JPH0639907Y2 - breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a breaker for crushing a crushed material by driving a chisel tip into the crushed material by vibration.

[Conventional technology]

In road construction and the like, a breaker used by hand is often used for crushing crushed materials such as concrete and asphalt. Such a breaker, for example, as disclosed in JP-A-53-123423,
The piston is reciprocated by the air supplied from the outside, and by this reaction, the chisel tip is vibrated and driven into the crushed material. In this type of breaker, the necessary striking force can be obtained by adjusting the grip amount of the throttle lever provided on the handle to adjust the air intake amount.

By the way, when the crushed material is crushed by the breaker as described above, the flea tip may bite into the crushed material to make it impossible to continue the impact. In such a case, it is not easy to pull out the chisel tip from the crushed material. Therefore, the chisel tip is pulled out by reciprocating the piston and pulling up the breaker body while vibrating the chisel tip.

[Problems to be solved by the device]

However, in the above conventional breaker, usually, the bottom of the handle is supported by the palm and the breaker body is pulled up to pull out the fleas tip from the crushed material. You have to operate the lever. For this reason, it becomes difficult to adjust the grip amount of the throttle lever, and the amount of air intake is often maximized. Become.

In this way, the conventional breaker cannot limit the amount of air intake when pulling out the chisel tip from the crushed object, so the breaker body is given an excessive impact force and the vibration of the body becomes large, so Was increasing fatigue. Further, the breaker has a problem that the piston and the piston collide with the cylinder due to the blank driving, and the cylinder and the piston are easily damaged.

[Means for Solving the Problems]

In order to solve the above problems, the breaker according to the present invention is a breaker in which a throttle lever for controlling the amount of intake air is rotatably attached to a handle, and the throttle lever has a lower end protruding downward. On the other hand, the handle is provided with a through hole for reciprocally moving the protrusion of the throttle lever between the inside and the outside of the handle.

[Action]

According to the above configuration, when the chisel tip biting into the crushed material is pulled out, the palm supporting the lower side of the handle closes the through hole, so that even if the throttle lever is pushed down by the thumb, the convex portion will contact the palm. It never goes out of the handle. Therefore, the throttle lever is not pushed further down, the amount of air introduced into the breaker is limited, and the reciprocating motion of the piston becomes small.

Therefore, the vibration of the breaker body is suppressed, the fatigue of the operator can be reduced, the collision of the piston with the cylinder can be eliminated, and the damage of the piston and the cylinder can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1 (a), the breaker according to the present embodiment has a back head 3 that holds a handle 2 on an upper portion 1 of a main body.
Is provided. The back head 3 is attached to the upper end of the cylinder 4, and the handle 2 is provided in the upper portion of the back head 3 in a direction orthogonal to the vibration direction (arrow BB 'direction) of the breaker body and penetrating the inside of the back head 3. It is fixed. An air introduction hole 5 having an opening at one end is provided inside the handle 2 so that air supplied from the outside can be taken into the breaker.

The inner pipe 6 is fixed to the air introduction hole 5, while the valve 7
Is provided, and by inserting the throttle spring 8 between one end side of the inner pipe 6 and the valve 7, the valve 7 is pressed against the step portion 5a provided in the air introduction hole 5. ing. Further, a communication hole 9 is provided between the air introduction hole 5 and the inner lower end surface of the back head 3 so that the air supplied via the valve 7 is introduced into the back head 3.

On the other end side of the handle 2, a hollow portion 10 is provided inside, and an elongated hole 11 penetrating the hollow portion 10 and the outside is provided above. A throttle lever 12 is axially supported by a pin 13 at the end of the elongated hole 11 on the back head 3 side so as to be rotatable in the direction of arrow C-C '. As shown in FIG. 1 (b), the throttle lever 12 is provided with a plate-like grip portion 12a on its upper end surface so that the throttle lever 12 can be easily gripped by hand. A convex portion 12b protruding downward is provided at a substantially central portion of the lower end portion. Further, a short hole 14 penetrating the hollow portion 10 and the outside is provided in the lower portion of the handle 2 at a position where the convex portion 12b abuts when the throttle lever 12 moves in the direction of the arrow C '. 12b is reciprocally movable between the cavity 10 and the outside.

Between the air introduction hole 5 and the hollow portion 10, a bush rod 15 which is movable in the axial direction of the handle 2 (direction of arrow D-D ') in a penetrating state makes one end abut against the valve 7,
The other end is provided so as to be brought into contact with the end of the throttle lever 12 on the pin 13 side. The valve 7 is moved in the direction of arrow D-D 'by the bush rod 15 that moves in response to the rotation of the throttle lever 12, and opens and closes the air intake path formed by the air introduction hole 5.

