Power units and power tools

Abstract

A power unit (20) delivers hydraulic oil under pressure to an electric tool head (11) and drives the electric tool head (11), the electric tool head (11) having mounted thereto a piston for operating a tool. The power unit (20) is provided with a first power unit (20a) and a second power unit (20b). The first power unit (20a) has a first hydraulic pump (23a), a first motor (21a), and a first flow passage (e) which delivers the hydraulic oil under pressure from the first hydraulic pump (23a) to the electric tool head (11). The second power unit (20b) has a second hydraulic pump (23b), a second motor (21b), and a second flow passage (f) which delivers the hydraulic oil under pressure from the second hydraulic pump (23b) to the electric tool head (11). The power unit (20) is further provided with: a combining joint (12) for combining the first flow passage (e) and the second flow passage (f); a pressure restriction device (26) for restricting an increase in pressure in the first flow passage (e); and a return device (25) for discharging the hydraulic oil from the second flow passage (f) to thereby enable the return operation of the piston. As a result of this configuration, the discharge performance is enhanced, enabling the application of the power unit to multiple variations.

Description

technical field [0001] The invention relates to a power unit and an electric tool. Background technique [0002] An electric tool having a power unit that drives a hydraulic pump by rotating a motor with a power source from a battery pack is widely used because it can be operated at a workplace far from the power source. [0003] Electric tools use a battery pack with a battery inside as a power source to rotate and drive a motor. The motor rotates and drives a hydraulic pump to generate hydraulic pressure, which is sent to the hydraulic cylinder to move the piston. In addition, the electric tool performs machining with a tool provided at the tip of the piston. Among these electric tools, a cutting tool for cutting thin wires and electric wires, a compression tool disclosed in Patent Document 1 and the like used when connecting crimp terminals to ends of electric wires are known. [0004] The compression tool is such an electric tool: after the piston 6 (refer to figure 2...

AI Technical Summary

Problems solved by technology

[0011] But, there is such problem in the structure of electric tool in the past, as Image 6 As shown in (b) and (c), even if multiple configurations of battery packs are connected in series and in parallel, since there is only one hydraulic pump, the discharge performance cannot be improved.

[0012] Additionally, if Image 6 As shown in (a), when a plurality of conventional power tools are installed, there is a problem that the weight increases, operability is hindered, and the cost increases.

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