JP2844397B2 - Continuous impact working machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous impact working machine capable of performing a task by generating a high frequency continuous impact force.

[0002]

2. Description of the Related Art For example, a continuous impact working machine typified by a concrete breaker or the like generally has a striking piston built in a cylindrical main body so as to be movable in an axial direction, and an expanding force by compressed air, or The rotation output of the prime mover is forcibly reciprocated by the reciprocating driving force converted by the crank mechanism, and the striking work body supported at the lower part of the main body is continuously hit in the axial direction by the reciprocation of the striking piston. Is done.

[0003] In such a reciprocating drive type continuous impact working machine, there is a problem that the reaction force generated when the above-mentioned striking piston is reciprocally driven vibrates the working machine body violently up and down. However, there is a problem that the impact frequency cannot be increased so much because the striking piston having the force is forcibly driven to reciprocate. A rotary type continuous impact working machine configured to solve such a problem of the reciprocating continuous impact working machine, to reduce vibration and to increase a shock frequency relatively freely, has already been developed.
It has been proposed by the applicant of the present application (for example, JP-A-1-67165 and JP-A-3-11572).

This rotary type continuous impact working machine basically has the same configuration as the example shown in the drawings of the present application. That is, a rotating body that is rotated by a power source and rotatably supported inside the housing is provided, while a striking body having a constant mass is movably held on the rotating body, and the rotating body rotates. In this case, the outermost circumference of the turning locus of the striking body is configured to interfere with the top of the striking body which is supported by the housing so as to be able to reciprocate in the axial direction.

[0005] In such a configuration, when the rotating body is rotated, each time the rotating body makes one rotation, the hitting body, which is loosely held therein, hits the top of the hitting work body, and The axial component of the force causes the striking body to vibrate with a strong force in the axial direction. If the overall center of gravity of the rotating body and the hitting body play-held on the rotating body is matched with the rotating axis of the rotating body, the reciprocating vibration as in the reciprocating type continuous impact working machine described above is obtained. It does not occur, and therefore, the frequency of the continuous impact can be increased by freely increasing the rotation speed of the rotating body.

[0006]

In the above-mentioned rotary type continuous impact working machine, particularly when the continuous operation is performed while increasing the rotation frequency of the rotating body to increase the impact frequency, the temperature inside the housing is increased. There is a problem that the lubrication function is remarkably increased and the lubrication function of the lubricant introduced into the housing is reduced.

As a result of intensive studies by the inventors to find out the mechanism of the temperature rise in the housing, the following facts have been found. That is, in the prediction at the design stage of the impact generating mechanism of such a continuous impact working machine, when the rotating body is rotated and this hits the cylindrical hitting body, the hitting body hits the top surface of the hitting work body. Because of the strong centrifugal force acting on the body, it does not immediately rebound from the top of the hitting body, but rolls the top of the body for a while and pushes down the body in the axial direction. Was to do. If the striking body rolls on the top surface of the striking body as described above, the striking body itself is also given a rotational force, and thus the top surface of the striking body is kept rotating. It was thought that if the contact was continuous, there would not be much relative friction between the peripheral surface of the striker and the top surface of the striker.

However, in practice, as the rotational speed of the rotating body is increased, each time the cylindrical striker hits the top surface of the striker, it is immediately repelled, and this striker and the top of the striker are repelled. It turned out that the contact time with the surface was extremely short. Therefore, the hit body is
Although it hits the top surface of the striking body with intense momentum, it did not roll enough to obtain the rotational force from the striking body,
Therefore, each time the striker hits the top surface of the striker, a large relative friction is generated between them, and it has been found that this is the main cause of the remarkable rise in the temperature inside the housing as described above. It is.

Accordingly, an object of the present invention is to provide a rotary continuous impact working machine as described above, in which a repulsion coefficient between a striking body which swings while being freely held by a rotating body and a striking body which strikes the top surface. When the impacting body that rotates at a high rotational speed collides with the top surface of the impacting body supported by the housing, the impacting body does not immediately repel, but rolls on the top surface of the impacting body for a while. It's about moving.

