JP2887570B2 - Belt sander machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt sander used for grinding and polishing wood and the like.

[0002]

2. Description of the Related Art An endless sanding belt is wound around a belt driving mechanism, and a stepping device having a pressing member controlled to be moved up and down by an elevating control device is arranged inside the endless sanding belt, and the pressing member of the stepping device is used. Various belt sander machines have been proposed in which one or a plurality of grinding heads for bringing an endless sanding belt into pressure contact with a work material are provided opposite a material feeding device via a material feeding passage.

On the other hand, when the sanding belt is pressed against the work material by a single tread pad over the entire width thereof, the belt is pressed at the edge of the work material so as to cover the edge, the corner falls, and the end droops. Is generated. Therefore, it is necessary to reduce the tread pressure of the tread pad at this edge. However, if this pressure control is performed uniformly in the width direction of the treading pad, it will prevent drooping at the edges in the width direction for work materials with different widths, irregular shapes, or frame materials. I can't.

In view of this, there is provided a stepping device in which a plurality of pressing members connected to rods of the air cylinder are arranged in the width direction, and a plurality of pressing members corresponding to each pressing member are provided in front of the stepping device. A work material detector is arranged in a row in the width direction, and a lifting / lowering control device is provided for individually controlling the pressure of each pressing member to each air cylinder based on the width direction row data from the work material detector group. Belt sander machines have been proposed in Japanese Patent Application Laid-Open Nos. 1-159165 and 1-246063. In any of these, the height of the pressing member is not controlled steplessly, but is intended to exclusively prevent dripping by converting the pressure into a high pressure and a low pressure to the air cylinder.

[0005]

The work material w to be applied includes materials having different thicknesses, such as a material having irregularities and a material having warpage. By the way, when these materials are ground and polished uniformly as in the case of the flat plate-shaped processing material as in the above-described conventional configuration, when a material having a dent or a warp is ground and polished at the center thin portion thereof, and the warp is generated. In the case of the material, there is a problem that the warped portion of the peripheral edge is excessively ground and polished.

To cope with this, a lifting motor is used as a drive source, and a lifting rod is screwed onto a screw rod which is rotated by the lifting motor, and the pressing member is steplessly moved by the lifting rod. A lift control device is configured to control the lifting and lowering, and a work material detector is provided in front of the treading device,
There has been proposed a configuration in which the elevation control device of the stepping device is controlled based on data from the workpiece detector.

By the way, in the structure in which the pressing member is raised and lowered by the screwing action of the screw rod using the lifting motor as described above, the height can be set accurately, but the response is slow. For this reason, the copying operation on the surface of the work material is delayed, and over-grinding or insufficient grinding is likely to occur. SUMMARY OF THE INVENTION It is an object of the present invention to provide a configuration that can solve the above-described problem caused by the delay of the copying performed by the elevating motor and that can apply a stable tread pressure.

[0008]

According to the present invention, the lifting control device of the stepping device is screwed to a lifting motor and a screw rod which is rotated by the lifting motor, and the lifting control is performed by the screw feeding action. A lifting / lowering rod which is fixed to the lifting / lowering rod, and a cylinder pressure rod which is linked to the pressing member, and which is at least set to a rod extension position when a work material arrives. is there.

In this configuration, the stepping device is configured by arranging a large number of pressing members, each of which is controlled to be individually raised and lowered by the lifting control device, in the width direction of the material feeding passage, and in front of the stepping device. A large number of workpiece detectors corresponding to each pressing member may be arranged in a row in the width direction, and the control of each elevation control device may be performed based on the width direction row data from the group of workpiece detectors. .

In such a configuration, the stepping cylinder may always be set at the rod extension position so as to elastically press the processing material. In this case, in order to prevent edge dripping of the workpiece, the lifting motor is driven and the pressing member is lowered as the edge of the workpiece arrives.

[0011] Further, the stepping pressure cylinder may be pressure-supplied and converted to the rod extension position in synchronization with the arrival of the work material, and the pressure supply may be released as the work material passes.

[0012]

The height position of the pressing member fixed to the lower surface of the stepping rod is steplessly controlled by a lifting / lowering motor controlled based on data from the workpiece detector or a workpiece detector group. Thus, a uniform tread pressure corresponding to the height of the work material is applied to the work material.

