Crop Sprayer Boom

Abstract

This utility model relates to agricultural engineering and is intended for use in plant sprayer designs. It comprises a root section and an end section pivotally connected via a four-link lever-type unfolding mechanism. The root section serves as the post in this mechanism, the end section serves as the second link, the rocker arm pivotally connected to the root section serves as the third link, and the connecting rod serves as the fourth link. The connecting rod is connected to the rocker arm via one hinge, to the end section via a second hinge, and to a drive hydraulic cylinder via a third hinge. The drive hydraulic cylinder is pivotally connected to the root section via an adjusting screw. The piston and rod ends of the drive hydraulic cylinder are connected to a two-way brake valve. This reduces wear on the hinge joints of the boom's end section unfolding mechanism.

Description

[0001] The technical solution relates to agricultural engineering and is intended for use in the design of plant sprayer booms.

[0002] From the description of invention patent RU 2697768, an articulated boom-nozzle holder for an agricultural sprayer is known, comprising a plurality of sequentially connected profile sections. Each profile section contains at least one hinge located between two sequentially connected profile sections. Said hinge has two articulated support elements, interconnected for rotation by a connecting shaft. The connecting shaft is located horizontally. To rotate adjacent profile sections from the unfolded to the folded position or vice versa, a hydraulic drive is provided, connected by two traction levers to the articulated support elements. The described articulated boom-nozzle holder is used in a set of two pieces, which are mounted on the left and right sides of an agricultural sprayer.When operating an agricultural sprayer in a field with the left and right nozzle booms unfolded, uneven field surfaces cause vibrations that are transmitted from the sprayer chassis to the articulated nozzle boom, causing it to swing. There are gaps in the movable joints of the profile section unfolding mechanism. Since there are multiple hinge joints—including the coupling shaft of the articulated support elements, the rotary pairs of the traction levers, and the hydraulic drive rod mounting assembly—these gaps combine to create a large total play. Vertical swinging of the nozzle boom on uneven fields, combined with this large total play, will accelerate damage to the pivot pins and holes in the articulated joints of the profile section unfolding mechanism, leading to their failure.

[0003] A known sprayer boom system from the description of the invention patent RU 2714429 is aimed at solving the said problem. The system includes a first sprayer boom connected to a second sprayer boom via a hinge with a horizontal axis of rotation. Rotational movement is achieved by means of a hydraulic drive, one end of which is secured via a hinge joint to a support on the first sprayer boom, and the other end is secured via a hinge joint to a rotary guide mechanism. The rotary guide mechanism consists of a first lever, the lower end of which is secured via a hinge joint via a first pin to a first connecting support located on the first sprayer boom, and a second lever, the lower end of which is secured via a hinge joint via a second pin to a second connecting support located on the second sprayer boom.The first and second levers are connected to each other by a hinge joint (using a third pin) located above the horizontal axis of rotation. The second lever is connected to the second support such that the second pin has a play in the oblong hole. A locking pin is movably mounted in a guide coupling secured to the second rod and is capable of coaxial mating with a locking sleeve secured to the first rod. The locking pin is pivotally connected to one end of the traction lever, the other end of which is pivotally connected to the second lever. The described device, in comparison with the articulated boom-nozzle holder from patent RU 2697768, reduces the large total play from several hinges of the guide rotation mechanism by fixing it with a locking pin inserted into the locking sleeve.However, complete elimination of play is not achieved, as the movable engagement of the locking pin with the guide sleeve and locking sleeve requires guaranteed clearances between the contacting cylindrical surfaces of the locking pin, guide sleeve, and locking sleeve. When the unfolded sprayer boom system is subject to vibration due to uneven terrain, the second boom will be able to rotate relative to the first boom within the specified reduced clearances, and wear on the hinge joints will persist, albeit to a lesser extent.

[0004] The described device is closest to the proposed technical solution and is selected as a prototype.

[0005] The technical problem solved by the proposed device is the elimination of the harmful effects of barbell swing.

