JPH10202493A - Belt sander - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt sander used for the final finish of a thin welded structure, having high machining accuracy as well as a stable travel function, allowing installation on a robot, and not requiring a high level of skill even in the case of a manual work. SOLUTION: A backup plate 3 is provided between a drive pulley 8 and a master idler pulley 19, and a belt 6 with abrasive grains is extended around the pulleys 8 and 19, and the plate 3. A pair of guide plates 1 having the same external shape as a track for the external surface of the belt 8 traveling along the bottom of the backup plate 3 and the external surface of the master idler pulley 19, are provided at both sides of the travel track of the belt 6. Furthermore, a guide plate position adjustment mechanism 2 is installed behind the master idler pulley 19, and used for adjusting the vertical and horizontal positions of the guide plates 1. Also, an automatic belt tension adjustment mechanism 13 for tensioning the belt 6 in an upward direction is laid between the drive pulley 8 and the master idler pulley 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt sander, and more particularly to a belt sander structure which facilitates a grinding operation and has improved processing accuracy.

[0002]

2. Description of the Related Art A disk sander using a grinding wheel disk or a polishing cloth disk and a belt sander using a polishing cloth belt are used to remove the excess weld bead portion of a thin welded structure. Grinding work is divided into roughing, medium processing, final finishing, etc., depending on the amount of excess weld bead, etc., and depending on the work efficiency and the skill of the user, the type of tool and grindstone, abrasive grain roughness, disc We choose the elasticity and use it properly.

[0003] In addition, due to the nature of sheet metal processing, the dimensional accuracy and shape accuracy of thin welded structures (hereinafter referred to as "workpieces") and the thickness of the weld bead build-up vary considerably. The compatibility of the workpiece at the time is poor. Therefore, when grinding is performed on a fixed track using a machine tool, the base material of the workpiece tends to bite due to grinding, and the tool interferes with the workpiece to break the tool. There is a possibility that. For this reason, it is difficult to mechanize and automate the grinding process, and in general, manual work is mainly performed, and furthermore, high skill is required. In addition, the workplace where such work is performed has become an aging workplace because the environment is bad and the young people dislike it due to flying dust and dust.

[0004] In order to improve such a grinding process and improve efficiency, in recent years, attempts have been made to mechanize and automate the grinding operation using robots for various kinds of medium-volume products. For example, compliance is provided by a spring or air pressure on the holding part or main body of the grinding tool, the tool is pressed against the processing surface with a constant force, and the tool is released under high load, the grinding load current is measured, and the trajectory of the tool is measured based on the value. To correct the
Alternatively, a method has been developed in which the processing location is automatically measured each time using a sensor, and processing is performed while correcting the trajectory based on the data.By adopting such a method alone or in combination, the grinding work can be performed. Mechanization and automation are in progress.

[0005] However, there are many technical restrictions on grinding using a robot, and the target material to be processed is limited to large- and medium-volume products manufactured under strict control. In other words, data is accumulated at the expense of a large number of workpieces as test pieces, and preparation work such as correction of setting conditions using those data is required. Only then can the robot be used as a dedicated machine. For this reason, at present, most of the general small lot thin welded structures manually perform all of the grinding steps.

[0006] Regardless of whether the work is performed manually or using a robot, there are a type in which the work is fixed and the work is processed by moving the work, depending on the size and processing method of the work. For small and lightweight mass-produced parts,
The workpiece is handled using a robot and the tool side is fixed. As an advantage of the method, there is little restriction on the selection of the size of the tool, and a stable and durable tool can be adopted, and the tool life can be extended. Furthermore, if an automatic loading / unloading device for a workpiece is installed, unmanned operation processing becomes possible. Further, even in the case of manual handling, the advantage due to the small restriction on the selection of the tool size is the same. On the other hand, in the case of a large workpiece, the workpiece is fixed and the tool is handled by a robot or manually.Therefore, the tool is limited, and it is difficult for the large workpiece and the small tool to be unbalanced. There is.

A disk sander is mainly used as a grinding tool used for the above-mentioned manual or robot machining. For roughing and semi-finishing, a disk grindstone is used as a grindstone, and the kind of the grindstone and the abrasive grain roughness are selected according to the machining shape and the capability of the robot body.
In the final finishing process, a polishing cloth disk having an elastic structure in which abrasive grains are adhered to a cloth is used as a grindstone, and the medium processing and the final finish are selectively used depending on the roughness of the abrasive grains.

