Cutter blade driving device

Abstract

To provide a reaping blade-driving device capable of readily ensuring the safety of operation by suppressing the generation of scattered materials during the operation and suppressing the generation of vibration and noise while suppressing the nipping of foreign materials by the reaping blade.SOLUTION: A base unit that supports the plurality of cutting blade units in a stacked state, and a driving mechanism that is supported by the base unit and performs a cutting operation by driving at least one of the cutting blade units, the cutting blade unit includes a plurality of cutting blades that protrude in different directions around the base unit, and the drive mechanism performs a cutting operation in which the cutting blade of one cutting blade unit and the cutting blade of another cutting blade unit overlap each other by causing at least one of the cutting blade units to perform a translational movement in an orbital path having no dead point.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cutting blade drive device. [Background technology]

[0002] BACKGROUND ART Conventionally, blade drive devices in which a rotary blade or a reciprocating blade performs cutting operations have been used for cutting grass, pruning plants and hedges, mowing lawns, and the like (see Patent Documents 1 and 2 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-89705 [Patent Document 2] Jikko No. 53-003171 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional blade drive devices that rotate a rotary blade, the blade rotates at high speed while changing its angle along the circumferential direction, so when stones or other debris on the ground hit the blade, they fly around in the surrounding area. For this reason, measures and precautions must be taken to prevent the debris from hitting the worker or people or objects in the vicinity of the work site.

[0005] Furthermore, conventional blade drive devices that reciprocate the blade have the problem that when a foreign object such as a stone is caught between the two blades, a large load is placed on the blade, making it prone to chipping or deformation.Furthermore, when the blade reciprocates, the speed of the blade, which moves at high speed, temporarily drops to zero when it changes direction, which creates the problem of vibration and noise being easily generated due to large speed changes.

[0006] Furthermore, when using two rotary or reciprocating blades to cut grass and other debris, as in conventional techniques, multiple blades arranged around the entire circumference of the rotary blade or along the entire length of the reciprocating blade all perform cutting operations simultaneously, resulting in a large cutting load on the entire blade. To handle this heavy load, the rotary or reciprocating blade needs to be driven with a correspondingly large driving force. If the driving force is insufficient, the blade may become locked and stop with grass or other debris caught in the blade. Frequent lock-ups can disrupt smooth operation.

[0007] Furthermore, if the driving force is increased to prevent the aforementioned lock-up, the weight of the drive unit may have to be increased, which hinders the weight reduction of the blade drive device and increases the labor burden during operation.

[0008] The present invention has been proposed to address these problems. Specifically, the objectives of the present invention are to prevent debris from flying off during operation in a blade drive device, making it easier to ensure work safety, to reduce the generation of vibrations and noise while preventing foreign objects from getting caught in the blade, to reduce the load on the blade to enable smooth operation without locking up, and to reduce the weight of the device, thereby reducing the labor burden during operation. [Means for solving the problem]

[0009] In order to solve the above problems, the cutting blade driving device according to the present invention has the following configuration. A blade drive device comprising: a blade unit having a plurality of blades arranged on a plane; a base unit that supports the plurality of blade units in a stacked state; and a drive mechanism that is supported by the base unit and performs a cutting operation by driving at least one of the blade units, wherein the blade unit has a plurality of blades that protrude in different directions around the base unit, and the drive mechanism translates at least one of the blade units in a circular orbit with no dead point, thereby performing a cutting operation in which the blade of one blade unit overlaps with the blade of another blade unit. [Effects of the Invention]

[0010] A blade drive device with these features can prevent debris from flying off during operation, making it easier to ensure work safety. It can also reduce the occurrence of vibration and noise while preventing foreign objects from getting caught in the blade. It can also reduce the load on the blade, enabling smooth operation without locking. It can also reduce the weight of the device, reducing the labor burden during operation. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a plan view of the cutting blade driving device according to the embodiment of the present invention. [Figure 2] FIG. 2 is a bottom view of the cutting blade driving device according to the embodiment of the present invention. [Figure 3] 1 is an exploded perspective view of a cutting blade driving device according to an embodiment of the present invention; [Figure 4] FIG. [Figure 5] FIG. 4 is an explanatory diagram showing the cutting operation of the cutting blade in the first region. [Figure 6] FIG. 10 is an explanatory diagram showing the cutting operation of the cutting blade in the second region. [Figure 7] 5 is an explanatory diagram showing the relationship between the arrangement of cutting blades in the cutting blade unit and the eccentric direction of an eccentric cam. FIG. [Figure 8] FIG. 10 is an exploded perspective view showing a modification of the blade driving device according to the embodiment of the present invention. [Figure 9] FIG. 10 is an exploded perspective view showing a modification of the blade driving device according to the embodiment of the present invention. [Figure 10] FIG. 10 is an explanatory diagram showing another embodiment of the blade driving device (a driving mechanism having a plurality of eccentric cams). [Figure 11] FIG. 6 is an explanatory view showing another embodiment (fixed blade unit) of the present invention. [Figure 12] FIG. 12 is a top view of the embodiment shown in FIG. [Figure 13] FIG. 10 is an explanatory diagram showing another embodiment of the cutting blade drive device (cutting blade unit having a diamond-shaped base portion). [Figure 14] 10 is an explanatory diagram showing another embodiment of the cutting blade drive device (cutting blade unit with different cutting blade pitch intervals). FIG. [Figure 15] FIG. 10 is an exploded perspective view showing another embodiment of the blade driving device (an example in which a foreign object intrusion prevention member is provided). [Figure 16] FIG. 10 is a plan view showing another embodiment of the blade driving device (an example in which a foreign object intrusion prevention member is provided). [Figure 17] FIG. 10 is an exploded perspective view showing another embodiment of the blade drive device (an example in which a foreign object sweep-out hole and a foreign object blocking member are provided). [Figure 18] FIG. 10 is a plan view showing another embodiment of the blade drive device (an example in which a foreign object sweep-out hole and a foreign object blocking member are provided). DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings denote parts with the same functions, and duplicated descriptions in each drawing will be omitted as appropriate.

