JPH021543Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an engine braking device that is installed using empty space.

[Problems to be solved by conventional technology and ideas] Generally speaking, engines that rotate rotating equipment such as mowers and cultivators have a direct connection between the engine output shaft and a rotating body such as a cutter blade (in the case of a mower). Some systems are connected through a clutch mechanism, while others are connected via a clutch mechanism. In either system, the rotary body such as the cutter blade continues to rotate for a while due to inertia even if the engine is stopped. For that reason,
In order to stop the rotation of the rotating body of the rotating equipment at any time, a clutch brake device for a working machine or the like is disclosed, for example, in Japanese Utility Model Application Publication No. 56-160331. However, this requires a special space for arranging the clutch and brake, is therefore longer in the axial direction, has a complicated structure, and is free from dust, sand, etc. like the mower mentioned above.
Not suitable for objects that are easily penetrated by pebbles, etc.

On the other hand, Japanese Patent Application Laid-open No. 150633/1983 discloses a safety device for rotating equipment such as mowers. however,
This also increases the length of the safety device in the axial direction, and has the disadvantage that, for example, the brake does not come to rest due to the reaction force of the spring, causing it to repeatedly rotate and stop.

Further, in Japanese Utility Model Publication No. 36-21728, a brake drum is mounted on a rotating shaft, and a brake body that can be pressed against a tapered surface of the brake drum formed on the outer periphery of the brake drum is supported by a manual release bolt. A technique has been disclosed in which the brake body is pressed against or separated from the brake drum taper surface of the brake drum using a cam lift by rotating this manual release bolt.

However, in the brake device disclosed in this prior art, since a brake drum is separately attached to the rotating shaft, the length of the brake device in the axial direction becomes longer and the overall device becomes larger. be.

Further, since the brake device is covered with a bearing bracket, it is difficult to dissipate heat generated during braking, and there is a problem with cooling performance.

[Purpose of the invention] The present invention was created in view of these circumstances.It can be installed using empty space, can be made compact without taking up any special space for installation, and can be installed using existing components. The structure is simple,
Moreover, it is an object of the present invention to provide an engine braking device that can perform braking reliably and has good cooling performance.

[Means and effects for solving the problem] In order to achieve the above object, the engine braking device according to the present invention includes a flywheel having cooling fins on the side opposite to the crankcase, which is pivoted to the crankshaft protruding from the crankcase. on the other hand,
A recoil starter unit consisting of a recoil case, a recoil center shaft, a recoil reel, a pawl, a recoil pulley, etc. is disposed on the cooling fin side of the flywheel, wherein the recoil pulley is coaxially attached to the flywheel, A brake drum tapered surface is formed in this recoil pulley to make the recoil pulley into a brake drum, and in this brake drum,
A cone brake body that can freely approach and separate from the taper surface of the brake drum and is biased by a spring is provided, and the cone brake body is configured to slide along a recoil center shaft extending into the brake drum. A through hole is formed that loosely fits into the shaft and passes through the recoil center shaft in the axial direction, while a member for moving the cone brake body against the spring is extended to the outside through the through hole of the recoil center shaft. It is composed of

[Embodiments of the invention] The invention will be specifically described below with reference to the drawings.

A first embodiment of the device of the present invention is shown in FIG. 1, which is a longitudinal cross-sectional view showing the main parts of the device in operation.

In this figure, numeral 1 is a crankshaft protruding from a crankcase (not shown), 2 is a flywheel pivotally attached to the end of this shaft 1, and cooling fins 2a are attached to the side of the flywheel 2 opposite to the crankcase (the top surface of the figure). has been erected. In addition, 3 is a fan cover that surrounds the flywheel 2, the crankcase, and a part of the cylinder;
is an opening formed in the fan cover 3 on the front side of the flywheel 2, and a recoil starter unit 5 is disposed on the front side of the flywheel 2 including the front side of this opening 4.

