Work machine

Abstract

To provide a work machine that enables stable assist operation.SOLUTION: A work machine comprises: a frame; an apron provided at the rear of the frame, the apron being rotatably connected to the frame so as to enable lowering and flipping up; and an assist mechanism connected to the frame and the apron, the assist mechanism including a gas spring and applying force in a direction to flip up the apron using the force of the gas spring. A force required to flip up the apron increases from 0 degree to a predetermined angle.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a working machine. In particular, the present invention relates to a rotary working machine that is attached to the rear part of a traveling body and tills a field while rotating a tilling rotor and advancing with the forward movement of the traveling body.

Background Art

[0002] Such a rotary working machine has a frame connected to a traveling body and an apron provided behind the frame and capable of descending and bouncing up and rotating about a fulcrum (first fulcrum) fixed to the frame. When scraping off the soil adhering to the front surface portion (the side facing the tilling rotor) of the apron or the tilling rotor or replacing the tilling claws provided on the tilling rotor, the apron is held in a bounced-up state.

[0003] However, since the apron has a certain weight and its center of gravity is behind the fulcrum (first fulcrum), the work of bouncing up the apron is heavy labor for the operator.

[0004] As described in Patent Document 1, in order to facilitate the work of bouncing up the apron, an apron bouncing assist mechanism (assist mechanism) that utilizes the elastic force of a gas spring to assist the bouncing-up force has been proposed. The assist mechanism (assist mechanism) described in this Patent Document 1 has a gas spring provided between a side cover provided at a widthwise end of the working machine body of the rotary working machine and a widthwise end of the apron, and the rod-side end of the gas spring is supported so as to be movable in the vertical direction along a guide hole provided in the side cover. The assist mechanisms (assist mechanisms) described in Patent Documents 2 and 3 are provided with an assist mechanism (assist mechanism) above a shield cover that covers above the tilling rotor.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, since the assist mechanism (auxiliary mechanism) described in Patent Document 1 is provided at the widthwise end of the apron, there is a risk that the gas spring may come into contact with obstacles such as ridges and side walls during work and be damaged.

[0007] In addition, in the assist mechanism (auxiliary mechanism) described in Patent Document 2, the piston rod of the gas spring is exposed, and in the assist mechanism (auxiliary mechanism) described in Patent Document 3, since the gas spring is used lying on its side, nitrogen gas may leak from the gas spring in both cases, and it is necessary to further improve the durability.

Means for Solving the Problems

[0008] The working machine according to an embodiment of the present invention is mounted on the rear part of a traveling body, and in the working machine that tills a field while rotating a tilling rotor and advancing with the forward travel of the traveling body, the working machine is a frame (a concept including a main frame and a shield cover. The same applies hereinafter.) connected to the traveling body, an apron provided behind the frame and capable of descending and bouncing up and rotating about a first fulcrum fixed to the frame, and having its center of gravity behind the fulcrum, and is provided between a second fulcrum fixed to the frame and a third fulcrum fixed to the apron, and the second An assist mechanism including a gas spring that applies a force in a direction to bounce up the apron by applying a force that changes the distance between the fulcrum and the third fulcrum. The gas spring includes a cylinder, a piston inserted into the interior of the cylinder, a piston rod extending from the piston, a rod guide for stabilizing the piston rod, and a free piston movable within the cylinder compartmented by the cylinder and the piston. Oil is filled between the free piston and the piston and between the piston and the rod guide within the cylinder. The assist mechanism further has a first cylindrical member and a second cylindrical member movable on the same axis. The second fulcrum and one end of the gas spring are connected to the first cylindrical member, and the third fulcrum and the other end of the gas spring are connected to the second cylindrical member.