[0013] As shown in FIGS. 1 to 3, the blade drive device 1 includes a plurality of cutting blade units 2 and a base unit 3 that supports the cutting blade units 2. In the illustrated example, the blade drive device 1 includes two cutting blade units 2A and 2B, but the number of cutting blade units 2 may be three or more. The blade drive device 1 performs a cutting operation by driving at least one of the multiple cutting blade units 2. Here, all of the multiple cutting blade units 2 may be driven, or one or more may be driven and the rest may be fixed. In the illustrated example, two cutting blade units 2A and 2B are provided and both are driven, but only one may be driven and the other may be fixed.

[0014] The cutting blade unit 2 has a plurality of cutting blades 20 arranged on a plane. In the two cutting blade units 2A and 2B shown in the figure, cutting blades 20A are arranged in the cutting blade unit 2A, and cutting blades 20B are arranged in the cutting blade unit 2B. Because the multiple cutting blade units 2A and 2B have the same shape, they will be referred to as cutting blade unit 2 when describing them without distinguishing between them. A cutting space C is formed for each of the multiple cutting blades 20 in the cutting blade unit 2. The cutting space C formed for each cutting blade 20A of one cutting blade unit 2A is opened and closed by the cutting blade 20B of the other cutting blade unit 2B, and the cutting operation is performed when the cutting blades 20A and 20B overlap.

[0015] The base unit 3 supports a plurality of overlapping cutting blade units 2. In the illustrated example, the driven cutting blade units 2A, 2B are supported movably on the base unit 3 in an overlapping state. If there are any fixed cutting blade units 2, they are fixed to the base unit 3 by fastening means or the like.

[0016] In the illustrated example, as shown in FIGS. 1 to 3, cutting blade unit 2A and cutting blade unit 2B are stacked with their bottom surfaces facing each other, and are each movably supported by base unit 3. Base unit 3 is made up of a first unit 3A on the flat surface side and a second unit 3B on the bottom surface side. A guide protrusion 3G protrudes from one of first unit 3A and second unit 3B toward the other (in the illustrated example, guide protrusion 3G protrudes from first unit 3A toward second unit 3B). By screwing fastening member 3C into guide protrusion 3G, first unit 3A is fixed to second unit 3B with cutting blade unit 2A and cutting blade unit 2B sandwiched between them.

[0017] The guide protrusion 3G passes through a guide hole 2G formed in the cutting blade unit 2. The guide hole 2G allows translational movement of the cutting blade unit 2 and guides the movement of the cutting blade unit 2 so that the orientation of the cutting blade 20 is maintained (so that the cutting blade 20 moves parallel). The cutting blade units 2A and 2B, which are sandwiched between the first unit 3A and the second unit 3B of the base unit 3, move within a movement range limited by the guide hole 2G, and the cutting blades 20A and 20B slide against each other, opening and closing the cutting space C formed for each cutting blade 20, and the cutting operation is performed when the cutting blades 20A and 20B overlap each other.

[0018] 1 to 3, each cutting blade 20 has a protruding shape (such as a mountain shape or a convex shape), and as shown in Fig. 3, a plurality of arranged cutting blades 20 protrude radially from the periphery of a disk-shaped base 21 (21A, 21B) to form cutting blade units 2 (2A, 2B). When supported by the base unit 3, the cutting blade units 2 (2A, 2B) include a plurality of cutting blades 20 (20A, 20B) that protrude in different directions around the periphery of the base unit 3.

[0019] In the illustrated example, the cutting blade 20 is detachable from the base 21. This allows the user to effectively perform maintenance by replacing only the cutting blade 20 when the cutting blade 20 becomes worn or damaged. Furthermore, maintenance requires less economical maintenance than replacing the entire cutting blade unit 2. The cutting blade 20 and the base 21 can also be configured as a single unit, in which case the entire cutting blade unit 2 can be replaced. In the illustrated example, the cutting blades 20 are arranged around the entire circumference of the disk-shaped base 21, and the multiple arranged cutting blades 20 all protrude in different directions.

[0020] 3, a drive mechanism 4 is disposed between the cutting blade unit 2A and the cutting blade unit 2B. The drive mechanism 4 translates at least one cutting blade unit 2 in a circular orbit without a dead center, thereby performing a cutting operation in which the cutting blade 20A of one cutting blade unit 2A and the cutting blade 20B of the other cutting blade unit 2B overlap each other.

[0021] Specifically, the drive mechanism 4 includes an eccentric cam 4A having a rotary shaft 40. The rotary shaft 40 serves as the center of rotation of the eccentrically rotating eccentric cam 4A, is journaled on the base unit 3, is prevented from coming off by a stopper ring 40S, and is driven to rotate by a drive means (e.g., an electric motor) (not shown) directly or via a transmission mechanism. As an example, the rotary shaft 40 is journaled via a bearing 30 on the first unit 3A side to which the drive means is connected, and the rotary shaft 40 is journaled via a bearing (not shown) incorporated in the second unit 3B side. The aforementioned guide protrusion 3G protrudes parallel to the rotary shaft 40.

[0022] In the example shown in Fig. 4, the eccentric cam 4A has a pair of cam bodies (first cam body 41 and second cam body 42) arranged side by side along the axial direction, which are fixed to the rotation shaft 40 with a phase difference and rotate eccentrically to drive the cutting blade unit 2A and the cutting blade unit 2B, respectively. Although an example is shown here in which a pair of cam bodies is provided, a cam body is provided for each cutting blade unit 2 to be driven. When only one cutting blade unit 2 is driven, a single cam body is fixed to the rotation shaft 40.

[0023] In the illustrated example, the phase difference between the first cam body 41 and the second cam body 42 is 180°. As a result, the eccentric direction Ed of the first cam body 41 (the direction of the line connecting the center 40P of the rotation shaft 40 and the center 41P of the first cam body 41) and the eccentric direction Ed1 of the second cam body 42 (the direction of the line connecting the center 40P of the rotation shaft 40 and the center 42P of the second cam body 42) are opposite to each other but on a straight line. Hereinafter, this direction will be referred to as the eccentric direction Ed of the eccentric cam 4A. The first cam body 41 and the second cam body 42 are cylindrical bodies with their central axes parallel to the rotation shaft 40 (the axis passing through the centers 41P and 42P), and the distance between the center 41P of the first cam body 41 (or the center 42P of the second cam body 42) and the center 40P of the rotation shaft 40 is the eccentric radius e of the eccentric cam 4A.