On the other hand, the raising and lowering rod moves up and down in synchronization with the arrival of the detection position according to data from the work material detector, but due to the screw feed operation accompanying the rotation of the screw rod, a rapid copying operation cannot be performed. . Therefore, at the time of the stepping force, the pressing force is applied to the pressing member by setting the stepping pressure cylinder to the rod extending position. Therefore, for example, even when the lifting rod is slightly above the proper position with respect to the surface of the workpiece, the pressing member presses against the surface of the workpiece due to the urging action of the stepping cylinder, and the response is delayed. Insufficient tread pressure due to this is eliminated as much as possible. Further, even when the lifting rod is located at a position lower than the proper position, the stepping pressure cylinder has a buffering action, thereby preventing overgrinding.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIGS. 1 and 2 show the case where the present invention is applied to a top-grinding type belt sander having a single grinding head.
At the lower part of the main body frame 1, there is provided a material feeding device 5 in which a material feeding belt 4 is stretched between running rolls 2 and 3, and an upper surface thereof is a material feeding passage 6. The driving roll 2 is rotated by a driving motor M. As shown in FIG. 5, a slit plate f having a groove formed on a peripheral surface thereof is supported on an output shaft of the driving motor M. The plate f is provided with a sensor k for detecting passage of the groove. That is,
The output of the sensor k makes it possible to detect the traveling amount of the workpiece w.

A sanding frame 7 is provided on the main body frame 1 at a position above the material feeding device 5, and a grinding head is mounted on the frame 1. That is, a steering roller 8 is provided at the upper end of the sanding frame 7, and a large-diameter drive roll 9 and a driven roll 1 are provided at the lower end thereof.
No. 0 is provided to constitute a drive mechanism, and a sanding belt 11 is stretched over the roll group. Further, between the rolls 9 and 10, a treading device 12 is provided on the sanding frame 7.

A mounting frame 30 is disposed on the sanding frame 7 at a position between the rolls 9 and 10, and the treading device 12 is hung on the mounting frame 30.

The structure of the stepping device 12 will be described with reference to FIGS. The tread frame 13 has a large number of vertical sliding grooves 14 arranged in the width direction. A mounting plate 15 in which a plurality of operation holes 16 communicating vertically with the sliding grooves 14 is fixed to the treading frame 13. The sliding groove 14 has an urging hole portion 14a having a diameter larger than the inner diameter of the operation hole 16 in which the sprung 17 is mounted, and the urging hole portion 1a thereunder.
The rubbing portion 14b has a smaller diameter than the rubbing portion 4a, and further opens downward to communicate with the pad mounting groove 18 which is long in the width direction.
A stepping rod 20 having the same diameter as the sliding portion 14b is mounted in the sliding groove 14. The stepping rod 20 has a locking flange 20a having substantially the same diameter as the pressing hole 14a at the position of the pressing hole 14a.
The upper end of the ridge 17 mounted around the rim abuts against the lower surface of the locking flange 20a to apply the urging force to the treading rod 20. The upper end portion 20b of the stepping rod 20 has the same diameter as the operation hole 16, and the upper end portion 20b is inserted into the operation hole 16.

Further, a pressing member 21 is fixed to the lower end of each treading rod 20 in the pad mounting groove 18, and a pad member 22 made of an elastic material such as sponge is disposed so as to cover the plurality of pressing members 21 from the lower surface. The pad member 22
Is covered with a wear-resistant cloth 23 fixed to both lower surfaces of the treading frame 13.

The lower part of the mounting frame 30 has a lower opening fitting hole 31 having a wide locking groove edge 32 at the upper edge. The main width of the fitting hole 31 is the same as that of the stepping frame. 1
3 and the locking groove edge 32 coincides with the mounting plate 15. For this reason, by pressing the mounting plate 15 from the side into the locking groove edge 32 and pushing the upper portion of the treading frame 13 into the main part of the fitting hole 31 so that the treading device 12 can easily fit the mounting frame 30. It will be mounted in the mounting hole 31. Then, as shown in FIG. 2, the projecting end of the mounting plate 15 from the mounting frame 30 is clamped by a locking piece 34 provided on a screw rod 33 screwed to the mounting frame 30. It will be fixed detachably.

Next, a description will be given of a configuration of a lift control device according to a principal part of the present invention for performing lift control of the stepping rod 20. The upper end of the stepping rod 20 is connected to the stepping cylinder 29 and the elevating motor 24.

That is, the lifting motor 24 is mounted on the mounting frame 3.
0 on the mounting plate 35 fixed to the
5 is connected to an upper end of a screw rod 27 vertically supported by a bearing 26 by a coupler 36. An elevating rod 28 is screwed into a male screw formed below the screw rod 27.