[0009] In the above working machine, it is desirable that the assist mechanism further has a first cylindrical member and a second cylindrical member movable on the same axis, the second fulcrum and one end of the gas spring are connected to the first cylindrical member, and the third fulcrum and the other end of the gas spring are connected to the second cylindrical member. Also, an opening directed downward may exist at one end on the apron side of the first cylindrical member or the second cylindrical member. Further, a resin collar may be interposed between the first cylindrical member and the second cylindrical member.

[0010] In the above working machine, it is desirable that the gas spring is configured to contract at the point where the apron descends.

[0011] In the above-described working machine, it is desirable that the assist mechanism has a locking mechanism that prevents a force from acting to change the distance between the second fulcrum and the third fulcrum at the point where the apron has descended. The locking mechanism has a rotatable restraining lever provided on the second cylindrical member, and prevents the first cylindrical member from protruding from the second cylindrical member by the restraining lever closing one end of the second cylindrical member, and may be configured to allow the first cylindrical member to protrude from the second cylindrical member by the restraining lever opening one end of the second cylindrical member. Further, the locking mechanism may have means for rotating the restraining lever in a direction to close one end of the second cylindrical member and means for temporarily fixing the restraining lever at a position to open one end of the second cylindrical member.

[0012] In the above-described working machine, the assist mechanism may include a plurality of gas springs.

Advantages of the Invention

[0013] According to the working machine of the present invention, a stable assist operation is possible, and a working machine that also prevents deterioration of the gas spring can be provided. Further, when the apron is in a lowered state, it is possible to prevent the apron from suddenly bouncing up.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the working machine of the present invention will be described with reference to the drawings. However, the working machine of the present invention can be implemented in many different modes and is not to be construed as limited to the description of the examples shown below. In the drawings referred to in the present embodiment, the same parts or parts having the same function are denoted by the same reference numerals, and the repeated description thereof will be omitted. For the sake of convenience of explanation, the terms "upper (top)" or "lower (bottom)" are used, but "upper (top)" or "lower (bottom)" indicates the direction in the working state of the working machine, respectively. Similarly, the terms "front (front side)" or "rear (rear side)" are used, but "front (front side)" indicates the direction of the traveling body that pulls the working machine with respect to the working machine, and "rear (rear side)" indicates the direction of the working machine with respect to the traveling body.

[0016] 〈Example〉 Using FIGS. 1 to 6, the overall configuration of the working machine according to an embodiment of the present invention and the configuration of the flipping assist mechanism (auxiliary mechanism) will be described. The working machine according to an embodiment of the present invention is a working machine that is connected to the rear part of a traveling body such as a tractor, for example, like a tilling machine or a weeding machine, and tills or stirs the soil by rotating the working claws. In the example, a tilling machine is used as an example of the working machine to describe the configuration of the present invention, but the working machine according to the present invention may be a weeding machine or a working machine other than a tilling machine or a weeding machine.

[0017] [Configuration of Working Machine 100] FIG. 1 is a rear view of the working machine according to an embodiment of the present invention. FIG. 2 is a side view of the working machine according to an embodiment of the present invention during tilling. FIG. 3 is a side view of the working machine according to an embodiment of the present invention when the apron is flipped up. The working machine 100 according to the embodiment includes a frame (including a main frame 110 and a shield cover 120), a tilling rotor 102, an apron 130, and the like.

[0018] The main frame 110 is connected to a traveling body such as a tractor. The main frame 110 is cylindrical and has a power transmission shaft inside. It obtains rotational power from a traveling body such as a tractor and changes the direction of the rotation axis to the left and right in the traveling direction. The power transmission shaft in the main frame 110 is connected to the chain case 105 on the side of the working machine 100, and power is transmitted to the rotation shaft 104 of the tilling rotor 102 by the chain transmission mechanism in this chain case 105.

[0019] The tilling rotor 102 is composed of a rotation shaft 104 and a number of tilling claws 103 provided on this rotation shaft 104. As shown in FIG. 1, the number of tilling claws 103 is bent to the right or left in the traveling direction, and the area (width) where each tilling claw 103 digs up the soil overlaps with the adjacent claw 103. This tilling rotor 102 rotates so as to scoop up the soil from the front to the rear in the traveling direction. As a result, soil adheres to the inside of the apron 130.