On the other hand, belt sanders are rarely used irrespective of whether they are manually or robotically used. The reasons are that a high level of technology is required, and that the grinding efficiency is inferior to a disk sander due to the belt type. Therefore, at present, the belt sander is used only for final finishing surface machining or chamfering work by a skilled worker.

FIG. 8 shows an example of the structure of a conventional belt sander. The belt sander includes a belt 6 with abrasive grains, a driving pulley 8, a master idler pulley 19, and a backup plate 3.
Etc. The belt 6 is bridged between the driving pulley 8 and the master idler pulley 19, and the backup plate 3 is arranged along the back surface of the belt 6. The tension of the belt 6 is adjusted by adjusting the position of the master idler pulley 19 by moving the adjustment flange 17 that supports the master idler pulley 19.

[0010] Such a conventional belt sander has low rigidity. In particular, since the movement direction of the master idler pulley 19 for automatically adjusting the tension of the belt 6 is the same as the grinding direction, the belt tension is loosened due to resistance during grinding, and the grinding force is likely to be reduced. Further, due to the fact that the bottom surface of the backup plate 3 is slightly curved and formed, the belt 6 easily escapes in the width direction, and the shape of the finished surface becomes unstable. Further, since the belt itself is a cloth, and since the master idler pulley 19 which receives resistance during grinding is a resin material having elasticity, there are disadvantages such as weakness against heat.

As described above, the work material (thin welded structure)
The problem in the case of performing the grinding work of the excess metal weld bead part manually or by using a robot is as follows. Since there are variations in the dimensions and shapes of the workpieces, it is not easy to mechanize and automate. In particular, when the material to be processed is a product of various types and small quantities, it is not economically feasible because the work required for determining the processing conditions becomes relatively large. Also, in the case of mass-produced products, a high degree of dimensional accuracy is required for the work material, which is not required for the finished product, in order to achieve automation, and it is also difficult to realize economically.

In addition, disc sanders which are currently used irrespective of whether they are used manually or by using a robot tend to cause grinding bite into the base material of the workpiece, resulting in quality deterioration and failure. Especially when high precision is required,
Machining using a robot is difficult, and high skill is required even in the case of manual operation.

C. On the other hand, belt sanders have poor grinding efficiency and are not suitable for automation. Further, the rigidity is low, the running of the belt tends to be unstable due to the grinding resistance, and the shape of the finished surface is not stable. Further, in the case of manual operation, high skill is required.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made by improving the structure of a belt sander used for final finishing of a thin welded structure.
An object of the present invention is to provide a belt sander which has improved grinding efficiency and stable running performance, can be used for mechanization / automation using a robot, and does not require a high level of skill even in a manual operation.

[0015]

According to the belt sander of the present invention, a backup plate is arranged between a driving pulley and a master idler pulley, a belt with abrasive grains is wound around these, and the belt runs. In the belt sander which performs grinding of the workpiece on the outer peripheral surface of the belt, the trajectory of the outer peripheral surface of the belt is provided on both sides of the running trajectory of the belt and passes through the bottom surface portion of the backup plate and the outer peripheral portion of the master idler pulley. A pair of guide plates having the same outer peripheral shape, such that the outer peripheral portions of these guide plates are aligned with the outer peripheral surface of the belt passing through the bottom surface portion of the backup plate and the outer peripheral portion of the master idler pulley, A guide plate position adjusting means for adjusting the positions of these guide plates in the vertical and front-rear directions, and a bell provided between the drive pulley and the master idler pulley. Always, characterized by comprising a belt automatic Zhang Shang adjusting means Hariageru with a predetermined force in the upward direction.

The belt sander of the present invention has a pair of guide plates having an outer peripheral shape along the bottom surface of the backup plate and the outer periphery of the master idler pulley as described above, and a guide plate position adjusting unit for adjusting the positions of these guide plates. Means, the guide plate guides both ends of the belt to stabilize the running of the belt, and the outer peripheral portions of these guide plates coincide with the trajectory of the outer peripheral surface of the belt, whereby the belt The depth of grinding perpendicular to the surface can be limited at the outer periphery of the guide plate. Also, since the belt automatic tension adjusting means is provided separately from the master idler pulley, even if there is a change in grinding resistance,
The belt tension can always be maintained within a certain range to prevent a reduction in grinding speed.

