Hydraulic circuit for adjusting coulter pressure and blower speed on an agricultural spreading machine

Abstract

The invention relates to a hydraulic circuit (10) for adjusting coulter pressure and blower speed on an agricultural spreading machine, comprising a first line section (22) which is configured to be connected to at least one coulter pressure adjusting cylinder (104) and to supply a hydraulic pressure to the coulter pressure adjusting cylinder (104), a second line section (28) which is configured to be connected to a hydraulically driven blower (108) and to supply a hydraulic pressure to the blower (108), and a hydraulic valve (14) for adjusting the hydraulic pressure in the first line section (22) and the hydraulic pressure in the second line section (28).

Description

[0001] The invention relates to a hydraulic circuit for adjusting the coulter pressure and fan speed on an agricultural spreading machine according to the preamble of patent claim 1, a hydraulic control block according to the preamble of patent claim 7, an agricultural spreading machine according to the preamble of patent claim 8 and a method for adjusting the coulter pressure and fan speed on an agricultural spreading machine according to the preamble of patent claim 9.

[0002] The pressure supply to the coulter pressure adjustment cylinders of an agricultural spreading machine is currently provided via a line section of a hydraulic circuit, which is also connected to a hydraulically driven fan. A two-way flow regulator is located upstream of the coulter pressure adjustment cylinder. Therefore, only the hydraulic pressure in the shared line section, which is set by the fan, is available for the coulter pressure.

[0003] At high fan speeds, for example when sowing barley, wheat, peas, or beans, a comparatively high hydraulic pressure is present in the common line area, so that the required coulter pressure can usually be easily adjusted at high fan speeds. At low fan speeds, for example when sowing rapeseed or grass, only a comparatively low hydraulic pressure is present in the common line area, which in many applications is not sufficient to generate the intended coulter pressure via the coulter pressure adjustment cylinder. Due to the insufficient coulter pressure, the intended sowing depths cannot then be maintained, which can impair germination and plant growth.

[0004] The object underlying the invention is therefore to enable coulter pressure settings on an agricultural spreading machine which are independent of the hydraulic pressure applied to the fan.

[0005] The problem is solved by a hydraulic circuit of the type mentioned above, wherein the hydraulic valve of the hydraulic circuit according to the invention is designed as a 3-way flow control valve. Due to the use of the 3-way flow control valve, the required hydraulic pressure is always present at the coulter pressure adjustment cylinder, regardless of the hydraulic pressure applied to the fan. Even at low fan speeds, where, for example, a hydraulic pressure of less than 50 bar must be applied to the fan, high hydraulic pressures, for example 100 bar or more, can be present at the coulter pressure adjustment cylinder. The hydraulic pressure applied to the coulter pressure adjustment cylinder can therefore be higher than the hydraulic pressure applied to the fan. The hydraulic valve designed as a 3-way flow control valve ensures that the coulter pressure can always be adjusted as desired, regardless of the hydraulic pressure required by the fan motor.At the same time, the speed of the fan can be adjusted independently of the coulter pressure via the tractor control unit.

[0006] In a preferred embodiment of the hydraulic circuit according to the invention, the first line section is connected to a first valve outlet of the hydraulic valve. The second line section is preferably connected to a second valve outlet of the hydraulic valve. The valve inlet of the hydraulic valve is connected to an inlet line of the hydraulic circuit, wherein hydraulic fluid can be introduced from a tractor-side hydraulic source into the inlet line of the hydraulic circuit via an inlet connection.

[0007] In a further preferred embodiment of the hydraulic circuit according to the invention, the first valve outlet of the hydraulic valve connected to the first line region is a priority outlet of the hydraulic valve that limits the volume flow to a volume flow limit. Alternatively, the second valve outlet of the hydraulic valve connected to the second line region can be a priority outlet of the hydraulic valve that limits the volume flow to a volume flow limit.

[0008] In another preferred embodiment of the hydraulic circuit according to the invention, the hydraulic valve is configured to limit the volume flow at the priority outlet to a volume flow limit in the range of 4-8 l / min, preferably in the range of 5-7 l / min. If the volume flow flowing into the hydraulic valve is above the volume flow limit, the excess volume flow above the volume flow limit is discharged from the hydraulic valve through a secondary outlet of the hydraulic valve. If the volume flow limit at the priority outlet of the hydraulic valve is, for example, 6 l / min, the volume flow portion above 6 l / min is discharged from the hydraulic valve through the secondary outlet rather than the priority outlet.