[0020] The apron 130 can be lowered and bounced up and rotated around a fulcrum 140 fixed to the shield cover 120. The center of gravity of the apron 130 is behind the fulcrum. Therefore, the apron 130 tends to descend due to its own weight. A stainless-steel leveling plate 131 is welded to the tip of the apron 130. The leveling plate 131 is configured to draw a loop from the inside to the outside of the apron 130. This leveling plate 131 levels the field dug up by the tilling rotor 102. Movable extension leveling plates 132 are provided at both ends of the leveling plate 131. By opening the extension leveling plates 132, it becomes possible to level a wide width range together with the leveling plate 131. A compression rod 142 is provided between the pedestal provided on the main frame 110 and the apron 130. The compression rod 142 functions to press the apron 130 and the leveling plate 131 against the field with a certain pressure when the apron 130 is in the lowered state. The magnitude of the force exerted by the compression rod 142 can be adjusted by the operator's operation. Since soil may adhere to the inside of the apron 130, the inside of the apron is covered with a rubber sheet. Also, the inside of the shield cover is covered with a rubber sheet.

[0021] In the embodiment, in addition to the above configuration, an apron bounce-up assist mechanism (auxiliary mechanism) 141 is further provided. The apron bounce-up assist mechanism (auxiliary mechanism) 141 is provided between a fulcrum 151 by a pedestal 111 provided on the main frame 110 and a fulcrum 152 by a pedestal 134 provided on the apron 130, and applies a force that changes the distance between the fulcrum 151 and the fulcrum 152. Specifically, by reducing the distance between the two, a force is applied in the direction of bouncing up the apron 130. This apron bounce-up assist mechanism 141 is provided with a lock mechanism 153. This lock mechanism 153 prevents a force in the direction of reducing the distance between the fulcrum 151 and the fulcrum 152 from acting in the state where the apron 130 has descended (Figure 2).

[0022] [Configuration of the bounce-up assist mechanism] FIG. 4 is a rear view of the jump assist mechanism 141 of the working machine according to an embodiment of the present invention. FIG. 5 is a side view of the jump assist mechanism 141 of the working machine according to an embodiment of the present invention during tilling. FIG. 6 is a side view of the jump assist mechanism 141 of the working machine according to an embodiment of the present invention when the apron jumps up. The jump assist mechanism 141 of the working machine according to the embodiment is composed of an inner cylindrical member 210, an outer cylindrical member 220, and a gas spring 250 located therein and the like.

[0023] [Configuration of Gas Spring] The gas spring 250 is composed of a cylindrical cylinder 251 that encloses a space inside, a piston 256 inserted inside the cylinder 251, a piston rod 252 extending from this piston 256, and a free piston 257. A bracket 253 is provided at the tip of the piston rod 252, and a bracket 254 is provided at the tip of the cylinder 251. Near the other ends of the piston rod 252 and the cylinder 251, a rod guide 258 for stabilizing the piston rod 252 is provided. The free piston 257 is movable within the cylinder compartmentalized by the cylinder 251 and the piston 256. An O-ring made of a plastic resin is fitted between the free piston and the inner wall of the cylinder 251. The first chamber 261 (the chamber on the right side of the free piston 257 in FIGS. 5 and 6) between the free piston 257 and the tip of the cylinder is filled with nitrogen. As the volume of this nitrogen changes, the gas spring 250 expands and contracts like a spring, and when the distance between the brackets 253 and 254 is small, it applies a force in the direction of increasing this distance. The second chamber 260 (the chamber on the left side of the free piston 257 in FIGS. 5 and 6) between the piston 256 and the free piston 257 inside the gas spring 250 and the third chamber 280 (the chamber on the left side of the piston 256 in FIGS. 5 and 6) between the piston 256 and the rod guide 258 are filled with oil. This oil prevents the leakage of the nitrogen gas outside the gas spring 250. An orifice (hole) 259 is formed in the piston 256 along the extension direction of the gas spring 250. The oil filled in the second chamber 260 and the third chamber 280 moves between each other through the orifice 259 formed in the piston 256. Specifically, as the piston rod 252 extends toward the outside of the cylinder 251, the oil in the third chamber 280 moves through the orifice 259 into the second chamber 260, and the distance between the piston 256 and the free piston 257 widens.

