JPS62107986A - Breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a breaker used for crushing solid materials such as concrete or hardened asphalt at road construction sites or construction sites. Regarding the installed portable breaker.

[Prior art and its problems]

This type of breaker normally strikes the head of a chisel, which is supported at the bottom of the main body so that it can reciprocate slightly up and down, with a hammer body that is reciprocated by compressed air or a mechanical reciprocating drive mechanism. It is designed to apply impact force to the chisel. By the way, this type of conventional breaker is used when the device is in a so-called dry striking state, such as when the object to be crushed breaks or when the output of the drive source is increased without touching the tip of the chisel to the object to be crushed. Another problem is that the main body of the device must receive strong repeated impact forces from the hammer body. In conventional breakers of this type, all of its members or the joints between the members must be made of strong members capable of withstanding the above-mentioned repeated impact forces, resulting in an extremely large total weight. In particular, for breakers in which the engine is integrally mounted in the head housing, the cylindrical body case in which the hammer body and the mechanism for reciprocating the hammer body are built into the lower part of the head housing, which has a relatively large weight ratio to the total weight, is installed. The structure is such that they are connected to each other, and the impact during an impact acts to peel off the main body case from the head housing with a continuous impact, and this causes the connecting bolt to connect the head housing and the main case. There is a problem that it gets corrupted in a short amount of time. In addition, an engine or motor is itself a precision device that is made up of many parts, and when the strong impact caused by the hammer force during a collision as described above acts continuously. , which may have a fatal effect on its function and lifespan. On the other hand, if the chisel is driven with a strong hammer force into an object to be crushed that has some viscosity, such as asphalt in the summer, the chisel may stick firmly to the object to be crushed, making it difficult to pull out the chisel easily. . In such a case, it has been found that it is better to put the device in a protruding state and actively vibrate the chisel strongly to release the compressed state between the chisel and the object to be crushed. In this way, in order to put a power source-equipped breaker into practical use, it is necessary to ensure that the impact force at the time of an impact does not act on the member connecting the main body case and the head housing, and that this impact force is applied to the head housing. It is necessary to ensure that the chisel is not transmitted to the housing so that the chisel can be positively protruded.

[Means to solve the problem]

In order to solve the above problem, the breaker of this invention:
The following technical measures have been taken: A cylindrical main body case is connected to the lower part of the head housing that houses the power source, and a hammer body that is reciprocated by the drive source is provided inside this main body case. In a breaker configured to apply an impact force, an elastic body that receives the impact force from the chisel is interposed in the lower part of the main body case, and a separation part is provided between the main body case and the head housing, and in this separation part , a connecting body whose upper end is fixed to the upper member so as not to be able to move downwardly and has a large diameter portion at the lower end, and between the large diameter portion of the connecting body and the upper member, the lower member and the lower member are in a compressed state. Elastic members are interposed in a layered manner.

[Action and effect]

For example, when pulling up the machine with the chisel biting into the object to be shredded, or when the chisel is far from the object to be shredded, the chisel is positioned at the lower end of its movable stroke, and the chisel is held against the elastic body. This can cause downward pressure. If you increase the engine speed in this state,
The hammer body continuously strikes the top of the chisel, which applies a continuous compressive force to the elastic body. At this time, due to the vibration isolation function of the elastic body, the impact force transmitted from the chisel to the case body is alleviated. On the other hand, a separation part is provided between the main body case and the head housing, but the lower member is always in a compressed state due to the elastic body interposed between it and the large diameter part of the connecting body. Since the upper member is elastically pressed, the upper and lower members are stably integrated in a normal state. Further, when the rod is thrust, although the impact from the chisel acting on the main body case is alleviated by the elastic body in the lower part of the main body case, a fairly strong downward impact force acts on the main body case. However, in the present invention, since the lower member is elastically pushed upward by a compressed elastic body interposed between the lower member and the large diameter portion of the connecting body, when a strong downward impact force is applied, While further compressing the elastic body, it is possible to move slightly elastically downward relative to the upper member. Therefore, even if a downward impact force is applied to the main body case at the time of thrusting, this force 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, no impact force is directly applied to this connecting body. As described above, the breaker of the present invention not only alleviates the impact transmitted from the chisel to the main body case during an impact, but even if a downward impact force is applied to the main body case, this is not directly transmitted to the head housing. Double shock insulation is provided between the chisel and the head housing, so even if you aggressively strike the rod, the joint between the main body case and the head housing, 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, the breaker 1 of the present invention has a cylinder housing a hammer mechanism or chisel 19 at the bottom of a head housing 3 housing an engine, a reduction gear (none of which are directly shown in the figure), and a crank mechanism 9. It has a form in which the main body case 2 is connected. A fixed cylinder tube 5 is provided inside the outer mantle 4 constituting the upper part of the main body case 2 so as to be double with respect to the mantle 4.
