JPH0546236U - Safety equipment for work machines with shoulder straps - Google Patents

Abstract

(57) [Abstract] [Purpose] In the brush cutter 10, the shoulder strap 30 is the operating rod.
It is possible to automatically stop the operation of the engine even when the worker falls from a position such as 12 and does not force the worker to suffer the pain of tightly gripping the work and without stopping the engine. The brush cutter 10 is handed over to effectively deal with the situation where the worker is replaced. [Composition] The pressure detection switch 54 is embedded in the shoulder rest portion 40 of the shoulder strap 30, and is turned on when the shoulder rest portion 40 is hung on the shoulder of the worker and pressure is applied to the shoulder rest portion 40. It Ignition device 72 for igniting the engine of the power unit 14
When the pressure detection switch 54 is turned on, the primary ignition coil
Both ends of 74 are short-circuited and the ignition operation is stopped.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a safety device for a working machine with a shoulder strap such as a brush cutter, and more particularly to a safety device capable of stopping a cutting blade when a worker falls over in a working machine with a shoulder strap.

[0002]

[Prior Art]

 Japanese Utility Model Application Laid-Open No. 64-17120 discloses that in a working machine with a shoulder strap such as a brush cutter, when the shoulder strap comes off the operating rod due to a change in work posture such as a fall of the operator, the prime mover is stopped. Disclose. Japanese Utility Model Laid-Open No. 163918/1989 discloses a brush cutter in which an operator can pull the lock plate to drop the brush cutter main body from the suspension fitting, and the engine is stopped in conjunction with the pulling of the lock plate. Is disclosed. Japanese Utility Model Publication No. 53-14588 discloses that in a brush cutter, a pressure detection switch is provided in the grip, and when the operator releases the grip of the grip, the engine speed is reduced to stop the rotation of the cutting blade. Is disclosed.

[0003]

[Problems to be solved by the device]

 In the safety device disclosed in Japanese Utility Model Laid-Open No. 64-17120, the prime mover cannot be stopped in an emergency when the shoulder strap cannot be removed from the operating rod. The safety device disclosed in Japanese Utility Model Laid-Open No. 1-163918 requires a worker to pull out the lock plate to stop the engine in an emergency, so if the operator is in a hurry, the lock plate Extraction is delayed, and it is too late. In the safety device disclosed in Japanese Utility Model Publication No. 53-14588, the worker needs to hold the grip firmly in order to maintain the rotation of the cutting blade at the time of working, which is a pain for the worker. Also, the operator may change hands without having to stop the engine and the operator may be replaced, which may easily lead to an accident. However, JP-A-64-17120, JP-A-1-163918, and JP-KOKAI-SHO. The safety device of Japanese Patent No. 53-14588 is difficult to handle such a situation.

The object of the invention of claim 1 is to (a) automatically stop the operation of the prime mover even when the operator falls over so that the shoulder strap does not come off the operating rod, and (b) during work. It is possible to effectively deal with the situation in which the operator takes turns by handing over the brush cutter without forcing the operator to suffer the trouble of tightly gripping the grip, and without stopping (c) the prime mover. It is to provide a safety device for working machines with shoulder straps that can be used. The object of the invention of claim 2 is to improve the invention of claim 1, and a shoulder strap with which the engine can be started without trouble even if the operator does not carry the shoulder strap on the shoulder is provided. It is to provide a safety device for a working machine.

[0005]

[Means for Solving the Problems]

 The invention will be described using the reference numerals of the drawings corresponding to the embodiments. The working machine (10) with a shoulder strap, which is the premise of claim 1, includes: (a) a power unit (14) including a prime mover and attached to the rear end side of the operating rod (12); and (b) an operating rod (12). The cutting blade (18) attached to the front end side of the blade and driven by the rotary power from the power unit (14), and (c) the shoulder strap () attached to the operating rod (12) and worn on the operator's shoulder ( 30). The safety device for the working machine (10) with a shoulder strap according to claim 1 stops the operation of the prime mover when (d) the pressure at the shoulder rest portion (40) of the shoulder strap (30) is less than a predetermined value. It has a prime mover stopping means (54, 72).

