Tilt device for hydraulic breaker and hydraulic breaker

Abstract

To provide a tilt device for hydraulic breakers and a hydraulic breaker that can suppress an increase in the burden on workers without requiring the addition of dedicated piping. [Solution] As shown in (a), the upper bracket 20 is provided with a connecting passage 27 that connects the left and right tilt cylinders 21L and 21R, and the connecting shaft 30 is provided with a communication control valve 31 that controls the connection state of the connecting passage 27. In the normal state when no pilot pressure is being received, the communication control valve 31 connects the connecting passage 27, and as shown in (b), grease is exchanged between the left and right grease chambers 26L and 26R as the tilt cylinder 21 extends and retracts. However, as shown in (c), when pilot pressure is supplied, the communication control valve 31 blocks the connecting passage 27 and grease is no longer exchanged between the left and right grease chambers 26L and 26R, so the cylinder rod 25 becomes immobile.

Description

Technical Field

[0004] , , , ,

[0005]

[0001] The present invention relates to a tilt device for a hydraulic breaker and a hydraulic breaker provided with the device.

Background Art

[0002] A hydraulic breaker is a hydraulic impact device that generates an impact force by reciprocatingly displacing a striking piston enclosed inside a main body by hydraulic control and striking a chisel. Therefore, during operation, for example, by pressing the chisel against a crushed material such as rock or concrete, an impact force is applied to the crushed material to crush it.

[0003] Generally, such a hydraulic breaker is attached to the tip of an arm provided on a host machine such as a hydraulic excavator by an arm pin and a link pin. As a result, the hydraulic breaker can swing back and forth by the expansion and contraction of a cylinder provided on the host machine. Due to such a configuration, the adjustment of the striking position in the left - right direction is also performed by the turning operation of the host machine or, in the case of a machine body capable of swinging the boom, by the boom swing. The adjustment of the striking position in the front - rear direction and the up - down direction is performed by the swinging operation of the boom and arm of the host machine.

[0004] By the way, a hydraulic breaker has a shape in which the chisel protrudes from the lower part of a main body wider than itself, and if excavation continues in a certain direction, the main body will touch the ground. Therefore, in order to perform excavation beyond the protruding length of the rod, the wall surface of the excavation part must be inclined. However, the excavation for inclining the side wall surface becomes over - excavation, and the volume to be excavated increases compared to the case where the wall surface is vertical. [[ID=2,8]]

[0005] To suppress such over-excavation, it is necessary to avoid the main body touching the ground by tilting the main machine itself or by using a hydraulic breaker equipped with a tilt function. In other words, in order to perform efficient excavation, it is necessary to ensure degrees of freedom around the axis in the longitudinal direction (rocking in the longitudinal direction) in addition to degrees of freedom around the axis in the longitudinal direction (rocking in the longitudinal direction) when the rod is in a vertical position.

[0006] The tilt of the main engine is achieved by raising one of the traveling devices (either left or right) onto a platform. However, this method increases the number of work steps required when adjusting the tilt angle or changing the excavation position, and can also lead to instability of the main engine during excavation or excessive load on the traveling device. Therefore, in order to suppress over-excavation, it is desirable that the hydraulic breaker be tiltable. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Official Gazette No. 3030092 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Patent Document 1 discloses a tilt device for a hydraulic breaker that includes an extendable / retractable device such as a hydraulic cylinder or screw and is capable of swinging (tilting) around a connecting pin, and a tilt device for a hydraulic breaker that maintains the tilt angle by manually adjusting the tilt angle and inserting and fixing the pin into a lock plate.

[0009] In a structure where tilting is performed by hydraulic cylinders, the base unit requires dedicated hydraulic piping and control valve structures for the tilting hydraulic cylinders. Such additional structures increase the manufacturing cost of the base unit, and extending the hydraulic piping to the end of the arm increases the risk of damage to the piping from flying debris, etc.

[0010] Furthermore, structures that tilt the hydraulic breaker using screws, or structures that maintain the tilt angle with a pin after manually tilting the hydraulic breaker, require the pin to be replaced each time the tilt angle is changed, which increases the burden on the worker.

[0011] Therefore, the present invention aims to provide a tilt device for a hydraulic breaker and a hydraulic breaker that can suppress an increase in the burden on the operator without requiring the addition of dedicated piping for tilt operation. [Means for solving the problem]

[0012] The present invention relates to a tilt device for a hydraulic breaker, which is provided on a bracket for mounting a hydraulic breaker to a hydraulic excavator. The device comprises an upper bracket having a mounting portion for the hydraulic excavator, a lower bracket to which the body of the hydraulic breaker is fixed, a connecting shaft that connects the lower bracket to the upper bracket so that it can swing from side to side as viewed from the operator of the hydraulic excavator, a tilt cylinder whose rod extends and retracts in accordance with the swinging of the lower bracket, and a communication control valve that switches between a state in which a passage connected to the working fluid chamber of the tilt cylinder is in a state in which it [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a hydraulic breaker bracket and hydraulic breaker that can suppress an increase in the burden on the worker without adding dedicated piping for tilt operation. [Brief explanation of the drawing]

[0014] [Figure 1] (a) A front view and (b) A side view showing the structure of a hydraulic breaker according to the first embodiment of the present invention. [Figure 2] This is an enlarged view of section I in Figure 1. [Figure 3] This is a fluid circuit diagram showing the structure of a tilt device according to the first embodiment of the present invention. [Figure 4] It is a diagram showing the structure of a connecting shaft according to the first embodiment of the present invention. [Figure 5] It is a diagram showing the structure of an upper bracket according to the first embodiment of the present invention. [Figure 6] It is a diagram simply showing a working method using a hydraulic breaker according to the first embodiment of the present invention. [Figure 7] It is a diagram for explaining the volume change of a fluid circuit according to the first embodiment of the present invention. [Figure 8] It is a diagram showing the structure according to the first modification of the first embodiment of the present invention. [Figure 9] It is a diagram showing the structure of a connecting shaft according to the second modification of the first embodiment of the present invention. [Figure 10] (a) The second embodiment of the present invention, (b) It is a diagram showing the structure of a hydraulic breaker according to a modification of the second embodiment. [Figure 11] It is a diagram showing the structure of a double-rod cylinder and a communication control valve according to the second embodiment of the present invention. [Figure 12] (a) A diagram showing the whole of a hydraulic breaker according to the third embodiment of the present invention, (b) A side view of an upper bracket, (c) It is a diagram showing the structure of a tilt device. [Figure 13] (a) A diagram showing the whole of a modification of a hydraulic breaker according to the third embodiment of the present invention, (b) A side view of an upper bracket, (c) It is a diagram showing the structure of a tilt device.

Mode for Carrying Out the Invention

[0015] Hereinafter, a tilt device for a hydraulic breaker according to the present invention and a hydraulic breaker provided with the device will be described with appropriate reference to the drawings. Note that the drawings are schematic. Therefore, it should be noted that the relationship between the thickness and the planar dimensions, the ratio, etc. are different from the actual ones, and there are also parts where the dimensional relationships and ratios are different between the drawings. Furthermore, the embodiments described below illustrate devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention is not limited to the following embodiments in terms of the material, shape, structure, arrangement, etc., of the components.

[0016] In the following explanation, when it is necessary to specify a direction, unless otherwise specified, the forward, backward, left, right, up, and down directions as seen from the operator of the motherboard, with a tilt angle of 0 degrees (the angle at which the axis of the chisel is aligned with the vertical direction of the motherboard), will be used as the reference. Therefore, basically, the left side of the diagram represents the right direction, and the left side represents the right direction. Note that in the side view of Figure 1, and in Figures 4 and 9, the right side of the diagram will be considered the front, and the left side will be considered the rear.

[0017] <First Embodiment> [Structure of hydraulic breaker] The structure of the hydraulic breaker will be explained with reference to Figure 1. As shown in Figure 1(a), the hydraulic breaker 1 is a hydraulic impact device that is attached to the work equipment of a base machine such as a hydraulic excavator to crush rocks and the like, and comprises a main body 2 equipped with an impact mechanism, a main body bracket 3, a lower bracket 10, an upper bracket 20, and a connecting shaft 30 that connects the lower bracket 10 and the upper bracket 20.

[0018] A chisel 4 for striking the material to be crushed is fitted to the lower part of the main body 2 so as to protrude downward, and the main body bracket 3 is fixed so as to cover the entire circumference of the main body 2. The lower bracket 10 is fixed to the upper part of the main body bracket 3, and the lower bracket 10 is connected to the upper bracket 20 at the top via a connecting shaft 30. Because the lower bracket 10 and the upper bracket 20 are connected by the connecting shaft 30, the main body bracket 3 and the lower bracket 10 become a swinging part that swings from side to side as viewed from the operator of the base machine such as a hydraulic excavator.

[0019] As will be explained in detail later, the upper bracket 20 is equipped with one tilt cylinder 21, which is a single-rod cylinder, on each side of the connecting shaft 30. The lower bracket 10 is equipped with a tilt block 11 that corresponds to each of the left and right tilt cylinders 21. In the following explanation, when the tilt cylinders 21 are described separately as left and right, they will be referred to as the right tilt cylinder 21R and the left tilt cylinder 21L. Similarly, when the tilt blocks 11 are described separately as left and right, they will be referred to as the right tilt block 11R and the left tilt block 11L. Hereafter, when it is necessary to distinguish between left and right, the designations L and R will be added to the designations accordingly.

[0020] As shown in Figure 1(b), the upper bracket 20 has a pair of left and right protruding parts formed on its upper surface to serve as attachment points to the mother machine. A link pin receiver 22 is formed on the front side into which a link pin (not shown) for attaching to the mother machine's link is inserted, and an arm pin receiver 23 is formed on the rear side into which an arm pin (not shown) for connecting to the mother machine's arm is inserted. When the hydraulic breaker 1 is attached to the mother machine, the arm pin becomes the axis that causes the hydraulic breaker 1 to swing back and forth from the operator's perspective, and the link pin becomes one of the axes of the link that generates the swinging force in the back and forth direction.

[0021] [Structure of the tilt mechanism] The structure of the tilt device provided on the lower bracket 10, upper bracket 20, and connecting shaft 30 will be described with reference to Figures 2 to 5. Note that the connecting passage 27 shown in Figure 2 is depicted schematically and does not necessarily coincide with the cutting line AA shown in Figure 1(b), and the accumulator 28 is omitted from the description in Figure 5. Furthermore, while the tilt device according to this embodiment uses grease as the working fluid, the type of working fluid in the implementation of the present invention is not limited to grease. For example, the working oil used for the operation of the hydraulic breaker 1 may be used to fill the tilt device.

[0022] As shown in Figure 2, the tube 24 of the tilt cylinder 21 is fixed to the upper bracket 20. The tube 24 houses the cylinder rod 25 so that it can move vertically, forming a grease chamber 26 at the top of its interior. Inside the upper bracket 20, a connecting passage 27 is formed to connect the left and right grease chambers 26L and 26R. The connecting portion of the connecting passage 27 is formed inside a connecting shaft 30, which will be described in detail later. The grease chambers 26 and the connecting passage 27 are filled with grease, which is the working fluid. The connecting passage 27 can be replaced by piping a hose or the like outside the upper bracket 20, but if such a structure is used, it is desirable to place a protective member for the hose.

[0023] When the lower bracket 10 and the upper bracket 20 are connected by the connecting shaft 30, the tip of the left tilt cylinder 21L abuts against the left tilt block 11L. Similarly, the tip of the right tilt cylinder 21R abuts against the left tilt block 11R. The protruding length of the cylinder rods 25 can be adjusted by adjusting the amount of grease filled in the grease chamber 26 and the connecting passage 27. The tilt block 11 is a cylindrical member with a flat cutout at the portion that is fixed to the lower bracket 10, and its upper circumferential surface contacts the tip of the cylinder rod 25. A sliding plate may be provided at the tip of the cylinder rod 25.

[0024] As shown in Figure 3(a), the fluid circuit constituting the tilt device is equipped with a connecting passage 27 connecting the left and right tilt cylinders 21L and 21R, an accumulator 28, a relief valve 29, and a grease nipple GN on the upper bracket 20, and a communication control valve 31 on the connecting shaft 30 that controls the connection state of the connecting passage 27. The communication control valve 31 is connected to the control valve CB, which is connected to the hydraulic pump Pp and the hydraulic oil tank T. The control valve CB does not supply pilot pressure to the communication control valve 31 in its natural state when it is not receiving pilot pressure. During this time, as shown in Figure 3(b), the communication control valve 31 is in a communication position that connects the two connecting passages 27, and grease is exchanged between the left and right grease chambers 26L and 26R as the tilt cylinder 21 extends and retracts.

[0025] However, as shown in Figure 3(c), while the striking mechanism inside the main body 2 is operating, pilot pressure is supplied to the control valve CB, which moves the communication control valve 31 to a position where pilot pressure is generated. As a result, the communication control valve 31 switches to a shut-off position that blocks the connection passage 27, and grease exchange between the left and right grease chambers 26L and 26R ceases. Consequently, the cylinder rod 25 becomes immobile.

[0026] The accumulator 28 has a structure in which a piston separates a gas chamber from a fluid chamber, and a compression spring is housed inside the chamber. The accumulator 28, which is connected to the hydraulic circuit, stores excess grease or discharges insufficient grease when the total volume of the left and right grease chambers 26L and 26R changes as the left and right tilt cylinders 21L and 21R extend and contract in conjunction with the tilt operation described later, and also absorbs changes in the volume of grease due to temperature changes, thereby preventing abnormal pressure from being generated in the fluid circuit, and also discharges grease when the grease in the passage becomes insufficient, thereby maintaining a state in which the cylinder rod 25 is always in contact with the tilt block 11. The relief valve 29 is set to open when a pressure higher than the pressure acting on the hydraulic breaker 1 due to its own weight is applied when the set pressure and tilt angle of the accumulator 28 are at their maximum. In particular, it is a safety valve that discharges grease when excessive pressure occurs during lubrication. The grease nipple GN is used when replenishing grease using the grease gun GG. If the amount of grease replenished exceeds the storage capacity of the accumulator 28, the excess amount of grease is discharged to the outside through the relief valve 29.

[0027] As shown in Figure 4, the connecting shaft 30 is supported at its center by the lower bracket 10 and at both ends by the upper bracket 20. As mentioned above, a communication control valve 31 is provided inside the connecting shaft 30. Specifically, the connecting shaft 30 has non-through spool holes 32L and 32R formed from both end faces toward the axial center, and the communication control valve 31 is formed by sealing a spring 33 and a spool 34 inside these holes. Therefore, the communication control valve 31 is composed of a left communication control valve 31L that controls the communication state of the passage leading to the left tilt cylinder 21L, and a right communication control valve 31R that controls the communication state of the passage leading to the right tilt cylinder 21R.

[0028] In order to supply pilot hydraulic pressure from the striking mechanism of the main body 2 to the spool 34, a pilot hydraulic passage 35 is formed so as to extend from the upper bracket 20 through the left spool hole 32L to the right spool hole 32R. The pilot hydraulic passage 35 is connected to a hydraulic port (not shown) and is a passage that guides pilot pressure p to the hydraulic fluid chambers formed on the outer ends of the left spool 34L and the right spool 34R. In other words, the left and right communication control valves 31L and 31R share a single hydraulic port for operation.

[0029] In addition to the pilot hydraulic passage 35, a grease passage 36 is formed connecting the left spool hole 32L and the right spool hole 32R. Furthermore, a portion of the connecting passage 27 leading to the left grease chamber 26L is formed in the left spool hole 3L, and a portion of the connecting passage 27 leading to the right grease chamber is formed in the right spool hole 32R. In other words, as shown in Figure 5, the left and right grease chambers 26L and 26R are connected via the connecting passage 27, the spool 34, and the grease passage 36. Furthermore, as shown in the figure, a grease nipple GN for replenishing grease is provided at one end of the connecting shaft 30, and a plug Pl is fixed to close an opening formed by machining to create a passage inside the upper bracket 20.

[0030] A switching groove 37 is formed in the central part of the spool 34. As explained using Figure 3, when the spool 34 is not receiving pilot pressure, the switching groove 37 is in a position that connects the grease passage 36 and the connecting passage 27, and when the spool 34 is receiving pilot pressure, it is in a position that blocks the grease passage 36 and the connecting passage 27.

[0031] Furthermore, the spool 34 is open to the atmosphere through an opening 38 formed in the axial center of the connecting shaft 30, located at the ends of the left and right spool holes 32L and 32R, so that the compartment on the spring 33 side does not become a gas spring. However, even if the opening 38 is not formed, it is not necessary to form the opening 38 if the hydraulic force acting on the spool is sufficiently high relative to the air pressure. Furthermore, the relief valve 29 described above is connected to the connecting passage 27. The relief valve 29 is located on the support portion of the lower bracket 10 and discharges grease to the lubrication portion when the pressure exceeds a preset level.

[0032] [Operation of the tilt device] The operation of the tilt device will be explained primarily by referring to Figures 6 and 7, and by referring to Figures 1 to 5 where necessary. In Figure 6, the boom BO and arm AR of the hydraulic excavator BH are shown with a simplified shape and represented by a dashed line. As shown in Figure 7, the hydraulic breaker 1 is used by connecting the upper bracket 20 to the tip of the arm AR of the main body, the hydraulic excavator BH. Link pins and arm pins are used to connect the arm AR and the hydraulic breaker 1, and hydraulic piping for supplying hydraulic fluid from the hydraulic excavator BH to operate the main body 2 is also connected at the same time. Note that the hydraulic piping connecting the hydraulic excavator BH and the hydraulic breaker is solely for the operation of the main body 2.

[0033] When performing trench excavation using the hydraulic breaker 1, tilt the hydraulic breaker 1 so that the tip of the chisel 4 faces the wall. For example, to tilt the chisel 4 so that it faces left from the operator's perspective, the tip of the chisel 4 is grounded with the main body 2 stopped, and the tilt is performed by the rotation of the hydraulic excavator BH and the movement of the boom BO and arm AR. At this time, as shown in Figures 2 and 3(b), the communication control valve 31 is in the communication position, so the cylinder rod 25 of the left tilt cylinder 21L is pressed and shortened, and grease flows out from the left grease chamber 26L. The flowed-out grease moves to the right grease chamber 26R, so the cylinder rod 25 of the right tilt cylinder 21 automatically extends.

[0034] Here, the contact point between the tilt block 11 and the rod 25 is located below the axis of the connecting shaft 30, which is the rotation center of the tilt operation. Therefore, the total volume of the left and right grease chambers 26L and 26R changes during the tilt operation. Specifically, as shown in Figure 7(a), the tip of the rod 25 abuts the left and right tilt blocks 11L and 11R at a distance g below the axis of the connecting shaft 30, which is the center of rotation during the tilt operation. Therefore, as shown in Figure 7(b), when the tilt angle is changed to θ°, both the left and right tilt blocks 11L and 11R rise by a vertical distance I. This is because the top plate of the lower bracket 10 to which the tilt blocks 11L and 11R are fixed is at a distance X from the axis of the connecting shaft 30, which is the center of rotation. Specifically, the vertical distance I can be expressed by Equation 1. I=X-Xcosθ=X(1-cosθ)...Equation 1

[0035] In addition, since the left and right tilt blocks 11L and 11R according to the present embodiment are not formed in a perfect semi-circular shape, the distance from the top plate of the lower bracket 10, which is a fixed part, to the position where the rod 25 abuts also changes as the tilt operation is performed. If the distance at a tilt angle of 0° is H, the changed distance can be expressed by Equation 2. h = lcosθ + r < H ··· Equation 2 l... Length of the non-semicircular part r... Radius of the semi-circular part In the present embodiment, since the height of the tilt block is shorter than the distance from the turning center to the fixed part of the tilt block (H < X), when a tilt operation of θ° is performed, the change amount of the vertical distance has the relationship of Equation 3. (H - h) < I ··· Equation 3

[0036] Therefore, the change amount of the total volume of the fluid circuit during the tilt operation can be expressed as in Equation 4. △V(θ°) = 2A{(H - h) - I} ··· Equation 4 A... Cross-sectional area of the grease chamber Here, from Equation 3 and Equation 4, △V < 0. That is, the total volume of the fluid circuit decreases.

[0037] Therefore, during the tilt operation, grease that attempts to move more than the capacity of the left grease chamber 26L or the right grease chamber 26R is temporarily stored in the accumulator 28 and discharged when the hydraulic breaker 1 returns to a vertical posture. Thus, in the present embodiment, the accumulator 28 keeps the pressure in the fluid circuit including the left and right grease chambers 26L and 26R substantially constant.

[0038] After tilting the lower bracket 10 to the desired angle, when the striking mechanism of the main body 2 is activated, striking force is transmitted to the chisel 4, and at the same time, pilot pressure p is supplied to the communication control valve 31, causing the spool of the communication control valve 31 to move to a position that blocks the grease passage 36 and the connecting passage 27, making it impossible for grease to move between the left and right grease chambers 26L and 26R. As a result, the tilt cylinder 21 cannot extend or retract, and the set tilt angle is maintained. Furthermore, at this time, the accumulator 28 and the relief valve 29 are also isolated from the connecting passage 27 and the left and right grease chambers 26L and 26R, so even if they receive a reaction force from the main body bracket 3 and the chisel 4, the grease in the left and right grease chambers 26L and 26R will not return to the accumulator 28 or be discharged to the outside from the relief valve 29.

[0039] To return the tilt angle to 0 degrees, with the operation of the main unit 2 stopped, the breaker is raised by operating the boom BO and arm AR so that there is no pressure applied to the chisel 4. At this time, the mass of the hydraulic breaker 1 itself acts to change the tilt angle to 0 degrees, and grease is exchanged between the left and right tilt cylinders 21L and 21R, causing the tilt angle to naturally return to 0 degrees.

[0040] [Modified version of the first embodiment] A first modification of the first embodiment will be described with reference to Figure 8. The first modification involves moving the connecting shaft 30 to the side of the lower bracket 10, compared to the configuration shown in Figure 2, and forming the contact portion of the tilt block 11 with the rod 25 into a larger diameter arc. With this structure, the tilt block 11 moves in a circular trajectory centered on the connecting shaft 30 during tilting, making it possible to reduce the total volume change of the fluid circuit associated with the tilting operation to zero. Specifically, the left and right tilt blocks 11 move along the same circumference with respect to the axis of the connecting shaft 30, which results in "X=0" in equation 1 as explained in the first embodiment.

[0041] Furthermore, in order to ensure zero volume change, the contact portion of the tilt block 11 with the rod 25 is formed in an arc shape when viewed from the front-to-back direction. The arc shape is such that the line connecting the centers of the arcs coincides with the center of the connecting shaft 30, which is the pivot axis during tilting. In other words, the tilt block 11 has a shape in which a portion of a member with a semicircular cross-section has been removed when viewed from the axial direction of the connecting shaft 30.

[0042] However, in this structure, the connecting shaft 30 is located closer to the lower bracket 10 than in the structure shown in the first embodiment, resulting in a dead space between the upper bracket 20 and the connecting shaft 30, and also leading to an increase in the size of the tilt block 11. In other words, the embodiment is a structure that allows for a change in the total volume of the fluid circuit in order to avoid increasing the size of the hydraulic breaker 1, and solves the above problem with the accumulator 28 and the relief valve 29. The modified version allows for an increase in the size of the hydraulic breaker 1 and is configured so that no change in the total volume of the fluid circuit occurs.

[0043] In particular, for small hydraulic breakers, while there is a strong demand for downsizing the entire device, the total volume change of the fluid circuit in the tilt mechanism tends to be low, making the structure shown in the embodiment suitable. Conversely, as the size of the hydraulic breaker increases, the outer diameter of the rod 25 also increases, and the total volume change of the fluid circuit also increases. That is, it becomes necessary to install a large accumulator 28 that can withstand strong pressure, which increases the cost of the device. Therefore, for hydraulic breakers that can tolerate some enlargement, especially large ones, there is an advantage in adopting the structure shown in the modified example, which can be addressed by changing the arrangement position of the connecting shaft 30. Additionally, the increased length of the bracket extends the distance from the mounting point of the hydraulic breaker 1 to the tip of the chisel, making it possible to excavate deeper trenches.

[0044] A second modified example of the first embodiment will be described with reference to Figure 9. The only differences between the first embodiment and this modified example are the support portion of the connecting shaft 30 in the lower bracket 10 and the upper bracket 20, and the structure of the communication control valve 31 housed within the connecting shaft 30; therefore, a description of other parts will be omitted. In the description of this modified example, the reference numerals will be lower bracket 40, upper bracket 50, and connecting shaft 60, and the same reference numerals with the last digit as those used in the first embodiment will be used for each part.

[0045] The modified tilt device for the hydraulic breaker has a structure in which the lower bracket 40 supports both ends of the connecting shaft 60, and the upper bracket 50 supports the central part. Therefore, the structure of the communication control valve 31 and the structure of the connecting passage 27 have been modified from the first embodiment to be suitable for the arrangement of the bracket.

[0046] Specifically, a communication control valve 61 equipped with only one spool 64 is housed inside the connecting shaft 60, and inside the upper bracket 50 and the connecting shaft 60, a pilot hydraulic passage 65 is formed from the front of the hydraulic breaker 1, a part 56R of the connecting passage 27 leading to the right grease chamber 26R, a grease passage 56A leading to the accumulator 28, and a part 56L of the connecting passage 27 leading to the left grease chamber 26L.

[0047] In the first embodiment shown in Figures 4 and 5, a grease passage 36 connecting the left and right spools 34L and 34R was formed inside the connecting shaft 30. However, in this modified example, the connecting passage 27 is connected by a switching groove 67. Therefore, no passage equivalent to the grease passage 36 is formed inside the connecting shaft 60 and the upper bracket 50.

[0048] [Effects of the First Embodiment and its Modified Forms] By installing the communication control valves 31 and 61 inside the connecting shafts 30 and 60, there is no need to add any structures to the outside of the hydraulic breaker 1, thus reducing manufacturing costs. Furthermore, by routing only the pilot pressure supply hose, which is branched from the operating piping of the striking mechanism, between the lower brackets 10 and 40 and the upper brackets 20 and 50, there is no need to place other piping externally, thus efficiently protecting the piping.

[0049] Furthermore, a relief valve 29 is provided in the connecting passage 27 so that grease is discharged to the connecting shafts 30 and 60 and their support parts, making it possible to utilize the discharged grease for lubrication. In addition, it is possible to use the same grease for lubrication and the lubricating grease for the tilt device operation. In other words, by simply lubricating through a specific lubrication port as part of routine maintenance, both the lubrication parts and the tilt device can be maintained, thereby reducing the maintenance burden on the worker.

[0050] <Second Embodiment> [structure] A second embodiment of the present invention will be described with reference to Figures 10 and 11. In the second embodiment of the present invention, unlike the first embodiment, the tilt lock unit 100 is located outside the hydraulic breaker 1.

[0051] In the first embodiment, the tilt cylinder 21 was fixed to the upper bracket 20. However, as shown in Figure 10(a), in the tilt device for a hydraulic breaker according to the second embodiment, a tilt lock unit 100, which integrates the tilt cylinder 101 and the communication control valve 105, is mounted on the outside of the upper bracket 80 and the lower bracket 70. Specifically, the tilt lock unit 100 is supported so as to be swingable around a support axis parallel to the axial direction of the connecting shaft 90 on an upper clevis 81, which is U-shaped in top view and fixed to the left side of the upper bracket 80, and one end of the rod 102 of the tilt cylinder 101 is supported so as to be swingable around a support axis parallel to the axial direction of the connecting shaft 90 on a lower clevis 71, which is fixed to the left side of the lower bracket 70.

[0052] Furthermore, as shown in Figure 10(b), the lower clevis 71 can also be fixed to the main body bracket 3. In other words, the end of the rod 102 only needs to be supported by the pivoting portion including the lower bracket 70 and the main body bracket 3.

[0053] As shown in Figure 11, the tilt lock unit 100 is composed of a tilt cylinder 101, which is a double rod cylinder, and a communication control valve 105. The tilt cylinder 101 has a front grease chamber 104F and a rear grease chamber 104R formed as working fluid chambers, and the front and rear grease chambers 104F and 104R are connected to the communication control valve 105 via a connecting passage 106 formed in the cylinder tube 103. The communication control valve 105 has substantially the same configuration as a modified example of the first embodiment, and connects the front and rear grease chambers 104F and 104R only when the striking mechanism of the main body 2 is not operating.

[0054] Differences from the first embodiment include the fact that the tilt lock unit 100 is located outside the upper bracket 80, and therefore a hose (not shown) for guiding pressurized oil to operate the main body 2 to the pilot passage 107, and a hydraulic port 107A for attaching the hose are provided. Additionally, because the tilt lock unit 100 is inclined, a grease nipple GN is located near the accumulator 28 to facilitate lubrication. The passage leading to the grease nipple GN is connected to the passage leading from the accumulator 28 to the communication control valve 105.

[0055] [Operation] The operation of the tilt device for a hydraulic breaker according to the second embodiment is substantially the same as the operation of the tilt device for a hydraulic breaker according to the first embodiment. When the mother unit is operated and tilting is performed, grease is exchanged between the front grease chamber 104F and the rear grease chamber 104R, changing the length to which the rod 102 protrudes from the front and rear of the cylinder tube 103. Then, when the main unit 2 is operated, the communication control valve 105 closes the connection passage 106, fixing the position of the rod 102 and simultaneously fixing the tilt angle.

[0056] [Effects of the second embodiment] One of the advantages of the second embodiment is that, since the tilt cylinder 101 is a double rod cylinder, the amount of grease flowing out and in due to the movement of the rod 102 matches in the front and rear grease chambers 104F and 104R. Therefore, regardless of the position of the tilt lock unit 100, the amount of movement of the accumulator 28 during tilt operation is less than in the first embodiment. Therefore, the accumulator 28 can be easily miniaturized and simplified, which helps to suppress increases in manufacturing costs.

[0057] Furthermore, by positioning the unitized tilt lock unit 100 outside the hydraulic breaker 1, access to the tilt lock unit 100 is greatly improved, reducing the effort required for maintenance.

[0058] <Third Embodiment> [structure] A third embodiment and modified examples of the present invention will be described with reference to Figures 12 and 13. As shown in Figure 12(a), the third embodiment includes a tilt lock unit 100, in which both ends of the tilt cylinder 101 are fixed to the upper bracket 130, and the body of the tilt lock unit 100 is supported by the lower bracket 120 so as to be able to swing around an axis parallel to the connecting shaft 90. Due to this structure, as shown in Figure 12(b), the connecting shaft 90 is not a shape that penetrates from the front to the rear of the upper bracket 130, but rather consists of two short shafts that connect the upper bracket 130 and the lower bracket 120 at the front and rear, respectively.

[0059] As shown in detail in Figure 12(c), both ends of the tilt cylinder 101 are fixed to the upper bracket 130. Therefore, the tilt lock unit 100 is connected to the lower bracket 120 by a tilt shaft 110 separate from the connecting shaft 90. Since the lower bracket 120 pivots around the connecting shaft 90, its relative vertical position relative to the fixed tilt shaft 110 changes. For this reason, a vertically elongated slit 121 is formed in the connection portion of the lower bracket 120 with the tilt shaft 110.

[0060] Alternatively, as shown in Figure 13(a), a portion of the lower bracket 140 may be extended to near the top plate of the upper bracket 150, and the tilt axis 110 may be held at the top of the connecting axis 90. In this structure, as shown in Figure 13(b), the tilt axis 110 passes through both the upper bracket 150 and the lower bracket 140. Therefore, as shown in Figure 13(c), a horizontally elongated arc-shaped slit 151 is formed in the upper bracket 150, and a vertically elongated slit 141 is formed in the support portion of the tilt axis 110 in the lower bracket 140. The slits 141 and 151 are formed to allow the tilt axis 110, which moves along an arc-shaped trajectory, to move smoothly.

[0061] [Operation / effect] The tilt lock unit 100 is positioned in the normal position where the rods of the tilt cylinder 101 are the same length on both sides, and the tilt axis 110 is positioned directly below or directly above the connecting axis 90. When tilted, the tilt lock unit 100 moves in the tilt direction. At this time, the formation of slits 121, 141, and 151 allows relative movement between the tilt axis 110 and the lower brackets 120, 140 and the upper brackets 130, 150.

[0062] [Effects of the Third Embodiment and its Modified Forms] The third embodiment and its modifications differ from the second embodiment in that the tilt lock unit 100 is not located outside the hydraulic breaker, making it easier to protect the tilt lock unit 100 and the piping for pilot pressure supply.

[0063] <Effects common to each embodiment> As explained above, the hydraulic breaker tilt device according to the present invention has a fluid circuit for the tilt device that is independent of the main unit, and there is no need to add dedicated piping for the tilt operation, thus suppressing increases in manufacturing costs and maintenance costs.

[0064] The communication control valve 31 is supplied with pilot pressure from the passage for operating the striking mechanism of the main body 2, so that the tilt angle is automatically maintained during striking and the tilt angle can be adjusted when not striking. This configuration allows the tilt angle to be set and maintained solely by operating the main unit, eliminating the need for the operator to directly operate the hydraulic breaker and to move away from the main unit's control panel. As a result, it significantly reduces the burden on the operator compared to conventional technology.

[0065] In the tilt cylinders 21 and 101 according to the present invention, the amount of grease moving between the grease chambers 26 is approximately equal regardless of whether the tilt operation is performed to the left or right. In particular, when a single double-rod cylinder is used as the tilt cylinder, the difference in grease capacity due to the rod volume between the front chamber and the rear chamber that occurs when a single-rod cylinder is used becomes zero, and the amount of rod movement is also equal, so the amount of grease flowing out of one grease chamber matches the amount of grease flowing into the other grease chamber. Therefore, it is possible to miniaturize the accumulator, and it is possible to achieve miniaturization and cost reduction of the device. However, even when using a single-rod cylinder, if there is at least one cylinder on each side, the difference in the amount of rod movement due to oscillation will be small, thus avoiding the need to enlarge the accumulator.

[0066] Since the connecting passage 27 that connects the grease chambers of the tilt cylinder 21 is formed inside the upper bracket, there is no need to install piping outside the hydraulic breaker, and the risk of damage to the piping can be reduced. [Explanation of Symbols]

[0067] 1...Hydraulic breaker, 2...Main body, 3...Main body bracket, 4...Chisel, 10, 40, 70, 120...Lower bracket, 20, 50, 80, 130, 150...Upper bracket, 21...Tilt cylinder, 22...Link pin receiver, 23...Arm pin receiver, 24...Tube, 25, 102...Cylinder rod, 26...Grease chamber, 27...Connecting passage, 28...Accumulator, 29...Relief valve, 30, 60, 90...Connecting shaft, 31, 61...Communication control valve, 32...Spool hole, 33, 63...Spring 34, 64…Spool, 35, 65…Pilot hydraulic passage, 36, 56…Grease passage, 37, 67…Switching groove, 38…Opening, 71…Lower clevis, 81…Upper clevis, 100…Tilt lock unit, 101…Tilt cylinder, 102…Rod, 103…Cylinder tube, 104…Grease chamber, 105…Communication control valve, 106…Connecting passage, 107…Pilot passage, 121, 141, 151…Slit, GN…Grease nipple, BH…Hydraulic excavator, BO…Boom, AR…Arm

Claims

1. A tilt device for a hydraulic breaker, which is provided on a bracket for mounting a hydraulic breaker to a work machine of an industrial machine, An upper bracket having a portion for attachment to the aforementioned work machine, The lower bracket to which the body of the hydraulic breaker is fixed, A connecting shaft is provided to connect the lower bracket to the upper bracket so that it can swing from side to side as viewed from the operator of the work machine, A tilt cylinder in which the rod extends and retracts in accordance with the swinging of the lower bracket, A connecting passage that connects the working fluid chambers of the tilt cylinder, A tilt device for a hydraulic breaker, characterized by comprising a communication control valve that switches the aforementioned connection passage between a connected state and a disconnected state.

2. The tilt device for a hydraulic breaker according to claim 1, characterized in that the connection passage is formed inside the member constituting the upper bracket.

3. The tilt cylinder is characterized by comprising at least two cylinders, one on each side of the connecting shaft on either the upper bracket or the lower bracket, with the tip of each rod abutting against the other of the upper bracket or the lower bracket, and as the lower bracket swings, the one on the left or right side is pressed against the lower bracket and shortened, causing it to discharge working fluid from its working fluid chamber, and the working fluid discharged into the working fluid chamber of the other one on the left or right side, causing the rod to extend, as described in claim 1.

4. The tilt cylinder is a double-rod cylinder, one end of the rod is pivotably supported on one of the upper bracket or the lower bracket and the main body bracket housing the body of the hydraulic breaker, the cylinder tube is pivotably supported on the other of the upper bracket or the other of the pivoting part, and one of the rods is pressed and shortened as the lower bracket swings, causing working fluid to be discharged from one working fluid chamber, and the discharged working fluid flows into the other working fluid chamber, as described in claim 1, for a hydraulic breaker tilt device.

5. The tilt cylinder is a double-rod cylinder, with both ends of the rod pivotably supported on either the upper bracket or the lower bracket, and the cylinder tube pivotably supported on the other of the upper bracket or the lower bracket, characterized in that the cylinder tube is pressed and moved as the lower bracket pivots, causing working fluid to be discharged from one working fluid chamber and the discharged working fluid to flow into the other working fluid chamber, as described in claim 1.

6. The hydraulic breaker tilt device according to any one of claims 1 to 4, characterized in that the communication control valve is supplied with pilot pressure from the working fluid that operates the hydraulic breaker, shuts off the connection passage while the hydraulic breaker is operating, and opens the connection passage while the operation of the hydraulic breaker is stopped.

7. The tilt device for a hydraulic breaker according to claim 1 or 2, characterized in that the communication control valve is provided inside the connecting shaft.

8. The tilt device for a hydraulic breaker according to any one of claims 1 to 4, characterized in that an accumulator is connected to the aforementioned connection passage.

9. Furthermore, the system is equipped with a safety valve that discharges the working fluid to the outside of the connecting passage when a pressure exceeding a set value is applied to the connecting passage. The tilt device for a hydraulic breaker according to any one of claims 1 to 4, characterized in that the safety valve is provided in the connecting passage at a position between the connecting shaft and the support portion of the connecting shaft from which the working fluid is discharged.

10. A hydraulic breaker characterized by comprising a tilt device for a hydraulic breaker as described in any one of claims 1 to 4.

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