JP3245982U - grass mower cutting blade unit - Google Patents

Abstract

[Problem] To provide a cutting blade unit for a lawn mower, which prevents damage to the blades due to collisions between rotating and oscillating blades, and damage to the blades and connecting members due to collisions between the blades, rod, and disc. . [Solution] A disk 4 that rotates based on the rotational power of a rotating shaft 2 connected to a center 5; a strip-shaped blade 7 that is arranged in a superimposed manner with respect to the disk and has a blade formed on its periphery; A connecting part 6 is provided at the end of the disc and slidably connects the blade to the disc, and the blade has a longitudinal opening 10 extending in the longitudinal direction. , a columnar portion extending over the end portion and inserted into the longitudinal opening, and a protruding portion protruding from the side surface of the columnar portion, the protruding portion being closer to the disk than the straight line passing through the center of the connecting portion and the center of the disk. is provided on the opposite rotation direction side. The shape of the connecting portion and the blade, and the length of the blade make it possible to suppress rotational swing and prevent damage to the blade due to collision between the blades. [Selection diagram] Figure 1

Description

The present invention relates to a cutting blade unit for a lawn mower.

BACKGROUND ART Conventionally, a rotatable blade disclosed in Patent Document 1 is known (see Patent Document 1). When the object to be cut is an overloaded object such as a stone or a fence, the rotatable blade body can rotate and oscillate from the object to be cut to escape from the overloaded object and protect the drive mechanism.

JP 2019-83768 Publication

However, although Patent Document 1 describes a blade body that can rotate and oscillate, when the rotational oscillation is not suppressed, depending on the blade length, there is a risk that the blade bodies that rotate and oscillate may be damaged due to collision with each other.

Further, there is a problem in that the rotating and oscillating blade body collides with the connecting member between the rod and the disk, and the blade body and the connecting member may be damaged.

The above technical problem can be solved by the present invention as follows.

A cutting blade unit for a lawn mower, which includes a disk that rotates based on the rotational power of a rotating shaft connected to the center, and a strip-shaped blade that is arranged in a superimposed manner with respect to the disk and has a blade formed on the periphery. A blade body, and a connecting part provided at an end of the disc and slidably connecting the blade body to the disc, the blade body having a longitudinal opening extending in the longitudinal direction. The connecting portion includes a columnar portion extending over the end portion and inserted into the longitudinal opening, and a protruding portion protruding from a side surface of the columnar portion, and the protruding portion is located at the center of the connecting portion. and is provided on the opposite rotation direction side of the disk with respect to a straight line passing through the center of the disk.

When the blade body rotates and oscillates, the protrusion comes into contact with the inner wall surface of the longitudinal opening, thereby suppressing the rotation and oscillation of the blade body.

The connecting portion is formed in a D-shaped convex shape on the mounting surface to the disk, and is formed in a D-shaped concave shape on the mounting surface of the disk to the connecting portion, and the concave and convex portions fit together, and the connecting portion It has a fixed part that is fixed so that it does not move relative to the disk.

When two or more of the blade bodies are attached to the disc, one of the blade bodies rotates and swings in the reverse rotation direction, the other rotates and swings in the forward rotation direction, and each of the blade bodies is in a state where the rotation is suppressed. The length of the blades is such that they do not touch each other.

According to the above-mentioned cutting blade unit, when the object to be cut has an excessive load such as a stone or a fence, the blade body can rotate and oscillate, so it is possible to escape from the excessive load and protect the drive mechanism. In order to suppress rotational oscillation, it is possible to prevent damage to the blade bodies due to collisions between the blade bodies, and also prevent damage to the blade bodies and damage to the connecting members due to collisions with the connecting members between the rod and the disc. be.

The purpose of this invention is to prevent the blades from colliding with each other by suppressing the rotational oscillation of the blade bodies and by limiting the length of the blade bodies, and to prevent collisions with the connection member between the blade body, rod, and disc. Through repeated experiments, it has been found that the present purpose can be more effectively achieved by providing the protrusion in the reverse rotation direction of the disc at an angle of 30 to 60 degrees from a straight line passing through the center of the connecting part and the center of the disc. can be achieved, but is not strictly limited to the specified angles.

It is an overall view showing a connecting part, a resin blade body, a ground disc, and a cutting blade disc. It is a perspective view of a connection part. It is a sectional view of a columnar part of a connection part. It is a figure of the fixing part to the disk of a connection part. It is a diagram when the resin blade body is oscillated and rotated in the reverse rotation direction. It is a diagram when the resin blade body is oscillatingly rotated in the forward rotation direction. It is a diagram of the fixing part to the connecting part of the disk. It is a diagram when the two resin blade bodies are oscillated and rotated in the forward rotation direction and the reverse rotation direction, respectively. It is an enlarged view of the connecting part and the resin blade body in a state where rotational oscillation is suppressed.