is inserted therein, and forms a cylinder space 7 that is continuous with a crank chamber 6 formed within the head housing 3. A movable cylinder 8 is fitted into the fixed cylinder tube 5 so as to be able to slide vertically and reciprocally, and the movable cylinder 8 is connected to a rotating disk 9 incorporated in the crank chamber 6, and this rotating disk A connecting rod 1 whose upper end is connected to an eccentric position of
It is connected to a crank mechanism 11 consisting of 0. Therefore, when the rotary disk 9 is rotationally driven, the movable cylinder 8 is reciprocated up and down. Note that the rotating disk 9 is rotated at a speed of about 1.00 Or
It is rotated at about pm. Furthermore, a through hole 17 is formed at the lower end of the movable cylinder 8, from which a lower striking rod 16 of a free piston 18 serving as a hammer body fitted into the movable cylinder 8 can protrude, as will be described later. Furthermore, the fixed cylinder tube 5
By providing ventilation holes 12 and 13 on the upper and lower sides of the cylinder, a portion of the cylinder space 7 above the movable cylinder 8 and a portion below the movable cylinder 8 are formed between the cylindrical jacket 4 and the fixed cylinder tube 5. The movable cylinder 8 is communicated through an annular space 14 to reduce the resistance to vertical movement of the movable cylinder 8 and to increase the speed of the vertical reciprocating movement of the movable cylinder 8. The movable cylinder 8 further includes a free piston 18 that can freely move up and down. This free piston 18 functions as a hammer body that strikes the top of the chisel 19, and a striking rod 16 is integrally formed at its lower part. 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. Between the outer circumference of the free piston 18 and the inner circumference of the movable cylinder 7,
Airtightness is ensured by the O-ring 20 fitted on the outer periphery of the free piston 18, and the space between the lower through-hole 17 of the movable cylinder 7 and the striking rod 16 is fitted into the inner periphery of the lower through-hole 17. Airtightness is ensured by the O-ring 21. Therefore, the interior of the movable cylinder 8 is divided into an upper air pressure chamber 22 and an upper air pressure chamber 23 by the free piston 18. These pneumatic chambers 22, 23 are alternately compressed by the inertia delay of the movement of the free piston 18 as the movable cylinder 8 moves up and down, and the elastic expansion of the compressed air accelerates the free piston 18. In this example,
By providing a through hole 8a of an appropriate distance 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 negative pressure and the free piston 18 By preventing the downward acceleration from being inhibited and by communicating the upper air pressure chamber 20 with the outside when the free piston 18 moves upward, the upper air pressure chamber becomes a negative pressure and inhibits the upward acceleration of the free piston. It prevents Further, at the lower ends of the cylindrical outer body 4 and the fixed cylinder tube 5, a lower wall of the cylinder space 7 is formed, and an axial support that supports the upper shaft portion 191 of the chisel 19 in a vertically slidable manner at the center thereof. A boss portion 26 having a hole 25 is connected thereto. Further, on the outermost periphery of the boss portion 26, a cylindrical body portion 241 having an outer diameter approximately equal to the outer diameter of the cylindrical outer mantle 4;
A lower case 24 having a bottom wall portion 242 and a chisel projection hole 243 drilled in the center of the bottom wall portion is connected by screw means 27 . The chisel 19 includes an upper shaft portion 191, an intermediate large diameter portion 192, a lower shaft portion 193, and a lower pointed end 194.