[0006] To solve the technical problem, a crop sprayer boom is proposed. It comprises a root section and a tip section, pivotally connected via a four-link lever mechanism. The main link in this mechanism is the root section, the second link is the tip section, the third link is a rocker arm pivotally connected to the root section, and the fourth link is a connecting rod. The connecting rod is connected to the rocker arm via one hinge, connected to the tip section via a second hinge, and connected to a drive hydraulic cylinder via a third hinge. The drive hydraulic cylinder is pivotally connected to the root section via an adjusting screw, and the piston and rod ends of the drive hydraulic cylinder are connected to a two-way brake valve.In a particular case of the design, the root section may contain a conical stop for mating with a conical counter part fixed to the end section in the position of full unfolding of the end section.

[0007] The proposed device allows to obtain a technical result, which consists in reducing the wear of the hinge joints of the mechanism for unfolding the end section of the rod.

[0008] The proposed agricultural sprayer boom shares features with the prototype described in patent RU 2714429, which includes a root section and an end section that rotates relative to it. The end section in the proposed device, like that in the prototype, is unfolded using a four-link lever mechanism (referred to in the prototype as a guiding rotary mechanism). The four-link lever mechanism's support is the root section (referred to in the prototype as the first boom), and the second link is the end section (referred to in the prototype as the second boom). The third link is the rocker arm (referred to in the prototype as the first lever), and the fourth link is the connecting rod (referred to in the prototype as the second lever). The links are connected by hinges with horizontal axes.Just like in the prototype, in the proposed device the connecting rod is pivotally connected to the drive hydraulic cylinder, which in turn is pivotally connected to the root section.

[0009] The difference is that the prototype's end section is secured in the unfolded position using a locking pin inserted into a locking sleeve. In the proposed device, the end section of the boom is locked by hydraulically locking the piston and rod cavities of the drive hydraulic cylinder using a two-way brake valve. Furthermore, in the prototype, the hydraulic cylinder is pivotally connected to the root section support hole using a pin, while in the proposed sprayer boom, an additional adjusting screw is used to pivotally attach the drive hydraulic cylinder to the root section. In a particular design, the root section may have a conical stop for mating with a conical mating part attached to the end section.

[0010] The proposed technical solution is illustrated by the drawings in Figs. 1, 2, 3, 4, 5, 6. Fig. 1 shows a general view of the boom of the agricultural crop sprayer in the unfolded state. Fig. 2 shows the device in an intermediate stage of folding. Fig. 3 shows an enlarged image of the four-link lever mechanism for unfolding and the drive hydraulic cylinder. Fig. 4 shows the hydraulic circuit for connecting the drive hydraulic cylinder to the two-way brake valve. Fig. 5 shows a conical stop, and Fig. 6 shows a self-propelled sprayer with a boom installed on it in a fully folded position.

[0011] According to Figs. 1 and 2, the proposed boom of a sprayer for agricultural crops includes a root section 1 and an end section 2, which, thanks to a hinge 3, can rotate relative to the root section 1 when moving from the folded position to the unfolded position and back. Known spray nozzles (not shown) are located along the entire length of the end and root sections. Folding and unfolding of the boom is carried out with the help of a four-link lever mechanism 4 (Fig. 2), in which the root section 1 is a stand with hinges 3 and 5. Through hinge 3, as already indicated, the end section 2 is connected, which is the second link of the four-link mechanism, and through hinge 5 the rocker arm 6 (Fig. 3), which is the third link of the four-link mechanism, is attached. The connecting rod 7 is the fourth link of the four-link mechanism. It is connected by hinge 8 to rocker 6 and by hinge 9 to end section 2.A drive hydraulic cylinder 11 is connected to the connecting rod by means of a hinge 10, which is connected by means of a hinge 12 to an adjusting screw 13 installed, as an example of a specific design, in an opening in a bracket 14 of the root section. The adjusting screw 13 may have a different design ensuring the same technical result. For example, as shown in Fig. 3, the threaded portion of the adjusting screw 13 may end in an eye 15, which is inserted into the fork-eye of the drive hydraulic cylinder. For setting the desired position of the adjusting screw, nut 17 is used, as an example. The piston and rod cavities of the drive hydraulic cylinder 11 are connected in a known manner to a two-way brake valve 18, connected to a hydraulic distributor 19, as shown in Fig. 4.To achieve the same technical result, various known designs of double-acting brake valves can be used in combination with corresponding known hydraulic distributors. Fig. 4 shows one example of a specific design.

