Blade water supply device

Abstract

A water supply device for a blade is provided which can continuously supply a sufficient amount of cooling water from a water supply tank to a blade and can reliably and smoothly supply water during cutting work. The cooling fan has a pressurized case 4 that surrounds the outside of the outer peripheral surface of the blade shaft 2 and forms a pressure chamber 45, an impeller 8 is fixed to the outer peripheral surface of the blade shaft 2 within the pressure chamber 45, and a radially inner region within the pressure chamber 45 is configured to communicate with an upstream supply passage (inlet chamber 44, water supply tank, etc.) that supplies cooling water to the pressure chamber 45, and a radially outer region within the pressure chamber 45 is configured to communicate with a downstream supply passage (water supply chamber 46, central water passage 21, etc.) that supplies cooling water to the blades 6.

Description

[Technical field]

[0001] The present invention relates to a device for supplying cooling water to blades used for cutting or milling asphalt pavement, concrete, stone, metal materials, etc., and in particular to a water supply device for blades that can be applied to working machines that use blades that rotate at high speeds, such as concrete cutters (devices that cut or mill the asphalt pavement surfaces and concrete surfaces of roads) used in road repair and removal work, etc. [Background technology]

[0002] Concrete cutters used in road repair and removal work, etc., include those equipped with a blade water supply device that can supply cooling water to both the left and right sides of the blade (known as wet concrete cutters, etc.). Wet concrete cutters can cool the blade disk and tip during cutting work and also prevent dust from scattering.

[0003] Conventional wet concrete cutters employ a water supply method in which multiple nozzles are disposed near the blade (for example, inside the blade cover), these nozzles are connected to a water supply tank by hoses, and cooling water is sprayed toward both the left and right sides of the blade.Also employed is a method in which a water passage is provided inside the blade shaft, one end of the blade shaft is connected to a water supply tank, and cooling water is sent from that end through the water passage inside the blade shaft to the opposite end, and is supplied to both sides of the blade from a position radially inward of the blade and the blade fixing means (for example, Patent Document 1).

[0004] In conventional wet concrete cutters, a method is often used in which cooling water is sent from a water tank to a position near the blade by gravity (gravity water supply method). In this case, the water tank needs to be installed at a higher position than the nozzle and the water channel inside the blade shaft. When using a concrete cutter that does not adopt a gravity water supply method, or when there are circumstances that make it impossible to supply water by gravity, a method is used in which a water supply pump is prepared and water is supplied at the same time as cutting work. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6120197 [Patent Document 2] Patent Publication No. 2022-062420 [Patent Document 3] Japanese Utility Model Application Publication No. 55-004114 [Patent Document 4] Japanese Utility Model Application Publication No. 55-004113 Summary of the Invention [Problem to be solved by the invention]

[0006] When cutting work is performed using a wet concrete cutter that employs a gravity water supply system, there is a problem that the supply pressure and flow rate decrease as the water level in the water supply tank drops. For example, when the amount of cooling water remaining in the water supply tank becomes small, the pressure and flow rate required to spray cooling water from the nozzle, or the pressure and flow rate required to send cooling water through the water passage inside the blade shaft and supply it to the blade from a position radially inside the blade and the blade fixing means, cannot be obtained, and a situation may occur in which the cooling water does not reach the blade. In this case, the blade cannot be properly cooled, which causes the blade to deteriorate and shorten its life, and the scattering of dust cannot be suppressed.

[0007] Therefore, in order to maintain the pressure and flow rate necessary to properly supply cooling water, it is necessary to replenish water into the water tank in parallel with cutting operations, or by interrupting cutting operations.

[0008] In addition, when using a water supply pump to perform cutting work and water supply work at the same time, a separate power source (battery, commercial power source, engine generator, etc.) must be secured to operate the water supply pump, which is very troublesome and incurs additional costs. Furthermore, the concrete cutter and the water supply pump must be operated simultaneously, which is difficult for one worker to perform alone.

[0009] The present invention seeks to solve such problems in the prior art, and aims to provide a water supply device for a blade that can continuously supply a sufficient amount of cooling water from a water supply tank to the blade, thereby enabling water supply operations to be carried out reliably and smoothly during cutting operations. [Means for solving the problem]

[0010] The water supply device for a blade according to the present invention can be applied to a device that rotates a blade fixed to a blade shaft to cut or mill an object, and is characterized in that it has a pressurized case that surrounds the outside of the outer surface of the blade shaft and forms a circular pressure chamber between the outer surface of the blade shaft, and an impeller is fixed to the outer surface of the blade shaft within the pressure chamber or formed integrally with the blade shaft, and the radially inner region of the pressure chamber is configured to communicate with an upstream supply passage that supplies cooling water to the pressure chamber, and the radially outer region of the pressure chamber is configured to communicate with a downstream supply passage that supplies cooling water to the blade, and as the impeller rotates within the pressure chamber, the pressure in the radially inner region of the pressure chamber decreases, causing cooling water to continuously flow into the pressure chamber from the upstream supply passage, and the pressure in the radially outer region of the pressure chamber increases, causing cooling water to continuously flow out of the pressure chamber to the downstream supply passage.

[0011] Furthermore, in this blade water supply device, it is preferable that a tangential flow passage having one end opening in the pressure chamber and extending in a tangential direction of the inner surface of the pressure chamber is connected to the pressure chamber, and that the cooling water flows from the radially outer region within the pressure chamber through the tangential flow passage to a downstream supply passage.

[0012] It is also preferable that the impeller has a plurality of blades, and each blade is formed such that a front end portion on the front side in the direction of rotation is located radially inward relative to a rear end portion on the rear side in the direction of rotation, and is configured to move fluid forward in the direction of rotation radially outward during rotation. It is also preferable that the blade shaft is rotatably supported by two bearings spaced apart in the longitudinal direction, and the pressurizing case is disposed between the bearings.

[0013] Furthermore, it is preferable that an air vent hole for releasing air that may be present in the pressure chamber is formed at a position higher than the position where the radially inner region of the pressure chamber communicates with the upstream supply passage.

[0014] In addition, it is preferable that a water supply chamber through which the blade shaft passes is formed in the pressurized case, the pressure chamber and the water supply chamber are connected via a connecting flow passage including a tangential flow passage, a central water passage extending along the central axis of the blade shaft, a first radial water passage having one end opening on the outer circumferential surface of the blade shaft in the water supply chamber and the other end reaching the central water passage, and a second radial water passage having one end opening on the outer circumferential surface of the blade shaft radially inside the blade fixing means and the other end reaching the central water passage are formed inside the blade shaft, and a flange flow passage is formed between the blade fixing means and the blade, or inside the blade fixing means, which connects from the outer circumferential surface of the blade shaft to the outer circumferential surface of the blade fixing means, and the cooling water flowing out of the pressure chamber is supplied to the blades through the connecting flow passage, the water supply chamber, the first radial water passage, the central water passage, the second radial water passage, and the flange flow passage.

[0015] Furthermore, it is preferable that an introduction chamber through which the blade shaft passes is formed in the pressurized case, the introduction chamber is connected to a water supply tank which supplies cooling water, and is configured to communicate with a radially inner region in the pressure chamber, and the cooling water supplied from the water supply tank is configured to flow from the introduction chamber into the radially inner region in the pressure chamber.

[0016] It is also preferable that a partition having an opening through which the blade shaft passes is formed between the pressure chamber and the introduction chamber in the pressurized case, the inner diameter of the opening in the partition is set to a dimension larger than the outer diameter of the blade shaft, and a gap between the opening and the blade shaft connects the radially inner region in the pressure chamber to the introduction chamber.

[0017] Furthermore, it is preferable that the impeller has a plurality of blades, and the distance between the tip of the blade and the partition wall is set to 1.5 mm or less. Effect of the Invention

[0018] The blade water supply device according to the present invention can obtain a higher supply pressure and flow rate than a conventional water supply device that delivers cooling water by gravity. Furthermore, regardless of the water level (remaining amount of water) in the water supply tank, a sufficient amount of cooling water can be continuously delivered and supplied to the blades. Furthermore, the water supply tank does not need to be installed at a high position, and can be installed at a position lower than the blade shaft. Therefore, it is expected that there will be an effect of increasing the degree of freedom in designing the mounting position of the water supply tank.

[0019] Furthermore, since the amount of cooling water supplied to the blades is proportional to the rotation speed of the impeller, when the output of the power source (engine, etc.) is increased during cutting work to rotate the blade shaft and impeller at high speed, a large amount of cooling water (a sufficient amount to cool the blades and prevent dust from scattering) is appropriately supplied; conversely, when idling, the amount of water supplied is reduced, automatically saving water. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a horizontal sectional view of a blade water supply device 1 according to the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the pressurizing case 4 shown in FIG. [Diagram 3] FIG. 3 is a vertical cross-sectional view of the water supply device 1 taken along line III-III shown in FIG. [Figure 4] FIG. 4 is a cross-sectional perspective view of the pressurizing case 4 taken along the line IV-IV shown in FIG. [Diagram 5] FIG. 5 is a perspective view of the impeller 8 shown in FIGS. [Figure 6] FIG. 6 is an enlarged cross-sectional view of the tip of the blade shaft 2 and the blade fixing means 3 shown in FIG. [Figure 7] FIG. 7 is a perspective view of the outer flange 32 of the blade fixing means 3 shown in FIG. [Figure 8] FIG. 8 is a vertical sectional view showing another example of the configuration of the pressurizing case 4 shown in FIG. [Figure 9] FIG. 9 is a cross-sectional perspective view showing another example of the configuration of the pressurizing case 4 shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a horizontal cross-sectional view of a water supply device for a blade 1 according to the present invention (an example applied to a concrete cutter that cuts or mills asphalt pavement surfaces of roads and concrete surfaces). As shown in the figure, this water supply device 1 is basically composed of a blade shaft 2, blade fixing means 3, and a pressurized case 4. Note that Fig. 1 shows a horizontal cross section of each element at the height position of the central axis of the blade shaft 2.

[0022] 1, the blade shaft 2 is rotatably supported by two bearings 5 ​​spaced apart in the longitudinal direction. The blade shaft 2 is configured to rotate at high speed by receiving a driving force transmitted from a prime mover (engine, electric motor, etc.) not shown.

[0023] A central water passage 21 extending along the central axis is formed inside the blade shaft 2. Furthermore, radial water passages 22 (first radial water passage 22a, second radial water passage 22b) extending radially are formed inside the blade shaft 2. One end of the radial water passage 22 opens on the outer circumferential surface of the blade shaft 2, and the other end reaches the central water passage 21. Therefore, the central water passage 21 formed inside the blade shaft 2 communicates with the external space of the blade shaft 2 via the radial water passage 22.

[0024] A means for fixing the blade 6 (blade fixing means 3) is attached to the tip of the blade shaft 2. The blade fixing means 3 is basically composed of an inner flange 31 and an outer flange 32. The inner flange 31 is fixed to the blade shaft 2. On the other hand, the outer flange 32 is structured to be sandwiched between the inner flange 31 and a nut 7. Then, as shown in FIG. 1, with the blade 6 sandwiched between the inner flange 31 and the outer flange 32, the nut 7 is attached to the tip of the blade shaft 2 and tightened, thereby fixing the blade 6 to the blade shaft 2.

[0025] A pressurizing case 4 is disposed in the middle of the blade shaft 2 (at a position between the two bearings 5), surrounding the outside of the outer circumferential surface of the blade shaft 2 and forming an annular small chamber (such as a pressure chamber) between the outer circumferential surface of the blade shaft 2. A hollow portion 41 having a circular cross section is formed inside the pressurizing case 4, and the blade shaft 2 is inserted coaxially into the hollow portion 41. An impeller 8 is also attached to the blade shaft 2.

[0026] 2 is an enlarged cross-sectional view of the pressurizing case 4 shown in FIG. 1. As shown in the figure, a partition wall 42 is formed inside the hollow portion 41 of the pressurizing case 4. A circular opening 42a is formed in the center of the partition wall 42. The inner diameter of the opening 42a is set to be larger than the outer diameter of the blade shaft 2 to be inserted. In this embodiment, the inner diameter of the opening 42a is set to 32 mm, and the outer dimension of the blade shaft 2 is set to 28 mm. Since the circular opening 42a is concentric with the blade shaft 2, when the blade shaft 2 is inserted into the hollow portion 41, a constant (2 mm) gap C is formed around the entire circumference between the opening 42a and the blade shaft 2.

[0027] Ring-shaped shaft seal members 43 (first shaft seal member 43a, second shaft seal member 43b, third shaft seal member 43c) are disposed in the hollow portion 41. All of these shaft seal members 43 are of a contact type, and are attached with their inner lip portions in contact with the blade shaft 2 and their outer portions in close contact with the inner circumferential surface of the hollow portion 41.

[0028] The first shaft seal member 43a is attached to one end of the cavity 41 (the end on the left side in FIG. 2, the end on the blade 6 side shown in FIG. 1). The second shaft seal member 43b is attached to the opposite end (the end on the right side in FIG. 2). The third shaft seal member 43c is attached to a position between the first shaft seal member 43a and the partition wall 42.

[0029] In this manner, the pressurizing case 4 has openings at both ends of the cavity 41 (between the inner peripheral surface of the cavity 41 and the outer peripheral surface of the blade shaft 2) closed by the first shaft seal member 43a and the second shaft seal member 43b. The shaft seal members 43a to 43c and the partition wall 42 divide the cavity 41 into three small chambers. More specifically, the cavity 41 is divided into an introduction chamber 44 between the second shaft seal member 43b and the partition wall 42, a pressure chamber 45 between the partition wall 42 and the third shaft seal member 43c, and a water supply chamber 46 between the third shaft seal member 43c and the first shaft seal member 43a.

[0030] Fig. 3 is a vertical cross-sectional view of the water supply device 1 taken along line III-III in Fig. 2. Fig. 4 is a cross-sectional perspective view of the pressurizing case 4 taken along line IV-IV in Fig. 3. As shown in these figures, a connection flow path 47 is formed inside the pressurizing case 4. This connection flow path 47 is for connecting and communicating the pressure chamber 45 and the water supply chamber 46. In this embodiment, the connection flow path 47 is composed of a main flow path 47a, a tangential flow path 47b, and a communication flow path 47c, as shown in Fig. 4.

[0031] The main flow path 47a extends radially outside the hollow portion 41 in a direction parallel to the central axis of the blade shaft 2 (see Figures 1 to 3), from a position on the side of the introduction chamber 44 (in a direction perpendicular to the central axis of the blade shaft 2) to a position on the side of the water supply chamber 46.

[0032] As shown in Fig. 3, the tangential flow passage 47b extends in the tangential direction of the inner peripheral surface of the cavity 41 (pressure chamber 45), with one end opening in the pressure chamber 45 and the other end opening in the main flow passage 47a. Therefore, the pressure chamber 45 and the main flow passage 47a communicate with each other through the tangential flow passage 47b. As shown in Fig. 4, the communication flow passage 47c has one end opening in the main flow passage 47a and the other end opening in the water supply chamber 46. Therefore, the main flow passage 47a and the water supply chamber 46 communicate with each other through the communication flow passage 47c.

[0033] 4, a water conduit 48 is formed inside the pressurization case 4. This water conduit 48 is for introducing cooling water into the introduction chamber 44 from the outside of the pressurization case 4. One end of the water conduit 48 opens at the outer surface of the pressurization case 4, and the other end opens at the introduction chamber 44. The outer opening of the water conduit 48 is connected to a water supply tank (not shown) by a hose, a pipe, or the like.

[0034] 4, an air vent hole 49 is formed between main flow path 47a and introduction chamber 44. This air vent hole 49 is for allowing air that may be present in pressure chamber 45 and connection flow path 47 to escape to the introduction chamber 44 side, thereby allowing a sufficient amount of cooling water to flow into pressure chamber 45 and connection flow path 47 when water supply device 1 is started, etc.

[0035] Furthermore, the cross-sectional area of ​​the air vent hole 49 is set to be much smaller than the cross-sectional area of ​​the gap C shown in Figure 2 (the gap between the opening 42a of the partition wall 42 and the blade shaft 2) and the cross-sectional area of ​​the connecting flow passage 47.

[0036] Fig. 5 is a perspective view of the impeller 8 shown in Figs. 1 to 3. The impeller 8 is basically composed of a cylindrical (or ring-shaped) base 81 and a plurality of (four here) blades 82 protruding in a direction parallel to the central axis from one side surface (a surface perpendicular to the central axis) of the base 81. As shown in Fig. 3, the impeller 8 is configured such that the base 81 is fixed to the outer circumferential surface of the blade shaft 2 within the pressure chamber 45 and rotates together with the blade shaft 2 in a predetermined direction (counterclockwise in Figs. 3 and 5).

[0037] The blades 82 of the impeller 8 are configured so that, when rotating, they can move (push out) the fluid radially outward in front of the rotation direction of the blades 82. More specifically, as shown in Fig. 5, each blade 82 is formed so that a front end 82a (end on the front side in the rotation direction) is located radially inward relative to a rear end 82b (end on the rear side in the rotation direction).

[0038] 2, the impeller 8 is disposed so that the axial tip portion of the blade 82 (the right end portion in FIG. 2) is located as close as possible to the partition wall 42. In this embodiment, the distance between the blade 82 and the partition wall 42 is set to 0.8 mm (preferably 1.5 mm or less).

[0039] Here, an operation mode of the blade water supply device 1 according to this embodiment will be described. This water supply device 1 can generate pressure required to supply cooling water from a water supply tank (not shown) to both sides of the blade 6 by supplying a rotational driving force from a prime mover (not shown) to the blade shaft 2 (see Figs. 1 to 3) to rotate the blade shaft 2 and the impeller 8 in a predetermined direction (counterclockwise in Fig. 3).

[0040] This supply pressure is generated within the pressurized case 4. However, it is necessary that a sufficient amount of water is present within the pressurized case 4. Therefore, when no water is present within the pressurized case 4 or when the amount of water is insufficient, first, a sufficient amount of water is introduced into the pressurized case 4. Specifically, water is supplied from a water supply tank (not shown) to the introduction chamber 44 via the water conduit 48 (see FIG. 4).

[0041] The introduction chamber 44 and the adjacent pressure chamber 45 are separated by the partition wall 42, and a gap C (see FIG. 2) is formed between the opening 42a of the partition wall 42 and the blade shaft 2. As shown in FIG. 4, the pressure chamber 45 is connected to the adjacent water supply chamber 46 by a connection flow path 47 (main flow path 47a, tangential flow path 47b, and communication flow path 47c). Therefore, when a sufficient amount of water is supplied to the introduction chamber 44, the water flows into the pressure chamber 45 through the gap C, and further flows into the water supply chamber 46 through the connection flow path 47.

[0042] When the water level in the introduction chamber 44 becomes higher than the top 42b of the opening 42a of the partition wall 42 (see FIG. 4), if there is no escape route for the air present in the space above the top 42b of the opening 42a of the partition wall 42 (hereinafter simply referred to as the "space above the pressure chamber 45, etc.") among the spaces in the pressure chamber 45, the connecting flow passage 47, and the water supply chamber 46, it becomes difficult to make a sufficient amount of water flow into the pressure chamber 45 and the connecting flow passage 47. In this case, air entrainment occurs when the impeller 8 is rotated, and there is a possibility that a sufficient supply pressure and flow rate cannot be obtained.

[0043] In this embodiment, as described above, air vent hole 49 (see FIG. 4) is formed between main flow path 47a of connecting flow path 47 and introduction chamber 44, and this air vent hole 49 is formed at a position sufficiently higher than the uppermost part 42b of opening 42a of partition wall 42, so that air in the upper space such as pressure chamber 45 can be released to the introduction chamber 44 side, and a sufficient amount of water can be made to flow into pressure chamber 45, connecting flow path 47, and water supply chamber 46. As a result, the problem of air entrainment can be preferably avoided when water supply device 1 is in operation.

[0044] When a sufficient amount of water exists in the pressurized case 4 and water can be continuously supplied from a water supply tank (not shown) to the introduction chamber 44, the pressure on the upstream side of the impeller 8 decreases and the pressure on the downstream side increases. As a result, water can be continuously flowed from the upstream water supply tank into the pressurized case 4, and water can be continuously pumped from the pressurized case 4 toward the blades 6 on the downstream side.

[0045] More specifically, when the impeller 8 is rotated, the water in the pressure chamber 45 is stirred by the blades 82 (see Figs. 3 and 5), generating a water current swirling in the same direction. In addition to the centrifugal force acting on the swirling water current, the pressure increases in the radially outer region of the pressure chamber 45 (the region along the inner circumferential surface of the pressure chamber 45) due to the action based on the shape of the blades 82 (a shape that can move the fluid ahead in the direction of rotation radially outward). Conversely, the pressure decreases in the radially inner region of the pressure chamber 45 (the region along the outer circumferential surface of the blade shaft 2).

[0046] 3, a tangential flow passage 47b opens on the inner peripheral surface of the pressure chamber 45. Since the tangential flow passage 47b extends in the tangential direction of the inner peripheral surface of the pressure chamber 45, the water swirling in the radially outer region of the pressure chamber 45 continuously flows into the tangential flow passage 47b due to inertial force, and is further pushed out from the tangential flow passage 47b toward the downstream side (the main flow passage 47a, the communication flow passage 47c, the water supply chamber 46, etc.) due to the pressure generated by the rotation of the impeller 8.

[0047] On the other hand, the radially inner region of the pressure chamber 45 is connected to the introduction chamber 44 (through which the blade shaft 2 passes) via the gap C (see Figure 2) between the opening 42a of the partition 42 and the blade shaft 2, so when the pressure in the radially inner region of the pressure chamber 45 decreases, the pressure difference with the introduction chamber 44 generates a water flow from the introduction chamber 44 through the gap C into the pressure chamber 45.

[0048] Furthermore, if the spacing between the blades 82 of the impeller 8 and the partition wall 42 is set large, some of the water swirling in the radially outer region of the pressure chamber 45 may pass through the gap between the blades 82 and the partition wall 42 and move to the radially inner region, thereby reducing the pressure difference generated by the rotation of the impeller 8 (the pressure difference between the radially outer region and the radially inner region of the pressure chamber 45, and the pressure difference between the radially inner region of the pressure chamber 45 and the introduction chamber 44).

[0049] In this embodiment, as described above, the spacing dimension between the blades 82 of the impeller 8 and the partition wall 42 is set to an extremely small value, so that the movement of water from the radially outer region to the radially inner region in the pressure chamber 45 can be minimized, and the pressure difference generated by the rotation of the impeller 8 can be maintained appropriately.

[0050] In this way, the water supply device 1 of this embodiment can continuously flow water into the pressure chamber 45 from the upstream side (inlet chamber 44, etc.) by continuously rotating the impeller 8 within the pressure chamber 45, and can also pressure-pump water from the pressure chamber 45 toward the downstream side (water supply chamber 46, etc.).

[0051] The water pushed out from the pressure chamber 45 flows into the water supply chamber 46, and is supplied to the blades 6 through a water passage formed inside the blade shaft 2. Specifically, as shown in FIG. 2, the blade shaft 2 is disposed so as to penetrate the water supply chamber 46, and inside the blade shaft 2, the central water passage 21, the first radial water passage 22a, and the second radial water passage 22b (see FIG. 1) are formed. Of these, the first radial water passage 22a has one end opening in the water supply chamber 46 and the other end reaching the central water passage 21, as shown in FIG. 2. Therefore, the water that has flowed into the water supply chamber 46 flows from the water supply chamber 46 into the first radial water passage 22a due to the pressure generated by the rotation of the impeller 8.

[0052] Since the first radial water passage 22a extends radially inside the blade shaft 2, centrifugal force acts on the water in the first radial water passage 22a when the blade shaft 2 rotates. This centrifugal force acts as resistance when water is flowed from the water supply chamber 46 into the first radial water passage 22a (i.e., when water is moved from the radial outside to the radial inside). However, in the water supply device 1 of this embodiment, a sufficiently large supply pressure can be generated during normal operation of the concrete cutter to which the device is applied, and water can be flowed from the water supply chamber 46 into the first radial water passage 22a without any problems.

[0053] For example, when the blade shaft 2 and the impeller 8 are rotated at a speed (3200 to 3600 rpm) used during normal operation of a concrete cutter, a large supply pressure of 24 to 28 kPa can be generated. Therefore, water can be made to flow from the water supply chamber 46 into the first radial water passage 22a without any problem, against the centrifugal force acting in the first radial water passage 22a.

[0054] The water that has flowed into the first radial water passage 22a passes through the central water passage 21 and is sent to the second radial water passage 22b, from which it flows out to the outside of the blade shaft 2. As shown in Fig. 6 (an enlarged cross-sectional view of the tip of the blade shaft 2 and the blade fixing means 3 shown in Fig. 1), the second radial water passage 22b is formed at a position radially inward of the blade fixing means 3 (the inner flange 31, the outer flange 32) and the blade 6 fixed thereto.

[0055] As shown in Fig. 7 (a perspective view of the outer flange 32 of the blade fixing means 3 shown in Fig. 6), a pressing portion 32a, a recess 32b, and a groove 32c are formed on the inner surface (the surface that comes into contact with the blade 6) of the outer flange 32 of the blade fixing means 3. Of these, the pressing portion 32a and the groove 32c are formed in a radially outer region on the inner surface of the outer flange 32, and the recess 32b is formed in a radially inner region (a region between the pressing portion 32a and a through hole 32d through which the blade shaft 2 is inserted).

[0056] The pressing portion 32a is a portion that comes into contact with and presses the side surface of the blade 6 to fix the blade 6, and is formed so as to be located on the same plane perpendicular to the central axis. Meanwhile, the recessed portion 32b and the groove portion 32c are shaped to be recessed in the thickness direction of the outer flange 32 from the plane of the pressing portion 32a. Therefore, when the outer flange 32 is pressed against the side surface of the blade 6, only the pressing portion 32a comes into contact with the side surface of the blade 6, and a space (gap) is formed between the outer flange 32 and the blade 6 in the portion where the recessed portion 32b and the groove portion 32c are formed.

[0057] The grooves 32c are formed to extend radially from the recesses 32b to the outer peripheral surface 32e of the outer flange 32. Therefore, as shown in Fig. 6, when the blade 6 is attached to the blade shaft 2 and is clamped and fixed between the inner flange 31 and the outer flange 32, a flow path (flange flow path) is formed between the outer flange 32 and the blade 6, which runs from the outer peripheral surface of the blade shaft 2 through the recesses 32b and the grooves 32c to the outer peripheral surface 32e of the outer flange 32.

[0058] Note that the inner surface of the inner flange 31 also has a pressing portion 31a, a recess 31b, and a groove 31c similar to the pressing portion 32a, the recess 32b, and the groove 32c shown in Fig. 7 (see Fig. 6). In other words, a flow path (flange flow path) is also formed between the inner flange 31 and the blade 6, which communicates with the outer circumferential surface of the blade shaft 2 through the recess 31b and the groove 31c to the outer circumferential surface 31e of the inner flange 31.

[0059] Therefore, the cooling water flowing out from the blade shaft 2 at a position radially inward of the blade fixing means 3 and the blade 6 is caused by centrifugal force to move radially outward through the recesses 31b, 32b and grooves 31c, 32c of the inner flange 31 and the outer flange 32, and finally the cooling water is supplied to both sides of the blade 6.

[0060] In this way, the water supply device 1 of this embodiment is configured so that the radially inner region within the pressure chamber 45 is connected to an upstream supply passage (inlet chamber 44, water supply tank, etc.) that supplies cooling water to the pressure chamber 45, and the radially outer region within the pressure chamber 45 is configured to be connected to a downstream supply passage (water feed chamber 46, central water passage 21, etc.) that supplies cooling water to the blades 6. By rotating the impeller 8 within the pressure chamber 45, the pressure in the radially inner region within the pressure chamber 45 can be reduced to allow cooling water to continuously flow into the pressure chamber 45 from the upstream supply passage, and the pressure in the radially outer region within the pressure chamber 45 can be increased to allow cooling water to continuously flow out from the pressure chamber 45 to the downstream supply passage, resulting in an appropriate supply of cooling water to both sides of the blades 6.

[0061] The water supply device 1 according to this embodiment can obtain a higher supply pressure and flow rate than a conventional water supply device that delivers cooling water by gravity. Moreover, regardless of the water level (remaining amount of water) in the water supply tank, a sufficient amount of cooling water can be continuously delivered and supplied to the blades 6. Furthermore, the water supply tank does not need to be installed at a high position, and can be placed at a position lower than the blade shaft 2. Therefore, it is expected to have the effect of increasing the degree of freedom in designing the mounting position of the water supply tank.

[0062] The amount of cooling water supplied to the blades 6 is proportional to the rotation speed of the impeller 8. Therefore, when the output of the power source (engine, etc.) is increased during cutting work to rotate the blade shaft 2 and impeller 8 at high speed, a large amount of cooling water (a sufficient amount to cool the blades 6 and prevent dust from scattering) is appropriately supplied, and conversely, when idling, the amount of water supplied is reduced, allowing water to be automatically saved.

[0063] The water supply device 1 of this embodiment operates by driving the blade shaft 2, so there is no need to prepare a dedicated power source.In addition, when the water supply device 1 is operated, the increased load on the power source of the blade shaft 2 (engine, electric motor, etc.) is extremely small and is barely noticeable.

[0064] In the above embodiment, the impeller 8 is manufactured separately from the blade shaft 2 and attached to the outer peripheral surface of the blade shaft 2, but it is also possible to use an element equivalent to the blades 82 of the impeller 8 shown in Figure 5 as being integrally formed on the outside of the outer peripheral surface of the shaft as the blade shaft 2.

[0065] In the above embodiment, the air vent hole 49 for releasing air that may be present in the space above the pressure chamber 45 etc. is formed in a position between the connecting flow path 47 and the introduction chamber 44 in the pressurized case 4, but as shown in Fig. 8 (an enlarged vertical cross-sectional view showing another example of the configuration of the pressurized case 4), the air vent hole 49 for communicating the pressure chamber 45 and the introduction chamber 44 may be formed in a position above the partition wall 42 (a position higher than the top 42b of the opening 42a). In this case as well, air that may be present in the space above the pressure chamber 45 etc. can be released to the introduction chamber 44 side.

[0066] 8, a vertical hole 92 may be formed penetrating from the outer upper surface 91 of the pressurizing case 4 to the pressure chamber 45 (or the connecting flow path 47 or the water supply chamber 46), one end of a hose 93 (or a pipe, etc.) may be connected to the upper end opening, and the other end may be connected to the introduction chamber 44 (or an element on the upstream side thereof, for example, the water conduit 48, or a hose connecting the water supply tank and the water conduit 48, etc.). In any case, by forming or arranging an air vent hole 49 or an element equivalent thereto at a position higher than the position (the uppermost part 42b of the opening 42a) where the radially inner region in the pressure chamber 45 communicates with the upstream supply path, it is possible to release air that may be present in the space above the pressure chamber 45, etc.

[0067] 9, the communication flow passage 47c of the connection flow passage 47 connecting the pressure chamber 45 and the water supply chamber 46 can be configured to extend downward from the terminal end of the main flow passage 47a and communicate with the water supply chamber 46 at a lower part of the water supply chamber 46 (a position lower than the central axis of the blade shaft 2). In this case, when the power source (engine, etc.) is stopped temporarily during cutting work, the phenomenon of air flowing back from the water supply chamber 46 to the pressure chamber 45 and the occurrence of air entrapment can be suitably avoided.

[0068] Furthermore, in the water supply device 1 of the above embodiment, cooling water is supplied to the blades 6 from the water supply chamber 46 through water passages (central water passage 21 and radial water passage 22) formed inside the blade shaft 2, but it is also possible to arrange nozzles at positions inside the blade cover (not shown) that is arranged to cover the outside of the blades 6 (preferably at positions where cooling water can be sprayed onto one side of the blade and at positions where cooling water can be sprayed onto the opposite side of the blade) and connect these nozzles to the tangential flow passages 47b (see Figure 3) with hoses or pipes, that is, to supply cooling water to the blades 6 through a path formed outside rather than inside the blade shaft 2.

[0069] In addition, in the above embodiment, flange flow paths (recesses 31b, 32b, grooves 31c, 32c) connecting the outer peripheral surface of the blade shaft 2 to the outer peripheral surfaces 31e, 32e of the blade fixing means 3 are formed between the inner flange 31 and the outer flange 32, respectively, and the blade 6, but the flange flow paths may also be formed inside the inner flange 31 and the outer flange 32.

[0070] Although the water supply device 1 of the above embodiment is applied to a concrete cutter that cuts or mills the asphalt pavement surface of a road or the surface of concrete, the application of the present invention is not limited to concrete cutters. In other words, the present invention can be widely applied to devices that cut or mill an object by rotating a blade fixed to a blade shaft, and in which it is necessary or effective to supply cooling water to the blade or prevent dust from scattering (for example, metal processing machines, etc.). [Explanation of symbols]

[0071] 1: Water supply device, 2: Blade shaft, 3: Blade fixing means; 4: Pressurized case, 5: Bearings, 6: Blade, 7: Nut, 8: impeller, 21:Central waterway, 22: Radial waterway, 22a: first radial waterway; 22b: second radial waterway, 31: inner flange, 31a: pressing part, 31b: recess, 31c: Groove, 31e: Outer surface, 32: outer flange, 32a: pressing part, 32b: recess, 32c: Groove, 32d: Through hole, 32e: Outer surface, 41: Cavity, 42: Bulkhead, 42a: opening, 42b:Top; 43: shaft seal member, 43a: first shaft seal member, 43b: second shaft seal member, 43c: third shaft seal member, 44: Introduction room, 45: Pressure chamber, 46: Water supply room, 47: connecting channel, 47a: Main channel, 47b: tangential flow path, 47c: connecting channel, 48: Waterway, 49: Air vent hole, 81: Base, 82: Feather, 82a: front end, 82b: Rear end, 91: Outer top surface, 92: Vertical hole, 93: Hose, C: Gap

Claims

1. A blade water supply device that is applied to an apparatus for cutting or milling an object by rotating a blade fixed to a blade shaft and supplies cooling water to the blade, a pressurizing case that surrounds the outside of an outer circumferential surface of the blade shaft and forms an annular pressure chamber between the outer circumferential surface of the blade shaft and the pressurizing case; An impeller is fixed to an outer circumferential surface of the blade shaft within the pressure chamber or is integrally formed with the blade shaft; a radially inner region of the pressure chamber is configured to communicate with an upstream supply passage that supplies cooling water to the pressure chamber; a radially outer region of the pressure chamber configured to communicate with a downstream supply passage that supplies cooling water to the blade; A water supply device for a blade, characterized in that, as the impeller rotates within the pressure chamber, the pressure in the radially inner region of the pressure chamber decreases, causing cooling water to continuously flow into the pressure chamber from the upstream supply passage, and the pressure in the radially outer region of the pressure chamber increases, causing cooling water to continuously flow out from the pressure chamber to the downstream supply passage.

2. a tangential flow passage extending in a tangential direction of an inner circumferential surface of the pressure chamber and connected to the pressure chamber; 2. The water supply device for blades according to claim 1, characterized in that the cooling water is arranged to flow from a radially outer region of the pressure chamber through a tangential flow path to a downstream supply passage.

3. The impeller has a plurality of blades, 2. The blade water supply device according to claim 1, characterized in that each blade is formed so that its front end portion on the forward side in the direction of rotation is positioned radially inward relative to its rear end portion on the rear side in the direction of rotation, and is configured to move fluid in front of the direction of rotation radially outward during rotation.

4. The blade shaft is rotatably supported by two bearings spaced apart in the longitudinal direction; 2. The blade water supply device according to claim 1, wherein the pressurized case is disposed at a position between the bearings.

5. 2. The blade water supply device according to claim 1, characterized in that an air vent hole for releasing air that may be present in the pressure chamber is formed at a position higher than a position where a radially inner region of the pressure chamber communicates with an upstream supply passage.

6. A water supply chamber through which the blade shaft passes is formed in the pressurized case, The pressure chamber and the water supply chamber are connected via a connecting flow path including a tangential flow path, A central water passage extending along the central axis of the blade shaft, a first radial water passage having one end opening on the outer circumferential surface of the blade shaft in the water supply chamber and the other end reaching the central water passage, and a second radial water passage having one end opening on the outer circumferential surface of the blade shaft radially inward of the blade fixing means and the other end reaching the central water passage are formed inside the blade shaft, A flange flow passage is formed between the blade fixing means and the blade, or inside the blade fixing means, the flange flow passage communicating from the outer circumferential surface of the blade shaft to the outer circumferential surface of the blade fixing means; A blade water supply device as described in any one of claims 1 to 5, characterized in that, as the impeller rotates within the pressure chamber, cooling water flowing out from the pressure chamber is supplied to the blades through the connecting flow passage, the water supply chamber, the first radial water passage, the central water passage, the second radial water passage, and the flange flow passages.

7. An introduction chamber through which the blade shaft passes is formed in the pressurized case; 2. The blade water supply device according to claim 1, characterized in that the introduction chamber is connected to a water supply tank that supplies cooling water and is configured to communicate with a radially inner region of the pressure chamber, and the cooling water supplied from the water supply tank is configured to flow from the introduction chamber into the radially inner region of the pressure chamber.

8. A partition wall having an opening through which the blade shaft is inserted is formed between the pressure chamber and the introduction chamber in the pressurizing case; A water supply device for a blade as described in claim 7, characterized in that the inner diameter of the opening in the partition is set to a dimension larger than the outer diameter of the blade shaft, and a gap between the opening and the blade shaft is configured to connect the radially inner region of the pressure chamber to the introduction chamber.

9. The impeller has a plurality of blades, 8. The water supply device for blades according to claim 7, wherein a distance between the tip of the blade and the partition wall is set to 1.5 mm or less.