JPH0710509B2 - Breaker - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a breaker used for crushing solid matter such as concrete or hardened asphalt at a road construction site or a construction site, and more specifically, a power source such as a small engine or a motor as an output source is integrated. The present invention relates to a built-in portable breaker.

[Prior art and its problems]

This type of breaker normally hits the chisel head, which is supported in the lower part of the main body so that it can reciprocate slightly in the vertical direction, by continuously striking it with a hammer body that is reciprocally driven by compressed air or a mechanical reciprocating drive mechanism. It is designed to give impact to. By the way, this type of conventional breaker is used when the device is in a so-called blank state, such as when the crushing target is cracked or when the output of the drive source is increased without hitting the tip of the chisel against the crushing target. In addition, there is a problem that the apparatus body must be subjected to a strong repeated impact force by the hammer body. In the conventional breaker of this type, all the members or the connecting portions between the members have to be made of a strong member capable of withstanding the above repeated impact force, and as a result, the total weight becomes extremely large. In particular, in a breaker in which an engine is integrally mounted in a head housing, a tubular body case in which a hammer pair and a mechanism for reciprocally driving the hammer body are incorporated is provided in a lower portion of the head housing, which has a relatively large weight ratio to the total weight. It is configured to be connected, and the hammer force at the time of idle driving acts so as to continuously peel off the main body case from the head housing, so that the bolt connecting the head housing and the main body case is for a single time. There is a problem of being damaged by. Further, the engine or the motor itself is a precise device configured by combining many parts, and if a strong impact due to the hammer force at the time of idle driving as described above continuously acts. , Its function and life may be fatally affected. On the other hand, if the chisel is driven with a strong hammering force into the object to be crushed that has a certain degree of viscosity such as asphalt in the summer, the chisel may bite firmly into the object to be crushed and it may be difficult to pull out the chisel easily. . In such a case, it has been found that, rather, it is better to leave the device idle and vigorously vibrate the chisel actively to release the crimped state between the chisel and the object to be crushed. As described above, in order to truly put the power source type breaker into practical use, the impact force at the time of a blank shot does not act on the member connecting the main body case and the head housing, and this impact force is applied to the head. It is necessary to prevent transmission to the housing so that the chisel can be positively driven into a blank state.

[Means for solving the problem]

In order to solve the above problems, the breaker of the present invention,
The following technical measures are taken. A cylindrical body case is connected to the lower part of the head housing that houses the power source, and a hammer body that can be reciprocated by the power source is provided in this body case. In a breaker configured to give an impact force, an elastic body that receives an impact force from the chisel is interposed in a lower portion of a main body case, and an upper member and a lower member are separated between the main body case and a head housing. A separation unit is provided, and in this separation unit,
An upper end is locked to the upper member so as not to move downward, and a connecting body having a large diameter portion at the lower end is provided, and the lower member is provided between the lower end large diameter portion of the connecting body and the upper member. It is characterized in that the lower member and the elastic member in a compressed state are directly laminated to the upper member and are interposed in a vertically laminated manner.

[Action and effect]

For example, when the aircraft is pulled up with the chisel sticking to the crushing object, or when the chisel is far from the crushable object, the chisel is positioned at the lower end of its movable stroke, and the chisel has an elastic body. It can be pressed downward. If the engine speed is increased in this state,
A hammer body continuously strikes the top of the chisel, which gives the elastic body a continuous compression force. At this time, the vibration insulating function of the elastic body reduces the impact force transmitted from the chisel to the case body. On the other hand, a separating portion is provided between the main body case and the head housing, but the lower member of the separating portion is always provided with the elastic body in a compressed state interposed between the large diameter portion of the connecting body. Since the upper member is elastically pressed in a direct contact state, the upper and lower members in a normal state are stably integrated. Further, at the time of idle driving, although the impact from the chisel acting on the body case is moderated by the elastic body at the lower portion of the body case, a considerably strong downward impact force acts on the body case. However, in the present invention, since the lower member is elastically pushed upward by the elastic body in a compressed state interposed between the lower member and the large diameter portion of the connecting body, when a strong downward impact force is applied. The elastic body can be slightly elastically moved downward with respect to the upper member while further compressing the elastic body. Therefore, even if a downward impact force acts on the main body case at the time of idle driving, this is not directly transmitted to the upper member or the head housing. Further, since the elastic body is interposed between the lower large-diameter portion of the connecting body and the lower member, the impact force does not directly act on the connecting body. As described above, with the breaker of the present invention, not only the impact transmitted from the chisel to the main body case during idle driving is mitigated, but even if a downward impact force is applied to the main body case, this is directly transmitted to the head housing. It has a double impact insulation between the chisel and the head housing, so even if you hit the ball aggressively, the connection between the main body case and the head housing or the engine etc. The power source itself will not be damaged by impact.