When grinding the excess weld bead portion of a thin welded structure as a workpiece using the belt sander of the present invention, the belt sander is parallel to the excess weld bead portion, and the left and right guides are set. The excess weld bead is located between the plates. In this state, the belt is driven, and the outer peripheral portion of the guide plate is pressed against the surface of the base material portion of the workpiece to perform the polishing operation. As a result, only the excess weld bead portion protruding from the surface of the base material within the width of the belt is ground and removed, and a finished surface flush with the surface of the base material is obtained.

When the belt sander of the present invention is mounted on a robot and used, the belt sander is pressed against the base material with a certain force using a compliance or force sensor. In this state, the belt sander is moved along a predetermined track.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of an example of a belt sander according to the present invention. In the figure, 6 is a belt with abrasive grains, 8 is a driving pulley, 19 is a master idler pulley,
4 is an idler pulley, 24 is a tension adjusting idler pulley, 13 is an automatic belt tension adjusting mechanism (belt automatic tension adjusting means), 1 is a guide plate, and 2 is a guide plate position adjusting mechanism (guide plate position adjusting means). Reference numeral 3 denotes a backup plate.

The drive motor 1 is mounted on the bracket body 14.
0, automatic belt tension adjusting mechanism 1 that supports drive pulley 8, idler pulley 4, and tension adjusting idler pulley 24
3. The adjustment flange 17 for supporting the master idler pulley 19 and the guide plate position adjustment mechanism 2 and the like are fixed. The belt 6 with abrasive grains is connected to each pulley 8, 24, 19, 4
It is passed over the outer circumference of.

The belt sander is of a type for mounting on a robot.
Further, the plate plate 28 is provided with a tool plate 12 used for connection with a robot and a power supply unit 15 for the drive motor 10. An air supply hole is provided in the tool plate 12, and the air supply hole is connected to the air nozzle 11 disposed in front of the master idler pulley 19 via a pipe joint 29 and an air pipe 27. The air nozzle 11 is used to prevent dust and chips from being caught.

FIGS. 2 and 3 show the details of the structure of the master idler pulley 19, the guide plate 1, the guide plate position adjusting mechanism 2, and the adjusting flange 17 supporting these. 2 is a perspective view of a section A in FIG. 1, and FIG. 3 is a perspective view of a section C in FIG.

As shown in FIGS. 2 and 3, the adjusting flange 17 is fixed to the bracket body 1 by a hexagon socket head bolt 17a.
Fixed to 4. A master idler pulley 19 is attached to a front portion of the adjustment flange 17 as follows.
That is, as shown in FIG. 3, an arm portion 41 is provided along one side surface of the adjustment flange 17, and the arm portion 41 extends forward in parallel with the main body portion of the adjustment flange 17, and It protrudes forward from the part. Arm 41
An adjustment groove 31 is formed between the adjustment flange 17 and the main body of the adjustment flange 17. The slight inclination of the arm portion 41 with respect to the main body portion of the adjusting flange 17 is adjusted by inserting and removing the adjusting double screw 18 buried in the side surface of the main body portion and having a tip protruding between the adjusting grooves 31. Further, the lock bolt 32 embedded on the side surface of the arm portion 41 is
And is used to prevent the adjustment double screw 18 from loosening.

The shaft 20 supporting the master idler pulley 19 is connected to the arm 4 via a collar 22 and a screw 20a.
The master idler pulley 19 is attached to a shaft 20 via a bearing 21. By adjusting the slight inclination of the arm portion 41 with respect to the main body portion of the adjusting flange 17 using the adjusting double screw 18 as described above, the minute inclination of the master idler pulley 19 with respect to the adjusting flange 17 is adjusted, and the master idler pulley is adjusted. The left and right tensions of the belt 6 stretched around the outer circumference of the belt 19 are adjusted.

The master idler pulley 19 is made of aluminum to increase rigidity so that a stable finished surface can be obtained by supporting the grinding resistance as a backup for the belt 6, and its outer shape has a centering function. The central portion is flat and a small taper is provided near both ends so that a flat surface can be easily formed.

The guide plate 1 is attached to both sides of the adjustment flange 17 as follows. That is, the guide plate 1
2 is attached to both side surfaces of the adjusting flange 17 via fixing bolts 26 and the upper end of the guide plate 1
As shown in FIG. 3, the tip of the adjusting tension screw 16a attached to the overhanging portion on the upper surface of the adjusting flange 17 abuts, and further, the rear end of the guide plate 1, as shown in FIG. The tip of the adjusting tension screw 16b attached to the rear projection is in contact. The upper, lower, left and right positions of the guide plate 1 are adjusted using these adjusting tension screws 16 a and 16 b, and the outer peripheral portion of the guide plate 1 is aligned with the track of the outer peripheral surface of the belt 6, and then the adjusting flange is fixed using the fixing bolt 26. The guide plate 1 is fixed to both side surfaces of the guide 17.