The upper shaft portion 191 is preferably vertically slidably supported in the support hole 25 via the bushing 27a, with the upper shaft portion 191 slightly protruding into the cylinder space 7 of the boss portion 26, and the lower portion The shaft portion 192 projects from the chisel projection hole 243 of the lower case 24 to the outside of the lower part. In the lower case 24, a coil-shaped suspension spring 28 having a relatively large spring coefficient is interposed between the intermediate large diameter portion 192 of the chisel 19 and the lower surface of the boss portion 26. The spring coefficient of this suspension spring 28 is determined by the relationship between the weight of the entire breaker and the force with which the operator presses the breaker body against the object G to be crushed. The amount of protrusion into the cylinder space is set to be appropriate. This suspension spring 28 substantially defines the upper end of the movable range of the chisel 19, and also acts as a vibration damper to prevent vibrations of the chisel 19 from being transmitted to the main body 2 when the breaker is activated. However, this suspension spring 28 can be omitted. This is because when the free piston 18, which is a hammer body, is driven up and down, the free piston 18 repeatedly hits the top of the chisel 19, and the reaction force causes the main body to float relative to the chisel 19. In other words, the chisel 19 This is because the balance is achieved at a position slightly lower than the upper end of the range of motion. In the present invention, the tip of the lower case 24 formed at the bottom of the main body 1 is filled with an elastic material 30 that resists the impactful downward movement of the large diameter portion 192 of the chisel 19. That is, in this example, as shown in FIGS. 1 and 2, the inner wall of the lower case 24 is used, and the following space forming member 31 is installed therein so that the length can be reduced only in the vertical axis direction. A substantially sealed space 29 is formed in which the pressure is changed, and an elastic material 30 is filled inside this space. This space forming member 3
1, the outer periphery is the inner surface 24 of the cylinder body 241 of the lower case 24.
A disk portion 312 that can slide up and down with a slight gap with respect to 1a and has a center hole 311 with an inner diameter smaller than the outer diameter of the large diameter portion 192 of the chisel 19, and a disk portion 312 below the center hole 312. It has a cylindrical portion 314 which extends and whose outer periphery fits into the inner periphery of the chisel protrusion hole 243 of the lower case 24 with a slight gap therebetween. As shown in detail in FIG. 2, the gap between the outer periphery of the disc portion 312 of the space forming member 31 and the inner periphery of the cylindrical body portion 241 is small, and the gap between the outer periphery of the cylindrical portion 314 and the inner periphery of the chisel protruding hole 243 is small. Since the gap with the circumferential surface is small, the ring surrounded by the inner surface of the cylinder body section 241 and the inner surface of the bottom wall section 242 of the lower case 24, as well as the lower surface of the disk section 312 and the outer surface of the cylindrical section 314 of the space forming member 31. A closed, substantially closed space 29 is formed. This substantially sealed space 29 has the characteristic that its volume can change only in the vertical axis direction when the space forming member 31 moves up and down. This substantially sealed space 29 is filled with a doughnut-shaped elastic material 30 made of, for example, heat-resistant rubber. The gap between the outer periphery of the disk portion 312 and the inner periphery of the cylindrical body portion 241 of the lower case, and the gap between the outer periphery of the cylindrical portion 314 and the inner periphery of the chisel protrusion hole 243 are as follows:
It is preferable to keep it to about 0.1 to Q,3n at most. Further, the upper surface of the outer peripheral portion of the disc portion 312 of the space forming member 31 is pressed by a snap ring 33 fitted to the inner wall of the lower case 24. The tip shaft portion 192 of the chisel 19, the shaft portion 191 of which is supported in the support hole 25, passes through the inside of the cylindrical portion 314 of the space forming member 31 and protrudes to the outside of the lower part of the main body, and the intermediate large diameter portion 192 extends into the space. By coming into contact with the upper surface of the disc portion 312 of the forming member 31, the lower end of its vertical movable range is determined. When the space forming member 31 is pushed down by the large diameter portion 192 of the chisel 19 hitting its upper surface, the substantially sealed space 29 is reduced to the extent that the elastic material 30 is elastically compressed, and the pressing force When released, it returns to its original state due to the restoring force of the elastic body. The substantially sealed space 29 can also be configured as shown in FIG. In this example, a cylindrical portion 244 corresponding to the cylindrical portion 314 of the space forming member 31 is attached to the lower case 24.
It is integrally formed upward from the chisel protruding hole 243 in the bottom wall part 242 of the lower case 24, and has an outer diameter slightly smaller than the inner diameter of the cylindrical body part 241 of the lower case 24, and has an inner diameter smaller than the outer diameter of the cylindrical part 244. A slightly larger color 315,
The inner periphery 331 is arranged so as to fit into the outer periphery of the upper end of the cylindrical portion 244 in a vertically slidable manner. A substantially sealed space 29 is formed by the inner surfaces of the cylindrical body portion 241, the bottom wall portion 242 to the cylindrical portion 244 of the lower case 24, and the lower surface of the collar 315, and is filled with the elastic material 30. Furthermore, the substantially sealed space 29 can also be configured as shown in FIG. In this case, the lower case 24 includes a first case 24a having a cylinder body 241 and an outward flange 245 formed at the lower end of the cylinder body 241, and a first case 24a having a diameter slightly larger than the outer diameter of the outward flange 245. a cylindrical portion 246 having an inner diameter; an upper inward flange portion 247 that overlaps the outward flange portion 245 at the upper end of the cylindrical portion and has an inner diameter slightly larger than the outer diameter of the cylindrical body portion 241;
The intermediate large diameter portion 19 of the chisel 19 is continuous from the lower edge of the chisel 19.