[Explanation of Examples]

Hereinafter, embodiments of the breaker of the present invention will be specifically described with reference to the drawings. As shown in FIG. 1, a breaker 1 of the present invention is a cylinder for accommodating a hammer mechanism or a chisel 19 under a head housing 3 for accommodating an engine and a reduction gear (neither directly shown in the figure) crank mechanism 9. The main body case 2 has a connected form. Inside the outer casing 4 which constitutes the upper part of the main body case 2, a fixed cylinder cylinder 5 is formed so as to be double with respect to the outer casing 4.
Is inserted therein, which forms a cylinder space 7 continuous with the crank chamber 6 formed in the head housing 3. A movable cylinder 8 is fitted in the fixed cylinder cylinder 5 so as to be vertically reciprocally slidable, and the movable cylinder 8 includes a rotating disk 9 incorporated in a crank chamber 6 and this rotating disk. Connecting rod whose upper end is connected to the eccentric position of
Is connected to a crank mechanism 11 composed of. Therefore, when the rotary disc 9 is rotationally driven, the movable cylinder 8 is vertically reciprocally driven. The rotating disk 9 is rotationally driven at about 1,000 rpm, for example, by the engine output obtained by reducing the rotation of the output shaft of the engine by the speed reducer. Further, as will be described later, a through hole 17 through which a lower striking rod 16 of a free piston 18 as a hammer body fitted therein can project is formed at the lower end of the movable cylinder 8. Further, by providing ventilation holes 12 and 13 at the upper and lower sides of the fixed cylinder cylinder 5, respectively, a portion of the cylinder space 7 above the movable cylinder 8 and a portion below the movable cylinder 8 can be separated from the tubular jacket 4 and the fixed cylinder cylinder. An annular space 14 formed between the movable cylinders 8 allows the movable cylinders 8 to move vertically, thereby reducing the vertical movement resistance of the movable cylinders 8 and increasing the vertical reciprocating movement of the movable cylinders 8. Further, inside the movable cylinder 8, a free piston 18 which can freely move up and down is inserted. The free piston 18 functions as a hammer body that strikes the top of the chisel 19, and a striking rod 16 is integrally formed on the lower portion thereof.
When the free piston 18 moves downward, the striking rod 16 projects from the lower through hole 17 of the movable cylinder 8 and strikes the top of the chisel 19 located below it. Between the outer circumference of the free piston 18 and the inner circumferential surface of the movable cylinder 8, airtightness is ensured by an O-ring 20 fitted on the outer circumference of the free piston 18, and the lower through hole 17 of the movable cylinder 8 and the impact are struck. An airtightness is secured between the rod 16 and the rod 16 by an O-ring 21 fitted on the inner periphery of the lower through hole 17. Therefore, the movable cylinder 8
The inside of is divided into an upper air pressure chamber 22 and a lower air pressure chamber 23 by a free piston 18. These pneumatic chambers 22 and 23 are alternately compressed due to the inertial delay of the movement of the free piston 18 accompanying the vertical movement of the movable cylinder 8, and the free piston 18 is accelerated by the elastic expansion of the compressed air.
