Wet type drilling tool

Abstract

To facilitate a drilling work in a narrow drilled part.SOLUTION: A wet type drilling tool 1 includes: an electrically-driven tool body to which a wet type core bit 12 is mounted; a water supply shank 11 that supplies water to the wet type core bit 12; a retention holder 16 that allows the wet type core bit 12 to slidably penetrate therethrough in its length direction and retains a suspension introduced from a drilled part during the drilling; and holder holding means that allows the electrically-driven tool body to elastically hold the retention holder 16. The holder holding means can be composed of an elastic arm 18, an anelastic arm 20, and holding means that fixes these arms to the electrically-driven tool body. Since breadth of the retention holder 16 and breadth of the holder holding means are smaller than breadth of the electrically-driven tool body or of the water supply shank 11, it is possible to narrow a range that interrupts a field of view of an operator around the drilled part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wet drilling tool used for interior and exterior construction of buildings. [Background technology]

[0002] As a wet drilling tool of this kind, a wet electric drill is known, as disclosed in Patent Document 1. This wet electric drill is a tool that drills holes by dripping water from a water injection set, and the outer peripheral shape of the drilling blade is a cone shape that expands from the power source toward the drilling surface. With this wet electric drill, the cutting water after drilling does not splash around the outer periphery and does not penetrate into the electric drill.

[0003] Also available on the market are hand-held electric drills in which cooling water is supplied via a water supply tube to a wet-use shank fitted with a diamond bit, and the cooling water is sucked up along with dust generated during drilling from a ring-shaped suction pad connected to a vacuum device, and then drained. The vacuum sets and associated hand-held wet drills are also available on the market. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-256063 A Summary of the Invention [Problem to be solved by the invention]

[0005] The wet electric drill disclosed in Patent Document 1 and commercially available handheld wet drills have a fixed core bit length and no depth adjustment mechanism, making it difficult to adjust the drilling depth. In addition, conventional wet electric drills have a complicated refrigerant circulation mechanism and are large in size, which places a heavy burden on the operator in terms of both operation and weight when used handheld, and furthermore, there is a problem that it is difficult to work in a narrow area to be drilled.

[0006] The main object of the present invention is to provide a small, lightweight, and simply constructed wet drilling tool that can solve these problems and facilitate drilling operations in narrow areas to be drilled. Other objects of the present invention will become apparent from the disclosure of this specification. [Means for solving the problem]

[0007] A wet drilling tool which is one embodiment of the present invention comprises an electric tool body on which a wet core bit is attached, a water supply shank which supplies water to the wet core bit, a storage holder which allows the wet core bit to slide freely along its length and stores the suspension liquid introduced from the portion to be drilled during drilling, and a holder holding means which elastically holds the storage holder to the electric tool body, wherein the width of the storage holder and the holder holding means is less than or equal to the width of the electric tool body or the water supply shank. Effect of the Invention

[0008] According to the present invention, it is possible to provide a small, lightweight, and simply structured wet drilling tool that facilitates drilling operations in narrow areas to be drilled. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a top perspective view of a wet-type power drill according to an embodiment of the present invention. [Diagram 2] 1 is a front view of a wet-type power drill according to an embodiment of the present invention; [Diagram 3] 1 is a front perspective view of a wet-type power drill according to an embodiment of the present invention; [Figure 4] FIG. 2 is a rear perspective view of the wet-type power drill according to the embodiment. [Diagram 5] 1 is a plan view of a wet-type power drill according to an embodiment of the present invention; [Figure 6] FIG. 2 is a top view of the wet-type power drill according to the embodiment. [Figure 7] FIG. 11 is a top perspective view of a wet-type power drill according to a first modified example. [Figure 8]FIG. 11 is a front view of a wet-type power drill according to a first modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention applied to a handheld wet electric drill will be described. The wet electric drill of this embodiment is configured with an electric drill body having a wet core bit, and a water supply and drainage control mechanism for supplying and discharging a refrigerant to the electric drill body. The wet core bit can be easily removed with only one tool. The refrigerant may be a semi-liquid such as compressed air or gel, but in consideration of versatility, this specification will describe an example in which cooling water supplied from a water supply device such as tap water is used as the refrigerant, and a suspension in which cuttings and the like are mixed in the cooling water is discharged using a known vacuum device, which is one of the refrigerant recovery mechanisms.

[0011] For convenience, in this specification and drawings, the X, Y, and Z directions are defined as front, back, left, right, up and down directions. The Z direction is vertically upward or vertically downward. The X and Y directions are horizontal directions perpendicular to the Z direction. In this specification, the X direction is described as the front-back direction, the Y direction as the left-right direction, and the Z direction as the up-down direction. In addition, in the drawings, the directions indicated by the arrows of the X-axis, Y-axis, and Z-axis may be called the front direction, the side direction, and the up direction, respectively. In addition, a wet electric drill viewed from above may be called a top view, a view from an obliquely upward direction may be called a diagonal top view, a view from the left (or right) direction may be called a left (right) side view, and a view from the lower left or right may be called an oblique view.

[0012] 1 to 6 are external views showing an example of the structure of a wet-type power drill according to this embodiment, where FIG. 1 is an upper oblique view, FIG. 2 is a front view, FIG. 3 is a front oblique view, FIG. 4 is a rear oblique view, FIG. 5 is a plan view, and FIG. 6 is a top view.

[0013] Referring to these figures, the wet-type power drill 1 according to this embodiment has a power tool main body. The power tool main body contains an electric motor 110 (including electrical components for controlling it) for applying a rotational driving force to a spindle, and other components housed in a handheld housing 100. The grip of the housing 100 is provided with an operation switch 102 that an operator operates when working, a battery 103 that serves as a power source for the electric motor 110, and other components.

[0014] A handle block 14 is provided at the front end of the electric motor 110 for mounting an operating handle 101 that is gripped by an operator when working. A female screw hole is threaded on the vertically lower surface of the handle block 14, and the operating handle 101 can be mounted to the handle block 14 by screwing a male screw on the operating handle 101 into the female screw hole. The operating handle 101 can be removed from the handle block 14. When mounted, the operating handle 101 has a thickness smaller than the width of the power tool body and the housing 100 when viewed from the front. This allows drilling work to be performed even in narrow spaces. A lock button 140 for locking the rotation of the water supply shaft portion 111 of the water supply shank 11, which will be described later, can be provided near the operating handle 101 on the handle block 14, for example, at a location where the operator's fingers touch when the operator is gripping the operating handle 101. By providing this lock button 140, for example, while the operator is holding the housing 100 or the handle block 101 with one hand, the operator can remove or attach the wet core bit 12 using only one tool with the other hand, thereby improving work efficiency. The components including the housing 100, the operating handle 101, the operating switch 102, the battery 103, and the electric motor 110 may be collectively referred to as the electric drill 10.

[0015] The wet-type power drill 1 includes a water supply / drainage control mechanism of a simple structure in addition to the power drill 10. The water supply / drainage control mechanism can be configured to include a water supply shank 11, a water storage holder 16, and a water supply unit 17.

[0016] [Water supply shank] The water supply shank 11 includes a water supply shaft portion 111 having a water supply passage formed on its rotation shaft, a shank body 112 to which the water supply passage of the water supply shaft portion 111 is connected, and a drain 113 for opening and closing the water supply passage of the shank body 112, and is fixed to the handle block 14 by a fixing device 115. The fixing device 115 may have any shape, but in this example, it is fixed by screws using an L-shaped metal member from the viewpoint of simplifying the structure. The shank shaft portion 111 is detachably attached with the wet core bit 12. The wet core bit 12 is a hard tool part equivalent to diamond, with a water supply passage formed inside or on the side toward the tip portion. The drain 113 supplies cooling water introduced from the water supply portion 17 via a refrigerant circulation device and a water supply hose (not shown) to the shank body 112.

[0017] The shank body 112 supplies cooling water to the wet core bit 12. The shank body 112 is, for example, a molded product made of aluminum or stainless steel, and a water storage space for cooling water is formed inside the shank body 112. The shank body 112 also has a pair of surfaces facing each other in the water storage space, and the spindle of the electric drill 110 is fixed to one surface via the water supply shaft portion 111, and the wet core bit 12 is fixed to the other surface via the water supply shaft portion 111. The shank body 112 not only supplies cooling water, but also plays a role in aligning the axes of the rotation axes of the spindle, the water supply shaft portion 111, and the wet core bit 12 during work, thereby gradually reducing the deviation of the axes during rotation. The base end of the wet core bit 12 is molded into a shape and size corresponding to the bit holding structure of the water supply shaft portion 111.

[0018] [Water supply section] The water supply unit 17 is provided along the side of the power tool body, parallel to the wet core bit 12, and at a lower position in a front view than an elastic arm 18 and a non-elastic arm 20 described later. Therefore, the supply of cooling water to the wet core bit 12 is performed at a position that is not in the operator's field of vision during drilling work, reducing the burden on the operator during drilling work. An input coupler 171 for connecting to a refrigerant circulation device is provided at the input end of the water supply unit 17, and an output coupler 173 for connecting to a drain 113 via a water supply hose (not shown) is provided at the output end. A flow rate check wheel 172 is provided between the input coupler 171 and the output coupler 173. The flow rate check wheel 172 is a water wheel type instrument that visually indicates the flow rate and flow speed of the cooling water, and is covered with a translucent resin cover. Therefore, it is possible to grasp how much cooling water is flowing to the shank body 112 through the rotation mode of the water wheel of the flow rate check wheel 172. Since the water supply unit 17 is arranged along the side of the electric motor 110, it is possible to prevent the width from expanding, and the operator's field of vision during work is not obstructed. In addition, drilling work in a narrow space is made easier.

[0019] [Storage holder] The reservoir holder 16 has a water reservoir 161 through which the wet core bit 12 slidably passes in the length direction and which stores the suspension sucked from the part to be drilled during drilling. The water reservoir 161 is a resin box having a substantially rectangular prism shape with a storage space (cavity) for the suspension formed therein, and as shown in Fig. 2, its width in front view is molded to be equal to or smaller than the width of the water supply shank 11 and the power tool body. The water reservoir 161 has flat surfaces on the front side facing the part to be drilled and on the back side facing the power tool body, and the flat surface on the front side is formed parallel to the part to be drilled.

[0020] A discharge nozzle 162 is provided below the rear side of the water storage unit 161 for discharging the stored suspension toward a refrigerant circulation device via a discharge hose (not shown). Since the discharge nozzle 162 is provided below the rear side of the water storage unit 161, the stored suspension can be easily discharged by gravity, and the view of the operator during the drilling operation is not obstructed. The discharge nozzle 162 may be fixed at a predetermined angle with respect to the Z axis, but the joint with the water storage unit 161 may be bellows-shaped so that the angle can be appropriately changed.

[0021] A suction pad 163 made of a soft material is provided along the outer edge of the wet core bit 12 at the rear side of the water storage section 161 where the wet core bit 12 is inserted. A generally truncated cone-shaped water absorption cap 164, also made of a soft material, is attached to the front side of the storage holder 16 at the part from which the wet core bit 12 protrudes. The diameter of the water absorption cap 164 becomes smaller toward the tip on the front side, and the tip is open (opening). A suction pad 165 made of a soft material, for example rubber, is provided on the inner wall near the opening of the water absorption cap 164.

[0022] In the reservoir holder 16 having such a structure, the flow rate of the suspension near the opening of the water absorption cap 164 is faster than the flow rate near the base end according to Bernoulli's theorem, improving the suction force near the suction pad 165. Therefore, even if a physical gap occurs between the opening of the water absorption cap 164 and the site to be perforated, the suspension introduced from the site to be perforated can be strongly sucked and stored in the water reservoir 161 and discharged from the discharge nozzle 162 without leaking.

[0023] A level 66 is provided on the rear side of the water storage section 161 near the suction pad 163 to visually indicate the relative angle of the wet core bit 12 with respect to the rotation axis of the area to be drilled. The operator can proceed with the work while looking at this level 66 when positioning the area to be drilled and during the drilling operation, making it easy to insert the wet core bit 12 at the desired angle with respect to the area to be drilled.

[0024] [Holder holding means] The reservoir holder 16 is elastically held to the power tool body by the holder holding means. That is, the holder holding means holds the reservoir holder 16 while biasing it as it approaches the power tool body as the wet core bit 12 protruding from the opening of the water suction cap 164 penetrates deeper into the part to be drilled. Conversely, the holder holding means de-energizes the reservoir holder 16, which moves away from the power tool body as the penetration depth of the wet core bit 12 becomes shallower, and holds it in a manner that attempts to return to the state before the drilling operation. As a result, the water suction cap 164 of the reservoir holder 16 is always pressed against the part to be drilled during the drilling operation.

[0025] There are various embodiments of the holder holding means, but in this embodiment, the holder holding means includes an elastic arm 18 consisting of a hard shaft with a spring wound around its outer surface, a non-elastic arm 20 consisting of a hard shaft without a spring wound around it, an arm base 19 fixed to the power tool body, and a position adjustment rail 22.

[0026] One end of each of the elastic arm 18 and the non-elastic arm 20 is fixed parallel to the wet core bit 12 on the upper rear side of the water storage section 161, and the other end is slidably held by the arm base 19 and the position adjustment rail 22 so as to follow the displacement of the storage holder 16. The non-elastic arm 20 can be, for example, a carbon shaft or a stainless steel shaft with a thickness equal to or smaller than the outer diameter of the wet core bit 12. This makes it possible to make the configuration for elastic holding, which tends to be large, smaller, lighter, and simpler.

[0027] The non-resilient arm 20 is provided with a depth adjustment block 21 for adjusting the range of its movement, i.e., the depth of the drilled portion into which the wet core bit 12 enters. The elastic arm 18 can be a shaft made of the same material as the non-resilient arm 20 with a spring wound around it. The elastic arm 18, the non-resilient arm 20, and the portion that holds them in the power tool body are all sized to be hidden by the storage holder 16 when viewed from the front.

[0028] The arm base 19 slidably holds the non-elastic arm 20 and the portion of the elastic arm 18 other than the spring. An arm stopper that restricts the range of movement of the elastic arm 18 and the elastic arm 20 is provided at the rear end of the arm base 19. In this embodiment, the initial position is set to a position that is the upper limit of the range of movement of the elastic arm 18 and the elastic arm 20 that are driven by the displacement of the storage holder 16. This arm stopper also serves as a detection piece (dog) of a microphotosensor described later, that is, a passive component for detecting the moving end or stop position of the elastic arm 18 or the elastic arm 20. Therefore, the number of sensor components can be reduced, which contributes to size and weight reduction.

[0029] The position adjustment rail 22 determines the position of the arm stopper and enables the operator to visually and quantitatively grasp how much the elastic arm 18 and non-elastic arm 20 sliding on the arm base 19 have been displaced from their initial positions, i.e., how deep the tip of the wet core bit 12 is in the area to be drilled.

[0030] [Switch box] A switch box 131 is provided directly above the arm base 19. The switch box 131 is provided with a refrigerant circulation switch 132 for switching the refrigerant circulation device ON / OFF, and a connector 133 for electrically connecting with electrical components of the refrigerant circulation device. The switch box 131 also houses a circuit board and a microphoto sensor for controlling the operation start timing and operation stop timing of the refrigerant circulation device and controlling the operation stop and operation restart of the refrigerant circulation device according to the position of the storage holder 16 when the refrigerant circulation switch 132 is ON. The microphoto sensor is a sensor that detects whether the elastic arm 18 and the elastic arm 20 are in the initial position based on the relative position with the arm stopper, and when they are in the initial position, the micro sensor is ON and the supply of cooling water is stopped.

[0031] [Example] Next, the operation of the wet-type power drill 1 of this embodiment will be described. When the elastic arm 18 and the non-elastic arm are in their initial positions, the tip of the wet core bit 12 is housed in the storage holder 16. When the refrigerant circulation switch 132 is turned ON, an ON signal is transmitted to the refrigerant circulation device via the connection connector 133, and the refrigerant circulation device starts the recovery operation of the suspension, but since the microphoto sensor in the switch box 131 is ON, the refrigerant circulation device is in a state where the supply of cooling water is stopped. This reliably prevents water leakage from the storage holder 16, and further improves safety during work.

[0032] When the operator projects the tip of the wet core bit 12 from the water suction cap 164 of the storage holder 16 and begins drilling a hole in the area to be drilled, the storage holder 16 is urged (pressed) toward the area to be drilled by the elastic arm 18. Then, the microphoto sensor turns OFF and the refrigerant circulation device starts the water supply operation of the cooling water. As a result, cooling water is supplied to the tip of the wet core bit 12 through the water suction part 17 and the water supply shank 11. This state continues unless the elastic arm 18 and the non-elastic arm 20 return to their initial positions.

[0033] When the operator stops (aborts) the drilling operation and the wet core bit 12 returns to the water suction cap 164 of the storage holder 16 due to the dissipating force of the elastic arm 18, the microphoto sensor 12 turns ON and the supply of cooling water is stopped. After that, the refrigerant circulation switch 132 is turned OFF to stop the recovery operation of the refrigerant circulation device.

[0034] <Effects and advantages of this embodiment> (1) In this embodiment, the width of the storage holder 16 (the horizontal size when viewed from the front) is less than the width of the power tool body and the water supply shank 11. Therefore, the area around the area to be drilled that is obstructed by the refrigerant circulation mechanism is reduced, and the wet core bit can be accurately positioned even if the area to be drilled is narrow. In addition, since the supply of cooling water to the wet core bit 12 and the discharge of the suspension liquid in the storage holder 16 are both performed in positions that are not in the operator's field of vision during drilling work, the burden placed on the operator during drilling work is reduced. In addition, by providing a lock button 140 for locking the rotation of the water supply shank 11 near the operating handle 101, the operator can hold the housing 100, etc. with one hand while using a single tool to remove or attach the wet core bit 12 with the other hand, thereby improving work efficiency.

[0035] (2) The holder holding means for holding the storage holder 16 includes an elastic arm 18 and a non-elastic arm 20, one end of which is fixed to the storage holder 16 and the other end of which moves in response to the displacement of the storage holder 16, and both are of a size that can be hidden by the storage holder 16 when viewed from the front, i.e., less than the width of the power tool body and the water supply shank 11. Therefore, compared to conventional wet electric drills of this type, a smaller (thinner), lighter, and simpler structure can be realized, and the burden on the operator during drilling work is reduced. The holder holding means also has an arm stopper that limits the range of movement of the elastic arm 18 and the non-elastic arm 20, and since the arm stopper also serves as a detection piece of a sensor that detects the upper limit of the range, it is possible to reduce the number of parts, contributing to smaller size and lighter weight.

[0036] (3) Since the operating handle 101 can be replaced, a work environment that can be changed according to the dominant hand of the operator can be realized.

[0037] (4) A spirit level 66 is provided on the back side of the storage holder 16 to visually indicate the relative angle of the wet core bit 12 with respect to the area to be drilled, so that the operator can enter the wet core bit 12 at the desired angle into the area to be drilled without having to look away during the drilling operation.

[0038] (5) A water supply section 17 for supplying cooling water along the side of the power tool body is located on the back side of the water supply shank 11. The water supply section 17 has a water wheel gauge that visually indicates the flow rate and flow speed of the cooling water during operation, making it easy to check to prevent accidental leakage of cooling water or suspension.

[0039] [Variation 1] In this embodiment, an example has been described in which the operating handle 101 is fixed vertically below the power tool body, but it is also possible to have female screw holes threaded on the right and left lateral faces as well as the vertically below face of the handle block 14, and to use the operating handle by changing the screw holes as appropriate depending on the part to be drilled and the dominant hand of the operator, that is, to use the operating handle 101 by attaching it so that it can be displaced left and right from the vertically below as a starting point. Note that the operating handle 101 is not limited to being fixed by screws, and can be displaced by a handle holding mechanism rotatably provided along the surface of the handle block 14 on a plane perpendicular to the rotation axis of the wet core bit 12.

[0040] Fig. 7 is a top perspective view showing a structural example of the wet-type power drill 2 according to the above embodiment (variation 1), and Fig. 8 is a front view thereof. Figs. 7 and 8 show an example in which the position of the operating handle 101 is changed by screwing. Components other than the handle block 14 and the operating handle 101 are the same as those in the wet-type power drill 1 shown in Figs. 1 to 6, and therefore reference numerals are omitted.

[0041] Since it is the portion forward of the water supply shank 11 that contributes to the drilling work at the site to be drilled, even the wet electric drill 2 of variant example 1 can achieve the same advantages and effects as this embodiment while improving the working environment for the operator. [Variation 2] In this embodiment, an example has been described in which the holder holding means is composed of two arms, the elastic arm 18 and the non-elastic arm 20, but the holder holding means may be composed of only one rigid shaft with a spring wound on its surface and its holding means. Also, the rigid shaft may be made a hollow cylinder to further reduce weight.

[0042] [Variation 3] In this embodiment, an example in which the spirit level 66 is provided only on the back side of the water storage section 161 has been described, but the spirit level 66 may also be provided in a portion along the housing 100 or in another portion that the operator can see during the drilling operation. By proceeding with the drilling operation after confirming that multiple spirit levels show the same result, the wet core bit 12 can be inserted at a more accurate angle into the portion to be drilled.

[0043] [Variation 4] In this embodiment, an example of a wet electric drill 1 has been described, but the wet drilling tool of the present invention can be applied in the same manner as this embodiment to not only the electric drill 10 but also other drilling tools to which a wet core bit 12 can be attached.

Claims

1. An electric tool body to which the wet core bit is attached; A water supply shank for supplying water to the wet core bit; a reservoir holder through which the wet core bit is slidably inserted in the length direction and which retains the suspension liquid introduced from the drilled portion during drilling; a holder holding means for elastically holding the storage holder to the power tool body, A wet drilling tool, characterized in that the width of the reservoir holder and the holder holding means is equal to or smaller than the width of the power tool body or the water supply shank.

2. A level is provided on the back side of the storage holder to visually indicate the relative angle of the wet core bit with respect to the drilled portion. A wet drilling tool according to claim 1.

3. A water supply section for supplying a refrigerant along a side surface of the power tool body is disposed on a rear side of the water supply shank, and the water supply section has a water wheel gauge for visually indicating a flow rate and a flow velocity of the refrigerant. A wet drilling tool according to claim 1.

4. The electric power tool body is provided with an operating handle that can be displaced in the left-right direction from a vertically downward starting point, and the operating handle has a thickness smaller than a width of the electric power tool body when attached vertically downward in a front view. A wet drilling tool according to claim 1.

5. A lock button for locking the rotation of the water supply shank is provided near the operating handle. A wet drilling tool according to claim 4.

6. The holder holding means has one or more arms made of a hard material, one end of which is fixed to the storage holder and the other end of which is adapted to follow the displacement of the storage holder, and a spring is wound around the outer surface of the arm. A wet drilling tool according to any one of claims 1 to 5.

7. the holder holding means has an arm stopper that limits the range of movement of the arm, and the arm stopper also serves as a detection piece of a sensor that detects the upper limit of the range. A wet drilling tool according to claim 6.

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