Cutting stock crusher

Abstract

The present invention comprises a stump breaker for use as an attachment for an excavator or other excavator or forest harvester to break down felled tree stumps to ground level, the stump breaker comprising interconnected and interacting assemblies including: an implement-side hydraulic motor assembly including a hydraulic motor housing; a hydraulic system required to control the hydraulic motor disposed within the hydraulic motor housing; and a gearbox connected to the hydraulic motor and mounted on a gearbox housing, the lower end of the gearbox housing being mounted on a flange, and a stump breaker blade holder together with the stump breaker blade being mounted on the flange.

Description

Technical Field

[0001] The present invention is in the field of mechanical engineering and includes an excavator or other excavating machine or an attachment for a forest harvester intended to remove stumps resulting from forest or tree felling. More specifically, the present invention relates to an attachment for a machine (i.e., a stump crusher) used to crush stumps to the same height as the ground.

Background Art

[0002] A very large number of different stump removal or crushing devices that can be attached to tractors, excavators, or other forestry machines or their cams are known in the art.

[0003] Patent Document 1 (GB2449953, 10.12.2008, Brian Mence) describes an automatically loaded wood crusher provided with means for collecting and inserting woody material, crushing means, and an outlet for the crushed material. Thus, in order to crush the material, the crusher includes a rotor and a drive device connected to the rotor, the rotor being equipped with a number of crushing elements, and the means for collecting and inserting the woody material is an excavator bucket. To use this device, it is necessary to previously uproot the stumps generated by tree felling, which is time-consuming and resource-intensive.

[0004] Patent Document 2 (CA2128259, January 5, 1999, Bot Silvio) describes a machine for grinding / milling tree stumps at the same height as the ground. This machine has a sled structure including a fastening loop for releasably connecting the sled to the movable cam of an excavator or other tilling machine. The sled has sliding skis for guiding the device by a cam that moves over the soil adjacent to the stump. The sled is equipped with a drive device having a transmission and an autonomous fuel source. The grinding wheel of the sled is attached to the sled so as to rotate about a horizontal axis and is connected to the transmission of the drive device. The grinding wheel has a working surface for rasping the stump with replaceable teeth, cutting and chipping the stump and digging it up and bringing it to the ground. This is a complex and clumsy device, time-consuming to operate, and the teeth of the working surface wear significantly.

[0005] Patent Document 3 (BR102018070436-2, April 22, 2020, HIMEV INDUSTRIA) describes a stump grinder having a central pivot head assembly attached and fixed near the center of the front of the machine to support and guide a cutter assembly. The rear part of the pivot head assembly is attached to the center of the front part of the frame or body of the stump grinder by a mounting plate. The mounting plate supports the rear part of the pivot head assembly that generally rotates about a vertical axis.

[0006] The main drawbacks of the prior art solutions are that special fasteners and drive devices are required, and the cutting heads used for stump removal cannot be used with the cams or implements of conventional excavators, tractors, or other forestry machines.

[0007] Patent Document 4 (US9382689B2 (CHAPMAN RICHARDT, et al, 05.07.2016)) discloses a stump grinder having a frame that supports a motor and a gearbox, and a bit assembly that is connected to the gearbox. The bit assembly includes a shaft attached to the gearbox assembly and a main bit assembly. The main bit assembly includes one or more cutting blades and a shaft. The shaft is connected to an upper bit assembly at the upper part of the shaft and to a guide bit assembly at the lower part of the shaft. The main bit assembly includes one or two lower cutting blades. The lower cutting edges are attached to the shaft at a point below the attachment point of the upper cutting edges. The lower cutting edges include both a cutting tip and a body. The cutting edges are adapted to engage or "bite into" the stump to be destroyed. The main drawback of the proposed stump grinder is the special frame that is connected to the vehicle. In this solution, since it is necessary to drive the vehicle individually for each stump, it is not possible to crush the stump in difficult-to-access terrain. In principle, the frame only allows the up and down movement of the stump grinder and its horizontal placement on the stump. There is no dynamic three-axis movement of the stump grinder without moving the vehicle, that is, after crushing the stump, the vehicle carrying the stump grinder must move to the next stump. Another drawback is related to the rigidity of the blades, that is, when the stump grinder is placed on the stump and pushed down, the blades may start to bend and break, significantly reducing the productivity of the machine.