In this example, by providing an appropriate number of through holes 8a in the side wall of the movable cylinder 8 and communicating the upper air pressure chamber 22 with the outside when the free piston 18 moves downward, the upper air pressure chamber 22 becomes a negative pressure. By preventing downward acceleration of the free piston 18 and communicating the lower air pressure chamber 20 to the outside when the free piston 18 moves upward, the lower air pressure chamber becomes negative pressure and It prevents from blocking the upward acceleration. Further, a lower wall of the cylinder space 7 is formed at the lower ends of the cylindrical outer shell 4 and the fixed cylinder cylinder 5, and an axial support for vertically slidably supporting the upper shaft portion 191 of the chisel 19 at the center thereof. A boss portion 26 having a hole 25 formed therein is connected. Further, on the outermost periphery of the boss portion 26, the tubular outer jacket 4
A cylindrical body portion 241 having an outer diameter substantially the same as the outer diameter of, a bottom wall portion 242,
A lower case 24 having a chisel protruding hole 243 opened at the center of the bottom wall is connected by a screw means 27. Chisel
19 includes an upper shaft portion 191, an intermediate large-diameter portion 192, and a lower shaft portion 193.
And a lower tip 194, the upper shaft portion 191 of which is slightly projected from the boss portion 26 into the cylinder space 7,
Preferably, it is slidably supported in the support hole 25 through a bush 27a, and the lower shaft portion 193 is projected from the chisel projecting hole 243 of the lower case 24 to the outside of the lower portion. Inside the lower case 24, the middle large-diameter portion 19 of the chisel 19 is
A coil-shaped suspension spring 28 having a relatively large spring coefficient is interposed between 2 and the lower surface of the boss portion 26. The spring coefficient of the suspension spring 28 is related to the weight of the entire breaker and the force with which the operator presses the breaker body against the crushing target G, and when the chisel 19 is abutted against the crushing target G, the upper shaft portion 191 of the chisel 19 is pressed. The protrusion amount into the cylinder space is set to be appropriate. The suspension spring 28 substantially defines the upper end of the movable range of the chisel 19, and also has a vibration isolation function of preventing the vibration of the chisel 19 from being transmitted to the main body 2 when the breaker is activated. However, the suspension spring 28 can be omitted. Because, when the free piston 18, which is a hammer body, is driven up and down, the free piston 18
Due to the reaction force caused by 18 repeatedly hitting the top of the chisel 19, the body floats up against the chisel 19, in other words,
This is because the chisel 19 balances at a position slightly lower than the upper end of its movable range. In the present invention, the tip end of the lower case 24 formed in the lower part of the main body 1 is filled with the elastic material 30 for cushioning the shocking downward movement of the large diameter portion 192 of the chisel 19. That is, in this example, as shown in FIG. 1 and FIG. 2, the inner wall of the lower case 24 is utilized, and the space forming member 31 as described below is loaded into the inner wall of the lower case 24 so that the length can be increased only in the vertical direction. A substantially closed space 29 that can be changed is formed, and the elastic material 30 is filled inside the space. The space forming member 31 has an outer periphery that can slide up and down with respect to the inner surface 241a of the barrel body 241 of the lower case 24 with a slight gap, and the chisel 19
Disc part 312 having a central hole 311 having an inner diameter smaller than the outer diameter of the large diameter part 192, and extending below the central hole 311 and having an outer periphery with respect to the inner periphery of the chisel protruding hole 243 of the lower case 24. It has a cylindrical portion 314 fitted through a slight gap. As shown in detail in FIG. 2, the disc portion of the space forming member 31.
Since the gap between the outer circumference of 312 and the inner circumference of the barrel 241 is small, and the gap between the outer circumference of the cylinder 314 and the inner circumferential surface of the chisel protruding hole 243 is small, the barrel 241 of the lower case 24 is small. The inner surface and the inner surface of the bottom wall portion 242, and the disc portion 3 of the space forming member 31.