2 and a bottom wall portion 249 having a center hole 248 smaller than the outer diameter of the lower shaft portion 193 of the chisel 19 and larger than the outer diameter of the lower shaft portion 193 of the chisel 19. In this case, the outer surface of the cylinder body 241 of the first case 24a and the outward flange 2
45 and the cylindrical portion 24 of the movable second case 24b
A substantially sealed space 29 is formed surrounded by the inner surface of 6 and the upper surface of the bottom wall portion 249, and is filled with an elastic material 30. Next, in the present invention, a separation part 34 is provided between the main body case 2 and the head housing 3, and in this separation part, the upper end 35
a is locked to the upper member 34a so as not to be able to move downward, and the lower end 3
5b is provided with a connecting body 35 having a large diameter portion 35C, and a lower member 35b and an elastic member 36 in a compressed state are interposed in a vertically laminated manner between the large diameter portion 35C of this connecting body 35 and the upper member 34a. do. In the example shown in FIGS. 1 and 5, the head housing 3
The flat lower surface of the upper member 34a of the separating portion is used as the upper member 34a of the separating portion, and the outward facing flange formed at the upper end of the cylindrical outer mantle 4 is the lower member 34b of the separating portion.
It is used as. A predetermined number of screw holes 37 are provided on the lower surface of the housing 3, and a through hole 38 corresponding to the above-mentioned screw hole 37 is provided in the outward facing collar of the cylindrical jacket 4, and a connecting body is passed through the through hole 38 from below. head bolt 35
into the tapped hole 37 and tighten it as far as it will go, and in this state, the head 35c of the bolt 35 and the outward facing collar 35
An annular elastic member 36 in a compressed state is interposed between it and b. In this example, a metal seat 39 is interposed between the Hl 35C of the bolt 35 and the elastic member 36 so that the entire elastic member 36 is in an evenly compressed state. Incidentally, this seat plate 39 is formed with a side wall portion 39a that holds the side portion of the elastic member 36, as shown in FIG. Even when the elastic member 36 is compressed and deformed by force, large local deformation in the lateral direction does not occur, and average deformation occurs in the vertical direction, which is convenient for extending the life of the elastic member 36. In addition, in FIG. 5, the 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, and seals between the housing 3 and the outward flange 34b. , is an O-ring that cushions the upward impact of the outward facing collar 34b. Further, in the example shown in FIG. 6, the cylindrical outer mantle 4 itself is divided into two parts, upper and lower parts, and the upper member and lower member formed in this way are formed with outward flanges 34a and 34b that vertically oppose each other, and these are Similarly, a connecting member 35 and an elastic member 36 are used to connect. That is, corresponding bolt through holes 41 and 42 are opened in both exterior flanges 34a and 34b, and headed bolts 35 as connecting members are inserted into these bolt through holes 41 and 42 from above, and a large diameter bolt is inserted into the lower part of the bolt through holes 41 and 42. With the double lock nut 35C screwed together, a compressed annular elastic member 36 is provided between the double lock nut 35c and the outward facing collar 34b. In this case, the double lock nut 35c and the elastic member 36
A seat plate 39 similar to the example shown in FIG. 5 is interposed between the two. By adopting the structure of the separation part as described above between the main body case or the head housing 3, the lower member 34b
It is always elastically pressed against the upper member 34a. Therefore, under normal conditions, the upper and lower members 34a and 34b are strongly integrated and do not rattle each other. On the other hand, when a strong downward impact force is applied to the lower member 34b, only the lower member can move elastically downward. Next, the operation of the breaker of the present invention will be explained with reference to examples shown in FIGS. 1, 2, and 5. When crushing an object, the tip of the chisel 19 is brought into contact with the object G, and the engine rotation is increased by operating a throttle operating lever provided on the handle. The rotational output of the engine 3 is normally transmitted to the rotating disk 9 of the crank mechanism 11 via a centrifugal clutch (not shown), so only when the engine reaches a predetermined rotational speed from an idling state. , the crank mechanism 11 is driven, and the movable cylinder 8 is caused to reciprocate up and down. 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 trying to push down the breaker 1. Therefore, as shown in FIG. 1, the large diameter portion 192 of the chisel 19 is spaced upward from the upper surface of the space forming member 31. When the movable cylinder 8 moves upward from the bottom dead center, the lower pressure chamber 2
3 is compressed by the inertial lag of the free piston 18. This situation continues until the movable cylinder 8 approaches the top dead center, and the next moment the free piston 18 moves upward at high speed due to the elastic force of the lower pressure chamber 23. and movable cylinder 8
When the piston passes through the top dead center and begins to descend, the upper air pressure chamber 22 is compressed to the maximum by the kinetic energy of the free piston moving upward at high speed and the force pushing down the movable cylinder 8. Then, at the next moment, the free piston 18 is rapidly accelerated downward by the powerful elastic expansion force of the upper air pressure chamber 22, which is compressed to the maximum. And this free piston 1.