[0008] Patent Document 5 (EP2077069A1, BIJL GROENTECHNIEK BV., July 8, 2009) discloses a tree stump drill for removing a tree stump, which includes a rotatable shaft, at least one knife extending radially and connected to the shaft, and a guide element. The guide element is annular and is arranged around the shaft away from the shaft. With the guide element of the tree stump drill, the drill can be better centered on the tree stump to be removed so as to effectively prevent the tree stump drill from sliding or slipping over the tree stump. The guide element supports and connects the blades. However, when the stump crusher is placed on the stump and presses down the structure of the guide element, the blades may start to bend and thus may break.

[0009] Patent Document 6 (EP0214977A1, KETONEN LAURI, March 25, 1987) discloses a tree harvester operating system in which the bidirectional rotation of the tree feeder motor is realized by alternately sending pressurized oil along an additional hose line from a power take-off, and the unidirectional rotation of the cross-cut saw is realized by preventing the operation of the tree feeder motor by an additional valve.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

[0011] Although the hydraulic system can be used in a stump crusher, when excavating a stump, the rotational force applied to the blade always changes. Therefore, it should be noted that the machine operator always needs to check the speed of the cutting head, the pressure applied to the cutting head, etc. As a result, the work becomes quite stressful. Therefore, a solution for a hydraulic control system that can automatically adapt to the resistance when excavating a stump is required. [Means for Solving the Problems]

[0012] The object of the stump crusher according to the present invention is achieved by a simple device that can be attached to an excavator or other forestry machinery tools by means of an attachment plate attached to the stump crusher. Therefore, it is possible to manufacture a corresponding adapter plate that facilitates the attachment of the stump crusher between the stump crusher and the machinery tool. The structure of the stump crusher itself consists of four interconnected assemblies. The lower part of the stump crusher (i.e., the blade holder) is attached to the gearbox housing. The hydraulic motor is connected to the gearbox inside the gearbox housing, and then the gearbox housing is attached to the motor housing. The motor housing has a hydraulic system for controlling the hydraulic motor at the upper part and an attachment plate for attaching the stump crusher to the tool of the working machine (e.g., the boom of an excavator). Thus, a uniform and compact stump crusher is formed by the blade holder composed of the attachment plate of the blade holder. The blade holder tower is welded to the center of the attachment plate, and a blade holder cone (i.e., an auger) is attached to the lower end thereof. Attached to the lower end of the blade holder tower is a vertical blade holder plate to which the replaceable blade of the stump crusher is attached. The blade holder plate is supported from the periphery of the attachment plate to the blade holder plate by blade holder reinforcing ribs to provide stability and reinforcement. The blade holder tower is also supported by two ribs. Its lower end is welded to the blade holder plate, and its upper end is welded to the attachment plate.

[0013] The circular mounting plate of the blade holder of the stump crusher is attached to the flange at the lower end of the gearbox housing by fasteners. The gearbox is fixed to the flange at the upper end of the gearbox by fasteners. Since the gearbox is connected to a hydraulic motor, when the motor rotates, the gearbox rotates together with the housing, and together with it, the blade holder of the stump crusher also rotates. The hydraulic motor is attached to the motor housing, and the motor housing is firmly fixed to the excavator's implement (i.e., the cam) via a mounting plate at the upper part of the motor housing. The hydraulic motor of the stump crusher is completely controlled by a hydraulic system housed in the motor housing. The excavator's hydraulic system is connected to the hydraulic system via hydraulic hoses such that two hoses are for the forward flow / return flow of hydraulic fluid (usually a special hydraulic oil), and a third hose is for the oil return discharge path. The hydraulic system includes a control valve / directional valve that instructs the supply or discharge of oil to the hydraulic motor. Further, the hydraulic system is provided with a pressure relief valve and a check valve, and a hydraulic accumulator is also added to the system to stabilize the operation of the hydraulic motor, so that the rotation of the blade holder of the stump crusher becomes uniform according to the force applied by the implement. This can enhance the productivity of the stump crusher for excavating stumps of various diameters.