The recoil starter unit 5 includes a recoil case 6 which is fastened to the fan cover 3 with, for example, bolts and is provided so as to cover the space in front of the fan opening 4, and a recoil case 6 which is connected to the fan cover 3 by bolts or the like and provided so as to cover the space in front of the fan opening 4. A recoil center shaft 7 protruding from the recoil center shaft 7, a recoil reel 9 rotatably loosely fitted onto the recoil center shaft 7 and around which a towing rope 8 is wound, a spiral coil 10 for rewinding the recoil reel 9, and a rotating plate 11.
, coil spring 12, and flywheel 2
The recoil pulley 13 is coaxially attached to the crankshaft 1 with a nut, and a pawl 15 that can be freely engaged and detached from an engagement hole 14 of the recoil pulley 13, but this is just an example and the invention is not limited to this. is not limited to this configuration.

A drum 16 is attached to the inner circumference of the recoil pulley 13 concentrically with the recoil pulley 13 by co-fastening or other attachment means. A brake drum 18 is formed with a tapered surface 17 whose diameter increases.

In the illustrated example, as described above, the recoil pulley 1
A separate drum 16 is attached inside the recoil pulley 13 to serve as a brake drum, but in the present invention, the tapered surface is also formed on the inner periphery of the recoil pulley 13 itself.
This recoil pulley 13 itself may be configured as a brake drum. And this brake drum 1
A cone brake body 19 is disposed within 8,
This brake body 19 has a cone-shaped lining 20
and a base body 21.

On the other hand, the recoil center shaft 7 has a guide 7a having a rotation preventing surface such as a prismatic or semicircular column on its tip side, and
The brake drum 18 is attached to the outer periphery of this guide 7a.
The inner cone brake body 19 is loosely fitted to be slidable in the axial direction.

Further, a retainer 7b is pivotally attached to the front part of the guide 7a, and a compression coil spring 22 is interposed between the retainer 7b and the cone brake body 19, and the cone brake body 19 is connected to the brake drum 18.
The narrow diameter direction of the tapered surface 17 (crankcase side)
The cone-shaped lining 20 is pressed against the brake drum tapered surface 17 to apply the brake.

Furthermore, the recoil center shaft 7 is
It has a through hole 23 penetrating approximately in the direction of its central axis,
A traction wire cable 24 having one end fixed to the cone brake body 19 is extended to the outside through a through hole 23 of the recoil center shaft 7.

On the other hand, a bearing 25 is provided at the top of the recoil case 6.
A link 26 is pivotally supported through the link 26, and the other end of the wire cable 24 is fixed to this link 26. Further, one end of, for example, a towing operation wire cable 27 extending from a hand-side brake operating section (not shown) is fixed to this link 26, and by pulling this wire cable 27 toward the hand side, the link 26 is moved as shown in FIG. By rotating clockwise, the wire cable 24 is pulled toward the side opposite to the crankcase, and the cone brake body 19 is slid in the direction of expanding the diameter of the brake drum tapered surface 17 against the biasing force of the coil spring 22. 19 and the brake drum tapered surface 17 to release the pressure contact and braking.

In such a configuration, when the brake operation wire cable 27 is not pulled toward the user's side, that is, when the engine is stopped, the cone brake body 19 is moved to the brake drum 1 by the compression coil spring 22.
The con-shaped lining 20 is pressed and slid in the narrow diameter direction (towards the crankcase) of the tapered surface 17 of 8.
is in pressure contact with the brake drum tapered surface 17, and the brake is applied.

When the engine is operated, the operating wire cable 27 is pulled toward the user's side and the link 26 is rotated clockwise in FIG. 1 to pull the wire cable 24 toward the opposite side of the crankcase. 19 to coil spring 2
The brake drum taper surface 17 resists the urging force of 2.
The pressure contact and braking between the brake body 19 and the brake drum tapered surface 17 are released by sliding the brake body 19 in the direction of diameter expansion.

Further, when the engine rotates, the cooling fins 2a provided upright on the flywheel 2 take in outside air from the recoil case side and send it to the cylinder block (not shown) and the cylinder head side, thereby cooling each section requiring cooling. On the other hand, since the recoil pulley 13 is cooled when the outside air is taken in from the recoil case side, the brake drum 18, which generates heat during braking, is efficiently cooled. Then,
Not only is seizure effectively prevented, but it can also handle high rotations.

