution device according to claim 5, characterized in that the pinch valves (1) are arranged in the pipes (8, 8'), starting from the distributor head to the liquid manure outlets in the immediate vicinity of the liquid manure outlets.

8. Use of a pinch valve (1) according to one of claims 1 to 4 in distribution devices for liquid manure.