[0014] The present invention is described in the appended claims.

[0015] Here, the structure of the stump crusher will be described in more detail with reference to the drawings.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Best Mode for Carrying Out the Invention

[0017] The stump crusher shown in Fig. 1 includes four interconnected and interacting assemblies. On the side of the working machine equipment, there is a hydraulic motor assembly 1 including a motor housing 10. On this side of the working machine equipment, a mounting plate 11 used to fix the stump crusher to the working machine equipment (for example, the boom of an excavator) is attached (for example, welded). If necessary, by using an adapter between the mounting plate 11 and the equipment (shown by a dashed line in the figure), the stump crusher can be used together with the equipment of various working machines (excavators, tractors, or other forestry machines). The hydraulic system required for controlling the hydraulic motor is arranged inside the motor housing 2. Its structure will be described below.

[0018] The motor housing houses a hydraulic motor 12, and a gearbox 20 is connected to the hydraulic motor 12 to ensure smooth and stable rotation of the stump crusher. The gearbox 20 is attached to a gearbox housing 21. Due to the operation of the hydraulic motor, rotation is transmitted to the gearbox, and the gearbox rotates together with the blade holder of the stump crusher. A bearing is arranged between the gearbox and the motor to ensure smooth and unobstructed rotation. A gearbox flange 22 is welded to the lower end of the gearbox housing 21, and the blade holder 3 of the stump crusher is attached thereto with a fastener 23.

[0019] The blade holder 3 of the root crusher consists of a circular mounting plate 31 of the blade holder attached to the gearbox flange 22 of the gearbox housing 21 by a fastener 23. A blade holder tower 32 is attached to the center of the mounting plate, and at its end there is a cone 33 of the root, which is a conical auger. This is necessary to facilitate the entry of the root crusher into the root. When the rotating root crusher is applied to the root, the auger begins to draw the root crusher into the root together with the root crusher, thus accelerating the reach of the blades of the root crusher to the root. At the same time, with the auger, the operator can guide the root crusher relatively accurately to the center of the root. The blade holder tower is supported from two sides by tower reinforcing ribs 34 to ensure rigidity, the upper end of which is welded to the mounting plate, and the lower end is welded to the blade holder of the root crusher. A horizontal blade holder 35 is arranged at the lower end of the blade holder of the root crusher. At about 2 / 3 of the distance from the blade holder tower, the blade holder is supported by a horizontal blade holder reinforcing rib 36, and the upper end of which is welded around the mounting plate of the blade holder. This avoids the blades of the root crusher from bending when the root crusher is pushed into the root. A step is formed in the blade holder of the root crusher to which the replaceable blade 37 of the root crusher is attached. In the exemplary embodiment shown in the drawings, the root crusher has two blade holders with replaceable blades 37. Thus, the structure of the blade holder assembly of the root crusher is balanced and the structure will not break under the forces acting on the structure.

[0020] A hydraulic system for controlling the hydraulic motor of a stump grinder includes three inlet nozzles 101, 102, 103 that are initially connected by hydraulic hoses to the hydraulic system of the excavator's implement. Thus, two inlet nozzles 101 and 102 are for the forward and return flow of the fluid (usually a special hydraulic oil) used by the hydraulic system, and the third nozzle 103 is for discharging the return flow of the oil. The nozzles are connected via pipes to a control valve / directional valve 104 that controls the operation of the hydraulic system and the motor. The control valve / directional valve 104 is used to direct oil to the hydraulic motor 12 via various connection channels (pipes) to start the hydraulic motor 12 and change the rotational speed of the hydraulic motor 12 according to the load resulting from stump excavation. The return flow of all fluids moving to the hydraulic system is through the control valve. Also, pressure limiters 106, 107 are arranged between the forward flow / return flow pipes. A check valve 115 is used within the hydraulic system to restrict the return flow of the hydraulic fluid. To control the operation of the motor, additional first and second control valves 108, 109 are attached to both outlets of the motor to control the fluid returning from the motor in front of the control valves. The first additional control valve 108 is also connected to the motor's control valve 110 via a pressure limiter 117. The second additional control valve 109 is connected to the engine control lever 116 and further connected to the hydraulic accumulator 111. An additional valve 112 is connected in front of a control valve 118 that is connected between the inlet nozzles to a proportional valve / pressure limiter 113. The control valve 118 equalizes the pressure during stump crushing and enables automatic control of the hydraulic motor by increasing or decreasing the speed of the hydraulic motor without operator intervention. Thus, the stump grinder according to the present invention can automatically adapt to the resistance force during stump excavation.