An annular substantially closed space 29 surrounded by the lower surface 12 and the outer surface of the cylindrical portion 314 is formed. The substantially closed space 29 has the property that its volume can change only in the vertical axis direction when the space forming member 31 moves up and down. Then, the substantially closed space 29 is filled with a donut-shaped elastic material 30 made of, for example, heat-resistant rubber. The gap between the outer circumference of the disk portion 312 and the inner circumference of the cylindrical body portion 241 of the lower case and the clearance between the outer circumference of the cylindrical portion 314 and the inner circumferential surface of the chisel protruding hole 243 are
It is preferable to keep it at most about 0.1 mm to 0.3 mm. Further, the upper surface of the outer peripheral portion of the disc portion 312 of the space forming member 31 is pressed by the snap ring 33 fitted to the inner wall of the lower case 24. The lower shaft portion 193 of the chisel 19 in which the shaft portion 191 is supported by the support hole 25 passes through the inside of the cylindrical portion 314 of the space forming member 31 and projects to the outside of the lower portion of the main body, and the intermediate large diameter portion 192 thereof is a space. By contacting the upper surface of the disk portion 312 of the forming member 31,
The lower end of the vertical movable range is determined. When the space forming member 31 is pushed down by hitting the large diameter portion 192 of the chisel 19 on its upper surface, the substantially closed space 29 is formed.
Is reduced to the extent that the elastic material 30 is elastically compressed, and
When the pressing force is released, it returns to its original state due to the restoring force of the elastic body. The substantially closed space 29 can also be constructed as shown in FIG. In this example, the cylindrical portion 244 corresponding to the cylindrical portion 314 of the space forming member 31 is replaced with the bottom wall portion 242 of the lower case 24.
The collar 315 is integrally formed upward from the chisel projecting hole 243, and has an outer diameter slightly smaller than the inner diameter of the barrel body 241 of the lower case 24 and an inner diameter slightly larger than the outer diameter of the cylindrical portion 244. The inner circumference 331 is the cylindrical portion 24
4 is arranged so as to be vertically slidably fitted on the outer periphery of the upper end of 4, and the barrel body 241 of the lower case 24,
The inner surface of the bottom wall portion 242 or the cylindrical portion 244 and the lower surface of the collar 315 form a substantially closed space 29 in which the elastic member 30 is provided.
Is filled. Further, the above-mentioned substantially closed space 29 can be constructed as shown in FIG. In this case, the lower case 24 includes the barrel body 241 and the outward flange portion formed at the lower end of the barrel body 241.
The first case 24a having 245 and the cylindrical portion 246 having an inner diameter slightly larger than the outer diameter of the outward flange 245 overlaps with the outward flange 245 at the upper end of the cylindrical portion, and the inner diameter is a cylinder. An upper inward flange 247, which is slightly larger than the outer diameter of the body 241, and a lower edge of the cylindrical portion 246, which is continuous with the upper inward flange 247 and is smaller than the outer diameter of the intermediate large-diameter portion 192 of the chisel 19 and the lower shaft 193 of the chisel 19. Bottom wall having a central hole 248 larger than the outer diameter of
249 and a movable second case 24b. In this case, the outer surface of the barrel body 241 of the first case 24a and the outward flange 24
A substantially closed space 29 surrounded by the upper surface of 5, the inner surface of the cylindrical portion 246 of the movable second case 24b and the upper surface of the bottom wall portion 249 is formed, and the elastic material 30 is filled therein. Next, in the present invention, the separating portion 34 is provided between the main body case 2 and the head housing 3, and in this separating portion, the upper end 35a is locked so as not to move downward with respect to the upper member 34a, and the large diameter portion is provided at the lower end 35b. The connecting body 35 having 35c is provided, and the large diameter portion 35c of the connecting body 35 is provided.
Between the upper member 34a and the upper member 34a, the lower member 35b and the elastic member 36 in the compressed state are interposed in a vertically stacked manner so that the lower member 35b directly contacts the upper member 34a. In the example shown in FIGS. 1 and 5, the head housing 3
The flat lower surface is used as the upper member 34a of the separating portion, and the outward flange formed on the upper end of the tubular jacket 4 is used as the lower member 34b of the separating portion. Then, on the lower surface of the housing 3, screw holes 37
And a through hole 38 corresponding to the screw hole 37 is provided in the outward flange of the tubular jacket 4, and a headed bolt 35 as a connecting body which is passed through the through hole 38 from below is provided in the screw hole 37.