[0009] In a further preferred embodiment of the hydraulic circuit according to the invention, the second valve outlet of the hydraulic valve connected to the second line section is a secondary outlet of the hydraulic valve, via which the volume flow that cannot be discharged via the priority outlet due to the volume flow limitation at the priority outlet can be discharged from the hydraulic valve. Alternatively, the first valve outlet of the hydraulic valve connected to the first line section can be a secondary outlet of the hydraulic valve, via which the volume flow that cannot be discharged via the priority outlet due to the volume flow limitation at the priority outlet can be discharged from the hydraulic valve.

[0010] In a further development, the hydraulic circuit according to the invention comprises a pressure relief valve configured to limit the hydraulic pressure in the first line section to a maximum pressure. If the first line section is connected to a coulter pressure adjustment cylinder and provides a hydraulic pressure to the coulter pressure adjustment cylinder, the hydraulic pressure specified for the coulter pressure adjustment cylinder can be adjusted via the pressure relief valve, provided that the pressure is limited by the pressure relief valve.

[0011] The object underlying the invention is further achieved by a hydraulic control block of the type mentioned above, wherein the hydraulic circuit of the hydraulic control block according to the invention is designed according to one of the embodiments described above. With regard to the advantages and modifications of the hydraulic control block according to the invention, reference is therefore first made to the advantages and modifications of the hydraulic circuit according to the invention.

[0012] The housing of the hydraulic control block, into which the hydraulic circuit is integrated, can be made of plastic or metal, for example. For example, the housing is an injection-molded plastic housing or an injection-molded aluminum housing.

[0013] The hydraulic control block preferably has a cylinder connection via which at least one coulter pressure adjustment cylinder can be connected to the first line section. The hydraulic control block preferably has a blower connection via which a hydraulically driven blower can be connected to the second line section. Furthermore, the hydraulic control block preferably has an inlet connection and a return connection. Hydraulic fluid from a tractor-side hydraulic source can be introduced into the hydraulic circuit via the inlet connection. Hydraulic fluid from the hydraulic circuit can be supplied to a tractor-side hydraulic tank via the return connection.

[0014] The object underlying the invention is further achieved by an agricultural spreading machine of the type mentioned above, wherein the hydraulic circuit of the agricultural spreading machine according to the invention is designed according to one of the embodiments described above or is a component of a previously described hydraulic control block. With regard to the advantages and modifications of the agricultural spreading machine according to the invention, reference is therefore first made to the advantages and modifications of the hydraulic circuit according to the invention and the advantages and modifications of the hydraulic control block according to the invention.

[0015] The agricultural spreading machine can, for example, be a seed drill. The spreading machine can be designed as an attachment. The coulter can be a sowing coulter of a precision seed drill unit. The coulter can be arranged together with other coulters on a carrier, with the coulter pressure adjustment cylinder acting on the carrier and generating a uniform coulter pressure for coulters arranged together on the carrier. In particular, the carrier is rotatable by means of the coulter pressure adjustment cylinder, with a coulter pressure being adjusted on the coulters arranged together on the carrier depending on the angle of rotation of the carrier. The number of coulters arranged together on the carrier is preferably taken into account for controlling the coulter pressure adjustment cylinder.

[0016] The object underlying the invention is further achieved by a method of the type mentioned at the outset, wherein the hydraulic valve, by means of which the hydraulic pressure in the first line region and the second line region is adjusted, is designed as a 3-way flow control valve. The method is preferably used to adjust the coulter pressure and the fan speed on an agricultural spreading machine according to one of the embodiments described above. In the method according to the invention, the coulter pressure and the fan speed are preferably adjusted by means of a hydraulic circuit according to one of the embodiments described above. With regard to the advantages and modifications of the method according to the invention, reference is therefore made to the advantages and modifications of the agricultural spreading machine according to the invention and the advantages and modifications of the hydraulic circuit according to the invention.

[0017] Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings. Fig. 1 an embodiment of the hydraulic circuit according to the invention including blower in a perspective view; and Fig. 2 an embodiment of the hydraulic circuit according to the invention including coulter pressure adjustment cylinder and blower in a schematic representation.