[0010]

In order to solve the above problems, the present invention employs the following technical means. That is, the present invention is a rotatable member rotatably supported in a housing, and rotatably driven by power, and has a cylindrical outer peripheral surface and is disposed such that an axis is parallel to a rotation axis of the rotator, A striking body which is loosely mounted on the rotating body so that a part of the cylindrical outer peripheral surface is exposed; and a flat top surface parallel to an axis of the rotating body, and the housing And a striking work body supported so as to be able to move by a fixed distance in the axial direction, wherein an axial buffer hole is formed in the top surface of the striking work body, and an axial movement of the striking work body is performed. The upper end of the stroke is defined so that the outermost periphery of the rotation trajectory of the hit body during rotation of the rotating body interferes with the top surface.

[0011]

The shape of the top surface of the hitting body in the present invention is a donut shape when the hitting body has a cylindrical shape and the buffer hole is a circular hole. The cross section at a predetermined distance in the depth direction of the hole also has a donut shape. In other words, the upper part of the striking body in the present invention has a pipe shape with a predetermined thickness opened upward, and the top surface of the upper part of the pipe-shaped striking body is the rotation axis of the rotating body. Is a parallel plane.

When an operation test of the continuous impact working machine of the present invention was performed using the striking working body having the above-described structure, the temperature rise in the housing was suppressed to an allowable range even when the rotating speed of the rotating body was relatively high. Was. This means that, during operation, the relative friction generated during a collision between the striker and the top surface of the striker has been reduced compared to before the improvement. This means that, during operation, the striking body is given a rotational force by coming into contact with the top surface of the striking work body, and this rotation is constantly maintained. This also means that during operation, when the striker hits the top surface of the striker, the contact between the striker and the striker is maintained for a predetermined period of time, rather than immediately repelling from the striker. While rolling on the top surface.

As a result of experiments, according to the present invention, according to the present invention, the above-described hitting work body supported by the housing is rotated while the rotating body for play holding the hitting body is rotated. In a rotary type continuous impact working machine of the type that repeatedly applies continuous impact force by the body, even if the rotation speed of the rotating body is increased relatively high, the temperature rise in the housing is suppressed to an allowable range. As a result, as before improvement, the problem that the lubrication function of the lubricant is deteriorated due to the rise in the temperature inside the housing and the above-mentioned temperature rise is further increased has been solved. .

[0014] The above-mentioned effect is obtained by locally elastically deforming the hitting body when hit by the hitting body;
This is considered to be due to the cooperative action of the hitting body being pressed against the top surface of the hitting body by the strong centrifugal force during operation. As described above, in the present invention, the coefficient of restitution between the above-mentioned striking body that rotates at a high speed while being idlely held by the rotating body and the top surface of the striking work body has an axial buffer hole in the top surface. Is reduced in a well-balanced manner by the simple configuration of forming

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. Continuous impact working machine 1 shown in the figure
Is an engine 2 as a power source, as shown in FIG.
This is an example in which a shovel-shaped striking body 3 is adopted as the hitting body 3 and the method of using the shovel as a whole is suitable.

A substantially barrel-shaped housing 5 having an axis perpendicular to the axis of the operation tube is connected to a distal end of the operation tube 4 whose base end extends to be connected to the engine 2. FIG.
As shown in FIG.
However, the supporting shafts 7a and 7b projecting from both ends
Are rotatably supported by the side walls 5a and 5b of the housing 5, so that the housing 5 is rotatably mounted with the same axis as the axis of the housing 5.

A bevel gear 8 is fixed to one support shaft 7a of the rotating body 6, and the bevel gear 8
It is inserted into the inside of the operation pipe 4 and meshes with a bevel gear 10 at the end of a transmission shaft 9 for transmitting the rotation output of the engine 2. Thus, when the rotational speed of the engine increases and the centrifugal clutch is connected to rotate the transmission shaft 9, the rotational force is transmitted to the rotating body 6 via the bevel gears 8, 10, and the rotating body 6 is rotated. 6 will be driven to rotate.

As shown in FIG. 2, the rotating body 6 has a function of a balance weight between a pair of left and right flange portions 6a and 6b from which the support shafts 7a and 7b are projected from the side surfaces. It has a form integrated by a cylindrical connecting portion 6c. Of course, the axis of the connecting portion 6b is displaced with respect to the axis of rotation of the rotating body 6.