[0024] The cam bodies (first cam body 41 and second cam body 42) of the eccentric cam 4A engage with engagement holes 22 (22A, 22B) provided in the base portion 21 (21A, 21B) of the cutting blade unit 2 (2A, 2B). When the rotary shaft 40 is driven to rotate, the cutting blade unit 2 (2A, 2B) is driven in response to the rotation of the eccentric cam 4A. In the illustrated example, the first cam body 41 of the eccentric cam 4A engages with the engagement hole 22A in the cutting blade unit 2A via a bearing 41A, and the second cam body 42 of the eccentric cam 4A engages with the engagement hole 22B in the cutting blade unit 2B via a bearing 42A.

[0025] When the eccentric cam 4A is driven to rotate, the cutting blade unit 2 (2A, 2B) moves translationally in accordance with the rotation of the eccentric cam 4A, tracing a movement trajectory of an orbital path (circular orbit), without changing the orientation of the cutting blade 20. At this time, because the first cam body 41 and the second cam body 42 are fixed to the rotation shaft 40 with a phase difference of 180°, the cutting blade unit 2A engaging with the first cam body 41 and the cutting blade unit 2B engaging with the second cam body 42 always have a phase difference of 180° in their orbits, and move in an orbital path with a phase difference.

[0026] The phase difference between the first cam body 41 and the second cam body 42 is not limited to 180°, and the phase difference can be any angle. By engaging the first cam body 41 and the second cam body 42, which have a phase difference of any angle, with the cutting blade units 2A, 2B, respectively, the multiple cutting blade units 2 move in an orbit with any phase difference.

[0027] 5 and 6, the cutting operation performed by the cutting blades 20 (20A, 20B) of the cutting blade unit 2 (2A, 2B) will be described. Here, attention is focused on the cutting blades 20 located in one region (first region S1: see FIG. 1) of the multiple arranged cutting blades 20 and the cutting blades 20 located in another region (second region S2: see FIG. 1) located in a different position. In the illustrated example, the first region S1 is located in a direction that passes through the center 40P of the rotation shaft 40 and is perpendicular to the eccentric direction Ed of the eccentric cam 4A, and the second region S2 is located in the same direction as the eccentric direction Ed of the eccentric cam 4A and passes through the center 40P of the rotation shaft 40.

[0028] In the first region S1, the first cutting blade 20A (denoted as 20A(1)) and the second cutting blade 20A (denoted as 20A(2)) of one cutting blade unit 2A are arranged. In addition, in the first region S1, the first cutting blade 20B (denoted as 20B(1)) and the second cutting blade 20B (denoted as 20B(2)) of another cutting blade unit 2B are arranged.

[0029] When the eccentric cam 4A is rotated 360°, the cutting blades 20A and 20B in the first region S1 move accordingly, and change from the state shown in FIG. 5(a) to the states shown in FIG. 5(b), (c), and (d) at each 90° rotation. When the eccentric cam 4A is rotated 360° or more, this change in state is repeated sequentially. The cutting blade unit 2 does not rotate itself when the eccentric cam 4A rotates, but performs translational movement without changing the orientation of the cutting blade 20.

[0030] 5(a), the cutting blade 20A(1) overlaps the cutting blade 20B(1), and then the cutting blade 20A(2) overlaps the cutting blade 20B(2) with a slight shift. In this state, the cutting space C1 formed by the cutting blade 20A(1) is in an open state, and the cutting space C2 formed by the cutting blade 20A(2) also opens at a slightly shifted timing.

[0031] In Fig. 5(b), cutting blade 20B(1) moves into cutting space C1, and cutting blade 20B(2) moves into cutting space C2, causing cutting spaces C1 and C2, which are open in Fig. 5(a), to close. At this time, because the protruding directions of cutting blade 20A(1) and cutting blade 20A(2) are different and the protruding directions of cutting blade 20B(1) and cutting blade 20B(2) are different, there is a slight difference between the timing at which cutting space C1 opens and closes and the timing at which cutting space C2 opens and closes.

[0032] The object to be cut enters the cutting spaces C1, C2 in the open state, and then the cutting spaces C1, C2 are closed, whereby the object to be cut in the cutting spaces C1, C2 is cut by the cutting blades 20A, 20B. In this cutting operation, there is a timing difference between the cutting operation in the cutting space C1 and the cutting operation in the cutting space C2 due to the difference in the opening and closing timing of the cutting spaces C1 and C2.

[0033] In FIG. 5(c), the cutting blade 20B(1) and the cutting blade 20A(2) overlap, causing the cutting space C1 formed by the cutting blade 20A(1) to open again, and the cutting space C2 formed by the cutting blade 20A(2) to open again at a slightly different timing. Then, in FIG. 5(d), the cutting blade 20B(1) moves into the cutting space C1, and the cutting blade 20B(2) moves into the cutting space C2, causing the cutting spaces C1 and C2, which were open in FIG. 5(c), to close. At this time, the cutting object in the cutting spaces C1 and C2 is cut by the cutting blades 20A and 20B. As described above, there is a timing difference between the cutting action in the cutting space C1 and the cutting action in the cutting space C2.

[0034] In Figure 5, we have explained the cutting space C1 formed by the cutting blade 20A(1) and the cutting space C2 formed by the adjacent cutting blade 20A(2), but a similar discrepancy in opening and closing timing occurs between the cutting space formed by a cutting blade 20A at any position and the cutting space formed by the adjacent cutting blade 20A, and a corresponding discrepancy in timing occurs in the cutting operation.

[0035] In the second region S2, which is located 90° apart from the first region S1 described above, as shown in FIG. 6, the cutting blade unit 2A has the twelfth arranged cutting blade 20A(12) and the thirteenth arranged cutting blade 20A(13) located therein, and the cutting blade unit 2B has the twelfth arranged cutting blade 20B(12) and the thirteenth arranged cutting blade 20B(13) located therein.

[0036] The states of cutting blades 20A(12) and 20A(13) and cutting blades 20B(12) and 20B(13) in the second region S2 change to (a), (b), (c), and (d) in Figure 6 at the same time that cutting blades 20A and 20B in the first region S1 change to (a), (b), (c), and (d) in Figure 5.

