JPH02167660A - Grinder for carpentry - Google Patents

Abstract

PURPOSE:To prevent the end sagging of a work W by relaxing the grinding of the end edge by reducing the rotating speed of a grinding wheel at the time when the end edge of a work arrives and providing a timing command means controlling a transmission by its changeover so as to grind the main face part at the optimum speed of the face thereof. CONSTITUTION:Grinding wheels 19a, 19b are driven by driving motors 20a, 20b with transmissions 21a, 21b capable of converting the speed in two states of a low speed rotation and a steady rotation. In the case, in the state of the end edge of the work arriving at the grinding wheels 19a, 19b, the speed change gear 20a, 20b are changed over to low speed side based on the command from a timing command means 30a and the grinding wheel is made at low speed rotation. Thus, the end edge can be ground without causing end sagging. Also on the main face part of the work the grinding wheel is subjected to steady rotating, a high speed grinding adapted for the material of the work is performed and a good finishing face can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a woodworking grinder that grinds and polishes a workpiece using a grinding wheel such as a roll brush.

<Problems to be Solved by the Invention> As a grinding machine using a grinding wheel, there is one in which the grinding wheel is arranged perpendicular to the traveling direction of the workpiece.

By the way, when grinding a workpiece with such a configuration, if the grinding wheel is rotated at an appropriate rotation speed for the finished surface, the front and rear edges will rotate at an excessively high speed, resulting in oversanding. This will cause the edges to sag. On the other hand, if the rotation speed is lowered in order to eliminate this edge sag, not only will the work efficiency deteriorate, but the finish of the main surface will deteriorate.

An object of the present invention is to provide a woodworking grinder that can prevent edge sagging without degrading the overall finish as much as possible.

<Means for Solving the Problems> The present invention provides a grinding wheel disposed above a material feeding device with a rotating shaft perpendicular to the material feeding direction, and the grinding wheel is rotated between low speed rotation and steady rotation. It is driven by a drive motor with a transmission that can change the speed in at least two modes, and the transmission is changed to a low speed side when the front and rear edges of the workpiece reach the grinding wheel position. The present invention is characterized in that it includes timing command means for switching control.

Effect〉 When the edge of the workpiece reaches the grinding wheel, the grinding wheel switches to low speed rotation.

For this reason, it can be ground without causing edge droop. In addition, the grinding wheel rotates steadily on the main surface of the workpiece, and high-speed grinding is performed that is suitable for the material of the workpiece, achieving a good finished surface.

<Example> An example of the woodworking grinder of the present invention will be described with reference to FIG. 1.2.

Reference numeral 1 denotes a machine frame, and a material feeding device 2 is disposed at the bottom of the machine frame in the front-rear direction.

To explain the configuration of the material feeding device 2, the material feeding frame 3
is provided with a driving material feeding roll 4 and a driven material feeding roll 5 driven by a material feeding motor 6 at the front and rear ends protruding from the machine frame 1, and the material feeding rolls 4 and 5 are provided with numerous ventilation holes. The material conveying belt 7 with holes formed therein runs over the belt.

Further, in the material feeding frame L/- frame 3, a suction port 9 is provided which is inscribed in the running upper part of the material feeding belt 7 at the position of the grinding heads 13a and 13b, which will be described later, and which sucks the grinding debris. . The material feeding frame 3 is supported by a screw shaft (not shown), and can be adjusted up and down by rotating the handle 10 to screw the screw shaft. The suction port 9 is a vacuum device (not shown) disposed outside the machine frame 1.
is connected to.

A mounting member 11 extends across the upper part of the machine frame l in the width direction, and dovetail guides 12 and 12 are formed on the front and rear surfaces of the mounting member 11.
Mounting frame 14.14 for grinding heads 13a, 13b
are installed so that they can be raised and lowered. On the machine frame l,
A rotation shaft 15.15 is passed between the front and rear of the installation member 11, and a vertical lifting screw 17 screwed onto the mounting frame 14 and held on the installation member 11 is connected to the screw portion of the rotation shaft 15, 15. By rotating a handle 16 connected via a bevel gear and provided at the end of the rotation shaft 15.15, the mounting frame 14 is raised and lowered along the lifting screw 17 and the dovetail guide 12. I have to. Grinding wheels 19a and 19b consisting of brush rolls are supported on the mounting frame 14, and a three-phase drive motor 20a is disposed on the mounting frame 14.
, 20b through a belt interlocking mechanism 22.

Further, the mouth end of a duct 23 for discharging grinding debris faces the lower part of the grinding wheels 19a, 19b, and a plurality of presser rolls 24 are pivotally supported at the upper part of the material feeding device 2.