[0018] The Fig. 1 shows a hydraulic circuit 10 for adjusting the coulter pressure and fan speed on an agricultural spreading machine. The hydraulic circuit 10 has an inlet line 12, via which a hydraulic fluid, for example hydraulic oil, can be introduced into the hydraulic circuit 10 from a tractor-side hydraulic source 202 (not shown). The hydraulic fluid reaches a hydraulic valve 14, which is designed as a 3-way flow control valve, via the inlet line 12. The inlet line 12 is connected to the valve inlet 16 of the hydraulic valve 14. The valve outlet 18 of the hydraulic valve 14, designed as a priority outlet, is to be connected to at least one coulter pressure adjustment cylinder 104 (not shown), so that a hydraulic pressure is specified for the coulter pressure adjustment cylinder 104 via the valve outlet 18. At the valve outlet 18, a volume flow is limited to a valve-specific volume flow.The volume flow limit value can, for example, be in the range of 4 to 8 l / min, in particular in the range of 5 to 7 l / min.

[0019] The second valve outlet 20 of the hydraulic valve 14 is a secondary outlet of the hydraulic valve 14, through which the volume flow that cannot be discharged via the priority outlet due to the volume flow limitation at the priority outlet can be discharged from the hydraulic valve 14. The valve outlet 20 is connected to a hydraulic drive 108 of the blower via the connecting line 106 and supplies a hydraulic pressure to the drive 108.

[0020] The Fig.2 shows a hydraulic circuit 10 integrated into a housing 52 of a hydraulic control block 50. The hydraulic control block 50 has an inlet connection 54, via which hydraulic fluid, for example hydraulic oil, can be introduced from a hydraulic source 202 of a tractor-side hydraulic unit 200 into the hydraulic circuit 10. For this purpose, an inlet line 100 runs between the inlet connection 54 of the hydraulic control block 50 and the hydraulic unit 200. Via an inlet line 12 connected to the inlet connection 54, the hydraulic fluid then reaches a hydraulic valve 14 designed as a 3-way flow control valve. The hydraulic fluid flowing into the hydraulic valve 14 via the valve inlet 16 can leave the hydraulic valve 14 again via the valve outlets 18, 20. The valve outlet 18 is designed as a priority outlet, so that a volume flow limitation to a volume flow limit value occurs at the priority outlet.This can, for example, be in the range of 5 to 7 l / min. The valve outlet 20 of the hydraulic valve 14 is a secondary outlet of the hydraulic valve 14, via which the volume flow that cannot be discharged via the priority outlet due to the volume flow limitation at the priority outlet is discharged from the hydraulic valve 14. From the valve outlet 18, the hydraulic fluid flows into a line section 22, which is connected to at least one coulter pressure adjustment cylinder 104 via a connecting line 102. The line section 22 supplies a hydraulic pressure to the coulter pressure adjustment cylinder 104. The hydraulic control block 50 has a cylinder connection 56, via which the coulter pressure adjustment cylinder 104 is connected to the line section 22.

[0021] The hydraulic circuit 10 further comprises a pressure relief valve 24, which limits the hydraulic pressure in the line region 22 to a maximum pressure. The hydraulic pressure specified for the coulter pressure adjustment cylinder 104 can thus be set via the pressure relief valve 24. The hydraulic fluid leaving the pressure relief valve 24 is fed to a return connection 60 via an outlet line 26. The return connection 60 is connected to a hydraulic tank 204 of the tractor-side hydraulic unit 200 via a return line 110, so that hydraulic fluid can be returned to the hydraulic tank 204 via the return line 110.

[0022] The valve outlet 20 of the hydraulic valve 14 is connected to another line section 28 of the hydraulic circuit 10. The line section 28 is connected to a hydraulic drive 108 of the blower and supplies a hydraulic pressure to the drive 108. The hydraulic valve 14 thus serves to adjust the hydraulic pressure in the line section 22 and to adjust the hydraulic pressure in the line section 28. The drive 108 of the blower is connected via the blower connection 58 and the connecting line 106 to the valve outlet 20 of the hydraulic valve 14, which is designed as a secondary outlet.

[0023] By using the hydraulic valve 14, designed as a 3-way flow control valve, the required hydraulic pressure is always present at the coulter pressure adjustment cylinder 104, regardless of the hydraulic pressure applied to the fan drive 108. Even at low fan speeds, where, for example, a hydraulic pressure of less than 50 bar must be applied to the fan drive 108, high hydraulic pressures, for example 100 bar and more, can be applied to the coulter pressure adjustment cylinder 104. The hydraulic pressure applied to the coulter pressure adjustment cylinder 104 can therefore be higher than the hydraulic pressure applied to the fan drive 108. The hydraulic valve 14, designed as a 3-way flow control valve, thus always ensures that the coulter pressure can be adjusted as desired.