[0037] That is, the positional relationship between the cutting blade 20A and the cutting blade 20B in (a) of Fig. 6 is the same as the state in (b) of Fig. 5, (b) of Fig. 6 is the same as the state in (c) of Fig. 5, (c) of Fig. 6 is the same as the state in (d) of Fig. 5, and the state in (d) of Fig. 6 is the same as the state in (a) of Fig. 5. In other words, there is a phase shift of 90° due to the rotation of the eccentric cam 4A between the opening and closing timing of the cutting space C1 in the first region S1 and the opening and closing timing of the cutting space C12 in the second region S2, and between the opening and closing timing of the cutting space C2 in the first region S1 and the opening and closing timing of the cutting space C13 in the second region S2.

[0038] That is, a timing difference corresponding to a phase shift of 90° occurs between the cutting operation in the cutting space C1 formed by the cutting blade 20A(1) and the cutting operation in the cutting space C12 formed by the cutting blade 20A(12) in the rotation of the eccentric cam 4A. Also, a timing difference corresponding to a phase shift of 90° occurs between the cutting operation in the cutting space C2 formed by the cutting blade 20A(2) and the cutting operation in the cutting space C13 formed by the cutting blade 20A(13) in the rotation of the eccentric cam 4A.

[0039] The movement of the cutting blade 20 (20A, 20B) will be described in more detail. When both cutting blade unit 2A and cutting blade unit 2B are driven by drive mechanism 4, both cutting blade 20A and cutting blade 20B move translationally on a circular orbit with no dead center. Furthermore, when one of cutting blade units 2A and 2B is fixed and the other is driven by drive mechanism 4, the driven cutting blade 20 (e.g., cutting blade 20B) moves translationally on a circular orbit with no dead center relative to the fixed cutting blade 20 (e.g., cutting blade 20A). In this case, the movement of cutting blade 20 becomes a circular orbit with a radius equal to the eccentric radius e of eccentric cam 4A, and the movement is translational without any change in angle.

[0040] As a result, overlapping cutting blades 20A, 20B open and close the cutting space as the tip positions of cutting blade 20 move up and down relative to one another. Therefore, if a large foreign object such as a stone gets into the cutting space of cutting blade 20A, cutting blade 20B moves relatively upward as it enters the cutting space, pushing the foreign object out of the cutting space and reducing the likelihood of the stone or other foreign object getting caught between cutting blade 20A and cutting blade 20B. This reduces the load on cutting blade 20 and reduces the risk of chipping or deformation of the cutting blade.

[0041] Furthermore, the range of movement of the cutting blade 20 is limited within the range of the eccentric radius e, and the movement speed of the cutting blade 20 is also low. As a result, even when driven by a high-speed motor, it is possible to reduce the amount of debris that flies around as the cutting blade 20 moves, and it is also possible to reduce the vibration and noise that accompanies the movement of the cutting blade 20. Furthermore, the use of a high-speed motor makes it possible to ensure sufficient torque even with a small motor, and it is possible to use a small and lightweight drive means to perform sufficient work even in areas with dense grass.

[0042] Because the range of movement of the cutting blade 20 is limited as described above, the cutting blades 20 provided around the entire circumference of the cutting blade unit 2 may wear unevenly depending on how the cutting blade drive device 1 is used. To address this, the state of wear of the cutting blades 20 across the entire cutting blade unit 2 can be evened out by rotating the cutting blade unit 2 so that the support state of the cutting blade unit 2 relative to the base unit 3 is changed as needed. In this case, the cutting blade unit 2 is provided with guide holes 2G through which three guide protrusions 3G provided on the base unit 3 pass, so that the support state of the cutting blade unit 2 relative to the base unit 3 can be changed by rotating the cutting blade unit 2 120° about the center of the base unit 3.

[0043] To realize the movements of cutting blade 20A and cutting blade 20B shown in Figures 5 and 6, it is necessary to create a state in which cutting blade 20A and cutting blade 20B overlap, opening the cutting space C formed by cutting blade 20A, and a state in which cutting blade 20B enters the cutting space C of cutting blade 20A, closing the cutting space C, in accordance with the rotation of eccentric cam 4A.

[0044] As shown in Fig. 7(a), in the cutting blade unit 2A, the arrangement of the cutting blades 20A that protrude radially from the center of the base 21A is asymmetrical with respect to a reference line LA. This reference line LA is a straight line that is perpendicular to the eccentric direction Ed of the eccentric cam 4A that engages the first cam body 41 with the engagement hole 22A of the cutting blade unit 2A and passes through the center of the cutting blade unit 2A (the center 41P of the first cam body 41). Similarly, as shown in Fig. 7(b), in the cutting blade unit 2B, the cutting blades 20B are arranged asymmetrically with respect to a reference line LB that is perpendicular to the eccentric direction Ed of the eccentric cam 4A that engages the second cam body 42 with the engagement hole 22B of the cutting blade unit 2B and passes through the center of the cutting blade unit 2B (the center 42P of the second cam body 42).

[0045] 7(c), when the first cam body 41 is engaged with the engagement hole 22A of the cutting blade unit 2A and the second cam body 42 is engaged with the engagement hole 22B of the cutting blade unit 2B, the back surfaces of the cutting blade units 2A and 2B face each other, and the eccentric cam 4A of the drive mechanism 4 is disposed between them, the reference lines LA and LB are shifted along the eccentric direction Ed by twice the eccentric radius e of the eccentric cam 4A. As a result, the cutting blades 20A and 20B that protrude in a direction perpendicular to the eccentric direction Ed of the eccentric cam 4A overlap each other (the state shown in FIGS. 5(a) and 5(c)), and the cutting blades 20A and 20B that protrude in a direction along the eccentric direction Ed are positioned such that the cutting blade 20B is located in the cutting space C of the cutting blade 20A (the state shown in FIGS. 5(b) and 5(d)).

[0046] When the eccentric cam 4A is rotated, the cutting blade units 2A and 2B move translationally in a circular orbit, so that the protruding directions of the cutting blades 20A and 20B do not change, but the positional relationship between the cutting blades 20A and 20B is such that the cutting blades 20A and 20B always overlap in the direction perpendicular to the eccentric direction Ed (the state shown in FIGS. 5(a) and 5(c)) depending on the rotation angle of the eccentric cam 4A. That is, the positional relationship between the cutting blades 20A and 20B at any position changes as shown in FIGS. 5(a) to 5(d) (or FIGS. 6(a) to 6(d)) while changing the timing depending on the rotation angle of the eccentric cam 4A.