[0012] The end section 2 has the ability to rotate to the final unfolded position until it contacts the flat stop 20 on the root section 1 (Fig. 3). In a particular case of the design, the root section can be equipped with a stop 21 of a conical shape, as shown in Fig. 5, for mating with the mating part 22 of a conical shape, fixed on the end section.

[0013] The proposed boom for an agricultural crop sprayer can be used on self-propelled sprayers, as well as trailed or mounted sprayers. Fig. 6 shows a self-propelled sprayer 23 equipped with the proposed boom in a folded position, in which the root section 1 is positioned along the self-propelled sprayer by rotating about the axis 24, and the end section 2 is placed on top of the root section, resting on a bracket 25. The sprayer is equipped with a tank 26 for the liquid preparation.

[0014] The proposed device operates as follows. To perform the treatment of plants with liquid protective preparations, the self-propelled sprayer 23 reaches the field, while the root section 1 of the boom is in the folded state along the body of the self-propelled sprayer, and the end section 2 of the boom is laid on top of the end section, resting on the bracket 25 (Fig. 6). Typically, the sprayer is equipped with two folding booms - right (shown in Fig. 6) and left, which in the folded position provide a decrease in the overall width for ease of movement along the roads to the field and back. Before performing a working pass across the field, the root section 1 of the boom is unfolded by turning it around the axis 24 and secured with any known clamps in a position perpendicular to the direction of movement of the sprayer. Then, by retracting the rod of the drive hydraulic cylinder 11 (Fig.2 and 3) move the link of the four-link lever mechanism - connecting rod 7, with the simultaneous rotation of rocker 6 on the axis of hinge 5 and end section 2 on the axis of hinge 3. End section 2 should take a fully unfolded position upon contact with stop 20. To ensure contact with stop 20, it is necessary, before driving out onto the field, to set the adjusting screw 13 by rotating nuts 17 to a position in which the hydraulic cylinder rod would have some travel reserve after the end section has contacted stop 20. Since in each of hinges 3, 5, 8, 9, 10 and 12 there are guaranteed gaps between the axes and holes, then after stopping the rotation of end section 2 upon contact with stop 20, the rod of the drive cylinder will still be able to move forward some distance, as far as the total gap in the listed hinges allows.After this, the pressure supply to the hydraulic cylinder is stopped, and the end section is fixed in the unfolded state thanks to the two-way brake valve 18, to which the piston and rod cavities of the drive hydraulic cylinder are connected.

[0015] When sprayer 23 is working across the field, the liquid product is supplied from tank 26 through nozzles to the plants in accordance with the application rate specified in the process specification. Due to unevenness in the field, the resulting jolts and vibrations of the chassis are transmitted to the large boom, which swings. Under the influence of the resulting inertial forces, end section 2 tends to rotate toward the folding direction. This is prevented by the absence of play in the hinge joints of the four-link folding mechanism, which is achieved by setting adjusting screw 13 to the required position, as well as by hydraulically locking the piston and rod cavities of the drive hydraulic cylinder, which are connected to a two-way brake valve. By preventing the hinge pins from colliding with the mating surfaces of the openings during boom swing, wear on the hinge joints of the end section folding mechanism is reduced.

[0016] By installing a conical, rather than flat, stop 21 on the root section to mate with a conical counter-part 22 secured to the end section, the technical result can be enhanced. In this case, the unfolded end section 2 is secured not only against rotation around the axis of hinge 3, but also against displacement along the line connecting hinge 3 and conical stop 21 within the radial clearance between the axis and the opening in hinge 3. This further eliminates abrasion wear that could otherwise occur due to shear movements caused by the inertial forces of the swinging boom of the agricultural sprayer.

Claims

1. A boom for spraying agricultural crops, including a root and an end section, pivotally connected by means of a four-link lever folding mechanism, the stand of which is the root section, the second link is the end section, the third link is a rocker arm pivotally connected to the root section, the fourth link is a connecting rod, which is connected by one hinge to the rocker arm, by a second hinge is connected to the end section, and by a third hinge is connected to a drive hydraulic cylinder, characterized in that the drive hydraulic cylinder is pivotally connected to the root section by means of an adjusting screw, and the piston and rod cavities of the drive hydraulic cylinder are connected to a two-way brake valve.

2. The device according to claim 1, characterized in that the root section contains a conical stop for mating with a conical counter part fixed to the end section in the position of full unfolding of the end section.

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