[0021] The proportional valve / pressure limiter 113 is connected to the hydraulic accumulator 111 and to the discharge path of the return flow of the fluid to the work machine's system. An additional throttle 114 is arranged between the hydraulic accumulator and the valve / pressure limiter 113.

[0022] The structure of the gearbox of the stump crusher is designed to reduce the angular velocity of the motor shaft in order to lower the rotational speed of the stump crusher, while increasing the torque and transmission force of the stump crusher. As the gearbox, a multi-stage planetary gearbox composed of an external gear and an internal gear is used. The purpose of using the gearbox is obvious to those skilled in the art, and the gearbox used in the structure of the stump crusher has no difference compared with the gearboxes known in the art, so the structure of the gearbox does not require further explanation. On the other hand, it is important to reduce the engine speed and increase the torque.

[0023] The operation of the stump crusher according to the present invention is simple and rapid. For example, it can be attached to an excavator with a minimum output of 74 kW (about 100 hp), a hydraulic pressure of the instrument of 195 - 350 bar (19500 kPa - 35000 kPa), an oil flow rate of 110 - 220 l / min, and an excavator weight of 16 - 30 t (tons), and when placed on the stump, it can guarantee sufficient pressure on the stump crusher. The weight of the stump crusher itself is in the range of 450 - 650 kg.

[0024] To use the stump crusher, attach it to the excavator's implement and, if necessary, use an adapter as a spacer to attach the stump crusher to implements of various sizes. Next, to control the motor of the stump crusher, the excavator's hydraulic system is connected to the hydraulic system via a hose. Using the excavator's implement, the stump crusher is lifted onto the stump of the felled tree, and the operator of the excavator can align the stump crusher with the center of the stump using a cone or auger at the end of the blade holder tower of the stump crusher. The operator starts the hydraulic motor of the stump crusher, uses the excavator's implement to push the auger into the stump, and as the stump crusher rotates, the auger pulls the stump crusher in, and the horizontal blade of the stump crusher crushes the stump to the same height as the ground or up to 1 meter below the ground. Next, the stump crusher is lifted and directed towards the next stump. An important part of the entire work process is that the hydraulic system automatically controls the motor speed without operator interference. It is also important that the stump does not need to be pulled out of the ground before crushing in the stump crushing process. As a result of crushing the stump with the stump crusher according to the present invention, a flat and horizontal ground remains, and a new tree can be planted there. Also, the area where the stump has been crushed can be immediately used by other machines without obstacles. Using the stump crusher according to the present invention is particularly time-saving and effective when renewing urban parks. By using the stump crusher, the stump can be removed in just 20 seconds, and it is also possible to excavate to a depth of up to 1 meter, and the new hole can be immediately used for planting a new tree.