Next, in order to stop the engine and stop the rotation of the rotating body of rotating equipment (for example, a cutter blade of a mower), the brake operation wire cable 27
The cone brake body 1 is released by the biasing force of the coil spring 22.
9 in the direction of the narrow diameter of the tapered surface 17 of the brake drum 18.

In addition, in the above-mentioned embodiment, the wire cable 2
4 toward the side opposite to the crankcase and the cone brake body 19 is slid in the direction of expanding the diameter of the brake drum 18 against the biasing force of the coil spring 22 to release the brake. to maintain the brake release state.
A holding mechanism is provided on the hand-side brake operating section or link section.

FIG. 2 shows a second embodiment of the device of the present invention in a vertical cross-sectional view of the essential parts in a state before operation.

In this embodiment, a tension coil spring 31 is used as the spring that biases the cone brake body 19, and the cone brake body 19 is constantly pulled and slid toward the opposite side of the crankcase, that is, in the direction of the expanding diameter of the brake drum 18. , this cone brake body 1
9 and the link 26 are connected by a pressing rod 32,
Further, by pulling the operating wire cable 27, the link 26 is connected to the link 26 so that the link 26 rotates counterclockwise in FIG.

In this configuration, the brake operating wire cable 2
7 is not towed, the brake is released, and by pulling the wire cable 27, the pressing rod 32 slides toward the crankcase, presses and slides the cone brake body 19, and causes the cone-shaped lining 20 to slide. Brake drum tapered surface 1
7 for braking.

In the device of the present invention, in each of the above-described embodiments, the recoil pulley 13 or the drum 16 (brake drum 18) is formed with a tapered surface 17 whose diameter increases toward the front. It is also configured to have a small diameter, so that the operation of applying and releasing the brake is opposite to that of each of the above-described embodiments.

Furthermore, the drum 16 may be integrally formed by bending the recoil pulley 13.

[Effects of the invention] As explained above, according to the invention, it can be arranged using empty space and can be made compact without requiring special space for installation, and the structure can be simplified by using existing members. Moreover, it has the effect of ensuring reliable braking.

Furthermore, since the brake drum is cooled by the cooling air sucked in by the cooling fins, the cooling efficiency during braking is good, and seizure and the like can not only be effectively prevented, but also high rotation speeds can be supported.

Furthermore, since the brake device according to the present invention is installed on the side of the recoil starter unit, it is not only less likely to become clogged with foreign matter such as grass, but also easier to maintain, compared to a brake device installed on the side of the actuating body, such as a cutter of a lawn mower. .

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part showing a first embodiment of the device of the present invention, and FIG. 2 is a longitudinal cross-sectional view of a main part showing a second embodiment. 1... Crankshaft, 2... Flywheel, 2a... Cooling fin, 5... Recoil starter unit, 7... Recoil center shaft,
13... Recoil pulley, 17... Brake drum tapered surface, 18... Brake drum, 19...
Cone brake body, 23... Through hole, 24, 32
...(move) member, 31...spring.

Claims (1)

[Scope of utility model registration request] A flywheel having cooling fins on the side opposite to the crankcase is attached to the crankshaft protruding from the crankcase, while a recoil case,
recoil center shaft, recoil reel,
A recoil starter unit consisting of a pawl, a recoil pulley, etc. is disposed on the cooling fin side of the flywheel, and the recoil pulley is coaxially mounted with the flywheel, and a brake drum taper surface is provided in the recoil pulley. The recoil pulley is formed into a brake drum, and a cone brake body that can freely approach and separate from the taper surface of the brake drum and is biased by a spring is disposed within the brake drum. A through hole is loosely fitted onto the recoil center shaft extending into the brake drum so as to slide along the shaft, and passes through the recoil center shaft in the axial direction, while the cone brake body is connected to the spring. A brake device for an engine, characterized in that a member that is moved against the recoil center shaft extends outward through a through hole of a recoil center shaft.