JPH0893801A - Flywheel brake of vertical shaft engine - Google Patents

Abstract

PURPOSE: To stop the inertial rotation of a flywheel in a short time by sufficiently increasing the pressure contact force of a brake shoe, to maintain the cooling effect of a cooling fan and to eliminate the enlargement of a fan cover. CONSTITUTION: A brake base frame 11 is fixed to an engine main body 1, and a brake main body 14 and a brake release lever 18 are mounted along the brake base frame. The brake main body 14 and a brake lever 16 are integratedly formed, and the rotating spindle 19 of the brake main body 14 is placed on the lower side than a brake shoe 15 in the rotating direction A of a flywheel 5 and positioned to the cylinder block 2 of a vertical type engine E, and the brake release lever 18 is pivoted to the brake base frame 11 through a lever spindle 21 so as to be rotated horizontally and a short arm part 18a is engaged with the brake lever 16 and a long arm part 18b is floatably projected from the lateral hole 7a of a fan cover 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical wheel flywheel brake mounted on a lawn mower or the like.

[0002]

2. Description of the Related Art In the above lawnmower and the like, a flywheel brake has been conventionally used in order to quickly stop the inertial rotation of the flywheel after the engine is stopped. A flywheel brake of this type is proposed by the applicant of the present invention, for example
The one disclosed in Japanese Patent No. 9223 is known.

As shown in FIG. 6, a brake shoe 55 is fixed to the inner surface of a brake band 51, one end of the brake band 51 is pivotally supported by a support shaft 59, and the other end of the brake lever 56 is supported. The brake shoe 55 is constructed so that it can be pressed against the outer peripheral surface 5b of the flywheel 5 of the vertical axis engine E by pulling at the action point portion 56b.
Is urged toward the brake operation side by the tension spring 20, and the brake lever 56 can be operated toward the brake release side by the operation lever 30 against the urging force of the tension spring 20.

In the above-mentioned conventional example, one end of the brake band 51 is pivotally supported by the support shaft 59 and the other end is pulled by the action point portion 56b of the brake lever 56 so that the brake shoe 55 is a flywheel of the vertical engine E. Since the structure is in pressure contact with the outer peripheral surface 5b of 5, the pressure contact force of the brake shoe 55 cannot be sufficiently increased. That is, the brake shoe 5
Since the pressure contact force of 5 acts as a component of the tensile force of the action point portion 56b, only a pressure contact force far smaller than the tensile force is obtained, and the flywheel is quickly moved after the engine is stopped. It may not be possible to stop it.

Further, since the flywheel brake is provided on the lateral side of the vertical axis engine E and is surrounded by the fan cover 7, the fan cover 7 largely projects to the lateral side. If the lateral side of the fan cover 7 is cut out in order to eliminate the protrusion of the fan cover 7, the cooling air generated by the fan 5 leaks out from the cutout, and the cooling effect is halved.

Therefore, prior to the present invention, the inventor of the present invention has shown in FIG.
Invented the flywheel brake described in. Hereinafter, this is referred to as a prior invention example. In this prior invention example, a brake base frame 11 fixed to a cylinder block side of an engine body, a brake body 14 pivotally supported on the brake base frame 11 by a pivot shaft 19 for horizontal rotation, and a brake body 14 are integrated. An extension spring 20 for urging the brake lever 16 formed on the brake operating side, a brake release lever 18 formed integrally with the brake body 14, a wire 22 for pulling the brake release lever 18 to the brake release side, and a brake base frame. Brake shoe 1 fixed to a brake body 14 and comprising a wire locking member 12 formed integrally with
5 is pressed against the outer peripheral surface 5b of the flywheel 5 to stop the rotation of the flywheel 5, and the brake release lever 18 is movably projected from the lateral hole 7a of the fan cover 7. Reference numeral 25 in FIG. 5 indicates a brake switch that is grounded when the flywheel brake is in an operating state.

[0007]

In the above-described invention example, the brake base frame 11 pivotally supporting the brake main body 14 is fixed to the engine main body near the cylinder block, and the brake release lever 18 is provided through the lateral hole 7a of the fan cover 7. Since the fan cover 7 is configured to be movably protruded, the protrusion of the fan cover 7 can be eliminated, and the leakage of the cooling air from the lateral hole 7a of the fan cover 7 can be minimized.