FIGS. 1 to 9 are diagrams showing the configuration of a connecting portion and a resin blade body according to one embodiment of the present invention. EMBODIMENT OF THE INVENTION Below, the form for implementing one aspect of this invention is demonstrated in detail using drawing.

FIG. 1 shows a state in which a connecting portion 6, a blade body 7, a grounding disc 3, and a cutting blade disc 4, which are the grass cutting parts of a lawn mower, are attached to a rod 1. Note that the operating section located in the opposite direction of the rod 1 is generally known and will not be explicitly described. Figure 1 shows a non-rotating grounding disc 3 that is used to slide while mowing, and a rotatable cutting blade disc 4 that is attached to the grounding disc and attached to a rotating shaft. This is an embodiment in which two connecting parts 6 are connected.

2 to 4 show the shape of the connecting portion 6. FIG. The connecting portion 6 is composed of a columnar portion 12 that connects the collar portion 11 and the seat portion 13, and a fixing portion 14 formed in a D-shaped convex shape on the back surface of the seat portion 13 for attaching the connecting portion 6 to the cutting blade disk 4. . The columnar part 12 of the connecting part 6 has a protruding part 15, and the protruding part 15 has a circular cross section and has two sides that touch the circumference from the apex of the protrusion that protrudes from the circumferential part to the outside of the circle. It is. When the blade body 7 rotates, one side 16 of these two sides and the other side 17 of the two sides contact the inner wall surface 18 of the longitudinal opening of the blade body 7, causing further rotation of the blade body 7. Control your agitation.

This will be explained in more detail. During mowing, as shown in FIG. 1, the cutting blade disc 4 is rotating in the counterclockwise forward rotation direction 19, so the blade body 7 is attached to the connecting portion 6 at the end face of the longitudinal opening 10 due to the centrifugal force of rotation. It becomes a state of being tethered. At this time, if there is an object to be cut, such as grass, the cutting blade part 8 of the blade body 7, which is connected to the cutting blade disc 4 rotating at high speed via the connecting part 6, comes into contact with the object to be cut, such as grass. Things are cut.

Note that if the object to be cut is a soft object such as grass, that is, an appropriately loaded object, the cutting blade section 8 can cut it, but if the object is hard, such as a stone or fence, that is, an overloaded object, the cutting blade section 8 can cut it. cannot be cut, and the blade body 7 is pushed back in the reverse rotation direction 20. At this time, if the rotational oscillation of the blade body 7 is not suppressed, there is a possibility that it will rotate 360 degrees depending on the pushing force. 4, there is a possibility that not only the blade body 7 but also the connecting member 21 will be damaged, and safety will be lowered due to a decrease in grass cutting performance and the scattering of damaged parts.

Furthermore, when a plurality of blade bodies 7 are provided, if the rotational oscillation of the blade bodies 7 is not suppressed, there is a possibility that the blade bodies 7 will rotate 360 degrees, and depending on the length of the blade bodies 7, the blade bodies 7 may collide with each other. There is also a possibility that the blade body 7 may be damaged, resulting in a reduction in grass cutting performance, and safety may be reduced due to the scattered parts of the blade. The purpose of the present invention is to prevent damage to the blade body 7 and the connecting member 21, which would cause deterioration in grass cutting performance and safety.

As shown in FIG. 3, the cross section of the columnar part 12 of the connecting part 6 according to the present invention has a protruding part 15, and the protruding part 15 has a cross section of the columnar part 13 with the center 22 of the connecting part as the center of a circle. It has a circular shape and has one side 16 of the two sides touching the circumference from the apex of the protrusion protruding outward from the circumference and the other side 17 of the two sides.

FIG. 5 shows the maximum rotational oscillation when the blade body 7 is pushed back by an overloaded object. As shown in FIG. 1, when there is no load, the blade 7 is unloaded and the cutting blade disc is at the position 23 of the blade when rotating at high speed. When the blade body 7 is pushed back by the overloaded object, the blade body 7 rotates in the opposite rotation direction, and one side 16 of the two sides of the columnar part 12 of the connecting part 16 and the inside of the blade body 7 The wall surface 18 makes contact. Due to this contact, the rotational oscillation of the blade body 7 is suppressed in the reverse rotation direction to the position of the blade body position 24 at the maximum rotational oscillation, and further rotational oscillation is suppressed.