A working machine (10) with a shoulder strap, which is the premise of claim 2, includes: (a) a power unit (14) including an engine and attached to a rear end side of an operating rod (12); and (b) an operating rod ( A cutting blade (18) attached to the front end side of (12) and driven by rotational power from a power unit (14), and (c) a shoulder strap that is detachably attached to the operating rod (12) and is hung on the operator's shoulder. It comprises a band (30). The safety device for the working machine (10) with a shoulder strap according to claim 2 is (d) operated by the pressure in the shoulder rest portion (40) of the shoulder strap (30) and turned on when the pressure is less than a predetermined value. The series connection circuit formed by the pressure detection switch (54) and the mounting part (26, 38) of the shoulder strap (30) on the operating rod (e) (e) and the pressure detection switch (54) is conductive. An ignition device (72) for stopping the ignition operation of the engine when in the state.

[0007]

[Action]

 In the invention of claim 1, the worker carries out the work by hanging the shoulder strap (30) on the shoulder and carrying the working machine (10) with the shoulder strap. At this time, the shoulder rest (40) of the shoulder strap (30) is under pressure as the weight of the working machine (10) with the shoulder strap is supported by the shoulder of the worker, and the shoulder rest The pressure at (40) is sufficiently large. Therefore, the operation of the prime mover is not stopped by the prime mover stopping means (54, 72).

On the other hand, when the worker falls, or when the worker is replaced by handing over the working machine (10) with the shoulder strap, the shoulder strap (30) is removed from the shoulder of the worker and the shoulder rest (40 ) On the operator's shoulder is released. As a result, the pressure in the shoulder rest (40) becomes less than the predetermined value, the prime mover stopping means (54, 72) stops the operation of the prime mover, and the rotation of the cutting blade (18) is stopped.

According to the second aspect of the invention, the worker carries the work by carrying the shoulder strap (30) on the shoulder and carrying the working machine (10) with the shoulder strap. At this time, the shoulder rest (40) of the shoulder strap (30) is under pressure as the weight of the working machine (10) with the shoulder strap is supported by the shoulder of the worker, and the shoulder rest The pressure at (40) is sufficiently large. Therefore, the pressure detection switch (54) is off, and the direct connection circuit formed by the pressure detection switch (54) and the attachment portion (26, 38) of the shoulder strap (30) to the operating rod (12) is It is in a non-conducting state. As a result, the ignition device (72) ignites the engine, and the engine continues to operate.

On the other hand, when the worker falls, or when the worker is replaced by handing over the working machine (10) with a shoulder strap, the shoulder strap (30) is removed from the shoulder of the worker and the shoulder rest (40 ) On the operator's shoulder is released. As a result, the pressure at the shoulder rest (40) becomes less than the predetermined value, and the pressure detection switch (54) is turned on. Since the shoulder strap (30) is attached to the operating rod (12), the pressure detection switch (54) and the mounting portion (26, 38) of the shoulder strap (30) to the operating rod (12) The series connection circuit thus formed becomes conductive. As a result, the ignition device (72) stops the ignition operation of the engine, the operation of the engine is stopped, and the rotation of the cutting blade (18) is stopped.

When the engine is started, the shoulder strap (30) is removed from the operating stick (12). As a result, even though the pressure detection switch (54) in the shoulder rest (40) of the shoulder strap (30) is on, the pressure detection switch (54) and the shoulder strap (30) to the operating stick (12) The series connection circuit formed by the mounting parts (26, 38) of () is in the non-conduction state, and the ignition device (72) is not in the state of stopping the ignition operation of the engine, and the engine starting operation is performed. Is possible. After starting the engine, the operator operates the shoulder strap (30) only after applying the shoulder rest (40) of the shoulder strap (30) to the shoulder, that is, after the pressure detection switch (54) is turned off. Attach it to the rod (12) and perform the work.