At the lower end of the elevating rod 28, a stepping cylinder 29 composed of an air cylinder is fixed. The cylinder rod 29 a is in contact with the upper end of the treading rod 20 in the operation hole 16 of the mounting plate 15 by the urging force of the spring 17. The elevating rod 28 is inserted into a groove of a guide frame 37 having its upper end fixed to the mounting plate 35, and is flattened on both sides so that it cannot rotate.

When the elevating motor 24 is driven, the screw rod 27 is rotated, and the screwing action causes the elevating rod 28 to move up and down in the guide frame 37. The treading rod 20 descends against the ridge 17, and the lower surface of the pressing member 21 comes into pressure contact with the inner surface of the pad member 22. The elevating amount per one rotation of the elevating motor 24 is about 0.2 mm, so that minute elevating control is possible.

Further, by controlling the internal pressure of the pedaling cylinder 29, when the cylinder rod 29a extends, the pedaling rod 20 descends, and the pressing member 21 is converted to the pressed position. The pressure in the pedaling cylinder 29 is set to about 0.2 to 0.6 kg / cm ² . The pressure of the tread cylinder 29 is controlled so that its internal pressure becomes constant during pressurization (rod extension state). For example, when the work material has a projection and the pressing member 21 rises, the tread cylinder 29 rises. Then, the gas is exhausted, and the stepping force is applied at a predetermined pressure following the surface of the pressing member 21.

The stepping pressure cylinder 29 may be always in a pressurized state, or may be pressurized only when a work material arrives, and the cylinder rod 29a may be set to the extended position.

The drive control of the elevating motor 24 is performed by an elevating control unit including a central control unit CPU as described later. The protruded detection rod t laterally on the lifting rod 28, the proximity switch SW ₀ for determining further said mounting frame proximity switch SW ₁ of 30 for the upper limit specified fixed to side, the reference point for lower limit specified Proximity switch SW
₂ are sequentially arranged from above. Then, the edge of the detection rod t is detected, and the proximity switches SW ₁ and SW ₂ are detected.
In this case, the ascending and descending drive of the elevating motor 24 is stopped. Also in the proximity switch SW _0, as will be described later, define a reference position of the pressing member 21, so as to coincide with the reference point of the stepless measurement cylinder L which will be described later. Furthermore, when turning off the power of the belt sander machine, lift motor 24 is so driven stopped with the detection rod t lifting lever 28 rises and was turned on proximity switch SW ₁ for upper limit specified.

Next, a description will be given of a configuration of a work material detector that generates width direction row data with thickness information of a control work material w for issuing a control command of a lift control device including the lift motor 24 and the like.

Such a workpiece detector is composed of a stepless measuring cylinder L and a detection roll 43, and is arranged in the width direction in the same number as the pressing members 21 corresponding to the pressing members 21 before and after. ing.

As shown in FIG. 4, the stepless measurement cylinder L has a piston p slidably mounted in a cylinder cylinder c and a measurement rod r having one end connected to the piston p. c and the piston p
Air chambers 38a and 38b are formed above and below the air chamber 3a.
Pressurized air flows through the air flow holes 39a and 39b through the air flow holes 8a and 38b to urge the measurement rod r in the extending direction. A bar code 40 is formed in the measurement rod r in the axial direction, and the sensor 41 mounted on the cylinder body c detects passage of each bar of the bar code 40. The position information of the measuring rod r (thickness information of the workpiece w) converted into an electric signal by the sensor 41 is input to the central control unit CPU via a lead wire 42. The position information of the measurement rod r can be read directly by the digital display D connected to the sensor 41, thereby facilitating the position adjustment of the measurement rod r.

On the other hand, the tip of the measuring rod r abuts on a bearing piece 38 of a detection roll 43 rotatably supported by a support shaft 44 fixed to the body frame 1 side. The detection roll 43 is pressed against the upper surface of the supplied workpiece w by the downward urging force of the measurement rod r, and moves up and down with the variation in the thickness of the workpiece w. Ascending and descending, the barcode 40 passes in front of the sensor 41,
The amount of elevation is detected and transmitted to the central control unit CPU as thickness information. Further, the support shaft 44
A plurality of detection rolls 43 are supported in front of and behind the pressing member 21, and stepless measurement cylinders L are respectively provided above the detection rolls 43. Therefore, this information is stored in the width direction with thickness information. It becomes column data.

Next, a control mechanism of the lift motor 24 by the central control unit CPU will be described. Central control unit CP
As shown in FIG. 6, a sensor k, a counter C for sequentially counting pulses from the sensor k, and a register R are connected to U, as shown in FIG. Switching control of the elevating motor 24 is performed.