In this state, an annular elastic member 36 in a compressed state is interposed between the head 35c of the bolt 35 and the outward brim 34b in this state. In this example, the metallic seat plate 39 is interposed between the head 35c of the bolt 35 and the elastic member 36 so that the entire elastic member 36 is in an average compressed state. It should be noted that, as shown in FIG. 5, the seat plate 39 has a side wall portion 39 for holding the side portion of the elastic member 36.
a is formed, and in this way, even when an additional compressive force acts on the elastic member 36 to cause it to compressively deform, a large local deformation in the lateral direction cannot occur, and an average in the longitudinal direction is generated. This deformation is convenient for extending the life of the elastic member 36. In FIG. 5, reference numeral 40 is interposed between the lower surface of the head housing 3 and the upper surface of the outward flange 34b in a slightly elastically compressed state to seal between the housing 3 and the outward flange 34b. , An O-ring that absorbs the upward impact of the outward flange 34b. Further, in the example shown in FIG. 6, the tubular outer shell 4 itself is vertically divided into two parts, and the upper and lower members thus formed are formed with outward flanges 34a and 34b vertically opposed to each other. Similarly, the connection member 35 and the elastic member 36 are used for connection.
That is, the bolt through holes 41, 42 corresponding to the outer flanges 34a, 34b of both sides are opened, the headed bolts 35 as connecting members are inserted into the bolt through holes 41, 42 from above, and the large diameter is formed in the lower part thereof. An annular elastic member 36 in a compressed state is interposed between the double lock nut 35c and the outward flange 34b in a state where the double lock nut 35c as a portion is screwed. In this case, double lock nut 35
A seat plate 39 similar to that in the example of FIG. 5 is interposed between c and the elastic member 36. By adopting the above-described configuration of the separating portion between the main body case and the head housing 3, the lower member 34b is always elastically pressed against the upper member 34a. Therefore, in the normal state, the upper and lower members 34a, 34b are strongly integrated so that they do not rattle each other.
When a strong downward impact force is applied to the lower member 34b,
Only the lower member can elastically move downward. Next, the operation of the breaker of the present invention will be described with reference to the examples shown in FIGS. 1, 2 and 5. Strike Mode When crushing an object to be crushed, the tip of the chisel 19 is brought into contact with the object G, and the throttle operating lever provided on the handle is operated to increase the rotation of the engine. Since the rotation output of the engine 3 is normally transmitted to the rotating disk 9 of the crank mechanism 11 via a centrifugal clutch (not shown), only when the engine reaches a predetermined rotation speed from the idling state. The crank mechanism 11 is driven, and the movable cylinder 8 is vertically reciprocated. In addition,
At this time, the suspension spring 28 is slightly compressed due to the weight of the entire breaker 1 and the force of the operator pushing down the breaker 1. Therefore, the chisel
As shown in FIG. 1, the large diameter portion 192 of the space 19 has a space forming member 31.
It is located at a position spaced upward from the upper surface of the. When the movable cylinder 8 moves upward from the bottom dead center, the lower air pressure chamber 23
Is compressed by the inertial delay of the free piston 18.
This situation continues until the movable cylinder 8 approaches the top dead center,
At the next moment, the free piston 18 moves upward at high speed by the elastic force of the lower air pressure chamber 23. Then, when the movable cylinder 8 passes through the top dead center and turns downward, the kinetic energy of the free piston that moves upward at high speed and the force for pushing down the movable cylinder 8 compress the upper pneumatic chamber 22 to the maximum extent. .