[0024] [Configuration of the combination of the inner and outer cylindrical members] The bounce assist mechanism 141 combines an inner cylindrical member 210 and an outer cylindrical member 220 to convert the force in the extension direction of the gas spring 250 into a force in the compression direction. The inner cylindrical member 210 and the outer cylindrical member 220 are movable on the same axis. A resin cylindrical collar (resin collar) (not shown) is provided between them to prevent the generation of abnormal noise due to the sliding between the inner cylindrical member 210 and the outer cylindrical member 220. The bracket 254 of the gas spring 250 is connected to the outer cylindrical member 220 by a pin 271. The pin 271 moves back and forth inside an elongated hole provided in the inner cylindrical member 210. The bracket 253 of the gas spring 250 is connected to the inner cylindrical member 210 by a pin 270. The fulcrum 151 is provided at one end of the inner cylindrical member, and the fulcrum 152 is provided on the outer cylindrical member. As a result, when a force is applied in the direction in which the gas spring 250 extends, conversely, the assist mechanism applies a force in the direction in which the distance between the fulcrum 151 and the fulcrum 152 compresses. As a result, the apron 130 is rotated in the upward bounce direction.

[0025] Based on the above configuration, the gas spring 250 inside the assist mechanism 141 is arranged substantially parallel to the ground (with some inclination), and is not arranged vertically. In a general gas spring, it is desirable to arrange the piston rod below the cylinder from the viewpoints of preventing gas leakage and deterioration of the gas spring. However, according to the embodiment, since the above-described gas spring is used, even if the gas spring is substantially parallel to the ground, gas leakage and deterioration of the gas spring can be suppressed.

[0026] [Configuration of the locking mechanism] The apron lifting assist mechanism 141 is provided with a lock mechanism 153. This lock mechanism 153 prevents a force in the direction of reducing the distance between the fulcrum 151 and the fulcrum 152 when the apron 130 is in the lowered state. As a result, during tilling, the assist mechanism 141 operates and the apron does not jump up. As shown in FIG. 4, the lock mechanism 153 is fixed to the outer cylindrical member 220 and includes a lock bar 230 that rotates about the fulcrum 231, a lever 240 extending therefrom, and a rotation restricting plate 233 that restricts the rotation of the lock bar 230.

[0027] When the lever 240 is tilted downward, the lock bar 230 closes one end of the outer cylindrical member 220, thereby restricting the inner cylindrical member 210 from protruding. As a result, the assist mechanism does not apply a force in the direction of compressing the distance between the fulcrum 151 and the fulcrum 152. When the lever 240 is tilted upward, the lock bar 230 opens one end of the outer cylindrical member 220, so that the inner cylindrical member 210 protrudes. As a result, the assist mechanism applies a force in the direction of compressing the distance between the fulcrum 151 and the fulcrum 152. In this way, during tilling, the lever 240 can be tilted downward to lock the operation of the assist mechanism.