[0012]

【Example】

 The present invention will be described below with reference to the embodiments shown in the drawings. FIG. 6 is a perspective view schematically showing the entire brush cutter 10. The brush cutter 10 includes a control rod 12 extending in a straight line, a power unit 14 including an engine (not shown) and coupled to a rear end of the control rod 12, and a gear device coupled to a front end of the control rod 12. 16 and the rotational power transmitted from the power unit 14 disposed on the lower surface side of the gear device 16 via a transmission shaft (not shown) in the operating rod 12 and a gear (not shown) of the gear device 16. It has a rotating cutting blade 18. The handle 20 is fixed to the operating rod 12 at the central portion and extends to the left and right. The throttle lever 22 is attached to the tip of the handle 20 and is operated by an operator to adjust the throttle valve opening of the power unit 14. The starter switch 24 includes an engine stop switch of the power unit 14, and is attached to the operating rod 12 slightly behind the position where the handle 20 is attached to the operating rod 12. The mounting bracket 26 is fitted to the operating rod 12 behind the starter switch 24 and has a triangular loop portion 28 on the upper side. The shoulder strap 30 is attached to the triangular loop portion 28 and is passed through the shoulder of the worker when the brush cutter 10 is used.

FIG. 2 is a detailed perspective view of the mounting member 26 and the shoulder strap 30. The shoulder strap 30 includes band body portions 32 and 34, and the band body portions 32 and 34 are connected to each other at a length adjusting metal fitting 36 on one end side, and a locking metal fitting 38 is attached to the other end side. The locking metal fitting 38 is provided with a portion in the circumferential direction that elastically expands when pushed, and the sides of the triangular loop portion 28 are moved in and out through the portion to connect with the triangular loop portion 28. It is supposed to do. The shoulder rest portion 40 is movably attached to the band body portion 32, and lead wires 42 and 44 are drawn out from both sides of the shoulder rest portion 40 toward the band body portions 32 and 34, respectively. The lead wire 44 is connected to the locking fitting 38 on the end side opposite to the shoulder rest portion 40. The fastening members 46 are provided on the inner surface sides of the band body portions 32 and 34 at appropriate intervals, the lead wires 42 and 44 are inserted, and they are retained in the band body portions 32 and 34.

FIG. 3 is a cross-sectional view of the fastening member 46. Both ends of the fastening member 46 are sewn to the band body portions 32 and 34, and the lead wires 42 and 44 are threaded at the central bulge portion.

FIG. 4 is a sectional view showing the structure of the shoulder rest portion 40. The cushion material 48 is arranged on the inner surface side of the band body portion 32, has a width corresponding to the shoulder of the operator, and is covered with the covering material 50. The insertion cover 52 is fixed to the covering material 50 so that the band body portion 32 can be inserted between the insertion cover 52 and the covering material 50. The pressure detection switch 54 is embedded in the cushion member 48 substantially in the center thereof and is connected to the lead wires 42 and 44. The pressure detection switch 54 has a tubular case 56 whose upper end flange is fixed to the cushion material 48, and a displacement member 58 which is relatively displaceable relative to the tubular case 56 in the thickness direction of the cushion material 48. is doing.