Then, at the next moment, the free piston 18 is directed downward and is rapidly accelerated by the strong elastic expansion force of the maximally compressed upper air pressure chamber 22. When the speed of the free piston 18 reaches the maximum speed, the striking rod 16 strikes the top surface of the chisel 19. At this time, the descending speed of the free piston reaches a maximum of several tens of meters per second. By repeating such an operation, the chisel 19 is repeatedly subjected to an impact force by the free piston 18 which is a hammer body. In this striking mode, the striking force of the free piston, which is the hammer body, is transmitted only to the crushing target via the chisel, so the breaker body 1
Is not hit by the free piston. Chisel Extraction or Idle Strike Mode As described above, the chisel 19 that is repeatedly impacted by the free piston 18 that is the hammer body in the impact striking mode causes the crushing target G to crack due to the impact energy. Once the crushing target cracks, the balance between the downward impact force applied to the chisel 19 and the reaction force that the chisel receives from the crushing target is lost. At this time, the device is in a blank state. Further, when the chisel strongly bites into a viscous object, the chisel is vigorously hit to vibrate the chisel to release the bite between the chisel and the object. FIG. 2 shows the state of the chisel 19 or the lower part of the main body in the pull-out or idle-driving mode of the chisel. In the chisel 19, the intermediate large diameter portion 192 is in contact with the upper surface of the disk portion 312 of the space forming member 31. In this state, when the engine rotation is increased and the striking rod 16 of the free piston 18 strikes the head of the chisel 19, the space forming member 31 is pushed down by the impact, and the elastic material 30 is compressed and deformed by that amount. Then, the space forming member 31 is pushed up by the next repulsive force of the elastic material 30. Thus, in this mode, the chisel 19 is vibrated to the extent that the elastic material 30 can be deformed. Moreover, since this vibration is generated by the high-speed hammer force of the free piston 18 as described above, it is a very strong vibration. At this time, the impact force transmitted to the main body case 2 by the hammer force of the free piston 18 is mitigated by the deformation of the elastic member 30, but
Since the kinetic energy of 18 is extremely large, a strong downward impact force still acts on the body case 2. However, in the present invention, as shown in detail in FIG.
Since the outer jacket 4 is connected to the head housing 3 in a state of being pressed by the elastic body 36, even if the main body case 2 is subjected to a strong downward impact as described above, the outer jacket 4 is elastically deformed. Since the member 36 can be moved downward while being further compressed, direct transmission of impact force to the head housing 3 is avoided. Also, the mantle 4
Head portion 35c of the connecting body 35 for connecting with the housing 3 of
Since the elastic member 36 is interposed between the outer collar and the outer flange of the outer shell 4, the impact does not directly act on the connecting member.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the breaker of the present invention, and FIG.
FIG. 4 is an enlarged cross-sectional view of the lower main part when the chisel is at the lower end of the movement, and FIG. 3 is an enlarged cross-sectional view of another embodiment of the lower main part.
FIG. 5 is an enlarged cross-sectional view of yet another embodiment of the lower main part, FIG. 5 is an enlarged cross-sectional view of an example of a separation part provided between the main body case and the head housing, and FIG. 6 is another example of the separation part. It is an expanded sectional view. 1 ... Breaker, 2 ... Cylindrical body case, 3 ... Head housing, 18 ... Free piston (hammer body), 19 ...
Chisel, 30 ... Elastic material, 34 ... Separation part, 34a ... Upper member, 34b ... Lower member, 35 ... Coupling body, 35c ... Large diameter part, 36
...... Elastic member.

Claims (1)

[Claims] 1. A cylindrical main body case is connected to a lower portion of a head housing for accommodating a power source, and a hammer body reciprocated by the power source is provided in the main body case, and the hammer body supports the lower portion of the main body case by the hammer body. In a breaker configured to give a connecting impact force to a chisel, an elastic body that receives an impact force from the chisel is interposed in a lower portion of the main body case, and an upper member and a lower member are provided between the main body case and the head housing. A separating portion is provided to separate the member, and in this separating portion, a connecting body having an upper end locked to the upper member so as not to move downward and a lower end having a large diameter portion is provided, and a lower end having a large diameter. A breaker, characterized in that a lower member and an elastic member in a compressed state are interposed between the upper portion and the upper portion so that the lower member directly contacts the upper member, and the lower member and the elastic member are placed in a compressed state.