However, in the above-described prior invention example, since the rotation support shaft 19 of the brake main body 14 is located on the upper side of the rotation direction (arrow A) of the flywheel 5 with respect to the brake shoe 15, the brake shoe 15 fly. Outer peripheral surface 5b of wheel 5
Therefore, the pressing force of the brake shoe 15 is halved, and the rotation of the flywheel 5 cannot be stopped in a short time. The present invention has been made in consideration of such a situation. The pressure contact force of the brake shoe is sufficiently increased to stop the rotation of the flywheel in a short time, and the cooling effect is maintained while maintaining the cooling effect of the fan cover 7. The technical issue is to eliminate the increase in size.

[0009]

In order to solve the above problems, the present invention is configured as follows. That is, the brake base frame 11 is fixed to the engine main body 1, and one end of the brake main body 14 is horizontally rotatably supported by the brake base frame 11 via the rotary support shaft 19, and the brake lever 16 pulls a spring. The brake shoe 15 fixed to the brake body 14 can be pressed against the outer peripheral surface 5b of the flywheel 5 by urging the brake lever 20 toward the brake operation side, and the brake lever 16 can be moved to the brake release lever 18 as well.
A vertical structure constituted so that the brake main body 14, the brake shoe 15, the brake lever 16, and the tension spring 20 are surrounded by a fan cover 7 so as to be operable on the brake release side against the urging force of the tension spring 20 via. In a flywheel brake for an axial engine, the brake body 14
The brake lever 16 is integrally formed with the brake body 14
The rotation support shaft 19 is positioned on the lower side of the rotation direction A of the flywheel 5 with respect to the brake shoe 15 and closer to the cylinder block 2 of the vertical axis engine E. The brake release lever 18 includes a lever support shaft 21. Via the brake base frame 11 so as to be horizontally rotatable, its short arm portion 18a is engaged with the brake lever 16, and its long arm portion 18b is movably projected from the lateral hole 7a of the fan cover 7. It is characterized by being configured.

[0010]

According to the present invention, the brake main body 14 and the brake lever 16 are integrally formed, and the rotation support shaft 19 of the brake main body 15 is located on the lower side of the rotation direction A of the flywheel 5 with respect to the brake shoe 15. Since the vertical axis engine E is located near the cylinder block 2, when the flywheel brake 10 is actuated, the brake shoe 15
The brake shoe 15 is strongly pressed in the direction in which the brake shoe 15 bites into the outer peripheral surface 5b of the flywheel 5 without weakening the pressing force of the tension spring 20. That is, even if the urging force of the tension spring 20 is the same as that of the conventional example, or even if the arm length of the brake lever 16 is short, the pressure contact force of the brake shoe 15 is significantly larger than that of the conventional example. Thereby, the rotation of the flywheel 5 can be stopped in a short time after the operation of stopping the engine.

Further, since the rotation support shaft 19 of the brake main body 14 is located on the lower side of the rotation direction A of the flywheel 5 with respect to the brake shoe 15 and closer to the cylinder block 2 of the vertical axis engine E, Wheel brake 10
Is located not on the horizontal side of the vertical axis engine E but on the cylinder block 2 side of the vertical axis engine E, so that the fan cover 7 does not largely project to the horizontal side.

The brake release lever 18 is pivotally supported by a lever support shaft 21 so as to be horizontally rotatable, its short arm portion 18a is engaged with the brake lever 16, and its long arm portion 18b is attached to the fan cover 7. Since it is configured to be movably protruded from the lateral hole 7a, the lateral hole 7a of the fan cover 7 needs only a minimum size such that the long arm portion 18b of the brake release lever 18 movably projects. Even if the cooling air generated by the fan leaks out from the lateral hole 7a, the cooling effect is not reduced by half. As a result, the fan cover 7 can be prevented from increasing in size while maintaining the cooling effect.

