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US-12623329-B2 - Electric tool

US12623329B2US 12623329 B2US12623329 B2US 12623329B2US-12623329-B2

Abstract

An electric tool is capable of automatic return. The electric tool having an oil tank, a hydraulic pump, a motor, a flow channel part, a trigger lever, a first link fitting that connects the trigger lever to an activation switch, a second link fitting that connects the trigger lever to a return switch, and a spring that biases the trigger lever in a returning direction of the trigger lever. The flow channel part includes a pressure increasing flow channel that communicates with the cylinder part, a return flow channel that communicates with the oil tank, a check valve that opens and closes the return flow channel, and a return pin that pushes the check valve to open the return flow channel.

Inventors

  • Takahito Hirabayashi
  • Masafumi Takeshima

Assignees

  • Maxell Izumi Co., Ltd.

Dates

Publication Date
20260512
Application Date
20220913

Claims (7)

  1. 1 . An electric tool comprising: a main body in which a cylinder part is disposed; and a work attachment connected to the main body and operated by a hydraulic pressure of the cylinder part, wherein the main body includes an oil tank, a hydraulic pump for feeding a hydraulic oil inside the oil tank to the cylinder part, a motor for driving the hydraulic pump, a rechargeable battery for supplying electric power to the motor, a flow channel part through which the hydraulic oil passes, a trigger lever, a first link fitting that connects the trigger lever to an activation switch, a second link fitting that connects the trigger lever to a return switch, and a spring that biases the trigger lever in a returning direction of the trigger lever, the flow channel part includes a pressure increasing flow channel that communicates with the cylinder part from the oil tank to feed the hydraulic oil, a return flow channel that communicates with the oil tank from the cylinder part to return the hydraulic oil, a check valve that opens and closes the return flow channel, and a return pin that pushes the check valve to open the return flow channel, the trigger lever is disposed on a side opposite to a side on which the return switch is disposed with respect to an axis passing through the cylinder part, the first link fitting includes a first contact part in contact with the activation switch, a rod-shaped part disposed along the axis, and a second contact part in contact with the trigger lever, the second link fitting includes a third contact part locked to the return switch, an annular part disposed in a direction intersecting the axis, and a support part supported by the trigger lever, and the trigger lever is configured for performing a series of operations from a pressure increasing operation to a return operation.
  2. 2 . The electric tool according to claim 1 , wherein the first link fitting includes a first contact part in contact with the activation switch, a rod-shaped part disposed along the axis, and a second contact part in contact with the trigger lever, and the second link fitting includes a third contact part locked to the return switch, an annular part disposed in a direction intersecting the axis, and a support part supported by the trigger lever.
  3. 3 . The electric tool according to claim 1 , wherein the main body includes a controller for controlling the motor, and a select switch for limiting an operating range of the trigger lever, the motor, the activation switch, and the controller are sequentially disposed along the axis, and the select switch is disposed close to the trigger lever.
  4. 4 . The electric tool according to claim 1 , wherein the flow channel part includes a pressure regulating valve that regulates a pressure on a high-pressure side, and the pressure regulating valve is disposed at a position closer to the cylinder part than the check valve.
  5. 5 . The electric tool according to claim 1 , wherein the flow channel part includes a pressure regulating valve that regulates a pressure on a high-pressure side, and the pressure regulating valve is disposed at a position closer to the cylinder part than the check valve.
  6. 6 . The electric tool according to claim 1 , wherein the electric tool has a pressure increasing mode in which the trigger lever is pushed to turn on the activation switch to feed the hydraulic oil to the cylinder part, a holding mode in which the trigger lever is returned to an intermediate position to turn off the activation switch in a state where the check valve is closed to hold the hydraulic oil fed to the cylinder part, and a return mode in which the trigger lever is returned to an initial position to open the check valve to return the hydraulic oil to the oil tank.
  7. 7 . The electric tool according to claim 1 , wherein the electric tool has a pressure increasing mode in which the trigger lever is pushed to turn on the activation switch to feed the hydraulic oil to the cylinder part, a holding mode in which the trigger lever is returned to an intermediate position to turn off the activation switch in a state where the check valve is closed to hold the hydraulic oil fed to the cylinder part, and a return mode in which the trigger lever is returned to an initial position to open the check valve to return the hydraulic oil to the oil tank.

Description

RELATED APPLICATIONS The present application is National Phase of International Application No. PCT/JP2022/034200 filed Sep. 13, 2022. TECHNICAL FIELD The present invention relates to a hydraulic electric tool. BACKGROUND ART In the related art, a hydraulic cutting tool having the following configuration has been proposed. In the configuration, a hydraulic oil is supplied by bringing one end side of an activation switch lever (synonymous with a trigger lever) into contact with a power switch (synonymous with an activation switch) and bringing the other end side of the activation switch lever into contact with an operation lever of a return valve (synonymous with a check valve) (PTL 1: JP-A-2001-009630). In addition, a hydraulic crimping tool having the following configuration has been proposed. In the configuration, a slide-type relief button for operating a release valve (synonymous with a check valve) via a lever is disposed in a vicinity of a power switch (synonymous with an activation switch) including a switch handle (synonymous with a trigger lever). While an operation of the switch handle is regulated, a hydraulic oil is supplied and released by operating the switch handle (PTL 2: JP-A-2000-343448 and PTL 3: JP-A-2000-343452). A compression tool or a cutting tool has been proposed as follows. The compression tool or the cutting tool includes a return device including a control substrate that delays opening of a return valve (synonymous with a check valve), a servo motor, a cam, and a lever that engages with a shutter of a return valve (synonymous with a check valve). The compression tool or the cutting tool includes a switch that controls the servo motor such that the lever is set to a position where the return valve is kept open when a drive button (synonymous with an activation switch) is released and the lever is set to a position where the return valve (synonymous with the check valve) is closed when the drive button is driven (PTL 4: JP-A-2017-213671). CITATION LIST Patent Literature PTL 1: JP-A-2001-009630PTL 2: JP-A-2000-343448PTL 3: JP-A-2000-343452PTL 4: JP-A-2017-213671 SUMMARY OF INVENTION Technical Problem The electric tools disclosed in PTL 1 to PTL 3 are inevitably limited to a pistol type main body due to a structure in which the trigger lever and the activation switch are close to each other and the trigger lever and the operation lever of the check valve are close to each other, and cannot be applied to a straight type main body. The electric tool disclosed in PTL 4 has a complicated structure in which the servo motor for closing the check valve is exclusively provided. Consequently, electric tool needs a large-scale configuration, requires additional component costs, and is less likely to be reduced in size. Solution to Problem The present invention is made in view of the above-described circumstances, and an object of the present invention is to provide an electric tool capable of auto-return and having a small configuration and excellent workability. The present invention has been accomplished under the solutions as disclosed below. According to the present invention, there is provided an electric tool including a main body in which a cylinder part is disposed, and a work attachment connected to the main body and operated by a hydraulic pressure of the cylinder part. The main body includes an oil tank, a hydraulic pump for feeding a hydraulic oil inside the oil tank to the cylinder part, a motor for driving the hydraulic pump, a rechargeable battery for supplying electric power to the motor, a flow channel part through which the hydraulic oil passes, a trigger lever, a first link fitting that connects the trigger lever to an activation switch, a second link fitting that connects the trigger lever to a return switch, and a spring that biases the trigger lever in a returning direction of the trigger lever. The flow channel part includes a pressure increasing flow channel that communicates with the cylinder part from the oil tank to feed the hydraulic oil, a return flow channel that communicates with the oil tank from the cylinder part to return the hydraulic oil, a check valve that opens and closes the return flow channel, and a return pin that pushes the check valve to open the return flow channel. The trigger lever is disposed on a side opposite to a side on which the return switch is disposed with respect to an axis passing through the cylinder part. According to this configuration, the activation switch and the trigger lever are connected by the first link fitting, and the return switch and the trigger lever are connected by the second link fitting. Accordingly, a straight type main body can be achieved while a simple configuration can be adopted. A series of operations from a pressure increasing operation to a return operation can be performed by operating the trigger lever in a combination of the activation switch, the first link fitting, the trigger lever, and the second link