[0047] In the above-described blade drive device 1, all of the cutting blades 20 in the cutting blade unit 2 are arranged at different angles by "360° / number of cutting blades." Therefore, a cutting blade 20 in any position and the cutting blade 20 arranged adjacent to it perform cutting operations with a phase difference of "360° / number of cutting blades." This significantly reduces the cutting load borne by the cutting blade unit 2 compared to when all of the cutting blades 20 in the cutting blade unit 2 perform cutting operations simultaneously.

[0048] Furthermore, in the above-described blade drive device 1, the blades 20 are arranged around the entire circumference of the blade unit 2. Therefore, the range in which the cutting operation is performed is the entire circumference of the blade unit 2, and mowing work can be performed in the direction in which the blade drive device 1 is moved without changing the orientation of the blade drive device 1.

[0049] 8 and 9 show a modified example of the cutting blade drive device 1 described above. In this example, a guide cam 5 is inserted into the guide hole 2G of the cutting blade unit 2 to stabilize the movement of the guide protrusion 3G within the guide hole 2G. The guide cam 5 has a first guide cam 5A inserted into the guide hole 2G of one cutting blade unit 2A and a second guide cam 5B inserted into the guide hole 2G of the other cutting blade unit 2B. The guide cams 5 (5A, 5B) are inserted into the guide hole 2G via guide hole bearings 6 and slide smoothly along the inner edge of the guide hole 2G. The guide cams 5 can be made of a slippery resin or other material, making it possible to omit the guide hole bearing 6. However, the inclusion of the guide hole bearing 6 allows the cutting blade unit 2 to operate more smoothly.

[0050] The guide cams 5 (5A, 5B) have an engagement portion 5C with which the guide protrusion 3G engages. A spacer tube 7 is disposed between the first guide cam 5A and the second guide cam 5B. The guide protrusion 3G passes through the spacer tube 7 and engages with the engagement portions 5C of the first guide cam 5A and the second guide cam 5B, respectively. When the guide cams 5 (5A, 5B) slide in response to the relative movement of the guide protrusion 3G within the guide hole 2G, the guide protrusion 3G engaged with the engagement portion 5C always moves smoothly along the inner edge of the guide hole 2G. The relative movement of the guide protrusion 3G within the guide hole 2G is due to the movement of the cutting blade unit 2 caused by the rotation of the eccentric cam 4A, so the sliding of the guide cams 5 (5A, 5B) occurs in synchronization with the rotation of the eccentric cam 4A.

[0051] In the example shown in FIG. 8, the first guide cam 5A and the second guide cam 5B are separate. In contrast, in the example shown in FIG. 9, the first guide cam 5A and the second guide cam 5B are connected by a spacer tube 7 to form a single guide cam 5. By integrating the first guide cam 5A and the second guide cam 5B, the movement of the first guide cam 5A and the second guide cam 5B can be stably synchronized with the movement of the eccentric cam 4A. This further facilitates the movement of the cutting blade units 2A and 2B. In this way, by inserting the guide cam 5 into the guide hole 2G and guiding the movement of the guide protrusion 3G within the guide hole 2G, vibrations and noise caused by the guide protrusion 3G hitting the inner edge of the guide hole 2G can be suppressed.

[0052] FIG. 10 shows a cutting blade drive device 1 according to another embodiment. In this cutting blade drive device 1, the cutting blade unit 2 (2A, 2B) is substantially the same as the embodiment shown in FIGS. 1 to 3, but the drive mechanism 4 uses multiple eccentric cams 4A. Here, an example is shown in which three eccentric cams 4A are used, but the number is not limited to three and may be four or more. The multiple eccentric cams 4A are engaged with the engagement holes 22 so that the eccentric directions Ed are parallel to one another. To engage the multiple eccentric cams 4A, the same number of engagement holes 22 are provided in the cutting blade unit 2, but the positions of the engagement holes are preferably arranged at equal intervals around the center of the cutting blade unit 2 in consideration of balance.

[0053] At least one of the multiple eccentric cams 4A is driven, and the remaining eccentric cams 4A are driven by the movement of the cutting blade unit 2. By arranging the multiple eccentric cams 4A with their eccentric directions parallel to one another, the multiple eccentric cams 4A function as parallel links, and the cutting blade unit 2 can be translated in a circular orbit without unstable reverse rotation, even without a guide for translating the cutting blade unit 2 (such as the above-mentioned guide protrusion 3G, guide hole 2G, and guide cam 5).

[0054] Fig. 10 shows the cutting operation of the cutting blade drive device 1 in conjunction with the rotation of the eccentric cam 4A. As shown in the figure, the cutting blade drive device 1 shown in Fig. 10 performs the same cutting operation as the cutting blade drive device 1 shown in Figs. 1 to 3, and as the eccentric direction Ed of the eccentric cam 4A changes from 0°, 90°, 180°, 270°, to 360°, the position of the cutting blade 20 changes as shown in Fig. 10(a), (b), (c), (d), and (a).

[0055] At this time, in the blade drive device 1, as in the previously described embodiment, the cutting spaces are opened with the cutting blades 20A and 20B overlapping in an orientation perpendicular to the eccentric direction Ed, and the cutting spaces are closed with the cutting blades 20B positioned between the cutting blades 20A in an orientation that coincides with the eccentric direction Ed. Therefore, in the blade drive device 1 shown in Fig. 10, as in the previously described embodiment, the timing at which one cutting space is opened and closed differs from the timing at which the other cutting spaces are opened and closed, resulting in a timing discrepancy in the cutting operations of each blade 20.

[0056] When multiple eccentric cams 4A are provided in the drive mechanism 4, basically, the cutting blade units 2A, 2B are driven by rotating the rotation shaft 40 of one eccentric cam 4A, and the other eccentric cams 4A rotate in response. However, to rotate the multiple eccentric cams 4A in a balanced manner, it is preferable to transmit a driving force to each of the rotation shafts 40. To achieve this, one rotation shaft 40 is used as the drive shaft, and the other rotation shafts 40 are driven via pinion gears engaged with this drive shaft, or a separate drive gear is rotated so that the rotation shafts of the multiple eccentric cams 4A are equally rotated by this drive gear.

[0057] Even when multiple eccentric cams 4A are provided for the drive mechanism 4, the range of movement of the cutting blade 20 is limited as described above, and the cutting blades 20 provided around the entire circumference of the cutting blade unit 2 may wear unevenly depending on how the cutting blade drive device 1 is used. To address this, as described above, rotation is performed to change the support state of the cutting blade unit 2 relative to the base unit 3 as needed, thereby evening out the wear of the cutting blades 20 across the entire cutting blade unit 2. When the cutting blade unit 2 is engaged with three eccentric cams 4A, the support state of the cutting blade unit 2 relative to the base unit 3 can be changed by rotating the cutting blade unit 2 120° about the center of the base unit 3 to shift the correspondence between the engagement holes 22 and the eccentric cams 4A.

[0058] 11 and 12 show a cutting blade drive device 1 according to another embodiment. The cutting blade drive device 1 shown in FIG. 11 differs from the cutting blade drive device 1 shown in FIGS. 1 to 3 in that a fixed blade unit 2S is disposed between the cutting blade unit 2A and the cutting blade unit 2B. The fixed blade unit 2S has a cutting blade 20S (20) on its periphery, and a base 21S (21) is provided with a through-hole 23 through which the guide protrusion 3G of the base unit 3 passes. Furthermore, a drive mechanism accommodating hole 24 that allows rotation of the eccentric cam 4A is provided in the center of the base 21S (21) of the fixed blade unit 2S.

[0059] The fixed blade unit 2S is sandwiched between the cutting blade units 2A and 2B, and the guide protrusions 3G are inserted into the through holes 23, thereby fixing the fixed blade unit 2S to the base unit 3. When the eccentric cam 4A of the drive mechanism 4 is rotated, the cutting blade units 2A and 2B move in a translational orbit relative to the fixed blade unit 2S, and the cutting spaces formed for each cutting blade 20S of the fixed blade unit 2S are opened and closed by the movement of the cutting blades 20A and 20B.

[0060] 12, the outer circumferential diameter D1 of the cutting blade units 2A, 2B is smaller than the outer circumferential diameter D2 of the fixed blade unit 2S by 2e (e: eccentricity radius). This allows the cutting blades 20A, 20B of the cutting blade units 2A, 2B to move within the range of the outer circumferential edge of the fixed blade unit 2S. As a result, when cutting grass or the like along a wall, if the work is performed with the cutting blade 20S of the fixed blade unit 2S abutting against the wall, the moving cutting blades 20A, 20B can be prevented from hitting the wall, and the grass or the like along the wall can be smoothly cut.

[0061] Instead of the fixed blade unit 2S described above, a fixed plate having a file function on the front and back sides can be provided and the cutting blade units 2A, 2B can be driven to sharpen the cutting blades 20A, 20B. The fixed plate used in this case is disk-shaped and has the same outer diameter as the fixed blade unit 2S, and includes a through-hole 23 and a drive mechanism accommodating hole 24. When the cutting blade units 2A, 2B become dull, the fixed plate described above can be sandwiched between the cutting blade units 2A, 2B and the cutting blade units 2A, 2B can be driven, allowing for easy maintenance to sharpen the cutting blades 20A, 20B.

[0062] 13 shows a blade driving device 1A according to another embodiment. In this embodiment, the shape of the blade unit 2 (2C, 2D) is different from that of the above-described embodiment, but the other configurations are the same (the base unit and drive mechanism, which are common configurations, are not shown).

[0063] In this embodiment, the two cutting blade units 2C, 2D have bases 21 (21C, 21D) with diamond-shaped peripheries. Adjacent sides of the periphery of the bases 21 (21C, 21D) are non-parallel, and a first region S11 is formed on a pair of parallel sides, and a second region S12 is formed on a pair of parallel sides that are non-parallel to the sides of the first region S11. In addition, a third region S13 is formed between the first region and the second region.

[0064] In such a cutting blade unit 2 (2C, 2D), the protruding directions of the multiple cutting blades 20 in the first region S11 are all parallel within the region, and the protruding directions of the multiple cutting blades 20 in the second region S12 are also all parallel within the region. The protruding directions of the cutting blades 20 in the first region S11 and the second region S12 are different from each other. Furthermore, the protruding directions of three of the multiple cutting blades 20 in the third region S13 are different from each other.

[0065] In this embodiment, the blade drive device 1A causes the blade unit 2 (2C, 2D) to translate in an orbital motion by the drive mechanism 4 (not shown), so that the cutting action performed by the blade 20 in the first region S11 and the cutting action performed by the blade 20 in the second region S12, which is located differently from the first region S11, are performed at different times. This is because the protrusion direction of the blade 20 in the first region S11 is different from the protrusion direction of the blade 20 in the second region S12. In this case, the multiple blades 20 in the first region S11, all of which have the same protrusion direction, perform the cutting action simultaneously, and the multiple blades 20 in the second region S12, all of which have the same protrusion direction, perform the cutting action simultaneously.

[0066] Furthermore, the three cutting blades 20 in the third region S13 project in different directions, and therefore the cutting operations in the cutting spaces formed by the respective cutting blades 20 are performed at different times.

[0067] With this type of blade driving device 1A, when performing mowing work by moving the cutting blade unit 2 in a direction intersecting the width of the first region S11 and the second region S12, the working width of one stroke can be widened by widening the width of the first region S11 and the second region S12. In this case, the cutting operation in the first region S11 and the cutting operation in the second region S12 are performed at different times, and even in the third region S13, the cutting operation of each cutting blade 20 is performed at different times, so it is possible to suppress an increase in cutting load while widening the working width.

[0068] FIG. 14 shows a blade drive device 1B according to another embodiment. This embodiment differs from the previously described embodiment in the shape of the blade unit 2 (2E, 2F). The base unit and drive mechanism (not shown) have the same configuration as the previously described embodiment, but the guide protrusions on the base unit can be omitted, and accordingly, the guide holes on the blade unit 2 (2E, 2F) can be omitted. The drive mechanism (not shown) in the blade drive device 1B is equipped with two eccentric cams, which engage with the engagement holes 22 of the blade unit 2 with their eccentric directions aligned.

[0069] In this embodiment, the two cutting blade units 2E, 2F have rectangular bases 21 (21E, 21F) that are elongated in one direction. The longitudinal periphery of the bases 21 (21E, 21F) is linear, and the cutting blades 20 are arranged in parallel, protruding in a direction perpendicular to the periphery.

[0070] Here, in cutting blade unit 2E, the interval (pitch interval) W1 between cutting blades 20 in the first region S21 is different from the interval (pitch interval) W2 between cutting blades 20 in the second region S22. In each of the first region S21 and the second region S22, the multiple cutting blades 20 are arranged at a constant pitch interval. On the other hand, in cutting blade unit 2F overlapping cutting blade unit 2E, the cutting blades 20 are all arranged at a constant pitch interval (W2).

[0071] In this embodiment of the blade driving device 1B, the cutting blade unit 2 (2E, 2F) is moved in a translational manner on a circular orbit by a driving mechanism not shown, so that the cutting operation performed in the cutting space for each blade 20 in the first region S21 and the cutting operation performed in the cutting space for each blade 20 in the second region S22, which is located at a position different from the first region S21, are performed at different times.

[0072] Furthermore, in the first region S21, the spacing W1 between the cutting blades 20 in the cutting blade unit 2E is different from the spacing W2 between the cutting blades 20 in the cutting blade unit 2F, so that the cutting operations performed in the cutting spaces of each cutting blade 20 in the first region S21 are performed at slightly different timings.

[0073] The timing difference at this time occurs because, in the first region S21, the pitch interval W1 of the cutting blade unit 2F is different from the pitch interval W2 of the cutting blade unit 2E, and therefore the timing at which the cutting space formed by each cutting blade 20 of the cutting blade unit 2E is opened and closed by the cutting blade 20 of the cutting blade unit 2F differs for each cutting blade 20. This causes a timing difference in the cutting operation of each cutting blade 20. Furthermore, in the second region S22, the pitch interval W2 of the cutting blade unit 2F is equal to the pitch interval W2 of the cutting blade unit 2E, and therefore all of the multiple cutting blades 20 in the second region S22 perform cutting operations at the same timing.

[0074] With this type of blade driving device 1B, when performing mowing work by moving the cutting blade unit 2 in a direction intersecting the widths of the first region S21 and the second region S22, the widths of the first region S21 and the second region S22 can be widened to widen the working width of one stroke. In this case, the timing of the cutting operation is made different between the first region S21 and the second region S22, and even within the first region S21, the timing of the cutting operation is made different for each cutting blade 20, so that an increase in the cutting load can be suppressed while widening the working width.

[0075] As described above, the blade driving device 1 (1A, 1B) according to an embodiment of the present invention comprises a blade unit 2 having a plurality of blades 20 arranged on a plane, and a base unit 3 that supports the plurality of blade units 2 in a stacked state, and performs a cutting operation by driving at least one of the blade units 2.The cutting operation is performed by opening and closing the cutting spaces formed for each blade 20 of the blade unit 2, and by differentiating the timing at which one cutting space is opened and closed from the timing at which the other cutting spaces are opened and closed, a timing difference is created in the cutting operation in the cutting spaces.

[0076] As a result, the blade drive device 1 (1A, 1B) can reduce the cutting load applied to the blade 20, preventing lock-stopping and enabling smooth mowing operations.Furthermore, the blade drive device can be made lighter while preventing lock-stopping, thereby enabling smooth mowing operations while reducing the labor burden during work.

[0077] Furthermore, in the blade driving device 1 (1A, 1B) according to an embodiment of the present invention, the blade unit 2 is provided with a plurality of blades 20 that protrude in different directions around the base unit 3, and the drive mechanism 4 moves at least one blade unit 2 in a translational motion in a circular orbit with no dead point, thereby performing a cutting operation in which the blade 20A of one blade unit 2A overlaps with the blade 20B of the other blade unit 2B.

[0078] According to this, the movement of the cutting blade 20 is a circular orbit without any change in angle, so that even if a foreign object such as a stone hits the cutting blade 20, no large force is applied to repel the object. Therefore, it is possible to suppress the generation of flying debris during work, and it is easier to ensure work safety. Furthermore, the movement of the cutting blades 20 is such that it is difficult for foreign objects to be pinched between the cutting blades 20, so it is possible to suppress the pinching of foreign objects by the cutting blades 20 and prevent damage to the cutting blades 20. Furthermore, the movement speed of the cutting blades 20 themselves can be reduced, and by making the circular orbit have no dead points, it is possible to suppress the generation of vibration and noise during work.

[0079] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes design changes within the scope of the present invention. Furthermore, the above-described embodiments can be combined by utilizing each other's technologies as long as there are no particular contradictions or problems in their purposes, configurations, etc.

[0080] For example, by forming an area in which the pitch intervals of the blades 20 are varied as in the embodiment shown in Figure 14 for the blade drive device 1 shown in Figures 1 to 3 and the blade unit 2 of the blade drive device 1A shown in Figure 13, the timing of the cutting operation can be further shifted for each blade 20, and the cutting load can be effectively distributed.

[0081] 11 and the fixed blade unit 2S for sharpening the blade described above can be added not only to the cutting blade drive device 1 shown in FIGS. 1 to 3, but also to the cutting blade drive device 1 equipped with a plurality of eccentric cams 4A shown in FIG. 10. Furthermore, by matching the configuration of the fixed blade unit 2S and the fixed plate to the configuration of the cutting blade units 2C to 2F, the fixed blade unit 2S and the fixed plate can also be added to the cutting blade drive devices 1A and 1B according to the embodiments shown in FIGS. 13 and 14.

[0082] Furthermore, a structure for preventing foreign objects such as grass and pebbles from entering the drive mechanism 4 can be added to the above-described cutting blade drive device 1.

[0083] 15 and 16 show an example in which foreign object intrusion prevention members 8 (8A, 8B) are attached to the opposing inner surfaces of the bases 21 (21A, 21B) of the cutting blade unit 2. In this case, the foreign object intrusion prevention member 8A is adhered to the inner peripheral surface of one of the bases 21A, leaving a gap between the fastening parts 25 that attach the cutting blade 20A to the periphery of the base 21A. Furthermore, the foreign object intrusion prevention member 8B is adhered to the inner peripheral surface of the other of the bases 21B, between the fastening parts 25, so as not to overlap with the foreign object intrusion prevention member 8A.

[0084] When such foreign object intrusion prevention members 8 (8A, 8B) are provided, the base 21 (21A, 21B) of the cutting blade unit 2 engages with the eccentric cam 4A of the drive mechanism 4, which is driven via the power transmission unit 4B, and moves translationally in a circular orbit with no dead center. As a result, the foreign object intrusion prevention members 8 (8A, 8B) move in conjunction with this movement. At this time, one foreign object intrusion prevention member 8A moves together with the base 21A to which it is attached, rubbing against the inner surface of the base 21B to which it is not attached. Similarly, the other foreign object intrusion prevention member 8B moves together with the base 21B to which it is attached, rubbing against the inner surface of the base 21A to which it is not attached. As a result, foreign objects that attempt to enter between the bases 21A and 21B are pushed outward by the movement of the foreign object intrusion prevention members 8 (8A, 8B), preventing the foreign objects from reaching the drive mechanism 4. The foreign object intrusion prevention members 8 (8A, 8B) are preferably made of a material that can easily slide on the inner surface while adhering closely to the inner surface of the base 21 (21A, 21B). As an example, the foreign object intrusion prevention members 8 can be made of a thinly molded felt material.

[0085] 17 and 18, a number of foreign matter sweeping holes 26 are provided in the base 21, and a foreign matter blocking member 9 is provided inside the base 21 (21A, 21B), thereby preventing foreign matter from entering the drive mechanism 4.

[0086] The numerous foreign object sweeping holes 26 formed in the base 21 function to discharge foreign objects that may have entered between the bases 21 (21A, 21B). The foreign object blocking member 9 present inside the bases 21 (21A, 21B) is provided so as to surround the periphery of the drive mechanism 4, and is itself fixed by a guide protrusion 3G of the base unit 3 penetrating through it. When the bases 21 (21A, 21B) engage with the eccentric cam 4A of the drive mechanism 4, which is driven via the power transmission unit 4B, and move translationally in a circular orbit with no dead center, this movement shifts the positions of the numerous foreign object sweeping holes 26 formed in the base 21. This causes the peripheral wall of the fixed foreign object blocking member 9 to move relative to the foreign object sweeping holes 26, and this relative movement sweeps foreign objects that have entered the base 21 outward through the foreign object sweeping holes 26. This prevents foreign matter from entering the drive mechanism 4.

[0087] Base 21 having many such foreign object discharge holes 26 can be formed by resin molding. Furthermore, by providing many foreign object discharge holes 26 in base 21, it is possible to reduce the weight of base 21, which in turn reduces the overall weight of blade drive device 1 and makes blade drive device 1 easier to handle. [Explanation of symbols]

[0088] 1, 1A, 1B: cutting blade drive device 2, 2A, 2B, 2C, 2D, 2E, 2F: Cutting blade unit 2G: Guide hole 2S: Fixed blade unit 20,20A,20B,20S: Cutting blade 21,21A,21B,21S: Base 22, 22A, 22B: Engagement holes 23: Through-hole 24: Drive mechanism accommodating hole 25: Fastening part 26: Foreign object sweep hole 3: Base unit 3A: First unit 3B: Second unit 3C: Fastening member 3G: Guide protrusion 30: Bearing 4: Drive mechanism 4A: Eccentric cam 4B: Power transmission section 40: Rotating shaft 40S: Stopper ring 41: First cam body 42: Second cam body 40P, 41P, 42P: Center 41A, 42A: Bearings 5: Guide cam 5A: First guide cam 5B: Second guide cam 5C: Engagement part 5D: Connection part 6: Guide hole bearing 7: Sliding tube 8, 8A, 8B: Foreign object intrusion prevention member 9: Foreign object blocking member C, C1, C2, C12, C13: Cutting space D1, D2: Outer diameter S1, S11, S21: 1st area S13: 3rd area S2, S12, S22: 2nd area e: Eccentricity radius Ed, Ed1: Eccentricity direction W1, W2: Pitch interval

Claims

1. The cutting tool comprises a cutting blade unit in which a plurality of cutting blades are arranged on a plane, a base unit that supports the plurality of cutting blade units in a stacked state, and a drive mechanism that is supported by the base unit and drives at least one of the cutting blade units to perform a cutting operation, The cutting blade unit includes a plurality of cutting blades that protrude in different directions around the periphery of the base unit, the drive mechanism translates at least one of the cutting blade units along a circular orbit without a dead point, thereby performing a cutting operation in which the cutting blade of one of the cutting blade units overlaps with the cutting blade of another of the cutting blade units. Blade drive device.

2. the drive mechanism moves the plurality of cutting blade units in circular orbits with a phase difference; The blade drive device according to claim 1.

3. The drive mechanism includes: an eccentric cam having a cam body fixed to a rotation shaft journaled on the base unit, the cam body eccentrically rotating, the cam body slidably engaging with the cutting blade unit; the base unit guides the movement of the cutting blade unit so that the cutting blade unit moves in a translational manner; The blade drive device according to claim 1.

4. 4. The blade driving device according to claim 3, wherein the eccentric cam has a plurality of cam bodies fixed to the rotary shaft with a phase difference.

5. The blade driving device according to claim 3 , wherein the driving mechanism includes a plurality of the eccentric cams, and at least one of the rotary shafts is rotationally driven directly or via a transmission mechanism.

6. the cutting operation is performed by opening and closing a cutting space formed by each cutting blade of one of the cutting blade units with the cutting blade of another cutting blade unit, The timing at which one cutting space is opened and closed is different from the timing at which the other cutting space is opened and closed. The blade drive device according to claim 1.

7. The cutting blade has a protruding shape, The cutting blade forming one of the cutting spaces and the cutting blade forming the other cutting space protrude in different directions. The blade driving device according to claim 6.

8. a fixed blade unit fixed to the base unit is disposed between the two cutting blade units driven by the drive mechanism; The blade drive device according to claim 1.

Images