FIG. 5 is a sectional view showing the structure of the pressure detection switch 54. The displacement member 58 includes a rod portion 60 penetrating the bottom wall of the tubular case 56 so as to be movable in the axial direction, and an upper end of the rod portion 60. It has a sliding upper flange 62 and a lower flange 64 located at the lower end of the rod portion 60. The coil spring 66 is fitted on the rod portion 60 between the bottom wall of the tubular case 56 and the lower flange 64, and urges the displacement member 58 downward. The movable terminal 68 is attached to the upper flange 62 and is displaced integrally with the upper flange 62, and the fixed terminal 70 is fixed to the upper surface side of the bottom wall of the tubular case 56. The lead wires 42 and 44 are connected to the movable terminal 68 and the fixed terminal 70, respectively. When the shoulder rest 40 is removed from the operator's shoulder and the cushioning material 48 is decompressed, the coil spring 66 pushes the displacement member 58 downward so that the movable terminal 68 and the fixed terminal 70 contact each other. However, the pressure detection switch 54 is on. On the other hand, when the shoulder rest 40 is applied to the operator's shoulder and the weight of the brush cutter 10 is applied to the operator's shoulder through the shoulder rest 40, the cushioning material 48 is compressed in the thickness direction, The displacement member 58 is pushed up against the coil spring 66, and the movable terminal 68 is separated from the fixed terminal 70, so that the pressure detection switch 54 is off.

FIG. 1 is an electric circuit diagram of the safety device. The lead wire 44 is connected to the locking metal fitting 38 on the end side opposite to the shoulder rest portion 40, and the locking metal fitting 38 is attached to the mounting metal fitting 26 and It is grounded through the operating rod 12. The lead wire 42 extends toward the power unit 14 (FIG. 6) along the operating rod 12 through the mounting bracket 26, and the primary ignition coil 74 of the ignition device 72 of the engine of the power unit 14 is not grounded. It is connected to the side terminal. As a result, the triangular loop portion 28, the locking fitting 38, the lead wire 44, the pressure detection switch 54, the lead wire 42, and the primary ignition coil 74 form a closed loop circuit. When the pressure detection switch 54 is on and the locking metal fitting 38 on the side of the band body portion 34 is connected to the triangular loop portion 28, both ends of the primary ignition coil 74 are short-circuited. The primary ignition current is not generated in the primary ignition coil 74, the ignition operation of the engine of the power unit 14 by the ignition device 72 is not performed, and the engine is stopped. On the other hand, when the pressure detection switch 54 is off or when the locking metal fitting 38 on the band body portion 34 side is removed from the triangular loop portion 28, the primary ignition coil 74 is not short-circuited. Therefore, the primary ignition current of the primary ignition coil 74 becomes effective, and the ignition operation of the engine of the power unit 14 by the ignition device 72 is permitted.

The operation of the embodiment will be described. The worker hangs the shoulder strap 30 on his shoulder and carries the brush cutter 10 to perform the work. The shoulder rest 40 of the shoulder strap 30 is under pressure due to the weight of the brush cutter 10 being supported by the shoulder of the worker, and the pressure detection switch 54 is off. As a result, the primary ignition coil 74 generates a primary ignition current, the ignition of the engine of the power unit 14 is effectively ignited by the ignition device 72, and the engine is in operation.

On the other hand, when the worker falls, or when the worker is replaced by handing over the brush cutter 10, the shoulder strap 30 is disengaged from the worker, and the pressure on the shoulder of the worker from the shoulder rest 40 is released. R. As a result, the pressure at the shoulder pad 40 becomes less than the predetermined value, the pressure detection switch 54 is turned on, and the pressure detection switch 54 has the locking fitting 38, the triangular loop portion 28, and the operating rod 12 on the lead wire 44 side. Since it is grounded via the primary ignition coil 74, both ends of the primary ignition coil 74 are short-circuited and the generation of the primary ignition current is stopped. Thus, the ignition operation of the engine of the power unit 14 by the ignition device 72 is stopped, the operation of the engine is stopped, and the rotation of the cutting blade 18 is stopped.