Since the guide plate 1 slides while guiding the belt sander in contact with the surface of the base material of the workpiece, the surface of the base material is easily damaged, and the base material is made of a hot-rolled steel plate. In this case, the hard scale on the surface of the base material causes wear on the guide plate side. To prevent this, the cross-sectional shape of the outer peripheral portion of the guide plate is given a curvature, the strength of the guide surface is increased, and the affinity with the base material of the workpiece is reduced to reduce the sliding resistance. Therefore, it is hardened.

As shown in FIG. 2, the backup plate 3 is fixed to the bottom surface of the adjustment flange 17 with a flathead screw 23. Since the backup plate 3 receives thrust resistance during grinding via the belt 6, it is quenched to reduce wear and frictional resistance.

FIG. 4 shows details of the automatic belt tension adjusting mechanism 13. The frame 35 is attached to the bracket body 14 by the reamer bolt 7 and the wing bolt 36.
The reamer bolt 7 is attached via a large washer 7A, and when the wing bolt 36 is loosened, the frame 35
Can be tilted up and down with respect to the bracket body 14 within a predetermined range. The plate coil spring 25 is disposed inside the frame 35, and the upper end of the plate coil spring 25 is
The tension adjusting idler pulley 24 disposed at the end of the frame 35 is supported, and the lower end of the plate coil spring 25 is supported by the spring receiver 5 fixed to the bracket body 14 side. Thus, the tension adjusting idler pulley 24 is pushed upward by the plate coil spring 25, and therefore always pulls the belt 6 with a constant force. At the time of replacing the belt 6, if the frame 35 is manually tilted downward and temporarily fixed with the wing bolts 36, the belt 6 is loosened, and thus the belt 6 can be easily replaced.

FIG. 5 shows an outline of a centering jig used for centering the outer peripheral portion of the guide plate 1 and the outer peripheral surface of the belt 6 on the same plane. This centering jig is used as follows.

After removing the belt 6 from the belt sander,
Loosen the fixing bolts 26 (FIGS. 2 and 3) of the left and right guide plates 1 and adjust the tension screws 16a (FIG. 2), 16b.
(FIG. 3) is retracted. Next, the bottom surface of the backup plate 3 (FIG. 2) is pressed against the Z mating surface 38 of the centering jig 43, and the outer peripheral surface of the master idler pulley 19 is
Press against mating surface 40. Next, a bolt is passed through the fixing hole 37 of the centering jig 43 from below, and the centering jig 43 is inserted.
Is fixed to the lower side of the adjustment flange 17. Further, the guide plate 1 is lightly pressed against the Y mating surfaces 39 on both sides of the centering jig 43, and the adjusting tension screws 16a and 16b are set lightly by hand in this state. And fixed with fixing bolts 26 (FIGS. 2 and 3). After the positioning of the guide plate 1 is completed in this way, the bolts passing through the fixing holes 37 are removed, the centering jig 43 is removed from the backup plate 3, and finally, the belt 6 is attached to the belt sander. Is set.

The accuracy with which the guide plate 1 moves in and out of the outer peripheral surface of the belt 6 appears as a step on the finished surface on the product.
In order to minimize this step, it is necessary to adjust the guide plate 1 to enter and exit from the outer peripheral surface of the belt 6, and to obtain a good finished surface, high-precision adjustment is required. However, the adjustment can be easily performed by using the centering jig 43 shown in FIG.

FIG. 6 shows another example of a guide plate used in the belt sander according to the present invention. In this example, in order to reduce the abrasion of the guide plate 1 and reduce the affinity for the base material to reduce the slide resistance, a round bar-shaped material made of a super-hard material such as tungsten carbide having a different material from the base material is used. The member 33 and the spherical member 34 are attached to the contact portion on the outer peripheral portion of the guide plate.

FIG. 7 shows another example of the belt sander according to the present invention. This belt sander is a type for manual operation, and the main body of the belt sander is common to the belt sander shown in FIG. The difference from the belt sander for mounting a robot shown in FIG. 1 is that the safety grip 45 and the grinding dust stopper 47 are attached to the belt sander main body, and the mounting direction of the drive motor 10 is changed to the belt sander main body. To make it easier to hold.