FIG. 6 shows the maximum rotational oscillation when the blade body 7 is pushed back by an overloaded object and rebounds, or when the rotational speed suddenly decreases. As shown in FIG. 1, when there is no load, the blade 7 is unloaded and the cutting blade disc is at the position 23 of the blade when rotating at high speed. If one side 16 of the two sides of the columnar part 12 of the connecting part 16 and the inner wall surface 18 of the blade body 7 come into strong contact, the blade body 7 will be bounced back in the forward rotation direction. Further, when the speed of the cutting blade disc 4 suddenly decreases for some reason, the blade body 7 rotates in the forward rotation direction. When rotating in these positive rotational directions, the other side 17 of the two sides of the columnar part 12 of the connecting part 16 and the inner wall surface 18 of the blade body 7 come into contact. Due to this contact, the rotational oscillation of the blade body 7 is suppressed in the forward rotation direction to the position of the blade body position 25 at the maximum rotational oscillation, and further rotational oscillation is suppressed.

FIG. 8 is a diagram when the two blade bodies are oscillatingly rotated in the forward and reverse directions, respectively. When the blade bodies 7 are in this positional relationship, the blade lengths are adjusted so that the blade bodies 7 do not come into contact with each other. By determining this, it becomes possible to prevent the blade bodies 7 from colliding with each other.

In this way, by suppressing further rotational oscillation and appropriately determining the length of the blade body 7, the blade body 7 can be prevented from colliding with the connecting member 21 between the rod, the grounding disc, and the cutting blade disc. Collisions between the bodies 7 can also be prevented.

Although the present invention has been described above, it goes without saying that the embodiment disclosed herein is an example and is not restrictive.

According to the present invention, by suppressing the rotational oscillation of the blade bodies and limiting the length of the blade bodies, it is possible to prevent the blade bodies from colliding with each other and against the connecting member between the blade body, the rod, and the disk. In addition to the hand-held mower having the pole 1 and the operating section according to the embodiment disclosed herein, the present invention can also be used as a hand-held mower with wheels or a riding mower.

1 Rod 2 Rotating shaft 3 Grounding disc 4 Cutting blade disc 5 Center of the disc 6 Connecting part 7 Blade body 8 Cutting blade part 9 Central opening 10 Longitudinal opening 11 Flange part 12 Column part 13 Seat part 14 D-shape on the back of the seat part Fixed part 15 formed in a convex manner Projecting part 16 One side 17 of the two sides 18 The other side 18 of the two sides Inner wall surface of the longitudinal opening of the blade 19 Forward rotation direction 20 Reverse rotation direction 21 Rod and grounding disk and the connection member 22 with the cutting blade disc.The center of the connecting part 23.The position of the blade when no load is applied and the cutting blade disc rotates at high speed 24.The position of the blade when the cutting blade disc is at its maximum rotational oscillation in the reverse direction 25.The maximum rotational oscillation in the forward rotation direction Blade position 26: A straight line passing through the center of the connecting part and the center of the disk

Claims (4)

A cutting blade unit for a brush cutter, which includes a disk that rotates based on the rotational power of a rotating shaft connected to the center, and a strip-shaped blade that is arranged in a superimposed manner with respect to the disk and has a blade formed on the periphery. A blade body, and a connecting part provided at an end of the disc and slidably connecting the blade body to the disc, the blade body having a longitudinal opening extending in the longitudinal direction. The connecting portion includes a columnar portion extending over the end portion and inserted into the longitudinal opening, and a protruding portion protruding from a side surface of the columnar portion, and the protruding portion is located at the center of the connecting portion. A cutting blade unit, characterized in that the cutting blade unit is provided on the side in the reverse rotation direction of the disk with respect to a straight line passing through the center of the disk. 2. The cutting blade unit according to claim 1, wherein when the blade body rotates, the protrusion comes into contact with an inner wall surface of the longitudinal opening, thereby suppressing the rotational vibration of the blade body. The connecting portion is formed in a D-shaped convex shape on the mounting surface to the disk, and is formed in a D-shaped concave shape on the mounting surface of the disk to the connecting portion, and the concave and convex portions fit together, and the connecting portion The cutting blade unit according to claim 1, further comprising a fixing portion fixed so as not to move relative to the disk. When two or more of the blade bodies are attached to the disc, one of the blade bodies rotates and swings in the reverse rotation direction, the other rotates and swings in the forward rotation direction, and each of the blade bodies is in a state where the rotation is suppressed. 2. The cutting blade unit according to claim 1, wherein the cutting blade unit has a length that is formed so that the blade bodies do not come into contact with each other.

Images