When the engine of the power unit 14 is started, the engaging metal fitting 38 on the band body portion 34 side of the shoulder strap 30 is removed from the triangular loop portion 28. As a result, even though the pressure detection switch 54 in the shoulder rest 40 of the shoulder strap 30 is on, the pressure detection switch 54 is not connected to the ground on the lead wire 44 side, and the primary ignition coil 74 is not short-circuited. In this state, the ignition operation of the engine of the power unit 14 by the ignition device 72 is in an effective state. As a result, when the engine is started, the ignition device 72 performs the ignition operation of the engine, the engine is started without any trouble, and the operation is continued after the start. After starting the engine, the operator applies the shoulder rest portion 40 of the shoulder strap 30 to the shoulder, that is, after the pressure detection switch 54 is turned off, the locking metal fitting 38 on the lead wire 44 side is made into a triangular loop. The work is carried out by engaging with the portion 28 and carrying the brush cutter 10 via the shoulder strap 30.

In the illustrated embodiment, the brush cutter 10 has been described, but the present invention is also applicable to other working machines with a shoulder strap such as an edge trimmer.

[0022]

[Effect of the device]

 According to the invention of claim 1, the pressure at the shoulder rest portion of the shoulder strap is detected, and when the shoulder rest portion comes off the operator's shoulder and the pressure at the shoulder rest portion is less than the predetermined value, the prime mover of the power unit. Since the operation of the operator is stopped, even if the operator falls down so that the shoulder strap does not come off from the operating stick, and because of the replacement of work, the operator can operate without stopping the operation of the prime mover. Even when handing over a work machine with a shoulder strap, the prime mover can be stopped to improve safety. In addition, the operator does not have to squeeze the grips in order to keep the prime mover in operation, thus avoiding unnecessary strain on the operator.

According to the invention of claim 2, the pressure detection switch which is turned on by the pressure of the shoulder rest portion of the shoulder strap and the mounting portion of the shoulder strap to the operating rod form a series connection circuit. When the connection circuit becomes conductive, the ignition device stops the ignition operation of the engine of the power section, so remove the shoulder strap from the operating rod, start the engine, and then start the shoulder strap. If you hang it on your shoulder, attach the shoulder strap to the operating rod, and then move on to the work, you can start the engine and the work thereafter without any hindrance.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a safety device.

FIG. 2 is a detailed perspective view of a mounting bracket and a shoulder strap.

FIG. 3 is a cross-sectional view of a fastening material.

FIG. 4 is a sectional view showing a structure of a shoulder pad.

FIG. 5 is a sectional view showing the structure of a pressure detection switch.

FIG. 6 is a perspective view schematically showing the entire brush cutter.

[Explanation of symbols]

 10 brush cutter (working machine with shoulder strap) 12 operating rod 14 power section 18 cutting blade 26 mounting bracket (mounting section) 30 shoulder strap 38 locking fitting (mounting section) 40 shoulder rest section 54 pressure detection switch (motor stop means) 72 Ignition device (motor stop means)

Claims (2)

[Scope of utility model registration request] 1. A power unit (14) including a prime mover, which is attached to the rear end side of the operating rod (12), and a rotary power from the power unit (14) attached to the front end side of the operating rod (12). A working machine (10) with a shoulder strap, comprising a driven cutting blade (18) and a shoulder strap (30) attached to the operating rod (12) and hung on the shoulder of an operator, wherein the shoulder strap is provided. (3
When the pressure in the shoulder rest part (40) of (0) is less than a predetermined value, the engine stopping means (54, 72) for stopping the operation of the engine.
A safety device for a working machine with a shoulder strap, characterized by comprising: 2. A power unit (14) including an engine and attached to the rear end side of the operating rod (12), and a rotary power from the power unit (14) attached to the front end side of the operating rod (12). In a working machine with a shoulder strap (10) including a driven cutting blade (18) and a shoulder strap (30) detachably attached to the operating rod (12) and hung on the shoulder of an operator, A pressure detection switch (54) that is operated by the pressure in the shoulder rest (40) of the shoulder strap (30) and is turned on when the pressure is less than a predetermined value, and the shoulder strap (30) to the operating rod (12). )
An ignition device (72) for stopping the ignition operation of the engine when the series connection circuit formed by the mounting portions (26, 38) and the pressure detection switch (54) is in a conducting state. Safety device for work machines with shoulder straps.