That is, the width direction row data D is input from the plurality of stepless measurement cylinders L to the central control unit CPU every time the counter C counts. Then, 1 is added to the count value of the counter C by the generation of the pulse signal from the sensor k, and when the count value reaches the count value ct stored in the register R, the lift motor 2
4 is performed. Note that this count target value ct
Corresponds to the distance from the stepless measuring cylinder L to the pressing member 21. Then, the thickness information generated from the stepless measuring cylinder L is sequentially input to the storage device RAM, and the count target value ct is digested, that is, the workpiece w
The drive control command corresponding to the thickness information is sent to the elevating motor 24 in synchronization with the arrival of the
From the workpiece w or the running of the workpiece w in synchronization with the accumulation of a predetermined number of pulse signals.
Then, with the driving of the lifting motor 24, the pressing member 21 linked to the treading cylinder 29 and the rod at the extended position moves up and down by the same lifting amount as the measurement rod r of the stepless measurement cylinder L. Become.

Accordingly, the difference in height between the treading surface of the treading device 12 and the lower edge of the detection roll 43 is set in advance, and the respective reference points are determined. Even if the thickness changes, the pedaling device 12 always receives the pedaling pressure due to the difference in height, so that substantially equal polishing can be performed over the entire surface of the workpiece w.

[0034] Here, the reference point of trampling surface of the treading apparatus 12 is defined by the proximity switch SW ₀ described above. In this case, the reference height is such that the tread surface of the tread device 12 is
It is set to be, for example, about 0.4 mm below the lower edge of the detection roll 43. Further, the reference point of the measuring rod r is adjusted by adjusting its protruding position so that the height with respect to the treading surface of the treading device 12 is about 0.4 mm with reference to the lower edge of the drive roll 9 and the like. What is necessary is just to make it a zero value. The reference position is slightly lower than the reference height of the workpiece w so that when the tip of the workpiece w passes, the measuring rod r is surely raised and the workpiece w is detected. Is set to

As described above, the pedaling cylinder 29
And the control to convert the pressure of the treading cylinder into a rod extension position in synchronization with the arrival of the workpiece, to release the pressure supply with the passage of the workpiece. Embodiments are proposed.

In the control mode in which the stepping pressure cylinder 29 is always set at the rod extension position, in order to prevent end dripping of the work material, the elevation motor 29 is driven with the arrival of the end edge of the work material. Then, the pressing member 21 is lowered.
At this time, depending on the lifting motor 29, the pressing member 2
A delay of 1 can be solved by slightly advancing the drive timing, and even if a shift occurs in the descending timing, the elastic force of the stepping pressure cylinder 29 causes a buffering elastic contact, so that the grinding and polishing can be performed without difficulty. The end drooping can be prevented.

In this control mode, the position in the non-stepping pressure state (standby position) is set as follows. That is, as described above, treading surface of the tread pressure device 12 with reference to the position of a predetermined dimension lower than the lower edge of the sensing roll 43, so as to detect the detection rod t in proximity switch SW ₀ at this position. Then, from this position, the pedaling cylinder 2
9 is maintained at the rod extending position, the lifting motor 24 is rotated in the reverse direction, and the pressing member 21 is floated by the ridge 17, and this is set to the standby position.

On the other hand, in the control mode in which the stepping cylinder 29 is pressure-supplied and converted to the rod extension position in synchronization with the arrival of the work material, the pressing force is rapidly increased in synchronization with the arrival of the front end of the work material. There is an advantage that the member 21 can be lowered.

In this control mode, the position in the non-stepping pressure state (standby position) is set as follows. That is, the treading cylinder 29 is maintained at the rod extension position, and the treading surface of the treading device 12 is located at a predetermined dimension below the lower edge of the detection roll 43 as described above, and the detection rod is detected at this position. t is detected by the proximity switch SW ₀ ,
At the standby position, the pressurizing of the treading cylinder 29 is released while the elevating motor 24 is kept as it is, and the pressing member 21 is floated by the spring 17.

In any of the above-described control modes, in any case, the end of the workpiece is prevented, and the required standby position is set by the above-described means.

The timing control of pressurizing the stepping pressure cylinder 29 in synchronization with the arrival of the work material and releasing the pressurization upon passage of the work material can be easily performed by detecting the work material by the stepless measuring cylinder L and controlling the delay by the counter C. Can do it.