8 reaches the maximum speed, the striking rod 16 strikes the top surface of the chisel 19. At this time, the free piston descends at a maximum speed of several tens of meters per second. By repeating such operations, the chisel 19 is repeatedly subjected to 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 object to be crushed via the chisel, so the breaker body 1 does not receive the striking force of the free piston. Chisel open or empty mode As mentioned above, in the striking mode, the chisel 19 receives repeated impacts from the free piston 18, which is a hammer body.
Eventually, the impact energy causes cracks to occur in the object G to be crushed. Once a crack occurs in the object to be crushed, the balance between the downward impact force applied to the chisel 19 and the reaction force that the chisel receives from the object to be crushed is lost. At this time, the device is in an extended state. In addition, when the chisel strongly bites into a viscous object, the chisel is actively thrust to vibrate, thereby releasing 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 this chisel extraction or protrusion mode. The chisel 19 has an intermediate large diameter portion 192 that is connected to the space forming member 3.
It is in contact with the upper surface of the disk portion 312 of No. 1. In this state, when the rotation of the engine is increased and the striking rod 16 of the free piston 15 hits the head of the chisel 19, the space forming member 31 is pushed down by the impact, and the elastic material 3o is compressed and deformed accordingly. Then, the space forming member 31 is pushed up by the next instantaneous repulsive force of the elastic member 3o. Thus, in this mode, the chisel 19 is vibrated to the extent that the elastic material 30 can be deformed. Furthermore, since this vibration is generated by the high-speed hammer force of the free piston 15 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 15 is alleviated by deforming the elastic member 30, but since the kinetic energy of the free piston 15 is extremely large, , a strong downward impact force still acts on the main body case 2. However, in the present invention, as shown in detail in FIG.
Since the mantle body 4 is connected to the head housing 3 while being pressed by the elastic body 36, even if a strong downward impact is applied to the main body case 2 as described above, the mantle body 4 will be able to resist this elastic body 36. Since the member 36 can be moved slightly downward while being further compressed, direct transmission of impact force to the head housing 3 is avoided. Furthermore, since the elastic member 36 is interposed between the head 35c of the connecting body 35 for connecting the mantle 4 and the housing 3 and the outward facing collar of the mantle 4, the above-mentioned impact is directly applied to the connecting member. It doesn't even work.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of one embodiment of the breaker of the present invention, Fig.
The figure is an enlarged cross-sectional view of the lower main part when the chisel is at the lower end of movement, FIG. 3 is an enlarged cross-sectional view of another embodiment of the lower main part, and FIG.
The figure is an enlarged cross-sectional view of still another example of the lower main part, FIG. 5 is an enlarged cross-sectional view of an example of the separating part provided between the main body case or the head housing, and FIG. 6 is an enlarged cross-sectional view of another example of the separating part. It is an enlarged sectional view. 1... Flaker, 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, 3
5... Connecting body, 35c... Large diameter portion, 36... Elastic member.

Claims (1)

[Claims] (1) A cylindrical main body case is connected to the lower part of the head housing that houses the power source, a hammer body that is reciprocated by the drive source is provided inside the main body case, and the chisel supported at the lower part of the main body case is In a breaker configured to apply a continuous impact force, an elastic body that receives the impact force from the chisel is interposed in the lower part of the main body case, and a separation part is provided between the main body case and the head housing. In the separation part, a connecting body is provided whose upper end is fixed to the upper member so as not to move downwardly and has a large diameter part at the lower end, and between the large diameter part of the connecting body and the upper member, the lower member and the compression A breaker characterized in that elastic members are interposed in a stacked manner on top and bottom.