JP4889448B2 - Hydraulic breaker - Google Patents

Description

  The present invention relates to a hydraulic breaker, and more particularly to a structure that reduces noise and vibration that are generated when a hydraulic breaker is actually struck, or when an struck object is crushed.

  As shown in FIG. 7, a hydraulic breaker used by being attached to a construction vehicle such as a hydraulic power shovel is configured to support a breaker body 100 with a bracket 20 and attach the bracket 20 to an arm of the construction vehicle. The breaker body 100 is configured to have a front head 160 on the tip end side in the axial direction of the cylinder 4 in which the piston 5 is slidably fitted so as to move forward and backward, and reciprocally moves in the axial direction in the front head 160. A possible chisel 130 is inserted.

  When the crushing operation is performed with this type of hydraulic breaker, the chisel 130 is pressed against the object 70 to be crushed, and the chisel 130 is hit with the piston 5 built in the upper side of the breaker body 100. As a result, a compressive stress wave traveling in the direction of the object to be crushed 70 is generated in the chisel 130 by the impact of the piston 5, and the chisel 3 moves forward in the direction of the object to be crushed 70. When this stress wave reaches the object 70 to be crushed, a part of the stress wave is used for crushing, and the rest is reflected by the lower end of the chisel 130 and returns toward the piston 5. The reflected wave at this time is a complicated one in which tension and compression are mixed, but if roughly classified, when the degree of crushing is small, the chisel 130 is moved backward in the direction of the piston 5 by the stress wave of compression, and the degree of crushing is reduced. When it is larger, the chisel 130 is advanced in the direction of the object 70 by the tensile stress wave. At this time, noise and vibration are generated. Therefore, in this type of breaker, attempts have been made to reduce noise and vibration, and various techniques have been disclosed (for example, see Patent Documents 1 and 2).

For example, in the technique described in Patent Document 1, the bush supporting the chisel is configured by a cushioning material such as nylon or resin, or a combination of a cushioning material and a metal, thereby reducing noise.
For example, in the technique described in Patent Document 2, a proposal has been made to reduce noise dissipation by blocking noise generated from a chisel with a resin and a metal ring.
Japanese Utility Model Publication No. 06-50774 Registered Utility Model No. 3019178

Here, the mechanism (mechanism) in which noise and vibration occur in this type of hydraulic breaker will be considered.
As shown in FIG. 7, when the chisel 130 moves backward in the direction of the piston 5, it collides with the front head 160 at the rear end peripheral portion 130 a and collides with the piston 5 at the rear end surface portion 130 b. At this time, since the chisel 130, the piston 5 and the front head 160 are generally made of alloy steel, noise and vibration are generated by such a collision. On the other hand, when the object to be crushed 70 is crushed, the chisel 130 advances in the direction of the object to be crushed 70, and the groove end portion 130c collides with the rod pin 170 that serves as a stopper that restricts the movement of the chisel 130. Therefore, noise and vibration are still generated.

  In particular, in this type of hydraulic breaker, the piston 5 moves up and down along the axial direction by the hydraulic pressure inside the breaker body 100. At this time, the breaker body 100 is opposite to the traveling direction of the piston 5. The hydraulic reaction force is received. Further, since the force due to the collision between the chisel 130, the front head 160, and the piston 5 is also applied, the breaker body 100 actually performs a striking motion while slightly moving up and down. And when this up-and-down movement is large, since the front-end | tip of the chisel 130 will leave | separate from the to-be-crushed object 70, it will become difficult to transmit the impact energy by the piston 5 to the to-be-crushed object 70 effectively. That is, the striking energy by the piston 5 is not used for crushing, but is reflected in the direction of the piston 5 at the tip of the chisel 130, thereby resulting in the striking energy being wasted in noise, vibration or heat generation.

  That is, considering that the reason for the generation of noise and vibration is the mechanism (mechanism) described above, the technique described in Patent Document 1 uses a cushioning material for the bushing itself that supports the chisel. It does not prevent the front head from colliding with the inside of the head, and also contributes little to the prevention of blurring when hitting with a chisel and increasing the rockability of the chisel. Therefore, the technique described in Patent Document 1 is still insufficient for reducing noise, and there remains room for study.

  Further, in the technique described in Patent Document 2, although proposals have been made to reduce the diffusion of noise generated from the chisel, this is a countermeasure for blocking sound generated from the chisel. In other words, in view of noise and vibration mechanism, noise is not cut or reduced directly, so there is still room for examination. In addition, the technology described in Patent Document 2 requires a large device around the chisel, leading to an increase in cost and a reduction in the chisel effective length, which also increases the chisel cost and effective length ratio. .

  Accordingly, the present invention has been made paying attention to such a problem, and is a hydraulic pressure that can reduce noise and vibration generated at the time of actual hitting or at the time of actual hitting and when the hit object is crushed. The purpose is to provide a breaker.

In order to solve the above-mentioned problems, a first invention of the present invention is a breaker body in which a front head is provided on the front end side in the axial direction of a cylinder in which a piston is slidably fitted so as to move forward and backward, A chisel that is removably inserted in the axial direction, a rod pin for restricting the reciprocating movement of the chisel , and a striking chamber in the front head so as to oppose the peripheral edge of the rear end of the chisel. The chisel has a large-diameter portion projecting in a radial direction at a portion located outside the front head, and the chisel has a large-diameter portion and a front portion. between the head, the chisel abuts the elastic member with respect to the large diameter portion and a front head in a predetermined position moved proximally in the axial direction is mounted Rutotomoni, after the chisel The peripheral portion has a gap in a direction opposite to the flange portion with respect to the flange portion formed in the hitting chamber at the predetermined position, so that the inner surface of the chisel and the front head are slid relative to each other. A portion other than the portion is in a non-contact state .

According to the first aspect of the present invention, between the large diameter portion and the front head of the chisel, is mounted the elastic body, when in contact with each other, chisel and the front head interior surface mutually, sliding of one another so can be a non-contact state at a portion other than, it is possible to avoid direct collision between the chisel and the front head. Therefore, it is possible to reduce noise and vibration that are generated when the hydraulic breaker is actually hit, or when the hit object and the hit object are crushed.

Furthermore, even if the breaker body vibrates slightly, if the amplitude is smaller than the amount of deformation in the axial direction of the elastic body, the state where the chisel is pressed against the object to be crushed can be maintained (improvement of rock formation). Therefore, the crushing efficiency is improved and the noise and vibration of the hydraulic breaker when hitting the object to be crushed can be reduced.
The second invention of the present invention is the hydraulic circuit breaker according to the first invention , wherein the breaker body has an elastic body mounting member facing the front end surface of the front head with a predetermined distance therebetween. are connected to the elastic body mounting member is in contact with the elastic body is further mounted to the large-diameter portion and the chisel at a predetermined position moved distally in the axial direction, the chisel When the large-diameter portion is in contact with the elastic body of the elastic body mounting member, there is a gap in the opposite direction between the chisel and the rod pin, so that portions other than the sliding portions of each other Is characterized by a non-contact state .

According to the second invention, an elastic body is also arranged on the tip side of the large-diameter portion of the chisel, and when the tip-side elastic body and the large-diameter portion of the chisel come into contact with each other, the chisel and the rod pin each other, in the portion other than the sliding portion of each other since there is provided such that the non-contact state, can be avoided even a direct collision between the chisel and the rod pin. Therefore, it is possible to further reduce noise and vibration generated when the hydraulic breaker is actually hit, or when the hit object and the hit object are crushed.

A third invention of the present invention is the hydraulic circuit breaker according to the first or second invention , wherein the elastic body contacting the front head includes the first elastic member and the first elastic member. A second elastic member having a lower elastic modulus than that of the one elastic member, and the first elastic member is disposed on the side in contact with the large-diameter portion, and the second elastic member The member is characterized in that it is arranged on the side opposite to the side in contact with the large diameter portion.

According to the third invention, since the first elastic member has a higher elastic modulus than the second elastic member, the second elastic member is protected from abrasion due to earth and sand, and the contact area of the second elastic member The surface pressure can be reduced and the durability can be improved. Therefore, the diameter of the large diameter portion of the chisel can be reduced, and material costs and processing costs can be suppressed.
The fourth invention of the present invention is a hydraulic circuit breaker according to the third invention , wherein the second elastic member is formed in an annular shape, and an inner peripheral surface thereof is the first circuit breaker. It is characterized in that it is brought into contact with the chisel from the radial direction by elastic deformation when a pressing force is applied by the contact of the large-diameter portion with the elastic member.

According to the fourth invention, the second elastic member is elastically deformed such that when the chisel is pressed against the object to be crushed, the second elastic member is sandwiched between the front head and the first elastic member and radially contracted. Therefore, when the chisel is pressed against the hit object, the support force of the chisel can be increased and the chisel blurring at the time of hitting can be reduced.

  As described above, according to the present invention, it is possible to provide a hydraulic breaker that can reduce noise and vibration that occur during actual hitting or during actual hitting and when the hit object is crushed.

Embodiments of the present invention will be described below with reference to the drawings as appropriate.
FIG. 1 is a diagram illustrating a work vehicle equipped with a hydraulic breaker according to the first embodiment.
As shown in the figure, the work vehicle 50 includes a traveling carriage 52, a turntable 54 that can turn on the running carriage 52, and an arm 56 that is supported by the turntable 54 so as to be raised and lowered. Yes. The work vehicle 50 is provided with a bracket 20 at the tip of the arm 56, and a hydraulic breaker 30 is mounted on the bracket 20.

Next, the hydraulic breaker will be described in detail.
FIG. 2 is a diagram for explaining the hydraulic breaker according to the first embodiment. FIG. 2 is an enlarged view of a portion A in FIG. 1 and shows the front head of the hydraulic breaker in a cross section including its axis. ing.
The hydraulic breaker 30 includes a breaker body 1 that is supported by the bracket 20. The breaker body 1 has a cylinder 4 at the center in the axial direction, and a front head 6 is connected to the front end side of the cylinder 4 and a back head 40 is connected to the rear end side. A piston 5 is slidably fitted into the cylinder 4 to form a known hydraulic striking mechanism. By supplying pressure oil to the cylinder 4 from a hydraulic supply source (not shown) via a switching valve, the piston 5 can be moved forward and backward.

  In the front head 6, the chisel 3 is inserted from the front end side, and a striking chamber 11 is formed between the rear end side of the chisel 3 and the piston 5. A front cap 12 is coaxially provided on the front end side of the inner peripheral surface of the front head 6. The chisel 3 is held coaxially with the piston 5 by the front cap 12 and can be reciprocated by a predetermined distance in the axial direction by striking the piston 5. The chisel 3 is restricted from moving in the axial direction by the rod pin 7 and its reciprocating range is limited.

  Here, the chisel 3 has a large-diameter portion 2 projecting in the radial direction at a position outside the front head 6. The large-diameter portion 2 has an annular shape on the front head 6 side, and the tip end side is formed with a conical surface whose diameter decreases as the cross section approaches the tip end side. An elastic body 8 is attached to the front head 6 at a position facing the large diameter portion 2 of the chisel 3 on the proximal end side in the axial direction. The elastic body 8 is formed of an annular rubber, and its inner diameter is slightly larger than the outer diameter on the base end side of the chisel 3. The elastic body 8 has an inner diameter that is reduced by elastic deformation when a pressing force is applied by the contact of the large-diameter portion 2 so that the elastic body 8 contacts the chisel 3 in the radial direction. It has become. Further, the outer diameter is substantially the same as the outer diameter of the front end portion of the front head 6, and chamfering is performed around the surface facing the front end side.

  The elastic body 8 and the large-diameter portion 2 of the chisel 3 are a predetermined position where the chisel 3 is retracted, and a contact surface 2 a facing the front head 6 side of the large-diameter portion 2 is an end surface 8 a of the elastic body 8. It comes to contact with. At this time, as the predetermined position, the position of the contact surface 2a in the axial direction and the position of the end surface 8a of the elastic body 8 are relative to the flange portion 11a formed in the striking chamber 11 in the front head 6. The rear end peripheral portion 3a of the chisel 3 is set at a position where it does not collide. That is, at the position where the chisel 3 is retracted, there is a gap in the facing direction (symbol D in the figure) between the flange portion 11a of the striking chamber 11 and the rear edge peripheral portion 3a of the chisel 3. The inner surfaces of the chisel 3 and the front head 6 are in a non-contact state at portions other than the sliding portions.

Next, functions and effects of the hydraulic breaker 30 will be described.
As described above, according to the hydraulic breaker 30, the chisel 3 is formed with the large diameter portion 2, and the elastic body 8 is mounted between the large diameter portion 2 and the front head 6. Therefore, it is possible to reduce noise and vibration by avoiding a direct collision between the base end side of the chisel 3 and the front end side of the front head 6.

  That is, according to the hydraulic breaker 30, when the elastic body 8, the large diameter portion 2 of the chisel 3 and the front head 6 are in contact with each other, the inner surfaces of the chisel 3 and the front head 6 are mutually connected. The portion other than the sliding portion is in a non-contact state, and does not collide with the flange portion 11a formed in the striking chamber 11 in the front head 6 even if the chisel 3 moves backward in the direction of the piston 5 after striking. Therefore, a direct collision between the chisel 3 and the front head 6 can be avoided even inside the front head 6. Therefore, noise and vibration at the time of hitting the object 70 can be further reduced. Further, since a direct collision between the chisel and the front head can be avoided even inside the front head 6, consumption of the chisel 3 and the front head 6 can be reduced.

  Further, according to the hydraulic breaker 30, the elastic body 8 is elastically deformed in the axial direction by pressing the chisel 3 against the object 70 to be crushed. Therefore, even if the breaker body 1 vibrates slightly in this state, its amplitude If it is smaller than the deformation amount of the elastic body 8, it is possible to reduce the blur of the chisel 3 at the time of hitting and to keep the chisel 3 pressed against the object 70 (improvement of rock formation). Therefore, the crushing efficiency is improved, and the noise and vibration of the hydraulic breaker 30 when hitting the object to be crushed 70 can be further reduced.

  Further, according to the hydraulic breaker 30, the elastic body 8 is disposed on the proximal end side of the large diameter portion 2 of the chisel 3, and the inner diameter of the elastic body 8 is reduced by the contact of the large diameter portion 2. Since it is elastically deformed and abuts against the chisel 3 from the radial direction, when the chisel 3 is pressed against the object to be crushed 70, the support force of the chisel 3 is increased and the chisel is less shaken when hitting can do. Therefore, even if the breaker body 1 vibrates slightly, the noise and vibration of the hydraulic breaker 30 when hitting the object 70 can be further reduced.

Next, another embodiment of the present invention will be described with reference to the drawings as appropriate. In each embodiment described below, points different from the first embodiment will be described, and illustration and description of the same configuration will be omitted.
FIG. 3 is a view for explaining a hydraulic breaker according to the second embodiment. FIG. 3 shows a front head of the hydraulic breaker in a cross section including its axis.

In the second embodiment, the elastic body 8 is higher in elasticity (relatively hard) than the first embodiment, and the elastic modulus is higher than that of the first elastic member 9. And the second (relatively soft) second elastic member 10 is different.
The elastic body 8 is configured such that the first elastic member 9 is disposed on the side in contact with the large-diameter portion 2 in the axial direction, and the second elastic member 10 is disposed on the side in contact with the large-diameter portion 2. Are arranged on the opposite side, that is, on the side of the front head 6 in the axial direction. Further, the second elastic member 10 has an elastic modulus whose inner diameter is reduced by elastic deformation when a pressing force is applied by the contact of the large diameter portion 2 to the first elastic member 9. It is made of a material with Other configurations are the same as those in the first embodiment.

  According to the hydraulic breaker of the second embodiment, when the chisel 3 is pressed against the object to be crushed 70, the elastic body 8 has the second elastic member 10 which is the front head 6 and the first elastic member. It is elastically deformed by being sandwiched between the members 9 and contracting in the radial direction. Thereby, when the chisel 3 is pressed against the hit object 70 as in the first embodiment, the support force of the chisel 3 can be increased.

Furthermore, even if the breaker body 1 vibrates slightly in this state, the chisel 3 is crushed by the elastic deformation in the axial direction of the elastic body 8 if the amplitude is smaller than the deformation amount of the second elastic member 10. The state pressed against 70 can be maintained (improvement of rock formation). Therefore, the crushing efficiency is improved, and the noise and vibration of the hydraulic breaker 30 when hitting the object to be crushed 70 can be further reduced.
Further, since the first elastic member 9 has a higher elastic modulus than the second elastic member 10, the second elastic member 10 is protected from abrasion due to earth and sand, and the contact area of the second elastic member 10 is ensured. Thus, the surface pressure can be reduced and the durability can be improved. Therefore, the diameter of the large diameter portion 2 of the chisel 3 can be reduced, and material costs and processing costs can be suppressed.

Next, the hydraulic breaker according to the third embodiment will be described in detail.
FIG. 4 is a view for explaining a hydraulic breaker according to the third embodiment. FIG. 4A shows a front head of the hydraulic breaker in a cross section including its axis. FIG. 5B is a view seen from the direction F of FIG.
In the third embodiment, an elastic body 18 is arranged on the front head 6 side which is the upper side of the large-diameter portion 2 of the chisel 3 and an elastic body is provided on the side opposite to the front head 6 which is the lower side. 19 is disposed, and a cylindrical sound insulating material 15 is disposed between the upper elastic body 18 and the lower elastic body 19.

  Specifically, the upper elastic body 18 has an annular flange 18 a on the base end side, and this flange 18 a is provided on the inner peripheral surface of the front head 6, and the front end side of the front cap 12. It is fixed by being fitted into an annular fixing groove 6m formed at the position. The elastic body 18 may be configured to be mounted between the large-diameter portion 2 of the chisel 3 and the front head 6 as in the above embodiment without providing the fixing groove 6m.

  Further, the hydraulic breaker includes a cylindrical base 13 that surrounds the breaker body 1. The base 13 is a peripheral wall member surrounding the periphery including the front head 6 of the breaker body 1, and a buffer member 22 such as rubber is interposed between the base 13 and the front head 6 of the breaker body 1. A portion where the buffer member 22 is not interposed is a gap S.

  The base 13 is fixed to the bracket 20 by welding, and an annular mounting plate 13t facing the direction perpendicular to the axial direction of the breaker body 1 is provided at the lower end portion of the base 13. As shown in FIG. 5B, the mounting plate 13t has a through-hole 13p that can be inserted through the shaft portion of the chisel 3 at the center, and a plurality of tap holes are formed around the through-hole 13p. The annular cap 14 is attached by a plurality of bolts 16 so that the movement of the breaker body 1 in the axial direction can be restricted. An annular fixing groove 14m is formed on the inner peripheral surface of the cap 14. On the other hand, the elastic body 19 has an annular flange 19a on the distal end side thereof. 19 a is held by being fitted into the fixing groove 14 m of the cap 14. The sound insulating material 15 is interposed between the elastic body 19 held by the cap 14 and the end surface of the front head 6, and when the cap 14 is attached by a plurality of bolts 16, the sound insulating material 15 is simultaneously axially moved. The position is fixed. In addition, the sound insulating material 15 may be fixed by a pin or the like instead of fixing by a bolt.

  Here, the elastic body 19 on the front end side and the large diameter portion 2 of the chisel 3 are set so that the groove end portion 3c of the chisel 3 and the rod pin 7 do not contact each other when they contact each other. Collisions are prevented. In other words, when the elastic body 19 on the front end side and the large diameter portion 2 of the chisel 3 are in contact with each other, the chisel 3 and the rod pin 7 are in a non-contact state in portions other than the sliding portions. It is provided to become. The cap 14 corresponds to the elastic body mounting member.

  According to the hydraulic breaker of the third embodiment, in addition to the operations and effects of the first embodiment, the elastic body 19 is also provided on the lower side of the large diameter portion 2. When abutting against the large diameter portion 2 of the chisel 3, there is a gap between the chisel 3 and the rod pin 7 in the facing direction (reference numeral E in the same figure), so that other than the sliding portions of each other The portion is provided so as to be in a non-contact state. Therefore, it is possible to further reduce the noise and vibration of the hydraulic breaker when the object 70 is struck and when the object 70 is crushed.

  Furthermore, according to the hydraulic breaker of the third embodiment, the base 13 is further provided on the outside of the breaker body 1 via the buffer member 22, and the gap S is provided between the base 13 and the front head 6. Therefore, this configuration functions as a silencer. Therefore, it is possible to further reduce the noise and vibration of the hydraulic breaker when the object 70 is hit and when the object is crushed.

Next, the hydraulic breaker according to the fourth embodiment will be described in detail.
FIG. 5 is a view for explaining a hydraulic breaker according to the fourth embodiment. FIG. 5 shows a front head of the hydraulic breaker in a cross section including its axis.
As shown in the figure, in the fourth embodiment, the chisel 3 has a large-diameter portion 2 at a portion located in the front head 6. And the annular elastic body 17 with a small elastic modulus is arrange | positioned at the front end side and base end side in the axial direction of this large diameter part 2, respectively.

  Specifically, an elastic body accommodating portion 6 a having an inner diameter larger than that of the large diameter portion 2 is formed in the front head 6 at a position corresponding to a range in which the large diameter portion 2 of the chisel 3 reciprocates. An annular fixing groove 6m is formed in each of the upper and lower ends of the elastic body accommodating portion 6a. On the other hand, of the two elastic bodies 17, the upper elastic body 17U has an annular flange 17t on the proximal end side, and the lower elastic body 17L has an annular flange 17t on the distal end side. is doing. Then, each flange portion 17t is fixed by being fitted into the upper and lower fixing grooves 6m of the elastic body accommodating portion 6a. Here, in this example, a relatively wide gap in the facing direction is ensured between the outer peripheral surface 2g of the large diameter portion 2 of the chisel 3 and the inner peripheral surface 6k of the elastic body accommodating portion 6a. . In this example, the two elastic bodies 17 are made of materials and shapes having the same elastic modulus, but they may have different shapes and elastic moduli.

  According to the hydraulic breaker of the fourth embodiment, the two elastic bodies 17 are respectively disposed above and below the large diameter portion 2, so that the chisel 3 collides with the front head 6 even if the chisel 3 moves forward or backward after hitting. This can be prevented. And since the large diameter part 2 is provided in the front head 6 and this large diameter part 2 is supported so as to be sandwiched between the upper and lower elastic bodies 17, the rod pin 7 can be dispensed with. Further, since these two elastic bodies 17 are mounted in the front head 6, it is possible to attenuate the collision sound and further reduce the noise compared to those mounted outside. In addition, since the upper and lower elastic bodies of the large diameter portion 2 are built in the front head 6, they are protected from the influence of earth and sand and outside air, so that they are more weatherproof than the external mounting type as in the first embodiment. Is excellent in terms of.

Next, the hydraulic breaker according to the fifth embodiment will be described in detail.
FIG. 6 is a view for explaining a hydraulic breaker according to the fifth embodiment. FIG. 6 shows a front head of the hydraulic breaker in a cross section including its axis.
In the fifth embodiment, the size of the gap between the outer peripheral surface 2g of the large-diameter portion 2 of the chisel 3 and the inner peripheral surface 6k of the elastic body accommodating portion 6a is managed with respect to the fourth embodiment. The difference is that the inner peripheral surface 6 k is configured to function as a sliding surface in the axial direction of the chisel 3.

  According to the hydraulic breaker of the fifth embodiment, since the contact portion between the two elastic bodies 17 and the inner peripheral surface 6k of the front head 6 contributes to the support of the chisel 3, the blur of the chisel 3 can be further reduced. Can do. Then, by applying a pressing force by the large-diameter portion 2 to the elastic body 17U on the base end side to cause elastic deformation, the chisel 3 is kept pressed against the object 70 even if the breaker body 1 vibrates ( Therefore, noise and vibration generated during actual hitting or during actual hitting and when the hit object is crushed can be suitably reduced.

As described above, according to the hydraulic breaker according to the present invention, it is possible to reduce noise and vibration generated during actual hitting, or during actual hitting and when the hit object is crushed.
Note that the hydraulic breaker according to the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in each of the above embodiments, the elastic body that contacts the large-diameter portion 2 of the chisel 3 has been described as being formed in an annular shape. However, the present invention is not limited to this, and the elastic body may have various shapes. Can do. Moreover, it is good also as a structure which provides two or more numbers apart in the circumferential direction, for example. However, considering the ease of mounting and maintenance, it is preferable to mount an elastic body integrally formed in an annular shape. In addition, as in the example of the second embodiment, the elastic body may be configured by combining two or more elastic members.

  In each of the above embodiments, the large-diameter portion 2 of the chisel 3 and the elastic body that contacts the chisel 3 are provided outside the front head (first embodiment), and are provided inside the front head (fourth embodiment). As illustrated in the fifth embodiment, etc., the large-diameter portion 2 of the chisel 3 and the elastic body in contact with the chisel 3 can be installed both inside and outside the front head. For example, considering the ease of mounting and maintenance, it is preferable to equip outside the front head. Moreover, it is preferable to equip it in the front head in consideration of the weather resistance that attenuates and further reduces the impact sound and protects against the influence of earth and sand or the outside air.

  Further, for example, in contrast to the fourth and fifth embodiments, a peripheral wall member such as a base 13 surrounding the front head 6 as in the example of the third embodiment is provided. A buffer member 22 may be interposed between the base member 13 and a gap S may be provided in a portion where the buffer member 22 is not interposed. In addition, when adding the structure which plays such a silencer function, since the apparatus around a chisel becomes large and leads to a cost increase, the adoption of equipment is selected in consideration of cost, use conditions, etc. suitably.

It is a figure explaining the work vehicle carrying the hydraulic breaker concerning a first embodiment. It is a figure explaining the hydraulic breaker which concerns on 1st embodiment, The figure expands the A section in FIG. 1, and has shown the front head part of the hydraulic breaker in the longitudinal cross-section. The right half shows the state where the chisel has advanced, and the left half shows the state where the chisel has moved backward. It is a figure explaining the hydraulic breaker which concerns on 2nd embodiment. It is a figure explaining the hydraulic breaker which concerns on 3rd embodiment. It is a figure explaining the hydraulic breaker which concerns on 4th embodiment. It is a figure explaining the hydraulic breaker which concerns on 5th embodiment. It is a figure explaining an example of the conventional hydraulic breaker.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Breaker main body 2 Large diameter part 2a Contact surface 3 Chisel 3a Rear edge peripheral part 3b Rear end surface part 3c Groove end part 4 Cylinder 5 Piston 6 Front head 7 Rod pin 8a End surface 8 Elastic body 9 1st elastic member 10 2nd elasticity Member 11 striking chamber 11a flange 12 front cap 13 base 14 cap 15 sound insulating material 16 bolt 17 elastic body 18 elastic body 19 elastic body 20 bracket 22 buffer member 30 hydraulic breaker 40 back head 50 working vehicle 52 traveling carriage 54 swivel base 56 arm 70 Objects to be crushed

Claims (4)

A breaker body in which a front head is provided on the tip end side in the axial direction of a cylinder in which a piston is slidably fitted back and forth, a chisel that is removably inserted in the front head in the axial direction, and the chisel A hydraulic pin breaker including a rod pin for restricting reciprocal movement and a flange formed in a striking chamber in the front head so as to be opposed to a rear end peripheral portion of the chisel ,
The chisel has a large-diameter portion projecting in a radial direction at a portion located outside the front head, and the chisel is disposed in the axial direction between the large-diameter portion of the chisel and the front head. abutting the elastic body with respect to the large diameter portion and a front head is mounted at a predetermined position moved proximally in Rutotomoni,
The rear end peripheral edge portion of the chisel has a gap in a direction opposite to the flange portion with respect to the flange portion formed in the hitting chamber at the predetermined position. Is a non-contact state at a portion other than the sliding portion of each other . The breaker body is connected to an elastic body mounting member that is opposed to the front end surface of the front head at a predetermined distance, and the chisel is located on the distal end side in the axial direction of the elastic body mounting member. An elastic body that comes into contact with the large-diameter portion at a predetermined position moved is further mounted , and when the large-diameter portion of the chisel comes into contact with the elastic body of the elastic body mounting member, the chisel and the chisel 2. The hydraulic breaker according to claim 1, wherein a gap is provided between the rod pins in a direction opposite to each other so that the portions other than the sliding portions are not in contact with each other . The elastic body that contacts the front head includes a first elastic member and a second elastic member having a lower elastic modulus than the first elastic member, and the first elastic member elastic member is disposed in side abutting on the large diameter portion, said second elastic member, according to claim 1, characterized in that disposed on the side opposite to the side abutting on the large diameter portion Or the hydraulic breaker of 2 . The second elastic member is formed in an annular shape, and its inner peripheral surface is elastically deformed when a pressing force is applied by the contact of the large-diameter portion with the first elastic member. The hydraulic breaker according to claim 3, wherein the hydraulic breaker is in contact with the chisel from a radial direction .

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