In this configuration, the lifting motor 24
Thus, the height position of each pressing member 21 is set steplessly in accordance with the shape of the work material in the width direction, and the stepping pressure is applied via the stepping pressure cylinder 29. For this reason, the lifting rod 28 is controlled by the data from the workpiece detector.
The elevator moves up and down in synchronization with the arrival of the detection position. However, since this elevating operation is performed by a screw feed operation accompanying rotation of the screw rod 27 by the elevating motor 24, a rapid copying operation cannot occur. By the way, since the stepping cylinder 29 is interposed, even if there is a delay in the elevating operation of the elevating rod 28, the surface of the work material is tread with substantially equal pressure.

For example, even when the elevating rod 28 is slightly above the proper position with respect to the surface of the workpiece, the pressing member 21 is pressed against the surface of the workpiece by the urging action of the treading cylinder 29, Insufficient tread pressure due to a delay in response is eliminated as much as possible. When the lifting rod 28 is located below the proper position, the stepping pressure cylinder 29 has a buffering action, thereby preventing overgrinding.

Thus, the upper surface of the work material w may be warped,
Even if there are minute irregularities, a substantially uniform stepping force acts on the surface, and the work material w is subjected to reasonable grinding and polishing by the sanding belt 11. Further, in such a configuration, the stepping cylinder 29 can resiliently press the pedal, and therefore, compared to a configuration in which the processing member is elastically contacted with only the pad member 22 such as a sponge disposed below the pressing member 21, it is more stable. It can apply a great tread pressure.

The present invention can be applied to a configuration in which a single pressing member is controlled by a single lifting control device. This case is suitable for a configuration in which there is no response on the surface of the workpiece in the width direction. The present invention can be similarly applied to a belt sander having a plurality of grinding heads.

[0046]

According to the present invention, as described above, the lifting control device of the stepping device is controlled by the screw rod 2 which is rotated by the lifting motor 24.
7 is controlled to be lifted by the screw feed operation 7
The stepping pressure cylinder 29 is fixed, and the cylinder rod 29a is linked to the pressing member 21 so that the stepping pressure cylinder is set to the rod extension position at least when the workpiece arrives. Even if it is not possible to respond quickly according to the surface shape of the work material, since the stepping cylinder 29 is provided, the delay operation of the elevating rod 28 is absorbed, and the pressing member 21 is stepped on the work material surface at a substantially constant pressure. In addition, due to the buffering action of the stepping cylinder 29, there is an excellent effect that a reasonable grinding is possible, over-grinding and defective grinding are eliminated, and an optimum surface processing can be performed.

[Brief description of the drawings]

FIG. 1 is a front view of a belt sander machine.

FIG. 2 is a longitudinal sectional side view of a part of a state where the treading device 12 is assembled.

FIG. 3 is a vertical sectional front view showing a state where the stepping device 12 is assembled.

FIG. 4 is a partially cutaway front view of a stepless measurement cylinder L.

FIG. 5 is a block diagram showing a control mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Sanding belt 12 Treading device 13 Treading frame 14 Sliding groove 15 Mounting plate 16 Operation hole 17 Ejection 18 Pad mounting groove 20 Treading rod 21 Pressing member 24 Lifting motor 27 Screw rod 28 Lifting rod 29 Stepping cylinder 29a Cylinder rod

Claims (2)

(57) [Claims] An endless sanding belt is wound around a belt drive mechanism, and a stepping device having a pressing member that is controlled to move up and down by an elevating control device is arranged inside the endless sanding belt. One or more grinding heads configured to press the endless sanding belt against the work material are provided opposite to the material feeding device via the material feeding passage, and a work material detector is provided in front of the treading device. A belt sander machine for controlling a lifting / lowering control device of a treading device based on data from the workpiece detector, wherein the lifting / lowering control device of the treading device is rotated by a lifting / lowering motor and the lifting / lowering motor. A lifting and lowering rod which is screwed to the moving screw rod and controlled to be raised and lowered by the screw feeding action; and a cylinder rod fixed to the lifting and lowering rod and linked to the pressing member, and at least Belt sander machine, characterized by being configured with a stamping pressure cylinder set in at the rod protraction position. 2. A stepping device comprising a plurality of pressing members, each of which is controlled to be individually raised and lowered by said lifting control device, in the width direction of a material feeding passage, and each pressing member is provided in front of the stepping device. A plurality of work material detectors corresponding to the above-mentioned are arranged in a row in the width direction, and control of each elevation control device is performed based on the width direction column data from the work material detector group. Item 3. A belt sander according to Item 1.