Explanation of Signs

[0025] 1 Hydraulic motor assembly 10 Motor housing 11 Mounting plate 2 Motor housing 12 Hydraulic motor 20 Gearbox 21 Gearbox housing 22 Gearbox flange 3 Blade holder 23 Fastener 31 Mounting plate of blade holder 32 Blade holder tower 33 Cone of cut-off stock crusher 34 Tower reinforcing rib 35 Horizontal blade holder 36 Horizontal blade holder reinforcing rib 37 Replaceable blade 101, 102, 103 Inlet nozzles for connecting hydraulic hoses 101 First nozzle for forward diversion 102 Second nozzle for return diversion 103 Third nozzle for discharging return flow of oil 104 Control valve / directional valve 106, 107, 117 Pressure limiters 108 First control valve 109 Second control valve 110 Control valve of motor 111 Hydraulic accumulator 112 Additional valve 113 Valve / pressure limiter 114 Additional throttle 115 Check valve 116 Engine control lever 118 Control valve

Claims

1. A stump crusher comprising assemblies that are interconnected and interact with each other, said assemblies comprising a hydraulic motor assembly (1) on the side of the work machine implement, said hydraulic motor assembly (1) comprising a hydraulic motor housing (10) and a mounting plate (11) attached to an end of said work machine implement for attaching said stump crusher to said work machine implement, a hydraulic system necessary for controlling the hydraulic motor (12), said hydraulic system being disposed within said hydraulic motor housing (2), a gearbox (20) connected to said hydraulic motor (12) and attached to a gearbox housing (21), a lower end of said gearbox housing (21) being attached to a gearbox flange (22), and a blade holder (3) of said stump crusher being attached to said gearbox flange (22), in said stump crusher as described above, said blade holder (3) of said stump crusher consists of a circular mounting plate (31) of said blade holder attached to said gearbox flange (22) by a fastener at a lower end of said gearbox housing (21), a blade holder tower (32) is attached to a center of said circular mounting plate (31), and a cone (33) of said stump crusher is at an end of said blade holder tower (32), said blade holder tower (32) is supported from two sides by tower reinforcing ribs (34) to ensure rigidity, an upper end of said tower reinforcing ribs (34) being welded to said circular mounting plate (31), and a lower end being welded to said blade holder of said stump crusher, a horizontal blade holder (35) is disposed at a lower end of said blade holder (3) of said stump crusher, said horizontal blade holder (35) being supported by a horizontal blade holder reinforcing rib (36) at a position that is about 2 / 3 of a distance from said blade holder tower (32) to an outer end in said horizontal blade holder (35), an upper end of said horizontal blade holder reinforcing rib (36) being attached around said circular mounting plate (31) of said blade holder, The horizontal blade holder (35) of the cutting stock crusher is provided with a step, and an exchangeable blade (37) of the cutting stock crusher is attached to the step. The cutting stock crusher is characterized by this.

2. The hydraulic system for controlling the hydraulic motor of the cutting stock crusher includes three inlet nozzles (101, 102, 103) to which the hydraulic system of the work machine equipment is connected by hydraulic hoses. Two inlet nozzles (101, 102) are for the forward flow and return flow of the fluid used in the hydraulic system, and the third inlet nozzle (103) is for the discharge of the return flow of the fluid. The three inlet nozzles (101, 102, 103) are connected to a control valve / directional valve (104) via pipes. The control valve / directional valve (104) is used to direct oil to the hydraulic motor via pipes in order to start the hydraulic motor and change the rotational speed. The return flow of the fluid moving within the hydraulic system is performed via the control valve / directional valve (104). The hydraulic system includes pressure limiters (106, 107) between the forward flow / return flow pipe and an additional first control valve (108) and an additional second control valve (109) both attached to the outlet of the motor in front of the control valve (110) that controls the operation of the motor. The cutting stock crusher according to claim 1 is characterized by this.

3. The additional first control valve (108) is connected to the control valve (110) of the motor via a pressure limiter (117). The additional second control valve (109) is connected to the motor control lever (116) and the hydraulic accumulator (111) of the cutting stock crusher. The cutting stock crusher according to claim 2 is characterized by this.

4. An additional third valve (112) is connected in front of a control valve (118) that is connected to a proportional valve / pressure limiter (113) between the two inlet nozzles (101, 102). The proportional valve / pressure limiter (113) is connected to the hydraulic accumulator (111) and the discharge path of the return flow of the fluid to the system of the machine. The cutting stock crusher according to claim 3 is characterized by this.

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