[0013]

Embodiments of the present invention will now be described in more detail with reference to the drawings. 1 is a plan view of an air-cooled vertical axis engine equipped with a flywheel brake of the present invention, FIG. 2 is a schematic side view of the engine, FIG. 3 is a plan view of a flywheel brake according to an embodiment of the present invention, and FIG. It is a side view of the flywheel brake. 1 and 2, reference numeral 1 is an engine body, 2 is a cylinder block, 3 is a power takeoff shaft for rotating a rotary blade (not shown), 5 is a flywheel,
5a is a fan blade of a flywheel fan, 6 is a ring gear for starting rotation, 7 is a fan cover, 8 is a fuel tank, and 10 is the entire flywheel brake.

Flywheel brake 1 according to this embodiment
As shown in FIGS. 1 to 4, 0 has the same basic structure as that of the previous invention. That is, the flywheel brake 10 includes a brake base frame 11 fixed to the engine body 1 of the vertical axis engine E, and a brake body 14 pivotally supported on the brake base frame 11 by a pivot shaft 19 so as to be horizontally rotatable. A tension spring 20 for urging the brake lever 16 integrally formed with the brake body 14 toward the brake operating side, a brake release lever 18 formed separately from the brake body 14,
A wire 22 for pulling the brake release lever 18 to the brake release side, a wire locking tool 12 formed integrally with the brake base frame 11, and a brake switch 25 that is grounded when the flywheel brake 10 is in an operating state are provided. The brake shoe 15 fixed to the brake body 14 is attached to the outer peripheral surface 5b of the flywheel 5 of the vertical engine E.
The flywheel 5 is configured to be pressed against to stop the rotation of the flywheel 5, and the brake release lever 18 is movably projected from the lateral hole 7a of the fan cover 7.

As shown in FIGS. 3 and 4, the brake base frame 11 is provided with a locking tool 11c on one end side of the tension spring 20.
The wire locking tool 12 and the stopper 13 that restricts the horizontal rotation of the brake body 14 are integrally formed.
The brake main frame 14 is attached to the brake base frame 11.
And brake release lever 18 and brake switch 25
And one end portion 11a of the brake base frame 11 is fixed to the left side surface of the engine body 1 and the other end portion 11b is fixed to the base end portion of the cylinder block 2 of the engine body 1. The main body 1 is detachably fixed to the cylinder block 2 side.

The brake body 14 has a fixed piece portion 14a to which a brake shoe 15 is fixed, and a tension spring 20.
Of the brake lever 25 and the contacted portion 17 with which the contact 26 of the brake switch 25 contacts are integrally formed, and one end of the brake lever 16 with respect to the brake shoe 15 in the rotation direction A of the flywheel 5 is formed. On the lower side, the brake base frame 11 is provided near the cylinder block 2 via a rotary support shaft 19.
It is rotatably pivoted horizontally. That is, by urging the brake lever 16 toward the braking side by the tension spring 20, the brake shoe 15 fixed to the brake body 14 can be pressed against the outer peripheral surface 5b of the flywheel 5.

The brake release lever 18 is pivotally supported by the brake base frame 11 via a lever support shaft 21 so as to be horizontally rotatable, and its short arm portion 18a engages with the brake lever 16 and its long arm portion. Reference numeral 18b projects movably from the lateral hole 7a of the fan cover 7. Brake release lever 18
2 is located below the fan blades 5a of the flywheel fan 5, the lateral holes 7a of the fan cover 7 are also opened below the fan blades 5a of the flywheel 5, as shown in FIG. There is.

The long arm portion 18 of the brake release lever 18
An operation wire 22 is locked to b, and is pulled / locked to the brake release side by the operation lever 30 during engine operation. Reference numeral 23 is a wire tube. That is, by releasing the brake release lever 18 via the operation wire 22 by the operation lever 30, the brake lever 16 can be operated to the brake release side against the biasing force of the tension spring 20.

Excluding the one end 11a of the brake base frame 11 and the brake release lever 18, the brake body 14, the brake shoe 15, the brake lever 16, and the tension spring 2 are provided.
0 and the brake switch 25 are covered with the fan cover 7. As a result, the fan cover 7 does not largely project to the lateral side, and the lateral hole 7a of the fan cover 7 is prevented.
Since the long arm 18b of the brake release lever 18 suffices to have a minimum size such that the long arm 18b projects movably, the cooling effect is halved even if the cooling air generated by the fan leaks out from the lateral hole 7a. Nor.

