JP4184471B2 - Air tool power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air tool such as an impact wrench or an air grinder operated by air pressure.
[0002]
[Prior art]
An air tool requires not only high-pressure air for driving its mechanical mechanism, but also an electric circuit built in to control the mechanism, that is, power for operation of a control board, a display lamp, etc. To do.
Therefore, in a conventional air tool that does not have an internal power supply, it is necessary to separately supply power by connecting a power supply cord in addition to a high-pressure air supply pipe.
In addition, in order to supply electric power to the air tool, there is an internal power supply type in which a storage battery is built in the air tool body.
[0003]
[Problems to be solved by the invention]
By the way, as in the former technique, connecting the two wires of the high-pressure air supply pipe and the power supply cord to the air tool reduces the operability of the air tool by routing the cord for securing the power supply. It will be bad. In the latter technology, a large-capacity storage battery is required due to an increase in power consumption of the electric circuit accompanying the advancement of control of the air tool, and the operability of the air tool deteriorates due to the increase in weight associated with the built-in storage battery. As well as battery replacement and charging.
[0004]
In view of the above problems, an object of the present invention is to provide a lightweight built-in power supply device that does not deteriorate the operability of an air tool.
Furthermore, an object of the present invention is to cool a heat generating part such as a control board by using low-temperature air obtained by incorporating a power supply device that uses high-pressure air for power generation.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an air tool power supply device according to the present invention is a spiral device for diverting high-pressure air to be introduced to obtain high-temperature air and low-temperature air in a power supply device for an air tool provided with a pneumatically operated mechanism. A built-in type shunt and a thermal power generator that generates electricity by the thermoelectric effect obtained by introducing the obtained high-temperature air and low-temperature air, generates power using high-pressure air used to drive the air tool, and generates the thermal power A control board of the control unit is arranged across a partition wall that divides the space on the low-temperature air side of the cooler, and the control board is cooled via the low-temperature air exhausted from the thermal power generator and the partition wall. It is characterized by that.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a power supply device for an air tool according to the present invention will be described with reference to the illustrated embodiments.
[0007]
FIG. 1 shows a hydraulic torque wrench as an example of an air tool to which a power supply device for an air tool of the present invention is applied.
The mechanism portion 2 of the torque wrench 1 mainly includes an air motor 20 that generates rotational torque, and a hydraulic impact torque generating device 21 that converts the rotational torque of the air motor 20 into impact torque and transmits the impact torque to the main shaft 22. As prepared. The high-pressure air that drives the air motor 20 is supplied to the air motor 20 through the supply path of the handle portion 10 and through the main valve operated by the trigger 11 and the forward / reverse rotation switching valve operated by the lever 12, thereby driving the air motor 20. The air is similarly exhausted from the exhaust port 13 through the exhaust passage passing through the handle portion 10.
[0008]
The hydraulic torque wrench 1 is provided with a magnetostrictive torque detection mechanism 33 for detecting torque applied to the main shaft 22 at the front part of the apparatus and a control board 34 for controlling the torque wrench 1 at the rear part. A control unit 3 is provided. The control unit 3 is provided with a control board 30, a display lamp 31 made of a light emitting diode, and a small-capacity storage battery 32.
Therefore, the control board 34 and the control unit 3 of these torque detection mechanisms 33 require a power source for their operation.
[0009]
Therefore, in this device, the power supply device 4 is built in between the air motor 20 and the control unit 3.
The power supply unit 4, the spiral flow divider 5 to obtain a hot air and cold air to divert high-pressure air introduced into the hydraulic torque wrench 1, load the temperature difference by introduction of hot air and cold air obtained Thus, the power generation means includes a thermal power generator 6 that generates power by the thermoelectric effect.
[0010]
Here, the spiral shunt 5 and the thermal power generator 6 will be briefly described. FIG. 2 shows the structure of the spiral shunt 5.
The spiral flow divider 5 has an axial hole 50a with one end closed, a cylindrical base body 50 having a plurality of radial discharge holes 50b in the vicinity of one end of the axial hole 50a, and screwed into one end of the base body 50. In addition, a conical portion 51a at the front end constricts the opening portion of the radial discharge hole 50b, and includes a valve body 51 that adjusts the discharge amount and a nozzle body 52 that closes the other end of the base body 50. The nozzle body 52 has an axial hole 52a having a smaller diameter than the axial hole 50a. The axial hole 52a is countersunk to the same diameter as the axial hole 50a at a contact portion with the base body 50, and the countersink hole 52b. A plurality of (six strips in the figure) narrow grooves 52c extending in the tangential direction with respect to the counterbore hole 52b are formed on the outer periphery of the groove 52b.
[0011]
The spiral flow divider 5 configured as described above introduces high-pressure air as a circumferential flow with respect to the axial hole 50a through the narrow groove 52c, thereby generating a swirling flow in the axial hole 50a and having a diameter at the end thereof. direction hole 50b side, the hot air as indicated by the solid line arrow is discharged in Figure 2, the axial bore 52a side, has a characteristic of low temperature air is discharged as indicated by a dotted line arrow in FIG.
[0012]
On the other hand, FIG. 3 shows the structure of the thermal power generator 6.
The thermoelectric generator 6 has a P-type element 61 and an N-type element 62, which are made of an N-type compound semiconductor in which a carrier carrying current is a hole and a P-type carrier and is an electron, joined via a copper junction electrode. A large number of pairs of PN pairs are connected in series in order to increase the amount of heat exchange and arranged in a plane, and a ceramic substrate 63 such as alumina having high insulation and good thermal conductivity is bonded to the outside of the bonding electrode. Have a configuration.
[0013]
The thermoelectric power generator 6 configured in this way has one end of the ceramic substrate 63 as the heat absorbing surface H and the other as the heat radiating surface L, so that a temperature difference is applied to both surfaces, thereby generating thermal energy by the Seebeck effect. Directly converted into electrical energy, a thermoelectromotive force is generated between the lead wire 64 connected to one end of the bonding electrode and the lead wire 65 connected to the other end.
[0014]
FIG. 4 shows, in cross section, a power supply device 4 in which such a spiral flow shunt 5 and a power generation means incorporating a thermal power generator 6 are combined.
The tangential narrow groove 52 c of the spiral flow divider 5 is connected to the air supply path 70, and the axial hole 52 a is connected to one space A of the power generation means partitioned by the thermal power generator 6 through the connection path 72. The radial hole 50 b is connected to the other space B of the power generation means by a connection path 71. A low-temperature air discharge path 73 from one space A is connected to the exhaust port 13 of the air tool 1 via the control unit 3 provided with the control board 30 and the like so as to cool the heat generating part such as the control board 30. The exhaust passage 74 that communicates with the exhaust passage 74 and the exhaust passage 76 for discharging the high-temperature air from the other space B communicate with the exhaust passage 74 directly.
In this case, the air supply path 70 for introducing the high-pressure air into the spiral flow divider 5 usually adopts a form branched from the intake path to the air motor 20.
Further, if necessary, a heat insulating material can be disposed around the power generation means incorporating the spiral flow divider 5 and the thermal power generator 6.
[0015]
In the torque wrench 1 consisting of such construction, supply of the high pressure air which is initiated by operation of the trigger 11 is branched into a hot air and cold air supply to the spiral flow divider 5, heat power of each power generation means It is supplied to the space A and the space B so as to flow along the heat absorbing surface H and the heat radiating surface L of the generator 6, whereby the thermoelectric generator 6 is loaded with a temperature difference and generates power.
The electric power obtained by this power generation is supplied to the control unit 2, that is, the control board 30 through the lead wires 64 and 65, and is converted to an appropriate voltage by a DC-DC converter (not shown) on the control board, so that the circuit directly It is used for the operation of the circuit while storing it in the small capacity storage battery 32 and using it as a buffer.
[0016]
Further, a low-temperature air discharge path 73 from one space A of the power generation means partitioned by the thermal power generator 6 is connected to the exhaust port 13 of the air tool 1 through the control unit 3 provided with the control board 30 and the like. By communicating with the exhaust path 74 that communicates, the heat generating part such as the control board 30 is cooled.
As described above, the heat generating part such as the control board 30 is directly cooled by the low-temperature air introduced into the control part 3, and when no heat insulating material is provided around the power generating means, It can cool indirectly through the partition W which divides one space A and the control part 3. FIG.
[0017]
As mentioned above, although the example which applied the hydraulic torque wrench to the power supply apparatus of the air tool of this invention was demonstrated, this power supply apparatus is widely applied as a power supply apparatus of air tools, such as an impact wrench and an air grinder operated by air pressure. It is something that can be done.
[0018]
【The invention's effect】
According to the power supply device for an air tool of the present invention, high-temperature air and low-temperature air are generated from the high-pressure air supplied to drive the tool by using a spiral-type shunt, and the temperature difference caused thereby is used to generate heat. The power tool can be used to generate power and operate the controller with that power to control the mechanism, eliminating the need for a power supply cord for control power supply and a built-in large storage battery. Therefore, the operability of the air tool can be improved.
[0019]
Then, a control board of the control unit is disposed across a partition wall that divides the space on the low-temperature air side of the thermal power generator, and the control board is disposed via the low-temperature air exhausted from the thermal power generator and the partition wall. It is possible to cool, thereby accelerating the heat dissipation of the control board, preventing the temperature of the board from rising, stabilizing the control operation, and making the control of the air tool more reliable.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a hydraulic torque wrench including a power supply device according to an embodiment of the present invention.
FIGS. 2A and 2B show a spiral shunt of the power supply device, in which FIG. 2A is a front cross-sectional view, and FIG.
FIGS. 3A and 3B show a thermal power generator of the power supply device, wherein FIG. 3A is a front view and FIG. 3B is a side view.
FIG. 4 is a front sectional view of the power supply device.
[Explanation of symbols]
1 Hydraulic torque wrench (air tool)
2 Mechanism part 3 Control part 30 Control board (heat generation part)
4 Power supply device 5 Spiral shunt 6 Thermal power generator 7 Low temperature air discharge path 8 Exhaust path 9 High temperature air discharge path

Claims (1)

In a power supply device for an air tool equipped with a pneumatically operated mechanism, a spiral-type shunt that diverts the introduced high-pressure air to obtain high-temperature air and low-temperature air, and thermoelectric power generated by introducing the obtained high-temperature air and low-temperature air A thermal power generator that generates electricity by the effect, generates power using high-pressure air used to drive the air tool, and separates a partition partitioning a space on the low-temperature air side of the thermal power generator, A power supply device for an air tool, characterized in that a control board is provided and the control board is cooled via low-temperature air exhausted from the thermoelectric generator and a partition wall .

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