As shown in FIG. 4, the flanges 6a, 6b of the rotating body are provided with holding holes 11, 11 on the opposite side to the connecting part 6b with respect to the rotation axis of the rotating body 6.
Are formed respectively. Then, the holding holes 11,
A hitting body 12 having a cylindrical shape is play-held at both ends of the hitting body 11. That is, the shape of the holding holes 11, 11 is formed so that the hitting body 12 can play freely. In the present embodiment, the holding holes 11, 11 are:
The inner surface has an elliptical shape in which the minimum curvature is substantially equal to the curvature of the circumference of the striker 12. Therefore, the hit body 12
Is rotatable with both ends constrained by the holding holes 11, and can play in a direction perpendicular to the axis within a range allowed by a gap between the holding holes 11 and 11.

Left and right side walls 5a, 5b of the housing 5
A donut disk-shaped guide plate 13, 13 is additionally provided on the inner surface of the body, and this restricts the movement of the hitting body 12 in the axial direction during operation. On the opposite side of the housing 5 from the operation tube 4, a shank portion 1 of the striker 3
4 is formed with a holder portion 15 for holding the actuator 4 reciprocally in a constant stroke in the axial direction. The axis of the holder 15 is parallel to the axis of the operation tube 4 and is disposed at the center of the rotating body 6 in the thickness direction.
As shown in FIG. 4, the operation tube 4 is viewed from the front.
Is displaced laterally by a predetermined amount with respect to the axis of.

In this embodiment, the shank portion 14 of the striking body 3 is divided into a first portion 14a which is rotatably held and a second portion 14b which is non-rotatably supported. The first portion 14a is provided on the outer peripheral wall 5c of the housing 5.
Are fitted and held by a boss-shaped first holder portion 15a which is connected and fixed to the housing 5 so as to penetrate the housing 5.
The second portion 14b of the shank portion 14 is fitted and held by a boss-shaped second holder portion 15b connected to the first holder portion 15a.

At the lower end of the first portion 14a, a large-diameter flange 16 is formed.
Steps 17a, 17b above and below a large-diameter hole 17 formed in the connection between the first holder 15a and the second holder 15b.
, The axial travel is restricted to a certain distance. The second portion 14b of the shank portion 14 is formed by forming a concave portion 18 on a side surface thereof over a predetermined length in the axial direction, and inserting and holding a stopper pin 19 passing through the concave portion 18 in the second holder portion 15b. In addition, the rotation is regulated and the axial travel is regulated to a certain distance. In addition, the recess 1
The rotation and movement stroke restricting means formed by the stopper 8 and the stopper pin 19 also serves to prevent the second portion 14b of the shank from coming off.

As shown in FIG. 4, the top surface 20 of the first portion 14a of the shank portion 14 is a flat surface parallel to the rotation axis of the rotating body 6, in this case, in other words, the first portion 14a Is formed as a flat flat surface orthogonal to the axis of. Further, an axial buffer hole 21 is formed in the top surface 20 at a predetermined depth. Furthermore, the upper end position of the movable stroke of the first portion 14a of the shank portion is combined with the fact that the axis of the shank portion 14 is displaced with respect to the axis of the operation tube 4 in a front view as described above. Is defined as follows.

That is, as shown in FIG. 4, when the first portion 14a is at the upper end of its movable stroke, the flat top surface 20 is attached to the cylindrical hit body 1 with the rotation of the rotating body 6.
It is defined so as to interfere with the outermost circumference of the second turning locus. In the state shown in FIG. 4, the outermost periphery of the turning trajectory of the striker 12 interferes with the top surface 20 most effectively. That is, if the position of the first portion 14a is temporarily changed as shown in FIG.
Above the position shown in FIG. 5, the peripheral surface of the striker 12 collides not with the top surface 20 of the first portion 14a of the shank but with the corner between the top surface 20 and the side surface.
Also, if the position of the first portion 14a is lower than the position shown in FIG. 4, the peripheral surface of the striker 12 collides with the top surface 20 for the first time at a portion that enters the edge of the top surface 20 from the edge. The force of pushing down the first portion 14a downward with the impact force by the centrifugal force is insufficient.