[0028] [Relationship between Assist Operating Force and Apron Angle] FIG. 7 is a graph showing the relationship between the assist operating force and the apron angle (the result of actual measurement using a tillage and weeding machine manufactured and sold by the applicant). When the assist mechanism does not act, it is understood that a substantially constant load is applied from around when the apron angle (the most lowered state is defined as 0°, and the rotation angle is defined as the apron angle as it rotates from this state) exceeds 10°. On the other hand, when the assist mechanism acts, the load decreases almost linearly from near the apron angle of 0°. And the load becomes zero at the point where the apron angle is about 60°. That is, from the operator's perspective, it gradually becomes lighter. Such a load tendency is observed from the positional relationship of each fulcrum in the above embodiment. The gas spring 250 described above has a greater force in the compressed state than in the extended state. However, as the fulcrum 152 approaches the fulcrum 151, the moving distance of the fulcrum 152 with respect to a predetermined rotation angle increases. Therefore, due to the "lever principle", the opposite characteristic (the greater the apron angle, the greater the force 1 exerted by the assist mechanism) is exhibited.

[0029] [Modification Example 1] In the above embodiment, a gas spring having a free piston is used. However, it is also possible to use a conventional gas spring without a free piston. In this case, it is desirable that the piston rod is located below the cylinder in the state where the apron is lowered, which is the normal state. This is because even in a conventional gas spring without a free piston, when the piston rod is located below the cylinder, the internal oil moves to the piston side, preventing the leakage of nitrogen gas.

[0030] [Modification Example 2] In the above embodiment, only one gas spring is shown. However, a plurality of gas springs may be used. In this way, it is possible to obtain sufficient assist force. In particular, in a large tillage and weeding machine or a rice weeding machine having a heavy apron, it is desirable to use a plurality of gas springs. In this case, the assist mechanisms may be arranged at intervals in the width direction of the working machine.

[0031] [Modification Example 3] In the above embodiment, an example in which only one gas spring is provided in one assist mechanism is shown. However, a plurality of gas springs may be used in one assist mechanism. In this way, it is possible to obtain sufficient assist force. Further, the cylindrical member does not have to be a cylinder, and may be an elliptical cylinder having an elliptical cross section or a rectangular tube having a rectangular cross section.

[0032] [Modification Example 4] In the above embodiment, the automatic locking mechanism is configured to only move the restraining lever up and down. However, a spring that biases the restraining lever to rotate in a direction to close one end of the second cylindrical member, and a guide shape (for example, providing a step in the guide) that temporarily fixes the restraining lever at a position where one end of the second cylindrical member is opened may be used. With such a configuration, the apron is automatically locked at the position where it has dropped the most by the biasing spring. Further, by providing a guide shape that temporarily fixes the restraining lever at a position where one end of the second cylindrical member is opened, the lock can be released at the position where the apron has dropped the most, and the apron can be bounced up in the unlocked state.

[0033] [Operational Effects According to the Embodiment] With the above configuration, the following operational effects are achieved.

[0034] First, according to the embodiment of the present invention, since the assist mechanism is not provided at the widthwise end of the apron, the gas spring does not come into contact with obstacles such as ridges and side walls during work and is not damaged. The assist mechanism is provided between the second fulcrum fixed to the frame and the third fulcrum fixed to the apron. Since the frame is a structural member and already has sufficient strength, the durability can be improved.

[0035] Second, on the premise of the configuration of the embodiment of the present invention, the gas spring must be arranged substantially horizontally and substantially parallel to the ground. In a general gas spring (one without a free piston), the possibility of gas leakage tends to be high. According to the embodiment of the present invention, the gas spring has a free piston inside, and the chambers between the free piston and the piston and between the piston and the rod guide are filled with oil respectively. As a result, the possibility that the gas such as nitrogen filled at the tip of the free piston leaks from the gas spring is reduced, the deterioration of the gas spring is prevented, and the life of the gas spring is significantly improved. This also contributes to the reduction of the maintenance cost of the working machine.