The drive motors 20a, 20b are connected to transmissions 21a, 21b each consisting of an inverter.

These transmissions 21a, 21b are driven by drive motors 20a, 20
This converts the frequency of the AC voltage that drives the AC voltage and applies the voltage to the drive motors 20a, 20b, and generates a high-frequency steady rotation output and a low-frequency low-speed rotation output. The voltage is applied to the motors 20a and 20b. This rotational output conversion is controlled by timing command means 30a, 30b shown in FIG. 3.4. The timing command means 30a and 30b (see FIGS. 3 and 4) are applied to the processed furniture W, respectively.

Details of the timing command means 30a will be explained with reference to FIG.

Grinding wheels 19a and 19b of the presser roll 24
The detection rollers 24a, 24b are located immediately in front of the detection rollers 24a, 24b, and the detection rollers 24a, 24b are provided with contact portions 31, 31, and the detection rollers 24a, 2 are provided directly below the corresponding contact portions 31, 31.
Limit switch LS that turns on when 4b rises;
, LS2 is installed.

The limit switches LS, LS2 are connected to the central control unit CPU, and input a detection signal accompanying the ON operation to the central control unit CPU. Also, on the output side of the central control unit CPU, there is a timer T corresponding to the grinding wheel 19a.
T, and a timer T corresponding to the grinding wheel 19b.
, T, are connected. This timer T2 is activated upon generation of a detection signal from the limit switch LS.

Further, the timer T+ corresponds to the transfer time t1 from directly below the detection roller 24a to directly below the grinding wheel 19a, and the timer T2 corresponds to the transfer time t and the front and rear crosspieces X13' of the workpiece W. It is set to the sum t3 of the transfer time t2 from the edge f to the trailing edge r. Then, in response to the time-up signal of the timer 11, the transmission 21a is changed to the low-speed side, and applies a low-frequency AC voltage to the drive motor 20a, causing the grinding wheel l'9a to rotate at a low speed, and the time-up signal of the timer T is transmitted. With the occurrence of
The transmission 21a returns to the steady speed side, and the drive motor 20
A high frequency AC voltage is applied to drive motor 20b.
Rotate at a steady speed.

Similarly, timers T, T, are activated when the beam mitt switch LSa is turned on, and timer T corresponds to the transfer time tt' from directly below the detection roller 24a to directly below the grinding wheel 19a. T is the sum ta of the transfer time j+' and the transfer time t2
′. And timer T.

The transmission 21b is changed to the low speed side by the tie-up signal, and the grinding wheel 19b is rotated at a low speed.
returns to the steady speed side and rotates the drive motor 20b at the steady speed.

Next, the operation of the above embodiment will be explained.

After driving the drive material feed roll 4 and causing the material feed belt 7 to run, a frame-shaped workpiece W is fed onto the material feed belt 7 (see FIG. 5). The front crosspiece X of this processed material W is the detection roller 2
4a, the detection roller 24a rises and the limit switch LS is turned on. Then, via the central control unit CPU, this detection signal causes the timer T,...
T is driven. As a result, when the leading edge f of the front crosspiece X arrives at the grinding wheel 19a, the timer T is set in advance corresponding to the time until the leading edge f arrives at the grinding wheel 19a. is switched to the low speed side, and a low frequency AC voltage is applied to the drive motor 20a. For this reason, the drive motor 20
The grinding wheel 19a driven by a is switched to the low rotation side, and a gentle grinding process is performed from the front edge f to the rear edge r of the front crosspiece X of the workpiece W. Furthermore, when the trailing edge r of the front crosspiece X arrives directly below the grinding wheel 19a, the timer 12 outputs a time-up signal corresponding to the arrival time, the transmission 21a switches to the steady speed side, and the drive motor 2' A high frequency voltage is applied to Oa, and the grinding wheel 19b rotates steadily at a high speed. Then, the vertical bars 2, 2 in the front and back direction of the workpiece W are subjected to optimal grinding.

Next, when the rear crosspiece y of the workpiece W comes to the detection roller 24a,
Similarly, by driving the timers T+ and Ta, and controlling the switching of the transmission 21a in response to the respective time-up signals, the rear crosspiece y
When the leading edge f reaches the grinding wheel 19a, the speed changes from steady speed (high speed) to low speed, and as the trailing edge r passes, the speed changes again to steady speed.