As is clear from the above, the shank portion 14
The reason for displacing the axial center of the operating pipe 4 with respect to the axial center of the operation tube 4 in front view is as shown in FIG. Thereafter, the rotating body 6 further rotates in the direction of the arrow, and the striking body 12
The reason is that the shank portion 14 can be sufficiently pressed down until the bottom reaches the bottom dead center.

In the housing 5, lubrication of a bearing for the rotating body 6, lubrication of the shank 14 of the hitting working body 3 in the holder 15 for axial vibration sliding, and shank 14 are provided. Lubrication at the contact portion between the top surface 20 and the striking body 12, and the holding holes 11, 11 of the rotating body 6
An appropriate amount of lubricant for lubricating the sliding of the cylindrical hitting body 12 against the inner peripheral surface of the cylindrical hitting body 12 is supplied.

In FIG. 5, reference numeral 22 denotes a centrifugal clutch clutch housing 23 which is a connecting portion between the operating pipe 4 and the engine 2. The rear handle is formed by connecting a pair of arm portions extending upward while being connected to each other by an axial grip member.
FIG. 2 shows a grip handle including a mounting ring fitted on the outer periphery of the operation tube 4 and a grip portion formed to protrude so as to extend laterally from the mounting ring. Reference numeral 25 denotes a throttle operation lever for controlling the rotation of the engine 2.

Next, the operation of the continuous impact working machine 1 having the above configuration will be described. The work machine 1 of the present example is in the form of a shovel as a whole. Therefore, the worker holds the rear handle 22 with the right hand and the grip handle 24 with the left hand, for example.
The entire body is supported, and the tip of a shovel-shaped striking work body 3 abuts against the ground on which a hole is to be dug. In the state where the striker 3 is hit against the object in this manner,
As shown in FIG. 4, the shank portion 14, more specifically, the first portion 14a of the striking body 3 is located at the uppermost end of its moving stroke. In this state, when the rotation speed of the engine 2 is gradually increased by operating the throttle operation lever 25, the centrifugal clutch is actuated and the rotation output of the engine is transmitted to the rotating body 6 via the transmission shaft 9 and the rotating body 6 6 starts high-speed rotation. With the rotation of the rotating body 6, the hitting body 12 collides with the top surface 20 of the first portion 14a of the shank for each turn thereof, and the hitting body 12 turns at a high speed in the axial direction due to the impact due to the collision. Therefore, the centrifugal force acting on the striker 12 causes the shank 1
4, the impact force in the axial direction acts repeatedly and continuously.

In the present invention, since the top surface 20 of the first portion 14a of the shank is provided with an axial buffer hole 21 in particular, as described above, the top surface 20 and the striking body 1 are formed.
The repulsive force at the time of collision with the top surface 2 is alleviated, and the impacting body 12 repels at the same time as colliding with the top surface 20 and does not separate from the top surface, but a predetermined short time, It rolls while maintaining the contact state.
In this way, the hitting body 12 is reliably given rotation in the direction of the arrow, and this rotation effectively functions because lubrication is performed between the holding holes 11 and 11, and the shank portion 1 is again turned on.
Continue until the top 4 is hit. Therefore, when the impact body 12 collides with the top surface 20 of the shank portion 14, mutual friction between the contact surfaces is greatly reduced, and heat is generated between the contact surfaces to increase the temperature inside the housing 5. To relax.

In this manner, the impacting body 12 repeatedly hits the top surface 20 of the shank portion 14 with the rotation of the rotating body 6 while the impacting body 12 is in contact with the top surface 20. Due to the rotating centrifugal force of the striking body 12 acting on
The striking body 3 is provided with a strong and high-frequency continuous axial impact force. The shovel-shaped striking work body 3 can be quickly penetrated into the soil by slightly pushing the entire work machine toward the tip while maintaining the above operation state.
Then, in order to excavate the soil subsequently, the entire work machine 1 may be tilted after releasing the throttle operation lever 25 in the same manner as operating a normal shovel.