The operation of the apparatus of the above embodiment will be described below. First, during operation of the engine, the operation lever 30 is pulled and locked to the brake release side, whereby the brake lever 16 is positioned on the brake release side via the operation wire 22 and the brake release lever 18. As a result, the brake body 14 and the brake shoe 15 are separated from the outer peripheral surface 5b of the flywheel.

When stopping the engine, the pulling / locking of the operating lever 30 is released. This operating lever 30
Is pulled toward the braking side by the tension spring 20 via the operation wire 22, the brake release lever 18 and the brake lever 16, and the contact 26 of the brake switch 25 and the contacted portion 17 of the brake main body 14 are interlocked with this operation. When they come into contact with each other, they come into contact with the ground and the fuel supply is stopped.

On the other hand, the brake shoe 15 presses the outer front surface 5b of the flywheel 5 in parallel with the operation of stopping the engine. That is, since the rotation support shaft 19 of the brake main body 15 is located on the lower side of the rotation direction A of the flywheel 5 with respect to the brake shoe 15 and closer to the cylinder block 2 of the vertical axis engine E, the brake shoe 15 is The pressing force of the tension spring 20 is not weakened, and the brake shoe 15 is strongly pressed in the direction of cutting into the outer peripheral surface 5b of the flywheel 5 on the contrary. As a result, the tension spring 2
Even if the biasing force of 0 is the same as that of the conventional example, or the arm length of the brake lever 16 is short, the pressure contact force of the brake shoe 15 is significantly larger than that of the conventional example or the prior invention example.

In the above embodiment, the air-cooled vertical axis engine is illustrated, but the present invention is not limited to this, and other types of engines can be appropriately modified and implemented.

[Brief description of drawings]

FIG. 1 is a plan view of an air-cooled vertical axis engine equipped with a flywheel brake of the present invention.

FIG. 2 is a schematic side view of the engine.

FIG. 3 is a plan view of a flywheel brake according to an embodiment of the present invention.

FIG. 4 is a side view of a flywheel brake according to an embodiment of the present invention.

FIG. 5 is a plan view of a flywheel brake according to a prior invention example.

FIG. 6 is a plan view of an air-cooled vertical axis engine according to a conventional example.

[Explanation of symbols]

E ... Vertical axis engine, 1 ... Engine body, 2 ... Cylinder block, 5 ... Flywheel, 5b ... Flywheel outer circumferential surface, 7 ... Fan cover, 7a ... Fan cover lateral hole, 1
0 ... Flywheel brake, 11 ... Brake base frame, 14
... brake main body, 15 ... brake shoe, 16 ... brake lever, 18 ... brake release lever, 18a ... short arm of brake release lever, 18b ... long arm of brake release lever, 20 ... tension spring, A ... flywheel Direction of rotation.

Claims (1)

[Claims] 1. A brake base frame (1) is attached to an engine body (1).
1) is fixed and one end of the brake main body (14) is horizontally rotatably supported on the brake base frame (11) through a rotation support shaft (19), and the brake lever (16) is pulled by a spring. By urging the brake operation side by (20), the brake body (1
The brake shoe (15) fixed to (4) is configured to be able to be pressed against the outer peripheral surface (5b) of the flywheel (5), and the brake lever (16) is pulled by a brake release lever (18). 20) is configured to be operable toward the brake release side against the urging force of the brake body (14), the brake shoe (15),
In a flywheel brake for a vertical axis engine constituted by surrounding a brake lever (16) and a tension spring (20) with a fan cover (7), the brake body (14) and the brake lever (16) are integrally formed, The rotation support shaft (19) of the brake body (14) is on the lower side of the rotation direction (A) of the flywheel (5) with respect to the brake shoe (15), and the cylinder block (2) of the vertical axis engine (E). The brake release lever (18) is located closer to the lever support shaft (2
1) via a brake base frame (11) so as to be horizontally rotatable, and a short arm portion (18a) thereof is engaged with the brake lever (16), and a long arm portion (18b) thereof is a fan. A flywheel brake for a vertical-axis engine, which is configured so as to movably project from a lateral hole (7a) of a cover (7).