On the other hand, on the lower part 16 of the main body, a front chuck holder 17 is attached to the lower end of the cylinder 4, and a chisel 18 is fixed and held in the opening of the lower end surface of the front chuck holder 17. A chisel 18 at the lower outside of the front chuck holder 17 has a chisel tip 18a formed at the lower end, and a protector 19 provided with an O-ring or a sealant is externally fitted and fixed near the front chuck holder 17. . The protector 19 is made of an Al alloy or the like, and prevents rock powder crushed by the chisel tip 18a or splashed water from entering the breaker through the gap between the front chuck holder 17 and the chisel 18. It is supposed to block.

In the above configuration, when performing the crushing work, the handle 2
Is pressed from above and the throttle lever 12 is pushed down in the arrow C'direction against the elastic force of the throttle spring 8, the bush rod 15 is pushed by the throttle lever 12 in the arrow D direction. At the same time, the valve 7 is also pushed in the direction of the arrow D to open the air introduction hole 5, so that the air taken in from the air introduction hole 5 is supplied to the inside of the breaker via the valve 7. Then, by the air, the cylinder 4
A piston (not shown) reciprocates in the direction of arrow BB ', and the reaction lowers the lower part 16 of the main body to vibrate violently in the same direction, so that the chisel tip 18a provided at the tip of the chisel 18 hits the crushed material. Crush. The striking force of the chisel tip 18a is made variable by adjusting the grip amount of the throttle lever 12 to move the valve 7 and controlling the air intake amount.

By the way, when the chisel tip 18a bites into the crushed material during work and is restrained, in order to pull out the chisel tip 18a from the crushed material,
Usually, as shown in FIG. 2, the lower side of the handle 2 is supported by the palm and the breaker body is pulled up. At this time, if the breaker body is pulled up while reciprocally moving the piston to give vibration to the breaker body, it is easy to pull out the chisel tip 18a. Therefore, the throttle lever 12 is pushed downward with the thumb to open the valve 7. When the throttle lever 12 is pushed down, the convex portion 12b of the throttle lever 12 tries to come out from the short hole 14 of the handlebar 2 to the outside.
Since the lower side is supported by the palm, the convex part 12b is
The throttle lever 12 cannot be pushed further down by making contact with the palm covering the 4's.
For this reason, the amount of intake air is limited, the reciprocating motion of the piston becomes small, and an excessive striking force is not applied to the breaker body. Also, if you push up the convex portion 12b with your finger,
The amount of air intake can be delicately limited.

By the action as described above, since the beating to the breaker body is suppressed, and the vibration of the breaker body is reduced, when pulling out the chisel tip 18a from the crushed material, it is possible to reduce the fatigue of the operator, The piston does not collide with the cylinder, and damage to the cylinder and the piston can be prevented.

In addition, during crushing work, the handle 2 is gripped from above, so
Even if the amount of grip of the throttle lever 12 is maximized and the convex portion 12b projects outward from the short hole 14, the handle 2 does not become difficult to grip. Further, the size, shape and position of the convex portion 12b are not limited to those described in the present embodiment, and in consideration of the magnitude of the striking force required for the chisel tip 18a and the position of the hand supporting the handle 2. Just decide.

[Effect of device]

In the breaker according to the present invention, as described above, in the breaker in which the throttle lever for controlling the air intake amount is rotatably attached to the handle, the throttle lever is provided with the downwardly protruding convex portion at the lower end portion. On the other hand, the handle is provided with a through hole that allows the convex portion of the throttle lever to reciprocate between the inside and the outside of the handle.

As a result, when pulling out the chisel tip that cut into the crushed material,
Since the through hole is blocked by the hand supporting the lower side of the handle, the throttle lever is not pushed further down because the convex portion abuts on the hand. Therefore, the amount of air entering the breaker is limited and the vibration of the breaker body is suppressed, so that the fatigue of the worker can be reduced and the workability can be improved. Further, it is possible to prevent the piston from colliding with the cylinder and prevent the piston and the cylinder from being damaged.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 (a) is a vertical sectional view showing the structure of the breaker. FIG. 1 (b) is a sectional view taken along the line AA of FIG. 1 (a) showing a handlebar and a throttle lever. FIG. 2 is a vertical cross-sectional view showing an operation state of the throttle lever when the breaker body is pulled up. 2 is a handle, 12 is a throttle lever, 12b is a convex portion, 14
Is a short hole (through hole).

Claims (1)

[Scope of utility model registration request] 1. A breaker in which a throttle lever for controlling the amount of intake air is rotatably attached to a handle, wherein the throttle lever is provided with a convex portion projecting downward at a lower end thereof while the handle is provided on the handle. The breaker is provided with a through hole for reciprocally moving the convex portion of the throttle lever between the inside and the outside of the handle.