On the other hand, when the striking body 3 does not hit the object, the shank portion 14 of the striking body 3 is locked at the lower end of its movable stroke.
The top surface 20 of the first portion 14a of the shank is located outside the outermost circumference of the turning trajectory of the hitting body 12, so that no impact force acts on the hitting work body 3. As described above, since the rotating body 6 includes the connecting portion 6c having a function as a balance weight, the center of gravity in the rotating state substantially coincides with the rotation axis, and therefore, the engine 2 is temporarily set by the throttle lever 25. Even if it is rotated at high speed, as long as the striking work body 3 is not abutted against the object, the vibration hardly occurs due to the rotation of the rotating body in the housing. As described above, for the first time, the continuous impact working machine 1 of the present invention solves the problem of lubrication when the rotary impact force generating mechanism is rotated at a high speed, and can be implemented.

Of course, the scope of the present invention is not limited to the above embodiment. The point of the present invention is that the rotating body 6 rotatably supported in the housing, the hitting body 12 loosely held on the rotating body, and the hitting working body 3 held axially slidably on the housing 5. In a rotary continuous impact generating mechanism configured to obtain an impact force by the impact of the striker 12 against the top surface of the striking body by the rotation of the rotating body 6, a temperature rise or lubrication in the housing is provided. In order to solve the problem described above, a shock absorbing hole 21 is formed on the top surface of the shank portion of the striker.

Therefore, there is no particular limitation on the specific means for driving the rotating body 6 provided in the housing 2 to rotate. Further, the specific configuration of the striker 3 is not limited, except that the shank portion is supported by the housing. That is, in the embodiment, the tip of the striker 3 is in the form of a shovel, but may be formed like a chisel of a concrete breaker, or when used as a pile driver, a shank portion. It is also possible to adopt a form in which a lower open cap that fits the top of a wooden stake is connected to the lower end of the stake. Further, in the case of a rust remover for removing shells, dirt, rust, and the like attached to the outer wall of the hull, the tip of the striker 3 has a spatula shape.

Further, in the present embodiment, since the striking work body 3 needs to be formed in the form of a shovel and cannot be rotated around an axis, the shank portion of the work body 3 needs to be rotatable about the axis. Although it is divided into a part and a second part that cannot rotate around the axis, the shank part is particularly preferred when the working body has a form like a chisel of a concrete breaker. It is not necessary to divide the shank into two parts as in the above, and the integral shank part may be supported on the holder part formed on the housing 5 while defining the axial movement stroke.

Further, in the present embodiment, the housing 5 or the rotating body 6 or the striking body 3 in the housing 5 is provided.
In order to achieve efficient transmission of impact force to the shank portion while reducing the size of the upper end shank portion 14, the axial center of the shank portion 14 is displaced with respect to the axial center of the operation pipe 4 in a front view. However, when the outer diameter of the shank portion 14 is sufficiently large, it is not necessary to particularly displace the axis of the shank portion 14 of the striker as described above.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an internal structure of an operation pipe of the working machine shown in FIG.

FIG. 2 is a longitudinal sectional view showing a specific configuration of an impact generating section of the work machine shown in FIG.

FIG. 3 is a view as seen in the direction of arrow III in FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is an overall perspective view of one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Continuous impact working machine 3 Striking body 5 Housing 6 Rotating body 12 Striking body 20 Top surface (of striking body) 21 Buffer hole

Claims (1)

(57) [Claims] 1. A rotating body rotatably supported in a housing and rotatably driven by power, a cylindrical outer peripheral surface, and an axis is arranged so as to be parallel to a rotation axis of the rotating body. A striking body which is loosely mounted on the rotating body so that a part of the cylindrical outer peripheral surface is exposed, and has a flat top surface parallel to the axis of the rotating body, and A continuous impact working machine having a striking work body movably supported by a constant distance in the axial direction, wherein an axial buffer hole is formed in a top surface of the striking work body, and the striking work body is moved in the axial direction. A continuous impact working machine, characterized in that the upper end of the rotary impactor is defined such that the outermost periphery of the rotation trajectory of the striker during the rotation of the rotary body interferes with the top surface.