Also, when the front crosspiece X passes the grinding wheel 19a and comes directly under the detection roller 24b, the limit switch LSa is activated in the same way.
turns on and the timer 1. T4 is driven and the front crosspiece
When the leading edge f reaches the grinding wheel 19b, the time-up signal from the timer T3 causes the transmission 21b to switch to the low speed side and the grinding wheel 19b to the low speed side, and the trailing edge f is placed directly below the grinding wheel 19b. When r arrives, timer T4 outputs a time-up signal and transmission 2
1b is switched, the grinding wheel 19b is rotated at high speed, and the vertical bars z, z in the front and back direction of the workpiece W are subjected to optimal grinding. Further, the rear crosspiece y of the workpiece W is ground in the same manner.

Thus, the workpiece W is ground twice by the grinding wheels 19a and 19b, and each leading edge f and trailing edge r is given mild grinding by low-speed rotation, and the edges thereof are Someone is prevented.

FIG. 4 shows another timing command means 30b, in which the grinding wheel 19a is controlled by the limit switches LS, LS, as the detection rollers 24a, 24b rise.
The conversion timing of 19b is based on the amount of rotation of the drive material feed roll 4 that causes the material feed belt 7 to run.

That is, the slit 12ii35 is fixed to the rotation axis of the drive material feed roll 4 or the shaft of the drive system of the material feed roll 4, such as the drive shaft of the material feed motor 6, and is formed in the circumferential direction of the slit plate 35. The passage through the slit is read by the proximity switch S■, and the read signal is input to the central control unit CPU. The central control unit CPU includes a grinding wheel 19a.
counters C+, Cz and grinding wheel 1 corresponding to
Counters C, C4 corresponding to 9b are connected, and the counters C+, Cz, C-, and C4 count the output based on the proximity switch SW from the central control unit CPU, and when a predetermined count value is reached, Transmission gear 21a, 2
1b is provided with a conversion signal.

This counter C,,C, is the detection roller 24a.

A grinding wheel 19a from a position directly below the detection roller 24b,
The counter C,,C, is set to correspond to the distance to the position directly below the workpiece W, and the counter C,,C, is set to correspond to the count value of the counter C,,C, and the front crosspiece X of the workpiece W.

The sum of count values corresponding to the width of the rear crosspiece y is set.

As a result, when the workpiece W moves a predetermined distance and is positioned directly below the grinding wheels 19a and 19b of the front crosspiece As it passes, a predetermined operation is performed to return to the steady speed side.

This timing command means 30b has the advantage that even if the material feeding speed varies due to changing the material feeding speed or some kind of load occurs, reliable timing setting is possible.

Incidentally, in the above-described embodiment, the present invention was applied to grinding a frame-shaped workpiece W, but the present invention can also be applied to a normal single plate. In this case, the vicinity of the leading edge or trailing edge will be ground at low speed. Further, in the embodiment, the grinding wheels 19a, 19
b) was applied using a roll brush, but it can also be applied to a normal grinding roll.

Furthermore, although the transmissions 21a and 21b of the above-mentioned embodiments use an electric means using an inverter as a speed change means, it may be a transmission using a mechanical means such as meshing control of gears.

<Effects of the Invention> As described above, the present invention provides that when the edge of the processed material arrives,
The rotational speed of the grinding wheel is lowered to reduce the amount of grinding of the edge, and the main surface is ground at the optimum speed for that surface, allowing machining without deteriorating the finish. This has excellent effects such as preventing the edge of the material W from sagging and allowing good grinding and polishing to be performed as a whole.

[Brief explanation of the drawing]

The attached drawings show an embodiment of the present invention, and FIG. 1 is a front view, FIG. 2 is a left side view of the same, and FIG. 3 is a timing command means 30a.
FIG. 4 is a conceptual diagram showing the timing command means 30b, and FIG. 5 is a schematic perspective view showing the grinding of the workpiece W. 35... Slit plate W... Processed material f... Front edge r... Trailing edge LS,
, LS2...limit switch T,, T2. T,
, T,-1・Timer c,, ca, c,, c,・
...Counter 2...Material feeding device 4...Drive material feeding roll 7...Material feeding belt 19a, 19b...Grinding wheels 20a, 20b...Drive motor 21a, 21b...Transmission 24a , 24b-detection rollers 30a, 30b...timing command means 20th

Claims (1)

[Claims] A grinding wheel is disposed above the material feeding device with the rotating shaft perpendicular to the material feeding direction, and the grinding wheel is driven by a drive motor with a transmission capable of changing the speed of at least two modes: low-speed rotation and steady rotation. The woodworking device is characterized in that it is equipped with timing command means for switching and controlling the transmission so that the transmission is changed to a low speed side when the front and rear edges of the workpiece reach the grinding wheel position. Grinding machine.