FIELD OF THE INVENTION
[0001] The present invention relates to a sander and particularly to a sander capable of
correcting airflow amount.
BACKGROUND OF THE INVENTION
[0002] A conventional machine tool usually is made in a small size and can be coupled with
different application tools to provide various types such as a grinder, sander, drilling
machine, electric wrench and the like. Such a machine tool can aid users to quickly
grind the surface of articles to make it smooth and flat. The machine tool can be
an electric machine tool driven by electric power or a pneumatic machine tool driven
by pressurized air. The conventional pneumatic sander mainly employs the pressurized
air as the power source to drive a sanding tool. During sanding operation air is circulated
inside the pneumatic sander. The air has air pressure to drive the sanding tool to
rotate. While the sanding tool is rotated, the air also must be discharged from the
interior of the pneumatic sander. Discharge of the air generates noises.
[0003] To solve the noise problem caused by discharge of air in the pneumatic sander,
TW patent No. M352423 discloses a machine tool noise muffling structure. It comprises a cap with a plurality
of apertures formed thereon and at least one post extended upwards from the cap. The
post is attached by noise muffling cotton. The cap and noise muffling cotton are interposed
by an air discharge space to discharge air and muffle the noise. While the muffling
cotton can be installed in an exhaust tube of the sander to reduce the noise caused
by discharge of the air, muffling cotton also impedes air circulation and reduces
airflow speed or amount that result in the problem of lowering rotational speed of
the drive motor.
SUMMARY OF THE INVENTION
[0004] The primary object of the present invention is to avert the problem of the machine
tools having reduced airflow amount to lower rotational speed of the motor caused
by block of the airflow due to installation of components in the air passage.
[0005] To achieve the foregoing object, the present invention provides a sander capable
of correcting airflow amount. The sander comprises a body and a correction valve.
The body includes an air intake passage to receive pressurized air, a drive motor
driven by the pressurized air to rotate at a rotational speed including a preset range
and an excessive range, and a regulation valve located on the air intake passage and
operable manually by a user to adjust the rotational speed of the drive motor in the
preset range. The correction valve is located in the air intake passage and coupled
with the regulation valve. The correction valve is installed on the air intake passage
and coupled with the regulation valve, and includes an adjustment portion operable
by a mechanical tool to proceed an adjustment displacement and a mask wall movable
by the adjustment portion to block the air intake passage. The adjustment portion
determines the flow amount of the pressurized air passing through the correction valve
according to the position thereof during the adjustment displacement to confine the
rotational speed of the drive motor from the excessive range to the preset range.
[0006] In one embodiment the proportion of the excessive range to the preset range is less
than 30%.
[0007] In another embodiment the air intake passage has a positioning notch to hold the
correction valve.
[0008] In yet another embodiment the correction valve is fixedly held in the positioning
notch via a clip ring.
[0009] In yet another embodiment the mask wall has an airflow directing hole to allow the
pressurized air to pass through.
[0010] In yet another embodiment the body includes an activation valve stem located on the
air intake passage and the air intake passage has an air nozzle to block the pressurized
air from entering the regulation valve. By pressing the activation valve stem, the
air nozzle is driven to deviate against the regulation valve so that the pressurized
air can pass through the regulation valve.
[0011] In yet another embodiment the body includes an activation member which butts the
activation valve stem and is depressible by a user to move the activation valve stem
downwards so that the air nozzle is deviated against the regulation valve.
[0012] In yet another embodiment the body includes a sanding disk driven by the drive motor
to rotate in a rotational displacement.
[0013] In yet another embodiment the regulation valve includes a control portion operable
manually by a user, and a throttle wall extended from the control portion to the air
intake passage and operable by the user to determine degree of masking the air intake
passage, and an airflow regulation port formed on the throttle wall to allow the pressurized
air to pass through.
[0014] In yet another embodiment the air intake passage includes an air intake duct to allow
the pressurized air to enter the regulation valve. The correction valve is located
between the regulation valve and drive motor to receive the pressurized air from the
regulation valve and send to the drive motor.
[0015] The invention, compared with the conventional techniques, provides many advantages,
notably:
- 1. The air intake passage is provided with a correction state (i.e.
excessive range).
- 2. The problem of reduced airflow amount to lower rotational speed of the motor caused
by block of the airflow due to installation of components in the air passage can be
resolved.
[0016] The foregoing, as well as additional objects, features and advantages of the invention
will be more readily apparent from the following detailed description, which proceeds
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017]
FIG. 1 is an exploded view of the sander providing airflow correction according to
the invention.
FIG. 2 is a sectional view of the sander providing airflow correction according to
the invention.
FIG. 3A is a schematic view of the sander of the invention with the correction valve
fully open.
FIG. 3B is a schematic view of the sander of the invention with the correction valve
half-open.
FIG. 4 is a schematic view of the sander of the invention in a use condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Please refer to FIGS. 1, 2 and 4, the present invention aims to provide a sander
capable of correcting airflow amount. The sander mainly comprises a body 1 and a correction
valve 2. The body 1 includes an air intake passage 11, a drive motor 12, a sanding
disk 13, a regulation valve 14, a positioning notch 15, an activation valve stem 16,
an activation member 17 and an air nozzle 18. The drive motor 12 is driven by pressurized
air to rotate. The sanding disk 13 is driven by the drive motor 12 to proceed a rotational
displacement. The drive motor 12 is rotated at a rotational speed including a preset
range and an excessive range. The proportion of the excessive range to the preset
range is less than 30%. The air intake passage 11 contains an air intake duct 111
to direct the pressurized air into the body 1. The activation valve stem 16 is located
on the air intake passage 11. The air intake passage 11 also contains the air nozzle
18 to block the pressurized air from entering the regulation valve 14 via the air
intake duct 111. The activation valve stem 16 butts the activation member 17 so that
a user can press the activation member 17 to drive the activation valve stem 16 to
move downwards, and consequently move the air nozzle 18 to deviate against the regulation
valve 14 to allow the pressurized air to pass through the regulation valve 14. The
regulation valve 14 is located on the air intake passage 11 and includes a control
portion 141 operable by a user's hand 3, a throttle wall 142 extended from the control
portion 141 towards the air intake passage 11 and operable by the user to determine
degree of masking the air intake passage 11 as desired, and an airflow regulation
port 143 formed on the throttle wall 142 to allow the pressurized air to pass through
to allow the user to adjust the rotational speed of the drive motor 12 in the preset
range. Thus the regulation valve 14 has an air supply state in which the user turns
the control portion 141 to allow the pressurized air to pass through the regulation
valve 14 in a preset range of the rotational speed of the drive motor 12, and an air
supply stopping state in which the user turns the control portion 141 to allow the
throttle wall 142 to block the pressurized air from passing through the airflow regulation
port 143.
[0019] The correction valve 2 is located on the air intake passage 11 and connected to the
regulation valve 14, and includes an adjustment portion 21, a mask wall 22 and an
airflow directing hole 23 formed on the mask wall 22 to allow the pressurized air
to pass through. The adjustment portion 21 is operable by a mechanical tool 4 to proceed
an adjustment displacement. Moreover, the adjustment portion 21 drives the mask wall
22 to block the air intake passage. Hence the flow amount of the pressurized air passing
through the correction valve 2 is determined according to the position of the adjustment
portion 21 during the adjustment displacement, thereby the rotational speed of the
drive motor 12 can be confined from the excessive range to the preset range.
[0020] Please refer to FIGS. 3A and 3B for the correction valve of the sander in a fully
open state and a half-open state. In this embodiment, the air intake passage 11 has
a positioning notch 15, and the correction valve 2 is fixedly held in the positioning
notch 15 through a clip ring 19. The proportion of the excessive range to the preset
range of the drive motor 12 is less than 30%. For instance, given the maximum rotational
speed upper limit of the drive motor 12 is at 11,000 rpm, if the preset rotational
speed of the drive motor 12 is 10,000 rpm, the excessive rotational speed of the drive
motor 12 can be adjusted to 10,000 rpm through the correction valve 2, i.e., when
the pressurized air enters the body 1 via the air intake duct 111, user can press
the activation member 17 to move the activation valve stem 16 downwards, and the air
nozzle 18 also is moved to deviate against the regulation valve 14 so that the pressurized
air can pass through the regulation valve 14. Then, user can turn the control portion
141 by his hand 3 to adjust the throttle wall 142 so that the pressurized air can
be blocked from passing through the airflow regulation port 143 or pass through the
airflow regulation port 143 due to the communication between the airflow regulation
port 143 and air intake passage 11, thereby adjust the rotational speed of the drive
motor 12 in the preset range. Next, through the mechanical tool 4 wedged in the adjustment
portion 21 of the correction valve 2 to execute an adjustment displacement, namely,
the mask wall 22 is driven by the adjustment portion 21 to block the air intake passage
11, such as the mask wall 22 does not block the air intake passage 11 (referring to
FIG. 3A) or the adjustment portion 21 is turned to allow the mask wall 22 to block
half of the air intake passage 11 (referring to FIG. 3B), the pressurized air enters
from the air intake duct 111 into the regulation valve 14 and is adjusted accordingly.
Since the correction valve 2 is located between the regulation valve 14 and drive
motor 12 to transmit the pressurized air to the drive motor 12, the flow amount of
the pressurized air can be adjusted via the adjustment displacement of the correction
valve 2 to confine the rotational speed of the drive motor 12 from the excessive range
to the preset range, thereby resolve the problem of reduced airflow amount to lower
rotational speed of the drive motor caused by block of airflow due to installation
of components (such as adding noise muffling cotton in the exhaust tube) in the air
passage. Moreover, as the assembly elements in batch production could have variances
in material weight or dimension, the airflow amount could also have errors. However,
it can be resolved by confining the rotational speed of the drive motor 12 from the
excessive range to the preset range through the adjustment displacement provided by
the correction valve 2, thereby improve production yield.
[0021] In summary there is disclosed a sander capable of correcting airflow amount comprises
a body 1 and a correction valve 2. The body 1 includes an air intake passage 11 to
receive pressurized air, a drive motor 12 driven by the pressurized air to rotate
at a rotational speed including a preset range and an excessive range, and a regulation
valve 14 located on the air intake passage 11 to adjust the rotational speed of the
drive motor 12 in the preset range. The correction valve 2 includes an adjustment
portion 21 operable in an adjustment displacement and a mask wall 22 movable by the
adjustment portion 21 to block the air intake passage 11. The adjustment portion 21
determines the flow amount of the pressurized air passing through the correction valve
2 according to the adjustment displacement thereof to confine the rotational speed
of the drive motor 12 from the excessive range to the preset range, thereby controls
the rotational speed of the drive motor in the preset range.
[0022] As a conclusion, the sander capable of correcting airflow amount of the invention
mainly includes a body and a correction valve. The body includes an air intake passage
to receive pressurized air, a drive motor driven by the pressurized air to rotate
at a rotational speed including a preset range and an excessive range, and a regulation
valve located on the air intake passage and operable manually by users to adjust the
rotational speed of the drive motor in the preset range. The correction valve is located
on the air intake passage and coupled with the regulation valve, and includes an adjustment
portion operable by a mechanical tool to proceed an adjustment displacement and a
mask wall movable by the adjustment portion to block the air intake passage. Based
on the location of the adjustment portion during the adjustment displacement, the
flow amount of the pressurized air passing through the correction valve can be determined
to confine the rotational speed of the drive motor from the excessive range to the
preset range, thus resolve the problem of reduced airflow amount to lower rotational
speed of the drive motor caused by block of airflow due to installation of component
in the air passage.
1. A sander providing airflow correction,
characterized by:
a body (1) including an air intake passage (11) to receive pressurized air, a drive
motor (12) driven by the pressurized air to rotate at a rotational speed including
a preset range and an excessive range, and a regulation valve (14) located on the
air intake passage (11) and operable manually by a user to adjust the rotational speed
of the drive motor (12) in the preset range; and
a correction valve (2) which is located on the air intake passage (11) and coupled
with the regulation valve (14), and includes an adjustment portion (21) operable by
a mechanical tool (4) to proceed an adjustment displacement and a mask wall (22) movable
by the adjustment portion (21) to block the air intake passage (11), the adjustment
portion (21) determining flow amount of the pressurized air passing through the correction
valve (2) according to the position thereof during the adjustment displacement to
confine the rotational speed of the drive motor (12) from the excessive range to the
preset range.
2. The sander of claim 1, wherein the proportion of the excessive range to the preset
range is less than 30%.
3. The sander of claim 1 or 2, wherein the air intake passage (11) includes a positioning
notch (15) to hold the correction valve (2).
4. The sander of claim 3, wherein the correction valve (2) is fixedly held in the positioning
notch (15) through a clip ring (19)
5. The sander of one of the preceding claims, wherein the mask wall (22) includes an
airflow directing hole (23) to allow the pressurized air to pass through.
6. The sander of one of the preceding claims, wherein the body (1) includes an activation
valve stem (16) located on the air intake passage (11), the air intake passage (11)
including an air nozzle (18) to block the pressurized air from entering the regulation
valve (14), the activation valve stem (16) being depressible to drive the air nozzle
(18) to deviate so that the pressurized air passes through the regulation valve (14).
7. The sander of claim 6, wherein the body (1) includes an activation member (17) which
butts the activation valve stem (16) and is depressible to move the activation valve
stem (16) downwards so that the air nozzle (18) is deviated against the regulation
valve (14).
8. The sander of one of the preceding claims, wherein the body (1) includes a sanding
disk (13) driven by the drive motor (12) to rotate in a rotational displacement.
9. The sander of one of the preceding claims, wherein the regulation valve (14) includes
a control portion (141) operable manually by the user, a throttle wall (142) extended
from the control portion (141) to the air intake passage (11) and operable by the
user to determine degree of masking the air intake passage (11), and an airflow regulation
port (143) formed on the throttle wall (142) to allow the pressurized air to pass
through.
10. The sander of one of the preceding claims, wherein the air intake passage (11) includes
an air intake duct (111) to direct the pressurized air into the regulation valve (14),
the correction valve (2) being located between the regulation valve (14) and the drive
motor (12) to transmit the pressurized air from the regulation valve (14) to the drive
motor (12).