[0036] Third, according to the embodiment of the present invention, in the state where the apron has descended (that is, the state during tilling. This state is maintained for a much longer time than the time when the apron has bounced up.), the piston rod of the gas spring is located below the cylinder. As a result, compared with the case where the piston rod of the gas spring is located above the cylinder, the possibility that the gas such as nitrogen leaks from the gas spring is reduced, the deterioration of the gas spring is prevented, and the life of the gas spring is significantly improved. This also contributes to the reduction of the maintenance cost of the working machine.

[0037] Fourth, according to the embodiment of the present invention, the force required to bounce up the apron is reduced by the force exerted by the assist mechanism. Furthermore, since the assist mechanism is adjusted so that the force gradually decreases within a predetermined angle range, the operator will not accidentally bounce up the apron from the state where the apron has descended during tilling. Once the apron is bounced up to a certain angle with a considerable amount of force (however, less than the force required when there is no assist mechanism), it becomes possible to bounce it up with an increasingly lighter force thereafter. That is, while reducing the force required to bounce up the apron, the force required to bounce up decreases as the rotation angle increases.

[0038] Fifthly, in the embodiment of the present invention, there are a first cylindrical member and a second cylindrical member that are movable on the same axis. A second fulcrum and one end of the gas spring are connected to the first cylindrical member, and a third fulcrum and the other end of the gas spring are connected to the second cylindrical member. From the position where they are connected, it has a double-cylinder structure in which force is applied during compression to a gas spring to which force is applied during extension. As a result, the piston rod of the gas spring is covered by the cylindrical member, and its surface is not soiled, and the life of the gas spring is greatly improved. This also contributes to reducing the maintenance cost of the working machine.

[0039] Sixthly, in the embodiment of the present invention, during tilling, the inner cylindrical member and the outer cylindrical member cover the piston rod of the gas spring in a state of double covering. That is, it protects the piston rod that deteriorates according to the surrounding environment.

[0040] Seventhly, in the embodiment of the present invention, there is an opening (small hole) directed downward at one end (apron side) of the inner cylindrical member. This small opening makes it possible to discharge the moisture accumulated in the inner cylindrical member.

[0041] Eighthly, in the embodiment of the present invention, since the gas spring is configured to contract at the point where the apron descends, the surface of the piston rod of the gas spring is not soiled during tilling, which is the longest time, and the life of the gas spring is greatly improved. This also contributes to reducing the maintenance cost of the working machine.

[0042] Ninthly, in the embodiment of the present invention, a resin collar is interposed between the outer cylindrical member and the inner cylindrical member in the assist mechanism. As a result, it is possible to prevent the generation of abnormal noise when the outer cylindrical member and the inner cylindrical member slide.

[0043] As described above, the present invention has been described with reference to the drawings, but the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the spirit of the present invention.

Description of Reference Numerals

[0044] 100: Working machine, 210: Inner cylindrical member, 220: Outer cylindrical member, 250: Gas spring, 251: Cylinder, 252: Piston rod, 256: Piston, 257: Free piston

Claims

1. A frame, an apron provided behind the frame and connected to the frame so as to be rotatable downward and upward, and an assist mechanism connected to the frame and the apron, including a gas spring and applying a force in a direction to lift the apron by utilizing the force of the gas spring. The working machine is provided with: The force required to lift the apron increases until the apron angle reaches a predetermined angle from 0 degree.

2. A shield cover, an apron provided behind the shield cover and connected to the shield cover so as to be rotatable downward and upward, and an assist mechanism connected to the shield cover and the apron, including a gas spring and applying a force in a direction to lift the apron by utilizing the force of the gas spring. The working machine is provided with: The force required to lift the apron increases until the apron angle reaches a predetermined angle from 0 degree.

3. The working machine according to claim 1, wherein the predetermined angle is 10° or less.

4. The working machine according to any one of claims 1 to 3, wherein the force required to lift the apron by the action of the assist mechanism changes from increasing to decreasing at the predetermined angle.

5. The working machine according to any one of claims 1 to 3, wherein the force required to lift the apron by the action of the assist mechanism decreases as the angle increases from the predetermined angle.

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