[0035]

According to the belt sander of the present invention, by using the guide plate to guide the belt sander on the surface of the base material of the workpiece, it is possible to accurately and easily grind the excess weld bead portion. It can be carried out. Therefore, a high level of skill is not required for manual operations. Further, since it can be mounted relatively easily on a robot with compliance, it is possible to realize unmanned operation or automation without requiring a large amount of test pieces as in the related art.

For this reason, the belt sander of the present invention can be used in automatic processing of a small number of various parts.
Further, even in the processing of a large number of parts, since it is possible to promptly shift to actual work without requiring much time for preparation as in the related art, the work efficiency is excellent and there is a great effect in terms of cost.

Further, in the case of automation, even if a surface other than a processing portion is erroneously processed, the surface is guided by the guide plate 1, so that the base material surface of the workpiece is not ground, and biting by a tool occurs. do not do. Similarly, it is possible to prevent biting or the like due to an adjustment error, so that there is little occurrence of defective products and high dimensional accuracy can be obtained for the processed shape.

In order to obtain a good finished surface, it is necessary to adjust the belt sander so that there is no step between the outer peripheral portion of the guide plate and the outer peripheral surface of the belt. It can be easily adjusted by using a jig.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a belt sander according to the present invention.

FIG. 2 is a perspective view of a section A in FIG. 1 showing details of a guide plate position adjusting mechanism and a mounting portion of a master idler pulley.

FIG. 3 is a perspective view of a section C in FIG. 1 showing details of a guide plate position adjusting mechanism and a mounting portion of a master idler pulley.

FIG. 4 is a perspective view illustrating details of a belt automatic tension adjusting mechanism.

FIG. 5 is a perspective view showing an outline of a centering jig used for positioning a guide plate of a belt sander according to the present invention.

FIG. 6 is a perspective view showing another example of the guide plate used in the belt sander according to the present invention.

FIG. 7 is a perspective view showing another example of the belt sander according to the present invention.

FIG. 8 is a perspective view showing an example of a conventional belt sander.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Guide plate, 2 ... Guide plate position adjusting device (guide plate position adjusting means) 3 ... Backup plate, 4 ... Idler pulley, 5
... spring receiver, 6 ... belt (belt with abrasive grains), 7 ... reamer bolt, 8 ... drive pulley,
9 T-plate, 10 driving motor, 11
... Air nozzle, 12 ... Tool plate, 13.
..Automatic belt tension adjusting mechanism (belt automatic tension adjusting means), 14: bracket body, 15: power supply device, 16a, 16b: adjusting tension screw, 17 ...
Adjustment flange, 18 ... Adjustment double screw, 19 ...
Master idler pulley, 20 ... shaft, 21 ...
・ Bearing, 22 ・ ・ ・ Collar, 23 ・ ・ ・ Counterhead screw,
Reference numeral 24: tensioning idler pulley, 25: plate coil spring, 26: fixing bolt, 27: air pipe, 28: plate plate, 29: pipe joint, 31
... Adjustment groove, 32 ... Lock bolt, 33 ...
Round bar-shaped member made of super hard material, 34 ... Spherical member made of super hard material, 35 ... Frame, 36 ... Butterfly bolt, 37 ... Fixed hole, 38 ... Z mating surface , 39
... Y mating surface, 40 ... R mating surface, 31 ... arm, 43 ... centering jig, 45 ... grip, 4
7 ... Grinding debris stop.

Claims (1)

[Claims] 1. A backup plate is disposed between a driving pulley and a master idler pulley, a belt with abrasive grains is wound around the pulley, and the belt is caused to travel so that a workpiece material is formed on the outer peripheral surface of the belt. In a belt sander for grinding, a pair of guide plates provided on both sides of a running track of the belt and having the same outer circumferential shape as the track of the outer circumferential surface of the belt passing through the bottom surface portion of the backup plate and the outer circumferential portion of the master idler pulley. The positions of these guide plates in the up-down and front-rear directions so that the outer peripheral portions of these guide plates are aligned with the trajectory of the outer peripheral surface of the belt passing through the bottom portion of the backup plate and the outer peripheral portion of the master idler pulley. A guide plate position adjusting means for adjusting the distance between the driving pulley and the master idler pulley, and a belt for constantly lifting the belt upward with a predetermined force. A belt sander, comprising: