Reciprocating cutting blade device and cutting blade unit

Abstract

The present invention expands the cuttable range by enabling a blade part to be provided also on the trailing edge side of a cutting blade. A reciprocating cutting blade device 1000 comprises: an operation rod 1 including a drive section 2 and a joint 3; and a cutting blade unit 100 attached to the joint 3 and configured to cause an upper blade 61 and a lower blade 71 to relatively reciprocate by means of the drive section 2. The cutting blade unit 100 comprises: a cutting blade body 60 in which the upper blade 61, which is provided with blade parts 63 at a predetermined interval on each of the leading edge and the trailing edge, and the lower blade 71, which is provided with blade parts 63 at a predetermined interval on each of the leading edge and the trailing edge, are vertically overlapped; a drive mechanism 30 for causing the upper blade 61 and the lower blade 71 to relatively reciprocate so that the blade parts 63 of the upper blade 61 and the blade parts 63 of the lower blade 71 meet; and a receiving section 20 for transmitting power for driving the drive mechanism 30 from the drive section 2 via the joint 3. The drive mechanism 30 is connected to the upper surface side of the cutting blade body 60 and is spaced apart from the rear end side of the cutting blade body 60.

Description

Reciprocating blade device and blade unit

[0001] The present disclosure relates to a reciprocating type cutting blade device and cutting blade unit that constitute the main part of a grass cutter, a pruner, or the like.

[0002] A known reciprocating blade device or reciprocating blade device for use in a brush cutter is one in which two reciprocating blade bodies 960 are provided with blade portions 963 at the front and rear thereof, as shown in FIG. 16 (see, for example, Patent Document 1). This reciprocating blade device 900 includes a pair of blade bodies 960 stacked one on top of the other in the thickness direction, and a transmission case 910 equipped with a drive mechanism 930 that reciprocates the blade bodies 960. As shown in FIG. 17, the drive mechanism 930 includes a pair of eccentric cams 936 and a pair of reciprocating bodies having fitting holes 934 that fit into the pair of eccentric cams 936, respectively. The reciprocating bodies are guided movably along an axis that is parallel to the direction of movement of the blade bodies 960 and passes through the rotation axis of the eccentric cams 936.

[0003] In this reciprocating cutting blade device 900, the operating rod 901 is connected at the center of the rear end of the transmission case 910. However, in this configuration of the reciprocating cutting blade device 900, it was not possible to provide a blade portion 963 at the portion where the transmission case 910 is connected. As a result, there were fewer blade portions 963 on the rear edge side of the cutting blade unit than on the front edge side, which caused a problem of reducing the area of ​​vegetation that could be cut when the transmission case 910 was pulled.

[0004] As shown in Fig. 17, the reciprocating cutter blade device 900 is configured to reciprocate the cutting blade body 960 by rotating the eccentric cam 936 around the rotation shaft 945. In this configuration, as shown in the schematic diagram of Fig. 18, the stroke amount ST of the reciprocating cutter blade body 960 is determined by the size of the eccentric cam 936. Therefore, in order to increase the stroke amount ST of the cutting blade body 960, the eccentric cam 936 must be made larger, which increases the rotational torque and wear of the eccentric cam 936 and requires corresponding rigidity, resulting in an increase in the size and cost of the device.

[0005] Japanese Patent Application Laid-Open No. 2021-023187

[0006] One objective of one aspect of the present disclosure is to provide a reciprocating type cutting blade device and cutting blade unit that widens the cutting area by providing a blade portion on the rear edge of the cutting blade. Another objective of another aspect is to provide a reciprocating type cutting blade device and cutting blade unit that are compactly configured while increasing the stroke length for reciprocating the cutting blade. Note that the description of these objectives does not preclude the existence of other objectives. Furthermore, it is not necessary for one aspect of the present disclosure to solve all of these objectives. Furthermore, other objectives may be extracted from the description of the specification, drawings, claims, etc. of the present disclosure. Means for solving the problem and effects of the invention

[0007] A reciprocating blade device according to a first embodiment is a reciprocating blade device comprising: a drive unit; an operating rod having a joint for connecting to an object to be driven by the drive unit; and a blade unit attached to the joint and configured to cause an upper blade and a lower blade to reciprocate relative to each other using the drive unit; the blade unit comprising a blade body having an upper blade with blade portions provided at a predetermined interval on each of its front and rear edges, and a lower blade with blade portions provided at a predetermined interval on each of its front and rear edges, stacked one above the other; a drive mechanism that causes the upper blade and lower blade to reciprocate relative to each other so that the blade portions of the upper blade and the lower blade cross cutting each other; and a receiving portion for transmitting power to drive the drive mechanism from the drive unit via the joint; the drive mechanism is connected to the upper surface side of the blade body and is spaced apart from the rear end side of the blade body. With the above configuration, the drive mechanism that reciprocates the cutting blade body is connected to the top side of the cutting blade body rather than the rear end side, and by providing a space at the rear end side, it is possible to form a continuous cutting edge at the rear end side of the cutting blade body as well.As a result, when cutting weeds and the like with a reciprocating cutting blade device, in addition to pushing the reciprocating cutting blade device out and cutting with the cutting blade body at the front edge, it is also possible to pull the reciprocating cutting blade device and cut with the cutting blade body at the rear end, improving work efficiency.

[0008] In the reciprocating blade device according to the second aspect, the drive mechanism is inclined relative to a plane extending from the rear end of the blade body, starting from the position where the drive mechanism is connected to the blade body. With the above configuration, connecting the drive mechanism at an angle to the blade body makes it possible to provide a space on the rear end side.

[0009] Furthermore, in a reciprocating type cutting blade device according to a third aspect, in any of the above aspects, the inclination angle at which the drive mechanism is inclined with respect to a plane extending from the rear end side of the cutting blade body is between 5° and 30°.

[0010] Furthermore, in a reciprocating type cutting blade device according to a fourth aspect, in any of the above aspects, the lower blade is provided with a lower pin on its upper surface, the upper blade is provided with an upper pin on its upper surface, and a pin slot through which the lower pin is inserted is opened in the upper surface at a position corresponding to the range of movement of the lower pin, and the drive mechanism includes a first crank rod having a first tilting shaft at one end, a first crank slot through which the lower pin is inserted at the other end, and a first crank intermediate hole at the middle, a second crank rod having a second tilting shaft at one end, a second crank slot through which the upper pin is inserted at the other end, and a second crank intermediate hole at the middle, a crank shaft that pivotally supports the first tilting shaft of the first crank rod and the second tilting shaft of the second crank rod so as to be able to tilt, and a drive mechanism for the first crank rod. The crankshaft cutting tool includes a first eccentric cam inserted into an intermediate hole, a second eccentric cam inserted into the second crank intermediate hole and eccentric to a different phase from the first eccentric cam, a crank gear arranged coaxially with the first eccentric cam and the second eccentric cam, and a speed change mechanism for connecting the crank gear to the drive unit via the receiving part while adjusting the rotation speed, wherein when the crank gear is rotated by the drive unit via the speed change mechanism, the first eccentric cam tilts the first crank rod around the crank shaft, causing the lower blade to reciprocate via the lower pin inserted into the first crank long hole, and the second eccentric cam tilts the second crank rod around the crank shaft, causing the upper blade to reciprocate via the upper pin inserted into the second crank long hole. With the above configuration, the first eccentric cam and the second eccentric cam are used to reciprocate the middle of the first and second crank rods connected in a V-shape, and the stroke of the lower blade and the upper blade connected to each end of the first and second crank rods can be made longer than the stroke of the eccentric cam, which results in a smaller eccentric cam and simplifies the configuration of the drive mechanism.Furthermore, by configuring the drive mechanism and the cutting blade body to be connected by inserting a lower pin and an upper pin into the first crank elongated hole and the second crank elongated hole of the first crank rod and the second crank rod, respectively, it is possible to position the drive mechanism in an inclined position relative to the cutting blade body, thereby realizing a configuration in which space is provided on the rear end side of the cutting blade body.

[0011] Furthermore, a reciprocating type cutting blade device according to a fifth aspect is a reciprocating type cutting blade device in any of the above aspects, comprising an operating rod provided with a drive unit at its rear end and a joint at its front end for connecting to an object to be driven by the drive unit, and a cutting blade unit attached to the joint and configured to relatively reciprocate an upper blade and a lower blade, which will be described later, using the drive unit, and the cutting blade unit comprises a cutting blade body in which an upper blade having blade portions at a predetermined interval on each of its front and rear edges and a lower blade having blade portions at a predetermined interval on each of its front and rear edges are stacked one on top of the other, a drive mechanism for relatively reciprocating the upper blade and the lower blade so that the blade portion of the upper blade and the blade portion of the lower blade cross each other, and a receiving portion for transmitting power for driving the drive mechanism from the drive portion via the joint, wherein the lower blade has a lower pin on its upper surface, and the upper blade has an upper pin on its upper surface, and a pin slot through which the lower pin is inserted is opened at a position corresponding to the range of movement of the lower pin on the upper surface, and the drive mechanism has a first tilt shaft at one end, a first crank slot through which the lower pin is inserted at the other end, and a first crank intermediate hole at the middle a first crank rod having a second tilt shaft at one end, a second crank elongated hole into which the upper pin is inserted at the other end, and a second crank intermediate hole at the middle; a crank shaft that pivotally supports the first tilt shaft of the first crank rod and the second tilt shaft of the second crank rod so as to be able to tilt; a first eccentric cam inserted into the first crank intermediate hole; a second eccentric cam inserted into the second crank intermediate hole and eccentric to a different phase from the first eccentric cam; and a crank gear provided coaxially with the first eccentric cam and the second eccentric cam. and a speed change mechanism for adjusting the rotation speed and connecting the crank gear and the drive unit via the receiving part, wherein when the crank gear is rotated by the drive unit via the speed change mechanism, the first eccentric cam tilts the first crank rod around the crank shaft, causing the lower blade to reciprocate through the lower pin inserted into the first crank long hole, and the second eccentric cam tilts the second crank rod around the crank shaft, causing the upper blade to reciprocate through the upper pin inserted into the second crank long hole.With the above configuration, the first eccentric cam and the second eccentric cam are used to reciprocate the middle of the first and second crank rods connected in a V-shape, and the stroke of the lower blade and the upper blade connected to each end of the first and second crank rods can be made longer than the stroke of the eccentric cam, which results in a smaller eccentric cam and simplifies the configuration of the drive mechanism.

[0012] Furthermore, in a reciprocating type cutting blade device according to a sixth aspect, in any of the above aspects, the first crank rod has the first tilting shaft, the first crank elongated hole, and the first crank intermediate hole arranged on the same plane, and the second crank rod has the second tilting shaft, the second crank elongated hole, and the second crank intermediate hole arranged on the same plane. With the above configuration, the crank rods do not need to be bent in the middle, and a structure that is less likely to generate gouging forces can be achieved, thereby improving the durability of the crank rods.

[0013] Furthermore, in a reciprocating blade device according to a seventh aspect, in any of the above aspects, the upper blade and the lower blade have the same shape and are formed with 180° rotational symmetry. This configuration allows the upper blade and the lower blade to be made common, thereby reducing manufacturing costs. Furthermore, if the cutting edge of the leading edge side blade becomes dull during use, the upper blade and the lower blade can be rotated 180° to switch the leading edge side and the trailing edge side blade, allowing continued use.

[0014] Furthermore, the reciprocating type cutting blade device according to an eighth aspect is any of the above aspects, and further includes a transmission case that houses the drive mechanism, and the transmission case is tilted with respect to the cutting blade body so that the rear side is higher than the front side, thereby forming a space between the rear side and a plane extending from the rear end side of the cutting blade body. With the above configuration, by tilting the transmission case with respect to the cutting blade body, a space can be formed on the rear end side.

[0015]

[0010] Furthermore, a ninth aspect of the present invention provides a cutting blade unit connected to a joint provided at one end of an operating rod having a drive unit and driven by the drive unit, the cutting blade unit comprising: a cutting blade body having an upper blade with cutting portions provided at a predetermined interval on its front and rear edges, and a lower blade with cutting portions provided at a predetermined interval on its front and rear edges, stacked one above the other; a drive mechanism for relatively reciprocating the upper blade and the lower blade so that the cutting portions of the upper blade and the lower blade cross each other; and a receiving portion for receiving, from the drive unit via the joint, power for relatively reciprocating the upper blade and the lower blade obtained by driving the drive mechanism, the power being provided by driving the drive mechanism; the drive mechanism being connected to an upper surface side of the cutting blade body and spaced apart from the rear end side of the cutting blade body. With the above configuration, the connection of the drive mechanism for reciprocating the cutting blade body is made at the top side rather than the rear end side of the cutting blade body, and a space is provided at the rear end side, thereby making it possible to form cutting portions continuously at the rear end side of the cutting blade body. As a result, when cutting weeds, etc., it is possible to push out the cutting blade unit and cut with the cutting blade body on the front edge side, and also to pull the cutting blade unit and cut with the cutting blade body on the rear end side, thereby improving work efficiency.

[0016] 1. An external perspective view showing a reciprocating cutting blade device according to a first embodiment. 2. An oblique view showing a cutting blade unit of the reciprocating cutting blade device of FIG. 1. 3. An oblique view of the cutting blade unit of FIG. 2, seen obliquely from below. 4. A side view of the cutting blade unit of FIG. 2, with the transmission case indicated by a broken line. 5. An exploded oblique view of the cutting blade body of the cutting blade unit of FIG. 2. 6. A sectional oblique view of the cutting blade unit of FIG. 2, taken along line VI-VI. 7. An exploded oblique view of the drive mechanism of the cutting blade unit of FIG. 5. 8. An oblique view of the connecting portion between the cutting blade unit and the drive mechanism. 9. An oblique view of the connecting portion between the cutting blade unit and the drive mechanism, seen from behind. 10. A plan view showing a state in which the drive mechanism reciprocates the cutting blade unit (a state in which the first crank rod and the second crank rod are open). 11. A plan view showing a state in which the drive mechanism reciprocates the cutting blade unit (a state in which the first crank rod and the second crank rod are closed). 12. A schematic diagram showing the stroke amount of the drive mechanism of FIG. 10. 13. A schematic diagram showing a reciprocating cutting blade device according to a second embodiment. 14. A perspective view of a reciprocating cutting blade device according to a third embodiment. Fig. 17 is a schematic diagram showing a reciprocating type cutting blade device according to a fourth embodiment. Fig. 18 is a perspective view showing a conventional reciprocating cutting blade device. Fig. 19 is an enlarged plan view showing a drive mechanism of the reciprocating cutting blade device of Fig. 16. Fig. 19 is a schematic diagram showing a stroke amount in the drive mechanism of Fig. 17.

[0017] The present disclosure will be described in more detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms including these terms) will be used as necessary. However, the use of these terms is intended to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present disclosure. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or components.

[0018] Furthermore, the embodiments shown below are specific examples of the technical ideas of the present disclosure, and are not intended to limit the present disclosure to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present disclosure. Furthermore, the content described in one embodiment can also be applied to other embodiments. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity of explanation. [Embodiment 1]

[0019] Figures 1 to 4 show a reciprocating cutting blade device 1000 according to embodiment 1. In these figures, Figure 1 is an external perspective view showing the reciprocating cutting blade device 1000 according to embodiment 1, Figure 2 is a perspective view showing the cutting blade unit 100 of the reciprocating cutting blade device 1000 of Figure 1, Figure 3 is a perspective view of the cutting blade unit 100 of Figure 2 seen obliquely from below, and Figure 4 is a side view of the cutting blade unit 100 of Figure 2, with the transmission case 10 indicated by a dashed line.

[0020] The reciprocating blade device 1000 shown in Figure 1 is an electric brush cutter. The brush cutter trims and cuts vegetation by sliding an upper blade 61 and a lower blade 71 that make up the blade body 60 back and forth relative to each other. The longitudinal direction of the blade body 60 is disposed in a direction that intersects with the longitudinal direction of the operating rod 1. A T-shaped blade unit 100 is attached to the tip of the operating rod 1. With this handheld work machine 10, an operator holds the operating handle 4 in his or her hand and, with the operating rod 1 at a predetermined angle relative to the work surface, drives the blade unit 100 to move the blade unit 100 along the work surface to perform brush cutting work.

[0021] With this handheld work machine 10, the longitudinal width of the cutting blade body 60 of the cutting blade unit 100 becomes the working width without swinging the operating rod 1 left or right. The operator can perform mowing within the working width by simply pushing the operating rod 1 forward. This allows the cutting blade unit 100 to be moved forward quickly, resulting in highly efficient mowing. Furthermore, since the mowing is performed with a reciprocating cutting blade device, the generation of flying debris during work is reduced. This ensures the safety of the operator and those around them, and allows mowing to be performed without damaging the property of others near the work site. Furthermore, by providing the cutting edge 63 on both the leading and trailing edges of the cutting blade body 60, the operator can easily remove any remaining grass by pulling the cutting blade unit 100 toward them. (Reciprocating Cutting Blade Device 1000)

[0022] The reciprocating type cutting blade device 1000 shown in FIGS. 1 to 4 includes an operating lever 1 and a cutting blade unit 100. The operating lever 1 includes a drive unit 2 at its rear end and a joint 3 at its front end. The drive unit 2 generates power to drive the cutting blade unit 100, which is the driven object. A rotating body such as a motor or an engine can be used as the drive unit 2. In the case of a motor, the battery that drives the motor is also included in the drive unit 2. The drive unit 2 includes, for example, a detachable battery pack as a power source for driving. Note that in the example of FIG. 1, the drive unit 2 is connected to the rear end of the operating lever 1, but the position where the drive unit is provided is not limited to the rear end of the operating lever and may be located in the middle. The drive unit may also be provided separately from the operating lever.

[0023] As shown in Figure 4, a drive shaft 6 that transmits power to a drive mechanism 30 is provided inside the operating rod 1. The joint 3 is a member for connecting the cutting blade unit 100, which is driven by the drive part 2, to the operating rod 1. The receiving part 20 on the cutting blade unit 100 side is connected to the joint 3 to drive the cutting blade unit 100.

[0024] The operating rod 1 may also be provided with an operating handle 4 in the middle for the operator to grip. In the example of Figure 1, the operating handle 4 is connected to the middle of the operating rod 1, making it easier to swing the cutting blade unit 100 connected to the tip of the operating rod 1 left and right. (Cutting blade unit 100)

[0025] The cutting blade unit 100 is attached to the tip of the operating rod 1. The cutting blade unit 100 includes a cutting blade body 60 having an upper blade 61 and a lower blade 71 stacked on top of each other, with multiple comb-shaped blade portions 63 protruding from the front edge side and the rear edge side, respectively. The upper blade 61 and the lower blade 71 of the cutting blade body 60 are configured to reciprocate relative to each other using a driving force obtained from the driving unit 2. The cutting blade unit 100 attached to the tip of the operating rod 1 may be interchangeable with another unit that can be driven by the driving unit 2. (Receiving portion 20)

[0026] The cutting blade unit 100 includes a cutting blade body 60, a drive mechanism 30, a receiving portion 20, and a transmission case 10. The receiving portion 20 is a member for transmitting power for driving the drive mechanism 30 from the drive unit 2 via a joint 3. The receiving portion 20 is formed in a cylindrical shape so that it can be connected to the joint 3 of the operating rod 1, as shown in Figures 2 to 4, etc. The receiving portion 20 is also attached to the transmission case 10 via an angle adjustment mechanism 23. The angle adjustment mechanism 23 allows the angle of the operating rod 1 relative to the working surface of the cutting blade body 60 to be adjusted.

[0027] As shown in Fig. 4, the receiving portion 20 can rotate about a vertical rotation shaft 21. As a result, the angle of the operating rod 1 extending from the receiving portion 20 of the reciprocating cutting blade device 1000 relative to the work surface can be adjusted as desired, as shown in Fig. 1. For example, by adjusting the angle of the operating rod 1 in accordance with the height of the operator, the height at which the device is held in the hand, the unevenness of the work surface, etc., the reciprocating cutting blade device 1000 can be made easy to use. A horizontal rotation shaft may also be provided in the cutting blade unit 100.

[0028] The cutting blade unit 100 shown in FIG. 1 is attached to a joint 3 and configured to rotate the drive unit 2 and reciprocate the upper blade 61 and lower blade 71 of the cutting blade body 60 via a drive mechanism 30. (Cutting blade body 60)

[0029] As shown in Figure 5, the cutting blade body 60 is composed of an upper blade 61 and a lower blade 71. The upper blade 61 has blade portions 63 provided at a predetermined interval on both its front and rear edges. The lower blade 71 also has blade portions 63 provided at a predetermined interval on both its front and rear edges. The cutting blade body 60 has the upper blade 61 and the lower blade 71 stacked one on top of the other and connected to each other so that they can move back and forth relative to each other. For this reason, the cutting blade body 60 is attached to a cutting blade guide 80 that does not move. The cutting blade guide 80 is fixed to the transmission case 10.

[0030] The lower blade 71 has a lower pin 75 on its upper surface. Meanwhile, the upper blade 61 also has an upper pin 65 on its upper surface. The upper blade 61 also has a pin slot 64, through which the lower pin 75 is inserted, on its upper surface at a position corresponding to the range of movement of the lower pin 75. In the example shown in FIG. 5 , the upper blade 61 and the lower blade 71 have a common shape, and the upper blade 61 can be used as the lower blade 71 by rotating it 180 degrees. This reduces the number of parts. For this reason, in the example shown in FIG. 5 , the lower blade 71 also has a pin slot 64. However, the upper blade and the lower blade may be designed to have different shapes. For example, the lower blade may have a shape without a pin slot.

[0031] The cutting blade body 60 is provided with two metal plates, an upper blade 61 and a lower blade 71, stacked on top of each other in the thickness direction. Each of the upper blades 61 and lower blades 71 constituting the cutting blade body 60 has a flat base 62, 72 extending in the longitudinal direction and a plurality of blade portions 63 protruding in a direction intersecting the longitudinal direction. The bases 62, 72 are supported by a cutting blade guide 80.

[0032] A lower pin 75 is provided at a position offset from the center (on the right side in FIG. 6 ) on the base 72 of the lower blade 71. An upper pin 65 is provided at a position offset from the center (on the left side in FIG. 6 ) on the base 62 of the upper blade 61. Furthermore, the base 62 of the upper blade 61 has an elongated pin hole 64 for inserting the lower pin 75. This elongated pin hole 64 functions as a guide for reciprocating the upper blade 61 and lower blade 71 relative to each other along the longitudinal direction.

[0033] The bases 62, 72 are also provided with a plurality of elongated holes through which adjustment screws pass along the longitudinal direction of the cutting blade body 60. These elongated holes also define the direction in which the cutting blade body 60 reciprocates.

[0034] The blades 63 provided on the upper blade 61 and the lower blade 71 are comb-shaped clipper blades, and by sliding the two upper blades 61 and lower blade 71 against each other in the longitudinal direction, they cut grass or other matter caught between the blades 63 of one upper blade 61 and the blades 63 of the other lower blade 71 (transmission case 10).

[0035] The transmission case 10 houses the drive mechanism 30 that reciprocates the cutting blade body 60. As shown in Figures 5 and 7, the transmission case 10 is divided into an upper case 11 and a lower case 12. The lower case 12 also has a case opening window 13 so as not to interfere with the connection between the drive unit 30 housed in the transmission case 10 and the cutting blade body 60 disposed outside the transmission case 10.

[0036] The transmission case 10 also has wheels 14 on its sides, which reduces frictional resistance when the cutting blade unit 100 is manually pushed or pulled by the work vehicle to move back and forth across the work surface. (Drive mechanism 30)

[0037] The drive mechanism 30 converts the rotation of the drive shaft 6 of the operating rod 1 into reciprocating motion. The drive mechanism 30 reciprocates the upper blade 61 and the lower blade 71 relative to each other so that the blade portion 63 of the upper blade 61 and the blade portion 63 of the lower blade 71 cross cut each other. The drive mechanism 30 is connected to the upper surface side of the central portion of the cutting blade body 60. The drive mechanism 30 is also separated from the rear end side of the cutting blade body 60. By connecting the drive mechanism 30 to the upper surface side of the cutting blade body 60 in this way, rather than the rear end side of the central portion, the rear end side of the cutting blade body 60 is free, and it is possible to provide the blade portion 63 over almost the entire surface of the rear end side of the cutting blade body 60.

[0038] 16, the drive mechanism 930 is located in the center of the rear end of the cutting blade body 960, so it is not possible to provide a blade portion 963B in this area. As a result of the blade portion 963 not being formed on the entire surface of the rear end of the cutting blade body 960, while the blade portion 963A on the front edge can cut vegetation and the like when the cutting blade unit is pushed out, the absence of the blade portion 963B in the center reduces the area that can be cut when the cutting blade unit is pulled back, resulting in poor workability.

[0039] In contrast, with the reciprocating cutting blade device 1000 according to this embodiment, it is possible to provide the cutting edge 63 on almost the entire surface of the cutting blade body 60, including the central portion on the rear end side, improving workability. For example, like a vacuum cleaner, the reciprocating cutting blade device 1000 can be moved back and forth to cut weeds, improving work efficiency and increasing convenience.

[0040] As shown in Figure 4, the drive mechanism 30 is inclined relative to a plane extending from the rear end of the cutting blade body 60, starting from the position where it is connected to the cutting blade body 60. By connecting the drive mechanism 30 at an angle relative to the cutting blade body 60 in this way, a space can be provided on the rear end side. In this case, the angle θ at which the drive mechanism 30 is inclined relative to the plane extending from the rear end of the cutting blade body 60 is set to 5° to 30°, preferably 10° to 15°, and more preferably 10°.

[0041] In the example of Figure 4, the transmission case 10 housing the drive mechanism 30 is tilted relative to the cutting blade body 60. By making the rear side of the transmission case 10 higher than the front side, a space is formed between the rear side and a plane extending from the rear end side of the cutting blade body 60. By tilting the transmission case 10 relative to the cutting blade body 60 in this way, a space can be provided on the rear end side of the cutting blade body 60.

[0042] The drive mechanism 30 will be described in detail below with reference to FIGS. 6 to 11. The drive mechanism 30 shown in the exploded perspective view of FIG. 7 includes a first crank rod 31, a second crank rod 41, a crankshaft 35, a first eccentric cam 36, a second eccentric cam 46, a crank gear 38, and a speed change mechanism 50. The first crank rod 31 has a first tilt shaft 32 at one end, a first crank elongated hole 33 into which the lower pin 75 is inserted at the other end, and a first crank intermediate hole 34 in the middle. To form the first crank intermediate hole 34 in the middle, the width of the middle portion of the first crank rod 31 is partially widened. The second crank rod 41 has a second tilt shaft 42 at one end, a second crank elongated hole 43 into which the upper pin 65 is inserted at the other end, and a second crank intermediate hole 44 in the middle. The second crank rod 41 also has a partially widened middle portion to form a second crank intermediate hole 44. The first crank intermediate hole 34 and the second crank intermediate hole 44 are each formed in a track shape.

[0043] The crankshaft 35 also supports the first tilt shaft 32 of the first crank rod 31 and the second tilt shaft 42 of the second crank rod 41 in a tiltable manner. (First eccentric cam 36, second eccentric cam 46)

[0044] The first eccentric cam 36 is inserted into the first crank intermediate hole 34. The second eccentric cam 46 is inserted into the second crank intermediate hole 44. The second eccentric cam 46 is eccentric to the first eccentric cam 36, with a different phase. The first eccentric cam 36 and the second eccentric cam 46 shown in FIG. 7 are disks that rotate eccentrically together with a phase difference of 180°. In the example shown in FIG. 7, the first eccentric cam 36 and the second eccentric cam 46 are fixed together in advance. However, the first eccentric cam and the second eccentric cam may be formed as separate members. The first eccentric cam 36 and the second eccentric cam 46 rotate about a coaxial cam rotation axis 45.

[0045] The crank gear 38 is provided coaxially with the cam rotation shaft 45 of the first eccentric cam 36 and the second eccentric cam 46. The crank gear 38 is rotated by a speed change mechanism 50. The rotation of the drive shaft 6 is transmitted by the speed change mechanism 50 and the crank gear 38, causing the first eccentric cam 36 and the second eccentric cam 46 to rotate around the cam rotation shaft 45.

[0046] Here, the first crank rod has a first tilt shaft, a first crank elongated hole, and a first crank intermediate hole that are arranged on the same plane. Similarly, the second crank rod has a second tilt shaft, a second crank elongated hole, and a second crank intermediate hole that are arranged on the same plane. By forming each crank rod flat without bending it in the middle, it is less likely to generate a gouging force compared to a configuration in which the middle is bent, and the durability of the crank rod can be improved. (Transmission mechanism 50)

[0047] The speed change mechanism 50 is a member for adjusting the rotation speed and connecting the crank gear 38 to the drive shaft 6 of the drive unit 2 via the receiving portion 20. In the example shown in Fig. 9, the speed change mechanism 50 is a reducer configured by combining multiple gears and for reducing the rotation speed of the drive shaft 6.

[0048] In this drive mechanism 30, the rotational motion of the drive unit 2, transmitted via the receiving portion 20, is adjusted by the speed change mechanism 50, and then the drive mechanism 30 relatively reciprocates the upper blade 61 and the lower blade 71, as shown in FIGS. 6, 8, and 9. That is, when the crank gear 38 is rotated by the drive unit 2 via the speed change mechanism 50, the first eccentric cam 36 tilts the first crank rod 31 about the crankshaft 35, as shown in FIGS. 10 and 11, causing the lower blade 71 to reciprocate via the lower pin 75 inserted in the first crank slot 33. Meanwhile, the second eccentric cam 46 tilts the second crank rod 41 about the crankshaft 35, causing the upper blade 61 to reciprocate via the upper pin 65 inserted in the second crank slot 43. As shown by the arrows in FIG. 10, when the first crank rod 31 and the second crank rod 41 move in the closing direction due to the rotation of the crank gear 38, the upper blade 61 moves rightward and the lower blade 71 moves leftward. 11, when the first crank rod 31 and the second crank rod 41 move in the opening direction, the upper blade 61 moves leftward and the lower blade 71 moves rightward (cutting blade guide 80).

[0049] The cutting blade guide 80 is attached to the transmission case 10. This cutting blade guide 80 sandwiches the bases 62, 72 of the pair of upper blades 61 and lower blades 71 and supports the cutting blade bodies 60 so that they can move freely in the longitudinal direction. In the example shown in Figures 5 and 6, the cutting blade guide 80 is composed of a pair of upper guide 81 and lower guide 82 that extend in the longitudinal direction of the cutting blade bodies 60. The upper guide 81 and the lower guide 82 are fastened together by guide screws 84 with a spacer 83 interposed therebetween. This maintains a space in which the pair of cutting blade bodies 60 can be accommodated. The cutting blade guide 80 is attached independently to the transmission case 10 while maintaining the space. The pair of cutting blade bodies 60 are accommodated in this space and are detachably attached to the cutting blade guide 80.

[0050] In this manner, by using the first eccentric cam 36 and the second eccentric cam 46 to reciprocate the middle of the first crank rod 31 and the second crank rod 41, which are connected in a V-shape, it is possible to make the stroke amounts ST2 and ST3, which cause the lower blade 71 and the upper blade 61 connected to each end of the first crank rod 31 and the second crank rod 41 to reciprocate, greater than the stroke amount ST1 of the eccentric cam. That is, as shown in Figure 12, by arranging the first eccentric cam 36 and the second eccentric cam 46 in the middle of the first crank rod 31 and the second crank rod 41, which are arranged in an isosceles triangle, the upper blade 61 and the lower blade 71 reciprocate at the portions corresponding to the bases of the first crank rod 31 and the second crank rod 41. 18 , by using the first crank rod 31 and the second crank rod 41 connected in a V-shape, it is possible to obtain stroke amounts ST2 and ST3 that are greater than the stroke amount ST1 obtained by movement using an eccentric cam. In other words, by disposing the eccentric cam at the middle of the crank gear 38 and driving the cutting blade body 60 connected to the rear end of the crank gear 38, the stroke amount can be increased the longer the distance from the middle to the rear end of the crank gear 38. As a result, the eccentric cam can be made smaller, which contributes to simplifying the configuration of the drive mechanism 30.

[0051] Furthermore, by configuring the drive mechanism 30 and the cutting blade body 60 to be connected by inserting the lower pin 75 and the upper pin 65 into the first crank elongated hole 33 and the second crank elongated hole 43 of the first crank rod 31 and the second crank rod 41, respectively, it is possible to place the drive mechanism 30 in an inclined position relative to the cutting blade body 60, and to realize a configuration in which a space is provided on the rear end side of the cutting blade body 60. In other words, the mechanism for connecting by inserting pins into the elongated holes can accommodate the reciprocating motion of the upper blade 61 and the lower blade 71 that slide horizontally, and can also be responsible for connecting the drive mechanism 30 and the cutting blade body 60 in an inclined position.

[0052] The upper blade 61 and lower blade 71 of the cutting blade body 60 preferably have the same shape and are formed with 180° rotational symmetry. This allows the upper blade 61 and lower blade 71 to be common, reducing manufacturing costs. Furthermore, when the cutting edge of the leading edge side cutting portion 63A of the cutting blade body 60 becomes dull during use, the upper blade 61 and lower blade 71 can be rotated 180° and the trailing edge side cutting blade 63B can be swapped with the leading edge side cutting blade, allowing continued use.

[0053] In particular, under normal use, when the reciprocating blade device is pushed out, the leading edge blade 63A frequently cuts, and the leading edge blade 63A inevitably wears out faster than the trailing edge blade 63B. While this normally requires the cutting blade body 60 to be resharpened, according to this embodiment, the trailing edge blade 63B can be used as the leading edge blade simply by rotating the upper blade 61 and the lower blade 71 180 degrees and resetting them. Generally, the trailing edge blade 63B wears out more slowly than the leading edge blade 63A, so the sharpness of the leading edge blade 63A can be restored in a simple manner. This results in an extension of the time until the cutting blade body needs to be sharpened, providing the advantage of allowing the reciprocating blade device to be used for a longer period of time.

[0054] Furthermore, the cutting blade unit 100 can be disassembled and the cutting blade body 60 can be rotated 180 degrees and then set again, or the cutting blade unit 100 can be rotated and used. For example, by rotating the operating lever 1 counterclockwise in the drawing using the vertical rotation shaft 21 shown in Figure 4 and using it so that the rear end side is pushed out, it becomes possible to easily perform cutting with the cutting blade at the rear end side when the cutting blade unit 100 is advanced.

[0055] As described above, by connecting the drive mechanism 30 that reciprocates the cutting blade body 60 to the top side of the cutting blade body 60 rather than the rear end side, and providing a space at the rear end side, it is possible to form a continuous blade portion 63 also at the rear end side of the cutting blade body 60. As a result, when cutting weeds and the like with the reciprocating cutting blade device 1000, in addition to pushing the reciprocating cutting blade device 1000 out to cut with the cutting blade body 60 on the front edge side, it is also possible to cut with the cutting blade body 60 on the rear end side when the reciprocating cutting blade device 1000 is pulled, improving work efficiency. [Embodiment 2]

[0056] In the first embodiment described above, the drive mechanism 30 is connected at an angle relative to a plane extending from the rear end of the cutting blade body 60, starting from the connection position with the cutting blade body 60. However, the present disclosure is not limited to this configuration for separating the drive mechanism from the rear end of the cutting blade body. For example, the crank rod may not be linear in cross section, but may have a step to form a space on the rear end side of the cutting blade body. Such an example is shown in the schematic side view of a reciprocating cutting blade device 2000 according to a second embodiment in FIG. 13 . This figure shows a schematic side view of the first crank rod 31′ and the second crank rod 41′ that constitute the drive mechanism 30′ of the cutting blade unit 200. In this figure, components similar to those in the first embodiment are designated by the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0057] The first crank rod 31' forms a step 39 between the first crank intermediate hole 34' and the first crank elongated hole 33'. Similarly, the second crank rod 41' forms a step 39 between the second crank intermediate hole 44' and the second crank elongated hole 43'. As a result, a space is provided at the rear end of the cutting blade body 60', which is composed of the upper blade 61' and the lower blade 71', and a blade portion 63' can be provided on the rear edge of the cutting blade body 60'. With this configuration, the drive mechanism 30' including the first crank rod 31' and the second crank rod 41' can be connected to the cutting blade body 60' without tilting it relative to the cutting blade body 60', i.e., the cutting blade body 60' and the drive mechanism 30' can be kept parallel to each other, and power from the drive unit can be transmitted. Note that in the second embodiment, the provision of a step between the first crank rod 31' and the second crank rod 41' makes it easier for gouging stress to occur compared to the drive mechanism 30 of the first embodiment, resulting in a slight loss of drive force. [Embodiment 3]

[0058] Furthermore, in the above example, the wheels 14 are provided on the side of the transmission case 10, but the present disclosure is not limited to this configuration, and the wheels may be provided in other positions. For example, in the example of a reciprocating cutting blade device 3000 according to embodiment 3 shown in the perspective view of FIG. 14, the wheels 14' are provided on the edge of the cutting blade guide 80' of the cutting blade unit 300. This has the advantage of allowing the horizontally long cutting blade unit 300 to move smoothly. On the other hand, because both sides of the horizontally long cutting blade unit 300 are supported by the wheels 14', the middle part is prone to bending, resulting in some loss of sliding of the cutting blade body. [Embodiment 4]

[0059] Furthermore, sleds may be provided instead of or in addition to the wheels. For example, in the example of the reciprocating cutting blade device 4000 according to the fourth embodiment shown in the perspective view of Fig. 15, a pair of sleds 15 are provided on the back side of the transmission case 10. This prevents the bottom surface of the transmission case 10 from directly rubbing against the work surface, and allows the cutting blade unit 400 to move more smoothly across the work surface.

[0060] The reciprocating cutting blade device and cutting blade unit according to the present disclosure can be suitably used in brush cutters and the like that cut or cut weeds.

[0061] 1000, 2000, 3000, 4000...Reciprocating type cutting blade device 100, 200, 300, 400...Cutting blade unit 1...Operation rod 2...Drive unit 3...Joint 4...Operation handle 6...Drive shaft 10...Transmission case 11...Upper case 12...Lower case 13...Case opening window 14, 14'...Wheels 15...Sled 20...Receiving portion 21...Vertical rotation shaft 23...Angle adjustment mechanism 30, 30'...Drive mechanism 31, 31'...First crank rod 32...First tilting shaft 33, 33'...First crank elongated hole 34, 34'...First crank intermediate hole 35...Crank shaft 36...First eccentric cam 38...Crank gear 39...Step 41, 41'...Second crank rod 42...Second tilting shaft 43, 43'... Second crank elongated hole 44, 44'... Second crank intermediate hole 45... Cam rotation shaft 46... Second eccentric cam 50... Speed ​​change mechanism 60, 60'... Cutting blade body 61, 61'... Upper blade 62, 72... Base 63, 63'... Blade portion; 63A... Front edge side blade portion; 63B... Rear edge side cutting blade 64... Pin elongated hole 65... Upper pin 71, 71'... Lower blade 75... Lower pin 80, 80'... Cutting blade guide 81... Upper guide 82... Lower guide 83... Spacer 84... Guide screw 900... Reciprocating cutting blade device 901... Operating rod 910... Transmission case 930... Drive mechanism 934... Fitting hole 936... Eccentric cam 945... Rotation shaft 960... Cutting blade body 963... cutting portion; 963A... cutting portion on the leading edge side ST, ST1, ST2, ST3... stroke amount

Claims

1. A reciprocating blade device comprising: a drive unit, an operating rod having a joint for connecting to an object to be driven by the drive unit, and a blade unit attached to the joint and configured to cause an upper blade and a lower blade to reciprocate relatively with each other using the drive unit, wherein the blade unit comprises: an upper blade having blade portions provided at a predetermined interval on each of its front and rear edges, and a lower blade having blade portions provided at a predetermined interval on each of its front and rear edges, a blade body formed by stacking these above and below; a drive mechanism for reciprocating the upper blade and lower blade relative to each other so that the blade portions of the upper blade and the lower blade cut and join together; and a receiving portion for transmitting power for driving the drive mechanism from the drive unit via the joint, wherein the drive mechanism is connected to an upper surface side of the blade body and is spaced apart from the rear end side of the blade body.

2. A reciprocating type cutting blade device according to claim 1, wherein the drive mechanism is inclined from the connection point with the cutting blade body relative to a plane extended from the rear end side of the cutting blade body.

3. A reciprocating type cutting blade device according to claim 2, wherein the drive mechanism is inclined at an angle of 5° to 30° with respect to a plane extending from the rear end side of the cutting blade body.

4. A reciprocating type cutting blade device according to claim 1, wherein the lower blade has a lower pin on its upper surface, the upper blade has an upper pin on its upper surface, and a pin slot through which the lower pin is inserted is opened on the upper surface at a position corresponding to the range of movement of the lower pin, and the drive mechanism comprises: a first crank rod having a first tilting shaft at one end, a first crank slot through which the lower pin is inserted at the other end, and a first crank intermediate hole at the middle; a second crank rod having a second tilting shaft at one end, a second crank slot through which the upper pin is inserted at the other end, and a second crank intermediate hole at the middle; a crank shaft which axially supports the first tilting shaft of the first crank rod and the second tilting shaft of the second crank rod so as to be able to tilt; a first eccentric cam inserted in the first crank intermediate hole; and a second eccentric cam inserted in the second crank intermediate hole, which is eccentric to a different phase from the first eccentric cam. a crank gear provided coaxially with the first eccentric cam and the second eccentric cam; and a speed change mechanism for adjusting the rotation speed and connecting the crank gear to the drive unit via the receiving portion, wherein when the crank gear is rotated by the drive unit via the speed change mechanism, the first eccentric cam causes the first crank rod to tilt about the crank shaft, causing the lower blade to reciprocate through the lower pin inserted in the first crank long hole, and the second eccentric cam causes the second crank rod to tilt about the crank shaft, causing the upper blade to reciprocate through the upper pin inserted in the second crank long hole.

5. A reciprocating blade device comprising: an operating rod having a drive section at its rear end and a joint at its front end for connecting to an object to be driven by the drive section; and a blade unit attached to the joint and configured to cause an upper blade and a lower blade to reciprocate relatively with each other using the drive section, wherein the blade unit comprises: an upper blade having blade portions provided at a predetermined interval on each of its front and rear edges; and a lower blade having blade portions provided at a predetermined interval on each of its front and rear edges; a blade body comprising an upper blade body and a lower blade body, the upper blade body and the lower blade body being stacked one on top of the other; a drive mechanism for reciprocating the upper blade body and the lower blade body relative to each other so that the blade portions of the upper blade and the lower blade cut and meet; and a receiving portion for transmitting power for driving the drive mechanism from the drive section via the joint, wherein the lower blade has a lower pin provided on its upper surface, the upper blade has an upper pin on its upper surface, and a pin slot through which the lower pin is inserted is opened on the upper surface at a position corresponding to the moving range of the lower pin, the drive mechanism comprising: a first crank rod having a first tilting shaft at one end, a first crank slot into which the lower pin is inserted at the other end, and a first crank intermediate hole at the middle; a second crank rod having a second tilting shaft at one end, a second crank slot into which the upper pin is inserted at the other end, and a second crank intermediate hole at the middle; a crank shaft supporting the first tilting shaft of the first crank rod and the second tilting shaft of the second crank rod so as to be able to tilt; a first eccentric cam inserted in the first crank intermediate hole; a second eccentric cam inserted in the second crank intermediate hole, and a crank gear provided coaxially with the first eccentric cam and the second eccentric cam; a speed change mechanism for adjusting the rotation speed of the crank gear and the drive unit via the receiving portion, wherein when the crank gear is rotated by the drive unit via the speed change mechanism, the first eccentric cam tilts the first crank rod about the crank shaft, and the lower blade is reciprocated through the lower pin inserted into the first crank long hole,The second eccentric cam causes the second crank rod to tilt around the crank shaft, thereby causing the upper blade to reciprocate through the upper pin inserted into the second crank long hole.

6. A reciprocating type cutting blade device according to claim 4 or 5, wherein the first crank rod has the first tilting shaft, the first crank long hole, and the first crank intermediate hole arranged on the same plane, and the second crank rod has the second tilting shaft, the second crank long hole, and the second crank intermediate hole arranged on the same plane.

7. A reciprocating type cutting blade device according to claim 4 or 5, wherein the upper blade and the lower blade have the same shape and are formed with 180° rotational symmetry.

8. A reciprocating type cutting blade device as claimed in claim 4 or 5, further comprising a transmission case for housing the drive mechanism, the transmission case being inclined with respect to the cutting blade body with its rear side being higher than its front side, thereby forming a space between the rear side and a plane extended from the rear end side of the cutting blade body.

9. A cutting blade unit connected to a joint provided at one end of an operating rod equipped with a drive unit and driven by the drive unit, comprising: an upper blade having blade portions provided at a predetermined interval on each of its front and rear edges, and a lower blade having blade portions provided at a predetermined interval on each of its front and rear edges, a cutting blade body formed by stacking these vertically; a drive mechanism for relatively reciprocating the upper blade and lower blade so that the blade portions of the upper blade and the lower blade cut and cross; and a receiving portion for receiving from the drive unit via the joint the power obtained by driving the drive mechanism for relatively reciprocating the upper blade and the lower blade, wherein the drive mechanism is connected to an upper surface side of the cutting blade body and is spaced from the rear end side of the cutting blade body.

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