JP6709723B2 - Electric tool - Google Patents

Description

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

BACKGROUND ART Conventionally, a power tool that is driven by an electric motor to perform a predetermined operation, such as a crimping tool for fixing a crimp terminal to a wire or a cable, a cutting tool for cutting a wire or a cable, has been known.

As an example, an electric tool described in Patent Document 1 has been proposed. This electric tool is a cordless type having a detachable battery in its main body, and a hydraulic pump is driven by an electric motor while an operator is pushing an activation switch knob. With this hydraulic pressure, the piston is pushed, and the action of closing the tip of the die in the tool head is obtained. As an example, if a crimping tool head is used, it can be used as a crimping tool for fixing crimp terminals to wires and cables. Alternatively, if a tool head for cutting is used, it can also be used as a cutting tool for cutting wires and cables.

JP, 2013-066897, A

Here, in the conventional electric tool as exemplified in Patent Document 1, when the work of crimping or cutting is completed, the piston is returned to the original position by the operation of the return lever, and the standby state for the next work is set. It was a configuration to do. Therefore, since the worker must once remove his finger from the start switch knob and push the return lever again, there has been a problem of an increase in labor and time due to an increase in operation by one step.

As a solution, a power tool having an automatic retreat function that automatically returns the piston to the starting position when the work is completed has also been developed. However, there are problems that the function cannot be canceled when the automatic reverse function is not required, and that the automatic reverse function cannot be stopped halfway during the operation. If the structure is such that the return valve that electrically returns the piston from the outside is operated, it is possible to cancel the function or stop halfway, but since a solenoid or a motor that electrically operates the return valve is required, Problems such as complicated structure, increased weight, and increased manufacturing cost may occur. Alternatively, a method may be considered in which the return valve is closed when the start switch knob is pushed and the return valve is opened when the start switch knob is released, but another problem that temporary pressing cannot be performed during work may occur.

The present invention has been made in view of the above circumstances, and with a simple structure using a hydraulic mechanism, it is possible to realize an automatic retreat function that automatically returns a piston to a starting position when work is completed, and an automatic retreat function. It is an object of the present invention to provide an electric power tool that can easily add a mechanism for releasing or stopping the operation.

As one embodiment, the above-mentioned problems are solved by the solution means disclosed below.

The disclosed electric power tool includes a piston that is reciprocally housed in a cylinder provided in a main body and is pushed by a fluid pressure, and a predetermined operation that is connected to a tip of the main body and is pushed by the piston. Is a power tool driven by an electric motor, the return flow path communicating the fluid from the cylinder to a fluid tank storing the fluid and allowing the fluid to flow therethrough; And a pressure regulating valve that is disposed in the operation flow path that branches off from and that is in an open position when the pressure of the fluid in the return flow path exceeds a predetermined value, and the pressure control valve that is disposed in the operation flow path. The operating pin pushed by the pressure of the inflowing fluid and the return valve which is disposed in the return passage and is in the open position by the pushing of the operating pin are required.

According to the present invention, without providing a solenoid or a motor for electrically operating the return valve, the simple mechanical structure using the hydraulic mechanism automatically moves the piston to the starting position when the predetermined work is completed. An automatic retract function for returning can be realized. In addition, it is possible to easily add a mechanism for canceling the automatic retreat function or stopping the automatic stop.

It is a perspective view (schematic diagram) which shows the example of the electric tool which concerns on embodiment of this invention. It is a front view (schematic diagram) of the electric tool shown in FIG. It is the schematic which shows the example of the internal mechanism of the electric tool shown in FIG. FIG. 2 is an enlarged view (schematic diagram) centering on a portion related to a piston pushing mechanism of the power tool shown in FIG. 1. It is an enlarged view (schematic diagram) centering on the part relevant to the mechanism which performs the automatic retreat function of the piston of the electric tool shown in FIG. It is explanatory drawing for demonstrating the automatic retreat function of the piston of the electric tool shown in FIG. It is an enlarged view (schematic diagram) centering on the part relevant to the mechanism which cancels the automatic retreat function of the piston of the electric tool shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view (schematic diagram) showing an example of the electric power tool 1, and FIG. 2 is a front view (schematic diagram). Further, FIG. 3 is a schematic diagram showing an example of an internal mechanism of the electric power tool 1. Further, FIG. 4 is an enlarged view (schematic diagram) centering on a portion related to the pushing mechanism of the piston 36 of the electric power tool 1. In all the drawings for explaining the embodiments, members having the same function are designated by the same reference numeral, and repeated description thereof may be omitted.

As shown in FIGS. 1 to 4, the electric power tool 1 according to the present embodiment is a cordless type electric power tool that an operator can grip and work with one hand. The tool head at the tip is configured to be replaceable. For example, by providing a tool head 14 for crimping at the tip portion, it can be used as a crimping tool for crimping a cable or the like and a crimp terminal by crimping. On the other hand, by providing a tool head (not shown) having a cutting cutter at the tip, it can be used as a cutting tool for cutting a cable or the like. Hereinafter, as the electric power tool 1 according to the present embodiment, a case of a crimping tool will be described as an example.

This electric power tool 1 is attachable to and detachable from a gun-shaped main body 10 that an operator grips, a mounting portion 12 provided at a tip end thereof, a tool head 14 that is replaceably mounted on the mounting portion 12. And a rechargeable battery 16. Further, inside the main body portion 10, an electric motor 22 driven by a power source of a battery 16, and a fluid pump (for example, hydraulic pressure) that is driven by the electric motor 22 to pressurize a fluid (operating oil, for example). A pump) 24, a control unit (not shown) for controlling driving, etc. are provided.

In the electric tool 1 having the above configuration, the tool head 14 performs a predetermined operation by the pressure of the fluid pressurized by the fluid pump 24. Hereinafter, a series of operations will be specifically described by taking the case where the tool head 14 performs the crimping operation as an example.

First, the electric motor 22 is driven by the worker pushing the start switch knob 18 of the main body 10. At this time, the rotational force is transmitted from the electric motor 22 via the speed reduction mechanism 26, and is converted by the swash plate cam 28 into the driving force of the direct-acting fluid pump 24. The fluid pressurized by the fluid pump 24 flows through the discharge flow passage 32 and flows into the cylinder 34 provided in the main body 10. In response to the pressure of this fluid, the piston 36 reciprocally housed in the cylinder 34 is pushed in one direction (direction toward the tip of the main body 10). Here, the operation arm 14 a of the tool head 14 is connected to the tip of the piston 36, and is pushed together with the piston 36 toward the tip of the main body 10. Therefore, by accommodating the cable and the crimp terminal between the fixed arm 14b of the tool head 14 and the operation arm 14a, the action of crimping these can be obtained.

In addition, in the present embodiment, the electric motor 22 is driven by supplying power from the battery 16 only while the activation switch knob 18 provided in the main body 10 is being pushed. However, the configuration is not limited to this, and when the start switch knob 18 is pushed, the driving of the electric motor 22 is started, and when the start switch knob 18 is pushed next, the electric motor 22 is driven. It is also possible to adopt a configuration in which the driving of is stopped.

Further, the electric power tool 1 according to the present embodiment has an automatic retreat function for automatically returning the piston 36 to the starting position when the work is completed. Here, a configuration for realizing the automatic backward movement function will be described in detail. FIG. 5 is an enlarged view (cross-sectional view) in plan view centering on a portion related to the mechanism for performing the automatic retract function, and FIG. 6 is an explanatory diagram for explaining the automatic retract function.

As shown in FIG. 5, a return passage 40 is provided which communicates from the cylinder 34 to a fluid tank (not shown) which stores the fluid and allows the fluid to flow therethrough. Here, an operation flow path 42 that branches from the return flow path 40 is provided, and a pressure regulating valve 44 that opens and closes the operation flow path 42 is provided in the middle of the operation flow path 42. The pressure regulating valve 44 serves to open the operation flow passage 42 when the pressure of the fluid in the return flow passage 40 becomes equal to or higher than a predetermined value so as to be in the open position.

According to this configuration, when the predetermined operation by the tool head 14 (as an example, the crimping operation) is completed, the fluid pressurized by the fluid pump 24 continues in the cylinder 34 in the state where the pushing motion of the piston 36 is stopped. As a result, the pressure of the fluid in the cylinder 34 and the return passage 40 communicating with the cylinder 34 becomes equal to or higher than a predetermined value set in advance. Therefore, since the pressure regulating valve 44 is in the open position and the operation flow path 42 is opened, the action of the pressurized fluid flowing from the return flow path 40 into the operation flow path 42 is obtained. By the way, normally, the operator can confirm that the predetermined operation by the tool head 14 is completed by the sound generated when the pressure regulating valve 44 is in the open position, and therefore the operation of pushing the start switch knob 18 is stopped.

Next, in the operation flow path 42, the tip end portion 46 a projects outside the operation flow path 42 at a position downstream of the pressure regulating valve 44 (side away from the branch portion with the return flow path 40 ). The operation pin 46 is provided so as to be able to reciprocate in the operation flow path 42 in this state. The operation pin 46 is normally urged by the urging member in the direction in which the distal end portion 46 a is directed into the operation flow passage 42, and the operation flow passage 42 is opened to allow the operation flow passage 40 to be operated. When a pressurized fluid flows into the passage 42, the pressure of the inflowing fluid pushes the fluid toward the outside of the operation flow passage 42.

With this configuration, when the pressure regulating valve 44 is in the open position and the operation flow path 42 is opened, the pressure of the fluid flowing from the return flow path 40 into the operation flow path 42 causes the operation pin 46 to move. An effect is obtained in which the tip end portion 46 a is pushed in the direction toward the outside of the operation flow channel 42.

Next, the return flow passage 40 is provided with a return valve 48 that opens and closes the return flow passage 40 at a position downstream of the branch portion with the operation flow passage 42 (side away from the branch portion). There is. The return valve 48 has a spherical valve body 48a, and normally urges the valve body 48a in one direction (in this case, toward the inside of the operation flow passage 42) to a closed position by an urging member. When the valve body 48a is pushed in the opposite direction (here, the direction toward the outside of the operation flow path 42) by the tip end portion 46a of the operation pin 46, the valve body 48a is opened and the return flow path 40 is opened. It acts to cause it.

According to this configuration, when the tip end portion 46a of the operation pin 46 is pushed in the direction toward the outside of the operation flow path 42 by the pressure of the fluid flowing from the inside of the return flow path 40 into the operation flow path 42, The return valve 48 is in the open position, and the return passage 40 is opened. Therefore, the fluid in the cylinder 34 flows through the return passage 40 and flows out to the fluid tank. At this time, since the operation of pushing the start switch knob 18 is stopped, the action of pushing the piston 36 in one direction (direction toward the tip of the main body 10) does not occur. Therefore, since the fluid in the cylinder 34 flows out to the fluid tank to reduce the pressure of the fluid in the cylinder 34, the urging force of the urging member 38 provided in the cylinder 34 exceeds the pressure. The piston 36 is pushed in the opposite direction (the direction away from the tip of the main body 10). That is, a retreat function for returning the piston 36 to the starting position is obtained. By the way, if the operation of pushing the start switch knob 18 is continued when the work is finished, the fluid flows from the discharge passage 32 into the cylinder 34 while flowing out from the cylinder 34 to the return passage 40. In this state, the piston 36 does not move in either direction.

As described above, when the worker presses the activation switch knob 18 of the main body 10 to operate the tool head 14 to perform a predetermined work (crimping or the like), when the work is finished, the tool head The movement of the movable part of 14 (as an example, the fixed arm 14b) stops (see FIG. 6A). At this time, since the pushing motion of the piston 36 is also stopped, the pressure of the fluid in the cylinder 34 and the return passage 40 communicating with the cylinder 34 becomes a predetermined value or more. As a result, the pressure regulating valve 44 is brought to the open position to open the operation flow path 42, and the pressurized fluid flows from the return flow path 40 into the operation flow path 42 (FIG. 6B). reference). As a result, the tip portion 46a of the operation pin 46 is pushed in the direction toward the outside of the operation flow path 42 by the pressure of the fluid flowing into the operation flow path 42, and the return valve 48 is in the open position (FIG. 6). (See (c)). Therefore, the return flow passage 40 is opened, and the fluid in the cylinder 34 flows through the return flow passage 40 and flows out to the fluid tank, so that the pressure of the fluid in the cylinder 34 decreases and the biasing member 38 The urging force returns the piston 36 to the starting position. That is, an automatic retreat function for automatically returning the piston 36 to the starting position upon completion of the work is realized.

According to the above configuration, the automatic retraction function of the piston 36 can be realized by a simple mechanical structure, specifically, a simple hydraulic mechanism using an operation flow path, an opening/closing valve, and the like. Therefore, since it is not necessary to provide a solenoid or a motor for electrically operating the return valve, it is possible to solve problems such as a complicated structure, an increase in weight, and an increase in manufacturing cost.

Furthermore, since the automatic reverse function is realized by using a simple hydraulic mechanism, it is possible to easily add a mechanism for canceling the automatic reverse function or a mechanism for stopping the automatic reverse function. Hereinafter, those mechanisms will be described in detail. FIG. 7 is an enlarged view (cross-sectional view) of a front view centering on a portion related to a mechanism for canceling the automatic retreat function and stopping on the way.

As shown in FIG. 7, an opening flow path 52 is provided that branches from the operation flow path 42. The branch portion is provided at a position between the disposition position of the pressure regulating valve 44 and the disposition position of the operation pin 46. Here, a pressure release valve 54 that opens and closes the opening flow path 52 is provided in the middle of the opening flow path 52. The pressure release valve 54 has a spherical valve body 54a, which is normally urged in one direction by the urging member so that the valve body 54a is in the closed position, and the valve 56 is opened by the tip portion 56a of the release pin 56. When the body 54a is pushed in the opposite direction, the body 54a is in the open position and has the action of opening the opening flow path 52.

According to this configuration, when the pressure regulating valve 44 is in the open position to open the operation flow path 42 and the fluid flows from the return flow path 40 into the operation flow path 42, the pressure is released. When the valve 54 is in the open position and the opening flow path 52 is opened, the fluid flows out from the operation flow path 42 to the opening flow path 52, so that the operation flow is obtained. The pressure in the passage 42 does not rise, and the action of pushing the operating pin 46 does not occur. Therefore, the return valve 48 does not reach the open position, and the return flow passage 40 does not open, so that the above-described retracting function of returning the piston 36 to the starting position does not work. On the contrary, when the pressure release valve 54 is in the closed position and the opening flow path 52 is not opened when the fluid flows from the return flow path 40 into the operation flow path 42, The retreat function for returning the piston 36 to the starting position acts.

In the present embodiment, a cam that performs an opening/closing operation of the opening flow path 52 (here, an opening position operation), that is, an operation (pushing) of the opening pin 56 that pushes the pressure release valve 54 to the opening position. Equipped with 60. The cam 60 is rotatably arranged and is normally urged in one direction, and is rotated in the opposite direction (direction of arrow A) to a predetermined position to open the pin. It serves to push 56, that is, to bring the pressure release valve 54 to the open position.

Here, the following two configurations are provided as an operating unit that operates (rotates) the cam 60 to a predetermined position.

As a first configuration of the operation unit, a link unit 62 that is connected to the activation switch knob 18 and converts movement of the activation switch knob 18 into rotation of the cam 60 is provided. According to this, in a state where the predetermined work by the tool head 14 is finished and the above-mentioned automatic retreat function is started, and the worker has stopped pushing the start switch knob 18, the worker again Pushes the start switch knob 18 (it is not necessary to continue pushing, it is sufficient to push once), and the tip portion 62a of the link portion 62 connected to the start switch knob 18 causes the cam 60 to reach a predetermined position. The action of rotating (turning) to the position occurs. Therefore, the pressure release valve 54 is at the open position, and the automatic retreat function of the piston 36 can be stopped during the operation. In this way, it is possible to realize the midway stop mechanism of the automatic retreat function by adding an extremely simple configuration.

As a second configuration of the above-mentioned operation portion, a lever portion 64 having two large and small operating dimensions and abutting against the cam 60 is provided. As an example, the lever portion 64 is a columnar member that is disposed so as to be movable in a direction parallel to the rotation axis C of the cam 60 and that can come into contact with the cam 60 with two working radii. According to this, an action (rotation) of the cam 60 is caused by bringing the portion of the lever portion 64 having a large action size into contact with the cam 60. It should be noted that the portion of the lever portion 64 having a small operation size may be configured not to contact the cam 60, or configured to contact the cam 60 to such an extent that the cam 60 is not moved (rotated) to a predetermined position.

According to this configuration, the lever portion 64 is moved to one position before the work is started, that is, before the start switch knob 18 is pushed, so that the portion having a small action size does not contact the cam 60 (or reaches a predetermined position). When the cam 60 is brought into a contact state in which it does not rotate, the cam 60 is not operated (rotated) to a predetermined position, so that the automatic retreat function can be activated. On the contrary, if the lever portion 64 is moved to the other position before the start switch knob 18 is pushed so that a portion having a large action size comes into contact with the cam 60, the cam 60 moves to a predetermined position. The action of (rotating) occurs. Therefore, the pressure release valve 54 is in the open position, and the automatic retraction function of the piston 36 can be released. In this way, it is possible to realize the cancellation mechanism of the automatic retreat function by adding an extremely simple configuration.

As described above, according to the power tool of the present invention, the predetermined work is completed by the simple mechanical structure using the hydraulic mechanism without providing the solenoid or the motor for electrically operating the return valve. Sometimes it is possible to realize an automatic retract function that automatically returns the piston to the starting position. In addition, it is possible to easily add a mechanism for canceling the automatic retreat function or stopping the automatic stop.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the present invention. In particular, the present power tool has been described by taking a crimping tool as an example, but the present invention is not limited to this and can be suitably applied to a cutting tool and the like.

DESCRIPTION OF SYMBOLS 1 Electric power tool 10 Main body part 12 Attachment part 14 Tool head 14a Operating arm 14b Fixed arm 16 Battery 18 Start switch knob 22 Electric motor 24 Fluid pump 26 Reduction mechanism 28 Swash plate cam 32 Discharge flow path 34 Cylinder 36 Piston 38 Energizing member 40 Return flow path 42 Operation flow path 44 Pressure regulation valve 46 Operation pin 46a Operation pin tip portion 48 Return valve 48a Return valve valve body 52 Opening flow path 54 Pressure release valve 54a Pressure release valve valve body 56 Release pin 56a Opening pin tip 60 Cam 62 Link 62a Link tip 64 Lever

Claims (1)

A piston that is reciprocally housed in a cylinder provided in the main body and is pushed by the pressure of the fluid, and a tool head that is connected to the tip of the main body and performs a predetermined operation by pushing the piston. An electric tool equipped with and driven by an electric motor,
A return flow path that communicates from the cylinder to a fluid tank that stores the fluid and allows the fluid to flow therethrough,
A pressure regulating valve that is disposed in an operation flow path branched from the return flow path and is in an open position when the pressure of the fluid in the return flow path becomes a predetermined value or more,
An operating pin that is disposed in the operating channel and that is pushed by the pressure of the inflowing fluid,
An electric tool, comprising: a return valve, which is disposed in the return flow path and is in an open position when the operation pin is pushed.

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