JP2020040157A - Electric tool - Google Patents

Abstract

To provide an electric tool which achieves downsizing while realizing a structure including a return pin.SOLUTION: An electric tool 10 according to the invention includes: a piston 30 which is housed in a cylinder 28 provided at a body part 12 in a reciprocating manner and pressed by pressure of a fluid; and a tool head 16 which is coupled to a tip of the body part 12 and performs predetermined operation by pressing of the piston. The electric tool 10 is driven by an electric motor 23 and includes: a return passage 36 which communicates from the cylinder 28 to a fluid tank 34 which stores the fluid and allows the fluid to flow; a return valve 40 which opens or closes the return passage 36; and a return pin 32 which moves the return valve 40 to an open position by pressing in a predetermined direction. The return pin 32 is disposed entirely or partially at an interior of the fluid tank 34.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power tool, and more particularly, to a piston that is reciprocally accommodated in a cylinder provided in a main body and is pushed by the pressure of a fluid, The present invention relates to a power tool that includes a tool head that performs a predetermined operation by pushing and is driven by an electric motor.

  2. Description of the Related Art Conventionally, electric tools that are driven by an electric motor and perform a predetermined operation, such as a cutting tool for cutting a wire or a cable or a crimping tool for fixing a crimp terminal to a wire or a cable, have been known.

  As an example, a power tool described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-175148) has been proposed. This electric tool is a cordless type having a detachable battery in a main body, and a hydraulic pump is driven by an electric motor while an operator pushes a start switch knob. This hydraulic pressure has the effect of pushing the piston and closing the tip of the die in the tool head. As an example, if a cutting tool head is used, it can be used as a cutting tool for cutting wires and cables. Alternatively, if a crimping tool head is used, it can be used as a crimping tool for fixing a crimp terminal to a wire or cable. Further, when the cutting or crimping operation is completed, the piston is retracted to the starting position, and a flow path for returning the liquid (hydraulic oil) in the cylinder to the fluid tank is opened in order to bring the piston into a standby state for the next operation. It has a return pin.

JP-A-2006-175148

  However, in order to provide a structure including a return pin as in the conventional power tool exemplified in Patent Document 1, the space must be naturally secured in the main body, and the power tool is increased in size, especially in the longitudinal direction. There was a problem that it became longer in the direction.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power tool capable of realizing a structure having a return pin and capable of achieving downsizing.

  The present invention solves the above-mentioned problems by a solution as described below as one embodiment.

  A power tool according to the present invention is configured such that a piston is reciprocally housed in a cylinder provided in a main body and is pushed by a pressure of a fluid, and the piston is connected to a tip of the main body and pushed by the piston. An electric tool driven by an electric motor, comprising: a tool head that performs a predetermined operation; and a return flow path that allows the fluid to flow from the cylinder to a fluid tank that stores the fluid; A return valve that opens and closes the flow path, and a return pin that opens the return valve by pushing in a predetermined direction, and the return pin is entirely or partially disposed inside the fluid tank. Requirements.

  According to this, since the whole or a part of the return pin is disposed inside the fluid tank, the space for the return pin provided outside the fluid tank can be reduced. The overall length can be shortened and the size can be reduced. Along with this, it is possible to reduce the number of members provided at the portion where the return pin is provided, to reduce the weight of the power tool and to reduce the material cost.

  Further, the return pin has a main body, and a pressing surface provided at one end of the main body, and the main body penetrates an outer wall of the fluid tank, and the pressing surface has the pressing surface. The fluid tank is preferably provided so as to be exposed outside the outer wall portion.

  Also, the main body portion is inserted into the outer wall portion of the fluid tank, and is separated from the first main body portion provided with the pressing surface at one end by a predetermined distance from the other end of the first main body portion, and A second main body provided so as to be able to contact the first main body, the first main body being in contact with the second main body when the first main body is pushed by the predetermined distance. It is preferable that the second main body is integrally movable.

  Further, the return pin has a main body and a pressing surface provided at one end of the main body, and both the main body and the pressing surface are inside the outer wall of the fluid tank. Preferably, they are provided.

  Further, the return pin is configured such that when the pressing surface provided on the outer surface of the outer wall portion configured to be elastically deformable of the fluid tank is pressed by a predetermined distance, the return surface is moved to the pressing point. On the other hand, it is preferable that they are arranged so as to be able to contact the contact points provided on the inner surface in a front-to-back positional relationship.

  Further, it is preferable that the outer wall portion of the fluid tank is formed using an elastomer material.

  According to the present invention, in contrast to a conventional power tool in which the entirety of the return pin is disposed outside the fluid tank, a configuration in which the entirety or a part of the return pin is disposed inside the fluid tank is used. The overall length can be shortened and the size can be reduced. Along with this, the number of members in the power tool can be reduced, the power tool can be reduced in weight, and the material cost can be reduced.

It is a front view (schematic diagram) which shows the example of the electric tool concerning embodiment of this invention. FIG. 2 is an enlarged view (schematic diagram) mainly showing a portion related to a piston pushing mechanism of the power tool shown in FIG. 1. FIG. 2 is an enlarged view (schematic diagram) focusing on a portion related to a retraction mechanism of a piston of the power tool shown in FIG. 1. FIG. 6 is an enlarged view (schematic diagram) showing another example (Modification 1) of the return pin shown in FIG. 3. FIG. 8 is an enlarged view (schematic diagram) showing another example (Modification 2) of the return pin shown in FIG. 3.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view (schematic diagram) showing an example of the power tool 10. As shown in FIG. FIG. 2 is an enlarged view (schematic diagram) focusing on a portion related to a pushing mechanism of the piston 30 of the power tool 10. In all the drawings for describing the embodiments, members having the same functions are denoted by the same reference numerals, and repeated description thereof may be omitted.

  As shown in FIG. 1, the power tool 10 according to the present embodiment is a cordless power tool that can be gripped with one hand by an operator to work. The tip tool head is configured to be replaceable. For example, by connecting a cutting tool head (a base 16 having a cutter) to the tip, it can be used as a cutting tool for cutting a cable or the like. On the other hand, by connecting a crimping tool head (a base (not shown)) to the tip, it can be used as a crimping tool for crimping a cable or the like and a crimp terminal by crimping. Hereinafter, as the power tool 10 according to the present embodiment, a case of a cutting tool will be described as an example.

  The power tool 10 includes a rod-shaped main body 12 that is gripped by an operator, a mounting portion 14 fixed to the tip thereof, a tool head 16 (base 16) that is exchangeably mounted on the mounting portion 14, and And a detachable rechargeable battery 18. The main body 12 has a start switch knob 22 and a return lever 31. The base 16 is supported by the mounting portion 14 so as to be rotatable around the shank 20 as an example. An electric motor 23 driven by a power supply of a battery 18 and a fluid pump (for example, hydraulic pressure) for driving a fluid (for example, hydraulic oil) driven by the electric motor 23 are provided inside the main body 12. Pump 26 is provided (FIG. 2). In addition, a fluid tank 34 for storing a fluid, a control unit (not shown) for controlling driving and the like are provided. The outer wall portion 34a of the fluid tank 34 is formed of an elastomer material (for example, nitrile rubber), and is configured to be elastically deformed according to the flow of the fluid.

  In the power tool 10 having the above configuration, the base 16 performs the cutting operation by the pressure of the fluid pressurized by the fluid pump 26. Hereinafter, a series of operations will be specifically described.

  First, the electric motor 23 is driven by the operator pressing the start switch knob 22 of the main body 12 (FIG. 2). At this time, the rotational force is transmitted from the electric motor 23 via the speed reduction mechanism 24, and is converted by the swash plate cam 25 into the driving force of the direct-acting fluid pump 26. The fluid pressurized by the fluid pump 26 flows into a cylinder 28 provided in the main body 12. Under the pressure of the fluid, the piston 30 housed in the cylinder 28 so as to be able to reciprocate is pushed in the direction from the main body 12 to the mounting part 14. At this time, the roller 29 provided at the tip of the piston 30 enters so as to push open an opening (not shown) formed at the rear end 16 b of the base 16. As a result, the rear end 16b operates in the opening direction, and the front end 16a pivotally supported by the shank 20 operates in the closing direction. Therefore, by storing the cables and the like in the concave portion 16c formed at the tip portion 16a of the base, an effect of cutting them can be obtained.

  In this embodiment, power is supplied from the battery 18 and the electric motor 23 is driven only while the start switch knob 22 provided on the main body 12 is pressed. However, the present invention is not limited to this configuration. When the start switch knob 22 is pushed, the driving of the electric motor 23 is started, and when the start switch knob 22 is pushed next, the electric motor 23 May be stopped.

  In addition, the power tool 10 has a function that, when the operation is completed, the piston 30 is retracted to the start position by operating the return lever 31 to be in a standby state for the next operation. That is, a pressing surface 32 a of the return pin 32 for opening a return flow path 36 for returning the fluid in the cylinder 28 to the fluid tank 34, which will be described later, is provided inside the electric tool 10 corresponding to the return lever 31. Therefore, the operator can press the pressing surface 32 a of the return pin 32 by pressing the return lever 31. Here, the retracting mechanism of the piston by operating the return pin 32 will be described in detail. FIG. 3 is an enlarged view (schematic diagram) focusing on a portion related to the retraction mechanism of the piston 30 of the power tool 10.

  As shown in FIG. 3, the main body 12 is provided with a return flow path 36 that communicates with the fluid tank 34 that stores the fluid from the cylinder 28 and allows the fluid to flow. A return valve 40 for opening and closing the return flow path 36 is provided in the middle of the return flow path 36. More specifically, first, the first flow path 36a communicates from inside the cylinder 28. Next, the first flow path 36a communicates with the second flow path 36b via the return valve 40. The second flow path 36b is formed by cutting a part of a main body 33 of the return pin 32 described later into a flow path, and communicates with the inside of the fluid tank 34. Each of the conduits constituting these flow paths is disposed at a position overlapping the fluid tank 34 in the longitudinal direction, but is not limited to this, and a part of the conduit does not overlap the fluid tank 34 in the longitudinal direction. May be arranged.

  Here, the return valve 40 provided between the first flow path 36a and the second flow path 36b has a spherical valve element 40b, and normally moves toward the second flow path 36b by the urging member 40a. And the valve body 40b is in the closed position. On the other hand, a return pin 32 is provided in a state where the operating portion 32b directed toward the first flow path 36a is in contact with or close to the valve body 40b. The return pin 32 includes, for example, a main body 33 formed as a substantially cylindrical member, a pushing surface 32a provided at one end thereof, and an operating portion 32b provided at the other end. The operating portion 32b is disposed inside the fluid tank 34, while the main body portion 33 is inserted through the outer wall portion 34a of the fluid tank 34 and the pushing surface 32a is exposed outside the outer wall portion 34a of the fluid tank 34. It is arranged to be. The insertion portion of the main body 33 is tightly fixed to the outer wall portion 34a of the fluid tank 34 by a fixing ring 48, so that leakage of fluid from the fluid tank 34 is prevented. However, the flexibility of the outer wall portion 34a formed of the elastomer material enables the movement toward the inside and outside of the moving fluid tank 34. The members of the fixing ring 48 are not limited, and for example, a metal ring, a rubber ring, or the like can be used.

  According to this configuration, the fluid pressurized by the fluid pump 26 flows into the cylinder 28, and a part of the fluid in the cylinder 28 flows into the first flow path 36a. However, since the valve element 40b of the return valve 40 is in the closed position, the fluid reaches the end of the first flow path 36a, but does not flow into the second flow path 36b via the return valve 40. Therefore, after the first flow path 36a and the inside of the cylinder 28 are filled with the fluid, the pressure of the fluid which is going to flow into the cylinder 28 further receives the pressure of the piston 30 in the direction from the main body 12 toward the mounting portion 14. Then, the cutting operation by the base 16 is performed.

  After the cutting operation by the base 16 is performed, the operator presses the pressing surface 32 a of the return pin 32 via the return lever 31. Thereby, the operating portion 32b of the return pin 32 moves in the direction toward the first flow path 36a, that is, in the direction opposite to the direction in which the valve body 40b of the return valve 40 is urged by the urging member 40a to the closed position. Then, the valve body 40b is pushed. Therefore, the valve element 40b is in the open position, and the second flow path 36b is opened. As a result, the effect that the pressurized fluid flows from the inside of the first passage 36a into the inside of the second passage 36b is obtained. In this way, an effect is obtained in which the fluid in the cylinder 28 flows through the return passage 36 and flows into the fluid tank 34. As a result, the fluid in the cylinder 28 flows out to the fluid tank 34, so that the pressure of the fluid in the cylinder 28 decreases. Therefore, the urging force of the urging member 42 provided in the cylinder 28 exceeds the pressure, and the piston 30 is pushed in the direction from the mounting portion 14 toward the main body 12. That is, an action of retracting the piston 30 to the starting position is obtained.

  In the conventional power tool 10 illustrated in Patent Document 1, the entirety of the return pin 32 related to the retraction mechanism of the piston 30 is entirely outside the fluid tank 34 (for example, on the battery 18 side of the fluid tank 34). It was a configuration to be arranged. On the other hand, in the present invention, the return pin 32 is configured such that the pressing surface 32a is exposed from the outer wall portion 34a of the fluid tank 34, and the other portion is disposed inside the fluid tank 34. And According to this configuration, the space in which the return pin 32 is provided in the main body 12 can be reduced, so that the total length of the power tool 10 can be shortened (up to about 15%), and downsizing can be realized. it can. Along with this, the member provided at the portion of the main body 12 where the return pin 32 is provided, for example, the central member 44 formed by using a metal member (for example, iron) is reduced. 26 can be shortened. As a result, the material cost can be reduced, the weight can be reduced, and the operation burden on the operator can be reduced.

(Modification 1)
As a modified example, as shown in FIG. 4, a main body 33 of the return pin 32 is inserted into an outer wall 34a of the fluid tank 34 and a first main body 33a provided with a pressing surface 32a at one end, It is also conceivable to adopt a configuration having a structure having a second main body portion 33b provided at a predetermined distance away from and in contact with the other end of the first main body portion 33a. As an example, the first main body portion 33a is externally fitted to a shaft 32c extending at one end of the second main body portion 33b, is connected to be reciprocable with each other, and is connected to the other end of the second main body portion 33b. It has a configuration in which an operating portion 32b is provided.

  According to this configuration, the first main body 33a and the second main body 33b move together for the first time when the first main body 33a comes into contact with the second main body 33b when pushed for a predetermined distance. It is possible. That is, even when the first main body 33a is pressed, the pressing of the return pin 32 is not started until the first main body 33a comes into contact with the second main body 33b. Therefore, according to the present example, even when the insertion portion of the main body 33 moves toward the inside of the fluid tank due to deformation or vibration of the fluid tank 34, the return pin 32 (the shaft 32c) is accordingly moved. Moving can be prevented. As a result, unintentional movement of the return pin 32 (the shaft 32c) causes the valve body 40b of the return valve 40 to be in the open position, thereby preventing adverse effects such as the fluid flowing backward from the fluid tank 34 to the return flow path 36. can do.

(Modification 2)
Further, as another modified example, as shown in FIG. 5, the return pin 32 may be configured such that the main body 33 and the pressing surface 32 a provided at one end of the main body 33 are both inside the outer wall 34 a of the fluid tank 34. It is also conceivable to adopt a configuration that is provided in the system. That is, the entirety of the return pin 32 is disposed inside the fluid tank 34. More specifically, the return pin 32 is pressed by a predetermined distance at a pressing point 34b provided on an outer surface of an outer wall portion 34a of which the pressing surface 32a is elastically deformable by an elastomer material of the fluid tank 34. In this case, the pressing point 34b is arranged so that it can be brought into contact with a contact point 34c provided on the inner surface in a positional relationship between the front and back with respect to the pushing point 34b. Since the pushing point 34b is provided inside the power tool 10 corresponding to the return lever 31 outside, the operator can press the pushing point 34b by pushing the return lever 31.

  According to this example, since the insertion portion of the main body portion 33 can not be provided on the outer wall portion 34a of the fluid tank 34, it is possible to prevent the fluid from flowing out from the insertion portion. Further, the entire length of the return pin 32 can be reduced by disposing the entirety of the return pin 32 inside the fluid tank 34. Thereby, the power tool 10 can be reduced in weight and material cost can be reduced. Furthermore, since the contact of the return pin 32 with the outside air is eliminated, the surface treatment (for example, oxide film treatment, plating, etc.) process of the return pin 32 formed by a metal member (for example, iron) can be omitted. . As a result, manufacturing costs can be reduced.

  As described above, according to the power tool of the present invention, the return pin related to the piston retreat mechanism is entirely or partially disposed inside the fluid tank. Further, it is disposed at a position where it is pushed directly or via an outer wall portion of the fluid tank which is configured to be elastically deformable. Thereby, the space where the return pin is provided in the main body can be reduced as compared with the conventional power tool in which the entire return pin is disposed outside the fluid tank. Therefore, the overall length of the power tool can be shortened, and downsizing can be realized. Along with this, it is possible to reduce the number of central members provided at the portion where the return pin is provided in the main body, and to further reduce the overall length of the fluid pump. As a result, the material cost can be reduced, and the weight can be reduced, so that the operation burden on the operator can be reduced.

  The present invention is not limited to the embodiments described above, and can be variously modified without departing from the present invention.

Reference Signs List 10 power tool 12 main body part 14 mounting part 16 tool head (base)
18 Battery 22 Start switch knob 23 Electric motor 26 Fluid pump 28 Cylinder 30 Piston 31 Return lever 32 Return pin 32a Pushing surface 32b Actuator 32c Shaft 33 Body 33a First body 33b Second body 34 Fluid tank 34a Outer wall 34b Pushing point 34c Contact point 36 Return flow path 36a First flow path 36b Second flow path 40 Return valve

Claims (6)

A piston, which is reciprocally housed in a cylinder provided in the main body and is pushed by the pressure of the fluid, and a tool head which is connected to the tip of the main body and performs a predetermined operation by pushing the piston. A power tool driven by an electric motor,
A return flow path that communicates from the cylinder to a fluid tank that stores the fluid, and that allows the fluid to flow;
A return valve for opening and closing the return flow path;
A return pin that pushes the return valve to an open position by pushing in a predetermined direction,
The power tool according to claim 1, wherein the return pin is entirely or partially disposed inside the fluid tank. The return pin has a main body, and a pressing surface provided at one end of the main body. The main body penetrates an outer wall of the fluid tank, and the pressing surface includes the fluid tank. The power tool according to claim 1, wherein the power tool is disposed so as to be exposed outside the outer wall portion of the power tool. The main body is inserted into the outer wall of the fluid tank and is provided with the pushing surface at one end, and is separated from and abuts a predetermined distance from the other end of the first main body. And a second main body provided so as to be able to contact the second main body when the first main body is pushed by the predetermined distance. The power tool according to claim 2, wherein the second main body is integrally movable. The return pin has a main body and a pressing surface provided at one end of the main body, and both the main body and the pressing surface are disposed inside the outer wall of the fluid tank. The power tool according to claim 1, wherein the power tool is used. The return pin is configured such that when the pressing surface is pressed by a predetermined distance, the pressing surface provided on the outer surface of the outer wall portion configured to be elastically deformable of the fluid tank is moved relative to the pressing point. 5. The power tool according to claim 4, wherein the power tool is provided so as to be able to contact a contact point provided on an inner surface having a front-to-back positional relationship. The power tool according to any one of claims 2 to 5, wherein the outer wall portion of the fluid tank is formed using an elastomer material.

Images