[0024] The coulter pressure adjustment cylinder 104 can, for example, act on a carrier on which several coulters, in particular sowing coulters, are arranged. Thus, the several sowing coulters can be subjected to a uniform coulter pressure via the common carrier. The carrier can also be rotatable by means of the coulter pressure adjustment cylinder 104, whereby a coulter pressure is adjusted on the common coulters arranged on the carrier depending on the angle of rotation of the carrier. The number of coulters mounted together on the carrier can be taken into account to control the pressure relief valve 24, which specifies the hydraulic pressure for the coulter pressure adjustment cylinder 104. List of reference symbols 10 Hydraulic circuit 12 Inlet line 14 Hydraulic valve 16 valve inlet 18 Valve outlet 20 valve outlet 22 Management area 24 Pressure relief valve 26 Outlet line 28 Management area 50 hydraulic control block 52 housings 54 Inlet connection 56 cylinder connection 58 Fan connection 60 return connection 100 supply line 102 connecting cable 104 coulter pressure adjustment cylinder 106 connecting cable 108 Drive 110 Return line 200 hydraulic unit 202 Hydraulic source 204 Hydraulic tank

Claims

[1] Hydraulic circuit (10) for adjusting the coulter pressure and fan speed on an agricultural spreading machine, with - a first line region (22) which is designed to be connected to at least one coulter pressure adjustment cylinder (104) and to provide a hydraulic pressure to the coulter pressure adjustment cylinder (104); - a second line region (28) which is designed to be connected to a hydraulically driven blower (108) and to provide a hydraulic pressure to the blower (108); and - a hydraulic valve (14) for adjusting the hydraulic pressure in the first line region (22) and the hydraulic pressure in the second line region (28); characterized by that the hydraulic valve (14) is designed as a 3-way flow control valve. [2] Hydraulic circuit (10) according to claim 1, characterized bythat the first line region (22) is connected to a first valve outlet (18) and the second line region (28) is connected to a second valve outlet (20) of the hydraulic valve (14). [3] Hydraulic circuit (10) according to claim 2, characterized by that the first valve outlet (18) of the hydraulic valve (14) connected to the first line region (22) is a priority outlet of the hydraulic valve (14) limiting the volume flow to a volume flow limit value. [4] Hydraulic circuit (10) according to claim 3, characterized by that the hydraulic valve (14) is designed to limit the volume flow at the priority outlet to a volume flow limit value in the range of 4 to 8 l / min, preferably in the range of 5 to 7 l / min. [5] Hydraulic circuit (10) according to claim 3 or 4, characterized bythat the second valve outlet (20) of the hydraulic valve (14) connected to the second line region (28) is a secondary outlet of the hydraulic valve (14), via which the volume flow that cannot be discharged via the priority outlet due to the volume flow limitation at the priority outlet can be discharged from the hydraulic valve (14). [6] Hydraulic circuit (10) according to one of the preceding claims, characterized by a pressure relief valve (24) which is designed to limit the hydraulic pressure in the first line region (22) to a maximum pressure. [7] Hydraulic control block (50), with - a housing (52), and - a hydraulic circuit (10) integrated into the housing (52); characterized by that the hydraulic circuit (10) is designed according to one of the preceding claims. [8] Agricultural spreading machine, in particular seed drill, with - at least one share, wherein the share pressure on the share is adjustable by means of a share pressure adjustment cylinder (104) of the spreading machine; - a hydraulically driven fan (108), the fan speed being adjustable via the hydraulic pressure applied to the fan (108); and - a hydraulic circuit (10) connected to the coulter pressure adjustment cylinder (104) and the blower (108) and configured to provide hydraulic pressure to the coulter pressure adjustment cylinder (104) and the blower (108); characterized by that the hydraulic circuit (10) is designed according to one of claims 1 to 6 or is part of a hydraulic control block (50) according to claim 7. [9] Method for adjusting the share pressure and the fan speed on an agricultural spreading machine, in particular on an agricultural spreading machine according to claim 8, by means of a hydraulic circuit (10), in particular a hydraulic circuit (10) according to one of claims 1 to 6, comprising the step: - Adjusting the hydraulic pressure in a first line region (22), which is connected to at least one coulter pressure adjustment cylinder (104) and predetermines a hydraulic pressure to the coulter pressure adjustment cylinder (104), and the hydraulic pressure in a second line region (28), which is connected to a hydraulically driven fan (108) and predetermines a hydraulic pressure to the fan (108), by means of a hydraulic valve (14) of the hydraulic circuit (10); characterized by that the hydraulic valve (14) is designed as a 3-way flow control valve.

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